该测评相关代码可以参见官方例程Ux_Device_HID_Standalone

定义USB2.0接口，设置速度为480MBit/s

在生成的代码中USB初始化流程如下

void MX_USB_OTG_HS_PCD_Init(void)
{

  /* USER CODE BEGIN USB_OTG_HS_PCD_Init 0 */

  /* USER CODE END USB_OTG_HS_PCD_Init 0 */

  /* USER CODE BEGIN USB_OTG_HS_PCD_Init 1 */

  /* USER CODE END USB_OTG_HS_PCD_Init 1 */
  hpcd_USB_OTG_HS.Instance = USB_OTG_HS;
  hpcd_USB_OTG_HS.Init.dev_endpoints = 9;
  hpcd_USB_OTG_HS.Init.speed = PCD_SPEED_HIGH;
  hpcd_USB_OTG_HS.Init.phy_itface = USB_OTG_HS_EMBEDDED_PHY;
  hpcd_USB_OTG_HS.Init.Sof_enable = DISABLE;
  hpcd_USB_OTG_HS.Init.low_power_enable = DISABLE;
  hpcd_USB_OTG_HS.Init.lpm_enable = DISABLE;
  hpcd_USB_OTG_HS.Init.use_dedicated_ep1 = DISABLE;
  hpcd_USB_OTG_HS.Init.vbus_sensing_enable = DISABLE;
  hpcd_USB_OTG_HS.Init.dma_enable = DISABLE;
  if (HAL_PCD_Init(&hpcd_USB_OTG_HS) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USB_OTG_HS_PCD_Init 2 */
  /* Set Rx FIFO */
  HAL_PCDEx_SetRxFiFo(&hpcd_USB_OTG_HS, 0x200);

  /* Set Tx FIFO 0 */
  HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 0, 0x10);

  /* Set Tx FIFO 1 */
  HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 1, 0x10);

  /* USER CODE END USB_OTG_HS_PCD_Init 2 */

}

为了让该USB设备在PC端枚举为鼠标设备，还需要进行USB设备的初始化，其中需要完成USBX的内存空间初始化以及USBX设备初始化

UINT MX_USBX_Init(VOID)
{
  UINT ret = UX_SUCCESS;
  UCHAR *pointer;

  /* USER CODE BEGIN MX_USBX_Init0 */

  /* USER CODE END MX_USBX_Init0 */

  pointer = ux_byte_pool_buffer;

  /* Initialize USBX Memory */
  if (ux_system_initialize(pointer, USBX_MEMORY_STACK_SIZE, UX_NULL, 0) != UX_SUCCESS)
  {
    /* USER CODE BEGIN USBX_SYSTEM_INITIALIZE_ERROR */
    return UX_ERROR;
    /* USER CODE END USBX_SYSTEM_INITIALIZE_ERROR */
  }

  ret = MX_USBX_Device_Init();
  if(ret != UX_SUCCESS)
  {
  /* USER CODE BEGIN MX_USBX_Device_Init_Error */
    while(1)
    {
    }
  /* USER CODE END MX_USBX_Device_Init_Error */
  }

  /* USER CODE BEGIN MX_USBX_Init1 */

  /* USER CODE END MX_USBX_Init1 */

  return ret;
}

对于USBX设备初始化，需要初始化USB堆栈空间以及启动USB设备

UINT MX_USBX_Device_Init(VOID)
{
  UINT ret = UX_SUCCESS;
  /* USER CODE BEGIN MX_USBX_Device_Init 0 */
  /* USER CODE END MX_USBX_Device_Init 0 */

  /* Initialize the Stack USB Device*/
  if (MX_USBX_Device_Stack_Init() != UX_SUCCESS)
  {
    /* USER CODE BEGIN MAIN_INITIALIZE_STACK_ERROR */
    return UX_ERROR;
    /* USER CODE END MAIN_INITIALIZE_STACK_ERROR */
  }

  /* USER CODE BEGIN MX_USBX_Device_Init 1 */
  HAL_Delay(20);
  USBX_APP_Device_Init();
  /* USER CODE END MX_USBX_Device_Init 1 */

  /* USER CODE BEGIN MX_USBX_Device_Init 2 */
  /* USER CODE END MX_USBX_Device_Init 2 */

  return ret;
}

在USB堆栈初始化中，枚举了USB设备的工作模式，同时初始化了USB设备作为鼠标设备的相关配置

UINT MX_USBX_Device_Stack_Init(void)
{
  UINT ret = UX_SUCCESS;
  UCHAR *device_framework_high_speed;
  UCHAR *device_framework_full_speed;
  ULONG device_framework_hs_length;
  ULONG device_framework_fs_length;
  ULONG string_framework_length;
  ULONG language_id_framework_length;
  UCHAR *string_framework;
  UCHAR *language_id_framework;

  /* USER CODE BEGIN MX_USBX_Device_Stack_Init 0 */

  /* USER CODE END MX_USBX_Device_Stack_Init 0 */
  /* Get Device Framework High Speed and get the length */
  device_framework_high_speed = USBD_Get_Device_Framework_Speed(USBD_HIGH_SPEED,
                                                                &device_framework_hs_length);

  /* Get Device Framework Full Speed and get the length */
  device_framework_full_speed = USBD_Get_Device_Framework_Speed(USBD_FULL_SPEED,
                                                                &device_framework_fs_length);

  /* Get String Framework and get the length */
  string_framework = USBD_Get_String_Framework(&string_framework_length);

  /* Get Language Id Framework and get the length */
  language_id_framework = USBD_Get_Language_Id_Framework(&language_id_framework_length);

  /* Install the device portion of USBX */
  if (ux_device_stack_initialize(device_framework_high_speed,
                                 device_framework_hs_length,
                                 device_framework_full_speed,
                                 device_framework_fs_length,
                                 string_framework,
                                 string_framework_length,
                                 language_id_framework,
                                 language_id_framework_length,
                                 UX_NULL) != UX_SUCCESS)
  {
    /* USER CODE BEGIN USBX_DEVICE_INITIALIZE_ERROR */
    return UX_ERROR;
    /* USER CODE END USBX_DEVICE_INITIALIZE_ERROR */
  }

  /* Initialize the hid mouse class parameters for the device */
  hid_mouse_parameter.ux_slave_class_hid_instance_activate         = USBD_HID_Mouse_Activate;
  hid_mouse_parameter.ux_slave_class_hid_instance_deactivate       = USBD_HID_Mouse_Deactivate;
  hid_mouse_parameter.ux_device_class_hid_parameter_report_address = USBD_HID_ReportDesc(INTERFACE_HID_MOUSE);
  hid_mouse_parameter.ux_device_class_hid_parameter_report_length  = USBD_HID_ReportDesc_length(INTERFACE_HID_MOUSE);
  hid_mouse_parameter.ux_device_class_hid_parameter_report_id      = UX_FALSE;
  hid_mouse_parameter.ux_device_class_hid_parameter_callback       = USBD_HID_Mouse_SetReport;
  hid_mouse_parameter.ux_device_class_hid_parameter_get_callback   = USBD_HID_Mouse_GetReport;

  /* USER CODE BEGIN HID_MOUSE_PARAMETER */

  /* USER CODE END HID_MOUSE_PARAMETER */

  /* Get hid mouse configuration number */
  hid_mouse_configuration_number = USBD_Get_Configuration_Number(CLASS_TYPE_HID, INTERFACE_HID_MOUSE);

  /* Find hid mouse interface number */
  hid_mouse_interface_number = USBD_Get_Interface_Number(CLASS_TYPE_HID, INTERFACE_HID_MOUSE);

  /* Initialize the device hid Mouse class */
  if (ux_device_stack_class_register(_ux_system_slave_class_hid_name,
                                     ux_device_class_hid_entry,
                                     hid_mouse_configuration_number,
                                     hid_mouse_interface_number,
                                     &hid_mouse_parameter) != UX_SUCCESS)
  {
    /* USER CODE BEGIN USBX_DEVICE_HID_MOUSE_REGISTER_ERROR */
    return UX_ERROR;
    /* USER CODE END USBX_DEVICE_HID_MOUSE_REGISTER_ERROR */
  }

  /* Initialize and link controller HAL driver */
  ux_dcd_stm32_initialize((ULONG)USB_OTG_HS, (ULONG)&hpcd_USB_OTG_HS);
  /* USER CODE BEGIN MX_USBX_Device_Stack_Init_PostTreatment */
  /* USER CODE END MX_USBX_Device_Stack_Init_PostTreatment */

  /* USER CODE BEGIN MX_USBX_Device_Stack_Init 1 */

  /* USER CODE END MX_USBX_Device_Stack_Init 1 */

  return ret;
}

最后，使用HAL_PCD_Start启动USB设备

VOID USBX_APP_Device_Init(VOID)
{
  /* USER CODE BEGIN USB_Device_Init_PreTreatment_0 */

  /* USER CODE END USB_Device_Init_PreTreatment_0 */


  /* USER CODE BEGIN USB_Device_Init_PreTreatment_1 */

  /* USER CODE END USB_Device_Init_PreTreatment_1 */

  /* Start the USB device */
  HAL_PCD_Start(&hpcd_USB_OTG_HS);

  /* USER CODE BEGIN USB_Device_Init_PostTreatment */

  /* USER CODE END USB_Device_Init_PostTreatment */
}

在主循环中，不断执行USB鼠标设备的相关任务

VOID USBX_Device_Process(VOID *arg)
{
  ux_device_stack_tasks_run();
  USBX_DEVICE_HID_MOUSE_Task();
}

在PC端完成该鼠标设备的枚举后，该任务通过开发板的按键，控制光标的移动

VOID USBX_DEVICE_HID_MOUSE_Task(VOID)
{
  ULONG tick;
  UX_SLAVE_DEVICE *device;
  UX_SLAVE_CLASS_HID_EVENT hid_event;

  device = &_ux_system_slave->ux_system_slave_device;
  ux_utility_memory_set(&hid_event, 0, sizeof(UX_SLAVE_CLASS_HID_EVENT));

  tick = HAL_GetTick();

  /* Check if the device state already configured */
  if ((device->ux_slave_device_state == UX_DEVICE_CONFIGURED) && (hid_mouse != UX_NULL))
  {

    /* Sleep for 10ms */
    if (ux_utility_time_elapsed(tick, HAL_GetTick()) > BUTTON_DETECT_WAIT)
    {
      return;
    }

    tick = HAL_GetTick();

    /* Check if user button is pressed */
    if (User_Button_State)
    {
      /* Get the new position */
      GetPointerData(&hid_event);

      /* Send an event to the hid */
      ux_device_class_hid_event_set(hid_mouse, &hid_event);

      /* Reset User Button state */
      User_Button_State = 0U;
    }
  }
}

打开设备管理器，可以看到开发板上USB2.0接口连接前后出现了新的USB HID设备

演示效果如下，可以看到板载按键能控制光标按照方形的运动轨迹运动