v4l2-common.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 <[e-mail]>
 *		based on code by Alan Cox, <[e-mail]>
 *
 */

/*
 * 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, <[e-mail]>
 *
 * Fixes:
 */

/*
 * Video4linux 1/2 integration by Justin Schoeman
 * <[e-mail]>
 * 2.4 PROCFS support ported from 2.4 kernels by
 *  Iñaki García Etxebarria <[e-mail]>
 * Makefile fix by "W. Michael Petullo" <[e-mail]>
 * 2.4 devfs support ported from 2.4 kernels by
 *  Dan Merillat <[e-mail]>
 * Added Gerd Knorrs v4l1 enhancements (Justin Schoeman)
 */

#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/i2c.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/div64.h>
#include <linux/video_decoder.h>
#define __OLD_VIDIOC_ /* To allow fixing old calls*/
#include <media/v4l2-common.h>
#include <media/v4l2-chip-ident.h>

#ifdef CONFIG_KMOD
#include <linux/kmod.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)
 */


char *v4l2_norm_to_name(v4l2_std_id id)
{
	char *name;
	u32 myid = id;

	/* HACK: ppc32 architecture doesn't have __ucmpdi2 function to handle
	   64 bit comparations. So, on that architecture, with some gcc variants,
	   compilation fails. Currently, the max value is 30bit wide.
	 */
	BUG_ON(myid != id);

	switch (myid) {
	case V4L2_STD_PAL:
		name="PAL";		break;
	case V4L2_STD_PAL_BG:
		name="PAL-BG";		break;
	case V4L2_STD_PAL_DK:
		name="PAL-DK";		break;
	case V4L2_STD_PAL_B:
		name="PAL-B";		break;
	case V4L2_STD_PAL_B1:
		name="PAL-B1";		break;
	case V4L2_STD_PAL_G:
		name="PAL-G";		break;
	case V4L2_STD_PAL_H:
		name="PAL-H";		break;
	case V4L2_STD_PAL_I:
		name="PAL-I";		break;
	case V4L2_STD_PAL_D:
		name="PAL-D";		break;
	case V4L2_STD_PAL_D1:
		name="PAL-D1";		break;
	case V4L2_STD_PAL_K:
		name="PAL-K";		break;
	case V4L2_STD_PAL_M:
		name="PAL-M";		break;
	case V4L2_STD_PAL_N:
		name="PAL-N";		break;
	case V4L2_STD_PAL_Nc:
		name="PAL-Nc";		break;
	case V4L2_STD_PAL_60:
		name="PAL-60";		break;
	case V4L2_STD_NTSC:
		name="NTSC";		break;
	case V4L2_STD_NTSC_M:
		name="NTSC-M";		break;
	case V4L2_STD_NTSC_M_JP:
		name="NTSC-M-JP";	break;
	case V4L2_STD_NTSC_443:
		name="NTSC-443";	break;
	case V4L2_STD_NTSC_M_KR:
		name="NTSC-M-KR";	break;
	case V4L2_STD_SECAM:
		name="SECAM";		break;
	case V4L2_STD_SECAM_DK:
		name="SECAM-DK";	break;
	case V4L2_STD_SECAM_B:
		name="SECAM-B";		break;
	case V4L2_STD_SECAM_D:
		name="SECAM-D";		break;
	case V4L2_STD_SECAM_G:
		name="SECAM-G";		break;
	case V4L2_STD_SECAM_H:
		name="SECAM-H";		break;
	case V4L2_STD_SECAM_K:
		name="SECAM-K";		break;
	case V4L2_STD_SECAM_K1:
		name="SECAM-K1";	break;
	case V4L2_STD_SECAM_L:
		name="SECAM-L";		break;
	case V4L2_STD_SECAM_LC:
		name="SECAM-LC";	break;
	default:
		name="Unknown";		break;
	}

	return name;
}

/* 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_525_60) {
		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 of enum types      */

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",
	[V4L2_FIELD_INTERLACED_TB] = "interlaced-tb",
	[V4L2_FIELD_INTERLACED_BT] = "interlaced-bt",
};

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",
	[V4L2_BUF_TYPE_SLICED_VBI_CAPTURE] = "sliced-vbi-cap",
	[V4L2_BUF_TYPE_SLICED_VBI_OUTPUT]  = "sliced-vbi-out",
	[V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY] = "video-out-over",
};


#define prt_names(a,arr) (((a)>=0)&&((a)<ARRAY_SIZE(arr)))?arr[a]:"unknown"

/* ------------------------------------------------------------------ */
/* debug help functions                                               */

#ifdef CONFIG_VIDEO_V4L1_COMPAT
static const char *v4l1_ioctls[] = {
	[_IOC_NR(VIDIOCGCAP)]       = "VIDIOCGCAP",
	[_IOC_NR(VIDIOCGCHAN)]      = "VIDIOCGCHAN",
	[_IOC_NR(VIDIOCSCHAN)]      = "VIDIOCSCHAN",
	[_IOC_NR(VIDIOCGTUNER)]     = "VIDIOCGTUNER",
	[_IOC_NR(VIDIOCSTUNER)]     = "VIDIOCSTUNER",
	[_IOC_NR(VIDIOCGPICT)]      = "VIDIOCGPICT",
	[_IOC_NR(VIDIOCSPICT)]      = "VIDIOCSPICT",
	[_IOC_NR(VIDIOCCAPTURE)]    = "VIDIOCCAPTURE",
	[_IOC_NR(VIDIOCGWIN)]       = "VIDIOCGWIN",
	[_IOC_NR(VIDIOCSWIN)]       = "VIDIOCSWIN",
	[_IOC_NR(VIDIOCGFBUF)]      = "VIDIOCGFBUF",
	[_IOC_NR(VIDIOCSFBUF)]      = "VIDIOCSFBUF",
	[_IOC_NR(VIDIOCKEY)]        = "VIDIOCKEY",
	[_IOC_NR(VIDIOCGFREQ)]      = "VIDIOCGFREQ",
	[_IOC_NR(VIDIOCSFREQ)]      = "VIDIOCSFREQ",
	[_IOC_NR(VIDIOCGAUDIO)]     = "VIDIOCGAUDIO",
	[_IOC_NR(VIDIOCSAUDIO)]     = "VIDIOCSAUDIO",
	[_IOC_NR(VIDIOCSYNC)]       = "VIDIOCSYNC",
	[_IOC_NR(VIDIOCMCAPTURE)]   = "VIDIOCMCAPTURE",
	[_IOC_NR(VIDIOCGMBUF)]      = "VIDIOCGMBUF",
	[_IOC_NR(VIDIOCGUNIT)]      = "VIDIOCGUNIT",
	[_IOC_NR(VIDIOCGCAPTURE)]   = "VIDIOCGCAPTURE",
	[_IOC_NR(VIDIOCSCAPTURE)]   = "VIDIOCSCAPTURE",
	[_IOC_NR(VIDIOCSPLAYMODE)]  = "VIDIOCSPLAYMODE",
	[_IOC_NR(VIDIOCSWRITEMODE)] = "VIDIOCSWRITEMODE",
	[_IOC_NR(VIDIOCGPLAYINFO)]  = "VIDIOCGPLAYINFO",
	[_IOC_NR(VIDIOCSMICROCODE)] = "VIDIOCSMICROCODE",
	[_IOC_NR(VIDIOCGVBIFMT)]    = "VIDIOCGVBIFMT",
	[_IOC_NR(VIDIOCSVBIFMT)]    = "VIDIOCSVBIFMT"
};
#define V4L1_IOCTLS ARRAY_SIZE(v4l1_ioctls)
#endif

static const char *v4l2_ioctls[] = {
	[_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",
	[_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",