Device migrations, driver migrations and more (#575)

Drivers/axs5106-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(axs5106-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel
+)

Drivers/axs5106-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/axs5106-module/README.md

@@ -0,0 +1,12 @@
+# AXS5106 touch controller
+
+A driver for the `AXS5106` I2C capacitive touch controller, used on the Waveshare ESP32-S3-Touch-LCD-1.47.
+
+Ported from the `esp_lcd_touch_axs5106` component bundled with Waveshare's official ESP-IDF factory demo firmware
+for this board (`ESP32-S3-Touch-LCD-1.47-Demo/ESP-IDF/01_factory/components/esp_lcd_touch_axs5106/esp_lcd_touch_axs5106.c`,
+downloadable from https://www.waveshare.com/wiki/ESP32-S3-Touch-LCD-1.47) - not a standalone repo.
+The original license was also Apache v2.0
+
+Supports up to 2 touch points.
+
+License: [Apache v2.0](LICENSE-Apache-2.0.md)

Drivers/axs5106-module/bindings/axs,axs5106.yaml

@@ -0,0 +1,53 @@
+description: AXS5106 capacitive touch controller
+
+include: ["i2c-device.yaml"]
+
+compatible: "axs,axs5106"
+
+bus: i2c
+
+properties:
+  x-max:
+    type: int
+    required: true
+    description: Maximum X coordinate reported by the controller (typically the panel's horizontal resolution)
+  y-max:
+    type: int
+    required: true
+    description: Maximum Y coordinate reported by the controller (typically the panel's vertical resolution)
+  swap-xy:
+    type: boolean
+    default: false
+    description: Swap the X and Y axes
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin
+  pin-interrupt:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Interrupt GPIO pin
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  interrupt-active-high:
+    type: boolean
+    default: false
+    description: Whether the interrupt pin is active high
+  transmit-timeout:
+    type: int
+    default: 100
+    description: Timeout (ms) for the register-address write half of a read transaction
+  receive-timeout:
+    type: int
+    default: 100
+    description: Timeout (ms) for the data-read half of a read transaction

Drivers/axs5106-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/axs5106-module/include/axs5106_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module axs5106_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/axs5106-module/include/bindings/axs5106.h

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/axs5106.h>
+
+DEFINE_DEVICETREE(axs5106, struct Axs5106Config)

Drivers/axs5106-module/include/drivers/axs5106.h

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/drivers/gpio.h>
+
+struct Axs5106Config {
+    uint8_t address;
+    uint16_t x_max;
+    uint16_t y_max;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    struct GpioPinSpec pin_reset;
+    struct GpioPinSpec pin_interrupt;
+    bool reset_active_high;
+    bool interrupt_active_high;
+    // Timeout (ms) for the register-address write half of a read, and for the data-read half,
+    // done as two separate I2C transactions - matches the vendor factory demo's
+    // i2c_master_transmit()/i2c_master_receive() split (each with its own 100ms timeout),
+    // rather than a single combined write-then-read transaction.
+    uint32_t transmit_timeout_ms;
+    uint32_t receive_timeout_ms;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/axs5106-module/source/axs5106.cpp

@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <drivers/axs5106.h>
+#include <axs5106_module.h>
+
+#include <tactility/check.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/gpio_controller.h>
+#include <tactility/drivers/gpio_descriptor.h>
+#include <tactility/drivers/i2c_controller.h>
+#include <tactility/drivers/pointer.h>
+#include <tactility/error.h>
+#include <tactility/log.h>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+
+#include <cstdlib>
+
+constexpr auto* TAG = "AXS5106";
+#define GET_CONFIG(device) (static_cast<const Axs5106Config*>((device)->config))
+
+// Register map and read/reset logic ported from the vendor factory demo
+// (ESP32-S3-Touch-LCD-1.47-Demo/ESP-IDF/01_factory/components/esp_lcd_touch_axs5106), which talks
+// to the chip directly over I2C rather than through esp_lcd_panel_io/esp_lcd_touch - that indirection
+// is what the previous version of this driver used, and reads through it consistently failed with
+// ESP_FAIL on real hardware.
+static constexpr uint8_t REG_TOUCH_POINTS = 0x01;
+static constexpr uint8_t TOUCH_DATA_LEN = 14;
+static constexpr uint8_t MAX_POINTS = 2;
+
+struct Axs5106Internal {
+    GpioDescriptor* reset_descriptor;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    uint8_t point_count;
+    uint16_t x[MAX_POINTS];
+    uint16_t y[MAX_POINTS];
+};
+
+// region Driver lifecycle
+
+// Matches the vendor demo's touch_axs5106_reset(): pulse the reset pin active for 10ms, then
+// release it for 10ms before any I2C traffic. No separate init step follows - the vendor demo's
+// touch_axs5106_init() is a no-op too.
+static error_t reset_pulse(GpioDescriptor* descriptor, bool active_high) {
+    bool idle_level = !active_high;
+
+    bool ok = gpio_descriptor_set_flags(descriptor, GPIO_FLAG_DIRECTION_OUTPUT) == ERROR_NONE;
+    ok = ok && gpio_descriptor_set_level(descriptor, active_high) == ERROR_NONE;
+    vTaskDelay(pdMS_TO_TICKS(10));
+    ok = ok && gpio_descriptor_set_level(descriptor, idle_level) == ERROR_NONE;
+    vTaskDelay(pdMS_TO_TICKS(10));
+
+    return ok ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t start(Device* device) {
+    auto* parent = device_get_parent(device);
+    check(device_get_type(parent) == &I2C_CONTROLLER_TYPE);
+
+    const auto* config = GET_CONFIG(device);
+
+    auto* internal = static_cast<Axs5106Internal*>(malloc(sizeof(Axs5106Internal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+    internal->reset_descriptor = nullptr;
+    internal->swap_xy = config->swap_xy;
+    internal->mirror_x = config->mirror_x;
+    internal->mirror_y = config->mirror_y;
+    internal->point_count = 0;
+
+    if (config->pin_reset.gpio_controller != nullptr) {
+        internal->reset_descriptor = gpio_descriptor_acquire(config->pin_reset.gpio_controller, config->pin_reset.pin, GPIO_OWNER_GPIO);
+        if (internal->reset_descriptor == nullptr) {
+            LOG_E(TAG, "Failed to acquire reset pin");
+            free(internal);
+            return ERROR_RESOURCE;
+        }
+
+        if (reset_pulse(internal->reset_descriptor, config->reset_active_high) != ERROR_NONE) {
+            LOG_E(TAG, "Failed to pulse reset pin");
+            gpio_descriptor_release(internal->reset_descriptor);
+            free(internal);
+            return ERROR_RESOURCE;
+        }
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+
+    if (internal->reset_descriptor != nullptr) {
+        gpio_descriptor_release(internal->reset_descriptor);
+    }
+
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region PointerApi
+
+static error_t axs5106_read_data(Device* device, TickType_t) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    const auto* config = GET_CONFIG(device);
+    auto* parent = device_get_parent(device);
+
+    // Matches the vendor demo's touch_axs5106_i2c_read(): the register address write and the
+    // data read are two separate transactions (i2c_master_transmit() then i2c_master_receive()),
+    // not a single write-then-read transaction with a repeated start.
+    uint8_t reg = REG_TOUCH_POINTS;
+    error_t error = i2c_controller_write(parent, config->address, &reg, 1, pdMS_TO_TICKS(config->transmit_timeout_ms));
+    if (error != ERROR_NONE) {
+        return error;
+    }
+
+    uint8_t data[TOUCH_DATA_LEN];
+    error = i2c_controller_read(parent, config->address, data, sizeof(data), pdMS_TO_TICKS(config->receive_timeout_ms));
+    if (error != ERROR_NONE) {
+        return error;
+    }
+
+    uint8_t points = data[1] & 0x0F;
+    if (points > MAX_POINTS) {
+        points = MAX_POINTS;
+    }
+    internal->point_count = points;
+
+    for (uint8_t i = 0; i < points; i++) {
+        internal->y[i] = static_cast<uint16_t>(((data[4 + i * 6] & 0x0F) << 8) | data[5 + i * 6]);
+        internal->x[i] = static_cast<uint16_t>(((data[2 + i * 6] & 0x0F) << 8) | data[3 + i * 6]);
+    }
+
+    return ERROR_NONE;
+}
+
+static bool axs5106_get_touched_points(Device* device, uint16_t* x, uint16_t* y, uint16_t* strength, uint8_t* point_count, uint8_t max_point_count) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    const auto* config = GET_CONFIG(device);
+
+    uint8_t count = internal->point_count;
+    if (count > max_point_count) {
+        count = max_point_count;
+    }
+
+    // Order matches esp_lcd_touch's own software coordinate adjustment (mirror X, mirror Y,
+    // then swap) so behavior lines up with the other touch modules in this codebase.
+    for (uint8_t i = 0; i < count; i++) {
+        uint16_t point_x = internal->x[i];
+        uint16_t point_y = internal->y[i];
+        if (internal->mirror_x) {
+            point_x = config->x_max - point_x;
+        }
+        if (internal->mirror_y) {
+            point_y = config->y_max - point_y;
+        }
+        if (internal->swap_xy) {
+            uint16_t tmp = point_x;
+            point_x = point_y;
+            point_y = tmp;
+        }
+        x[i] = point_x;
+        y[i] = point_y;
+        if (strength != nullptr) {
+            strength[i] = 0;
+        }
+
+        LOG_I(TAG, "%d, %d", point_x, point_y);
+    }
+
+    *point_count = count;
+    return count > 0;
+}
+
+static error_t axs5106_set_swap_xy(Device* device, bool swap) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    internal->swap_xy = swap;
+    return ERROR_NONE;
+}
+
+static error_t axs5106_get_swap_xy(Device* device, bool* swap) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    *swap = internal->swap_xy;
+    return ERROR_NONE;
+}
+
+static error_t axs5106_set_mirror_x(Device* device, bool mirror) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    internal->mirror_x = mirror;
+    return ERROR_NONE;
+}
+
+static error_t axs5106_get_mirror_x(Device* device, bool* mirror) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    *mirror = internal->mirror_x;
+    return ERROR_NONE;
+}
+
+static error_t axs5106_set_mirror_y(Device* device, bool mirror) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    internal->mirror_y = mirror;
+    return ERROR_NONE;
+}
+
+static error_t axs5106_get_mirror_y(Device* device, bool* mirror) {
+    auto* internal = static_cast<Axs5106Internal*>(device_get_driver_data(device));
+    *mirror = internal->mirror_y;
+    return ERROR_NONE;
+}
+
+// endregion
+
+static const PointerApi axs5106_pointer_api = {
+    // Unsupported (null per PointerApi's contract): neither the vendor demo nor the original
+    // esp_lcd_touch component implements a sleep mode for this chip.
+    .enter_sleep = nullptr,
+    .exit_sleep = nullptr,
+    .read_data = axs5106_read_data,
+    .get_touched_points = axs5106_get_touched_points,
+    .set_swap_xy = axs5106_set_swap_xy,
+    .get_swap_xy = axs5106_get_swap_xy,
+    .set_mirror_x = axs5106_set_mirror_x,
+    .get_mirror_x = axs5106_get_mirror_x,
+    .set_mirror_y = axs5106_set_mirror_y,
+    .get_mirror_y = axs5106_get_mirror_y,
+};
+
+Driver axs5106_driver = {
+    .name = "axs5106",
+    .compatible = (const char*[]) { "axs,axs5106", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &axs5106_pointer_api,
+    .device_type = &POINTER_TYPE,
+    .owner = &axs5106_module,
+    .internal = nullptr
+};

Drivers/axs5106-module/source/module.cpp

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver axs5106_driver;
+
+static error_t start() {
+    /* We crash when construct fails, because if a single driver fails to construct,
+     * there is no guarantee that the previously constructed drivers can be destroyed */
+    check(driver_construct_add(&axs5106_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    /* We crash when destruct fails, because if a single driver fails to destruct,
+     * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&axs5106_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+Module axs5106_module = {
+    .name = "axs5106",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+} // extern "C"

Drivers/ch422g-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(ch422g-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel
+)

Drivers/ch422g-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/ch422g-module/README.md

@@ -0,0 +1,10 @@
+# CH422G I/O expander
+
+A driver for the `CH422G` I2C-bus I/O expander by WCH, commonly used on Waveshare ESP32
+display boards to drive display/touch reset and enable lines.
+
+Exposes EXIO0-7 as a `GPIO_CONTROLLER_TYPE` device. The chip has no register to configure
+per-pin direction and no readback for its output register, so only output pins are supported
+and the driver keeps a local shadow of the last written value.
+
+License: [Apache v2.0](LICENSE-Apache-2.0.md)

Drivers/ch422g-module/bindings/wch,ch422g.yaml

@@ -0,0 +1,8 @@
+description: >
+  WCH CH422G I2C IO expander. Exposes EXIO0-7 as a GPIO_CONTROLLER_TYPE device. The chip
+  has no per-pin direction register and no readback for its output register, so only
+  output pins are supported; the driver keeps a local shadow of the last written value.
+
+include: ["i2c-device.yaml"]
+
+compatible: "wch,ch422g"

Drivers/ch422g-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/ch422g-module/include/bindings/ch422g.h

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/ch422g.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+DEFINE_DEVICETREE(ch422g, struct Ch422gConfig)
+
+#ifdef __cplusplus
+}
+#endif

Drivers/ch422g-module/include/ch422g_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module ch422g_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/ch422g-module/include/drivers/ch422g.h

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Ch422gConfig {
+    /** Address of the WR_SET (system config) pseudo-register. RD_IO and WR_IO are separate
+     *  fixed pseudo-addresses (the chip has no address-select pins, so this is always 0x24). */
+    uint8_t address;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/ch422g-module/source/ch422g.cpp

@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <drivers/ch422g.h>
+#include <ch422g_module.h>
+#include <tactility/check.h>
+#include <tactility/concurrent/mutex.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/gpio_controller.h>
+#include <tactility/drivers/gpio_descriptor.h>
+#include <tactility/drivers/i2c_controller.h>
+#include <tactility/log.h>
+
+#include <new>
+
+constexpr auto* TAG = "CH422G";
+
+#define GET_CONFIG(device) (static_cast<const Ch422gConfig*>((device)->config))
+
+// The chip has no address-select pins: RD_IO and WR_IO are always at these fixed
+// pseudo-addresses, regardless of what's configured as the WR_SET (system config) address.
+constexpr uint8_t CH422G_ADDR_RD_IO = 0x26;
+constexpr uint8_t CH422G_ADDR_WR_IO = 0x38;
+
+// WR_SET bit that switches EXIO0-7 into GPIO output mode.
+constexpr uint8_t CH422G_SYSTEM_CONFIG_IO_OE = 0x01;
+
+struct Ch422gContext {
+    Mutex mutex {};
+    // WR_IO has no readback, so the last written value is tracked here for read-modify-write.
+    uint8_t output_shadow = 0x00;
+};
+
+static error_t start(Device* device) {
+    auto* parent = device_get_parent(device);
+    if (device_get_type(parent) != &I2C_CONTROLLER_TYPE) {
+        LOG_E(TAG, "Parent device is not I2C");
+        return ERROR_RESOURCE;
+    }
+
+    uint8_t wr_set = CH422G_SYSTEM_CONFIG_IO_OE;
+    if (i2c_controller_write(parent, GET_CONFIG(device)->address, &wr_set, 1, portMAX_DELAY) != ERROR_NONE) {
+        LOG_E(TAG, "Failed to configure system register");
+        return ERROR_RESOURCE;
+    }
+
+    auto* context = new(std::nothrow) Ch422gContext();
+    if (context == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+    mutex_construct(&context->mutex);
+
+    // Drive all outputs low, matching the shadow's initial value.
+    if (i2c_controller_write(parent, CH422G_ADDR_WR_IO, &context->output_shadow, 1, portMAX_DELAY) != ERROR_NONE) {
+        LOG_W(TAG, "Failed to initialize outputs (non-fatal)");
+    }
+
+    error_t error = gpio_controller_init_descriptors(device, 8, context);
+    if (error != ERROR_NONE) {
+        mutex_destruct(&context->mutex);
+        delete context;
+        return error;
+    }
+
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* context = static_cast<Ch422gContext*>(gpio_controller_get_controller_context(device));
+    check(gpio_controller_deinit_descriptors(device) == ERROR_NONE);
+    mutex_destruct(&context->mutex);
+    delete context;
+    return ERROR_NONE;
+}
+
+extern "C" {
+
+static error_t set_level(GpioDescriptor* descriptor, bool high) {
+    auto* context = static_cast<Ch422gContext*>(descriptor->controller_context);
+    auto* parent = device_get_parent(descriptor->controller);
+    uint8_t bit = 1 << descriptor->pin;
+
+    mutex_lock(&context->mutex);
+    uint8_t new_shadow = high ? (context->output_shadow | bit) : static_cast<uint8_t>(context->output_shadow & ~bit);
+    error_t err = i2c_controller_write(parent, CH422G_ADDR_WR_IO, &new_shadow, 1, portMAX_DELAY);
+    if (err == ERROR_NONE) {
+        context->output_shadow = new_shadow;
+    }
+    mutex_unlock(&context->mutex);
+
+    return err;
+}
+
+static error_t get_level(GpioDescriptor* descriptor, bool* high) {
+    auto* parent = device_get_parent(descriptor->controller);
+    uint8_t bits;
+
+    error_t err = i2c_controller_read(parent, CH422G_ADDR_RD_IO, &bits, 1, portMAX_DELAY);
+    if (err != ERROR_NONE) {
+        return err;
+    }
+
+    *high = (bits & (1 << descriptor->pin)) != 0;
+    return ERROR_NONE;
+}
+
+static error_t set_flags(GpioDescriptor*, gpio_flags_t flags) {
+    // The chip has no per-pin direction register: EXIO0-7 are outputs once WR_SET enables
+    // IO_OE. Pull-up/down and high-impedance (true input mode) are not present either.
+    if (flags & (GPIO_FLAG_DIRECTION_INPUT | GPIO_FLAG_PULL_UP | GPIO_FLAG_PULL_DOWN | GPIO_FLAG_HIGH_IMPEDANCE)) {
+        return ERROR_NOT_SUPPORTED;
+    }
+    return ERROR_NONE;
+}
+
+static error_t get_flags(GpioDescriptor*, gpio_flags_t* flags) {
+    *flags = GPIO_FLAG_DIRECTION_OUTPUT;
+    return ERROR_NONE;
+}
+
+static error_t get_native_pin_number(GpioDescriptor*, void*) {
+    return ERROR_NOT_SUPPORTED;
+}
+
+static error_t add_callback(GpioDescriptor*, void (*)(void*), void*) {
+    return ERROR_NOT_SUPPORTED;
+}
+
+static error_t remove_callback(GpioDescriptor*) {
+    return ERROR_NOT_SUPPORTED;
+}
+
+static error_t enable_interrupt(GpioDescriptor*) {
+    return ERROR_NOT_SUPPORTED;
+}
+
+static error_t disable_interrupt(GpioDescriptor*) {
+    return ERROR_NOT_SUPPORTED;
+}
+
+const static GpioControllerApi ch422g_gpio_api = {
+    .set_level = set_level,
+    .get_level = get_level,
+    .set_flags = set_flags,
+    .get_flags = get_flags,
+    .get_native_pin_number = get_native_pin_number,
+    .add_callback = add_callback,
+    .remove_callback = remove_callback,
+    .enable_interrupt = enable_interrupt,
+    .disable_interrupt = disable_interrupt
+};
+
+Driver ch422g_driver = {
+    .name = "ch422g",
+    .compatible = (const char*[]) { "wch,ch422g", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = static_cast<const void*>(&ch422g_gpio_api),
+    .device_type = &GPIO_CONTROLLER_TYPE,
+    .owner = &ch422g_module,
+    .internal = nullptr
+};
+
+}

Drivers/ch422g-module/source/module.cpp

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver ch422g_driver;
+
+static error_t start() {
+    /* We crash when construct fails, because if a single driver fails to construct,
+     * there is no guarantee that the previously constructed drivers can be destroyed */
+    check(driver_construct_add(&ch422g_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    /* We crash when destruct fails, because if a single driver fails to destruct,
+     * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&ch422g_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+Module ch422g_module = {
+    .name = "ch422g",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+}

Drivers/cst816t-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(cst816t-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel
+)

Drivers/cst816t-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/cst816t-module/README.md

@@ -0,0 +1,16 @@
+# CST816T touch controller
+
+A driver for the `CST816T` I2C capacitive touch controller by Hynitron.
+
+Implemented directly against the register. (no `esp_lcd_touch` dependency)
+
+- Manufacturer datasheet: https://github.com/koendv/cst816t/blob/master/extras/DS-CST816T%E6%95%B0%E6%8D%AE%E6%89%8B%E5%86%8CV2.2.pdf
+- Original/reference code: https://github.com/koendv/cst816t (Arduino driver, `src/cst816t.cpp`/`src/cst816t.h`), licensed under [The Unlicense](https://github.com/koendv/cst816t/blob/master/LICENSE)
+
+Single-touch only: the datasheet advertises "genuine two-point" support, but neither of the sources above documents a second touch-point register set, so only one point is read.
+
+`enter_sleep`/`exit_sleep` are unimplemented (`nullptr` in the `PointerApi`, per its "null if not supported" contract).
+The reference driver defines `REG_SLEEP_MODE` (0xE5) but never writes it, and the datasheet says waking from sleep needs
+a hardware reset pulse anyway, not a register write.
+
+License: [Apache v2.0](LICENSE-Apache-2.0.md)

Drivers/cst816t-module/bindings/hynitron,cst816t.yaml

@@ -0,0 +1,45 @@
+description: Hynitron CST816T capacitive touch controller
+
+include: ["i2c-device.yaml"]
+
+compatible: "hynitron,cst816t"
+
+bus: i2c
+
+properties:
+  x-max:
+    type: int
+    required: true
+    description: Maximum X coordinate reported by the controller (typically the panel's horizontal resolution)
+  y-max:
+    type: int
+    required: true
+    description: Maximum Y coordinate reported by the controller (typically the panel's vertical resolution)
+  swap-xy:
+    type: boolean
+    default: false
+    description: Swap the X and Y axes
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin
+  pin-interrupt:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Interrupt GPIO pin (currently unused - reads are polled via read_data())
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  interrupt-active-high:
+    type: boolean
+    default: false
+    description: Whether the interrupt pin is active high

Drivers/cst816t-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/cst816t-module/include/bindings/cst816t.h

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/cst816t.h>
+
+DEFINE_DEVICETREE(cst816t, struct Cst816tConfig)

Drivers/cst816t-module/include/cst816t_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module cst816t_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/cst816t-module/include/drivers/cst816t.h

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/drivers/gpio.h>
+
+struct Cst816tConfig {
+    uint8_t address;
+    uint16_t x_max;
+    uint16_t y_max;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    struct GpioPinSpec pin_reset;
+    struct GpioPinSpec pin_interrupt;
+    bool reset_active_high;
+    bool interrupt_active_high;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/cst816t-module/source/cst816t.cpp

@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <drivers/cst816t.h>
+#include <cst816t_module.h>
+
+#include <tactility/check.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/gpio_controller.h>
+#include <tactility/drivers/gpio_descriptor.h>
+#include <tactility/drivers/i2c_controller.h>
+#include <tactility/drivers/pointer.h>
+#include <tactility/error.h>
+#include <tactility/log.h>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+
+#include <cstdlib>
+
+constexpr auto* TAG = "CST816T";
+#define GET_CONFIG(device) (static_cast<const Cst816tConfig*>((device)->config))
+
+// Register map and reset/bring-up sequence taken from https://github.com/koendv/cst816t
+// (src/cst816t.cpp) - the manufacturer datasheet (DS-CST816T V2.2) covers electrical
+// characteristics and I2C timing only, not the register map.
+static constexpr uint8_t REG_GESTURE_ID = 0x01;
+static constexpr uint8_t REG_CHIP_ID = 0xA7;
+static constexpr uint8_t REG_DIS_AUTOSLEEP = 0xFE;
+
+static constexpr TickType_t TIMEOUT = pdMS_TO_TICKS(50);
+
+struct Cst816tInternal {
+    GpioDescriptor* reset_descriptor;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    bool touched;
+    uint16_t x;
+    uint16_t y;
+};
+
+// region Driver lifecycle
+
+// Timings match the reference driver linked above: it holds RST high for 100ms (well past the
+// datasheet's Tpor/Tron minimum of 100ms), pulses it low for 10ms (Trst minimum is 0.1ms), then
+// waits another 100ms (Tron) for the chip to finish reinitializing before any I2C traffic.
+static error_t reset_pulse(GpioDescriptor* descriptor, bool active_high) {
+    bool idle_level = !active_high;
+
+    bool ok = gpio_descriptor_set_flags(descriptor, GPIO_FLAG_DIRECTION_OUTPUT) == ERROR_NONE;
+    ok = ok && gpio_descriptor_set_level(descriptor, idle_level) == ERROR_NONE;
+    vTaskDelay(pdMS_TO_TICKS(100));
+    ok = ok && gpio_descriptor_set_level(descriptor, active_high) == ERROR_NONE;
+    vTaskDelay(pdMS_TO_TICKS(10));
+    ok = ok && gpio_descriptor_set_level(descriptor, idle_level) == ERROR_NONE;
+    vTaskDelay(pdMS_TO_TICKS(100));
+
+    return ok ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t start(Device* device) {
+    auto* parent = device_get_parent(device);
+    check(device_get_type(parent) == &I2C_CONTROLLER_TYPE);
+
+    const auto* config = GET_CONFIG(device);
+
+    auto* internal = static_cast<Cst816tInternal*>(malloc(sizeof(Cst816tInternal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+    internal->reset_descriptor = nullptr;
+    internal->swap_xy = config->swap_xy;
+    internal->mirror_x = config->mirror_x;
+    internal->mirror_y = config->mirror_y;
+    internal->touched = false;
+    internal->x = 0;
+    internal->y = 0;
+
+    if (config->pin_reset.gpio_controller != nullptr) {
+        internal->reset_descriptor = gpio_descriptor_acquire(config->pin_reset.gpio_controller, config->pin_reset.pin, GPIO_OWNER_GPIO);
+        if (internal->reset_descriptor == nullptr) {
+            LOG_E(TAG, "Failed to acquire reset pin");
+            free(internal);
+            return ERROR_RESOURCE;
+        }
+
+        if (reset_pulse(internal->reset_descriptor, config->reset_active_high) != ERROR_NONE) {
+            LOG_E(TAG, "Failed to pulse reset pin");
+            gpio_descriptor_release(internal->reset_descriptor);
+            free(internal);
+            return ERROR_RESOURCE;
+        }
+    }
+
+    uint8_t chip_id = 0;
+    if (i2c_controller_register8_get(parent, config->address, REG_CHIP_ID, &chip_id, TIMEOUT) != ERROR_NONE) {
+        LOG_E(TAG, "Failed to read chip ID");
+        if (internal->reset_descriptor != nullptr) {
+            gpio_descriptor_release(internal->reset_descriptor);
+        }
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+    LOG_I(TAG, "Chip ID 0x%02X", chip_id);
+
+    // Auto-sleep would otherwise drop the controller into standby after ~2s of inactivity,
+    // adding wake-up latency to the next touch; disabled since exit_sleep() isn't implemented
+    // here (see README) so there'd be no way back out once it kicked in.
+    uint8_t dis_auto_sleep = 0xFF;
+    if (i2c_controller_register8_set(parent, config->address, REG_DIS_AUTOSLEEP, dis_auto_sleep, TIMEOUT) != ERROR_NONE) {
+        LOG_W(TAG, "Failed to disable auto-sleep (non-fatal)");
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+
+    if (internal->reset_descriptor != nullptr) {
+        gpio_descriptor_release(internal->reset_descriptor);
+    }
+
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region PointerApi
+
+static error_t cst816t_read_data(Device* device, TickType_t) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    const auto* config = GET_CONFIG(device);
+    auto* parent = device_get_parent(device);
+
+    // Burst-reads gesture_id, finger_num and X/Y in one transaction, matching the reference
+    // driver: the chip presents them as one contiguous 6-byte block starting at REG_GESTURE_ID.
+    uint8_t data[6];
+    error_t error = i2c_controller_read_register(parent, config->address, REG_GESTURE_ID, data, sizeof(data), TIMEOUT);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+
+    uint8_t finger_num = data[1];
+    internal->touched = finger_num > 0;
+    // Top nibble of the high byte is reserved/event-type; the coordinate itself is 12-bit.
+    internal->x = static_cast<uint16_t>(((data[2] & 0x0F) << 8) | data[3]);
+    internal->y = static_cast<uint16_t>(((data[4] & 0x0F) << 8) | data[5]);
+
+    return ERROR_NONE;
+}
+
+// Single-touch only - see README for why.
+static bool cst816t_get_touched_points(Device* device, uint16_t* x, uint16_t* y, uint16_t* strength, uint8_t* point_count, uint8_t max_point_count) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    const auto* config = GET_CONFIG(device);
+
+    if (!internal->touched || max_point_count == 0) {
+        *point_count = 0;
+        return false;
+    }
+
+    // Order matches esp_lcd_touch's own software coordinate adjustment (mirror X, mirror Y,
+    // then swap) so behavior lines up with the other touch modules in this codebase.
+    uint16_t point_x = internal->x;
+    uint16_t point_y = internal->y;
+    if (internal->mirror_x) {
+        point_x = config->x_max - point_x;
+    }
+    if (internal->mirror_y) {
+        point_y = config->y_max - point_y;
+    }
+    if (internal->swap_xy) {
+        uint16_t tmp = point_x;
+        point_x = point_y;
+        point_y = tmp;
+    }
+
+    x[0] = point_x;
+    y[0] = point_y;
+    if (strength != nullptr) {
+        strength[0] = 0;
+    }
+    *point_count = 1;
+    return true;
+}
+
+static error_t cst816t_set_swap_xy(Device* device, bool swap) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    internal->swap_xy = swap;
+    return ERROR_NONE;
+}
+
+static error_t cst816t_get_swap_xy(Device* device, bool* swap) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    *swap = internal->swap_xy;
+    return ERROR_NONE;
+}
+
+static error_t cst816t_set_mirror_x(Device* device, bool mirror) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    internal->mirror_x = mirror;
+    return ERROR_NONE;
+}
+
+static error_t cst816t_get_mirror_x(Device* device, bool* mirror) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    *mirror = internal->mirror_x;
+    return ERROR_NONE;
+}
+
+static error_t cst816t_set_mirror_y(Device* device, bool mirror) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    internal->mirror_y = mirror;
+    return ERROR_NONE;
+}
+
+static error_t cst816t_get_mirror_y(Device* device, bool* mirror) {
+    auto* internal = static_cast<Cst816tInternal*>(device_get_driver_data(device));
+    *mirror = internal->mirror_y;
+    return ERROR_NONE;
+}
+
+// endregion
+
+static const PointerApi cst816t_pointer_api = {
+    // Unsupported (null per PointerApi's contract): the reference driver defines
+    // REG_SLEEP_MODE (0xE5) but never writes it, and the datasheet says waking up needs a
+    // hardware reset pulse rather than a register write.
+    .enter_sleep = nullptr,
+    .exit_sleep = nullptr,
+    .read_data = cst816t_read_data,
+    .get_touched_points = cst816t_get_touched_points,
+    .set_swap_xy = cst816t_set_swap_xy,
+    .get_swap_xy = cst816t_get_swap_xy,
+    .set_mirror_x = cst816t_set_mirror_x,
+    .get_mirror_x = cst816t_get_mirror_x,
+    .set_mirror_y = cst816t_set_mirror_y,
+    .get_mirror_y = cst816t_get_mirror_y,
+};
+
+Driver cst816t_driver = {
+    .name = "cst816t",
+    .compatible = (const char*[]) { "hynitron,cst816t", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &cst816t_pointer_api,
+    .device_type = &POINTER_TYPE,
+    .owner = &cst816t_module,
+    .internal = nullptr
+};

Drivers/cst816t-module/source/module.cpp

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver cst816t_driver;
+
+static error_t start() {
+    return driver_construct_add(&cst816t_driver);
+}
+
+static error_t stop() {
+    return driver_remove_destruct(&cst816t_driver);
+}
+
+Module cst816t_module = {
+    .name = "cst816t",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+} // extern "C"

Drivers/gc9a01-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(gc9a01-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel platform-esp32 esp_lcd_gc9a01 driver
+)

Drivers/gc9a01-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/gc9a01-module/README.md

@@ -0,0 +1,5 @@
+# GC9A01 display
+
+A driver for the `GC9A01` round display panel by Galaxycore, over SPI.
+
+License: [Apache v2.0](LICENSE-Apache-2.0.md)

Drivers/gc9a01-module/bindings/galaxycore,gc9a01.yaml

@@ -0,0 +1,67 @@
+description: Galaxycore GC9A01 round display panel
+
+bus: spi
+
+compatible: "galaxycore,gc9a01"
+
+properties:
+  horizontal-resolution:
+    type: int
+    required: true
+    description: Horizontal resolution in pixels
+  vertical-resolution:
+    type: int
+    required: true
+    description: Vertical resolution in pixels
+  gap-x:
+    type: int
+    default: 0
+    description: X offset applied to all draw operations
+  gap-y:
+    type: int
+    default: 0
+    description: Y offset applied to all draw operations
+  swap-xy:
+    type: boolean
+    default: false
+    description: Swap the X and Y axes
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  invert-color:
+    type: boolean
+    default: false
+    description: Invert the panel's color output
+  bgr-order:
+    type: boolean
+    default: false
+    description: Use BGR element order instead of RGB
+  pixel-clock-hz:
+    type: int
+    default: 80000000
+    description: SPI pixel clock frequency in Hz
+  transaction-queue-depth:
+    type: int
+    default: 10
+    description: Size of the internal SPI transaction queue
+  pin-dc:
+    type: phandles
+    required: true
+    description: Data/Command GPIO pin
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  backlight:
+    type: phandle
+    default: "NULL"
+    description: Optional reference to this display's backlight device

Drivers/gc9a01-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/gc9a01-module/include/bindings/gc9a01.h

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/gc9a01.h>
+
+DEFINE_DEVICETREE(gc9a01, struct Gc9a01Config)

Drivers/gc9a01-module/include/drivers/gc9a01.h

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/device.h>
+#include <tactility/drivers/gpio.h>
+
+struct Gc9a01Config {
+    uint16_t horizontal_resolution;
+    uint16_t vertical_resolution;
+    int32_t gap_x;
+    int32_t gap_y;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    bool invert_color;
+    bool bgr_order;
+    uint32_t pixel_clock_hz;
+    uint8_t transaction_queue_depth;
+    struct GpioPinSpec pin_dc;
+    struct GpioPinSpec pin_reset;
+    bool reset_active_high;
+    // Optional reference to this display's backlight device, NULL if none.
+    struct Device* backlight;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/gc9a01-module/include/gc9a01_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module gc9a01_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/gc9a01-module/source/gc9a01.cpp

@@ -0,0 +1,322 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <drivers/gc9a01.h>
+#include <gc9a01_module.h>
+
+#include <tactility/check.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/display.h>
+#include <tactility/drivers/esp32_spi.h>
+#include <tactility/drivers/spi_controller.h>
+#include <tactility/error.h>
+#include <tactility/log.h>
+
+#include <esp_err.h>
+#include <esp_lcd_gc9a01.h>
+#include <esp_lcd_io_spi.h>
+#include <esp_lcd_panel_io.h>
+#include <esp_lcd_panel_ops.h>
+
+#include <freertos/semphr.h>
+
+#include <cstdlib>
+
+constexpr auto* TAG = "GC9A01";
+#define GET_CONFIG(device) (static_cast<const Gc9a01Config*>((device)->config))
+
+struct Gc9a01Internal {
+    esp_lcd_panel_io_handle_t io_handle;
+    esp_lcd_panel_handle_t panel_handle;
+    // See st7796-module's identical field for why this exists: draw_bitmap() must block until
+    // the transfer physically completes (DisplayApi's synchronous contract).
+    SemaphoreHandle_t draw_done_semaphore;
+};
+
+static bool IRAM_ATTR on_color_trans_done(esp_lcd_panel_io_handle_t, esp_lcd_panel_io_event_data_t*, void* user_ctx) {
+    auto* internal = static_cast<Gc9a01Internal*>(user_ctx);
+    BaseType_t high_task_woken = pdFALSE;
+    xSemaphoreGiveFromISR(internal->draw_done_semaphore, &high_task_woken);
+    return high_task_woken == pdTRUE;
+}
+
+static int pin_or_unused(const struct GpioPinSpec& pin) {
+    return pin.gpio_controller == nullptr ? -1 : static_cast<int>(pin.pin);
+}
+
+// region Driver lifecycle
+
+static error_t start(Device* device) {
+    auto* parent = device_get_parent(device);
+    check(device_get_type(parent) == &SPI_CONTROLLER_TYPE);
+
+    const auto* spi_config = static_cast<const Esp32SpiConfig*>(parent->config);
+    const auto* config = GET_CONFIG(device);
+
+    struct GpioPinSpec cs_pin;
+    if (esp32_spi_get_cs_pin(device, &cs_pin) != ERROR_NONE) {
+        LOG_E(TAG, "Failed to resolve CS pin");
+        return ERROR_RESOURCE;
+    }
+
+    auto* internal = static_cast<Gc9a01Internal*>(malloc(sizeof(Gc9a01Internal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    internal->draw_done_semaphore = xSemaphoreCreateBinary();
+    if (internal->draw_done_semaphore == nullptr) {
+        free(internal);
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    esp_lcd_panel_io_spi_config_t io_config = {
+        .cs_gpio_num = pin_or_unused(cs_pin),
+        .dc_gpio_num = pin_or_unused(config->pin_dc),
+        .spi_mode = 0,
+        .pclk_hz = config->pixel_clock_hz,
+        .trans_queue_depth = config->transaction_queue_depth,
+        .on_color_trans_done = on_color_trans_done,
+        .user_ctx = internal,
+        .lcd_cmd_bits = 8,
+        .lcd_param_bits = 8,
+        .cs_ena_pretrans = 0,
+        .cs_ena_posttrans = 0,
+        .flags = {
+            .dc_high_on_cmd = 0,
+            .dc_low_on_data = 0,
+            .dc_low_on_param = 0,
+            .octal_mode = 0,
+            .quad_mode = 0,
+            .sio_mode = 0,
+            .lsb_first = 0,
+            .cs_high_active = 0,
+        },
+    };
+
+    esp_err_t ret = esp_lcd_new_panel_io_spi((esp_lcd_spi_bus_handle_t)spi_config->host, &io_config, &internal->io_handle);
+    if (ret != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel IO: %s", esp_err_to_name(ret));
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    esp_lcd_panel_dev_config_t panel_config = {
+        .reset_gpio_num = pin_or_unused(config->pin_reset),
+        .rgb_ele_order = config->bgr_order ? LCD_RGB_ELEMENT_ORDER_BGR : LCD_RGB_ELEMENT_ORDER_RGB,
+        .data_endian = LCD_RGB_DATA_ENDIAN_LITTLE,
+        .bits_per_pixel = 16,
+        .flags = { .reset_active_high = config->reset_active_high },
+        .vendor_config = nullptr,
+    };
+
+    ret = esp_lcd_new_panel_gc9a01(internal->io_handle, &panel_config, &internal->panel_handle);
+    if (ret != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel: %s", esp_err_to_name(ret));
+        esp_lcd_panel_io_del(internal->io_handle);
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    // Bring-up sequence, order matches the deprecated HAL's Gc9a01Display (proven correct on real
+    // Waveshare S3 Touch LCD 1.28 hardware). Every failure path below must clean up fully: unlike
+    // stop_device, this is never retried by the kernel if start_device fails.
+    bool ok =
+        esp_lcd_panel_reset(internal->panel_handle) == ESP_OK &&
+        esp_lcd_panel_init(internal->panel_handle) == ESP_OK;
+
+    if (ok) {
+        ok = (config->gap_x == 0 && config->gap_y == 0) || esp_lcd_panel_set_gap(internal->panel_handle, config->gap_x, config->gap_y) == ESP_OK;
+    }
+    ok = ok && (!config->swap_xy || esp_lcd_panel_swap_xy(internal->panel_handle, true) == ESP_OK);
+    ok = ok && ((!config->mirror_x && !config->mirror_y) || esp_lcd_panel_mirror(internal->panel_handle, config->mirror_x, config->mirror_y) == ESP_OK);
+    ok = ok && (!config->invert_color || esp_lcd_panel_invert_color(internal->panel_handle, true) == ESP_OK);
+    ok = ok && esp_lcd_panel_disp_on_off(internal->panel_handle, true) == ESP_OK;
+
+    if (!ok) {
+        LOG_E(TAG, "Failed to bring up panel");
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+
+    if (internal->panel_handle != nullptr) {
+        if (esp_lcd_panel_del(internal->panel_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel");
+            return ERROR_RESOURCE;
+        }
+        internal->panel_handle = nullptr;
+    }
+
+    if (internal->io_handle != nullptr) {
+        if (esp_lcd_panel_io_del(internal->io_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel IO");
+            return ERROR_RESOURCE;
+        }
+        internal->io_handle = nullptr;
+    }
+
+    vSemaphoreDelete(internal->draw_done_semaphore);
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region DisplayApi
+
+static error_t gc9a01_reset(Device* device) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_reset(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t gc9a01_init(Device* device) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_init(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t gc9a01_draw_bitmap(Device* device, int32_t x_start, int32_t y_start, int32_t x_end, int32_t y_end, const void* color_data) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+
+    xSemaphoreTake(internal->draw_done_semaphore, 0);
+
+    if (esp_lcd_panel_draw_bitmap(internal->panel_handle, x_start, y_start, x_end, y_end, color_data) != ESP_OK) {
+        return ERROR_RESOURCE;
+    }
+
+    xSemaphoreTake(internal->draw_done_semaphore, portMAX_DELAY);
+    return ERROR_NONE;
+}
+
+static error_t gc9a01_mirror(Device* device, bool x_axis, bool y_axis) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_mirror(internal->panel_handle, x_axis, y_axis) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t gc9a01_swap_xy(Device* device, bool swap_axes) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_swap_xy(internal->panel_handle, swap_axes) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static bool gc9a01_get_swap_xy(Device* device) {
+    return GET_CONFIG(device)->swap_xy;
+}
+
+static bool gc9a01_get_mirror_x(Device* device) {
+    return GET_CONFIG(device)->mirror_x;
+}
+
+static bool gc9a01_get_mirror_y(Device* device) {
+    return GET_CONFIG(device)->mirror_y;
+}
+
+static error_t gc9a01_set_gap(Device* device, int32_t x_gap, int32_t y_gap) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_set_gap(internal->panel_handle, x_gap, y_gap) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static int32_t gc9a01_get_gap_x(Device* device) {
+    return GET_CONFIG(device)->gap_x;
+}
+
+static int32_t gc9a01_get_gap_y(Device* device) {
+    return GET_CONFIG(device)->gap_y;
+}
+
+static error_t gc9a01_invert_color(Device* device, bool invert_color_data) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_invert_color(internal->panel_handle, invert_color_data) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t gc9a01_disp_on_off(Device* device, bool on_off) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_on_off(internal->panel_handle, on_off) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t gc9a01_disp_sleep(Device* device, bool sleep) {
+    auto* internal = static_cast<Gc9a01Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_sleep(internal->panel_handle, sleep) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// The deprecated HAL's Gc9a01Display always set swap_bytes=true on its lvgl_port config
+// regardless of rgb_ele_order, so the byte-swapped format applies unconditionally here too -
+// bgr_order only affects the panel's hardware element order (applied in start(), above).
+static enum DisplayColorFormat gc9a01_get_color_format(Device*) {
+    return DISPLAY_COLOR_FORMAT_RGB565_SWAPPED;
+}
+
+static uint16_t gc9a01_get_resolution_x(Device* device) {
+    return GET_CONFIG(device)->horizontal_resolution;
+}
+
+static uint16_t gc9a01_get_resolution_y(Device* device) {
+    return GET_CONFIG(device)->vertical_resolution;
+}
+
+static void gc9a01_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
+    *out_buffer = nullptr;
+}
+
+static uint8_t gc9a01_get_frame_buffer_count(Device*) {
+    return 0;
+}
+
+static error_t gc9a01_get_backlight(Device* device, Device** backlight) {
+    auto* configured_backlight = GET_CONFIG(device)->backlight;
+    if (configured_backlight == nullptr) {
+        return ERROR_NOT_SUPPORTED;
+    }
+    *backlight = configured_backlight;
+    return ERROR_NONE;
+}
+
+// endregion
+
+static const DisplayApi gc9a01_display_api = {
+    .capabilities = DISPLAY_CAPABILITY_CAP_MIRROR | DISPLAY_CAPABILITY_CAP_SWAP_XY |
+        DISPLAY_CAPABILITY_CAP_SET_GAP | DISPLAY_CAPABILITY_INVERT_COLOR | DISPLAY_CAPABILITY_ON_OFF |
+        DISPLAY_CAPABILITY_SLEEP | DISPLAY_CAPABILITY_BACKLIGHT,
+    .reset = gc9a01_reset,
+    .init = gc9a01_init,
+    .draw_bitmap = gc9a01_draw_bitmap,
+    .mirror = gc9a01_mirror,
+    .swap_xy = gc9a01_swap_xy,
+    .get_swap_xy = gc9a01_get_swap_xy,
+    .get_mirror_x = gc9a01_get_mirror_x,
+    .get_mirror_y = gc9a01_get_mirror_y,
+    .set_gap = gc9a01_set_gap,
+    .get_gap_x = gc9a01_get_gap_x,
+    .get_gap_y = gc9a01_get_gap_y,
+    .invert_color = gc9a01_invert_color,
+    .disp_on_off = gc9a01_disp_on_off,
+    .disp_sleep = gc9a01_disp_sleep,
+    .get_color_format = gc9a01_get_color_format,
+    .get_resolution_x = gc9a01_get_resolution_x,
+    .get_resolution_y = gc9a01_get_resolution_y,
+    .get_frame_buffer = gc9a01_get_frame_buffer,
+    .get_frame_buffer_count = gc9a01_get_frame_buffer_count,
+    .get_backlight = gc9a01_get_backlight,
+    .has_capability = nullptr,
+};
+
+Driver gc9a01_driver = {
+    .name = "gc9a01",
+    .compatible = (const char*[]) { "galaxycore,gc9a01", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &gc9a01_display_api,
+    .device_type = &DISPLAY_TYPE,
+    .owner = &gc9a01_module,
+    .internal = nullptr
+};

Drivers/gc9a01-module/source/module.cpp

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver gc9a01_driver;
+
+static error_t start() {
+    /* We crash when construct fails, because if a single driver fails to construct,
+     * there is no guarantee that the previously constructed drivers can be destroyed */
+    check(driver_construct_add(&gc9a01_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    /* We crash when destruct fails, because if a single driver fails to destruct,
+     * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&gc9a01_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+Module gc9a01_module = {
+    .name = "gc9a01",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+} // extern "C"

Drivers/ili9881c-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(ili9881c-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel platform-esp32 esp_lcd_ili9881c esp_lcd driver esp_hw_support
+)

Drivers/ili9881c-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/ili9881c-module/bindings/ilitek,ili9881c.yaml

@@ -0,0 +1,128 @@
+description: >
+  Ilitek ILI9881C MIPI-DSI display panel, driven over ESP-IDF's esp_lcd_ili9881c component
+  (DPI/DBI interface, ESP32-P4 and other SOC_MIPI_DSI_SUPPORTED targets only). Owns the MIPI DSI
+  PHY LDO channel and DSI bus directly, so unlike SPI/RGB panels it has no parent bus controller
+  device.
+
+compatible: "ilitek,ili9881c"
+
+properties:
+  horizontal-resolution:
+    type: int
+    required: true
+    description: Horizontal resolution in pixels
+  vertical-resolution:
+    type: int
+    required: true
+    description: Vertical resolution in pixels
+  bits-per-pixel:
+    type: int
+    default: 16
+    description: Color depth in bits per pixel (16, 18 or 24)
+  bgr-order:
+    type: boolean
+    default: false
+    description: Use BGR element order instead of RGB
+  invert-color:
+    type: boolean
+    default: false
+    description: Invert the panel's color output
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin. Falls back to a software reset (sent over the DBI command
+      interface) if not set.
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  ldo-channel:
+    type: int
+    required: true
+    description: LDO channel index powering the MIPI DSI PHY (chan_id in esp_ldo_channel_config_t)
+  ldo-voltage-mv:
+    type: int
+    required: true
+    description: Voltage to supply to the MIPI DSI PHY LDO channel, in mV
+  dsi-bus-id:
+    type: int
+    default: 0
+    description: Which DSI controller to use, index from 0
+  num-data-lanes:
+    type: int
+    default: 2
+    description: Number of MIPI DSI data lanes. Also used as the vendor config's lane count. 0
+      falls back to the maximum available.
+  lane-bit-rate-mbps:
+    type: int
+    required: true
+    description: MIPI DSI lane bit rate, in Mbps
+  dpi-clock-freq-mhz:
+    type: int
+    required: true
+    description: MIPI DPI clock frequency, in MHz
+  hsync-pulse-width:
+    type: int
+    required: true
+    description: Horizontal sync width, in PCLK periods
+  hsync-back-porch:
+    type: int
+    required: true
+    description: Number of PCLK periods between hsync and the start of line active data
+  hsync-front-porch:
+    type: int
+    required: true
+    description: Number of PCLK periods between the end of active data and the next hsync
+  vsync-pulse-width:
+    type: int
+    required: true
+    description: Vertical sync width, in lines
+  vsync-back-porch:
+    type: int
+    required: true
+    description: Number of invalid lines between vsync and the start of the frame
+  vsync-front-porch:
+    type: int
+    required: true
+    description: Number of invalid lines between the end of the frame and the next vsync
+  num-fbs:
+    type: int
+    default: 1
+    description: Number of screen-sized frame buffers to allocate (0 or 1 = single-buffered)
+  use-dma2d:
+    type: boolean
+    default: true
+    description: Use DMA2D to copy user buffers into the frame buffer when necessary (only
+      meaningful on SOC_DMA2D_SUPPORTED targets - must be false otherwise)
+  disable-lp:
+    type: boolean
+    default: false
+    description: Disable MIPI DSI low-power mode
+  allow-tearing:
+    type: boolean
+    default: false
+    description: By default, when draw_bitmap's color_data is one of the panel's own frame
+      buffers (i.e. LVGL is bound directly onto them), draw_bitmap waits for a full scan-out to
+      complete before returning so the caller can't start overwriting a buffer still being
+      displayed. Set this to trade away that tear-free guarantee for lower latency (e.g. when
+      other tasks occasionally block timing for long enough that waiting causes visible stalls).
+  init-sequence:
+    type: array
+    element-type: uint8_t
+    description: >
+      Custom vendor bring-up sequence, flattened into bytes as a run of
+      [cmd, data-length, delay-ms, data-length bytes of data...] entries, e.g.
+      `init-sequence = [0x11 0 120  0x29 0 20];`.
+      Omit to use the ILI9881C component's own built-in default sequence.
+  backlight:
+    type: phandle
+    default: "NULL"
+    description: Optional reference to this display's backlight device

Drivers/ili9881c-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/ili9881c-module/include/bindings/ili9881c.h

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/ili9881c.h>
+
+// The devicetree compiler derives the expected config typedef name from the compatible
+// string's suffix (e.g. "ilitek,ili9881c" -> ili9881c_config_dt), not from the node name or
+// driver name, so the tag here must match that exactly.
+DEFINE_DEVICETREE(ili9881c, struct Ili9881cConfig)

Drivers/ili9881c-module/include/drivers/ili9881c.h

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/device.h>
+#include <tactility/drivers/gpio.h>
+
+struct Ili9881cConfig {
+    uint16_t horizontal_resolution;
+    uint16_t vertical_resolution;
+    uint8_t bits_per_pixel;
+    bool bgr_order;
+    bool invert_color;
+    bool mirror_x;
+    bool mirror_y;
+
+    // Reset pin for the panel. GPIO_PIN_SPEC_NONE falls back to a software reset sent over the
+    // DBI command interface (see esp_lcd_ili9881c's panel_ili9881c_reset()).
+    struct GpioPinSpec pin_reset;
+    bool reset_active_high;
+
+    // LDO channel powering the MIPI DSI PHY - the PHY has no power of its own until this is
+    // acquired, so it must happen before the DSI bus is created. Both fields are int32_t (not
+    // uint32_t) to exactly match esp_ldo_channel_config_t's plain `int` fields - assigning a
+    // uint32_t into that struct's brace-init would be a narrowing conversion (-Werror=narrowing).
+    int32_t ldo_channel;
+    int32_t ldo_voltage_mv;
+
+    uint8_t dsi_bus_id;
+    // Number of MIPI DSI data lanes. Also passed straight through as the vendor config's
+    // mipi_config.lane_num (unlike jd9165, ili9881c_vendor_config_t tracks this separately from
+    // the DSI bus config). 0 falls back to the maximum available.
+    uint8_t num_data_lanes;
+    uint32_t lane_bit_rate_mbps;
+
+    uint32_t dpi_clock_freq_mhz;
+    uint32_t hsync_pulse_width;
+    uint32_t hsync_back_porch;
+    uint32_t hsync_front_porch;
+    uint32_t vsync_pulse_width;
+    uint32_t vsync_back_porch;
+    uint32_t vsync_front_porch;
+    // Number of screen-sized frame buffers the driver allocates (0 or 1 = single-buffered).
+    uint8_t num_fbs;
+    bool use_dma2d;
+    bool disable_lp;
+
+    // See the 'allow-tearing' binding property.
+    bool allow_tearing;
+
+    // Custom vendor init sequence, flattened as bytes: a run of
+    // [cmd, data_len, delay_ms, data_len bytes of data...] entries. NULL/0 falls back to the
+    // ILI9881C component's own built-in default sequence (see vendor_specific_init_default in
+    // esp_lcd_ili9881c.c) - not guaranteed to match any particular panel's actual bring-up
+    // requirements.
+    const uint8_t* init_sequence;
+    uint32_t init_sequence_length;
+
+    // Optional reference to this display's backlight device, NULL if none.
+    struct Device* backlight;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/ili9881c-module/include/ili9881c_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module ili9881c_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/ili9881c-module/source/ili9881c.cpp

@@ -0,0 +1,526 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <soc/soc_caps.h>
+#if SOC_MIPI_DSI_SUPPORTED
+
+#include <drivers/ili9881c.h>
+#include <ili9881c_module.h>
+
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/display.h>
+#include <tactility/error.h>
+#include <tactility/log.h>
+
+#include <esp_err.h>
+#include <esp_ldo_regulator.h>
+#include <esp_lcd_ili9881c.h>
+#include <esp_lcd_mipi_dsi.h>
+#include <esp_lcd_panel_io.h>
+#include <esp_lcd_panel_ops.h>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+
+#include <cstdlib>
+
+constexpr auto* TAG = "ILI9881C";
+#define GET_CONFIG(device) (static_cast<const Ili9881cConfig*>((device)->config))
+
+// Generic lvgl-module display glue (Modules/lvgl-module/source/lvgl_display.c) only ever asks
+// for frame buffer index 0 and 1, so caching more than that would be dead weight.
+constexpr size_t MAX_CACHED_FRAME_BUFFERS = 2;
+
+struct Ili9881cInternal {
+    esp_ldo_channel_handle_t ldo_handle;
+    esp_lcd_dsi_bus_handle_t dsi_bus_handle;
+    esp_lcd_panel_io_handle_t io_handle;
+    esp_lcd_panel_handle_t panel_handle;
+    void* frame_buffers[MAX_CACHED_FRAME_BUFFERS];
+    uint8_t frame_buffer_count;
+    // Size of each buffer in frame_buffers, in bytes - used to range-check whether a given
+    // draw_bitmap() color_data pointer is actually one of them (see draw_bitmap() below).
+    size_t frame_buffer_size_bytes;
+    // Signaled by on_refresh_done once per real scan-out of a whole frame. Only waited on in
+    // draw_bitmap() when color_data is one of frame_buffers and avoid_tearing is set - see the
+    // comment there for why.
+    SemaphoreHandle_t frame_complete_semaphore;
+    // Heap-allocated only when the devicetree supplies a custom init_sequence (see
+    // parse_init_sequence()) - nullptr otherwise, since the vendor's built-in default sequence
+    // needs no parsing. Its .data pointers alias directly into the devicetree's static const
+    // byte buffer, so only this struct array itself needs freeing in stop().
+    ili9881c_lcd_init_cmd_t* parsed_init_cmds;
+};
+
+// esp_lcd_dpi_panel's draw_bitmap() has a zero-copy path when color_data is one of the panel's
+// own frame buffers (as returned by esp_lcd_dpi_panel_get_frame_buffer()): it just repoints which
+// buffer is scanned out and returns almost instantly - well before the DSI peripheral has
+// actually finished scanning out the *previous* buffer, let alone started on this one. Callers in
+// full/direct LVGL render mode render straight into these real frame buffers, so if draw_bitmap()
+// returned that quickly, LVGL would be free to start overwriting the *other* buffer - which may
+// still be mid-scanout - producing visible tearing/flashing. on_refresh_done fires once per actual
+// whole-frame scan-out completion (continuously, at the panel's refresh rate, independent of
+// draw_bitmap calls), so waiting for the next occurrence after each draw_bitmap() genuinely blocks
+// until it's safe to start writing into the frame buffers again - unless avoid_tearing is false,
+// in which case the caller has opted out of this wait (see the binding property).
+static bool on_refresh_done(esp_lcd_panel_handle_t, esp_lcd_dpi_panel_event_data_t*, void* user_ctx) {
+    auto* internal = static_cast<Ili9881cInternal*>(user_ctx);
+    BaseType_t high_task_woken = pdFALSE;
+    xSemaphoreGiveFromISR(internal->frame_complete_semaphore, &high_task_woken);
+    return high_task_woken == pdTRUE;
+}
+
+static int pin_or_unused(const GpioPinSpec& pin) {
+    return pin.gpio_controller == nullptr ? -1 : static_cast<int>(pin.pin);
+}
+
+static lcd_color_format_t color_format_from_bits_per_pixel(uint8_t bits_per_pixel) {
+    switch (bits_per_pixel) {
+        case 18: return LCD_COLOR_FMT_RGB666;
+        case 24: return LCD_COLOR_FMT_RGB888;
+        default: return LCD_COLOR_FMT_RGB565;
+    }
+}
+
+// Unpacks the devicetree's flat [cmd, data_len, delay_ms, data_len bytes...] encoding (produced
+// by the devicetree compiler's "array" property type - see init-sequence in
+// bindings/ilitek,ili9881c.yaml) into a heap-allocated ili9881c_lcd_init_cmd_t array. Each entry's
+// .data points directly into `bytes`, which is the devicetree's static const buffer and outlives
+// the device, so no per-entry copy is needed.
+static bool parse_init_sequence(const uint8_t* bytes, uint32_t length, ili9881c_lcd_init_cmd_t** out_cmds, uint16_t* out_count) {
+    uint32_t count = 0;
+    for (uint32_t offset = 0; offset < length; count++) {
+        if (offset + 3 > length) {
+            LOG_E(TAG, "init-sequence truncated: entry header runs past the end of the array");
+            return false;
+        }
+        offset += 3 + bytes[offset + 1];
+        if (offset > length) {
+            LOG_E(TAG, "init-sequence truncated: entry data runs past the end of the array");
+            return false;
+        }
+    }
+
+    auto* cmds = static_cast<ili9881c_lcd_init_cmd_t*>(malloc(count * sizeof(ili9881c_lcd_init_cmd_t)));
+    if (cmds == nullptr) {
+        return false;
+    }
+
+    uint32_t offset = 0;
+    for (uint32_t i = 0; i < count; i++) {
+        uint8_t data_len = bytes[offset + 1];
+        cmds[i] = {
+            .cmd = bytes[offset],
+            .data = data_len > 0 ? &bytes[offset + 3] : nullptr,
+            .data_bytes = data_len,
+            .delay_ms = bytes[offset + 2],
+        };
+        offset += 3 + data_len;
+    }
+
+    *out_cmds = cmds;
+    *out_count = (uint16_t)count;
+    return true;
+}
+
+// region Driver lifecycle
+
+static error_t start(Device* device) {
+    const auto* config = GET_CONFIG(device);
+
+    auto* internal = static_cast<Ili9881cInternal*>(malloc(sizeof(Ili9881cInternal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+    internal->parsed_init_cmds = nullptr;
+
+    const ili9881c_lcd_init_cmd_t* init_cmds = nullptr;
+    uint16_t init_cmds_size = 0;
+    if (config->init_sequence != nullptr && config->init_sequence_length > 0) {
+        if (!parse_init_sequence(config->init_sequence, config->init_sequence_length, &internal->parsed_init_cmds, &init_cmds_size)) {
+            LOG_E(TAG, "Failed to parse init-sequence property");
+            free(internal);
+            return ERROR_INVALID_ARGUMENT;
+        }
+        init_cmds = internal->parsed_init_cmds;
+    }
+
+    // The MIPI DSI PHY has no power of its own until this LDO channel is enabled - must happen
+    // before the DSI bus is created.
+    esp_ldo_channel_config_t ldo_config = {
+        .chan_id = config->ldo_channel,
+        .voltage_mv = config->ldo_voltage_mv,
+        .flags = {},
+    };
+    if (esp_ldo_acquire_channel(&ldo_config, &internal->ldo_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to acquire LDO channel for MIPI DSI PHY");
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    const esp_lcd_dsi_bus_config_t bus_config = {
+        .bus_id = config->dsi_bus_id,
+        .num_data_lanes = config->num_data_lanes,
+        .phy_clk_src = MIPI_DSI_PHY_CLK_SRC_DEFAULT,
+        .lane_bit_rate_mbps = config->lane_bit_rate_mbps,
+    };
+    if (esp_lcd_new_dsi_bus(&bus_config, &internal->dsi_bus_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to create MIPI DSI bus");
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    const esp_lcd_dbi_io_config_t dbi_config = {
+        .virtual_channel = 0,
+        .lcd_cmd_bits = 8,
+        .lcd_param_bits = 8,
+    };
+    if (esp_lcd_new_panel_io_dbi(internal->dsi_bus_handle, &dbi_config, &internal->io_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel IO");
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    const lcd_color_format_t color_format = color_format_from_bits_per_pixel(config->bits_per_pixel);
+    const esp_lcd_dpi_panel_config_t dpi_config = {
+        .virtual_channel = 0,
+        .dpi_clk_src = MIPI_DSI_DPI_CLK_SRC_DEFAULT,
+        .dpi_clock_freq_mhz = config->dpi_clock_freq_mhz,
+        .pixel_format = (lcd_color_rgb_pixel_format_t)0, // deprecated field - in/out_color_format below take precedence
+        .in_color_format = color_format,
+        .out_color_format = color_format,
+        .num_fbs = config->num_fbs,
+        .video_timing = {
+            .h_size = config->horizontal_resolution,
+            .v_size = config->vertical_resolution,
+            .hsync_pulse_width = config->hsync_pulse_width,
+            .hsync_back_porch = config->hsync_back_porch,
+            .hsync_front_porch = config->hsync_front_porch,
+            .vsync_pulse_width = config->vsync_pulse_width,
+            .vsync_back_porch = config->vsync_back_porch,
+            .vsync_front_porch = config->vsync_front_porch,
+        },
+        .flags = {
+            .use_dma2d = config->use_dma2d,
+            .disable_lp = config->disable_lp,
+        },
+    };
+
+    ili9881c_vendor_config_t vendor_config = {
+        .init_cmds = init_cmds,
+        .init_cmds_size = init_cmds_size,
+        .mipi_config = {
+            .dsi_bus = internal->dsi_bus_handle,
+            .dpi_config = &dpi_config,
+            .lane_num = config->num_data_lanes,
+        },
+    };
+
+    const esp_lcd_panel_dev_config_t panel_config = {
+        .reset_gpio_num = pin_or_unused(config->pin_reset),
+        .rgb_ele_order = config->bgr_order ? LCD_RGB_ELEMENT_ORDER_BGR : LCD_RGB_ELEMENT_ORDER_RGB,
+        .data_endian = LCD_RGB_DATA_ENDIAN_LITTLE,
+        .bits_per_pixel = config->bits_per_pixel,
+        .flags = { .reset_active_high = config->reset_active_high },
+        .vendor_config = &vendor_config,
+    };
+
+    if (esp_lcd_new_panel_ili9881c(internal->io_handle, &panel_config, &internal->panel_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel");
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    // Bring-up sequence: reset() pulses (or software-resets) the panel and init() pushes
+    // init_cmds over the DBI command interface before bringing up the underlying DPI peripheral.
+    // swap_xy/set_gap are intentionally not called: the ILI9881C driver doesn't override them and
+    // the underlying raw DPI panel doesn't implement them either, so both would just fail with
+    // ESP_ERR_NOT_SUPPORTED (see DisplayApi below). Every failure path here must clean up fully:
+    // unlike stop_device, this is never retried by the kernel if start_device fails (see
+    // device_start() in TactilityKernel), so a partial failure here would leak.
+    bool ok =
+        esp_lcd_panel_reset(internal->panel_handle) == ESP_OK &&
+        esp_lcd_panel_init(internal->panel_handle) == ESP_OK &&
+        esp_lcd_panel_invert_color(internal->panel_handle, config->invert_color) == ESP_OK &&
+        esp_lcd_panel_mirror(internal->panel_handle, config->mirror_x, config->mirror_y) == ESP_OK &&
+        esp_lcd_panel_disp_on_off(internal->panel_handle, true) == ESP_OK;
+
+    if (!ok) {
+        LOG_E(TAG, "Failed to bring up panel");
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    internal->frame_buffer_count = 0;
+    internal->frame_buffer_size_bytes = (size_t)config->horizontal_resolution * config->vertical_resolution *
+        ((config->bits_per_pixel + 7) / 8);
+    if (config->num_fbs > 0) {
+        // esp_lcd_dpi_panel_get_frame_buffer() is variadic: the number of out-pointer arguments
+        // passed must match fb_num exactly, so this can't be a loop.
+        size_t fb_num = config->num_fbs < MAX_CACHED_FRAME_BUFFERS ? config->num_fbs : MAX_CACHED_FRAME_BUFFERS;
+        esp_err_t ret;
+        switch (fb_num) {
+            case 1:
+                ret = esp_lcd_dpi_panel_get_frame_buffer(internal->panel_handle, 1, &internal->frame_buffers[0]);
+                break;
+            case 2:
+                ret = esp_lcd_dpi_panel_get_frame_buffer(internal->panel_handle, 2, &internal->frame_buffers[0], &internal->frame_buffers[1]);
+                break;
+            default:
+                ret = ESP_OK;
+                break;
+        }
+
+        if (ret != ESP_OK) {
+            LOG_E(TAG, "Failed to get frame buffer(s): %s", esp_err_to_name(ret));
+            esp_lcd_panel_del(internal->panel_handle);
+            esp_lcd_panel_io_del(internal->io_handle);
+            esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+            esp_ldo_release_channel(internal->ldo_handle);
+            free(internal->parsed_init_cmds);
+            free(internal);
+            return ERROR_RESOURCE;
+        }
+        internal->frame_buffer_count = (uint8_t)fb_num;
+    }
+
+    internal->frame_complete_semaphore = xSemaphoreCreateBinary();
+    if (internal->frame_complete_semaphore == nullptr) {
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    esp_lcd_dpi_panel_event_callbacks_t callbacks = {};
+    callbacks.on_refresh_done = on_refresh_done;
+    if (esp_lcd_dpi_panel_register_event_callbacks(internal->panel_handle, &callbacks, internal) != ESP_OK) {
+        LOG_E(TAG, "Failed to register panel event callbacks");
+        vSemaphoreDelete(internal->frame_complete_semaphore);
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+
+    if (internal->panel_handle != nullptr) {
+        if (esp_lcd_panel_del(internal->panel_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel");
+            return ERROR_RESOURCE;
+        }
+        internal->panel_handle = nullptr;
+    }
+
+    if (internal->io_handle != nullptr) {
+        if (esp_lcd_panel_io_del(internal->io_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel IO");
+            return ERROR_RESOURCE;
+        }
+        internal->io_handle = nullptr;
+    }
+
+    if (internal->dsi_bus_handle != nullptr) {
+        if (esp_lcd_del_dsi_bus(internal->dsi_bus_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete DSI bus");
+            return ERROR_RESOURCE;
+        }
+        internal->dsi_bus_handle = nullptr;
+    }
+
+    if (internal->ldo_handle != nullptr) {
+        if (esp_ldo_release_channel(internal->ldo_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to release LDO channel");
+            return ERROR_RESOURCE;
+        }
+        internal->ldo_handle = nullptr;
+    }
+
+    vSemaphoreDelete(internal->frame_complete_semaphore);
+    free(internal->parsed_init_cmds);
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region DisplayApi
+
+static error_t ili9881c_reset(Device* device) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+    return esp_lcd_panel_reset(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t ili9881c_init(Device* device) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+    return esp_lcd_panel_init(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// Only block for scan-out completion when color_data is actually one of the panel's own frame
+// buffers (see on_refresh_done's comment above for why that matters) and allow_tearing is not
+// set - i.e. this specific call is a zero-copy flip, not a plain CPU copy into the panel's buffer
+// from a caller-owned one (e.g. LVGL bound in owned-buffer mode), which has no reuse race to
+// guard against and shouldn't pay the up-to-one-frame latency cost for every partial update.
+static bool ili9881c_color_data_is_frame_buffer(const Ili9881cInternal* internal, const void* color_data) {
+    const auto* ptr = static_cast<const uint8_t*>(color_data);
+    for (uint8_t i = 0; i < internal->frame_buffer_count; i++) {
+        const auto* base = static_cast<const uint8_t*>(internal->frame_buffers[i]);
+        if (ptr >= base && ptr < base + internal->frame_buffer_size_bytes) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static error_t ili9881c_draw_bitmap(Device* device, int32_t x_start, int32_t y_start, int32_t x_end, int32_t y_end, const void* color_data) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+
+    bool wait_for_scanout = !GET_CONFIG(device)->allow_tearing && ili9881c_color_data_is_frame_buffer(internal, color_data);
+    if (wait_for_scanout) {
+        xSemaphoreTake(internal->frame_complete_semaphore, 0); // clear any already-pending signal
+    }
+
+    if (esp_lcd_panel_draw_bitmap(internal->panel_handle, x_start, y_start, x_end, y_end, color_data) != ESP_OK) {
+        return ERROR_RESOURCE;
+    }
+
+    if (wait_for_scanout) {
+        xSemaphoreTake(internal->frame_complete_semaphore, portMAX_DELAY);
+    }
+
+    return ERROR_NONE;
+}
+
+// Mirror is always implemented by LCD command (MADCTL), unconditionally, by esp_lcd_ili9881c -
+// see panel_ili9881c_mirror() in esp_lcd_ili9881c.c. Unlike esp_lcd_rgb_panel's software
+// rotate_mask trick, this isn't tied to draw_bitmap's copy path, so it stays available even when
+// LVGL is bound directly onto the panel's own frame buffers.
+static error_t ili9881c_mirror(Device* device, bool x_axis, bool y_axis) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+    return esp_lcd_panel_mirror(internal->panel_handle, x_axis, y_axis) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static bool ili9881c_get_mirror_x(Device* device) {
+    return GET_CONFIG(device)->mirror_x;
+}
+
+static bool ili9881c_get_mirror_y(Device* device) {
+    return GET_CONFIG(device)->mirror_y;
+}
+
+// swap_xy/set_gap are not exposed: esp_lcd_ili9881c doesn't override them and the underlying raw
+// MIPI DPI panel doesn't implement them either (esp_lcd_panel_dpi.c never assigns those function
+// pointers), so esp_lcd_panel_swap_xy()/set_gap() would just return ESP_ERR_NOT_SUPPORTED.
+
+static error_t ili9881c_invert_color(Device* device, bool invert_color_data) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+    return esp_lcd_panel_invert_color(internal->panel_handle, invert_color_data) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t ili9881c_disp_on_off(Device* device, bool on_off) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_on_off(internal->panel_handle, on_off) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// disp_sleep is not exposed: esp_lcd_ili9881c doesn't override it either (only
+// del/init/reset/mirror/invert_color/disp_on_off - see esp_lcd_ili9881c.c).
+
+// bgr_order only selects the panel controller's rgb_ele_order (applied in start(), above) so the
+// R/B swap happens on-chip. LVGL always fills the same-layout buffer either way - there's no
+// separate "BGR" memory layout to produce, unlike the SPI byte-order swap some other panels need.
+static enum DisplayColorFormat ili9881c_get_color_format(Device* device) {
+    return GET_CONFIG(device)->bits_per_pixel == 24 ? DISPLAY_COLOR_FORMAT_RGB888 : DISPLAY_COLOR_FORMAT_RGB565;
+}
+
+static uint16_t ili9881c_get_resolution_x(Device* device) {
+    return GET_CONFIG(device)->horizontal_resolution;
+}
+
+static uint16_t ili9881c_get_resolution_y(Device* device) {
+    return GET_CONFIG(device)->vertical_resolution;
+}
+
+static void ili9881c_get_frame_buffer(Device* device, uint8_t index, void** out_buffer) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+    *out_buffer = index < internal->frame_buffer_count ? internal->frame_buffers[index] : nullptr;
+}
+
+static uint8_t ili9881c_get_frame_buffer_count(Device* device) {
+    auto* internal = static_cast<Ili9881cInternal*>(device_get_driver_data(device));
+    return internal->frame_buffer_count;
+}
+
+static error_t ili9881c_get_backlight(Device* device, Device** backlight) {
+    auto* configured_backlight = GET_CONFIG(device)->backlight;
+    if (configured_backlight == nullptr) {
+        return ERROR_NOT_SUPPORTED;
+    }
+    *backlight = configured_backlight;
+    return ERROR_NONE;
+}
+
+// endregion
+
+static const DisplayApi ili9881c_display_api = {
+    .capabilities = DISPLAY_CAPABILITY_CAP_MIRROR | DISPLAY_CAPABILITY_INVERT_COLOR |
+        DISPLAY_CAPABILITY_ON_OFF | DISPLAY_CAPABILITY_BACKLIGHT,
+    .reset = ili9881c_reset,
+    .init = ili9881c_init,
+    .draw_bitmap = ili9881c_draw_bitmap,
+    .mirror = ili9881c_mirror,
+    .swap_xy = nullptr,
+    .get_swap_xy = nullptr,
+    .get_mirror_x = ili9881c_get_mirror_x,
+    .get_mirror_y = ili9881c_get_mirror_y,
+    .set_gap = nullptr,
+    .invert_color = ili9881c_invert_color,
+    .disp_on_off = ili9881c_disp_on_off,
+    .disp_sleep = nullptr,
+    .get_color_format = ili9881c_get_color_format,
+    .get_resolution_x = ili9881c_get_resolution_x,
+    .get_resolution_y = ili9881c_get_resolution_y,
+    .get_frame_buffer = ili9881c_get_frame_buffer,
+    .get_frame_buffer_count = ili9881c_get_frame_buffer_count,
+    .get_backlight = ili9881c_get_backlight,
+    .has_capability = nullptr,
+};
+
+Driver ili9881c_driver = {
+    .name = "ili9881c",
+    .compatible = (const char*[]) { "ilitek,ili9881c", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &ili9881c_display_api,
+    .device_type = &DISPLAY_TYPE,
+    .owner = &ili9881c_module,
+    .internal = nullptr
+};
+
+#endif // SOC_MIPI_DSI_SUPPORTED

Drivers/ili9881c-module/source/module.cpp

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver ili9881c_driver;
+
+static error_t start() {
+    /* We crash when construct fails, because if a single driver fails to construct,
+     * there is no guarantee that the previously constructed drivers can be destroyed */
+    check(driver_construct_add(&ili9881c_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    /* We crash when destruct fails, because if a single driver fails to destruct,
+     * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&ili9881c_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+Module ili9881c_module = {
+    .name = "ili9881c",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+} // extern "C"

Drivers/ina226-module/bindings/ti,ina226.yaml

@@ -10,3 +10,16 @@ properties:
     required: true
     # shunt value should be a minimum of 1
     description: Shunt resistor value in milliohms
+  power-supply:
+    type: boolean
+    default: false
+    description: Expose a power-supply device that reports battery voltage/capacity read from the INA226's bus voltage input
+  power-supply-reference-voltage-mv:
+    type: int
+    default: 4200
+    description: Battery voltage (in mV) considered 100% capacity, used to compute POWER_SUPPLY_PROP_CAPACITY
+  power-supply-min-voltage-mv:
+    type: int
+    default: 3200
+    description: Battery voltage (in mV) considered 0% capacity, used to compute POWER_SUPPLY_PROP_CAPACITY.
+      Depends on the pack's cell count - the default is a rough 1S LiPo floor.

Drivers/ina226-module/include/drivers/ina226.h

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 #pragma once
 
+#include <stdbool.h>
 #include <stdint.h>
 #include <tactility/error.h>
 
@@ -13,6 +14,12 @@ extern "C" {
 struct Ina226Config {
     uint8_t address;
     uint16_t shunt_milliohms;
+    /** Expose a power-supply child device that reports battery voltage/capacity off the bus voltage reading */
+    bool power_supply;
+    /** Battery voltage (mV) considered 100% capacity, used to derive POWER_SUPPLY_PROP_CAPACITY */
+    uint32_t power_supply_reference_voltage_mv;
+    /** Battery voltage (mV) considered 0% capacity, used to derive POWER_SUPPLY_PROP_CAPACITY */
+    uint32_t power_supply_min_voltage_mv;
 };
 
 /** Bus voltage in volts (1.25 mV/LSB) */

Drivers/ina226-module/source/ina226.cpp

@@ -1,11 +1,16 @@
 // SPDX-License-Identifier: Apache-2.0
 #include <drivers/ina226.h>
 #include <ina226_module.h>
+#include <tactility/check.h>
 #include <tactility/device.h>
 #include <tactility/drivers/i2c_controller.h>
+#include <tactility/drivers/power_supply.h>
 #include <tactility/log.h>
 
-#define TAG "INA226"
+#include <cstdlib>
+#include <new>
+
+constexpr auto* TAG = "INA226";
 
 // ---------------------------------------------------------------------------
 // Register map
@@ -30,6 +35,124 @@ static constexpr TickType_t TIMEOUT = pdMS_TO_TICKS(50);
 
 #define GET_CONFIG(device) (static_cast<const Ina226Config*>((device)->config))
 
+struct Ina226Internal {
+    Device* power_supply_device;
+};
+
+// ---------------------------------------------------------------------------
+// Power supply
+// ---------------------------------------------------------------------------
+
+static bool ps_supports_property(Device*, PowerSupplyProperty property) {
+    return property == POWER_SUPPLY_PROP_VOLTAGE || property == POWER_SUPPLY_PROP_CAPACITY;
+}
+
+// battery_mv <= min_mv -> 0%, battery_mv >= reference_mv -> 100%, linear in between. min_mv is
+// configurable (power-supply-min-voltage-mv) since it depends on the pack's cell count - a 1S
+// LiPo's empty floor is very different from e.g. a 2S pack's.
+static int estimate_capacity_from_mv(int battery_mv, uint32_t min_mv, uint32_t reference_mv) {
+    if ((uint32_t)battery_mv <= min_mv) return 0;
+    if ((uint32_t)battery_mv >= reference_mv) return 100;
+    return (battery_mv - (int)min_mv) * 100 / ((int)reference_mv - (int)min_mv);
+}
+
+static error_t ps_get_property(Device* device, PowerSupplyProperty property, PowerSupplyPropertyValue* out_value) {
+    if (property != POWER_SUPPLY_PROP_VOLTAGE && property != POWER_SUPPLY_PROP_CAPACITY) {
+        return ERROR_NOT_SUPPORTED;
+    }
+
+    auto* parent = device_get_parent(device);
+
+    float volts;
+    error_t error = ina226_read_bus_voltage(parent, &volts);
+    if (error != ERROR_NONE) {
+        return error;
+    }
+    int battery_mv = static_cast<int>(volts * 1000.0f);
+
+    const auto* parent_config = GET_CONFIG(parent);
+    out_value->int_value = (property == POWER_SUPPLY_PROP_VOLTAGE)
+        ? battery_mv
+        : estimate_capacity_from_mv(battery_mv, parent_config->power_supply_min_voltage_mv, parent_config->power_supply_reference_voltage_mv);
+    return ERROR_NONE;
+}
+
+static bool ps_supports_charge_control(Device*) { return false; }
+static bool ps_is_allowed_to_charge(Device*) { return false; }
+static error_t ps_set_allowed_to_charge(Device*, bool) { return ERROR_NOT_SUPPORTED; }
+static bool ps_supports_quick_charge(Device*) { return false; }
+static bool ps_is_quick_charge_enabled(Device*) { return false; }
+static error_t ps_set_quick_charge_enabled(Device*, bool) { return ERROR_NOT_SUPPORTED; }
+static bool ps_supports_power_off(Device*) { return false; }
+static error_t ps_power_off(Device*) { return ERROR_NOT_SUPPORTED; }
+
+static constexpr PowerSupplyApi INA226_POWER_SUPPLY_API = {
+    .supports_property = ps_supports_property,
+    .get_property = ps_get_property,
+    .supports_charge_control = ps_supports_charge_control,
+    .is_allowed_to_charge = ps_is_allowed_to_charge,
+    .set_allowed_to_charge = ps_set_allowed_to_charge,
+    .supports_quick_charge = ps_supports_quick_charge,
+    .is_quick_charge_enabled = ps_is_quick_charge_enabled,
+    .set_quick_charge_enabled = ps_set_quick_charge_enabled,
+    .supports_power_off = ps_supports_power_off,
+    .power_off = ps_power_off,
+};
+
+// Registered (driver_construct_add() in module.cpp) so driver_bind() has a valid ->internal,
+// but never matched against a devicetree node: ina226 wires it up directly by pointer.
+Driver ina226_power_supply_driver = {
+    .name = "ina226-power-supply",
+    .compatible = (const char*[]) { "ina226-power-supply", nullptr },
+    .start_device = nullptr,
+    .stop_device = nullptr,
+    .api = &INA226_POWER_SUPPLY_API,
+    .device_type = &POWER_SUPPLY_TYPE,
+    .owner = &ina226_module,
+    .internal = nullptr
+};
+
+static error_t create_power_supply_child(Device* parent, Device*& out_child) {
+    auto* child = new(std::nothrow) Device { .address = 0, .name = "ina226-power-supply", .config = nullptr, .parent = nullptr, .internal = nullptr };
+    if (child == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    error_t error = device_construct(child);
+    if (error != ERROR_NONE) {
+        delete child;
+        return error;
+    }
+
+    device_set_parent(child, parent);
+    device_set_driver(child, &ina226_power_supply_driver);
+
+    error = device_add(child);
+    if (error != ERROR_NONE) {
+        device_destruct(child);
+        delete child;
+        return error;
+    }
+
+    error = device_start(child);
+    if (error != ERROR_NONE) {
+        device_remove(child);
+        device_destruct(child);
+        delete child;
+        return error;
+    }
+
+    out_child = child;
+    return ERROR_NONE;
+}
+
+static void destroy_power_supply_child(Device* child) {
+    check(device_stop(child) == ERROR_NONE);
+    check(device_remove(child) == ERROR_NONE);
+    check(device_destruct(child) == ERROR_NONE);
+    delete child;
+}
+
 // ---------------------------------------------------------------------------
 // Driver lifecycle
 // ---------------------------------------------------------------------------
@@ -77,6 +200,23 @@ static error_t start(Device* device) {
         return ERROR_RESOURCE;
     }
 
+    auto* internal = static_cast<Ina226Internal*>(malloc(sizeof(Ina226Internal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+    internal->power_supply_device = nullptr;
+    device_set_driver_data(device, internal);
+
+    if (GET_CONFIG(device)->power_supply) {
+        error_t error = create_power_supply_child(device, internal->power_supply_device);
+        if (error != ERROR_NONE) {
+            LOG_E(TAG, "Failed to create power-supply device");
+            free(internal);
+            device_set_driver_data(device, nullptr);
+            return error;
+        }
+    }
+
     LOG_I(TAG, "INA226 started (addr=0x%02X, shunt=%umΩ, cal=0x%04X)", addr, GET_CONFIG(device)->shunt_milliohms, cal_value);
     return ERROR_NONE;
 }
@@ -88,6 +228,12 @@ static error_t stop(Device* device) {
         return ERROR_RESOURCE;
     }
 
+    auto* internal = static_cast<Ina226Internal*>(device_get_driver_data(device));
+    if (internal->power_supply_device != nullptr) {
+        destroy_power_supply_child(internal->power_supply_device);
+        internal->power_supply_device = nullptr;
+    }
+
     auto addr = GET_CONFIG(device)->address;
 
     // Put device into shutdown mode to save power
@@ -95,6 +241,9 @@ static error_t stop(Device* device) {
         LOG_E(TAG, "Failed to shutdown INA226 (ignored)");
     }
 
+    free(internal);
+    device_set_driver_data(device, nullptr);
+
     return ERROR_NONE;
 }
 

Drivers/ina226-module/source/module.cpp

@@ -6,17 +6,20 @@
 extern "C" {
 
 extern Driver ina226_driver;
+extern Driver ina226_power_supply_driver;
 
 static error_t start() {
     /* We crash when construct fails, because if a single driver fails to construct,
      * there is no guarantee that the previously constructed drivers can be destroyed */
     check(driver_construct_add(&ina226_driver) == ERROR_NONE);
+    check(driver_construct_add(&ina226_power_supply_driver) == ERROR_NONE);
     return ERROR_NONE;
 }
 
 static error_t stop() {
     /* We crash when destruct fails, because if a single driver fails to destruct,
      * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&ina226_power_supply_driver) == ERROR_NONE);
     check(driver_remove_destruct(&ina226_driver) == ERROR_NONE);
     return ERROR_NONE;
 }

Drivers/jd9853-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(jd9853-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel platform-esp32 JD9853 esp_lcd driver
+)

Drivers/jd9853-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/jd9853-module/README.md

@@ -0,0 +1,5 @@
+# JD9853 display
+
+A driver for the `JD9853` display panel by Jadard, over SPI.
+
+License: [Apache v2.0](LICENSE-Apache-2.0.md)

Drivers/jd9853-module/bindings/jadard,jd9853.yaml

@@ -0,0 +1,73 @@
+description: Jadard JD9853 display panel
+
+bus: spi
+
+compatible: "jadard,jd9853"
+
+properties:
+  horizontal-resolution:
+    type: int
+    required: true
+    description: Horizontal resolution in pixels
+  vertical-resolution:
+    type: int
+    required: true
+    description: Vertical resolution in pixels
+  gap-x:
+    type: int
+    default: 0
+    description: X offset applied to all draw operations
+  gap-y:
+    type: int
+    default: 0
+    description: Y offset applied to all draw operations
+  swap-xy:
+    type: boolean
+    default: false
+    description: Swap the X and Y axes
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  invert-color:
+    type: boolean
+    default: false
+    description: Invert the panel's color output
+  bgr-order:
+    type: boolean
+    default: false
+    description: Use BGR element order instead of RGB
+  pixel-clock-hz:
+    type: int
+    default: 40000000
+    description: SPI pixel clock frequency in Hz
+  transaction-queue-depth:
+    type: int
+    default: 10
+    description: Size of the internal SPI transaction queue
+  gamma-curve:
+    type: int
+    default: 1
+    min: 0
+    max: 3
+    description: Gamma curve preset index [0,3], sent via the MIPI DCS GAMSET (0x26) command at bring-up
+  pin-dc:
+    type: phandles
+    required: true
+    description: Data/Command GPIO pin
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  backlight:
+    type: phandle
+    default: "NULL"
+    description: Optional reference to this display's backlight device

Drivers/jd9853-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/jd9853-module/include/bindings/jd9853.h

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/jd9853.h>
+
+DEFINE_DEVICETREE(jd9853, struct Jd9853Config)

Drivers/jd9853-module/include/drivers/jd9853.h

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/device.h>
+#include <tactility/drivers/gpio.h>
+
+struct Jd9853Config {
+    uint16_t horizontal_resolution;
+    uint16_t vertical_resolution;
+    int32_t gap_x;
+    int32_t gap_y;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    bool invert_color;
+    bool bgr_order;
+    uint32_t pixel_clock_hz;
+    uint8_t transaction_queue_depth;
+    // Gamma curve preset index [0,3], sent via the MIPI DCS GAMSET (0x26) command at bring-up.
+    uint8_t gamma_curve;
+    struct GpioPinSpec pin_dc;
+    struct GpioPinSpec pin_reset;
+    bool reset_active_high;
+    // Optional reference to this display's backlight device, NULL if none.
+    struct Device* backlight;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/jd9853-module/include/jd9853_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module jd9853_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/jd9853-module/source/jd9853.cpp

@@ -0,0 +1,335 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <drivers/jd9853.h>
+#include <jd9853_module.h>
+
+#include <tactility/check.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/display.h>
+#include <tactility/drivers/esp32_spi.h>
+#include <tactility/drivers/spi_controller.h>
+#include <tactility/error.h>
+#include <tactility/log.h>
+
+#include <esp_err.h>
+#include <esp_lcd_io_spi.h>
+#include <esp_lcd_jd9853.h>
+#include <esp_lcd_panel_commands.h>
+#include <esp_lcd_panel_io.h>
+#include <esp_lcd_panel_ops.h>
+
+#include <freertos/semphr.h>
+
+#include <cstdlib>
+
+constexpr auto* TAG = "JD9853";
+#define GET_CONFIG(device) (static_cast<const Jd9853Config*>((device)->config))
+
+// Maps gamma-curve devicetree index [0,3] to the MIPI DCS GAMSET (0x26) parameter value. Mirrors
+// the deprecated HAL's Jd9853Display::setGammaCurve() (Drivers/JD9853) - note the non-linear
+// mapping, not index+1.
+static const uint8_t GAMMA_CURVE_VALUES[4] = { 0x01, 0x04, 0x02, 0x08 };
+
+struct Jd9853Internal {
+    esp_lcd_panel_io_handle_t io_handle;
+    esp_lcd_panel_handle_t panel_handle;
+    // See st7796-module's identical field for why this exists: draw_bitmap() must block until
+    // the transfer physically completes (DisplayApi's synchronous contract).
+    SemaphoreHandle_t draw_done_semaphore;
+};
+
+static bool IRAM_ATTR on_color_trans_done(esp_lcd_panel_io_handle_t, esp_lcd_panel_io_event_data_t*, void* user_ctx) {
+    auto* internal = static_cast<Jd9853Internal*>(user_ctx);
+    BaseType_t high_task_woken = pdFALSE;
+    xSemaphoreGiveFromISR(internal->draw_done_semaphore, &high_task_woken);
+    return high_task_woken == pdTRUE;
+}
+
+static int pin_or_unused(const struct GpioPinSpec& pin) {
+    return pin.gpio_controller == nullptr ? -1 : static_cast<int>(pin.pin);
+}
+
+// region Driver lifecycle
+
+static error_t start(Device* device) {
+    auto* parent = device_get_parent(device);
+    check(device_get_type(parent) == &SPI_CONTROLLER_TYPE);
+
+    const auto* spi_config = static_cast<const Esp32SpiConfig*>(parent->config);
+    const auto* config = GET_CONFIG(device);
+
+    struct GpioPinSpec cs_pin;
+    if (esp32_spi_get_cs_pin(device, &cs_pin) != ERROR_NONE) {
+        LOG_E(TAG, "Failed to resolve CS pin");
+        return ERROR_RESOURCE;
+    }
+
+    auto* internal = static_cast<Jd9853Internal*>(malloc(sizeof(Jd9853Internal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    internal->draw_done_semaphore = xSemaphoreCreateBinary();
+    if (internal->draw_done_semaphore == nullptr) {
+        free(internal);
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    esp_lcd_panel_io_spi_config_t io_config = {
+        .cs_gpio_num = pin_or_unused(cs_pin),
+        .dc_gpio_num = pin_or_unused(config->pin_dc),
+        .spi_mode = 0,
+        .pclk_hz = config->pixel_clock_hz,
+        .trans_queue_depth = config->transaction_queue_depth,
+        .on_color_trans_done = on_color_trans_done,
+        .user_ctx = internal,
+        .lcd_cmd_bits = 8,
+        .lcd_param_bits = 8,
+        .cs_ena_pretrans = 0,
+        .cs_ena_posttrans = 0,
+        .flags = {
+            .dc_high_on_cmd = 0,
+            .dc_low_on_data = 0,
+            .dc_low_on_param = 0,
+            .octal_mode = 0,
+            .quad_mode = 0,
+            .sio_mode = 0,
+            .lsb_first = 0,
+            .cs_high_active = 0,
+        },
+    };
+
+    esp_err_t ret = esp_lcd_new_panel_io_spi((esp_lcd_spi_bus_handle_t)spi_config->host, &io_config, &internal->io_handle);
+    if (ret != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel IO: %s", esp_err_to_name(ret));
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    jd9853_vendor_config_t vendor_config = {
+        .init_cmds = nullptr,
+        .init_cmds_size = 0,
+    };
+
+    esp_lcd_panel_dev_config_t panel_config = {
+        .reset_gpio_num = pin_or_unused(config->pin_reset),
+        .rgb_ele_order = config->bgr_order ? LCD_RGB_ELEMENT_ORDER_BGR : LCD_RGB_ELEMENT_ORDER_RGB,
+        .data_endian = LCD_RGB_DATA_ENDIAN_LITTLE,
+        .bits_per_pixel = 16,
+        .flags = { .reset_active_high = config->reset_active_high },
+        .vendor_config = &vendor_config,
+    };
+
+    ret = esp_lcd_new_panel_jd9853(internal->io_handle, &panel_config, &internal->panel_handle);
+    if (ret != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel: %s", esp_err_to_name(ret));
+        esp_lcd_panel_io_del(internal->io_handle);
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    // Bring-up sequence, order matches the deprecated HAL's Jd9853Display (proven correct on real
+    // Waveshare S3 Touch LCD 1.47 hardware). Every failure path below must clean up fully: unlike
+    // stop_device, this is never retried by the kernel if start_device fails.
+    bool ok =
+        esp_lcd_panel_reset(internal->panel_handle) == ESP_OK &&
+        esp_lcd_panel_init(internal->panel_handle) == ESP_OK &&
+        (!config->invert_color || esp_lcd_panel_invert_color(internal->panel_handle, true) == ESP_OK);
+
+    if (ok) {
+        ok = (config->gap_x == 0 && config->gap_y == 0) || esp_lcd_panel_set_gap(internal->panel_handle, config->gap_x, config->gap_y) == ESP_OK;
+    }
+    ok = ok && (!config->swap_xy || esp_lcd_panel_swap_xy(internal->panel_handle, true) == ESP_OK);
+    ok = ok && ((!config->mirror_x && !config->mirror_y) || esp_lcd_panel_mirror(internal->panel_handle, config->mirror_x, config->mirror_y) == ESP_OK);
+    ok = ok && (!config->invert_color || esp_lcd_panel_invert_color(internal->panel_handle, true) == ESP_OK);
+    ok = ok && (config->gamma_curve >= 4 || esp_lcd_panel_io_tx_param(internal->io_handle, LCD_CMD_GAMSET, &GAMMA_CURVE_VALUES[config->gamma_curve], 1) == ESP_OK);
+    ok = ok && esp_lcd_panel_disp_on_off(internal->panel_handle, true) == ESP_OK;
+
+    if (!ok) {
+        LOG_E(TAG, "Failed to bring up panel");
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+
+    if (internal->panel_handle != nullptr) {
+        if (esp_lcd_panel_del(internal->panel_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel");
+            return ERROR_RESOURCE;
+        }
+        internal->panel_handle = nullptr;
+    }
+
+    if (internal->io_handle != nullptr) {
+        if (esp_lcd_panel_io_del(internal->io_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel IO");
+            return ERROR_RESOURCE;
+        }
+        internal->io_handle = nullptr;
+    }
+
+    vSemaphoreDelete(internal->draw_done_semaphore);
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region DisplayApi
+
+static error_t jd9853_reset(Device* device) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_reset(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t jd9853_init(Device* device) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_init(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t jd9853_draw_bitmap(Device* device, int32_t x_start, int32_t y_start, int32_t x_end, int32_t y_end, const void* color_data) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+
+    xSemaphoreTake(internal->draw_done_semaphore, 0);
+
+    if (esp_lcd_panel_draw_bitmap(internal->panel_handle, x_start, y_start, x_end, y_end, color_data) != ESP_OK) {
+        return ERROR_RESOURCE;
+    }
+
+    xSemaphoreTake(internal->draw_done_semaphore, portMAX_DELAY);
+    return ERROR_NONE;
+}
+
+static error_t jd9853_mirror(Device* device, bool x_axis, bool y_axis) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_mirror(internal->panel_handle, x_axis, y_axis) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t jd9853_swap_xy(Device* device, bool swap_axes) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_swap_xy(internal->panel_handle, swap_axes) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static bool jd9853_get_swap_xy(Device* device) {
+    return GET_CONFIG(device)->swap_xy;
+}
+
+static bool jd9853_get_mirror_x(Device* device) {
+    return GET_CONFIG(device)->mirror_x;
+}
+
+static bool jd9853_get_mirror_y(Device* device) {
+    return GET_CONFIG(device)->mirror_y;
+}
+
+static error_t jd9853_set_gap(Device* device, int32_t x_gap, int32_t y_gap) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_set_gap(internal->panel_handle, x_gap, y_gap) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static int32_t jd9853_get_gap_x(Device* device) {
+    return GET_CONFIG(device)->gap_x;
+}
+
+static int32_t jd9853_get_gap_y(Device* device) {
+    return GET_CONFIG(device)->gap_y;
+}
+
+static error_t jd9853_invert_color(Device* device, bool invert_color_data) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_invert_color(internal->panel_handle, invert_color_data) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t jd9853_disp_on_off(Device* device, bool on_off) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_on_off(internal->panel_handle, on_off) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t jd9853_disp_sleep(Device* device, bool sleep) {
+    auto* internal = static_cast<Jd9853Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_sleep(internal->panel_handle, sleep) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// The deprecated HAL's Jd9853Display always set swap_bytes=true on its lvgl_port config
+// regardless of rgb_ele_order, so the byte-swapped format applies unconditionally here too -
+// bgr_order only affects the panel's hardware element order (applied in start(), above).
+static enum DisplayColorFormat jd9853_get_color_format(Device*) {
+    return DISPLAY_COLOR_FORMAT_RGB565_SWAPPED;
+}
+
+static uint16_t jd9853_get_resolution_x(Device* device) {
+    return GET_CONFIG(device)->horizontal_resolution;
+}
+
+static uint16_t jd9853_get_resolution_y(Device* device) {
+    return GET_CONFIG(device)->vertical_resolution;
+}
+
+static void jd9853_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
+    *out_buffer = nullptr;
+}
+
+static uint8_t jd9853_get_frame_buffer_count(Device*) {
+    return 0;
+}
+
+static error_t jd9853_get_backlight(Device* device, Device** backlight) {
+    auto* configured_backlight = GET_CONFIG(device)->backlight;
+    if (configured_backlight == nullptr) {
+        return ERROR_NOT_SUPPORTED;
+    }
+    *backlight = configured_backlight;
+    return ERROR_NONE;
+}
+
+// endregion
+
+static const DisplayApi jd9853_display_api = {
+    .capabilities = DISPLAY_CAPABILITY_CAP_MIRROR | DISPLAY_CAPABILITY_CAP_SWAP_XY |
+        DISPLAY_CAPABILITY_CAP_SET_GAP | DISPLAY_CAPABILITY_INVERT_COLOR | DISPLAY_CAPABILITY_ON_OFF |
+        DISPLAY_CAPABILITY_SLEEP | DISPLAY_CAPABILITY_BACKLIGHT,
+    .reset = jd9853_reset,
+    .init = jd9853_init,
+    .draw_bitmap = jd9853_draw_bitmap,
+    .mirror = jd9853_mirror,
+    .swap_xy = jd9853_swap_xy,
+    .get_swap_xy = jd9853_get_swap_xy,
+    .get_mirror_x = jd9853_get_mirror_x,
+    .get_mirror_y = jd9853_get_mirror_y,
+    .set_gap = jd9853_set_gap,
+    .get_gap_x = jd9853_get_gap_x,
+    .get_gap_y = jd9853_get_gap_y,
+    .invert_color = jd9853_invert_color,
+    .disp_on_off = jd9853_disp_on_off,
+    .disp_sleep = jd9853_disp_sleep,
+    .get_color_format = jd9853_get_color_format,
+    .get_resolution_x = jd9853_get_resolution_x,
+    .get_resolution_y = jd9853_get_resolution_y,
+    .get_frame_buffer = jd9853_get_frame_buffer,
+    .get_frame_buffer_count = jd9853_get_frame_buffer_count,
+    .get_backlight = jd9853_get_backlight,
+    .has_capability = nullptr,
+};
+
+Driver jd9853_driver = {
+    .name = "jd9853",
+    .compatible = (const char*[]) { "jadard,jd9853", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &jd9853_display_api,
+    .device_type = &DISPLAY_TYPE,
+    .owner = &jd9853_module,
+    .internal = nullptr
+};

Drivers/jd9853-module/source/module.cpp

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver jd9853_driver;
+
+static error_t start() {
+    /* We crash when construct fails, because if a single driver fails to construct,
+     * there is no guarantee that the previously constructed drivers can be destroyed */
+    check(driver_construct_add(&jd9853_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    /* We crash when destruct fails, because if a single driver fails to destruct,
+     * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&jd9853_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+Module jd9853_module = {
+    .name = "jd9853",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+} // extern "C"

Drivers/m5pm1-module/bindings/m5stack,m5pm1.yaml

@@ -3,3 +3,16 @@ description: M5Stack M5PM1 Power Management IC
 include: ["i2c-device.yaml"]
 
 compatible: "m5stack,m5pm1"
+
+properties:
+  power-supply-reference-voltage-mv:
+    type: int
+    default: 4200
+    description: Battery voltage (in mV) considered 100% capacity, used to compute POWER_SUPPLY_PROP_CAPACITY
+  speaker-amp-enable-at-boot:
+    type: boolean
+    default: false
+    description: >
+      Enable the speaker amplifier (PM1_G3) at driver start. Off by default -- the pin is
+      configured but left low -- to avoid a pop and needless power draw before audio starts;
+      boards without dynamic amp control from their audio path can turn this on.

Drivers/m5pm1-module/include/drivers/m5pm1.h

@@ -13,6 +13,10 @@ extern "C" {
 
 struct M5pm1Config {
     uint8_t address;
+    /** Battery voltage (mV) considered 100% capacity, used to derive POWER_SUPPLY_PROP_CAPACITY */
+    uint32_t power_supply_reference_voltage_mv;
+    /** Enable the speaker amplifier (PM1_G3) at driver start, instead of leaving it low */
+    bool speaker_amp_enable_at_boot;
 };
 
 // ---------------------------------------------------------------------------

Drivers/m5pm1-module/source/m5pm1.cpp

@@ -1,13 +1,22 @@
 // SPDX-License-Identifier: Apache-2.0
 #include <drivers/m5pm1.h>
 #include <m5pm1_module.h>
+#include <tactility/check.h>
 #include <tactility/device.h>
+#include <tactility/driver.h>
 #include <tactility/drivers/i2c_controller.h>
+#include <tactility/drivers/power_supply.h>
 #include <tactility/log.h>
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
 
-#define TAG "M5PM1"
+#include <new>
+
+constexpr auto* TAG = "M5PM1";
+
+// Rough LiPo discharge curve floor, used together with the configured reference voltage
+// (the 100% point) to estimate a charge percentage from the sensed battery voltage.
+static constexpr uint16_t POWER_SUPPLY_MIN_MV = 3200;
 
 // ---------------------------------------------------------------------------
 // Register map
@@ -57,6 +66,127 @@ static constexpr TickType_t TIMEOUT = pdMS_TO_TICKS(50);
 
 #define GET_CONFIG(device) (static_cast<const M5pm1Config*>((device)->config))
 
+// ---------------------------------------------------------------------------
+// Power supply child device
+// ---------------------------------------------------------------------------
+
+static int estimate_capacity_from_mv(uint16_t battery_mv, uint32_t reference_mv) {
+    if (battery_mv <= POWER_SUPPLY_MIN_MV) return 0;
+    if (battery_mv >= reference_mv) return 100;
+    return (battery_mv - POWER_SUPPLY_MIN_MV) * 100 / ((int)reference_mv - POWER_SUPPLY_MIN_MV);
+}
+
+static bool ps_supports_property(Device*, PowerSupplyProperty property) {
+    return property == POWER_SUPPLY_PROP_IS_CHARGING ||
+        property == POWER_SUPPLY_PROP_VOLTAGE ||
+        property == POWER_SUPPLY_PROP_CAPACITY;
+}
+
+static error_t ps_get_property(Device* device, PowerSupplyProperty property, PowerSupplyPropertyValue* out_value) {
+    // device_get_parent() here is the m5pm1 device itself (this child's parent), not the I2C bus.
+    auto* parent = device_get_parent(device);
+
+    if (property == POWER_SUPPLY_PROP_IS_CHARGING) {
+        bool charging;
+        error_t error = m5pm1_is_charging(parent, &charging);
+        if (error != ERROR_NONE) return error;
+        out_value->int_value = charging ? 1 : 0;
+        return ERROR_NONE;
+    }
+
+    if (property == POWER_SUPPLY_PROP_VOLTAGE || property == POWER_SUPPLY_PROP_CAPACITY) {
+        uint16_t battery_mv;
+        error_t error = m5pm1_get_battery_voltage(parent, &battery_mv);
+        if (error != ERROR_NONE) return error;
+        out_value->int_value = (property == POWER_SUPPLY_PROP_VOLTAGE)
+            ? battery_mv
+            : estimate_capacity_from_mv(battery_mv, GET_CONFIG(parent)->power_supply_reference_voltage_mv);
+        return ERROR_NONE;
+    }
+
+    return ERROR_NOT_SUPPORTED;
+}
+
+static bool ps_supports_charge_control(Device*) { return false; }
+static bool ps_is_allowed_to_charge(Device*) { return false; }
+static error_t ps_set_allowed_to_charge(Device*, bool) { return ERROR_NOT_SUPPORTED; }
+static bool ps_supports_quick_charge(Device*) { return false; }
+static bool ps_is_quick_charge_enabled(Device*) { return false; }
+static error_t ps_set_quick_charge_enabled(Device*, bool) { return ERROR_NOT_SUPPORTED; }
+static bool ps_supports_power_off(Device*) { return true; }
+static error_t ps_power_off(Device* device) { return m5pm1_shutdown(device_get_parent(device)); }
+
+static constexpr PowerSupplyApi M5PM1_POWER_SUPPLY_API = {
+    .supports_property = ps_supports_property,
+    .get_property = ps_get_property,
+    .supports_charge_control = ps_supports_charge_control,
+    .is_allowed_to_charge = ps_is_allowed_to_charge,
+    .set_allowed_to_charge = ps_set_allowed_to_charge,
+    .supports_quick_charge = ps_supports_quick_charge,
+    .is_quick_charge_enabled = ps_is_quick_charge_enabled,
+    .set_quick_charge_enabled = ps_set_quick_charge_enabled,
+    .supports_power_off = ps_supports_power_off,
+    .power_off = ps_power_off,
+};
+
+// Registered (driver_construct_add() in module.cpp) so driver_bind() has a valid ->internal,
+// but never matched against a devicetree node: m5pm1_driver wires it up directly by pointer.
+Driver m5pm1_power_supply_driver = {
+    .name = "m5pm1-power-supply",
+    .compatible = (const char*[]) { "m5pm1-power-supply", nullptr },
+    .start_device = nullptr,
+    .stop_device = nullptr,
+    .api = &M5PM1_POWER_SUPPLY_API,
+    .device_type = &POWER_SUPPLY_TYPE,
+    .owner = &m5pm1_module,
+    .internal = nullptr
+};
+
+struct M5pm1Internal {
+    Device* power_supply_device = nullptr;
+};
+
+static error_t create_power_supply_child(Device* parent, Device*& out_child) {
+    auto* child = new(std::nothrow) Device { .address = 0, .name = "m5pm1-power-supply", .config = nullptr, .parent = nullptr, .internal = nullptr };
+    if (child == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    error_t error = device_construct(child);
+    if (error != ERROR_NONE) {
+        delete child;
+        return error;
+    }
+
+    device_set_parent(child, parent);
+    device_set_driver(child, &m5pm1_power_supply_driver);
+
+    error = device_add(child);
+    if (error != ERROR_NONE) {
+        device_destruct(child);
+        delete child;
+        return error;
+    }
+
+    error = device_start(child);
+    if (error != ERROR_NONE) {
+        device_remove(child);
+        device_destruct(child);
+        delete child;
+        return error;
+    }
+
+    out_child = child;
+    return ERROR_NONE;
+}
+
+static void destroy_power_supply_child(Device* child) {
+    check(device_stop(child) == ERROR_NONE);
+    check(device_remove(child) == ERROR_NONE);
+    check(device_destruct(child) == ERROR_NONE);
+    delete child;
+}
+
 // ---------------------------------------------------------------------------
 // Driver lifecycle
 // ---------------------------------------------------------------------------
@@ -83,6 +213,19 @@ static error_t start(Device* device) {
         vTaskDelay(pdMS_TO_TICKS(20 * (attempt + 1)));
     }
 
+    auto* internal = new(std::nothrow) M5pm1Internal();
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    error_t error = create_power_supply_child(device, internal->power_supply_device);
+    if (error != ERROR_NONE) {
+        delete internal;
+        return error;
+    }
+
+    device_set_driver_data(device, internal);
+
     if (!awake) {
         LOG_E(TAG, "M5PM1 not responding — LCD power will not be enabled");
         return ERROR_NONE; // non-fatal: don't crash the kernel
@@ -126,10 +269,22 @@ static error_t start(Device* device) {
         LOG_W(TAG, "Failed to configure speaker amp pin");
     }
 
+    if (spk_ok && GET_CONFIG(device)->speaker_amp_enable_at_boot) {
+        if (i2c_controller_register8_set_bits(i2c, addr, REG_GPIO_OUT, SPEAKER_AMP_BIT, TIMEOUT) == ERROR_NONE) {
+            LOG_I(TAG, "Speaker amp enabled at boot");
+        } else {
+            LOG_W(TAG, "Failed to enable speaker amp at boot");
+        }
+    }
+
     return ERROR_NONE;
 }
 
 static error_t stop(Device* device) {
+    auto* internal = static_cast<M5pm1Internal*>(device_get_driver_data(device));
+    destroy_power_supply_child(internal->power_supply_device);
+    device_set_driver_data(device, nullptr);
+    delete internal;
     return ERROR_NONE;
 }
 

Drivers/m5pm1-module/source/module.cpp

@@ -6,17 +6,20 @@
 extern "C" {
 
 extern Driver m5pm1_driver;
+extern Driver m5pm1_power_supply_driver;
 
 static error_t start() {
     /* We crash when construct fails, because if a single driver fails to construct,
      * there is no guarantee that the previously constructed drivers can be destroyed */
     check(driver_construct_add(&m5pm1_driver) == ERROR_NONE);
+    check(driver_construct_add(&m5pm1_power_supply_driver) == ERROR_NONE);
     return ERROR_NONE;
 }
 
 static error_t stop() {
     /* We crash when destruct fails, because if a single driver fails to destruct,
      * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&m5pm1_power_supply_driver) == ERROR_NONE);
     check(driver_remove_destruct(&m5pm1_driver) == ERROR_NONE);
     return ERROR_NONE;
 }

Drivers/st7123-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(st7123-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel platform-esp32 esp_lcd_st7123 esp_lcd_touch_st7123 esp_lcd driver esp_hw_support
+)

Drivers/st7123-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/st7123-module/README.md

@@ -0,0 +1,18 @@
+# ST7123 display + touch controller
+
+Two drivers for the Sitronix `ST7123`, sharing this module since they're the same physical chip
+family and commonly used together:
+
+- **`st7123`** (`sitronix,st7123`) - the MIPI-DSI display panel itself, driven over ESP-IDF's
+  `esp_lcd_st7123` component (DPI/DBI interface, ESP32-P4 and other `SOC_MIPI_DSI_SUPPORTED`
+  targets only). Owns the MIPI DSI PHY LDO channel and DSI bus directly, so unlike SPI/RGB panels
+  it has no parent bus controller device.
+- **`st7123-touch`** (`sitronix,st7123-touch`) - the panel's in-cell capacitive touch controller,
+  a separate I2C device, driven over ESP-IDF's `esp_lcd_touch_st7123` component. Sits at a fixed
+  I2C address (0x55) - the devicetree `reg` is documentation only, not used to probe the bus.
+  Reset is usually wired through the board's IO expander rather than a direct SoC GPIO (every
+  known user of this driver so far does it that way), hence `pin-reset` defaults unset; it's
+  still exposed for parity with the other touch drivers (e.g. `gt911-module`) in case a board
+  wires it directly.
+
+License: [Apache v2.0](LICENSE-Apache-2.0.md)

Drivers/st7123-module/bindings/sitronix,st7123-touch.yaml

@@ -0,0 +1,47 @@
+description: Sitronix ST7123 in-cell capacitive touch controller, driven over ESP-IDF's
+  esp_lcd_touch_st7123 component
+
+include: ["i2c-device.yaml"]
+
+compatible: "sitronix,st7123-touch"
+
+bus: i2c
+
+properties:
+  x-max:
+    type: int
+    required: true
+    description: Maximum X coordinate reported by the controller (typically the panel's horizontal resolution)
+  y-max:
+    type: int
+    required: true
+    description: Maximum Y coordinate reported by the controller (typically the panel's vertical resolution)
+  swap-xy:
+    type: boolean
+    default: false
+    description: Swap the X and Y axes
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin. Most boards wire this through an IO expander and handle the
+      reset pulse themselves rather than through this driver - leave unset in that case.
+  pin-interrupt:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Interrupt GPIO pin
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  interrupt-active-high:
+    type: boolean
+    default: false
+    description: Whether the interrupt pin is active high

Drivers/st7123-module/bindings/sitronix,st7123.yaml

@@ -0,0 +1,127 @@
+description: >
+  Sitronix ST7123 MIPI-DSI display panel, driven over ESP-IDF's esp_lcd_st7123 component
+  (DPI/DBI interface, ESP32-P4 and other SOC_MIPI_DSI_SUPPORTED targets only). Owns the MIPI DSI
+  PHY LDO channel and DSI bus directly, so unlike SPI/RGB panels it has no parent bus controller
+  device.
+
+compatible: "sitronix,st7123"
+
+properties:
+  horizontal-resolution:
+    type: int
+    required: true
+    description: Horizontal resolution in pixels
+  vertical-resolution:
+    type: int
+    required: true
+    description: Vertical resolution in pixels
+  bits-per-pixel:
+    type: int
+    default: 16
+    description: Color depth in bits per pixel (16, 18 or 24)
+  bgr-order:
+    type: boolean
+    default: false
+    description: Use BGR element order instead of RGB
+  invert-color:
+    type: boolean
+    default: false
+    description: Invert the panel's color output
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin. Falls back to a software reset (sent over the DBI command
+      interface) if not set.
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  ldo-channel:
+    type: int
+    required: true
+    description: LDO channel index powering the MIPI DSI PHY (chan_id in esp_ldo_channel_config_t)
+  ldo-voltage-mv:
+    type: int
+    required: true
+    description: Voltage to supply to the MIPI DSI PHY LDO channel, in mV
+  dsi-bus-id:
+    type: int
+    default: 0
+    description: Which DSI controller to use, index from 0
+  num-data-lanes:
+    type: int
+    default: 2
+    description: Number of MIPI DSI data lanes. 0 falls back to the maximum available.
+  lane-bit-rate-mbps:
+    type: int
+    required: true
+    description: MIPI DSI lane bit rate, in Mbps
+  dpi-clock-freq-mhz:
+    type: int
+    required: true
+    description: MIPI DPI clock frequency, in MHz
+  hsync-pulse-width:
+    type: int
+    required: true
+    description: Horizontal sync width, in PCLK periods
+  hsync-back-porch:
+    type: int
+    required: true
+    description: Number of PCLK periods between hsync and the start of line active data
+  hsync-front-porch:
+    type: int
+    required: true
+    description: Number of PCLK periods between the end of active data and the next hsync
+  vsync-pulse-width:
+    type: int
+    required: true
+    description: Vertical sync width, in lines
+  vsync-back-porch:
+    type: int
+    required: true
+    description: Number of invalid lines between vsync and the start of the frame
+  vsync-front-porch:
+    type: int
+    required: true
+    description: Number of invalid lines between the end of the frame and the next vsync
+  num-fbs:
+    type: int
+    default: 1
+    description: Number of screen-sized frame buffers to allocate (0 or 1 = single-buffered)
+  use-dma2d:
+    type: boolean
+    default: true
+    description: Use DMA2D to copy user buffers into the frame buffer when necessary (only
+      meaningful on SOC_DMA2D_SUPPORTED targets - must be false otherwise)
+  disable-lp:
+    type: boolean
+    default: false
+    description: Disable MIPI DSI low-power mode
+  allow-tearing:
+    type: boolean
+    default: false
+    description: By default, when draw_bitmap's color_data is one of the panel's own frame
+      buffers (i.e. LVGL is bound directly onto them), draw_bitmap waits for a full scan-out to
+      complete before returning so the caller can't start overwriting a buffer still being
+      displayed. Set this to trade away that tear-free guarantee for lower latency (e.g. when
+      other tasks occasionally block timing for long enough that waiting causes visible stalls).
+  init-sequence:
+    type: array
+    element-type: uint8_t
+    description: >
+      Custom vendor bring-up sequence, flattened into bytes as a run of
+      [cmd, data-length, delay-ms, data-length bytes of data...] entries, e.g.
+      `init-sequence = [0x11 0 120  0x29 0 20];`.
+      Omit to use the ST7123 component's own built-in default sequence.
+  backlight:
+    type: phandle
+    default: "NULL"
+    description: Optional reference to this display's backlight device

Drivers/st7123-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/st7123-module/include/bindings/st7123.h

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/st7123.h>
+
+// The devicetree compiler derives the expected config typedef name from the compatible
+// string's suffix (e.g. "sitronix,st7123" -> st7123_config_dt), not from the node name or
+// driver name, so the tag here must match that exactly.
+DEFINE_DEVICETREE(st7123, struct St7123Config)

Drivers/st7123-module/include/bindings/st7123_touch.h

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/st7123_touch.h>
+
+// The devicetree compiler derives the expected config typedef name from the compatible
+// string's suffix, with hyphens replaced by underscores (e.g. "sitronix,st7123-touch" ->
+// st7123_touch_config_dt), not from the node name or driver name, so the tag here must match
+// that exactly.
+DEFINE_DEVICETREE(st7123_touch, struct St7123TouchConfig)

Drivers/st7123-module/include/drivers/st7123.h

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/device.h>
+#include <tactility/drivers/gpio.h>
+
+struct St7123Config {
+    uint16_t horizontal_resolution;
+    uint16_t vertical_resolution;
+    uint8_t bits_per_pixel;
+    bool bgr_order;
+    bool invert_color;
+    bool mirror_x;
+    bool mirror_y;
+
+    // Reset pin for the panel. GPIO_PIN_SPEC_NONE falls back to a software reset sent over the
+    // DBI command interface (see esp_lcd_st7123's panel_st7123_reset()).
+    struct GpioPinSpec pin_reset;
+    bool reset_active_high;
+
+    // LDO channel powering the MIPI DSI PHY - the PHY has no power of its own until this is
+    // acquired, so it must happen before the DSI bus is created. Both fields are int32_t (not
+    // uint32_t) to exactly match esp_ldo_channel_config_t's plain `int` fields - assigning a
+    // uint32_t into that struct's brace-init would be a narrowing conversion (-Werror=narrowing).
+    int32_t ldo_channel;
+    int32_t ldo_voltage_mv;
+
+    uint8_t dsi_bus_id;
+    // Number of MIPI DSI data lanes. 0 falls back to the maximum available.
+    uint8_t num_data_lanes;
+    uint32_t lane_bit_rate_mbps;
+
+    uint32_t dpi_clock_freq_mhz;
+    uint32_t hsync_pulse_width;
+    uint32_t hsync_back_porch;
+    uint32_t hsync_front_porch;
+    uint32_t vsync_pulse_width;
+    uint32_t vsync_back_porch;
+    uint32_t vsync_front_porch;
+    // Number of screen-sized frame buffers the driver allocates (0 or 1 = single-buffered).
+    uint8_t num_fbs;
+    bool use_dma2d;
+    bool disable_lp;
+
+    // See the 'allow-tearing' binding property.
+    bool allow_tearing;
+
+    // Custom vendor init sequence, flattened as bytes: a run of
+    // [cmd, data_len, delay_ms, data_len bytes of data...] entries. NULL/0 falls back to the
+    // ST7123 component's own built-in default sequence (see vendor_specific_init_default in
+    // esp_lcd_st7123.c) - not guaranteed to match any particular panel's actual bring-up
+    // requirements.
+    const uint8_t* init_sequence;
+    uint32_t init_sequence_length;
+
+    // Optional reference to this display's backlight device, NULL if none.
+    struct Device* backlight;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/st7123-module/include/drivers/st7123_touch.h

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/drivers/gpio.h>
+
+struct St7123TouchConfig {
+    // Devicetree address hint. esp_lcd_touch_st7123 always talks to the controller's one fixed
+    // address (0x55 - see ESP_LCD_TOUCH_IO_I2C_ST7123_ADDRESS), so this isn't actually used to
+    // probe the bus - it just documents the wiring like any other i2c-device node.
+    uint8_t address;
+    uint16_t x_max;
+    uint16_t y_max;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    // Reset is wired through the board's IO expander rather than a direct SoC GPIO on every
+    // known user of this driver so far, hence GPIO_PIN_SPEC_NONE by default - but exposed here
+    // for parity with the other touch drivers (e.g. gt911-module) in case a board wires it directly.
+    struct GpioPinSpec pin_reset;
+    struct GpioPinSpec pin_interrupt;
+    bool reset_active_high;
+    bool interrupt_active_high;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/st7123-module/include/st7123_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module st7123_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/st7123-module/source/module.cpp

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver st7123_driver;
+extern Driver st7123_touch_driver;
+
+static error_t start() {
+    /* We crash when construct fails, because if a single driver fails to construct,
+     * there is no guarantee that the previously constructed drivers can be destroyed */
+    check(driver_construct_add(&st7123_driver) == ERROR_NONE);
+    check(driver_construct_add(&st7123_touch_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    /* We crash when destruct fails, because if a single driver fails to destruct,
+     * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&st7123_touch_driver) == ERROR_NONE);
+    check(driver_remove_destruct(&st7123_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+Module st7123_module = {
+    .name = "st7123",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+} // extern "C"

Drivers/st7123-module/source/st7123.cpp

@@ -0,0 +1,525 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <soc/soc_caps.h>
+#if SOC_MIPI_DSI_SUPPORTED
+
+#include <drivers/st7123.h>
+#include <st7123_module.h>
+
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/display.h>
+#include <tactility/error.h>
+#include <tactility/log.h>
+
+#include <esp_err.h>
+#include <esp_ldo_regulator.h>
+#include <esp_lcd_st7123.h>
+#include <esp_lcd_mipi_dsi.h>
+#include <esp_lcd_panel_io.h>
+#include <esp_lcd_panel_ops.h>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+
+#include <cstdlib>
+
+constexpr auto* TAG = "ST7123";
+#define GET_CONFIG(device) (static_cast<const St7123Config*>((device)->config))
+
+// Generic lvgl-module display glue (Modules/lvgl-module/source/lvgl_display.c) only ever asks
+// for frame buffer index 0 and 1, so caching more than that would be dead weight.
+constexpr size_t MAX_CACHED_FRAME_BUFFERS = 2;
+
+struct St7123Internal {
+    esp_ldo_channel_handle_t ldo_handle;
+    esp_lcd_dsi_bus_handle_t dsi_bus_handle;
+    esp_lcd_panel_io_handle_t io_handle;
+    esp_lcd_panel_handle_t panel_handle;
+    void* frame_buffers[MAX_CACHED_FRAME_BUFFERS];
+    uint8_t frame_buffer_count;
+    // Size of each buffer in frame_buffers, in bytes - used to range-check whether a given
+    // draw_bitmap() color_data pointer is actually one of them (see draw_bitmap() below).
+    size_t frame_buffer_size_bytes;
+    // Signaled by on_refresh_done once per real scan-out of a whole frame. Only waited on in
+    // draw_bitmap() when color_data is one of frame_buffers and avoid_tearing is set - see the
+    // comment there for why.
+    SemaphoreHandle_t frame_complete_semaphore;
+    // Heap-allocated only when the devicetree supplies a custom init_sequence (see
+    // parse_init_sequence()) - nullptr otherwise, since the vendor's built-in default sequence
+    // needs no parsing. Its .data pointers alias directly into the devicetree's static const
+    // byte buffer, so only this struct array itself needs freeing in stop().
+    st7123_lcd_init_cmd_t* parsed_init_cmds;
+};
+
+// esp_lcd_dpi_panel's draw_bitmap() has a zero-copy path when color_data is one of the panel's
+// own frame buffers (as returned by esp_lcd_dpi_panel_get_frame_buffer()): it just repoints which
+// buffer is scanned out and returns almost instantly - well before the DSI peripheral has
+// actually finished scanning out the *previous* buffer, let alone started on this one. Callers in
+// full/direct LVGL render mode render straight into these real frame buffers, so if draw_bitmap()
+// returned that quickly, LVGL would be free to start overwriting the *other* buffer - which may
+// still be mid-scanout - producing visible tearing/flashing. on_refresh_done fires once per actual
+// whole-frame scan-out completion (continuously, at the panel's refresh rate, independent of
+// draw_bitmap calls), so waiting for the next occurrence after each draw_bitmap() genuinely blocks
+// until it's safe to start writing into the frame buffers again - unless avoid_tearing is false,
+// in which case the caller has opted out of this wait (see the binding property).
+static bool on_refresh_done(esp_lcd_panel_handle_t, esp_lcd_dpi_panel_event_data_t*, void* user_ctx) {
+    auto* internal = static_cast<St7123Internal*>(user_ctx);
+    BaseType_t high_task_woken = pdFALSE;
+    xSemaphoreGiveFromISR(internal->frame_complete_semaphore, &high_task_woken);
+    return high_task_woken == pdTRUE;
+}
+
+static int pin_or_unused(const GpioPinSpec& pin) {
+    return pin.gpio_controller == nullptr ? -1 : static_cast<int>(pin.pin);
+}
+
+static lcd_color_format_t color_format_from_bits_per_pixel(uint8_t bits_per_pixel) {
+    switch (bits_per_pixel) {
+        case 18: return LCD_COLOR_FMT_RGB666;
+        case 24: return LCD_COLOR_FMT_RGB888;
+        default: return LCD_COLOR_FMT_RGB565;
+    }
+}
+
+// Unpacks the devicetree's flat [cmd, data_len, delay_ms, data_len bytes...] encoding (produced
+// by the devicetree compiler's "array" property type - see init-sequence in
+// bindings/sitronix,st7123.yaml) into a heap-allocated st7123_lcd_init_cmd_t array. Each entry's
+// .data points directly into `bytes`, which is the devicetree's static const buffer and outlives
+// the device, so no per-entry copy is needed.
+static bool parse_init_sequence(const uint8_t* bytes, uint32_t length, st7123_lcd_init_cmd_t** out_cmds, uint16_t* out_count) {
+    uint32_t count = 0;
+    for (uint32_t offset = 0; offset < length; count++) {
+        if (offset + 3 > length) {
+            LOG_E(TAG, "init-sequence truncated: entry header runs past the end of the array");
+            return false;
+        }
+        offset += 3 + bytes[offset + 1];
+        if (offset > length) {
+            LOG_E(TAG, "init-sequence truncated: entry data runs past the end of the array");
+            return false;
+        }
+    }
+
+    auto* cmds = static_cast<st7123_lcd_init_cmd_t*>(malloc(count * sizeof(st7123_lcd_init_cmd_t)));
+    if (cmds == nullptr) {
+        return false;
+    }
+
+    uint32_t offset = 0;
+    for (uint32_t i = 0; i < count; i++) {
+        uint8_t data_len = bytes[offset + 1];
+        cmds[i] = {
+            .cmd = bytes[offset],
+            .data = data_len > 0 ? &bytes[offset + 3] : nullptr,
+            .data_bytes = data_len,
+            .delay_ms = bytes[offset + 2],
+        };
+        offset += 3 + data_len;
+    }
+
+    *out_cmds = cmds;
+    *out_count = (uint16_t)count;
+    return true;
+}
+
+// region Driver lifecycle
+
+static error_t start(Device* device) {
+    const auto* config = GET_CONFIG(device);
+
+    auto* internal = static_cast<St7123Internal*>(malloc(sizeof(St7123Internal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+    internal->parsed_init_cmds = nullptr;
+
+    const st7123_lcd_init_cmd_t* init_cmds = nullptr;
+    uint16_t init_cmds_size = 0;
+    if (config->init_sequence != nullptr && config->init_sequence_length > 0) {
+        if (!parse_init_sequence(config->init_sequence, config->init_sequence_length, &internal->parsed_init_cmds, &init_cmds_size)) {
+            LOG_E(TAG, "Failed to parse init-sequence property");
+            free(internal);
+            return ERROR_INVALID_ARGUMENT;
+        }
+        init_cmds = internal->parsed_init_cmds;
+    }
+
+    // The MIPI DSI PHY has no power of its own until this LDO channel is enabled - must happen
+    // before the DSI bus is created.
+    esp_ldo_channel_config_t ldo_config = {
+        .chan_id = config->ldo_channel,
+        .voltage_mv = config->ldo_voltage_mv,
+        .flags = {},
+    };
+    if (esp_ldo_acquire_channel(&ldo_config, &internal->ldo_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to acquire LDO channel for MIPI DSI PHY");
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    const esp_lcd_dsi_bus_config_t bus_config = {
+        .bus_id = config->dsi_bus_id,
+        .num_data_lanes = config->num_data_lanes,
+        .phy_clk_src = MIPI_DSI_PHY_CLK_SRC_DEFAULT,
+        .lane_bit_rate_mbps = config->lane_bit_rate_mbps,
+    };
+    if (esp_lcd_new_dsi_bus(&bus_config, &internal->dsi_bus_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to create MIPI DSI bus");
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    const esp_lcd_dbi_io_config_t dbi_config = {
+        .virtual_channel = 0,
+        .lcd_cmd_bits = 8,
+        .lcd_param_bits = 8,
+    };
+    if (esp_lcd_new_panel_io_dbi(internal->dsi_bus_handle, &dbi_config, &internal->io_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel IO");
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    const lcd_color_format_t color_format = color_format_from_bits_per_pixel(config->bits_per_pixel);
+    const esp_lcd_dpi_panel_config_t dpi_config = {
+        .virtual_channel = 0,
+        .dpi_clk_src = MIPI_DSI_DPI_CLK_SRC_DEFAULT,
+        .dpi_clock_freq_mhz = config->dpi_clock_freq_mhz,
+        .pixel_format = (lcd_color_rgb_pixel_format_t)0, // deprecated field - in/out_color_format below take precedence
+        .in_color_format = color_format,
+        .out_color_format = color_format,
+        .num_fbs = config->num_fbs,
+        .video_timing = {
+            .h_size = config->horizontal_resolution,
+            .v_size = config->vertical_resolution,
+            .hsync_pulse_width = config->hsync_pulse_width,
+            .hsync_back_porch = config->hsync_back_porch,
+            .hsync_front_porch = config->hsync_front_porch,
+            .vsync_pulse_width = config->vsync_pulse_width,
+            .vsync_back_porch = config->vsync_back_porch,
+            .vsync_front_porch = config->vsync_front_porch,
+        },
+        .flags = {
+            .use_dma2d = config->use_dma2d,
+            .disable_lp = config->disable_lp,
+        },
+    };
+
+    st7123_vendor_config_t vendor_config = {
+        .init_cmds = init_cmds,
+        .init_cmds_size = init_cmds_size,
+        .mipi_config = {
+            .dsi_bus = internal->dsi_bus_handle,
+            .dpi_config = &dpi_config,
+        },
+    };
+
+    const esp_lcd_panel_dev_config_t panel_config = {
+        .reset_gpio_num = pin_or_unused(config->pin_reset),
+        .rgb_ele_order = config->bgr_order ? LCD_RGB_ELEMENT_ORDER_BGR : LCD_RGB_ELEMENT_ORDER_RGB,
+        .data_endian = LCD_RGB_DATA_ENDIAN_LITTLE,
+        .bits_per_pixel = config->bits_per_pixel,
+        .flags = { .reset_active_high = config->reset_active_high },
+        .vendor_config = &vendor_config,
+    };
+
+    if (esp_lcd_new_panel_st7123(internal->io_handle, &panel_config, &internal->panel_handle) != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel");
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    // Bring-up sequence: reset() pulses (or software-resets) the panel and init() pushes
+    // init_cmds over the DBI command interface before bringing up the underlying DPI peripheral.
+    // swap_xy/set_gap are intentionally not called: the ST7123 driver doesn't override them and
+    // the underlying raw DPI panel doesn't implement them either, so both would just fail with
+    // ESP_ERR_NOT_SUPPORTED (see DisplayApi below). Every failure path here must clean up fully:
+    // unlike stop_device, this is never retried by the kernel if start_device fails (see
+    // device_start() in TactilityKernel), so a partial failure here would leak.
+    bool ok =
+        esp_lcd_panel_reset(internal->panel_handle) == ESP_OK &&
+        esp_lcd_panel_init(internal->panel_handle) == ESP_OK &&
+        esp_lcd_panel_invert_color(internal->panel_handle, config->invert_color) == ESP_OK &&
+        esp_lcd_panel_mirror(internal->panel_handle, config->mirror_x, config->mirror_y) == ESP_OK &&
+        esp_lcd_panel_disp_on_off(internal->panel_handle, true) == ESP_OK;
+
+    if (!ok) {
+        LOG_E(TAG, "Failed to bring up panel");
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    internal->frame_buffer_count = 0;
+    internal->frame_buffer_size_bytes = (size_t)config->horizontal_resolution * config->vertical_resolution *
+        ((config->bits_per_pixel + 7) / 8);
+    if (config->num_fbs > 0) {
+        // esp_lcd_dpi_panel_get_frame_buffer() is variadic: the number of out-pointer arguments
+        // passed must match fb_num exactly, so this can't be a loop.
+        size_t fb_num = config->num_fbs < MAX_CACHED_FRAME_BUFFERS ? config->num_fbs : MAX_CACHED_FRAME_BUFFERS;
+        esp_err_t ret;
+        switch (fb_num) {
+            case 1:
+                ret = esp_lcd_dpi_panel_get_frame_buffer(internal->panel_handle, 1, &internal->frame_buffers[0]);
+                break;
+            case 2:
+                ret = esp_lcd_dpi_panel_get_frame_buffer(internal->panel_handle, 2, &internal->frame_buffers[0], &internal->frame_buffers[1]);
+                break;
+            default:
+                ret = ESP_OK;
+                break;
+        }
+
+        if (ret != ESP_OK) {
+            LOG_E(TAG, "Failed to get frame buffer(s): %s", esp_err_to_name(ret));
+            esp_lcd_panel_del(internal->panel_handle);
+            esp_lcd_panel_io_del(internal->io_handle);
+            esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+            esp_ldo_release_channel(internal->ldo_handle);
+            free(internal->parsed_init_cmds);
+            free(internal);
+            return ERROR_RESOURCE;
+        }
+        internal->frame_buffer_count = (uint8_t)fb_num;
+    }
+
+    internal->frame_complete_semaphore = xSemaphoreCreateBinary();
+    if (internal->frame_complete_semaphore == nullptr) {
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    esp_lcd_dpi_panel_event_callbacks_t callbacks = {};
+    callbacks.on_refresh_done = on_refresh_done;
+    if (esp_lcd_dpi_panel_register_event_callbacks(internal->panel_handle, &callbacks, internal) != ESP_OK) {
+        LOG_E(TAG, "Failed to register panel event callbacks");
+        vSemaphoreDelete(internal->frame_complete_semaphore);
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        esp_lcd_del_dsi_bus(internal->dsi_bus_handle);
+        esp_ldo_release_channel(internal->ldo_handle);
+        free(internal->parsed_init_cmds);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+
+    if (internal->panel_handle != nullptr) {
+        if (esp_lcd_panel_del(internal->panel_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel");
+            return ERROR_RESOURCE;
+        }
+        internal->panel_handle = nullptr;
+    }
+
+    if (internal->io_handle != nullptr) {
+        if (esp_lcd_panel_io_del(internal->io_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel IO");
+            return ERROR_RESOURCE;
+        }
+        internal->io_handle = nullptr;
+    }
+
+    if (internal->dsi_bus_handle != nullptr) {
+        if (esp_lcd_del_dsi_bus(internal->dsi_bus_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete DSI bus");
+            return ERROR_RESOURCE;
+        }
+        internal->dsi_bus_handle = nullptr;
+    }
+
+    if (internal->ldo_handle != nullptr) {
+        if (esp_ldo_release_channel(internal->ldo_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to release LDO channel");
+            return ERROR_RESOURCE;
+        }
+        internal->ldo_handle = nullptr;
+    }
+
+    vSemaphoreDelete(internal->frame_complete_semaphore);
+    free(internal->parsed_init_cmds);
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region DisplayApi
+
+static error_t st7123_reset(Device* device) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_reset(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_init(Device* device) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_init(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// Only block for scan-out completion when color_data is actually one of the panel's own frame
+// buffers (see on_refresh_done's comment above for why that matters) and allow_tearing is not
+// set - i.e. this specific call is a zero-copy flip, not a plain CPU copy into the panel's buffer
+// from a caller-owned one (e.g. LVGL bound in owned-buffer mode), which has no reuse race to
+// guard against and shouldn't pay the up-to-one-frame latency cost for every partial update.
+static bool st7123_color_data_is_frame_buffer(const St7123Internal* internal, const void* color_data) {
+    const auto* ptr = static_cast<const uint8_t*>(color_data);
+    for (uint8_t i = 0; i < internal->frame_buffer_count; i++) {
+        const auto* base = static_cast<const uint8_t*>(internal->frame_buffers[i]);
+        if (ptr >= base && ptr < base + internal->frame_buffer_size_bytes) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static error_t st7123_draw_bitmap(Device* device, int32_t x_start, int32_t y_start, int32_t x_end, int32_t y_end, const void* color_data) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+
+    bool wait_for_scanout = !GET_CONFIG(device)->allow_tearing && st7123_color_data_is_frame_buffer(internal, color_data);
+    if (wait_for_scanout) {
+        xSemaphoreTake(internal->frame_complete_semaphore, 0); // clear any already-pending signal
+    }
+
+    if (esp_lcd_panel_draw_bitmap(internal->panel_handle, x_start, y_start, x_end, y_end, color_data) != ESP_OK) {
+        return ERROR_RESOURCE;
+    }
+
+    if (wait_for_scanout) {
+        xSemaphoreTake(internal->frame_complete_semaphore, portMAX_DELAY);
+    }
+
+    return ERROR_NONE;
+}
+
+// Mirror is always implemented by LCD command (MADCTL), unconditionally, by esp_lcd_st7123 - see
+// panel_st7123_mirror() in esp_lcd_st7123.c. Unlike esp_lcd_rgb_panel's software rotate_mask
+// trick, this isn't tied to draw_bitmap's copy path, so it stays available even when LVGL is
+// bound directly onto the panel's own frame buffers.
+static error_t st7123_mirror(Device* device, bool x_axis, bool y_axis) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_mirror(internal->panel_handle, x_axis, y_axis) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static bool st7123_get_mirror_x(Device* device) {
+    return GET_CONFIG(device)->mirror_x;
+}
+
+static bool st7123_get_mirror_y(Device* device) {
+    return GET_CONFIG(device)->mirror_y;
+}
+
+// swap_xy/set_gap are not exposed: esp_lcd_st7123 doesn't override them and the underlying raw
+// MIPI DPI panel doesn't implement them either (esp_lcd_panel_dpi.c never assigns those function
+// pointers), so esp_lcd_panel_swap_xy()/set_gap() would just return ESP_ERR_NOT_SUPPORTED.
+
+static error_t st7123_invert_color(Device* device, bool invert_color_data) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_invert_color(internal->panel_handle, invert_color_data) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_disp_on_off(Device* device, bool on_off) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_on_off(internal->panel_handle, on_off) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// disp_sleep is not exposed: esp_lcd_st7123 doesn't override it either (only
+// del/init/reset/mirror/invert_color/disp_on_off - see esp_lcd_st7123.c).
+
+// bgr_order only selects the panel controller's rgb_ele_order (applied in start(), above) so the
+// R/B swap happens on-chip. LVGL always fills the same-layout buffer either way - there's no
+// separate "BGR" memory layout to produce, unlike the SPI byte-order swap some other panels need.
+static enum DisplayColorFormat st7123_get_color_format(Device* device) {
+    return GET_CONFIG(device)->bits_per_pixel == 24 ? DISPLAY_COLOR_FORMAT_RGB888 : DISPLAY_COLOR_FORMAT_RGB565;
+}
+
+static uint16_t st7123_get_resolution_x(Device* device) {
+    return GET_CONFIG(device)->horizontal_resolution;
+}
+
+static uint16_t st7123_get_resolution_y(Device* device) {
+    return GET_CONFIG(device)->vertical_resolution;
+}
+
+static void st7123_get_frame_buffer(Device* device, uint8_t index, void** out_buffer) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+    *out_buffer = index < internal->frame_buffer_count ? internal->frame_buffers[index] : nullptr;
+}
+
+static uint8_t st7123_get_frame_buffer_count(Device* device) {
+    auto* internal = static_cast<St7123Internal*>(device_get_driver_data(device));
+    return internal->frame_buffer_count;
+}
+
+static error_t st7123_get_backlight(Device* device, Device** backlight) {
+    auto* configured_backlight = GET_CONFIG(device)->backlight;
+    if (configured_backlight == nullptr) {
+        return ERROR_NOT_SUPPORTED;
+    }
+    *backlight = configured_backlight;
+    return ERROR_NONE;
+}
+
+// endregion
+
+static const DisplayApi st7123_display_api = {
+    .capabilities = DISPLAY_CAPABILITY_CAP_MIRROR | DISPLAY_CAPABILITY_INVERT_COLOR |
+        DISPLAY_CAPABILITY_ON_OFF | DISPLAY_CAPABILITY_BACKLIGHT,
+    .reset = st7123_reset,
+    .init = st7123_init,
+    .draw_bitmap = st7123_draw_bitmap,
+    .mirror = st7123_mirror,
+    .swap_xy = nullptr,
+    .get_swap_xy = nullptr,
+    .get_mirror_x = st7123_get_mirror_x,
+    .get_mirror_y = st7123_get_mirror_y,
+    .set_gap = nullptr,
+    .invert_color = st7123_invert_color,
+    .disp_on_off = st7123_disp_on_off,
+    .disp_sleep = nullptr,
+    .get_color_format = st7123_get_color_format,
+    .get_resolution_x = st7123_get_resolution_x,
+    .get_resolution_y = st7123_get_resolution_y,
+    .get_frame_buffer = st7123_get_frame_buffer,
+    .get_frame_buffer_count = st7123_get_frame_buffer_count,
+    .get_backlight = st7123_get_backlight,
+    .has_capability = nullptr,
+};
+
+Driver st7123_driver = {
+    .name = "st7123",
+    .compatible = (const char*[]) { "sitronix,st7123", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &st7123_display_api,
+    .device_type = &DISPLAY_TYPE,
+    .owner = &st7123_module,
+    .internal = nullptr
+};
+
+#endif // SOC_MIPI_DSI_SUPPORTED

Drivers/st7123-module/source/st7123_touch.cpp

@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <drivers/st7123_touch.h>
+#include <st7123_module.h>
+
+#include <tactility/check.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/esp32_i2c.h>
+#include <tactility/drivers/esp32_i2c_master.h>
+#include <tactility/drivers/i2c_controller.h>
+#include <tactility/drivers/pointer.h>
+#include <tactility/log.h>
+
+#include <esp_err.h>
+#include <esp_lcd_io_i2c.h>
+#include <esp_lcd_panel_io.h>
+#include <esp_lcd_touch.h>
+#include <esp_lcd_touch_st7123.h>
+
+#include <cstdlib>
+
+#define TAG "St7123Touch"
+#define GET_CONFIG(device) (static_cast<const St7123TouchConfig*>((device)->config))
+
+struct St7123TouchInternal {
+    esp_lcd_panel_io_handle_t io_handle;
+    esp_lcd_touch_handle_t touch_handle;
+};
+
+static gpio_num_t pin_or_nc(const GpioPinSpec& pin) {
+    return pin.gpio_controller == nullptr ? GPIO_NUM_NC : static_cast<gpio_num_t>(pin.pin);
+}
+
+// region Driver lifecycle
+
+// Unlike GT911, ST7123's I2C address is fixed (see ESP_LCD_TOUCH_IO_I2C_ST7123_ADDRESS) - no
+// probing needed, the devicetree "reg" hint is purely documentation here.
+static esp_err_t create_io_handle(Device* parent, esp_lcd_panel_io_handle_t* out_handle) {
+    esp_lcd_panel_io_i2c_config_t io_config = ESP_LCD_TOUCH_IO_I2C_ST7123_CONFIG();
+
+    auto* parent_driver = device_get_driver(parent);
+    if (driver_is_compatible(parent_driver, "espressif,esp32-i2c")) {
+        auto port = static_cast<const Esp32I2cConfig*>(parent->config)->port;
+        return esp_lcd_new_panel_io_i2c_v1(port, &io_config, out_handle);
+    }
+    if (driver_is_compatible(parent_driver, "espressif,esp32-i2c-master")) {
+        auto bus = esp32_i2c_master_get_bus_handle(parent);
+        io_config.scl_speed_hz = esp32_i2c_master_get_clock_frequency(parent);
+        return esp_lcd_new_panel_io_i2c_v2(bus, &io_config, out_handle);
+    }
+
+    LOG_E(TAG, "Unsupported I2C driver");
+    return ESP_ERR_NOT_SUPPORTED;
+}
+
+static error_t start(Device* device) {
+    auto* parent = device_get_parent(device);
+    check(device_get_type(parent) == &I2C_CONTROLLER_TYPE);
+
+    const auto* config = GET_CONFIG(device);
+
+    auto* internal = static_cast<St7123TouchInternal*>(malloc(sizeof(St7123TouchInternal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    esp_err_t ret = create_io_handle(parent, &internal->io_handle);
+    if (ret != ESP_OK) {
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    esp_lcd_touch_config_t touch_config = {
+        .x_max = config->x_max,
+        .y_max = config->y_max,
+        .rst_gpio_num = pin_or_nc(config->pin_reset),
+        .int_gpio_num = pin_or_nc(config->pin_interrupt),
+        .levels = {
+            .reset = config->reset_active_high ? 1u : 0u,
+            .interrupt = config->interrupt_active_high ? 1u : 0u,
+        },
+        .flags = {
+            .swap_xy = config->swap_xy ? 1u : 0u,
+            .mirror_x = config->mirror_x ? 1u : 0u,
+            .mirror_y = config->mirror_y ? 1u : 0u,
+        },
+        .process_coordinates = nullptr,
+        .interrupt_callback = nullptr,
+        .user_data = nullptr,
+        .driver_data = nullptr,
+    };
+
+    ret = esp_lcd_touch_new_i2c_st7123(internal->io_handle, &touch_config, &internal->touch_handle);
+    if (ret != ESP_OK) {
+        LOG_E(TAG, "Failed to create touch handle: %s", esp_err_to_name(ret));
+        esp_lcd_panel_io_del(internal->io_handle);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+
+    // esp_lcd_touch_del() only releases the touch-side resources; the panel IO handle is owned
+    // separately and needs its own deletion.
+    if (internal->touch_handle != nullptr) {
+        if (esp_lcd_touch_del(internal->touch_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete touch handle");
+            return ERROR_RESOURCE;
+        }
+        internal->touch_handle = nullptr;
+    }
+
+    if (internal->io_handle != nullptr) {
+        if (esp_lcd_panel_io_del(internal->io_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel IO handle");
+            return ERROR_RESOURCE;
+        }
+        internal->io_handle = nullptr;
+    }
+
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region PointerApi
+
+static error_t st7123_touch_enter_sleep(Device* device) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_enter_sleep(internal->touch_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_touch_exit_sleep(Device* device) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_exit_sleep(internal->touch_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_touch_read_data(Device* device, TickType_t timeout) {
+    (void)timeout; // esp_lcd_touch_read_data() has no timeout parameter
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_read_data(internal->touch_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static bool st7123_touch_get_touched_points(Device* device, uint16_t* x, uint16_t* y, uint16_t* strength, uint8_t* point_count, uint8_t max_point_count) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_get_coordinates(internal->touch_handle, x, y, strength, point_count, max_point_count);
+}
+
+static error_t st7123_touch_set_swap_xy(Device* device, bool swap) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_set_swap_xy(internal->touch_handle, swap) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_touch_get_swap_xy(Device* device, bool* swap) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_get_swap_xy(internal->touch_handle, swap) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_touch_set_mirror_x(Device* device, bool mirror) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_set_mirror_x(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_touch_get_mirror_x(Device* device, bool* mirror) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_get_mirror_x(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_touch_set_mirror_y(Device* device, bool mirror) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_set_mirror_y(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7123_touch_get_mirror_y(Device* device, bool* mirror) {
+    auto* internal = static_cast<St7123TouchInternal*>(device_get_driver_data(device));
+    return esp_lcd_touch_get_mirror_y(internal->touch_handle, mirror) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// endregion
+
+static const PointerApi st7123_touch_pointer_api = {
+    .enter_sleep = st7123_touch_enter_sleep,
+    .exit_sleep = st7123_touch_exit_sleep,
+    .read_data = st7123_touch_read_data,
+    .get_touched_points = st7123_touch_get_touched_points,
+    .set_swap_xy = st7123_touch_set_swap_xy,
+    .get_swap_xy = st7123_touch_get_swap_xy,
+    .set_mirror_x = st7123_touch_set_mirror_x,
+    .get_mirror_x = st7123_touch_get_mirror_x,
+    .set_mirror_y = st7123_touch_set_mirror_y,
+    .get_mirror_y = st7123_touch_get_mirror_y,
+};
+
+Driver st7123_touch_driver = {
+    .name = "st7123-touch",
+    .compatible = (const char*[]) { "sitronix,st7123-touch", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &st7123_touch_pointer_api,
+    .device_type = &POINTER_TYPE,
+    .owner = &st7123_module,
+    .internal = nullptr
+};

Drivers/st7796-i8080-module/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.20)
+
+include("${CMAKE_CURRENT_LIST_DIR}/../../Buildscripts/module.cmake")
+
+file(GLOB_RECURSE SOURCE_FILES "source/*.c*")
+
+tactility_add_module(st7796-i8080-module
+    SRCS ${SOURCE_FILES}
+    INCLUDE_DIRS include/
+    REQUIRES TactilityKernel platform-esp32 esp_lcd_st7796 driver
+)

Drivers/st7796-i8080-module/LICENSE-Apache-2.0.md

@@ -0,0 +1,195 @@
+Apache License
+==============
+
+_Version 2.0, January 2004_  
+_&lt;<http://www.apache.org/licenses/>&gt;_
+
+### Terms and Conditions for use, reproduction, and distribution
+
+#### 1. Definitions
+
+“License” shall mean the terms and conditions for use, reproduction, and
+distribution as defined by Sections 1 through 9 of this document.
+
+“Licensor” shall mean the copyright owner or entity authorized by the copyright
+owner that is granting the License.
+
+“Legal Entity” shall mean the union of the acting entity and all other entities
+that control, are controlled by, or are under common control with that entity.
+For the purposes of this definition, “control” means **(i)** the power, direct or
+indirect, to cause the direction or management of such entity, whether by
+contract or otherwise, or **(ii)** ownership of fifty percent (50%) or more of the
+outstanding shares, or **(iii)** beneficial ownership of such entity.
+
+“You” (or “Your”) shall mean an individual or Legal Entity exercising
+permissions granted by this License.
+
+“Source” form shall mean the preferred form for making modifications, including
+but not limited to software source code, documentation source, and configuration
+files.
+
+“Object” form shall mean any form resulting from mechanical transformation or
+translation of a Source form, including but not limited to compiled object code,
+generated documentation, and conversions to other media types.
+
+“Work” shall mean the work of authorship, whether in Source or Object form, made
+available under the License, as indicated by a copyright notice that is included
+in or attached to the work (an example is provided in the Appendix below).
+
+“Derivative Works” shall mean any work, whether in Source or Object form, that
+is based on (or derived from) the Work and for which the editorial revisions,
+annotations, elaborations, or other modifications represent, as a whole, an
+original work of authorship. For the purposes of this License, Derivative Works
+shall not include works that remain separable from, or merely link (or bind by
+name) to the interfaces of, the Work and Derivative Works thereof.
+
+“Contribution” shall mean any work of authorship, including the original version
+of the Work and any modifications or additions to that Work or Derivative Works
+thereof, that is intentionally submitted to Licensor for inclusion in the Work
+by the copyright owner or by an individual or Legal Entity authorized to submit
+on behalf of the copyright owner. For the purposes of this definition,
+“submitted” means any form of electronic, verbal, or written communication sent
+to the Licensor or its representatives, including but not limited to
+communication on electronic mailing lists, source code control systems, and
+issue tracking systems that are managed by, or on behalf of, the Licensor for
+the purpose of discussing and improving the Work, but excluding communication
+that is conspicuously marked or otherwise designated in writing by the copyright
+owner as “Not a Contribution.”
+
+“Contributor” shall mean Licensor and any individual or Legal Entity on behalf
+of whom a Contribution has been received by Licensor and subsequently
+incorporated within the Work.
+
+#### 2. Grant of Copyright License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable copyright license to reproduce, prepare Derivative Works of,
+publicly display, publicly perform, sublicense, and distribute the Work and such
+Derivative Works in Source or Object form.
+
+#### 3. Grant of Patent License
+
+Subject to the terms and conditions of this License, each Contributor hereby
+grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free,
+irrevocable (except as stated in this section) patent license to make, have
+made, use, offer to sell, sell, import, and otherwise transfer the Work, where
+such license applies only to those patent claims licensable by such Contributor
+that are necessarily infringed by their Contribution(s) alone or by combination
+of their Contribution(s) with the Work to which such Contribution(s) was
+submitted. If You institute patent litigation against any entity (including a
+cross-claim or counterclaim in a lawsuit) alleging that the Work or a
+Contribution incorporated within the Work constitutes direct or contributory
+patent infringement, then any patent licenses granted to You under this License
+for that Work shall terminate as of the date such litigation is filed.
+
+#### 4. Redistribution
+
+You may reproduce and distribute copies of the Work or Derivative Works thereof
+in any medium, with or without modifications, and in Source or Object form,
+provided that You meet the following conditions:
+
+* **(a)** You must give any other recipients of the Work or Derivative Works a copy of
+this License; and
+* **(b)** You must cause any modified files to carry prominent notices stating that You
+changed the files; and
+* **(c)** You must retain, in the Source form of any Derivative Works that You distribute,
+all copyright, patent, trademark, and attribution notices from the Source form
+of the Work, excluding those notices that do not pertain to any part of the
+Derivative Works; and
+* **(d)** If the Work includes a “NOTICE” text file as part of its distribution, then any
+Derivative Works that You distribute must include a readable copy of the
+attribution notices contained within such NOTICE file, excluding those notices
+that do not pertain to any part of the Derivative Works, in at least one of the
+following places: within a NOTICE text file distributed as part of the
+Derivative Works; within the Source form or documentation, if provided along
+with the Derivative Works; or, within a display generated by the Derivative
+Works, if and wherever such third-party notices normally appear. The contents of
+the NOTICE file are for informational purposes only and do not modify the
+License. You may add Your own attribution notices within Derivative Works that
+You distribute, alongside or as an addendum to the NOTICE text from the Work,
+provided that such additional attribution notices cannot be construed as
+modifying the License.
+
+You may add Your own copyright statement to Your modifications and may provide
+additional or different license terms and conditions for use, reproduction, or
+distribution of Your modifications, or for any such Derivative Works as a whole,
+provided Your use, reproduction, and distribution of the Work otherwise complies
+with the conditions stated in this License.
+
+#### 5. Submission of Contributions
+
+Unless You explicitly state otherwise, any Contribution intentionally submitted
+for inclusion in the Work by You to the Licensor shall be under the terms and
+conditions of this License, without any additional terms or conditions.
+Notwithstanding the above, nothing herein shall supersede or modify the terms of
+any separate license agreement you may have executed with Licensor regarding
+such Contributions.
+
+#### 6. Trademarks
+
+This License does not grant permission to use the trade names, trademarks,
+service marks, or product names of the Licensor, except as required for
+reasonable and customary use in describing the origin of the Work and
+reproducing the content of the NOTICE file.
+
+#### 7. Disclaimer of Warranty
+
+Unless required by applicable law or agreed to in writing, Licensor provides the
+Work (and each Contributor provides its Contributions) on an “AS IS” BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied,
+including, without limitation, any warranties or conditions of TITLE,
+NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are
+solely responsible for determining the appropriateness of using or
+redistributing the Work and assume any risks associated with Your exercise of
+permissions under this License.
+
+#### 8. Limitation of Liability
+
+In no event and under no legal theory, whether in tort (including negligence),
+contract, or otherwise, unless required by applicable law (such as deliberate
+and grossly negligent acts) or agreed to in writing, shall any Contributor be
+liable to You for damages, including any direct, indirect, special, incidental,
+or consequential damages of any character arising as a result of this License or
+out of the use or inability to use the Work (including but not limited to
+damages for loss of goodwill, work stoppage, computer failure or malfunction, or
+any and all other commercial damages or losses), even if such Contributor has
+been advised of the possibility of such damages.
+
+#### 9. Accepting Warranty or Additional Liability
+
+While redistributing the Work or Derivative Works thereof, You may choose to
+offer, and charge a fee for, acceptance of support, warranty, indemnity, or
+other liability obligations and/or rights consistent with this License. However,
+in accepting such obligations, You may act only on Your own behalf and on Your
+sole responsibility, not on behalf of any other Contributor, and only if You
+agree to indemnify, defend, and hold each Contributor harmless for any liability
+incurred by, or claims asserted against, such Contributor by reason of your
+accepting any such warranty or additional liability.
+
+_END OF TERMS AND CONDITIONS_
+
+### APPENDIX: How to apply the Apache License to your work
+
+To apply the Apache License to your work, attach the following boilerplate
+notice, with the fields enclosed by brackets `[]` replaced with your own
+identifying information. (Don't include the brackets!) The text should be
+enclosed in the appropriate comment syntax for the file format. We also
+recommend that a file or class name and description of purpose be included on
+the same “printed page” as the copyright notice for easier identification within
+third-party archives.
+
+    Copyright [yyyy] [name of copyright owner]
+    
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+    
+      http://www.apache.org/licenses/LICENSE-2.0
+    
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+

Drivers/st7796-i8080-module/README.md

@@ -0,0 +1,6 @@
+# ST7796 (i8080) display
+
+A driver for the `ST7796` display panel by Sitronix, driven over an i8080 (8080-series
+parallel) bus. See [ST7796 (SPI)](../st7796-module) for the SPI variant.
+
+License: [Apache v2.0](LICENSE-Apache-2.0.md)

Drivers/st7796-i8080-module/bindings/sitronix,st7796-i8080.yaml

@@ -0,0 +1,69 @@
+description: Sitronix ST7796 display panel over an i8080 (parallel) bus
+
+compatible: "sitronix,st7796-i8080"
+
+bus: i8080
+
+properties:
+  horizontal-resolution:
+    type: int
+    required: true
+    description: Horizontal resolution in pixels
+  vertical-resolution:
+    type: int
+    required: true
+    description: Vertical resolution in pixels
+  gap-x:
+    type: int
+    default: 0
+    description: X offset applied to all draw operations
+  gap-y:
+    type: int
+    default: 0
+    description: Y offset applied to all draw operations
+  swap-xy:
+    type: boolean
+    default: false
+    description: Swap the X and Y axes
+  mirror-x:
+    type: boolean
+    default: false
+    description: Mirror the X axis
+  mirror-y:
+    type: boolean
+    default: false
+    description: Mirror the Y axis
+  invert-color:
+    type: boolean
+    default: false
+    description: Invert the panel's color output
+  bgr-order:
+    type: boolean
+    default: false
+    description: Use BGR element order instead of RGB
+  pixel-clock-hz:
+    type: int
+    default: 16000000
+    description: i80 bus write-clock frequency in Hz
+  transaction-queue-depth:
+    type: int
+    default: 10
+    description: Size of the internal transaction queue
+  gamma-curve:
+    type: int
+    default: 1
+    min: 0
+    max: 3
+    description: Gamma curve preset index [0,3], sent via the MIPI DCS GAMSET (0x26) command at bring-up
+  pin-reset:
+    type: phandles
+    default: GPIO_PIN_SPEC_NONE
+    description: Reset GPIO pin
+  reset-active-high:
+    type: boolean
+    default: false
+    description: Whether the reset pin is active high
+  backlight:
+    type: phandle
+    default: "NULL"
+    description: Optional reference to this display's backlight device

Drivers/st7796-i8080-module/devicetree.yaml

@@ -0,0 +1,3 @@
+dependencies:
+  - TactilityKernel
+bindings: bindings

Drivers/st7796-i8080-module/include/bindings/st7796_i8080.h

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/st7796_i8080.h>
+
+DEFINE_DEVICETREE(st7796_i8080, struct St7796I8080Config)

Drivers/st7796-i8080-module/include/drivers/st7796_i8080.h

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <tactility/device.h>
+#include <tactility/drivers/gpio.h>
+
+struct St7796I8080Config {
+    uint16_t horizontal_resolution;
+    uint16_t vertical_resolution;
+    int32_t gap_x;
+    int32_t gap_y;
+    bool swap_xy;
+    bool mirror_x;
+    bool mirror_y;
+    bool invert_color;
+    bool bgr_order;
+    uint32_t pixel_clock_hz;
+    uint8_t transaction_queue_depth;
+    // Gamma curve preset index [0,3], sent via the MIPI DCS GAMSET (0x26) command at bring-up.
+    uint8_t gamma_curve;
+    struct GpioPinSpec pin_reset;
+    bool reset_active_high;
+    // Optional reference to this display's backlight device, NULL if none.
+    struct Device* backlight;
+};
+
+#ifdef __cplusplus
+}
+#endif

Drivers/st7796-i8080-module/include/st7796_i8080_module.h

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/module.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern struct Module st7796_i8080_module;
+
+#ifdef __cplusplus
+}
+#endif

Drivers/st7796-i8080-module/source/module.cpp

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/check.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+extern Driver st7796_i8080_driver;
+
+static error_t start() {
+    /* We crash when construct fails, because if a single driver fails to construct,
+     * there is no guarantee that the previously constructed drivers can be destroyed */
+    check(driver_construct_add(&st7796_i8080_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    /* We crash when destruct fails, because if a single driver fails to destruct,
+     * there is no guarantee that the previously destroyed drivers can be recovered */
+    check(driver_remove_destruct(&st7796_i8080_driver) == ERROR_NONE);
+    return ERROR_NONE;
+}
+
+Module st7796_i8080_module = {
+    .name = "st7796_i8080",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+} // extern "C"

Drivers/st7796-i8080-module/source/st7796_i8080.cpp

@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <drivers/st7796_i8080.h>
+#include <st7796_i8080_module.h>
+
+#include <tactility/check.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/display.h>
+#include <tactility/drivers/esp32_i8080.h>
+#include <tactility/drivers/i8080_controller.h>
+#include <tactility/error.h>
+#include <tactility/log.h>
+
+#include <esp_err.h>
+#include <esp_lcd_panel_commands.h>
+#include <esp_lcd_panel_io.h>
+#include <esp_lcd_panel_ops.h>
+#include <esp_lcd_st7796.h>
+
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <cstdlib>
+
+constexpr auto* TAG = "ST7796I8080";
+#define GET_CONFIG(device) (static_cast<const St7796I8080Config*>((device)->config))
+
+// Maps gamma-curve devicetree index [0,3] to the MIPI DCS GAMSET (0x26) parameter value. Mirrors
+// the deprecated HAL's St7796Display::setGammaCurve() (Drivers/ST7796) - note the non-linear
+// mapping, not index+1.
+static const uint8_t GAMMA_CURVE_VALUES[4] = { 0x01, 0x04, 0x02, 0x08 };
+
+struct St7796I8080Internal {
+    esp_lcd_panel_io_handle_t io_handle;
+    esp_lcd_panel_handle_t panel_handle;
+    // See ili9341-module's identical field for why this exists: draw_bitmap() must block until
+    // the transfer physically completes (DisplayApi's synchronous contract).
+    SemaphoreHandle_t draw_done_semaphore;
+};
+
+static bool IRAM_ATTR on_color_trans_done(esp_lcd_panel_io_handle_t, esp_lcd_panel_io_event_data_t*, void* user_ctx) {
+    auto* internal = static_cast<St7796I8080Internal*>(user_ctx);
+    BaseType_t high_task_woken = pdFALSE;
+    xSemaphoreGiveFromISR(internal->draw_done_semaphore, &high_task_woken);
+    return high_task_woken == pdTRUE;
+}
+
+static int pin_or_unused(const struct GpioPinSpec& pin) {
+    return pin.gpio_controller == nullptr ? -1 : static_cast<int>(pin.pin);
+}
+
+// region Driver lifecycle
+
+static error_t start(Device* device) {
+    auto* parent = device_get_parent(device);
+    check(device_get_type(parent) == &I8080_CONTROLLER_TYPE);
+
+    esp_lcd_i80_bus_handle_t bus_handle;
+    if (esp32_i8080_get_bus_handle(device, &bus_handle) != ERROR_NONE) {
+        LOG_E(TAG, "Failed to resolve i80 bus handle");
+        return ERROR_RESOURCE;
+    }
+
+    struct GpioPinSpec cs_pin;
+    if (esp32_i8080_get_cs_pin(device, &cs_pin) != ERROR_NONE) {
+        LOG_E(TAG, "Failed to resolve CS pin");
+        return ERROR_RESOURCE;
+    }
+
+    const auto* config = GET_CONFIG(device);
+
+    auto* internal = static_cast<St7796I8080Internal*>(malloc(sizeof(St7796I8080Internal)));
+    if (internal == nullptr) {
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    internal->draw_done_semaphore = xSemaphoreCreateBinary();
+    if (internal->draw_done_semaphore == nullptr) {
+        free(internal);
+        return ERROR_OUT_OF_MEMORY;
+    }
+
+    esp_lcd_panel_io_i80_config_t io_config = {
+        .cs_gpio_num = pin_or_unused(cs_pin),
+        .pclk_hz = config->pixel_clock_hz,
+        .trans_queue_depth = config->transaction_queue_depth,
+        .on_color_trans_done = on_color_trans_done,
+        .user_ctx = internal,
+        .lcd_cmd_bits = 8,
+        .lcd_param_bits = 8,
+        .dc_levels = {
+            .dc_idle_level = 0,
+            .dc_cmd_level = 0,
+            .dc_dummy_level = 0,
+            .dc_data_level = 1,
+        },
+        .flags = {
+            .cs_active_high = 0,
+            .reverse_color_bits = 0,
+            .swap_color_bytes = 1,
+            .pclk_active_neg = 0,
+            .pclk_idle_low = 0,
+        },
+    };
+
+    esp_err_t ret = esp_lcd_new_panel_io_i80(bus_handle, &io_config, &internal->io_handle);
+    if (ret != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel IO: %s", esp_err_to_name(ret));
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    esp_lcd_panel_dev_config_t panel_config = {
+        .reset_gpio_num = pin_or_unused(config->pin_reset),
+        .rgb_ele_order = config->bgr_order ? LCD_RGB_ELEMENT_ORDER_BGR : LCD_RGB_ELEMENT_ORDER_RGB,
+        .data_endian = LCD_RGB_DATA_ENDIAN_LITTLE,
+        .bits_per_pixel = 16,
+        .flags = { .reset_active_high = config->reset_active_high },
+        .vendor_config = nullptr,
+    };
+
+    ret = esp_lcd_new_panel_st7796(internal->io_handle, &panel_config, &internal->panel_handle);
+    if (ret != ESP_OK) {
+        LOG_E(TAG, "Failed to create panel: %s", esp_err_to_name(ret));
+        esp_lcd_panel_io_del(internal->io_handle);
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    // Bring-up sequence, order matches the deprecated HAL's St7796i8080Display (proven correct on
+    // real WT32-SC01 Plus hardware). Every failure path below must clean up fully, same reasoning
+    // as ili9341-module's start().
+    bool ok =
+        esp_lcd_panel_reset(internal->panel_handle) == ESP_OK &&
+        esp_lcd_panel_init(internal->panel_handle) == ESP_OK &&
+        (!config->invert_color || esp_lcd_panel_invert_color(internal->panel_handle, true) == ESP_OK);
+
+    // set_gap() just stores x_gap/y_gap and adds them as raw offsets wherever draw_bitmap()'s
+    // (already logical, post-swap) x/y land - independent of swap_xy/mirror state, so gap_x/gap_y
+    // are passed through unswapped (matches st7796-module, the SPI sibling of this driver).
+    if (ok) {
+        ok = (config->gap_x == 0 && config->gap_y == 0) || esp_lcd_panel_set_gap(internal->panel_handle, config->gap_x, config->gap_y) == ESP_OK;
+    }
+    ok = ok && (!config->swap_xy || esp_lcd_panel_swap_xy(internal->panel_handle, true) == ESP_OK);
+    ok = ok && ((!config->mirror_x && !config->mirror_y) || esp_lcd_panel_mirror(internal->panel_handle, config->mirror_x, config->mirror_y) == ESP_OK);
+    ok = ok && (!config->invert_color || esp_lcd_panel_invert_color(internal->panel_handle, true) == ESP_OK);
+    ok = ok && (config->gamma_curve >= 4 || esp_lcd_panel_io_tx_param(internal->io_handle, LCD_CMD_GAMSET, &GAMMA_CURVE_VALUES[config->gamma_curve], 1) == ESP_OK);
+    ok = ok && esp_lcd_panel_disp_on_off(internal->panel_handle, true) == ESP_OK;
+
+    if (!ok) {
+        LOG_E(TAG, "Failed to bring up panel");
+        esp_lcd_panel_del(internal->panel_handle);
+        esp_lcd_panel_io_del(internal->io_handle);
+        vSemaphoreDelete(internal->draw_done_semaphore);
+        free(internal);
+        return ERROR_RESOURCE;
+    }
+
+    device_set_driver_data(device, internal);
+    return ERROR_NONE;
+}
+
+static error_t stop(Device* device) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+
+    if (internal->panel_handle != nullptr) {
+        if (esp_lcd_panel_del(internal->panel_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel");
+            return ERROR_RESOURCE;
+        }
+        internal->panel_handle = nullptr;
+    }
+
+    if (internal->io_handle != nullptr) {
+        if (esp_lcd_panel_io_del(internal->io_handle) != ESP_OK) {
+            LOG_E(TAG, "Failed to delete panel IO");
+            return ERROR_RESOURCE;
+        }
+        internal->io_handle = nullptr;
+    }
+
+    vSemaphoreDelete(internal->draw_done_semaphore);
+    free(internal);
+    device_set_driver_data(device, nullptr);
+    return ERROR_NONE;
+}
+
+// endregion
+
+// region DisplayApi
+
+static error_t st7796_i8080_reset(Device* device) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_reset(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7796_i8080_init(Device* device) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_init(internal->panel_handle) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7796_i8080_draw_bitmap(Device* device, int32_t x_start, int32_t y_start, int32_t x_end, int32_t y_end, const void* color_data) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+
+    xSemaphoreTake(internal->draw_done_semaphore, 0);
+
+    if (esp_lcd_panel_draw_bitmap(internal->panel_handle, x_start, y_start, x_end, y_end, color_data) != ESP_OK) {
+        return ERROR_RESOURCE;
+    }
+
+    xSemaphoreTake(internal->draw_done_semaphore, portMAX_DELAY);
+    return ERROR_NONE;
+}
+
+static error_t st7796_i8080_mirror(Device* device, bool x_axis, bool y_axis) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_mirror(internal->panel_handle, x_axis, y_axis) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7796_i8080_swap_xy(Device* device, bool swap_axes) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_swap_xy(internal->panel_handle, swap_axes) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// Reads the devicetree-configured baseline, not live hardware state - see st7796-module (the SPI
+// sibling of this driver) for the full reasoning.
+static bool st7796_i8080_get_swap_xy(Device* device) {
+    return GET_CONFIG(device)->swap_xy;
+}
+
+static bool st7796_i8080_get_mirror_x(Device* device) {
+    return GET_CONFIG(device)->mirror_x;
+}
+
+static bool st7796_i8080_get_mirror_y(Device* device) {
+    return GET_CONFIG(device)->mirror_y;
+}
+
+static error_t st7796_i8080_set_gap(Device* device, int32_t x_gap, int32_t y_gap) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_set_gap(internal->panel_handle, x_gap, y_gap) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static int32_t st7796_i8080_get_gap_x(Device* device) {
+    return GET_CONFIG(device)->gap_x;
+}
+
+static int32_t st7796_i8080_get_gap_y(Device* device) {
+    return GET_CONFIG(device)->gap_y;
+}
+
+static error_t st7796_i8080_invert_color(Device* device, bool invert_color_data) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_invert_color(internal->panel_handle, invert_color_data) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7796_i8080_disp_on_off(Device* device, bool on_off) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_on_off(internal->panel_handle, on_off) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static error_t st7796_i8080_disp_sleep(Device* device, bool sleep) {
+    auto* internal = static_cast<St7796I8080Internal*>(device_get_driver_data(device));
+    return esp_lcd_panel_disp_sleep(internal->panel_handle, sleep) == ESP_OK ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+// swap_color_bytes=1 in the panel IO config means the i80 peripheral itself byte-swaps each
+// RGB565 pixel over the parallel bus - same reasoning as st7789-i8080-module's identical knob.
+static enum DisplayColorFormat st7796_i8080_get_color_format(Device*) {
+    return DISPLAY_COLOR_FORMAT_RGB565_SWAPPED;
+}
+
+static uint16_t st7796_i8080_get_resolution_x(Device* device) {
+    return GET_CONFIG(device)->horizontal_resolution;
+}
+
+static uint16_t st7796_i8080_get_resolution_y(Device* device) {
+    return GET_CONFIG(device)->vertical_resolution;
+}
+
+static void st7796_i8080_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
+    *out_buffer = nullptr;
+}
+
+static uint8_t st7796_i8080_get_frame_buffer_count(Device*) {
+    return 0;
+}
+
+static error_t st7796_i8080_get_backlight(Device* device, Device** backlight) {
+    auto* configured_backlight = GET_CONFIG(device)->backlight;
+    if (configured_backlight == nullptr) {
+        return ERROR_NOT_SUPPORTED;
+    }
+    *backlight = configured_backlight;
+    return ERROR_NONE;
+}
+
+// endregion
+
+static const DisplayApi st7796_i8080_display_api = {
+    .capabilities = DISPLAY_CAPABILITY_CAP_MIRROR | DISPLAY_CAPABILITY_CAP_SWAP_XY |
+        DISPLAY_CAPABILITY_CAP_SET_GAP | DISPLAY_CAPABILITY_INVERT_COLOR | DISPLAY_CAPABILITY_ON_OFF |
+        DISPLAY_CAPABILITY_SLEEP | DISPLAY_CAPABILITY_BACKLIGHT,
+    .reset = st7796_i8080_reset,
+    .init = st7796_i8080_init,
+    .draw_bitmap = st7796_i8080_draw_bitmap,
+    .mirror = st7796_i8080_mirror,
+    .swap_xy = st7796_i8080_swap_xy,
+    .get_swap_xy = st7796_i8080_get_swap_xy,
+    .get_mirror_x = st7796_i8080_get_mirror_x,
+    .get_mirror_y = st7796_i8080_get_mirror_y,
+    .set_gap = st7796_i8080_set_gap,
+    .get_gap_x = st7796_i8080_get_gap_x,
+    .get_gap_y = st7796_i8080_get_gap_y,
+    .invert_color = st7796_i8080_invert_color,
+    .disp_on_off = st7796_i8080_disp_on_off,
+    .disp_sleep = st7796_i8080_disp_sleep,
+    .get_color_format = st7796_i8080_get_color_format,
+    .get_resolution_x = st7796_i8080_get_resolution_x,
+    .get_resolution_y = st7796_i8080_get_resolution_y,
+    .get_frame_buffer = st7796_i8080_get_frame_buffer,
+    .get_frame_buffer_count = st7796_i8080_get_frame_buffer_count,
+    .get_backlight = st7796_i8080_get_backlight,
+    .has_capability = nullptr,
+};
+
+Driver st7796_i8080_driver = {
+    .name = "st7796_i8080",
+    .compatible = (const char*[]) { "sitronix,st7796-i8080", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = &st7796_i8080_display_api,
+    .device_type = &DISPLAY_TYPE,
+    .owner = &st7796_i8080_module,
+    .internal = nullptr
+};