[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / media / video / v4l2-fh.c

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

int v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
{
	fh->vdev = vdev;
	INIT_LIST_HEAD(&fh->list);
	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
	fh->prio = V4L2_PRIORITY_UNSET;

	/*
	 * fh->events only needs to be initialized if the driver
	 * supports the VIDIOC_SUBSCRIBE_EVENT ioctl.
	 */
	if (vdev->ioctl_ops && vdev->ioctl_ops->vidioc_subscribe_event)
		return v4l2_event_init(fh);

	fh->events = NULL;

	return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fh_init);

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

	if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->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);
	if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->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;

	fh->vdev = NULL;

	v4l2_event_free(fh);
}
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	*
	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 <linux/bitops.h>
73cb4206	26	#include <linux/slab.h>
1babcb46 SA	27	#include <media/v4l2-dev.h>
1babcb46 SA	28	#include <media/v4l2-fh.h>
c3b5b024 SA	29	#include <media/v4l2-event.h>
c3b5b024 SA	30	#include <media/v4l2-ioctl.h>
1babcb46 SA	31
	32	int v4l2_fh_init(struct v4l2_fh fh, struct video_device vdev)
	33	{
	34	fh->vdev = vdev;
	35	INIT_LIST_HEAD(&fh->list);
	36	set_bit(V4L2_FL_USES_V4L2_FH, &fh->vdev->flags);
fc5602be	37	fh->prio = V4L2_PRIORITY_UNSET;
1babcb46	38
d3d7c963 SA	39	/*
	40	* fh->events only needs to be initialized if the driver
	41	* supports the VIDIOC_SUBSCRIBE_EVENT ioctl.
	42	*/
	43	if (vdev->ioctl_ops && vdev->ioctl_ops->vidioc_subscribe_event)
	44	return v4l2_event_init(fh);
	45
	46	fh->events = NULL;
	47
	48	return 0;
1babcb46 SA	49	}
	50	EXPORT_SYMBOL_GPL(v4l2_fh_init);
	51
	52	void v4l2_fh_add(struct v4l2_fh *fh)
	53	{
	54	unsigned long flags;
	55
b1a873a3 HV	56	if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->flags))
b1a873a3 HV	57	v4l2_prio_open(fh->vdev->prio, &fh->prio);
1babcb46 SA	58	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	59	list_add(&fh->list, &fh->vdev->fh_list);
	60	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	61	}
	62	EXPORT_SYMBOL_GPL(v4l2_fh_add);
	63
73cb4206 HV	64	int v4l2_fh_open(struct file *filp)
	65	{
	66	struct video_device *vdev = video_devdata(filp);
	67	struct v4l2_fh fh = kzalloc(sizeof(fh), GFP_KERNEL);
	68
	69	filp->private_data = fh;
	70	if (fh == NULL)
	71	return -ENOMEM;
	72	v4l2_fh_init(fh, vdev);
	73	v4l2_fh_add(fh);
	74	return 0;
	75	}
	76	EXPORT_SYMBOL_GPL(v4l2_fh_open);
	77
1babcb46 SA	78	void v4l2_fh_del(struct v4l2_fh *fh)
	79	{
	80	unsigned long flags;
	81
	82	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	83	list_del_init(&fh->list);
	84	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
b1a873a3 HV	85	if (test_bit(V4L2_FL_USE_FH_PRIO, &fh->vdev->flags))
b1a873a3 HV	86	v4l2_prio_close(fh->vdev->prio, fh->prio);
1babcb46 SA	87	}
	88	EXPORT_SYMBOL_GPL(v4l2_fh_del);
	89
	90	void v4l2_fh_exit(struct v4l2_fh *fh)
	91	{
	92	if (fh->vdev == NULL)
	93	return;
	94
	95	fh->vdev = NULL;
c3b5b024 SA	96
c3b5b024 SA	97	v4l2_event_free(fh);
1babcb46 SA	98	}
1babcb46 SA	99	EXPORT_SYMBOL_GPL(v4l2_fh_exit);
73cb4206 HV	100
	101	int v4l2_fh_release(struct file *filp)
	102	{
	103	struct v4l2_fh *fh = filp->private_data;
	104
	105	if (fh) {
	106	v4l2_fh_del(fh);
	107	v4l2_fh_exit(fh);
	108	kfree(fh);
	109	}
	110	return 0;
	111	}
	112	EXPORT_SYMBOL_GPL(v4l2_fh_release);
dfddb244 HV	113
	114	int v4l2_fh_is_singular(struct v4l2_fh *fh)
	115	{
	116	unsigned long flags;
	117	int is_singular;
	118
	119	if (fh == NULL \|\| fh->vdev == NULL)
	120	return 0;
	121	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
	122	is_singular = list_is_singular(&fh->list);
	123	spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
	124	return is_singular;
	125	}
	126	EXPORT_SYMBOL_GPL(v4l2_fh_is_singular);