applications: nrf_desktop: Disable advertising when connected via USB

applications/nrf_desktop/configuration/nrf54h20dk_nrf54h20_cpuapp/prj.conf

@@ -37,6 +37,11 @@ CONFIG_DESKTOP_USB_ENABLE=y
 # Enable the only USB stack that supports USBHS
 CONFIG_DESKTOP_USB_STACK_NEXT=y
 
+# Suspend Bluetooth advertising when USB is connected to improve
+# USBHS report rate.
+CONFIG_DESKTOP_BLE_ADV_CTRL_ENABLE=y
+CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB=y
+
 CONFIG_DESKTOP_DFU_MCUMGR_ENABLE=y
 CONFIG_CAF_INIT_LOG_BLE_SMP_TRANSFER_EVENTS=n
 

applications/nrf_desktop/configuration/nrf54h20dk_nrf54h20_cpuapp/prj_release.conf

@@ -32,6 +32,11 @@ CONFIG_DESKTOP_USB_ENABLE=y
 # Enable the only USB stack that supports USBHS
 CONFIG_DESKTOP_USB_STACK_NEXT=y
 
+# Suspend Bluetooth advertising when USB is connected to improve
+# USBHS report rate.
+CONFIG_DESKTOP_BLE_ADV_CTRL_ENABLE=y
+CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB=y
+
 CONFIG_DESKTOP_DFU_MCUMGR_ENABLE=y
 
 # The LLPM must be explicitly enabled, as the Bluetooth Controller

applications/nrf_desktop/configuration/nrf54lm20pdk_nrf54lm20a_cpuapp/prj.conf

@@ -45,6 +45,11 @@ CONFIG_DESKTOP_USB_ENABLE=y
 # Enable the only USB stack that supports USBHS
 CONFIG_DESKTOP_USB_STACK_NEXT=y
 
+# Suspend Bluetooth advertising when USB is connected to improve
+# USBHS report rate.
+CONFIG_DESKTOP_BLE_ADV_CTRL_ENABLE=y
+CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB=y
+
 CONFIG_DESKTOP_BLE_USE_DEFAULT_ID=y
 
 CONFIG_DESKTOP_BLE_PEER_CONTROL=y

applications/nrf_desktop/configuration/nrf54lm20pdk_nrf54lm20a_cpuapp/prj_release.conf

@@ -40,6 +40,11 @@ CONFIG_DESKTOP_USB_ENABLE=y
 # Enable the only USB stack that supports USBHS
 CONFIG_DESKTOP_USB_STACK_NEXT=y
 
+# Suspend Bluetooth advertising when USB is connected to improve
+# USBHS report rate.
+CONFIG_DESKTOP_BLE_ADV_CTRL_ENABLE=y
+CONFIG_DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB=y
+
 CONFIG_DESKTOP_BLE_PEER_CONTROL=y
 CONFIG_DESKTOP_BLE_PEER_CONTROL_BUTTON=0x0000
 CONFIG_DESKTOP_BLE_PEER_ERASE_ON_START=y

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

@@ -15,6 +15,7 @@ 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) 2024 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/Kconfig.usb_state

@@ -57,6 +57,18 @@ config DESKTOP_USB_PM_REQ_NO_PM_LATENCY
 	  latency and ensures high performance. While USB is active, application
 	  power down is blocked anyway.
 
+config DESKTOP_USB_PM_RESTRICT_REMOVE_DELAY_MS
+	int "Delay in milliseconds before removing power manager level restriction"
+	range 0 10000
+	default 3000 if DESKTOP_BLE_ADV_CTRL_SUSPEND_ON_USB
+	default 0
+	depends on DESKTOP_USB_PM_ENABLE
+	help
+	  Delay in milliseconds before removing power manager level restriction.
+	  This is used to allow the USB to be disconnected without immediate system off.
+	  It allows user to take actions, like e.g. restart advertising, after disconnecting
+	  the USB cable without going through reboot.
+
 config DESKTOP_USB_HID_REPORT_SENT_ON_SOF
 	bool "Submit HID report sent event on USB Start of Frame (SOF) [EXPERIMENTAL]"
 	default y if UDC_DRIVER_HAS_HIGH_SPEED_SUPPORT

applications/nrf_desktop/src/modules/ble_adv_ctrl.c

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2024 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 bool ble_adv_suspended;
+
+
+static void broadcast_ble_adv_req(bool suspend)
+{
+	if (suspend) {
+		struct module_suspend_req_event *event = new_module_suspend_req_event();
+
+		event->module_id = MODULE_ID(ble_adv);
+		APP_EVENT_SUBMIT(event);
+	} else {
+		struct module_resume_req_event *event = new_module_resume_req_event();
+
+		event->module_id = MODULE_ID(ble_adv);
+		APP_EVENT_SUBMIT(event);
+	}
+}
+
+static bool handle_module_state_event(const struct module_state_event *event)
+{
+	return false;
+}
+
+static bool handle_usb_state_event(const struct usb_state_event *event)
+{
+	bool 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_module_state_event(aeh)) {
+		return handle_module_state_event(cast_module_state_event(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);
+APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
+#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 */

applications/nrf_desktop/src/modules/usb_state_pm.c

@@ -19,6 +19,14 @@ LOG_MODULE_REGISTER(MODULE, CONFIG_DESKTOP_USB_STATE_LOG_LEVEL);
 #include <caf/events/force_power_down_event.h>
 
 
+static bool initialized;
+static struct k_work_delayable pm_restrict_remove_work;
+
+static void pm_restrict_remove_work_fn(struct k_work *work)
+{
+	power_manager_restrict(MODULE_IDX(MODULE), POWER_MANAGER_LEVEL_MAX);
+}
+
 static void update_pm_policy_latency_req(bool enable)
 {
 	static bool enabled;
@@ -45,11 +53,17 @@ static bool app_event_handler(const struct app_event_header *aeh)
 		const struct usb_state_event *event = cast_usb_state_event(aeh);
 
 		LOG_DBG("USB state change detected");
+		__ASSERT_NO_MSG(initialized);
 
 		if (IS_ENABLED(CONFIG_DESKTOP_USB_PM_REQ_NO_PM_LATENCY)) {
 			update_pm_policy_latency_req(event->state == USB_STATE_ACTIVE);
 		}
 
+		if (CONFIG_DESKTOP_USB_PM_RESTRICT_REMOVE_DELAY_MS) {
+			/* Cancel the work if it is scheduled. */
+			k_work_cancel_delayable(&pm_restrict_remove_work);
+		}
+
 		switch (event->state) {
 		case USB_STATE_POWERED:
 			power_manager_restrict(MODULE_IDX(MODULE), POWER_MANAGER_LEVEL_SUSPENDED);
@@ -58,7 +72,23 @@ static bool app_event_handler(const struct app_event_header *aeh)
 			power_manager_restrict(MODULE_IDX(MODULE), POWER_MANAGER_LEVEL_ALIVE);
 			break;
 		case USB_STATE_DISCONNECTED:
-			power_manager_restrict(MODULE_IDX(MODULE), POWER_MANAGER_LEVEL_MAX);
+			if (CONFIG_DESKTOP_USB_PM_RESTRICT_REMOVE_DELAY_MS) {
+				/* Remove the restriction after the delay to allow the user to
+				 * take actions like e.g. restart advertising without going
+				 * through system off.
+				 */
+				k_work_schedule(
+					&pm_restrict_remove_work,
+					K_MSEC(CONFIG_DESKTOP_USB_PM_RESTRICT_REMOVE_DELAY_MS));
+			} else {
+				power_manager_restrict(MODULE_IDX(MODULE), POWER_MANAGER_LEVEL_MAX);
+			}
+			/* When disconnecting USB cable, the USB_STATE_SUSPENDED event may
+			 * or may not appear before the USB_STATE_DISCONNECTED event. Force power
+			 * down for application to behave consistently even if the
+			 * USB_STATE_SUSPENDED event doesn't appear.
+			 */
+			force_power_down();
 			break;
 		case USB_STATE_SUSPENDED:
 			LOG_DBG("USB suspended");
@@ -76,9 +106,11 @@ static bool app_event_handler(const struct app_event_header *aeh)
 		const struct module_state_event *event = cast_module_state_event(aeh);
 
 		if (check_state(event, MODULE_ID(main), MODULE_STATE_READY)) {
-			static bool initialized;
-
 			__ASSERT_NO_MSG(!initialized);
+			if (CONFIG_DESKTOP_USB_PM_RESTRICT_REMOVE_DELAY_MS) {
+				k_work_init_delayable(&pm_restrict_remove_work,
+						      pm_restrict_remove_work_fn);
+			}
 			initialized = true;
 		}
 		return false;

include/caf/events/module_state_event.h

@@ -202,6 +202,11 @@ enum module_state {
 	 */
 	MODULE_STATE_STANDBY,
 
+	/** Module is suspended in reaction to @ref module_suspend_req_event. The module is resumed
+	 *  by @ref module_resume_req_event.
+	 */
+	MODULE_STATE_SUSPENDED,
+
 	/** Module reported fatal error. */
 	MODULE_STATE_ERROR,
 

include/caf/events/module_suspend_event.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+#ifndef _MODULE_SUSPEND_EVENT_H_
+#define _MODULE_SUSPEND_EVENT_H_
+
+/**
+ * @file
+ * @defgroup caf_module_suspend_event CAF Module Suspend Event
+ * @{
+ * @brief CAF Module Suspend Event.
+ */
+
+
+#include <zephyr/sys/atomic.h>
+#include <app_event_manager.h>
+#include <app_event_manager_profiler_tracer.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct module_suspend_req_event {
+	/** Event header. */
+	struct app_event_header header;
+
+	/** ID of the module. */
+	const void *module_id;
+};
+
+APP_EVENT_TYPE_DECLARE(module_suspend_req_event);
+
+struct module_resume_req_event {
+	/** Event header. */
+	struct app_event_header header;
+
+	/** ID of the module. */
+	const void *module_id;
+};
+
+APP_EVENT_TYPE_DECLARE(module_resume_req_event);
+
+#endif /* _MODULE_SUSPEND_EVENT_H_ */

subsys/caf/events/CMakeLists.txt

@@ -8,6 +8,10 @@ zephyr_sources_ifdef(CONFIG_CAF_MODULE_STATE_EVENTS
 	module_state_event.c
 )
 
+zephyr_sources_ifdef(CONFIG_CAF_MODULE_SUSPEND_EVENTS
+	module_suspend_event.c
+)
+
 zephyr_sources_ifdef(CONFIG_CAF_PM_EVENTS
 	power_event.c
 )

subsys/caf/events/Kconfig

@@ -137,6 +137,7 @@ rsource "Kconfig.factory_reset_event"
 rsource "Kconfig.force_power_down_event"
 rsource "Kconfig.keep_alive_event"
 rsource "Kconfig.module_state_event"
+rsource "Kconfig.module_suspend_event"
 rsource "Kconfig.power_manager_event"
 rsource "Kconfig.sensor_event"
 

subsys/caf/events/Kconfig.module_suspend_event

@@ -0,0 +1,17 @@
+#
+# Copyright (c) 2024 Nordic Semiconductor
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+config CAF_MODULE_SUSPEND_EVENTS
+	bool "Enable module suspend/resume request events"
+	depends on CAF_MODULE_STATE_EVENTS
+	help
+	  Enable support for module suspend/resume request events.
+
+config CAF_INIT_LOG_MODULE_SUSPEND_EVENTS
+	bool "Log module suspend/resume request events"
+	depends on CAF_MODULE_SUSPEND_EVENTS
+	depends on LOG
+	default y

subsys/caf/events/module_state_event.c

@@ -15,6 +15,7 @@ static const char * const state_name[] = {
 	[MODULE_STATE_READY] = "READY",
 	[MODULE_STATE_OFF] = "OFF",
 	[MODULE_STATE_STANDBY] = "STANDBY",
+	[MODULE_STATE_SUSPENDED] = "SUSPENDED",
 	[MODULE_STATE_ERROR] = "ERROR",
 };