1 /*
2  * v4l2-event.h
3  *
4  * V4L2 events.
5  *
6  * Copyright (C) 2009--2010 Nokia Corporation.
7  *
8  * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
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.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  */
24 
25 #ifndef V4L2_EVENT_H
26 #define V4L2_EVENT_H
27 
28 #include <linux/types.h>
29 #include <linux/videodev2.h>
30 #include <linux/wait.h>
31 
32 struct v4l2_fh;
33 struct video_device;
34 
35 struct v4l2_kevent {
36 	struct list_head	list;
37 	struct v4l2_event	event;
38 };
39 
40 struct v4l2_subscribed_event {
41 	struct list_head	list;
42 	u32			type;
43 };
44 
45 struct v4l2_events {
46 	wait_queue_head_t	wait;
47 	struct list_head	subscribed; /* Subscribed events */
48 	struct list_head	free; /* Events ready for use */
49 	struct list_head	available; /* Dequeueable event */
50 	unsigned int		navailable;
51 	unsigned int		nallocated; /* Number of allocated events */
52 	u32			sequence;
53 };
54 
55 int v4l2_event_init(struct v4l2_fh *fh);
56 int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n);
57 void v4l2_event_free(struct v4l2_fh *fh);
58 int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
59 		       int nonblocking);
60 void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev);
61 int v4l2_event_pending(struct v4l2_fh *fh);
62 int v4l2_event_subscribe(struct v4l2_fh *fh,
63 			 struct v4l2_event_subscription *sub);
64 int v4l2_event_unsubscribe(struct v4l2_fh *fh,
65 			   struct v4l2_event_subscription *sub);
66 
67 #endif /* V4L2_EVENT_H */
68