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-rw-r--r--drivers/media/video/v4l2-ctrls.c20
-rw-r--r--include/media/v4l2-ctrls.h9
2 files changed, 29 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index 7d58e4d420cd..909117203610 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -2394,3 +2394,23 @@ int v4l2_ctrl_log_status(struct file *file, void *fh)
return 0;
}
EXPORT_SYMBOL(v4l2_ctrl_log_status);
+
+int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
+ struct v4l2_event_subscription *sub)
+{
+ if (sub->type == V4L2_EVENT_CTRL)
+ return v4l2_event_subscribe(fh, sub, 0);
+ return -EINVAL;
+}
+EXPORT_SYMBOL(v4l2_ctrl_subscribe_event);
+
+unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
+{
+ struct v4l2_fh *fh = file->private_data;
+
+ if (v4l2_event_pending(fh))
+ return POLLPRI;
+ poll_wait(file, &fh->wait, wait);
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_ctrl_poll);
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 5f246c277ff8..3dbd06638506 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -33,6 +33,7 @@ struct video_device;
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
@@ -496,6 +497,14 @@ void v4l2_ctrl_del_event(struct v4l2_ctrl *ctrl,
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);

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