feat: LED indicators displaying

app/CMakeLists.txt

@@ -88,6 +88,7 @@ add_subdirectory(src/split)
 target_sources_ifdef(CONFIG_USB_DEVICE_STACK app PRIVATE src/usb.c)
 target_sources_ifdef(CONFIG_ZMK_RGB_UNDERGLOW app PRIVATE src/rgb_underglow.c)
 target_sources_ifdef(CONFIG_ZMK_BACKLIGHT app PRIVATE src/backlight.c)
+target_sources_ifdef(CONFIG_ZMK_LED_INDICATORS app PRIVATE src/led_indicators.c)
 target_sources(app PRIVATE src/main.c)
 
 add_subdirectory(src/display/)

app/Kconfig

@@ -282,6 +282,20 @@ config ZMK_BACKLIGHT_AUTO_OFF_USB
 #ZMK_BACKLIGHT
 endif
 
+menuconfig ZMK_LED_INDICATORS
+	bool "LED indicators"
+	select LED
+
+if ZMK_LED_INDICATORS
+
+config ZMK_LED_INDICATORS_BRT
+	int "Brightness in percent"
+	range 1 100
+	default 80
+
+#ZMK_LED_INDICATORS
+endif
+
 #Display/LED Options
 endmenu
 

app/include/zmk/led_indicators.h

@@ -10,6 +10,12 @@
 #include <zmk/hid.h>
 #include <zmk/led_indicators_types.h>
 
+#define ZMK_LED_NUMLOCK_BIT BIT(0)
+#define ZMK_LED_CAPSLOCK_BIT BIT(1)
+#define ZMK_LED_SCROLLLOCK_BIT BIT(2)
+#define ZMK_LED_COMPOSE_BIT BIT(3)
+#define ZMK_LED_KANA_BIT BIT(4)
+
 zmk_leds_flags_t zmk_leds_get_current_flags();
 zmk_leds_flags_t zmk_leds_get_flags(enum zmk_endpoint endpoint, uint8_t profile);
 void zmk_leds_update_flags(zmk_leds_flags_t leds, enum zmk_endpoint endpoint, uint8_t profile);

app/src/led_indicators.c

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <kernel.h>
+#include <device.h>
+#include <init.h>
+
+#include <logging/log.h>
+#include <drivers/led.h>
+
+#include <zmk/event_manager.h>
+#include <zmk/led_indicators.h>
+#include <zmk/events/led_indicator_changed.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#ifndef DT_NODE_CHILD_IDX
+
+#define CHILD_IDX(idx, child_id, node_id) (DT_SAME_NODE(child_id, node_id) ? idx : 0)
+#define ADD_COMMA(node_id) node_id,
+#define DT_NODE_CHILD_IDX(node_id)                                                                 \
+    (FOR_EACH_IDX_FIXED_ARG(CHILD_IDX, (+), node_id,                                               \
+                            DT_FOREACH_CHILD(DT_PARENT(node_id), ADD_COMMA) DT_ROOT))
+
+#endif
+
+struct zmk_led_cfg {
+    const struct device *dev;
+    int index;
+    int indicator;
+};
+
+#define LED_CFG_IMPL(node_id, indicator_bit)                                                       \
+    (struct zmk_led_cfg) {                                                                         \
+        .dev = DEVICE_DT_GET(DT_PARENT(node_id)), .index = DT_NODE_CHILD_IDX(node_id),             \
+        .indicator = indicator_bit,                                                                \
+    }
+
+#define LED_CFG(chosen, indicator_bit)                                                             \
+    IF_ENABLED(DT_HAS_CHOSEN(chosen), (LED_CFG_IMPL(DT_CHOSEN(chosen), indicator_bit)))
+
+static const struct zmk_led_cfg led_indicators[] = {LIST_DROP_EMPTY(
+    LED_CFG(zmk_led_numlock, ZMK_LED_NUMLOCK_BIT), LED_CFG(zmk_led_capslock, ZMK_LED_CAPSLOCK_BIT),
+    LED_CFG(zmk_led_scrolllock, ZMK_LED_SCROLLLOCK_BIT),
+    LED_CFG(zmk_led_compose, ZMK_LED_COMPOSE_BIT), LED_CFG(zmk_led_kana, ZMK_LED_KANA_BIT))};
+
+static int leds_init(const struct device *_arg) {
+    for (int i = 0; i < ARRAY_SIZE(led_indicators); i++) {
+        if (!device_is_ready(led_indicators[i].dev)) {
+            LOG_ERR("LED device \"%s\" is not ready", led_indicators[i].dev->name);
+            return -ENODEV;
+        }
+    }
+
+    return 0;
+}
+
+static int leds_listener(const zmk_event_t *eh) {
+    zmk_leds_flags_t flags = zmk_leds_get_current_flags();
+
+    for (int i = 0; i < ARRAY_SIZE(led_indicators); i++) {
+        uint8_t value = (flags & led_indicators[i].indicator) ? CONFIG_ZMK_LED_INDICATORS_BRT : 0;
+        int rc = led_set_brightness(led_indicators[i].dev, led_indicators[i].index, value);
+        if (rc != 0) {
+            LOG_ERR("Failed to set LED indicator %d: %d", i, rc);
+        }
+    }
+
+    return ZMK_EV_EVENT_BUBBLE;
+}
+
+ZMK_LISTENER(leds_listener, leds_listener);
+ZMK_SUBSCRIPTION(leds_listener, zmk_led_changed);
+
+SYS_INIT(leds_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);