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   1 /*
   2  * linux/drivers/video/fbmon.c
   3  *
   4  * Copyright (C) 2002 James Simmons <jsimmons@users.sf.net>
   5  *
   6  * Credits:
   7  *
   8  * The EDID Parser is a conglomeration from the following sources:
   9  *
  10  *   1. SciTech SNAP Graphics Architecture
  11  *      Copyright (C) 1991-2002 SciTech Software, Inc. All rights reserved.
  12  *
  13  *   2. XFree86 4.3.0, interpret_edid.c
  14  *      Copyright 1998 by Egbert Eich <Egbert.Eich@Physik.TU-Darmstadt.DE>
  15  *
  16  *   3. John Fremlin <vii@users.sourceforge.net> and
  17  *      Ani Joshi <ajoshi@unixbox.com>
  18  *
  19  * Generalized Timing Formula is derived from:
  20  *
  21  *      GTF Spreadsheet by Andy Morrish (1/5/97)
  22  *      available at http://www.vesa.org
  23  *
  24  * This file is subject to the terms and conditions of the GNU General Public
  25  * License.  See the file COPYING in the main directory of this archive
  26  * for more details.
  27  *
  28  */
  29 #include <linux/fb.h>
  30 #include <linux/module.h>
  31 #include <linux/pci.h>
  32 #include <video/edid.h>
  33 #ifdef CONFIG_PPC_OF
  34 #include <asm/prom.h>
  35 #include <asm/pci-bridge.h>
  36 #endif
  37 #include "edid.h"
  38
  39 /*
  40  * EDID parser
  41  */
  42
  43 #undef DEBUG  /* define this for verbose EDID parsing output */
  44
  45 #ifdef DEBUG
  46 #define DPRINTK(fmt, args...) printk(fmt,## args)
  47 #else
  48 #define DPRINTK(fmt, args...)
  49 #endif
  50
  51 #define FBMON_FIX_HEADER 1
  52 #define FBMON_FIX_INPUT  2
  53
  54 #ifdef CONFIG_FB_MODE_HELPERS
  55 struct broken_edid {
  56         u8  manufacturer[4];
  57         u32 model;
  58         u32 fix;
  59 };
  60
  61 static struct broken_edid brokendb[] = {
  62         /* DEC FR-PCXAV-YZ */
  63         {
  64                 .manufacturer = "DEC",
  65                 .model        = 0x073a,
  66                 .fix          = FBMON_FIX_HEADER,
  67         },
  68         /* ViewSonic PF775a */
  69         {
  70                 .manufacturer = "VSC",
  71                 .model        = 0x5a44,
  72                 .fix          = FBMON_FIX_INPUT,
  73         },
  74 };
  75
  76 static const unsigned char edid_v1_header[] = { 0x00, 0xff, 0xff, 0xff,
  77         0xff, 0xff, 0xff, 0x00
  78 };
  79
  80 static void copy_string(unsigned char *c, unsigned char *s)
  81 {
  82   int i;
  83   c = c + 5;
  84   for (i = 0; (i < 13 && *c != 0x0A); i++)
  85     *(s++) = *(c++);
  86   *s = 0;
  87   while (i-- && (*--s == 0x20)) *s = 0;
  88 }
  89
  90 static int check_edid(unsigned char *edid)
  91 {
  92         unsigned char *block = edid + ID_MANUFACTURER_NAME, manufacturer[4];
  93         unsigned char *b;
  94         u32 model;
  95         int i, fix = 0, ret = 0;
  96
  97         manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
  98         manufacturer[1] = ((block[0] & 0x03) << 3) +
  99                 ((block[1] & 0xe0) >> 5) + '@';
 100         manufacturer[2] = (block[1] & 0x1f) + '@';
 101         manufacturer[3] = 0;
 102         model = block[2] + (block[3] << 8);
 103
 104         for (i = 0; i < ARRAY_SIZE(brokendb); i++) {
 105                 if (!strncmp(manufacturer, brokendb[i].manufacturer, 4) &&
 106                         brokendb[i].model == model) {
 107                         printk("fbmon: The EDID Block of "
 108                                "Manufacturer: %s Model: 0x%x is known to "
 109                                "be broken,\n",  manufacturer, model);
 110                         fix = brokendb[i].fix;
 111                         break;
 112                 }
 113         }
 114
 115         switch (fix) {
 116         case FBMON_FIX_HEADER:
 117                 for (i = 0; i < 8; i++) {
 118                         if (edid[i] != edid_v1_header[i])
 119                                 ret = fix;
 120                 }
 121                 break;
 122         case FBMON_FIX_INPUT:
 123                 b = edid + EDID_STRUCT_DISPLAY;
 124                 /* Only if display is GTF capable will
 125                    the input type be reset to analog */
 126                 if (b[4] & 0x01 && b[0] & 0x80)
 127                         ret = fix;
 128                 break;
 129         }
 130
 131         return ret;
 132 }
 133
 134 static void fix_edid(unsigned char *edid, int fix)
 135 {
 136         unsigned char *b;
 137
 138         switch (fix) {
 139         case FBMON_FIX_HEADER:
 140                 printk("fbmon: trying a header reconstruct\n");
 141                 memcpy(edid, edid_v1_header, 8);
 142                 break;
 143         case FBMON_FIX_INPUT:
 144                 printk("fbmon: trying to fix input type\n");
 145                 b = edid + EDID_STRUCT_DISPLAY;
 146                 b[0] &= ~0x80;
 147                 edid[127] += 0x80;
 148         }
 149 }
 150
 151 static int edid_checksum(unsigned char *edid)
 152 {
 153         unsigned char i, csum = 0, all_null = 0;
 154         int err = 0, fix = check_edid(edid);
 155
 156         if (fix)
 157                 fix_edid(edid, fix);
 158
 159         for (i = 0; i < EDID_LENGTH; i++) {
 160                 csum += edid[i];
 161                 all_null |= edid[i];
 162         }
 163
 164         if (csum == 0x00 && all_null) {
 165                 /* checksum passed, everything's good */
 166                 err = 1;
 167         }
 168
 169         return err;
 170 }
 171
 172 static int edid_check_header(unsigned char *edid)
 173 {
 174         int i, err = 1, fix = check_edid(edid);
 175
 176         if (fix)
 177                 fix_edid(edid, fix);
 178
 179         for (i = 0; i < 8; i++) {
 180                 if (edid[i] != edid_v1_header[i])
 181                         err = 0;
 182         }
 183
 184         return err;
 185 }
 186
 187 static void parse_vendor_block(unsigned char *block, struct fb_monspecs *specs)
 188 {
 189         specs->manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
 190         specs->manufacturer[1] = ((block[0] & 0x03) << 3) +
 191                 ((block[1] & 0xe0) >> 5) + '@';
 192         specs->manufacturer[2] = (block[1] & 0x1f) + '@';
 193         specs->manufacturer[3] = 0;
 194         specs->model = block[2] + (block[3] << 8);
 195         specs->serial = block[4] + (block[5] << 8) +
 196                (block[6] << 16) + (block[7] << 24);
 197         specs->year = block[9] + 1990;
 198         specs->week = block[8];
 199         DPRINTK("   Manufacturer: %s\n", specs->manufacturer);
 200         DPRINTK("   Model: %x\n", specs->model);
 201         DPRINTK("   Serial#: %u\n", specs->serial);
 202         DPRINTK("   Year: %u Week %u\n", specs->year, specs->week);
 203 }
 204
 205 static void get_dpms_capabilities(unsigned char flags,
 206                                   struct fb_monspecs *specs)
 207 {
 208         specs->dpms = 0;
 209         if (flags & DPMS_ACTIVE_OFF)
 210                 specs->dpms |= FB_DPMS_ACTIVE_OFF;
 211         if (flags & DPMS_SUSPEND)
 212                 specs->dpms |= FB_DPMS_SUSPEND;
 213         if (flags & DPMS_STANDBY)
 214                 specs->dpms |= FB_DPMS_STANDBY;
 215         DPRINTK("      DPMS: Active %s, Suspend %s, Standby %s\n",
 216                (flags & DPMS_ACTIVE_OFF) ? "yes" : "no",
 217                (flags & DPMS_SUSPEND)    ? "yes" : "no",
 218                (flags & DPMS_STANDBY)    ? "yes" : "no");
 219 }
 220
 221 static void get_chroma(unsigned char *block, struct fb_monspecs *specs)
 222 {
 223         int tmp;
 224
 225         DPRINTK("      Chroma\n");
 226         /* Chromaticity data */
 227         tmp = ((block[5] & (3 << 6)) >> 6) | (block[0x7] << 2);
 228         tmp *= 1000;
 229         tmp += 512;
 230         specs->chroma.redx = tmp/1024;
 231         DPRINTK("         RedX:     0.%03d ", specs->chroma.redx);
 232
 233         tmp = ((block[5] & (3 << 4)) >> 4) | (block[0x8] << 2);
 234         tmp *= 1000;
 235         tmp += 512;
 236         specs->chroma.redy = tmp/1024;
 237         DPRINTK("RedY:     0.%03d\n", specs->chroma.redy);
 238
 239         tmp = ((block[5] & (3 << 2)) >> 2) | (block[0x9] << 2);
 240         tmp *= 1000;
 241         tmp += 512;
 242         specs->chroma.greenx = tmp/1024;
 243         DPRINTK("         GreenX:   0.%03d ", specs->chroma.greenx);
 244
 245         tmp = (block[5] & 3) | (block[0xa] << 2);
 246         tmp *= 1000;
 247         tmp += 512;
 248         specs->chroma.greeny = tmp/1024;
 249         DPRINTK("GreenY:   0.%03d\n", specs->chroma.greeny);
 250
 251         tmp = ((block[6] & (3 << 6)) >> 6) | (block[0xb] << 2);
 252         tmp *= 1000;
 253         tmp += 512;
 254         specs->chroma.bluex = tmp/1024;
 255         DPRINTK("         BlueX:    0.%03d ", specs->chroma.bluex);
 256
 257         tmp = ((block[6] & (3 << 4)) >> 4) | (block[0xc] << 2);
 258         tmp *= 1000;
 259         tmp += 512;
 260         specs->chroma.bluey = tmp/1024;
 261         DPRINTK("BlueY:    0.%03d\n", specs->chroma.bluey);
 262
 263         tmp = ((block[6] & (3 << 2)) >> 2) | (block[0xd] << 2);
 264         tmp *= 1000;
 265         tmp += 512;
 266         specs->chroma.whitex = tmp/1024;
 267         DPRINTK("         WhiteX:   0.%03d ", specs->chroma.whitex);
 268
 269         tmp = (block[6] & 3) | (block[0xe] << 2);
 270         tmp *= 1000;
 271         tmp += 512;
 272         specs->chroma.whitey = tmp/1024;
 273         DPRINTK("WhiteY:   0.%03d\n", specs->chroma.whitey);
 274 }
 275
 276 static int edid_is_serial_block(unsigned char *block)
 277 {
 278         if ((block[0] == 0x00) && (block[1] == 0x00) &&
 279             (block[2] == 0x00) && (block[3] == 0xff) &&
 280             (block[4] == 0x00))
 281                 return 1;
 282         else
 283                 return 0;
 284 }
 285
 286 static int edid_is_ascii_block(unsigned char *block)
 287 {
 288         if ((block[0] == 0x00) && (block[1] == 0x00) &&
 289             (block[2] == 0x00) && (block[3] == 0xfe) &&
 290             (block[4] == 0x00))
 291                 return 1;
 292         else
 293                 return 0;
 294 }
 295
 296 static int edid_is_limits_block(unsigned char *block)
 297 {
 298         if ((block[0] == 0x00) && (block[1] == 0x00) &&
 299             (block[2] == 0x00) && (block[3] == 0xfd) &&
 300             (block[4] == 0x00))
 301                 return 1;
 302         else
 303                 return 0;
 304 }
 305
 306 static int edid_is_monitor_block(unsigned char *block)
 307 {
 308         if ((block[0] == 0x00) && (block[1] == 0x00) &&
 309             (block[2] == 0x00) && (block[3] == 0xfc) &&
 310             (block[4] == 0x00))
 311                 return 1;
 312         else
 313                 return 0;
 314 }
 315
 316 static void calc_mode_timings(int xres, int yres, int refresh,
 317                               struct fb_videomode *mode)
 318 {
 319         struct fb_var_screeninfo *var;
 320
 321         var = kzalloc(sizeof(struct fb_var_screeninfo), GFP_KERNEL);
 322
 323         if (var) {
 324                 var->xres = xres;
 325                 var->yres = yres;
 326                 fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON,
 327                             refresh, var, NULL);
 328                 mode->xres = xres;
 329                 mode->yres = yres;
 330                 mode->pixclock = var->pixclock;
 331                 mode->refresh = refresh;
 332                 mode->left_margin = var->left_margin;
 333                 mode->right_margin = var->right_margin;
 334                 mode->upper_margin = var->upper_margin;
 335                 mode->lower_margin = var->lower_margin;
 336                 mode->hsync_len = var->hsync_len;
 337                 mode->vsync_len = var->vsync_len;
 338                 mode->vmode = 0;
 339                 mode->sync = 0;
 340                 kfree(var);
 341         }
 342 }
 343
 344 static int get_est_timing(unsigned char *block, struct fb_videomode *mode)
 345 {
 346         int num = 0;
 347         unsigned char c;
 348
 349         c = block[0];
 350         if (c&0x80) {
 351                 calc_mode_timings(720, 400, 70, &mode[num]);
 352                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 353                 DPRINTK("      720x400@70Hz\n");
 354         }
 355         if (c&0x40) {
 356                 calc_mode_timings(720, 400, 88, &mode[num]);
 357                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 358                 DPRINTK("      720x400@88Hz\n");
 359         }
 360         if (c&0x20) {
 361                 mode[num++] = vesa_modes[3];
 362                 DPRINTK("      640x480@60Hz\n");
 363         }
 364         if (c&0x10) {
 365                 calc_mode_timings(640, 480, 67, &mode[num]);
 366                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 367                 DPRINTK("      640x480@67Hz\n");
 368         }
 369         if (c&0x08) {
 370                 mode[num++] = vesa_modes[4];
 371                 DPRINTK("      640x480@72Hz\n");
 372         }
 373         if (c&0x04) {
 374                 mode[num++] = vesa_modes[5];
 375                 DPRINTK("      640x480@75Hz\n");
 376         }
 377         if (c&0x02) {
 378                 mode[num++] = vesa_modes[7];
 379                 DPRINTK("      800x600@56Hz\n");
 380         }
 381         if (c&0x01) {
 382                 mode[num++] = vesa_modes[8];
 383                 DPRINTK("      800x600@60Hz\n");
 384         }
 385
 386         c = block[1];
 387         if (c&0x80) {
 388                 mode[num++] = vesa_modes[9];
 389                 DPRINTK("      800x600@72Hz\n");
 390         }
 391         if (c&0x40) {
 392                 mode[num++] = vesa_modes[10];
 393                 DPRINTK("      800x600@75Hz\n");
 394         }
 395         if (c&0x20) {
 396                 calc_mode_timings(832, 624, 75, &mode[num]);
 397                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 398                 DPRINTK("      832x624@75Hz\n");
 399         }
 400         if (c&0x10) {
 401                 mode[num++] = vesa_modes[12];
 402                 DPRINTK("      1024x768@87Hz Interlaced\n");
 403         }
 404         if (c&0x08) {
 405                 mode[num++] = vesa_modes[13];
 406                 DPRINTK("      1024x768@60Hz\n");
 407         }
 408         if (c&0x04) {
 409                 mode[num++] = vesa_modes[14];
 410                 DPRINTK("      1024x768@70Hz\n");
 411         }
 412         if (c&0x02) {
 413                 mode[num++] = vesa_modes[15];
 414                 DPRINTK("      1024x768@75Hz\n");
 415         }
 416         if (c&0x01) {
 417                 mode[num++] = vesa_modes[21];
 418                 DPRINTK("      1280x1024@75Hz\n");
 419         }
 420         c = block[2];
 421         if (c&0x80) {
 422                 mode[num++] = vesa_modes[17];
 423                 DPRINTK("      1152x870@75Hz\n");
 424         }
 425         DPRINTK("      Manufacturer's mask: %x\n",c&0x7F);
 426         return num;
 427 }
 428
 429 static int get_std_timing(unsigned char *block, struct fb_videomode *mode)
 430 {
 431         int xres, yres = 0, refresh, ratio, i;
 432
 433         xres = (block[0] + 31) * 8;
 434         if (xres <= 256)
 435                 return 0;
 436
 437         ratio = (block[1] & 0xc0) >> 6;
 438         switch (ratio) {
 439         case 0:
 440                 yres = xres;
 441                 break;
 442         case 1:
 443                 yres = (xres * 3)/4;
 444                 break;
 445         case 2:
 446                 yres = (xres * 4)/5;
 447                 break;
 448         case 3:
 449                 yres = (xres * 9)/16;
 450                 break;
 451         }
 452         refresh = (block[1] & 0x3f) + 60;
 453
 454         DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
 455         for (i = 0; i < VESA_MODEDB_SIZE; i++) {
 456                 if (vesa_modes[i].xres == xres &&
 457                     vesa_modes[i].yres == yres &&
 458                     vesa_modes[i].refresh == refresh) {
 459                         *mode = vesa_modes[i];
 460                         mode->flag |= FB_MODE_IS_STANDARD;
 461                         return 1;
 462                 }
 463         }
 464         calc_mode_timings(xres, yres, refresh, mode);
 465         return 1;
 466 }
 467
 468 static int get_dst_timing(unsigned char *block,
 469                           struct fb_videomode *mode)
 470 {
 471         int j, num = 0;
 472
 473         for (j = 0; j < 6; j++, block+= STD_TIMING_DESCRIPTION_SIZE)
 474                 num += get_std_timing(block, &mode[num]);
 475
 476         return num;
 477 }
 478
 479 static void get_detailed_timing(unsigned char *block,
 480                                 struct fb_videomode *mode)
 481 {
 482         mode->xres = H_ACTIVE;
 483         mode->yres = V_ACTIVE;
 484         mode->pixclock = PIXEL_CLOCK;
 485         mode->pixclock /= 1000;
 486         mode->pixclock = KHZ2PICOS(mode->pixclock);
 487         mode->right_margin = H_SYNC_OFFSET;
 488         mode->left_margin = (H_ACTIVE + H_BLANKING) -
 489                 (H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
 490         mode->upper_margin = V_BLANKING - V_SYNC_OFFSET -
 491                 V_SYNC_WIDTH;
 492         mode->lower_margin = V_SYNC_OFFSET;
 493         mode->hsync_len = H_SYNC_WIDTH;
 494         mode->vsync_len = V_SYNC_WIDTH;
 495         if (HSYNC_POSITIVE)
 496                 mode->sync |= FB_SYNC_HOR_HIGH_ACT;
 497         if (VSYNC_POSITIVE)
 498                 mode->sync |= FB_SYNC_VERT_HIGH_ACT;
 499         mode->refresh = PIXEL_CLOCK/((H_ACTIVE + H_BLANKING) *
 500                                      (V_ACTIVE + V_BLANKING));
 501         mode->vmode = 0;
 502         mode->flag = FB_MODE_IS_DETAILED;
 503
 504         DPRINTK("      %d MHz ",  PIXEL_CLOCK/1000000);
 505         DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET,
 506                H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
 507         DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET,
 508                V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
 509         DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-",
 510                (VSYNC_POSITIVE) ? "+" : "-");
 511 }
 512
 513 /**
 514  * fb_create_modedb - create video mode database
 515  * @edid: EDID data
 516  * @dbsize: database size
 517  *
 518  * RETURNS: struct fb_videomode, @dbsize contains length of database
 519  *
 520  * DESCRIPTION:
 521  * This function builds a mode database using the contents of the EDID
 522  * data
 523  */
 524 static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize)
 525 {
 526         struct fb_videomode *mode, *m;
 527         unsigned char *block;
 528         int num = 0, i;
 529
 530         mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
 531         if (mode == NULL)
 532                 return NULL;
 533
 534         if (edid == NULL || !edid_checksum(edid) ||
 535             !edid_check_header(edid)) {
 536                 kfree(mode);
 537                 return NULL;
 538         }
 539
 540         *dbsize = 0;
 541
 542         DPRINTK("   Detailed Timings\n");
 543         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 544         for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
 545                 int first = 1;
 546
 547                 if (!(block[0] == 0x00 && block[1] == 0x00)) {
 548                         get_detailed_timing(block, &mode[num]);
 549                         if (first) {
 550                                 mode[num].flag |= FB_MODE_IS_FIRST;
 551                                 first = 0;
 552                         }
 553                         num++;
 554                 }
 555         }
 556
 557         DPRINTK("   Supported VESA Modes\n");
 558         block = edid + ESTABLISHED_TIMING_1;
 559         num += get_est_timing(block, &mode[num]);
 560
 561         DPRINTK("   Standard Timings\n");
 562         block = edid + STD_TIMING_DESCRIPTIONS_START;
 563         for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
 564                 num += get_std_timing(block, &mode[num]);
 565
 566         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 567         for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
 568                 if (block[0] == 0x00 && block[1] == 0x00 && block[3] == 0xfa)
 569                         num += get_dst_timing(block + 5, &mode[num]);
 570         }
 571
 572         /* Yikes, EDID data is totally useless */
 573         if (!num) {
 574                 kfree(mode);
 575                 return NULL;
 576         }
 577
 578         *dbsize = num;
 579         m = kmalloc(num * sizeof(struct fb_videomode), GFP_KERNEL);
 580         if (!m)
 581                 return mode;
 582         memmove(m, mode, num * sizeof(struct fb_videomode));
 583         kfree(mode);
 584         return m;
 585 }
 586
 587 /**
 588  * fb_destroy_modedb - destroys mode database
 589  * @modedb: mode database to destroy
 590  *
 591  * DESCRIPTION:
 592  * Destroy mode database created by fb_create_modedb
 593  */
 594 void fb_destroy_modedb(struct fb_videomode *modedb)
 595 {
 596         kfree(modedb);
 597 }
 598
 599 static int fb_get_monitor_limits(unsigned char *edid, struct fb_monspecs *specs)
 600 {
 601         int i, retval = 1;
 602         unsigned char *block;
 603
 604         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 605
 606         DPRINTK("      Monitor Operating Limits: ");
 607
 608         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
 609                 if (edid_is_limits_block(block)) {
 610                         specs->hfmin = H_MIN_RATE * 1000;
 611                         specs->hfmax = H_MAX_RATE * 1000;
 612                         specs->vfmin = V_MIN_RATE;
 613                         specs->vfmax = V_MAX_RATE;
 614                         specs->dclkmax = MAX_PIXEL_CLOCK * 1000000;
 615                         specs->gtf = (GTF_SUPPORT) ? 1 : 0;
 616                         retval = 0;
 617                         DPRINTK("From EDID\n");
 618                         break;
 619                 }
 620         }
 621
 622         /* estimate monitor limits based on modes supported */
 623         if (retval) {
 624                 struct fb_videomode *modes, *mode;
 625                 int num_modes, i, hz, hscan, pixclock;
 626                 int vtotal, htotal;
 627
 628                 modes = fb_create_modedb(edid, &num_modes);
 629                 if (!modes) {
 630                         DPRINTK("None Available\n");
 631                         return 1;
 632                 }
 633
 634                 retval = 0;
 635                 for (i = 0; i < num_modes; i++) {
 636                         mode = &modes[i];
 637                         pixclock = PICOS2KHZ(modes[i].pixclock) * 1000;
 638                         htotal = mode->xres + mode->right_margin + mode->hsync_len
 639                                 + mode->left_margin;
 640                         vtotal = mode->yres + mode->lower_margin + mode->vsync_len
 641                                 + mode->upper_margin;
 642
 643                         if (mode->vmode & FB_VMODE_INTERLACED)
 644                                 vtotal /= 2;
 645
 646                         if (mode->vmode & FB_VMODE_DOUBLE)
 647                                 vtotal *= 2;
 648
 649                         hscan = (pixclock + htotal / 2) / htotal;
 650                         hscan = (hscan + 500) / 1000 * 1000;
 651                         hz = (hscan + vtotal / 2) / vtotal;
 652
 653                         if (specs->dclkmax == 0 || specs->dclkmax < pixclock)
 654                                 specs->dclkmax = pixclock;
 655
 656                         if (specs->dclkmin == 0 || specs->dclkmin > pixclock)
 657                                 specs->dclkmin = pixclock;
 658
 659                         if (specs->hfmax == 0 || specs->hfmax < hscan)
 660                                 specs->hfmax = hscan;
 661
 662                         if (specs->hfmin == 0 || specs->hfmin > hscan)
 663                                 specs->hfmin = hscan;
 664
 665                         if (specs->vfmax == 0 || specs->vfmax < hz)
 666                                 specs->vfmax = hz;
 667
 668                         if (specs->vfmin == 0 || specs->vfmin > hz)
 669                                 specs->vfmin = hz;
 670                 }
 671                 DPRINTK("Extrapolated\n");
 672                 fb_destroy_modedb(modes);
 673         }
 674         DPRINTK("           H: %d-%dKHz V: %d-%dHz DCLK: %dMHz\n",
 675                 specs->hfmin/1000, specs->hfmax/1000, specs->vfmin,
 676                 specs->vfmax, specs->dclkmax/1000000);
 677         return retval;
 678 }
 679
 680 static void get_monspecs(unsigned char *edid, struct fb_monspecs *specs)
 681 {
 682         unsigned char c, *block;
 683
 684         block = edid + EDID_STRUCT_DISPLAY;
 685
 686         fb_get_monitor_limits(edid, specs);
 687
 688         c = block[0] & 0x80;
 689         specs->input = 0;
 690         if (c) {
 691                 specs->input |= FB_DISP_DDI;
 692                 DPRINTK("      Digital Display Input");
 693         } else {
 694                 DPRINTK("      Analog Display Input: Input Voltage - ");
 695                 switch ((block[0] & 0x60) >> 5) {
 696                 case 0:
 697                         DPRINTK("0.700V/0.300V");
 698                         specs->input |= FB_DISP_ANA_700_300;
 699                         break;
 700                 case 1:
 701                         DPRINTK("0.714V/0.286V");
 702                         specs->input |= FB_DISP_ANA_714_286;
 703                         break;
 704                 case 2:
 705                         DPRINTK("1.000V/0.400V");
 706                         specs->input |= FB_DISP_ANA_1000_400;
 707                         break;
 708                 case 3:
 709                         DPRINTK("0.700V/0.000V");
 710                         specs->input |= FB_DISP_ANA_700_000;
 711                         break;
 712                 }
 713         }
 714         DPRINTK("\n      Sync: ");
 715         c = block[0] & 0x10;
 716         if (c)
 717                 DPRINTK("      Configurable signal level\n");
 718         c = block[0] & 0x0f;
 719         specs->signal = 0;
 720         if (c & 0x10) {
 721                 DPRINTK("Blank to Blank ");
 722                 specs->signal |= FB_SIGNAL_BLANK_BLANK;
 723         }
 724         if (c & 0x08) {
 725                 DPRINTK("Separate ");
 726                 specs->signal |= FB_SIGNAL_SEPARATE;
 727         }
 728         if (c & 0x04) {
 729                 DPRINTK("Composite ");
 730                 specs->signal |= FB_SIGNAL_COMPOSITE;
 731         }
 732         if (c & 0x02) {
 733                 DPRINTK("Sync on Green ");
 734                 specs->signal |= FB_SIGNAL_SYNC_ON_GREEN;
 735         }
 736         if (c & 0x01) {
 737                 DPRINTK("Serration on ");
 738                 specs->signal |= FB_SIGNAL_SERRATION_ON;
 739         }
 740         DPRINTK("\n");
 741         specs->max_x = block[1];
 742         specs->max_y = block[2];
 743         DPRINTK("      Max H-size in cm: ");
 744         if (specs->max_x)
 745                 DPRINTK("%d\n", specs->max_x);
 746         else
 747                 DPRINTK("variable\n");
 748         DPRINTK("      Max V-size in cm: ");
 749         if (specs->max_y)
 750                 DPRINTK("%d\n", specs->max_y);
 751         else
 752                 DPRINTK("variable\n");
 753
 754         c = block[3];
 755         specs->gamma = c+100;
 756         DPRINTK("      Gamma: ");
 757         DPRINTK("%d.%d\n", specs->gamma/100, specs->gamma % 100);
 758
 759         get_dpms_capabilities(block[4], specs);
 760
 761         switch ((block[4] & 0x18) >> 3) {
 762         case 0:
 763                 DPRINTK("      Monochrome/Grayscale\n");
 764                 specs->input |= FB_DISP_MONO;
 765                 break;
 766         case 1:
 767                 DPRINTK("      RGB Color Display\n");
 768                 specs->input |= FB_DISP_RGB;
 769                 break;
 770         case 2:
 771                 DPRINTK("      Non-RGB Multicolor Display\n");
 772                 specs->input |= FB_DISP_MULTI;
 773                 break;
 774         default:
 775                 DPRINTK("      Unknown\n");
 776                 specs->input |= FB_DISP_UNKNOWN;
 777                 break;
 778         }
 779
 780         get_chroma(block, specs);
 781
 782         specs->misc = 0;
 783         c = block[4] & 0x7;
 784         if (c & 0x04) {
 785                 DPRINTK("      Default color format is primary\n");
 786                 specs->misc |= FB_MISC_PRIM_COLOR;
 787         }
 788         if (c & 0x02) {
 789                 DPRINTK("      First DETAILED Timing is preferred\n");
 790                 specs->misc |= FB_MISC_1ST_DETAIL;
 791         }
 792         if (c & 0x01) {
 793                 printk("      Display is GTF capable\n");
 794                 specs->gtf = 1;
 795         }
 796 }
 797
 798 static int edid_is_timing_block(unsigned char *block)
 799 {
 800         if ((block[0] != 0x00) || (block[1] != 0x00) ||
 801             (block[2] != 0x00) || (block[4] != 0x00))
 802                 return 1;
 803         else
 804                 return 0;
 805 }
 806
 807 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
 808 {
 809         int i;
 810         unsigned char *block;
 811
 812         if (edid == NULL || var == NULL)
 813                 return 1;
 814
 815         if (!(edid_checksum(edid)))
 816                 return 1;
 817
 818         if (!(edid_check_header(edid)))
 819                 return 1;
 820
 821         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 822
 823         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
 824                 if (edid_is_timing_block(block)) {
 825                         var->xres = var->xres_virtual = H_ACTIVE;
 826                         var->yres = var->yres_virtual = V_ACTIVE;
 827                         var->height = var->width = -1;
 828                         var->right_margin = H_SYNC_OFFSET;
 829                         var->left_margin = (H_ACTIVE + H_BLANKING) -
 830                                 (H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
 831                         var->upper_margin = V_BLANKING - V_SYNC_OFFSET -
 832                                 V_SYNC_WIDTH;
 833                         var->lower_margin = V_SYNC_OFFSET;
 834                         var->hsync_len = H_SYNC_WIDTH;
 835                         var->vsync_len = V_SYNC_WIDTH;
 836                         var->pixclock = PIXEL_CLOCK;
 837                         var->pixclock /= 1000;
 838                         var->pixclock = KHZ2PICOS(var->pixclock);
 839
 840                         if (HSYNC_POSITIVE)
 841                                 var->sync |= FB_SYNC_HOR_HIGH_ACT;
 842                         if (VSYNC_POSITIVE)
 843                                 var->sync |= FB_SYNC_VERT_HIGH_ACT;
 844                         return 0;
 845                 }
 846         }
 847         return 1;
 848 }
 849
 850 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
 851 {
 852         unsigned char *block;
 853         int i, found = 0;
 854
 855         if (edid == NULL)
 856                 return;
 857
 858         if (!(edid_checksum(edid)))
 859                 return;
 860
 861         if (!(edid_check_header(edid)))
 862                 return;
 863
 864         memset(specs, 0, sizeof(struct fb_monspecs));
 865
 866         specs->version = edid[EDID_STRUCT_VERSION];
 867         specs->revision = edid[EDID_STRUCT_REVISION];
 868
 869         DPRINTK("========================================\n");
 870         DPRINTK("Display Information (EDID)\n");
 871         DPRINTK("========================================\n");
 872         DPRINTK("   EDID Version %d.%d\n", (int) specs->version,
 873                (int) specs->revision);
 874
 875         parse_vendor_block(edid + ID_MANUFACTURER_NAME, specs);
 876
 877         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 878         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
 879                 if (edid_is_serial_block(block)) {
 880                         copy_string(block, specs->serial_no);
 881                         DPRINTK("   Serial Number: %s\n", specs->serial_no);
 882                 } else if (edid_is_ascii_block(block)) {
 883                         copy_string(block, specs->ascii);
 884                         DPRINTK("   ASCII Block: %s\n", specs->ascii);
 885                 } else if (edid_is_monitor_block(block)) {
 886                         copy_string(block, specs->monitor);
 887                         DPRINTK("   Monitor Name: %s\n", specs->monitor);
 888                 }
 889         }
 890
 891         DPRINTK("   Display Characteristics:\n");
 892         get_monspecs(edid, specs);
 893
 894         specs->modedb = fb_create_modedb(edid, &specs->modedb_len);
 895
 896         /*
 897          * Workaround for buggy EDIDs that sets that the first
 898          * detailed timing is preferred but has not detailed
 899          * timing specified
 900          */
 901         for (i = 0; i < specs->modedb_len; i++) {
 902                 if (specs->modedb[i].flag & FB_MODE_IS_DETAILED) {
 903                         found = 1;
 904                         break;
 905                 }
 906         }
 907
 908         if (!found)
 909                 specs->misc &= ~FB_MISC_1ST_DETAIL;
 910
 911         DPRINTK("========================================\n");
 912 }
 913
 914 /*
 915  * VESA Generalized Timing Formula (GTF)
 916  */
 917
 918 #define FLYBACK                     550
 919 #define V_FRONTPORCH                1
 920 #define H_OFFSET                    40
 921 #define H_SCALEFACTOR               20
 922 #define H_BLANKSCALE                128
 923 #define H_GRADIENT                  600
 924 #define C_VAL                       30
 925 #define M_VAL                       300
 926
 927 struct __fb_timings {
 928         u32 dclk;
 929         u32 hfreq;
 930         u32 vfreq;
 931         u32 hactive;
 932         u32 vactive;
 933         u32 hblank;
 934         u32 vblank;
 935         u32 htotal;
 936         u32 vtotal;
 937 };
 938
 939 /**
 940  * fb_get_vblank - get vertical blank time
 941  * @hfreq: horizontal freq
 942  *
 943  * DESCRIPTION:
 944  * vblank = right_margin + vsync_len + left_margin
 945  *
 946  *    given: right_margin = 1 (V_FRONTPORCH)
 947  *           vsync_len    = 3
 948  *           flyback      = 550
 949  *
 950  *                          flyback * hfreq
 951  *           left_margin  = --------------- - vsync_len
 952  *                           1000000
 953  */
 954 static u32 fb_get_vblank(u32 hfreq)
 955 {
 956         u32 vblank;
 957
 958         vblank = (hfreq * FLYBACK)/1000;
 959         vblank = (vblank + 500)/1000;
 960         return (vblank + V_FRONTPORCH);
 961 }
 962
 963 /**
 964  * fb_get_hblank_by_freq - get horizontal blank time given hfreq
 965  * @hfreq: horizontal freq
 966  * @xres: horizontal resolution in pixels
 967  *
 968  * DESCRIPTION:
 969  *
 970  *           xres * duty_cycle
 971  * hblank = ------------------
 972  *           100 - duty_cycle
 973  *
 974  * duty cycle = percent of htotal assigned to inactive display
 975  * duty cycle = C - (M/Hfreq)
 976  *
 977  * where: C = ((offset - scale factor) * blank_scale)
 978  *            -------------------------------------- + scale factor
 979  *                        256
 980  *        M = blank_scale * gradient
 981  *
 982  */
 983 static u32 fb_get_hblank_by_hfreq(u32 hfreq, u32 xres)
 984 {
 985         u32 c_val, m_val, duty_cycle, hblank;
 986
 987         c_val = (((H_OFFSET - H_SCALEFACTOR) * H_BLANKSCALE)/256 +
 988                  H_SCALEFACTOR) * 1000;
 989         m_val = (H_BLANKSCALE * H_GRADIENT)/256;
 990         m_val = (m_val * 1000000)/hfreq;
 991         duty_cycle = c_val - m_val;
 992         hblank = (xres * duty_cycle)/(100000 - duty_cycle);
 993         return (hblank);
 994 }
 995
 996 /**
 997  * fb_get_hblank_by_dclk - get horizontal blank time given pixelclock
 998  * @dclk: pixelclock in Hz
 999  * @xres: horizontal resolution in pixels
1000  *
1001  * DESCRIPTION:
1002  *
1003  *           xres * duty_cycle
1004  * hblank = ------------------
1005  *           100 - duty_cycle
1006  *
1007  * duty cycle = percent of htotal assigned to inactive display
1008  * duty cycle = C - (M * h_period)
1009  *
1010  * where: h_period = SQRT(100 - C + (0.4 * xres * M)/dclk) + C - 100
1011  *                   -----------------------------------------------
1012  *                                    2 * M
1013  *        M = 300;
1014  *        C = 30;
1015
1016  */
1017 static u32 fb_get_hblank_by_dclk(u32 dclk, u32 xres)
1018 {
1019         u32 duty_cycle, h_period, hblank;
1020
1021         dclk /= 1000;
1022         h_period = 100 - C_VAL;
1023         h_period *= h_period;
1024         h_period += (M_VAL * xres * 2 * 1000)/(5 * dclk);
1025         h_period *=10000;
1026
1027         h_period = int_sqrt(h_period);
1028         h_period -= (100 - C_VAL) * 100;
1029         h_period *= 1000;
1030         h_period /= 2 * M_VAL;
1031
1032         duty_cycle = C_VAL * 1000 - (M_VAL * h_period)/100;
1033         hblank = (xres * duty_cycle)/(100000 - duty_cycle) + 8;
1034         hblank &= ~15;
1035         return (hblank);
1036 }
1037
1038 /**
1039  * fb_get_hfreq - estimate hsync
1040  * @vfreq: vertical refresh rate
1041  * @yres: vertical resolution
1042  *
1043  * DESCRIPTION:
1044  *
1045  *          (yres + front_port) * vfreq * 1000000
1046  * hfreq = -------------------------------------
1047  *          (1000000 - (vfreq * FLYBACK)
1048  *
1049  */
1050
1051 static u32 fb_get_hfreq(u32 vfreq, u32 yres)
1052 {
1053         u32 divisor, hfreq;
1054
1055         divisor = (1000000 - (vfreq * FLYBACK))/1000;
1056         hfreq = (yres + V_FRONTPORCH) * vfreq  * 1000;
1057         return (hfreq/divisor);
1058 }
1059
1060 static void fb_timings_vfreq(struct __fb_timings *timings)
1061 {
1062         timings->hfreq = fb_get_hfreq(timings->vfreq, timings->vactive);
1063         timings->vblank = fb_get_vblank(timings->hfreq);
1064         timings->vtotal = timings->vactive + timings->vblank;
1065         timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1066                                                  timings->hactive);
1067         timings->htotal = timings->hactive + timings->hblank;
1068         timings->dclk = timings->htotal * timings->hfreq;
1069 }
1070
1071 static void fb_timings_hfreq(struct __fb_timings *timings)
1072 {
1073         timings->vblank = fb_get_vblank(timings->hfreq);
1074         timings->vtotal = timings->vactive + timings->vblank;
1075         timings->vfreq = timings->hfreq/timings->vtotal;
1076         timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1077                                                  timings->hactive);
1078         timings->htotal = timings->hactive + timings->hblank;
1079         timings->dclk = timings->htotal * timings->hfreq;
1080 }
1081
1082 static void fb_timings_dclk(struct __fb_timings *timings)
1083 {
1084         timings->hblank = fb_get_hblank_by_dclk(timings->dclk,
1085                                                 timings->hactive);
1086         timings->htotal = timings->hactive + timings->hblank;
1087         timings->hfreq = timings->dclk/timings->htotal;
1088         timings->vblank = fb_get_vblank(timings->hfreq);
1089         timings->vtotal = timings->vactive + timings->vblank;
1090         timings->vfreq = timings->hfreq/timings->vtotal;
1091 }
1092
1093 /*
1094  * fb_get_mode - calculates video mode using VESA GTF
1095  * @flags: if: 0 - maximize vertical refresh rate
1096  *             1 - vrefresh-driven calculation;
1097  *             2 - hscan-driven calculation;
1098  *             3 - pixelclock-driven calculation;
1099  * @val: depending on @flags, ignored, vrefresh, hsync or pixelclock
1100  * @var: pointer to fb_var_screeninfo
1101  * @info: pointer to fb_info
1102  *
1103  * DESCRIPTION:
1104  * Calculates video mode based on monitor specs using VESA GTF.
1105  * The GTF is best for VESA GTF compliant monitors but is
1106  * specifically formulated to work for older monitors as well.
1107  *
1108  * If @flag==0, the function will attempt to maximize the
1109  * refresh rate.  Otherwise, it will calculate timings based on
1110  * the flag and accompanying value.
1111  *
1112  * If FB_IGNOREMON bit is set in @flags, monitor specs will be
1113  * ignored and @var will be filled with the calculated timings.
1114  *
1115  * All calculations are based on the VESA GTF Spreadsheet
1116  * available at VESA's public ftp (http://www.vesa.org).
1117  *
1118  * NOTES:
1119  * The timings generated by the GTF will be different from VESA
1120  * DMT.  It might be a good idea to keep a table of standard
1121  * VESA modes as well.  The GTF may also not work for some displays,
1122  * such as, and especially, analog TV.
1123  *
1124  * REQUIRES:
1125  * A valid info->monspecs, otherwise 'safe numbers' will be used.
1126  */
1127 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_info *info)
1128 {
1129         struct __fb_timings *timings;
1130         u32 interlace = 1, dscan = 1;
1131         u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax, err = 0;
1132
1133
1134         timings = kzalloc(sizeof(struct __fb_timings), GFP_KERNEL);
1135
1136         if (!timings)
1137                 return -ENOMEM;
1138
1139         /*
1140          * If monspecs are invalid, use values that are enough
1141          * for 640x480@60
1142          */
1143         if (!info || !info->monspecs.hfmax || !info->monspecs.vfmax ||
1144             !info->monspecs.dclkmax ||
1145             info->monspecs.hfmax < info->monspecs.hfmin ||
1146             info->monspecs.vfmax < info->monspecs.vfmin ||
1147             info->monspecs.dclkmax < info->monspecs.dclkmin) {
1148                 hfmin = 29000; hfmax = 30000;
1149                 vfmin = 60; vfmax = 60;
1150                 dclkmin = 0; dclkmax = 25000000;
1151         } else {
1152                 hfmin = info->monspecs.hfmin;
1153                 hfmax = info->monspecs.hfmax;
1154                 vfmin = info->monspecs.vfmin;
1155                 vfmax = info->monspecs.vfmax;
1156                 dclkmin = info->monspecs.dclkmin;
1157                 dclkmax = info->monspecs.dclkmax;
1158         }
1159
1160         timings->hactive = var->xres;
1161         timings->vactive = var->yres;
1162         if (var->vmode & FB_VMODE_INTERLACED) {
1163                 timings->vactive /= 2;
1164                 interlace = 2;
1165         }
1166         if (var->vmode & FB_VMODE_DOUBLE) {
1167                 timings->vactive *= 2;
1168                 dscan = 2;
1169         }
1170
1171         switch (flags & ~FB_IGNOREMON) {
1172         case FB_MAXTIMINGS: /* maximize refresh rate */
1173                 timings->hfreq = hfmax;
1174                 fb_timings_hfreq(timings);
1175                 if (timings->vfreq > vfmax) {
1176                         timings->vfreq = vfmax;
1177                         fb_timings_vfreq(timings);
1178                 }
1179                 if (timings->dclk > dclkmax) {
1180                         timings->dclk = dclkmax;
1181                         fb_timings_dclk(timings);
1182                 }
1183                 break;
1184         case FB_VSYNCTIMINGS: /* vrefresh driven */
1185                 timings->vfreq = val;
1186                 fb_timings_vfreq(timings);
1187                 break;
1188         case FB_HSYNCTIMINGS: /* hsync driven */
1189                 timings->hfreq = val;
1190                 fb_timings_hfreq(timings);
1191                 break;
1192         case FB_DCLKTIMINGS: /* pixelclock driven */
1193                 timings->dclk = PICOS2KHZ(val) * 1000;
1194                 fb_timings_dclk(timings);
1195                 break;
1196         default:
1197                 err = -EINVAL;
1198
1199         }
1200
1201         if (err || (!(flags & FB_IGNOREMON) &&
1202             (timings->vfreq < vfmin || timings->vfreq > vfmax ||
1203              timings->hfreq < hfmin || timings->hfreq > hfmax ||
1204              timings->dclk < dclkmin || timings->dclk > dclkmax))) {
1205                 err = -EINVAL;
1206         } else {
1207                 var->pixclock = KHZ2PICOS(timings->dclk/1000);
1208                 var->hsync_len = (timings->htotal * 8)/100;
1209                 var->right_margin = (timings->hblank/2) - var->hsync_len;
1210                 var->left_margin = timings->hblank - var->right_margin -
1211                         var->hsync_len;
1212                 var->vsync_len = (3 * interlace)/dscan;
1213                 var->lower_margin = (1 * interlace)/dscan;
1214                 var->upper_margin = (timings->vblank * interlace)/dscan -
1215                         (var->vsync_len + var->lower_margin);
1216         }
1217
1218         kfree(timings);
1219         return err;
1220 }
1221 #else
1222 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
1223 {
1224         return 1;
1225 }
1226 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1227 {
1228         specs = NULL;
1229 }
1230 void fb_destroy_modedb(struct fb_videomode *modedb)
1231 {
1232 }
1233 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var,
1234                 struct fb_info *info)
1235 {
1236         return -EINVAL;
1237 }
1238 #endif /* CONFIG_FB_MODE_HELPERS */
1239
1240 /*
1241  * fb_validate_mode - validates var against monitor capabilities
1242  * @var: pointer to fb_var_screeninfo
1243  * @info: pointer to fb_info
1244  *
1245  * DESCRIPTION:
1246  * Validates video mode against monitor capabilities specified in
1247  * info->monspecs.
1248  *
1249  * REQUIRES:
1250  * A valid info->monspecs.
1251  */
1252 int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
1253 {
1254         u32 hfreq, vfreq, htotal, vtotal, pixclock;
1255         u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;
1256
1257         /*
1258          * If monspecs are invalid, use values that are enough
1259          * for 640x480@60
1260          */
1261         if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
1262             !info->monspecs.dclkmax ||
1263             info->monspecs.hfmax < info->monspecs.hfmin ||
1264             info->monspecs.vfmax < info->monspecs.vfmin ||
1265             info->monspecs.dclkmax < info->monspecs.dclkmin) {
1266                 hfmin = 29000; hfmax = 30000;
1267                 vfmin = 60; vfmax = 60;
1268                 dclkmin = 0; dclkmax = 25000000;
1269         } else {
1270                 hfmin = info->monspecs.hfmin;
1271                 hfmax = info->monspecs.hfmax;
1272                 vfmin = info->monspecs.vfmin;
1273                 vfmax = info->monspecs.vfmax;
1274                 dclkmin = info->monspecs.dclkmin;
1275                 dclkmax = info->monspecs.dclkmax;
1276         }
1277
1278         if (!var->pixclock)
1279                 return -EINVAL;
1280         pixclock = PICOS2KHZ(var->pixclock) * 1000;
1281
1282         htotal = var->xres + var->right_margin + var->hsync_len +
1283                 var->left_margin;
1284         vtotal = var->yres + var->lower_margin + var->vsync_len +
1285                 var->upper_margin;
1286
1287         if (var->vmode & FB_VMODE_INTERLACED)
1288                 vtotal /= 2;
1289         if (var->vmode & FB_VMODE_DOUBLE)
1290                 vtotal *= 2;
1291
1292         hfreq = pixclock/htotal;
1293         hfreq = (hfreq + 500) / 1000 * 1000;
1294
1295         vfreq = hfreq/vtotal;
1296
1297         return (vfreq < vfmin || vfreq > vfmax ||
1298                 hfreq < hfmin || hfreq > hfmax ||
1299                 pixclock < dclkmin || pixclock > dclkmax) ?
1300                 -EINVAL : 0;
1301 }
1302
1303 #if defined(CONFIG_FIRMWARE_EDID) && defined(CONFIG_X86)
1304
1305 /*
1306  * We need to ensure that the EDID block is only returned for
1307  * the primary graphics adapter.
1308  */
1309
1310 const unsigned char *fb_firmware_edid(struct device *device)
1311 {
1312         struct pci_dev *dev = NULL;
1313         struct resource *res = NULL;
1314         unsigned char *edid = NULL;
1315
1316         if (device)
1317                 dev = to_pci_dev(device);
1318
1319         if (dev)
1320                 res = &dev->resource[PCI_ROM_RESOURCE];
1321
1322         if (res && res->flags & IORESOURCE_ROM_SHADOW)
1323                 edid = edid_info.dummy;
1324
1325         return edid;
1326 }
1327 #else
1328 const unsigned char *fb_firmware_edid(struct device *device)
1329 {
1330         return NULL;
1331 }
1332 #endif
1333 EXPORT_SYMBOL(fb_firmware_edid);
1334
1335 EXPORT_SYMBOL(fb_parse_edid);
1336 EXPORT_SYMBOL(fb_edid_to_monspecs);
1337 EXPORT_SYMBOL(fb_get_mode);
1338 EXPORT_SYMBOL(fb_validate_mode);
1339 EXPORT_SYMBOL(fb_destroy_modedb);