157 lines
4.1 KiB
C
157 lines
4.1 KiB
C
/*
|
|
* Media device
|
|
*
|
|
* Copyright (C) 2010 Nokia Corporation
|
|
*
|
|
* Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
|
|
* Sakari Ailus <sakari.ailus@iki.fi>
|
|
*
|
|
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/ioctl.h>
|
|
|
|
#include <media/media-device.h>
|
|
#include <media/media-devnode.h>
|
|
#include <media/media-entity.h>
|
|
|
|
static const struct media_file_operations media_device_fops = {
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
/* -----------------------------------------------------------------------------
|
|
* sysfs
|
|
*/
|
|
|
|
static ssize_t show_model(struct device *cd,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct media_device *mdev = to_media_device(to_media_devnode(cd));
|
|
|
|
return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
|
|
}
|
|
|
|
static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
|
|
|
|
/* -----------------------------------------------------------------------------
|
|
* Registration/unregistration
|
|
*/
|
|
|
|
static void media_device_release(struct media_devnode *mdev)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* media_device_register - register a media device
|
|
* @mdev: The media device
|
|
*
|
|
* The caller is responsible for initializing the media device before
|
|
* registration. The following fields must be set:
|
|
*
|
|
* - dev must point to the parent device
|
|
* - model must be filled with the device model name
|
|
*/
|
|
int __must_check media_device_register(struct media_device *mdev)
|
|
{
|
|
int ret;
|
|
|
|
if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
|
|
return -EINVAL;
|
|
|
|
mdev->entity_id = 1;
|
|
INIT_LIST_HEAD(&mdev->entities);
|
|
spin_lock_init(&mdev->lock);
|
|
|
|
/* Register the device node. */
|
|
mdev->devnode.fops = &media_device_fops;
|
|
mdev->devnode.parent = mdev->dev;
|
|
mdev->devnode.release = media_device_release;
|
|
ret = media_devnode_register(&mdev->devnode);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
|
|
if (ret < 0) {
|
|
media_devnode_unregister(&mdev->devnode);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(media_device_register);
|
|
|
|
/**
|
|
* media_device_unregister - unregister a media device
|
|
* @mdev: The media device
|
|
*
|
|
*/
|
|
void media_device_unregister(struct media_device *mdev)
|
|
{
|
|
struct media_entity *entity;
|
|
struct media_entity *next;
|
|
|
|
list_for_each_entry_safe(entity, next, &mdev->entities, list)
|
|
media_device_unregister_entity(entity);
|
|
|
|
device_remove_file(&mdev->devnode.dev, &dev_attr_model);
|
|
media_devnode_unregister(&mdev->devnode);
|
|
}
|
|
EXPORT_SYMBOL_GPL(media_device_unregister);
|
|
|
|
/**
|
|
* media_device_register_entity - Register an entity with a media device
|
|
* @mdev: The media device
|
|
* @entity: The entity
|
|
*/
|
|
int __must_check media_device_register_entity(struct media_device *mdev,
|
|
struct media_entity *entity)
|
|
{
|
|
/* Warn if we apparently re-register an entity */
|
|
WARN_ON(entity->parent != NULL);
|
|
entity->parent = mdev;
|
|
|
|
spin_lock(&mdev->lock);
|
|
if (entity->id == 0)
|
|
entity->id = mdev->entity_id++;
|
|
else
|
|
mdev->entity_id = max(entity->id + 1, mdev->entity_id);
|
|
list_add_tail(&entity->list, &mdev->entities);
|
|
spin_unlock(&mdev->lock);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(media_device_register_entity);
|
|
|
|
/**
|
|
* media_device_unregister_entity - Unregister an entity
|
|
* @entity: The entity
|
|
*
|
|
* If the entity has never been registered this function will return
|
|
* immediately.
|
|
*/
|
|
void media_device_unregister_entity(struct media_entity *entity)
|
|
{
|
|
struct media_device *mdev = entity->parent;
|
|
|
|
if (mdev == NULL)
|
|
return;
|
|
|
|
spin_lock(&mdev->lock);
|
|
list_del(&entity->list);
|
|
spin_unlock(&mdev->lock);
|
|
entity->parent = NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(media_device_unregister_entity);
|