feat(ble): Add the ability to enable and disable advertising

Added functionality to enable and disable BLE advertising using new &bt behavior bindings, adds documentation for the new parameters and a note that default behavior is unchanged

Co-Authored-By: Nicolas Munnich <98408764+Nick-Munnich@users.noreply.github.com>
Co-Authored-By: Cem Aksoylar <caksoylar@users.noreply.github.com>

app/include/dt-bindings/zmk/bt.h

@@ -10,6 +10,9 @@
 #define BT_SEL_CMD 3
 #define BT_CLR_ALL_CMD 4
 #define BT_DISC_CMD 5
+#define BT_ADV_OFF_CMD 6
+#define BT_ADV_ON_CMD 7
+#define BT_ADV_TOG_CMD 8
 
 /*
 Note: Some future commands will include additional parameters, so we
@@ -22,3 +25,6 @@ defines these aliases up front.
 #define BT_SEL BT_SEL_CMD
 #define BT_CLR_ALL BT_CLR_ALL_CMD 0
 #define BT_DISC BT_DISC_CMD
+#define BT_ADV_OFF BT_ADV_OFF_CMD 0
+#define BT_ADV_ON BT_ADV_ON_CMD 0
+#define BT_ADV_TOG BT_ADV_TOG_CMD 0

app/include/zmk/ble.h

@@ -20,6 +20,12 @@
 #define ZMK_BLE_PROFILE_COUNT CONFIG_BT_MAX_PAIRED
 #endif
 
+enum advertising_type {
+    ZMK_ADV_NONE,
+    ZMK_ADV_DIR,
+    ZMK_ADV_CONN,
+};
+
 void zmk_ble_clear_bonds(void);
 int zmk_ble_prof_next(void);
 int zmk_ble_prof_prev(void);
@@ -41,6 +47,9 @@ int zmk_ble_unpair_all(void);
 
 int zmk_ble_set_device_name(char *name);
 
+void zmk_ble_adv_enabled_set(bool adv_enabled);
+bool zmk_ble_adv_enabled_get(void);
+
 #if IS_ENABLED(CONFIG_ZMK_SPLIT_ROLE_CENTRAL)
 int zmk_ble_put_peripheral_addr(const bt_addr_le_t *addr);
 #endif /* IS_ENABLED(CONFIG_ZMK_SPLIT_ROLE_CENTRAL) */

app/src/behaviors/behavior_bt.c

@@ -43,6 +43,21 @@ static const struct behavior_parameter_value_metadata no_arg_values[] = {
         .type = BEHAVIOR_PARAMETER_VALUE_TYPE_VALUE,
         .value = BT_CLR_CMD,
     },
+    {
+        .display_name = "Disconnect All and Stop Advertising",
+        .type = BEHAVIOR_PARAMETER_VALUE_TYPE_VALUE,
+        .value = BT_ADV_OFF_CMD,
+    },
+    {
+        .display_name = "Start Advertising",
+        .type = BEHAVIOR_PARAMETER_VALUE_TYPE_VALUE,
+        .value = BT_ADV_ON_CMD,
+    },
+    {
+        .display_name = "Toggle Advertising",
+        .type = BEHAVIOR_PARAMETER_VALUE_TYPE_VALUE,
+        .value = BT_ADV_TOG_CMD,
+    },
 };
 
 static const struct behavior_parameter_metadata_set no_args_set = {
@@ -105,6 +120,15 @@ static int on_keymap_binding_pressed(struct zmk_behavior_binding *binding,
         return 0;
     case BT_DISC_CMD:
         return zmk_ble_prof_disconnect(binding->param2);
+    case BT_ADV_ON_CMD:
+        zmk_ble_adv_enabled_set(true);
+        return 0;
+    case BT_ADV_OFF_CMD:
+        zmk_ble_adv_enabled_set(false);
+        return 0;
+    case BT_ADV_TOG_CMD:
+        zmk_ble_adv_enabled_set(zmk_ble_adv_enabled_get() ? false : true);
+        return 0;
     default:
         LOG_ERR("Unknown BT command: %d", binding->param1);
     }

app/src/ble.c

@@ -47,11 +47,7 @@ RING_BUF_DECLARE(passkey_entries, PASSKEY_DIGITS);
 
 #endif /* IS_ENABLED(CONFIG_ZMK_BLE_PASSKEY_ENTRY) */
 
-enum advertising_type {
-    ZMK_ADV_NONE,
-    ZMK_ADV_DIR,
-    ZMK_ADV_CONN,
-} advertising_status;
+enum advertising_type advertising_status;
 
 #define CURR_ADV(adv) (adv << 4)
 
@@ -63,6 +59,8 @@ enum advertising_type {
 static struct zmk_ble_profile profiles[ZMK_BLE_PROFILE_COUNT];
 static uint8_t active_profile;
 
+static bool permit_adv = true;
+
 #define DEVICE_NAME CONFIG_BT_DEVICE_NAME
 #define DEVICE_NAME_LEN (sizeof(DEVICE_NAME) - 1)
 
@@ -167,9 +165,9 @@ int update_advertising(void) {
     struct bt_conn *conn;
     enum advertising_type desired_adv = ZMK_ADV_NONE;
 
-    if (zmk_ble_active_profile_is_open()) {
+    if (permit_adv && zmk_ble_active_profile_is_open()) {
         desired_adv = ZMK_ADV_CONN;
-    } else if (!zmk_ble_active_profile_is_connected()) {
+    } else if (permit_adv && !zmk_ble_active_profile_is_connected()) {
         desired_adv = ZMK_ADV_CONN;
         // Need to fix directed advertising for privacy centrals. See
         // https://github.com/zephyrproject-rtos/zephyr/pull/14984 char
@@ -210,6 +208,28 @@ static void update_advertising_callback(struct k_work *work) { update_advertisin
 
 K_WORK_DEFINE(update_advertising_work, update_advertising_callback);
 
+void zmk_ble_adv_enabled_set(bool adv_enabled) {
+    if (adv_enabled) {
+        if (advertising_status != ZMK_ADV_CONN) {
+            permit_adv = true;
+            LOG_DBG("Enabling adv");
+        }
+        update_advertising();
+    } else {
+        permit_adv = false;
+        LOG_DBG("Disabling adv and disconnecting");
+        for (int i = 0; i < ZMK_BLE_PROFILE_COUNT; i++) {
+            int err = zmk_ble_prof_disconnect(i);
+            if (err) {
+                LOG_DBG("Failed to disconnect profile %d : %d", i, err);
+            }
+        }
+        update_advertising();
+    }
+}
+
+bool zmk_ble_adv_enabled_get(void) { return permit_adv; }
+
 static void clear_profile_bond(uint8_t profile) {
     if (bt_addr_le_cmp(&profiles[profile].peer, BT_ADDR_LE_ANY)) {
         bt_unpair(BT_ID_DEFAULT, &profiles[profile].peer);

docs/docs/keymaps/behaviors/bluetooth.md

@@ -46,12 +46,19 @@ Here is a table describing the command for each define:
 | `BT_PRV`     | Switch to the previous profile, cycling through to the last one when the beginning is reached.                                                                                     |
 | `BT_SEL`     | Select the 0-indexed profile by number; must include a number as an argument in the keymap to work correctly, e.g. `BT_SEL 0`.                                                     |
 | `BT_DISC`    | Disconnect from the 0-indexed profile by number, if it's currently connected and inactive; must include a number as an argument in the keymap to work correctly, e.g. `BT_DISC 0`. |
+| `BT_ADV_OFF` | Disable advertising and disconnect from all profiles                                                                                                                               |
+| `BT_ADV_ON`  | Enable advertising and attempt to reconnect to profiles                                                                                                                            |
+| `BT_ADV_TOG` | Toggle advertising on and off                                                                                                                                                      |
 
 :::note[Selected profile persistence]
 The profile that is selected by the `BT_SEL`/`BT_PRV`/`BT_NXT` actions will be saved to flash storage and hence persist across restarts and firmware flashes.
 However it will only be saved after [`CONFIG_ZMK_SETTINGS_SAVE_DEBOUNCE`](../../config/system.md#general) milliseconds in order to reduce potential wear on the flash memory.
 :::
 
+:::note[Advertising]
+Bluetooth advertising is enabled in all situations by default, and doesn't have to be explicitly enabled via the bindings above.
+:::
+
 ## Bluetooth Behavior
 
 The bluetooth behavior completes an bluetooth action given on press.