[linux.git] / include / media / v4l2-event.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * v4l2-event.h
 *
 * V4L2 events.
 *
 * Copyright (C) 2009--2010 Nokia Corporation.
 *
 * Contact: Sakari Ailus <[email protected]>
 */

#ifndef V4L2_EVENT_H
#define V4L2_EVENT_H

#include <linux/types.h>
#include <linux/videodev2.h>
#include <linux/wait.h>

struct v4l2_fh;
struct v4l2_subdev;
struct v4l2_subscribed_event;
struct video_device;

/**
 * struct v4l2_kevent - Internal kernel event struct.
 * @list:	List node for the v4l2_fh->available list.
 * @sev:	Pointer to parent v4l2_subscribed_event.
 * @event:	The event itself.
 * @ts:		The timestamp of the event.
 */
struct v4l2_kevent {
	struct list_head	list;
	struct v4l2_subscribed_event *sev;
	struct v4l2_event	event;
	u64			ts;
};

/**
 * struct v4l2_subscribed_event_ops - Subscribed event operations.
 *
 * @add:	Optional callback, called when a new listener is added
 * @del:	Optional callback, called when a listener stops listening
 * @replace:	Optional callback that can replace event 'old' with event 'new'.
 * @merge:	Optional callback that can merge event 'old' into event 'new'.
 */
struct v4l2_subscribed_event_ops {
	int  (*add)(struct v4l2_subscribed_event *sev, unsigned int elems);
	void (*del)(struct v4l2_subscribed_event *sev);
	void (*replace)(struct v4l2_event *old, const struct v4l2_event *new);
	void (*merge)(const struct v4l2_event *old, struct v4l2_event *new);
};

/**
 * struct v4l2_subscribed_event - Internal struct representing a subscribed
 *		event.
 *
 * @list:	List node for the v4l2_fh->subscribed list.
 * @type:	Event type.
 * @id:	Associated object ID (e.g. control ID). 0 if there isn't any.
 * @flags:	Copy of v4l2_event_subscription->flags.
 * @fh:	Filehandle that subscribed to this event.
 * @node:	List node that hooks into the object's event list
 *		(if there is one).
 * @ops:	v4l2_subscribed_event_ops
 * @elems:	The number of elements in the events array.
 * @first:	The index of the events containing the oldest available event.
 * @in_use:	The number of queued events.
 * @events:	An array of @elems events.
 */
struct v4l2_subscribed_event {
	struct list_head	list;
	u32			type;
	u32			id;
	u32			flags;
	struct v4l2_fh		*fh;
	struct list_head	node;
	const struct v4l2_subscribed_event_ops *ops;
	unsigned int		elems;
	unsigned int		first;
	unsigned int		in_use;
	struct v4l2_kevent	events[];
};

/**
 * v4l2_event_dequeue - Dequeue events from video device.
 *
 * @fh: pointer to struct v4l2_fh
 * @event: pointer to struct v4l2_event
 * @nonblocking: if not zero, waits for an event to arrive
 */
int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
		       int nonblocking);

/**
 * v4l2_event_queue - Queue events to video device.
 *
 * @vdev: pointer to &struct video_device
 * @ev: pointer to &struct v4l2_event
 *
 * The event will be queued for all &struct v4l2_fh file handlers.
 *
 * .. note::
 *    The driver's only responsibility is to fill in the type and the data
 *    fields. The other fields will be filled in by V4L2.
 */
void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev);

/**
 * v4l2_event_queue_fh - Queue events to video device.
 *
 * @fh: pointer to &struct v4l2_fh
 * @ev: pointer to &struct v4l2_event
 *
 *
 * The event will be queued only for the specified &struct v4l2_fh file handler.
 *
 * .. note::
 *    The driver's only responsibility is to fill in the type and the data
 *    fields. The other fields will be filled in by V4L2.
 */
void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev);

/**
 * v4l2_event_wake_all - Wake all filehandles.
 *
 * Used when unregistering a video device.
 *
 * @vdev: pointer to &struct video_device
 */
void v4l2_event_wake_all(struct video_device *vdev);

/**
 * v4l2_event_pending - Check if an event is available
 *
 * @fh: pointer to &struct v4l2_fh
 *
 * Returns the number of pending events.
 */
int v4l2_event_pending(struct v4l2_fh *fh);

/**
 * v4l2_event_subscribe - Subscribes to an event
 *
 * @fh: pointer to &struct v4l2_fh
 * @sub: pointer to &struct v4l2_event_subscription
 * @elems: size of the events queue
 * @ops: pointer to &v4l2_subscribed_event_ops
 *
 * .. note::
 *
 *    if @elems is zero, the framework will fill in a default value,
 *    with is currently 1 element.
 */
int v4l2_event_subscribe(struct v4l2_fh *fh,
			 const struct v4l2_event_subscription *sub,
			 unsigned int elems,
			 const struct v4l2_subscribed_event_ops *ops);
/**
 * v4l2_event_unsubscribe - Unsubscribes to an event
 *
 * @fh: pointer to &struct v4l2_fh
 * @sub: pointer to &struct v4l2_event_subscription
 */
int v4l2_event_unsubscribe(struct v4l2_fh *fh,
			   const struct v4l2_event_subscription *sub);
/**
 * v4l2_event_unsubscribe_all - Unsubscribes to all events
 *
 * @fh: pointer to &struct v4l2_fh
 */
void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);

/**
 * v4l2_event_subdev_unsubscribe - Subdev variant of v4l2_event_unsubscribe()
 *
 * @sd: pointer to &struct v4l2_subdev
 * @fh: pointer to &struct v4l2_fh
 * @sub: pointer to &struct v4l2_event_subscription
 *
 * .. note::
 *
 *	This function should be used for the &struct v4l2_subdev_core_ops
 *	%unsubscribe_event field.
 */
int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd,
				  struct v4l2_fh *fh,
				  struct v4l2_event_subscription *sub);
/**
 * v4l2_src_change_event_subscribe - helper function that calls
 *	v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE.
 *
 * @fh: pointer to struct v4l2_fh
 * @sub: pointer to &struct v4l2_event_subscription
 */
int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
				    const struct v4l2_event_subscription *sub);
/**
 * v4l2_src_change_event_subdev_subscribe - Variant of v4l2_event_subscribe(),
 *	meant to subscribe only events of the type %V4L2_EVENT_SOURCE_CHANGE.
 *
 * @sd: pointer to &struct v4l2_subdev
 * @fh: pointer to &struct v4l2_fh
 * @sub: pointer to &struct v4l2_event_subscription
 */
int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
					   struct v4l2_fh *fh,
					   struct v4l2_event_subscription *sub);
#endif /* V4L2_EVENT_H */
Commit	Line	Data
1802d0be	1	/* SPDX-License-Identifier: GPL-2.0-only */
c3b5b024 SA	2	/*
	3	* v4l2-event.h
	4	*
	5	* V4L2 events.
	6	*
	7	* Copyright (C) 2009--2010 Nokia Corporation.
	8	*
8c5dff90	9	* Contact: Sakari Ailus <[email protected]>
c3b5b024 SA	10	*/
	11
	12	#ifndef V4L2_EVENT_H
	13	#define V4L2_EVENT_H
	14
	15	#include <linux/types.h>
	16	#include <linux/videodev2.h>
	17	#include <linux/wait.h>
	18
	19	struct v4l2_fh;
4f4d14b7	20	struct v4l2_subdev;
f1e393de	21	struct v4l2_subscribed_event;
c3b5b024 SA	22	struct video_device;
c3b5b024 SA	23
b6fce850 MCC	24	/**
	25	* struct v4l2_kevent - Internal kernel event struct.
	26	* @list: List node for the v4l2_fh->available list.
	27	* @sev: Pointer to parent v4l2_subscribed_event.
	28	* @event: The event itself.
63635b54	29	* @ts: The timestamp of the event.
9d4ee1ad	30	*/
c3b5b024 SA	31	struct v4l2_kevent {
c3b5b024 SA	32	struct list_head list;
f1e393de	33	struct v4l2_subscribed_event *sev;
c3b5b024	34	struct v4l2_event event;
63635b54	35	u64 ts;
c3b5b024 SA	36	};
c3b5b024 SA	37
9d4ee1ad MCC	38	/**
9d4ee1ad MCC	39	* struct v4l2_subscribed_event_ops - Subscribed event operations.
b6fce850 MCC	40	*
	41	* @add: Optional callback, called when a new listener is added
	42	* @del: Optional callback, called when a listener stops listening
	43	* @replace: Optional callback that can replace event 'old' with event 'new'.
	44	* @merge: Optional callback that can merge event 'old' into event 'new'.
	45	*/
c53c2549	46	struct v4l2_subscribed_event_ops {
9d4ee1ad	47	int (add)(struct v4l2_subscribed_event sev, unsigned int elems);
c53c2549 HG	48	void (del)(struct v4l2_subscribed_event sev);
	49	void (replace)(struct v4l2_event old, const struct v4l2_event *new);
	50	void (merge)(const struct v4l2_event old, struct v4l2_event *new);
	51	};
	52
b6fce850	53	/**
9d4ee1ad MCC	54	* struct v4l2_subscribed_event - Internal struct representing a subscribed
	55	* event.
	56	*
b6fce850 MCC	57	* @list: List node for the v4l2_fh->subscribed list.
	58	* @type: Event type.
	59	* @id: Associated object ID (e.g. control ID). 0 if there isn't any.
	60	* @flags: Copy of v4l2_event_subscription->flags.
	61	* @fh: Filehandle that subscribed to this event.
9d4ee1ad MCC	62	* @node: List node that hooks into the object's event list
9d4ee1ad MCC	63	* (if there is one).
b6fce850 MCC	64	* @ops: v4l2_subscribed_event_ops
	65	* @elems: The number of elements in the events array.
	66	* @first: The index of the events containing the oldest available event.
	67	* @in_use: The number of queued events.
	68	* @events: An array of @elems events.
	69	*/
c3b5b024 SA	70	struct v4l2_subscribed_event {
	71	struct list_head list;
	72	u32 type;
6e239399	73	u32 id;
77068d36	74	u32 flags;
77068d36	75	struct v4l2_fh *fh;
77068d36	76	struct list_head node;
c53c2549	77	const struct v4l2_subscribed_event_ops *ops;
9d4ee1ad MCC	78	unsigned int elems;
	79	unsigned int first;
	80	unsigned int in_use;
f1e393de	81	struct v4l2_kevent events[];
c3b5b024 SA	82	};
c3b5b024 SA	83
9d4ee1ad MCC	84	/**
	85	* v4l2_event_dequeue - Dequeue events from video device.
	86	*
	87	* @fh: pointer to struct v4l2_fh
	88	* @event: pointer to struct v4l2_event
	89	* @nonblocking: if not zero, waits for an event to arrive
	90	*/
c3b5b024 SA	91	int v4l2_event_dequeue(struct v4l2_fh fh, struct v4l2_event event,
c3b5b024 SA	92	int nonblocking);
9d4ee1ad MCC	93
	94	/**
	95	* v4l2_event_queue - Queue events to video device.
	96	*
	97	* @vdev: pointer to &struct video_device
	98	* @ev: pointer to &struct v4l2_event
	99	*
	100	* The event will be queued for all &struct v4l2_fh file handlers.
	101	*
	102	* .. note::
	103	* The driver's only responsibility is to fill in the type and the data
28955a61	104	* fields. The other fields will be filled in by V4L2.
9d4ee1ad	105	*/
c3b5b024	106	void v4l2_event_queue(struct video_device vdev, const struct v4l2_event ev);
9d4ee1ad MCC	107
	108	/**
	109	* v4l2_event_queue_fh - Queue events to video device.
	110	*
	111	* @fh: pointer to &struct v4l2_fh
	112	* @ev: pointer to &struct v4l2_event
	113	*
	114	*
	115	* The event will be queued only for the specified &struct v4l2_fh file handler.
	116	*
	117	* .. note::
	118	* The driver's only responsibility is to fill in the type and the data
28955a61	119	* fields. The other fields will be filled in by V4L2.
9d4ee1ad	120	*/
6e239399	121	void v4l2_event_queue_fh(struct v4l2_fh fh, const struct v4l2_event ev);
9d4ee1ad	122
28955a61 HV	123	/**
	124	* v4l2_event_wake_all - Wake all filehandles.
	125	*
	126	* Used when unregistering a video device.
	127	*
	128	* @vdev: pointer to &struct video_device
	129	*/
	130	void v4l2_event_wake_all(struct video_device *vdev);
	131
9d4ee1ad MCC	132	/**
	133	* v4l2_event_pending - Check if an event is available
	134	*
	135	* @fh: pointer to &struct v4l2_fh
	136	*
	137	* Returns the number of pending events.
	138	*/
c3b5b024	139	int v4l2_event_pending(struct v4l2_fh *fh);
9d4ee1ad MCC	140
	141	/**
	142	* v4l2_event_subscribe - Subscribes to an event
	143	*
	144	* @fh: pointer to &struct v4l2_fh
	145	* @sub: pointer to &struct v4l2_event_subscription
	146	* @elems: size of the events queue
	147	* @ops: pointer to &v4l2_subscribed_event_ops
	148	*
	149	* .. note::
	150	*
	151	* if @elems is zero, the framework will fill in a default value,
	152	* with is currently 1 element.
	153	*/
c3b5b024	154	int v4l2_event_subscribe(struct v4l2_fh *fh,
9d4ee1ad MCC	155	const struct v4l2_event_subscription *sub,
9d4ee1ad MCC	156	unsigned int elems,
c53c2549	157	const struct v4l2_subscribed_event_ops *ops);
9d4ee1ad MCC	158	/**
	159	* v4l2_event_unsubscribe - Unsubscribes to an event
	160	*
	161	* @fh: pointer to &struct v4l2_fh
	162	* @sub: pointer to &struct v4l2_event_subscription
	163	*/
c3b5b024	164	int v4l2_event_unsubscribe(struct v4l2_fh *fh,
85f5fe39	165	const struct v4l2_event_subscription *sub);
9d4ee1ad MCC	166	/**
	167	* v4l2_event_unsubscribe_all - Unsubscribes to all events
	168	*
	169	* @fh: pointer to &struct v4l2_fh
	170	*/
f1e393de	171	void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
9d4ee1ad MCC	172
	173	/**
	174	* v4l2_event_subdev_unsubscribe - Subdev variant of v4l2_event_unsubscribe()
	175	*
	176	* @sd: pointer to &struct v4l2_subdev
	177	* @fh: pointer to &struct v4l2_fh
	178	* @sub: pointer to &struct v4l2_event_subscription
	179	*
	180	* .. note::
	181	*
	182	* This function should be used for the &struct v4l2_subdev_core_ops
	183	* %unsubscribe_event field.
	184	*/
	185	int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd,
	186	struct v4l2_fh *fh,
4f4d14b7	187	struct v4l2_event_subscription *sub);
9d4ee1ad	188	/**
e383ce07	189	* v4l2_src_change_event_subscribe - helper function that calls
4a3fad70	190	* v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE.
9d4ee1ad MCC	191	*
	192	* @fh: pointer to struct v4l2_fh
	193	* @sub: pointer to &struct v4l2_event_subscription
	194	*/
3cbe6e5b	195	int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
9d4ee1ad MCC	196	const struct v4l2_event_subscription *sub);
	197	/**
	198	* v4l2_src_change_event_subdev_subscribe - Variant of v4l2_event_subscribe(),
	199	* meant to subscribe only events of the type %V4L2_EVENT_SOURCE_CHANGE.
	200	*
	201	* @sd: pointer to &struct v4l2_subdev
	202	* @fh: pointer to &struct v4l2_fh
	203	* @sub: pointer to &struct v4l2_event_subscription
	204	*/
3cbe6e5b	205	int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
9d4ee1ad MCC	206	struct v4l2_fh *fh,
9d4ee1ad MCC	207	struct v4l2_event_subscription *sub);
c3b5b024	208	#endif /* V4L2_EVENT_H */