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

/*
 * v4l2-event.c
 *
 * V4L2 events.
 *
 * Copyright (C) 2009--2010 Nokia Corporation.
 *
 * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
 *
 * 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>

int v4l2_event_init(struct v4l2_fh *fh)
{
	fh->events = kzalloc(sizeof(*fh->events), GFP_KERNEL);
	if (fh->events == NULL)
		return -ENOMEM;

	init_waitqueue_head(&fh->events->wait);

	INIT_LIST_HEAD(&fh->events->free);
	INIT_LIST_HEAD(&fh->events->available);
	INIT_LIST_HEAD(&fh->events->subscribed);

	fh->events->sequence = -1;

	return 0;
}

int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n)
{
	struct v4l2_events *events = fh->events;
	unsigned long flags;

	if (!events) {
		WARN_ON(1);
		return -ENOMEM;
	}

	while (events->nallocated < n) {
		struct v4l2_kevent *kev;

		kev = kzalloc(sizeof(*kev), GFP_KERNEL);
		if (kev == NULL)
			return -ENOMEM;

		spin_lock_irqsave(&fh->vdev->fh_lock, flags);
		list_add_tail(&kev->list, &events->free);
		events->nallocated++;
		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	}

	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_event_alloc);

#define list_kfree(list, type, member)				\
	while (!list_empty(list)) {				\
		type *hi;					\
		hi = list_first_entry(list, type, member);	\
		list_del(&hi->member);				\
		kfree(hi);					\
	}

void v4l2_event_free(struct v4l2_fh *fh)
{
	struct v4l2_events *events = fh->events;

	if (!events)
		return;

	list_kfree(&events->free, struct v4l2_kevent, list);
	list_kfree(&events->available, struct v4l2_kevent, list);
	list_kfree(&events->subscribed, struct v4l2_subscribed_event, list);

	kfree(events);
	fh->events = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_event_free);

static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
{
	struct v4l2_events *events = fh->events;
	struct v4l2_kevent *kev;
	unsigned long flags;

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

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

	WARN_ON(events->navailable == 0);

	kev = list_first_entry(&events->available, struct v4l2_kevent, list);
	list_move(&kev->list, &events->free);
	events->navailable--;

	kev->event.pending = events->navailable;
	*event = kev->event;

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

	return 0;
}

int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
		       int nonblocking)
{
	struct v4l2_events *events = fh->events;
	int ret;

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

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

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

	return ret;
}

/* Caller must hold fh->event->lock! */
static struct v4l2_subscribed_event *v4l2_event_subscribed(
	struct v4l2_fh *fh, u32 type)
{
	struct v4l2_events *events = fh->events;
	struct v4l2_subscribed_event *sev;

	WARN_ON(!spin_is_locked(&fh->vdev->fh_lock));

	list_for_each_entry(sev, &events->subscribed, list) {
		if (sev->type == type)
			return sev;
	}

	return NULL;
}

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) {
		struct v4l2_events *events = fh->events;
		struct v4l2_kevent *kev;

		/* Are we subscribed? */
		if (!v4l2_event_subscribed(fh, ev->type))
			continue;

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

		/* Do we have any free events? */
		if (list_empty(&events->free))
			continue;

		/* Take one and fill it. */
		kev = list_first_entry(&events->free, struct v4l2_kevent, list);
		kev->event.type = ev->type;
		kev->event.u = ev->u;
		kev->event.timestamp = timestamp;
		kev->event.sequence = events->sequence;
		list_move_tail(&kev->list, &events->available);

		events->navailable++;

		wake_up_all(&events->wait);
	}

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

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

int v4l2_event_subscribe(struct v4l2_fh *fh,
			 struct v4l2_event_subscription *sub)
{
	struct v4l2_events *events = fh->events;
	struct v4l2_subscribed_event *sev;
	unsigned long flags;

	if (fh->events == NULL) {
		WARN_ON(1);
		return -ENOMEM;
	}

	sev = kmalloc(sizeof(*sev), GFP_KERNEL);
	if (!sev)
		return -ENOMEM;

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

	if (v4l2_event_subscribed(fh, sub->type) == NULL) {
		INIT_LIST_HEAD(&sev->list);
		sev->type = sub->type;

		list_add(&sev->list, &events->subscribed);
		sev = NULL;
	}

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

	kfree(sev);

	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_event_subscribe);

static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
{
	struct v4l2_events *events = fh->events;
	struct v4l2_subscribed_event *sev;
	unsigned long flags;

	do {
		sev = NULL;

		spin_lock_irqsave(&fh->vdev->fh_lock, flags);
		if (!list_empty(&events->subscribed)) {
			sev = list_first_entry(&events->subscribed,
				       struct v4l2_subscribed_event, list);
			list_del(&sev->list);
		}
		spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
		kfree(sev);
	} while (sev);
}

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

	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);
	if (sev != NULL)
		list_del(&sev->list);

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

	kfree(sev);

	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);
Commit	Line	Data
c3b5b024 SA	1	/*
	2	* v4l2-event.c
	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	#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>
	31
	32	int v4l2_event_init(struct v4l2_fh *fh)
	33	{
	34	fh->events = kzalloc(sizeof(*fh->events), GFP_KERNEL);
	35	if (fh->events == NULL)
	36	return -ENOMEM;
	37
	38	init_waitqueue_head(&fh->events->wait);
	39
	40	INIT_LIST_HEAD(&fh->events->free);
	41	INIT_LIST_HEAD(&fh->events->available);
	42	INIT_LIST_HEAD(&fh->events->subscribed);
	43
	44	fh->events->sequence = -1;
	45
	46	return 0;
	47	}
	48
	49	int v4l2_event_alloc(struct v4l2_fh *fh, unsigned int n)
	50	{
	51	struct v4l2_events *events = fh->events;
	52	unsigned long flags;
	53
	54	if (!events) {
	55	WARN_ON(1);
	56	return -ENOMEM;
	57	}
	58
	59	while (events->nallocated < n) {
	60	struct v4l2_kevent *kev;
	61
	62	kev = kzalloc(sizeof(*kev), GFP_KERNEL);
	63	if (kev == NULL)
	64	return -ENOMEM;
65
66	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
67	list_add_tail(&kev->list, &events->free);
68	events->nallocated++;
69	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
70	}
71
72	return 0;
73	}
74	EXPORT_SYMBOL_GPL(v4l2_event_alloc);
75
76	#define list_kfree(list, type, member) \
77	while (!list_empty(list)) { \
78	type *hi; \
79	hi = list_first_entry(list, type, member); \
80	list_del(&hi->member); \
81	kfree(hi); \
82	}
83
84	void v4l2_event_free(struct v4l2_fh *fh)
85	{
86	struct v4l2_events *events = fh->events;
87
88	if (!events)
89	return;
90
91	list_kfree(&events->free, struct v4l2_kevent, list);
92	list_kfree(&events->available, struct v4l2_kevent, list);
93	list_kfree(&events->subscribed, struct v4l2_subscribed_event, list);
94
95	kfree(events);
96	fh->events = NULL;
97	}
98	EXPORT_SYMBOL_GPL(v4l2_event_free);
99
100	static int __v4l2_event_dequeue(struct v4l2_fh fh, struct v4l2_event event)
101	{
102	struct v4l2_events *events = fh->events;
103	struct v4l2_kevent *kev;
104	unsigned long flags;
105
106	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
107
108	if (list_empty(&events->available)) {
109	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
110	return -ENOENT;
111	}
112
113	WARN_ON(events->navailable == 0);
114
115	kev = list_first_entry(&events->available, struct v4l2_kevent, list);
116	list_move(&kev->list, &events->free);
117	events->navailable--;
118
119	kev->event.pending = events->navailable;
120	*event = kev->event;
121
122	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
123
124	return 0;
125	}
126
127	int v4l2_event_dequeue(struct v4l2_fh fh, struct v4l2_event event,
128	int nonblocking)
129	{
130	struct v4l2_events *events = fh->events;
131	int ret;
132
133	if (nonblocking)
134	return __v4l2_event_dequeue(fh, event);
135
136	do {
137	ret = wait_event_interruptible(events->wait,
138	events->navailable != 0);
139	if (ret < 0)
140	return ret;
141
142	ret = __v4l2_event_dequeue(fh, event);
143	} while (ret == -ENOENT);
144
145	return ret;
146	}
147
148	/* Caller must hold fh->event->lock! */
149	static struct v4l2_subscribed_event *v4l2_event_subscribed(
150	struct v4l2_fh *fh, u32 type)
151	{
152	struct v4l2_events *events = fh->events;
153	struct v4l2_subscribed_event *sev;
154
155	WARN_ON(!spin_is_locked(&fh->vdev->fh_lock));
156
157	list_for_each_entry(sev, &events->subscribed, list) {
158	if (sev->type == type)
159	return sev;
160	}
161
162	return NULL;
163	}
164
165	void v4l2_event_queue(struct video_device vdev, const struct v4l2_event ev)
166	{
167	struct v4l2_fh *fh;
168	unsigned long flags;
169	struct timespec timestamp;
170
171	ktime_get_ts(&timestamp);
172
173	spin_lock_irqsave(&vdev->fh_lock, flags);
174
175	list_for_each_entry(fh, &vdev->fh_list, list) {
176	struct v4l2_events *events = fh->events;
177	struct v4l2_kevent *kev;
178
179	/* Are we subscribed? */
180	if (!v4l2_event_subscribed(fh, ev->type))
181	continue;
182
183	/* Increase event sequence number on fh. */
184	events->sequence++;
185
186	/* Do we have any free events? */
187	if (list_empty(&events->free))
188	continue;
189
190	/* Take one and fill it. */
191	kev = list_first_entry(&events->free, struct v4l2_kevent, list);
192	kev->event.type = ev->type;
193	kev->event.u = ev->u;
194	kev->event.timestamp = timestamp;
195	kev->event.sequence = events->sequence;
196	list_move_tail(&kev->list, &events->available);
197
198	events->navailable++;
199
200	wake_up_all(&events->wait);
201	}
202
203	spin_unlock_irqrestore(&vdev->fh_lock, flags);
204	}
205	EXPORT_SYMBOL_GPL(v4l2_event_queue);
206
207	int v4l2_event_pending(struct v4l2_fh *fh)
208	{
209	return fh->events->navailable;
210	}
211	EXPORT_SYMBOL_GPL(v4l2_event_pending);
212
213	int v4l2_event_subscribe(struct v4l2_fh *fh,
214	struct v4l2_event_subscription *sub)
215	{
216	struct v4l2_events *events = fh->events;
217	struct v4l2_subscribed_event *sev;
218	unsigned long flags;
219
220	if (fh->events == NULL) {
221	WARN_ON(1);
222	return -ENOMEM;
223	}
224
225	sev = kmalloc(sizeof(*sev), GFP_KERNEL);
226	if (!sev)
227	return -ENOMEM;
228
229	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
230
231	if (v4l2_event_subscribed(fh, sub->type) == NULL) {
232	INIT_LIST_HEAD(&sev->list);
233	sev->type = sub->type;
234
235	list_add(&sev->list, &events->subscribed);
236	sev = NULL;
237	}
238
239	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
240
241	kfree(sev);
242
243	return 0;
244	}
245	EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
246
247	static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
248	{
249	struct v4l2_events *events = fh->events;
250	struct v4l2_subscribed_event *sev;
251	unsigned long flags;
252
253	do {
254	sev = NULL;
255
256	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
257	if (!list_empty(&events->subscribed)) {
258	sev = list_first_entry(&events->subscribed,
259	struct v4l2_subscribed_event, list);
260	list_del(&sev->list);
261	}
262	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
263	kfree(sev);
264	} while (sev);
265	}
266
267	int v4l2_event_unsubscribe(struct v4l2_fh *fh,
268	struct v4l2_event_subscription *sub)
269	{
270	struct v4l2_subscribed_event *sev;
271	unsigned long flags;
272
273	if (sub->type == V4L2_EVENT_ALL) {
274	v4l2_event_unsubscribe_all(fh);
275	return 0;
276	}
277
278	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
279
280	sev = v4l2_event_subscribed(fh, sub->type);
281	if (sev != NULL)
282	list_del(&sev->list);
283
284	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
285
286	kfree(sev);
287
288	return 0;
289	}
290	EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);