static ssize_t show_index(struct device *cd,
struct device_attribute *attr, char *buf)
{
- struct video_device *vfd = container_of(cd, struct video_device, dev);
+ struct video_device *vdev = to_video_device(cd);
- return sprintf(buf, "%i\n", vfd->index);
+ return sprintf(buf, "%i\n", vdev->index);
}
static ssize_t show_name(struct device *cd,
struct device_attribute *attr, char *buf)
{
- struct video_device *vfd = container_of(cd, struct video_device, dev);
+ struct video_device *vdev = to_video_device(cd);
- return sprintf(buf, "%.*s\n", (int)sizeof(vfd->name), vfd->name);
+ return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
}
static struct device_attribute video_device_attrs[] = {
}
EXPORT_SYMBOL(video_device_alloc);
-void video_device_release(struct video_device *vfd)
+void video_device_release(struct video_device *vdev)
{
- kfree(vfd);
+ kfree(vdev);
}
EXPORT_SYMBOL(video_device_release);
-void video_device_release_empty(struct video_device *vfd)
+void video_device_release_empty(struct video_device *vdev)
{
/* Do nothing */
/* Only valid when the video_device struct is a static. */
}
EXPORT_SYMBOL(video_device_release_empty);
-/* Called when the last user of the character device is gone. */
-static void v4l2_chardev_release(struct kobject *kobj)
+static inline void video_get(struct video_device *vdev)
{
- struct video_device *vfd = container_of(kobj, struct video_device, cdev.kobj);
+ get_device(&vdev->dev);
+}
+
+static inline void video_put(struct video_device *vdev)
+{
+ put_device(&vdev->dev);
+}
+
+/* Called when the last user of the video device exits. */
+static void v4l2_device_release(struct device *cd)
+{
+ struct video_device *vdev = to_video_device(cd);
mutex_lock(&videodev_lock);
- if (video_device[vfd->minor] != vfd) {
+ if (video_device[vdev->minor] != vdev) {
mutex_unlock(&videodev_lock);
- BUG();
+ /* should not happen */
+ WARN_ON(1);
return;
}
/* Free up this device for reuse */
- video_device[vfd->minor] = NULL;
- clear_bit(vfd->num, video_nums[vfd->vfl_type]);
- mutex_unlock(&videodev_lock);
+ video_device[vdev->minor] = NULL;
- /* Release the character device */
- vfd->cdev_release(kobj);
- /* Release video_device and perform other
- cleanups as needed. */
- if (vfd->release)
- vfd->release(vfd);
-}
+ /* Delete the cdev on this minor as well */
+ cdev_del(vdev->cdev);
+ /* Just in case some driver tries to access this from
+ the release() callback. */
+ vdev->cdev = NULL;
-/* The new kobj_type for the character device */
-static struct kobj_type v4l2_ktype_cdev_default = {
- .release = v4l2_chardev_release,
-};
+ /* Mark minor as free */
+ clear_bit(vdev->num, video_nums[vdev->vfl_type]);
-static void video_release(struct device *cd)
-{
- struct video_device *vfd = container_of(cd, struct video_device, dev);
+ mutex_unlock(&videodev_lock);
- /* It's now safe to delete the char device.
- This will either trigger the v4l2_chardev_release immediately (if
- the refcount goes to 0) or later when the last user of the
- character device closes it. */
- cdev_del(&vfd->cdev);
+ /* Release video_device and perform other
+ cleanups as needed. */
+ vdev->release(vdev);
}
static struct class video_class = {
.name = VIDEO_NAME,
.dev_attrs = video_device_attrs,
- .dev_release = video_release,
};
struct video_device *video_devdata(struct file *file)
}
EXPORT_SYMBOL(video_devdata);
+static ssize_t v4l2_read(struct file *filp, char __user *buf,
+ size_t sz, loff_t *off)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (!vdev->fops->read)
+ return -EINVAL;
+ if (video_is_unregistered(vdev))
+ return -EIO;
+ return vdev->fops->read(filp, buf, sz, off);
+}
+
+static ssize_t v4l2_write(struct file *filp, const char __user *buf,
+ size_t sz, loff_t *off)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (!vdev->fops->write)
+ return -EINVAL;
+ if (video_is_unregistered(vdev))
+ return -EIO;
+ return vdev->fops->write(filp, buf, sz, off);
+}
+
+static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (!vdev->fops->poll || video_is_unregistered(vdev))
+ return DEFAULT_POLLMASK;
+ return vdev->fops->poll(filp, poll);
+}
+
+static int v4l2_ioctl(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (!vdev->fops->ioctl)
+ return -ENOTTY;
+ /* Allow ioctl to continue even if the device was unregistered.
+ Things like dequeueing buffers might still be useful. */
+ return vdev->fops->ioctl(inode, filp, cmd, arg);
+}
+
+static long v4l2_unlocked_ioctl(struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (!vdev->fops->unlocked_ioctl)
+ return -ENOTTY;
+ /* Allow ioctl to continue even if the device was unregistered.
+ Things like dequeueing buffers might still be useful. */
+ return vdev->fops->unlocked_ioctl(filp, cmd, arg);
+}
+
+#ifdef CONFIG_COMPAT
+static long v4l2_compat_ioctl(struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (!vdev->fops->compat_ioctl)
+ return -ENOIOCTLCMD;
+ /* Allow ioctl to continue even if the device was unregistered.
+ Things like dequeueing buffers might still be useful. */
+ return vdev->fops->compat_ioctl(filp, cmd, arg);
+}
+#endif
+
+static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
+{
+ struct video_device *vdev = video_devdata(filp);
+
+ if (!vdev->fops->mmap ||
+ video_is_unregistered(vdev))
+ return -ENODEV;
+ return vdev->fops->mmap(filp, vm);
+}
+
+/* Override for the open function */
+static int v4l2_open(struct inode *inode, struct file *filp)
+{
+ struct video_device *vdev;
+ int ret;
+
+ /* Check if the video device is available */
+ mutex_lock(&videodev_lock);
+ vdev = video_devdata(filp);
+ /* return ENODEV if the video device has been removed
+ already or if it is not registered anymore. */
+ if (vdev == NULL || video_is_unregistered(vdev)) {
+ mutex_unlock(&videodev_lock);
+ return -ENODEV;
+ }
+ /* and increase the device refcount */
+ video_get(vdev);
+ mutex_unlock(&videodev_lock);
+ ret = vdev->fops->open(inode, filp);
+ /* decrease the refcount in case of an error */
+ if (ret)
+ video_put(vdev);
+ return ret;
+}
+
+/* Override for the release function */
+static int v4l2_release(struct inode *inode, struct file *filp)
+{
+ struct video_device *vdev = video_devdata(filp);
+ int ret = vdev->fops->release(inode, filp);
+
+ /* decrease the refcount unconditionally since the release()
+ return value is ignored. */
+ video_put(vdev);
+ return ret;
+}
+
+static const struct file_operations v4l2_unlocked_fops = {
+ .owner = THIS_MODULE,
+ .read = v4l2_read,
+ .write = v4l2_write,
+ .open = v4l2_open,
+ .mmap = v4l2_mmap,
+ .unlocked_ioctl = v4l2_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = v4l2_compat_ioctl,
+#endif
+ .release = v4l2_release,
+ .poll = v4l2_poll,
+ .llseek = no_llseek,
+};
+
+static const struct file_operations v4l2_fops = {
+ .owner = THIS_MODULE,
+ .read = v4l2_read,
+ .write = v4l2_write,
+ .open = v4l2_open,
+ .mmap = v4l2_mmap,
+ .ioctl = v4l2_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = v4l2_compat_ioctl,
+#endif
+ .release = v4l2_release,
+ .poll = v4l2_poll,
+ .llseek = no_llseek,
+};
+
/**
* get_index - assign stream number based on parent device
- * @vdev: video_device to assign index number to, vdev->dev should be assigned
- * @num: -1 if auto assign, requested number otherwise
+ * @vdev: video_device to assign index number to, vdev->parent should be assigned
+ * @num: -1 if auto assign, requested number otherwise
*
+ * Note that when this is called the new device has not yet been registered
+ * in the video_device array.
*
- * returns -ENFILE if num is already in use, a free index number if
+ * Returns -ENFILE if num is already in use, a free index number if
* successful.
*/
static int get_index(struct video_device *vdev, int num)
for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
if (video_device[i] != NULL &&
- video_device[i] != vdev &&
video_device[i]->parent == vdev->parent) {
used |= 1 << video_device[i]->index;
}
return i > max_index ? -ENFILE : i;
}
-static const struct file_operations video_fops;
-
-int video_register_device(struct video_device *vfd, int type, int nr)
+int video_register_device(struct video_device *vdev, int type, int nr)
{
- return video_register_device_index(vfd, type, nr, -1);
+ return video_register_device_index(vdev, type, nr, -1);
}
EXPORT_SYMBOL(video_register_device);
/**
* video_register_device_index - register video4linux devices
- * @vfd: video device structure we want to register
+ * @vdev: video device structure we want to register
* @type: type of device to register
* @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
* -1 == first free)
*
* %VFL_TYPE_RADIO - A radio card
*/
-
-int video_register_device_index(struct video_device *vfd, int type, int nr,
+int video_register_device_index(struct video_device *vdev, int type, int nr,
int index)
{
int i = 0;
int minor_offset = 0;
int minor_cnt = VIDEO_NUM_DEVICES;
const char *name_base;
- void *priv = video_get_drvdata(vfd);
+ void *priv = video_get_drvdata(vdev);
- /* the release callback MUST be present */
- BUG_ON(!vfd->release);
+ /* A minor value of -1 marks this video device as never
+ having been registered */
+ if (vdev)
+ vdev->minor = -1;
- if (vfd == NULL)
+ /* the release callback MUST be present */
+ WARN_ON(!vdev || !vdev->release);
+ if (!vdev || !vdev->release)
return -EINVAL;
+ /* Part 1: check device type */
switch (type) {
case VFL_TYPE_GRABBER:
name_base = "video";
return -EINVAL;
}
- vfd->vfl_type = type;
+ vdev->vfl_type = type;
+ vdev->cdev = NULL;
+ /* Part 2: find a free minor, kernel number and device index. */
#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
/* Keep the ranges for the first four types for historical
* reasons.
}
#endif
- /* Initialize the character device */
- cdev_init(&vfd->cdev, vfd->fops);
- vfd->cdev.owner = vfd->fops->owner;
- /* pick a minor number */
+ /* Pick a minor number */
mutex_lock(&videodev_lock);
nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr);
if (nr == minor_cnt)
return -ENFILE;
}
#endif
- vfd->minor = i + minor_offset;
- vfd->num = nr;
+ vdev->minor = i + minor_offset;
+ vdev->num = nr;
set_bit(nr, video_nums[type]);
- BUG_ON(video_device[vfd->minor]);
- video_device[vfd->minor] = vfd;
-
- ret = get_index(vfd, index);
- vfd->index = ret;
-
+ /* Should not happen since we thought this minor was free */
+ WARN_ON(video_device[vdev->minor] != NULL);
+ ret = vdev->index = get_index(vdev, index);
mutex_unlock(&videodev_lock);
if (ret < 0) {
printk(KERN_ERR "%s: get_index failed\n", __func__);
- goto fail_minor;
+ goto cleanup;
}
- ret = cdev_add(&vfd->cdev, MKDEV(VIDEO_MAJOR, vfd->minor), 1);
+ /* Part 3: Initialize the character device */
+ vdev->cdev = cdev_alloc();
+ if (vdev->cdev == NULL) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+ if (vdev->fops->unlocked_ioctl)
+ vdev->cdev->ops = &v4l2_unlocked_fops;
+ else
+ vdev->cdev->ops = &v4l2_fops;
+ vdev->cdev->owner = vdev->fops->owner;
+ ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
if (ret < 0) {
printk(KERN_ERR "%s: cdev_add failed\n", __func__);
- goto fail_minor;
+ kfree(vdev->cdev);
+ vdev->cdev = NULL;
+ goto cleanup;
}
- /* sysfs class */
- memset(&vfd->dev, 0, sizeof(vfd->dev));
+
+ /* Part 4: register the device with sysfs */
+ memset(&vdev->dev, 0, sizeof(vdev->dev));
/* The memset above cleared the device's drvdata, so
put back the copy we made earlier. */
- video_set_drvdata(vfd, priv);
- vfd->dev.class = &video_class;
- vfd->dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
- if (vfd->parent)
- vfd->dev.parent = vfd->parent;
- dev_set_name(&vfd->dev, "%s%d", name_base, nr);
- ret = device_register(&vfd->dev);
+ video_set_drvdata(vdev, priv);
+ vdev->dev.class = &video_class;
+ vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
+ if (vdev->parent)
+ vdev->dev.parent = vdev->parent;
+ dev_set_name(&vdev->dev, "%s%d", name_base, nr);
+ ret = device_register(&vdev->dev);
if (ret < 0) {
printk(KERN_ERR "%s: device_register failed\n", __func__);
- goto del_cdev;
+ goto cleanup;
}
- /* Remember the cdev's release function */
- vfd->cdev_release = vfd->cdev.kobj.ktype->release;
- /* Install our own */
- vfd->cdev.kobj.ktype = &v4l2_ktype_cdev_default;
- return 0;
+ /* Register the release callback that will be called when the last
+ reference to the device goes away. */
+ vdev->dev.release = v4l2_device_release;
-del_cdev:
- cdev_del(&vfd->cdev);
+ /* Part 5: Activate this minor. The char device can now be used. */
+ mutex_lock(&videodev_lock);
+ video_device[vdev->minor] = vdev;
+ mutex_unlock(&videodev_lock);
+ return 0;
-fail_minor:
+cleanup:
mutex_lock(&videodev_lock);
- video_device[vfd->minor] = NULL;
- clear_bit(vfd->num, video_nums[type]);
+ if (vdev->cdev)
+ cdev_del(vdev->cdev);
+ clear_bit(vdev->num, video_nums[type]);
mutex_unlock(&videodev_lock);
- vfd->minor = -1;
+ /* Mark this video device as never having been registered. */
+ vdev->minor = -1;
return ret;
}
EXPORT_SYMBOL(video_register_device_index);
/**
* video_unregister_device - unregister a video4linux device
- * @vfd: the device to unregister
+ * @vdev: the device to unregister
*
- * This unregisters the passed device and deassigns the minor
- * number. Future open calls will be met with errors.
+ * This unregisters the passed device. Future open calls will
+ * be met with errors.
*/
-
-void video_unregister_device(struct video_device *vfd)
+void video_unregister_device(struct video_device *vdev)
{
- device_unregister(&vfd->dev);
+ /* Check if vdev was ever registered at all */
+ if (!vdev || vdev->minor < 0)
+ return;
+
+ mutex_lock(&videodev_lock);
+ set_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
+ mutex_unlock(&videodev_lock);
+ device_unregister(&vdev->dev);
}
EXPORT_SYMBOL(video_unregister_device);
struct v4l2_ioctl_callbacks;
+/* Flag to mark the video_device struct as unregistered.
+ Drivers can set this flag if they want to block all future
+ device access. It is set by video_unregister_device. */
+#define V4L2_FL_UNREGISTERED (0)
+
/*
* Newer version of video_device, handled by videodev2.c
* This version moves redundant code from video device code to
/* sysfs */
struct device dev; /* v4l device */
- struct cdev cdev; /* character device */
- void (*cdev_release)(struct kobject *kobj);
+ struct cdev *cdev; /* character device */
struct device *parent; /* device parent */
/* device info */
char name[32];
int vfl_type;
+ /* 'minor' is set to -1 if the registration failed */
int minor;
u16 num;
+ /* use bitops to set/clear/test flags */
+ unsigned long flags;
/* attribute to differentiate multiple indices on one physical device */
int index;
v4l2_std_id current_norm; /* Current tvnorm */
/* callbacks */
- void (*release)(struct video_device *vfd);
+ void (*release)(struct video_device *vdev);
/* ioctl callbacks */
const struct v4l2_ioctl_ops *ioctl_ops;
/* dev to video-device */
#define to_video_device(cd) container_of(cd, struct video_device, dev)
-/* Register and unregister devices. Note that if video_register_device fails,
+/* Register video devices. Note that if video_register_device fails,
the release() callback of the video_device structure is *not* called, so
the caller is responsible for freeing any data. Usually that means that
- you call video_device_release() on failure. */
-int __must_check video_register_device(struct video_device *vfd, int type, int nr);
-int __must_check video_register_device_index(struct video_device *vfd,
+ you call video_device_release() on failure.
+
+ Also note that vdev->minor is set to -1 if the registration failed. */
+int __must_check video_register_device(struct video_device *vdev, int type, int nr);
+int __must_check video_register_device_index(struct video_device *vdev,
int type, int nr, int index);
-void video_unregister_device(struct video_device *vfd);
+
+/* Unregister video devices. Will do nothing if vdev == NULL or
+ vdev->minor < 0. */
+void video_unregister_device(struct video_device *vdev);
/* helper functions to alloc/release struct video_device, the
latter can also be used for video_device->release(). */
struct video_device * __must_check video_device_alloc(void);
-/* this release function frees the vfd pointer */
-void video_device_release(struct video_device *vfd);
+/* this release function frees the vdev pointer */
+void video_device_release(struct video_device *vdev);
/* this release function does nothing, use when the video_device is a
static global struct. Note that having a static video_device is
a dubious construction at best. */
-void video_device_release_empty(struct video_device *vfd);
+void video_device_release_empty(struct video_device *vdev);
/* helper functions to access driver private data. */
-static inline void *video_get_drvdata(struct video_device *dev)
+static inline void *video_get_drvdata(struct video_device *vdev)
{
- return dev_get_drvdata(&dev->dev);
+ return dev_get_drvdata(&vdev->dev);
}
-static inline void video_set_drvdata(struct video_device *dev, void *data)
+static inline void video_set_drvdata(struct video_device *vdev, void *data)
{
- dev_set_drvdata(&dev->dev, data);
+ dev_set_drvdata(&vdev->dev, data);
}
struct video_device *video_devdata(struct file *file);
return video_get_drvdata(video_devdata(file));
}
+static inline int video_is_unregistered(struct video_device *vdev)
+{
+ return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
+}
+
#endif /* _V4L2_DEV_H */
projects / linux-2.6-omap-h63xx.git / commitdiff