refactor(ble): Use auto phy/conn for split

app/Kconfig

@@ -148,7 +148,7 @@ config BT_PERIPHERAL_PREF_MIN_INT
 config BT_PERIPHERAL_PREF_MAX_INT
 	default 12
 
-config BT_PERIPHERAL_PREF_SLAVE_LATENCY
+config BT_PERIPHERAL_PREF_LATENCY
 	default 30
 
 config BT_PERIPHERAL_PREF_TIMEOUT
@@ -175,6 +175,7 @@ menuconfig ZMK_SPLIT_BLE
 	depends on ZMK_BLE
 	default y
 	select BT_USER_PHY_UPDATE
+	select BT_AUTO_PHY_UPDATE
 
 if ZMK_SPLIT_BLE
 
@@ -223,6 +224,9 @@ config BT_MAX_PAIRED
 config BT_MAX_CONN
 	default 1
 
+config BT_PERIPHERAL_PREF_MAX_INT
+	default 6
+
 #!ZMK_SPLIT_BLE_ROLE_CENTRAL
 endif
 

app/src/ble.c

@@ -398,15 +398,6 @@ static void connected(struct bt_conn *conn, uint8_t err) {
 
     LOG_DBG("Connected %s", log_strdup(addr));
 
-    err = bt_conn_le_param_update(conn, BT_LE_CONN_PARAM(0x0006, 0x000c, 30, 400));
-    if (err) {
-        LOG_WRN("Failed to update LE parameters (err %d)", err);
-    }
-
-#if IS_SPLIT_PERIPHERAL
-    bt_conn_le_phy_update(conn, BT_CONN_LE_PHY_PARAM_2M);
-#endif
-
     if (bt_conn_set_security(conn, BT_SECURITY_L2)) {
         LOG_ERR("Failed to set security");
     }

app/src/split/bluetooth/central.c

@@ -403,12 +403,6 @@ static bool split_central_eir_found(struct bt_data *data, void *user_data) {
                             BT_HCI_OP_LE_CREATE_CONN);
                     start_scan();
                 }
-
-                err = bt_conn_le_phy_update(slot->conn, BT_CONN_LE_PHY_PARAM_2M);
-                if (err) {
-                    LOG_ERR("Update phy conn failed (err %d)", err);
-                    start_scan();
-                }
             }
 
             return false;