WinUSB Device

This section mainly introduces the winusb driver. Winusb is a general driver provided by Windows to allow users to access USB custom class devices in a user-friendly manner. It is essentially CDC ACM, but without baud rate setting commands. WINUSB versions are divided into V1/V2 versions according to USB versions. V2 version requires BOS descriptor, while V1 version does not. V2 version requires setting USB2.1 version number in device descriptor.

Note

Changing any winusb descriptor configuration may result in successful enumeration but inability to recognize the device. You need to delete all registry entries under ComputerHKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlusbflags, then unplug and replug the device to take effect.

  • V1 version descriptor registration

const struct usb_descriptor winusbv1_descriptor = {
    .device_descriptor_callback = device_descriptor_callback,
    .config_descriptor_callback = config_descriptor_callback,
    .device_quality_descriptor_callback = device_quality_descriptor_callback,
    .string_descriptor_callback = string_descriptor_callback,
    .msosv1_descriptor = &msosv1_desc
};

OR

usbd_msosv1_desc_register(busid, &msosv1_desc);

  • V2 version descriptor registration

const struct usb_descriptor winusbv2_descriptor = {
    .device_descriptor_callback = device_descriptor_callback,
    .config_descriptor_callback = config_descriptor_callback,
    .device_quality_descriptor_callback = device_quality_descriptor_callback,
    .string_descriptor_callback = string_descriptor_callback,
    .msosv2_descriptor = &msosv2_desc,
    .bos_descriptor = &bos_desc,
};

OR

usbd_bos_desc_register(busid, &bos_desc);
usbd_msosv2_desc_register(busid, &msosv2_desc);

  • Interface descriptor registration

/* Interface 0 */
USB_INTERFACE_DESCRIPTOR_INIT(0x00, 0x00, 0x02, 0xFF, 0x00, 0x00, 0x02),
/* Endpoint OUT 2 */
USB_ENDPOINT_DESCRIPTOR_INIT(WINUSB_OUT_EP, USB_ENDPOINT_TYPE_BULK, WINUSB_EP_MPS, 0x00),
/* Endpoint IN 1 */
USB_ENDPOINT_DESCRIPTOR_INIT(WINUSB_IN_EP, USB_ENDPOINT_TYPE_BULK, WINUSB_EP_MPS, 0x00),

  • Read and write operations are the same as CDC ACM, no further elaboration