edid.c 14 KB

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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. #include <common.h>
  12. #include <edid.h>
  13. #include <errno.h>
  14. #include <fdtdec.h>
  15. #include <linux/ctype.h>
  16. #include <linux/string.h>
  17. int edid_check_info(struct edid1_info *edid_info)
  18. {
  19. if ((edid_info == NULL) || (edid_info->version == 0))
  20. return -1;
  21. if (memcmp(edid_info->header, "\x0\xff\xff\xff\xff\xff\xff\x0", 8))
  22. return -1;
  23. if (edid_info->version == 0xff && edid_info->revision == 0xff)
  24. return -1;
  25. return 0;
  26. }
  27. int edid_check_checksum(u8 *edid_block)
  28. {
  29. u8 checksum = 0;
  30. int i;
  31. for (i = 0; i < 128; i++)
  32. checksum += edid_block[i];
  33. return (checksum == 0) ? 0 : -EINVAL;
  34. }
  35. int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
  36. unsigned int *hmax, unsigned int *vmin,
  37. unsigned int *vmax)
  38. {
  39. int i;
  40. struct edid_monitor_descriptor *monitor;
  41. *hmin = *hmax = *vmin = *vmax = 0;
  42. if (edid_check_info(edid))
  43. return -1;
  44. for (i = 0; i < ARRAY_SIZE(edid->monitor_details.descriptor); i++) {
  45. monitor = &edid->monitor_details.descriptor[i];
  46. if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE) {
  47. *hmin = monitor->data.range_data.horizontal_min;
  48. *hmax = monitor->data.range_data.horizontal_max;
  49. *vmin = monitor->data.range_data.vertical_min;
  50. *vmax = monitor->data.range_data.vertical_max;
  51. return 0;
  52. }
  53. }
  54. return -1;
  55. }
  56. /* Set all parts of a timing entry to the same value */
  57. static void set_entry(struct timing_entry *entry, u32 value)
  58. {
  59. entry->min = value;
  60. entry->typ = value;
  61. entry->max = value;
  62. }
  63. /**
  64. * decode_timing() - Decoding an 18-byte detailed timing record
  65. *
  66. * @buf: Pointer to EDID detailed timing record
  67. * @timing: Place to put timing
  68. */
  69. static void decode_timing(u8 *buf, struct display_timing *timing)
  70. {
  71. uint x_mm, y_mm;
  72. unsigned int ha, hbl, hso, hspw, hborder;
  73. unsigned int va, vbl, vso, vspw, vborder;
  74. struct edid_detailed_timing *t = (struct edid_detailed_timing *)buf;
  75. /* Edid contains pixel clock in terms of 10KHz */
  76. set_entry(&timing->pixelclock, (buf[0] + (buf[1] << 8)) * 10000);
  77. x_mm = (buf[12] + ((buf[14] & 0xf0) << 4));
  78. y_mm = (buf[13] + ((buf[14] & 0x0f) << 8));
  79. ha = (buf[2] + ((buf[4] & 0xf0) << 4));
  80. hbl = (buf[3] + ((buf[4] & 0x0f) << 8));
  81. hso = (buf[8] + ((buf[11] & 0xc0) << 2));
  82. hspw = (buf[9] + ((buf[11] & 0x30) << 4));
  83. hborder = buf[15];
  84. va = (buf[5] + ((buf[7] & 0xf0) << 4));
  85. vbl = (buf[6] + ((buf[7] & 0x0f) << 8));
  86. vso = ((buf[10] >> 4) + ((buf[11] & 0x0c) << 2));
  87. vspw = ((buf[10] & 0x0f) + ((buf[11] & 0x03) << 4));
  88. vborder = buf[16];
  89. set_entry(&timing->hactive, ha);
  90. set_entry(&timing->hfront_porch, hso);
  91. set_entry(&timing->hback_porch, hbl - hso - hspw);
  92. set_entry(&timing->hsync_len, hspw);
  93. set_entry(&timing->vactive, va);
  94. set_entry(&timing->vfront_porch, vso);
  95. set_entry(&timing->vback_porch, vbl - vso - vspw);
  96. set_entry(&timing->vsync_len, vspw);
  97. timing->flags = 0;
  98. if (EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(*t))
  99. timing->flags |= DISPLAY_FLAGS_HSYNC_HIGH;
  100. else
  101. timing->flags |= DISPLAY_FLAGS_HSYNC_LOW;
  102. if (EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(*t))
  103. timing->flags |= DISPLAY_FLAGS_VSYNC_HIGH;
  104. else
  105. timing->flags |= DISPLAY_FLAGS_VSYNC_LOW;
  106. if (EDID_DETAILED_TIMING_FLAG_INTERLACED(*t))
  107. timing->flags = DISPLAY_FLAGS_INTERLACED;
  108. debug("Detailed mode clock %u Hz, %d mm x %d mm\n"
  109. " %04x %04x %04x %04x hborder %x\n"
  110. " %04x %04x %04x %04x vborder %x\n",
  111. timing->pixelclock.typ,
  112. x_mm, y_mm,
  113. ha, ha + hso, ha + hso + hspw,
  114. ha + hbl, hborder,
  115. va, va + vso, va + vso + vspw,
  116. va + vbl, vborder);
  117. }
  118. /**
  119. * Check if HDMI vendor specific data block is present in CEA block
  120. * @param info CEA extension block
  121. * @return true if block is found
  122. */
  123. static bool cea_is_hdmi_vsdb_present(struct edid_cea861_info *info)
  124. {
  125. u8 end, i = 0;
  126. /* check for end of data block */
  127. end = info->dtd_offset;
  128. if (end == 0)
  129. end = sizeof(info->data);
  130. if (end < 4 || end > sizeof(info->data))
  131. return false;
  132. end -= 4;
  133. while (i < end) {
  134. /* Look for vendor specific data block of appropriate size */
  135. if ((EDID_CEA861_DB_TYPE(*info, i) == EDID_CEA861_DB_VENDOR) &&
  136. (EDID_CEA861_DB_LEN(*info, i) >= 5)) {
  137. u8 *db = &info->data[i + 1];
  138. u32 oui = db[0] | (db[1] << 8) | (db[2] << 16);
  139. if (oui == HDMI_IEEE_OUI)
  140. return true;
  141. }
  142. i += EDID_CEA861_DB_LEN(*info, i) + 1;
  143. }
  144. return false;
  145. }
  146. int edid_get_timing(u8 *buf, int buf_size, struct display_timing *timing,
  147. int *panel_bits_per_colourp)
  148. {
  149. struct edid1_info *edid = (struct edid1_info *)buf;
  150. bool timing_done;
  151. int i;
  152. if (buf_size < sizeof(*edid) || edid_check_info(edid)) {
  153. debug("%s: Invalid buffer\n", __func__);
  154. return -EINVAL;
  155. }
  156. if (!EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(*edid)) {
  157. debug("%s: No preferred timing\n", __func__);
  158. return -ENOENT;
  159. }
  160. /* Look for detailed timing */
  161. timing_done = false;
  162. for (i = 0; i < 4; i++) {
  163. struct edid_monitor_descriptor *desc;
  164. desc = &edid->monitor_details.descriptor[i];
  165. if (desc->zero_flag_1 != 0) {
  166. decode_timing((u8 *)desc, timing);
  167. timing_done = true;
  168. break;
  169. }
  170. }
  171. if (!timing_done)
  172. return -EINVAL;
  173. if (!EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid)) {
  174. debug("%s: Not a digital display\n", __func__);
  175. return -ENOSYS;
  176. }
  177. if (edid->version != 1 || edid->revision < 4) {
  178. debug("%s: EDID version %d.%d does not have required info\n",
  179. __func__, edid->version, edid->revision);
  180. *panel_bits_per_colourp = -1;
  181. } else {
  182. *panel_bits_per_colourp =
  183. ((edid->video_input_definition & 0x70) >> 3) + 4;
  184. }
  185. timing->hdmi_monitor = false;
  186. if (edid->extension_flag && (buf_size >= EDID_EXT_SIZE)) {
  187. struct edid_cea861_info *info =
  188. (struct edid_cea861_info *)(buf + sizeof(*edid));
  189. if (info->extension_tag == EDID_CEA861_EXTENSION_TAG)
  190. timing->hdmi_monitor = cea_is_hdmi_vsdb_present(info);
  191. }
  192. return 0;
  193. }
  194. /**
  195. * Snip the tailing whitespace/return of a string.
  196. *
  197. * @param string The string to be snipped
  198. * @return the snipped string
  199. */
  200. static char *snip(char *string)
  201. {
  202. char *s;
  203. /*
  204. * This is always a 13 character buffer
  205. * and it's not always terminated.
  206. */
  207. string[12] = '\0';
  208. s = &string[strlen(string) - 1];
  209. while (s >= string && (isspace(*s) || *s == '\n' || *s == '\r' ||
  210. *s == '\0'))
  211. *(s--) = '\0';
  212. return string;
  213. }
  214. /**
  215. * Print an EDID monitor descriptor block
  216. *
  217. * @param monitor The EDID monitor descriptor block
  218. * @have_timing Modifies to 1 if the desciptor contains timing info
  219. */
  220. static void edid_print_dtd(struct edid_monitor_descriptor *monitor,
  221. unsigned int *have_timing)
  222. {
  223. unsigned char *bytes = (unsigned char *)monitor;
  224. struct edid_detailed_timing *timing =
  225. (struct edid_detailed_timing *)monitor;
  226. if (bytes[0] == 0 && bytes[1] == 0) {
  227. if (monitor->type == EDID_MONITOR_DESCRIPTOR_SERIAL)
  228. printf("Monitor serial number: %s\n",
  229. snip(monitor->data.string));
  230. else if (monitor->type == EDID_MONITOR_DESCRIPTOR_ASCII)
  231. printf("Monitor ID: %s\n",
  232. snip(monitor->data.string));
  233. else if (monitor->type == EDID_MONITOR_DESCRIPTOR_NAME)
  234. printf("Monitor name: %s\n",
  235. snip(monitor->data.string));
  236. else if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE)
  237. printf("Monitor range limits, horizontal sync: "
  238. "%d-%d kHz, vertical refresh: "
  239. "%d-%d Hz, max pixel clock: "
  240. "%d MHz\n",
  241. monitor->data.range_data.horizontal_min,
  242. monitor->data.range_data.horizontal_max,
  243. monitor->data.range_data.vertical_min,
  244. monitor->data.range_data.vertical_max,
  245. monitor->data.range_data.pixel_clock_max * 10);
  246. } else {
  247. uint32_t pixclock, h_active, h_blanking, v_active, v_blanking;
  248. uint32_t h_total, v_total, vfreq;
  249. pixclock = EDID_DETAILED_TIMING_PIXEL_CLOCK(*timing);
  250. h_active = EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*timing);
  251. h_blanking = EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*timing);
  252. v_active = EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*timing);
  253. v_blanking = EDID_DETAILED_TIMING_VERTICAL_BLANKING(*timing);
  254. h_total = h_active + h_blanking;
  255. v_total = v_active + v_blanking;
  256. if (v_total > 0 && h_total > 0)
  257. vfreq = pixclock / (v_total * h_total);
  258. else
  259. vfreq = 1; /* Error case */
  260. printf("\t%dx%d\%c\t%d Hz (detailed)\n", h_active,
  261. v_active, h_active > 1000 ? ' ' : '\t', vfreq);
  262. *have_timing = 1;
  263. }
  264. }
  265. /**
  266. * Get the manufacturer name from an EDID info.
  267. *
  268. * @param edid_info The EDID info to be printed
  269. * @param name Returns the string of the manufacturer name
  270. */
  271. static void edid_get_manufacturer_name(struct edid1_info *edid, char *name)
  272. {
  273. name[0] = EDID1_INFO_MANUFACTURER_NAME_CHAR1(*edid) + 'A' - 1;
  274. name[1] = EDID1_INFO_MANUFACTURER_NAME_CHAR2(*edid) + 'A' - 1;
  275. name[2] = EDID1_INFO_MANUFACTURER_NAME_CHAR3(*edid) + 'A' - 1;
  276. name[3] = '\0';
  277. }
  278. void edid_print_info(struct edid1_info *edid_info)
  279. {
  280. int i;
  281. char manufacturer[4];
  282. unsigned int have_timing = 0;
  283. uint32_t serial_number;
  284. if (edid_check_info(edid_info)) {
  285. printf("Not a valid EDID\n");
  286. return;
  287. }
  288. printf("EDID version: %d.%d\n",
  289. edid_info->version, edid_info->revision);
  290. printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info));
  291. edid_get_manufacturer_name(edid_info, manufacturer);
  292. printf("Manufacturer: %s\n", manufacturer);
  293. serial_number = EDID1_INFO_SERIAL_NUMBER(*edid_info);
  294. if (serial_number != 0xffffffff) {
  295. if (strcmp(manufacturer, "MAG") == 0)
  296. serial_number -= 0x7000000;
  297. if (strcmp(manufacturer, "OQI") == 0)
  298. serial_number -= 456150000;
  299. if (strcmp(manufacturer, "VSC") == 0)
  300. serial_number -= 640000000;
  301. }
  302. printf("Serial number: %08x\n", serial_number);
  303. printf("Manufactured in week: %d year: %d\n",
  304. edid_info->week, edid_info->year + 1990);
  305. printf("Video input definition: %svoltage level %d%s%s%s%s%s\n",
  306. EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid_info) ?
  307. "digital signal, " : "analog signal, ",
  308. EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(*edid_info),
  309. EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(*edid_info) ?
  310. ", blank to black" : "",
  311. EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(*edid_info) ?
  312. ", separate sync" : "",
  313. EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(*edid_info) ?
  314. ", composite sync" : "",
  315. EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(*edid_info) ?
  316. ", sync on green" : "",
  317. EDID1_INFO_VIDEO_INPUT_SERRATION_V(*edid_info) ?
  318. ", serration v" : "");
  319. printf("Monitor is %s\n",
  320. EDID1_INFO_FEATURE_RGB(*edid_info) ? "RGB" : "non-RGB");
  321. printf("Maximum visible display size: %d cm x %d cm\n",
  322. edid_info->max_size_horizontal,
  323. edid_info->max_size_vertical);
  324. printf("Power management features: %s%s, %s%s, %s%s\n",
  325. EDID1_INFO_FEATURE_ACTIVE_OFF(*edid_info) ?
  326. "" : "no ", "active off",
  327. EDID1_INFO_FEATURE_SUSPEND(*edid_info) ? "" : "no ", "suspend",
  328. EDID1_INFO_FEATURE_STANDBY(*edid_info) ? "" : "no ", "standby");
  329. printf("Estabilished timings:\n");
  330. if (EDID1_INFO_ESTABLISHED_TIMING_720X400_70(*edid_info))
  331. printf("\t720x400\t\t70 Hz (VGA 640x400, IBM)\n");
  332. if (EDID1_INFO_ESTABLISHED_TIMING_720X400_88(*edid_info))
  333. printf("\t720x400\t\t88 Hz (XGA2)\n");
  334. if (EDID1_INFO_ESTABLISHED_TIMING_640X480_60(*edid_info))
  335. printf("\t640x480\t\t60 Hz (VGA)\n");
  336. if (EDID1_INFO_ESTABLISHED_TIMING_640X480_67(*edid_info))
  337. printf("\t640x480\t\t67 Hz (Mac II, Apple)\n");
  338. if (EDID1_INFO_ESTABLISHED_TIMING_640X480_72(*edid_info))
  339. printf("\t640x480\t\t72 Hz (VESA)\n");
  340. if (EDID1_INFO_ESTABLISHED_TIMING_640X480_75(*edid_info))
  341. printf("\t640x480\t\t75 Hz (VESA)\n");
  342. if (EDID1_INFO_ESTABLISHED_TIMING_800X600_56(*edid_info))
  343. printf("\t800x600\t\t56 Hz (VESA)\n");
  344. if (EDID1_INFO_ESTABLISHED_TIMING_800X600_60(*edid_info))
  345. printf("\t800x600\t\t60 Hz (VESA)\n");
  346. if (EDID1_INFO_ESTABLISHED_TIMING_800X600_72(*edid_info))
  347. printf("\t800x600\t\t72 Hz (VESA)\n");
  348. if (EDID1_INFO_ESTABLISHED_TIMING_800X600_75(*edid_info))
  349. printf("\t800x600\t\t75 Hz (VESA)\n");
  350. if (EDID1_INFO_ESTABLISHED_TIMING_832X624_75(*edid_info))
  351. printf("\t832x624\t\t75 Hz (Mac II)\n");
  352. if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(*edid_info))
  353. printf("\t1024x768\t87 Hz Interlaced (8514A)\n");
  354. if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(*edid_info))
  355. printf("\t1024x768\t60 Hz (VESA)\n");
  356. if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(*edid_info))
  357. printf("\t1024x768\t70 Hz (VESA)\n");
  358. if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(*edid_info))
  359. printf("\t1024x768\t75 Hz (VESA)\n");
  360. if (EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(*edid_info))
  361. printf("\t1280x1024\t75 (VESA)\n");
  362. if (EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(*edid_info))
  363. printf("\t1152x870\t75 (Mac II)\n");
  364. /* Standard timings. */
  365. printf("Standard timings:\n");
  366. for (i = 0; i < ARRAY_SIZE(edid_info->standard_timings); i++) {
  367. unsigned int aspect = 10000;
  368. unsigned int x, y;
  369. unsigned char xres, vfreq;
  370. xres = EDID1_INFO_STANDARD_TIMING_XRESOLUTION(*edid_info, i);
  371. vfreq = EDID1_INFO_STANDARD_TIMING_VFREQ(*edid_info, i);
  372. if ((xres != vfreq) ||
  373. ((xres != 0) && (xres != 1)) ||
  374. ((vfreq != 0) && (vfreq != 1))) {
  375. switch (EDID1_INFO_STANDARD_TIMING_ASPECT(*edid_info,
  376. i)) {
  377. case ASPECT_625:
  378. aspect = 6250;
  379. break;
  380. case ASPECT_75:
  381. aspect = 7500;
  382. break;
  383. case ASPECT_8:
  384. aspect = 8000;
  385. break;
  386. case ASPECT_5625:
  387. aspect = 5625;
  388. break;
  389. }
  390. x = (xres + 31) * 8;
  391. y = x * aspect / 10000;
  392. printf("\t%dx%d%c\t%d Hz\n", x, y,
  393. x > 1000 ? ' ' : '\t', (vfreq & 0x3f) + 60);
  394. have_timing = 1;
  395. }
  396. }
  397. /* Detailed timing information. */
  398. for (i = 0; i < ARRAY_SIZE(edid_info->monitor_details.descriptor);
  399. i++) {
  400. edid_print_dtd(&edid_info->monitor_details.descriptor[i],
  401. &have_timing);
  402. }
  403. if (!have_timing)
  404. printf("\tNone\n");
  405. }