uboot/common/edid.c
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   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
  19int 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
  33int 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
  44int 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 */
  69static 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 */
  82static 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 */
 143static 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
 171int 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 */
 234static 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 */
 258static 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 */
 313static 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
 321void 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}
 463