Status led driver

app/boards/arm/tornblue/CMakeLists.txt

@@ -9,3 +9,8 @@ set_property(GLOBAL APPEND PROPERTY extra_post_build_commands
   -o ${PROJECT_BINARY_DIR}/${CONFIG_KERNEL_BIN_NAME}.uf2
   ${PROJECT_BINARY_DIR}/${CONFIG_KERNEL_BIN_NAME}.bin
 )
+
+zephyr_library()
+zephyr_library_sources(led_driver.c)
+zephyr_library_include_directories(${ZEPHYR_BASE}/drivers)
+zephyr_library_include_directories(${CMAKE_SOURCE_DIR}/include)

app/boards/arm/tornblue/led_driver.c

@@ -0,0 +1,63 @@
+#include <init.h>
+#include <device.h>
+#include <devicetree.h>
+//#include <drivers/led.h>
+#include <drivers/gpio.h>
+
+#include <logging/log.h>
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#include <zmk/keymap.h>
+#include <zmk/event_manager.h>
+#include <zmk/events/layer_state_changed.h>
+
+/* The devicetree node identifier for the "led0" alias. */
+#define LED1_NODE DT_ALIAS(led1)
+#define LED2_NODE DT_ALIAS(led2)
+#define LED3_NODE DT_ALIAS(led3)
+
+#if DT_NODE_HAS_STATUS(LED1_NODE, okay)
+#define LED1    DT_GPIO_LABEL(LED1_NODE, gpios)
+#define PIN1    DT_GPIO_PIN(LED1_NODE, gpios)
+#define FLAGS1  DT_GPIO_FLAGS(LED1_NODE, gpios)
+#else
+#error "Unsupported board: led1 devicetree alias is not defined"
+#endif
+
+#if DT_NODE_HAS_STATUS(LED2_NODE, okay)
+#define LED2    DT_GPIO_LABEL(LED2_NODE, gpios)
+#define PIN2    DT_GPIO_PIN(LED2_NODE, gpios)
+#define FLAGS2  DT_GPIO_FLAGS(LED2_NODE, gpios)
+#else
+#error "Unsupported board: led2 devicetree alias is not defined"
+#endif
+
+#if DT_NODE_HAS_STATUS(LED3_NODE, okay)
+#define LED3    DT_GPIO_LABEL(LED3_NODE, gpios)
+#define PIN3    DT_GPIO_PIN(LED3_NODE, gpios)
+#define FLAGS3  DT_GPIO_FLAGS(LED3_NODE, gpios)
+#else
+#error "Unsupported board: led3 devicetree alias is not defined"
+#endif
+
+int led_event_handler(const zmk_event_t *eh) {
+    const struct zmk_layer_state_changed *ev = as_zmk_layer_state_changed(eh);
+    if (ev == NULL) {
+        return -ENOTSUP;
+    }
+
+    const struct device *dev = device_get_binding(LED1);
+    gpio_pin_configure(dev, PIN1, GPIO_OUTPUT_ACTIVE | FLAGS1);
+    gpio_pin_configure(dev, PIN2, GPIO_OUTPUT_ACTIVE | FLAGS2);
+    gpio_pin_configure(dev, PIN3, GPIO_OUTPUT_ACTIVE | FLAGS3);
+
+    const uint8_t layer_active = zmk_keymap_highest_layer_active();
+    gpio_pin_set(dev, PIN3, layer_active == 3 /* Nav */);
+    gpio_pin_set(dev, PIN2, layer_active == 7 /* Symbol */);
+    gpio_pin_set(dev, PIN1, layer_active == 6 /* Num */);
+
+    return 0;
+}
+
+ZMK_LISTENER(led_foo, led_event_handler);
+ZMK_SUBSCRIPTION(led_foo, zmk_layer_state_changed);