Device migrations and driver improvements (#576)

Devices/m5stack-stackchan/source/module.cpp

@@ -0,0 +1,64 @@
+#include <drivers/py32ioexpander.h>
+
+#include <tactility/check.h>
+#include <tactility/device.h>
+#include <tactility/device_listener.h>
+#include <tactility/module.h>
+
+#include <cstring>
+
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+
+extern "C" {
+
+// Boot LED pattern (red/green/blue sweep across the 12-LED WS2812C ring).
+// Confirms the PY32L020 body IO expander is working.
+static void run_led_boot_pattern(Device* py32) {
+    static constexpr uint8_t LED_COUNT = 12;
+    static constexpr uint8_t COLORS[][3] = {
+        { 255,   0,   0 }, // red
+        {   0, 255,   0 }, // green
+        {   0,   0, 255 }, // blue
+    };
+
+    py32_led_set_count(py32, LED_COUNT);
+    for (const auto& color : COLORS) {
+        for (uint8_t i = 0; i < LED_COUNT; i++) {
+            py32_led_set_color(py32, i, color[0], color[1], color[2]);
+        }
+        py32_led_refresh(py32);
+        vTaskDelay(pdMS_TO_TICKS(150));
+    }
+    py32_led_disable(py32);
+}
+
+static void on_device_event(Device* device, DeviceEvent event, void* context) {
+    (void)context;
+    if (event != DEVICE_EVENT_STARTED) {
+        return;
+    }
+    if (strcmp(device->name, "py32") == 0) {
+        run_led_boot_pattern(device);
+    }
+}
+
+static error_t start() {
+    device_listener_add(on_device_event, nullptr);
+    return ERROR_NONE;
+}
+
+static error_t stop() {
+    device_listener_remove(on_device_event);
+    return ERROR_NONE;
+}
+
+Module m5stack_stackchan_module = {
+    .name = "m5stack-stackchan",
+    .start = start,
+    .stop = stop,
+    .symbols = nullptr,
+    .internal = nullptr
+};
+
+}