In version v2.0_Cube of usb_device.c , the provided code is the following:
void HAL_PCDEx_BCD_Callback(PCD_HandleTypeDef *hpcd, PCD_BCD_MsgTypeDef msg)
{
USBD_HandleTypeDef usbdHandle = hUsbDeviceFS;
/* USER CODE BEGIN 7 */
if (hpcd->battery_charging_active == ENABLE)
{
switch(msg)
{
case PCD_BCD_CONTACT_DETECTION:
break;
case PCD_BCD_STD_DOWNSTREAM_PORT:
break;
case PCD_BCD_CHARGING_DOWNSTREAM_PORT:
break;
case PCD_BCD_DEDICATED_CHARGING_PORT:
break;
case PCD_BCD_DISCOVERY_COMPLETED:
USBD_Start(&usbdHandle);
break;
case PCD_BCD_ERROR:
default:
break;
}
}
/* USER CODE END 7 */
}
So it looks like when Battery Charging Detection BCD discovery is completed, no matter what the result is (SDP, CDP, or DCP), the USB device should always start with USBD_Start(&usbdHandle);
However this is not the case. In HAL_PCDEx_BCD_VBUSDetect , we see this
/* Battery Charging capability discovery finished Start Enumeration */
(void)HAL_PCDEx_DeActivateBCD(hpcd);
#if (USE_HAL_PCD_REGISTER_CALLBACKS == 1U)
hpcd->BCDCallback(hpcd, PCD_BCD_DISCOVERY_COMPLETED);
#else
HAL_PCDEx_BCD_Callback(hpcd, PCD_BCD_DISCOVERY_COMPLETED);
#endif /* USE_HAL_PCD_REGISTER_CALLBACKS */
which deactivates BCD before calling the Callback function with PCD_BCD_DISCOVERY_COMPLETED.
Since HAL_PCDEx_BCD_Callback checks if (hpcd->battery_charging_active == ENABLE) before entering switch statement, case PCD_BCD_DISCOVERY_COMPLETED is never reached and USB device does not get started.
