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

/*
 * v4l2-fh.c
 *
 * V4L2 file handles.
 *
 * 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 <linux/bitops.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>

void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
{
	fh->vdev = vdev;
	/* Inherit from video_device. May be overridden by the driver. */
	fh->ctrl_handler = vdev->ctrl_handler;
	INIT_LIST_HEAD(&fh->list);
	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
	/*
	 * determine_valid_ioctls() does not know if struct v4l2_fh
	 * is used by this driver, but here we do. So enable the
	 * prio ioctls here.
	 */
	set_bit(_IOC_NR(VIDIOC_G_PRIORITY), vdev->valid_ioctls);
	set_bit(_IOC_NR(VIDIOC_S_PRIORITY), vdev->valid_ioctls);
	fh->prio = V4L2_PRIORITY_UNSET;
	init_waitqueue_head(&fh->wait);
	INIT_LIST_HEAD(&fh->available);
	INIT_LIST_HEAD(&fh->subscribed);
	fh->sequence = -1;
}
EXPORT_SYMBOL_GPL(v4l2_fh_init);

void v4l2_fh_add(struct v4l2_fh *fh)
{
	unsigned long flags;

	v4l2_prio_open(fh->vdev->prio, &fh->prio);
	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	list_add(&fh->list, &fh->vdev->fh_list);
	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
}
EXPORT_SYMBOL_GPL(v4l2_fh_add);

int v4l2_fh_open(struct file *filp)
{
	struct video_device *vdev = video_devdata(filp);
	struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);

	filp->private_data = fh;
	if (fh == NULL)
		return -ENOMEM;
	v4l2_fh_init(fh, vdev);
	v4l2_fh_add(fh);
	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fh_open);

void v4l2_fh_del(struct v4l2_fh *fh)
{
	unsigned long flags;

	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	list_del_init(&fh->list);
	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	v4l2_prio_close(fh->vdev->prio, fh->prio);
}
EXPORT_SYMBOL_GPL(v4l2_fh_del);

void v4l2_fh_exit(struct v4l2_fh *fh)
{
	if (fh->vdev == NULL)
		return;
	v4l2_event_unsubscribe_all(fh);
	fh->vdev = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_fh_exit);

int v4l2_fh_release(struct file *filp)
{
	struct v4l2_fh *fh = filp->private_data;

	if (fh) {
		v4l2_fh_del(fh);
		v4l2_fh_exit(fh);
		kfree(fh);
	}
	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fh_release);

int v4l2_fh_is_singular(struct v4l2_fh *fh)
{
	unsigned long flags;
	int is_singular;

	if (fh == NULL || fh->vdev == NULL)
		return 0;
	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	is_singular = list_is_singular(&fh->list);
	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	return is_singular;
}
EXPORT_SYMBOL_GPL(v4l2_fh_is_singular);
Commit	Line	Data
1babcb46 SA	1	/*
	2	* v4l2-fh.c
	3	*
	4	* V4L2 file handles.
	5	*
	6	* Copyright (C) 2009--2010 Nokia Corporation.
	7	*
8c5dff90	8	* Contact: Sakari Ailus <sakari.ailus@iki.fi>
1babcb46 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 <linux/bitops.h>
73cb4206	26	#include <linux/slab.h>
35a24636	27	#include <linux/export.h>
1babcb46 SA	28	#include <media/v4l2-dev.h>
1babcb46 SA	29	#include <media/v4l2-fh.h>
c3b5b024 SA	30	#include <media/v4l2-event.h>
c3b5b024 SA	31	#include <media/v4l2-ioctl.h>
1babcb46	32
523f46d6	33	void v4l2_fh_init(struct v4l2_fh fh, struct video_device vdev)
1babcb46 SA	34	{
1babcb46 SA	35	fh->vdev = vdev;
2d28b686 HV	36	/* Inherit from video_device. May be overridden by the driver. */
2d28b686 HV	37	fh->ctrl_handler = vdev->ctrl_handler;
1babcb46 SA	38	INIT_LIST_HEAD(&fh->list);
1babcb46 SA	39	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
b7284bb0 RM	40	/*
	41	* determine_valid_ioctls() does not know if struct v4l2_fh
	42	* is used by this driver, but here we do. So enable the
	43	* prio ioctls here.
	44	*/
	45	set_bit(_IOC_NR(VIDIOC_G_PRIORITY), vdev->valid_ioctls);
	46	set_bit(_IOC_NR(VIDIOC_S_PRIORITY), vdev->valid_ioctls);
fc5602be	47	fh->prio = V4L2_PRIORITY_UNSET;
523f46d6	48	init_waitqueue_head(&fh->wait);
523f46d6 HV	49	INIT_LIST_HEAD(&fh->available);
	50	INIT_LIST_HEAD(&fh->subscribed);
	51	fh->sequence = -1;
1babcb46 SA	52	}
	53	EXPORT_SYMBOL_GPL(v4l2_fh_init);
	54
	55	void v4l2_fh_add(struct v4l2_fh *fh)
	56	{
	57	unsigned long flags;
	58
b7284bb0	59	v4l2_prio_open(fh->vdev->prio, &fh->prio);
1babcb46 SA	60	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	61	list_add(&fh->list, &fh->vdev->fh_list);
	62	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	63	}
	64	EXPORT_SYMBOL_GPL(v4l2_fh_add);
	65
73cb4206 HV	66	int v4l2_fh_open(struct file *filp)
	67	{
	68	struct video_device *vdev = video_devdata(filp);
	69	struct v4l2_fh fh = kzalloc(sizeof(fh), GFP_KERNEL);
	70
	71	filp->private_data = fh;
	72	if (fh == NULL)
	73	return -ENOMEM;
	74	v4l2_fh_init(fh, vdev);
	75	v4l2_fh_add(fh);
	76	return 0;
	77	}
	78	EXPORT_SYMBOL_GPL(v4l2_fh_open);
	79
1babcb46 SA	80	void v4l2_fh_del(struct v4l2_fh *fh)
	81	{
	82	unsigned long flags;
	83
	84	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	85	list_del_init(&fh->list);
	86	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
b7284bb0	87	v4l2_prio_close(fh->vdev->prio, fh->prio);
1babcb46 SA	88	}
	89	EXPORT_SYMBOL_GPL(v4l2_fh_del);
	90
	91	void v4l2_fh_exit(struct v4l2_fh *fh)
	92	{
	93	if (fh->vdev == NULL)
	94	return;
f1e393de	95	v4l2_event_unsubscribe_all(fh);
6e239399	96	fh->vdev = NULL;
1babcb46 SA	97	}
1babcb46 SA	98	EXPORT_SYMBOL_GPL(v4l2_fh_exit);
73cb4206 HV	99
	100	int v4l2_fh_release(struct file *filp)
	101	{
	102	struct v4l2_fh *fh = filp->private_data;
	103
	104	if (fh) {
	105	v4l2_fh_del(fh);
	106	v4l2_fh_exit(fh);
	107	kfree(fh);
	108	}
	109	return 0;
	110	}
	111	EXPORT_SYMBOL_GPL(v4l2_fh_release);
dfddb244 HV	112
	113	int v4l2_fh_is_singular(struct v4l2_fh *fh)
	114	{
	115	unsigned long flags;
	116	int is_singular;
	117
	118	if (fh == NULL \|\| fh->vdev == NULL)
	119	return 0;
	120	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	121	is_singular = list_is_singular(&fh->list);
	122	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	123	return is_singular;
	124	}
	125	EXPORT_SYMBOL_GPL(v4l2_fh_is_singular);