[mirror_ubuntu-jammy-kernel.git] / include / media / v4l2-event.h

/*
 * v4l2-event.h
 *
 * V4L2 events.
 *
 * Copyright (C) 2009--2010 Nokia Corporation.
 *
 * Contact: Sakari Ailus <sakari.ailus@iki.fi>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#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.
 */
struct v4l2_kevent {
	struct list_head	list;
	struct v4l2_subscribed_event *sev;
	struct v4l2_event	event;
};

/**
 * 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_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
c3b5b024 SA	1	/*
	2	* v4l2-event.h
	3	*
	4	* V4L2 events.
	5	*
	6	* Copyright (C) 2009--2010 Nokia Corporation.
	7	*
8c5dff90	8	* Contact: Sakari Ailus <sakari.ailus@iki.fi>
c3b5b024 SA	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* version 2 as published by the Free Software Foundation.
	13	*
	14	* This program is distributed in the hope that it will be useful, but
	15	* WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* General Public License for more details.
c3b5b024 SA	18	*/
	19
	20	#ifndef V4L2_EVENT_H
	21	#define V4L2_EVENT_H
	22
	23	#include <linux/types.h>
	24	#include <linux/videodev2.h>
	25	#include <linux/wait.h>
	26
	27	struct v4l2_fh;
4f4d14b7	28	struct v4l2_subdev;
f1e393de	29	struct v4l2_subscribed_event;
c3b5b024 SA	30	struct video_device;
c3b5b024 SA	31
b6fce850 MCC	32	/**
	33	* struct v4l2_kevent - Internal kernel event struct.
	34	* @list: List node for the v4l2_fh->available list.
	35	* @sev: Pointer to parent v4l2_subscribed_event.
	36	* @event: The event itself.
9d4ee1ad	37	*/
c3b5b024 SA	38	struct v4l2_kevent {
c3b5b024 SA	39	struct list_head list;
f1e393de	40	struct v4l2_subscribed_event *sev;
c3b5b024 SA	41	struct v4l2_event event;
	42	};
	43
9d4ee1ad MCC	44	/**
9d4ee1ad MCC	45	* struct v4l2_subscribed_event_ops - Subscribed event operations.
b6fce850 MCC	46	*
	47	* @add: Optional callback, called when a new listener is added
	48	* @del: Optional callback, called when a listener stops listening
	49	* @replace: Optional callback that can replace event 'old' with event 'new'.
	50	* @merge: Optional callback that can merge event 'old' into event 'new'.
	51	*/
c53c2549	52	struct v4l2_subscribed_event_ops {
9d4ee1ad	53	int (add)(struct v4l2_subscribed_event sev, unsigned int elems);
c53c2549 HG	54	void (del)(struct v4l2_subscribed_event sev);
	55	void (replace)(struct v4l2_event old, const struct v4l2_event *new);
	56	void (merge)(const struct v4l2_event old, struct v4l2_event *new);
	57	};
	58
b6fce850	59	/**
9d4ee1ad MCC	60	* struct v4l2_subscribed_event - Internal struct representing a subscribed
	61	* event.
	62	*
b6fce850 MCC	63	* @list: List node for the v4l2_fh->subscribed list.
	64	* @type: Event type.
	65	* @id: Associated object ID (e.g. control ID). 0 if there isn't any.
	66	* @flags: Copy of v4l2_event_subscription->flags.
	67	* @fh: Filehandle that subscribed to this event.
9d4ee1ad MCC	68	* @node: List node that hooks into the object's event list
9d4ee1ad MCC	69	* (if there is one).
b6fce850 MCC	70	* @ops: v4l2_subscribed_event_ops
	71	* @elems: The number of elements in the events array.
	72	* @first: The index of the events containing the oldest available event.
	73	* @in_use: The number of queued events.
	74	* @events: An array of @elems events.
	75	*/
c3b5b024 SA	76	struct v4l2_subscribed_event {
	77	struct list_head list;
	78	u32 type;
6e239399	79	u32 id;
77068d36	80	u32 flags;
77068d36	81	struct v4l2_fh *fh;
77068d36	82	struct list_head node;
c53c2549	83	const struct v4l2_subscribed_event_ops *ops;
9d4ee1ad MCC	84	unsigned int elems;
	85	unsigned int first;
	86	unsigned int in_use;
f1e393de	87	struct v4l2_kevent events[];
c3b5b024 SA	88	};
c3b5b024 SA	89
9d4ee1ad MCC	90	/**
	91	* v4l2_event_dequeue - Dequeue events from video device.
	92	*
	93	* @fh: pointer to struct v4l2_fh
	94	* @event: pointer to struct v4l2_event
	95	* @nonblocking: if not zero, waits for an event to arrive
	96	*/
c3b5b024 SA	97	int v4l2_event_dequeue(struct v4l2_fh fh, struct v4l2_event event,
c3b5b024 SA	98	int nonblocking);
9d4ee1ad MCC	99
	100	/**
	101	* v4l2_event_queue - Queue events to video device.
	102	*
	103	* @vdev: pointer to &struct video_device
	104	* @ev: pointer to &struct v4l2_event
	105	*
	106	* The event will be queued for all &struct v4l2_fh file handlers.
	107	*
	108	* .. note::
	109	* The driver's only responsibility is to fill in the type and the data
	110	* fields.The other fields will be filled in by V4L2.
	111	*/
c3b5b024	112	void v4l2_event_queue(struct video_device vdev, const struct v4l2_event ev);
9d4ee1ad MCC	113
	114	/**
	115	* v4l2_event_queue_fh - Queue events to video device.
	116	*
	117	* @fh: pointer to &struct v4l2_fh
	118	* @ev: pointer to &struct v4l2_event
	119	*
	120	*
	121	* The event will be queued only for the specified &struct v4l2_fh file handler.
	122	*
	123	* .. note::
	124	* The driver's only responsibility is to fill in the type and the data
	125	* fields.The other fields will be filled in by V4L2.
	126	*/
6e239399	127	void v4l2_event_queue_fh(struct v4l2_fh fh, const struct v4l2_event ev);
9d4ee1ad MCC	128
	129	/**
	130	* v4l2_event_pending - Check if an event is available
	131	*
	132	* @fh: pointer to &struct v4l2_fh
	133	*
	134	* Returns the number of pending events.
	135	*/
c3b5b024	136	int v4l2_event_pending(struct v4l2_fh *fh);
9d4ee1ad MCC	137
	138	/**
	139	* v4l2_event_subscribe - Subscribes to an event
	140	*
	141	* @fh: pointer to &struct v4l2_fh
	142	* @sub: pointer to &struct v4l2_event_subscription
	143	* @elems: size of the events queue
	144	* @ops: pointer to &v4l2_subscribed_event_ops
	145	*
	146	* .. note::
	147	*
	148	* if @elems is zero, the framework will fill in a default value,
	149	* with is currently 1 element.
	150	*/
c3b5b024	151	int v4l2_event_subscribe(struct v4l2_fh *fh,
9d4ee1ad MCC	152	const struct v4l2_event_subscription *sub,
9d4ee1ad MCC	153	unsigned int elems,
c53c2549	154	const struct v4l2_subscribed_event_ops *ops);
9d4ee1ad MCC	155	/**
	156	* v4l2_event_unsubscribe - Unsubscribes to an event
	157	*
	158	* @fh: pointer to &struct v4l2_fh
	159	* @sub: pointer to &struct v4l2_event_subscription
	160	*/
c3b5b024	161	int v4l2_event_unsubscribe(struct v4l2_fh *fh,
85f5fe39	162	const struct v4l2_event_subscription *sub);
9d4ee1ad MCC	163	/**
	164	* v4l2_event_unsubscribe_all - Unsubscribes to all events
	165	*
	166	* @fh: pointer to &struct v4l2_fh
	167	*/
f1e393de	168	void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
9d4ee1ad MCC	169
	170	/**
	171	* v4l2_event_subdev_unsubscribe - Subdev variant of v4l2_event_unsubscribe()
	172	*
	173	* @sd: pointer to &struct v4l2_subdev
	174	* @fh: pointer to &struct v4l2_fh
	175	* @sub: pointer to &struct v4l2_event_subscription
	176	*
	177	* .. note::
	178	*
	179	* This function should be used for the &struct v4l2_subdev_core_ops
	180	* %unsubscribe_event field.
	181	*/
	182	int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd,
	183	struct v4l2_fh *fh,
4f4d14b7	184	struct v4l2_event_subscription *sub);
9d4ee1ad	185	/**
e383ce07	186	* v4l2_src_change_event_subscribe - helper function that calls
4a3fad70	187	* v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE.
9d4ee1ad MCC	188	*
	189	* @fh: pointer to struct v4l2_fh
	190	* @sub: pointer to &struct v4l2_event_subscription
	191	*/
3cbe6e5b	192	int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
9d4ee1ad MCC	193	const struct v4l2_event_subscription *sub);
	194	/**
	195	* v4l2_src_change_event_subdev_subscribe - Variant of v4l2_event_subscribe(),
	196	* meant to subscribe only events of the type %V4L2_EVENT_SOURCE_CHANGE.
	197	*
	198	* @sd: pointer to &struct v4l2_subdev
	199	* @fh: pointer to &struct v4l2_fh
	200	* @sub: pointer to &struct v4l2_event_subscription
	201	*/
3cbe6e5b	202	int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
9d4ee1ad MCC	203	struct v4l2_fh *fh,
9d4ee1ad MCC	204	struct v4l2_event_subscription *sub);
c3b5b024	205	#endif /* V4L2_EVENT_H */