caf: modules: ble_adv: Power down on disconnection with reason 0x15

Force power down if bonded peer disconnects with reason 0x15 (Remote
Device Terminated due to Power Off).

Jira: NCSDK-24458

Signed-off-by: Marek Pieta <[email protected]>
Signed-off-by: Pekka Niskanen <[email protected]>
Signed-off-by: Divya Pillai <[email protected]>

Author: MarekPieta

doc/nrf/libraries/caf/ble_adv.rst

@@ -19,6 +19,7 @@ The following Kconfig options are available for this module:
 
 * :kconfig:option:`CONFIG_CAF_BLE_ADV`
 * :kconfig:option:`CONFIG_CAF_BLE_ADV_PM_EVENTS`
+* :kconfig:option:`CONFIG_CAF_BLE_ADV_POWER_DOWN_ON_DISCONNECTION_REASON_0X15`
 * :kconfig:option:`CONFIG_CAF_BLE_ADV_DIRECT_ADV`
 * :kconfig:option:`CONFIG_CAF_BLE_ADV_FAST_ADV`
 * :kconfig:option:`CONFIG_CAF_BLE_ADV_FAST_ADV_TIMEOUT`
@@ -98,6 +99,17 @@ This is done to ensure that the user does not try to connect to the device that
 
    The :kconfig:option:`CONFIG_CAF_BLE_ADV_GRACE_PERIOD` is enabled by default if the Swift Pair advertising data provider is enabled in the configuration.
 
+Force power down on bonded peer power off
+-----------------------------------------
+
+You can use the :kconfig:option:`CONFIG_CAF_BLE_ADV_POWER_DOWN_ON_DISCONNECTION_REASON_0X15` Kconfig option to force power down when a bonded peer disconnects with reason ``0x15`` (Remote Device Terminated due to Power Off).
+On a Bluetooth LE peer event (:c:struct:`ble_peer_event`) reporting :c:enumerator:`PEER_STATE_DISCONNECTED` (:c:member:`ble_peer_event.state`) with reason ``0x15`` (:c:member:`ble_peer_event.reason`), the module performs the following:
+
+ * Instantly stops Bluetooth LE advertising (the module enters power down state).
+ * Submits a force power down event (:c:struct:`force_power_down_event`).
+
+You can use this feature to prevent a bonded peer from waking up until activity on the peripheral is detected.
+
 Implementation details
 **********************
 
@@ -127,7 +139,7 @@ The Bluetooth LE bond module broadcasts information related to bond control usin
 The |ble_adv| reacts on :c:struct:`ble_peer_operation_event` related to the Bluetooth peer change or erase advertising.
 The module performs one of the following operations:
 
-* If there is a peer connected over Bluetooth, the |ble_adv| triggers disconnection and submits a :c:struct:`ble_peer_event` with :c:member:`ble_peer_event.state` set to :c:enum:`PEER_STATE_DISCONNECTING` to let other application modules prepare for the planned disconnection.
+* If there is a peer connected over Bluetooth, the |ble_adv| triggers disconnection and submits a :c:struct:`ble_peer_event` with :c:member:`ble_peer_event.state` set to :c:enumerator:`PEER_STATE_DISCONNECTING` to let other application modules prepare for the planned disconnection.
 * Otherwise, the Bluetooth advertising with the newly selected Bluetooth local identity is started.
 
 Avoiding connection requests from unbonded centrals when bonded

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -1014,6 +1014,11 @@ Common Application Framework (CAF)
   * Added :c:member:`ble_peer_event.reason` to inform about reason code related to state of the Bluetooth LE peer.
     The field is used to propagate information about error code related to a connection establishment failure and disconnection reason.
 
+* :ref:`caf_ble_adv`:
+
+  * Added the :kconfig:option:`CONFIG_CAF_BLE_ADV_POWER_DOWN_ON_DISCONNECTION_REASON_0X15` Kconfig option.
+    You can use this option to force system power down when a bonded peer disconnects with reason ``0x15`` (Remote Device Terminated due to Power Off).
+
 Shell libraries
 ---------------
 

subsys/caf/modules/Kconfig.ble_adv

@@ -18,6 +18,15 @@ config CAF_BLE_ADV_PM_EVENTS
 	depends on CAF_PM_EVENTS
 	default y
 
+config CAF_BLE_ADV_POWER_DOWN_ON_DISCONNECTION_REASON_0X15
+	bool "Force power down on disconnection with reason 0x15"
+	depends on CAF_BLE_ADV_PM_EVENTS
+	select CAF_FORCE_POWER_DOWN_EVENTS
+	help
+	  Force power down when a bonded peer disconnects with reason 0x15
+	  (Remote Device Terminated due to Power Off). The module instantly
+	  stops Bluetooth LE advertising and submits a force_power_down event.
+
 config CAF_BLE_ADV_DIRECT_ADV
 	bool "Advertise to bonded peer directly"
 	depends on SETTINGS

subsys/caf/modules/ble_adv.c

@@ -17,6 +17,7 @@
 #define MODULE ble_adv
 #include <caf/events/module_state_event.h>
 #include <caf/events/ble_common_event.h>
+#include <caf/events/force_power_down_event.h>
 #include <caf/events/power_event.h>
 
 #include <zephyr/logging/log.h>
@@ -876,6 +877,22 @@ static bool handle_ble_peer_event(const struct ble_peer_event *event)
 		break;
 
 	case PEER_STATE_DISCONNECTED:
+		if (IS_ENABLED(CONFIG_CAF_BLE_ADV_POWER_DOWN_ON_DISCONNECTION_REASON_0X15)) {
+			bt_addr_le_t addr;
+
+			bond_addr_get(cur_identity, &addr);
+			/* Check if disconnected peer was bonded. */
+			if (bt_addr_le_cmp(&addr, BT_ADDR_LE_ANY) &&
+			    !bt_addr_le_cmp(&addr, bt_conn_get_dst(event->id))) {
+				if ((event->reason == BT_HCI_ERR_REMOTE_POWER_OFF) &&
+				    (state != STATE_OFF)) {
+					LOG_INF("Bonded peer power off, force system power down");
+					update_state(STATE_OFF);
+					force_power_down();
+				}
+			}
+		}
+
 		if (state != STATE_OFF) {
 			req_new_adv_session = true;
 			req_fast_adv = true;