437 lines
9.4 KiB
C
437 lines
9.4 KiB
C
/*
|
|
* 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/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/init.h>
|
|
#include <linux/kmod.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/devfs_fs_kernel.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/system.h>
|
|
#include <asm/semaphore.h>
|
|
|
|
#include <linux/videodev.h>
|
|
|
|
#define VIDEO_NUM_DEVICES 256
|
|
#define VIDEO_NAME "video4linux"
|
|
|
|
/*
|
|
* sysfs stuff
|
|
*/
|
|
|
|
static ssize_t show_name(struct class_device *cd, char *buf)
|
|
{
|
|
struct video_device *vfd = container_of(cd, struct video_device, class_dev);
|
|
return sprintf(buf,"%.*s\n",(int)sizeof(vfd->name),vfd->name);
|
|
}
|
|
|
|
static CLASS_DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
|
|
|
|
struct video_device *video_device_alloc(void)
|
|
{
|
|
struct video_device *vfd;
|
|
|
|
vfd = kmalloc(sizeof(*vfd),GFP_KERNEL);
|
|
if (NULL == vfd)
|
|
return NULL;
|
|
memset(vfd,0,sizeof(*vfd));
|
|
return vfd;
|
|
}
|
|
|
|
void video_device_release(struct video_device *vfd)
|
|
{
|
|
kfree(vfd);
|
|
}
|
|
|
|
static void video_release(struct class_device *cd)
|
|
{
|
|
struct video_device *vfd = container_of(cd, struct video_device, class_dev);
|
|
|
|
#if 1 /* needed until all drivers are fixed */
|
|
if (!vfd->release)
|
|
return;
|
|
#endif
|
|
vfd->release(vfd);
|
|
}
|
|
|
|
static struct class video_class = {
|
|
.name = VIDEO_NAME,
|
|
.release = video_release,
|
|
};
|
|
|
|
/*
|
|
* Active devices
|
|
*/
|
|
|
|
static struct video_device *video_device[VIDEO_NUM_DEVICES];
|
|
static DECLARE_MUTEX(videodev_lock);
|
|
|
|
struct video_device* video_devdata(struct file *file)
|
|
{
|
|
return video_device[iminor(file->f_dentry->d_inode)];
|
|
}
|
|
|
|
/*
|
|
* Open a video device.
|
|
*/
|
|
static int video_open(struct inode *inode, struct file *file)
|
|
{
|
|
unsigned int minor = iminor(inode);
|
|
int err = 0;
|
|
struct video_device *vfl;
|
|
struct file_operations *old_fops;
|
|
|
|
if(minor>=VIDEO_NUM_DEVICES)
|
|
return -ENODEV;
|
|
down(&videodev_lock);
|
|
vfl=video_device[minor];
|
|
if(vfl==NULL) {
|
|
up(&videodev_lock);
|
|
request_module("char-major-%d-%d", VIDEO_MAJOR, minor);
|
|
down(&videodev_lock);
|
|
vfl=video_device[minor];
|
|
if (vfl==NULL) {
|
|
up(&videodev_lock);
|
|
return -ENODEV;
|
|
}
|
|
}
|
|
old_fops = file->f_op;
|
|
file->f_op = fops_get(vfl->fops);
|
|
if(file->f_op->open)
|
|
err = file->f_op->open(inode,file);
|
|
if (err) {
|
|
fops_put(file->f_op);
|
|
file->f_op = fops_get(old_fops);
|
|
}
|
|
fops_put(old_fops);
|
|
up(&videodev_lock);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* helper function -- handles userspace copying for ioctl arguments
|
|
*/
|
|
|
|
static unsigned int
|
|
video_fix_command(unsigned int cmd)
|
|
{
|
|
switch (cmd) {
|
|
case VIDIOC_OVERLAY_OLD:
|
|
cmd = VIDIOC_OVERLAY;
|
|
break;
|
|
case VIDIOC_S_PARM_OLD:
|
|
cmd = VIDIOC_S_PARM;
|
|
break;
|
|
case VIDIOC_S_CTRL_OLD:
|
|
cmd = VIDIOC_S_CTRL;
|
|
break;
|
|
case VIDIOC_G_AUDIO_OLD:
|
|
cmd = VIDIOC_G_AUDIO;
|
|
break;
|
|
case VIDIOC_G_AUDOUT_OLD:
|
|
cmd = VIDIOC_G_AUDOUT;
|
|
break;
|
|
case VIDIOC_CROPCAP_OLD:
|
|
cmd = VIDIOC_CROPCAP;
|
|
break;
|
|
}
|
|
return cmd;
|
|
}
|
|
|
|
int
|
|
video_usercopy(struct inode *inode, struct file *file,
|
|
unsigned int cmd, unsigned long arg,
|
|
int (*func)(struct inode *inode, struct file *file,
|
|
unsigned int cmd, void *arg))
|
|
{
|
|
char sbuf[128];
|
|
void *mbuf = NULL;
|
|
void *parg = NULL;
|
|
int err = -EINVAL;
|
|
|
|
cmd = video_fix_command(cmd);
|
|
|
|
/* Copy arguments into temp kernel buffer */
|
|
switch (_IOC_DIR(cmd)) {
|
|
case _IOC_NONE:
|
|
parg = NULL;
|
|
break;
|
|
case _IOC_READ:
|
|
case _IOC_WRITE:
|
|
case (_IOC_WRITE | _IOC_READ):
|
|
if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
|
|
parg = sbuf;
|
|
} else {
|
|
/* too big to allocate from stack */
|
|
mbuf = kmalloc(_IOC_SIZE(cmd),GFP_KERNEL);
|
|
if (NULL == mbuf)
|
|
return -ENOMEM;
|
|
parg = mbuf;
|
|
}
|
|
|
|
err = -EFAULT;
|
|
if (_IOC_DIR(cmd) & _IOC_WRITE)
|
|
if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
|
|
goto out;
|
|
break;
|
|
}
|
|
|
|
/* call driver */
|
|
err = func(inode, file, cmd, parg);
|
|
if (err == -ENOIOCTLCMD)
|
|
err = -EINVAL;
|
|
if (err < 0)
|
|
goto out;
|
|
|
|
/* Copy results into user buffer */
|
|
switch (_IOC_DIR(cmd))
|
|
{
|
|
case _IOC_READ:
|
|
case (_IOC_WRITE | _IOC_READ):
|
|
if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
|
|
err = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
out:
|
|
if (mbuf)
|
|
kfree(mbuf);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* open/release helper functions -- handle exclusive opens
|
|
*/
|
|
int video_exclusive_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct video_device *vfl = video_devdata(file);
|
|
int retval = 0;
|
|
|
|
down(&vfl->lock);
|
|
if (vfl->users) {
|
|
retval = -EBUSY;
|
|
} else {
|
|
vfl->users++;
|
|
}
|
|
up(&vfl->lock);
|
|
return retval;
|
|
}
|
|
|
|
int video_exclusive_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct video_device *vfl = video_devdata(file);
|
|
|
|
vfl->users--;
|
|
return 0;
|
|
}
|
|
|
|
static 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
|
|
*/
|
|
|
|
int video_register_device(struct video_device *vfd, int type, int nr)
|
|
{
|
|
int i=0;
|
|
int base;
|
|
int end;
|
|
char *name_base;
|
|
|
|
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_lock);
|
|
if (nr >= 0 && nr < end-base) {
|
|
/* use the one the driver asked for */
|
|
i = base+nr;
|
|
if (NULL != video_device[i]) {
|
|
up(&videodev_lock);
|
|
return -ENFILE;
|
|
}
|
|
} else {
|
|
/* use first free */
|
|
for(i=base;i<end;i++)
|
|
if (NULL == video_device[i])
|
|
break;
|
|
if (i == end) {
|
|
up(&videodev_lock);
|
|
return -ENFILE;
|
|
}
|
|
}
|
|
video_device[i]=vfd;
|
|
vfd->minor=i;
|
|
up(&videodev_lock);
|
|
|
|
sprintf(vfd->devfs_name, "v4l/%s%d", name_base, i - base);
|
|
devfs_mk_cdev(MKDEV(VIDEO_MAJOR, vfd->minor),
|
|
S_IFCHR | S_IRUSR | S_IWUSR, vfd->devfs_name);
|
|
init_MUTEX(&vfd->lock);
|
|
|
|
/* sysfs class */
|
|
memset(&vfd->class_dev, 0x00, sizeof(vfd->class_dev));
|
|
if (vfd->dev)
|
|
vfd->class_dev.dev = vfd->dev;
|
|
vfd->class_dev.class = &video_class;
|
|
vfd->class_dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
|
|
strlcpy(vfd->class_dev.class_id, vfd->devfs_name + 4, BUS_ID_SIZE);
|
|
class_device_register(&vfd->class_dev);
|
|
class_device_create_file(&vfd->class_dev,
|
|
&class_device_attr_name);
|
|
|
|
#if 1 /* needed until all drivers are fixed */
|
|
if (!vfd->release)
|
|
printk(KERN_WARNING "videodev: \"%s\" has no release callback. "
|
|
"Please fix your driver for proper sysfs support, see "
|
|
"http://lwn.net/Articles/36850/\n", 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)
|
|
{
|
|
down(&videodev_lock);
|
|
if(video_device[vfd->minor]!=vfd)
|
|
panic("videodev: bad unregister");
|
|
|
|
devfs_remove(vfd->devfs_name);
|
|
video_device[vfd->minor]=NULL;
|
|
class_device_unregister(&vfd->class_dev);
|
|
up(&videodev_lock);
|
|
}
|
|
|
|
|
|
static struct file_operations video_fops=
|
|
{
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.open = video_open,
|
|
};
|
|
|
|
/*
|
|
* Initialise video for linux
|
|
*/
|
|
|
|
static int __init videodev_init(void)
|
|
{
|
|
int ret;
|
|
|
|
printk(KERN_INFO "Linux video capture interface: v1.00\n");
|
|
if (register_chrdev(VIDEO_MAJOR, VIDEO_NAME, &video_fops)) {
|
|
printk(KERN_WARNING "video_dev: unable to get major %d\n", VIDEO_MAJOR);
|
|
return -EIO;
|
|
}
|
|
|
|
ret = class_register(&video_class);
|
|
if (ret < 0) {
|
|
unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME);
|
|
printk(KERN_WARNING "video_dev: class_register failed\n");
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit videodev_exit(void)
|
|
{
|
|
class_unregister(&video_class);
|
|
unregister_chrdev(VIDEO_MAJOR, VIDEO_NAME);
|
|
}
|
|
|
|
module_init(videodev_init)
|
|
module_exit(videodev_exit)
|
|
|
|
EXPORT_SYMBOL(video_register_device);
|
|
EXPORT_SYMBOL(video_unregister_device);
|
|
EXPORT_SYMBOL(video_devdata);
|
|
EXPORT_SYMBOL(video_usercopy);
|
|
EXPORT_SYMBOL(video_exclusive_open);
|
|
EXPORT_SYMBOL(video_exclusive_release);
|
|
EXPORT_SYMBOL(video_device_alloc);
|
|
EXPORT_SYMBOL(video_device_release);
|
|
|
|
MODULE_AUTHOR("Alan Cox");
|
|
MODULE_DESCRIPTION("Device registrar for Video4Linux drivers");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
|
|
/*
|
|
* Local variables:
|
|
* c-basic-offset: 8
|
|
* End:
|
|
*/
|