/*
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 (v4l2_dev == NULL)
return -EINVAL;
INIT_LIST_HEAD(&v4l2_dev->subdevs);
spin_lock_init(&v4l2_dev->lock);
v4l2_dev->dev = dev;
if (dev == NULL) {
/* If dev == NULL, then name must be filled in by the caller */
WARN_ON(!v4l2_dev->name[0]);
return 0;
}
/* Set name to driver name + device name if it is empty. */
if (!v4l2_dev->name[0])
snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
dev->driver->name, dev_name(dev));
if (dev_get_drvdata(dev))
v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
dev_set_drvdata(dev, v4l2_dev);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_device_register);
int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
atomic_t *instance)
{
int num = atomic_inc_return(instance) - 1;
int len = strlen(basename);
if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
"%s-%d", basename, num);
else
snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
"%s%d", basename, num);
return num;
}
EXPORT_SYMBOL_GPL(v4l2_device_set_name);
void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
{
if (v4l2_dev->dev) {
dev_set_drvdata(v4l2_dev->dev, NULL);
v4l2_dev->dev = NULL;
}
}
EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
{
struct v4l2_subdev *sd, *next;
if (v4l2_dev == NULL)
return;
v4l2_device_disconnect(v4l2_dev);
/* Unregister subdevs */
list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
v4l2_device_unregister_subdev(sd);
if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
struct i2c_client *client = v4l2_get_subdevdata(sd);
/* We need to unregister the i2c client explicitly.
We cannot rely on i2c_del_adapter to always
unregister clients for us, since if the i2c bus
is a platform bus, then it is never deleted. */
if (client)
i2c_unregister_device(client);
}
}
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister);
int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
struct v4l2_subdev *sd)
{
/* Check for valid input */
if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
return -EINVAL;
/* Warn if we apparently re-register a subdev */
WARN_ON(sd->v4l2_dev != NULL);
if (!try_module_get(sd->owner))
return -ENODEV;
sd->v4l2_dev = v4l2_dev;
spin_lock(&v4l2_dev->lock);
list_add_tail(&sd->list, &v4l2_dev->subdevs);
spin_unlock(&v4l2_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->v4l2_dev == NULL)
return;
spin_lock(&sd->v4l2_dev->lock);
list_del(&sd->list);
spin_unlock(&sd->v4l2_dev->lock);
sd->v4l2_dev = NULL;
module_put(sd->owner);
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
