Partial reimplementation of TactilityC GPIO (#469)

* **New Features**
  * Added a GPIO hardware abstraction layer for reading pin levels from applications.
  * Applications can now query the number of available GPIO pins so they can adapt to different devices.
* **Chores**
  * Integrations updated so GPIO capabilities are discoverable and exported to running applications.

TactilityC/CMakeLists.txt

@@ -8,7 +8,7 @@ if (DEFINED ENV{ESP_IDF_VERSION})
         INCLUDE_DIRS "Include/"
         PRIV_INCLUDE_DIRS "Private/"
         REQUIRES lvgl
-        PRIV_REQUIRES Tactility TactilityCore elf_loader
+        PRIV_REQUIRES Tactility TactilityCore elf_loader TactilityKernel
     )
 
     if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
@@ -28,6 +28,7 @@ else()
     target_link_libraries(TactilityC
         PRIVATE Tactility
         PRIVATE TactilityCore
+        PRIVATE TactilityKernel
         PUBLIC lvgl
     )
 endif()

TactilityC/Include/tt_hal_gpio.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Logical GPIO pin identifier used by the HAL. Typically maps to the SoC GPIO number. */
+typedef unsigned int GpioPin;
+/** Value indicating that no GPIO pin is used/applicable. */
+#define GPIO_NO_PIN -1
+
+/** Read the current logic level of a pin.
+ * The pin should be configured for input or input/output.
+ * @param[in] pin The pin to read.
+ * @return true if the level is high, false if low. If the pin is invalid, the
+ *         behavior is implementation-defined and may return false.
+ */
+bool tt_hal_gpio_get_level(GpioPin pin);
+
+/** Get the number of GPIO pins available on this platform.
+ * @return The count of valid GPIO pins.
+ */
+int tt_hal_gpio_get_pin_count();
+
+#ifdef __cplusplus
+}
+#endif

TactilityC/Source/tt_hal_gpio.cpp

@@ -0,0 +1,39 @@
+#include "tt_hal_gpio.h"
+#include <Tactility/hal/gpio/Gpio.h>
+#include <tactility/device.h>
+#include <tactility/drivers/gpio_controller.h>
+
+extern "C" {
+
+using namespace tt::hal;
+
+static Device* find_first_gpio_controller() {
+    Device* device_result = nullptr;
+    for_each_device_of_type(&GPIO_CONTROLLER_TYPE, &device_result, [](Device* device, void* context) {
+        if (device_is_ready(device)) {
+            auto** device_result_ptr = static_cast<Device**>(context);
+            *device_result_ptr = device;
+            return false;
+        }
+        return true;
+    });
+    return device_result;
+}
+
+bool tt_hal_gpio_get_level(GpioPin pin) {
+    Device* device_result = find_first_gpio_controller();
+    if (device_result == nullptr) return false;
+    bool pin_state = false;
+    if (!gpio_controller_get_level(device_result, pin, &pin_state)) return false;
+    return pin_state;
+}
+
+int tt_hal_gpio_get_pin_count() {
+    Device* device_result = find_first_gpio_controller();
+    if (device_result == nullptr) return 0;
+    uint32_t pin_count = 0;
+    if (!gpio_controller_get_pin_count(device_result, &pin_count)) return 0;
+    return (int)pin_count;
+}
+
+}

TactilityC/Source/tt_init.cpp

@@ -8,6 +8,7 @@
 #include "tt_hal.h"
 #include "tt_hal_device.h"
 #include "tt_hal_display.h"
+#include "tt_hal_gpio.h"
 #include "tt_hal_touch.h"
 #include "tt_hal_uart.h"
 #include <tt_lock.h>
@@ -217,6 +218,8 @@ const esp_elfsym main_symbols[] {
     ESP_ELFSYM_EXPORT(tt_hal_display_driver_lock),
     ESP_ELFSYM_EXPORT(tt_hal_display_driver_unlock),
     ESP_ELFSYM_EXPORT(tt_hal_display_driver_supported),
+    ESP_ELFSYM_EXPORT(tt_hal_gpio_get_level),
+    ESP_ELFSYM_EXPORT(tt_hal_gpio_get_pin_count),
     ESP_ELFSYM_EXPORT(tt_hal_touch_driver_supported),
     ESP_ELFSYM_EXPORT(tt_hal_touch_driver_alloc),
     ESP_ELFSYM_EXPORT(tt_hal_touch_driver_free),