xref: /openbmc/u-boot/common/edid.c (revision 6e87ae1c)
1 /*
2  * Copyright (c) 2012 The Chromium OS Authors.
3  *
4  * (C) Copyright 2010
5  * Petr Stetiar <ynezz@true.cz>
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  *
9  * Contains stolen code from ddcprobe project which is:
10  * Copyright (C) Nalin Dahyabhai <bigfun@pobox.com>
11  */
12 
13 #include <common.h>
14 #include <edid.h>
15 #include <errno.h>
16 #include <fdtdec.h>
17 #include <linux/ctype.h>
18 #include <linux/string.h>
19 
20 int edid_check_info(struct edid1_info *edid_info)
21 {
22 	if ((edid_info == NULL) || (edid_info->version == 0))
23 		return -1;
24 
25 	if (memcmp(edid_info->header, "\x0\xff\xff\xff\xff\xff\xff\x0", 8))
26 		return -1;
27 
28 	if (edid_info->version == 0xff && edid_info->revision == 0xff)
29 		return -1;
30 
31 	return 0;
32 }
33 
34 int edid_check_checksum(u8 *edid_block)
35 {
36 	u8 checksum = 0;
37 	int i;
38 
39 	for (i = 0; i < 128; i++)
40 		checksum += edid_block[i];
41 
42 	return (checksum == 0) ? 0 : -EINVAL;
43 }
44 
45 int edid_get_ranges(struct edid1_info *edid, unsigned int *hmin,
46 		    unsigned int *hmax, unsigned int *vmin,
47 		    unsigned int *vmax)
48 {
49 	int i;
50 	struct edid_monitor_descriptor *monitor;
51 
52 	*hmin = *hmax = *vmin = *vmax = 0;
53 	if (edid_check_info(edid))
54 		return -1;
55 
56 	for (i = 0; i < ARRAY_SIZE(edid->monitor_details.descriptor); i++) {
57 		monitor = &edid->monitor_details.descriptor[i];
58 		if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE) {
59 			*hmin = monitor->data.range_data.horizontal_min;
60 			*hmax = monitor->data.range_data.horizontal_max;
61 			*vmin = monitor->data.range_data.vertical_min;
62 			*vmax = monitor->data.range_data.vertical_max;
63 			return 0;
64 		}
65 	}
66 	return -1;
67 }
68 
69 /* Set all parts of a timing entry to the same value */
70 static void set_entry(struct timing_entry *entry, u32 value)
71 {
72 	entry->min = value;
73 	entry->typ = value;
74 	entry->max = value;
75 }
76 
77 /**
78  * decode_timing() - Decoding an 18-byte detailed timing record
79  *
80  * @buf:	Pointer to EDID detailed timing record
81  * @timing:	Place to put timing
82  */
83 static void decode_timing(u8 *buf, struct display_timing *timing)
84 {
85 	uint x_mm, y_mm;
86 	unsigned int ha, hbl, hso, hspw, hborder;
87 	unsigned int va, vbl, vso, vspw, vborder;
88 	struct edid_detailed_timing *t = (struct edid_detailed_timing *)buf;
89 
90 	/* Edid contains pixel clock in terms of 10KHz */
91 	set_entry(&timing->pixelclock, (buf[0] + (buf[1] << 8)) * 10000);
92 	x_mm = (buf[12] + ((buf[14] & 0xf0) << 4));
93 	y_mm = (buf[13] + ((buf[14] & 0x0f) << 8));
94 	ha = (buf[2] + ((buf[4] & 0xf0) << 4));
95 	hbl = (buf[3] + ((buf[4] & 0x0f) << 8));
96 	hso = (buf[8] + ((buf[11] & 0xc0) << 2));
97 	hspw = (buf[9] + ((buf[11] & 0x30) << 4));
98 	hborder = buf[15];
99 	va = (buf[5] + ((buf[7] & 0xf0) << 4));
100 	vbl = (buf[6] + ((buf[7] & 0x0f) << 8));
101 	vso = ((buf[10] >> 4) + ((buf[11] & 0x0c) << 2));
102 	vspw = ((buf[10] & 0x0f) + ((buf[11] & 0x03) << 4));
103 	vborder = buf[16];
104 
105 	set_entry(&timing->hactive, ha);
106 	set_entry(&timing->hfront_porch, hso);
107 	set_entry(&timing->hback_porch, hbl - hso - hspw);
108 	set_entry(&timing->hsync_len, hspw);
109 
110 	set_entry(&timing->vactive, va);
111 	set_entry(&timing->vfront_porch, vso);
112 	set_entry(&timing->vback_porch, vbl - vso - vspw);
113 	set_entry(&timing->vsync_len, vspw);
114 
115 	timing->flags = 0;
116 	if (EDID_DETAILED_TIMING_FLAG_HSYNC_POLARITY(*t))
117 		timing->flags |= DISPLAY_FLAGS_HSYNC_HIGH;
118 	else
119 		timing->flags |= DISPLAY_FLAGS_HSYNC_LOW;
120 	if (EDID_DETAILED_TIMING_FLAG_VSYNC_POLARITY(*t))
121 		timing->flags |= DISPLAY_FLAGS_VSYNC_HIGH;
122 	else
123 		timing->flags |= DISPLAY_FLAGS_VSYNC_LOW;
124 
125 	if (EDID_DETAILED_TIMING_FLAG_INTERLACED(*t))
126 		timing->flags = DISPLAY_FLAGS_INTERLACED;
127 
128 	debug("Detailed mode clock %u Hz, %d mm x %d mm\n"
129 	      "               %04x %04x %04x %04x hborder %x\n"
130 	      "               %04x %04x %04x %04x vborder %x\n",
131 	      timing->pixelclock.typ,
132 	      x_mm, y_mm,
133 	      ha, ha + hso, ha + hso + hspw,
134 	      ha + hbl, hborder,
135 	      va, va + vso, va + vso + vspw,
136 	      va + vbl, vborder);
137 }
138 
139 /**
140  * Check if HDMI vendor specific data block is present in CEA block
141  * @param info	CEA extension block
142  * @return true if block is found
143  */
144 static bool cea_is_hdmi_vsdb_present(struct edid_cea861_info *info)
145 {
146 	u8 end, i = 0;
147 
148 	/* check for end of data block */
149 	end = info->dtd_offset;
150 	if (end == 0)
151 		end = 127;
152 	if (end < 4 || end > 127)
153 		return false;
154 	end -= 4;
155 
156 	while (i < end) {
157 		/* Look for vendor specific data block of appropriate size */
158 		if ((EDID_CEA861_DB_TYPE(*info, i) == EDID_CEA861_DB_VENDOR) &&
159 		    (EDID_CEA861_DB_LEN(*info, i) >= 5)) {
160 			u8 *db = &info->data[i + 1];
161 			u32 oui = db[0] | (db[1] << 8) | (db[2] << 16);
162 
163 			if (oui == HDMI_IEEE_OUI)
164 				return true;
165 		}
166 		i += EDID_CEA861_DB_LEN(*info, i) + 1;
167 	}
168 
169 	return false;
170 }
171 
172 int edid_get_timing(u8 *buf, int buf_size, struct display_timing *timing,
173 		    int *panel_bits_per_colourp)
174 {
175 	struct edid1_info *edid = (struct edid1_info *)buf;
176 	bool timing_done;
177 	int i;
178 
179 	if (buf_size < sizeof(*edid) || edid_check_info(edid)) {
180 		debug("%s: Invalid buffer\n", __func__);
181 		return -EINVAL;
182 	}
183 
184 	if (!EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(*edid)) {
185 		debug("%s: No preferred timing\n", __func__);
186 		return -ENOENT;
187 	}
188 
189 	/* Look for detailed timing */
190 	timing_done = false;
191 	for (i = 0; i < 4; i++) {
192 		struct edid_monitor_descriptor *desc;
193 
194 		desc = &edid->monitor_details.descriptor[i];
195 		if (desc->zero_flag_1 != 0) {
196 			decode_timing((u8 *)desc, timing);
197 			timing_done = true;
198 			break;
199 		}
200 	}
201 	if (!timing_done)
202 		return -EINVAL;
203 
204 	if (!EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid)) {
205 		debug("%s: Not a digital display\n", __func__);
206 		return -ENOSYS;
207 	}
208 	if (edid->version != 1 || edid->revision < 4) {
209 		debug("%s: EDID version %d.%d does not have required info\n",
210 		      __func__, edid->version, edid->revision);
211 		*panel_bits_per_colourp = -1;
212 	} else  {
213 		*panel_bits_per_colourp =
214 			((edid->video_input_definition & 0x70) >> 3) + 4;
215 	}
216 
217 	timing->hdmi_monitor = false;
218 	if (edid->extension_flag && (buf_size >= EDID_EXT_SIZE)) {
219 		struct edid_cea861_info *info =
220 			(struct edid_cea861_info *)(buf + sizeof(*edid));
221 
222 		if (info->extension_tag == EDID_CEA861_EXTENSION_TAG)
223 			timing->hdmi_monitor = cea_is_hdmi_vsdb_present(info);
224 	}
225 
226 	return 0;
227 }
228 
229 /**
230  * Snip the tailing whitespace/return of a string.
231  *
232  * @param string	The string to be snipped
233  * @return the snipped string
234  */
235 static char *snip(char *string)
236 {
237 	char *s;
238 
239 	/*
240 	 * This is always a 13 character buffer
241 	 * and it's not always terminated.
242 	 */
243 	string[12] = '\0';
244 	s = &string[strlen(string) - 1];
245 
246 	while (s >= string && (isspace(*s) || *s == '\n' || *s == '\r' ||
247 			*s == '\0'))
248 		*(s--) = '\0';
249 
250 	return string;
251 }
252 
253 /**
254  * Print an EDID monitor descriptor block
255  *
256  * @param monitor	The EDID monitor descriptor block
257  * @have_timing		Modifies to 1 if the desciptor contains timing info
258  */
259 static void edid_print_dtd(struct edid_monitor_descriptor *monitor,
260 			   unsigned int *have_timing)
261 {
262 	unsigned char *bytes = (unsigned char *)monitor;
263 	struct edid_detailed_timing *timing =
264 			(struct edid_detailed_timing *)monitor;
265 
266 	if (bytes[0] == 0 && bytes[1] == 0) {
267 		if (monitor->type == EDID_MONITOR_DESCRIPTOR_SERIAL)
268 			printf("Monitor serial number: %s\n",
269 			       snip(monitor->data.string));
270 		else if (monitor->type == EDID_MONITOR_DESCRIPTOR_ASCII)
271 			printf("Monitor ID: %s\n",
272 			       snip(monitor->data.string));
273 		else if (monitor->type == EDID_MONITOR_DESCRIPTOR_NAME)
274 			printf("Monitor name: %s\n",
275 			       snip(monitor->data.string));
276 		else if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE)
277 			printf("Monitor range limits, horizontal sync: "
278 			       "%d-%d kHz, vertical refresh: "
279 			       "%d-%d Hz, max pixel clock: "
280 			       "%d MHz\n",
281 			       monitor->data.range_data.horizontal_min,
282 			       monitor->data.range_data.horizontal_max,
283 			       monitor->data.range_data.vertical_min,
284 			       monitor->data.range_data.vertical_max,
285 			       monitor->data.range_data.pixel_clock_max * 10);
286 	} else {
287 		uint32_t pixclock, h_active, h_blanking, v_active, v_blanking;
288 		uint32_t h_total, v_total, vfreq;
289 
290 		pixclock = EDID_DETAILED_TIMING_PIXEL_CLOCK(*timing);
291 		h_active = EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*timing);
292 		h_blanking = EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*timing);
293 		v_active = EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*timing);
294 		v_blanking = EDID_DETAILED_TIMING_VERTICAL_BLANKING(*timing);
295 
296 		h_total = h_active + h_blanking;
297 		v_total = v_active + v_blanking;
298 		if (v_total * h_total)
299 			vfreq = pixclock / (v_total * h_total);
300 		else
301 			vfreq = 1; /* Error case */
302 		printf("\t%dx%d\%c\t%d Hz (detailed)\n", h_active,
303 		       v_active, h_active > 1000 ? ' ' : '\t', vfreq);
304 		*have_timing = 1;
305 	}
306 }
307 
308 /**
309  * Get the manufacturer name from an EDID info.
310  *
311  * @param edid_info     The EDID info to be printed
312  * @param name		Returns the string of the manufacturer name
313  */
314 static void edid_get_manufacturer_name(struct edid1_info *edid, char *name)
315 {
316 	name[0] = EDID1_INFO_MANUFACTURER_NAME_CHAR1(*edid) + 'A' - 1;
317 	name[1] = EDID1_INFO_MANUFACTURER_NAME_CHAR2(*edid) + 'A' - 1;
318 	name[2] = EDID1_INFO_MANUFACTURER_NAME_CHAR3(*edid) + 'A' - 1;
319 	name[3] = '\0';
320 }
321 
322 void edid_print_info(struct edid1_info *edid_info)
323 {
324 	int i;
325 	char manufacturer[4];
326 	unsigned int have_timing = 0;
327 	uint32_t serial_number;
328 
329 	if (edid_check_info(edid_info)) {
330 		printf("Not a valid EDID\n");
331 		return;
332 	}
333 
334 	printf("EDID version: %d.%d\n",
335 	       edid_info->version, edid_info->revision);
336 
337 	printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info));
338 
339 	edid_get_manufacturer_name(edid_info, manufacturer);
340 	printf("Manufacturer: %s\n", manufacturer);
341 
342 	serial_number = EDID1_INFO_SERIAL_NUMBER(*edid_info);
343 	if (serial_number != 0xffffffff) {
344 		if (strcmp(manufacturer, "MAG") == 0)
345 			serial_number -= 0x7000000;
346 		if (strcmp(manufacturer, "OQI") == 0)
347 			serial_number -= 456150000;
348 		if (strcmp(manufacturer, "VSC") == 0)
349 			serial_number -= 640000000;
350 	}
351 	printf("Serial number: %08x\n", serial_number);
352 	printf("Manufactured in week: %d year: %d\n",
353 	       edid_info->week, edid_info->year + 1990);
354 
355 	printf("Video input definition: %svoltage level %d%s%s%s%s%s\n",
356 	       EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid_info) ?
357 	       "digital signal, " : "analog signal, ",
358 	       EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(*edid_info),
359 	       EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(*edid_info) ?
360 	       ", blank to black" : "",
361 	       EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(*edid_info) ?
362 	       ", separate sync" : "",
363 	       EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(*edid_info) ?
364 	       ", composite sync" : "",
365 	       EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(*edid_info) ?
366 	       ", sync on green" : "",
367 	       EDID1_INFO_VIDEO_INPUT_SERRATION_V(*edid_info) ?
368 	       ", serration v" : "");
369 
370 	printf("Monitor is %s\n",
371 	       EDID1_INFO_FEATURE_RGB(*edid_info) ? "RGB" : "non-RGB");
372 
373 	printf("Maximum visible display size: %d cm x %d cm\n",
374 	       edid_info->max_size_horizontal,
375 	       edid_info->max_size_vertical);
376 
377 	printf("Power management features: %s%s, %s%s, %s%s\n",
378 	       EDID1_INFO_FEATURE_ACTIVE_OFF(*edid_info) ?
379 	       "" : "no ", "active off",
380 	       EDID1_INFO_FEATURE_SUSPEND(*edid_info) ? "" : "no ", "suspend",
381 	       EDID1_INFO_FEATURE_STANDBY(*edid_info) ? "" : "no ", "standby");
382 
383 	printf("Estabilished timings:\n");
384 	if (EDID1_INFO_ESTABLISHED_TIMING_720X400_70(*edid_info))
385 		printf("\t720x400\t\t70 Hz (VGA 640x400, IBM)\n");
386 	if (EDID1_INFO_ESTABLISHED_TIMING_720X400_88(*edid_info))
387 		printf("\t720x400\t\t88 Hz (XGA2)\n");
388 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_60(*edid_info))
389 		printf("\t640x480\t\t60 Hz (VGA)\n");
390 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_67(*edid_info))
391 		printf("\t640x480\t\t67 Hz (Mac II, Apple)\n");
392 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_72(*edid_info))
393 		printf("\t640x480\t\t72 Hz (VESA)\n");
394 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_75(*edid_info))
395 		printf("\t640x480\t\t75 Hz (VESA)\n");
396 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_56(*edid_info))
397 		printf("\t800x600\t\t56 Hz (VESA)\n");
398 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_60(*edid_info))
399 		printf("\t800x600\t\t60 Hz (VESA)\n");
400 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_72(*edid_info))
401 		printf("\t800x600\t\t72 Hz (VESA)\n");
402 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_75(*edid_info))
403 		printf("\t800x600\t\t75 Hz (VESA)\n");
404 	if (EDID1_INFO_ESTABLISHED_TIMING_832X624_75(*edid_info))
405 		printf("\t832x624\t\t75 Hz (Mac II)\n");
406 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(*edid_info))
407 		printf("\t1024x768\t87 Hz Interlaced (8514A)\n");
408 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(*edid_info))
409 		printf("\t1024x768\t60 Hz (VESA)\n");
410 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(*edid_info))
411 		printf("\t1024x768\t70 Hz (VESA)\n");
412 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(*edid_info))
413 		printf("\t1024x768\t75 Hz (VESA)\n");
414 	if (EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(*edid_info))
415 		printf("\t1280x1024\t75 (VESA)\n");
416 	if (EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(*edid_info))
417 		printf("\t1152x870\t75 (Mac II)\n");
418 
419 	/* Standard timings. */
420 	printf("Standard timings:\n");
421 	for (i = 0; i < ARRAY_SIZE(edid_info->standard_timings); i++) {
422 		unsigned int aspect = 10000;
423 		unsigned int x, y;
424 		unsigned char xres, vfreq;
425 
426 		xres = EDID1_INFO_STANDARD_TIMING_XRESOLUTION(*edid_info, i);
427 		vfreq = EDID1_INFO_STANDARD_TIMING_VFREQ(*edid_info, i);
428 		if ((xres != vfreq) ||
429 		    ((xres != 0) && (xres != 1)) ||
430 		    ((vfreq != 0) && (vfreq != 1))) {
431 			switch (EDID1_INFO_STANDARD_TIMING_ASPECT(*edid_info,
432 					i)) {
433 			case ASPECT_625:
434 				aspect = 6250;
435 				break;
436 			case ASPECT_75:
437 				aspect = 7500;
438 				break;
439 			case ASPECT_8:
440 				aspect = 8000;
441 				break;
442 			case ASPECT_5625:
443 				aspect = 5625;
444 				break;
445 			}
446 			x = (xres + 31) * 8;
447 			y = x * aspect / 10000;
448 			printf("\t%dx%d%c\t%d Hz\n", x, y,
449 			       x > 1000 ? ' ' : '\t', (vfreq & 0x3f) + 60);
450 			have_timing = 1;
451 		}
452 	}
453 
454 	/* Detailed timing information. */
455 	for (i = 0; i < ARRAY_SIZE(edid_info->monitor_details.descriptor);
456 			i++) {
457 		edid_print_dtd(&edid_info->monitor_details.descriptor[i],
458 			       &have_timing);
459 	}
460 
461 	if (!have_timing)
462 		printf("\tNone\n");
463 }
464