int (*get_pkt_len) (unsigned char *pkt, int len);
int (*read_data) (unsigned char *pkt, int *x, int *y, int *touch, int *press);
int (*init) (struct usbtouch_usb *usbtouch);
int (*get_pkt_len) (unsigned char *pkt, int len);
int (*read_data) (unsigned char *pkt, int *x, int *y, int *touch, int *press);
int (*init) (struct usbtouch_usb *usbtouch);