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 <common.h>
  13 #include <edid.h>
  14 #include <errno.h>
  15 #include <fdtdec.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 int edid_get_timing(u8 *buf, int buf_size, struct display_timing *timing,
 172                     int *panel_bits_per_colourp)
 173 {
 174         struct edid1_info *edid = (struct edid1_info *)buf;
 175         bool timing_done;
 176         int i;
 177
 178         if (buf_size < sizeof(*edid) || edid_check_info(edid)) {
 179                 debug("%s: Invalid buffer\n", __func__);
 180                 return -EINVAL;
 181         }
 182
 183         if (!EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(*edid)) {
 184                 debug("%s: No preferred timing\n", __func__);
 185                 return -ENOENT;
 186         }
 187
 188         /* Look for detailed timing */
 189         timing_done = false;
 190         for (i = 0; i < 4; i++) {
 191                 struct edid_monitor_descriptor *desc;
 192
 193                 desc = &edid->monitor_details.descriptor[i];
 194                 if (desc->zero_flag_1 != 0) {
 195                         decode_timing((u8 *)desc, timing);
 196                         timing_done = true;
 197                         break;
 198                 }
 199         }
 200         if (!timing_done)
 201                 return -EINVAL;
 202
 203         if (!EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid)) {
 204                 debug("%s: Not a digital display\n", __func__);
 205                 return -ENOSYS;
 206         }
 207         if (edid->version != 1 || edid->revision < 4) {
 208                 debug("%s: EDID version %d.%d does not have required info\n",
 209                       __func__, edid->version, edid->revision);
 210                 *panel_bits_per_colourp = -1;
 211         } else  {
 212                 *panel_bits_per_colourp =
 213                         ((edid->video_input_definition & 0x70) >> 3) + 4;
 214         }
 215
 216         timing->hdmi_monitor = false;
 217         if (edid->extension_flag && (buf_size >= EDID_EXT_SIZE)) {
 218                 struct edid_cea861_info *info =
 219                         (struct edid_cea861_info *)(buf + sizeof(*edid));
 220
 221                 if (info->extension_tag == EDID_CEA861_EXTENSION_TAG)
 222                         timing->hdmi_monitor = cea_is_hdmi_vsdb_present(info);
 223         }
 224
 225         return 0;
 226 }
 227
 228 /**
 229  * Snip the tailing whitespace/return of a string.
 230  *
 231  * @param string        The string to be snipped
 232  * @return the snipped string
 233  */
 234 static char *snip(char *string)
 235 {
 236         char *s;
 237
 238         /*
 239          * This is always a 13 character buffer
 240          * and it's not always terminated.
 241          */
 242         string[12] = '\0';
 243         s = &string[strlen(string) - 1];
 244
 245         while (s >= string && (isspace(*s) || *s == '\n' || *s == '\r' ||
 246                         *s == '\0'))
 247                 *(s--) = '\0';
 248
 249         return string;
 250 }
 251
 252 /**
 253  * Print an EDID monitor descriptor block
 254  *
 255  * @param monitor       The EDID monitor descriptor block
 256  * @have_timing         Modifies to 1 if the desciptor contains timing info
 257  */
 258 static void edid_print_dtd(struct edid_monitor_descriptor *monitor,
 259                            unsigned int *have_timing)
 260 {
 261         unsigned char *bytes = (unsigned char *)monitor;
 262         struct edid_detailed_timing *timing =
 263                         (struct edid_detailed_timing *)monitor;
 264
 265         if (bytes[0] == 0 && bytes[1] == 0) {
 266                 if (monitor->type == EDID_MONITOR_DESCRIPTOR_SERIAL)
 267                         printf("Monitor serial number: %s\n",
 268                                snip(monitor->data.string));
 269                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_ASCII)
 270                         printf("Monitor ID: %s\n",
 271                                snip(monitor->data.string));
 272                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_NAME)
 273                         printf("Monitor name: %s\n",
 274                                snip(monitor->data.string));
 275                 else if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE)
 276                         printf("Monitor range limits, horizontal sync: "
 277                                "%d-%d kHz, vertical refresh: "
 278                                "%d-%d Hz, max pixel clock: "
 279                                "%d MHz\n",
 280                                monitor->data.range_data.horizontal_min,
 281                                monitor->data.range_data.horizontal_max,
 282                                monitor->data.range_data.vertical_min,
 283                                monitor->data.range_data.vertical_max,
 284                                monitor->data.range_data.pixel_clock_max * 10);
 285         } else {
 286                 uint32_t pixclock, h_active, h_blanking, v_active, v_blanking;
 287                 uint32_t h_total, v_total, vfreq;
 288
 289                 pixclock = EDID_DETAILED_TIMING_PIXEL_CLOCK(*timing);
 290                 h_active = EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*timing);
 291                 h_blanking = EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*timing);
 292                 v_active = EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*timing);
 293                 v_blanking = EDID_DETAILED_TIMING_VERTICAL_BLANKING(*timing);
 294
 295                 h_total = h_active + h_blanking;
 296                 v_total = v_active + v_blanking;
 297                 if (v_total > 0 && h_total > 0)
 298                         vfreq = pixclock / (v_total * h_total);
 299                 else
 300                         vfreq = 1; /* Error case */
 301                 printf("\t%dx%d\%c\t%d Hz (detailed)\n", h_active,
 302                        v_active, h_active > 1000 ? ' ' : '\t', vfreq);
 303                 *have_timing = 1;
 304         }
 305 }
 306
 307 /**
 308  * Get the manufacturer name from an EDID info.
 309  *
 310  * @param edid_info     The EDID info to be printed
 311  * @param name          Returns the string of the manufacturer name
 312  */
 313 static void edid_get_manufacturer_name(struct edid1_info *edid, char *name)
 314 {
 315         name[0] = EDID1_INFO_MANUFACTURER_NAME_CHAR1(*edid) + 'A' - 1;
 316         name[1] = EDID1_INFO_MANUFACTURER_NAME_CHAR2(*edid) + 'A' - 1;
 317         name[2] = EDID1_INFO_MANUFACTURER_NAME_CHAR3(*edid) + 'A' - 1;
 318         name[3] = '\0';
 319 }
 320
 321 void edid_print_info(struct edid1_info *edid_info)
 322 {
 323         int i;
 324         char manufacturer[4];
 325         unsigned int have_timing = 0;
 326         uint32_t serial_number;
 327
 328         if (edid_check_info(edid_info)) {
 329                 printf("Not a valid EDID\n");
 330                 return;
 331         }
 332
 333         printf("EDID version: %d.%d\n",
 334                edid_info->version, edid_info->revision);
 335
 336         printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info));
 337
 338         edid_get_manufacturer_name(edid_info, manufacturer);
 339         printf("Manufacturer: %s\n", manufacturer);
 340
 341         serial_number = EDID1_INFO_SERIAL_NUMBER(*edid_info);
 342         if (serial_number != 0xffffffff) {
 343                 if (strcmp(manufacturer, "MAG") == 0)
 344                         serial_number -= 0x7000000;
 345                 if (strcmp(manufacturer, "OQI") == 0)
 346                         serial_number -= 456150000;
 347                 if (strcmp(manufacturer, "VSC") == 0)
 348                         serial_number -= 640000000;
 349         }
 350         printf("Serial number: %08x\n", serial_number);
 351         printf("Manufactured in week: %d year: %d\n",
 352                edid_info->week, edid_info->year + 1990);
 353
 354         printf("Video input definition: %svoltage level %d%s%s%s%s%s\n",
 355                EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid_info) ?
 356                "digital signal, " : "analog signal, ",
 357                EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(*edid_info),
 358                EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(*edid_info) ?
 359                ", blank to black" : "",
 360                EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(*edid_info) ?
 361                ", separate sync" : "",
 362                EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(*edid_info) ?
 363                ", composite sync" : "",
 364                EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(*edid_info) ?
 365                ", sync on green" : "",
 366                EDID1_INFO_VIDEO_INPUT_SERRATION_V(*edid_info) ?
 367                ", serration v" : "");
 368
 369         printf("Monitor is %s\n",
 370                EDID1_INFO_FEATURE_RGB(*edid_info) ? "RGB" : "non-RGB");
 371
 372         printf("Maximum visible display size: %d cm x %d cm\n",
 373                edid_info->max_size_horizontal,
 374                edid_info->max_size_vertical);
 375
 376         printf("Power management features: %s%s, %s%s, %s%s\n",
 377                EDID1_INFO_FEATURE_ACTIVE_OFF(*edid_info) ?
 378                "" : "no ", "active off",
 379                EDID1_INFO_FEATURE_SUSPEND(*edid_info) ? "" : "no ", "suspend",
 380                EDID1_INFO_FEATURE_STANDBY(*edid_info) ? "" : "no ", "standby");
 381
 382         printf("Estabilished timings:\n");
 383         if (EDID1_INFO_ESTABLISHED_TIMING_720X400_70(*edid_info))
 384                 printf("\t720x400\t\t70 Hz (VGA 640x400, IBM)\n");
 385         if (EDID1_INFO_ESTABLISHED_TIMING_720X400_88(*edid_info))
 386                 printf("\t720x400\t\t88 Hz (XGA2)\n");
 387         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_60(*edid_info))
 388                 printf("\t640x480\t\t60 Hz (VGA)\n");
 389         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_67(*edid_info))
 390                 printf("\t640x480\t\t67 Hz (Mac II, Apple)\n");
 391         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_72(*edid_info))
 392                 printf("\t640x480\t\t72 Hz (VESA)\n");
 393         if (EDID1_INFO_ESTABLISHED_TIMING_640X480_75(*edid_info))
 394                 printf("\t640x480\t\t75 Hz (VESA)\n");
 395         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_56(*edid_info))
 396                 printf("\t800x600\t\t56 Hz (VESA)\n");
 397         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_60(*edid_info))
 398                 printf("\t800x600\t\t60 Hz (VESA)\n");
 399         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_72(*edid_info))
 400                 printf("\t800x600\t\t72 Hz (VESA)\n");
 401         if (EDID1_INFO_ESTABLISHED_TIMING_800X600_75(*edid_info))
 402                 printf("\t800x600\t\t75 Hz (VESA)\n");
 403         if (EDID1_INFO_ESTABLISHED_TIMING_832X624_75(*edid_info))
 404                 printf("\t832x624\t\t75 Hz (Mac II)\n");
 405         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(*edid_info))
 406                 printf("\t1024x768\t87 Hz Interlaced (8514A)\n");
 407         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(*edid_info))
 408                 printf("\t1024x768\t60 Hz (VESA)\n");
 409         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(*edid_info))
 410                 printf("\t1024x768\t70 Hz (VESA)\n");
 411         if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(*edid_info))
 412                 printf("\t1024x768\t75 Hz (VESA)\n");
 413         if (EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(*edid_info))
 414                 printf("\t1280x1024\t75 (VESA)\n");
 415         if (EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(*edid_info))
 416                 printf("\t1152x870\t75 (Mac II)\n");
 417
 418         /* Standard timings. */
 419         printf("Standard timings:\n");
 420         for (i = 0; i < ARRAY_SIZE(edid_info->standard_timings); i++) {
 421                 unsigned int aspect = 10000;
 422                 unsigned int x, y;
 423                 unsigned char xres, vfreq;
 424
 425                 xres = EDID1_INFO_STANDARD_TIMING_XRESOLUTION(*edid_info, i);
 426                 vfreq = EDID1_INFO_STANDARD_TIMING_VFREQ(*edid_info, i);
 427                 if ((xres != vfreq) ||
 428                     ((xres != 0) && (xres != 1)) ||
 429                     ((vfreq != 0) && (vfreq != 1))) {
 430                         switch (EDID1_INFO_STANDARD_TIMING_ASPECT(*edid_info,
 431                                         i)) {
 432                         case ASPECT_625:
 433                                 aspect = 6250;
 434                                 break;
 435                         case ASPECT_75:
 436                                 aspect = 7500;
 437                                 break;
 438                         case ASPECT_8:
 439                                 aspect = 8000;
 440                                 break;
 441                         case ASPECT_5625:
 442                                 aspect = 5625;
 443                                 break;
 444                         }
 445                         x = (xres + 31) * 8;
 446                         y = x * aspect / 10000;
 447                         printf("\t%dx%d%c\t%d Hz\n", x, y,
 448                                x > 1000 ? ' ' : '\t', (vfreq & 0x3f) + 60);
 449                         have_timing = 1;
 450                 }
 451         }
 452
 453         /* Detailed timing information. */
 454         for (i = 0; i < ARRAY_SIZE(edid_info->monitor_details.descriptor);
 455                         i++) {
 456                 edid_print_dtd(&edid_info->monitor_details.descriptor[i],
 457                                &have_timing);
 458         }
 459
 460         if (!have_timing)
 461                 printf("\tNone\n");
 462 }