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>
#define __OLD_VIDIOC_ /* To allow fixing old calls*/
#include <media/v4l2-common.h>
#include <media/v4l2-chip-ident.h>

#include <linux/kmod.h>

#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)
 */


/* ----------------------------------------------------------------- */
/* 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;
}
EXPORT_SYMBOL(v4l2_prio_init);

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;
}
EXPORT_SYMBOL(v4l2_prio_change);

int v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local)
{
	return v4l2_prio_change(global,local,V4L2_PRIORITY_DEFAULT);
}
EXPORT_SYMBOL(v4l2_prio_open);

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;
}
EXPORT_SYMBOL(v4l2_prio_close);

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;
}
EXPORT_SYMBOL(v4l2_prio_max);

int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority *local)
{
	if (*local < v4l2_prio_max(global))
		return -EBUSY;
	return 0;
}
EXPORT_SYMBOL(v4l2_prio_check);

/* ----------------------------------------------------------------- */

/* Helper functions for control handling			     */

/* Check for correctness of the ctrl's value based on the data from
   struct v4l2_queryctrl and the available menu items. Note that
   menu_items may be NULL, in that case it is ignored. */
int v4l2_ctrl_check(struct v4l2_ext_control *ctrl, struct v4l2_queryctrl *qctrl,
		const char **menu_items)
{
	if (qctrl->flags & V4L2_CTRL_FLAG_DISABLED)
		return -EINVAL;
	if (qctrl->flags & V4L2_CTRL_FLAG_GRABBED)
		return -EBUSY;
	if (qctrl->type == V4L2_CTRL_TYPE_BUTTON ||
	    qctrl->type == V4L2_CTRL_TYPE_INTEGER64 ||
	    qctrl->type == V4L2_CTRL_TYPE_CTRL_CLASS)
		return 0;
	if (ctrl->value < qctrl->minimum || ctrl->value > qctrl->maximum)
		return -ERANGE;
	if (qctrl->type == V4L2_CTRL_TYPE_MENU && menu_items != NULL) {
		if (menu_items[ctrl->value] == NULL ||
		    menu_items[ctrl->value][0] == '\0')
			return -EINVAL;
	}
	return 0;
}
EXPORT_SYMBOL(v4l2_ctrl_check);

/* Returns NULL or a character pointer array containing the menu for
   the given control ID. The pointer array ends with a NULL pointer.
   An empty string signifies a menu entry that is invalid. This allows
   drivers to disable certain options if it is not supported. */
const char **v4l2_ctrl_get_menu(u32 id)
{
	static const char *mpeg_audio_sampling_freq[] = {
		"44.1 kHz",
		"48 kHz",
		"32 kHz",
		NULL
	};
	static const char *mpeg_audio_encoding[] = {
		"Layer I",
		"Layer II",
		"Layer III",
		NULL
	};
	static const char *mpeg_audio_l1_bitrate[] = {
		"32 kbps",
		"64 kbps",
		"96 kbps",
		"128 kbps",
		"160 kbps",
		"192 kbps",
		"224 kbps",
		"256 kbps",
		"288 kbps",
		"320 kbps",
		"352 kbps",
		"384 kbps",
		"416 kbps",
		"448 kbps",
		NULL
	};
	static const char *mpeg_audio_l2_bitrate[] = {
		"32 kbps",
		"48 kbps",
		"56 kbps",
		"64 kbps",
		"80 kbps",
		"96 kbps",
		"112 kbps",
		"128 kbps",
		"160 kbps",
		"192 kbps",
		"224 kbps",
		"256 kbps",
		"320 kbps",
		"384 kbps",
		NULL
	};
	static const char *mpeg_audio_l3_bitrate[] = {
		"32 kbps",
		"40 kbps",
		"48 kbps",
		"56 kbps",
		"64 kbps",
		"80 kbps",
		"96 kbps",
		"112 kbps",
		"128 kbps",
		"160 kbps",
		"192 kbps",
		"224 kbps",
		"256 kbps",
		"320 kbps",
		NULL
	};
	static const char *mpeg_audio_mode[] = {
		"Stereo",
		"Joint Stereo",
		"Dual",
		"Mono",
		NULL
	};
	static const char *mpeg_audio_mode_extension[] = {
		"Bound 4",
		"Bound 8",
		"Bound 12",
		"Bound 16",
		NULL
	};
	static const char *mpeg_audio_emphasis[] = {
		"No Emphasis",
		"50/15 us",
		"CCITT J17",
		NULL
	};
	static const char *mpeg_audio_crc[] = {
		"No CRC",
		"16-bit CRC",
		NULL
	};
	static const char *mpeg_video_encoding[] = {
		"MPEG-1",
		"MPEG-2",
		NULL
	};
	static const char *mpeg_video_aspect[] = {
		"1x1",
		"4x3",
		"16x9",
		"2.21x1",
		NULL
	};
	static const char *mpeg_video_bitrate_mode[] = {
		"Variable Bitrate",
		"Constant Bitrate",
		NULL
	};
	static const char *mpeg_stream_type[] = {
		"MPEG-2 Program Stream",
		"MPEG-2 Transport Stream",
		"MPEG-1 System Stream",
		"MPEG-2 DVD-compatible Stream",
		"MPEG-1 VCD-compatible Stream",
		"MPEG-2 SVCD-compatible Stream",
		NULL
	};
	static const char *mpeg_stream_vbi_fmt[] = {
		"No VBI",
		"Private packet, IVTV format",
		NULL
	};

	switch (id) {
		case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
			return mpeg_audio_sampling_freq;
		case V4L2_CID_MPEG_AUDIO_ENCODING:
			return mpeg_audio_encoding;
		case V4L2_CID_MPEG_AUDIO_L1_BITRATE:
			return mpeg_audio_l1_bitrate;
		case V4L2_CID_MPEG_AUDIO_L2_BITRATE:
			return mpeg_audio_l2_bitrate;
		case V4L2_CID_MPEG_AUDIO_L3_BITRATE:
			return mpeg_audio_l3_bitrate;
		case V4L2_CID_MPEG_AUDIO_MODE:
			return mpeg_audio_mode;
		case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION:
			return mpeg_audio_mode_extension;
		case V4L2_CID_MPEG_AUDIO_EMPHASIS:
			return mpeg_audio_emphasis;
		case V4L2_CID_MPEG_AUDIO_CRC:
			return mpeg_audio_crc;
		case V4L2_CID_MPEG_VIDEO_ENCODING:
			return mpeg_video_encoding;
		case V4L2_CID_MPEG_VIDEO_ASPECT:
			return mpeg_video_aspect;
		case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
			return mpeg_video_bitrate_mode;
		case V4L2_CID_MPEG_STREAM_TYPE:
			return mpeg_stream_type;
		case V4L2_CID_MPEG_STREAM_VBI_FMT:
			return mpeg_stream_vbi_fmt;
		default:
			return NULL;
	}
}
EXPORT_SYMBOL(v4l2_ctrl_get_menu);

/* Fill in a struct v4l2_queryctrl */
int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 min, s32 max, s32 step, s32 def)
{
	const char *name;

	qctrl->flags = 0;
	switch (qctrl->id) {
	/* USER controls */
	case V4L2_CID_USER_CLASS: 	name = "User Controls"; break;
	case V4L2_CID_AUDIO_VOLUME: 	name = "Volume"; break;
	case V4L2_CID_AUDIO_MUTE: 	name = "Mute"; break;
	case V4L2_CID_AUDIO_BALANCE: 	name = "Balance"; break;
	case V4L2_CID_AUDIO_BASS: 	name = "Bass"; break;
	case V4L2_CID_AUDIO_TREBLE: 	name = "Treble"; break;
	case V4L2_CID_AUDIO_LOUDNESS: 	name = "Loudness"; break;
	case V4L2_CID_BRIGHTNESS: 	name = "Brightness"; break;
	case V4L2_CID_CONTRAST: 	name = "Contrast"; break;
	case V4L2_CID_SATURATION: 	name = "Saturation"; break;
	case V4L2_CID_HUE: 		name = "Hue"; break;

	/* MPEG controls */
	case V4L2_CID_MPEG_CLASS: 		name = "MPEG Encoder Controls"; break;
	case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ: name = "Audio Sampling Frequency"; break;
	case V4L2_CID_MPEG_AUDIO_ENCODING: 	name = "Audio Encoding Layer"; break;
	case V4L2_CID_MPEG_AUDIO_L1_BITRATE: 	name = "Audio Layer I Bitrate"; break;
	case V4L2_CID_MPEG_AUDIO_L2_BITRATE: 	name = "Audio Layer II Bitrate"; break;
	case V4L2_CID_MPEG_AUDIO_L3_BITRATE: 	name = "Audio Layer III Bitrate"; break;
	case V4L2_CID_MPEG_AUDIO_MODE: 		name = "Audio Stereo Mode"; break;
	case V4L2_CID_MPEG_AUDIO_MODE_EXTENSION: name = "Audio Stereo Mode Extension"; break;
	case V4L2_CID_MPEG_AUDIO_EMPHASIS: 	name = "Audio Emphasis"; break;
	case V4L2_CID_MPEG_AUDIO_CRC: 		name = "Audio CRC"; break;
	case V4L2_CID_MPEG_AUDIO_MUTE: 		name = "Audio Mute"; break;