applications: nrf_desktop: Add BLE advertising control module

Change adds a small application module that suspends BLE advertising
while USB HID is active.

Jira: NCSDK-24220

Signed-off-by: Marek Pieta <[email protected]>
Signed-off-by: Aleksander Strzebonski <[email protected]>

Author: MarekPieta

applications/nrf_desktop/src/modules/CMakeLists.txt

@@ -4,6 +4,9 @@
 # SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
 #
 
+target_sources_ifdef(CONFIG_DESKTOP_BLE_ADV_CTRL_ENABLE
+		     app PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/ble_adv_ctrl.c)
+
 target_sources_ifdef(CONFIG_DESKTOP_BLE_BOND_ENABLE
 		     app PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/ble_bond.c)
 

applications/nrf_desktop/src/modules/Kconfig

@@ -25,6 +25,7 @@ rsource "Kconfig.hid_state"
 rsource "Kconfig.led_state"
 rsource "Kconfig.led_stream"
 rsource "Kconfig.usb_state"
+rsource "Kconfig.ble_adv_ctrl"
 rsource "Kconfig.ble_bond"
 rsource "Kconfig.ble_conn_params"
 rsource "Kconfig.ble_latency"

applications/nrf_desktop/src/modules/Kconfig.ble_adv_ctrl

@@ -0,0 +1,27 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+menuconfig DESKTOP_BLE_ADV_CTRL_ENABLE
+	bool "Bluetooth LE advertising control module"
+	depends on CAF_BLE_ADV
+	select CAF_MODULE_SUSPEND_EVENTS
+	help
+	  The module controls suspend/resume of CAF Bluetooth LE advertising
+	  module.
+
+if DESKTOP_BLE_ADV_CTRL_ENABLE
+
+config DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB
+	bool "Suspend Bluetooth LE adverising when USB is connected"
+	depends on DESKTOP_USB_ENABLE
+	help
+	  Suspend CAF Bluetooth LE advertising module while HID USB is active.
+
+module = DESKTOP_BLE_ADV_CTRL
+module-str = BLE advertising control
+source "subsys/logging/Kconfig.template.log_config"
+
+endif # DESKTOP_BLE_ADV_CTRL_ENABLE

applications/nrf_desktop/src/modules/ble_adv_ctrl.c

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+#define MODULE ble_adv_ctrl
+#include <caf/events/module_state_event.h>
+#include <caf/events/module_suspend_event.h>
+#include "usb_event.h"
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(MODULE, CONFIG_DESKTOP_BLE_ADV_CTRL_LOG_LEVEL);
+
+
+static void broadcast_ble_adv_req(bool suspend)
+{
+	if (suspend) {
+		struct module_suspend_req_event *event = new_module_suspend_req_event();
+
+		event->sink_module_id = MODULE_ID(ble_adv);
+		event->src_module_id = MODULE_ID(MODULE);
+		APP_EVENT_SUBMIT(event);
+	} else {
+		struct module_resume_req_event *event = new_module_resume_req_event();
+
+		event->sink_module_id = MODULE_ID(ble_adv);
+		event->src_module_id = MODULE_ID(MODULE);
+		APP_EVENT_SUBMIT(event);
+	}
+}
+
+static bool handle_usb_state_event(const struct usb_state_event *event)
+{
+	static bool ble_adv_suspended;
+	bool new_ble_adv_suspended;
+
+	if (ble_adv_suspended) {
+		new_ble_adv_suspended = (event->state != USB_STATE_DISCONNECTED);
+	} else {
+		new_ble_adv_suspended = (event->state == USB_STATE_ACTIVE);
+	}
+
+	if (new_ble_adv_suspended != ble_adv_suspended) {
+		ble_adv_suspended = new_ble_adv_suspended;
+		broadcast_ble_adv_req(ble_adv_suspended);
+	}
+
+	return false;
+}
+
+static bool app_event_handler(const struct app_event_header *aeh)
+{
+	if (IS_ENABLED(CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB) &&
+	    is_usb_state_event(aeh)) {
+		return handle_usb_state_event(cast_usb_state_event(aeh));
+	}
+
+	/* If event is unhandled, unsubscribe. */
+	__ASSERT_NO_MSG(false);
+
+	return false;
+}
+
+APP_EVENT_LISTENER(MODULE, app_event_handler);
+#ifdef CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB
+APP_EVENT_SUBSCRIBE(MODULE, usb_state_event);
+#endif /* CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB */