feat(usb): 引入统一的USB状态事件系统

重构USB事件管理，将原有的多个专用事件（usb_device_state_event、
usb_function_ready_event、usb_prepare_event）合并为统一的
usb_state_event。新的事件系统采用位标志方式管理USB状态，
提供更灵活的状态跟踪机制。

BREAKING CHANGE: 移除了旧的USB相关事件类型，需要更新依赖这些
事件的模块代码。

CMakeLists.txt

@@ -61,7 +61,5 @@ target_sources(app PRIVATE
   src/events/time_sync_event.c
   src/events/usb_cdc_rx_event.c
   src/events/usb_cdc_tx_event.c
-  src/events/usb_device_state_event.c
+  src/events/usb_state_event.c
-  src/events/usb_function_ready_event.c
-  src/events/usb_prepare_event.c
 )

inc/events/usb_device_state_event.h

@@ -1,32 +0,0 @@
-#ifndef BLINKY_USB_DEVICE_STATE_EVENT_H_
-#define BLINKY_USB_DEVICE_STATE_EVENT_H_
-
-#include <app_event_manager.h>
-#include <app_event_manager_profiler_tracer.h>
-
-#include "usb_device_module.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-struct usb_device_state_event {
-	struct app_event_header header;
-	enum usb_device_state state;
-};
-
-APP_EVENT_TYPE_DECLARE(usb_device_state_event);
-
-static inline void submit_usb_device_state_event(enum usb_device_state state)
-{
-	struct usb_device_state_event *event = new_usb_device_state_event();
-
-	event->state = state;
-	APP_EVENT_SUBMIT(event);
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* BLINKY_USB_DEVICE_STATE_EVENT_H_ */

inc/events/usb_function_ready_event.h

@@ -1,32 +0,0 @@
-#ifndef BLINKY_USB_FUNCTION_READY_EVENT_H_
-#define BLINKY_USB_FUNCTION_READY_EVENT_H_
-
-#include <app_event_manager.h>
-#include <app_event_manager_profiler_tracer.h>
-
-#include "usb_device_module.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-struct usb_function_ready_event {
-	struct app_event_header header;
-	uint8_t function_mask;
-};
-
-APP_EVENT_TYPE_DECLARE(usb_function_ready_event);
-
-static inline void submit_usb_function_ready_event(uint8_t function_mask)
-{
-	struct usb_function_ready_event *event = new_usb_function_ready_event();
-
-	event->function_mask = function_mask;
-	APP_EVENT_SUBMIT(event);
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* BLINKY_USB_FUNCTION_READY_EVENT_H_ */

inc/events/usb_prepare_event.h

@@ -1,26 +0,0 @@
-#ifndef BLINKY_USB_PREPARE_EVENT_H_
-#define BLINKY_USB_PREPARE_EVENT_H_
-
-#include <app_event_manager.h>
-#include <app_event_manager_profiler_tracer.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-struct usb_prepare_event {
-	struct app_event_header header;
-};
-
-APP_EVENT_TYPE_DECLARE(usb_prepare_event);
-
-static inline void submit_usb_prepare_event(void)
-{
-	APP_EVENT_SUBMIT(new_usb_prepare_event());
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* BLINKY_USB_PREPARE_EVENT_H_ */

inc/events/usb_state_event.h

@@ -0,0 +1,82 @@
+#ifndef BLINKY_USB_STATE_EVENT_H_
+#define BLINKY_USB_STATE_EVENT_H_
+
+#include <stdint.h>
+
+#include <app_event_manager.h>
+#include <app_event_manager_profiler_tracer.h>
+#include <zephyr/sys/util.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum usb_state_event_op {
+	USB_STATE_EVENT_OP_SET_BITS,
+	USB_STATE_EVENT_OP_CLEAR_BITS,
+	USB_STATE_EVENT_OP_SNAPSHOT,
+};
+
+enum usb_state_flag {
+	USB_STATEF_PREPARE = BIT(0),
+	USB_STATEF_HID_READY = BIT(1),
+	USB_STATEF_CDC_READY = BIT(2),
+	USB_STATEF_STACK_READY = BIT(3),
+	USB_STATEF_POWERED = BIT(4),
+	USB_STATEF_ACTIVE = BIT(5),
+	USB_STATEF_SUSPENDED = BIT(6),
+	USB_STATEF_STACK_RUNNING = BIT(31),
+};
+
+struct usb_state_event {
+	struct app_event_header header;
+	const void *src_module_id;
+	const void *sink_module_id;
+	uint8_t op;
+	uint32_t flags;
+};
+
+APP_EVENT_TYPE_DECLARE(usb_state_event);
+
+static inline void submit_usb_state_event(const void *src_module_id,
+					  const void *sink_module_id,
+					  uint8_t op,
+					  uint32_t flags)
+{
+	struct usb_state_event *event = new_usb_state_event();
+
+	event->src_module_id = src_module_id;
+	event->sink_module_id = sink_module_id;
+	event->op = op;
+	event->flags = flags;
+	APP_EVENT_SUBMIT(event);
+}
+
+static inline void submit_usb_state_set(const void *src_module_id,
+					const void *sink_module_id,
+					uint32_t flags)
+{
+	submit_usb_state_event(src_module_id, sink_module_id,
+			       USB_STATE_EVENT_OP_SET_BITS, flags);
+}
+
+static inline void submit_usb_state_clear(const void *src_module_id,
+					  const void *sink_module_id,
+					  uint32_t flags)
+{
+	submit_usb_state_event(src_module_id, sink_module_id,
+			       USB_STATE_EVENT_OP_CLEAR_BITS, flags);
+}
+
+static inline void submit_usb_state_snapshot(const void *src_module_id,
+					     uint32_t flags)
+{
+	submit_usb_state_event(src_module_id, NULL,
+			       USB_STATE_EVENT_OP_SNAPSHOT, flags);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_USB_STATE_EVENT_H_ */

src/events/usb_device_state_event.c

@@ -1,46 +0,0 @@
-#include "usb_device_state_event.h"
-
-static const char *usb_device_state_name(enum usb_device_state state)
-{
-	switch (state) {
-	case USB_DEVICE_STATE_DISCONNECTED:
-		return "disconnected";
-	case USB_DEVICE_STATE_POWERED:
-		return "powered";
-	case USB_DEVICE_STATE_ACTIVE:
-		return "active";
-	case USB_DEVICE_STATE_SUSPENDED:
-		return "suspended";
-	default:
-		return "?";
-	}
-}
-
-static void log_usb_device_state_event(const struct app_event_header *aeh)
-{
-	const struct usb_device_state_event *event =
-		cast_usb_device_state_event(aeh);
-
-	APP_EVENT_MANAGER_LOG(aeh, "state:%s",
-			      usb_device_state_name(event->state));
-}
-
-static void profile_usb_device_state_event(struct log_event_buf *buf,
-					   const struct app_event_header *aeh)
-{
-	const struct usb_device_state_event *event =
-		cast_usb_device_state_event(aeh);
-
-	nrf_profiler_log_encode_uint8(buf, event->state);
-}
-
-APP_EVENT_INFO_DEFINE(usb_device_state_event,
-		      ENCODE(NRF_PROFILER_ARG_U8),
-		      ENCODE("state"),
-		      profile_usb_device_state_event);
-
-APP_EVENT_TYPE_DEFINE(usb_device_state_event,
-		      log_usb_device_state_event,
-		      &usb_device_state_event_info,
-		      APP_EVENT_FLAGS_CREATE(
-			      APP_EVENT_TYPE_FLAGS_INIT_LOG_ENABLE));

src/events/usb_function_ready_event.c

@@ -1,42 +0,0 @@
-#include "usb_function_ready_event.h"
-
-static const char *usb_function_name(uint8_t function_mask)
-{
-	switch (function_mask) {
-	case USB_FUNCTION_HID:
-		return "hid";
-	case USB_FUNCTION_CDC_ACM:
-		return "cdc_acm";
-	default:
-		return "?";
-	}
-}
-
-static void log_usb_function_ready_event(const struct app_event_header *aeh)
-{
-	const struct usb_function_ready_event *event =
-		cast_usb_function_ready_event(aeh);
-
-	APP_EVENT_MANAGER_LOG(aeh, "function:%s",
-			      usb_function_name(event->function_mask));
-}
-
-static void profile_usb_function_ready_event(struct log_event_buf *buf,
-					     const struct app_event_header *aeh)
-{
-	const struct usb_function_ready_event *event =
-		cast_usb_function_ready_event(aeh);
-
-	nrf_profiler_log_encode_uint8(buf, event->function_mask);
-}
-
-APP_EVENT_INFO_DEFINE(usb_function_ready_event,
-		      ENCODE(NRF_PROFILER_ARG_U8),
-		      ENCODE("function_mask"),
-		      profile_usb_function_ready_event);
-
-APP_EVENT_TYPE_DEFINE(usb_function_ready_event,
-		      log_usb_function_ready_event,
-		      &usb_function_ready_event_info,
-		      APP_EVENT_FLAGS_CREATE(
-			      APP_EVENT_TYPE_FLAGS_INIT_LOG_ENABLE));

src/events/usb_prepare_event.c

@@ -1,24 +0,0 @@
-#include "usb_prepare_event.h"
-
-static void log_usb_prepare_event(const struct app_event_header *aeh)
-{
-	APP_EVENT_MANAGER_LOG(aeh, "prepare");
-}
-
-static void profile_usb_prepare_event(struct log_event_buf *buf,
-				      const struct app_event_header *aeh)
-{
-	ARG_UNUSED(buf);
-	ARG_UNUSED(aeh);
-}
-
-APP_EVENT_INFO_DEFINE(usb_prepare_event,
-		      ENCODE(),
-		      ENCODE(),
-		      profile_usb_prepare_event);
-
-APP_EVENT_TYPE_DEFINE(usb_prepare_event,
-		      log_usb_prepare_event,
-		      &usb_prepare_event_info,
-		      APP_EVENT_FLAGS_CREATE(
-			      APP_EVENT_TYPE_FLAGS_INIT_LOG_ENABLE));

src/events/usb_state_event.c

@@ -0,0 +1,54 @@
+#include <caf/events/module_state_event.h>
+
+#include "usb_state_event.h"
+
+static const char *usb_state_event_op_name(uint8_t op)
+{
+	switch ((enum usb_state_event_op)op) {
+	case USB_STATE_EVENT_OP_SET_BITS:
+		return "set_bits";
+	case USB_STATE_EVENT_OP_CLEAR_BITS:
+		return "clear_bits";
+	case USB_STATE_EVENT_OP_SNAPSHOT:
+		return "snapshot";
+	default:
+		return "?";
+	}
+}
+
+static const char *module_name_or_any(const void *module_id)
+{
+	return (module_id != NULL) ? module_name_get(module_id) : "*";
+}
+
+static void log_usb_state_event(const struct app_event_header *aeh)
+{
+	const struct usb_state_event *event = cast_usb_state_event(aeh);
+
+	APP_EVENT_MANAGER_LOG(aeh,
+			      "src:%s sink:%s op:%s flags:0x%08x",
+			      module_name_or_any(event->src_module_id),
+			      module_name_or_any(event->sink_module_id),
+			      usb_state_event_op_name(event->op),
+			      event->flags);
+}
+
+static void profile_usb_state_event(struct log_event_buf *buf,
+				    const struct app_event_header *aeh)
+{
+	const struct usb_state_event *event = cast_usb_state_event(aeh);
+
+	nrf_profiler_log_encode_uint8(buf, event->op);
+	nrf_profiler_log_encode_uint32(buf, event->flags);
+}
+
+APP_EVENT_INFO_DEFINE(usb_state_event,
+		      ENCODE(NRF_PROFILER_ARG_U8, NRF_PROFILER_ARG_U32),
+		      ENCODE("op", "flags"),
+		      profile_usb_state_event);
+
+APP_EVENT_TYPE_DEFINE(usb_state_event,
+		      log_usb_state_event,
+		      &usb_state_event_info,
+		      APP_EVENT_FLAGS_CREATE(
+			      APP_EVENT_TYPE_FLAGS_INIT_LOG_ENABLE));

src/protocol_module.c

@@ -25,7 +25,7 @@
 #include "hid_led_event.h"
 #include "key_function_event.h"
 #include "protocol_module.h"
-#include "usb_device_state_event.h"
+#include "usb_state_event.h"
 
 LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
 
@@ -430,9 +430,14 @@ static bool handle_hid_led_event(const struct hid_led_event *event)
 	return false;
 }
 
-static bool handle_usb_device_state_event(const struct usb_device_state_event *event)
+static bool handle_usb_state_event(const struct usb_state_event *event)
 {
-	usb_active = (event->state == USB_DEVICE_STATE_ACTIVE);
+	if ((event->op != USB_STATE_EVENT_OP_SNAPSHOT) ||
+	    (event->src_module_id != MODULE_ID(usb_device_module))) {
+		return false;
+	}
+
+	usb_active = (event->flags & USB_STATEF_ACTIVE) != 0U;
 	if (!usb_active) {
 		hello_done = false;
 	}
@@ -450,8 +455,8 @@ static bool app_event_handler(const struct app_event_header *aeh)
 		return handle_hid_led_event(cast_hid_led_event(aeh));
 	}
 
-	if (is_usb_device_state_event(aeh)) {
+	if (is_usb_state_event(aeh)) {
-		return handle_usb_device_state_event(cast_usb_device_state_event(aeh));
+		return handle_usb_state_event(cast_usb_state_event(aeh));
 	}
 
 	if (is_module_state_event(aeh)) {
@@ -517,6 +522,6 @@ APP_EVENT_LISTENER(MODULE, app_event_handler);
 APP_EVENT_SUBSCRIBE(MODULE, hid_led_event);
 APP_EVENT_SUBSCRIBE(MODULE, key_function_event);
 APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
-APP_EVENT_SUBSCRIBE(MODULE, usb_device_state_event);
+APP_EVENT_SUBSCRIBE(MODULE, usb_state_event);
 APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
 APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);

src/usb_cdc_module.c

@@ -18,10 +18,7 @@
 
 #include "usb_cdc_rx_event.h"
 #include "usb_cdc_tx_event.h"
-#include "usb_function_ready_event.h"
+#include "usb_state_event.h"
-#include "usb_prepare_event.h"
-#include "usb_device_module.h"
-#include "usb_device_state_event.h"
 
 LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
 
@@ -46,6 +43,13 @@ static bool usb_function_prepared;
 static bool dtr_ready;
 static bool rx_enabled;
 
+static bool is_usb_owner_snapshot(const struct usb_state_event *event)
+{
+	return (event->op == USB_STATE_EVENT_OP_SNAPSHOT) &&
+	       (event->src_module_id == MODULE_ID(usb_device_module)) &&
+	       (event->sink_module_id == NULL);
+}
+
 static void reset_ring_buffers(void)
 {
 	unsigned int key = irq_lock();
@@ -276,22 +280,21 @@ static void module_pause(void)
 	running = false;
 }
 
-static bool handle_usb_prepare_event(const struct usb_prepare_event *event)
+static bool handle_usb_state_event(const struct usb_state_event *event)
 {
-	ARG_UNUSED(event);
+	if (!is_usb_owner_snapshot(event)) {
-
-	if (!running || usb_function_prepared) {
 		return false;
 	}
 
+	if (running && !usb_function_prepared &&
+	    ((event->flags & USB_STATEF_PREPARE) != 0U)) {
 		usb_function_prepared = true;
-	submit_usb_function_ready_event(USB_FUNCTION_CDC_ACM);
+		submit_usb_state_set(MODULE_ID(MODULE),
-	return false;
+				     MODULE_ID(usb_device_module),
-}
+				     USB_STATEF_CDC_READY);
+	}
 
-static bool handle_usb_device_state_event(const struct usb_device_state_event *event)
+	bool new_usb_active = (event->flags & USB_STATEF_ACTIVE) != 0U;
-{
-	bool new_usb_active = (event->state == USB_DEVICE_STATE_ACTIVE);
 
 	if (new_usb_active == usb_active) {
 		return false;
@@ -336,12 +339,8 @@ static bool handle_usb_cdc_tx_event(const struct usb_cdc_tx_event *event)
 
 static bool app_event_handler(const struct app_event_header *aeh)
 {
-	if (is_usb_device_state_event(aeh)) {
+	if (is_usb_state_event(aeh)) {
-		return handle_usb_device_state_event(cast_usb_device_state_event(aeh));
+		return handle_usb_state_event(cast_usb_state_event(aeh));
-	}
-
-	if (is_usb_prepare_event(aeh)) {
-		return handle_usb_prepare_event(cast_usb_prepare_event(aeh));
 	}
 
 	if (is_usb_cdc_tx_event(aeh)) {
@@ -403,8 +402,7 @@ static bool app_event_handler(const struct app_event_header *aeh)
 
 APP_EVENT_LISTENER(MODULE, app_event_handler);
 APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
-APP_EVENT_SUBSCRIBE(MODULE, usb_prepare_event);
+APP_EVENT_SUBSCRIBE(MODULE, usb_state_event);
-APP_EVENT_SUBSCRIBE(MODULE, usb_device_state_event);
 APP_EVENT_SUBSCRIBE(MODULE, usb_cdc_tx_event);
 APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
 APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);

src/usb_device_module.c

@@ -13,10 +13,7 @@
 
 #include <caf/events/power_manager_event.h>
 
-#include "usb_device_module.h"
+#include "usb_state_event.h"
-#include "usb_device_state_event.h"
-#include "usb_function_ready_event.h"
-#include "usb_prepare_event.h"
 
 LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
 
@@ -24,7 +21,7 @@ LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
 #define USB_DEVICE_PID 0x52F0
 #define USB_DEVICE_MANUFACTURER "Atguigu"
 #define USB_DEVICE_PRODUCT "WH Mini Keyboard"
-#define USB_REQUIRED_FUNCTION_MASK (USB_FUNCTION_HID | USB_FUNCTION_CDC_ACM)
+#define USB_REQUIRED_READY_MASK (USB_STATEF_HID_READY | USB_STATEF_CDC_READY)
 
 USBD_DEVICE_DEFINE(blinky_usbd, DEVICE_DT_GET(DT_NODELABEL(usbd)),
 		   USB_DEVICE_VID, USB_DEVICE_PID);
@@ -42,20 +39,69 @@ static const char *const class_blocklist[] = {
 
 static bool initialized;
 static bool running;
-static bool prepare_broadcasted;
 static bool usbd_initialized;
 static bool usb_enabled;
-static uint8_t ready_function_mask;
+static uint32_t usb_state_flags;
-static enum usb_device_state device_state = USB_DEVICE_STATE_DISCONNECTED;
 
-static void update_usb_device_state(enum usb_device_state state)
+enum usb_runtime_state {
+	USB_RUNTIME_STATE_DISCONNECTED,
+	USB_RUNTIME_STATE_POWERED,
+	USB_RUNTIME_STATE_ACTIVE,
+	USB_RUNTIME_STATE_SUSPENDED,
+};
+
+static enum usb_runtime_state device_state = USB_RUNTIME_STATE_DISCONNECTED;
+
+static void broadcast_usb_state(void)
+{
+	submit_usb_state_snapshot(MODULE_ID(MODULE), usb_state_flags);
+}
+
+static void set_usb_state_flags(uint32_t mask)
+{
+	usb_state_flags |= mask;
+}
+
+static void clear_usb_state_flags(uint32_t mask)
+{
+	usb_state_flags &= ~mask;
+}
+
+static void update_usb_runtime_state(enum usb_runtime_state state)
 {
 	if (device_state == state) {
 		return;
 	}
 
 	device_state = state;
-	submit_usb_device_state_event(state);
+
+	switch (state) {
+	case USB_RUNTIME_STATE_DISCONNECTED:
+		clear_usb_state_flags(USB_STATEF_POWERED |
+				      USB_STATEF_ACTIVE |
+				      USB_STATEF_SUSPENDED);
+		break;
+
+	case USB_RUNTIME_STATE_POWERED:
+		set_usb_state_flags(USB_STATEF_POWERED);
+		clear_usb_state_flags(USB_STATEF_ACTIVE | USB_STATEF_SUSPENDED);
+		break;
+
+	case USB_RUNTIME_STATE_ACTIVE:
+		set_usb_state_flags(USB_STATEF_POWERED | USB_STATEF_ACTIVE);
+		clear_usb_state_flags(USB_STATEF_SUSPENDED);
+		break;
+
+	case USB_RUNTIME_STATE_SUSPENDED:
+		set_usb_state_flags(USB_STATEF_POWERED | USB_STATEF_SUSPENDED);
+		clear_usb_state_flags(USB_STATEF_ACTIVE);
+		break;
+
+	default:
+		break;
+	}
+
+	broadcast_usb_state();
 }
 
 static void update_power_manager_restriction(bool vbus_present)
@@ -114,7 +160,7 @@ static void usbd_msg_cb(struct usbd_context *const usbd_ctx,
 				LOG_ERR("usbd_enable failed (%d)", err);
 			} else {
 				usb_enabled = true;
-				update_usb_device_state(USB_DEVICE_STATE_POWERED);
+				update_usb_runtime_state(USB_RUNTIME_STATE_POWERED);
 			}
 		}
 		break;
@@ -130,26 +176,26 @@ static void usbd_msg_cb(struct usbd_context *const usbd_ctx,
 		}
 
 		usb_enabled = false;
-		update_usb_device_state(USB_DEVICE_STATE_DISCONNECTED);
+		update_usb_runtime_state(USB_RUNTIME_STATE_DISCONNECTED);
 		break;
 
 	case USBD_MSG_CONFIGURATION:
 		if (msg->status) {
-			update_usb_device_state(USB_DEVICE_STATE_ACTIVE);
+			update_usb_runtime_state(USB_RUNTIME_STATE_ACTIVE);
 		} else if (usb_enabled) {
-			update_usb_device_state(USB_DEVICE_STATE_POWERED);
+			update_usb_runtime_state(USB_RUNTIME_STATE_POWERED);
 		}
 		break;
 
 	case USBD_MSG_SUSPEND:
 		if (usb_enabled) {
-			update_usb_device_state(USB_DEVICE_STATE_SUSPENDED);
+			update_usb_runtime_state(USB_RUNTIME_STATE_SUSPENDED);
 		}
 		break;
 
 	case USBD_MSG_RESUME:
 		if (usb_enabled) {
-			update_usb_device_state(USB_DEVICE_STATE_ACTIVE);
+			update_usb_runtime_state(USB_RUNTIME_STATE_ACTIVE);
 		}
 		break;
 
@@ -181,6 +227,7 @@ static int usb_stack_init(void)
 	}
 
 	usbd_initialized = true;
+	set_usb_state_flags(USB_STATEF_STACK_READY);
 
 	if (!usbd_can_detect_vbus(&blinky_usbd)) {
 		err = usbd_enable(&blinky_usbd);
@@ -190,19 +237,33 @@ static int usb_stack_init(void)
 		}
 
 		usb_enabled = true;
-		update_usb_device_state(USB_DEVICE_STATE_POWERED);
+		update_usb_runtime_state(USB_RUNTIME_STATE_POWERED);
 	}
 
 	return 0;
 }
 
+static int try_start_usb_stack(void)
+{
+	if (usbd_initialized) {
+		return 0;
+	}
+
+	if ((usb_state_flags & USB_REQUIRED_READY_MASK) != USB_REQUIRED_READY_MASK) {
+		set_usb_state_flags(USB_STATEF_PREPARE);
+		return 0;
+	}
+
+	clear_usb_state_flags(USB_STATEF_PREPARE);
+	return usb_stack_init();
+}
+
 static int module_init(void)
 {
-	device_state = USB_DEVICE_STATE_DISCONNECTED;
+	device_state = USB_RUNTIME_STATE_DISCONNECTED;
 	usb_enabled = false;
-	ready_function_mask = 0U;
-	prepare_broadcasted = false;
 	usbd_initialized = false;
+	usb_state_flags = 0U;
 	update_power_manager_restriction(false);
 
 	return 0;
@@ -215,16 +276,12 @@ static int module_start(void)
 	}
 
 	running = true;
+	set_usb_state_flags(USB_STATEF_STACK_RUNNING);
 
-	if (usbd_initialized || prepare_broadcasted) {
+	int err = try_start_usb_stack();
-		return 0;
-	}
 
-	ready_function_mask = 0U;
+	broadcast_usb_state();
-	prepare_broadcasted = true;
+	return err;
-	submit_usb_prepare_event();
-
-	return 0;
 }
 
 static void module_pause(void)
@@ -234,6 +291,8 @@ static void module_pause(void)
 	}
 
 	running = false;
+	clear_usb_state_flags(USB_STATEF_STACK_RUNNING);
+	broadcast_usb_state();
 }
 
 static bool handle_module_state_event(const struct module_state_event *event)
@@ -266,28 +325,32 @@ static bool handle_module_state_event(const struct module_state_event *event)
 	return false;
 }
 
-static bool handle_usb_function_ready_event(const struct usb_function_ready_event *event)
+static bool handle_usb_state_event(const struct usb_state_event *event)
 {
-	int err;
+	if ((event->op == USB_STATE_EVENT_OP_SNAPSHOT) ||
-
+	    (event->sink_module_id != MODULE_ID(MODULE))) {
-	if (!running || !prepare_broadcasted || usbd_initialized) {
 		return false;
 	}
 
-	ready_function_mask |= event->function_mask;
+	if (event->op == USB_STATE_EVENT_OP_SET_BITS) {
-
+		usb_state_flags |= event->flags;
-	if ((ready_function_mask & USB_REQUIRED_FUNCTION_MASK) !=
+	} else if (event->op == USB_STATE_EVENT_OP_CLEAR_BITS) {
-	    USB_REQUIRED_FUNCTION_MASK) {
+		usb_state_flags &= ~event->flags;
+	} else {
 		return false;
 	}
 
-	err = usb_stack_init();
+	int err = running ? try_start_usb_stack() : 0;
 	if (err) {
 		module_set_state(MODULE_STATE_ERROR);
 		return false;
 	}
 
+	broadcast_usb_state();
+
+	if (usbd_initialized) {
 		module_set_state(MODULE_STATE_READY);
+	}
 	return false;
 }
 
@@ -297,8 +360,8 @@ static bool app_event_handler(const struct app_event_header *aeh)
 		return handle_module_state_event(cast_module_state_event(aeh));
 	}
 
-	if (is_usb_function_ready_event(aeh)) {
+	if (is_usb_state_event(aeh)) {
-		return handle_usb_function_ready_event(cast_usb_function_ready_event(aeh));
+		return handle_usb_state_event(cast_usb_state_event(aeh));
 	}
 
 	if (is_power_down_event(aeh)) {
@@ -329,6 +392,6 @@ static bool app_event_handler(const struct app_event_header *aeh)
 
 APP_EVENT_LISTENER(MODULE, app_event_handler);
 APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
-APP_EVENT_SUBSCRIBE(MODULE, usb_function_ready_event);
+APP_EVENT_SUBSCRIBE(MODULE, usb_state_event);
 APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
 APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);

src/usb_hid_module.c

@@ -21,10 +21,7 @@
 #include "hid_tx_report_event.h"
 #include "keyboard_core.h"
 #include "set_protocol_event.h"
-#include "usb_function_ready_event.h"
+#include "usb_state_event.h"
-#include "usb_prepare_event.h"
-#include "usb_device_module.h"
-#include "usb_device_state_event.h"
 
 LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
 
@@ -152,6 +149,13 @@ static void submit_usb_transport_state_event(void)
 		keyboard_protocol_mode);
 }
 
+static bool is_usb_owner_snapshot(const struct usb_state_event *event)
+{
+	return (event->op == USB_STATE_EVENT_OP_SNAPSHOT) &&
+	       (event->src_module_id == MODULE_ID(usb_device_module)) &&
+	       (event->sink_module_id == NULL);
+}
+
 static void keyboard_iface_ready(const struct device *dev, const bool ready)
 {
 	struct usb_hid_interface_state *iface = iface_from_dev(dev);
@@ -418,17 +422,16 @@ static void module_pause(void)
 	submit_usb_transport_state_event();
 }
 
-static bool handle_usb_prepare_event(const struct usb_prepare_event *event)
+static bool handle_usb_state_event(const struct usb_state_event *event)
 {
-	int err;
+	if (!is_usb_owner_snapshot(event)) {
-
-	ARG_UNUSED(event);
-
-	if (!running || usb_function_prepared) {
 		return false;
 	}
 
-	err = usb_hid_register_devices();
+	if (running && !usb_function_prepared &&
+	    ((event->flags & USB_STATEF_PREPARE) != 0U)) {
+		int err = usb_hid_register_devices();
+
 		if (err) {
 			LOG_ERR("hid_device_register failed (%d)", err);
 			module_set_state(MODULE_STATE_ERROR);
@@ -436,13 +439,12 @@ static bool handle_usb_prepare_event(const struct usb_prepare_event *event)
 		}
 
 		usb_function_prepared = true;
-	submit_usb_function_ready_event(USB_FUNCTION_HID);
+		submit_usb_state_set(MODULE_ID(MODULE),
-	return false;
+				     MODULE_ID(usb_device_module),
-}
+				     USB_STATEF_HID_READY);
+	}
 
-static bool handle_usb_device_state_event(const struct usb_device_state_event *event)
+	bool new_usb_active = (event->flags & USB_STATEF_ACTIVE) != 0U;
-{
-	bool new_usb_active = (event->state == USB_DEVICE_STATE_ACTIVE);
 
 	if (new_usb_active == usb_active) {
 		return false;
@@ -538,12 +540,8 @@ static bool app_event_handler(const struct app_event_header *aeh)
 		return handle_hid_tx_report_event(cast_hid_tx_report_event(aeh));
 	}
 
-	if (is_usb_device_state_event(aeh)) {
+	if (is_usb_state_event(aeh)) {
-		return handle_usb_device_state_event(cast_usb_device_state_event(aeh));
+		return handle_usb_state_event(cast_usb_state_event(aeh));
-	}
-
-	if (is_usb_prepare_event(aeh)) {
-		return handle_usb_prepare_event(cast_usb_prepare_event(aeh));
 	}
 
 	if (is_module_state_event(aeh)) {
@@ -602,7 +600,6 @@ static bool app_event_handler(const struct app_event_header *aeh)
 APP_EVENT_LISTENER(MODULE, app_event_handler);
 APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
 APP_EVENT_SUBSCRIBE(MODULE, hid_tx_report_event);
-APP_EVENT_SUBSCRIBE(MODULE, usb_prepare_event);
+APP_EVENT_SUBSCRIBE(MODULE, usb_state_event);
-APP_EVENT_SUBSCRIBE(MODULE, usb_device_state_event);
 APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
 APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);