检测STM32L442 USB断开

Question

我正在开发一个使用STM32L442KC的项目，我无法检测到何时断开了USB设备模式(USB电缆拔出)。

我能做些什么来检测USB断开？有什么打扰吗？还是我需要检查一下旗子？

更新：

下面是由STM32CubeMX生成的IRQ。它没有HAL_PCD_DisconnectCallback回调，当电缆拔出时不调用HAL_PCD_SuspendCallback。

void HAL_PCD_IRQHandler(PCD_HandleTypeDef *hpcd)
{
  uint32_t wInterrupt_Mask = 0;

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_CTR))
  {
    /* servicing of the endpoint correct transfer interrupt */
    /* clear of the CTR flag into the sub */
    PCD_EP_ISR_Handler(hpcd);
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_RESET))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_RESET);
    HAL_PCD_ResetCallback(hpcd);
    HAL_PCD_SetAddress(hpcd, 0);
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_PMAOVR))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_PMAOVR);    
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_ERR))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_ERR); 
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_WKUP))
  {

    hpcd->Instance->CNTR &= ~(USB_CNTR_LPMODE);

    /*set wInterrupt_Mask global variable*/
    wInterrupt_Mask = USB_CNTR_CTRM  | USB_CNTR_WKUPM | USB_CNTR_SUSPM | USB_CNTR_ERRM \
      | USB_CNTR_SOFM | USB_CNTR_ESOFM | USB_CNTR_RESETM;

    /*Set interrupt mask*/
    hpcd->Instance->CNTR = wInterrupt_Mask;

    /* enable L1REQ interrupt */ 
    if (hpcd->Init.lpm_enable ==1)
    {
      wInterrupt_Mask |= USB_CNTR_L1REQM;

      /* Enable LPM support and enable ACK answer to LPM request*/
      USB_TypeDef *USBx = hpcd->Instance;
      hpcd->lpm_active = ENABLE;
      hpcd->LPM_State = LPM_L0;

      USBx->LPMCSR |= (USB_LPMCSR_LMPEN);
      USBx->LPMCSR |= (USB_LPMCSR_LPMACK);
    } 

    if(hpcd->LPM_State == LPM_L1)
    {
      hpcd->LPM_State = LPM_L0;
      HAL_PCDEx_LPM_Callback(hpcd, PCD_LPM_L0_ACTIVE);
    }

    HAL_PCD_ResumeCallback(hpcd);

    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_WKUP);     
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_SUSP))
  {    
    /* clear of the ISTR bit must be done after setting of CNTR_FSUSP */
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_SUSP);  

    /* Force low-power mode in the macrocell */
    hpcd->Instance->CNTR |= USB_CNTR_FSUSP;
    hpcd->Instance->CNTR |= USB_CNTR_LPMODE;

    if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_WKUP) == 0)
    {
      HAL_PCD_SuspendCallback(hpcd);
    }
  }

  /* Handle LPM Interrupt */ 
  if(__HAL_PCD_GET_FLAG(hpcd, USB_ISTR_L1REQ))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_L1REQ);      
    if( hpcd->LPM_State == LPM_L0)
    {   
      /* Force suspend and low-power mode before going to L1 state*/
      hpcd->Instance->CNTR |= USB_CNTR_LPMODE;
      hpcd->Instance->CNTR |= USB_CNTR_FSUSP;

      hpcd->LPM_State = LPM_L1;
      hpcd->BESL = (hpcd->Instance->LPMCSR & USB_LPMCSR_BESL) >>2 ;  
      HAL_PCDEx_LPM_Callback(hpcd, PCD_LPM_L1_ACTIVE);
    }
    else
    {
      HAL_PCD_SuspendCallback(hpcd);
    }
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_SOF))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_SOF); 
    HAL_PCD_SOFCallback(hpcd);
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_ESOF))
  {
    /* clear ESOF flag in ISTR */
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_ESOF); 
  }
}

Answer 1

在STM32 F7中，您可以在函数void HAL_PCD_SuspendCallback(PCD_HandleTypeDef *hpcd)、文件usbd_conf.c中检测到断开连接。我希望在L4中也是如此。

Answer 2

我不知道您的stm32，但是我使用STM32CubeMX生成代码，我的董事会是"stm32f4"，我有一个名为"usb_host.c“的文件。在这个文件中，我有一个函数：

static void USBH_UserProcess  (USBH_HandleTypeDef *phost, uint8_t id)
{
  /* USER CODE BEGIN CALL_BACK_1 */
  switch(id)
  {
  case HOST_USER_SELECT_CONFIGURATION:
  break;

  case HOST_USER_DISCONNECTION:
  Appli_state = APPLICATION_DISCONNECT;
  break;

  case HOST_USER_CLASS_ACTIVE:
      printf("READY\n");
  Appli_state = APPLICATION_READY;
  break;

  case HOST_USER_CONNECTION:
  Appli_state = APPLICATION_START;
  break;

  default:
  break;
  }
  /* USER CODE END CALL_BACK_1 */
}

，我完成了，

如果你想要你自己的回调：

static void USBH_UserProcess  (USBH_HandleTypeDef *phost, uint8_t id)
{
  /* USER CODE BEGIN CALL_BACK_1 */
    FATFS_USBcallback(phost, id);
  /* USER CODE END CALL_BACK_1 */
}

在另一份文件中：

void (*__usbChangedCallback)(ApplicationTypeDef) = NULL;

void FATFS_setStateChangedCallback(void (*callback)(ApplicationTypeDef)){
    __usbChangedCallback = callback;
}

void FATFS_USBcallback(USBH_HandleTypeDef *phost, uint8_t id){
    
    switch(id){
        case HOST_USER_SELECT_CONFIGURATION:
        break;
        case HOST_USER_DISCONNECTION:
            state = APPLICATION_DISCONNECT;
        break;
        case HOST_USER_CLASS_ACTIVE:
            FATFS_PRINTF("APPLICATION_READY\n");
            state = APPLICATION_READY;
            break;
        case HOST_USER_CONNECTION:
            FATFS_PRINTF("APPLICATION_START\n");
            state = APPLICATION_START;
        break;
        default:
        break;
    }
    
    if(__usbChangedCallback != NULL)
        __usbChangedCallback(state);
}

实现您自己的回调：

void myCallback(ApplicationTypeDef state){
    //bla bla bla
}

在那之后，做任何你需要做的事：

FATFS_setStateChangedCallback(myCallback);

好好享受吧。