6 * Copyright (C) 2009--2010 Nokia Corporation.
8 * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
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.
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
25 #include <media/v4l2-dev.h>
26 #include <media/v4l2-fh.h>
27 #include <media/v4l2-event.h>
28 #include <media/v4l2-ctrls.h>
30 #include <linux/sched.h>
31 #include <linux/slab.h>
33 static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
35 int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n)
39 while (fh->nallocated < n) {
40 struct v4l2_kevent *kev;
42 kev = kzalloc(sizeof(*kev), GFP_KERNEL);
46 spin_lock_irqsave(&fh->vdev->fh_lock, flags);
47 list_add_tail(&kev->list, &fh->free);
49 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
54 EXPORT_SYMBOL_GPL(v4l2_event_alloc);
56 #define list_kfree(list, type, member) \
57 while (!list_empty(list)) { \
59 hi = list_first_entry(list, type, member); \
60 list_del(&hi->member); \
64 void v4l2_event_free(struct v4l2_fh *fh)
66 list_kfree(&fh->free, struct v4l2_kevent, list);
67 list_kfree(&fh->available, struct v4l2_kevent, list);
68 v4l2_event_unsubscribe_all(fh);
70 EXPORT_SYMBOL_GPL(v4l2_event_free);
72 static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
74 struct v4l2_kevent *kev;
77 spin_lock_irqsave(&fh->vdev->fh_lock, flags);
79 if (list_empty(&fh->available)) {
80 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
84 WARN_ON(fh->navailable == 0);
86 kev = list_first_entry(&fh->available, struct v4l2_kevent, list);
87 list_move(&kev->list, &fh->free);
90 kev->event.pending = fh->navailable;
93 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
98 int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
104 return __v4l2_event_dequeue(fh, event);
106 /* Release the vdev lock while waiting */
108 mutex_unlock(fh->vdev->lock);
111 ret = wait_event_interruptible(fh->wait,
112 fh->navailable != 0);
116 ret = __v4l2_event_dequeue(fh, event);
117 } while (ret == -ENOENT);
120 mutex_lock(fh->vdev->lock);
124 EXPORT_SYMBOL_GPL(v4l2_event_dequeue);
126 /* Caller must hold fh->vdev->fh_lock! */
127 static struct v4l2_subscribed_event *v4l2_event_subscribed(
128 struct v4l2_fh *fh, u32 type, u32 id)
130 struct v4l2_subscribed_event *sev;
132 assert_spin_locked(&fh->vdev->fh_lock);
134 list_for_each_entry(sev, &fh->subscribed, list) {
135 if (sev->type == type && sev->id == id)
142 static void __v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev,
143 const struct timespec *ts)
145 struct v4l2_subscribed_event *sev;
146 struct v4l2_kevent *kev;
148 /* Are we subscribed? */
149 sev = v4l2_event_subscribed(fh, ev->type, ev->id);
153 /* Increase event sequence number on fh. */
156 /* Do we have any free events? */
157 if (list_empty(&fh->free))
160 /* Take one and fill it. */
161 kev = list_first_entry(&fh->free, struct v4l2_kevent, list);
162 kev->event.type = ev->type;
163 kev->event.u = ev->u;
164 kev->event.id = ev->id;
165 kev->event.timestamp = *ts;
166 kev->event.sequence = fh->sequence;
167 list_move_tail(&kev->list, &fh->available);
171 wake_up_all(&fh->wait);
174 void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev)
178 struct timespec timestamp;
180 ktime_get_ts(×tamp);
182 spin_lock_irqsave(&vdev->fh_lock, flags);
184 list_for_each_entry(fh, &vdev->fh_list, list) {
185 __v4l2_event_queue_fh(fh, ev, ×tamp);
188 spin_unlock_irqrestore(&vdev->fh_lock, flags);
190 EXPORT_SYMBOL_GPL(v4l2_event_queue);
192 void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev)
195 struct timespec timestamp;
197 ktime_get_ts(×tamp);
199 spin_lock_irqsave(&fh->vdev->fh_lock, flags);
200 __v4l2_event_queue_fh(fh, ev, ×tamp);
201 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
203 EXPORT_SYMBOL_GPL(v4l2_event_queue_fh);
205 int v4l2_event_pending(struct v4l2_fh *fh)
207 return fh->navailable;
209 EXPORT_SYMBOL_GPL(v4l2_event_pending);
211 int v4l2_event_subscribe(struct v4l2_fh *fh,
212 struct v4l2_event_subscription *sub)
214 struct v4l2_subscribed_event *sev, *found_ev;
215 struct v4l2_ctrl *ctrl = NULL;
216 struct v4l2_ctrl_fh *ctrl_fh = NULL;
219 if (sub->type == V4L2_EVENT_CTRL) {
220 ctrl = v4l2_ctrl_find(fh->ctrl_handler, sub->id);
225 sev = kmalloc(sizeof(*sev), GFP_KERNEL);
229 ctrl_fh = kzalloc(sizeof(*ctrl_fh), GFP_KERNEL);
237 spin_lock_irqsave(&fh->vdev->fh_lock, flags);
239 found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
241 INIT_LIST_HEAD(&sev->list);
242 sev->type = sub->type;
245 list_add(&sev->list, &fh->subscribed);
249 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
251 /* v4l2_ctrl_add_fh uses a mutex, so do this outside the spin lock */
256 v4l2_ctrl_add_fh(fh->ctrl_handler, ctrl_fh, sub);
263 EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
265 static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
267 struct v4l2_event_subscription sub;
268 struct v4l2_subscribed_event *sev;
274 spin_lock_irqsave(&fh->vdev->fh_lock, flags);
275 if (!list_empty(&fh->subscribed)) {
276 sev = list_first_entry(&fh->subscribed,
277 struct v4l2_subscribed_event, list);
278 sub.type = sev->type;
281 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
283 v4l2_event_unsubscribe(fh, &sub);
287 int v4l2_event_unsubscribe(struct v4l2_fh *fh,
288 struct v4l2_event_subscription *sub)
290 struct v4l2_subscribed_event *sev;
293 if (sub->type == V4L2_EVENT_ALL) {
294 v4l2_event_unsubscribe_all(fh);
298 spin_lock_irqsave(&fh->vdev->fh_lock, flags);
300 sev = v4l2_event_subscribed(fh, sub->type, sub->id);
302 list_del(&sev->list);
304 spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
305 if (sev->type == V4L2_EVENT_CTRL) {
306 struct v4l2_ctrl *ctrl = v4l2_ctrl_find(fh->ctrl_handler, sev->id);
309 v4l2_ctrl_del_fh(ctrl, fh);
316 EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);