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/*
V4L2 device support.
Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/types.h>
#include <linux/ioctl.h>
#include <linux/i2c.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
{
if (dev == NULL || v4l2_dev == NULL)
return -EINVAL;
/* Warn if we apparently re-register a device */
WARN_ON(dev_get_drvdata(dev));
INIT_LIST_HEAD(&v4l2_dev->subdevs);
spin_lock_init(&v4l2_dev->lock);
v4l2_dev->dev = dev;
snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
dev->driver->name, dev->bus_id);
dev_set_drvdata(dev, v4l2_dev);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_device_register);
void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
{
struct v4l2_subdev *sd, *next;
if (v4l2_dev == NULL || v4l2_dev->dev == NULL)
return;
dev_set_drvdata(v4l2_dev->dev, NULL);
/* unregister subdevs */
list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list)
v4l2_device_unregister_subdev(sd);
v4l2_dev->dev = NULL;
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister);
int v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd)
{
/* Check for valid input */
if (dev == NULL || sd == NULL || !sd->name[0])
return -EINVAL;
/* Warn if we apparently re-register a subdev */
WARN_ON(sd->dev);
if (!try_module_get(sd->owner))
return -ENODEV;
sd->dev = dev;
spin_lock(&dev->lock);
list_add_tail(&sd->list, &dev->subdevs);
spin_unlock(&dev->lock);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
{
/* return if it isn't registered */
if (sd == NULL || sd->dev == NULL)
return;
spin_lock(&sd->dev->lock);
list_del(&sd->list);
spin_unlock(&sd->dev->lock);
sd->dev = NULL;
module_put(sd->owner);
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
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