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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@cymru.net>
*
* Fixes:
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/videodev.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#define VIDEO_NUM_DEVICES 256
/*
* Active devices
*/
static struct video_device *video_device[VIDEO_NUM_DEVICES];
/*
* Initialiser list
*/
struct video_init
{
char *name;
int (*init)(struct video_init *);
};
extern int init_bttv_cards(struct video_init *);
static struct video_init video_init_list[]={
#ifdef CONFIG_VIDEO_BT848
{"bttv", init_bttv_cards},
#endif
#ifdef CONFIG_VIDEO_BWQCAM
{"bttv", init_bw_qcams},
#endif
#ifdef CONFIG_VIDEO_PMS
{"bttv", init_pms_cards},
#endif
{"end", NULL}
};
/*
* 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)
{
int err;
struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
return vfl->read(vfl, buf, count, file->f_flags&O_NONBLOCK);
}
/*
* 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)
{
int err;
struct video_device *vfl=video_device[MINOR(file->f_dentry->d_inode->i_rdev)];
return vfl->write(vfl, buf, count, file->f_flags&O_NONBLOCK);
}
/*
* Open a video device.
*/
static int video_open(struct inode *inode, struct file *file)
{
unsigned int minor = MINOR(inode->i_rdev);
int err;
struct video_device *vfl;
if(minor>=VIDEO_NUM_DEVICES)
return -ENODEV;
vfl=video_device[minor];
if(vfl==NULL)
return -ENODEV;
if(vfl->busy)
return -EBUSY;
vfl->busy=1; /* In case vfl->open sleeps */
if(vfl->open)
{
err=vfl->open(vfl,0); /* Tell the device it is open */
if(err)
{
vfl->busy=0;
return err;
}
}
return 0;
}
/*
* Last close of a video for Linux device
*/
static int video_release(struct inode *inode, struct file *file)
{
struct video_device *vfl=video_device[MINOR(inode->i_rdev)];
if(vfl->close)
vfl->close(vfl);
vfl->busy=0;
return 0;
}
/*
* Question: Should we be able to capture and then seek around the
* image ?
*/
static long long video_lseek(struct file * file,
long long offset, int origin)
{
return -ESPIPE;
}
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
*/
/*
* Video For Linux device drivers request registration here.
*/
int video_register_device(struct video_device *vfd)
{
int i=0;
int base=0;
int err;
for(i=base;i<base+VIDEO_NUM_DEVICES;i++)
{
if(video_device[i]==NULL)
{
video_device[i]=vfd;
vfd->minor=i;
/* The init call may sleep so we book the slot out
then call */
MOD_INC_USE_COUNT;
err=vfd->initialize(vfd);
if(err<0)
{
video_device[i]=NULL;
MOD_DEC_USE_COUNT;
return err;
}
return 0;
}
}
return -ENFILE;
}
/*
* Unregister an unused video for linux device
*/
void video_unregister_device(struct video_device *vfd)
{
if(video_device[vfd->minor]!=vfd)
panic("vfd: bad unregister");
video_device[vfd->minor]=NULL;
MOD_DEC_USE_COUNT;
}
static struct file_operations video_fops=
{
video_lseek,
video_read,
video_write,
NULL, /* readdir */
NULL, /* poll */
video_ioctl,
NULL, /* mmap */
video_open,
video_release
};
/*
* Initialise video for linux
*/
int videodev_init(void)
{
struct video_init *vfli = video_init_list;
printk(KERN_INFO "Linux video capture interface: v0.01 ALPHA\n");
if(register_chrdev(VIDEO_MAJOR,"video_capture", &video_fops))
{
printk("video_dev: unable to get major %d\n", VIDEO_MAJOR);
return -EIO;
}
/*
* Init kernel installed video drivers
*/
while(vfli->init!=NULL)
{
vfli->init(vfli);
vfli++;
}
return 0;
}
#ifdef MODULE
int init_module(void)
{
return videodev_init();
}
void cleanup_module(void)
{
unregister_chrdev(VIDEO_MAJOR, "video_capture");
}
#endif
EXPORT_SYMBOL(video_register_device);
EXPORT_SYMBOL(video_unregister_device);
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