[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / media / video / v4l2-dev.c

/*
 * 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 <asm/system.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(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);

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);

	mutex_lock(&videodev_lock);
	if (video_device[vdev->minor] != vdev) {
		mutex_unlock(&videodev_lock);
		/* should not happen */
		WARN_ON(1);
		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 minor as free */
	clear_bit(vdev->num, video_nums[vdev->vfl_type]);

	mutex_unlock(&videodev_lock);

	/* 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,
};

struct video_device *video_devdata(struct file *file)
{
	return video_device[iminor(file->f_path.dentry->d_inode)];
}
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(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_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_unregistered(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);

	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 = 0;

	/* 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);
	if (vdev->fops->open)
		ret = vdev->fops->open(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 = 0;

	if (vdev->fops->release)
		vdev->fops->release(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,
	.get_unmapped_area = v4l2_get_unmapped_area,
	.mmap = v4l2_mmap,
	.unlocked_ioctl = v4l2_unlocked_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = v4l2_compat_ioctl32,
#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,
	.get_unmapped_area = v4l2_get_unmapped_area,
	.mmap = v4l2_mmap,
	.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 number (0 == /dev/video0, 1 == /dev/video1, ...
 *             -1 == first free)
 *
 *	The registration code assigns minor numbers based on the type
 *	requested. -ENFILE is returned in all the device slots for this
 *	category are full. If not then the minor field is set and the
 *	driver initialize function is called (if non %NULL).
 *
 *	Zero is returned on success.
 *
 *	Valid types are
 *
 *	%VFL_TYPE_GRABBER - A frame grabber
 *
 *	%VFL_TYPE_VTX - A teletext device
 *
 *	%VFL_TYPE_VBI - Vertical blank data (undecoded)
 *
 *	%VFL_TYPE_RADIO - A radio card
 */
int video_register_device(struct video_device *vdev, int type, int nr)
{
	int i = 0;
	int ret;
	int minor_offset = 0;
	int minor_cnt = VIDEO_NUM_DEVICES;
	const char *name_base;
	void *priv = video_get_drvdata(vdev);

	/* A minor value of -1 marks this video device as never
	   having been registered */
	vdev->minor = -1;

	/* the release callback MUST be present */
	WARN_ON(!vdev->release);
	if (!vdev->release)
		return -EINVAL;

	/* Part 1: check device type */
	switch (type) {
	case VFL_TYPE_GRABBER:
		name_base = "video";
		break;
	case VFL_TYPE_VTX:
		name_base = "vtx";
		break;
	case VFL_TYPE_VBI:
		name_base = "vbi";
		break;
	case VFL_TYPE_RADIO:
		name_base = "radio";
		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 && vdev->v4l2_dev->dev)
		vdev->parent = vdev->v4l2_dev->dev;

	/* 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.
	 * 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_VTX:
		minor_offset = 192;
		minor_cnt = 32;
		break;
	case VFL_TYPE_VBI:
		minor_offset = 224;
		minor_cnt = 32;
		break;
	default:
		minor_offset = 128;
		minor_cnt = 64;
		break;
	}
#endif

	/* 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)
		nr = find_first_zero_bit(video_nums[type], minor_cnt);
	if (nr == minor_cnt) {
		printk(KERN_ERR "could not get a free kernel number\n");
		mutex_unlock(&videodev_lock);
		return -ENFILE;
	}
#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
	/* 1-on-1 mapping of kernel number to minor number */
	i = nr;
#else
	/* The kernel number and minor numbers are independent */
	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;
	set_bit(nr, video_nums[type]);
	/* 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;
	}
	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__);
		kfree(vdev->cdev);
		vdev->cdev = NULL;
		goto cleanup;
	}

	/* 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(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 cleanup;
	}
	/* Register the release callback that will be called when the last
	   reference to the device goes away. */
	vdev->dev.release = v4l2_device_release;

	/* 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;

cleanup:
	mutex_lock(&videodev_lock);
	if (vdev->cdev)
		cdev_del(vdev->cdev);
	clear_bit(vdev->num, video_nums[type]);
	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 || 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);

/*
 *	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);
}

module_init(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:
 */
Commit	Line	Data
27a5e6d3 HV	1	/*
	2	* Video capture interface for Linux version 2
	3	*
	4	* A generic video device interface for the LINUX operating system
	5	* using a set of device structures/vectors for low level operations.
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*
d9b01449	12	* Authors: Alan Cox, <alan@lxorguk.ukuu.org.uk> (version 1)
27a5e6d3 HV	13	* Mauro Carvalho Chehab <mchehab@infradead.org> (version 2)
	14	*
	15	* Fixes: 20000516 Claudio Matsuoka <claudio@conectiva.com>
	16	* - Added procfs support
	17	*/
	18
	19	#include <linux/module.h>
	20	#include <linux/types.h>
	21	#include <linux/kernel.h>
	22	#include <linux/mm.h>
	23	#include <linux/string.h>
	24	#include <linux/errno.h>
	25	#include <linux/init.h>
	26	#include <linux/kmod.h>
	27	#include <linux/slab.h>
27a5e6d3 HV	28	#include <asm/uaccess.h>
	29	#include <asm/system.h>
	30
	31	#include <media/v4l2-common.h>
9bea3514	32	#include <media/v4l2-device.h>
bec43661	33	#include <media/v4l2-ioctl.h>
27a5e6d3 HV	34
	35	#define VIDEO_NUM_DEVICES 256
	36	#define VIDEO_NAME "video4linux"
	37
	38	/*
	39	* sysfs stuff
	40	*/
	41
	42	static ssize_t show_index(struct device *cd,
	43	struct device_attribute attr, char buf)
	44	{
dc93a70c	45	struct video_device *vdev = to_video_device(cd);
bfa8a273	46
dc93a70c	47	return sprintf(buf, "%i\n", vdev->index);
27a5e6d3 HV	48	}
	49
	50	static ssize_t show_name(struct device *cd,
	51	struct device_attribute attr, char buf)
	52	{
dc93a70c	53	struct video_device *vdev = to_video_device(cd);
bfa8a273	54
dc93a70c	55	return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
27a5e6d3 HV	56	}
	57
	58	static struct device_attribute video_device_attrs[] = {
	59	__ATTR(name, S_IRUGO, show_name, NULL),
	60	__ATTR(index, S_IRUGO, show_index, NULL),
	61	__ATTR_NULL
	62	};
	63
7f8ecfab HV	64	/*
	65	* Active devices
	66	*/
	67	static struct video_device *video_device[VIDEO_NUM_DEVICES];
	68	static DEFINE_MUTEX(videodev_lock);
dd89601d	69	static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
7f8ecfab	70
27a5e6d3 HV	71	struct video_device *video_device_alloc(void)
27a5e6d3 HV	72	{
bfa8a273	73	return kzalloc(sizeof(struct video_device), GFP_KERNEL);
27a5e6d3 HV	74	}
	75	EXPORT_SYMBOL(video_device_alloc);
	76
dc93a70c	77	void video_device_release(struct video_device *vdev)
27a5e6d3	78	{
dc93a70c	79	kfree(vdev);
27a5e6d3 HV	80	}
	81	EXPORT_SYMBOL(video_device_release);
	82
dc93a70c	83	void video_device_release_empty(struct video_device *vdev)
f9e86b5e HV	84	{
	85	/* Do nothing */
	86	/* Only valid when the video_device struct is a static. */
	87	}
	88	EXPORT_SYMBOL(video_device_release_empty);
	89
dc93a70c	90	static inline void video_get(struct video_device *vdev)
7f8ecfab	91	{
dc93a70c HV	92	get_device(&vdev->dev);
	93	}
	94
	95	static inline void video_put(struct video_device *vdev)
	96	{
	97	put_device(&vdev->dev);
	98	}
	99
	100	/* Called when the last user of the video device exits. */
	101	static void v4l2_device_release(struct device *cd)
	102	{
	103	struct video_device *vdev = to_video_device(cd);
7f8ecfab HV	104
7f8ecfab HV	105	mutex_lock(&videodev_lock);
dc93a70c	106	if (video_device[vdev->minor] != vdev) {
6ea9a182	107	mutex_unlock(&videodev_lock);
dc93a70c HV	108	/* should not happen */
dc93a70c HV	109	WARN_ON(1);
6ea9a182 HV	110	return;
6ea9a182 HV	111	}
7f8ecfab HV	112
7f8ecfab HV	113	/* Free up this device for reuse */
dc93a70c	114	video_device[vdev->minor] = NULL;
7f8ecfab	115
dc93a70c HV	116	/* Delete the cdev on this minor as well */
	117	cdev_del(vdev->cdev);
	118	/* Just in case some driver tries to access this from
	119	the release() callback. */
	120	vdev->cdev = NULL;
7f8ecfab	121
dc93a70c HV	122	/* Mark minor as free */
dc93a70c HV	123	clear_bit(vdev->num, video_nums[vdev->vfl_type]);
7f8ecfab	124
dc93a70c	125	mutex_unlock(&videodev_lock);
27a5e6d3	126
dc93a70c HV	127	/* Release video_device and perform other
	128	cleanups as needed. */
	129	vdev->release(vdev);
27a5e6d3 HV	130	}
	131
	132	static struct class video_class = {
	133	.name = VIDEO_NAME,
	134	.dev_attrs = video_device_attrs,
27a5e6d3 HV	135	};
27a5e6d3 HV	136
27a5e6d3 HV	137	struct video_device video_devdata(struct file file)
	138	{
	139	return video_device[iminor(file->f_path.dentry->d_inode)];
	140	}
	141	EXPORT_SYMBOL(video_devdata);
	142
dc93a70c HV	143	static ssize_t v4l2_read(struct file filp, char __user buf,
	144	size_t sz, loff_t *off)
	145	{
	146	struct video_device *vdev = video_devdata(filp);
	147
	148	if (!vdev->fops->read)
	149	return -EINVAL;
	150	if (video_is_unregistered(vdev))
	151	return -EIO;
	152	return vdev->fops->read(filp, buf, sz, off);
	153	}
	154
	155	static ssize_t v4l2_write(struct file filp, const char __user buf,
	156	size_t sz, loff_t *off)
	157	{
	158	struct video_device *vdev = video_devdata(filp);
	159
	160	if (!vdev->fops->write)
	161	return -EINVAL;
	162	if (video_is_unregistered(vdev))
	163	return -EIO;
	164	return vdev->fops->write(filp, buf, sz, off);
	165	}
	166
	167	static unsigned int v4l2_poll(struct file filp, struct poll_table_struct poll)
	168	{
	169	struct video_device *vdev = video_devdata(filp);
	170
	171	if (!vdev->fops->poll \|\| video_is_unregistered(vdev))
	172	return DEFAULT_POLLMASK;
	173	return vdev->fops->poll(filp, poll);
	174	}
	175
	176	static int v4l2_ioctl(struct inode inode, struct file filp,
	177	unsigned int cmd, unsigned long arg)
	178	{
	179	struct video_device *vdev = video_devdata(filp);
	180
	181	if (!vdev->fops->ioctl)
	182	return -ENOTTY;
	183	/* Allow ioctl to continue even if the device was unregistered.
	184	Things like dequeueing buffers might still be useful. */
bec43661	185	return vdev->fops->ioctl(filp, cmd, arg);
dc93a70c HV	186	}
	187
	188	static long v4l2_unlocked_ioctl(struct file *filp,
	189	unsigned int cmd, unsigned long arg)
	190	{
	191	struct video_device *vdev = video_devdata(filp);
	192
	193	if (!vdev->fops->unlocked_ioctl)
	194	return -ENOTTY;
	195	/* Allow ioctl to continue even if the device was unregistered.
	196	Things like dequeueing buffers might still be useful. */
	197	return vdev->fops->unlocked_ioctl(filp, cmd, arg);
	198	}
	199
c01f1a5a DG	200	#ifdef CONFIG_MMU
	201	#define v4l2_get_unmapped_area NULL
	202	#else
	203	static unsigned long v4l2_get_unmapped_area(struct file *filp,
	204	unsigned long addr, unsigned long len, unsigned long pgoff,
	205	unsigned long flags)
	206	{
	207	struct video_device *vdev = video_devdata(filp);
	208
	209	if (!vdev->fops->get_unmapped_area)
	210	return -ENOSYS;
	211	if (video_is_unregistered(vdev))
	212	return -ENODEV;
	213	return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
	214	}
	215	#endif
	216
dc93a70c HV	217	static int v4l2_mmap(struct file filp, struct vm_area_struct vm)
	218	{
	219	struct video_device *vdev = video_devdata(filp);
	220
	221	if (!vdev->fops->mmap \|\|
	222	video_is_unregistered(vdev))
	223	return -ENODEV;
	224	return vdev->fops->mmap(filp, vm);
	225	}
	226
	227	/* Override for the open function */
	228	static int v4l2_open(struct inode inode, struct file filp)
	229	{
	230	struct video_device *vdev;
65d9ff9c	231	int ret = 0;
dc93a70c HV	232
	233	/* Check if the video device is available */
	234	mutex_lock(&videodev_lock);
	235	vdev = video_devdata(filp);
	236	/* return ENODEV if the video device has been removed
	237	already or if it is not registered anymore. */
	238	if (vdev == NULL \|\| video_is_unregistered(vdev)) {
	239	mutex_unlock(&videodev_lock);
	240	return -ENODEV;
	241	}
	242	/* and increase the device refcount */
	243	video_get(vdev);
	244	mutex_unlock(&videodev_lock);
65d9ff9c HV	245	if (vdev->fops->open)
	246	ret = vdev->fops->open(filp);
	247
dc93a70c HV	248	/* decrease the refcount in case of an error */
	249	if (ret)
	250	video_put(vdev);
	251	return ret;
	252	}
	253
	254	/* Override for the release function */
	255	static int v4l2_release(struct inode inode, struct file filp)
	256	{
	257	struct video_device *vdev = video_devdata(filp);
65d9ff9c HV	258	int ret = 0;
	259
	260	if (vdev->fops->release)
	261	vdev->fops->release(filp);
dc93a70c HV	262
	263	/* decrease the refcount unconditionally since the release()
	264	return value is ignored. */
	265	video_put(vdev);
	266	return ret;
	267	}
	268
	269	static const struct file_operations v4l2_unlocked_fops = {
	270	.owner = THIS_MODULE,
	271	.read = v4l2_read,
	272	.write = v4l2_write,
	273	.open = v4l2_open,
c01f1a5a	274	.get_unmapped_area = v4l2_get_unmapped_area,
dc93a70c HV	275	.mmap = v4l2_mmap,
	276	.unlocked_ioctl = v4l2_unlocked_ioctl,
	277	#ifdef CONFIG_COMPAT
9bb7cde7	278	.compat_ioctl = v4l2_compat_ioctl32,
dc93a70c HV	279	#endif
	280	.release = v4l2_release,
	281	.poll = v4l2_poll,
	282	.llseek = no_llseek,
	283	};
	284
	285	static const struct file_operations v4l2_fops = {
	286	.owner = THIS_MODULE,
	287	.read = v4l2_read,
	288	.write = v4l2_write,
	289	.open = v4l2_open,
c01f1a5a	290	.get_unmapped_area = v4l2_get_unmapped_area,
dc93a70c HV	291	.mmap = v4l2_mmap,
	292	.ioctl = v4l2_ioctl,
	293	#ifdef CONFIG_COMPAT
9bb7cde7	294	.compat_ioctl = v4l2_compat_ioctl32,
dc93a70c HV	295	#endif
	296	.release = v4l2_release,
	297	.poll = v4l2_poll,
	298	.llseek = no_llseek,
	299	};
	300
27a5e6d3	301	/**
7ae0cd9b	302	* get_index - assign stream index number based on parent device
dc93a70c	303	* @vdev: video_device to assign index number to, vdev->parent should be assigned
27a5e6d3	304	*
dc93a70c	305	* Note that when this is called the new device has not yet been registered
7ae0cd9b	306	* in the video_device array, but it was able to obtain a minor number.
27a5e6d3	307	*
7ae0cd9b HV	308	* This means that we can always obtain a free stream index number since
	309	* the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
	310	* use of the video_device array.
	311	*
	312	* Returns a free index number.
27a5e6d3	313	*/
7ae0cd9b	314	static int get_index(struct video_device *vdev)
27a5e6d3	315	{
775a05dd HV	316	/* This can be static since this function is called with the global
	317	videodev_lock held. */
	318	static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
27a5e6d3 HV	319	int i;
27a5e6d3 HV	320
7ae0cd9b	321	/* Some drivers do not set the parent. In that case always return 0. */
806e5b7c	322	if (vdev->parent == NULL)
7ae0cd9b	323	return 0;
775a05dd HV	324
775a05dd HV	325	bitmap_zero(used, VIDEO_NUM_DEVICES);
806e5b7c	326
27a5e6d3 HV	327	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
27a5e6d3 HV	328	if (video_device[i] != NULL &&
5e85e732	329	video_device[i]->parent == vdev->parent) {
775a05dd	330	set_bit(video_device[i]->index, used);
27a5e6d3 HV	331	}
	332	}
	333
7ae0cd9b	334	return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
27a5e6d3 HV	335	}
27a5e6d3 HV	336
27a5e6d3	337	/**
7ae0cd9b	338	* video_register_device - register video4linux devices
dc93a70c	339	* @vdev: video device structure we want to register
27a5e6d3 HV	340	* @type: type of device to register
	341	* @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
	342	* -1 == first free)
	343	*
	344	* The registration code assigns minor numbers based on the type
	345	* requested. -ENFILE is returned in all the device slots for this
	346	* category are full. If not then the minor field is set and the
	347	* driver initialize function is called (if non %NULL).
	348	*
	349	* Zero is returned on success.
	350	*
	351	* Valid types are
	352	*
	353	* %VFL_TYPE_GRABBER - A frame grabber
	354	*
	355	* %VFL_TYPE_VTX - A teletext device
	356	*
	357	* %VFL_TYPE_VBI - Vertical blank data (undecoded)
	358	*
	359	* %VFL_TYPE_RADIO - A radio card
	360	*/
7ae0cd9b	361	int video_register_device(struct video_device *vdev, int type, int nr)
27a5e6d3 HV	362	{
27a5e6d3 HV	363	int i = 0;
27a5e6d3	364	int ret;
dd89601d HV	365	int minor_offset = 0;
	366	int minor_cnt = VIDEO_NUM_DEVICES;
	367	const char *name_base;
dc93a70c	368	void *priv = video_get_drvdata(vdev);
27a5e6d3	369
dc93a70c HV	370	/* A minor value of -1 marks this video device as never
dc93a70c HV	371	having been registered */
428c8d19	372	vdev->minor = -1;
ee7aa9f8	373
dc93a70c	374	/* the release callback MUST be present */
428c8d19 TP	375	WARN_ON(!vdev->release);
428c8d19 TP	376	if (!vdev->release)
f3b9f50e HK	377	return -EINVAL;
f3b9f50e HK	378
dc93a70c	379	/* Part 1: check device type */
27a5e6d3 HV	380	switch (type) {
27a5e6d3 HV	381	case VFL_TYPE_GRABBER:
27a5e6d3 HV	382	name_base = "video";
	383	break;
	384	case VFL_TYPE_VTX:
27a5e6d3 HV	385	name_base = "vtx";
	386	break;
	387	case VFL_TYPE_VBI:
27a5e6d3 HV	388	name_base = "vbi";
	389	break;
	390	case VFL_TYPE_RADIO:
27a5e6d3 HV	391	name_base = "radio";
	392	break;
	393	default:
	394	printk(KERN_ERR "%s called with unknown type: %d\n",
	395	__func__, type);
46f2c21c	396	return -EINVAL;
27a5e6d3 HV	397	}
27a5e6d3 HV	398
dc93a70c HV	399	vdev->vfl_type = type;
dc93a70c HV	400	vdev->cdev = NULL;
00575961	401	if (vdev->v4l2_dev && vdev->v4l2_dev->dev)
9bea3514	402	vdev->parent = vdev->v4l2_dev->dev;
dd89601d	403
dc93a70c	404	/* Part 2: find a free minor, kernel number and device index. */
dd89601d HV	405	#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
	406	/* Keep the ranges for the first four types for historical
	407	* reasons.
	408	* Newer devices (not yet in place) should use the range
	409	* of 128-191 and just pick the first free minor there
	410	* (new style). */
	411	switch (type) {
	412	case VFL_TYPE_GRABBER:
	413	minor_offset = 0;
	414	minor_cnt = 64;
	415	break;
	416	case VFL_TYPE_RADIO:
	417	minor_offset = 64;
	418	minor_cnt = 64;
	419	break;
	420	case VFL_TYPE_VTX:
	421	minor_offset = 192;
	422	minor_cnt = 32;
	423	break;
	424	case VFL_TYPE_VBI:
	425	minor_offset = 224;
	426	minor_cnt = 32;
	427	break;
	428	default:
	429	minor_offset = 128;
	430	minor_cnt = 64;
	431	break;
	432	}
	433	#endif
	434
dc93a70c	435	/* Pick a minor number */
27a5e6d3	436	mutex_lock(&videodev_lock);
dd89601d HV	437	nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr);
	438	if (nr == minor_cnt)
	439	nr = find_first_zero_bit(video_nums[type], minor_cnt);
	440	if (nr == minor_cnt) {
	441	printk(KERN_ERR "could not get a free kernel number\n");
	442	mutex_unlock(&videodev_lock);
	443	return -ENFILE;
27a5e6d3	444	}
dd89601d HV	445	#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
	446	/* 1-on-1 mapping of kernel number to minor number */
	447	i = nr;
	448	#else
	449	/* The kernel number and minor numbers are independent */
	450	for (i = 0; i < VIDEO_NUM_DEVICES; i++)
	451	if (video_device[i] == NULL)
	452	break;
	453	if (i == VIDEO_NUM_DEVICES) {
	454	mutex_unlock(&videodev_lock);
	455	printk(KERN_ERR "could not get a free minor\n");
	456	return -ENFILE;
	457	}
	458	#endif
dc93a70c HV	459	vdev->minor = i + minor_offset;
dc93a70c HV	460	vdev->num = nr;
dd89601d	461	set_bit(nr, video_nums[type]);
dc93a70c HV	462	/* Should not happen since we thought this minor was free */
dc93a70c HV	463	WARN_ON(video_device[vdev->minor] != NULL);
7ae0cd9b	464	vdev->index = get_index(vdev);
27a5e6d3 HV	465	mutex_unlock(&videodev_lock);
27a5e6d3 HV	466
dc93a70c HV	467	/* Part 3: Initialize the character device */
	468	vdev->cdev = cdev_alloc();
	469	if (vdev->cdev == NULL) {
	470	ret = -ENOMEM;
	471	goto cleanup;
	472	}
	473	if (vdev->fops->unlocked_ioctl)
	474	vdev->cdev->ops = &v4l2_unlocked_fops;
	475	else
	476	vdev->cdev->ops = &v4l2_fops;
	477	vdev->cdev->owner = vdev->fops->owner;
	478	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
7f8ecfab HV	479	if (ret < 0) {
7f8ecfab HV	480	printk(KERN_ERR "%s: cdev_add failed\n", __func__);
dc93a70c HV	481	kfree(vdev->cdev);
	482	vdev->cdev = NULL;
	483	goto cleanup;
7f8ecfab	484	}
dc93a70c HV	485
	486	/* Part 4: register the device with sysfs */
	487	memset(&vdev->dev, 0, sizeof(vdev->dev));
9d95af9d HV	488	/* The memset above cleared the device's drvdata, so
9d95af9d HV	489	put back the copy we made earlier. */
dc93a70c HV	490	video_set_drvdata(vdev, priv);
	491	vdev->dev.class = &video_class;
	492	vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
	493	if (vdev->parent)
	494	vdev->dev.parent = vdev->parent;
	495	dev_set_name(&vdev->dev, "%s%d", name_base, nr);
	496	ret = device_register(&vdev->dev);
27a5e6d3 HV	497	if (ret < 0) {
27a5e6d3 HV	498	printk(KERN_ERR "%s: device_register failed\n", __func__);
dc93a70c	499	goto cleanup;
27a5e6d3	500	}
dc93a70c HV	501	/* Register the release callback that will be called when the last
	502	reference to the device goes away. */
	503	vdev->dev.release = v4l2_device_release;
27a5e6d3	504
dc93a70c HV	505	/* Part 5: Activate this minor. The char device can now be used. */
	506	mutex_lock(&videodev_lock);
	507	video_device[vdev->minor] = vdev;
	508	mutex_unlock(&videodev_lock);
	509	return 0;
7f8ecfab	510
dc93a70c	511	cleanup:
27a5e6d3	512	mutex_lock(&videodev_lock);
dc93a70c HV	513	if (vdev->cdev)
	514	cdev_del(vdev->cdev);
	515	clear_bit(vdev->num, video_nums[type]);
27a5e6d3	516	mutex_unlock(&videodev_lock);
dc93a70c HV	517	/* Mark this video device as never having been registered. */
dc93a70c HV	518	vdev->minor = -1;
27a5e6d3 HV	519	return ret;
27a5e6d3 HV	520	}
7ae0cd9b	521	EXPORT_SYMBOL(video_register_device);
27a5e6d3 HV	522
	523	/**
	524	* video_unregister_device - unregister a video4linux device
dc93a70c	525	* @vdev: the device to unregister
27a5e6d3	526	*
dc93a70c HV	527	* This unregisters the passed device. Future open calls will
dc93a70c HV	528	* be met with errors.
27a5e6d3	529	*/
dc93a70c	530	void video_unregister_device(struct video_device *vdev)
27a5e6d3	531	{
dc93a70c HV	532	/* Check if vdev was ever registered at all */
	533	if (!vdev \|\| vdev->minor < 0)
	534	return;
	535
	536	mutex_lock(&videodev_lock);
	537	set_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
	538	mutex_unlock(&videodev_lock);
	539	device_unregister(&vdev->dev);
27a5e6d3 HV	540	}
	541	EXPORT_SYMBOL(video_unregister_device);
	542
27a5e6d3 HV	543	/*
	544	* Initialise video for linux
	545	*/
27a5e6d3 HV	546	static int __init videodev_init(void)
27a5e6d3 HV	547	{
7f8ecfab	548	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
27a5e6d3 HV	549	int ret;
	550
	551	printk(KERN_INFO "Linux video capture interface: v2.00\n");
7f8ecfab HV	552	ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
	553	if (ret < 0) {
	554	printk(KERN_WARNING "videodev: unable to get major %d\n",
	555	VIDEO_MAJOR);
	556	return ret;
27a5e6d3 HV	557	}
	558
	559	ret = class_register(&video_class);
	560	if (ret < 0) {
7f8ecfab	561	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
27a5e6d3 HV	562	printk(KERN_WARNING "video_dev: class_register failed\n");
	563	return -EIO;
	564	}
	565
	566	return 0;
	567	}
	568
	569	static void __exit videodev_exit(void)
	570	{
7f8ecfab HV	571	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
7f8ecfab HV	572
27a5e6d3	573	class_unregister(&video_class);
7f8ecfab	574	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
27a5e6d3 HV	575	}
	576
	577	module_init(videodev_init)
	578	module_exit(videodev_exit)
	579
	580	MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
	581	MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
	582	MODULE_LICENSE("GPL");
cbb72b0f	583	MODULE_ALIAS_CHARDEV_MAJOR(VIDEO_MAJOR);
27a5e6d3 HV	584
	585
	586	/*
	587	* Local variables:
	588	* c-basic-offset: 8
	589	* End:
	590	*/