feat: 添加CDC协议通信模块支持

- 集成nanopb库用于protobuf序列化
- 创建cdc_wrapper_module.c实现帧解析功能
- 实现protocol_module.c处理协议编解码
- 定义device_comm.proto通信协议
- 修改CMakeLists.txt添加protobuf源文件
- 更新配置启用NANOPB支持
- 移除usb_cdc_module中基于行的处理逻辑

CMakeLists.txt

@@ -4,12 +4,19 @@ cmake_minimum_required(VERSION 3.20.0)
 find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
 project(blinky)
 
+list(APPEND CMAKE_MODULE_PATH ${ZEPHYR_BASE}/modules/nanopb)
+include(nanopb)
+
 zephyr_include_directories(
   inc
   inc/events
 )
 add_subdirectory(drivers)
 
+zephyr_nanopb_sources(app
+  proto/device_comm.proto
+)
+
 target_sources(app PRIVATE
   src/main.c
   src/battery_module.c
@@ -17,9 +24,15 @@ target_sources(app PRIVATE
   src/ble_adv_uuid16.c
   src/ble_bas_module.c
   src/ble_hid_module.c
+  src/display_module.c
   src/encoder_module.c
   src/hid_flowctrl_module.c
   src/keyboard_core_module.c
+  src/ui/ui_main.c
+  src/cdc_wrapper_module.c
+  src/protocol_module.c
+  src/usb_cdc_module.c
+  src/usb_device_module.c
   src/usb_hid_module.c
   src/events/bat_state_event.c
   src/events/encoder_event.c
@@ -31,4 +44,9 @@ target_sources(app PRIVATE
   src/events/keyboard_hid_report_event.c
   src/events/mode_switch_event.c
   src/events/set_protocol_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_function_ready_event.c
+  src/events/usb_prepare_event.c
 )

boards/atguigu/mini_keyboard/mini_keyboard-pinctrl.dtsi

@@ -30,4 +30,32 @@
 			bias-pull-up;
 		};
 	};
+
+	spi3_default: spi3_default {
+		group1 {
+			psels = <NRF_PSEL(SPIM_SCK, 1, 13)>,
+				<NRF_PSEL(SPIM_MOSI, 0, 28)>;
+		};
+	};
+
+	spi3_sleep: spi3_sleep {
+		group1 {
+			psels = <NRF_PSEL(SPIM_SCK, 1, 13)>,
+				<NRF_PSEL(SPIM_MOSI, 0, 28)>;
+			low-power-enable;
+		};
+	};
+
+	pwm0_default: pwm0_default {
+		group1 {
+			psels = <NRF_PSEL(PWM_OUT0, 1, 11)>;
+		};
+	};
+
+	pwm0_sleep: pwm0_sleep {
+		group1 {
+			psels = <NRF_PSEL(PWM_OUT0, 1, 11)>;
+			low-power-enable;
+		};
+	};
 };

boards/atguigu/mini_keyboard/mini_keyboard.dts

@@ -2,6 +2,8 @@
 #include <nordic/nrf52840_qiaa.dtsi>
 #include "mini_keyboard-pinctrl.dtsi"
 #include <zephyr/dt-bindings/adc/adc.h>
+#include <zephyr/dt-bindings/mipi_dbi/mipi_dbi.h>
+#include <zephyr/dt-bindings/pwm/pwm.h>
 
 / {
 	model = "Mini keyboard";
@@ -11,11 +13,13 @@
 		zephyr,sram = &sram0;
 		zephyr,flash = &flash0;
 		zephyr,code-partition = &slot0_partition;
+		zephyr,display = &screen_lcd;
 	};
 
 	aliases {
         led0 = &myled0;
 		qdec0 = &qdec;
+		backlight = &backlight;
     };
 
 	hid_kbd: hid_kbd {
@@ -36,12 +40,57 @@
 		in-polling-period-us = <1000>;
 	};
 
-    leds {
+	leds {
-        compatible = "gpio-leds";
+		compatible = "gpio-leds";
-        myled0: led_0 {
+		myled0: led_0 {
-            gpios = <&gpio1 2 GPIO_ACTIVE_LOW>;
+			gpios = <&gpio1 2 GPIO_ACTIVE_LOW>;
-        };
+		};
-    };
+	};
+
+	pwm_leds {
+		compatible = "pwm-leds";
+		status = "okay";
+
+		backlight: pwm_led_0 {
+			pwms = <&pwm0 0 PWM_MSEC(10) PWM_POLARITY_INVERTED>;
+		};
+	};
+
+	mipi_dbi_screen: mipi_dbi_screen {
+		compatible = "zephyr,mipi-dbi-spi";
+		spi-dev = <&spi3>;
+		dc-gpios = <&gpio0 3 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&gpio1 10 GPIO_ACTIVE_LOW>;
+		write-only;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		screen_lcd: st7789v@0 {
+			compatible = "sitronix,st7789v";
+			status = "okay";
+			reg = <0>;
+			mipi-max-frequency = <32000000>;
+			width = <320>;
+			height = <172>;
+			x-offset = <0>;
+			y-offset = <34>;
+			vcom = <0x34>;
+			gctrl = <0x00>;
+			mdac = <0xA0>;
+			gamma = <0x01>;
+			colmod = <0x05>;
+			lcm = <0x2c>;
+			porch-param = [ 0c 0c 00 33 33  ];
+			cmd2en-param = [ 5a 69 02 01  ];
+			pwctrl1-param = [ a4 a1  ];
+			pvgam-param = [ f0 04 08 0a 0a 05 25 33 3c 24 0e 0f 27 2f ];
+			nvgam-param = [ f0 02 06 06 04 22 25 32 3b 3a 15 17 2d 37 ];
+			ram-param = [ 00 f0  ];
+			rgb-param = [ cd 08 14  ];
+			ready-time-ms = <120>;
+			mipi-mode = "MIPI_DBI_MODE_SPI_4WIRE";
+		};
+	};
 
 	vbatt: vbatt {
 		compatible = "voltage-divider";
@@ -90,6 +139,7 @@
 
 &uicr {
 	nfct-pins-as-gpios;
+	gpio-as-nreset;
 };
 
 &adc {
@@ -148,6 +198,21 @@
 	status = "okay";
 };
 
+&spi3 {
+	status = "okay";
+	pinctrl-0 = <&spi3_default>;
+	pinctrl-1 = <&spi3_sleep>;
+	pinctrl-names = "default", "sleep";
+	cs-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
+};
+
+&pwm0 {
+	status = "okay";
+	pinctrl-0 = <&pwm0_default>;
+	pinctrl-1 = <&pwm0_sleep>;
+	pinctrl-names = "default", "sleep";
+};
+
 &qdec {
 	status = "okay";
 	pinctrl-0 = <&encoder_default>;
@@ -160,9 +225,14 @@
 
 &usbd {
 	status = "okay";
-	num-bidir-endpoints = <0>;
+	num-bidir-endpoints = <1>;
-	num-in-endpoints = <2>;
+	num-in-endpoints = <7>;
-	num-out-endpoints = <1>;
+	num-out-endpoints = <7>;
 	num-isoin-endpoints = <0>;
 	num-isoout-endpoints = <0>;
+
+	cdc_acm_uart0: cdc_acm_uart0 {
+		compatible = "zephyr,cdc-acm-uart";
+		label = "CDC_ACM_0";
+	};
 };

inc/cdc_wrapper_module.h

@@ -0,0 +1,12 @@
+#ifndef BLINKY_CDC_WRAPPER_MODULE_H_
+#define BLINKY_CDC_WRAPPER_MODULE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_CDC_WRAPPER_MODULE_H_ */

inc/click_detector_def.h

@@ -0,0 +1,15 @@
+/*
+ * This configuration file is included only once from the CAF click detector
+ * module and defines the keys that should produce click events.
+ */
+
+#include <caf/click_detector.h>
+
+const struct {} click_detector_def_include_once;
+
+static const struct click_detector_config click_detector_config[] = {
+	{
+		.key_id = 0x180,
+		.consume_button_event = true,
+	},
+};

inc/events/usb_cdc_rx_event.h

@@ -0,0 +1,22 @@
+#ifndef BLINKY_USB_CDC_RX_EVENT_H_
+#define BLINKY_USB_CDC_RX_EVENT_H_
+
+#include <app_event_manager.h>
+#include <app_event_manager_profiler_tracer.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct usb_cdc_rx_event {
+	struct app_event_header header;
+	struct event_dyndata dyndata;
+};
+
+APP_EVENT_TYPE_DYNDATA_DECLARE(usb_cdc_rx_event);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_USB_CDC_RX_EVENT_H_ */

inc/events/usb_cdc_tx_event.h

@@ -0,0 +1,22 @@
+#ifndef BLINKY_USB_CDC_TX_EVENT_H_
+#define BLINKY_USB_CDC_TX_EVENT_H_
+
+#include <app_event_manager.h>
+#include <app_event_manager_profiler_tracer.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct usb_cdc_tx_event {
+	struct app_event_header header;
+	struct event_dyndata dyndata;
+};
+
+APP_EVENT_TYPE_DYNDATA_DECLARE(usb_cdc_tx_event);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_USB_CDC_TX_EVENT_H_ */

inc/events/usb_device_state_event.h

@@ -0,0 +1,24 @@
+#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);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_USB_DEVICE_STATE_EVENT_H_ */

inc/events/usb_function_ready_event.h

@@ -0,0 +1,24 @@
+#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);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_USB_FUNCTION_READY_EVENT_H_ */

inc/events/usb_prepare_event.h

@@ -0,0 +1,21 @@
+#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);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_USB_PREPARE_EVENT_H_ */

inc/protocol_module.h

@@ -0,0 +1,26 @@
+#ifndef BLINKY_PROTOCOL_MODULE_H_
+#define BLINKY_PROTOCOL_MODULE_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define CDC_PROTO_TYPE_HELLO_REQ 0x01U
+#define CDC_PROTO_TYPE_HELLO_RSP 0x02U
+
+int protocol_module_process_cdc_packet(uint8_t req_type,
+				       const uint8_t *req_payload,
+				       size_t req_payload_len,
+				       uint8_t *rsp_type,
+				       uint8_t *rsp_payload,
+				       size_t rsp_payload_buf_size,
+				       size_t *rsp_payload_len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_PROTOCOL_MODULE_H_ */

inc/usb_device_module.h

@@ -0,0 +1,26 @@
+#ifndef BLINKY_USB_DEVICE_MODULE_H_
+#define BLINKY_USB_DEVICE_MODULE_H_
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+enum usb_function {
+	USB_FUNCTION_HID = 0x01,
+	USB_FUNCTION_CDC_ACM = 0x02,
+};
+
+enum usb_device_state {
+	USB_DEVICE_STATE_DISCONNECTED,
+	USB_DEVICE_STATE_POWERED,
+	USB_DEVICE_STATE_ACTIVE,
+	USB_DEVICE_STATE_SUSPENDED,
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_USB_DEVICE_MODULE_H_ */

prj.conf

@@ -1,8 +1,13 @@
 CONFIG_CAF=y
 CONFIG_CAF_BUTTONS=y
 CONFIG_CAF_BUTTONS_DEF_PATH="buttons_def.h"
+CONFIG_CAF_CLICK_DETECTOR=y
+CONFIG_CAF_CLICK_DETECTOR_DEF_PATH="click_detector_def.h"
 CONFIG_GPIO=y
 CONFIG_I2C=y
+CONFIG_LED=y
+CONFIG_PWM=y
+CONFIG_SPI=y
 CONFIG_NRFX_RTC2=y
 CONFIG_NRFX_GPPI=y
 CONFIG_NRFX_QDEC=y
@@ -10,6 +15,9 @@ CONFIG_PINCTRL_DYNAMIC=y
 CONFIG_REBOOT=y
 CONFIG_SENSOR=y
 CONFIG_ADC=y
+CONFIG_DISPLAY=y
+CONFIG_DISPLAY_LOG_LEVEL_ERR=y
+CONFIG_MIPI_DBI_LOG_LEVEL_ERR=y
 CONFIG_SETTINGS=y
 CONFIG_SETTINGS_NVS=y
 CONFIG_FLASH=y
@@ -22,7 +30,14 @@ CONFIG_ASSERT=y
 
 # USB HID next stack
 CONFIG_USB_DEVICE_STACK_NEXT=y
+CONFIG_SERIAL=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+CONFIG_UART_LINE_CTRL=y
+CONFIG_UART_USE_RUNTIME_CONFIGURE=y
+CONFIG_NANOPB=y
 CONFIG_USBD_HID_SUPPORT=y
+CONFIG_USBD_CDC_ACM_CLASS=y
+CONFIG_CDC_ACM_SERIAL_INITIALIZE_AT_BOOT=n
 
 # BLE
 CONFIG_BT=y
@@ -78,8 +93,29 @@ CONFIG_CAF_BLE_ADV_FAST_ADV=y
 CONFIG_CAF_BLE_ADV_FILTER_ACCEPT_LIST=y
 CONFIG_CAF_BLE_ADV_MODULE_SUSPEND_EVENTS=y
 CONFIG_CAF_BLE_BOND=y
+CONFIG_CAF_BLE_BOND_PEER_ERASE_CLICK=y
+CONFIG_CAF_BLE_BOND_PEER_ERASE_CLICK_KEY_ID=0x180
+CONFIG_CAF_BLE_BOND_PEER_ERASE_CLICK_LONG=y
+CONFIG_CAF_BLE_BOND_PEER_ERASE_CLICK_TIMEOUT=-1
 CONFIG_CAF_MODULE_SUSPEND_EVENTS=y
 CONFIG_BT_ADV_PROV_FLAGS=y
 CONFIG_BT_ADV_PROV_GAP_APPEARANCE=y
 CONFIG_BT_ADV_PROV_DEVICE_NAME=y
 CONFIG_BT_ADV_PROV_DEVICE_NAME_SD=y
+
+# LVGL
+CONFIG_LVGL=y
+CONFIG_LV_Z_AUTO_INIT=n
+CONFIG_LV_Z_RUN_LVGL_ON_WORKQUEUE=y
+CONFIG_LV_Z_LVGL_WORKQUEUE_STACK_SIZE=16384
+CONFIG_LV_Z_LVGL_MUTEX=y
+CONFIG_LV_COLOR_DEPTH_16=y
+CONFIG_LV_COLOR_16_SWAP=y
+CONFIG_LV_Z_BITS_PER_PIXEL=16
+CONFIG_LV_Z_VDB_SIZE=25
+CONFIG_LV_Z_DOUBLE_VDB=y
+CONFIG_LV_Z_MEM_POOL_SIZE=16384
+CONFIG_LV_USE_LABEL=y
+CONFIG_LV_FONT_MONTSERRAT_14=y
+CONFIG_LV_FONT_MONTSERRAT_32=y
+CONFIG_MAIN_STACK_SIZE=4096

proto/device_comm.proto

@@ -0,0 +1,21 @@
+syntax = "proto3";
+
+message HelloReq {
+  uint32 protocol_version = 1;
+}
+
+message HelloRsp {
+  uint32 protocol_version = 1;
+  uint32 vendor_id = 2;
+  uint32 product_id = 3;
+  uint32 firmware_major = 4;
+  uint32 firmware_minor = 5;
+  uint32 capability_flags = 6;
+}
+
+message CdcPacketBody {
+  oneof body {
+    HelloReq hello_req = 1;
+    HelloRsp hello_rsp = 2;
+  }
+}

src/cdc_wrapper_module.c

@@ -0,0 +1,275 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <app_event_manager.h>
+
+#define MODULE cdc_wrapper_module
+#include <caf/events/module_state_event.h>
+#include <caf/events/power_event.h>
+
+#include <zephyr/logging/log.h>
+
+#include "protocol_module.h"
+#include "usb_cdc_rx_event.h"
+#include "usb_cdc_tx_event.h"
+
+LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
+
+#define CDC_WRAPPER_HEAD1 0xAAU
+#define CDC_WRAPPER_HEAD2 0x55U
+#define CDC_WRAPPER_MAX_PAYLOAD_LEN 64U
+#define CDC_WRAPPER_MAX_FRAME_LEN (2U + 1U + 1U + CDC_WRAPPER_MAX_PAYLOAD_LEN + 1U)
+
+enum frame_parse_state {
+	FRAME_PARSE_HEAD1,
+	FRAME_PARSE_HEAD2,
+	FRAME_PARSE_LEN,
+	FRAME_PARSE_TYPE,
+	FRAME_PARSE_PAYLOAD,
+	FRAME_PARSE_CHECKSUM,
+};
+
+struct cdc_frame_parser {
+	enum frame_parse_state state;
+	uint8_t len;
+	uint8_t type;
+	uint8_t checksum;
+	uint8_t payload[CDC_WRAPPER_MAX_PAYLOAD_LEN];
+	size_t payload_pos;
+};
+
+static bool initialized;
+static bool running;
+static struct cdc_frame_parser parser;
+
+static void parser_reset(void)
+{
+	parser.state = FRAME_PARSE_HEAD1;
+	parser.len = 0U;
+	parser.type = 0U;
+	parser.checksum = 0U;
+	parser.payload_pos = 0U;
+}
+
+static uint8_t frame_checksum(uint8_t len, uint8_t type,
+			      const uint8_t *payload, size_t payload_len)
+{
+	uint8_t checksum = CDC_WRAPPER_HEAD1 ^ CDC_WRAPPER_HEAD2 ^ len ^ type;
+
+	for (size_t i = 0; i < payload_len; i++) {
+		checksum ^= payload[i];
+	}
+
+	return checksum;
+}
+
+static void submit_tx_frame(uint8_t type, const uint8_t *payload, size_t payload_len)
+{
+	struct usb_cdc_tx_event *event;
+	size_t frame_len = 2U + 1U + 1U + payload_len + 1U;
+
+	event = new_usb_cdc_tx_event(frame_len);
+	event->dyndata.data[0] = CDC_WRAPPER_HEAD1;
+	event->dyndata.data[1] = CDC_WRAPPER_HEAD2;
+	event->dyndata.data[2] = (uint8_t)payload_len;
+	event->dyndata.data[3] = type;
+	memcpy(&event->dyndata.data[4], payload, payload_len);
+	event->dyndata.data[4U + payload_len] =
+		frame_checksum((uint8_t)payload_len, type, payload, payload_len);
+	APP_EVENT_SUBMIT(event);
+}
+
+static void process_complete_frame(void)
+{
+	uint8_t rsp_type;
+	uint8_t rsp_payload[CDC_WRAPPER_MAX_PAYLOAD_LEN];
+	size_t rsp_payload_len = 0U;
+	int err;
+
+	err = protocol_module_process_cdc_packet(parser.type,
+						 parser.payload,
+						 parser.payload_pos,
+						 &rsp_type,
+						 rsp_payload,
+						 sizeof(rsp_payload),
+						 &rsp_payload_len);
+	if (err == -ENOTSUP) {
+		LOG_WRN("Ignore unsupported CDC packet type:0x%02x", parser.type);
+		return;
+	}
+
+	if (err) {
+		LOG_WRN("Protocol processing failed (%d)", err);
+		return;
+	}
+
+	LOG_INF("CDC HelloRsp encoded len:%u", (uint32_t)rsp_payload_len);
+	submit_tx_frame(rsp_type, rsp_payload, rsp_payload_len);
+}
+
+static void consume_byte(uint8_t byte)
+{
+	switch (parser.state) {
+	case FRAME_PARSE_HEAD1:
+		if (byte == CDC_WRAPPER_HEAD1) {
+			parser.state = FRAME_PARSE_HEAD2;
+		}
+		break;
+
+	case FRAME_PARSE_HEAD2:
+		if (byte == CDC_WRAPPER_HEAD2) {
+			parser.state = FRAME_PARSE_LEN;
+		} else if (byte != CDC_WRAPPER_HEAD1) {
+			parser.state = FRAME_PARSE_HEAD1;
+		}
+		break;
+
+	case FRAME_PARSE_LEN:
+		if (byte > CDC_WRAPPER_MAX_PAYLOAD_LEN) {
+			LOG_WRN("Drop CDC frame with invalid len:%u", byte);
+			parser_reset();
+			break;
+		}
+
+		parser.len = byte;
+		parser.payload_pos = 0U;
+		parser.state = FRAME_PARSE_TYPE;
+		break;
+
+	case FRAME_PARSE_TYPE:
+		parser.type = byte;
+		parser.state = (parser.len == 0U) ? FRAME_PARSE_CHECKSUM :
+						 FRAME_PARSE_PAYLOAD;
+		break;
+
+	case FRAME_PARSE_PAYLOAD:
+		parser.payload[parser.payload_pos++] = byte;
+		if (parser.payload_pos >= parser.len) {
+			parser.state = FRAME_PARSE_CHECKSUM;
+		}
+		break;
+
+	case FRAME_PARSE_CHECKSUM:
+		if (byte != frame_checksum(parser.len, parser.type,
+					       parser.payload, parser.payload_pos)) {
+			LOG_WRN("Drop CDC frame with invalid checksum");
+			parser_reset();
+			break;
+		}
+
+		process_complete_frame();
+		parser_reset();
+		break;
+
+	default:
+		parser_reset();
+		break;
+	}
+}
+
+static bool handle_usb_cdc_rx_event(const struct usb_cdc_rx_event *event)
+{
+	if (!running) {
+		return false;
+	}
+
+	for (size_t i = 0; i < event->dyndata.size; i++) {
+		consume_byte(event->dyndata.data[i]);
+	}
+
+	return false;
+}
+
+static int module_init(void)
+{
+	parser_reset();
+	return 0;
+}
+
+static int module_start(void)
+{
+	if (running) {
+		return 0;
+	}
+
+	running = true;
+	return 0;
+}
+
+static void module_pause(void)
+{
+	if (!running) {
+		return;
+	}
+
+	running = false;
+	parser_reset();
+}
+
+static bool app_event_handler(const struct app_event_header *aeh)
+{
+	if (is_usb_cdc_rx_event(aeh)) {
+		return handle_usb_cdc_rx_event(cast_usb_cdc_rx_event(aeh));
+	}
+
+	if (is_module_state_event(aeh)) {
+		const struct module_state_event *event = cast_module_state_event(aeh);
+
+		if (check_state(event, MODULE_ID(main), MODULE_STATE_READY)) {
+			int err;
+
+			if (!initialized) {
+				err = module_init();
+				if (err) {
+					module_set_state(MODULE_STATE_ERROR);
+					return false;
+				}
+
+				initialized = true;
+			}
+
+			err = module_start();
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	if (is_power_down_event(aeh)) {
+		if (initialized) {
+			module_pause();
+			module_set_state(MODULE_STATE_STANDBY);
+		}
+
+		return false;
+	}
+
+	if (is_wake_up_event(aeh)) {
+		if (initialized) {
+			int err = module_start();
+
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	return false;
+}
+
+APP_EVENT_LISTENER(MODULE, app_event_handler);
+APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
+APP_EVENT_SUBSCRIBE(MODULE, usb_cdc_rx_event);
+APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
+APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);

src/display_module.c

@@ -0,0 +1,225 @@
+#include <errno.h>
+#include <stdbool.h>
+
+#include <app_event_manager.h>
+
+#define MODULE display_module
+#include <caf/events/module_state_event.h>
+#include <caf/events/power_event.h>
+
+#include <lvgl_zephyr.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/display.h>
+#include <zephyr/drivers/led.h>
+#include <zephyr/logging/log.h>
+
+#include "bat_state_event.h"
+#include "hid_led_event.h"
+#include "mode_switch_event.h"
+#include "ui/ui_main.h"
+
+LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
+
+BUILD_ASSERT(DT_HAS_CHOSEN(zephyr_display), "Missing zephyr,display chosen node");
+BUILD_ASSERT(DT_NODE_HAS_STATUS(DT_ALIAS(backlight), okay),
+	     "Missing backlight alias");
+
+static const struct device *const display_dev =
+	DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
+static const struct device *const backlight_dev =
+	DEVICE_DT_GET(DT_PARENT(DT_ALIAS(backlight)));
+static const uint32_t backlight_idx = DT_NODE_CHILD_IDX(DT_ALIAS(backlight));
+static struct ui_main_model ui_model = {
+	.theme_color = LV_COLOR_MAKE(0x4C, 0x9E, 0xF5),
+	.inactive_border_color = LV_COLOR_MAKE(0x3A, 0x44, 0x52),
+	.mode = MODE_SWITCH_BLE,
+};
+static bool initialized;
+static bool running;
+static bool lvgl_initialized;
+
+static int backlight_set(bool on)
+{
+	if (on) {
+		return led_on(backlight_dev, backlight_idx);
+	}
+
+	return led_off(backlight_dev, backlight_idx);
+}
+
+static int module_init(void)
+{
+	int err;
+
+	LOG_INF("Display init on %s", display_dev->name);
+
+	if (!device_is_ready(display_dev)) {
+		LOG_ERR("Display device %s not ready", display_dev->name);
+		return -ENODEV;
+	}
+
+	if (!device_is_ready(backlight_dev)) {
+		LOG_ERR("Backlight device %s not ready", backlight_dev->name);
+		return -ENODEV;
+	}
+
+	err = backlight_set(false);
+	if (err) {
+		LOG_ERR("Backlight off failed (%d)", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int module_start(void)
+{
+	int err;
+
+	if (running) {
+		return 0;
+	}
+
+	if (!lvgl_initialized) {
+		err = lvgl_init();
+		if (err) {
+			LOG_ERR("lvgl_init failed (%d)", err);
+			return err;
+		}
+
+		lvgl_initialized = true;
+
+		lvgl_lock();
+		ui_main_init(&ui_model, "WH Mini", "Hello World");
+		lvgl_unlock();
+	}
+
+	err = backlight_set(true);
+	if (err) {
+		LOG_ERR("Backlight enable failed (%d)", err);
+		return err;
+	}
+
+	err = display_blanking_off(display_dev);
+	if (err) {
+		LOG_ERR("display_blanking_off failed (%d)", err);
+		(void)backlight_set(false);
+		return err;
+	}
+
+	running = true;
+	LOG_INF("LVGL display started");
+
+	return 0;
+}
+
+static void module_pause(void)
+{
+	if (!running) {
+		return;
+	}
+
+	(void)display_blanking_on(display_dev);
+	(void)backlight_set(false);
+	running = false;
+	LOG_INF("LVGL display paused");
+}
+
+static void refresh_ui(void)
+{
+	if (!lvgl_initialized) {
+		return;
+	}
+
+	lvgl_lock();
+	ui_main_refresh_all(&ui_model, "WH Mini", "Hello World");
+	lvgl_unlock();
+}
+
+static bool app_event_handler(const struct app_event_header *aeh)
+{
+	if (is_bat_state_event(aeh)) {
+		const struct bat_state_event *event = cast_bat_state_event(aeh);
+
+		ui_model.battery_level = event->soc;
+		ui_model.charging = event->charging;
+		ui_model.full = event->full;
+		refresh_ui();
+		return false;
+	}
+
+	if (is_mode_switch_event(aeh)) {
+		const struct mode_switch_event *event = cast_mode_switch_event(aeh);
+
+		ui_model.mode = event->mode;
+		refresh_ui();
+		return false;
+	}
+
+	if (is_hid_led_event(aeh)) {
+		const struct hid_led_event *event = cast_hid_led_event(aeh);
+
+		ui_model.led_mask = event->led_bm;
+		refresh_ui();
+		return false;
+	}
+
+	if (is_module_state_event(aeh)) {
+		const struct module_state_event *event = cast_module_state_event(aeh);
+		int err;
+
+		if (check_state(event, MODULE_ID(main), MODULE_STATE_READY)) {
+			if (!initialized) {
+				err = module_init();
+				if (err) {
+					module_set_state(MODULE_STATE_ERROR);
+					return false;
+				}
+
+				initialized = true;
+			}
+
+			err = module_start();
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	if (is_power_down_event(aeh)) {
+		if (initialized) {
+			module_pause();
+			module_set_state(MODULE_STATE_STANDBY);
+		}
+
+		return false;
+	}
+
+	if (is_wake_up_event(aeh)) {
+		if (initialized) {
+			int err = module_start();
+
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	return false;
+}
+
+APP_EVENT_LISTENER(MODULE, app_event_handler);
+APP_EVENT_SUBSCRIBE(MODULE, bat_state_event);
+APP_EVENT_SUBSCRIBE(MODULE, hid_led_event);
+APP_EVENT_SUBSCRIBE(MODULE, module_state_event);
+APP_EVENT_SUBSCRIBE(MODULE, mode_switch_event);
+APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
+APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);

src/events/usb_cdc_rx_event.c

@@ -0,0 +1,73 @@
+#include <ctype.h>
+#include <stdio.h>
+
+#include "usb_cdc_rx_event.h"
+
+#define USB_CDC_RX_EVENT_LOG_BUF_LEN 384
+
+static void log_usb_cdc_rx_event(const struct app_event_header *aeh)
+{
+	const struct usb_cdc_rx_event *event = cast_usb_cdc_rx_event(aeh);
+	char log_buf[USB_CDC_RX_EVENT_LOG_BUF_LEN];
+	int pos;
+
+	pos = snprintf(log_buf, sizeof(log_buf), "len:%zu ascii:\"",
+		       event->dyndata.size);
+	if ((pos < 0) || (pos >= sizeof(log_buf))) {
+		APP_EVENT_MANAGER_LOG(aeh, "log message preparation failure");
+		return;
+	}
+
+	for (size_t i = 0; i < event->dyndata.size; i++) {
+		int tmp = snprintf(&log_buf[pos], sizeof(log_buf) - pos, "%c",
+				   isprint(event->dyndata.data[i]) ?
+					   event->dyndata.data[i] : '.');
+
+		if ((tmp < 0) || ((pos + tmp) >= sizeof(log_buf))) {
+			APP_EVENT_MANAGER_LOG(aeh, "len:%zu ascii:\"...\"",
+					      event->dyndata.size);
+			return;
+		}
+
+		pos += tmp;
+	}
+
+	pos += snprintf(&log_buf[pos], sizeof(log_buf) - pos, "\" hex:");
+	if ((pos < 0) || (pos >= sizeof(log_buf))) {
+		APP_EVENT_MANAGER_LOG(aeh, "len:%zu ascii:\"...\"",
+				      event->dyndata.size);
+		return;
+	}
+
+	for (size_t i = 0; i < event->dyndata.size; i++) {
+		int tmp = snprintf(&log_buf[pos], sizeof(log_buf) - pos, " %02x",
+				   event->dyndata.data[i]);
+
+		if ((tmp < 0) || ((pos + tmp) >= sizeof(log_buf))) {
+			break;
+		}
+
+		pos += tmp;
+	}
+
+	APP_EVENT_MANAGER_LOG(aeh, "%s", log_buf);
+}
+
+static void profile_usb_cdc_rx_event(struct log_event_buf *buf,
+				     const struct app_event_header *aeh)
+{
+	const struct usb_cdc_rx_event *event = cast_usb_cdc_rx_event(aeh);
+
+	nrf_profiler_log_encode_uint8(buf, (uint8_t)event->dyndata.size);
+}
+
+APP_EVENT_INFO_DEFINE(usb_cdc_rx_event,
+		      ENCODE(NRF_PROFILER_ARG_U8),
+		      ENCODE("len"),
+		      profile_usb_cdc_rx_event);
+
+APP_EVENT_TYPE_DEFINE(usb_cdc_rx_event,
+		      log_usb_cdc_rx_event,
+		      &usb_cdc_rx_event_info,
+		      APP_EVENT_FLAGS_CREATE(
+			      APP_EVENT_TYPE_FLAGS_INIT_LOG_ENABLE));

src/events/usb_cdc_tx_event.c

@@ -0,0 +1,62 @@
+#include <ctype.h>
+#include <stdio.h>
+
+#include "usb_cdc_tx_event.h"
+
+#define USB_CDC_TX_EVENT_LOG_BUF_LEN 256
+
+static void log_usb_cdc_tx_event(const struct app_event_header *aeh)
+{
+	const struct usb_cdc_tx_event *event = cast_usb_cdc_tx_event(aeh);
+	char log_buf[USB_CDC_TX_EVENT_LOG_BUF_LEN];
+	int pos;
+
+	pos = snprintf(log_buf, sizeof(log_buf), "len:%zu ascii:\"",
+		       event->dyndata.size);
+	if ((pos < 0) || (pos >= sizeof(log_buf))) {
+		APP_EVENT_MANAGER_LOG(aeh, "log message preparation failure");
+		return;
+	}
+
+	for (size_t i = 0; i < event->dyndata.size; i++) {
+		int tmp = snprintf(&log_buf[pos], sizeof(log_buf) - pos, "%c",
+				   isprint(event->dyndata.data[i]) ?
+					   event->dyndata.data[i] : '.');
+
+		if ((tmp < 0) || ((pos + tmp) >= sizeof(log_buf))) {
+			APP_EVENT_MANAGER_LOG(aeh, "len:%zu ascii:\"...\"",
+					      event->dyndata.size);
+			return;
+		}
+
+		pos += tmp;
+	}
+
+	pos += snprintf(&log_buf[pos], sizeof(log_buf) - pos, "\"");
+	if ((pos < 0) || (pos >= sizeof(log_buf))) {
+		APP_EVENT_MANAGER_LOG(aeh, "len:%zu ascii:\"...\"",
+				      event->dyndata.size);
+		return;
+	}
+
+	APP_EVENT_MANAGER_LOG(aeh, "%s", log_buf);
+}
+
+static void profile_usb_cdc_tx_event(struct log_event_buf *buf,
+				     const struct app_event_header *aeh)
+{
+	const struct usb_cdc_tx_event *event = cast_usb_cdc_tx_event(aeh);
+
+	nrf_profiler_log_encode_uint8(buf, (uint8_t)event->dyndata.size);
+}
+
+APP_EVENT_INFO_DEFINE(usb_cdc_tx_event,
+		      ENCODE(NRF_PROFILER_ARG_U8),
+		      ENCODE("len"),
+		      profile_usb_cdc_tx_event);
+
+APP_EVENT_TYPE_DEFINE(usb_cdc_tx_event,
+		      log_usb_cdc_tx_event,
+		      &usb_cdc_tx_event_info,
+		      APP_EVENT_FLAGS_CREATE(
+			      APP_EVENT_TYPE_FLAGS_INIT_LOG_ENABLE));

src/events/usb_device_state_event.c

@@ -0,0 +1,46 @@
+#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

@@ -0,0 +1,42 @@
+#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

@@ -0,0 +1,24 @@
+#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/protocol_module.c

@@ -0,0 +1,133 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <zephyr/logging/log.h>
+
+#include <pb_decode.h>
+#include <pb_encode.h>
+
+#include <proto/device_comm.pb.h>
+
+#include "protocol_module.h"
+
+LOG_MODULE_REGISTER(protocol_module, LOG_LEVEL_INF);
+
+#define PROTOCOL_VERSION 1U
+#define PROTOCOL_VENDOR_ID 0x1915U
+#define PROTOCOL_PRODUCT_ID 0x52F0U
+#define PROTOCOL_FIRMWARE_MAJOR 0U
+#define PROTOCOL_FIRMWARE_MINOR 0U
+#define PROTOCOL_CAPABILITY_FLAGS 0U
+
+static bool type_matches_body(uint8_t type, const CdcPacketBody *body)
+{
+	switch (type) {
+	case CDC_PROTO_TYPE_HELLO_REQ:
+		return body->which_body == CdcPacketBody_hello_req_tag;
+	case CDC_PROTO_TYPE_HELLO_RSP:
+		return body->which_body == CdcPacketBody_hello_rsp_tag;
+	default:
+		return false;
+	}
+}
+
+static int decode_body(const uint8_t *payload, size_t payload_len,
+		       CdcPacketBody *body)
+{
+	pb_istream_t stream;
+
+	if ((payload == NULL) || (body == NULL)) {
+		return -EINVAL;
+	}
+
+	*body = (CdcPacketBody)CdcPacketBody_init_zero;
+	stream = pb_istream_from_buffer(payload, payload_len);
+
+	if (!pb_decode(&stream, CdcPacketBody_fields, body)) {
+		LOG_WRN("pb_decode failed: %s", PB_GET_ERROR(&stream));
+		return -EBADMSG;
+	}
+
+	return 0;
+}
+
+static int encode_hello_rsp(uint8_t *rsp_payload, size_t rsp_payload_buf_size,
+			    size_t *rsp_payload_len)
+{
+	CdcPacketBody body = CdcPacketBody_init_zero;
+	pb_ostream_t stream;
+
+	if ((rsp_payload == NULL) || (rsp_payload_len == NULL)) {
+		return -EINVAL;
+	}
+
+	body.which_body = CdcPacketBody_hello_rsp_tag;
+	body.body.hello_rsp.protocol_version = PROTOCOL_VERSION;
+	body.body.hello_rsp.vendor_id = PROTOCOL_VENDOR_ID;
+	body.body.hello_rsp.product_id = PROTOCOL_PRODUCT_ID;
+	body.body.hello_rsp.firmware_major = PROTOCOL_FIRMWARE_MAJOR;
+	body.body.hello_rsp.firmware_minor = PROTOCOL_FIRMWARE_MINOR;
+	body.body.hello_rsp.capability_flags = PROTOCOL_CAPABILITY_FLAGS;
+
+	stream = pb_ostream_from_buffer(rsp_payload, rsp_payload_buf_size);
+
+	if (!pb_encode(&stream, CdcPacketBody_fields, &body)) {
+		LOG_WRN("pb_encode failed: %s", PB_GET_ERROR(&stream));
+		return -EIO;
+	}
+
+	*rsp_payload_len = stream.bytes_written;
+	return 0;
+}
+
+int protocol_module_process_cdc_packet(uint8_t req_type,
+				       const uint8_t *req_payload,
+				       size_t req_payload_len,
+				       uint8_t *rsp_type,
+				       uint8_t *rsp_payload,
+				       size_t rsp_payload_buf_size,
+				       size_t *rsp_payload_len)
+{
+	CdcPacketBody body;
+	int err;
+
+	if ((rsp_type == NULL) || (rsp_payload == NULL) || (rsp_payload_len == NULL)) {
+		return -EINVAL;
+	}
+
+	err = decode_body(req_payload, req_payload_len, &body);
+	if (err) {
+		return err;
+	}
+
+	if (!type_matches_body(req_type, &body)) {
+		LOG_WRN("CDC type/body mismatch type:0x%02x body_case:%d",
+			req_type, body.which_body);
+		return -EBADMSG;
+	}
+
+	switch (req_type) {
+	case CDC_PROTO_TYPE_HELLO_REQ:
+		LOG_INF("HelloReq protocol_version:%u",
+			body.body.hello_req.protocol_version);
+
+		if (body.body.hello_req.protocol_version != PROTOCOL_VERSION) {
+			LOG_WRN("Unexpected protocol version:%u",
+				body.body.hello_req.protocol_version);
+		}
+
+		err = encode_hello_rsp(rsp_payload, rsp_payload_buf_size, rsp_payload_len);
+		if (err) {
+			return err;
+		}
+
+		*rsp_type = CDC_PROTO_TYPE_HELLO_RSP;
+		return 0;
+
+	default:
+		LOG_WRN("Unsupported CDC protocol type:0x%02x", req_type);
+		return -ENOTSUP;
+	}
+}

src/ui/ui_main.c

@@ -0,0 +1,291 @@
+#include <string.h>
+
+#include <lvgl.h>
+#include <zephyr/sys/printk.h>
+
+#include "ui_main.h"
+
+enum ui_status_id {
+	UI_STATUS_USB = 0,
+	UI_STATUS_BLE,
+	UI_STATUS_NUMLOCK,
+	UI_STATUS_CAPSLOCK,
+	UI_STATUS_COUNT,
+};
+
+enum {
+	UI_LED_MASK_NUM_LOCK = BIT(0),
+	UI_LED_MASK_CAPS_LOCK = BIT(1),
+};
+
+struct ui_main_ctx {
+	lv_obj_t *status_badges[UI_STATUS_COUNT];
+	lv_obj_t *status_labels[UI_STATUS_COUNT];
+	lv_obj_t *battery_icon;
+	lv_obj_t *battery_label;
+	lv_obj_t *battery_state_label;
+	lv_obj_t *date_label;
+	lv_obj_t *time_label;
+};
+
+static struct ui_main_ctx g_ui;
+static bool ui_initialized;
+
+static const char *const status_texts[UI_STATUS_COUNT] = {
+	LV_SYMBOL_USB,
+	LV_SYMBOL_BLUETOOTH,
+	"1",
+	"A",
+};
+
+static lv_color_t ui_main_get_battery_color(uint8_t battery_level)
+{
+	if (battery_level > 70U) {
+		return lv_color_hex(0x8BD450);
+	}
+
+	if (battery_level >= 20U) {
+		return lv_color_hex(0xF4D35E);
+	}
+
+	return lv_color_hex(0xE63946);
+}
+
+static const char *ui_main_get_battery_symbol(uint8_t battery_level)
+{
+	if (battery_level > 85U) {
+		return LV_SYMBOL_BATTERY_FULL;
+	}
+
+	if (battery_level > 60U) {
+		return LV_SYMBOL_BATTERY_3;
+	}
+
+	if (battery_level > 35U) {
+		return LV_SYMBOL_BATTERY_2;
+	}
+
+	if (battery_level >= 20U) {
+		return LV_SYMBOL_BATTERY_1;
+	}
+
+	return LV_SYMBOL_BATTERY_EMPTY;
+}
+
+static bool ui_main_status_is_active(enum ui_status_id id,
+				     const struct ui_main_model *model)
+{
+	switch (id) {
+	case UI_STATUS_USB:
+		return model->mode == MODE_SWITCH_USB;
+
+	case UI_STATUS_BLE:
+		return model->mode == MODE_SWITCH_BLE;
+
+	case UI_STATUS_NUMLOCK:
+		return (model->led_mask & UI_LED_MASK_NUM_LOCK) != 0U;
+
+	case UI_STATUS_CAPSLOCK:
+		return (model->led_mask & UI_LED_MASK_CAPS_LOCK) != 0U;
+
+	default:
+		return false;
+	}
+}
+
+static void ui_main_create_status_chip(lv_obj_t *parent, enum ui_status_id id)
+{
+	lv_obj_t *badge = lv_obj_create(parent);
+	lv_obj_t *label = lv_label_create(badge);
+
+	lv_obj_remove_style_all(badge);
+	lv_obj_set_size(badge, 50, 32);
+	lv_obj_set_style_radius(badge, 10, 0);
+	lv_obj_set_style_bg_opa(badge, LV_OPA_COVER, 0);
+	lv_obj_set_style_pad_all(badge, 0, 0);
+
+	lv_label_set_text(label, status_texts[id]);
+	lv_obj_set_width(label, LV_PCT(100));
+	lv_obj_set_style_text_font(label, &lv_font_montserrat_14, 0);
+	lv_obj_set_style_text_align(label, LV_TEXT_ALIGN_CENTER, 0);
+	lv_obj_center(label);
+
+	g_ui.status_badges[id] = badge;
+	g_ui.status_labels[id] = label;
+}
+
+void ui_main_refresh_status_bar(const struct ui_main_model *model)
+{
+	for (uint32_t i = 0; i < UI_STATUS_COUNT; i++) {
+		lv_obj_t *badge = g_ui.status_badges[i];
+		lv_obj_t *label = g_ui.status_labels[i];
+		bool active = ui_main_status_is_active((enum ui_status_id)i, model);
+
+		if ((badge == NULL) || (label == NULL)) {
+			continue;
+		}
+
+		lv_obj_set_style_border_width(badge, 3, 0);
+		lv_obj_set_style_border_color(
+			badge,
+			active ? model->theme_color : model->inactive_border_color, 0);
+		lv_obj_set_style_bg_color(
+			badge,
+			active ? lv_color_hex(0x1D2735) : lv_color_hex(0x161A20), 0);
+		lv_obj_set_style_text_color(
+			label,
+			active ? lv_color_white() : lv_color_hex(0x7C8798), 0);
+	}
+}
+
+void ui_main_refresh_battery(const struct ui_main_model *model)
+{
+	char battery_text[8];
+	const char *state_symbol = "";
+	lv_color_t battery_color;
+	lv_color_t state_color = lv_color_white();
+
+	if ((g_ui.battery_icon == NULL) || (g_ui.battery_label == NULL) ||
+	    (g_ui.battery_state_label == NULL)) {
+		return;
+	}
+
+	battery_color = ui_main_get_battery_color(model->battery_level);
+	snprintk(battery_text, sizeof(battery_text), "%u%%", model->battery_level);
+
+	if (model->full) {
+		state_symbol = LV_SYMBOL_USB;
+		state_color = lv_color_hex(0x4C9EF5);
+	} else if (model->charging) {
+		state_symbol = LV_SYMBOL_CHARGE;
+		state_color = lv_color_hex(0xF4D35E);
+	}
+
+	lv_label_set_text(g_ui.battery_icon,
+			  ui_main_get_battery_symbol(model->battery_level));
+	lv_obj_set_style_text_color(g_ui.battery_icon, battery_color, 0);
+	lv_label_set_text(g_ui.battery_label, battery_text);
+	lv_label_set_text(g_ui.battery_state_label, state_symbol);
+	lv_obj_set_style_text_color(g_ui.battery_state_label, state_color, 0);
+}
+
+void ui_main_refresh_datetime(const char *date_text, const char *time_text)
+{
+	if ((g_ui.date_label == NULL) || (g_ui.time_label == NULL)) {
+		return;
+	}
+
+	lv_label_set_text(g_ui.date_label, date_text);
+	lv_label_set_text(g_ui.time_label, time_text);
+}
+
+void ui_main_refresh_all(const struct ui_main_model *model,
+			 const char *date_text,
+			 const char *time_text)
+{
+	ui_main_refresh_status_bar(model);
+	ui_main_refresh_battery(model);
+	ui_main_refresh_datetime(date_text, time_text);
+}
+
+void ui_main_init(const struct ui_main_model *model,
+		  const char *date_text,
+		  const char *time_text)
+{
+	lv_obj_t *screen = lv_screen_active();
+	lv_obj_t *content;
+	lv_obj_t *top_row;
+	lv_obj_t *battery_wrap;
+	lv_obj_t *middle_row;
+	lv_obj_t *bottom_row;
+
+	if (ui_initialized) {
+		return;
+	}
+
+	memset(&g_ui, 0, sizeof(g_ui));
+
+	lv_obj_clean(screen);
+	lv_obj_set_style_bg_color(screen, lv_color_hex(0x0F1115), 0);
+	lv_obj_set_style_bg_grad_color(screen, lv_color_hex(0x1A1F29), 0);
+	lv_obj_set_style_bg_grad_dir(screen, LV_GRAD_DIR_VER, 0);
+	lv_obj_set_style_bg_opa(screen, LV_OPA_COVER, 0);
+	lv_obj_set_style_text_color(screen, lv_color_white(), 0);
+	lv_obj_set_style_pad_all(screen, 0, 0);
+	lv_obj_set_scrollbar_mode(screen, LV_SCROLLBAR_MODE_OFF);
+
+	content = lv_obj_create(screen);
+	lv_obj_remove_style_all(content);
+	lv_obj_set_size(content, LV_PCT(100), LV_PCT(100));
+	lv_obj_set_style_bg_opa(content, LV_OPA_TRANSP, 0);
+	lv_obj_set_style_pad_left(content, 14, 0);
+	lv_obj_set_style_pad_right(content, 14, 0);
+	lv_obj_set_style_pad_top(content, 8, 0);
+	lv_obj_set_style_pad_bottom(content, 8, 0);
+	lv_obj_set_layout(content, LV_LAYOUT_FLEX);
+	lv_obj_set_flex_flow(content, LV_FLEX_FLOW_COLUMN);
+	lv_obj_set_flex_align(content, LV_FLEX_ALIGN_START, LV_FLEX_ALIGN_CENTER,
+			      LV_FLEX_ALIGN_CENTER);
+
+	top_row = lv_obj_create(content);
+	lv_obj_remove_style_all(top_row);
+	lv_obj_set_width(top_row, LV_PCT(100));
+	lv_obj_set_flex_grow(top_row, 1);
+	lv_obj_set_style_bg_opa(top_row, LV_OPA_TRANSP, 0);
+	lv_obj_set_layout(top_row, LV_LAYOUT_FLEX);
+	lv_obj_set_flex_flow(top_row, LV_FLEX_FLOW_ROW);
+	lv_obj_set_flex_align(top_row, LV_FLEX_ALIGN_SPACE_BETWEEN,
+			      LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+
+	g_ui.date_label = lv_label_create(top_row);
+	lv_obj_set_style_text_font(g_ui.date_label, &lv_font_montserrat_14, 0);
+	lv_obj_set_style_text_color(g_ui.date_label, lv_color_hex(0xD8DEE9), 0);
+
+	battery_wrap = lv_obj_create(top_row);
+	lv_obj_remove_style_all(battery_wrap);
+	lv_obj_set_width(battery_wrap, LV_SIZE_CONTENT);
+	lv_obj_set_layout(battery_wrap, LV_LAYOUT_FLEX);
+	lv_obj_set_flex_flow(battery_wrap, LV_FLEX_FLOW_ROW);
+	lv_obj_set_flex_align(battery_wrap, LV_FLEX_ALIGN_CENTER,
+			      LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+	lv_obj_set_style_pad_column(battery_wrap, 4, 0);
+
+	g_ui.battery_icon = lv_label_create(battery_wrap);
+	lv_obj_set_style_text_font(g_ui.battery_icon, &lv_font_montserrat_14, 0);
+
+	g_ui.battery_label = lv_label_create(battery_wrap);
+	lv_obj_set_style_text_font(g_ui.battery_label, &lv_font_montserrat_14, 0);
+	lv_obj_set_style_text_color(g_ui.battery_label, lv_color_hex(0xD8DEE9), 0);
+
+	g_ui.battery_state_label = lv_label_create(battery_wrap);
+	lv_obj_set_style_text_font(g_ui.battery_state_label, &lv_font_montserrat_14, 0);
+
+	middle_row = lv_obj_create(content);
+	lv_obj_remove_style_all(middle_row);
+	lv_obj_set_width(middle_row, LV_PCT(100));
+	lv_obj_set_flex_grow(middle_row, 2);
+	lv_obj_set_style_bg_opa(middle_row, LV_OPA_TRANSP, 0);
+
+	g_ui.time_label = lv_label_create(middle_row);
+	lv_obj_set_style_text_font(g_ui.time_label, &lv_font_montserrat_32, 0);
+	lv_obj_set_style_text_color(g_ui.time_label, lv_color_white(), 0);
+	lv_obj_center(g_ui.time_label);
+
+	bottom_row = lv_obj_create(content);
+	lv_obj_remove_style_all(bottom_row);
+	lv_obj_set_width(bottom_row, LV_PCT(100));
+	lv_obj_set_flex_grow(bottom_row, 1);
+	lv_obj_set_style_bg_opa(bottom_row, LV_OPA_TRANSP, 0);
+	lv_obj_set_layout(bottom_row, LV_LAYOUT_FLEX);
+	lv_obj_set_flex_flow(bottom_row, LV_FLEX_FLOW_ROW);
+	lv_obj_set_flex_align(bottom_row, LV_FLEX_ALIGN_CENTER,
+			      LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
+	lv_obj_set_style_pad_column(bottom_row, 6, 0);
+
+	for (uint32_t i = 0; i < UI_STATUS_COUNT; i++) {
+		ui_main_create_status_chip(bottom_row, (enum ui_status_id)i);
+	}
+
+	ui_main_refresh_all(model, date_text, time_text);
+	ui_initialized = true;
+}

src/ui/ui_main.h

@@ -0,0 +1,39 @@
+#ifndef BLINKY_UI_MAIN_H_
+#define BLINKY_UI_MAIN_H_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <lvgl.h>
+
+#include "mode_switch_event.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ui_main_model {
+	lv_color_t theme_color;
+	lv_color_t inactive_border_color;
+	uint8_t battery_level;
+	enum mode_switch_mode mode;
+	uint8_t led_mask;
+	bool charging;
+	bool full;
+};
+
+void ui_main_init(const struct ui_main_model *model,
+		  const char *date_text,
+		  const char *time_text);
+void ui_main_refresh_all(const struct ui_main_model *model,
+			 const char *date_text,
+			 const char *time_text);
+void ui_main_refresh_status_bar(const struct ui_main_model *model);
+void ui_main_refresh_battery(const struct ui_main_model *model);
+void ui_main_refresh_datetime(const char *date_text, const char *time_text);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BLINKY_UI_MAIN_H_ */

src/usb_cdc_module.c

@@ -0,0 +1,426 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <app_event_manager.h>
+
+#define MODULE usb_cdc_module
+#include <caf/events/module_state_event.h>
+#include <caf/events/power_event.h>
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/uart.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/sys/ring_buffer.h>
+#include <zephyr/sys/util.h>
+
+#include "usb_cdc_rx_event.h"
+#include "usb_cdc_tx_event.h"
+#include "usb_function_ready_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);
+
+#define USB_CDC_RX_RING_BUF_SIZE 256
+#define USB_CDC_TX_RING_BUF_SIZE 256
+#define USB_CDC_RX_CHUNK_SIZE 32
+#define USB_CDC_CONTROL_POLL_INTERVAL K_MSEC(100)
+#define USB_CDC_EXPECTED_BAUDRATE 115200U
+
+static const struct device *const cdc_dev = DEVICE_DT_GET_ONE(zephyr_cdc_acm_uart);
+
+static uint8_t rx_ring_buffer[USB_CDC_RX_RING_BUF_SIZE];
+static uint8_t tx_ring_buffer[USB_CDC_TX_RING_BUF_SIZE];
+static struct ring_buf rx_ringbuf;
+static struct ring_buf tx_ringbuf;
+static struct k_work rx_work;
+static struct k_work_delayable control_work;
+static bool initialized;
+static bool running;
+static bool usb_active;
+static bool usb_function_prepared;
+static bool dtr_ready;
+static bool rx_enabled;
+
+static void submit_usb_cdc_rx_event(const uint8_t *data, size_t len)
+{
+	struct usb_cdc_rx_event *event = new_usb_cdc_rx_event(len);
+
+	memcpy(event->dyndata.data, data, len);
+	APP_EVENT_SUBMIT(event);
+}
+
+static void submit_usb_function_ready_event(void)
+{
+	struct usb_function_ready_event *event = new_usb_function_ready_event();
+
+	event->function_mask = USB_FUNCTION_CDC_ACM;
+	APP_EVENT_SUBMIT(event);
+}
+
+static void reset_ring_buffers(void)
+{
+	unsigned int key = irq_lock();
+
+	ring_buf_init(&rx_ringbuf, sizeof(rx_ring_buffer), rx_ring_buffer);
+	ring_buf_init(&tx_ringbuf, sizeof(tx_ring_buffer), tx_ring_buffer);
+
+	irq_unlock(key);
+}
+
+static void disable_uart_io(void)
+{
+	uart_irq_rx_disable(cdc_dev);
+	uart_irq_tx_disable(cdc_dev);
+	rx_enabled = false;
+	dtr_ready = false;
+	reset_ring_buffers();
+}
+
+static void kick_tx(void)
+{
+	if (!running || !usb_active || !dtr_ready) {
+		return;
+	}
+
+	uart_irq_tx_enable(cdc_dev);
+}
+
+static void validate_line_coding(void)
+{
+	uint32_t baudrate = 0U;
+	int err;
+
+	err = uart_line_ctrl_get(cdc_dev, UART_LINE_CTRL_BAUD_RATE, &baudrate);
+	if (err) {
+		LOG_WRN("Failed to get CDC baudrate (%d)", err);
+	} else {
+		LOG_INF("CDC baudrate %u", baudrate);
+		if (baudrate != USB_CDC_EXPECTED_BAUDRATE) {
+			LOG_WRN("Expected CDC baudrate %u, got %u",
+				USB_CDC_EXPECTED_BAUDRATE, baudrate);
+		}
+	}
+
+#ifdef CONFIG_UART_USE_RUNTIME_CONFIGURE
+	{
+		struct uart_config cfg;
+
+		err = uart_config_get(cdc_dev, &cfg);
+		if (err) {
+			LOG_WRN("uart_config_get failed (%d)", err);
+		} else {
+			LOG_INF("CDC line coding data:%u stop:%u parity:%u flow:%u",
+				cfg.data_bits, cfg.stop_bits, cfg.parity,
+				cfg.flow_ctrl);
+			if ((cfg.data_bits != UART_CFG_DATA_BITS_8) ||
+			    (cfg.stop_bits != UART_CFG_STOP_BITS_1) ||
+			    (cfg.parity != UART_CFG_PARITY_NONE) ||
+			    (cfg.flow_ctrl != UART_CFG_FLOW_CTRL_NONE)) {
+				LOG_WRN("Expected CDC line coding 115200 8N1 no flow control");
+			}
+		}
+	}
+#endif
+}
+
+static void rx_work_handler(struct k_work *work)
+{
+	uint8_t buffer[USB_CDC_RX_CHUNK_SIZE];
+
+	ARG_UNUSED(work);
+
+	while (true) {
+		uint32_t len;
+		unsigned int key = irq_lock();
+
+		len = ring_buf_get(&rx_ringbuf, buffer, sizeof(buffer));
+		irq_unlock(key);
+
+		if (len == 0U) {
+			return;
+		}
+
+		submit_usb_cdc_rx_event(buffer, len);
+	}
+}
+
+static void control_work_handler(struct k_work *work)
+{
+	uint32_t dtr = 0U;
+	int err;
+
+	ARG_UNUSED(work);
+
+	if (!running || !usb_active) {
+		return;
+	}
+
+	err = uart_line_ctrl_get(cdc_dev, UART_LINE_CTRL_DTR, &dtr);
+	if (err) {
+		LOG_WRN("Failed to get CDC DTR (%d)", err);
+		goto reschedule;
+	}
+
+	if (dtr && !dtr_ready) {
+		dtr_ready = true;
+		LOG_INF("CDC DTR set");
+		validate_line_coding();
+
+		err = uart_line_ctrl_set(cdc_dev, UART_LINE_CTRL_DCD, 1);
+		if (err) {
+			LOG_WRN("Failed to set DCD (%d)", err);
+		}
+
+		err = uart_line_ctrl_set(cdc_dev, UART_LINE_CTRL_DSR, 1);
+		if (err) {
+			LOG_WRN("Failed to set DSR (%d)", err);
+		}
+
+		if (!rx_enabled) {
+			uart_irq_rx_enable(cdc_dev);
+			rx_enabled = true;
+		}
+
+		kick_tx();
+	} else if (!dtr && dtr_ready) {
+		LOG_INF("CDC DTR cleared");
+		disable_uart_io();
+	}
+
+reschedule:
+	k_work_reschedule(&control_work, USB_CDC_CONTROL_POLL_INTERVAL);
+}
+
+static void cdc_interrupt_handler(const struct device *dev, void *user_data)
+{
+	ARG_UNUSED(user_data);
+
+	while (uart_irq_update(dev) && uart_irq_is_pending(dev)) {
+		if (uart_irq_rx_ready(dev)) {
+			uint8_t buffer[USB_CDC_RX_CHUNK_SIZE];
+			int recv_len = uart_fifo_read(dev, buffer, sizeof(buffer));
+
+			if (recv_len < 0) {
+				LOG_ERR("Failed to read CDC RX FIFO");
+				continue;
+			}
+
+			if (recv_len > 0) {
+				uint32_t written;
+				unsigned int key = irq_lock();
+
+				written = ring_buf_put(&rx_ringbuf, buffer,
+						       (uint32_t)recv_len);
+				irq_unlock(key);
+
+				if (written < (uint32_t)recv_len) {
+					LOG_WRN("Drop %d CDC RX bytes", recv_len - (int)written);
+				}
+
+				k_work_submit(&rx_work);
+			}
+		}
+
+		if (uart_irq_tx_ready(dev)) {
+			uint8_t buffer[USB_CDC_RX_CHUNK_SIZE];
+			uint32_t len;
+			int sent_len;
+			unsigned int key = irq_lock();
+
+			len = ring_buf_get(&tx_ringbuf, buffer, sizeof(buffer));
+			irq_unlock(key);
+
+			if (len == 0U) {
+				uart_irq_tx_disable(dev);
+				continue;
+			}
+
+			sent_len = uart_fifo_fill(dev, buffer, len);
+			if (sent_len < 0) {
+				LOG_ERR("Failed to write CDC TX FIFO");
+				uart_irq_tx_disable(dev);
+			} else if ((uint32_t)sent_len < len) {
+				LOG_WRN("Drop %u CDC TX bytes",
+					(unsigned int)(len - (uint32_t)sent_len));
+			}
+		}
+	}
+}
+
+static int module_init(void)
+{
+	if (!device_is_ready(cdc_dev)) {
+		LOG_ERR("CDC ACM device not ready");
+		return -ENODEV;
+	}
+
+	reset_ring_buffers();
+	k_work_init(&rx_work, rx_work_handler);
+	k_work_init_delayable(&control_work, control_work_handler);
+	uart_irq_callback_set(cdc_dev, cdc_interrupt_handler);
+	usb_function_prepared = false;
+	return 0;
+}
+
+static int module_start(void)
+{
+	if (running) {
+		return 0;
+	}
+
+	running = true;
+	if (usb_active) {
+		k_work_reschedule(&control_work, K_NO_WAIT);
+	}
+
+	return 0;
+}
+
+static void module_pause(void)
+{
+	if (!running) {
+		return;
+	}
+
+	k_work_cancel_delayable(&control_work);
+	disable_uart_io();
+	running = false;
+}
+
+static bool handle_usb_prepare_event(const struct usb_prepare_event *event)
+{
+	ARG_UNUSED(event);
+
+	if (!running || usb_function_prepared) {
+		return false;
+	}
+
+	usb_function_prepared = true;
+	submit_usb_function_ready_event();
+	return false;
+}
+
+static bool handle_usb_device_state_event(const struct usb_device_state_event *event)
+{
+	bool new_usb_active = (event->state == USB_DEVICE_STATE_ACTIVE);
+
+	if (new_usb_active == usb_active) {
+		return false;
+	}
+
+	usb_active = new_usb_active;
+
+	if (!usb_active) {
+		k_work_cancel_delayable(&control_work);
+		disable_uart_io();
+	} else if (running) {
+		k_work_reschedule(&control_work, K_NO_WAIT);
+	}
+
+	return false;
+}
+
+static bool handle_usb_cdc_tx_event(const struct usb_cdc_tx_event *event)
+{
+	uint32_t written;
+	unsigned int key;
+
+	if (!running || !usb_active || !dtr_ready) {
+		return false;
+	}
+
+	key = irq_lock();
+	written = ring_buf_put(&tx_ringbuf, event->dyndata.data,
+			       (uint32_t)event->dyndata.size);
+	irq_unlock(key);
+
+	if (written < event->dyndata.size) {
+		LOG_WRN("Drop %zu CDC TX bytes", event->dyndata.size - written);
+	}
+
+	if (written > 0U) {
+		kick_tx();
+	}
+
+	return false;
+}
+
+static bool app_event_handler(const struct app_event_header *aeh)
+{
+	if (is_usb_device_state_event(aeh)) {
+		return handle_usb_device_state_event(cast_usb_device_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)) {
+		return handle_usb_cdc_tx_event(cast_usb_cdc_tx_event(aeh));
+	}
+
+	if (is_module_state_event(aeh)) {
+		const struct module_state_event *event = cast_module_state_event(aeh);
+
+		if (check_state(event, MODULE_ID(main), MODULE_STATE_READY)) {
+			int err;
+
+			if (!initialized) {
+				err = module_init();
+				if (err) {
+					module_set_state(MODULE_STATE_ERROR);
+					return false;
+				}
+
+				initialized = true;
+			}
+
+			err = module_start();
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	if (is_power_down_event(aeh)) {
+		if (initialized) {
+			module_pause();
+			module_set_state(MODULE_STATE_STANDBY);
+		}
+
+		return false;
+	}
+
+	if (is_wake_up_event(aeh)) {
+		if (initialized) {
+			int err = module_start();
+
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	return false;
+}
+
+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_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_cdc_test_module.c

@@ -0,0 +1,164 @@
+#include <stdbool.h>
+#include <string.h>
+
+#include <app_event_manager.h>
+
+#define MODULE usb_cdc_test_module
+#include <caf/events/module_state_event.h>
+#include <caf/events/power_event.h>
+
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include "usb_cdc_tx_event.h"
+#include "usb_device_state_event.h"
+
+LOG_MODULE_REGISTER(MODULE, LOG_LEVEL_INF);
+
+#define USB_CDC_TEST_PERIOD K_SECONDS(1)
+
+static const uint8_t hello_message[] = "hello\r\n";
+
+static struct k_work_delayable hello_work;
+static bool initialized;
+static bool running;
+static bool usb_active;
+
+static void submit_hello_message(void)
+{
+	struct usb_cdc_tx_event *event =
+		new_usb_cdc_tx_event(sizeof(hello_message) - 1U);
+
+	memcpy(event->dyndata.data, hello_message, sizeof(hello_message) - 1U);
+	APP_EVENT_SUBMIT(event);
+}
+
+static void hello_work_handler(struct k_work *work)
+{
+	ARG_UNUSED(work);
+
+	if (!running || !usb_active) {
+		return;
+	}
+
+	submit_hello_message();
+	k_work_reschedule(&hello_work, USB_CDC_TEST_PERIOD);
+}
+
+static int module_init(void)
+{
+	k_work_init_delayable(&hello_work, hello_work_handler);
+	return 0;
+}
+
+static int module_start(void)
+{
+	if (running) {
+		return 0;
+	}
+
+	running = true;
+	if (usb_active) {
+		k_work_reschedule(&hello_work, USB_CDC_TEST_PERIOD);
+	}
+
+	return 0;
+}
+
+static void module_pause(void)
+{
+	if (!running) {
+		return;
+	}
+
+	k_work_cancel_delayable(&hello_work);
+	running = false;
+}
+
+static bool handle_usb_device_state_event(const struct usb_device_state_event *event)
+{
+	bool new_usb_active = (event->state == USB_DEVICE_STATE_ACTIVE);
+
+	if (new_usb_active == usb_active) {
+		return false;
+	}
+
+	usb_active = new_usb_active;
+
+	if (!running) {
+		return false;
+	}
+
+	if (usb_active) {
+		k_work_reschedule(&hello_work, USB_CDC_TEST_PERIOD);
+	} else {
+		k_work_cancel_delayable(&hello_work);
+	}
+
+	return false;
+}
+
+static bool app_event_handler(const struct app_event_header *aeh)
+{
+	if (is_usb_device_state_event(aeh)) {
+		return handle_usb_device_state_event(cast_usb_device_state_event(aeh));
+	}
+
+	if (is_module_state_event(aeh)) {
+		const struct module_state_event *event = cast_module_state_event(aeh);
+
+		if (check_state(event, MODULE_ID(main), MODULE_STATE_READY)) {
+			int err;
+
+			if (!initialized) {
+				err = module_init();
+				if (err) {
+					module_set_state(MODULE_STATE_ERROR);
+					return false;
+				}
+
+				initialized = true;
+			}
+
+			err = module_start();
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	if (is_power_down_event(aeh)) {
+		if (initialized) {
+			module_pause();
+			module_set_state(MODULE_STATE_STANDBY);
+		}
+
+		return false;
+	}
+
+	if (is_wake_up_event(aeh)) {
+		if (initialized) {
+			int err = module_start();
+
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	return false;
+}
+
+APP_EVENT_LISTENER(MODULE, app_event_handler);
+APP_EVENT_SUBSCRIBE(MODULE, module_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);

src/usb_device_module.c

@@ -0,0 +1,349 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <app_event_manager.h>
+
+#define MODULE usb_device_module
+#include <caf/events/module_state_event.h>
+#include <caf/events/power_event.h>
+
+#include <zephyr/logging/log.h>
+#include <zephyr/usb/usbd.h>
+
+#include <caf/events/power_manager_event.h>
+
+#include "usb_device_module.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);
+
+#define USB_DEVICE_VID 0x1915
+#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)
+
+USBD_DEVICE_DEFINE(blinky_usbd, DEVICE_DT_GET(DT_NODELABEL(usbd)),
+		   USB_DEVICE_VID, USB_DEVICE_PID);
+
+USBD_DESC_LANG_DEFINE(blinky_lang);
+USBD_DESC_MANUFACTURER_DEFINE(blinky_mfr, USB_DEVICE_MANUFACTURER);
+USBD_DESC_PRODUCT_DEFINE(blinky_product, USB_DEVICE_PRODUCT);
+
+USBD_DESC_CONFIG_DEFINE(blinky_fs_cfg_desc, "FS Configuration");
+USBD_CONFIGURATION_DEFINE(blinky_fs_config, 0, 250, &blinky_fs_cfg_desc);
+
+static const char *const class_blocklist[] = {
+	NULL,
+};
+
+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 enum usb_device_state device_state = USB_DEVICE_STATE_DISCONNECTED;
+
+static 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);
+}
+
+static void submit_usb_prepare_event(void)
+{
+	struct usb_prepare_event *event = new_usb_prepare_event();
+
+	APP_EVENT_SUBMIT(event);
+}
+
+static void update_usb_device_state(enum usb_device_state state)
+{
+	if (device_state == state) {
+		return;
+	}
+
+	device_state = state;
+	submit_usb_device_state_event(state);
+}
+
+static void update_power_manager_restriction(bool vbus_present)
+{
+	power_manager_restrict(MODULE_IDX(MODULE),
+			       vbus_present ? POWER_MANAGER_LEVEL_ALIVE :
+					      POWER_MANAGER_LEVEL_SUSPENDED);
+}
+
+static int usb_descriptors_init(void)
+{
+	int err;
+
+	err = usbd_add_descriptor(&blinky_usbd, &blinky_lang);
+	if (err) {
+		return err;
+	}
+
+	err = usbd_add_descriptor(&blinky_usbd, &blinky_mfr);
+	if (err) {
+		return err;
+	}
+
+	err = usbd_add_descriptor(&blinky_usbd, &blinky_product);
+	if (err) {
+		return err;
+	}
+
+	err = usbd_add_configuration(&blinky_usbd, USBD_SPEED_FS, &blinky_fs_config);
+	if (err) {
+		return err;
+	}
+
+	err = usbd_register_all_classes(&blinky_usbd, USBD_SPEED_FS, 1, class_blocklist);
+	if (err) {
+		return err;
+	}
+
+	usbd_device_set_code_triple(&blinky_usbd, USBD_SPEED_FS, 0, 0, 0);
+
+	return 0;
+}
+
+static void usbd_msg_cb(struct usbd_context *const usbd_ctx,
+			const struct usbd_msg *const msg)
+{
+	ARG_UNUSED(usbd_ctx);
+
+	switch (msg->type) {
+	case USBD_MSG_VBUS_READY:
+		update_power_manager_restriction(true);
+		if (!usb_enabled) {
+			int err = usbd_enable(&blinky_usbd);
+
+			if (err) {
+				LOG_ERR("usbd_enable failed (%d)", err);
+			} else {
+				usb_enabled = true;
+				update_usb_device_state(USB_DEVICE_STATE_POWERED);
+			}
+		}
+		break;
+
+	case USBD_MSG_VBUS_REMOVED:
+		update_power_manager_restriction(false);
+		if (usb_enabled) {
+			int err = usbd_disable(&blinky_usbd);
+
+			if (err) {
+				LOG_ERR("usbd_disable failed (%d)", err);
+			}
+		}
+
+		usb_enabled = false;
+		update_usb_device_state(USB_DEVICE_STATE_DISCONNECTED);
+		break;
+
+	case USBD_MSG_CONFIGURATION:
+		if (msg->status) {
+			update_usb_device_state(USB_DEVICE_STATE_ACTIVE);
+		} else if (usb_enabled) {
+			update_usb_device_state(USB_DEVICE_STATE_POWERED);
+		}
+		break;
+
+	case USBD_MSG_SUSPEND:
+		if (usb_enabled) {
+			update_usb_device_state(USB_DEVICE_STATE_SUSPENDED);
+		}
+		break;
+
+	case USBD_MSG_RESUME:
+		if (usb_enabled) {
+			update_usb_device_state(USB_DEVICE_STATE_ACTIVE);
+		}
+		break;
+
+	default:
+		break;
+	}
+}
+
+static int usb_stack_init(void)
+{
+	int err;
+
+	err = usbd_msg_register_cb(&blinky_usbd, usbd_msg_cb);
+	if (err) {
+		LOG_ERR("usbd_msg_register_cb failed (%d)", err);
+		return err;
+	}
+
+	err = usb_descriptors_init();
+	if (err) {
+		LOG_ERR("usb descriptor init failed (%d)", err);
+		return err;
+	}
+
+	err = usbd_init(&blinky_usbd);
+	if (err) {
+		LOG_ERR("usbd_init failed (%d)", err);
+		return err;
+	}
+
+	usbd_initialized = true;
+
+	if (!usbd_can_detect_vbus(&blinky_usbd)) {
+		err = usbd_enable(&blinky_usbd);
+		if (err) {
+			LOG_ERR("usbd_enable failed (%d)", err);
+			return err;
+		}
+
+		usb_enabled = true;
+		update_usb_device_state(USB_DEVICE_STATE_POWERED);
+	}
+
+	return 0;
+}
+
+static int module_init(void)
+{
+	device_state = USB_DEVICE_STATE_DISCONNECTED;
+	usb_enabled = false;
+	ready_function_mask = 0U;
+	prepare_broadcasted = false;
+	usbd_initialized = false;
+	update_power_manager_restriction(false);
+
+	return 0;
+}
+
+static int module_start(void)
+{
+	if (running) {
+		return 0;
+	}
+
+	running = true;
+
+	if (usbd_initialized || prepare_broadcasted) {
+		return 0;
+	}
+
+	ready_function_mask = 0U;
+	prepare_broadcasted = true;
+	submit_usb_prepare_event();
+
+	return 0;
+}
+
+static void module_pause(void)
+{
+	if (!running) {
+		return;
+	}
+
+	running = false;
+}
+
+static bool handle_module_state_event(const struct module_state_event *event)
+{
+	if (!check_state(event, MODULE_ID(main), MODULE_STATE_READY)) {
+		return false;
+	}
+
+	if (!initialized) {
+		int err = module_init();
+
+		if (err) {
+			module_set_state(MODULE_STATE_ERROR);
+			return false;
+		}
+
+		initialized = true;
+	}
+
+	if (!running) {
+		int err = module_start();
+
+		if (err) {
+			module_set_state(MODULE_STATE_ERROR);
+		} else if (usbd_initialized) {
+			module_set_state(MODULE_STATE_READY);
+		}
+	}
+
+	return false;
+}
+
+static bool handle_usb_function_ready_event(const struct usb_function_ready_event *event)
+{
+	int err;
+
+	if (!running || !prepare_broadcasted || usbd_initialized) {
+		return false;
+	}
+
+	ready_function_mask |= event->function_mask;
+
+	if ((ready_function_mask & USB_REQUIRED_FUNCTION_MASK) !=
+	    USB_REQUIRED_FUNCTION_MASK) {
+		return false;
+	}
+
+	err = usb_stack_init();
+	if (err) {
+		module_set_state(MODULE_STATE_ERROR);
+		return false;
+	}
+
+	module_set_state(MODULE_STATE_READY);
+	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_usb_function_ready_event(aeh)) {
+		return handle_usb_function_ready_event(cast_usb_function_ready_event(aeh));
+	}
+
+	if (is_power_down_event(aeh)) {
+		if (initialized) {
+			module_pause();
+			module_set_state(MODULE_STATE_STANDBY);
+		}
+
+		return false;
+	}
+
+	if (is_wake_up_event(aeh)) {
+		if (initialized) {
+			int err = module_start();
+
+			if (err) {
+				module_set_state(MODULE_STATE_ERROR);
+			} else if (usbd_initialized) {
+				module_set_state(MODULE_STATE_READY);
+			}
+		}
+
+		return false;
+	}
+
+	return false;
+}
+
+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_EARLY(MODULE, power_down_event);
+APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);

src/usb_hid_module.c

@@ -12,10 +12,8 @@
 #include <zephyr/device.h>
 #include <zephyr/drivers/usb/udc_buf.h>
 #include <zephyr/logging/log.h>
-#include <zephyr/sys/byteorder.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/usb/class/usbd_hid.h>
-#include <zephyr/usb/usbd.h>
 
 #include "hid_led_event.h"
 #include "hid_report_sent_event.h"
@@ -23,15 +21,13 @@
 #include "hid_tx_report_event.h"
 #include "keyboard_core.h"
 #include "set_protocol_event.h"
+#include "usb_function_ready_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);
 
-#define USB_HID_VID 0x1915
-#define USB_HID_PID 0x52F0
-#define USB_HID_MANUFACTURER "Atguigu"
-#define USB_HID_PRODUCT "WH Mini Keyboard"
-#define USB_HID_POLLING_US 1000U
-
 #define KBD_LED_REPORT_SIZE 1U
 
 enum usb_hid_interface {
@@ -106,7 +102,8 @@ static enum keyboard_protocol_mode keyboard_protocol_mode =
 	KEYBOARD_PROTOCOL_MODE_REPORT;
 static bool initialized;
 static bool running;
-static bool usb_enabled;
+static bool usb_active;
+static bool usb_function_prepared;
 static bool keyboard_report_in_flight;
 static bool consumer_report_in_flight;
 static uint16_t keyboard_in_flight_sequence;
@@ -115,20 +112,6 @@ static uint16_t consumer_in_flight_sequence;
 UDC_STATIC_BUF_DEFINE(keyboard_tx_buf, KEYBOARD_NKRO_REPORT_SIZE);
 UDC_STATIC_BUF_DEFINE(consumer_tx_buf, KEYBOARD_CONSUMER_REPORT_SIZE);
 
-USBD_DEVICE_DEFINE(blinky_usbd, DEVICE_DT_GET(DT_NODELABEL(usbd)),
-		   USB_HID_VID, USB_HID_PID);
-
-USBD_DESC_LANG_DEFINE(blinky_lang);
-USBD_DESC_MANUFACTURER_DEFINE(blinky_mfr, USB_HID_MANUFACTURER);
-USBD_DESC_PRODUCT_DEFINE(blinky_product, USB_HID_PRODUCT);
-
-USBD_DESC_CONFIG_DEFINE(blinky_fs_cfg_desc, "FS Configuration");
-USBD_CONFIGURATION_DEFINE(blinky_fs_config, 0, 250, &blinky_fs_cfg_desc);
-
-static const char *const class_blocklist[] = {
-	NULL,
-};
-
 static struct usb_hid_interface_state *iface_from_dev(const struct device *dev)
 {
 	for (size_t i = 0; i < ARRAY_SIZE(hid_ifaces); i++) {
@@ -146,6 +129,17 @@ static enum keyboard_protocol_mode usb_proto_to_keyboard_proto(uint8_t proto)
 					    : KEYBOARD_PROTOCOL_MODE_REPORT;
 }
 
+static void reset_usb_runtime_state(void)
+{
+	for (size_t i = 0; i < ARRAY_SIZE(hid_ifaces); i++) {
+		hid_ifaces[i].ready = false;
+	}
+
+	usb_active = false;
+	keyboard_report_in_flight = false;
+	consumer_report_in_flight = false;
+}
+
 static void submit_set_protocol_event(enum keyboard_protocol_mode protocol_mode)
 {
 	struct set_protocol_event *event = new_set_protocol_event();
@@ -167,12 +161,13 @@ static void submit_hid_led_event(uint8_t led_bm)
 static void submit_transport_state_event(void)
 {
 	struct hid_transport_state_event *event = new_hid_transport_state_event();
+	bool ready = running && usb_active;
 
 	event->transport = HID_TRANSPORT_USB;
-	event->ready = usb_enabled;
+	event->ready = ready;
-	event->keys_ready = usb_enabled &&
+	event->keys_ready = ready &&
 			    hid_ifaces[USB_HID_INTERFACE_KEYBOARD].ready;
-	event->consumer_ready = usb_enabled &&
+	event->consumer_ready = ready &&
 				hid_ifaces[USB_HID_INTERFACE_CONSUMER].ready;
 	event->protocol_mode = keyboard_protocol_mode;
 
@@ -192,6 +187,14 @@ static void submit_hid_report_sent_event(enum keyboard_report_type report_type,
 	APP_EVENT_SUBMIT(event);
 }
 
+static void submit_usb_function_ready_event(void)
+{
+	struct usb_function_ready_event *event = new_usb_function_ready_event();
+
+	event->function_mask = USB_FUNCTION_HID;
+	APP_EVENT_SUBMIT(event);
+}
+
 static void keyboard_iface_ready(const struct device *dev, const bool ready)
 {
 	struct usb_hid_interface_state *iface = iface_from_dev(dev);
@@ -204,8 +207,8 @@ static void keyboard_iface_ready(const struct device *dev, const bool ready)
 	if (!ready) {
 		keyboard_report_in_flight = false;
 	}
-	LOG_INF("%s interface %s",
+
-		dev->name, ready ? "ready" : "not ready");
+	LOG_INF("%s interface %s", dev->name, ready ? "ready" : "not ready");
 	submit_transport_state_event();
 }
 
@@ -316,8 +319,8 @@ static void consumer_iface_ready(const struct device *dev, const bool ready)
 	if (!ready) {
 		consumer_report_in_flight = false;
 	}
-	LOG_INF("%s interface %s",
+
-		dev->name, ready ? "ready" : "not ready");
+	LOG_INF("%s interface %s", dev->name, ready ? "ready" : "not ready");
 	submit_transport_state_event();
 }
 
@@ -400,81 +403,6 @@ static const struct hid_device_ops consumer_ops = {
 	.output_report = consumer_output_report,
 };
 
-static void usbd_msg_cb(struct usbd_context *const usbd_ctx,
-			const struct usbd_msg *const msg)
-{
-	ARG_UNUSED(usbd_ctx);
-
-	if (msg->type == USBD_MSG_VBUS_READY) {
-		if (!usb_enabled) {
-			int err = usbd_enable(&blinky_usbd);
-
-			if (err) {
-				LOG_ERR("usbd_enable failed (%d)", err);
-			} else {
-				usb_enabled = true;
-				submit_transport_state_event();
-			}
-		}
-
-		return;
-	}
-
-	if (msg->type == USBD_MSG_VBUS_REMOVED) {
-		if (usb_enabled) {
-			int err = usbd_disable(&blinky_usbd);
-
-			if (err) {
-				LOG_ERR("usbd_disable failed (%d)", err);
-			} else {
-				usb_enabled = false;
-				for (size_t i = 0; i < ARRAY_SIZE(hid_ifaces); i++) {
-					hid_ifaces[i].ready = false;
-				}
-				keyboard_report_in_flight = false;
-				consumer_report_in_flight = false;
-				submit_transport_state_event();
-			}
-		}
-
-		return;
-	}
-}
-
-static int usb_descriptors_init(void)
-{
-	int err;
-
-	err = usbd_add_descriptor(&blinky_usbd, &blinky_lang);
-	if (err) {
-		return err;
-	}
-
-	err = usbd_add_descriptor(&blinky_usbd, &blinky_mfr);
-	if (err) {
-		return err;
-	}
-
-	err = usbd_add_descriptor(&blinky_usbd, &blinky_product);
-	if (err) {
-		return err;
-	}
-
-	err = usbd_add_configuration(&blinky_usbd, USBD_SPEED_FS, &blinky_fs_config);
-	if (err) {
-		return err;
-	}
-
-	err = usbd_register_all_classes(&blinky_usbd, USBD_SPEED_FS, 1, class_blocklist);
-	if (err) {
-		return err;
-	}
-
-	usbd_device_set_code_triple(&blinky_usbd, USBD_SPEED_FS, 0, 0, 0);
-
-	return 0;
-}
-
 static int usb_hid_register_devices(void)
 {
 	int err;
@@ -507,41 +435,9 @@ static int usb_hid_register_devices(void)
 
 static int module_init(void)
 {
-	int err;
+	reset_usb_runtime_state();
-
+	keyboard_protocol_mode = KEYBOARD_PROTOCOL_MODE_REPORT;
-	err = usb_hid_register_devices();
+	usb_function_prepared = false;
-	if (err) {
-		LOG_ERR("hid_device_register failed (%d)", err);
-		return err;
-	}
-
-	err = usbd_msg_register_cb(&blinky_usbd, usbd_msg_cb);
-	if (err) {
-		LOG_ERR("usbd_msg_register_cb failed (%d)", err);
-		return err;
-	}
-
-	err = usb_descriptors_init();
-	if (err) {
-		LOG_ERR("usb descriptor init failed (%d)", err);
-		return err;
-	}
-
-	err = usbd_init(&blinky_usbd);
-	if (err) {
-		LOG_ERR("usbd_init failed (%d)", err);
-		return err;
-	}
-
-	if (!usbd_can_detect_vbus(&blinky_usbd)) {
-		err = usbd_enable(&blinky_usbd);
-		if (err) {
-			LOG_ERR("usbd_enable failed (%d)", err);
-			return err;
-		}
-
-		usb_enabled = true;
-	}
 
 	return 0;
 }
@@ -560,13 +456,54 @@ static int module_start(void)
 static void module_pause(void)
 {
 	running = false;
+	submit_transport_state_event();
+}
+
+static bool handle_usb_prepare_event(const struct usb_prepare_event *event)
+{
+	int err;
+
+	ARG_UNUSED(event);
+
+	if (!running || usb_function_prepared) {
+		return false;
+	}
+
+	err = usb_hid_register_devices();
+	if (err) {
+		LOG_ERR("hid_device_register failed (%d)", err);
+		module_set_state(MODULE_STATE_ERROR);
+		return false;
+	}
+
+	usb_function_prepared = true;
+	submit_usb_function_ready_event();
+	return false;
+}
+
+static bool handle_usb_device_state_event(const struct usb_device_state_event *event)
+{
+	bool new_usb_active = (event->state == USB_DEVICE_STATE_ACTIVE);
+
+	if (new_usb_active == usb_active) {
+		return false;
+	}
+
+	if (!new_usb_active) {
+		reset_usb_runtime_state();
+	} else {
+		usb_active = true;
+	}
+
+	submit_transport_state_event();
+	return false;
 }
 
 static bool handle_hid_tx_report_event(const struct hid_tx_report_event *event)
 {
 	int err;
 
-	if (!running || (event->transport != HID_TRANSPORT_USB)) {
+	if (!running || !usb_active || (event->transport != HID_TRANSPORT_USB)) {
 		return false;
 	}
 
@@ -640,6 +577,14 @@ 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)) {
+		return handle_usb_device_state_event(cast_usb_device_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)) {
 		const struct module_state_event *event = cast_module_state_event(aeh);
 
@@ -690,12 +635,13 @@ static bool app_event_handler(const struct app_event_header *aeh)
 		return false;
 	}
 
-	__ASSERT_NO_MSG(false);
 	return false;
 }
 
 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_device_state_event);
 APP_EVENT_SUBSCRIBE_EARLY(MODULE, power_down_event);
 APP_EVENT_SUBSCRIBE(MODULE, wake_up_event);