v4l2_frequency   1422 include/linux/videodev2.h #define VIDIOC_G_FREQUENCY	_IOWR('V', 56, struct v4l2_frequency)
v4l2_frequency   1423 include/linux/videodev2.h #define VIDIOC_S_FREQUENCY	 _IOW('V', 57, struct v4l2_frequency)
v4l2_frequency    211 include/media/v4l2-ioctl.h 					struct v4l2_frequency *a);
v4l2_frequency    213 include/media/v4l2-ioctl.h 					struct v4l2_frequency *a);