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linux/drivers/media/video/v4l2-fh.c
Paul Gortmaker 35a246363e drivers/media: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required
These two macros were in module.h but now module.h is no longer
sprayed across every source file imaginable, so the users need
to expicitly call out their use of them.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:51 -04:00

121 lines
3.1 KiB
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 <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);
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;
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;
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);