Driver improvements (#535)

- New drivers:
  - SD SPI
  - spi_peripheral
  - touch_placeholder
  - display_placeholder
- Devicetree compiler:
  - Implement phandle-arrays
  - Implement device addresses
- Add placeholder drivers to all devices with a SPI display
- SPI driver: add `cs-pins` and set them to high on driver start
- FileSystem: add `file_system_set_owner()` and `file_system_get_owner()`
- File locking is now checking if the related `FileSystem` is part of a shared SPI bus
- Add `device_get_child_count()`
- SDMMC driver: Remove default of `slot` value
- Fix for Crowpanel Basic 3.5" display (add delay to booting)
- Fix for LilyGO T-HMI SD card mounting (delayed mounting by disabling it initially in the dts)

TactilityKernel/source/device.cpp

@@ -328,6 +328,10 @@ void device_for_each_child(Device* device, void* callbackContext, bool(*on_devic
     }
 }
 
+size_t device_get_child_count(Device* device) {
+    return device->internal->children.size();
+}
+
 void device_for_each_of_type(const DeviceType* type, void* callbackContext, bool(*on_device)(Device* device, void* context)) {
     ledger_lock();
     for (auto* device : ledger.devices) {

TactilityKernel/source/drivers/display.cpp

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/drivers/display.h>
+
+extern "C" {
+
+const struct DeviceType DISPLAY_TYPE {
+    .name = "display"
+};
+
+}

TactilityKernel/source/drivers/display_placeholder.cpp

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/drivers/display_placeholder.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/display.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+static error_t start(Device*) { return ERROR_NONE; }
+static error_t stop(Device*) { return ERROR_NONE; }
+
+extern Module root_module;
+
+Driver display_placeholder_driver = {
+    .name = "display_placeholder",
+    .compatible = (const char*[]) { "display-placeholder", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = nullptr,
+    .device_type = &DISPLAY_TYPE,
+    .owner = &root_module,
+    .internal = nullptr
+};
+
+}

TactilityKernel/source/drivers/sdcard.cpp

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/drivers/sdcard.h>
+
+extern "C" {
+
+const struct DeviceType SDCARD_TYPE {
+    .name = "sdcard"
+};
+
+}

TactilityKernel/source/drivers/spi_peripheral.cpp

@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/drivers/spi_peripheral.h>
+#include <tactility/driver.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+static error_t start(Device*) { return ERROR_NONE; }
+static error_t stop(Device*) { return ERROR_NONE; }
+
+const DeviceType SPI_PERIPHERAL_TYPE = {
+    .name = "spi_peripheral"
+};
+
+extern Module root_module;
+
+Driver spi_peripheral_driver = {
+    .name = "spi_peripheral",
+    .compatible = (const char*[]) { "spi-peripheral", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = nullptr,
+    .device_type = &SPI_PERIPHERAL_TYPE,
+    .owner = &root_module,
+    .internal = nullptr
+};
+
+}

TactilityKernel/source/drivers/touch.cpp

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/drivers/touch.h>
+
+extern "C" {
+
+const struct DeviceType TOUCH_TYPE {
+    .name = "touch"
+};
+
+}

TactilityKernel/source/drivers/touch_placeholder.cpp

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/drivers/touch_placeholder.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/touch.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+static error_t start(Device*) { return ERROR_NONE; }
+static error_t stop(Device*) { return ERROR_NONE; }
+
+extern Module root_module;
+
+Driver touch_placeholder_driver = {
+    .name = "touch_placeholder",
+    .compatible = (const char*[]) { "touch-placeholder", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = nullptr,
+    .device_type = &TOUCH_TYPE,
+    .owner = &root_module,
+    .internal = nullptr
+};
+
+}

TactilityKernel/source/filesystem/file_system.cpp

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include <algorithm>
+#include <tactility/device.h>
 #include <tactility/concurrent/mutex.h>
 #include <tactility/concurrent/recursive_mutex.h>
 #include <tactility/filesystem/file_system.h>
@@ -10,6 +11,7 @@
 struct FileSystem {
     const FileSystemApi* api;
     void* data;
+    Device* owner;
 };
 
 // Global list of file systems and its mutex
@@ -42,6 +44,7 @@ FileSystem* file_system_add(const FileSystemApi* fs_api, void* data) {
     check(fs != nullptr);
     fs->api = fs_api;
     fs->data = data;
+    fs->owner = nullptr;
     ledger.file_systems.push_back(fs);
     
     ledger.unlock();
@@ -90,4 +93,12 @@ error_t file_system_get_path(FileSystem* fs, char* out_path, size_t out_path_siz
     return fs->api->get_path(fs->data, out_path, out_path_size);
 }
 
+void file_system_set_owner(FileSystem* fs, Device* owner) {
+    fs->owner = owner;
+}
+
+Device* file_system_get_owner(FileSystem* fs) {
+    return fs->owner;
+}
+
 }

TactilityKernel/source/kernel_init.cpp

@@ -14,6 +14,12 @@ extern const ModuleSymbol KERNEL_SYMBOLS[];
 static error_t start() {
     extern Driver root_driver;
     if (driver_construct_add(&root_driver) != ERROR_NONE) return ERROR_RESOURCE;
+    extern Driver display_placeholder_driver;
+    if (driver_construct_add(&display_placeholder_driver) != ERROR_NONE) return ERROR_RESOURCE;
+    extern Driver touch_placeholder_driver;
+    if (driver_construct_add(&touch_placeholder_driver) != ERROR_NONE) return ERROR_RESOURCE;
+    extern Driver spi_peripheral_driver;
+    if (driver_construct_add(&spi_peripheral_driver) != ERROR_NONE) return ERROR_RESOURCE;
     return ERROR_NONE;
 }