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/*
* Video capture interface for Linux
*
* 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.
*
* Author: Alan Cox, <alan@redhat.com>
*
* Fixes: 20000516 Claudio Matsuoka <claudio@conectiva.com>
* - Added procfs support
*/
#include <linux/config.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/videodev.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/semaphore.h>
#include <linux/kmod.h>
#define VIDEO_NUM_DEVICES 256
/*
* Active devices
*/
static struct video_device *video_device[VIDEO_NUM_DEVICES];
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
#include <linux/proc_fs.h>
struct videodev_proc_data {
struct list_head proc_list;
char name[16];
struct video_device *vdev;
struct proc_dir_entry *proc_entry;
};
static struct proc_dir_entry *video_dev_proc_entry = NULL;
struct proc_dir_entry *video_proc_entry = NULL;
EXPORT_SYMBOL(video_proc_entry);
LIST_HEAD(videodev_proc_list);
#endif /* CONFIG_PROC_FS && CONFIG_VIDEO_PROC_FS */
/*
* Read will do some smarts later on. Buffer pin etc.
*/
static ssize_t video_read(struct file *file,
char *buf, size_t count, loff_t *ppos)
{
struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
if(vfl->read)
return vfl->read(vfl, buf, count, file->f_flags&O_NONBLOCK);
else
return -EINVAL;
}
/*
* Write for now does nothing. No reason it shouldnt do overlay setting
* for some boards I guess..
*/
static ssize_t video_write(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
if(vfl->write)
return vfl->write(vfl, buf, count, file->f_flags&O_NONBLOCK);
else
return 0;
}
/*
* Poll to see if we're readable, can probably be used for timing on incoming
* frames, etc..
*/
static unsigned int video_poll(struct file *file, poll_table * wait)
{
struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
if(vfl->poll)
return vfl->poll(vfl, file, wait);
else
return 0;
}
/*
* Open a video device.
*/
static int video_open(struct inode *inode, struct file *file)
{
unsigned int minor = MINOR(inode->i_rdev);
int err, retval = 0;
struct video_device *vfl;
if(minor>=VIDEO_NUM_DEVICES)
return -ENODEV;
lock_kernel();
vfl=video_device[minor];
if(vfl==NULL) {
char modname[20];
sprintf (modname, "char-major-%d-%d", VIDEO_MAJOR, minor);
request_module(modname);
vfl=video_device[minor];
if (vfl==NULL) {
retval = -ENODEV;
goto error_out;
}
}
if(vfl->busy) {
retval = -EBUSY;
goto error_out;
}
vfl->busy=1; /* In case vfl->open sleeps */
if(vfl->owner)
__MOD_INC_USE_COUNT(vfl->owner);
if(vfl->open)
{
err=vfl->open(vfl,0); /* Tell the device it is open */
if(err)
{
vfl->busy=0;
if(vfl->owner)
__MOD_DEC_USE_COUNT(vfl->owner);
unlock_kernel();
return err;
}
}
unlock_kernel();
return 0;
error_out:
unlock_kernel();
return retval;
}
/*
* Last close of a video for Linux device
*/
static int video_release(struct inode *inode, struct file *file)
{
struct video_device *vfl;
lock_kernel();
vfl=video_device[MINOR(inode->i_rdev)];
if(vfl->close)
vfl->close(vfl);
vfl->busy=0;
if(vfl->owner)
__MOD_DEC_USE_COUNT(vfl->owner);
unlock_kernel();
return 0;
}
static int video_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct video_device *vfl=video_device[MINOR(inode->i_rdev)];
int err=vfl->ioctl(vfl, cmd, (void *)arg);
if(err!=-ENOIOCTLCMD)
return err;
switch(cmd)
{
default:
return -EINVAL;
}
}
/*
* We need to do MMAP support
*/
int video_mmap(struct file *file, struct vm_area_struct *vma)
{
int ret = -EINVAL;
struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
if(vfl->mmap) {
lock_kernel();
ret = vfl->mmap(vfl, (char *)vma->vm_start,
(unsigned long)(vma->vm_end-vma->vm_start));
unlock_kernel();
}
return ret;
}
/*
* /proc support
*/
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
/* Hmm... i'd like to see video_capability information here, but
* how can I access it (without changing the other drivers? -claudio
*/
static int videodev_proc_read(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
char *out = page;
struct video_device *vfd = data;
struct videodev_proc_data *d;
struct list_head *tmp;
int len;
char c = ' ';
list_for_each (tmp, &videodev_proc_list) {
d = list_entry(tmp, struct videodev_proc_data, proc_list);
if (vfd == d->vdev)
break;
}
/* Sanity check */
if (tmp == &videodev_proc_list)
goto skip;
#define PRINT_VID_TYPE(x) do { if (vfd->type & x) \
out += sprintf (out, "%c%s", c, #x); c='|';} while (0)
out += sprintf (out, "name : %s\n", vfd->name);
out += sprintf (out, "type :");
PRINT_VID_TYPE(VID_TYPE_CAPTURE);
PRINT_VID_TYPE(VID_TYPE_TUNER);
PRINT_VID_TYPE(VID_TYPE_TELETEXT);
PRINT_VID_TYPE(VID_TYPE_OVERLAY);
PRINT_VID_TYPE(VID_TYPE_CHROMAKEY);
PRINT_VID_TYPE(VID_TYPE_CLIPPING);
PRINT_VID_TYPE(VID_TYPE_FRAMERAM);
PRINT_VID_TYPE(VID_TYPE_SCALES);
PRINT_VID_TYPE(VID_TYPE_MONOCHROME);
PRINT_VID_TYPE(VID_TYPE_SUBCAPTURE);
PRINT_VID_TYPE(VID_TYPE_MPEG_DECODER);
PRINT_VID_TYPE(VID_TYPE_MPEG_ENCODER);
PRINT_VID_TYPE(VID_TYPE_MJPEG_DECODER);
PRINT_VID_TYPE(VID_TYPE_MJPEG_ENCODER);
out += sprintf (out, "\n");
out += sprintf (out, "hardware : 0x%x\n", vfd->hardware);
#if 0
out += sprintf (out, "channels : %d\n", d->vcap.channels);
out += sprintf (out, "audios : %d\n", d->vcap.audios);
out += sprintf (out, "maxwidth : %d\n", d->vcap.maxwidth);
out += sprintf (out, "maxheight : %d\n", d->vcap.maxheight);
out += sprintf (out, "minwidth : %d\n", d->vcap.minwidth);
out += sprintf (out, "minheight : %d\n", d->vcap.minheight);
#endif
skip:
len = out - page;
len -= off;
if (len < count) {
*eof = 1;
if (len <= 0)
return 0;
} else
len = count;
*start = page + off;
return len;
}
static void videodev_proc_create(void)
{
video_proc_entry = create_proc_entry("video", S_IFDIR, &proc_root);
if (video_proc_entry == NULL) {
printk("video_dev: unable to initialise /proc/video\n");
return;
}
video_proc_entry->owner = THIS_MODULE;
video_dev_proc_entry = create_proc_entry("dev", S_IFDIR, video_proc_entry);
if (video_dev_proc_entry == NULL) {
printk("video_dev: unable to initialise /proc/video/dev\n");
return;
}
video_dev_proc_entry->owner = THIS_MODULE;
}
#ifdef MODULE
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
static void videodev_proc_destroy(void)
{
if (video_dev_proc_entry != NULL)
remove_proc_entry("dev", video_proc_entry);
if (video_proc_entry != NULL)
remove_proc_entry("video", &proc_root);
}
#endif
#endif
static void videodev_proc_create_dev (struct video_device *vfd, char *name)
{
struct videodev_proc_data *d;
struct proc_dir_entry *p;
if (video_dev_proc_entry == NULL)
return;
d = kmalloc (sizeof (struct videodev_proc_data), GFP_KERNEL);
if (!d)
return;
p = create_proc_entry(name, S_IFREG|S_IRUGO|S_IWUSR, video_dev_proc_entry);
if (!p)
return;
p->data = vfd;
p->read_proc = videodev_proc_read;
d->proc_entry = p;
d->vdev = vfd;
strcpy (d->name, name);
/* How can I get capability information ? */
list_add (&d->proc_list, &videodev_proc_list);
}
static void videodev_proc_destroy_dev (struct video_device *vfd)
{
struct list_head *tmp;
struct videodev_proc_data *d;
list_for_each (tmp, &videodev_proc_list) {
d = list_entry(tmp, struct videodev_proc_data, proc_list);
if (vfd == d->vdev) {
remove_proc_entry(d->name, video_dev_proc_entry);
list_del (&d->proc_list);
kfree(d);
break;
}
}
}
#endif /* CONFIG_VIDEO_PROC_FS */
extern struct file_operations video_fops;
/**
* video_register_device - register video4linux devices
* @vfd: 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
*/
static DECLARE_MUTEX(videodev_register_lock);
int video_register_device(struct video_device *vfd, int type, int nr)
{
int i=0;
int base;
int err;
int end;
char *name_base;
char name[16];
switch(type)
{
case VFL_TYPE_GRABBER:
base=0;
end=64;
name_base = "video";
break;
case VFL_TYPE_VTX:
base=192;
end=224;
name_base = "vtx";
break;
case VFL_TYPE_VBI:
base=224;
end=240;
name_base = "vbi";
break;
case VFL_TYPE_RADIO:
base=64;
end=128;
name_base = "radio";
break;
default:
return -1;
}
/* pick a minor number */
down(&videodev_register_lock);
if (-1 == nr) {
/* use first free */
for(i=base;i<end;i++)
if (NULL == video_device[i])
break;
if (i == end) {
up(&videodev_register_lock);
return -ENFILE;
}
} else {
/* use the one the driver asked for */
i = base+nr;
if (NULL != video_device[i]) {
up(&videodev_register_lock);
return -ENFILE;
}
}
video_device[i]=vfd;
vfd->minor=i;
up(&videodev_register_lock);
/* The init call may sleep so we book the slot out
then call */
MOD_INC_USE_COUNT;
if(vfd->initialize) {
err=vfd->initialize(vfd);
if(err<0) {
video_device[i]=NULL;
MOD_DEC_USE_COUNT;
return err;
}
}
sprintf (name, "v4l/%s%d", name_base, i - base);
/*
* Start the device root only. Anything else
* has serious privacy issues.
*/
vfd->devfs_handle =
devfs_register (NULL, name, DEVFS_FL_DEFAULT,
VIDEO_MAJOR, vfd->minor,
S_IFCHR | S_IRUSR | S_IWUSR,
&video_fops,
NULL);
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
sprintf (name, "%s%d", name_base, i - base);
videodev_proc_create_dev (vfd, name);
#endif
return 0;
}
/**
* video_unregister_device - unregister a video4linux device
* @vfd: the device to unregister
*
* This unregisters the passed device and deassigns the minor
* number. Future open calls will be met with errors.
*/
void video_unregister_device(struct video_device *vfd)
{
if(video_device[vfd->minor]!=vfd)
panic("vfd: bad unregister");
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
videodev_proc_destroy_dev (vfd);
#endif
devfs_unregister (vfd->devfs_handle);
video_device[vfd->minor]=NULL;
MOD_DEC_USE_COUNT;
}
static struct file_operations video_fops=
{
owner: THIS_MODULE,
llseek: no_llseek,
read: video_read,
write: video_write,
ioctl: video_ioctl,
mmap: video_mmap,
open: video_open,
release: video_release,
poll: video_poll,
};
/*
* Initialise video for linux
*/
static int __init videodev_init(void)
{
printk(KERN_INFO "Linux video capture interface: v1.00\n");
if(devfs_register_chrdev(VIDEO_MAJOR,"video_capture", &video_fops))
{
printk("video_dev: unable to get major %d\n", VIDEO_MAJOR);
return -EIO;
}
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
videodev_proc_create ();
#endif
return 0;
}
static void __exit videodev_exit(void)
{
#ifdef MODULE
#if defined(CONFIG_PROC_FS) && defined(CONFIG_VIDEO_PROC_FS)
videodev_proc_destroy ();
#endif
#endif
devfs_unregister_chrdev(VIDEO_MAJOR, "video_capture");
}
module_init(videodev_init)
module_exit(videodev_exit)
EXPORT_SYMBOL(video_register_device);
EXPORT_SYMBOL(video_unregister_device);
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("Device registrar for Video4Linux drivers");
MODULE_LICENSE("GPL");
/*
* Local variables:
* c-basic-offset: 8
* End:
*/
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