xref: /freebsd/sys/dev/videomode/edid.c (revision 685dc743dc3b5645e34836464128e1c0558b404b)
1 /* $NetBSD: edid.c,v 1.12 2013/02/08 16:35:10 skrll Exp $ */
2 
3 /*-
4  * Copyright (c) 2006 Itronix Inc.
5  * All rights reserved.
6  *
7  * Written by Garrett D'Amore for Itronix Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of Itronix Inc. may not be used to endorse
18  *    or promote products derived from this software without specific
19  *    prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND ANY EXPRESS
22  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
25  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/libkern.h>
40 #include <dev/videomode/videomode.h>
41 #include <dev/videomode/ediddevs.h>
42 #include <dev/videomode/edidreg.h>
43 #include <dev/videomode/edidvar.h>
44 #include <dev/videomode/vesagtf.h>
45 
46 #define	EDIDVERBOSE	1
47 #define	DIVIDE(x,y)	(((x) + ((y) / 2)) / (y))
48 
49 /* These are reversed established timing order */
50 static const char *_edid_modes[] =  {
51 	"1280x1024x75",
52 	"1024x768x75",
53 	"1024x768x70",
54 	"1024x768x60",
55 	"1024x768x87i",
56 	"832x624x74",	/* rounding error, 74.55 Hz aka "832x624x75" */
57 	"800x600x75",
58 	"800x600x72",
59 	"800x600x60",
60 	"800x600x56",
61 	"640x480x75",
62 	"640x480x72",
63 	"640x480x67",
64 	"640x480x60",
65 	"720x400x87",	/* rounding error, 87.85 Hz aka "720x400x88" */
66 	"720x400x70",
67 };
68 
69 #ifdef	EDIDVERBOSE
70 struct edid_vendor {
71 	const char	*vendor;
72 	const char	*name;
73 };
74 
75 struct edid_product {
76 	const char	*vendor;
77 	uint16_t	product;
78 	const char	*name;
79 };
80 
81 #include <dev/videomode/ediddevs_data.h>
82 #endif	/* EDIDVERBOSE */
83 
84 static const char *
85 edid_findvendor(const char *vendor)
86 {
87 #ifdef	EDIDVERBOSE
88 	int	n;
89 
90 	for (n = 0; n < edid_nvendors; n++)
91 		if (memcmp(edid_vendors[n].vendor, vendor, 3) == 0)
92 			return edid_vendors[n].name;
93 #endif
94 	return NULL;
95 }
96 
97 static const char *
98 edid_findproduct(const char *vendor, uint16_t product)
99 {
100 #ifdef	EDIDVERBOSE
101 	int	n;
102 
103 	for (n = 0; n < edid_nproducts; n++)
104 		if (edid_products[n].product == product &&
105 		    memcmp(edid_products[n].vendor, vendor, 3) == 0)
106 			return edid_products[n].name;
107 #endif	/* EDIDVERBOSE */
108 	return NULL;
109 
110 }
111 
112 static void
113 edid_strchomp(char *ptr)
114 {
115 	for (;;) {
116 		switch (*ptr) {
117 		case '\0':
118 			return;
119 		case '\r':
120 		case '\n':
121 			*ptr = '\0';
122 			return;
123 		}
124 		ptr++;
125 	}
126 }
127 
128 int
129 edid_is_valid(uint8_t *d)
130 {
131 	int sum = 0, i;
132 	uint8_t sig[8] = EDID_SIGNATURE;
133 
134 	if (memcmp(d, sig, 8) != 0)
135 		return EINVAL;
136 
137 	for (i = 0; i < 128; i++)
138 		sum += d[i];
139 	if ((sum & 0xff) != 0)
140 		return EINVAL;
141 
142 	return 0;
143 }
144 
145 void
146 edid_print(struct edid_info *edid)
147 {
148 	int	i;
149 
150 	if (edid == NULL)
151 		return;
152 	printf("Vendor: [%s] %s\n", edid->edid_vendor, edid->edid_vendorname);
153 	printf("Product: [%04X] %s\n", edid->edid_product,
154 	    edid->edid_productname);
155 	printf("Serial number: %s\n", edid->edid_serial);
156 	printf("Manufactured %d Week %d\n",
157 	    edid->edid_year, edid->edid_week);
158 	printf("EDID Version %d.%d\n", edid->edid_version,
159 	    edid->edid_revision);
160 	printf("EDID Comment: %s\n", edid->edid_comment);
161 
162 	printf("Video Input: %x\n", edid->edid_video_input);
163 	if (edid->edid_video_input & EDID_VIDEO_INPUT_DIGITAL) {
164 		printf("\tDigital");
165 		if (edid->edid_video_input & EDID_VIDEO_INPUT_DFP1_COMPAT)
166 			printf(" (DFP 1.x compatible)");
167 		printf("\n");
168 	} else {
169 		printf("\tAnalog\n");
170 		switch (EDID_VIDEO_INPUT_LEVEL(edid->edid_video_input)) {
171 		case 0:
172 			printf("\t-0.7, 0.3V\n");
173 			break;
174 		case 1:
175 			printf("\t-0.714, 0.286V\n");
176 			break;
177 		case 2:
178 			printf("\t-1.0, 0.4V\n");
179 			break;
180 		case 3:
181 			printf("\t-0.7, 0.0V\n");
182 			break;
183 		}
184 		if (edid->edid_video_input & EDID_VIDEO_INPUT_BLANK_TO_BLACK)
185 			printf("\tBlank-to-black setup\n");
186 		if (edid->edid_video_input & EDID_VIDEO_INPUT_SEPARATE_SYNCS)
187 			printf("\tSeparate syncs\n");
188 		if (edid->edid_video_input & EDID_VIDEO_INPUT_COMPOSITE_SYNC)
189 			printf("\tComposite sync\n");
190 		if (edid->edid_video_input & EDID_VIDEO_INPUT_SYNC_ON_GRN)
191 			printf("\tSync on green\n");
192 		if (edid->edid_video_input & EDID_VIDEO_INPUT_SERRATION)
193 			printf("\tSerration vsync\n");
194 	}
195 
196 	printf("Gamma: %d.%02d\n",
197 	    edid->edid_gamma / 100, edid->edid_gamma % 100);
198 
199 	printf("Max Size: %d cm x %d cm\n",
200 	    edid->edid_max_hsize, edid->edid_max_vsize);
201 
202 	printf("Features: %x\n", edid->edid_features);
203 	if (edid->edid_features & EDID_FEATURES_STANDBY)
204 		printf("\tDPMS standby\n");
205 	if (edid->edid_features & EDID_FEATURES_SUSPEND)
206 		printf("\tDPMS suspend\n");
207 	if (edid->edid_features & EDID_FEATURES_ACTIVE_OFF)
208 		printf("\tDPMS active-off\n");
209 	switch (EDID_FEATURES_DISP_TYPE(edid->edid_features)) {
210 	case EDID_FEATURES_DISP_TYPE_MONO:
211 		printf("\tMonochrome\n");
212 		break;
213 	case EDID_FEATURES_DISP_TYPE_RGB:
214 		printf("\tRGB\n");
215 		break;
216 	case EDID_FEATURES_DISP_TYPE_NON_RGB:
217 		printf("\tMulticolor\n");
218 		break;
219 	case EDID_FEATURES_DISP_TYPE_UNDEFINED:
220 		printf("\tUndefined monitor type\n");
221 		break;
222 	}
223 	if (edid->edid_features & EDID_FEATURES_STD_COLOR)
224 		printf("\tStandard color space\n");
225 	if (edid->edid_features & EDID_FEATURES_PREFERRED_TIMING)
226 		printf("\tPreferred timing\n");
227 	if (edid->edid_features & EDID_FEATURES_DEFAULT_GTF)
228 		printf("\tDefault GTF supported\n");
229 
230 	printf("Chroma Info:\n");
231 	printf("\tRed X: 0.%03d\n", edid->edid_chroma.ec_redx);
232 	printf("\tRed Y: 0.%03d\n", edid->edid_chroma.ec_redy);
233 	printf("\tGrn X: 0.%03d\n", edid->edid_chroma.ec_greenx);
234 	printf("\tGrn Y: 0.%03d\n", edid->edid_chroma.ec_greeny);
235 	printf("\tBlu X: 0.%03d\n", edid->edid_chroma.ec_bluex);
236 	printf("\tBlu Y: 0.%03d\n", edid->edid_chroma.ec_bluey);
237 	printf("\tWht X: 0.%03d\n", edid->edid_chroma.ec_whitex);
238 	printf("\tWht Y: 0.%03d\n", edid->edid_chroma.ec_whitey);
239 
240 	if (edid->edid_have_range) {
241 		printf("Range:\n");
242 		printf("\tHorizontal: %d - %d kHz\n",
243 		    edid->edid_range.er_min_hfreq,
244 		    edid->edid_range.er_max_hfreq);
245 		printf("\tVertical: %d - %d Hz\n",
246 		    edid->edid_range.er_min_vfreq,
247 		    edid->edid_range.er_max_vfreq);
248 		printf("\tMax Dot Clock: %d MHz\n",
249 		    edid->edid_range.er_max_clock);
250 		if (edid->edid_range.er_have_gtf2) {
251 			printf("\tGTF2 hfreq: %d\n",
252 			    edid->edid_range.er_gtf2_hfreq);
253 			printf("\tGTF2 C: %d\n", edid->edid_range.er_gtf2_c);
254 			printf("\tGTF2 M: %d\n", edid->edid_range.er_gtf2_m);
255 			printf("\tGTF2 J: %d\n", edid->edid_range.er_gtf2_j);
256 			printf("\tGTF2 K: %d\n", edid->edid_range.er_gtf2_k);
257 		}
258 	}
259 	printf("Video modes:\n");
260 	for (i = 0; i < edid->edid_nmodes; i++) {
261 		printf("\t%dx%d @ %dHz",
262 		    edid->edid_modes[i].hdisplay,
263 		    edid->edid_modes[i].vdisplay,
264 		    DIVIDE(DIVIDE(edid->edid_modes[i].dot_clock * 1000,
265 		    edid->edid_modes[i].htotal), edid->edid_modes[i].vtotal));
266 		printf(" (%d %d %d %d %d %d %d",
267 		    edid->edid_modes[i].dot_clock,
268 		    edid->edid_modes[i].hsync_start,
269 		    edid->edid_modes[i].hsync_end,
270 		    edid->edid_modes[i].htotal,
271 		    edid->edid_modes[i].vsync_start,
272 		    edid->edid_modes[i].vsync_end,
273 		    edid->edid_modes[i].vtotal);
274 		printf(" %s%sH %s%sV)\n",
275 		    edid->edid_modes[i].flags & VID_PHSYNC ? "+" : "",
276 		    edid->edid_modes[i].flags & VID_NHSYNC ? "-" : "",
277 		    edid->edid_modes[i].flags & VID_PVSYNC ? "+" : "",
278 		    edid->edid_modes[i].flags & VID_NVSYNC ? "-" : "");
279 	}
280 	if (edid->edid_preferred_mode)
281 		printf("Preferred mode: %dx%d @ %dHz\n",
282 		    edid->edid_preferred_mode->hdisplay,
283 		    edid->edid_preferred_mode->vdisplay,
284 		    DIVIDE(DIVIDE(edid->edid_preferred_mode->dot_clock * 1000,
285 		    edid->edid_preferred_mode->htotal),
286 		    edid->edid_preferred_mode->vtotal));
287 
288 	printf("Number of extension blocks: %d\n", edid->edid_ext_block_count);
289 }
290 
291 static const struct videomode *
292 edid_mode_lookup_list(const char *name)
293 {
294 	int	i;
295 
296 	for (i = 0; i < videomode_count; i++)
297 		if (strcmp(name, videomode_list[i].name) == 0)
298 			return &videomode_list[i];
299 	return NULL;
300 }
301 
302 static struct videomode *
303 edid_search_mode(struct edid_info *edid, const struct videomode *mode)
304 {
305 	int	refresh, i;
306 
307 	refresh = DIVIDE(DIVIDE(mode->dot_clock * 1000,
308 	    mode->htotal), mode->vtotal);
309 	for (i = 0; i < edid->edid_nmodes; i++) {
310 		if (mode->hdisplay == edid->edid_modes[i].hdisplay &&
311 		    mode->vdisplay == edid->edid_modes[i].vdisplay &&
312 		    refresh == DIVIDE(DIVIDE(
313 		    edid->edid_modes[i].dot_clock * 1000,
314 		    edid->edid_modes[i].htotal), edid->edid_modes[i].vtotal)) {
315 			return &edid->edid_modes[i];
316 		}
317 	}
318 	return NULL;
319 }
320 
321 static int
322 edid_std_timing(uint8_t *data, struct videomode *vmp)
323 {
324 	unsigned			x, y, f;
325 	const struct videomode		*lookup;
326 	char				name[80];
327 
328 	if ((data[0] == 1 && data[1] == 1) ||
329 	    (data[0] == 0 && data[1] == 0) ||
330 	    (data[0] == 0x20 && data[1] == 0x20))
331 		return 0;
332 
333 	x = EDID_STD_TIMING_HRES(data);
334 	switch (EDID_STD_TIMING_RATIO(data)) {
335 	case EDID_STD_TIMING_RATIO_16_10:
336 		y = x * 10 / 16;
337 		break;
338 	case EDID_STD_TIMING_RATIO_4_3:
339 		y = x * 3 / 4;
340 		break;
341 	case EDID_STD_TIMING_RATIO_5_4:
342 		y = x * 4 / 5;
343 		break;
344 	case EDID_STD_TIMING_RATIO_16_9:
345 	default:
346 		y = x * 9 / 16;
347 		break;
348 	}
349 	f = EDID_STD_TIMING_VFREQ(data);
350 
351 	/* first try to lookup the mode as a DMT timing */
352 	snprintf(name, sizeof(name), "%dx%dx%d", x, y, f);
353 	if ((lookup = edid_mode_lookup_list(name)) != NULL) {
354 		*vmp = *lookup;
355 	} else {
356 		/* failing that, calculate it using gtf */
357 		/*
358 		 * Hmm. I'm not using alternate GTF timings, which
359 		 * could, in theory, be present.
360 		 */
361 		vesagtf_mode(x, y, f, vmp);
362 	}
363 	return 1;
364 }
365 
366 static int
367 edid_det_timing(uint8_t *data, struct videomode *vmp)
368 {
369 	unsigned	hactive, hblank, hsyncwid, hsyncoff;
370 	unsigned	vactive, vblank, vsyncwid, vsyncoff;
371 	uint8_t		flags;
372 
373 	flags = EDID_DET_TIMING_FLAGS(data);
374 
375 	/* we don't support stereo modes (for now) */
376 	if (flags & (EDID_DET_TIMING_FLAG_STEREO |
377 		EDID_DET_TIMING_FLAG_STEREO_MODE))
378 		return 0;
379 
380 	vmp->dot_clock = EDID_DET_TIMING_DOT_CLOCK(data) / 1000;
381 
382 	hactive = EDID_DET_TIMING_HACTIVE(data);
383 	hblank = EDID_DET_TIMING_HBLANK(data);
384 	hsyncwid = EDID_DET_TIMING_HSYNC_WIDTH(data);
385 	hsyncoff = EDID_DET_TIMING_HSYNC_OFFSET(data);
386 
387 	vactive = EDID_DET_TIMING_VACTIVE(data);
388 	vblank = EDID_DET_TIMING_VBLANK(data);
389 	vsyncwid = EDID_DET_TIMING_VSYNC_WIDTH(data);
390 	vsyncoff = EDID_DET_TIMING_VSYNC_OFFSET(data);
391 
392 	/* Borders are contained within the blank areas. */
393 
394 	vmp->hdisplay = hactive;
395 	vmp->htotal = hactive + hblank;
396 	vmp->hsync_start = hactive + hsyncoff;
397 	vmp->hsync_end = vmp->hsync_start + hsyncwid;
398 
399 	vmp->vdisplay = vactive;
400 	vmp->vtotal = vactive + vblank;
401 	vmp->vsync_start = vactive + vsyncoff;
402 	vmp->vsync_end = vmp->vsync_start + vsyncwid;
403 
404 	vmp->flags = 0;
405 
406 	if (flags & EDID_DET_TIMING_FLAG_INTERLACE)
407 		vmp->flags |= VID_INTERLACE;
408 	if (flags & EDID_DET_TIMING_FLAG_HSYNC_POSITIVE)
409 		vmp->flags |= VID_PHSYNC;
410 	else
411 		vmp->flags |= VID_NHSYNC;
412 
413 	if (flags & EDID_DET_TIMING_FLAG_VSYNC_POSITIVE)
414 		vmp->flags |= VID_PVSYNC;
415 	else
416 		vmp->flags |= VID_NVSYNC;
417 
418 	return 1;
419 }
420 
421 static void
422 edid_block(struct edid_info *edid, uint8_t *data)
423 {
424 	int			i;
425 	struct videomode	mode, *exist_mode;
426 
427 	if (EDID_BLOCK_IS_DET_TIMING(data)) {
428 		if (!edid_det_timing(data, &mode))
429 			return;
430 		/* Does this mode already exist? */
431 		exist_mode = edid_search_mode(edid, &mode);
432 		if (exist_mode != NULL) {
433 			*exist_mode = mode;
434 			if (edid->edid_preferred_mode == NULL)
435 				edid->edid_preferred_mode = exist_mode;
436 		} else {
437 			edid->edid_modes[edid->edid_nmodes] = mode;
438 			if (edid->edid_preferred_mode == NULL)
439 				edid->edid_preferred_mode =
440 				    &edid->edid_modes[edid->edid_nmodes];
441 			edid->edid_nmodes++;
442 		}
443 		return;
444 	}
445 
446 	switch (EDID_BLOCK_TYPE(data)) {
447 	case EDID_DESC_BLOCK_TYPE_SERIAL:
448 		memcpy(edid->edid_serial, data + EDID_DESC_ASCII_DATA_OFFSET,
449 		    EDID_DESC_ASCII_DATA_LEN);
450 		edid->edid_serial[sizeof(edid->edid_serial) - 1] = 0;
451 		break;
452 
453 	case EDID_DESC_BLOCK_TYPE_ASCII:
454 		memcpy(edid->edid_comment, data + EDID_DESC_ASCII_DATA_OFFSET,
455 		    EDID_DESC_ASCII_DATA_LEN);
456 		edid->edid_comment[sizeof(edid->edid_comment) - 1] = 0;
457 		break;
458 
459 	case EDID_DESC_BLOCK_TYPE_RANGE:
460 		edid->edid_have_range = 1;
461 		edid->edid_range.er_min_vfreq =	EDID_DESC_RANGE_MIN_VFREQ(data);
462 		edid->edid_range.er_max_vfreq =	EDID_DESC_RANGE_MAX_VFREQ(data);
463 		edid->edid_range.er_min_hfreq =	EDID_DESC_RANGE_MIN_HFREQ(data);
464 		edid->edid_range.er_max_hfreq =	EDID_DESC_RANGE_MAX_HFREQ(data);
465 		edid->edid_range.er_max_clock = EDID_DESC_RANGE_MAX_CLOCK(data);
466 		if (!EDID_DESC_RANGE_HAVE_GTF2(data))
467 			break;
468 		edid->edid_range.er_have_gtf2 = 1;
469 		edid->edid_range.er_gtf2_hfreq =
470 		    EDID_DESC_RANGE_GTF2_HFREQ(data);
471 		edid->edid_range.er_gtf2_c = EDID_DESC_RANGE_GTF2_C(data);
472 		edid->edid_range.er_gtf2_m = EDID_DESC_RANGE_GTF2_M(data);
473 		edid->edid_range.er_gtf2_j = EDID_DESC_RANGE_GTF2_J(data);
474 		edid->edid_range.er_gtf2_k = EDID_DESC_RANGE_GTF2_K(data);
475 		break;
476 
477 	case EDID_DESC_BLOCK_TYPE_NAME:
478 		/* copy the product name into place */
479 		memcpy(edid->edid_productname,
480 		    data + EDID_DESC_ASCII_DATA_OFFSET,
481 		    EDID_DESC_ASCII_DATA_LEN);
482 		break;
483 
484 	case EDID_DESC_BLOCK_TYPE_STD_TIMING:
485 		data += EDID_DESC_STD_TIMING_START;
486 		for (i = 0; i < EDID_DESC_STD_TIMING_COUNT; i++) {
487 			if (edid_std_timing(data, &mode)) {
488 				/* Does this mode already exist? */
489 				exist_mode = edid_search_mode(edid, &mode);
490 				if (exist_mode == NULL) {
491 					edid->edid_modes[edid->edid_nmodes] =
492 					    mode;
493 					edid->edid_nmodes++;
494 				}
495 			}
496 			data += 2;
497 		}
498 		break;
499 
500 	case EDID_DESC_BLOCK_TYPE_COLOR_POINT:
501 		/* XXX: not implemented yet */
502 		break;
503 	}
504 }
505 
506 /*
507  * Gets EDID version in BCD, e.g. EDID v1.3  returned as 0x0103
508  */
509 int
510 edid_parse(uint8_t *data, struct edid_info *edid)
511 {
512 	uint16_t		manfid, estmodes;
513 	const struct videomode	*vmp;
514 	int			i;
515 	const char		*name;
516 	int max_dotclock = 0;
517 	int mhz;
518 
519 	if (edid_is_valid(data) != 0)
520 		return -1;
521 
522 	/* get product identification */
523 	manfid = EDID_VENDOR_ID(data);
524 	edid->edid_vendor[0] = EDID_MANFID_0(manfid);
525 	edid->edid_vendor[1] = EDID_MANFID_1(manfid);
526 	edid->edid_vendor[2] = EDID_MANFID_2(manfid);
527 	edid->edid_vendor[3] = 0;	/* null terminate for convenience */
528 
529 	edid->edid_product = data[EDID_OFFSET_PRODUCT_ID] +
530 	    (data[EDID_OFFSET_PRODUCT_ID + 1] << 8);
531 
532 	name = edid_findvendor(edid->edid_vendor);
533 	if (name != NULL)
534 		strlcpy(edid->edid_vendorname, name,
535 		    sizeof(edid->edid_vendorname));
536 	else
537 		edid->edid_vendorname[0] = '\0';
538 
539 	name = edid_findproduct(edid->edid_vendor, edid->edid_product);
540 	if (name != NULL)
541 		strlcpy(edid->edid_productname, name,
542 		    sizeof(edid->edid_productname));
543 	else
544 	    edid->edid_productname[0] = '\0';
545 
546 	snprintf(edid->edid_serial, sizeof(edid->edid_serial), "%08x",
547 	    EDID_SERIAL_NUMBER(data));
548 
549 	edid->edid_week = EDID_WEEK(data);
550 	edid->edid_year = EDID_YEAR(data);
551 
552 	/* get edid revision */
553 	edid->edid_version = EDID_VERSION(data);
554 	edid->edid_revision = EDID_REVISION(data);
555 
556 	edid->edid_video_input = EDID_VIDEO_INPUT(data);
557 	edid->edid_max_hsize = EDID_MAX_HSIZE(data);
558 	edid->edid_max_vsize = EDID_MAX_VSIZE(data);
559 
560 	edid->edid_gamma = EDID_GAMMA(data);
561 	edid->edid_features = EDID_FEATURES(data);
562 
563 	edid->edid_chroma.ec_redx = EDID_CHROMA_REDX(data);
564 	edid->edid_chroma.ec_redy = EDID_CHROMA_REDX(data);
565 	edid->edid_chroma.ec_greenx = EDID_CHROMA_GREENX(data);
566 	edid->edid_chroma.ec_greeny = EDID_CHROMA_GREENY(data);
567 	edid->edid_chroma.ec_bluex = EDID_CHROMA_BLUEX(data);
568 	edid->edid_chroma.ec_bluey = EDID_CHROMA_BLUEY(data);
569 	edid->edid_chroma.ec_whitex = EDID_CHROMA_WHITEX(data);
570 	edid->edid_chroma.ec_whitey = EDID_CHROMA_WHITEY(data);
571 
572 	edid->edid_ext_block_count = EDID_EXT_BLOCK_COUNT(data);
573 
574 	/* lookup established modes */
575 	edid->edid_nmodes = 0;
576 	edid->edid_preferred_mode = NULL;
577 	estmodes = EDID_EST_TIMING(data);
578 	/* Iterate in esztablished timing order */
579 	for (i = 15; i >= 0; i--) {
580 		if (estmodes & (1 << i)) {
581 			vmp = edid_mode_lookup_list(_edid_modes[i]);
582 			if (vmp != NULL) {
583 				edid->edid_modes[edid->edid_nmodes] = *vmp;
584 				edid->edid_nmodes++;
585 			}
586 #ifdef DIAGNOSTIC
587 			  else
588 				printf("no data for est. mode %s\n",
589 				    _edid_modes[i]);
590 #endif
591 		}
592 	}
593 
594 	/* do standard timing section */
595 	for (i = 0; i < EDID_STD_TIMING_COUNT; i++) {
596 		struct videomode	mode, *exist_mode;
597 		if (edid_std_timing(data + EDID_OFFSET_STD_TIMING + i * 2,
598 			&mode)) {
599 			/* Does this mode already exist? */
600 			exist_mode = edid_search_mode(edid, &mode);
601 			if (exist_mode == NULL) {
602 				edid->edid_modes[edid->edid_nmodes] = mode;
603 				edid->edid_nmodes++;
604 			}
605 		}
606 	}
607 
608 	/* do detailed timings and descriptors */
609 	for (i = 0; i < EDID_BLOCK_COUNT; i++) {
610 		edid_block(edid, data + EDID_OFFSET_DESC_BLOCK +
611 		    i * EDID_BLOCK_SIZE);
612 	}
613 
614 	edid_strchomp(edid->edid_vendorname);
615 	edid_strchomp(edid->edid_productname);
616 	edid_strchomp(edid->edid_serial);
617 	edid_strchomp(edid->edid_comment);
618 
619 	/*
620 	 * XXX
621 	 * some monitors lie about their maximum supported dot clock
622 	 * by claiming to support modes which need a higher dot clock
623 	 * than the stated maximum.
624 	 * For sanity's sake we bump it to the highest dot clock we find
625 	 * in the list of supported modes
626 	 */
627 	for (i = 0; i < edid->edid_nmodes; i++)
628 		if (edid->edid_modes[i].dot_clock > max_dotclock)
629 			max_dotclock = edid->edid_modes[i].dot_clock;
630 	if (bootverbose) {
631 		printf("edid: max_dotclock according to supported modes: %d\n",
632 		    max_dotclock);
633 	}
634 	mhz = (max_dotclock + 999) / 1000;
635 
636 	if (edid->edid_have_range) {
637 		if (mhz > edid->edid_range.er_max_clock)
638 			edid->edid_range.er_max_clock = mhz;
639 	} else
640 		edid->edid_range.er_max_clock = mhz;
641 
642 	return 0;
643 }
644