struct v4l2_subdev;
struct v4l2_subscribed_event;
struct v4l2_fh;
+struct poll_table_struct;
/** struct v4l2_ctrl_ops - The control operations that the driver has to provide.
* @g_volatile_ctrl: Get a new value for this control. Generally only relevant
void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
struct v4l2_subscribed_event *sev);
+/* Can be used as a vidioc_log_status function that just dumps all controls
+ associated with the filehandle. */
+int v4l2_ctrl_log_status(struct file *file, void *fh);
+
+/* Can be used as a vidioc_subscribe_event function that just subscribes
+ control events. */
+int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
+ struct v4l2_event_subscription *sub);
+
+/* Can be used as a poll function that just polls for control events. */
+unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait);
+
/* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);