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208 lines
6.0 KiB
208 lines
6.0 KiB
/* SPDX-License-Identifier: GPL-2.0-only */ |
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/* |
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* v4l2-event.h |
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* |
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* V4L2 events. |
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* |
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* Copyright (C) 2009--2010 Nokia Corporation. |
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* |
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* Contact: Sakari Ailus <[email protected]> |
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*/ |
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#ifndef V4L2_EVENT_H |
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#define V4L2_EVENT_H |
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#include <linux/types.h> |
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#include <linux/videodev2.h> |
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#include <linux/wait.h> |
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struct v4l2_fh; |
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struct v4l2_subdev; |
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struct v4l2_subscribed_event; |
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struct video_device; |
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/** |
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* struct v4l2_kevent - Internal kernel event struct. |
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* @list: List node for the v4l2_fh->available list. |
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* @sev: Pointer to parent v4l2_subscribed_event. |
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* @event: The event itself. |
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* @ts: The timestamp of the event. |
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*/ |
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struct v4l2_kevent { |
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struct list_head list; |
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struct v4l2_subscribed_event *sev; |
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struct v4l2_event event; |
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u64 ts; |
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}; |
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/** |
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* struct v4l2_subscribed_event_ops - Subscribed event operations. |
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* |
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* @add: Optional callback, called when a new listener is added |
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* @del: Optional callback, called when a listener stops listening |
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* @replace: Optional callback that can replace event 'old' with event 'new'. |
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* @merge: Optional callback that can merge event 'old' into event 'new'. |
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*/ |
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struct v4l2_subscribed_event_ops { |
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int (*add)(struct v4l2_subscribed_event *sev, unsigned int elems); |
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void (*del)(struct v4l2_subscribed_event *sev); |
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void (*replace)(struct v4l2_event *old, const struct v4l2_event *new); |
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void (*merge)(const struct v4l2_event *old, struct v4l2_event *new); |
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}; |
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/** |
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* struct v4l2_subscribed_event - Internal struct representing a subscribed |
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* event. |
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* |
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* @list: List node for the v4l2_fh->subscribed list. |
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* @type: Event type. |
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* @id: Associated object ID (e.g. control ID). 0 if there isn't any. |
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* @flags: Copy of v4l2_event_subscription->flags. |
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* @fh: Filehandle that subscribed to this event. |
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* @node: List node that hooks into the object's event list |
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* (if there is one). |
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* @ops: v4l2_subscribed_event_ops |
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* @elems: The number of elements in the events array. |
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* @first: The index of the events containing the oldest available event. |
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* @in_use: The number of queued events. |
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* @events: An array of @elems events. |
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*/ |
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struct v4l2_subscribed_event { |
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struct list_head list; |
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u32 type; |
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u32 id; |
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u32 flags; |
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struct v4l2_fh *fh; |
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struct list_head node; |
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const struct v4l2_subscribed_event_ops *ops; |
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unsigned int elems; |
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unsigned int first; |
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unsigned int in_use; |
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struct v4l2_kevent events[]; |
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}; |
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/** |
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* v4l2_event_dequeue - Dequeue events from video device. |
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* |
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* @fh: pointer to struct v4l2_fh |
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* @event: pointer to struct v4l2_event |
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* @nonblocking: if not zero, waits for an event to arrive |
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*/ |
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int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event, |
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int nonblocking); |
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/** |
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* v4l2_event_queue - Queue events to video device. |
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* |
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* @vdev: pointer to &struct video_device |
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* @ev: pointer to &struct v4l2_event |
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* |
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* The event will be queued for all &struct v4l2_fh file handlers. |
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* |
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* .. note:: |
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* The driver's only responsibility is to fill in the type and the data |
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* fields. The other fields will be filled in by V4L2. |
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*/ |
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void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev); |
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/** |
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* v4l2_event_queue_fh - Queue events to video device. |
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* |
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* @fh: pointer to &struct v4l2_fh |
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* @ev: pointer to &struct v4l2_event |
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* |
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* |
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* The event will be queued only for the specified &struct v4l2_fh file handler. |
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* |
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* .. note:: |
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* The driver's only responsibility is to fill in the type and the data |
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* fields. The other fields will be filled in by V4L2. |
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*/ |
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void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev); |
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/** |
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* v4l2_event_wake_all - Wake all filehandles. |
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* |
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* Used when unregistering a video device. |
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* |
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* @vdev: pointer to &struct video_device |
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*/ |
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void v4l2_event_wake_all(struct video_device *vdev); |
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/** |
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* v4l2_event_pending - Check if an event is available |
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* |
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* @fh: pointer to &struct v4l2_fh |
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* |
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* Returns the number of pending events. |
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*/ |
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int v4l2_event_pending(struct v4l2_fh *fh); |
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/** |
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* v4l2_event_subscribe - Subscribes to an event |
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* |
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* @fh: pointer to &struct v4l2_fh |
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* @sub: pointer to &struct v4l2_event_subscription |
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* @elems: size of the events queue |
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* @ops: pointer to &v4l2_subscribed_event_ops |
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* |
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* .. note:: |
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* |
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* if @elems is zero, the framework will fill in a default value, |
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* with is currently 1 element. |
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*/ |
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int v4l2_event_subscribe(struct v4l2_fh *fh, |
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const struct v4l2_event_subscription *sub, |
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unsigned int elems, |
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const struct v4l2_subscribed_event_ops *ops); |
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/** |
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* v4l2_event_unsubscribe - Unsubscribes to an event |
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* |
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* @fh: pointer to &struct v4l2_fh |
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* @sub: pointer to &struct v4l2_event_subscription |
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*/ |
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int v4l2_event_unsubscribe(struct v4l2_fh *fh, |
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const struct v4l2_event_subscription *sub); |
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/** |
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* v4l2_event_unsubscribe_all - Unsubscribes to all events |
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* |
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* @fh: pointer to &struct v4l2_fh |
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*/ |
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void v4l2_event_unsubscribe_all(struct v4l2_fh *fh); |
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/** |
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* v4l2_event_subdev_unsubscribe - Subdev variant of v4l2_event_unsubscribe() |
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* |
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* @sd: pointer to &struct v4l2_subdev |
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* @fh: pointer to &struct v4l2_fh |
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* @sub: pointer to &struct v4l2_event_subscription |
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* |
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* .. note:: |
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* |
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* This function should be used for the &struct v4l2_subdev_core_ops |
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* %unsubscribe_event field. |
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*/ |
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int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, |
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struct v4l2_fh *fh, |
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struct v4l2_event_subscription *sub); |
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/** |
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* v4l2_src_change_event_subscribe - helper function that calls |
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* v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE. |
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* |
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* @fh: pointer to struct v4l2_fh |
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* @sub: pointer to &struct v4l2_event_subscription |
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*/ |
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int v4l2_src_change_event_subscribe(struct v4l2_fh *fh, |
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const struct v4l2_event_subscription *sub); |
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/** |
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* v4l2_src_change_event_subdev_subscribe - Variant of v4l2_event_subscribe(), |
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* meant to subscribe only events of the type %V4L2_EVENT_SOURCE_CHANGE. |
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* |
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* @sd: pointer to &struct v4l2_subdev |
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* @fh: pointer to &struct v4l2_fh |
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* @sub: pointer to &struct v4l2_event_subscription |
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*/ |
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int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd, |
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struct v4l2_fh *fh, |
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struct v4l2_event_subscription *sub); |
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#endif /* V4L2_EVENT_H */
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