[mirror_ubuntu-artful-kernel.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.
 */

#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>
#include <media/v4l2-mc.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;
	v4l_disable_media_source(fh->vdev);
	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.
1babcb46 SA	18	*/
	19
	20	#include <linux/bitops.h>
73cb4206	21	#include <linux/slab.h>
35a24636	22	#include <linux/export.h>
1babcb46 SA	23	#include <media/v4l2-dev.h>
1babcb46 SA	24	#include <media/v4l2-fh.h>
c3b5b024 SA	25	#include <media/v4l2-event.h>
c3b5b024 SA	26	#include <media/v4l2-ioctl.h>
77fa4e07	27	#include <media/v4l2-mc.h>
1babcb46	28
523f46d6	29	void v4l2_fh_init(struct v4l2_fh fh, struct video_device vdev)
1babcb46 SA	30	{
1babcb46 SA	31	fh->vdev = vdev;
2d28b686 HV	32	/* Inherit from video_device. May be overridden by the driver. */
2d28b686 HV	33	fh->ctrl_handler = vdev->ctrl_handler;
1babcb46 SA	34	INIT_LIST_HEAD(&fh->list);
1babcb46 SA	35	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
b7284bb0 RM	36	/*
	37	* determine_valid_ioctls() does not know if struct v4l2_fh
	38	* is used by this driver, but here we do. So enable the
	39	* prio ioctls here.
	40	*/
	41	set_bit(_IOC_NR(VIDIOC_G_PRIORITY), vdev->valid_ioctls);
	42	set_bit(_IOC_NR(VIDIOC_S_PRIORITY), vdev->valid_ioctls);
fc5602be	43	fh->prio = V4L2_PRIORITY_UNSET;
523f46d6	44	init_waitqueue_head(&fh->wait);
523f46d6 HV	45	INIT_LIST_HEAD(&fh->available);
	46	INIT_LIST_HEAD(&fh->subscribed);
	47	fh->sequence = -1;
1babcb46 SA	48	}
	49	EXPORT_SYMBOL_GPL(v4l2_fh_init);
	50
	51	void v4l2_fh_add(struct v4l2_fh *fh)
	52	{
	53	unsigned long flags;
	54
b7284bb0	55	v4l2_prio_open(fh->vdev->prio, &fh->prio);
1babcb46 SA	56	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	57	list_add(&fh->list, &fh->vdev->fh_list);
	58	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	59	}
	60	EXPORT_SYMBOL_GPL(v4l2_fh_add);
	61
73cb4206 HV	62	int v4l2_fh_open(struct file *filp)
	63	{
	64	struct video_device *vdev = video_devdata(filp);
	65	struct v4l2_fh fh = kzalloc(sizeof(fh), GFP_KERNEL);
	66
	67	filp->private_data = fh;
	68	if (fh == NULL)
	69	return -ENOMEM;
	70	v4l2_fh_init(fh, vdev);
	71	v4l2_fh_add(fh);
	72	return 0;
	73	}
	74	EXPORT_SYMBOL_GPL(v4l2_fh_open);
	75
1babcb46 SA	76	void v4l2_fh_del(struct v4l2_fh *fh)
	77	{
	78	unsigned long flags;
	79
	80	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	81	list_del_init(&fh->list);
	82	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
b7284bb0	83	v4l2_prio_close(fh->vdev->prio, fh->prio);
1babcb46 SA	84	}
	85	EXPORT_SYMBOL_GPL(v4l2_fh_del);
	86
	87	void v4l2_fh_exit(struct v4l2_fh *fh)
	88	{
	89	if (fh->vdev == NULL)
	90	return;
77fa4e07	91	v4l_disable_media_source(fh->vdev);
f1e393de	92	v4l2_event_unsubscribe_all(fh);
6e239399	93	fh->vdev = NULL;
1babcb46 SA	94	}
1babcb46 SA	95	EXPORT_SYMBOL_GPL(v4l2_fh_exit);
73cb4206 HV	96
	97	int v4l2_fh_release(struct file *filp)
	98	{
	99	struct v4l2_fh *fh = filp->private_data;
	100
	101	if (fh) {
	102	v4l2_fh_del(fh);
	103	v4l2_fh_exit(fh);
	104	kfree(fh);
	105	}
	106	return 0;
	107	}
	108	EXPORT_SYMBOL_GPL(v4l2_fh_release);
dfddb244 HV	109
	110	int v4l2_fh_is_singular(struct v4l2_fh *fh)
	111	{
	112	unsigned long flags;
	113	int is_singular;
	114
	115	if (fh == NULL \|\| fh->vdev == NULL)
	116	return 0;
	117	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	118	is_singular = list_is_singular(&fh->list);
	119	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	120	return is_singular;
	121	}
	122	EXPORT_SYMBOL_GPL(v4l2_fh_is_singular);