diff options
Diffstat (limited to 'drivers/media/media-devnode.c')
| -rw-r--r-- | drivers/media/media-devnode.c | 168 |
1 files changed, 97 insertions, 71 deletions
diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c index ebf9626e5ae5..e887120d19aa 100644 --- a/drivers/media/media-devnode.c +++ b/drivers/media/media-devnode.c @@ -44,6 +44,7 @@ #include <linux/uaccess.h> #include <media/media-devnode.h> +#include <media/media-device.h> #define MEDIA_NUM_DEVICES 256 #define MEDIA_NAME "media" @@ -59,21 +60,19 @@ static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES); /* Called when the last user of the media device exits. */ static void media_devnode_release(struct device *cd) { - struct media_devnode *mdev = to_media_devnode(cd); + struct media_devnode *devnode = to_media_devnode(cd); mutex_lock(&media_devnode_lock); - - /* Delete the cdev on this minor as well */ - cdev_del(&mdev->cdev); - /* Mark device node number as free */ - clear_bit(mdev->minor, media_devnode_nums); - + clear_bit(devnode->minor, media_devnode_nums); mutex_unlock(&media_devnode_lock); /* Release media_devnode and perform other cleanups as needed. */ - if (mdev->release) - mdev->release(mdev); + if (devnode->release) + devnode->release(devnode); + + kfree(devnode); + pr_debug("%s: Media Devnode Deallocated\n", __func__); } static struct bus_type media_bus_type = { @@ -83,37 +82,37 @@ static struct bus_type media_bus_type = { static ssize_t media_read(struct file *filp, char __user *buf, size_t sz, loff_t *off) { - struct media_devnode *mdev = media_devnode_data(filp); + struct media_devnode *devnode = media_devnode_data(filp); - if (!mdev->fops->read) + if (!devnode->fops->read) return -EINVAL; - if (!media_devnode_is_registered(mdev)) + if (!media_devnode_is_registered(devnode)) return -EIO; - return mdev->fops->read(filp, buf, sz, off); + return devnode->fops->read(filp, buf, sz, off); } 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); + struct media_devnode *devnode = media_devnode_data(filp); - if (!mdev->fops->write) + if (!devnode->fops->write) return -EINVAL; - if (!media_devnode_is_registered(mdev)) + if (!media_devnode_is_registered(devnode)) return -EIO; - return mdev->fops->write(filp, buf, sz, off); + return devnode->fops->write(filp, buf, sz, off); } static unsigned int media_poll(struct file *filp, struct poll_table_struct *poll) { - struct media_devnode *mdev = media_devnode_data(filp); + struct media_devnode *devnode = media_devnode_data(filp); - if (!media_devnode_is_registered(mdev)) + if (!media_devnode_is_registered(devnode)) return POLLERR | POLLHUP; - if (!mdev->fops->poll) + if (!devnode->fops->poll) return DEFAULT_POLLMASK; - return mdev->fops->poll(filp, poll); + return devnode->fops->poll(filp, poll); } static long @@ -121,12 +120,12 @@ __media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg, long (*ioctl_func)(struct file *filp, unsigned int cmd, unsigned long arg)) { - struct media_devnode *mdev = media_devnode_data(filp); + struct media_devnode *devnode = media_devnode_data(filp); if (!ioctl_func) return -ENOTTY; - if (!media_devnode_is_registered(mdev)) + if (!media_devnode_is_registered(devnode)) return -EIO; return ioctl_func(filp, cmd, arg); @@ -134,9 +133,9 @@ __media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg, static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { - struct media_devnode *mdev = media_devnode_data(filp); + struct media_devnode *devnode = media_devnode_data(filp); - return __media_ioctl(filp, cmd, arg, mdev->fops->ioctl); + return __media_ioctl(filp, cmd, arg, devnode->fops->ioctl); } #ifdef CONFIG_COMPAT @@ -144,9 +143,9 @@ static long media_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) static long media_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { - struct media_devnode *mdev = media_devnode_data(filp); + struct media_devnode *devnode = media_devnode_data(filp); - return __media_ioctl(filp, cmd, arg, mdev->fops->compat_ioctl); + return __media_ioctl(filp, cmd, arg, devnode->fops->compat_ioctl); } #endif /* CONFIG_COMPAT */ @@ -154,7 +153,7 @@ static long media_compat_ioctl(struct file *filp, unsigned int cmd, /* Override for the open function */ static int media_open(struct inode *inode, struct file *filp) { - struct media_devnode *mdev; + struct media_devnode *devnode; int ret; /* Check if the media device is available. This needs to be done with @@ -164,23 +163,24 @@ static int media_open(struct inode *inode, struct file *filp) * a crash. */ mutex_lock(&media_devnode_lock); - mdev = container_of(inode->i_cdev, struct media_devnode, cdev); + devnode = 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)) { + if (!media_devnode_is_registered(devnode)) { mutex_unlock(&media_devnode_lock); return -ENXIO; } /* and increase the device refcount */ - get_device(&mdev->dev); + get_device(&devnode->dev); mutex_unlock(&media_devnode_lock); - filp->private_data = mdev; + filp->private_data = devnode; - if (mdev->fops->open) { - ret = mdev->fops->open(filp); + if (devnode->fops->open) { + ret = devnode->fops->open(filp); if (ret) { - put_device(&mdev->dev); + put_device(&devnode->dev); + filp->private_data = NULL; return ret; } } @@ -191,15 +191,18 @@ static int media_open(struct inode *inode, struct file *filp) /* Override for the release function */ static int media_release(struct inode *inode, struct file *filp) { - struct media_devnode *mdev = media_devnode_data(filp); + struct media_devnode *devnode = media_devnode_data(filp); + + if (devnode->fops->release) + devnode->fops->release(filp); - if (mdev->fops->release) - mdev->fops->release(filp); + filp->private_data = NULL; /* decrease the refcount unconditionally since the release() return value is ignored. */ - put_device(&mdev->dev); - filp->private_data = NULL; + put_device(&devnode->dev); + + pr_debug("%s: Media Release\n", __func__); return 0; } @@ -219,7 +222,8 @@ static const struct file_operations media_devnode_fops = { /** * media_devnode_register - register a media device node - * @mdev: media device node structure we want to register + * @media_dev: struct media_device we want to register a device node + * @devnode: media device node structure we want to register * * The registration code assigns minor numbers and registers the new device node * with the kernel. An error is returned if no free minor number can be found, @@ -231,7 +235,8 @@ static const struct file_operations media_devnode_fops = { * the media_devnode structure is *not* called, so the caller is responsible for * freeing any data. */ -int __must_check media_devnode_register(struct media_devnode *mdev, +int __must_check media_devnode_register(struct media_device *mdev, + struct media_devnode *devnode, struct module *owner) { int minor; @@ -243,68 +248,89 @@ int __must_check media_devnode_register(struct media_devnode *mdev, if (minor == MEDIA_NUM_DEVICES) { mutex_unlock(&media_devnode_lock); pr_err("could not get a free minor\n"); + kfree(devnode); return -ENFILE; } set_bit(minor, media_devnode_nums); mutex_unlock(&media_devnode_lock); - mdev->minor = minor; + devnode->minor = minor; + devnode->media_dev = mdev; + + /* Part 1: Initialize dev now to use dev.kobj for cdev.kobj.parent */ + devnode->dev.bus = &media_bus_type; + devnode->dev.devt = MKDEV(MAJOR(media_dev_t), devnode->minor); + devnode->dev.release = media_devnode_release; + if (devnode->parent) + devnode->dev.parent = devnode->parent; + dev_set_name(&devnode->dev, "media%d", devnode->minor); + device_initialize(&devnode->dev); /* Part 2: Initialize and register the character device */ - cdev_init(&mdev->cdev, &media_devnode_fops); - mdev->cdev.owner = owner; + cdev_init(&devnode->cdev, &media_devnode_fops); + devnode->cdev.owner = owner; + devnode->cdev.kobj.parent = &devnode->dev.kobj; - ret = cdev_add(&mdev->cdev, MKDEV(MAJOR(media_dev_t), mdev->minor), 1); + ret = cdev_add(&devnode->cdev, MKDEV(MAJOR(media_dev_t), devnode->minor), 1); if (ret < 0) { pr_err("%s: cdev_add failed\n", __func__); - goto error; + goto cdev_add_error; } - /* Part 3: Register the media device */ - mdev->dev.bus = &media_bus_type; - mdev->dev.devt = MKDEV(MAJOR(media_dev_t), mdev->minor); - mdev->dev.release = media_devnode_release; - if (mdev->parent) - mdev->dev.parent = mdev->parent; - dev_set_name(&mdev->dev, "media%d", mdev->minor); - ret = device_register(&mdev->dev); + /* Part 3: Add the media device */ + ret = device_add(&devnode->dev); if (ret < 0) { - pr_err("%s: device_register failed\n", __func__); - goto error; + pr_err("%s: device_add failed\n", __func__); + goto device_add_error; } /* Part 4: Activate this minor. The char device can now be used. */ - set_bit(MEDIA_FLAG_REGISTERED, &mdev->flags); + set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); return 0; -error: - cdev_del(&mdev->cdev); - clear_bit(mdev->minor, media_devnode_nums); +device_add_error: + cdev_del(&devnode->cdev); +cdev_add_error: + mutex_lock(&media_devnode_lock); + clear_bit(devnode->minor, media_devnode_nums); + devnode->media_dev = NULL; + mutex_unlock(&media_devnode_lock); + + put_device(&devnode->dev); return ret; } +void media_devnode_unregister_prepare(struct media_devnode *devnode) +{ + /* Check if devnode was ever registered at all */ + if (!media_devnode_is_registered(devnode)) + return; + + mutex_lock(&media_devnode_lock); + clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); + mutex_unlock(&media_devnode_lock); +} + /** * media_devnode_unregister - unregister a media device node - * @mdev: the device node to unregister + * @devnode: 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. + * Should be called after media_devnode_unregister_prepare() */ -void media_devnode_unregister(struct media_devnode *mdev) +void media_devnode_unregister(struct media_devnode *devnode) { - /* 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); + /* Delete the cdev on this minor as well */ + cdev_del(&devnode->cdev); mutex_unlock(&media_devnode_lock); - device_unregister(&mdev->dev); + device_del(&devnode->dev); + devnode->media_dev = NULL; + put_device(&devnode->dev); } /* |