[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 <linux/smp_lock.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);
}

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(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(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 = v4l_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,
	.mmap = v4l2_mmap,
	.ioctl = v4l2_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = v4l_compat_ioctl32,
#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->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
 * successful.
 */
static int get_index(struct video_device *vdev, int num)
{
	u32 used = 0;
	const int max_index = sizeof(used) * 8 - 1;
	int i;

	/* Currently a single v4l driver instance cannot create more than
	   32 devices.
	   Increase to u64 or an array of u32 if more are needed. */
	if (num > max_index) {
		printk(KERN_ERR "videodev: %s num is too large\n", __func__);
		return -EINVAL;
	}

	/* Some drivers do not set the parent. In that case always return 0. */
	if (vdev->parent == NULL)
		return 0;

	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
		if (video_device[i] != NULL &&
		    video_device[i]->parent == vdev->parent) {
			used |= 1 << video_device[i]->index;
		}
	}

	if (num >= 0) {
		if (used & (1 << num))
			return -ENFILE;
		return num;
	}

	i = ffz(used);
	return i > max_index ? -ENFILE : i;
}

int video_register_device(struct video_device *vdev, int type, int nr)
{
	return video_register_device_index(vdev, type, nr, -1);
}
EXPORT_SYMBOL(video_register_device);

/**
 *	video_register_device_index - 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)
 *	@index: stream number based on parent device;
 *		-1 if auto assign, requested number otherwise
 *
 *	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_index(struct video_device *vdev, int type, int nr,
					int index)
{
	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 */
	if (vdev)
		vdev->minor = -1;

	/* 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";
		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->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);
	ret = vdev->index = get_index(vdev, index);
	mutex_unlock(&videodev_lock);

	if (ret < 0) {
		printk(KERN_ERR "%s: get_index failed\n", __func__);
		goto cleanup;
	}

	/* 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_index);

/**
 *	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");


/*
 * 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>
	28	#include <linux/smp_lock.h>
	29	#include <asm/uaccess.h>
	30	#include <asm/system.h>
	31
	32	#include <media/v4l2-common.h>
9bea3514	33	#include <media/v4l2-device.h>
bec43661	34	#include <media/v4l2-ioctl.h>
27a5e6d3 HV	35
	36	#define VIDEO_NUM_DEVICES 256
	37	#define VIDEO_NAME "video4linux"
	38
	39	/*
	40	* sysfs stuff
	41	*/
	42
	43	static ssize_t show_index(struct device *cd,
	44	struct device_attribute attr, char buf)
	45	{
dc93a70c	46	struct video_device *vdev = to_video_device(cd);
bfa8a273	47
dc93a70c	48	return sprintf(buf, "%i\n", vdev->index);
27a5e6d3 HV	49	}
	50
	51	static ssize_t show_name(struct device *cd,
	52	struct device_attribute attr, char buf)
	53	{
dc93a70c	54	struct video_device *vdev = to_video_device(cd);
bfa8a273	55
dc93a70c	56	return sprintf(buf, "%.*s\n", (int)sizeof(vdev->name), vdev->name);
27a5e6d3 HV	57	}
	58
	59	static struct device_attribute video_device_attrs[] = {
	60	__ATTR(name, S_IRUGO, show_name, NULL),
	61	__ATTR(index, S_IRUGO, show_index, NULL),
	62	__ATTR_NULL
	63	};
	64
7f8ecfab HV	65	/*
	66	* Active devices
	67	*/
	68	static struct video_device *video_device[VIDEO_NUM_DEVICES];
	69	static DEFINE_MUTEX(videodev_lock);
dd89601d	70	static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
7f8ecfab	71
27a5e6d3 HV	72	struct video_device *video_device_alloc(void)
27a5e6d3 HV	73	{
bfa8a273	74	return kzalloc(sizeof(struct video_device), GFP_KERNEL);
27a5e6d3 HV	75	}
	76	EXPORT_SYMBOL(video_device_alloc);
	77
dc93a70c	78	void video_device_release(struct video_device *vdev)
27a5e6d3	79	{
dc93a70c	80	kfree(vdev);
27a5e6d3 HV	81	}
	82	EXPORT_SYMBOL(video_device_release);
	83
dc93a70c	84	void video_device_release_empty(struct video_device *vdev)
f9e86b5e HV	85	{
	86	/* Do nothing */
	87	/* Only valid when the video_device struct is a static. */
	88	}
	89	EXPORT_SYMBOL(video_device_release_empty);
	90
dc93a70c	91	static inline void video_get(struct video_device *vdev)
7f8ecfab	92	{
dc93a70c HV	93	get_device(&vdev->dev);
	94	}
	95
	96	static inline void video_put(struct video_device *vdev)
	97	{
	98	put_device(&vdev->dev);
	99	}
	100
	101	/* Called when the last user of the video device exits. */
	102	static void v4l2_device_release(struct device *cd)
	103	{
	104	struct video_device *vdev = to_video_device(cd);
7f8ecfab HV	105
7f8ecfab HV	106	mutex_lock(&videodev_lock);
dc93a70c	107	if (video_device[vdev->minor] != vdev) {
6ea9a182	108	mutex_unlock(&videodev_lock);
dc93a70c HV	109	/* should not happen */
dc93a70c HV	110	WARN_ON(1);
6ea9a182 HV	111	return;
6ea9a182 HV	112	}
7f8ecfab HV	113
7f8ecfab HV	114	/* Free up this device for reuse */
dc93a70c	115	video_device[vdev->minor] = NULL;
7f8ecfab	116
dc93a70c HV	117	/* Delete the cdev on this minor as well */
	118	cdev_del(vdev->cdev);
	119	/* Just in case some driver tries to access this from
	120	the release() callback. */
	121	vdev->cdev = NULL;
7f8ecfab	122
dc93a70c HV	123	/* Mark minor as free */
dc93a70c HV	124	clear_bit(vdev->num, video_nums[vdev->vfl_type]);
7f8ecfab	125
dc93a70c	126	mutex_unlock(&videodev_lock);
27a5e6d3	127
dc93a70c HV	128	/* Release video_device and perform other
	129	cleanups as needed. */
	130	vdev->release(vdev);
27a5e6d3 HV	131	}
	132
	133	static struct class video_class = {
	134	.name = VIDEO_NAME,
	135	.dev_attrs = video_device_attrs,
27a5e6d3 HV	136	};
27a5e6d3 HV	137
27a5e6d3 HV	138	struct video_device video_devdata(struct file file)
	139	{
	140	return video_device[iminor(file->f_path.dentry->d_inode)];
	141	}
	142	EXPORT_SYMBOL(video_devdata);
	143
dc93a70c HV	144	static ssize_t v4l2_read(struct file filp, char __user buf,
	145	size_t sz, loff_t *off)
	146	{
	147	struct video_device *vdev = video_devdata(filp);
	148
	149	if (!vdev->fops->read)
	150	return -EINVAL;
	151	if (video_is_unregistered(vdev))
	152	return -EIO;
	153	return vdev->fops->read(filp, buf, sz, off);
	154	}
	155
	156	static ssize_t v4l2_write(struct file filp, const char __user buf,
	157	size_t sz, loff_t *off)
	158	{
	159	struct video_device *vdev = video_devdata(filp);
	160
	161	if (!vdev->fops->write)
	162	return -EINVAL;
	163	if (video_is_unregistered(vdev))
	164	return -EIO;
	165	return vdev->fops->write(filp, buf, sz, off);
	166	}
	167
	168	static unsigned int v4l2_poll(struct file filp, struct poll_table_struct poll)
	169	{
	170	struct video_device *vdev = video_devdata(filp);
	171
	172	if (!vdev->fops->poll \|\| video_is_unregistered(vdev))
	173	return DEFAULT_POLLMASK;
	174	return vdev->fops->poll(filp, poll);
	175	}
	176
	177	static int v4l2_ioctl(struct inode inode, struct file filp,
	178	unsigned int cmd, unsigned long arg)
	179	{
	180	struct video_device *vdev = video_devdata(filp);
	181
	182	if (!vdev->fops->ioctl)
	183	return -ENOTTY;
	184	/* Allow ioctl to continue even if the device was unregistered.
	185	Things like dequeueing buffers might still be useful. */
bec43661	186	return vdev->fops->ioctl(filp, cmd, arg);
dc93a70c HV	187	}
	188
	189	static long v4l2_unlocked_ioctl(struct file *filp,
	190	unsigned int cmd, unsigned long arg)
	191	{
	192	struct video_device *vdev = video_devdata(filp);
	193
	194	if (!vdev->fops->unlocked_ioctl)
	195	return -ENOTTY;
	196	/* Allow ioctl to continue even if the device was unregistered.
	197	Things like dequeueing buffers might still be useful. */
	198	return vdev->fops->unlocked_ioctl(filp, cmd, arg);
	199	}
	200
dc93a70c HV	201	static int v4l2_mmap(struct file filp, struct vm_area_struct vm)
	202	{
	203	struct video_device *vdev = video_devdata(filp);
	204
	205	if (!vdev->fops->mmap \|\|
	206	video_is_unregistered(vdev))
	207	return -ENODEV;
	208	return vdev->fops->mmap(filp, vm);
	209	}
	210
	211	/* Override for the open function */
	212	static int v4l2_open(struct inode inode, struct file filp)
	213	{
	214	struct video_device *vdev;
	215	int ret;
	216
	217	/* Check if the video device is available */
	218	mutex_lock(&videodev_lock);
	219	vdev = video_devdata(filp);
	220	/* return ENODEV if the video device has been removed
	221	already or if it is not registered anymore. */
	222	if (vdev == NULL \|\| video_is_unregistered(vdev)) {
	223	mutex_unlock(&videodev_lock);
	224	return -ENODEV;
	225	}
	226	/* and increase the device refcount */
	227	video_get(vdev);
	228	mutex_unlock(&videodev_lock);
bec43661	229	ret = vdev->fops->open(filp);
dc93a70c HV	230	/* decrease the refcount in case of an error */
	231	if (ret)
	232	video_put(vdev);
	233	return ret;
	234	}
	235
	236	/* Override for the release function */
	237	static int v4l2_release(struct inode inode, struct file filp)
	238	{
	239	struct video_device *vdev = video_devdata(filp);
bec43661	240	int ret = vdev->fops->release(filp);
dc93a70c HV	241
	242	/* decrease the refcount unconditionally since the release()
	243	return value is ignored. */
	244	video_put(vdev);
	245	return ret;
	246	}
	247
	248	static const struct file_operations v4l2_unlocked_fops = {
	249	.owner = THIS_MODULE,
	250	.read = v4l2_read,
	251	.write = v4l2_write,
	252	.open = v4l2_open,
	253	.mmap = v4l2_mmap,
	254	.unlocked_ioctl = v4l2_unlocked_ioctl,
	255	#ifdef CONFIG_COMPAT
bec43661	256	.compat_ioctl = v4l_compat_ioctl32,
dc93a70c HV	257	#endif
	258	.release = v4l2_release,
	259	.poll = v4l2_poll,
	260	.llseek = no_llseek,
	261	};
	262
	263	static const struct file_operations v4l2_fops = {
	264	.owner = THIS_MODULE,
	265	.read = v4l2_read,
	266	.write = v4l2_write,
	267	.open = v4l2_open,
	268	.mmap = v4l2_mmap,
	269	.ioctl = v4l2_ioctl,
	270	#ifdef CONFIG_COMPAT
bec43661	271	.compat_ioctl = v4l_compat_ioctl32,
dc93a70c HV	272	#endif
	273	.release = v4l2_release,
	274	.poll = v4l2_poll,
	275	.llseek = no_llseek,
	276	};
	277
27a5e6d3 HV	278	/**
27a5e6d3 HV	279	* get_index - assign stream number based on parent device
dc93a70c HV	280	* @vdev: video_device to assign index number to, vdev->parent should be assigned
dc93a70c HV	281	* @num: -1 if auto assign, requested number otherwise
27a5e6d3	282	*
dc93a70c HV	283	* Note that when this is called the new device has not yet been registered
dc93a70c HV	284	* in the video_device array.
27a5e6d3	285	*
dc93a70c	286	* Returns -ENFILE if num is already in use, a free index number if
27a5e6d3 HV	287	* successful.
	288	*/
	289	static int get_index(struct video_device *vdev, int num)
	290	{
	291	u32 used = 0;
	292	const int max_index = sizeof(used) * 8 - 1;
	293	int i;
	294
	295	/* Currently a single v4l driver instance cannot create more than
	296	32 devices.
	297	Increase to u64 or an array of u32 if more are needed. */
	298	if (num > max_index) {
	299	printk(KERN_ERR "videodev: %s num is too large\n", __func__);
	300	return -EINVAL;
	301	}
	302
806e5b7c HV	303	/* Some drivers do not set the parent. In that case always return 0. */
	304	if (vdev->parent == NULL)
	305	return 0;
	306
27a5e6d3 HV	307	for (i = 0; i < VIDEO_NUM_DEVICES; i++) {
27a5e6d3 HV	308	if (video_device[i] != NULL &&
5e85e732	309	video_device[i]->parent == vdev->parent) {
27a5e6d3 HV	310	used \|= 1 << video_device[i]->index;
	311	}
	312	}
	313
	314	if (num >= 0) {
	315	if (used & (1 << num))
	316	return -ENFILE;
	317	return num;
	318	}
	319
	320	i = ffz(used);
	321	return i > max_index ? -ENFILE : i;
	322	}
	323
dc93a70c	324	int video_register_device(struct video_device *vdev, int type, int nr)
27a5e6d3	325	{
dc93a70c	326	return video_register_device_index(vdev, type, nr, -1);
27a5e6d3 HV	327	}
	328	EXPORT_SYMBOL(video_register_device);
	329
	330	/**
edc9189c	331	* video_register_device_index - register video4linux devices
dc93a70c	332	* @vdev: video device structure we want to register
27a5e6d3 HV	333	* @type: type of device to register
	334	* @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
	335	* -1 == first free)
edc9189c RD	336	* @index: stream number based on parent device;
edc9189c RD	337	* -1 if auto assign, requested number otherwise
27a5e6d3 HV	338	*
	339	* The registration code assigns minor numbers based on the type
	340	* requested. -ENFILE is returned in all the device slots for this
	341	* category are full. If not then the minor field is set and the
	342	* driver initialize function is called (if non %NULL).
	343	*
	344	* Zero is returned on success.
	345	*
	346	* Valid types are
	347	*
	348	* %VFL_TYPE_GRABBER - A frame grabber
	349	*
	350	* %VFL_TYPE_VTX - A teletext device
	351	*
	352	* %VFL_TYPE_VBI - Vertical blank data (undecoded)
	353	*
	354	* %VFL_TYPE_RADIO - A radio card
	355	*/
dc93a70c	356	int video_register_device_index(struct video_device *vdev, int type, int nr,
27a5e6d3 HV	357	int index)
	358	{
	359	int i = 0;
27a5e6d3	360	int ret;
dd89601d HV	361	int minor_offset = 0;
	362	int minor_cnt = VIDEO_NUM_DEVICES;
	363	const char *name_base;
dc93a70c	364	void *priv = video_get_drvdata(vdev);
27a5e6d3	365
dc93a70c HV	366	/* A minor value of -1 marks this video device as never
	367	having been registered */
	368	if (vdev)
	369	vdev->minor = -1;
ee7aa9f8	370
dc93a70c HV	371	/* the release callback MUST be present */
	372	WARN_ON(!vdev \|\| !vdev->release);
	373	if (!vdev \|\| !vdev->release)
f3b9f50e HK	374	return -EINVAL;
f3b9f50e HK	375
dc93a70c	376	/* Part 1: check device type */
27a5e6d3 HV	377	switch (type) {
27a5e6d3 HV	378	case VFL_TYPE_GRABBER:
27a5e6d3 HV	379	name_base = "video";
	380	break;
	381	case VFL_TYPE_VTX:
27a5e6d3 HV	382	name_base = "vtx";
	383	break;
	384	case VFL_TYPE_VBI:
27a5e6d3 HV	385	name_base = "vbi";
	386	break;
	387	case VFL_TYPE_RADIO:
27a5e6d3 HV	388	name_base = "radio";
	389	break;
	390	default:
	391	printk(KERN_ERR "%s called with unknown type: %d\n",
	392	__func__, type);
46f2c21c	393	return -EINVAL;
27a5e6d3 HV	394	}
27a5e6d3 HV	395
dc93a70c HV	396	vdev->vfl_type = type;
dc93a70c HV	397	vdev->cdev = NULL;
9bea3514 HV	398	if (vdev->v4l2_dev)
9bea3514 HV	399	vdev->parent = vdev->v4l2_dev->dev;
dd89601d	400
dc93a70c	401	/* Part 2: find a free minor, kernel number and device index. */
dd89601d HV	402	#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
	403	/* Keep the ranges for the first four types for historical
	404	* reasons.
	405	* Newer devices (not yet in place) should use the range
	406	* of 128-191 and just pick the first free minor there
	407	* (new style). */
	408	switch (type) {
	409	case VFL_TYPE_GRABBER:
	410	minor_offset = 0;
	411	minor_cnt = 64;
	412	break;
	413	case VFL_TYPE_RADIO:
	414	minor_offset = 64;
	415	minor_cnt = 64;
	416	break;
	417	case VFL_TYPE_VTX:
	418	minor_offset = 192;
	419	minor_cnt = 32;
	420	break;
	421	case VFL_TYPE_VBI:
	422	minor_offset = 224;
	423	minor_cnt = 32;
	424	break;
	425	default:
	426	minor_offset = 128;
	427	minor_cnt = 64;
	428	break;
	429	}
	430	#endif
	431
dc93a70c	432	/* Pick a minor number */
27a5e6d3	433	mutex_lock(&videodev_lock);
dd89601d HV	434	nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr);
	435	if (nr == minor_cnt)
	436	nr = find_first_zero_bit(video_nums[type], minor_cnt);
	437	if (nr == minor_cnt) {
	438	printk(KERN_ERR "could not get a free kernel number\n");
	439	mutex_unlock(&videodev_lock);
	440	return -ENFILE;
27a5e6d3	441	}
dd89601d HV	442	#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
	443	/* 1-on-1 mapping of kernel number to minor number */
	444	i = nr;
	445	#else
	446	/* The kernel number and minor numbers are independent */
	447	for (i = 0; i < VIDEO_NUM_DEVICES; i++)
	448	if (video_device[i] == NULL)
	449	break;
	450	if (i == VIDEO_NUM_DEVICES) {
	451	mutex_unlock(&videodev_lock);
	452	printk(KERN_ERR "could not get a free minor\n");
	453	return -ENFILE;
	454	}
	455	#endif
dc93a70c HV	456	vdev->minor = i + minor_offset;
dc93a70c HV	457	vdev->num = nr;
dd89601d	458	set_bit(nr, video_nums[type]);
dc93a70c HV	459	/* Should not happen since we thought this minor was free */
	460	WARN_ON(video_device[vdev->minor] != NULL);
	461	ret = vdev->index = get_index(vdev, index);
27a5e6d3 HV	462	mutex_unlock(&videodev_lock);
	463
	464	if (ret < 0) {
	465	printk(KERN_ERR "%s: get_index failed\n", __func__);
dc93a70c	466	goto cleanup;
27a5e6d3 HV	467	}
27a5e6d3 HV	468
dc93a70c HV	469	/* Part 3: Initialize the character device */
	470	vdev->cdev = cdev_alloc();
	471	if (vdev->cdev == NULL) {
	472	ret = -ENOMEM;
	473	goto cleanup;
	474	}
	475	if (vdev->fops->unlocked_ioctl)
	476	vdev->cdev->ops = &v4l2_unlocked_fops;
	477	else
	478	vdev->cdev->ops = &v4l2_fops;
	479	vdev->cdev->owner = vdev->fops->owner;
	480	ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
7f8ecfab HV	481	if (ret < 0) {
7f8ecfab HV	482	printk(KERN_ERR "%s: cdev_add failed\n", __func__);
dc93a70c HV	483	kfree(vdev->cdev);
	484	vdev->cdev = NULL;
	485	goto cleanup;
7f8ecfab	486	}
dc93a70c HV	487
	488	/* Part 4: register the device with sysfs */
	489	memset(&vdev->dev, 0, sizeof(vdev->dev));
9d95af9d HV	490	/* The memset above cleared the device's drvdata, so
9d95af9d HV	491	put back the copy we made earlier. */
dc93a70c HV	492	video_set_drvdata(vdev, priv);
	493	vdev->dev.class = &video_class;
	494	vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
	495	if (vdev->parent)
	496	vdev->dev.parent = vdev->parent;
	497	dev_set_name(&vdev->dev, "%s%d", name_base, nr);
	498	ret = device_register(&vdev->dev);
27a5e6d3 HV	499	if (ret < 0) {
27a5e6d3 HV	500	printk(KERN_ERR "%s: device_register failed\n", __func__);
dc93a70c	501	goto cleanup;
27a5e6d3	502	}
dc93a70c HV	503	/* Register the release callback that will be called when the last
	504	reference to the device goes away. */
	505	vdev->dev.release = v4l2_device_release;
27a5e6d3	506
dc93a70c HV	507	/* Part 5: Activate this minor. The char device can now be used. */
	508	mutex_lock(&videodev_lock);
	509	video_device[vdev->minor] = vdev;
	510	mutex_unlock(&videodev_lock);
	511	return 0;
7f8ecfab	512
dc93a70c	513	cleanup:
27a5e6d3	514	mutex_lock(&videodev_lock);
dc93a70c HV	515	if (vdev->cdev)
	516	cdev_del(vdev->cdev);
	517	clear_bit(vdev->num, video_nums[type]);
27a5e6d3	518	mutex_unlock(&videodev_lock);
dc93a70c HV	519	/* Mark this video device as never having been registered. */
dc93a70c HV	520	vdev->minor = -1;
27a5e6d3 HV	521	return ret;
	522	}
	523	EXPORT_SYMBOL(video_register_device_index);
	524
	525	/**
	526	* video_unregister_device - unregister a video4linux device
dc93a70c	527	* @vdev: the device to unregister
27a5e6d3	528	*
dc93a70c HV	529	* This unregisters the passed device. Future open calls will
dc93a70c HV	530	* be met with errors.
27a5e6d3	531	*/
dc93a70c	532	void video_unregister_device(struct video_device *vdev)
27a5e6d3	533	{
dc93a70c HV	534	/* Check if vdev was ever registered at all */
	535	if (!vdev \|\| vdev->minor < 0)
	536	return;
	537
	538	mutex_lock(&videodev_lock);
	539	set_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
	540	mutex_unlock(&videodev_lock);
	541	device_unregister(&vdev->dev);
27a5e6d3 HV	542	}
	543	EXPORT_SYMBOL(video_unregister_device);
	544
27a5e6d3 HV	545	/*
	546	* Initialise video for linux
	547	*/
27a5e6d3 HV	548	static int __init videodev_init(void)
27a5e6d3 HV	549	{
7f8ecfab	550	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
27a5e6d3 HV	551	int ret;
	552
	553	printk(KERN_INFO "Linux video capture interface: v2.00\n");
7f8ecfab HV	554	ret = register_chrdev_region(dev, VIDEO_NUM_DEVICES, VIDEO_NAME);
	555	if (ret < 0) {
	556	printk(KERN_WARNING "videodev: unable to get major %d\n",
	557	VIDEO_MAJOR);
	558	return ret;
27a5e6d3 HV	559	}
	560
	561	ret = class_register(&video_class);
	562	if (ret < 0) {
7f8ecfab	563	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
27a5e6d3 HV	564	printk(KERN_WARNING "video_dev: class_register failed\n");
	565	return -EIO;
	566	}
	567
	568	return 0;
	569	}
	570
	571	static void __exit videodev_exit(void)
	572	{
7f8ecfab HV	573	dev_t dev = MKDEV(VIDEO_MAJOR, 0);
7f8ecfab HV	574
27a5e6d3	575	class_unregister(&video_class);
7f8ecfab	576	unregister_chrdev_region(dev, VIDEO_NUM_DEVICES);
27a5e6d3 HV	577	}
	578
	579	module_init(videodev_init)
	580	module_exit(videodev_exit)
	581
	582	MODULE_AUTHOR("Alan Cox, Mauro Carvalho Chehab <mchehab@infradead.org>");
	583	MODULE_DESCRIPTION("Device registrar for Video4Linux drivers v2");
	584	MODULE_LICENSE("GPL");
	585
	586
	587	/*
	588	* Local variables:
	589	* c-basic-offset: 8
	590	* End:
	591	*/