使用WinUSB读写USB设备

Windows为WinUSB设备提供了API，主要通过以下几个步骤访问设备。

通过扩展描述符中的GUID查看接口的路径
用接口的路径作为参数，调用CreateFile打开接口
使用WinUsb_Initialize得到WinUSB句柄
通过WinUsb_WritePipe和WinUsb_ReadPipe对接口进行读写操作

// ensure data size is not multiple of endpoint Max Packet size or we will send a zero length packet
UCHAR test_data_out[256-1];

UCHAR test_data_in[1024];

int main()
{
  const TCHAR* path = get_first_interface_device_path(_T("{1D4B2365-4749-48EA-B38A-7C6FDDDD7E23}"));
  if (path == NULL) {
    printf("device not found\n");
    return 0;
  }
  _tprintf(_T("Got device interface %s\n"), path);


  HANDLE hDev = CreateFile(path,
    GENERIC_WRITE | GENERIC_READ,
    FILE_SHARE_WRITE | FILE_SHARE_READ,
    NULL,
    OPEN_EXISTING,
    FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
    NULL);

  if (INVALID_HANDLE_VALUE == hDev) {

    printf("fail to open device, last error %d\n", GetLastError());
    return 0;
  }

  WINUSB_INTERFACE_HANDLE hWinusb;

  BOOL bResult = WinUsb_Initialize(hDev, &hWinusb);

  if (!bResult) {
    CloseHandle(hDev);
    printf("Fail to invoke WinUsb_Initialize, last error %d\n", GetLastError());
    return 0;
  }

  ULONG transferred;
  for (int i = 0; i<sizeof(test_data_out); i++) {
    test_data_out[i] = i;
  }
  bResult = WinUsb_WritePipe(hWinusb, 0x01, test_data_out, sizeof(test_data_out), &transferred, NULL);
  if (!bResult) {
    printf("Fail to invoke WinUsb_WritePipe, last error %d\n", GetLastError());
    goto error;
  }
  printf("Write %d bytes data\n", transferred);

  bResult = WinUsb_ReadPipe(hWinusb, 0x81, test_data_in, sizeof(test_data_in), &transferred, NULL);
  if (!bResult) {
    printf("Fail to invoke WinUsb_WritePipe, last error %d\n", GetLastError());
    goto error;
  }
  printf("Read back %d bytes data\n", transferred);

error:

  WinUsb_Free(hWinusb);
  CloseHandle(hDev);

  exit(0);
}