How to disable USB Mass storage at runtime.

[ABatt.1]

I to all,

I have a project where an STM32F013RTC use an SD card.

At run time the SD is share with FAT_FS or it is used as USB mass storage device, but not at the same time.

I need to disable USB module.

The configuration is made from CubeMX, so I have the function MX_USB_DEVICE_Init() to enable and configure USB.

void MX_USB_DEVICE_Init(void)
{
  /* USER CODE BEGIN USB_DEVICE_Init_PreTreatment */
 
  /* USER CODE END USB_DEVICE_Init_PreTreatment */
 
  /* Init Device Library, add supported class and start the library. */
  if (USBD_Init(&hUsbDeviceFS, &FS_Desc, DEVICE_FS) != USBD_OK)
  {
    Error_Handler();
  }
  if (USBD_RegisterClass(&hUsbDeviceFS, &USBD_MSC) != USBD_OK)
  {
    Error_Handler();
  }
  if (USBD_MSC_RegisterStorage(&hUsbDeviceFS, &USBD_Storage_Interface_fops_FS) != USBD_OK)
  {
    Error_Handler();
  }
  if (USBD_Start(&hUsbDeviceFS) != USBD_OK)
  {
    Error_Handler();
  }
 
  /* USER CODE BEGIN USB_DEVICE_Init_PostTreatment */
 
  /* USER CODE END USB_DEVICE_Init_PostTreatment */
}

I wrote a function to disable USB:

void MX_USB_DEVICE_DeInit(void){
	USBD_DeInit(&hUsbDeviceFS);
}

But this cause an Hard Fault reset.

Thre is an HAL function to disable USB module ?

[TDK]

Perhaps debug the hard fault to determine the reason for the error.

HAL libraries are not created with robustness in mind, especially for uncommon scenarios.

[ABatt.1]

Hi TDK,

Hard fault is rised at exit of this function

void MSC_BOT_DeInit(USBD_HandleTypeDef *pdev){
 
 USBD_MSC_BOT_HandleTypeDef *hmsc = (USBD_MSC_BOT_HandleTypeDef *)pdev->pClassData;
 
 hmsc->bot_state = USBD_BOT_IDLE;
}

It is called in USBD_MSC_DeInit();

uint8_t USBD_MSC_DeInit(USBD_HandleTypeDef *pdev,
                         uint8_t cfgidx){
  /* Close MSC EPs */
  USBD_LL_CloseEP(pdev, MSC_EPOUT_ADDR);
  pdev->ep_out[MSC_EPOUT_ADDR & 0xFU].is_used = 0U;
 
  /* Close EP IN */
  USBD_LL_CloseEP(pdev, MSC_EPIN_ADDR);
  pdev->ep_in[MSC_EPIN_ADDR & 0xFU].is_used = 0U;
 
  /* De-Init the BOT layer */
  MSC_BOT_DeInit(pdev);
 
  /* Free MSC Class Resources */
  if (pdev->pClassData != NULL)
  {
    USBD_free(pdev->pClassData);
    pdev->pClassData  = NULL;
  }
 
  return USBD_OK;
}

Every pointer used is not NULL.

For the scenarios, this is simply:

int main(void)
{
  /* USER CODE BEGIN 1 */
 
  /* USER CODE END 1 */
 
  /* MCU Configuration--------------------------------------------------------*/
 
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
 
  /* USER CODE BEGIN Init */
 
  /* USER CODE END Init */
 
  /* Configure the system clock */
  SystemClock_Config();
 
  /* USER CODE BEGIN SysInit */
 
  /* USER CODE END SysInit */
 
  /* Initialize all configured peripherals */
  MX_USB_DEVICE_Init();
  /* USER CODE BEGIN 2 */
 
  MX_USB_DEVICE_DeInit();

I did this to avoid having to manually modify the code every time I change something in CubeMX (the project is still in the prototype phase)

[ABatt.1 · Accepted solution]

HI, I resolved the issue by using low level function provided from HAL:

void MX_USB_DEVICE_Stop(void){
	USBD_LL_Stop(&hUsbDeviceFS);
}
 
void MX_USB_DEVICE_Start(void){
	USBD_LL_Start(&hUsbDeviceFS);
}

I add this two in USB_device.c ( forv isibility of hUsbDeviceFS).

It works fine!