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linux/drivers/media/video/v4l2-common.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2 
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

283 lines
8.7 KiB
C
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/*
* Video for Linux Two
*
* A generic video device interface for the LINUX operating system
* using a set of device structures/vectors for low level operations.
*
* This file replaces the videodev.c file that comes with the
* regular kernel distribution.
*
* 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: Bill Dirks <bdirks@pacbell.net>
* based on code by Alan Cox, <alan@cymru.net>
*
*/
/*
* 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:
*/
/*
* Video4linux 1/2 integration by Justin Schoeman
* <justin@suntiger.ee.up.ac.za>
* 2.4 PROCFS support ported from 2.4 kernels by
* Iñaki García Etxebarria <garetxe@euskalnet.net>
* Makefile fix by "W. Michael Petullo" <mike@flyn.org>
* 2.4 devfs support ported from 2.4 kernels by
* Dan Merillat <dan@merillat.org>
* Added Gerd Knorrs v4l1 enhancements (Justin Schoeman)
*/
#include <linux/config.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 <asm/uaccess.h>
#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/div64.h>
#ifdef CONFIG_KMOD
#include <linux/kmod.h>
#endif
#if defined(CONFIG_UST) || defined(CONFIG_UST_MODULE)
#include <linux/ust.h>
#endif
#include <linux/videodev.h>
MODULE_AUTHOR("Bill Dirks, Justin Schoeman, Gerd Knorr");
MODULE_DESCRIPTION("misc helper functions for v4l2 device drivers");
MODULE_LICENSE("GPL");
/*
*
* V 4 L 2 D R I V E R H E L P E R A P I
*
*/
/*
* Video Standard Operations (contributed by Michael Schimek)
*/
#if 0 /* seems to have no users */
/* This is the recommended method to deal with the framerate fields. More
sophisticated drivers will access the fields directly. */
unsigned int
v4l2_video_std_fps(struct v4l2_standard *vs)
{
if (vs->frameperiod.numerator > 0)
return (((vs->frameperiod.denominator << 8) /
vs->frameperiod.numerator) +
(1 << 7)) / (1 << 8);
return 0;
}
EXPORT_SYMBOL(v4l2_video_std_fps);
#endif
/* Fill in the fields of a v4l2_standard structure according to the
'id' and 'transmission' parameters. Returns negative on error. */
int v4l2_video_std_construct(struct v4l2_standard *vs,
int id, char *name)
{
u32 index = vs->index;
memset(vs, 0, sizeof(struct v4l2_standard));
vs->index = index;
vs->id = id;
if (id & (V4L2_STD_NTSC | V4L2_STD_PAL_M)) {
vs->frameperiod.numerator = 1001;
vs->frameperiod.denominator = 30000;
vs->framelines = 525;
} else {
vs->frameperiod.numerator = 1;
vs->frameperiod.denominator = 25;
vs->framelines = 625;
}
strlcpy(vs->name,name,sizeof(vs->name));
return 0;
}
/* ----------------------------------------------------------------- */
/* priority handling */
#define V4L2_PRIO_VALID(val) (val == V4L2_PRIORITY_BACKGROUND || \
val == V4L2_PRIORITY_INTERACTIVE || \
val == V4L2_PRIORITY_RECORD)
int v4l2_prio_init(struct v4l2_prio_state *global)
{
memset(global,0,sizeof(*global));
return 0;
}
int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
enum v4l2_priority new)
{
if (!V4L2_PRIO_VALID(new))
return -EINVAL;
if (*local == new)
return 0;
atomic_inc(&global->prios[new]);
if (V4L2_PRIO_VALID(*local))
atomic_dec(&global->prios[*local]);
*local = new;
return 0;
}
int v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
{
return v4l2_prio_change(global,local,V4L2_PRIORITY_DEFAULT);
}
int v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority *local)
{
if (V4L2_PRIO_VALID(*local))
atomic_dec(&global->prios[*local]);
return 0;
}
enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global)
{
if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0)
return V4L2_PRIORITY_RECORD;
if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0)
return V4L2_PRIORITY_INTERACTIVE;
if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0)
return V4L2_PRIORITY_BACKGROUND;
return V4L2_PRIORITY_UNSET;
}
int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority *local)
{
if (*local < v4l2_prio_max(global))
return -EBUSY;
return 0;
}
/* ----------------------------------------------------------------- */
/* some arrays for pretty-printing debug messages */
char *v4l2_field_names[] = {
[V4L2_FIELD_ANY] = "any",
[V4L2_FIELD_NONE] = "none",
[V4L2_FIELD_TOP] = "top",
[V4L2_FIELD_BOTTOM] = "bottom",
[V4L2_FIELD_INTERLACED] = "interlaced",
[V4L2_FIELD_SEQ_TB] = "seq-tb",
[V4L2_FIELD_SEQ_BT] = "seq-bt",
[V4L2_FIELD_ALTERNATE] = "alternate",
};
char *v4l2_type_names[] = {
[V4L2_BUF_TYPE_VIDEO_CAPTURE] = "video-cap",
[V4L2_BUF_TYPE_VIDEO_OVERLAY] = "video-over",
[V4L2_BUF_TYPE_VIDEO_OUTPUT] = "video-out",
[V4L2_BUF_TYPE_VBI_CAPTURE] = "vbi-cap",
[V4L2_BUF_TYPE_VBI_OUTPUT] = "vbi-out",
};
char *v4l2_ioctl_names[256] = {
#if __GNUC__ >= 3
[0 ... 255] = "UNKNOWN",
#endif
[_IOC_NR(VIDIOC_QUERYCAP)] = "VIDIOC_QUERYCAP",
[_IOC_NR(VIDIOC_RESERVED)] = "VIDIOC_RESERVED",
[_IOC_NR(VIDIOC_ENUM_FMT)] = "VIDIOC_ENUM_FMT",
[_IOC_NR(VIDIOC_G_FMT)] = "VIDIOC_G_FMT",
[_IOC_NR(VIDIOC_S_FMT)] = "VIDIOC_S_FMT",
#if 0
[_IOC_NR(VIDIOC_G_COMP)] = "VIDIOC_G_COMP",
[_IOC_NR(VIDIOC_S_COMP)] = "VIDIOC_S_COMP",
#endif
[_IOC_NR(VIDIOC_REQBUFS)] = "VIDIOC_REQBUFS",
[_IOC_NR(VIDIOC_QUERYBUF)] = "VIDIOC_QUERYBUF",
[_IOC_NR(VIDIOC_G_FBUF)] = "VIDIOC_G_FBUF",
[_IOC_NR(VIDIOC_S_FBUF)] = "VIDIOC_S_FBUF",
[_IOC_NR(VIDIOC_OVERLAY)] = "VIDIOC_OVERLAY",
[_IOC_NR(VIDIOC_QBUF)] = "VIDIOC_QBUF",
[_IOC_NR(VIDIOC_DQBUF)] = "VIDIOC_DQBUF",
[_IOC_NR(VIDIOC_STREAMON)] = "VIDIOC_STREAMON",
[_IOC_NR(VIDIOC_STREAMOFF)] = "VIDIOC_STREAMOFF",
[_IOC_NR(VIDIOC_G_PARM)] = "VIDIOC_G_PARM",
[_IOC_NR(VIDIOC_S_PARM)] = "VIDIOC_S_PARM",
[_IOC_NR(VIDIOC_G_STD)] = "VIDIOC_G_STD",
[_IOC_NR(VIDIOC_S_STD)] = "VIDIOC_S_STD",
[_IOC_NR(VIDIOC_ENUMSTD)] = "VIDIOC_ENUMSTD",
[_IOC_NR(VIDIOC_ENUMINPUT)] = "VIDIOC_ENUMINPUT",
[_IOC_NR(VIDIOC_G_CTRL)] = "VIDIOC_G_CTRL",
[_IOC_NR(VIDIOC_S_CTRL)] = "VIDIOC_S_CTRL",
[_IOC_NR(VIDIOC_G_TUNER)] = "VIDIOC_G_TUNER",
[_IOC_NR(VIDIOC_S_TUNER)] = "VIDIOC_S_TUNER",
[_IOC_NR(VIDIOC_G_AUDIO)] = "VIDIOC_G_AUDIO",
[_IOC_NR(VIDIOC_S_AUDIO)] = "VIDIOC_S_AUDIO",
[_IOC_NR(VIDIOC_QUERYCTRL)] = "VIDIOC_QUERYCTRL",
[_IOC_NR(VIDIOC_QUERYMENU)] = "VIDIOC_QUERYMENU",
[_IOC_NR(VIDIOC_G_INPUT)] = "VIDIOC_G_INPUT",
[_IOC_NR(VIDIOC_S_INPUT)] = "VIDIOC_S_INPUT",
[_IOC_NR(VIDIOC_G_OUTPUT)] = "VIDIOC_G_OUTPUT",
[_IOC_NR(VIDIOC_S_OUTPUT)] = "VIDIOC_S_OUTPUT",
[_IOC_NR(VIDIOC_ENUMOUTPUT)] = "VIDIOC_ENUMOUTPUT",
[_IOC_NR(VIDIOC_G_AUDOUT)] = "VIDIOC_G_AUDOUT",
[_IOC_NR(VIDIOC_S_AUDOUT)] = "VIDIOC_S_AUDOUT",
[_IOC_NR(VIDIOC_G_MODULATOR)] = "VIDIOC_G_MODULATOR",
[_IOC_NR(VIDIOC_S_MODULATOR)] = "VIDIOC_S_MODULATOR",
[_IOC_NR(VIDIOC_G_FREQUENCY)] = "VIDIOC_G_FREQUENCY",
[_IOC_NR(VIDIOC_S_FREQUENCY)] = "VIDIOC_S_FREQUENCY",
[_IOC_NR(VIDIOC_CROPCAP)] = "VIDIOC_CROPCAP",
[_IOC_NR(VIDIOC_G_CROP)] = "VIDIOC_G_CROP",
[_IOC_NR(VIDIOC_S_CROP)] = "VIDIOC_S_CROP",
[_IOC_NR(VIDIOC_G_JPEGCOMP)] = "VIDIOC_G_JPEGCOMP",
[_IOC_NR(VIDIOC_S_JPEGCOMP)] = "VIDIOC_S_JPEGCOMP",
[_IOC_NR(VIDIOC_QUERYSTD)] = "VIDIOC_QUERYSTD",
[_IOC_NR(VIDIOC_TRY_FMT)] = "VIDIOC_TRY_FMT",
};
/* ----------------------------------------------------------------- */
EXPORT_SYMBOL(v4l2_video_std_construct);
EXPORT_SYMBOL(v4l2_prio_init);
EXPORT_SYMBOL(v4l2_prio_change);
EXPORT_SYMBOL(v4l2_prio_open);
EXPORT_SYMBOL(v4l2_prio_close);
EXPORT_SYMBOL(v4l2_prio_max);
EXPORT_SYMBOL(v4l2_prio_check);
EXPORT_SYMBOL(v4l2_field_names);
EXPORT_SYMBOL(v4l2_type_names);
EXPORT_SYMBOL(v4l2_ioctl_names);
/*
* Local variables:
* c-basic-offset: 8
* End:
*/
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