[deliverable/linux.git] / drivers / media / v4l2-core / v4l2-event.c

/*
 * v4l2-event.c
 *
 * V4L2 events.
 *
 * Copyright (C) 2009--2010 Nokia Corporation.
 *
 * Contact: Sakari Ailus <sakari.ailus@iki.fi>
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/export.h>

static unsigned sev_pos(const struct v4l2_subscribed_event *sev, unsigned idx)
{
	idx += sev->first;
	return idx >= sev->elems ? idx - sev->elems : idx;
}

static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
{
	struct v4l2_kevent *kev;
	unsigned long flags;

	spin_lock_irqsave(&fh->vdev->fh_lock, flags);

	if (list_empty(&fh->available)) {
		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
		return -ENOENT;
	}

	WARN_ON(fh->navailable == 0);

	kev = list_first_entry(&fh->available, struct v4l2_kevent, list);
	list_del(&kev->list);
	fh->navailable--;

	kev->event.pending = fh->navailable;
	*event = kev->event;
	kev->sev->first = sev_pos(kev->sev, 1);
	kev->sev->in_use--;

	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);

	return 0;
}

int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
		       int nonblocking)
{
	int ret;

	if (nonblocking)
		return __v4l2_event_dequeue(fh, event);

	/* Release the vdev lock while waiting */
	if (fh->vdev->lock)
		mutex_unlock(fh->vdev->lock);

	do {
		ret = wait_event_interruptible(fh->wait,
					       fh->navailable != 0);
		if (ret < 0)
			break;

		ret = __v4l2_event_dequeue(fh, event);
	} while (ret == -ENOENT);

	if (fh->vdev->lock)
		mutex_lock(fh->vdev->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(v4l2_event_dequeue);

/* Caller must hold fh->vdev->fh_lock! */
static struct v4l2_subscribed_event *v4l2_event_subscribed(
		struct v4l2_fh *fh, u32 type, u32 id)
{
	struct v4l2_subscribed_event *sev;

	assert_spin_locked(&fh->vdev->fh_lock);

	list_for_each_entry(sev, &fh->subscribed, list)
		if (sev->type == type && sev->id == id)
			return sev;

	return NULL;
}

static void __v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev,
		const struct timespec *ts)
{
	struct v4l2_subscribed_event *sev;
	struct v4l2_kevent *kev;
	bool copy_payload = true;

	/* Are we subscribed? */
	sev = v4l2_event_subscribed(fh, ev->type, ev->id);
	if (sev == NULL)
		return;

	/*
	 * If the event has been added to the fh->subscribed list, but its
	 * add op has not completed yet elems will be 0, treat this as
	 * not being subscribed.
	 */
	if (!sev->elems)
		return;

	/* Increase event sequence number on fh. */
	fh->sequence++;

	/* Do we have any free events? */
	if (sev->in_use == sev->elems) {
		/* no, remove the oldest one */
		kev = sev->events + sev_pos(sev, 0);
		list_del(&kev->list);
		sev->in_use--;
		sev->first = sev_pos(sev, 1);
		fh->navailable--;
		if (sev->elems == 1) {
			if (sev->ops && sev->ops->replace) {
				sev->ops->replace(&kev->event, ev);
				copy_payload = false;
			}
		} else if (sev->ops && sev->ops->merge) {
			struct v4l2_kevent *second_oldest =
				sev->events + sev_pos(sev, 0);
			sev->ops->merge(&kev->event, &second_oldest->event);
		}
	}

	/* Take one and fill it. */
	kev = sev->events + sev_pos(sev, sev->in_use);
	kev->event.type = ev->type;
	if (copy_payload)
		kev->event.u = ev->u;
	kev->event.id = ev->id;
	kev->event.timestamp = *ts;
	kev->event.sequence = fh->sequence;
	sev->in_use++;
	list_add_tail(&kev->list, &fh->available);

	fh->navailable++;

	wake_up_all(&fh->wait);
}

void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev)
{
	struct v4l2_fh *fh;
	unsigned long flags;
	struct timespec timestamp;

	ktime_get_ts(&timestamp);

	spin_lock_irqsave(&vdev->fh_lock, flags);

	list_for_each_entry(fh, &vdev->fh_list, list)
		__v4l2_event_queue_fh(fh, ev, &timestamp);

	spin_unlock_irqrestore(&vdev->fh_lock, flags);
}
EXPORT_SYMBOL_GPL(v4l2_event_queue);

void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev)
{
	unsigned long flags;
	struct timespec timestamp;

	ktime_get_ts(&timestamp);

	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	__v4l2_event_queue_fh(fh, ev, &timestamp);
	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
}
EXPORT_SYMBOL_GPL(v4l2_event_queue_fh);

int v4l2_event_pending(struct v4l2_fh *fh)
{
	return fh->navailable;
}
EXPORT_SYMBOL_GPL(v4l2_event_pending);

int v4l2_event_subscribe(struct v4l2_fh *fh,
			 const struct v4l2_event_subscription *sub, unsigned elems,
			 const struct v4l2_subscribed_event_ops *ops)
{
	struct v4l2_subscribed_event *sev, *found_ev;
	unsigned long flags;
	unsigned i;

	if (sub->type == V4L2_EVENT_ALL)
		return -EINVAL;

	if (elems < 1)
		elems = 1;

	sev = kzalloc(sizeof(*sev) + sizeof(struct v4l2_kevent) * elems, GFP_KERNEL);
	if (!sev)
		return -ENOMEM;
	for (i = 0; i < elems; i++)
		sev->events[i].sev = sev;
	sev->type = sub->type;
	sev->id = sub->id;
	sev->flags = sub->flags;
	sev->fh = fh;
	sev->ops = ops;

	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
	if (!found_ev)
		list_add(&sev->list, &fh->subscribed);
	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);

	if (found_ev) {
		kfree(sev);
		return 0; /* Already listening */
	}

	if (sev->ops && sev->ops->add) {
		int ret = sev->ops->add(sev, elems);
		if (ret) {
			sev->ops = NULL;
			v4l2_event_unsubscribe(fh, sub);
			return ret;
		}
	}

	/* Mark as ready for use */
	sev->elems = elems;

	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_event_subscribe);

void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
{
	struct v4l2_event_subscription sub;
	struct v4l2_subscribed_event *sev;
	unsigned long flags;

	do {
		sev = NULL;

		spin_lock_irqsave(&fh->vdev->fh_lock, flags);
		if (!list_empty(&fh->subscribed)) {
			sev = list_first_entry(&fh->subscribed,
					struct v4l2_subscribed_event, list);
			sub.type = sev->type;
			sub.id = sev->id;
		}
		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
		if (sev)
			v4l2_event_unsubscribe(fh, &sub);
	} while (sev);
}
EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe_all);

int v4l2_event_unsubscribe(struct v4l2_fh *fh,
			   const struct v4l2_event_subscription *sub)
{
	struct v4l2_subscribed_event *sev;
	unsigned long flags;
	int i;

	if (sub->type == V4L2_EVENT_ALL) {
		v4l2_event_unsubscribe_all(fh);
		return 0;
	}

	spin_lock_irqsave(&fh->vdev->fh_lock, flags);

	sev = v4l2_event_subscribed(fh, sub->type, sub->id);
	if (sev != NULL) {
		/* Remove any pending events for this subscription */
		for (i = 0; i < sev->in_use; i++) {
			list_del(&sev->events[sev_pos(sev, i)].list);
			fh->navailable--;
		}
		list_del(&sev->list);
	}

	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);

	if (sev && sev->ops && sev->ops->del)
		sev->ops->del(sev);

	kfree(sev);

	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);

int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, struct v4l2_fh *fh,
				  struct v4l2_event_subscription *sub)
{
	return v4l2_event_unsubscribe(fh, sub);
}
EXPORT_SYMBOL_GPL(v4l2_event_subdev_unsubscribe);

static void v4l2_event_src_replace(struct v4l2_event *old,
				const struct v4l2_event *new)
{
	u32 old_changes = old->u.src_change.changes;

	old->u.src_change = new->u.src_change;
	old->u.src_change.changes |= old_changes;
}

static void v4l2_event_src_merge(const struct v4l2_event *old,
				struct v4l2_event *new)
{
	new->u.src_change.changes |= old->u.src_change.changes;
}

static const struct v4l2_subscribed_event_ops v4l2_event_src_ch_ops = {
	.replace = v4l2_event_src_replace,
	.merge = v4l2_event_src_merge,
};

int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
				const struct v4l2_event_subscription *sub)
{
	if (sub->type == V4L2_EVENT_SOURCE_CHANGE)
		return v4l2_event_subscribe(fh, sub, 0, &v4l2_event_src_ch_ops);
	return -EINVAL;
}
EXPORT_SYMBOL_GPL(v4l2_src_change_event_subscribe);

int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
		struct v4l2_fh *fh, struct v4l2_event_subscription *sub)
{
	return v4l2_src_change_event_subscribe(fh, sub);
}
EXPORT_SYMBOL_GPL(v4l2_src_change_event_subdev_subscribe);
Commit	Line	Data
c3b5b024 SA	1	/*
	2	* v4l2-event.c
	3	*
	4	* V4L2 events.
	5	*
	6	* Copyright (C) 2009--2010 Nokia Corporation.
	7	*
8c5dff90	8	* Contact: Sakari Ailus <sakari.ailus@iki.fi>
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.
	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	#include <media/v4l2-dev.h>
	26	#include <media/v4l2-fh.h>
	27	#include <media/v4l2-event.h>
	28
	29	#include <linux/sched.h>
	30	#include <linux/slab.h>
35a24636	31	#include <linux/export.h>
c3b5b024	32
f1e393de	33	static unsigned sev_pos(const struct v4l2_subscribed_event *sev, unsigned idx)
c3b5b024	34	{
f1e393de HV	35	idx += sev->first;
f1e393de HV	36	return idx >= sev->elems ? idx - sev->elems : idx;
c3b5b024	37	}
c3b5b024 SA	38
	39	static int __v4l2_event_dequeue(struct v4l2_fh fh, struct v4l2_event event)
	40	{
c3b5b024 SA	41	struct v4l2_kevent *kev;
	42	unsigned long flags;
	43
	44	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	45
523f46d6	46	if (list_empty(&fh->available)) {
c3b5b024 SA	47	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	48	return -ENOENT;
	49	}
	50
523f46d6	51	WARN_ON(fh->navailable == 0);
c3b5b024	52
523f46d6	53	kev = list_first_entry(&fh->available, struct v4l2_kevent, list);
f1e393de	54	list_del(&kev->list);
523f46d6	55	fh->navailable--;
c3b5b024	56
523f46d6	57	kev->event.pending = fh->navailable;
c3b5b024	58	*event = kev->event;
f1e393de HV	59	kev->sev->first = sev_pos(kev->sev, 1);
f1e393de HV	60	kev->sev->in_use--;
c3b5b024 SA	61
	62	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	63
	64	return 0;
	65	}
	66
	67	int v4l2_event_dequeue(struct v4l2_fh fh, struct v4l2_event event,
	68	int nonblocking)
	69	{
c3b5b024 SA	70	int ret;
	71
	72	if (nonblocking)
	73	return __v4l2_event_dequeue(fh, event);
	74
ee6869af HV	75	/* Release the vdev lock while waiting */
	76	if (fh->vdev->lock)
	77	mutex_unlock(fh->vdev->lock);
	78
c3b5b024	79	do {
523f46d6 HV	80	ret = wait_event_interruptible(fh->wait,
523f46d6 HV	81	fh->navailable != 0);
c3b5b024	82	if (ret < 0)
ee6869af	83	break;
c3b5b024 SA	84
	85	ret = __v4l2_event_dequeue(fh, event);
	86	} while (ret == -ENOENT);
	87
ee6869af HV	88	if (fh->vdev->lock)
	89	mutex_lock(fh->vdev->lock);
	90
c3b5b024 SA	91	return ret;
c3b5b024 SA	92	}
0a4f8d07	93	EXPORT_SYMBOL_GPL(v4l2_event_dequeue);
c3b5b024	94
6e239399	95	/* Caller must hold fh->vdev->fh_lock! */
c3b5b024	96	static struct v4l2_subscribed_event *v4l2_event_subscribed(
6e239399	97	struct v4l2_fh *fh, u32 type, u32 id)
c3b5b024	98	{
c3b5b024 SA	99	struct v4l2_subscribed_event *sev;
c3b5b024 SA	100
f3cd385a	101	assert_spin_locked(&fh->vdev->fh_lock);
c3b5b024	102
3f66f0ed	103	list_for_each_entry(sev, &fh->subscribed, list)
6e239399	104	if (sev->type == type && sev->id == id)
c3b5b024	105	return sev;
c3b5b024 SA	106
	107	return NULL;
	108	}
	109
6e239399 HV	110	static void __v4l2_event_queue_fh(struct v4l2_fh fh, const struct v4l2_event ev,
	111	const struct timespec *ts)
	112	{
6e239399 HV	113	struct v4l2_subscribed_event *sev;
6e239399 HV	114	struct v4l2_kevent *kev;
2151bdc8	115	bool copy_payload = true;
6e239399 HV	116
	117	/* Are we subscribed? */
	118	sev = v4l2_event_subscribed(fh, ev->type, ev->id);
	119	if (sev == NULL)
	120	return;
	121
c53c2549 HG	122	/*
	123	* If the event has been added to the fh->subscribed list, but its
	124	* add op has not completed yet elems will be 0, treat this as
	125	* not being subscribed.
	126	*/
	127	if (!sev->elems)
	128	return;
	129
6e239399	130	/* Increase event sequence number on fh. */
523f46d6	131	fh->sequence++;
6e239399 HV	132
6e239399 HV	133	/* Do we have any free events? */
f1e393de HV	134	if (sev->in_use == sev->elems) {
	135	/* no, remove the oldest one */
	136	kev = sev->events + sev_pos(sev, 0);
	137	list_del(&kev->list);
	138	sev->in_use--;
	139	sev->first = sev_pos(sev, 1);
	140	fh->navailable--;
2151bdc8	141	if (sev->elems == 1) {
c53c2549 HG	142	if (sev->ops && sev->ops->replace) {
c53c2549 HG	143	sev->ops->replace(&kev->event, ev);
2151bdc8 HV	144	copy_payload = false;
2151bdc8 HV	145	}
c53c2549	146	} else if (sev->ops && sev->ops->merge) {
2151bdc8 HV	147	struct v4l2_kevent *second_oldest =
2151bdc8 HV	148	sev->events + sev_pos(sev, 0);
c53c2549	149	sev->ops->merge(&kev->event, &second_oldest->event);
2151bdc8	150	}
f1e393de	151	}
6e239399 HV	152
6e239399 HV	153	/* Take one and fill it. */
f1e393de	154	kev = sev->events + sev_pos(sev, sev->in_use);
6e239399	155	kev->event.type = ev->type;
2151bdc8 HV	156	if (copy_payload)
2151bdc8 HV	157	kev->event.u = ev->u;
6e239399 HV	158	kev->event.id = ev->id;
6e239399 HV	159	kev->event.timestamp = *ts;
523f46d6	160	kev->event.sequence = fh->sequence;
f1e393de HV	161	sev->in_use++;
f1e393de HV	162	list_add_tail(&kev->list, &fh->available);
6e239399	163
523f46d6	164	fh->navailable++;
6e239399	165
523f46d6	166	wake_up_all(&fh->wait);
6e239399 HV	167	}
6e239399 HV	168
c3b5b024 SA	169	void v4l2_event_queue(struct video_device vdev, const struct v4l2_event ev)
	170	{
	171	struct v4l2_fh *fh;
	172	unsigned long flags;
	173	struct timespec timestamp;
	174
	175	ktime_get_ts(&timestamp);
	176
	177	spin_lock_irqsave(&vdev->fh_lock, flags);
	178
3f66f0ed	179	list_for_each_entry(fh, &vdev->fh_list, list)
6e239399	180	__v4l2_event_queue_fh(fh, ev, &timestamp);
c3b5b024 SA	181
	182	spin_unlock_irqrestore(&vdev->fh_lock, flags);
	183	}
	184	EXPORT_SYMBOL_GPL(v4l2_event_queue);
	185
6e239399 HV	186	void v4l2_event_queue_fh(struct v4l2_fh fh, const struct v4l2_event ev)
	187	{
	188	unsigned long flags;
	189	struct timespec timestamp;
	190
	191	ktime_get_ts(&timestamp);
	192
	193	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	194	__v4l2_event_queue_fh(fh, ev, &timestamp);
	195	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	196	}
	197	EXPORT_SYMBOL_GPL(v4l2_event_queue_fh);
	198
c3b5b024 SA	199	int v4l2_event_pending(struct v4l2_fh *fh)
c3b5b024 SA	200	{
523f46d6	201	return fh->navailable;
c3b5b024 SA	202	}
	203	EXPORT_SYMBOL_GPL(v4l2_event_pending);
	204
	205	int v4l2_event_subscribe(struct v4l2_fh *fh,
85f5fe39	206	const struct v4l2_event_subscription *sub, unsigned elems,
c53c2549	207	const struct v4l2_subscribed_event_ops *ops)
c3b5b024	208	{
6e239399	209	struct v4l2_subscribed_event sev, found_ev;
c3b5b024	210	unsigned long flags;
f1e393de	211	unsigned i;
c3b5b024	212
b36b5059 HG	213	if (sub->type == V4L2_EVENT_ALL)
	214	return -EINVAL;
	215
f1e393de HV	216	if (elems < 1)
f1e393de HV	217	elems = 1;
6e239399	218
f1e393de	219	sev = kzalloc(sizeof(sev) + sizeof(struct v4l2_kevent) elems, GFP_KERNEL);
c3b5b024 SA	220	if (!sev)
c3b5b024 SA	221	return -ENOMEM;
f1e393de HV	222	for (i = 0; i < elems; i++)
	223	sev->events[i].sev = sev;
	224	sev->type = sub->type;
	225	sev->id = sub->id;
	226	sev->flags = sub->flags;
	227	sev->fh = fh;
c53c2549	228	sev->ops = ops;
c3b5b024 SA	229
c3b5b024 SA	230	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
6e239399	231	found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
f1e393de	232	if (!found_ev)
523f46d6	233	list_add(&sev->list, &fh->subscribed);
c3b5b024 SA	234	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
c3b5b024 SA	235
c53c2549	236	if (found_ev) {
77068d36	237	kfree(sev);
c53c2549 HG	238	return 0; /* Already listening */
	239	}
	240
	241	if (sev->ops && sev->ops->add) {
6e6d76cd	242	int ret = sev->ops->add(sev, elems);
c53c2549 HG	243	if (ret) {
	244	sev->ops = NULL;
	245	v4l2_event_unsubscribe(fh, sub);
	246	return ret;
	247	}
	248	}
	249
c53c2549 HG	250	/* Mark as ready for use */
	251	sev->elems = elems;
	252
c3b5b024 SA	253	return 0;
	254	}
	255	EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
	256
f1e393de	257	void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
c3b5b024	258	{
6e239399	259	struct v4l2_event_subscription sub;
c3b5b024 SA	260	struct v4l2_subscribed_event *sev;
	261	unsigned long flags;
	262
	263	do {
	264	sev = NULL;
	265
	266	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
523f46d6 HV	267	if (!list_empty(&fh->subscribed)) {
523f46d6 HV	268	sev = list_first_entry(&fh->subscribed,
6e239399 HV	269	struct v4l2_subscribed_event, list);
	270	sub.type = sev->type;
	271	sub.id = sev->id;
c3b5b024 SA	272	}
c3b5b024 SA	273	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
6e239399 HV	274	if (sev)
6e239399 HV	275	v4l2_event_unsubscribe(fh, &sub);
c3b5b024 SA	276	} while (sev);
c3b5b024 SA	277	}
f1e393de	278	EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe_all);
c3b5b024 SA	279
c3b5b024 SA	280	int v4l2_event_unsubscribe(struct v4l2_fh *fh,
85f5fe39	281	const struct v4l2_event_subscription *sub)
c3b5b024 SA	282	{
	283	struct v4l2_subscribed_event *sev;
	284	unsigned long flags;
78c87e86	285	int i;
c3b5b024 SA	286
	287	if (sub->type == V4L2_EVENT_ALL) {
	288	v4l2_event_unsubscribe_all(fh);
	289	return 0;
	290	}
	291
	292	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	293
6e239399	294	sev = v4l2_event_subscribed(fh, sub->type, sub->id);
77068d36	295	if (sev != NULL) {
78c87e86 HG	296	/* Remove any pending events for this subscription */
	297	for (i = 0; i < sev->in_use; i++) {
	298	list_del(&sev->events[sev_pos(sev, i)].list);
	299	fh->navailable--;
	300	}
c3b5b024	301	list_del(&sev->list);
77068d36	302	}
c3b5b024 SA	303
c3b5b024 SA	304	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
c53c2549 HG	305
	306	if (sev && sev->ops && sev->ops->del)
	307	sev->ops->del(sev);
	308
c3b5b024 SA	309	kfree(sev);
	310
	311	return 0;
	312	}
	313	EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);
4f4d14b7 SN	314
	315	int v4l2_event_subdev_unsubscribe(struct v4l2_subdev sd, struct v4l2_fh fh,
	316	struct v4l2_event_subscription *sub)
	317	{
	318	return v4l2_event_unsubscribe(fh, sub);
	319	}
	320	EXPORT_SYMBOL_GPL(v4l2_event_subdev_unsubscribe);
3cbe6e5b AK	321
	322	static void v4l2_event_src_replace(struct v4l2_event *old,
	323	const struct v4l2_event *new)
	324	{
	325	u32 old_changes = old->u.src_change.changes;
	326
	327	old->u.src_change = new->u.src_change;
	328	old->u.src_change.changes \|= old_changes;
	329	}
	330
	331	static void v4l2_event_src_merge(const struct v4l2_event *old,
	332	struct v4l2_event *new)
	333	{
	334	new->u.src_change.changes \|= old->u.src_change.changes;
	335	}
	336
	337	static const struct v4l2_subscribed_event_ops v4l2_event_src_ch_ops = {
	338	.replace = v4l2_event_src_replace,
	339	.merge = v4l2_event_src_merge,
	340	};
	341
	342	int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
	343	const struct v4l2_event_subscription *sub)
	344	{
	345	if (sub->type == V4L2_EVENT_SOURCE_CHANGE)
	346	return v4l2_event_subscribe(fh, sub, 0, &v4l2_event_src_ch_ops);
	347	return -EINVAL;
	348	}
	349	EXPORT_SYMBOL_GPL(v4l2_src_change_event_subscribe);
	350
	351	int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
	352	struct v4l2_fh fh, struct v4l2_event_subscription sub)
	353	{
	354	return v4l2_src_change_event_subscribe(fh, sub);
	355	}
	356	EXPORT_SYMBOL_GPL(v4l2_src_change_event_subdev_subscribe);