feat: handle LED indicators report

app/src/hid_indicators.c

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include <zmk/ble.h>
+#include <zmk/endpoints.h>
+#include <zmk/hid_indicators.h>
+#include <zmk/events/hid_indicators_changed.h>
+#include <zmk/events/endpoint_changed.h>
+#include <zmk/split/bluetooth/central.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+static zmk_hid_indicators hid_indicators[ZMK_ENDPOINT_COUNT];
+
+zmk_hid_indicators zmk_hid_indicators_get_current_profile(void) {
+    return zmk_hid_indicators_get_profile(zmk_endpoints_selected());
+}
+
+zmk_hid_indicators zmk_hid_indicators_get_profile(struct zmk_endpoint_instance endpoint) {
+    int profile = zmk_endpoint_instance_to_index(endpoint);
+    return hid_indicators[profile];
+}
+
+static void raise_led_changed_event(struct k_work *_work) {
+    ZMK_EVENT_RAISE(new_zmk_hid_indicators_changed((struct zmk_hid_indicators_changed){
+        .indicators = zmk_hid_indicators_get_current_profile()}));
+}
+
+static K_WORK_DEFINE(led_changed_work, raise_led_changed_event);
+
+void zmk_hid_indicators_set_profile(zmk_hid_indicators indicators,
+                                    struct zmk_endpoint_instance endpoint) {
+    int profile = zmk_endpoint_instance_to_index(endpoint);
+
+    // This write is not happening on the main thread. To prevent potential data races, every
+    // operation involving hid_indicators must be atomic. Currently, each function either reads
+    // or writes only one entry at a time, so it is safe to do these operations without a lock.
+    hid_indicators[profile] = indicators;
+
+    k_work_submit(&led_changed_work);
+}
+
+void zmk_hid_indicators_process_report(struct zmk_hid_led_report_body *report,
+                                       struct zmk_endpoint_instance endpoint) {
+    uint8_t indicators = report->leds;
+    zmk_hid_indicators_set_profile(indicators, endpoint);
+
+    LOG_DBG("Update HID indicators: endpoint=%d, indicators=%x", endpoint.transport, indicators);
+}
+
+static int profile_listener(const zmk_event_t *eh) {
+    raise_led_changed_event(NULL);
+    return 0;
+}
+
+static ZMK_LISTENER(profile_listener, profile_listener);
+static ZMK_SUBSCRIPTION(profile_listener, zmk_endpoint_changed);