fbmon.c

Linux环境下视频显示卡设备的驱动程序源代码

/*
 * linux/drivers/video/fbmon.c
 *
 * Copyright (C) 2002 James Simmons <[e-mail]>
 *
 * 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 <[e-mail]>
 *
 *   3. John Fremlin <[e-mail]> and
 *      Ani Joshi <[e-mail]>
 *
 * 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 <video/edid.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(unsigned char *edid, int fix)
{
	int i;
	unsigned char *b, csum = 0;

	switch (fix) {
	case FBMON_FIX_HEADER:
		printk("fbmon: trying a header reconstruct\n");
		memcpy(edid, edid_v1_header, 8);
		break;
	case FBMON_FIX_INPUT:
		printk("fbmon: trying to fix input type\n");
		b = edid + EDID_STRUCT_DISPLAY;
		b[0] &= ~0x80;
		edid[127] += 0x80;
		break;
	case FBMON_FIX_TIMINGS:
		printk("fbmon: trying to fix monitor timings\n");
		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
		for (i = 0; i < 4; i++) {
			if (!(edid_is_serial_block(b) ||
			      edid_is_ascii_block(b) ||
			      edid_is_monitor_block(b) ||
			      edid_is_timing_block(b))) {
				b[0] = 0x00;
				b[1] = 0x00;
				b[2] = 0x00;
				b[3] = 0xfd;
				b[4] = 0x00;
				b[5] = 60;   /* vfmin */
				b[6] = 60;   /* vfmax */
				b[7] = 30;   /* hfmin */
				b[8] = 75;   /* hfmax */
				b[9] = 17;   /* pixclock - 170 MHz*/
				b[10] = 0;   /* GTF */
				break;
			}

			b += DETAILED_TIMING_DESCRIPTION_SIZE;
		}

		for (i = 0; i < EDID_LENGTH - 1; i++)
			csum += edid[i];

		edid[127] = 256 - csum;
		break;
	}
}

static int edid_checksum(unsigned char *edid)
{
	unsigned char i, csum = 0, all_null = 0;
	int err = 0, fix = check_edid(edid);

	if (fix)
		fix_edid(edid, fix);

	for (i = 0; i < EDID_LENGTH; i++) {
		csum += edid[i];
		all_null |= edid[i];
	}

	if (csum == 0x00 && all_null) {
		/* checksum passed, everything's good */
		err = 1;
	}

	return err;
}

static int edid_check_header(unsigned char *edid)
{
	int i, err = 1, fix = check_edid(edid);

	if (fix)
		fix_edid(edid, fix);

	for (i = 0; i < 8; i++) {
		if (edid[i] != edid_v1_header[i])
			err = 0;
	}

	return err;
}

static void parse_vendor_block(unsigned char *block, struct fb_monspecs *specs)
{
	specs->manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
	specs->manufacturer[1] = ((block[0] & 0x03) << 3) +
		((block[1] & 0xe0) >> 5) + '@';
	specs->manufacturer[2] = (block[1] & 0x1f) + '@';
	specs->manufacturer[3] = 0;
	specs->model = block[2] + (block[3] << 8);
	specs->serial = block[4] + (block[5] << 8) +
	       (block[6] << 16) + (block[7] << 24);
	specs->year = block[9] + 1990;
	specs->week = block[8];
	DPRINTK("   Manufacturer: %s\n", specs->manufacturer);
	DPRINTK("   Model: %x\n", specs->model);
	DPRINTK("   Serial#: %u\n", specs->serial);
	DPRINTK("   Year: %u Week %u\n", specs->year, specs->week);
}

static void get_dpms_capabilities(unsigned char flags,
				  struct fb_monspecs *specs)
{
	specs->dpms = 0;
	if (flags & DPMS_ACTIVE_OFF)
		specs->dpms |= FB_DPMS_ACTIVE_OFF;
	if (flags & DPMS_SUSPEND)
		specs->dpms |= FB_DPMS_SUSPEND;
	if (flags & DPMS_STANDBY)
		specs->dpms |= FB_DPMS_STANDBY;
	DPRINTK("      DPMS: Active %s, Suspend %s, Standby %s\n",
	       (flags & DPMS_ACTIVE_OFF) ? "yes" : "no",
	       (flags & DPMS_SUSPEND)    ? "yes" : "no",
	       (flags & DPMS_STANDBY)    ? "yes" : "no");
}

static void get_chroma(unsigned char *block, struct fb_monspecs *specs)
{
	int tmp;

	DPRINTK("      Chroma\n");
	/* Chromaticity data */
	tmp = ((block[5] & (3 << 6)) >> 6) | (block[0x7] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.redx = tmp/1024;
	DPRINTK("         RedX:     0.%03d ", specs->chroma.redx);

	tmp = ((block[5] & (3 << 4)) >> 4) | (block[0x8] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.redy = tmp/1024;
	DPRINTK("RedY:     0.%03d\n", specs->chroma.redy);

	tmp = ((block[5] & (3 << 2)) >> 2) | (block[0x9] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.greenx = tmp/1024;
	DPRINTK("         GreenX:   0.%03d ", specs->chroma.greenx);

	tmp = (block[5] & 3) | (block[0xa] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.greeny = tmp/1024;
	DPRINTK("GreenY:   0.%03d\n", specs->chroma.greeny);

	tmp = ((block[6] & (3 << 6)) >> 6) | (block[0xb] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.bluex = tmp/1024;
	DPRINTK("         BlueX:    0.%03d ", specs->chroma.bluex);

	tmp = ((block[6] & (3 << 4)) >> 4) | (block[0xc] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.bluey = tmp/1024;
	DPRINTK("BlueY:    0.%03d\n", specs->chroma.bluey);

	tmp = ((block[6] & (3 << 2)) >> 2) | (block[0xd] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.whitex = tmp/1024;
	DPRINTK("         WhiteX:   0.%03d ", specs->chroma.whitex);

	tmp = (block[6] & 3) | (block[0xe] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.whitey = tmp/1024;
	DPRINTK("WhiteY:   0.%03d\n", specs->chroma.whitey);
}

static void calc_mode_timings(int xres, int yres, int refresh,
			      struct fb_videomode *mode)
{
	struct fb_var_screeninfo *var;

	var = kzalloc(sizeof(struct fb_var_screeninfo), GFP_KERNEL);

	if (var) {
		var->xres = xres;
		var->yres = yres;
		fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON,
			    refresh, var, NULL);
		mode->xres = xres;
		mode->yres = yres;
		mode->pixclock = var->pixclock;
		mode->refresh = refresh;
		mode->left_margin = var->left_margin;
		mode->right_margin = var->right_margin;
		mode->upper_margin = var->upper_margin;
		mode->lower_margin = var->lower_margin;
		mode->hsync_len = var->hsync_len;
		mode->vsync_len = var->vsync_len;
		mode->vmode = 0;
		mode->sync = 0;
		kfree(var);
	}
}

static int get_est_timing(unsigned char *block, struct fb_videomode *mode)
{
	int num = 0;
	unsigned char c;

	c = block[0];
	if (c&0x80) {
		calc_mode_timings(720, 400, 70, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      720x400@70Hz\n");
	}
	if (c&0x40) {
		calc_mode_timings(720, 400, 88, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      720x400@88Hz\n");
	}
	if (c&0x20) {
		mode[num++] = vesa_modes[3];
		DPRINTK("      640x480@60Hz\n");
	}
	if (c&0x10) {
		calc_mode_timings(640, 480, 67, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      640x480@67Hz\n");
	}
	if (c&0x08) {
		mode[num++] = vesa_modes[4];
		DPRINTK("      640x480@72Hz\n");
	}
	if (c&0x04) {
		mode[num++] = vesa_modes[5];
		DPRINTK("      640x480@75Hz\n");
	}
	if (c&0x02) {
		mode[num++] = vesa_modes[7];
		DPRINTK("      800x600@56Hz\n");
	}
	if (c&0x01) {
		mode[num++] = vesa_modes[8];
		DPRINTK("      800x600@60Hz\n");
	}

	c = block[1];
	if (c&0x80) {
		mode[num++] = vesa_modes[9];
		DPRINTK("      800x600@72Hz\n");
	}
	if (c&0x40) {
		mode[num++] = vesa_modes[10];
		DPRINTK("      800x600@75Hz\n");
	}
	if (c&0x20) {
		calc_mode_timings(832, 624, 75, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      832x624@75Hz\n");
	}
	if (c&0x10) {
		mode[num++] = vesa_modes[12];