ClabureDB: Classified Bug-Reports Database

   /*
    * 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 <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];
                 DPRINTK("      1024x768@87Hz Interlaced\n");
         }
         if (c&0x08) {
                 mode[num++] = vesa_modes[13];
                 DPRINTK("      1024x768@60Hz\n");
         }
         if (c&0x04) {
                 mode[num++] = vesa_modes[14];
                 DPRINTK("      1024x768@70Hz\n");
         }
         if (c&0x02) {
                 mode[num++] = vesa_modes[15];
                 DPRINTK("      1024x768@75Hz\n");
         }
         if (c&0x01) {
                 mode[num++] = vesa_modes[21];
                 DPRINTK("      1280x1024@75Hz\n");
         }
         c = block[2];
         if (c&0x80) {
                 mode[num++] = vesa_modes[17];
                 DPRINTK("      1152x870@75Hz\n");
         }
         DPRINTK("      Manufacturer's mask: %x\n",c&0x7F);
         return num;
 }
 
 static int get_std_timing(unsigned char *block, struct fb_videomode *mode)
 {
         int xres, yres = 0, refresh, ratio, i;
 
         xres = (block[0] + 31) * 8;
         if (xres <= 256)
                 return 0;
 
         ratio = (block[1] & 0xc0) >> 6;
         switch (ratio) {
         case 0:
                 yres = xres;
                 break;
         case 1:
                 yres = (xres * 3)/4;
                 break;
         case 2:
                 yres = (xres * 4)/5;
                 break;
         case 3:
                 yres = (xres * 9)/16;
                 break;
         }
         refresh = (block[1] & 0x3f) + 60;
 
         DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
         for (i = 0; i < VESA_MODEDB_SIZE; i++) {
                 if (vesa_modes[i].xres == xres &&
                     vesa_modes[i].yres == yres &&
                     vesa_modes[i].refresh == refresh) {
                         *mode = vesa_modes[i];
                         mode->flag |= FB_MODE_IS_STANDARD;
                         return 1;
                 }
         }
         calc_mode_timings(xres, yres, refresh, mode);
         return 1;
 }
 
 static int get_dst_timing(unsigned char *block,
                           struct fb_videomode *mode)
 {
         int j, num = 0;
 
         for (j = 0; j < 6; j++, block += STD_TIMING_DESCRIPTION_SIZE)
                 num += get_std_timing(block, &mode[num]);
 
         return num;
 }
 
 static void get_detailed_timing(unsigned char *block,
                                 struct fb_videomode *mode)
 {
         mode->xres = H_ACTIVE;
         mode->yres = V_ACTIVE;
         mode->pixclock = PIXEL_CLOCK;
         mode->pixclock /= 1000;
         mode->pixclock = KHZ2PICOS(mode->pixclock);
         mode->right_margin = H_SYNC_OFFSET;
         mode->left_margin = (H_ACTIVE + H_BLANKING) -
                 (H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
         mode->upper_margin = V_BLANKING - V_SYNC_OFFSET -
                 V_SYNC_WIDTH;
         mode->lower_margin = V_SYNC_OFFSET;
         mode->hsync_len = H_SYNC_WIDTH;
         mode->vsync_len = V_SYNC_WIDTH;
         if (HSYNC_POSITIVE)
                 mode->sync |= FB_SYNC_HOR_HIGH_ACT;
         if (VSYNC_POSITIVE)
                 mode->sync |= FB_SYNC_VERT_HIGH_ACT;
         mode->refresh = PIXEL_CLOCK/((H_ACTIVE + H_BLANKING) *
                                      (V_ACTIVE + V_BLANKING));
         if (INTERLACED) {
                 mode->yres *= 2;
                 mode->upper_margin *= 2;
                 mode->lower_margin *= 2;
                 mode->vsync_len *= 2;
                 mode->vmode |= FB_VMODE_INTERLACED;
         }
         mode->flag = FB_MODE_IS_DETAILED;
 
         DPRINTK("      %d MHz ",  PIXEL_CLOCK/1000000);
         DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET,
                H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
         DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET,
                V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
         DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-",
                (VSYNC_POSITIVE) ? "+" : "-");
 }
 
 /**
  * fb_create_modedb - create video mode database
  * @edid: EDID data
  * @dbsize: database size
  *
  * RETURNS: struct fb_videomode, @dbsize contains length of database
  *
  * DESCRIPTION:
  * This function builds a mode database using the contents of the EDID
  * data
  */
 static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize)
 {
         struct fb_videomode *mode, *m;
         unsigned char *block;
         int num = 0, i, first = 1;
 
         mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
         if (mode == NULL)
                 return NULL;
 
         if (edid == NULL || !edid_checksum(edid) ||
             !edid_check_header(edid)) {
                 kfree(mode);
                 return NULL;
         }
 
         *dbsize = 0;
 
         DPRINTK("   Detailed Timings\n");
         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
         for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
                 if (!(block[0] == 0x00 && block[1] == 0x00)) {
                         get_detailed_timing(block, &mode[num]);
                         if (first) {
                                 mode[num].flag |= FB_MODE_IS_FIRST;
                                 first = 0;
                         }
                         num++;
                 }
         }
 
         DPRINTK("   Supported VESA Modes\n");
         block = edid + ESTABLISHED_TIMING_1;
         num += get_est_timing(block, &mode[num]);
 
         DPRINTK("   Standard Timings\n");
         block = edid + STD_TIMING_DESCRIPTIONS_START;
         for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
                 num += get_std_timing(block, &mode[num]);
 
         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
         for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
                 if (block[0] == 0x00 && block[1] == 0x00 && block[3] == 0xfa)
                         num += get_dst_timing(block + 5, &mode[num]);
         }
 
         /* Yikes, EDID data is totally useless */
         if (!num) {
                 kfree(mode);
                 return NULL;
         }
 
         *dbsize = num;
         m = kmalloc(num * sizeof(struct fb_videomode), GFP_KERNEL);
         if (!m)
                 return mode;
         memmove(m, mode, num * sizeof(struct fb_videomode));
         kfree(mode);
         return m;
 }
 
 /**
  * fb_destroy_modedb - destroys mode database
  * @modedb: mode database to destroy
  *
  * DESCRIPTION:
  * Destroy mode database created by fb_create_modedb
  */
 void fb_destroy_modedb(struct fb_videomode *modedb)
 {
         kfree(modedb);
 }
 
 static int fb_get_monitor_limits(unsigned char *edid, struct fb_monspecs *specs)
 {
         int i, retval = 1;
         unsigned char *block;
 
         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 
         DPRINTK("      Monitor Operating Limits: ");
 
         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
                 if (edid_is_limits_block(block)) {
                         specs->hfmin = H_MIN_RATE * 1000;
                         specs->hfmax = H_MAX_RATE * 1000;
                         specs->vfmin = V_MIN_RATE;
                         specs->vfmax = V_MAX_RATE;
                         specs->dclkmax = MAX_PIXEL_CLOCK * 1000000;
                         specs->gtf = (GTF_SUPPORT) ? 1 : 0;
                         retval = 0;
                         DPRINTK("From EDID\n");
                         break;
                 }
         }
 
         /* estimate monitor limits based on modes supported */
         if (retval) {
                 struct fb_videomode *modes, *mode;
                 int num_modes, hz, hscan, pixclock;
                 int vtotal, htotal;
 
                 modes = fb_create_modedb(edid, &num_modes);
                 if (!modes) {
                         DPRINTK("None Available\n");
                         return 1;
                 }
 
                 retval = 0;
                 for (i = 0; i < num_modes; i++) {
                         mode = &modes[i];
                         pixclock = PICOS2KHZ(modes[i].pixclock) * 1000;
                         htotal = mode->xres + mode->right_margin + mode->hsync_len
                                 + mode->left_margin;
                         vtotal = mode->yres + mode->lower_margin + mode->vsync_len
                                 + mode->upper_margin;
 
                         if (mode->vmode & FB_VMODE_INTERLACED)
                                 vtotal /= 2;
 
                         if (mode->vmode & FB_VMODE_DOUBLE)
                                 vtotal *= 2;
 
                         hscan = (pixclock + htotal / 2) / htotal;
                         hscan = (hscan + 500) / 1000 * 1000;
                         hz = (hscan + vtotal / 2) / vtotal;
 
                         if (specs->dclkmax == 0 || specs->dclkmax < pixclock)
                                 specs->dclkmax = pixclock;
 
                         if (specs->dclkmin == 0 || specs->dclkmin > pixclock)
                                 specs->dclkmin = pixclock;
 
                         if (specs->hfmax == 0 || specs->hfmax < hscan)
                                 specs->hfmax = hscan;
 
                         if (specs->hfmin == 0 || specs->hfmin > hscan)
                                 specs->hfmin = hscan;
 
                         if (specs->vfmax == 0 || specs->vfmax < hz)
                                 specs->vfmax = hz;
 
                         if (specs->vfmin == 0 || specs->vfmin > hz)
                                 specs->vfmin = hz;
                 }
                 DPRINTK("Extrapolated\n");
                 fb_destroy_modedb(modes);
         }
         DPRINTK("           H: %d-%dKHz V: %d-%dHz DCLK: %dMHz\n",
                 specs->hfmin/1000, specs->hfmax/1000, specs->vfmin,
                 specs->vfmax, specs->dclkmax/1000000);
         return retval;
 }
 
 static void get_monspecs(unsigned char *edid, struct fb_monspecs *specs)
 {
         unsigned char c, *block;
 
         block = edid + EDID_STRUCT_DISPLAY;
 
         fb_get_monitor_limits(edid, specs);
 
         c = block[0] & 0x80;
         specs->input = 0;
         if (c) {
                 specs->input |= FB_DISP_DDI;
                 DPRINTK("      Digital Display Input");
         } else {
                 DPRINTK("      Analog Display Input: Input Voltage - ");
                 switch ((block[0] & 0x60) >> 5) {
                 case 0:
                         DPRINTK("0.700V/0.300V");
                         specs->input |= FB_DISP_ANA_700_300;
                         break;
                 case 1:
                         DPRINTK("0.714V/0.286V");
                         specs->input |= FB_DISP_ANA_714_286;
                         break;
                 case 2:
                         DPRINTK("1.000V/0.400V");
                         specs->input |= FB_DISP_ANA_1000_400;
                         break;
                 case 3:
                         DPRINTK("0.700V/0.000V");
                         specs->input |= FB_DISP_ANA_700_000;
                         break;
                 }
         }
         DPRINTK("\n      Sync: ");
         c = block[0] & 0x10;
         if (c)
                 DPRINTK("      Configurable signal level\n");
         c = block[0] & 0x0f;
         specs->signal = 0;
         if (c & 0x10) {
                 DPRINTK("Blank to Blank ");
                 specs->signal |= FB_SIGNAL_BLANK_BLANK;
         }
         if (c & 0x08) {
                 DPRINTK("Separate ");
                 specs->signal |= FB_SIGNAL_SEPARATE;
         }
         if (c & 0x04) {
                 DPRINTK("Composite ");
                 specs->signal |= FB_SIGNAL_COMPOSITE;
         }
         if (c & 0x02) {
                 DPRINTK("Sync on Green ");
                 specs->signal |= FB_SIGNAL_SYNC_ON_GREEN;
         }
         if (c & 0x01) {
                 DPRINTK("Serration on ");
                 specs->signal |= FB_SIGNAL_SERRATION_ON;
         }
         DPRINTK("\n");
         specs->max_x = block[1];
         specs->max_y = block[2];
         DPRINTK("      Max H-size in cm: ");
         if (specs->max_x)
                 DPRINTK("%d\n", specs->max_x);
         else
                 DPRINTK("variable\n");
         DPRINTK("      Max V-size in cm: ");
         if (specs->max_y)
                 DPRINTK("%d\n", specs->max_y);
         else
                 DPRINTK("variable\n");
 
         c = block[3];
         specs->gamma = c+100;
         DPRINTK("      Gamma: ");
         DPRINTK("%d.%d\n", specs->gamma/100, specs->gamma % 100);
 
         get_dpms_capabilities(block[4], specs);
 
         switch ((block[4] & 0x18) >> 3) {
         case 0:
                 DPRINTK("      Monochrome/Grayscale\n");
                 specs->input |= FB_DISP_MONO;
                 break;
         case 1:
                 DPRINTK("      RGB Color Display\n");
                 specs->input |= FB_DISP_RGB;
                 break;
         case 2:
                 DPRINTK("      Non-RGB Multicolor Display\n");
                 specs->input |= FB_DISP_MULTI;
                 break;
         default:
                 DPRINTK("      Unknown\n");
                 specs->input |= FB_DISP_UNKNOWN;
                 break;
         }
 
         get_chroma(block, specs);
 
         specs->misc = 0;
         c = block[4] & 0x7;
         if (c & 0x04) {
                 DPRINTK("      Default color format is primary\n");
                 specs->misc |= FB_MISC_PRIM_COLOR;
         }
         if (c & 0x02) {
                 DPRINTK("      First DETAILED Timing is preferred\n");
                 specs->misc |= FB_MISC_1ST_DETAIL;
         }
         if (c & 0x01) {
                 printk("      Display is GTF capable\n");
                 specs->gtf = 1;
         }
 }
 
 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
 {
         int i;
         unsigned char *block;
 
         if (edid == NULL || var == NULL)
                 return 1;
 
         if (!(edid_checksum(edid)))
                 return 1;
 
         if (!(edid_check_header(edid)))
                 return 1;
 
         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 
         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
                 if (edid_is_timing_block(block)) {
                         var->xres = var->xres_virtual = H_ACTIVE;
                         var->yres = var->yres_virtual = V_ACTIVE;
                         var->height = var->width = 0;
                         var->right_margin = H_SYNC_OFFSET;
                         var->left_margin = (H_ACTIVE + H_BLANKING) -
                                 (H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
                         var->upper_margin = V_BLANKING - V_SYNC_OFFSET -
                                 V_SYNC_WIDTH;
                         var->lower_margin = V_SYNC_OFFSET;
                         var->hsync_len = H_SYNC_WIDTH;
                         var->vsync_len = V_SYNC_WIDTH;
                         var->pixclock = PIXEL_CLOCK;
                         var->pixclock /= 1000;
                         var->pixclock = KHZ2PICOS(var->pixclock);
 
                         if (HSYNC_POSITIVE)
                                 var->sync |= FB_SYNC_HOR_HIGH_ACT;
                         if (VSYNC_POSITIVE)
                                 var->sync |= FB_SYNC_VERT_HIGH_ACT;
                         return 0;
                 }
         }
         return 1;
 }
 
 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
 {
         unsigned char *block;
         int i, found = 0;
 
         if (edid == NULL)
                 return;
 
         if (!(edid_checksum(edid)))
                 return;
 
         if (!(edid_check_header(edid)))
                 return;
 
         memset(specs, 0, sizeof(struct fb_monspecs));
 
         specs->version = edid[EDID_STRUCT_VERSION];
         specs->revision = edid[EDID_STRUCT_REVISION];
 
         DPRINTK("========================================\n");
         DPRINTK("Display Information (EDID)\n");
         DPRINTK("========================================\n");
         DPRINTK("   EDID Version %d.%d\n", (int) specs->version,
                (int) specs->revision);
 
         parse_vendor_block(edid + ID_MANUFACTURER_NAME, specs);
 
         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
                 if (edid_is_serial_block(block)) {
                         copy_string(block, specs->serial_no);
                         DPRINTK("   Serial Number: %s\n", specs->serial_no);
                 } else if (edid_is_ascii_block(block)) {
                         copy_string(block, specs->ascii);
                         DPRINTK("   ASCII Block: %s\n", specs->ascii);
                 } else if (edid_is_monitor_block(block)) {
                         copy_string(block, specs->monitor);
                         DPRINTK("   Monitor Name: %s\n", specs->monitor);
                 }
         }
 
         DPRINTK("   Display Characteristics:\n");
         get_monspecs(edid, specs);
 
         specs->modedb = fb_create_modedb(edid, &specs->modedb_len);
 
         /*
          * Workaround for buggy EDIDs that sets that the first
          * detailed timing is preferred but has not detailed
          * timing specified
          */
         for (i = 0; i < specs->modedb_len; i++) {
                 if (specs->modedb[i].flag & FB_MODE_IS_DETAILED) {
                         found = 1;
                         break;
                 }
         }
 
         if (!found)
                 specs->misc &= ~FB_MISC_1ST_DETAIL;
 
         DPRINTK("========================================\n");
 }
 
 /*
  * VESA Generalized Timing Formula (GTF)
  */
 
 #define FLYBACK                     550
 #define V_FRONTPORCH                1
 #define H_OFFSET                    40
 #define H_SCALEFACTOR               20
 #define H_BLANKSCALE                128
 #define H_GRADIENT                  600
 #define C_VAL                       30
 #define M_VAL                       300
 
 struct __fb_timings {
         u32 dclk;
         u32 hfreq;
         u32 vfreq;
         u32 hactive;
         u32 vactive;
         u32 hblank;
         u32 vblank;
         u32 htotal;
         u32 vtotal;
 };
 
/**
 * fb_get_vblank - get vertical blank time
 * @hfreq: horizontal freq
 *
 * DESCRIPTION:
 * vblank = right_margin + vsync_len + left_margin
 *
 *    given: right_margin = 1 (V_FRONTPORCH)
 *           vsync_len    = 3
 *           flyback      = 550
 *
 *                          flyback * hfreq
 *           left_margin  = --------------- - vsync_len
 *                           1000000
 */
static u32 fb_get_vblank(u32 hfreq)
{
        u32 vblank;

        vblank = (hfreq * FLYBACK)/1000;
        vblank = (vblank + 500)/1000;
        return (vblank + V_FRONTPORCH);
}

/**
 * fb_get_hblank_by_freq - get horizontal blank time given hfreq
 * @hfreq: horizontal freq
 * @xres: horizontal resolution in pixels
 *
 * DESCRIPTION:
 *
 *           xres * duty_cycle
 * hblank = ------------------
 *           100 - duty_cycle
 *
 * duty cycle = percent of htotal assigned to inactive display
 * duty cycle = C - (M/Hfreq)
 *
 * where: C = ((offset - scale factor) * blank_scale)
 *            -------------------------------------- + scale factor
 *                        256
 *        M = blank_scale * gradient
 *
 */
static u32 fb_get_hblank_by_hfreq(u32 hfreq, u32 xres)
{
        u32 c_val, m_val, duty_cycle, hblank;

        c_val = (((H_OFFSET - H_SCALEFACTOR) * H_BLANKSCALE)/256 +
                 H_SCALEFACTOR) * 1000;
        m_val = (H_BLANKSCALE * H_GRADIENT)/256;
        m_val = (m_val * 1000000)/hfreq;
        duty_cycle = c_val - m_val;
        hblank = (xres * duty_cycle)/(100000 - duty_cycle);
        return (hblank);
}

/**
 * fb_get_hblank_by_dclk - get horizontal blank time given pixelclock
 * @dclk: pixelclock in Hz
 * @xres: horizontal resolution in pixels
 *
 * DESCRIPTION:
 *
 *           xres * duty_cycle
 * hblank = ------------------
 *           100 - duty_cycle
 *
 * duty cycle = percent of htotal assigned to inactive display
 * duty cycle = C - (M * h_period)
 *
 * where: h_period = SQRT(100 - C + (0.4 * xres * M)/dclk) + C - 100
 *                   -----------------------------------------------
 *                                    2 * M
 *        M = 300;
 *        C = 30;

 */
static u32 fb_get_hblank_by_dclk(u32 dclk, u32 xres)
{
        u32 duty_cycle, h_period, hblank;

        dclk /= 1000;
        h_period = 100 - C_VAL;
        h_period *= h_period;
        h_period += (M_VAL * xres * 2 * 1000)/(5 * dclk);
        h_period *= 10000;

        h_period = int_sqrt(h_period);
        h_period -= (100 - C_VAL) * 100;
        h_period *= 1000;
        h_period /= 2 * M_VAL;

        duty_cycle = C_VAL * 1000 - (M_VAL * h_period)/100;
        hblank = (xres * duty_cycle)/(100000 - duty_cycle) + 8;
        hblank &= ~15;
        return (hblank);
}

/**
 * fb_get_hfreq - estimate hsync
 * @vfreq: vertical refresh rate
 * @yres: vertical resolution
 *
 * DESCRIPTION:
 *
 *          (yres + front_port) * vfreq * 1000000
 * hfreq = -------------------------------------
 *          (1000000 - (vfreq * FLYBACK)
 *
 */

static u32 fb_get_hfreq(u32 vfreq, u32 yres)
{
        u32 divisor, hfreq;

        divisor = (1000000 - (vfreq * FLYBACK))/1000;
        hfreq = (yres + V_FRONTPORCH) * vfreq  * 1000;
        return (hfreq/divisor);
}

static void fb_timings_vfreq(struct __fb_timings *timings)
{
        timings->hfreq = fb_get_hfreq(timings->vfreq, timings->vactive);
        timings->vblank = fb_get_vblank(timings->hfreq);
        timings->vtotal = timings->vactive + timings->vblank;
        timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
                                                 timings->hactive);
        timings->htotal = timings->hactive + timings->hblank;
        timings->dclk = timings->htotal * timings->hfreq;
}

static void fb_timings_hfreq(struct __fb_timings *timings)
{
        timings->vblank = fb_get_vblank(timings->hfreq);
        timings->vtotal = timings->vactive + timings->vblank;
        timings->vfreq = timings->hfreq/timings->vtotal;
        timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
                                                 timings->hactive);
        timings->htotal = timings->hactive + timings->hblank;
        timings->dclk = timings->htotal * timings->hfreq;
}

static void fb_timings_dclk(struct __fb_timings *timings)
{
        timings->hblank = fb_get_hblank_by_dclk(timings->dclk,
                                                timings->hactive);
        timings->htotal = timings->hactive + timings->hblank;
        timings->hfreq = timings->dclk/timings->htotal;
        timings->vblank = fb_get_vblank(timings->hfreq);
        timings->vtotal = timings->vactive + timings->vblank;
        timings->vfreq = timings->hfreq/timings->vtotal;
}

/*
 * fb_get_mode - calculates video mode using VESA GTF
 * @flags: if: 0 - maximize vertical refresh rate
 *             1 - vrefresh-driven calculation;
 *             2 - hscan-driven calculation;
 *             3 - pixelclock-driven calculation;
 * @val: depending on @flags, ignored, vrefresh, hsync or pixelclock
 * @var: pointer to fb_var_screeninfo
 * @info: pointer to fb_info
 *
 * DESCRIPTION:
 * Calculates video mode based on monitor specs using VESA GTF.
 * The GTF is best for VESA GTF compliant monitors but is
 * specifically formulated to work for older monitors as well.
 *
 * If @flag==0, the function will attempt to maximize the
 * refresh rate.  Otherwise, it will calculate timings based on
 * the flag and accompanying value.
 *
 * If FB_IGNOREMON bit is set in @flags, monitor specs will be
 * ignored and @var will be filled with the calculated timings.
 *
 * All calculations are based on the VESA GTF Spreadsheet
 * available at VESA's public ftp (http://www.vesa.org).
 *
 * NOTES:
 * The timings generated by the GTF will be different from VESA
 * DMT.  It might be a good idea to keep a table of standard
 * VESA modes as well.  The GTF may also not work for some displays,
 * such as, and especially, analog TV.
 *
 * REQUIRES:
 * A valid info->monspecs, otherwise 'safe numbers' will be used.
 */
int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_info *info)
{
        struct __fb_timings *timings;
        u32 interlace = 1, dscan = 1;
        u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax, err = 0;


        timings = kzalloc(sizeof(struct __fb_timings), GFP_KERNEL);

        if (!timings)
                return -ENOMEM;

        /*
         * If monspecs are invalid, use values that are enough
         * for 640x480@60
         */
        if (!info || !info->monspecs.hfmax || !info->monspecs.vfmax ||
            !info->monspecs.dclkmax ||
            info->monspecs.hfmax < info->monspecs.hfmin ||
            info->monspecs.vfmax < info->monspecs.vfmin ||
            info->monspecs.dclkmax < info->monspecs.dclkmin) {
                hfmin = 29000; hfmax = 30000;
                vfmin = 60; vfmax = 60;
                dclkmin = 0; dclkmax = 25000000;
        } else {
                hfmin = info->monspecs.hfmin;
                hfmax = info->monspecs.hfmax;
                vfmin = info->monspecs.vfmin;
                vfmax = info->monspecs.vfmax;
                dclkmin = info->monspecs.dclkmin;
                dclkmax = info->monspecs.dclkmax;
        }

        timings->hactive = var->xres;
        timings->vactive = var->yres;
        if (var->vmode & FB_VMODE_INTERLACED) {
                timings->vactive /= 2;
                interlace = 2;
        }
        if (var->vmode & FB_VMODE_DOUBLE) {
                timings->vactive *= 2;
                dscan = 2;
        }

        switch (flags & ~FB_IGNOREMON) {
        case FB_MAXTIMINGS: /* maximize refresh rate */
                timings->hfreq = hfmax;
                fb_timings_hfreq(timings);
                if (timings->vfreq > vfmax) {
                        timings->vfreq = vfmax;
                        fb_timings_vfreq(timings);
                }
                if (timings->dclk > dclkmax) {
                        timings->dclk = dclkmax;
                        fb_timings_dclk(timings);
                }
                break;
        case FB_VSYNCTIMINGS: /* vrefresh driven */
                timings->vfreq = val;
                fb_timings_vfreq(timings);
                break;
        case FB_HSYNCTIMINGS: /* hsync driven */
                timings->hfreq = val;
                fb_timings_hfreq(timings);
                break;
        case FB_DCLKTIMINGS: /* pixelclock driven */
                timings->dclk = PICOS2KHZ(val) * 1000;
                fb_timings_dclk(timings);
                break;
        default:
                err = -EINVAL;

        }

        if (err || (!(flags & FB_IGNOREMON) &&
            (timings->vfreq < vfmin || timings->vfreq > vfmax ||
             timings->hfreq < hfmin || timings->hfreq > hfmax ||
             timings->dclk < dclkmin || timings->dclk > dclkmax))) {
                err = -EINVAL;
        } else {
                var->pixclock = KHZ2PICOS(timings->dclk/1000);
                var->hsync_len = (timings->htotal * 8)/100;
                var->right_margin = (timings->hblank/2) - var->hsync_len;
                var->left_margin = timings->hblank - var->right_margin -
                        var->hsync_len;
                var->vsync_len = (3 * interlace)/dscan;
                var->lower_margin = (1 * interlace)/dscan;
                var->upper_margin = (timings->vblank * interlace)/dscan -
                        (var->vsync_len + var->lower_margin);
        }

        kfree(timings);
        return err;
}
#else
int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
{
        return 1;
}
void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
{
        specs = NULL;
}
void fb_destroy_modedb(struct fb_videomode *modedb)
{
}
int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var,
                struct fb_info *info)
{
        return -EINVAL;
}
#endif /* CONFIG_FB_MODE_HELPERS */

/*
 * fb_validate_mode - validates var against monitor capabilities
 * @var: pointer to fb_var_screeninfo
 * @info: pointer to fb_info
 *
 * DESCRIPTION:
 * Validates video mode against monitor capabilities specified in
 * info->monspecs.
 *
 * REQUIRES:
 * A valid info->monspecs.
 */
int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
{
        u32 hfreq, vfreq, htotal, vtotal, pixclock;
        u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;

        /*
         * If monspecs are invalid, use values that are enough
         * for 640x480@60
         */
        if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
            !info->monspecs.dclkmax ||
            info->monspecs.hfmax < info->monspecs.hfmin ||
            info->monspecs.vfmax < info->monspecs.vfmin ||
            info->monspecs.dclkmax < info->monspecs.dclkmin) {
                hfmin = 29000; hfmax = 30000;
                vfmin = 60; vfmax = 60;
                dclkmin = 0; dclkmax = 25000000;
        } else {
                hfmin = info->monspecs.hfmin;
                hfmax = info->monspecs.hfmax;
                vfmin = info->monspecs.vfmin;
                vfmax = info->monspecs.vfmax;
                dclkmin = info->monspecs.dclkmin;
                dclkmax = info->monspecs.dclkmax;
        }

        if (!var->pixclock)
                return -EINVAL;
        pixclock = PICOS2KHZ(var->pixclock) * 1000;

        htotal = var->xres + var->right_margin + var->hsync_len +
                var->left_margin;
        vtotal = var->yres + var->lower_margin + var->vsync_len +
                var->upper_margin;

        if (var->vmode & FB_VMODE_INTERLACED)
                vtotal /= 2;
        if (var->vmode & FB_VMODE_DOUBLE)
                vtotal *= 2;

        hfreq = pixclock/htotal;
        hfreq = (hfreq + 500) / 1000 * 1000;

        vfreq = hfreq/vtotal;

        return (vfreq < vfmin || vfreq > vfmax ||
                hfreq < hfmin || hfreq > hfmax ||
                pixclock < dclkmin || pixclock > dclkmax) ?
                -EINVAL : 0;
}

#if defined(CONFIG_FIRMWARE_EDID) && defined(CONFIG_X86)

/*
 * We need to ensure that the EDID block is only returned for
 * the primary graphics adapter.
 */

const unsigned char *fb_firmware_edid(struct device *device)
{
        struct pci_dev *dev = NULL;
        struct resource *res = NULL;
        unsigned char *edid = NULL;

        if (device)
                dev = to_pci_dev(device);

        if (dev)
                res = &dev->resource[PCI_ROM_RESOURCE];

        if (res && res->flags & IORESOURCE_ROM_SHADOW)
                edid = edid_info.dummy;

        return edid;
}
#else
const unsigned char *fb_firmware_edid(struct device *device)
{
        return NULL;
}
#endif
EXPORT_SYMBOL(fb_firmware_edid);

EXPORT_SYMBOL(fb_parse_edid);
EXPORT_SYMBOL(fb_edid_to_monspecs);
EXPORT_SYMBOL(fb_get_mode);
EXPORT_SYMBOL(fb_validate_mode);
EXPORT_SYMBOL(fb_destroy_modedb);