/*
* 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 <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_debug(struct device *cd,
struct device_attribute *attr, char *buf)
{
struct video_device *vdev = to_video_device(cd);
return sprintf(buf, "%i\n", vdev->debug);
}
static ssize_t set_debug(struct device *cd, struct device_attribute *attr,
const char *buf, size_t len)
{
struct video_device *vdev = to_video_device(cd);
int res = 0;
u16 value;
res = kstrtou16(buf, 0, &value);
if (res)
return res;
vdev->debug = value;
return len;
}
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(debug, 0644, show_debug, set_debug),
__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(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
/* Device node utility functions */
/* Note: these utility functions all assume that vfl_type is in the range
[0, VFL_TYPE_MAX-1]. */
#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
/* Return the bitmap corresponding to vfl_type. */
static inline unsigned long *devnode_bits(int vfl_type)
{
/* Any types not assigned to fixed minor ranges must be mapped to
one single bitmap for the purposes of finding a free node number
since all those unassigned types use the same minor range. */
int idx = (vfl_type > VFL_TYPE_RADIO) ? VFL_TYPE_MAX - 1 : vfl_type;
return devnode_nums[idx];
}
#else
/* Return the bitmap corresponding to vfl_type. */
static inline unsigned long *devnode_bits(int vfl_type)
{
return devnode_nums[vfl_type];
}
#endif
/* Mark device node number vdev->num as used */
static inline void devnode_set(struct video_device *vdev)
{
set_bit(vdev->num, devnode_bits(vdev->vfl_type));
}
/* Mark device node number vdev->num as unused */
static inline void devnode_clear(struct video_device *vdev)
{
clear_bit(vdev->num, devnode_bits(vdev->vfl_type));
}
/* Try to find a free device node number in the range [from, to> */
static inline int devnode_find(struct video_device *vdev, int from, int to)
{
return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from);
}
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