/* Override for the open function */
static int media_open(struct inode *inode, struct file *filp)
{
struct media_devnode *mdev;
int ret;
/* Check if the media device is available. This needs to be done with
* the media_devnode_lock held to prevent an open/unregister race:
* without the lock, the device could be unregistered and freed between
* the media_devnode_is_registered() and get_device() calls, leading to
* a crash.
*/
mutex_lock(&media_devnode_lock);
mdev = container_of(inode->i_cdev, struct media_devnode, cdev);
/* return ENXIO if the media device has been removed
already or if it is not registered anymore. */
if (!media_devnode_is_registered(mdev)) {
mutex_unlock(&media_devnode_lock);
return -ENXIO;
}
/* and increase the device refcount */
get_device(&mdev->dev);
mutex_unlock(&media_devnode_lock);
filp->private_data = mdev;
if (mdev->fops->open) {
ret = mdev->fops->open(filp);
if (ret) {
put_device(&mdev->dev);
return ret;
}
}
return 0;
}
static ssize_t media_write(struct file *filp, const char __user *buf,
size_t sz, loff_t *off)
{
struct media_devnode *mdev = media_devnode_data(filp);
if (!mdev->fops->write)
return -EINVAL;
if (!media_devnode_is_registered(mdev))
return -EIO;
return mdev->fops->write(filp, buf, sz, off);
}
/**
* media_devnode_unregister - unregister a media device node
* @mdev: the device node to unregister
*
* This unregisters the passed device. Future open calls will be met with
* errors.
*
* This function can safely be called if the device node has never been
* registered or has already been unregistered.
*/
void media_devnode_unregister(struct media_devnode *mdev)
{
/* Check if mdev was ever registered at all */
if (!media_devnode_is_registered(mdev))
return;
mutex_lock(&media_devnode_lock);
clear_bit(MEDIA_FLAG_REGISTERED, &mdev->flags);
mutex_unlock(&media_devnode_lock);
device_unregister(&mdev->dev);
}
static unsigned int media_poll(struct file *filp,
struct poll_table_struct *poll)
{
struct media_devnode *mdev = media_devnode_data(filp);
if (!media_devnode_is_registered(mdev))
return POLLERR | POLLHUP;
if (!mdev->fops->poll)
return DEFAULT_POLLMASK;
return mdev->fops->poll(filp, poll);
}
static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct media_devnode *mdev = media_devnode_data(filp);
if (!mdev->fops->ioctl)
return -ENOTTY;
if (!media_devnode_is_registered(mdev))
return -EIO;
return mdev->fops->ioctl(filp, cmd, arg);
}
static void au0828_unregister_media_device(struct au0828_dev *dev)
{
#ifdef CONFIG_MEDIA_CONTROLLER
if (dev->media_dev &&
media_devnode_is_registered(&dev->media_dev->devnode)) {
/* clear enable_source, disable_source */
dev->media_dev->source_priv = NULL;
dev->media_dev->enable_source = NULL;
dev->media_dev->disable_source = NULL;
media_device_unregister(dev->media_dev);
media_device_cleanup(dev->media_dev);
kfree(dev->media_dev);
dev->media_dev = NULL;
}
#endif
}
