Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 1 | /* |
| 2 | * v4l2-event.h |
| 3 | * |
| 4 | * V4L2 events. |
| 5 | * |
| 6 | * Copyright (C) 2009--2010 Nokia Corporation. |
| 7 | * |
Sakari Ailus | 8c5dff9 | 2012-10-28 06:44:17 -0300 | [diff] [blame] | 8 | * Contact: Sakari Ailus <sakari.ailus@iki.fi> |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 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. |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 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 | |
Hans Verkuil | 3ad57c3 | 2011-06-20 12:00:36 -0300 | [diff] [blame] | 27 | /* |
| 28 | * Overview: |
| 29 | * |
| 30 | * Events are subscribed per-filehandle. An event specification consists of a |
| 31 | * type and is optionally associated with an object identified through the |
| 32 | * 'id' field. So an event is uniquely identified by the (type, id) tuple. |
| 33 | * |
| 34 | * The v4l2-fh struct has a list of subscribed events. The v4l2_subscribed_event |
| 35 | * struct is added to that list, one for every subscribed event. |
| 36 | * |
| 37 | * Each v4l2_subscribed_event struct ends with an array of v4l2_kevent structs. |
| 38 | * This array (ringbuffer, really) is used to store any events raised by the |
| 39 | * driver. The v4l2_kevent struct links into the 'available' list of the |
| 40 | * v4l2_fh struct so VIDIOC_DQEVENT will know which event to dequeue first. |
| 41 | * |
| 42 | * Finally, if the event subscription is associated with a particular object |
| 43 | * such as a V4L2 control, then that object needs to know about that as well |
| 44 | * so that an event can be raised by that object. So the 'node' field can |
| 45 | * be used to link the v4l2_subscribed_event struct into a list of that |
| 46 | * object. |
| 47 | * |
| 48 | * So to summarize: |
| 49 | * |
| 50 | * struct v4l2_fh has two lists: one of the subscribed events, and one of the |
| 51 | * pending events. |
| 52 | * |
| 53 | * struct v4l2_subscribed_event has a ringbuffer of raised (pending) events of |
| 54 | * that particular type. |
| 55 | * |
| 56 | * If struct v4l2_subscribed_event is associated with a specific object, then |
| 57 | * that object will have an internal list of struct v4l2_subscribed_event so |
| 58 | * it knows who subscribed an event to that object. |
| 59 | */ |
| 60 | |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 61 | struct v4l2_fh; |
Sylwester Nawrocki | 4f4d14b | 2013-01-22 18:58:57 -0300 | [diff] [blame] | 62 | struct v4l2_subdev; |
Hans Verkuil | f1e393d | 2011-06-13 19:24:17 -0300 | [diff] [blame] | 63 | struct v4l2_subscribed_event; |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 64 | struct video_device; |
| 65 | |
Mauro Carvalho Chehab | b6fce85 | 2015-08-22 08:28:39 -0300 | [diff] [blame] | 66 | /** |
| 67 | * struct v4l2_kevent - Internal kernel event struct. |
| 68 | * @list: List node for the v4l2_fh->available list. |
| 69 | * @sev: Pointer to parent v4l2_subscribed_event. |
| 70 | * @event: The event itself. |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 71 | */ |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 72 | struct v4l2_kevent { |
| 73 | struct list_head list; |
Hans Verkuil | f1e393d | 2011-06-13 19:24:17 -0300 | [diff] [blame] | 74 | struct v4l2_subscribed_event *sev; |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 75 | struct v4l2_event event; |
| 76 | }; |
| 77 | |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 78 | /** |
| 79 | * struct v4l2_subscribed_event_ops - Subscribed event operations. |
Mauro Carvalho Chehab | b6fce85 | 2015-08-22 08:28:39 -0300 | [diff] [blame] | 80 | * |
| 81 | * @add: Optional callback, called when a new listener is added |
| 82 | * @del: Optional callback, called when a listener stops listening |
| 83 | * @replace: Optional callback that can replace event 'old' with event 'new'. |
| 84 | * @merge: Optional callback that can merge event 'old' into event 'new'. |
| 85 | */ |
Hans de Goede | c53c254 | 2012-04-08 12:59:46 -0300 | [diff] [blame] | 86 | struct v4l2_subscribed_event_ops { |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 87 | int (*add)(struct v4l2_subscribed_event *sev, unsigned int elems); |
Hans de Goede | c53c254 | 2012-04-08 12:59:46 -0300 | [diff] [blame] | 88 | void (*del)(struct v4l2_subscribed_event *sev); |
| 89 | void (*replace)(struct v4l2_event *old, const struct v4l2_event *new); |
| 90 | void (*merge)(const struct v4l2_event *old, struct v4l2_event *new); |
| 91 | }; |
| 92 | |
Mauro Carvalho Chehab | b6fce85 | 2015-08-22 08:28:39 -0300 | [diff] [blame] | 93 | /** |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 94 | * struct v4l2_subscribed_event - Internal struct representing a subscribed |
| 95 | * event. |
| 96 | * |
Mauro Carvalho Chehab | b6fce85 | 2015-08-22 08:28:39 -0300 | [diff] [blame] | 97 | * @list: List node for the v4l2_fh->subscribed list. |
| 98 | * @type: Event type. |
| 99 | * @id: Associated object ID (e.g. control ID). 0 if there isn't any. |
| 100 | * @flags: Copy of v4l2_event_subscription->flags. |
| 101 | * @fh: Filehandle that subscribed to this event. |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 102 | * @node: List node that hooks into the object's event list |
| 103 | * (if there is one). |
Mauro Carvalho Chehab | b6fce85 | 2015-08-22 08:28:39 -0300 | [diff] [blame] | 104 | * @ops: v4l2_subscribed_event_ops |
| 105 | * @elems: The number of elements in the events array. |
| 106 | * @first: The index of the events containing the oldest available event. |
| 107 | * @in_use: The number of queued events. |
| 108 | * @events: An array of @elems events. |
| 109 | */ |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 110 | struct v4l2_subscribed_event { |
| 111 | struct list_head list; |
| 112 | u32 type; |
Hans Verkuil | 6e23939 | 2011-06-07 11:13:44 -0300 | [diff] [blame] | 113 | u32 id; |
Hans Verkuil | 77068d3 | 2011-06-13 18:55:58 -0300 | [diff] [blame] | 114 | u32 flags; |
Hans Verkuil | 77068d3 | 2011-06-13 18:55:58 -0300 | [diff] [blame] | 115 | struct v4l2_fh *fh; |
Hans Verkuil | 77068d3 | 2011-06-13 18:55:58 -0300 | [diff] [blame] | 116 | struct list_head node; |
Hans de Goede | c53c254 | 2012-04-08 12:59:46 -0300 | [diff] [blame] | 117 | const struct v4l2_subscribed_event_ops *ops; |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 118 | unsigned int elems; |
| 119 | unsigned int first; |
| 120 | unsigned int in_use; |
Hans Verkuil | f1e393d | 2011-06-13 19:24:17 -0300 | [diff] [blame] | 121 | struct v4l2_kevent events[]; |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 122 | }; |
| 123 | |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 124 | /** |
| 125 | * v4l2_event_dequeue - Dequeue events from video device. |
| 126 | * |
| 127 | * @fh: pointer to struct v4l2_fh |
| 128 | * @event: pointer to struct v4l2_event |
| 129 | * @nonblocking: if not zero, waits for an event to arrive |
| 130 | */ |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 131 | int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event, |
| 132 | int nonblocking); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 133 | |
| 134 | /** |
| 135 | * v4l2_event_queue - Queue events to video device. |
| 136 | * |
| 137 | * @vdev: pointer to &struct video_device |
| 138 | * @ev: pointer to &struct v4l2_event |
| 139 | * |
| 140 | * The event will be queued for all &struct v4l2_fh file handlers. |
| 141 | * |
| 142 | * .. note:: |
| 143 | * The driver's only responsibility is to fill in the type and the data |
| 144 | * fields.The other fields will be filled in by V4L2. |
| 145 | */ |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 146 | void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 147 | |
| 148 | /** |
| 149 | * v4l2_event_queue_fh - Queue events to video device. |
| 150 | * |
| 151 | * @fh: pointer to &struct v4l2_fh |
| 152 | * @ev: pointer to &struct v4l2_event |
| 153 | * |
| 154 | * |
| 155 | * The event will be queued only for the specified &struct v4l2_fh file handler. |
| 156 | * |
| 157 | * .. note:: |
| 158 | * The driver's only responsibility is to fill in the type and the data |
| 159 | * fields.The other fields will be filled in by V4L2. |
| 160 | */ |
Hans Verkuil | 6e23939 | 2011-06-07 11:13:44 -0300 | [diff] [blame] | 161 | void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 162 | |
| 163 | /** |
| 164 | * v4l2_event_pending - Check if an event is available |
| 165 | * |
| 166 | * @fh: pointer to &struct v4l2_fh |
| 167 | * |
| 168 | * Returns the number of pending events. |
| 169 | */ |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 170 | int v4l2_event_pending(struct v4l2_fh *fh); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 171 | |
| 172 | /** |
| 173 | * v4l2_event_subscribe - Subscribes to an event |
| 174 | * |
| 175 | * @fh: pointer to &struct v4l2_fh |
| 176 | * @sub: pointer to &struct v4l2_event_subscription |
| 177 | * @elems: size of the events queue |
| 178 | * @ops: pointer to &v4l2_subscribed_event_ops |
| 179 | * |
| 180 | * .. note:: |
| 181 | * |
| 182 | * if @elems is zero, the framework will fill in a default value, |
| 183 | * with is currently 1 element. |
| 184 | */ |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 185 | int v4l2_event_subscribe(struct v4l2_fh *fh, |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 186 | const struct v4l2_event_subscription *sub, |
| 187 | unsigned int elems, |
Hans de Goede | c53c254 | 2012-04-08 12:59:46 -0300 | [diff] [blame] | 188 | const struct v4l2_subscribed_event_ops *ops); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 189 | /** |
| 190 | * v4l2_event_unsubscribe - Unsubscribes to an event |
| 191 | * |
| 192 | * @fh: pointer to &struct v4l2_fh |
| 193 | * @sub: pointer to &struct v4l2_event_subscription |
| 194 | */ |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 195 | int v4l2_event_unsubscribe(struct v4l2_fh *fh, |
Hans Verkuil | 85f5fe3 | 2012-09-04 11:46:09 -0300 | [diff] [blame] | 196 | const struct v4l2_event_subscription *sub); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 197 | /** |
| 198 | * v4l2_event_unsubscribe_all - Unsubscribes to all events |
| 199 | * |
| 200 | * @fh: pointer to &struct v4l2_fh |
| 201 | */ |
Hans Verkuil | f1e393d | 2011-06-13 19:24:17 -0300 | [diff] [blame] | 202 | void v4l2_event_unsubscribe_all(struct v4l2_fh *fh); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 203 | |
| 204 | /** |
| 205 | * v4l2_event_subdev_unsubscribe - Subdev variant of v4l2_event_unsubscribe() |
| 206 | * |
| 207 | * @sd: pointer to &struct v4l2_subdev |
| 208 | * @fh: pointer to &struct v4l2_fh |
| 209 | * @sub: pointer to &struct v4l2_event_subscription |
| 210 | * |
| 211 | * .. note:: |
| 212 | * |
| 213 | * This function should be used for the &struct v4l2_subdev_core_ops |
| 214 | * %unsubscribe_event field. |
| 215 | */ |
| 216 | int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, |
| 217 | struct v4l2_fh *fh, |
Sylwester Nawrocki | 4f4d14b | 2013-01-22 18:58:57 -0300 | [diff] [blame] | 218 | struct v4l2_event_subscription *sub); |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 219 | /** |
Mauro Carvalho Chehab | e383ce0 | 2016-09-22 07:59:03 -0300 | [diff] [blame] | 220 | * v4l2_src_change_event_subscribe - helper function that calls |
| 221 | * v4l2_event_subscribe() if the event is %V4L2_EVENT_SOURCE_CHANGE. |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 222 | * |
| 223 | * @fh: pointer to struct v4l2_fh |
| 224 | * @sub: pointer to &struct v4l2_event_subscription |
| 225 | */ |
Arun Kumar K | 3cbe6e5 | 2014-05-14 03:59:42 -0300 | [diff] [blame] | 226 | int v4l2_src_change_event_subscribe(struct v4l2_fh *fh, |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 227 | const struct v4l2_event_subscription *sub); |
| 228 | /** |
| 229 | * v4l2_src_change_event_subdev_subscribe - Variant of v4l2_event_subscribe(), |
| 230 | * meant to subscribe only events of the type %V4L2_EVENT_SOURCE_CHANGE. |
| 231 | * |
| 232 | * @sd: pointer to &struct v4l2_subdev |
| 233 | * @fh: pointer to &struct v4l2_fh |
| 234 | * @sub: pointer to &struct v4l2_event_subscription |
| 235 | */ |
Arun Kumar K | 3cbe6e5 | 2014-05-14 03:59:42 -0300 | [diff] [blame] | 236 | int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd, |
Mauro Carvalho Chehab | 9d4ee1a | 2016-07-22 07:27:06 -0300 | [diff] [blame] | 237 | struct v4l2_fh *fh, |
| 238 | struct v4l2_event_subscription *sub); |
Sakari Ailus | c3b5b02 | 2010-03-01 05:14:18 -0300 | [diff] [blame] | 239 | #endif /* V4L2_EVENT_H */ |