xref: /openbmc/u-boot/common/edid.c (revision d39c346c)
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 
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 	debug("Detailed mode clock %u Hz, %d mm x %d mm\n"
115 	      "               %04x %04x %04x %04x hborder %x\n"
116 	      "               %04x %04x %04x %04x vborder %x\n",
117 	      timing->pixelclock.typ,
118 	      x_mm, y_mm,
119 	      ha, ha + hso, ha + hso + hspw,
120 	      ha + hbl, hborder,
121 	      va, va + vso, va + vso + vspw,
122 	      va + vbl, vborder);
123 }
124 
125 int edid_get_timing(u8 *buf, int buf_size, struct display_timing *timing,
126 		    int *panel_bits_per_colourp)
127 {
128 	struct edid1_info *edid = (struct edid1_info *)buf;
129 	bool timing_done;
130 	int i;
131 
132 	if (buf_size < sizeof(*edid) || edid_check_info(edid)) {
133 		debug("%s: Invalid buffer\n", __func__);
134 		return -EINVAL;
135 	}
136 
137 	if (!EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(*edid)) {
138 		debug("%s: No preferred timing\n", __func__);
139 		return -ENOENT;
140 	}
141 
142 	/* Look for detailed timing */
143 	timing_done = false;
144 	for (i = 0; i < 4; i++) {
145 		struct edid_monitor_descriptor *desc;
146 
147 		desc = &edid->monitor_details.descriptor[i];
148 		if (desc->zero_flag_1 != 0) {
149 			decode_timing((u8 *)desc, timing);
150 			timing_done = true;
151 			break;
152 		}
153 	}
154 	if (!timing_done)
155 		return -EINVAL;
156 
157 	if (!EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid)) {
158 		debug("%s: Not a digital display\n", __func__);
159 		return -ENOSYS;
160 	}
161 	if (edid->version != 1 || edid->revision < 4) {
162 		debug("%s: EDID version %d.%d does not have required info\n",
163 		      __func__, edid->version, edid->revision);
164 		*panel_bits_per_colourp = -1;
165 	} else  {
166 		*panel_bits_per_colourp =
167 			((edid->video_input_definition & 0x70) >> 3) + 4;
168 	}
169 
170 	return 0;
171 }
172 
173 /**
174  * Snip the tailing whitespace/return of a string.
175  *
176  * @param string	The string to be snipped
177  * @return the snipped string
178  */
179 static char *snip(char *string)
180 {
181 	char *s;
182 
183 	/*
184 	 * This is always a 13 character buffer
185 	 * and it's not always terminated.
186 	 */
187 	string[12] = '\0';
188 	s = &string[strlen(string) - 1];
189 
190 	while (s >= string && (isspace(*s) || *s == '\n' || *s == '\r' ||
191 			*s == '\0'))
192 		*(s--) = '\0';
193 
194 	return string;
195 }
196 
197 /**
198  * Print an EDID monitor descriptor block
199  *
200  * @param monitor	The EDID monitor descriptor block
201  * @have_timing		Modifies to 1 if the desciptor contains timing info
202  */
203 static void edid_print_dtd(struct edid_monitor_descriptor *monitor,
204 			   unsigned int *have_timing)
205 {
206 	unsigned char *bytes = (unsigned char *)monitor;
207 	struct edid_detailed_timing *timing =
208 			(struct edid_detailed_timing *)monitor;
209 
210 	if (bytes[0] == 0 && bytes[1] == 0) {
211 		if (monitor->type == EDID_MONITOR_DESCRIPTOR_SERIAL)
212 			printf("Monitor serial number: %s\n",
213 			       snip(monitor->data.string));
214 		else if (monitor->type == EDID_MONITOR_DESCRIPTOR_ASCII)
215 			printf("Monitor ID: %s\n",
216 			       snip(monitor->data.string));
217 		else if (monitor->type == EDID_MONITOR_DESCRIPTOR_NAME)
218 			printf("Monitor name: %s\n",
219 			       snip(monitor->data.string));
220 		else if (monitor->type == EDID_MONITOR_DESCRIPTOR_RANGE)
221 			printf("Monitor range limits, horizontal sync: "
222 			       "%d-%d kHz, vertical refresh: "
223 			       "%d-%d Hz, max pixel clock: "
224 			       "%d MHz\n",
225 			       monitor->data.range_data.horizontal_min,
226 			       monitor->data.range_data.horizontal_max,
227 			       monitor->data.range_data.vertical_min,
228 			       monitor->data.range_data.vertical_max,
229 			       monitor->data.range_data.pixel_clock_max * 10);
230 	} else {
231 		uint32_t pixclock, h_active, h_blanking, v_active, v_blanking;
232 		uint32_t h_total, v_total, vfreq;
233 
234 		pixclock = EDID_DETAILED_TIMING_PIXEL_CLOCK(*timing);
235 		h_active = EDID_DETAILED_TIMING_HORIZONTAL_ACTIVE(*timing);
236 		h_blanking = EDID_DETAILED_TIMING_HORIZONTAL_BLANKING(*timing);
237 		v_active = EDID_DETAILED_TIMING_VERTICAL_ACTIVE(*timing);
238 		v_blanking = EDID_DETAILED_TIMING_VERTICAL_BLANKING(*timing);
239 
240 		h_total = h_active + h_blanking;
241 		v_total = v_active + v_blanking;
242 		if (v_total * h_total)
243 			vfreq = pixclock / (v_total * h_total);
244 		else
245 			vfreq = 1; /* Error case */
246 		printf("\t%dx%d\%c\t%d Hz (detailed)\n", h_active,
247 		       v_active, h_active > 1000 ? ' ' : '\t', vfreq);
248 		*have_timing = 1;
249 	}
250 }
251 
252 /**
253  * Get the manufacturer name from an EDID info.
254  *
255  * @param edid_info     The EDID info to be printed
256  * @param name		Returns the string of the manufacturer name
257  */
258 static void edid_get_manufacturer_name(struct edid1_info *edid, char *name)
259 {
260 	name[0] = EDID1_INFO_MANUFACTURER_NAME_CHAR1(*edid) + 'A' - 1;
261 	name[1] = EDID1_INFO_MANUFACTURER_NAME_CHAR2(*edid) + 'A' - 1;
262 	name[2] = EDID1_INFO_MANUFACTURER_NAME_CHAR3(*edid) + 'A' - 1;
263 	name[3] = '\0';
264 }
265 
266 void edid_print_info(struct edid1_info *edid_info)
267 {
268 	int i;
269 	char manufacturer[4];
270 	unsigned int have_timing = 0;
271 	uint32_t serial_number;
272 
273 	if (edid_check_info(edid_info)) {
274 		printf("Not a valid EDID\n");
275 		return;
276 	}
277 
278 	printf("EDID version: %d.%d\n",
279 	       edid_info->version, edid_info->revision);
280 
281 	printf("Product ID code: %04x\n", EDID1_INFO_PRODUCT_CODE(*edid_info));
282 
283 	edid_get_manufacturer_name(edid_info, manufacturer);
284 	printf("Manufacturer: %s\n", manufacturer);
285 
286 	serial_number = EDID1_INFO_SERIAL_NUMBER(*edid_info);
287 	if (serial_number != 0xffffffff) {
288 		if (strcmp(manufacturer, "MAG") == 0)
289 			serial_number -= 0x7000000;
290 		if (strcmp(manufacturer, "OQI") == 0)
291 			serial_number -= 456150000;
292 		if (strcmp(manufacturer, "VSC") == 0)
293 			serial_number -= 640000000;
294 	}
295 	printf("Serial number: %08x\n", serial_number);
296 	printf("Manufactured in week: %d year: %d\n",
297 	       edid_info->week, edid_info->year + 1990);
298 
299 	printf("Video input definition: %svoltage level %d%s%s%s%s%s\n",
300 	       EDID1_INFO_VIDEO_INPUT_DIGITAL(*edid_info) ?
301 	       "digital signal, " : "analog signal, ",
302 	       EDID1_INFO_VIDEO_INPUT_VOLTAGE_LEVEL(*edid_info),
303 	       EDID1_INFO_VIDEO_INPUT_BLANK_TO_BLACK(*edid_info) ?
304 	       ", blank to black" : "",
305 	       EDID1_INFO_VIDEO_INPUT_SEPARATE_SYNC(*edid_info) ?
306 	       ", separate sync" : "",
307 	       EDID1_INFO_VIDEO_INPUT_COMPOSITE_SYNC(*edid_info) ?
308 	       ", composite sync" : "",
309 	       EDID1_INFO_VIDEO_INPUT_SYNC_ON_GREEN(*edid_info) ?
310 	       ", sync on green" : "",
311 	       EDID1_INFO_VIDEO_INPUT_SERRATION_V(*edid_info) ?
312 	       ", serration v" : "");
313 
314 	printf("Monitor is %s\n",
315 	       EDID1_INFO_FEATURE_RGB(*edid_info) ? "RGB" : "non-RGB");
316 
317 	printf("Maximum visible display size: %d cm x %d cm\n",
318 	       edid_info->max_size_horizontal,
319 	       edid_info->max_size_vertical);
320 
321 	printf("Power management features: %s%s, %s%s, %s%s\n",
322 	       EDID1_INFO_FEATURE_ACTIVE_OFF(*edid_info) ?
323 	       "" : "no ", "active off",
324 	       EDID1_INFO_FEATURE_SUSPEND(*edid_info) ? "" : "no ", "suspend",
325 	       EDID1_INFO_FEATURE_STANDBY(*edid_info) ? "" : "no ", "standby");
326 
327 	printf("Estabilished timings:\n");
328 	if (EDID1_INFO_ESTABLISHED_TIMING_720X400_70(*edid_info))
329 		printf("\t720x400\t\t70 Hz (VGA 640x400, IBM)\n");
330 	if (EDID1_INFO_ESTABLISHED_TIMING_720X400_88(*edid_info))
331 		printf("\t720x400\t\t88 Hz (XGA2)\n");
332 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_60(*edid_info))
333 		printf("\t640x480\t\t60 Hz (VGA)\n");
334 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_67(*edid_info))
335 		printf("\t640x480\t\t67 Hz (Mac II, Apple)\n");
336 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_72(*edid_info))
337 		printf("\t640x480\t\t72 Hz (VESA)\n");
338 	if (EDID1_INFO_ESTABLISHED_TIMING_640X480_75(*edid_info))
339 		printf("\t640x480\t\t75 Hz (VESA)\n");
340 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_56(*edid_info))
341 		printf("\t800x600\t\t56 Hz (VESA)\n");
342 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_60(*edid_info))
343 		printf("\t800x600\t\t60 Hz (VESA)\n");
344 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_72(*edid_info))
345 		printf("\t800x600\t\t72 Hz (VESA)\n");
346 	if (EDID1_INFO_ESTABLISHED_TIMING_800X600_75(*edid_info))
347 		printf("\t800x600\t\t75 Hz (VESA)\n");
348 	if (EDID1_INFO_ESTABLISHED_TIMING_832X624_75(*edid_info))
349 		printf("\t832x624\t\t75 Hz (Mac II)\n");
350 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_87I(*edid_info))
351 		printf("\t1024x768\t87 Hz Interlaced (8514A)\n");
352 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_60(*edid_info))
353 		printf("\t1024x768\t60 Hz (VESA)\n");
354 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_70(*edid_info))
355 		printf("\t1024x768\t70 Hz (VESA)\n");
356 	if (EDID1_INFO_ESTABLISHED_TIMING_1024X768_75(*edid_info))
357 		printf("\t1024x768\t75 Hz (VESA)\n");
358 	if (EDID1_INFO_ESTABLISHED_TIMING_1280X1024_75(*edid_info))
359 		printf("\t1280x1024\t75 (VESA)\n");
360 	if (EDID1_INFO_ESTABLISHED_TIMING_1152X870_75(*edid_info))
361 		printf("\t1152x870\t75 (Mac II)\n");
362 
363 	/* Standard timings. */
364 	printf("Standard timings:\n");
365 	for (i = 0; i < ARRAY_SIZE(edid_info->standard_timings); i++) {
366 		unsigned int aspect = 10000;
367 		unsigned int x, y;
368 		unsigned char xres, vfreq;
369 
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 
398 	/* Detailed timing information. */
399 	for (i = 0; i < ARRAY_SIZE(edid_info->monitor_details.descriptor);
400 			i++) {
401 		edid_print_dtd(&edid_info->monitor_details.descriptor[i],
402 			       &have_timing);
403 	}
404 
405 	if (!have_timing)
406 		printf("\tNone\n");
407 }
408