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// SPDX-License-Identifier: GPL-2.0-only
/*
* v4l2-fh.c
*
* V4L2 file handles.
*
* Copyright (C) 2009--2010 Nokia Corporation.
*
* Contact: Sakari Ailus <sakari.ailus@iki.fi>
*/
#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;
mutex_init(&fh->subscribe_lock);
}
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);
mutex_destroy(&fh->subscribe_lock);
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);
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