VIDIOC_CROPCAP
v4l2_disable_ioctl(vfd, VIDIOC_CROPCAP);
__set_bit(_IOC_NR(VIDIOC_CROPCAP), valid_ioctls);
IOCTL_INFO(VIDIOC_CROPCAP, v4l_cropcap, v4l_print_cropcap, INFO_FL_CLEAR(v4l2_cropcap, type)),