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

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