v4l2_subdev_routing
struct v4l2_subdev_routing *routing = parg;
struct v4l2_subdev_routing *routing = arg;
struct v4l2_subdev_routing *routing = arg;
which = ((struct v4l2_subdev_routing *)arg)->which;
#define VIDIOC_SUBDEV_G_ROUTING _IOWR('V', 38, struct v4l2_subdev_routing)
#define VIDIOC_SUBDEV_S_ROUTING _IOWR('V', 39, struct v4l2_subdev_routing)