Implement connection keycode logic (#25176)

quantum/connection/connection.c

@@ -0,0 +1,147 @@
+// Copyright 2025 QMK
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include "connection.h"
+#include "eeconfig.h"
+#include "usb_util.h"
+#include "util.h"
+
+// ======== DEPRECATED DEFINES - DO NOT USE ========
+#ifdef OUTPUT_DEFAULT
+#    undef CONNECTION_HOST_DEFAULT
+#    define CONNECTION_HOST_DEFAULT OUTPUT_DEFAULT
+#endif
+
+__attribute__((weak)) void set_output_user(uint8_t output) {}
+// ========
+
+#ifdef BLUETOOTH_ENABLE
+#    ifdef BLUETOOTH_BLUEFRUIT_LE
+#        include "bluefruit_le.h"
+#        define bluetooth_is_connected() bluefruit_le_is_connected()
+#    else
+// TODO: drivers should check if BT is connected here
+#        define bluetooth_is_connected() true
+#    endif
+#endif
+
+#define CONNECTION_HOST_INVALID 0xFF
+
+#ifndef CONNECTION_HOST_DEFAULT
+#    define CONNECTION_HOST_DEFAULT CONNECTION_HOST_AUTO
+#endif
+
+static const connection_host_t host_candidates[] = {
+    CONNECTION_HOST_AUTO,
+    CONNECTION_HOST_USB,
+#ifdef BLUETOOTH_ENABLE
+    CONNECTION_HOST_BLUETOOTH,
+#endif
+#if 0
+    CONNECTION_HOST_2P4GHZ,
+#endif
+};
+
+#define HOST_CANDIDATES_COUNT ARRAY_SIZE(host_candidates)
+
+static connection_config_t config = {.desired_host = CONNECTION_HOST_INVALID};
+
+void eeconfig_update_connection_default(void) {
+    config.desired_host = CONNECTION_HOST_DEFAULT;
+
+    eeconfig_update_connection(&config);
+}
+
+void connection_init(void) {
+    eeconfig_read_connection(&config);
+    if (config.desired_host == CONNECTION_HOST_INVALID) {
+        eeconfig_update_connection_default();
+    }
+}
+
+__attribute__((weak)) void connection_host_changed_user(connection_host_t host) {}
+__attribute__((weak)) void connection_host_changed_kb(connection_host_t host) {}
+
+static void handle_host_changed(void) {
+    connection_host_changed_user(config.desired_host);
+    connection_host_changed_kb(config.desired_host);
+
+    // TODO: Remove deprecated callback
+    set_output_user(config.desired_host);
+}
+
+void connection_set_host_noeeprom(connection_host_t host) {
+    if (config.desired_host == host) {
+        return;
+    }
+
+    config.desired_host = host;
+
+    handle_host_changed();
+}
+
+void connection_set_host(connection_host_t host) {
+    connection_set_host_noeeprom(host);
+
+    eeconfig_update_connection(&config);
+}
+
+void connection_next_host_noeeprom(void) {
+    uint8_t next = 0;
+    for (uint8_t i = 0; i < HOST_CANDIDATES_COUNT; i++) {
+        if (host_candidates[i] == config.desired_host) {
+            next = i == HOST_CANDIDATES_COUNT - 1 ? 0 : i + 1;
+            break;
+        }
+    }
+
+    connection_set_host_noeeprom(host_candidates[next]);
+}
+
+void connection_next_host(void) {
+    connection_next_host_noeeprom();
+
+    eeconfig_update_connection(&config);
+}
+
+void connection_prev_host_noeeprom(void) {
+    uint8_t next = 0;
+    for (uint8_t i = 0; i < HOST_CANDIDATES_COUNT; i++) {
+        if (host_candidates[i] == config.desired_host) {
+            next = i == 0 ? HOST_CANDIDATES_COUNT - 1 : i - 1;
+            break;
+        }
+    }
+
+    connection_set_host_noeeprom(host_candidates[next]);
+}
+
+void connection_prev_host(void) {
+    connection_prev_host_noeeprom();
+
+    eeconfig_update_connection(&config);
+}
+
+connection_host_t connection_get_host_raw(void) {
+    return config.desired_host;
+}
+
+connection_host_t connection_auto_detect_host(void) {
+    if (usb_connected_state()) {
+        return CONNECTION_HOST_USB;
+    }
+
+#ifdef BLUETOOTH_ENABLE
+    if (bluetooth_is_connected()) {
+        return CONNECTION_HOST_BLUETOOTH;
+    }
+#endif
+
+    return CONNECTION_HOST_NONE;
+}
+
+connection_host_t connection_get_host(void) {
+    if (config.desired_host == CONNECTION_HOST_AUTO) {
+        return connection_auto_detect_host();
+    }
+    return config.desired_host;
+}