git.oblomov.eu Git - linux-2.6/blob - drivers/video/fbmon.c

   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/tty.h>
  30 #include <linux/fb.h>
  31 #include <linux/module.h>
  32 #ifdef CONFIG_PPC_OF
  33 #include <linux/pci.h>
  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, struct fb_videomode *mode)
 317 {
 318         struct fb_var_screeninfo var;
 319         struct fb_info info;
 320
 321         var.xres = xres;
 322         var.yres = yres;
 323         fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON,
 324                     refresh, &var, &info);
 325         mode->xres = xres;
 326         mode->yres = yres;
 327         mode->pixclock = var.pixclock;
 328         mode->refresh = refresh;
 329         mode->left_margin = var.left_margin;
 330         mode->right_margin = var.right_margin;
 331         mode->upper_margin = var.upper_margin;
 332         mode->lower_margin = var.lower_margin;
 333         mode->hsync_len = var.hsync_len;
 334         mode->vsync_len = var.vsync_len;
 335         mode->vmode = 0;
 336         mode->sync = 0;
 337 }
 338
 339 static int get_est_timing(unsigned char *block, struct fb_videomode *mode)
 340 {
 341         int num = 0;
 342         unsigned char c;
 343
 344         c = block[0];
 345         if (c&0x80) {
 346                 calc_mode_timings(720, 400, 70, &mode[num]);
 347                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 348                 DPRINTK("      720x400@70Hz\n");
 349         }
 350         if (c&0x40) {
 351                 calc_mode_timings(720, 400, 88, &mode[num]);
 352                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 353                 DPRINTK("      720x400@88Hz\n");
 354         }
 355         if (c&0x20) {
 356                 mode[num++] = vesa_modes[3];
 357                 DPRINTK("      640x480@60Hz\n");
 358         }
 359         if (c&0x10) {
 360                 calc_mode_timings(640, 480, 67, &mode[num]);
 361                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 362                 DPRINTK("      640x480@67Hz\n");
 363         }
 364         if (c&0x08) {
 365                 mode[num++] = vesa_modes[4];
 366                 DPRINTK("      640x480@72Hz\n");
 367         }
 368         if (c&0x04) {
 369                 mode[num++] = vesa_modes[5];
 370                 DPRINTK("      640x480@75Hz\n");
 371         }
 372         if (c&0x02) {
 373                 mode[num++] = vesa_modes[7];
 374                 DPRINTK("      800x600@56Hz\n");
 375         }
 376         if (c&0x01) {
 377                 mode[num++] = vesa_modes[8];
 378                 DPRINTK("      800x600@60Hz\n");
 379         }
 380
 381         c = block[1];
 382         if (c&0x80) {
 383                 mode[num++] = vesa_modes[9];
 384                 DPRINTK("      800x600@72Hz\n");
 385         }
 386         if (c&0x40) {
 387                 mode[num++] = vesa_modes[10];
 388                 DPRINTK("      800x600@75Hz\n");
 389         }
 390         if (c&0x20) {
 391                 calc_mode_timings(832, 624, 75, &mode[num]);
 392                 mode[num++].flag = FB_MODE_IS_CALCULATED;
 393                 DPRINTK("      832x624@75Hz\n");
 394         }
 395         if (c&0x10) {
 396                 mode[num++] = vesa_modes[12];
 397                 DPRINTK("      1024x768@87Hz Interlaced\n");
 398         }
 399         if (c&0x08) {
 400                 mode[num++] = vesa_modes[13];
 401                 DPRINTK("      1024x768@60Hz\n");
 402         }
 403         if (c&0x04) {
 404                 mode[num++] = vesa_modes[14];
 405                 DPRINTK("      1024x768@70Hz\n");
 406         }
 407         if (c&0x02) {
 408                 mode[num++] = vesa_modes[15];
 409                 DPRINTK("      1024x768@75Hz\n");
 410         }
 411         if (c&0x01) {
 412                 mode[num++] = vesa_modes[21];
 413                 DPRINTK("      1280x1024@75Hz\n");
 414         }
 415         c = block[2];
 416         if (c&0x80) {
 417                 mode[num++] = vesa_modes[17];
 418                 DPRINTK("      1152x870@75Hz\n");
 419         }
 420         DPRINTK("      Manufacturer's mask: %x\n",c&0x7F);
 421         return num;
 422 }
 423
 424 static int get_std_timing(unsigned char *block, struct fb_videomode *mode)
 425 {
 426         int xres, yres = 0, refresh, ratio, i;
 427
 428         xres = (block[0] + 31) * 8;
 429         if (xres <= 256)
 430                 return 0;
 431
 432         ratio = (block[1] & 0xc0) >> 6;
 433         switch (ratio) {
 434         case 0:
 435                 yres = xres;
 436                 break;
 437         case 1:
 438                 yres = (xres * 3)/4;
 439                 break;
 440         case 2:
 441                 yres = (xres * 4)/5;
 442                 break;
 443         case 3:
 444                 yres = (xres * 9)/16;
 445                 break;
 446         }
 447         refresh = (block[1] & 0x3f) + 60;
 448
 449         DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
 450         for (i = 0; i < VESA_MODEDB_SIZE; i++) {
 451                 if (vesa_modes[i].xres == xres &&
 452                     vesa_modes[i].yres == yres &&
 453                     vesa_modes[i].refresh == refresh) {
 454                         *mode = vesa_modes[i];
 455                         mode->flag |= FB_MODE_IS_STANDARD;
 456                         return 1;
 457                 }
 458         }
 459         calc_mode_timings(xres, yres, refresh, mode);
 460         return 1;
 461 }
 462
 463 static int get_dst_timing(unsigned char *block,
 464                           struct fb_videomode *mode)
 465 {
 466         int j, num = 0;
 467
 468         for (j = 0; j < 6; j++, block+= STD_TIMING_DESCRIPTION_SIZE)
 469                 num += get_std_timing(block, &mode[num]);
 470
 471         return num;
 472 }
 473
 474 static void get_detailed_timing(unsigned char *block,
 475                                 struct fb_videomode *mode)
 476 {
 477         mode->xres = H_ACTIVE;
 478         mode->yres = V_ACTIVE;
 479         mode->pixclock = PIXEL_CLOCK;
 480         mode->pixclock /= 1000;
 481         mode->pixclock = KHZ2PICOS(mode->pixclock);
 482         mode->right_margin = H_SYNC_OFFSET;
 483         mode->left_margin = (H_ACTIVE + H_BLANKING) -
 484                 (H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
 485         mode->upper_margin = V_BLANKING - V_SYNC_OFFSET -
 486                 V_SYNC_WIDTH;
 487         mode->lower_margin = V_SYNC_OFFSET;
 488         mode->hsync_len = H_SYNC_WIDTH;
 489         mode->vsync_len = V_SYNC_WIDTH;
 490         if (HSYNC_POSITIVE)
 491                 mode->sync |= FB_SYNC_HOR_HIGH_ACT;
 492         if (VSYNC_POSITIVE)
 493                 mode->sync |= FB_SYNC_VERT_HIGH_ACT;
 494         mode->refresh = PIXEL_CLOCK/((H_ACTIVE + H_BLANKING) *
 495                                      (V_ACTIVE + V_BLANKING));
 496         mode->vmode = 0;
 497         mode->flag = FB_MODE_IS_DETAILED;
 498
 499         DPRINTK("      %d MHz ",  PIXEL_CLOCK/1000000);
 500         DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET,
 501                H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
 502         DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET,
 503                V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
 504         DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-",
 505                (VSYNC_POSITIVE) ? "+" : "-");
 506 }
 507
 508 /**
 509  * fb_create_modedb - create video mode database
 510  * @edid: EDID data
 511  * @dbsize: database size
 512  *
 513  * RETURNS: struct fb_videomode, @dbsize contains length of database
 514  *
 515  * DESCRIPTION:
 516  * This function builds a mode database using the contents of the EDID
 517  * data
 518  */
 519 static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize)
 520 {
 521         struct fb_videomode *mode, *m;
 522         unsigned char *block;
 523         int num = 0, i;
 524
 525         mode = kmalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
 526         if (mode == NULL)
 527                 return NULL;
 528         memset(mode, 0, 50 * sizeof(struct fb_videomode));
 529
 530         if (edid == NULL || !edid_checksum(edid) ||
 531             !edid_check_header(edid)) {
 532                 kfree(mode);
 533                 return NULL;
 534         }
 535
 536         *dbsize = 0;
 537
 538         DPRINTK("   Supported VESA Modes\n");
 539         block = edid + ESTABLISHED_TIMING_1;
 540         num += get_est_timing(block, &mode[num]);
 541
 542         DPRINTK("   Standard Timings\n");
 543         block = edid + STD_TIMING_DESCRIPTIONS_START;
 544         for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
 545                 num += get_std_timing(block, &mode[num]);
 546
 547         DPRINTK("   Detailed Timings\n");
 548         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 549         for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
 550                 int first = 1;
 551
 552                 if (block[0] == 0x00 && block[1] == 0x00) {
 553                         if (block[3] == 0xfa) {
 554                                 num += get_dst_timing(block + 5, &mode[num]);
 555                         }
 556                 } else  {
 557                         get_detailed_timing(block, &mode[num]);
 558                         if (first) {
 559                                 mode[num].flag |= FB_MODE_IS_FIRST;
 560                                 first = 0;
 561                         }
 562                         num++;
 563                 }
 564         }
 565
 566         /* Yikes, EDID data is totally useless */
 567         if (!num) {
 568                 kfree(mode);
 569                 return NULL;
 570         }
 571
 572         *dbsize = num;
 573         m = kmalloc(num * sizeof(struct fb_videomode), GFP_KERNEL);
 574         if (!m)
 575                 return mode;
 576         memmove(m, mode, num * sizeof(struct fb_videomode));
 577         kfree(mode);
 578         return m;
 579 }
 580
 581 /**
 582  * fb_destroy_modedb - destroys mode database
 583  * @modedb: mode database to destroy
 584  *
 585  * DESCRIPTION:
 586  * Destroy mode database created by fb_create_modedb
 587  */
 588 void fb_destroy_modedb(struct fb_videomode *modedb)
 589 {
 590         kfree(modedb);
 591 }
 592
 593 static int fb_get_monitor_limits(unsigned char *edid, struct fb_monspecs *specs)
 594 {
 595         int i, retval = 1;
 596         unsigned char *block;
 597
 598         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 599
 600         DPRINTK("      Monitor Operating Limits: ");
 601         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
 602                 if (edid_is_limits_block(block)) {
 603                         specs->hfmin = H_MIN_RATE * 1000;
 604                         specs->hfmax = H_MAX_RATE * 1000;
 605                         specs->vfmin = V_MIN_RATE;
 606                         specs->vfmax = V_MAX_RATE;
 607                         specs->dclkmax = MAX_PIXEL_CLOCK * 1000000;
 608                         specs->gtf = (GTF_SUPPORT) ? 1 : 0;
 609                         retval = 0;
 610                         DPRINTK("From EDID\n");
 611                         break;
 612                 }
 613         }
 614
 615         /* estimate monitor limits based on modes supported */
 616         if (retval) {
 617                 struct fb_videomode *modes;
 618                 int num_modes, i, hz, hscan, pixclock;
 619
 620                 modes = fb_create_modedb(edid, &num_modes);
 621                 if (!modes) {
 622                         DPRINTK("None Available\n");
 623                         return 1;
 624                 }
 625
 626                 retval = 0;
 627                 for (i = 0; i < num_modes; i++) {
 628                         hz = modes[i].refresh;
 629                         pixclock = PICOS2KHZ(modes[i].pixclock) * 1000;
 630                         hscan = (modes[i].yres * 105 * hz + 5000)/100;
 631
 632                         if (specs->dclkmax == 0 || specs->dclkmax < pixclock)
 633                                 specs->dclkmax = pixclock;
 634                         if (specs->dclkmin == 0 || specs->dclkmin > pixclock)
 635                                 specs->dclkmin = pixclock;
 636                         if (specs->hfmax == 0 || specs->hfmax < hscan)
 637                                 specs->hfmax = hscan;
 638                         if (specs->hfmin == 0 || specs->hfmin > hscan)
 639                                 specs->hfmin = hscan;
 640                         if (specs->vfmax == 0 || specs->vfmax < hz)
 641                                 specs->vfmax = hz;
 642                         if (specs->vfmin == 0 || specs->vfmin > hz)
 643                                 specs->vfmin = hz;
 644                 }
 645                 DPRINTK("Extrapolated\n");
 646                 fb_destroy_modedb(modes);
 647         }
 648         DPRINTK("           H: %d-%dKHz V: %d-%dHz DCLK: %dMHz\n",
 649                 specs->hfmin/1000, specs->hfmax/1000, specs->vfmin,
 650                 specs->vfmax, specs->dclkmax/1000000);
 651         return retval;
 652 }
 653
 654 static void get_monspecs(unsigned char *edid, struct fb_monspecs *specs)
 655 {
 656         unsigned char c, *block;
 657
 658         block = edid + EDID_STRUCT_DISPLAY;
 659
 660         fb_get_monitor_limits(edid, specs);
 661
 662         c = block[0] & 0x80;
 663         specs->input = 0;
 664         if (c) {
 665                 specs->input |= FB_DISP_DDI;
 666                 DPRINTK("      Digital Display Input");
 667         } else {
 668                 DPRINTK("      Analog Display Input: Input Voltage - ");
 669                 switch ((block[0] & 0x60) >> 5) {
 670                 case 0:
 671                         DPRINTK("0.700V/0.300V");
 672                         specs->input |= FB_DISP_ANA_700_300;
 673                         break;
 674                 case 1:
 675                         DPRINTK("0.714V/0.286V");
 676                         specs->input |= FB_DISP_ANA_714_286;
 677                         break;
 678                 case 2:
 679                         DPRINTK("1.000V/0.400V");
 680                         specs->input |= FB_DISP_ANA_1000_400;
 681                         break;
 682                 case 3:
 683                         DPRINTK("0.700V/0.000V");
 684                         specs->input |= FB_DISP_ANA_700_000;
 685                         break;
 686                 }
 687         }
 688         DPRINTK("\n      Sync: ");
 689         c = block[0] & 0x10;
 690         if (c)
 691                 DPRINTK("      Configurable signal level\n");
 692         c = block[0] & 0x0f;
 693         specs->signal = 0;
 694         if (c & 0x10) {
 695                 DPRINTK("Blank to Blank ");
 696                 specs->signal |= FB_SIGNAL_BLANK_BLANK;
 697         }
 698         if (c & 0x08) {
 699                 DPRINTK("Separate ");
 700                 specs->signal |= FB_SIGNAL_SEPARATE;
 701         }
 702         if (c & 0x04) {
 703                 DPRINTK("Composite ");
 704                 specs->signal |= FB_SIGNAL_COMPOSITE;
 705         }
 706         if (c & 0x02) {
 707                 DPRINTK("Sync on Green ");
 708                 specs->signal |= FB_SIGNAL_SYNC_ON_GREEN;
 709         }
 710         if (c & 0x01) {
 711                 DPRINTK("Serration on ");
 712                 specs->signal |= FB_SIGNAL_SERRATION_ON;
 713         }
 714         DPRINTK("\n");
 715         specs->max_x = block[1];
 716         specs->max_y = block[2];
 717         DPRINTK("      Max H-size in cm: ");
 718         if (specs->max_x)
 719                 DPRINTK("%d\n", specs->max_x);
 720         else
 721                 DPRINTK("variable\n");
 722         DPRINTK("      Max V-size in cm: ");
 723         if (specs->max_y)
 724                 DPRINTK("%d\n", specs->max_y);
 725         else
 726                 DPRINTK("variable\n");
 727
 728         c = block[3];
 729         specs->gamma = c+100;
 730         DPRINTK("      Gamma: ");
 731         DPRINTK("%d.%d\n", specs->gamma/100, specs->gamma % 100);
 732
 733         get_dpms_capabilities(block[4], specs);
 734
 735         switch ((block[4] & 0x18) >> 3) {
 736         case 0:
 737                 DPRINTK("      Monochrome/Grayscale\n");
 738                 specs->input |= FB_DISP_MONO;
 739                 break;
 740         case 1:
 741                 DPRINTK("      RGB Color Display\n");
 742                 specs->input |= FB_DISP_RGB;
 743                 break;
 744         case 2:
 745                 DPRINTK("      Non-RGB Multicolor Display\n");
 746                 specs->input |= FB_DISP_MULTI;
 747                 break;
 748         default:
 749                 DPRINTK("      Unknown\n");
 750                 specs->input |= FB_DISP_UNKNOWN;
 751                 break;
 752         }
 753
 754         get_chroma(block, specs);
 755
 756         specs->misc = 0;
 757         c = block[4] & 0x7;
 758         if (c & 0x04) {
 759                 DPRINTK("      Default color format is primary\n");
 760                 specs->misc |= FB_MISC_PRIM_COLOR;
 761         }
 762         if (c & 0x02) {
 763                 DPRINTK("      First DETAILED Timing is preferred\n");
 764                 specs->misc |= FB_MISC_1ST_DETAIL;
 765         }
 766         if (c & 0x01) {
 767                 printk("      Display is GTF capable\n");
 768                 specs->gtf = 1;
 769         }
 770 }
 771
 772 static int edid_is_timing_block(unsigned char *block)
 773 {
 774         if ((block[0] != 0x00) || (block[1] != 0x00) ||
 775             (block[2] != 0x00) || (block[4] != 0x00))
 776                 return 1;
 777         else
 778                 return 0;
 779 }
 780
 781 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
 782 {
 783         int i;
 784         unsigned char *block;
 785
 786         if (edid == NULL || var == NULL)
 787                 return 1;
 788
 789         if (!(edid_checksum(edid)))
 790                 return 1;
 791
 792         if (!(edid_check_header(edid)))
 793                 return 1;
 794
 795         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 796
 797         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
 798                 if (edid_is_timing_block(block)) {
 799                         var->xres = var->xres_virtual = H_ACTIVE;
 800                         var->yres = var->yres_virtual = V_ACTIVE;
 801                         var->height = var->width = -1;
 802                         var->right_margin = H_SYNC_OFFSET;
 803                         var->left_margin = (H_ACTIVE + H_BLANKING) -
 804                                 (H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
 805                         var->upper_margin = V_BLANKING - V_SYNC_OFFSET -
 806                                 V_SYNC_WIDTH;
 807                         var->lower_margin = V_SYNC_OFFSET;
 808                         var->hsync_len = H_SYNC_WIDTH;
 809                         var->vsync_len = V_SYNC_WIDTH;
 810                         var->pixclock = PIXEL_CLOCK;
 811                         var->pixclock /= 1000;
 812                         var->pixclock = KHZ2PICOS(var->pixclock);
 813
 814                         if (HSYNC_POSITIVE)
 815                                 var->sync |= FB_SYNC_HOR_HIGH_ACT;
 816                         if (VSYNC_POSITIVE)
 817                                 var->sync |= FB_SYNC_VERT_HIGH_ACT;
 818                         return 0;
 819                 }
 820         }
 821         return 1;
 822 }
 823
 824 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
 825 {
 826         unsigned char *block;
 827         int i;
 828
 829         if (edid == NULL)
 830                 return;
 831
 832         if (!(edid_checksum(edid)))
 833                 return;
 834
 835         if (!(edid_check_header(edid)))
 836                 return;
 837
 838         memset(specs, 0, sizeof(struct fb_monspecs));
 839
 840         specs->version = edid[EDID_STRUCT_VERSION];
 841         specs->revision = edid[EDID_STRUCT_REVISION];
 842
 843         DPRINTK("========================================\n");
 844         DPRINTK("Display Information (EDID)\n");
 845         DPRINTK("========================================\n");
 846         DPRINTK("   EDID Version %d.%d\n", (int) specs->version,
 847                (int) specs->revision);
 848
 849         parse_vendor_block(edid + ID_MANUFACTURER_NAME, specs);
 850
 851         block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
 852         for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
 853                 if (edid_is_serial_block(block)) {
 854                         copy_string(block, specs->serial_no);
 855                         DPRINTK("   Serial Number: %s\n", specs->serial_no);
 856                 } else if (edid_is_ascii_block(block)) {
 857                         copy_string(block, specs->ascii);
 858                         DPRINTK("   ASCII Block: %s\n", specs->ascii);
 859                 } else if (edid_is_monitor_block(block)) {
 860                         copy_string(block, specs->monitor);
 861                         DPRINTK("   Monitor Name: %s\n", specs->monitor);
 862                 }
 863         }
 864
 865         DPRINTK("   Display Characteristics:\n");
 866         get_monspecs(edid, specs);
 867
 868         specs->modedb = fb_create_modedb(edid, &specs->modedb_len);
 869         DPRINTK("========================================\n");
 870 }
 871
 872 /*
 873  * VESA Generalized Timing Formula (GTF)
 874  */
 875
 876 #define FLYBACK                     550
 877 #define V_FRONTPORCH                1
 878 #define H_OFFSET                    40
 879 #define H_SCALEFACTOR               20
 880 #define H_BLANKSCALE                128
 881 #define H_GRADIENT                  600
 882 #define C_VAL                       30
 883 #define M_VAL                       300
 884
 885 struct __fb_timings {
 886         u32 dclk;
 887         u32 hfreq;
 888         u32 vfreq;
 889         u32 hactive;
 890         u32 vactive;
 891         u32 hblank;
 892         u32 vblank;
 893         u32 htotal;
 894         u32 vtotal;
 895 };
 896
 897 /**
 898  * fb_get_vblank - get vertical blank time
 899  * @hfreq: horizontal freq
 900  *
 901  * DESCRIPTION:
 902  * vblank = right_margin + vsync_len + left_margin
 903  *
 904  *    given: right_margin = 1 (V_FRONTPORCH)
 905  *           vsync_len    = 3
 906  *           flyback      = 550
 907  *
 908  *                          flyback * hfreq
 909  *           left_margin  = --------------- - vsync_len
 910  *                           1000000
 911  */
 912 static u32 fb_get_vblank(u32 hfreq)
 913 {
 914         u32 vblank;
 915
 916         vblank = (hfreq * FLYBACK)/1000;
 917         vblank = (vblank + 500)/1000;
 918         return (vblank + V_FRONTPORCH);
 919 }
 920
 921 /**
 922  * fb_get_hblank_by_freq - get horizontal blank time given hfreq
 923  * @hfreq: horizontal freq
 924  * @xres: horizontal resolution in pixels
 925  *
 926  * DESCRIPTION:
 927  *
 928  *           xres * duty_cycle
 929  * hblank = ------------------
 930  *           100 - duty_cycle
 931  *
 932  * duty cycle = percent of htotal assigned to inactive display
 933  * duty cycle = C - (M/Hfreq)
 934  *
 935  * where: C = ((offset - scale factor) * blank_scale)
 936  *            -------------------------------------- + scale factor
 937  *                        256
 938  *        M = blank_scale * gradient
 939  *
 940  */
 941 static u32 fb_get_hblank_by_hfreq(u32 hfreq, u32 xres)
 942 {
 943         u32 c_val, m_val, duty_cycle, hblank;
 944
 945         c_val = (((H_OFFSET - H_SCALEFACTOR) * H_BLANKSCALE)/256 +
 946                  H_SCALEFACTOR) * 1000;
 947         m_val = (H_BLANKSCALE * H_GRADIENT)/256;
 948         m_val = (m_val * 1000000)/hfreq;
 949         duty_cycle = c_val - m_val;
 950         hblank = (xres * duty_cycle)/(100000 - duty_cycle);
 951         return (hblank);
 952 }
 953
 954 /**
 955  * fb_get_hblank_by_dclk - get horizontal blank time given pixelclock
 956  * @dclk: pixelclock in Hz
 957  * @xres: horizontal resolution in pixels
 958  *
 959  * DESCRIPTION:
 960  *
 961  *           xres * duty_cycle
 962  * hblank = ------------------
 963  *           100 - duty_cycle
 964  *
 965  * duty cycle = percent of htotal assigned to inactive display
 966  * duty cycle = C - (M * h_period)
 967  *
 968  * where: h_period = SQRT(100 - C + (0.4 * xres * M)/dclk) + C - 100
 969  *                   -----------------------------------------------
 970  *                                    2 * M
 971  *        M = 300;
 972  *        C = 30;
 973
 974  */
 975 static u32 fb_get_hblank_by_dclk(u32 dclk, u32 xres)
 976 {
 977         u32 duty_cycle, h_period, hblank;
 978
 979         dclk /= 1000;
 980         h_period = 100 - C_VAL;
 981         h_period *= h_period;
 982         h_period += (M_VAL * xres * 2 * 1000)/(5 * dclk);
 983         h_period *=10000;
 984
 985         h_period = int_sqrt(h_period);
 986         h_period -= (100 - C_VAL) * 100;
 987         h_period *= 1000;
 988         h_period /= 2 * M_VAL;
 989
 990         duty_cycle = C_VAL * 1000 - (M_VAL * h_period)/100;
 991         hblank = (xres * duty_cycle)/(100000 - duty_cycle) + 8;
 992         hblank &= ~15;
 993         return (hblank);
 994 }
 995
 996 /**
 997  * fb_get_hfreq - estimate hsync
 998  * @vfreq: vertical refresh rate
 999  * @yres: vertical resolution
1000  *
1001  * DESCRIPTION:
1002  *
1003  *          (yres + front_port) * vfreq * 1000000
1004  * hfreq = -------------------------------------
1005  *          (1000000 - (vfreq * FLYBACK)
1006  *
1007  */
1008
1009 static u32 fb_get_hfreq(u32 vfreq, u32 yres)
1010 {
1011         u32 divisor, hfreq;
1012
1013         divisor = (1000000 - (vfreq * FLYBACK))/1000;
1014         hfreq = (yres + V_FRONTPORCH) * vfreq  * 1000;
1015         return (hfreq/divisor);
1016 }
1017
1018 static void fb_timings_vfreq(struct __fb_timings *timings)
1019 {
1020         timings->hfreq = fb_get_hfreq(timings->vfreq, timings->vactive);
1021         timings->vblank = fb_get_vblank(timings->hfreq);
1022         timings->vtotal = timings->vactive + timings->vblank;
1023         timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1024                                                  timings->hactive);
1025         timings->htotal = timings->hactive + timings->hblank;
1026         timings->dclk = timings->htotal * timings->hfreq;
1027 }
1028
1029 static void fb_timings_hfreq(struct __fb_timings *timings)
1030 {
1031         timings->vblank = fb_get_vblank(timings->hfreq);
1032         timings->vtotal = timings->vactive + timings->vblank;
1033         timings->vfreq = timings->hfreq/timings->vtotal;
1034         timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
1035                                                  timings->hactive);
1036         timings->htotal = timings->hactive + timings->hblank;
1037         timings->dclk = timings->htotal * timings->hfreq;
1038 }
1039
1040 static void fb_timings_dclk(struct __fb_timings *timings)
1041 {
1042         timings->hblank = fb_get_hblank_by_dclk(timings->dclk,
1043                                                 timings->hactive);
1044         timings->htotal = timings->hactive + timings->hblank;
1045         timings->hfreq = timings->dclk/timings->htotal;
1046         timings->vblank = fb_get_vblank(timings->hfreq);
1047         timings->vtotal = timings->vactive + timings->vblank;
1048         timings->vfreq = timings->hfreq/timings->vtotal;
1049 }
1050
1051 /*
1052  * fb_get_mode - calculates video mode using VESA GTF
1053  * @flags: if: 0 - maximize vertical refresh rate
1054  *             1 - vrefresh-driven calculation;
1055  *             2 - hscan-driven calculation;
1056  *             3 - pixelclock-driven calculation;
1057  * @val: depending on @flags, ignored, vrefresh, hsync or pixelclock
1058  * @var: pointer to fb_var_screeninfo
1059  * @info: pointer to fb_info
1060  *
1061  * DESCRIPTION:
1062  * Calculates video mode based on monitor specs using VESA GTF.
1063  * The GTF is best for VESA GTF compliant monitors but is
1064  * specifically formulated to work for older monitors as well.
1065  *
1066  * If @flag==0, the function will attempt to maximize the
1067  * refresh rate.  Otherwise, it will calculate timings based on
1068  * the flag and accompanying value.
1069  *
1070  * If FB_IGNOREMON bit is set in @flags, monitor specs will be
1071  * ignored and @var will be filled with the calculated timings.
1072  *
1073  * All calculations are based on the VESA GTF Spreadsheet
1074  * available at VESA's public ftp (http://www.vesa.org).
1075  *
1076  * NOTES:
1077  * The timings generated by the GTF will be different from VESA
1078  * DMT.  It might be a good idea to keep a table of standard
1079  * VESA modes as well.  The GTF may also not work for some displays,
1080  * such as, and especially, analog TV.
1081  *
1082  * REQUIRES:
1083  * A valid info->monspecs, otherwise 'safe numbers' will be used.
1084  */
1085 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_info *info)
1086 {
1087         struct __fb_timings timings;
1088         u32 interlace = 1, dscan = 1;
1089         u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;
1090
1091         /*
1092          * If monspecs are invalid, use values that are enough
1093          * for 640x480@60
1094          */
1095         if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
1096             !info->monspecs.dclkmax ||
1097             info->monspecs.hfmax < info->monspecs.hfmin ||
1098             info->monspecs.vfmax < info->monspecs.vfmin ||
1099             info->monspecs.dclkmax < info->monspecs.dclkmin) {
1100                 hfmin = 29000; hfmax = 30000;
1101                 vfmin = 60; vfmax = 60;
1102                 dclkmin = 0; dclkmax = 25000000;
1103         } else {
1104                 hfmin = info->monspecs.hfmin;
1105                 hfmax = info->monspecs.hfmax;
1106                 vfmin = info->monspecs.vfmin;
1107                 vfmax = info->monspecs.vfmax;
1108                 dclkmin = info->monspecs.dclkmin;
1109                 dclkmax = info->monspecs.dclkmax;
1110         }
1111
1112         memset(&timings, 0, sizeof(struct __fb_timings));
1113         timings.hactive = var->xres;
1114         timings.vactive = var->yres;
1115         if (var->vmode & FB_VMODE_INTERLACED) {
1116                 timings.vactive /= 2;
1117                 interlace = 2;
1118         }
1119         if (var->vmode & FB_VMODE_DOUBLE) {
1120                 timings.vactive *= 2;
1121                 dscan = 2;
1122         }
1123
1124         switch (flags & ~FB_IGNOREMON) {
1125         case FB_MAXTIMINGS: /* maximize refresh rate */
1126                 timings.hfreq = hfmax;
1127                 fb_timings_hfreq(&timings);
1128                 if (timings.vfreq > vfmax) {
1129                         timings.vfreq = vfmax;
1130                         fb_timings_vfreq(&timings);
1131                 }
1132                 if (timings.dclk > dclkmax) {
1133                         timings.dclk = dclkmax;
1134                         fb_timings_dclk(&timings);
1135                 }
1136                 break;
1137         case FB_VSYNCTIMINGS: /* vrefresh driven */
1138                 timings.vfreq = val;
1139                 fb_timings_vfreq(&timings);
1140                 break;
1141         case FB_HSYNCTIMINGS: /* hsync driven */
1142                 timings.hfreq = val;
1143                 fb_timings_hfreq(&timings);
1144                 break;
1145         case FB_DCLKTIMINGS: /* pixelclock driven */
1146                 timings.dclk = PICOS2KHZ(val) * 1000;
1147                 fb_timings_dclk(&timings);
1148                 break;
1149         default:
1150                 return -EINVAL;
1151
1152         }
1153
1154         if (!(flags & FB_IGNOREMON) &&
1155             (timings.vfreq < vfmin || timings.vfreq > vfmax ||
1156              timings.hfreq < hfmin || timings.hfreq > hfmax ||
1157              timings.dclk < dclkmin || timings.dclk > dclkmax))
1158                 return -EINVAL;
1159
1160         var->pixclock = KHZ2PICOS(timings.dclk/1000);
1161         var->hsync_len = (timings.htotal * 8)/100;
1162         var->right_margin = (timings.hblank/2) - var->hsync_len;
1163         var->left_margin = timings.hblank - var->right_margin - var->hsync_len;
1164
1165         var->vsync_len = (3 * interlace)/dscan;
1166         var->lower_margin = (1 * interlace)/dscan;
1167         var->upper_margin = (timings.vblank * interlace)/dscan -
1168                 (var->vsync_len + var->lower_margin);
1169
1170         return 0;
1171 }
1172 #else
1173 int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
1174 {
1175         return 1;
1176 }
1177 void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
1178 {
1179         specs = NULL;
1180 }
1181 void fb_destroy_modedb(struct fb_videomode *modedb)
1182 {
1183 }
1184 int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var,
1185                 struct fb_info *info)
1186 {
1187         return -EINVAL;
1188 }
1189 #endif /* CONFIG_FB_MODE_HELPERS */
1190
1191 /*
1192  * fb_validate_mode - validates var against monitor capabilities
1193  * @var: pointer to fb_var_screeninfo
1194  * @info: pointer to fb_info
1195  *
1196  * DESCRIPTION:
1197  * Validates video mode against monitor capabilities specified in
1198  * info->monspecs.
1199  *
1200  * REQUIRES:
1201  * A valid info->monspecs.
1202  */
1203 int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
1204 {
1205         u32 hfreq, vfreq, htotal, vtotal, pixclock;
1206         u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;
1207
1208         /*
1209          * If monspecs are invalid, use values that are enough
1210          * for 640x480@60
1211          */
1212         if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
1213             !info->monspecs.dclkmax ||
1214             info->monspecs.hfmax < info->monspecs.hfmin ||
1215             info->monspecs.vfmax < info->monspecs.vfmin ||
1216             info->monspecs.dclkmax < info->monspecs.dclkmin) {
1217                 hfmin = 29000; hfmax = 30000;
1218                 vfmin = 60; vfmax = 60;
1219                 dclkmin = 0; dclkmax = 25000000;
1220         } else {
1221                 hfmin = info->monspecs.hfmin;
1222                 hfmax = info->monspecs.hfmax;
1223                 vfmin = info->monspecs.vfmin;
1224                 vfmax = info->monspecs.vfmax;
1225                 dclkmin = info->monspecs.dclkmin;
1226                 dclkmax = info->monspecs.dclkmax;
1227         }
1228
1229         if (!var->pixclock)
1230                 return -EINVAL;
1231         pixclock = PICOS2KHZ(var->pixclock) * 1000;
1232
1233         htotal = var->xres + var->right_margin + var->hsync_len +
1234                 var->left_margin;
1235         vtotal = var->yres + var->lower_margin + var->vsync_len +
1236                 var->upper_margin;
1237
1238         if (var->vmode & FB_VMODE_INTERLACED)
1239                 vtotal /= 2;
1240         if (var->vmode & FB_VMODE_DOUBLE)
1241                 vtotal *= 2;
1242
1243         hfreq = pixclock/htotal;
1244         vfreq = hfreq/vtotal;
1245
1246         return (vfreq < vfmin || vfreq > vfmax ||
1247                 hfreq < hfmin || hfreq > hfmax ||
1248                 pixclock < dclkmin || pixclock > dclkmax) ?
1249                 -EINVAL : 0;
1250 }
1251
1252 EXPORT_SYMBOL(fb_parse_edid);
1253 EXPORT_SYMBOL(fb_edid_to_monspecs);
1254
1255 EXPORT_SYMBOL(fb_get_mode);
1256 EXPORT_SYMBOL(fb_validate_mode);
1257 EXPORT_SYMBOL(fb_destroy_modedb);