path: root/drivers/video/fbdev/core/fbmon.c

/*
 * linux/drivers/video/fbmon.c
 *
 * Copyright (C) 2002 James Simmons <jsimmons@users.sf.net>
 *
 * Credits:
 *
 * The EDID Parser is a conglomeration from the following sources:
 *
 *   1. SciTech SNAP Graphics Architecture
 *      Copyright (C) 1991-2002 SciTech Software, Inc. All rights reserved.
 *
 *   2. XFree86 4.3.0, interpret_edid.c
 *      Copyright 1998 by Egbert Eich <Egbert.Eich@Physik.TU-Darmstadt.DE>
 *
 *   3. John Fremlin <vii@users.sourceforge.net> and
 *      Ani Joshi <ajoshi@unixbox.com>
 *
 * Generalized Timing Formula is derived from:
 *
 *      GTF Spreadsheet by Andy Morrish (1/5/97)
 *      available at http://www.vesa.org
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 */
#include <linux/fb.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <video/edid.h>
#include <video/of_videomode.h>
#include <video/videomode.h>
#ifdef CONFIG_PPC_OF
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#endif
#include "../edid.h"

/*
 * EDID parser
 */

#undef DEBUG  /* define this for verbose EDID parsing output */

#ifdef DEBUG
#define DPRINTK(fmt, args...) printk(fmt,## args)
#else
#define DPRINTK(fmt, args...)
#endif

#define FBMON_FIX_HEADER  1
#define FBMON_FIX_INPUT   2
#define FBMON_FIX_TIMINGS 3

#ifdef CONFIG_FB_MODE_HELPERS
struct broken_edid {
	u8  manufacturer[4];
	u32 model;
	u32 fix;
};

static const struct broken_edid brokendb[] = {
	/* DEC FR-PCXAV-YZ */
	{
		.manufacturer = "DEC",
		.model        = 0x073a,
		.fix          = FBMON_FIX_HEADER,
	},
	/* ViewSonic PF775a */
	{
		.manufacturer = "VSC",
		.model        = 0x5a44,
		.fix          = FBMON_FIX_INPUT,
	},
	/* Sharp UXGA? */
	{
		.manufacturer = "SHP",
		.model        = 0x138e,
		.fix          = FBMON_FIX_TIMINGS,
	},
};

static const unsigned char edid_v1_header[] = { 0x00, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0x00
};

static void copy_string(unsigned char *c, unsigned char *s)
{
  int i;
  c = c + 5;
  for (i = 0; (i < 13 && *c != 0x0A); i++)
    *(s++) = *(c++);
  *s = 0;
  while (i-- && (*--s == 0x20)) *s = 0;
}

static int edid_is_serial_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xff) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_ascii_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xfe) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_limits_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xfd) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_monitor_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xfc) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_timing_block(unsigned char *block)
{
	if ((block[0] != 0x00) || (block[1] != 0x00) ||
	    (block[2] != 0x00) || (block[4] != 0x00))
		return 1;
	else
		return 0;
}

static int check_edid(unsigned char *edid)
{
	unsigned char *block = edid + ID_MANUFACTURER_NAME, manufacturer[4];
	unsigned char *b;
	u32 model;
	int i, fix = 0, ret = 0;

	manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
	manufacturer[1] = ((block[0] & 0x03) << 3) +
		((block[1] & 0xe0) >> 5) + '@';
	manufacturer[2] = (block[1] & 0x1f) + '@';
	manufacturer[3] = 0;
	model = block[2] + (block[3] << 8);

	for (i = 0; i < ARRAY_SIZE(brokendb); i++) {
		if (!strncmp(manufacturer, brokendb[i].manufacturer, 4) &&
			brokendb[i].model == model) {
			fix = brokendb[i].fix;
			break;
		}
	}

	switch (fix) {
	case FBMON_FIX_HEADER:
		for (i = 0; i < 8; i++) {
			if (edid[i] != edid_v1_header[i]) {
				ret = fix;
				break;
			}
		}
		break;
	case FBMON_FIX_INPUT:
		b = edid + EDID_STRUCT_DISPLAY;
		/* Only if display is GTF capable will
		   the input type be reset to analog */
		if (b[4] & 0x01 && b[0] & 0x80)
			ret = fix;
		break;
	case FBMON_FIX_TIMINGS:
		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
		ret = fix;

		for (i = 0; i < 4; i++) {
			if (edid_is_limits_block(b)) {
				ret = 0;
				break;
			}

			b += DETAILED_TIMING_DESCRIPTION_SIZE;
		}

		break;
	}

	if (ret)
		printk("fbmon: The EDID Block of "
		       "Manufacturer: %s Model: 0x%x is known to "
		       "be broken,\n",  manufacturer, model);

	return ret;
}

static void fix_edid(unsigne