6 * Copyright (C) 2009--2010 Nokia Corporation.
8 * Contact: Sakari Ailus <sakari.ailus@iki.fi>
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.
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.
23 #include <linux/types.h>
24 #include <linux/videodev2.h>
25 #include <linux/wait.h>
29 struct v4l2_subscribed_event;
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.
37 * @ts: The timestamp of the event.
40 struct list_head list;
41 struct v4l2_subscribed_event *sev;
42 struct v4l2_event event;
47 * struct v4l2_subscribed_event_ops - Subscribed event operations.
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'.
54 struct v4l2_subscribed_event_ops {
55 int (*add)(struct v4l2_subscribed_event *sev, unsigned int elems);
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);
62 * struct v4l2_subscribed_event - Internal struct representing a subscribed
65 * @list: List node for the v4l2_fh->subscribed list.
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.
70 * @node: List node that hooks into the object's event list
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.
78 struct v4l2_subscribed_event {
79 struct list_head list;
84 struct list_head node;
85 const struct v4l2_subscribed_event_ops *ops;
89 struct v4l2_kevent events[];
93 * v4l2_event_dequeue - Dequeue events from video device.
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
99 int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
103 * v4l2_event_queue - Queue events to video device.
105 * @vdev: pointer to &struct video_device
106 * @ev: pointer to &struct v4l2_event
108 * The event will be queued for all &struct v4l2_fh file handlers.
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.
114 void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev);
117 * v4l2_event_queue_fh - Queue events to video device.
119 * @fh: pointer to &struct v4l2_fh
120 * @ev: pointer to &struct v4l2_event
123 * The event will be queued only for the specified &struct v4l2_fh file handler.
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.
129 void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev);
132 * v4l2_event_pending - Check if an event is available
134 * @fh: pointer to &struct v4l2_fh
136 * Returns the number of pending events.
138 int v4l2_event_pending(struct v4l2_fh *fh);
141 * v4l2_event_subscribe - Subscribes to an event
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
150 * if @elems is zero, the framework will fill in a default value,
151 * with is currently 1 element.
153 int v4l2_event_subscribe(struct v4l2_fh *fh,
154 const struct v4l2_event_subscription *sub,
156 const struct v4l2_subscribed_event_ops *ops);
158 * v4l2_event_unsubscribe - Unsubscribes to an event
160 * @fh: pointer to &struct v4l2_fh
161 * @sub: pointer to &struct v4l2_event_subscription
163 int v4l2_event_unsubscribe(struct v4l2_fh *fh,
164 const struct v4l2_event_subscription *sub);
166 * v4l2_event_unsubscribe_all - Unsubscribes to all events
168 * @fh: pointer to &struct v4l2_fh
170 void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
173 * v4l2_event_subdev_unsubscribe - Subdev variant of v4l2_event_unsubscribe()
175 * @sd: pointer to &struct v4l2_subdev
176 * @fh: pointer to &struct v4l2_fh
177 * @sub: pointer to &struct v4l2_event_subscription
181 * This function should be used for the &struct v4l2_subdev_core_ops
182 * %unsubscribe_event field.
184 int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd,
186 struct v4l2_event_subscription *sub);
188 * v4l2_src_change_event_subscribe - helper function that calls
189 * v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE.
191 * @fh: pointer to struct v4l2_fh
192 * @sub: pointer to &struct v4l2_event_subscription
194 int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
195 const struct v4l2_event_subscription *sub);
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.
200 * @sd: pointer to &struct v4l2_subdev
201 * @fh: pointer to &struct v4l2_fh
202 * @sub: pointer to &struct v4l2_event_subscription
204 int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
206 struct v4l2_event_subscription *sub);
207 #endif /* V4L2_EVENT_H */