common/edid.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2012 The Chromium OS Authors.
   4  *
   5  * (C) Copyright 2010
   6  * Petr Stetiar <ynezz@true.cz>
   7  *
   8  * Contains stolen code from ddcprobe project which is:
   9  * Copyright (C) Nalin Dahyabhai <bigfun@pobox.com>
  10  */
  11
  12 #include <edid.h>
  13 #include <errno.h>
  14 #include <fdtdec.h>
  15 #include <log.h>
  16 #include <linux/ctype.h>
  17 #include <linux/string.h>
  18
  19 int edid_check_info(struct edid1_info *edid_info)
  20 {
  21         if ((edid_info == NULL) || (edid_info->version == 0))
  22                 return -1;
  23
  24         if (memcmp(edid_info->header, "\x0\xff\xff\xff\xff\xff\xff\x0", 8))
  25                 return -1;
  26
  27         if (edid_info->version == 0xff && edid_info->revision == 0xff)
  28                 return -1;
  29
  30         return 0;
  31 }
  32
  33 int edid_check_checksum(u8 *edid_block)
  34 {
  35         u8 checksum = 0;
  36         int i;
  37
  38         for (i = 0; i < 128; i++)
  39                 checksum += edid_block[i];
  40
  41         return (checksum == 0) ? 0 : -EINVAL;
  42 }
  43
  44 int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
  45                     unsigned int *hmax, unsigned int *vmin,
  46                     unsigned int *vmax)
  47 {
  48         int i;
  49         struct edid_monitor_descriptor *monitor;
  50
  51         *hmin = *hmax = *vmin = *vmax = 0;
  52         if (edid_check_info(edid))
  53                 return -1;
  54
  55         for (i = 0; i < ARRAY_SIZE(edid->monitor_details.descriptor); i++) {
  56                 monitor = &edid->monitor_details.descriptor[i];
  57                 if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE) {
  58                         *hmin = monitor->data.range_data.horizontal_min;
  59                         *hmax = monitor->data.range_data.horizontal_max;
  60                         *vmin = monitor->data.range_data.vertical_min;
  61                         *vmax = monitor->data.range_data.vertical_max;
  62                         return 0;
  63                 }
  64         }
  65         return -1;
  66 }
  67
  68 /* Set all parts of a timing entry to the same value */
  69 static void set_entry(struct timing_entry *entry, u32 value)
  70 {
  71         entry->min = value;
  72         entry->typ = value;
  73         entry->max = value;
  74 }
  75
  76 /**
  77  * decode_timing() - Decoding an 18-byte detailed timing record
  78  *
  79  * @buf:        Pointer to EDID detailed timing record
  80  * @timing:     Place to put timing
  81  */
  82 static void decode_timing(u8 *buf, struct display_timing *timing)
  83 {
  84         uint x_mm, y_mm;
  85         unsigned int ha, hbl, hso, hspw, hborder;
  86         unsigned int va, vbl, vso, vspw, vborder;
  87         struct edid_detailed_timing *t = (struct edid_detailed_timing *)buf;
  88
  89         /* Edid contains pixel clock in terms of 10KHz */
  90         set_entry(&timing->pixelclock, (buf[0] + (buf[1] << 8)) * 10000);
  91         x_mm = (buf[12] + ((buf[14] & 0xf0) << 4));
  92         y_mm = (buf[13] + ((buf[14] & 0x0f) << 8));
  93         ha = (buf[2] + ((buf[4] & 0xf0) << 4));
  94         hbl = (buf[3] + ((buf[4] & 0x0f) << 8));
  95         hso = (buf[8] + ((buf[11] & 0xc0) << 2));
  96         hspw = (buf[9] + ((buf[11] & 0x30) << 4));
  97         hborder = buf[15];
  98         va = (buf[5] + ((buf[7] & 0xf0) << 4));
  99         vbl = (buf[6] + ((buf[7] & 0x0f) << 8));
 100         vso = ((buf[10] >> 4) + ((buf[11] & 0x0c) << 2));
 101         vspw = ((buf[10] & 0x0f) + ((buf[11] & 0x03) << 4));
 102         vborder = buf[16];
 103
 104         set_entry(&timing->hactive, ha);
 105         set_entry(&timing->hfront_porch, hso);
 106         set_entry(&timing->hback_porch, hbl - hso - hspw);
 107         set_entry(&timing->hsync_len, hspw);
 108
 109         set_entry(&timing->vactive, va);
 110         set_entry(&timing->vfront_porch, vso);
 111         set_entry(&timing->vback_porch, vbl - vso - vspw);
 112         set_entry(&timing->vsync_len, vspw);
 113
 114         timing->flags = 0;
 115         if (EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(*t))
 116                 timing->flags |= DISPLAY_FLAGS_HSYNC_HIGH;
 117         else
 118                 timing->flags |= DISPLAY_FLAGS_HSYNC_LOW;
 119         if (EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(*t))
 120                 timing->flags |= DISPLAY_FLAGS_VSYNC_HIGH;
 121         else
 122                 timing->flags |= DISPLAY_FLAGS_VSYNC_LOW;
 123
 124         if (EDID_DETAILED_TIMING_FLAG_INTERLACED(*t))
 125                 timing->flags = DISPLAY_FLAGS_INTERLACED;
 126
 127         debug("Detailed mode clock %u Hz, %d mm x %d mm\n"
 128               "               %04x %04x %04x %04x hborder %x\n"
 129               "               %04x %04x %04x %04x vborder %x\n",
 130               timing->pixelclock.typ,
 131               x_mm, y_mm,
 132               ha, ha + hso, ha + hso + hspw,
 133               ha + hbl, hborder,
 134               va, va + vso, va + vso + vspw,
 135               va + vbl, vborder);
 136 }
 137
 138 /**
 139  * Check if HDMI vendor specific data block is present in CEA block
 140  * @param info  CEA extension block
 141  * Return: true if block is found
 142  */
 143 static bool cea_is_hdmi_vsdb_present(struct edid_cea861_info *info)
 144 {
 145         u8 end, i = 0;
 146
 147         /* check for end of data block */
 148         end = info->dtd_offset;
 149         if (end == 0)
 150                 end = sizeof(info->data);
 151         if (end < 4 || end > sizeof(info->data))
 152                 return false;
 153         end -= 4;
 154
 155         while (i < end) {
 156                 /* Look for vendor specific data block of appropriate size */
 157                 if ((EDID_CEA861_DB_TYPE(*info, i) == EDID_CEA861_DB_VENDOR) &&
 158                     (EDID_CEA861_DB_LEN(*info, i) >= 5)) {
 159                         u8 *db = &info->data[i + 1];
 160                         u32 oui = db[0] | (db[1] << 8) | (db[2] << 16);
 161
 162                         if (oui == HDMI_IEEE_OUI)
 163                                 return true;
 164                 }
 165                 i += EDID_CEA861_DB_LEN(*info, i) + 1;
 166         }
 167
 168         return false;
 169 }
 170
 171 static bool edid_find_valid_timing(void *buf, int count,
 172                                    struct display_timing *timing,
 173                                    bool (*mode_valid)(void *priv,
 174                                         const struct display_timing *timing),
 175                                    void *mode_valid_priv)
 176 {
 177         struct edid_detailed_timing *t = buf;
 178         bool found = false;
 179         int i;
 180
 181         for (i = 0; i < count && !found; i++, t++)
 182                 if (EDID_DETAILED_TIMING_PIXEL_CLOCK(*t) != 0) {
 183                         decode_timing((u8 *)t, timing);
 184                         if (mode_valid)
 185                                 found = mode_valid(mode_valid_priv,
 186                                                    timing);
 187                         else
 188                                 found = true;
 189                 }
 190
 191         return found;
 192 }
 193
 194 int edid_get_timing_validate(u8 *buf, int buf_size,
 195                              struct display_timing *timing,
 196                              int *panel_bits_per_colourp,
 197                              bool (*mode_valid)(void *priv,
 198                                         const struct display_timing *timing),
 199                              void *mode_valid_priv)
 200 {
 201         struct edid1_info *edid = (struct edid1_info *)buf;
 202         bool found;
 203
 204         if (buf_size < sizeof(*edid) || edid_check_info(edid)) {
 205                 debug("%s: Invalid buffer\n", __func__);
 206                 return -EINVAL;
 207         }
 208
 209         if (!EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid)) {
 210                 debug("%s: Not a digital display\n", __func__);
 211                 return -ENOSYS;
 212         }
 213
 214         if (!EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(*edid)) {
 215                 debug("%s: No preferred timing\n", __func__);
 216                 return -ENOENT;
 217         }
 218
 219         /* Look for detailed timing in base EDID */
 220         found = edid_find_valid_timing(edid->monitor_details.descriptor, 4,
 221                                        timing, mode_valid, mode_valid_priv);
 222
 223         /* Look for detailed timing in CTA-861 Extension Block */
 224         if (!found && edid->extension_flag && buf_size >= EDID_EXT_SIZE) {
 225                 struct edid_cea861_info *info =
 226                         (struct edid_cea861_info *)(buf + sizeof(*edid));
 227
 228                 if (info->extension_tag == EDID_CEA861_EXTENSION_TAG) {
 229                         int count = EDID_CEA861_DTD_COUNT(*info);
 230                         int offset = info->dtd_offset;
 231                         int size = count * sizeof(struct edid_detailed_timing);
 232
 233                         if (offset >= 4 && offset + size < EDID_SIZE)
 234                                 found = edid_find_valid_timing(
 235                                         (u8 *)info + offset, count, timing,
 236                                         mode_valid, mode_valid_priv);
 237                 }
 238         }
 239
 240         if (!found)
 241                 return -EINVAL;
 242
 243         if (edid->version != 1 || edid->revision < 4) {
 244                 debug("%s: EDID version %d.%d does not have required info\n",
 245                       __func__, edid->version, edid->revision);
 246                 *panel_bits_per_colourp = -1;
 247         } else  {
 248                 *panel_bits_per_colourp =
 249                         ((edid->video_input_definition & 0x70) >> 3) + 4;
 250         }
 251
 252         timing->hdmi_monitor = false;
 253         if (edid->extension_flag && (buf_size >= EDID_EXT_SIZE)) {
 254                 struct edid_cea861_info *info =
 255                         (struct edid_cea861_info *)(buf + sizeof(*edid));
 256
 257                 if (info->extension_tag == EDID_CEA861_EXTENSION_TAG)
 258                         timing->hdmi_monitor = cea_is_hdmi_vsdb_present(info);
 259         }
 260
 261         return 0;
 262 }
 263
 264 int edid_get_timing(u8 *buf, int buf_size, struct display_timing *timing,
 265                     int *panel_bits_per_colourp)
 266 {
 267         return edid_get_timing_validate(buf, buf_size, timing,
 268                                         panel_bits_per_colourp, NULL, NULL);
 269 }
 270
 271 /**
 272  * Snip the tailing whitespace/return of a string.
 273  *
 274  * @param string        The string to be snipped
 275  * Return: the snipped string
 276  */
 277 static char *snip(char *string)
 278 {
 279         char *s;
 280
 281         /*
 282          * This is always a 13 character buffer
 283          * and it's not always terminated.
 284          */
 285         string[12] = '\0';
 286         s = &string[strlen(string) - 1];
 287
 288         while (s >= string && (isspace(*s) || *s == '\n' || *s == '\r' ||
 289                         *s == '\0'))
 290                 *(s--) = '\0';
 291
 292         return string;
 293 }
 294
 295 /**
 296  * Print an EDID monitor descriptor block
 297  *
 298  * @param monitor       The EDID monitor descriptor block
 299  * @have_timing         Modifies to 1 if the desciptor contains timing info
 300  */
 301 static void edid_print_dtd(struct edid_monitor_descriptor *monitor,
 302                            unsigned int *have_timing)
 303 {
 304         unsigned char *bytes = (unsigned char *)monitor;
 305         struct edid_detailed_timing *timing =
 306                         (struct edid_detailed_timing *)monitor;
 307
 308         if (bytes[0] == 0 && bytes[1] == 0) {
 309                 if (monitor->type == EDID_MONITOR_DESCRIPTOR_SERIAL)
 310                         printf("Monitor serial number: %s\n",
 311                                snip(monitor->data.string));
 312                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_ASCII)
 313                         printf("Monitor ID: %s\n",
 314                                snip(monitor->data.string));
 315                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_NAME)
 316                         printf("Monitor name: %s\n",
 317                                snip(monitor->data.string));
 318                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE)
 319                         printf("Monitor range limits, horizontal sync: "
 320                                "%d-%d kHz, vertical refresh: "
 321                                "%d-%d Hz, max pixel clock: "
 322                                "%d MHz\n",
 323                                monitor->data.range_data.horizontal_min,
 324                                monitor->data.range_data.horizontal_max,
 325                                monitor->data.range_data.vertical_min,
 326                                monitor->data.range_data.vertical_max,
 327                                monitor->data.range_data.pixel_clock_max * 10);
 328         } else {
 329                 uint32_t pixclock, h_active, h_blanking, v_active, v_blanking;
 330                 uint32_t h_total, v_total, vfreq;
 331
 332                 pixclock = EDID_DETAILED_TIMING_PIXEL_CLOCK(*timing);
 333                 h_active = EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*timing);
 334                 h_blanking = EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*timing);
 335                 v_active = EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*timing);
 336                 v_blanking = EDID_DETAILED_TIMING_VERTICAL_BLANKING(*timing);
 337
 338                 h_total = h_active + h_blanking;
 339                 v_total = v_active + v_blanking;
 340                 if (v_total > 0 && h_total > 0)
 341                         vfreq = pixclock / (v_total * h_total);
 342                 else
 343                         vfreq = 1; /* Error case */
 344                 printf("\t%dx%d\%c\t%d Hz (detailed)\n", h_active,
 345                        v_active, h_active > 1000 ? ' ' : '\t', vfreq);
 346                 *have_timing = 1;
 347         }
 348 }
 349
 350 /**
 351  * Get the manufacturer name from an EDID info.
 352  *
 353  * @param edid_info     The EDID info to be printed
 354  * @param name          Returns the string of the manufacturer name
 355  */
 356 static void edid_get_manufacturer_name(struct edid1_info *edid, char *name)
 357 {
 358         name[0] = EDID1_INFO_MANUFACTURER_NAME_CHAR1(*edid) + 'A' - 1;
 359         name[1] = EDID1_INFO_MANUFACTURER_NAME_CHAR2(*edid) + 'A' - 1;
 360         name[2] = EDID1_INFO_MANUFACTURER_NAME_CHAR3(*edid) + 'A' - 1;
 361         name[3] = '\0';
 362 }
 363
 364 void edid_print_info(struct edid1_info *edid_info)
 365 {
 366         int i;
 367         char manufacturer[4];
 368         unsigned int have_timing = 0;
 369         uint32_t serial_number;
 370
 371         if (edid_check_info(edid_info)) {
 372                 printf("Not a valid EDID\n");
 373                 return;
 374         }
 375
 376         printf("EDID version: %d.%d\n",
 377                edid_info->version, edid_info->revision);
 378
 379         printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info));
 380
 381         edid_get_manufacturer_name(edid_info, manufacturer);
 382         printf("Manufacturer: %s\n", manufacturer);
 383
 384         serial_number = EDID1_INFO_SERIAL_NUMBER(*edid_info);
 385         if (serial_number != 0xffffffff) {
 386                 if (strcmp(manufacturer, "MAG") == 0)
 387                         serial_number -= 0x7000000;
 388                 if (strcmp(manufacturer, "OQI") == 0)
 389                         serial_number -= 456150000;
 390                 if (strcmp(manufacturer, "VSC") == 0)
 391                         serial_number -= 640000000;
 392         }
 393         printf("Serial number: %08x\n", serial_number);
 394         printf("Manufactured in week: %d year: %d\n",
 395                edid_info->week, edid_info->year + 1990);
 396
 397         printf("Video input definition: %svoltage level %d%s%s%s%s%s\n",
 398                EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid_info) ?
 399                "digital signal, " : "analog signal, ",
 400                EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(*edid_info),
 401                EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(*edid_info) ?
 402                ", blank to black" : "",
 403                EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(*edid_info) ?
 404                ", separate sync" : "",
 405                EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(*edid_info) ?
 406                ", composite sync" : "",
 407                EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(*edid_info) ?
 408                ", sync on green" : "",
 409                EDID1_INFO_VIDEO_INPUT_SERRATION_V(*edid_info) ?
 410                ", serration v" : "");
 411
 412         printf("Monitor is %s\n",
 413                EDID1_INFO_FEATURE_RGB(*edid_info) ? "RGB" : "non-RGB");
 414
 415         printf("Maximum visible display size: %d cm x %d cm\n",
 416                edid_info->max_size_horizontal,
 417                edid_info->max_size_vertical);
 418
 419         printf("Power management features: %s%s, %s%s, %s%s\n",
 420                EDID1_INFO_FEATURE_ACTIVE_OFF(*edid_info) ?
 421                "" : "no ", "active off",
 422                EDID1_INFO_FEATURE_SUSPEND(*edid_info) ? "" : "no ", "suspend",
 423                EDID1_INFO_FEATURE_STANDBY(*edid_info) ? "" : "no ", "standby");
 424
 425         printf("Estabilished timings:\n");
 426         if (EDID1_INFO_ESTABLISHED_TIMING_720X400_70(*edid_info))
 427                 printf("\t720x400\t\t70 Hz (VGA 640x400, IBM)\n");
 428         if (EDID1_INFO_ESTABLISHED_TIMING_720X400_88(*edid_info))
 429                 printf("\t720x400\t\t88 Hz (XGA2)\n");
 430         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_60(*edid_info))
 431                 printf("\t640x480\t\t60 Hz (VGA)\n");
 432         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_67(*edid_info))
 433                 printf("\t640x480\t\t67 Hz (Mac II, Apple)\n");
 434         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_72(*edid_info))
 435                 printf("\t640x480\t\t72 Hz (VESA)\n");
 436         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_75(*edid_info))
 437                 printf("\t640x480\t\t75 Hz (VESA)\n");
 438         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_56(*edid_info))
 439                 printf("\t800x600\t\t56 Hz (VESA)\n");
 440         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_60(*edid_info))
 441                 printf("\t800x600\t\t60 Hz (VESA)\n");
 442         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_72(*edid_info))
 443                 printf("\t800x600\t\t72 Hz (VESA)\n");
 444         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_75(*edid_info))
 445                 printf("\t800x600\t\t75 Hz (VESA)\n");
 446         if (EDID1_INFO_ESTABLISHED_TIMING_832X624_75(*edid_info))
 447                 printf("\t832x624\t\t75 Hz (Mac II)\n");
 448         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(*edid_info))
 449                 printf("\t1024x768\t87 Hz Interlaced (8514A)\n");
 450         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(*edid_info))
 451                 printf("\t1024x768\t60 Hz (VESA)\n");
 452         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(*edid_info))
 453                 printf("\t1024x768\t70 Hz (VESA)\n");
 454         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(*edid_info))
 455                 printf("\t1024x768\t75 Hz (VESA)\n");
 456         if (EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(*edid_info))
 457                 printf("\t1280x1024\t75 (VESA)\n");
 458         if (EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(*edid_info))
 459                 printf("\t1152x870\t75 (Mac II)\n");
 460
 461         /* Standard timings. */
 462         printf("Standard timings:\n");
 463         for (i = 0; i < ARRAY_SIZE(edid_info->standard_timings); i++) {
 464                 unsigned int aspect = 10000;
 465                 unsigned int x, y;
 466                 unsigned char xres, vfreq;
 467
 468                 xres = EDID1_INFO_STANDARD_TIMING_XRESOLUTION(*edid_info, i);
 469                 vfreq = EDID1_INFO_STANDARD_TIMING_VFREQ(*edid_info, i);
 470                 if ((xres != vfreq) ||
 471                     ((xres != 0) && (xres != 1)) ||
 472                     ((vfreq != 0) && (vfreq != 1))) {
 473                         switch (EDID1_INFO_STANDARD_TIMING_ASPECT(*edid_info,
 474                                         i)) {
 475                         case ASPECT_625:
 476                                 aspect = 6250;
 477                                 break;
 478                         case ASPECT_75:
 479                                 aspect = 7500;
 480                                 break;
 481                         case ASPECT_8:
 482                                 aspect = 8000;
 483                                 break;
 484                         case ASPECT_5625:
 485                                 aspect = 5625;
 486                                 break;
 487                         }
 488                         x = (xres + 31) * 8;
 489                         y = x * aspect / 10000;
 490                         printf("\t%dx%d%c\t%d Hz\n", x, y,
 491                                x > 1000 ? ' ' : '\t', (vfreq & 0x3f) + 60);
 492                         have_timing = 1;
 493                 }
 494         }
 495
 496         /* Detailed timing information. */
 497         for (i = 0; i < ARRAY_SIZE(edid_info->monitor_details.descriptor);
 498                         i++) {
 499                 edid_print_dtd(&edid_info->monitor_details.descriptor[i],
 500                                &have_timing);
 501         }
 502
 503         if (!have_timing)
 504                 printf("\tNone\n");
 505 }