xref: /openbmc/linux/drivers/gpu/drm/drm_edid.c (revision 63dc02bd)
1 /*
2  * Copyright (c) 2006 Luc Verhaegen (quirks list)
3  * Copyright (c) 2007-2008 Intel Corporation
4  *   Jesse Barnes <jesse.barnes@intel.com>
5  * Copyright 2010 Red Hat, Inc.
6  *
7  * DDC probing routines (drm_ddc_read & drm_do_probe_ddc_edid) originally from
8  * FB layer.
9  *   Copyright (C) 2006 Dennis Munsie <dmunsie@cecropia.com>
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sub license,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice (including the
19  * next paragraph) shall be included in all copies or substantial portions
20  * of the Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
25  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
28  * DEALINGS IN THE SOFTWARE.
29  */
30 #include <linux/kernel.h>
31 #include <linux/slab.h>
32 #include <linux/i2c.h>
33 #include <linux/export.h>
34 #include "drmP.h"
35 #include "drm_edid.h"
36 #include "drm_edid_modes.h"
37 
38 #define version_greater(edid, maj, min) \
39 	(((edid)->version > (maj)) || \
40 	 ((edid)->version == (maj) && (edid)->revision > (min)))
41 
42 #define EDID_EST_TIMINGS 16
43 #define EDID_STD_TIMINGS 8
44 #define EDID_DETAILED_TIMINGS 4
45 
46 /*
47  * EDID blocks out in the wild have a variety of bugs, try to collect
48  * them here (note that userspace may work around broken monitors first,
49  * but fixes should make their way here so that the kernel "just works"
50  * on as many displays as possible).
51  */
52 
53 /* First detailed mode wrong, use largest 60Hz mode */
54 #define EDID_QUIRK_PREFER_LARGE_60		(1 << 0)
55 /* Reported 135MHz pixel clock is too high, needs adjustment */
56 #define EDID_QUIRK_135_CLOCK_TOO_HIGH		(1 << 1)
57 /* Prefer the largest mode at 75 Hz */
58 #define EDID_QUIRK_PREFER_LARGE_75		(1 << 2)
59 /* Detail timing is in cm not mm */
60 #define EDID_QUIRK_DETAILED_IN_CM		(1 << 3)
61 /* Detailed timing descriptors have bogus size values, so just take the
62  * maximum size and use that.
63  */
64 #define EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE	(1 << 4)
65 /* Monitor forgot to set the first detailed is preferred bit. */
66 #define EDID_QUIRK_FIRST_DETAILED_PREFERRED	(1 << 5)
67 /* use +hsync +vsync for detailed mode */
68 #define EDID_QUIRK_DETAILED_SYNC_PP		(1 << 6)
69 
70 struct detailed_mode_closure {
71 	struct drm_connector *connector;
72 	struct edid *edid;
73 	bool preferred;
74 	u32 quirks;
75 	int modes;
76 };
77 
78 #define LEVEL_DMT	0
79 #define LEVEL_GTF	1
80 #define LEVEL_GTF2	2
81 #define LEVEL_CVT	3
82 
83 static struct edid_quirk {
84 	char *vendor;
85 	int product_id;
86 	u32 quirks;
87 } edid_quirk_list[] = {
88 	/* Acer AL1706 */
89 	{ "ACR", 44358, EDID_QUIRK_PREFER_LARGE_60 },
90 	/* Acer F51 */
91 	{ "API", 0x7602, EDID_QUIRK_PREFER_LARGE_60 },
92 	/* Unknown Acer */
93 	{ "ACR", 2423, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
94 
95 	/* Belinea 10 15 55 */
96 	{ "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
97 	{ "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },
98 
99 	/* Envision Peripherals, Inc. EN-7100e */
100 	{ "EPI", 59264, EDID_QUIRK_135_CLOCK_TOO_HIGH },
101 	/* Envision EN2028 */
102 	{ "EPI", 8232, EDID_QUIRK_PREFER_LARGE_60 },
103 
104 	/* Funai Electronics PM36B */
105 	{ "FCM", 13600, EDID_QUIRK_PREFER_LARGE_75 |
106 	  EDID_QUIRK_DETAILED_IN_CM },
107 
108 	/* LG Philips LCD LP154W01-A5 */
109 	{ "LPL", 0, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
110 	{ "LPL", 0x2a00, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
111 
112 	/* Philips 107p5 CRT */
113 	{ "PHL", 57364, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
114 
115 	/* Proview AY765C */
116 	{ "PTS", 765, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
117 
118 	/* Samsung SyncMaster 205BW.  Note: irony */
119 	{ "SAM", 541, EDID_QUIRK_DETAILED_SYNC_PP },
120 	/* Samsung SyncMaster 22[5-6]BW */
121 	{ "SAM", 596, EDID_QUIRK_PREFER_LARGE_60 },
122 	{ "SAM", 638, EDID_QUIRK_PREFER_LARGE_60 },
123 };
124 
125 /*** DDC fetch and block validation ***/
126 
127 static const u8 edid_header[] = {
128 	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
129 };
130 
131  /*
132  * Sanity check the header of the base EDID block.  Return 8 if the header
133  * is perfect, down to 0 if it's totally wrong.
134  */
135 int drm_edid_header_is_valid(const u8 *raw_edid)
136 {
137 	int i, score = 0;
138 
139 	for (i = 0; i < sizeof(edid_header); i++)
140 		if (raw_edid[i] == edid_header[i])
141 			score++;
142 
143 	return score;
144 }
145 EXPORT_SYMBOL(drm_edid_header_is_valid);
146 
147 
148 /*
149  * Sanity check the EDID block (base or extension).  Return 0 if the block
150  * doesn't check out, or 1 if it's valid.
151  */
152 bool drm_edid_block_valid(u8 *raw_edid)
153 {
154 	int i;
155 	u8 csum = 0;
156 	struct edid *edid = (struct edid *)raw_edid;
157 
158 	if (raw_edid[0] == 0x00) {
159 		int score = drm_edid_header_is_valid(raw_edid);
160 		if (score == 8) ;
161 		else if (score >= 6) {
162 			DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
163 			memcpy(raw_edid, edid_header, sizeof(edid_header));
164 		} else {
165 			goto bad;
166 		}
167 	}
168 
169 	for (i = 0; i < EDID_LENGTH; i++)
170 		csum += raw_edid[i];
171 	if (csum) {
172 		DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
173 
174 		/* allow CEA to slide through, switches mangle this */
175 		if (raw_edid[0] != 0x02)
176 			goto bad;
177 	}
178 
179 	/* per-block-type checks */
180 	switch (raw_edid[0]) {
181 	case 0: /* base */
182 		if (edid->version != 1) {
183 			DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
184 			goto bad;
185 		}
186 
187 		if (edid->revision > 4)
188 			DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
189 		break;
190 
191 	default:
192 		break;
193 	}
194 
195 	return 1;
196 
197 bad:
198 	if (raw_edid) {
199 		printk(KERN_ERR "Raw EDID:\n");
200 		print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
201 			       raw_edid, EDID_LENGTH, false);
202 	}
203 	return 0;
204 }
205 EXPORT_SYMBOL(drm_edid_block_valid);
206 
207 /**
208  * drm_edid_is_valid - sanity check EDID data
209  * @edid: EDID data
210  *
211  * Sanity-check an entire EDID record (including extensions)
212  */
213 bool drm_edid_is_valid(struct edid *edid)
214 {
215 	int i;
216 	u8 *raw = (u8 *)edid;
217 
218 	if (!edid)
219 		return false;
220 
221 	for (i = 0; i <= edid->extensions; i++)
222 		if (!drm_edid_block_valid(raw + i * EDID_LENGTH))
223 			return false;
224 
225 	return true;
226 }
227 EXPORT_SYMBOL(drm_edid_is_valid);
228 
229 #define DDC_SEGMENT_ADDR 0x30
230 /**
231  * Get EDID information via I2C.
232  *
233  * \param adapter : i2c device adaptor
234  * \param buf     : EDID data buffer to be filled
235  * \param len     : EDID data buffer length
236  * \return 0 on success or -1 on failure.
237  *
238  * Try to fetch EDID information by calling i2c driver function.
239  */
240 static int
241 drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
242 		      int block, int len)
243 {
244 	unsigned char start = block * EDID_LENGTH;
245 	int ret, retries = 5;
246 
247 	/* The core i2c driver will automatically retry the transfer if the
248 	 * adapter reports EAGAIN. However, we find that bit-banging transfers
249 	 * are susceptible to errors under a heavily loaded machine and
250 	 * generate spurious NAKs and timeouts. Retrying the transfer
251 	 * of the individual block a few times seems to overcome this.
252 	 */
253 	do {
254 		struct i2c_msg msgs[] = {
255 			{
256 				.addr	= DDC_ADDR,
257 				.flags	= 0,
258 				.len	= 1,
259 				.buf	= &start,
260 			}, {
261 				.addr	= DDC_ADDR,
262 				.flags	= I2C_M_RD,
263 				.len	= len,
264 				.buf	= buf,
265 			}
266 		};
267 		ret = i2c_transfer(adapter, msgs, 2);
268 		if (ret == -ENXIO) {
269 			DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
270 					adapter->name);
271 			break;
272 		}
273 	} while (ret != 2 && --retries);
274 
275 	return ret == 2 ? 0 : -1;
276 }
277 
278 static bool drm_edid_is_zero(u8 *in_edid, int length)
279 {
280 	int i;
281 	u32 *raw_edid = (u32 *)in_edid;
282 
283 	for (i = 0; i < length / 4; i++)
284 		if (*(raw_edid + i) != 0)
285 			return false;
286 	return true;
287 }
288 
289 static u8 *
290 drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
291 {
292 	int i, j = 0, valid_extensions = 0;
293 	u8 *block, *new;
294 
295 	if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
296 		return NULL;
297 
298 	/* base block fetch */
299 	for (i = 0; i < 4; i++) {
300 		if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
301 			goto out;
302 		if (drm_edid_block_valid(block))
303 			break;
304 		if (i == 0 && drm_edid_is_zero(block, EDID_LENGTH)) {
305 			connector->null_edid_counter++;
306 			goto carp;
307 		}
308 	}
309 	if (i == 4)
310 		goto carp;
311 
312 	/* if there's no extensions, we're done */
313 	if (block[0x7e] == 0)
314 		return block;
315 
316 	new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);
317 	if (!new)
318 		goto out;
319 	block = new;
320 
321 	for (j = 1; j <= block[0x7e]; j++) {
322 		for (i = 0; i < 4; i++) {
323 			if (drm_do_probe_ddc_edid(adapter,
324 				  block + (valid_extensions + 1) * EDID_LENGTH,
325 				  j, EDID_LENGTH))
326 				goto out;
327 			if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH)) {
328 				valid_extensions++;
329 				break;
330 			}
331 		}
332 		if (i == 4)
333 			dev_warn(connector->dev->dev,
334 			 "%s: Ignoring invalid EDID block %d.\n",
335 			 drm_get_connector_name(connector), j);
336 	}
337 
338 	if (valid_extensions != block[0x7e]) {
339 		block[EDID_LENGTH-1] += block[0x7e] - valid_extensions;
340 		block[0x7e] = valid_extensions;
341 		new = krealloc(block, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
342 		if (!new)
343 			goto out;
344 		block = new;
345 	}
346 
347 	return block;
348 
349 carp:
350 	dev_warn(connector->dev->dev, "%s: EDID block %d invalid.\n",
351 		 drm_get_connector_name(connector), j);
352 
353 out:
354 	kfree(block);
355 	return NULL;
356 }
357 
358 /**
359  * Probe DDC presence.
360  *
361  * \param adapter : i2c device adaptor
362  * \return 1 on success
363  */
364 static bool
365 drm_probe_ddc(struct i2c_adapter *adapter)
366 {
367 	unsigned char out;
368 
369 	return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
370 }
371 
372 /**
373  * drm_get_edid - get EDID data, if available
374  * @connector: connector we're probing
375  * @adapter: i2c adapter to use for DDC
376  *
377  * Poke the given i2c channel to grab EDID data if possible.  If found,
378  * attach it to the connector.
379  *
380  * Return edid data or NULL if we couldn't find any.
381  */
382 struct edid *drm_get_edid(struct drm_connector *connector,
383 			  struct i2c_adapter *adapter)
384 {
385 	struct edid *edid = NULL;
386 
387 	if (drm_probe_ddc(adapter))
388 		edid = (struct edid *)drm_do_get_edid(connector, adapter);
389 
390 	connector->display_info.raw_edid = (char *)edid;
391 
392 	return edid;
393 
394 }
395 EXPORT_SYMBOL(drm_get_edid);
396 
397 /*** EDID parsing ***/
398 
399 /**
400  * edid_vendor - match a string against EDID's obfuscated vendor field
401  * @edid: EDID to match
402  * @vendor: vendor string
403  *
404  * Returns true if @vendor is in @edid, false otherwise
405  */
406 static bool edid_vendor(struct edid *edid, char *vendor)
407 {
408 	char edid_vendor[3];
409 
410 	edid_vendor[0] = ((edid->mfg_id[0] & 0x7c) >> 2) + '@';
411 	edid_vendor[1] = (((edid->mfg_id[0] & 0x3) << 3) |
412 			  ((edid->mfg_id[1] & 0xe0) >> 5)) + '@';
413 	edid_vendor[2] = (edid->mfg_id[1] & 0x1f) + '@';
414 
415 	return !strncmp(edid_vendor, vendor, 3);
416 }
417 
418 /**
419  * edid_get_quirks - return quirk flags for a given EDID
420  * @edid: EDID to process
421  *
422  * This tells subsequent routines what fixes they need to apply.
423  */
424 static u32 edid_get_quirks(struct edid *edid)
425 {
426 	struct edid_quirk *quirk;
427 	int i;
428 
429 	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
430 		quirk = &edid_quirk_list[i];
431 
432 		if (edid_vendor(edid, quirk->vendor) &&
433 		    (EDID_PRODUCT_ID(edid) == quirk->product_id))
434 			return quirk->quirks;
435 	}
436 
437 	return 0;
438 }
439 
440 #define MODE_SIZE(m) ((m)->hdisplay * (m)->vdisplay)
441 #define MODE_REFRESH_DIFF(m,r) (abs((m)->vrefresh - target_refresh))
442 
443 /**
444  * edid_fixup_preferred - set preferred modes based on quirk list
445  * @connector: has mode list to fix up
446  * @quirks: quirks list
447  *
448  * Walk the mode list for @connector, clearing the preferred status
449  * on existing modes and setting it anew for the right mode ala @quirks.
450  */
451 static void edid_fixup_preferred(struct drm_connector *connector,
452 				 u32 quirks)
453 {
454 	struct drm_display_mode *t, *cur_mode, *preferred_mode;
455 	int target_refresh = 0;
456 
457 	if (list_empty(&connector->probed_modes))
458 		return;
459 
460 	if (quirks & EDID_QUIRK_PREFER_LARGE_60)
461 		target_refresh = 60;
462 	if (quirks & EDID_QUIRK_PREFER_LARGE_75)
463 		target_refresh = 75;
464 
465 	preferred_mode = list_first_entry(&connector->probed_modes,
466 					  struct drm_display_mode, head);
467 
468 	list_for_each_entry_safe(cur_mode, t, &connector->probed_modes, head) {
469 		cur_mode->type &= ~DRM_MODE_TYPE_PREFERRED;
470 
471 		if (cur_mode == preferred_mode)
472 			continue;
473 
474 		/* Largest mode is preferred */
475 		if (MODE_SIZE(cur_mode) > MODE_SIZE(preferred_mode))
476 			preferred_mode = cur_mode;
477 
478 		/* At a given size, try to get closest to target refresh */
479 		if ((MODE_SIZE(cur_mode) == MODE_SIZE(preferred_mode)) &&
480 		    MODE_REFRESH_DIFF(cur_mode, target_refresh) <
481 		    MODE_REFRESH_DIFF(preferred_mode, target_refresh)) {
482 			preferred_mode = cur_mode;
483 		}
484 	}
485 
486 	preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
487 }
488 
489 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
490 					   int hsize, int vsize, int fresh)
491 {
492 	struct drm_display_mode *mode = NULL;
493 	int i;
494 
495 	for (i = 0; i < drm_num_dmt_modes; i++) {
496 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
497 		if (hsize == ptr->hdisplay &&
498 			vsize == ptr->vdisplay &&
499 			fresh == drm_mode_vrefresh(ptr)) {
500 			/* get the expected default mode */
501 			mode = drm_mode_duplicate(dev, ptr);
502 			break;
503 		}
504 	}
505 	return mode;
506 }
507 EXPORT_SYMBOL(drm_mode_find_dmt);
508 
509 typedef void detailed_cb(struct detailed_timing *timing, void *closure);
510 
511 static void
512 cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
513 {
514 	int i, n = 0;
515 	u8 d = ext[0x02];
516 	u8 *det_base = ext + d;
517 
518 	n = (127 - d) / 18;
519 	for (i = 0; i < n; i++)
520 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
521 }
522 
523 static void
524 vtb_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
525 {
526 	unsigned int i, n = min((int)ext[0x02], 6);
527 	u8 *det_base = ext + 5;
528 
529 	if (ext[0x01] != 1)
530 		return; /* unknown version */
531 
532 	for (i = 0; i < n; i++)
533 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
534 }
535 
536 static void
537 drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
538 {
539 	int i;
540 	struct edid *edid = (struct edid *)raw_edid;
541 
542 	if (edid == NULL)
543 		return;
544 
545 	for (i = 0; i < EDID_DETAILED_TIMINGS; i++)
546 		cb(&(edid->detailed_timings[i]), closure);
547 
548 	for (i = 1; i <= raw_edid[0x7e]; i++) {
549 		u8 *ext = raw_edid + (i * EDID_LENGTH);
550 		switch (*ext) {
551 		case CEA_EXT:
552 			cea_for_each_detailed_block(ext, cb, closure);
553 			break;
554 		case VTB_EXT:
555 			vtb_for_each_detailed_block(ext, cb, closure);
556 			break;
557 		default:
558 			break;
559 		}
560 	}
561 }
562 
563 static void
564 is_rb(struct detailed_timing *t, void *data)
565 {
566 	u8 *r = (u8 *)t;
567 	if (r[3] == EDID_DETAIL_MONITOR_RANGE)
568 		if (r[15] & 0x10)
569 			*(bool *)data = true;
570 }
571 
572 /* EDID 1.4 defines this explicitly.  For EDID 1.3, we guess, badly. */
573 static bool
574 drm_monitor_supports_rb(struct edid *edid)
575 {
576 	if (edid->revision >= 4) {
577 		bool ret;
578 		drm_for_each_detailed_block((u8 *)edid, is_rb, &ret);
579 		return ret;
580 	}
581 
582 	return ((edid->input & DRM_EDID_INPUT_DIGITAL) != 0);
583 }
584 
585 static void
586 find_gtf2(struct detailed_timing *t, void *data)
587 {
588 	u8 *r = (u8 *)t;
589 	if (r[3] == EDID_DETAIL_MONITOR_RANGE && r[10] == 0x02)
590 		*(u8 **)data = r;
591 }
592 
593 /* Secondary GTF curve kicks in above some break frequency */
594 static int
595 drm_gtf2_hbreak(struct edid *edid)
596 {
597 	u8 *r = NULL;
598 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
599 	return r ? (r[12] * 2) : 0;
600 }
601 
602 static int
603 drm_gtf2_2c(struct edid *edid)
604 {
605 	u8 *r = NULL;
606 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
607 	return r ? r[13] : 0;
608 }
609 
610 static int
611 drm_gtf2_m(struct edid *edid)
612 {
613 	u8 *r = NULL;
614 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
615 	return r ? (r[15] << 8) + r[14] : 0;
616 }
617 
618 static int
619 drm_gtf2_k(struct edid *edid)
620 {
621 	u8 *r = NULL;
622 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
623 	return r ? r[16] : 0;
624 }
625 
626 static int
627 drm_gtf2_2j(struct edid *edid)
628 {
629 	u8 *r = NULL;
630 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
631 	return r ? r[17] : 0;
632 }
633 
634 /**
635  * standard_timing_level - get std. timing level(CVT/GTF/DMT)
636  * @edid: EDID block to scan
637  */
638 static int standard_timing_level(struct edid *edid)
639 {
640 	if (edid->revision >= 2) {
641 		if (edid->revision >= 4 && (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF))
642 			return LEVEL_CVT;
643 		if (drm_gtf2_hbreak(edid))
644 			return LEVEL_GTF2;
645 		return LEVEL_GTF;
646 	}
647 	return LEVEL_DMT;
648 }
649 
650 /*
651  * 0 is reserved.  The spec says 0x01 fill for unused timings.  Some old
652  * monitors fill with ascii space (0x20) instead.
653  */
654 static int
655 bad_std_timing(u8 a, u8 b)
656 {
657 	return (a == 0x00 && b == 0x00) ||
658 	       (a == 0x01 && b == 0x01) ||
659 	       (a == 0x20 && b == 0x20);
660 }
661 
662 /**
663  * drm_mode_std - convert standard mode info (width, height, refresh) into mode
664  * @t: standard timing params
665  * @timing_level: standard timing level
666  *
667  * Take the standard timing params (in this case width, aspect, and refresh)
668  * and convert them into a real mode using CVT/GTF/DMT.
669  */
670 static struct drm_display_mode *
671 drm_mode_std(struct drm_connector *connector, struct edid *edid,
672 	     struct std_timing *t, int revision)
673 {
674 	struct drm_device *dev = connector->dev;
675 	struct drm_display_mode *m, *mode = NULL;
676 	int hsize, vsize;
677 	int vrefresh_rate;
678 	unsigned aspect_ratio = (t->vfreq_aspect & EDID_TIMING_ASPECT_MASK)
679 		>> EDID_TIMING_ASPECT_SHIFT;
680 	unsigned vfreq = (t->vfreq_aspect & EDID_TIMING_VFREQ_MASK)
681 		>> EDID_TIMING_VFREQ_SHIFT;
682 	int timing_level = standard_timing_level(edid);
683 
684 	if (bad_std_timing(t->hsize, t->vfreq_aspect))
685 		return NULL;
686 
687 	/* According to the EDID spec, the hdisplay = hsize * 8 + 248 */
688 	hsize = t->hsize * 8 + 248;
689 	/* vrefresh_rate = vfreq + 60 */
690 	vrefresh_rate = vfreq + 60;
691 	/* the vdisplay is calculated based on the aspect ratio */
692 	if (aspect_ratio == 0) {
693 		if (revision < 3)
694 			vsize = hsize;
695 		else
696 			vsize = (hsize * 10) / 16;
697 	} else if (aspect_ratio == 1)
698 		vsize = (hsize * 3) / 4;
699 	else if (aspect_ratio == 2)
700 		vsize = (hsize * 4) / 5;
701 	else
702 		vsize = (hsize * 9) / 16;
703 
704 	/* HDTV hack, part 1 */
705 	if (vrefresh_rate == 60 &&
706 	    ((hsize == 1360 && vsize == 765) ||
707 	     (hsize == 1368 && vsize == 769))) {
708 		hsize = 1366;
709 		vsize = 768;
710 	}
711 
712 	/*
713 	 * If this connector already has a mode for this size and refresh
714 	 * rate (because it came from detailed or CVT info), use that
715 	 * instead.  This way we don't have to guess at interlace or
716 	 * reduced blanking.
717 	 */
718 	list_for_each_entry(m, &connector->probed_modes, head)
719 		if (m->hdisplay == hsize && m->vdisplay == vsize &&
720 		    drm_mode_vrefresh(m) == vrefresh_rate)
721 			return NULL;
722 
723 	/* HDTV hack, part 2 */
724 	if (hsize == 1366 && vsize == 768 && vrefresh_rate == 60) {
725 		mode = drm_cvt_mode(dev, 1366, 768, vrefresh_rate, 0, 0,
726 				    false);
727 		mode->hdisplay = 1366;
728 		mode->hsync_start = mode->hsync_start - 1;
729 		mode->hsync_end = mode->hsync_end - 1;
730 		return mode;
731 	}
732 
733 	/* check whether it can be found in default mode table */
734 	mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate);
735 	if (mode)
736 		return mode;
737 
738 	switch (timing_level) {
739 	case LEVEL_DMT:
740 		break;
741 	case LEVEL_GTF:
742 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
743 		break;
744 	case LEVEL_GTF2:
745 		/*
746 		 * This is potentially wrong if there's ever a monitor with
747 		 * more than one ranges section, each claiming a different
748 		 * secondary GTF curve.  Please don't do that.
749 		 */
750 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
751 		if (drm_mode_hsync(mode) > drm_gtf2_hbreak(edid)) {
752 			drm_mode_destroy(dev, mode);
753 			mode = drm_gtf_mode_complex(dev, hsize, vsize,
754 						    vrefresh_rate, 0, 0,
755 						    drm_gtf2_m(edid),
756 						    drm_gtf2_2c(edid),
757 						    drm_gtf2_k(edid),
758 						    drm_gtf2_2j(edid));
759 		}
760 		break;
761 	case LEVEL_CVT:
762 		mode = drm_cvt_mode(dev, hsize, vsize, vrefresh_rate, 0, 0,
763 				    false);
764 		break;
765 	}
766 	return mode;
767 }
768 
769 /*
770  * EDID is delightfully ambiguous about how interlaced modes are to be
771  * encoded.  Our internal representation is of frame height, but some
772  * HDTV detailed timings are encoded as field height.
773  *
774  * The format list here is from CEA, in frame size.  Technically we
775  * should be checking refresh rate too.  Whatever.
776  */
777 static void
778 drm_mode_do_interlace_quirk(struct drm_display_mode *mode,
779 			    struct detailed_pixel_timing *pt)
780 {
781 	int i;
782 	static const struct {
783 		int w, h;
784 	} cea_interlaced[] = {
785 		{ 1920, 1080 },
786 		{  720,  480 },
787 		{ 1440,  480 },
788 		{ 2880,  480 },
789 		{  720,  576 },
790 		{ 1440,  576 },
791 		{ 2880,  576 },
792 	};
793 
794 	if (!(pt->misc & DRM_EDID_PT_INTERLACED))
795 		return;
796 
797 	for (i = 0; i < ARRAY_SIZE(cea_interlaced); i++) {
798 		if ((mode->hdisplay == cea_interlaced[i].w) &&
799 		    (mode->vdisplay == cea_interlaced[i].h / 2)) {
800 			mode->vdisplay *= 2;
801 			mode->vsync_start *= 2;
802 			mode->vsync_end *= 2;
803 			mode->vtotal *= 2;
804 			mode->vtotal |= 1;
805 		}
806 	}
807 
808 	mode->flags |= DRM_MODE_FLAG_INTERLACE;
809 }
810 
811 /**
812  * drm_mode_detailed - create a new mode from an EDID detailed timing section
813  * @dev: DRM device (needed to create new mode)
814  * @edid: EDID block
815  * @timing: EDID detailed timing info
816  * @quirks: quirks to apply
817  *
818  * An EDID detailed timing block contains enough info for us to create and
819  * return a new struct drm_display_mode.
820  */
821 static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
822 						  struct edid *edid,
823 						  struct detailed_timing *timing,
824 						  u32 quirks)
825 {
826 	struct drm_display_mode *mode;
827 	struct detailed_pixel_timing *pt = &timing->data.pixel_data;
828 	unsigned hactive = (pt->hactive_hblank_hi & 0xf0) << 4 | pt->hactive_lo;
829 	unsigned vactive = (pt->vactive_vblank_hi & 0xf0) << 4 | pt->vactive_lo;
830 	unsigned hblank = (pt->hactive_hblank_hi & 0xf) << 8 | pt->hblank_lo;
831 	unsigned vblank = (pt->vactive_vblank_hi & 0xf) << 8 | pt->vblank_lo;
832 	unsigned hsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc0) << 2 | pt->hsync_offset_lo;
833 	unsigned hsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x30) << 4 | pt->hsync_pulse_width_lo;
834 	unsigned vsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc) >> 2 | pt->vsync_offset_pulse_width_lo >> 4;
835 	unsigned vsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x3) << 4 | (pt->vsync_offset_pulse_width_lo & 0xf);
836 
837 	/* ignore tiny modes */
838 	if (hactive < 64 || vactive < 64)
839 		return NULL;
840 
841 	if (pt->misc & DRM_EDID_PT_STEREO) {
842 		printk(KERN_WARNING "stereo mode not supported\n");
843 		return NULL;
844 	}
845 	if (!(pt->misc & DRM_EDID_PT_SEPARATE_SYNC)) {
846 		printk(KERN_WARNING "composite sync not supported\n");
847 	}
848 
849 	/* it is incorrect if hsync/vsync width is zero */
850 	if (!hsync_pulse_width || !vsync_pulse_width) {
851 		DRM_DEBUG_KMS("Incorrect Detailed timing. "
852 				"Wrong Hsync/Vsync pulse width\n");
853 		return NULL;
854 	}
855 	mode = drm_mode_create(dev);
856 	if (!mode)
857 		return NULL;
858 
859 	mode->type = DRM_MODE_TYPE_DRIVER;
860 
861 	if (quirks & EDID_QUIRK_135_CLOCK_TOO_HIGH)
862 		timing->pixel_clock = cpu_to_le16(1088);
863 
864 	mode->clock = le16_to_cpu(timing->pixel_clock) * 10;
865 
866 	mode->hdisplay = hactive;
867 	mode->hsync_start = mode->hdisplay + hsync_offset;
868 	mode->hsync_end = mode->hsync_start + hsync_pulse_width;
869 	mode->htotal = mode->hdisplay + hblank;
870 
871 	mode->vdisplay = vactive;
872 	mode->vsync_start = mode->vdisplay + vsync_offset;
873 	mode->vsync_end = mode->vsync_start + vsync_pulse_width;
874 	mode->vtotal = mode->vdisplay + vblank;
875 
876 	/* Some EDIDs have bogus h/vtotal values */
877 	if (mode->hsync_end > mode->htotal)
878 		mode->htotal = mode->hsync_end + 1;
879 	if (mode->vsync_end > mode->vtotal)
880 		mode->vtotal = mode->vsync_end + 1;
881 
882 	drm_mode_do_interlace_quirk(mode, pt);
883 
884 	drm_mode_set_name(mode);
885 
886 	if (quirks & EDID_QUIRK_DETAILED_SYNC_PP) {
887 		pt->misc |= DRM_EDID_PT_HSYNC_POSITIVE | DRM_EDID_PT_VSYNC_POSITIVE;
888 	}
889 
890 	mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
891 		DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
892 	mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
893 		DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
894 
895 	mode->width_mm = pt->width_mm_lo | (pt->width_height_mm_hi & 0xf0) << 4;
896 	mode->height_mm = pt->height_mm_lo | (pt->width_height_mm_hi & 0xf) << 8;
897 
898 	if (quirks & EDID_QUIRK_DETAILED_IN_CM) {
899 		mode->width_mm *= 10;
900 		mode->height_mm *= 10;
901 	}
902 
903 	if (quirks & EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE) {
904 		mode->width_mm = edid->width_cm * 10;
905 		mode->height_mm = edid->height_cm * 10;
906 	}
907 
908 	return mode;
909 }
910 
911 static bool
912 mode_is_rb(const struct drm_display_mode *mode)
913 {
914 	return (mode->htotal - mode->hdisplay == 160) &&
915 	       (mode->hsync_end - mode->hdisplay == 80) &&
916 	       (mode->hsync_end - mode->hsync_start == 32) &&
917 	       (mode->vsync_start - mode->vdisplay == 3);
918 }
919 
920 static bool
921 mode_in_hsync_range(const struct drm_display_mode *mode,
922 		    struct edid *edid, u8 *t)
923 {
924 	int hsync, hmin, hmax;
925 
926 	hmin = t[7];
927 	if (edid->revision >= 4)
928 	    hmin += ((t[4] & 0x04) ? 255 : 0);
929 	hmax = t[8];
930 	if (edid->revision >= 4)
931 	    hmax += ((t[4] & 0x08) ? 255 : 0);
932 	hsync = drm_mode_hsync(mode);
933 
934 	return (hsync <= hmax && hsync >= hmin);
935 }
936 
937 static bool
938 mode_in_vsync_range(const struct drm_display_mode *mode,
939 		    struct edid *edid, u8 *t)
940 {
941 	int vsync, vmin, vmax;
942 
943 	vmin = t[5];
944 	if (edid->revision >= 4)
945 	    vmin += ((t[4] & 0x01) ? 255 : 0);
946 	vmax = t[6];
947 	if (edid->revision >= 4)
948 	    vmax += ((t[4] & 0x02) ? 255 : 0);
949 	vsync = drm_mode_vrefresh(mode);
950 
951 	return (vsync <= vmax && vsync >= vmin);
952 }
953 
954 static u32
955 range_pixel_clock(struct edid *edid, u8 *t)
956 {
957 	/* unspecified */
958 	if (t[9] == 0 || t[9] == 255)
959 		return 0;
960 
961 	/* 1.4 with CVT support gives us real precision, yay */
962 	if (edid->revision >= 4 && t[10] == 0x04)
963 		return (t[9] * 10000) - ((t[12] >> 2) * 250);
964 
965 	/* 1.3 is pathetic, so fuzz up a bit */
966 	return t[9] * 10000 + 5001;
967 }
968 
969 static bool
970 mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
971 	      struct detailed_timing *timing)
972 {
973 	u32 max_clock;
974 	u8 *t = (u8 *)timing;
975 
976 	if (!mode_in_hsync_range(mode, edid, t))
977 		return false;
978 
979 	if (!mode_in_vsync_range(mode, edid, t))
980 		return false;
981 
982 	if ((max_clock = range_pixel_clock(edid, t)))
983 		if (mode->clock > max_clock)
984 			return false;
985 
986 	/* 1.4 max horizontal check */
987 	if (edid->revision >= 4 && t[10] == 0x04)
988 		if (t[13] && mode->hdisplay > 8 * (t[13] + (256 * (t[12]&0x3))))
989 			return false;
990 
991 	if (mode_is_rb(mode) && !drm_monitor_supports_rb(edid))
992 		return false;
993 
994 	return true;
995 }
996 
997 /*
998  * XXX If drm_dmt_modes ever regrows the CVT-R modes (and it will) this will
999  * need to account for them.
1000  */
1001 static int
1002 drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
1003 			struct detailed_timing *timing)
1004 {
1005 	int i, modes = 0;
1006 	struct drm_display_mode *newmode;
1007 	struct drm_device *dev = connector->dev;
1008 
1009 	for (i = 0; i < drm_num_dmt_modes; i++) {
1010 		if (mode_in_range(drm_dmt_modes + i, edid, timing)) {
1011 			newmode = drm_mode_duplicate(dev, &drm_dmt_modes[i]);
1012 			if (newmode) {
1013 				drm_mode_probed_add(connector, newmode);
1014 				modes++;
1015 			}
1016 		}
1017 	}
1018 
1019 	return modes;
1020 }
1021 
1022 static void
1023 do_inferred_modes(struct detailed_timing *timing, void *c)
1024 {
1025 	struct detailed_mode_closure *closure = c;
1026 	struct detailed_non_pixel *data = &timing->data.other_data;
1027 	int gtf = (closure->edid->features & DRM_EDID_FEATURE_DEFAULT_GTF);
1028 
1029 	if (gtf && data->type == EDID_DETAIL_MONITOR_RANGE)
1030 		closure->modes += drm_gtf_modes_for_range(closure->connector,
1031 							  closure->edid,
1032 							  timing);
1033 }
1034 
1035 static int
1036 add_inferred_modes(struct drm_connector *connector, struct edid *edid)
1037 {
1038 	struct detailed_mode_closure closure = {
1039 		connector, edid, 0, 0, 0
1040 	};
1041 
1042 	if (version_greater(edid, 1, 0))
1043 		drm_for_each_detailed_block((u8 *)edid, do_inferred_modes,
1044 					    &closure);
1045 
1046 	return closure.modes;
1047 }
1048 
1049 static int
1050 drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
1051 {
1052 	int i, j, m, modes = 0;
1053 	struct drm_display_mode *mode;
1054 	u8 *est = ((u8 *)timing) + 5;
1055 
1056 	for (i = 0; i < 6; i++) {
1057 		for (j = 7; j > 0; j--) {
1058 			m = (i * 8) + (7 - j);
1059 			if (m >= ARRAY_SIZE(est3_modes))
1060 				break;
1061 			if (est[i] & (1 << j)) {
1062 				mode = drm_mode_find_dmt(connector->dev,
1063 							 est3_modes[m].w,
1064 							 est3_modes[m].h,
1065 							 est3_modes[m].r
1066 							 /*, est3_modes[m].rb */);
1067 				if (mode) {
1068 					drm_mode_probed_add(connector, mode);
1069 					modes++;
1070 				}
1071 			}
1072 		}
1073 	}
1074 
1075 	return modes;
1076 }
1077 
1078 static void
1079 do_established_modes(struct detailed_timing *timing, void *c)
1080 {
1081 	struct detailed_mode_closure *closure = c;
1082 	struct detailed_non_pixel *data = &timing->data.other_data;
1083 
1084 	if (data->type == EDID_DETAIL_EST_TIMINGS)
1085 		closure->modes += drm_est3_modes(closure->connector, timing);
1086 }
1087 
1088 /**
1089  * add_established_modes - get est. modes from EDID and add them
1090  * @edid: EDID block to scan
1091  *
1092  * Each EDID block contains a bitmap of the supported "established modes" list
1093  * (defined above).  Tease them out and add them to the global modes list.
1094  */
1095 static int
1096 add_established_modes(struct drm_connector *connector, struct edid *edid)
1097 {
1098 	struct drm_device *dev = connector->dev;
1099 	unsigned long est_bits = edid->established_timings.t1 |
1100 		(edid->established_timings.t2 << 8) |
1101 		((edid->established_timings.mfg_rsvd & 0x80) << 9);
1102 	int i, modes = 0;
1103 	struct detailed_mode_closure closure = {
1104 		connector, edid, 0, 0, 0
1105 	};
1106 
1107 	for (i = 0; i <= EDID_EST_TIMINGS; i++) {
1108 		if (est_bits & (1<<i)) {
1109 			struct drm_display_mode *newmode;
1110 			newmode = drm_mode_duplicate(dev, &edid_est_modes[i]);
1111 			if (newmode) {
1112 				drm_mode_probed_add(connector, newmode);
1113 				modes++;
1114 			}
1115 		}
1116 	}
1117 
1118 	if (version_greater(edid, 1, 0))
1119 		    drm_for_each_detailed_block((u8 *)edid,
1120 						do_established_modes, &closure);
1121 
1122 	return modes + closure.modes;
1123 }
1124 
1125 static void
1126 do_standard_modes(struct detailed_timing *timing, void *c)
1127 {
1128 	struct detailed_mode_closure *closure = c;
1129 	struct detailed_non_pixel *data = &timing->data.other_data;
1130 	struct drm_connector *connector = closure->connector;
1131 	struct edid *edid = closure->edid;
1132 
1133 	if (data->type == EDID_DETAIL_STD_MODES) {
1134 		int i;
1135 		for (i = 0; i < 6; i++) {
1136 			struct std_timing *std;
1137 			struct drm_display_mode *newmode;
1138 
1139 			std = &data->data.timings[i];
1140 			newmode = drm_mode_std(connector, edid, std,
1141 					       edid->revision);
1142 			if (newmode) {
1143 				drm_mode_probed_add(connector, newmode);
1144 				closure->modes++;
1145 			}
1146 		}
1147 	}
1148 }
1149 
1150 /**
1151  * add_standard_modes - get std. modes from EDID and add them
1152  * @edid: EDID block to scan
1153  *
1154  * Standard modes can be calculated using the appropriate standard (DMT,
1155  * GTF or CVT. Grab them from @edid and add them to the list.
1156  */
1157 static int
1158 add_standard_modes(struct drm_connector *connector, struct edid *edid)
1159 {
1160 	int i, modes = 0;
1161 	struct detailed_mode_closure closure = {
1162 		connector, edid, 0, 0, 0
1163 	};
1164 
1165 	for (i = 0; i < EDID_STD_TIMINGS; i++) {
1166 		struct drm_display_mode *newmode;
1167 
1168 		newmode = drm_mode_std(connector, edid,
1169 				       &edid->standard_timings[i],
1170 				       edid->revision);
1171 		if (newmode) {
1172 			drm_mode_probed_add(connector, newmode);
1173 			modes++;
1174 		}
1175 	}
1176 
1177 	if (version_greater(edid, 1, 0))
1178 		drm_for_each_detailed_block((u8 *)edid, do_standard_modes,
1179 					    &closure);
1180 
1181 	/* XXX should also look for standard codes in VTB blocks */
1182 
1183 	return modes + closure.modes;
1184 }
1185 
1186 static int drm_cvt_modes(struct drm_connector *connector,
1187 			 struct detailed_timing *timing)
1188 {
1189 	int i, j, modes = 0;
1190 	struct drm_display_mode *newmode;
1191 	struct drm_device *dev = connector->dev;
1192 	struct cvt_timing *cvt;
1193 	const int rates[] = { 60, 85, 75, 60, 50 };
1194 	const u8 empty[3] = { 0, 0, 0 };
1195 
1196 	for (i = 0; i < 4; i++) {
1197 		int uninitialized_var(width), height;
1198 		cvt = &(timing->data.other_data.data.cvt[i]);
1199 
1200 		if (!memcmp(cvt->code, empty, 3))
1201 			continue;
1202 
1203 		height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 4) + 1) * 2;
1204 		switch (cvt->code[1] & 0x0c) {
1205 		case 0x00:
1206 			width = height * 4 / 3;
1207 			break;
1208 		case 0x04:
1209 			width = height * 16 / 9;
1210 			break;
1211 		case 0x08:
1212 			width = height * 16 / 10;
1213 			break;
1214 		case 0x0c:
1215 			width = height * 15 / 9;
1216 			break;
1217 		}
1218 
1219 		for (j = 1; j < 5; j++) {
1220 			if (cvt->code[2] & (1 << j)) {
1221 				newmode = drm_cvt_mode(dev, width, height,
1222 						       rates[j], j == 0,
1223 						       false, false);
1224 				if (newmode) {
1225 					drm_mode_probed_add(connector, newmode);
1226 					modes++;
1227 				}
1228 			}
1229 		}
1230 	}
1231 
1232 	return modes;
1233 }
1234 
1235 static void
1236 do_cvt_mode(struct detailed_timing *timing, void *c)
1237 {
1238 	struct detailed_mode_closure *closure = c;
1239 	struct detailed_non_pixel *data = &timing->data.other_data;
1240 
1241 	if (data->type == EDID_DETAIL_CVT_3BYTE)
1242 		closure->modes += drm_cvt_modes(closure->connector, timing);
1243 }
1244 
1245 static int
1246 add_cvt_modes(struct drm_connector *connector, struct edid *edid)
1247 {
1248 	struct detailed_mode_closure closure = {
1249 		connector, edid, 0, 0, 0
1250 	};
1251 
1252 	if (version_greater(edid, 1, 2))
1253 		drm_for_each_detailed_block((u8 *)edid, do_cvt_mode, &closure);
1254 
1255 	/* XXX should also look for CVT codes in VTB blocks */
1256 
1257 	return closure.modes;
1258 }
1259 
1260 static void
1261 do_detailed_mode(struct detailed_timing *timing, void *c)
1262 {
1263 	struct detailed_mode_closure *closure = c;
1264 	struct drm_display_mode *newmode;
1265 
1266 	if (timing->pixel_clock) {
1267 		newmode = drm_mode_detailed(closure->connector->dev,
1268 					    closure->edid, timing,
1269 					    closure->quirks);
1270 		if (!newmode)
1271 			return;
1272 
1273 		if (closure->preferred)
1274 			newmode->type |= DRM_MODE_TYPE_PREFERRED;
1275 
1276 		drm_mode_probed_add(closure->connector, newmode);
1277 		closure->modes++;
1278 		closure->preferred = 0;
1279 	}
1280 }
1281 
1282 /*
1283  * add_detailed_modes - Add modes from detailed timings
1284  * @connector: attached connector
1285  * @edid: EDID block to scan
1286  * @quirks: quirks to apply
1287  */
1288 static int
1289 add_detailed_modes(struct drm_connector *connector, struct edid *edid,
1290 		   u32 quirks)
1291 {
1292 	struct detailed_mode_closure closure = {
1293 		connector,
1294 		edid,
1295 		1,
1296 		quirks,
1297 		0
1298 	};
1299 
1300 	if (closure.preferred && !version_greater(edid, 1, 3))
1301 		closure.preferred =
1302 		    (edid->features & DRM_EDID_FEATURE_PREFERRED_TIMING);
1303 
1304 	drm_for_each_detailed_block((u8 *)edid, do_detailed_mode, &closure);
1305 
1306 	return closure.modes;
1307 }
1308 
1309 #define HDMI_IDENTIFIER 0x000C03
1310 #define AUDIO_BLOCK	0x01
1311 #define VIDEO_BLOCK     0x02
1312 #define VENDOR_BLOCK    0x03
1313 #define SPEAKER_BLOCK	0x04
1314 #define EDID_BASIC_AUDIO	(1 << 6)
1315 
1316 /**
1317  * Search EDID for CEA extension block.
1318  */
1319 u8 *drm_find_cea_extension(struct edid *edid)
1320 {
1321 	u8 *edid_ext = NULL;
1322 	int i;
1323 
1324 	/* No EDID or EDID extensions */
1325 	if (edid == NULL || edid->extensions == 0)
1326 		return NULL;
1327 
1328 	/* Find CEA extension */
1329 	for (i = 0; i < edid->extensions; i++) {
1330 		edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
1331 		if (edid_ext[0] == CEA_EXT)
1332 			break;
1333 	}
1334 
1335 	if (i == edid->extensions)
1336 		return NULL;
1337 
1338 	return edid_ext;
1339 }
1340 EXPORT_SYMBOL(drm_find_cea_extension);
1341 
1342 static int
1343 do_cea_modes (struct drm_connector *connector, u8 *db, u8 len)
1344 {
1345 	struct drm_device *dev = connector->dev;
1346 	u8 * mode, cea_mode;
1347 	int modes = 0;
1348 
1349 	for (mode = db; mode < db + len; mode++) {
1350 		cea_mode = (*mode & 127) - 1; /* CEA modes are numbered 1..127 */
1351 		if (cea_mode < drm_num_cea_modes) {
1352 			struct drm_display_mode *newmode;
1353 			newmode = drm_mode_duplicate(dev,
1354 						     &edid_cea_modes[cea_mode]);
1355 			if (newmode) {
1356 				drm_mode_probed_add(connector, newmode);
1357 				modes++;
1358 			}
1359 		}
1360 	}
1361 
1362 	return modes;
1363 }
1364 
1365 static int
1366 add_cea_modes(struct drm_connector *connector, struct edid *edid)
1367 {
1368 	u8 * cea = drm_find_cea_extension(edid);
1369 	u8 * db, dbl;
1370 	int modes = 0;
1371 
1372 	if (cea && cea[1] >= 3) {
1373 		for (db = cea + 4; db < cea + cea[2]; db += dbl + 1) {
1374 			dbl = db[0] & 0x1f;
1375 			if (((db[0] & 0xe0) >> 5) == VIDEO_BLOCK)
1376 				modes += do_cea_modes (connector, db+1, dbl);
1377 		}
1378 	}
1379 
1380 	return modes;
1381 }
1382 
1383 static void
1384 parse_hdmi_vsdb(struct drm_connector *connector, uint8_t *db)
1385 {
1386 	connector->eld[5] |= (db[6] >> 7) << 1;  /* Supports_AI */
1387 
1388 	connector->dvi_dual = db[6] & 1;
1389 	connector->max_tmds_clock = db[7] * 5;
1390 
1391 	connector->latency_present[0] = db[8] >> 7;
1392 	connector->latency_present[1] = (db[8] >> 6) & 1;
1393 	connector->video_latency[0] = db[9];
1394 	connector->audio_latency[0] = db[10];
1395 	connector->video_latency[1] = db[11];
1396 	connector->audio_latency[1] = db[12];
1397 
1398 	DRM_LOG_KMS("HDMI: DVI dual %d, "
1399 		    "max TMDS clock %d, "
1400 		    "latency present %d %d, "
1401 		    "video latency %d %d, "
1402 		    "audio latency %d %d\n",
1403 		    connector->dvi_dual,
1404 		    connector->max_tmds_clock,
1405 	      (int) connector->latency_present[0],
1406 	      (int) connector->latency_present[1],
1407 		    connector->video_latency[0],
1408 		    connector->video_latency[1],
1409 		    connector->audio_latency[0],
1410 		    connector->audio_latency[1]);
1411 }
1412 
1413 static void
1414 monitor_name(struct detailed_timing *t, void *data)
1415 {
1416 	if (t->data.other_data.type == EDID_DETAIL_MONITOR_NAME)
1417 		*(u8 **)data = t->data.other_data.data.str.str;
1418 }
1419 
1420 /**
1421  * drm_edid_to_eld - build ELD from EDID
1422  * @connector: connector corresponding to the HDMI/DP sink
1423  * @edid: EDID to parse
1424  *
1425  * Fill the ELD (EDID-Like Data) buffer for passing to the audio driver.
1426  * Some ELD fields are left to the graphics driver caller:
1427  * - Conn_Type
1428  * - HDCP
1429  * - Port_ID
1430  */
1431 void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
1432 {
1433 	uint8_t *eld = connector->eld;
1434 	u8 *cea;
1435 	u8 *name;
1436 	u8 *db;
1437 	int sad_count = 0;
1438 	int mnl;
1439 	int dbl;
1440 
1441 	memset(eld, 0, sizeof(connector->eld));
1442 
1443 	cea = drm_find_cea_extension(edid);
1444 	if (!cea) {
1445 		DRM_DEBUG_KMS("ELD: no CEA Extension found\n");
1446 		return;
1447 	}
1448 
1449 	name = NULL;
1450 	drm_for_each_detailed_block((u8 *)edid, monitor_name, &name);
1451 	for (mnl = 0; name && mnl < 13; mnl++) {
1452 		if (name[mnl] == 0x0a)
1453 			break;
1454 		eld[20 + mnl] = name[mnl];
1455 	}
1456 	eld[4] = (cea[1] << 5) | mnl;
1457 	DRM_DEBUG_KMS("ELD monitor %s\n", eld + 20);
1458 
1459 	eld[0] = 2 << 3;		/* ELD version: 2 */
1460 
1461 	eld[16] = edid->mfg_id[0];
1462 	eld[17] = edid->mfg_id[1];
1463 	eld[18] = edid->prod_code[0];
1464 	eld[19] = edid->prod_code[1];
1465 
1466 	if (cea[1] >= 3)
1467 		for (db = cea + 4; db < cea + cea[2]; db += dbl + 1) {
1468 			dbl = db[0] & 0x1f;
1469 
1470 			switch ((db[0] & 0xe0) >> 5) {
1471 			case AUDIO_BLOCK:
1472 				/* Audio Data Block, contains SADs */
1473 				sad_count = dbl / 3;
1474 				memcpy(eld + 20 + mnl, &db[1], dbl);
1475 				break;
1476 			case SPEAKER_BLOCK:
1477                                 /* Speaker Allocation Data Block */
1478 				eld[7] = db[1];
1479 				break;
1480 			case VENDOR_BLOCK:
1481 				/* HDMI Vendor-Specific Data Block */
1482 				if (db[1] == 0x03 && db[2] == 0x0c && db[3] == 0)
1483 					parse_hdmi_vsdb(connector, db);
1484 				break;
1485 			default:
1486 				break;
1487 			}
1488 		}
1489 	eld[5] |= sad_count << 4;
1490 	eld[2] = (20 + mnl + sad_count * 3 + 3) / 4;
1491 
1492 	DRM_DEBUG_KMS("ELD size %d, SAD count %d\n", (int)eld[2], sad_count);
1493 }
1494 EXPORT_SYMBOL(drm_edid_to_eld);
1495 
1496 /**
1497  * drm_av_sync_delay - HDMI/DP sink audio-video sync delay in millisecond
1498  * @connector: connector associated with the HDMI/DP sink
1499  * @mode: the display mode
1500  */
1501 int drm_av_sync_delay(struct drm_connector *connector,
1502 		      struct drm_display_mode *mode)
1503 {
1504 	int i = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
1505 	int a, v;
1506 
1507 	if (!connector->latency_present[0])
1508 		return 0;
1509 	if (!connector->latency_present[1])
1510 		i = 0;
1511 
1512 	a = connector->audio_latency[i];
1513 	v = connector->video_latency[i];
1514 
1515 	/*
1516 	 * HDMI/DP sink doesn't support audio or video?
1517 	 */
1518 	if (a == 255 || v == 255)
1519 		return 0;
1520 
1521 	/*
1522 	 * Convert raw EDID values to millisecond.
1523 	 * Treat unknown latency as 0ms.
1524 	 */
1525 	if (a)
1526 		a = min(2 * (a - 1), 500);
1527 	if (v)
1528 		v = min(2 * (v - 1), 500);
1529 
1530 	return max(v - a, 0);
1531 }
1532 EXPORT_SYMBOL(drm_av_sync_delay);
1533 
1534 /**
1535  * drm_select_eld - select one ELD from multiple HDMI/DP sinks
1536  * @encoder: the encoder just changed display mode
1537  * @mode: the adjusted display mode
1538  *
1539  * It's possible for one encoder to be associated with multiple HDMI/DP sinks.
1540  * The policy is now hard coded to simply use the first HDMI/DP sink's ELD.
1541  */
1542 struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
1543 				     struct drm_display_mode *mode)
1544 {
1545 	struct drm_connector *connector;
1546 	struct drm_device *dev = encoder->dev;
1547 
1548 	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
1549 		if (connector->encoder == encoder && connector->eld[0])
1550 			return connector;
1551 
1552 	return NULL;
1553 }
1554 EXPORT_SYMBOL(drm_select_eld);
1555 
1556 /**
1557  * drm_detect_hdmi_monitor - detect whether monitor is hdmi.
1558  * @edid: monitor EDID information
1559  *
1560  * Parse the CEA extension according to CEA-861-B.
1561  * Return true if HDMI, false if not or unknown.
1562  */
1563 bool drm_detect_hdmi_monitor(struct edid *edid)
1564 {
1565 	u8 *edid_ext;
1566 	int i, hdmi_id;
1567 	int start_offset, end_offset;
1568 	bool is_hdmi = false;
1569 
1570 	edid_ext = drm_find_cea_extension(edid);
1571 	if (!edid_ext)
1572 		goto end;
1573 
1574 	/* Data block offset in CEA extension block */
1575 	start_offset = 4;
1576 	end_offset = edid_ext[2];
1577 
1578 	/*
1579 	 * Because HDMI identifier is in Vendor Specific Block,
1580 	 * search it from all data blocks of CEA extension.
1581 	 */
1582 	for (i = start_offset; i < end_offset;
1583 		/* Increased by data block len */
1584 		i += ((edid_ext[i] & 0x1f) + 1)) {
1585 		/* Find vendor specific block */
1586 		if ((edid_ext[i] >> 5) == VENDOR_BLOCK) {
1587 			hdmi_id = edid_ext[i + 1] | (edid_ext[i + 2] << 8) |
1588 				  edid_ext[i + 3] << 16;
1589 			/* Find HDMI identifier */
1590 			if (hdmi_id == HDMI_IDENTIFIER)
1591 				is_hdmi = true;
1592 			break;
1593 		}
1594 	}
1595 
1596 end:
1597 	return is_hdmi;
1598 }
1599 EXPORT_SYMBOL(drm_detect_hdmi_monitor);
1600 
1601 /**
1602  * drm_detect_monitor_audio - check monitor audio capability
1603  *
1604  * Monitor should have CEA extension block.
1605  * If monitor has 'basic audio', but no CEA audio blocks, it's 'basic
1606  * audio' only. If there is any audio extension block and supported
1607  * audio format, assume at least 'basic audio' support, even if 'basic
1608  * audio' is not defined in EDID.
1609  *
1610  */
1611 bool drm_detect_monitor_audio(struct edid *edid)
1612 {
1613 	u8 *edid_ext;
1614 	int i, j;
1615 	bool has_audio = false;
1616 	int start_offset, end_offset;
1617 
1618 	edid_ext = drm_find_cea_extension(edid);
1619 	if (!edid_ext)
1620 		goto end;
1621 
1622 	has_audio = ((edid_ext[3] & EDID_BASIC_AUDIO) != 0);
1623 
1624 	if (has_audio) {
1625 		DRM_DEBUG_KMS("Monitor has basic audio support\n");
1626 		goto end;
1627 	}
1628 
1629 	/* Data block offset in CEA extension block */
1630 	start_offset = 4;
1631 	end_offset = edid_ext[2];
1632 
1633 	for (i = start_offset; i < end_offset;
1634 			i += ((edid_ext[i] & 0x1f) + 1)) {
1635 		if ((edid_ext[i] >> 5) == AUDIO_BLOCK) {
1636 			has_audio = true;
1637 			for (j = 1; j < (edid_ext[i] & 0x1f); j += 3)
1638 				DRM_DEBUG_KMS("CEA audio format %d\n",
1639 					      (edid_ext[i + j] >> 3) & 0xf);
1640 			goto end;
1641 		}
1642 	}
1643 end:
1644 	return has_audio;
1645 }
1646 EXPORT_SYMBOL(drm_detect_monitor_audio);
1647 
1648 /**
1649  * drm_add_display_info - pull display info out if present
1650  * @edid: EDID data
1651  * @info: display info (attached to connector)
1652  *
1653  * Grab any available display info and stuff it into the drm_display_info
1654  * structure that's part of the connector.  Useful for tracking bpp and
1655  * color spaces.
1656  */
1657 static void drm_add_display_info(struct edid *edid,
1658 				 struct drm_display_info *info)
1659 {
1660 	u8 *edid_ext;
1661 
1662 	info->width_mm = edid->width_cm * 10;
1663 	info->height_mm = edid->height_cm * 10;
1664 
1665 	/* driver figures it out in this case */
1666 	info->bpc = 0;
1667 	info->color_formats = 0;
1668 
1669 	/* Only defined for 1.4 with digital displays */
1670 	if (edid->revision < 4)
1671 		return;
1672 
1673 	if (!(edid->input & DRM_EDID_INPUT_DIGITAL))
1674 		return;
1675 
1676 	switch (edid->input & DRM_EDID_DIGITAL_DEPTH_MASK) {
1677 	case DRM_EDID_DIGITAL_DEPTH_6:
1678 		info->bpc = 6;
1679 		break;
1680 	case DRM_EDID_DIGITAL_DEPTH_8:
1681 		info->bpc = 8;
1682 		break;
1683 	case DRM_EDID_DIGITAL_DEPTH_10:
1684 		info->bpc = 10;
1685 		break;
1686 	case DRM_EDID_DIGITAL_DEPTH_12:
1687 		info->bpc = 12;
1688 		break;
1689 	case DRM_EDID_DIGITAL_DEPTH_14:
1690 		info->bpc = 14;
1691 		break;
1692 	case DRM_EDID_DIGITAL_DEPTH_16:
1693 		info->bpc = 16;
1694 		break;
1695 	case DRM_EDID_DIGITAL_DEPTH_UNDEF:
1696 	default:
1697 		info->bpc = 0;
1698 		break;
1699 	}
1700 
1701 	info->color_formats = DRM_COLOR_FORMAT_RGB444;
1702 	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB444)
1703 		info->color_formats = DRM_COLOR_FORMAT_YCRCB444;
1704 	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB422)
1705 		info->color_formats = DRM_COLOR_FORMAT_YCRCB422;
1706 
1707 	/* Get data from CEA blocks if present */
1708 	edid_ext = drm_find_cea_extension(edid);
1709 	if (!edid_ext)
1710 		return;
1711 
1712 	info->cea_rev = edid_ext[1];
1713 }
1714 
1715 /**
1716  * drm_add_edid_modes - add modes from EDID data, if available
1717  * @connector: connector we're probing
1718  * @edid: edid data
1719  *
1720  * Add the specified modes to the connector's mode list.
1721  *
1722  * Return number of modes added or 0 if we couldn't find any.
1723  */
1724 int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
1725 {
1726 	int num_modes = 0;
1727 	u32 quirks;
1728 
1729 	if (edid == NULL) {
1730 		return 0;
1731 	}
1732 	if (!drm_edid_is_valid(edid)) {
1733 		dev_warn(connector->dev->dev, "%s: EDID invalid.\n",
1734 			 drm_get_connector_name(connector));
1735 		return 0;
1736 	}
1737 
1738 	quirks = edid_get_quirks(edid);
1739 
1740 	/*
1741 	 * EDID spec says modes should be preferred in this order:
1742 	 * - preferred detailed mode
1743 	 * - other detailed modes from base block
1744 	 * - detailed modes from extension blocks
1745 	 * - CVT 3-byte code modes
1746 	 * - standard timing codes
1747 	 * - established timing codes
1748 	 * - modes inferred from GTF or CVT range information
1749 	 *
1750 	 * We get this pretty much right.
1751 	 *
1752 	 * XXX order for additional mode types in extension blocks?
1753 	 */
1754 	num_modes += add_detailed_modes(connector, edid, quirks);
1755 	num_modes += add_cvt_modes(connector, edid);
1756 	num_modes += add_standard_modes(connector, edid);
1757 	num_modes += add_established_modes(connector, edid);
1758 	num_modes += add_inferred_modes(connector, edid);
1759 	num_modes += add_cea_modes(connector, edid);
1760 
1761 	if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
1762 		edid_fixup_preferred(connector, quirks);
1763 
1764 	drm_add_display_info(edid, &connector->display_info);
1765 
1766 	return num_modes;
1767 }
1768 EXPORT_SYMBOL(drm_add_edid_modes);
1769 
1770 /**
1771  * drm_add_modes_noedid - add modes for the connectors without EDID
1772  * @connector: connector we're probing
1773  * @hdisplay: the horizontal display limit
1774  * @vdisplay: the vertical display limit
1775  *
1776  * Add the specified modes to the connector's mode list. Only when the
1777  * hdisplay/vdisplay is not beyond the given limit, it will be added.
1778  *
1779  * Return number of modes added or 0 if we couldn't find any.
1780  */
1781 int drm_add_modes_noedid(struct drm_connector *connector,
1782 			int hdisplay, int vdisplay)
1783 {
1784 	int i, count, num_modes = 0;
1785 	struct drm_display_mode *mode;
1786 	struct drm_device *dev = connector->dev;
1787 
1788 	count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
1789 	if (hdisplay < 0)
1790 		hdisplay = 0;
1791 	if (vdisplay < 0)
1792 		vdisplay = 0;
1793 
1794 	for (i = 0; i < count; i++) {
1795 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
1796 		if (hdisplay && vdisplay) {
1797 			/*
1798 			 * Only when two are valid, they will be used to check
1799 			 * whether the mode should be added to the mode list of
1800 			 * the connector.
1801 			 */
1802 			if (ptr->hdisplay > hdisplay ||
1803 					ptr->vdisplay > vdisplay)
1804 				continue;
1805 		}
1806 		if (drm_mode_vrefresh(ptr) > 61)
1807 			continue;
1808 		mode = drm_mode_duplicate(dev, ptr);
1809 		if (mode) {
1810 			drm_mode_probed_add(connector, mode);
1811 			num_modes++;
1812 		}
1813 	}
1814 	return num_modes;
1815 }
1816 EXPORT_SYMBOL(drm_add_modes_noedid);
1817