int _get_usb_string_descriptor (libusb_device_handle *udh, int index,
unsigned char* data, int length);
-int _usb_control_transfer (struct usb_dev_handle *udh, int request_type,
+int _usb_control_transfer (libusb_device_handle *udh, int request_type,
int request, int value, int index,
unsigned char *data, int length,
unsigned int timeout);