linux_old1/drivers/media/video/v4l2-fh.c

80 lines
2.0 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 <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->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;
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);
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);
}
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);