v4l2_query_ext_ctrl  785 include/media/v4l2-ctrls.h int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctrl *qc);
v4l2_query_ext_ctrl  162 include/media/v4l2-ioctl.h 					struct v4l2_query_ext_ctrl *a);
v4l2_query_ext_ctrl 2100 include/uapi/linux/videodev2.h #define VIDIOC_QUERY_EXT_CTRL	_IOWR('V', 103, struct v4l2_query_ext_ctrl)