init android origin source code

1 files changed, 803 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/drivers/media/video/v4l2-dev.c b/ANDROID_3.4.5/drivers/media/video/v4l2-dev.c
new file mode 100644
index 00000000..70bec548
--- /dev/null
+++ b/ANDROID_3.4.5/drivers/media/video/v4l2-dev.c
@@ -0,0 +1,803 @@
+/*
+ * Video capture interface for Linux version 2
+ *
+ *	A generic video device interface for the LINUX operating system
+ *	using a set of device structures/vectors for low level operations.
+ *
+ *	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.
+ *
+ * Authors:	Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
+ *              Mauro Carvalho Chehab <mchehab@infradead.org> (version 2)
+ *
+ * Fixes:	20000516  Claudio Matsuoka <claudio@conectiva.com>
+ *		- Added procfs support
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+
+#include <media/v4l2-common.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+
+#define VIDEO_NUM_DEVICES	256
+#define VIDEO_NAME              "video4linux"
+
+/*
+ *	sysfs stuff
+ */
+
+static ssize_t show_index(struct device *cd,
+			 struct device_attribute *attr, char *buf)
+{
+	struct video_device *vdev = to_video_device(cd);
+
+	return sprintf(buf, "%i\n", vdev->index);
+}
+
+static ssize_t show_name(struct device *cd,
+			 struct device_attribute *attr, char *buf)
+{
+	struct video_device *vdev = to_video_device(cd);
+
+	return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
+}
+
+static struct device_attribute video_device_attrs[] = {
+	__ATTR(name, S_IRUGO, show_name, NULL),
+	__ATTR(index, S_IRUGO, show_index, NULL),
+	__ATTR_NULL
+};
+
+/*
+ *	Active devices
+ */
+static struct video_device *video_device[VIDEO_NUM_DEVICES];
+static DEFINE_MUTEX(videodev_lock);
+static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
+
+/* Device node utility functions */
+
+/* Note: these utility functions all assume that vfl_type is in the range
+   [0, VFL_TYPE_MAX-1]. */
+
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+/* Return the bitmap corresponding to vfl_type. */
+static inline unsigned long *devnode_bits(int vfl_type)
+{
+	/* Any types not assigned to fixed minor ranges must be mapped to
+	   one single bitmap for the purposes of finding a free node number
+	   since all those unassigned types use the same minor range. */
+	int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type;
+
+	return devnode_nums[idx];
+}
+#else
+/* Return the bitmap corresponding to vfl_type. */
+static inline unsigned long *devnode_bits(int vfl_type)
+{
+	return devnode_nums[vfl_type];
+}
+#endif
+
+/* Mark device node number vdev->num as used */
+static inline void devnode_set(struct video_device *vdev)
+{
+	set_bit(vdev->num, devnode_bits(vdev->vfl_type));
+}
+
+/* Mark device node number vdev->num as unused */
+static inline void devnode_clear(struct video_device *vdev)
+{
+	clear_bit(vdev->num, devnode_bits(vdev->vfl_type));
+}
+
+/* Try to find a free device node number in the range [from, to> */
+static inline int devnode_find(struct video_device *vdev, int from, int to)
+{
+	return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from);
+}
+
+struct video_device *video_device_alloc(void)
+{
+	return kzalloc(sizeof(struct video_device), GFP_KERNEL);
+}
+EXPORT_SYMBOL(video_device_alloc);
+
+void video_device_release(struct video_device *vdev)
+{
+	kfree(vdev);
+}
+EXPORT_SYMBOL(video_device_release);
+
+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);
+
+static inline void video_get(struct video_device *vdev)
+{
+	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);
+	struct v4l2_device *v4l2_dev = vdev->v4l2_dev;
+
+	mutex_lock(&videodev_lock);
+	if (WARN_ON(video_device[vdev->minor] != vdev)) {
+		/* should not happen */
+		mutex_unlock(&videodev_lock);
+		return;
+	}
+
+	/* Free up this device for reuse */
+	video_device[vdev->minor] = NULL;
+
+	/* 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;
+
+	/* Mark device node number as free */
+	devnode_clear(vdev);
+
+	mutex_unlock(&videodev_lock);
+
+#if defined(CONFIG_MEDIA_CONTROLLER)
+	if (v4l2_dev && v4l2_dev->mdev &&
+	    vdev->vfl_type != VFL_TYPE_SUBDEV)
+		media_device_unregister_entity(&vdev->entity);
+#endif
+
+	/* Do not call v4l2_device_put if there is no release callback set.
+	 * Drivers that have no v4l2_device release callback might free the
+	 * v4l2_dev instance in the video_device release callback below, so we
+	 * must perform this check here.
+	 *
+	 * TODO: In the long run all drivers that use v4l2_device should use the
+	 * v4l2_device release callback. This check will then be unnecessary.
+	 */
+	if (v4l2_dev && v4l2_dev->release == NULL)
+		v4l2_dev = NULL;
+
+	/* Release video_device and perform other
+	   cleanups as needed. */
+	vdev->release(vdev);
+
+	/* Decrease v4l2_device refcount */
+	if (v4l2_dev)
+		v4l2_device_put(v4l2_dev);
+}
+
+static struct class video_class = {
+	.name = VIDEO_NAME,
+	.dev_attrs = video_device_attrs,
+};
+
+struct video_device *video_devdata(struct file *file)
+{
+	return video_device[iminor(file->f_path.dentry->d_inode)];
+}
+EXPORT_SYMBOL(video_devdata);
+
+
+/* Priority handling */
+
+static inline bool prio_is_valid(enum v4l2_priority prio)
+{
+	return prio == V4L2_PRIORITY_BACKGROUND ||
+	       prio == V4L2_PRIORITY_INTERACTIVE ||
+	       prio == V4L2_PRIORITY_RECORD;
+}
+
+void v4l2_prio_init(struct v4l2_prio_state *global)
+{
+	memset(global, 0, sizeof(*global));
+}
+EXPORT_SYMBOL(v4l2_prio_init);
+
+int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
+		     enum v4l2_priority new)
+{
+	if (!prio_is_valid(new))
+		return -EINVAL;
+	if (*local == new)
+		return 0;
+
+	atomic_inc(&global->prios[new]);
+	if (prio_is_valid(*local))
+		atomic_dec(&global->prios[*local]);
+	*local = new;
+	return 0;
+}
+EXPORT_SYMBOL(v4l2_prio_change);
+
+void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
+{
+	v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT);
+}
+EXPORT_SYMBOL(v4l2_prio_open);
+
+void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local)
+{
+	if (prio_is_valid(local))
+		atomic_dec(&global->prios[local]);
+}
+EXPORT_SYMBOL(v4l2_prio_close);
+
+enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
+{
+	if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
+		return V4L2_PRIORITY_RECORD;
+	if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
+		return V4L2_PRIORITY_INTERACTIVE;
+	if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
+		return V4L2_PRIORITY_BACKGROUND;
+	return V4L2_PRIORITY_UNSET;
+}
+EXPORT_SYMBOL(v4l2_prio_max);
+
+int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local)
+{
+	return (local < v4l2_prio_max(global)) ? -EBUSY : 0;
+}
+EXPORT_SYMBOL(v4l2_prio_check);
+
+
+static ssize_t v4l2_read(struct file *filp, char __user *buf,
+		size_t sz, loff_t *off)
+{
+	struct video_device *vdev = video_devdata(filp);
+	int ret = -ENODEV;
+
+	if (!vdev->fops->read)
+		return -EINVAL;
+	if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+		return -ERESTARTSYS;
+	if (video_is_registered(vdev))
+		ret = vdev->fops->read(filp, buf, sz, off);
+	if (vdev->lock)
+		mutex_unlock(vdev->lock);
+	return ret;
+}
+
+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);
+	int ret = -ENODEV;
+
+	if (!vdev->fops->write)
+		return -EINVAL;
+	if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+		return -ERESTARTSYS;
+	if (video_is_registered(vdev))
+		ret = vdev->fops->write(filp, buf, sz, off);
+	if (vdev->lock)
+		mutex_unlock(vdev->lock);
+	return ret;
+}
+
+static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
+{
+	struct video_device *vdev = video_devdata(filp);
+	int ret = POLLERR | POLLHUP;
+
+	if (!vdev->fops->poll)
+		return DEFAULT_POLLMASK;
+	if (vdev->lock)
+		mutex_lock(vdev->lock);
+	if (video_is_registered(vdev))
+		ret = vdev->fops->poll(filp, poll);
+	if (vdev->lock)
+		mutex_unlock(vdev->lock);
+	return ret;
+}
+
+static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct video_device *vdev = video_devdata(filp);
+	int ret = -ENODEV;
+
+	if (vdev->fops->unlocked_ioctl) {
+		if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+			return -ERESTARTSYS;
+		if (video_is_registered(vdev))
+			ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
+		if (vdev->lock)
+			mutex_unlock(vdev->lock);
+	} else if (vdev->fops->ioctl) {
+		/* This code path is a replacement for the BKL. It is a major
+		 * hack but it will have to do for those drivers that are not
+		 * yet converted to use unlocked_ioctl.
+		 *
+		 * There are two options: if the driver implements struct
+		 * v4l2_device, then the lock defined there is used to
+		 * serialize the ioctls. Otherwise the v4l2 core lock defined
+		 * below is used. This lock is really bad since it serializes
+		 * completely independent devices.
+		 *
+		 * Both variants suffer from the same problem: if the driver
+		 * sleeps, then it blocks all ioctls since the lock is still
+		 * held. This is very common for VIDIOC_DQBUF since that
+		 * normally waits for a frame to arrive. As a result any other
+		 * ioctl calls will proceed very, very slowly since each call
+		 * will have to wait for the VIDIOC_QBUF to finish. Things that
+		 * should take 0.01s may now take 10-20 seconds.
+		 *
+		 * The workaround is to *not* take the lock for VIDIOC_DQBUF.
+		 * This actually works OK for videobuf-based drivers, since
+		 * videobuf will take its own internal lock.
+		 */
+		static DEFINE_MUTEX(v4l2_ioctl_mutex);
+		struct mutex *m = vdev->v4l2_dev ?
+			&vdev->v4l2_dev->ioctl_lock : &v4l2_ioctl_mutex;
+
+		if (cmd != VIDIOC_DQBUF && mutex_lock_interruptible(m))
+			return -ERESTARTSYS;
+		if (video_is_registered(vdev))
+			ret = vdev->fops->ioctl(filp, cmd, arg);
+		if (cmd != VIDIOC_DQBUF)
+			mutex_unlock(m);
+	} else
+		ret = -ENOTTY;
+
+	return ret;
+}
+
+#ifdef CONFIG_MMU
+#define v4l2_get_unmapped_area NULL
+#else
+static unsigned long v4l2_get_unmapped_area(struct file *filp,
+		unsigned long addr, unsigned long len, unsigned long pgoff,
+		unsigned long flags)
+{
+	struct video_device *vdev = video_devdata(filp);
+
+	if (!vdev->fops->get_unmapped_area)
+		return -ENOSYS;
+	if (!video_is_registered(vdev))
+		return -ENODEV;
+	return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
+}
+#endif
+
+static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
+{
+	struct video_device *vdev = video_devdata(filp);
+	int ret = -ENODEV;
+
+	if (!vdev->fops->mmap)
+		return ret;
+	if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+		return -ERESTARTSYS;
+	if (video_is_registered(vdev))
+		ret = vdev->fops->mmap(filp, vm);
+	if (vdev->lock)
+		mutex_unlock(vdev->lock);
+	return ret;
+}
+
+/* Override for the open function */
+static int v4l2_open(struct inode *inode, struct file *filp)
+{
+	struct video_device *vdev;
+	int ret = 0;
+
+	/* Check if the video device is available */
+	mutex_lock(&videodev_lock);
+	vdev = video_devdata(filp);
+	/* return ENODEV if the video device has already been removed. */
+	if (vdev == NULL || !video_is_registered(vdev)) {
+		mutex_unlock(&videodev_lock);
+		return -ENODEV;
+	}
+	/* and increase the device refcount */
+	video_get(vdev);
+	mutex_unlock(&videodev_lock);
+	if (vdev->fops->open) {
+		if (vdev->lock && mutex_lock_interruptible(vdev->lock)) {
+			ret = -ERESTARTSYS;
+			goto err;
+		}
+		if (video_is_registered(vdev))
+			ret = vdev->fops->open(filp);
+		else
+			ret = -ENODEV;
+		if (vdev->lock)
+			mutex_unlock(vdev->lock);
+	}
+
+err:
+	/* 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 = 0;
+
+	if (vdev->fops->release) {
+		if (vdev->lock)
+			mutex_lock(vdev->lock);
+		vdev->fops->release(filp);
+		if (vdev->lock)
+			mutex_unlock(vdev->lock);
+	}
+	/* decrease the refcount unconditionally since the release()
+	   return value is ignored. */
+	video_put(vdev);
+	return ret;
+}
+
+static const struct file_operations v4l2_fops = {
+	.owner = THIS_MODULE,
+	.read = v4l2_read,
+	.write = v4l2_write,
+	.open = v4l2_open,
+	.get_unmapped_area = v4l2_get_unmapped_area,
+	.mmap = v4l2_mmap,
+	.unlocked_ioctl = v4l2_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = v4l2_compat_ioctl32,
+#endif
+	.release = v4l2_release,
+	.poll = v4l2_poll,
+	.llseek = no_llseek,
+};
+
+/**
+ * get_index - assign stream index number based on parent device
+ * @vdev: video_device to assign index number to, vdev->parent should be assigned
+ *
+ * Note that when this is called the new device has not yet been registered
+ * in the video_device array, but it was able to obtain a minor number.
+ *
+ * This means that we can always obtain a free stream index number since
+ * the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
+ * use of the video_device array.
+ *
+ * Returns a free index number.
+ */
+static int get_index(struct video_device *vdev)
+{
+	/* This can be static since this function is called with the global
+	   videodev_lock held. */
+	static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
+	int i;
+
+	/* Some drivers do not set the parent. In that case always return 0. */
+	if (vdev->parent == NULL)
+		return 0;
+
+	bitmap_zero(used, VIDEO_NUM_DEVICES);
+
+	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
+		if (video_device[i] != NULL &&
+		    video_device[i]->parent == vdev->parent) {
+			set_bit(video_device[i]->index, used);
+		}
+	}
+
+	return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
+}
+
+/**
+ *	__video_register_device - register video4linux devices
+ *	@vdev: video device structure we want to register
+ *	@type: type of device to register
+ *	@nr:   which device node number (0 == /dev/video0, 1 == /dev/video1, ...
+ *             -1 == first free)
+ *	@warn_if_nr_in_use: warn if the desired device node number
+ *	       was already in use and another number was chosen instead.
+ *	@owner: module that owns the video device node
+ *
+ *	The registration code assigns minor numbers and device node numbers
+ *	based on the requested type and registers the new device node with
+ *	the kernel.
+ *
+ *	This function assumes that struct video_device was zeroed when it
+ *	was allocated and does not contain any stale date.
+ *
+ *	An error is returned if no free minor or device node number could be
+ *	found, or if the registration of the device node failed.
+ *
+ *	Zero is returned on success.
+ *
+ *	Valid types are
+ *
+ *	%VFL_TYPE_GRABBER - A frame grabber
+ *
+ *	%VFL_TYPE_VBI - Vertical blank data (undecoded)
+ *
+ *	%VFL_TYPE_RADIO - A radio card
+ *
+ *	%VFL_TYPE_SUBDEV - A subdevice
+ */
+int __video_register_device(struct video_device *vdev, int type, int nr,
+		int warn_if_nr_in_use, struct module *owner)
+{
+	int i = 0;
+	int ret;
+	int minor_offset = 0;
+	int minor_cnt = VIDEO_NUM_DEVICES;
+	const char *name_base;
+
+	/* A minor value of -1 marks this video device as never
+	   having been registered */
+	vdev->minor = -1;
+
+	/* the release callback MUST be present */
+	if (WARN_ON(!vdev->release))
+		return -EINVAL;
+
+	/* v4l2_fh support */
+	spin_lock_init(&vdev->fh_lock);
+	INIT_LIST_HEAD(&vdev->fh_list);
+
+	/* Part 1: check device type */
+	switch (type) {
+	case VFL_TYPE_GRABBER:
+		name_base = "video";
+		break;
+	case VFL_TYPE_VBI:
+		name_base = "vbi";
+		break;
+	case VFL_TYPE_RADIO:
+		name_base = "radio";
+		break;
+	case VFL_TYPE_SUBDEV:
+		name_base = "v4l-subdev";
+		break;
+	default:
+		printk(KERN_ERR "%s called with unknown type: %d\n",
+		       __func__, type);
+		return -EINVAL;
+	}
+
+	vdev->vfl_type = type;
+	vdev->cdev = NULL;
+	if (vdev->v4l2_dev) {
+		if (vdev->v4l2_dev->dev)
+			vdev->parent = vdev->v4l2_dev->dev;
+		if (vdev->ctrl_handler == NULL)
+			vdev->ctrl_handler = vdev->v4l2_dev->ctrl_handler;
+		/* If the prio state pointer is NULL, then use the v4l2_device
+		   prio state. */
+		if (vdev->prio == NULL)
+			vdev->prio = &vdev->v4l2_dev->prio;
+	}
+
+	/* Part 2: find a free minor, device node number and device index. */
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+	/* Keep the ranges for the first four types for historical
+	 * reasons.
+	 * Newer devices (not yet in place) should use the range
+	 * of 128-191 and just pick the first free minor there
+	 * (new style). */
+	switch (type) {
+	case VFL_TYPE_GRABBER:
+		minor_offset = 0;
+		minor_cnt = 64;
+		break;
+	case VFL_TYPE_RADIO:
+		minor_offset = 64;
+		minor_cnt = 64;
+		break;
+	case VFL_TYPE_VBI:
+		minor_offset = 224;
+		minor_cnt = 32;
+		break;
+	default:
+		minor_offset = 128;
+		minor_cnt = 64;
+		break;
+	}
+#endif
+
+	/* Pick a device node number */
+	mutex_lock(&videodev_lock);
+	nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
+	if (nr == minor_cnt)
+		nr = devnode_find(vdev, 0, minor_cnt);
+	if (nr == minor_cnt) {
+		printk(KERN_ERR "could not get a free device node number\n");
+		mutex_unlock(&videodev_lock);
+		return -ENFILE;
+	}
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+	/* 1-on-1 mapping of device node number to minor number */
+	i = nr;
+#else
+	/* The device node number and minor numbers are independent, so
+	   we just find the first free minor number. */
+	for (i = 0; i < VIDEO_NUM_DEVICES; i++)
+		if (video_device[i] == NULL)
+			break;
+	if (i == VIDEO_NUM_DEVICES) {
+		mutex_unlock(&videodev_lock);
+		printk(KERN_ERR "could not get a free minor\n");
+		return -ENFILE;
+	}
+#endif
+	vdev->minor = i + minor_offset;
+	vdev->num = nr;
+	devnode_set(vdev);
+
+	/* Should not happen since we thought this minor was free */
+	WARN_ON(video_device[vdev->minor] != NULL);
+	vdev->index = get_index(vdev);
+	mutex_unlock(&videodev_lock);
+
+	/* Part 3: Initialize the character device */
+	vdev->cdev = cdev_alloc();
+	if (vdev->cdev == NULL) {
+		ret = -ENOMEM;
+		goto cleanup;
+	}
+	vdev->cdev->ops = &v4l2_fops;
+	vdev->cdev->owner = owner;
+	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
+	if (ret < 0) {
+		printk(KERN_ERR "%s: cdev_add failed\n", __func__);
+		kfree(vdev->cdev);
+		vdev->cdev = NULL;
+		goto cleanup;
+	}
+
+	/* Part 4: register the device with sysfs */
+	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, vdev->num);
+	ret = device_register(&vdev->dev);
+	if (ret < 0) {
+		printk(KERN_ERR "%s: device_register failed\n", __func__);
+		goto cleanup;
+	}
+	/* Register the release callback that will be called when the last
+	   reference to the device goes away. */
+	vdev->dev.release = v4l2_device_release;
+
+	if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
+		printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
+			name_base, nr, video_device_node_name(vdev));
+
+	/* Increase v4l2_device refcount */
+	if (vdev->v4l2_dev)
+		v4l2_device_get(vdev->v4l2_dev);
+
+#if defined(CONFIG_MEDIA_CONTROLLER)
+	/* Part 5: Register the entity. */
+	if (vdev->v4l2_dev && vdev->v4l2_dev->mdev &&
+	    vdev->vfl_type != VFL_TYPE_SUBDEV) {
+		vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L;
+		vdev->entity.name = vdev->name;
+		vdev->entity.info.v4l.major = VIDEO_MAJOR;
+		vdev->entity.info.v4l.minor = vdev->minor;
+		ret = media_device_register_entity(vdev->v4l2_dev->mdev,
+			&vdev->entity);
+		if (ret < 0)
+			printk(KERN_WARNING
+			       "%s: media_device_register_entity failed\n",
+			       __func__);
+	}
+#endif
+	/* Part 6: Activate this minor. The char device can now be used. */
+	set_bit(V4L2_FL_REGISTERED, &vdev->flags);
+	mutex_lock(&videodev_lock);
+	video_device[vdev->minor] = vdev;
+	mutex_unlock(&videodev_lock);
+
+	return 0;
+
+cleanup:
+	mutex_lock(&videodev_lock);
+	if (vdev->cdev)
+		cdev_del(vdev->cdev);
+	devnode_clear(vdev);
+	mutex_unlock(&videodev_lock);
+	/* Mark this video device as never having been registered. */
+	vdev->minor = -1;
+	return ret;
+}
+EXPORT_SYMBOL(__video_register_device);
+
+/**
+ *	video_unregister_device - unregister a video4linux device
+ *	@vdev: the device to unregister
+ *
+ *	This unregisters the passed device. Future open calls will
+ *	be met with errors.
+ */
+void video_unregister_device(struct video_device *vdev)
+{
+	/* Check if vdev was ever registered at all */
+	if (!vdev || !video_is_registered(vdev))
+		return;
+
+	mutex_lock(&videodev_lock);
+	/* This must be in a critical section to prevent a race with v4l2_open.
+	 * Once this bit has been cleared video_get may never be called again.
+	 */
+	clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
+	mutex_unlock(&videodev_lock);
+	device_unregister(&vdev->dev);
+}
+EXPORT_SYMBOL(video_unregister_device);
+
+/*
+ *	Initialise video for linux
+ */
+static int __init videodev_init(void)
+{
+	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
+	int ret;
+
+	printk(KERN_INFO "Linux video capture interface: v2.00\n");
+	ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
+	if (ret < 0) {
+		printk(KERN_WARNING "videodev: unable to get major %d\n",
+				VIDEO_MAJOR);
+		return ret;
+	}
+
+	ret = class_register(&video_class);
+	if (ret < 0) {
+		unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
+		printk(KERN_WARNING "video_dev: class_register failed\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void __exit videodev_exit(void)
+{
+	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
+
+	class_unregister(&video_class);
+	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
+}
+
+subsys_initcall(videodev_init);
+module_exit(videodev_exit)
+
+MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
+MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
+
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * End:
+ */