xref: /linux/drivers/gpu/drm/drm_edid.c (revision c9895ed5a84dc3cbc86a9d6d5656d8c187f53380)
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 "drmP.h"
34 #include "drm_edid.h"
35 #include "drm_edid_modes.h"
36 
37 #define version_greater(edid, maj, min) \
38 	(((edid)->version > (maj)) || \
39 	 ((edid)->version == (maj) && (edid)->revision > (min)))
40 
41 #define EDID_EST_TIMINGS 16
42 #define EDID_STD_TIMINGS 8
43 #define EDID_DETAILED_TIMINGS 4
44 
45 /*
46  * EDID blocks out in the wild have a variety of bugs, try to collect
47  * them here (note that userspace may work around broken monitors first,
48  * but fixes should make their way here so that the kernel "just works"
49  * on as many displays as possible).
50  */
51 
52 /* First detailed mode wrong, use largest 60Hz mode */
53 #define EDID_QUIRK_PREFER_LARGE_60		(1 << 0)
54 /* Reported 135MHz pixel clock is too high, needs adjustment */
55 #define EDID_QUIRK_135_CLOCK_TOO_HIGH		(1 << 1)
56 /* Prefer the largest mode at 75 Hz */
57 #define EDID_QUIRK_PREFER_LARGE_75		(1 << 2)
58 /* Detail timing is in cm not mm */
59 #define EDID_QUIRK_DETAILED_IN_CM		(1 << 3)
60 /* Detailed timing descriptors have bogus size values, so just take the
61  * maximum size and use that.
62  */
63 #define EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE	(1 << 4)
64 /* Monitor forgot to set the first detailed is preferred bit. */
65 #define EDID_QUIRK_FIRST_DETAILED_PREFERRED	(1 << 5)
66 /* use +hsync +vsync for detailed mode */
67 #define EDID_QUIRK_DETAILED_SYNC_PP		(1 << 6)
68 
69 struct detailed_mode_closure {
70 	struct drm_connector *connector;
71 	struct edid *edid;
72 	bool preferred;
73 	u32 quirks;
74 	int modes;
75 };
76 
77 #define LEVEL_DMT	0
78 #define LEVEL_GTF	1
79 #define LEVEL_GTF2	2
80 #define LEVEL_CVT	3
81 
82 static struct edid_quirk {
83 	char *vendor;
84 	int product_id;
85 	u32 quirks;
86 } edid_quirk_list[] = {
87 	/* Acer AL1706 */
88 	{ "ACR", 44358, EDID_QUIRK_PREFER_LARGE_60 },
89 	/* Acer F51 */
90 	{ "API", 0x7602, EDID_QUIRK_PREFER_LARGE_60 },
91 	/* Unknown Acer */
92 	{ "ACR", 2423, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
93 
94 	/* Belinea 10 15 55 */
95 	{ "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
96 	{ "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },
97 
98 	/* Envision Peripherals, Inc. EN-7100e */
99 	{ "EPI", 59264, EDID_QUIRK_135_CLOCK_TOO_HIGH },
100 	/* Envision EN2028 */
101 	{ "EPI", 8232, EDID_QUIRK_PREFER_LARGE_60 },
102 
103 	/* Funai Electronics PM36B */
104 	{ "FCM", 13600, EDID_QUIRK_PREFER_LARGE_75 |
105 	  EDID_QUIRK_DETAILED_IN_CM },
106 
107 	/* LG Philips LCD LP154W01-A5 */
108 	{ "LPL", 0, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
109 	{ "LPL", 0x2a00, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
110 
111 	/* Philips 107p5 CRT */
112 	{ "PHL", 57364, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
113 
114 	/* Proview AY765C */
115 	{ "PTS", 765, EDID_QUIRK_FIRST_DETAILED_PREFERRED },
116 
117 	/* Samsung SyncMaster 205BW.  Note: irony */
118 	{ "SAM", 541, EDID_QUIRK_DETAILED_SYNC_PP },
119 	/* Samsung SyncMaster 22[5-6]BW */
120 	{ "SAM", 596, EDID_QUIRK_PREFER_LARGE_60 },
121 	{ "SAM", 638, EDID_QUIRK_PREFER_LARGE_60 },
122 };
123 
124 /*** DDC fetch and block validation ***/
125 
126 static const u8 edid_header[] = {
127 	0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
128 };
129 
130 /*
131  * Sanity check the EDID block (base or extension).  Return 0 if the block
132  * doesn't check out, or 1 if it's valid.
133  */
134 static bool
135 drm_edid_block_valid(u8 *raw_edid)
136 {
137 	int i;
138 	u8 csum = 0;
139 	struct edid *edid = (struct edid *)raw_edid;
140 
141 	if (raw_edid[0] == 0x00) {
142 		int score = 0;
143 
144 		for (i = 0; i < sizeof(edid_header); i++)
145 			if (raw_edid[i] == edid_header[i])
146 				score++;
147 
148 		if (score == 8) ;
149 		else if (score >= 6) {
150 			DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
151 			memcpy(raw_edid, edid_header, sizeof(edid_header));
152 		} else {
153 			goto bad;
154 		}
155 	}
156 
157 	for (i = 0; i < EDID_LENGTH; i++)
158 		csum += raw_edid[i];
159 	if (csum) {
160 		DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
161 
162 		/* allow CEA to slide through, switches mangle this */
163 		if (raw_edid[0] != 0x02)
164 			goto bad;
165 	}
166 
167 	/* per-block-type checks */
168 	switch (raw_edid[0]) {
169 	case 0: /* base */
170 		if (edid->version != 1) {
171 			DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
172 			goto bad;
173 		}
174 
175 		if (edid->revision > 4)
176 			DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
177 		break;
178 
179 	default:
180 		break;
181 	}
182 
183 	return 1;
184 
185 bad:
186 	if (raw_edid) {
187 		DRM_ERROR("Raw EDID:\n");
188 		print_hex_dump_bytes(KERN_ERR, DUMP_PREFIX_NONE, raw_edid, EDID_LENGTH);
189 		printk("\n");
190 	}
191 	return 0;
192 }
193 
194 /**
195  * drm_edid_is_valid - sanity check EDID data
196  * @edid: EDID data
197  *
198  * Sanity-check an entire EDID record (including extensions)
199  */
200 bool drm_edid_is_valid(struct edid *edid)
201 {
202 	int i;
203 	u8 *raw = (u8 *)edid;
204 
205 	if (!edid)
206 		return false;
207 
208 	for (i = 0; i <= edid->extensions; i++)
209 		if (!drm_edid_block_valid(raw + i * EDID_LENGTH))
210 			return false;
211 
212 	return true;
213 }
214 EXPORT_SYMBOL(drm_edid_is_valid);
215 
216 #define DDC_ADDR 0x50
217 #define DDC_SEGMENT_ADDR 0x30
218 /**
219  * Get EDID information via I2C.
220  *
221  * \param adapter : i2c device adaptor
222  * \param buf     : EDID data buffer to be filled
223  * \param len     : EDID data buffer length
224  * \return 0 on success or -1 on failure.
225  *
226  * Try to fetch EDID information by calling i2c driver function.
227  */
228 static int
229 drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
230 		      int block, int len)
231 {
232 	unsigned char start = block * EDID_LENGTH;
233 	struct i2c_msg msgs[] = {
234 		{
235 			.addr	= DDC_ADDR,
236 			.flags	= 0,
237 			.len	= 1,
238 			.buf	= &start,
239 		}, {
240 			.addr	= DDC_ADDR,
241 			.flags	= I2C_M_RD,
242 			.len	= len,
243 			.buf	= buf,
244 		}
245 	};
246 
247 	if (i2c_transfer(adapter, msgs, 2) == 2)
248 		return 0;
249 
250 	return -1;
251 }
252 
253 static u8 *
254 drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
255 {
256 	int i, j = 0, valid_extensions = 0;
257 	u8 *block, *new;
258 
259 	if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
260 		return NULL;
261 
262 	/* base block fetch */
263 	for (i = 0; i < 4; i++) {
264 		if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
265 			goto out;
266 		if (drm_edid_block_valid(block))
267 			break;
268 	}
269 	if (i == 4)
270 		goto carp;
271 
272 	/* if there's no extensions, we're done */
273 	if (block[0x7e] == 0)
274 		return block;
275 
276 	new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);
277 	if (!new)
278 		goto out;
279 	block = new;
280 
281 	for (j = 1; j <= block[0x7e]; j++) {
282 		for (i = 0; i < 4; i++) {
283 			if (drm_do_probe_ddc_edid(adapter,
284 				  block + (valid_extensions + 1) * EDID_LENGTH,
285 				  j, EDID_LENGTH))
286 				goto out;
287 			if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH)) {
288 				valid_extensions++;
289 				break;
290 			}
291 		}
292 		if (i == 4)
293 			dev_warn(connector->dev->dev,
294 			 "%s: Ignoring invalid EDID block %d.\n",
295 			 drm_get_connector_name(connector), j);
296 	}
297 
298 	if (valid_extensions != block[0x7e]) {
299 		block[EDID_LENGTH-1] += block[0x7e] - valid_extensions;
300 		block[0x7e] = valid_extensions;
301 		new = krealloc(block, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
302 		if (!new)
303 			goto out;
304 		block = new;
305 	}
306 
307 	return block;
308 
309 carp:
310 	dev_warn(connector->dev->dev, "%s: EDID block %d invalid.\n",
311 		 drm_get_connector_name(connector), j);
312 
313 out:
314 	kfree(block);
315 	return NULL;
316 }
317 
318 /**
319  * Probe DDC presence.
320  *
321  * \param adapter : i2c device adaptor
322  * \return 1 on success
323  */
324 static bool
325 drm_probe_ddc(struct i2c_adapter *adapter)
326 {
327 	unsigned char out;
328 
329 	return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
330 }
331 
332 /**
333  * drm_get_edid - get EDID data, if available
334  * @connector: connector we're probing
335  * @adapter: i2c adapter to use for DDC
336  *
337  * Poke the given i2c channel to grab EDID data if possible.  If found,
338  * attach it to the connector.
339  *
340  * Return edid data or NULL if we couldn't find any.
341  */
342 struct edid *drm_get_edid(struct drm_connector *connector,
343 			  struct i2c_adapter *adapter)
344 {
345 	struct edid *edid = NULL;
346 
347 	if (drm_probe_ddc(adapter))
348 		edid = (struct edid *)drm_do_get_edid(connector, adapter);
349 
350 	connector->display_info.raw_edid = (char *)edid;
351 
352 	return edid;
353 
354 }
355 EXPORT_SYMBOL(drm_get_edid);
356 
357 /*** EDID parsing ***/
358 
359 /**
360  * edid_vendor - match a string against EDID's obfuscated vendor field
361  * @edid: EDID to match
362  * @vendor: vendor string
363  *
364  * Returns true if @vendor is in @edid, false otherwise
365  */
366 static bool edid_vendor(struct edid *edid, char *vendor)
367 {
368 	char edid_vendor[3];
369 
370 	edid_vendor[0] = ((edid->mfg_id[0] & 0x7c) >> 2) + '@';
371 	edid_vendor[1] = (((edid->mfg_id[0] & 0x3) << 3) |
372 			  ((edid->mfg_id[1] & 0xe0) >> 5)) + '@';
373 	edid_vendor[2] = (edid->mfg_id[1] & 0x1f) + '@';
374 
375 	return !strncmp(edid_vendor, vendor, 3);
376 }
377 
378 /**
379  * edid_get_quirks - return quirk flags for a given EDID
380  * @edid: EDID to process
381  *
382  * This tells subsequent routines what fixes they need to apply.
383  */
384 static u32 edid_get_quirks(struct edid *edid)
385 {
386 	struct edid_quirk *quirk;
387 	int i;
388 
389 	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
390 		quirk = &edid_quirk_list[i];
391 
392 		if (edid_vendor(edid, quirk->vendor) &&
393 		    (EDID_PRODUCT_ID(edid) == quirk->product_id))
394 			return quirk->quirks;
395 	}
396 
397 	return 0;
398 }
399 
400 #define MODE_SIZE(m) ((m)->hdisplay * (m)->vdisplay)
401 #define MODE_REFRESH_DIFF(m,r) (abs((m)->vrefresh - target_refresh))
402 
403 /**
404  * edid_fixup_preferred - set preferred modes based on quirk list
405  * @connector: has mode list to fix up
406  * @quirks: quirks list
407  *
408  * Walk the mode list for @connector, clearing the preferred status
409  * on existing modes and setting it anew for the right mode ala @quirks.
410  */
411 static void edid_fixup_preferred(struct drm_connector *connector,
412 				 u32 quirks)
413 {
414 	struct drm_display_mode *t, *cur_mode, *preferred_mode;
415 	int target_refresh = 0;
416 
417 	if (list_empty(&connector->probed_modes))
418 		return;
419 
420 	if (quirks & EDID_QUIRK_PREFER_LARGE_60)
421 		target_refresh = 60;
422 	if (quirks & EDID_QUIRK_PREFER_LARGE_75)
423 		target_refresh = 75;
424 
425 	preferred_mode = list_first_entry(&connector->probed_modes,
426 					  struct drm_display_mode, head);
427 
428 	list_for_each_entry_safe(cur_mode, t, &connector->probed_modes, head) {
429 		cur_mode->type &= ~DRM_MODE_TYPE_PREFERRED;
430 
431 		if (cur_mode == preferred_mode)
432 			continue;
433 
434 		/* Largest mode is preferred */
435 		if (MODE_SIZE(cur_mode) > MODE_SIZE(preferred_mode))
436 			preferred_mode = cur_mode;
437 
438 		/* At a given size, try to get closest to target refresh */
439 		if ((MODE_SIZE(cur_mode) == MODE_SIZE(preferred_mode)) &&
440 		    MODE_REFRESH_DIFF(cur_mode, target_refresh) <
441 		    MODE_REFRESH_DIFF(preferred_mode, target_refresh)) {
442 			preferred_mode = cur_mode;
443 		}
444 	}
445 
446 	preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
447 }
448 
449 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
450 					   int hsize, int vsize, int fresh)
451 {
452 	struct drm_display_mode *mode = NULL;
453 	int i;
454 
455 	for (i = 0; i < drm_num_dmt_modes; i++) {
456 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
457 		if (hsize == ptr->hdisplay &&
458 			vsize == ptr->vdisplay &&
459 			fresh == drm_mode_vrefresh(ptr)) {
460 			/* get the expected default mode */
461 			mode = drm_mode_duplicate(dev, ptr);
462 			break;
463 		}
464 	}
465 	return mode;
466 }
467 EXPORT_SYMBOL(drm_mode_find_dmt);
468 
469 typedef void detailed_cb(struct detailed_timing *timing, void *closure);
470 
471 static void
472 cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
473 {
474 	int i, n = 0;
475 	u8 rev = ext[0x01], d = ext[0x02];
476 	u8 *det_base = ext + d;
477 
478 	switch (rev) {
479 	case 0:
480 		/* can't happen */
481 		return;
482 	case 1:
483 		/* have to infer how many blocks we have, check pixel clock */
484 		for (i = 0; i < 6; i++)
485 			if (det_base[18*i] || det_base[18*i+1])
486 				n++;
487 		break;
488 	default:
489 		/* explicit count */
490 		n = min(ext[0x03] & 0x0f, 6);
491 		break;
492 	}
493 
494 	for (i = 0; i < n; i++)
495 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
496 }
497 
498 static void
499 vtb_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
500 {
501 	unsigned int i, n = min((int)ext[0x02], 6);
502 	u8 *det_base = ext + 5;
503 
504 	if (ext[0x01] != 1)
505 		return; /* unknown version */
506 
507 	for (i = 0; i < n; i++)
508 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
509 }
510 
511 static void
512 drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
513 {
514 	int i;
515 	struct edid *edid = (struct edid *)raw_edid;
516 
517 	if (edid == NULL)
518 		return;
519 
520 	for (i = 0; i < EDID_DETAILED_TIMINGS; i++)
521 		cb(&(edid->detailed_timings[i]), closure);
522 
523 	for (i = 1; i <= raw_edid[0x7e]; i++) {
524 		u8 *ext = raw_edid + (i * EDID_LENGTH);
525 		switch (*ext) {
526 		case CEA_EXT:
527 			cea_for_each_detailed_block(ext, cb, closure);
528 			break;
529 		case VTB_EXT:
530 			vtb_for_each_detailed_block(ext, cb, closure);
531 			break;
532 		default:
533 			break;
534 		}
535 	}
536 }
537 
538 static void
539 is_rb(struct detailed_timing *t, void *data)
540 {
541 	u8 *r = (u8 *)t;
542 	if (r[3] == EDID_DETAIL_MONITOR_RANGE)
543 		if (r[15] & 0x10)
544 			*(bool *)data = true;
545 }
546 
547 /* EDID 1.4 defines this explicitly.  For EDID 1.3, we guess, badly. */
548 static bool
549 drm_monitor_supports_rb(struct edid *edid)
550 {
551 	if (edid->revision >= 4) {
552 		bool ret;
553 		drm_for_each_detailed_block((u8 *)edid, is_rb, &ret);
554 		return ret;
555 	}
556 
557 	return ((edid->input & DRM_EDID_INPUT_DIGITAL) != 0);
558 }
559 
560 static void
561 find_gtf2(struct detailed_timing *t, void *data)
562 {
563 	u8 *r = (u8 *)t;
564 	if (r[3] == EDID_DETAIL_MONITOR_RANGE && r[10] == 0x02)
565 		*(u8 **)data = r;
566 }
567 
568 /* Secondary GTF curve kicks in above some break frequency */
569 static int
570 drm_gtf2_hbreak(struct edid *edid)
571 {
572 	u8 *r = NULL;
573 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
574 	return r ? (r[12] * 2) : 0;
575 }
576 
577 static int
578 drm_gtf2_2c(struct edid *edid)
579 {
580 	u8 *r = NULL;
581 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
582 	return r ? r[13] : 0;
583 }
584 
585 static int
586 drm_gtf2_m(struct edid *edid)
587 {
588 	u8 *r = NULL;
589 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
590 	return r ? (r[15] << 8) + r[14] : 0;
591 }
592 
593 static int
594 drm_gtf2_k(struct edid *edid)
595 {
596 	u8 *r = NULL;
597 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
598 	return r ? r[16] : 0;
599 }
600 
601 static int
602 drm_gtf2_2j(struct edid *edid)
603 {
604 	u8 *r = NULL;
605 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
606 	return r ? r[17] : 0;
607 }
608 
609 /**
610  * standard_timing_level - get std. timing level(CVT/GTF/DMT)
611  * @edid: EDID block to scan
612  */
613 static int standard_timing_level(struct edid *edid)
614 {
615 	if (edid->revision >= 2) {
616 		if (edid->revision >= 4 && (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF))
617 			return LEVEL_CVT;
618 		if (drm_gtf2_hbreak(edid))
619 			return LEVEL_GTF2;
620 		return LEVEL_GTF;
621 	}
622 	return LEVEL_DMT;
623 }
624 
625 /*
626  * 0 is reserved.  The spec says 0x01 fill for unused timings.  Some old
627  * monitors fill with ascii space (0x20) instead.
628  */
629 static int
630 bad_std_timing(u8 a, u8 b)
631 {
632 	return (a == 0x00 && b == 0x00) ||
633 	       (a == 0x01 && b == 0x01) ||
634 	       (a == 0x20 && b == 0x20);
635 }
636 
637 /**
638  * drm_mode_std - convert standard mode info (width, height, refresh) into mode
639  * @t: standard timing params
640  * @timing_level: standard timing level
641  *
642  * Take the standard timing params (in this case width, aspect, and refresh)
643  * and convert them into a real mode using CVT/GTF/DMT.
644  */
645 static struct drm_display_mode *
646 drm_mode_std(struct drm_connector *connector, struct edid *edid,
647 	     struct std_timing *t, int revision)
648 {
649 	struct drm_device *dev = connector->dev;
650 	struct drm_display_mode *m, *mode = NULL;
651 	int hsize, vsize;
652 	int vrefresh_rate;
653 	unsigned aspect_ratio = (t->vfreq_aspect & EDID_TIMING_ASPECT_MASK)
654 		>> EDID_TIMING_ASPECT_SHIFT;
655 	unsigned vfreq = (t->vfreq_aspect & EDID_TIMING_VFREQ_MASK)
656 		>> EDID_TIMING_VFREQ_SHIFT;
657 	int timing_level = standard_timing_level(edid);
658 
659 	if (bad_std_timing(t->hsize, t->vfreq_aspect))
660 		return NULL;
661 
662 	/* According to the EDID spec, the hdisplay = hsize * 8 + 248 */
663 	hsize = t->hsize * 8 + 248;
664 	/* vrefresh_rate = vfreq + 60 */
665 	vrefresh_rate = vfreq + 60;
666 	/* the vdisplay is calculated based on the aspect ratio */
667 	if (aspect_ratio == 0) {
668 		if (revision < 3)
669 			vsize = hsize;
670 		else
671 			vsize = (hsize * 10) / 16;
672 	} else if (aspect_ratio == 1)
673 		vsize = (hsize * 3) / 4;
674 	else if (aspect_ratio == 2)
675 		vsize = (hsize * 4) / 5;
676 	else
677 		vsize = (hsize * 9) / 16;
678 
679 	/* HDTV hack, part 1 */
680 	if (vrefresh_rate == 60 &&
681 	    ((hsize == 1360 && vsize == 765) ||
682 	     (hsize == 1368 && vsize == 769))) {
683 		hsize = 1366;
684 		vsize = 768;
685 	}
686 
687 	/*
688 	 * If this connector already has a mode for this size and refresh
689 	 * rate (because it came from detailed or CVT info), use that
690 	 * instead.  This way we don't have to guess at interlace or
691 	 * reduced blanking.
692 	 */
693 	list_for_each_entry(m, &connector->probed_modes, head)
694 		if (m->hdisplay == hsize && m->vdisplay == vsize &&
695 		    drm_mode_vrefresh(m) == vrefresh_rate)
696 			return NULL;
697 
698 	/* HDTV hack, part 2 */
699 	if (hsize == 1366 && vsize == 768 && vrefresh_rate == 60) {
700 		mode = drm_cvt_mode(dev, 1366, 768, vrefresh_rate, 0, 0,
701 				    false);
702 		mode->hdisplay = 1366;
703 		mode->hsync_start = mode->hsync_start - 1;
704 		mode->hsync_end = mode->hsync_end - 1;
705 		return mode;
706 	}
707 
708 	/* check whether it can be found in default mode table */
709 	mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate);
710 	if (mode)
711 		return mode;
712 
713 	switch (timing_level) {
714 	case LEVEL_DMT:
715 		break;
716 	case LEVEL_GTF:
717 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
718 		break;
719 	case LEVEL_GTF2:
720 		/*
721 		 * This is potentially wrong if there's ever a monitor with
722 		 * more than one ranges section, each claiming a different
723 		 * secondary GTF curve.  Please don't do that.
724 		 */
725 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
726 		if (drm_mode_hsync(mode) > drm_gtf2_hbreak(edid)) {
727 			kfree(mode);
728 			mode = drm_gtf_mode_complex(dev, hsize, vsize,
729 						    vrefresh_rate, 0, 0,
730 						    drm_gtf2_m(edid),
731 						    drm_gtf2_2c(edid),
732 						    drm_gtf2_k(edid),
733 						    drm_gtf2_2j(edid));
734 		}
735 		break;
736 	case LEVEL_CVT:
737 		mode = drm_cvt_mode(dev, hsize, vsize, vrefresh_rate, 0, 0,
738 				    false);
739 		break;
740 	}
741 	return mode;
742 }
743 
744 /*
745  * EDID is delightfully ambiguous about how interlaced modes are to be
746  * encoded.  Our internal representation is of frame height, but some
747  * HDTV detailed timings are encoded as field height.
748  *
749  * The format list here is from CEA, in frame size.  Technically we
750  * should be checking refresh rate too.  Whatever.
751  */
752 static void
753 drm_mode_do_interlace_quirk(struct drm_display_mode *mode,
754 			    struct detailed_pixel_timing *pt)
755 {
756 	int i;
757 	static const struct {
758 		int w, h;
759 	} cea_interlaced[] = {
760 		{ 1920, 1080 },
761 		{  720,  480 },
762 		{ 1440,  480 },
763 		{ 2880,  480 },
764 		{  720,  576 },
765 		{ 1440,  576 },
766 		{ 2880,  576 },
767 	};
768 
769 	if (!(pt->misc & DRM_EDID_PT_INTERLACED))
770 		return;
771 
772 	for (i = 0; i < ARRAY_SIZE(cea_interlaced); i++) {
773 		if ((mode->hdisplay == cea_interlaced[i].w) &&
774 		    (mode->vdisplay == cea_interlaced[i].h / 2)) {
775 			mode->vdisplay *= 2;
776 			mode->vsync_start *= 2;
777 			mode->vsync_end *= 2;
778 			mode->vtotal *= 2;
779 			mode->vtotal |= 1;
780 		}
781 	}
782 
783 	mode->flags |= DRM_MODE_FLAG_INTERLACE;
784 }
785 
786 /**
787  * drm_mode_detailed - create a new mode from an EDID detailed timing section
788  * @dev: DRM device (needed to create new mode)
789  * @edid: EDID block
790  * @timing: EDID detailed timing info
791  * @quirks: quirks to apply
792  *
793  * An EDID detailed timing block contains enough info for us to create and
794  * return a new struct drm_display_mode.
795  */
796 static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
797 						  struct edid *edid,
798 						  struct detailed_timing *timing,
799 						  u32 quirks)
800 {
801 	struct drm_display_mode *mode;
802 	struct detailed_pixel_timing *pt = &timing->data.pixel_data;
803 	unsigned hactive = (pt->hactive_hblank_hi & 0xf0) << 4 | pt->hactive_lo;
804 	unsigned vactive = (pt->vactive_vblank_hi & 0xf0) << 4 | pt->vactive_lo;
805 	unsigned hblank = (pt->hactive_hblank_hi & 0xf) << 8 | pt->hblank_lo;
806 	unsigned vblank = (pt->vactive_vblank_hi & 0xf) << 8 | pt->vblank_lo;
807 	unsigned hsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc0) << 2 | pt->hsync_offset_lo;
808 	unsigned hsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x30) << 4 | pt->hsync_pulse_width_lo;
809 	unsigned vsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc) >> 2 | pt->vsync_offset_pulse_width_lo >> 4;
810 	unsigned vsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x3) << 4 | (pt->vsync_offset_pulse_width_lo & 0xf);
811 
812 	/* ignore tiny modes */
813 	if (hactive < 64 || vactive < 64)
814 		return NULL;
815 
816 	if (pt->misc & DRM_EDID_PT_STEREO) {
817 		printk(KERN_WARNING "stereo mode not supported\n");
818 		return NULL;
819 	}
820 	if (!(pt->misc & DRM_EDID_PT_SEPARATE_SYNC)) {
821 		printk(KERN_WARNING "composite sync not supported\n");
822 	}
823 
824 	/* it is incorrect if hsync/vsync width is zero */
825 	if (!hsync_pulse_width || !vsync_pulse_width) {
826 		DRM_DEBUG_KMS("Incorrect Detailed timing. "
827 				"Wrong Hsync/Vsync pulse width\n");
828 		return NULL;
829 	}
830 	mode = drm_mode_create(dev);
831 	if (!mode)
832 		return NULL;
833 
834 	mode->type = DRM_MODE_TYPE_DRIVER;
835 
836 	if (quirks & EDID_QUIRK_135_CLOCK_TOO_HIGH)
837 		timing->pixel_clock = cpu_to_le16(1088);
838 
839 	mode->clock = le16_to_cpu(timing->pixel_clock) * 10;
840 
841 	mode->hdisplay = hactive;
842 	mode->hsync_start = mode->hdisplay + hsync_offset;
843 	mode->hsync_end = mode->hsync_start + hsync_pulse_width;
844 	mode->htotal = mode->hdisplay + hblank;
845 
846 	mode->vdisplay = vactive;
847 	mode->vsync_start = mode->vdisplay + vsync_offset;
848 	mode->vsync_end = mode->vsync_start + vsync_pulse_width;
849 	mode->vtotal = mode->vdisplay + vblank;
850 
851 	/* Some EDIDs have bogus h/vtotal values */
852 	if (mode->hsync_end > mode->htotal)
853 		mode->htotal = mode->hsync_end + 1;
854 	if (mode->vsync_end > mode->vtotal)
855 		mode->vtotal = mode->vsync_end + 1;
856 
857 	drm_mode_do_interlace_quirk(mode, pt);
858 
859 	drm_mode_set_name(mode);
860 
861 	if (quirks & EDID_QUIRK_DETAILED_SYNC_PP) {
862 		pt->misc |= DRM_EDID_PT_HSYNC_POSITIVE | DRM_EDID_PT_VSYNC_POSITIVE;
863 	}
864 
865 	mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
866 		DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
867 	mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
868 		DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
869 
870 	mode->width_mm = pt->width_mm_lo | (pt->width_height_mm_hi & 0xf0) << 4;
871 	mode->height_mm = pt->height_mm_lo | (pt->width_height_mm_hi & 0xf) << 8;
872 
873 	if (quirks & EDID_QUIRK_DETAILED_IN_CM) {
874 		mode->width_mm *= 10;
875 		mode->height_mm *= 10;
876 	}
877 
878 	if (quirks & EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE) {
879 		mode->width_mm = edid->width_cm * 10;
880 		mode->height_mm = edid->height_cm * 10;
881 	}
882 
883 	return mode;
884 }
885 
886 static bool
887 mode_is_rb(const struct drm_display_mode *mode)
888 {
889 	return (mode->htotal - mode->hdisplay == 160) &&
890 	       (mode->hsync_end - mode->hdisplay == 80) &&
891 	       (mode->hsync_end - mode->hsync_start == 32) &&
892 	       (mode->vsync_start - mode->vdisplay == 3);
893 }
894 
895 static bool
896 mode_in_hsync_range(const struct drm_display_mode *mode,
897 		    struct edid *edid, u8 *t)
898 {
899 	int hsync, hmin, hmax;
900 
901 	hmin = t[7];
902 	if (edid->revision >= 4)
903 	    hmin += ((t[4] & 0x04) ? 255 : 0);
904 	hmax = t[8];
905 	if (edid->revision >= 4)
906 	    hmax += ((t[4] & 0x08) ? 255 : 0);
907 	hsync = drm_mode_hsync(mode);
908 
909 	return (hsync <= hmax && hsync >= hmin);
910 }
911 
912 static bool
913 mode_in_vsync_range(const struct drm_display_mode *mode,
914 		    struct edid *edid, u8 *t)
915 {
916 	int vsync, vmin, vmax;
917 
918 	vmin = t[5];
919 	if (edid->revision >= 4)
920 	    vmin += ((t[4] & 0x01) ? 255 : 0);
921 	vmax = t[6];
922 	if (edid->revision >= 4)
923 	    vmax += ((t[4] & 0x02) ? 255 : 0);
924 	vsync = drm_mode_vrefresh(mode);
925 
926 	return (vsync <= vmax && vsync >= vmin);
927 }
928 
929 static u32
930 range_pixel_clock(struct edid *edid, u8 *t)
931 {
932 	/* unspecified */
933 	if (t[9] == 0 || t[9] == 255)
934 		return 0;
935 
936 	/* 1.4 with CVT support gives us real precision, yay */
937 	if (edid->revision >= 4 && t[10] == 0x04)
938 		return (t[9] * 10000) - ((t[12] >> 2) * 250);
939 
940 	/* 1.3 is pathetic, so fuzz up a bit */
941 	return t[9] * 10000 + 5001;
942 }
943 
944 static bool
945 mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
946 	      struct detailed_timing *timing)
947 {
948 	u32 max_clock;
949 	u8 *t = (u8 *)timing;
950 
951 	if (!mode_in_hsync_range(mode, edid, t))
952 		return false;
953 
954 	if (!mode_in_vsync_range(mode, edid, t))
955 		return false;
956 
957 	if ((max_clock = range_pixel_clock(edid, t)))
958 		if (mode->clock > max_clock)
959 			return false;
960 
961 	/* 1.4 max horizontal check */
962 	if (edid->revision >= 4 && t[10] == 0x04)
963 		if (t[13] && mode->hdisplay > 8 * (t[13] + (256 * (t[12]&0x3))))
964 			return false;
965 
966 	if (mode_is_rb(mode) && !drm_monitor_supports_rb(edid))
967 		return false;
968 
969 	return true;
970 }
971 
972 /*
973  * XXX If drm_dmt_modes ever regrows the CVT-R modes (and it will) this will
974  * need to account for them.
975  */
976 static int
977 drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
978 			struct detailed_timing *timing)
979 {
980 	int i, modes = 0;
981 	struct drm_display_mode *newmode;
982 	struct drm_device *dev = connector->dev;
983 
984 	for (i = 0; i < drm_num_dmt_modes; i++) {
985 		if (mode_in_range(drm_dmt_modes + i, edid, timing)) {
986 			newmode = drm_mode_duplicate(dev, &drm_dmt_modes[i]);
987 			if (newmode) {
988 				drm_mode_probed_add(connector, newmode);
989 				modes++;
990 			}
991 		}
992 	}
993 
994 	return modes;
995 }
996 
997 static void
998 do_inferred_modes(struct detailed_timing *timing, void *c)
999 {
1000 	struct detailed_mode_closure *closure = c;
1001 	struct detailed_non_pixel *data = &timing->data.other_data;
1002 	int gtf = (closure->edid->features & DRM_EDID_FEATURE_DEFAULT_GTF);
1003 
1004 	if (gtf && data->type == EDID_DETAIL_MONITOR_RANGE)
1005 		closure->modes += drm_gtf_modes_for_range(closure->connector,
1006 							  closure->edid,
1007 							  timing);
1008 }
1009 
1010 static int
1011 add_inferred_modes(struct drm_connector *connector, struct edid *edid)
1012 {
1013 	struct detailed_mode_closure closure = {
1014 		connector, edid, 0, 0, 0
1015 	};
1016 
1017 	if (version_greater(edid, 1, 0))
1018 		drm_for_each_detailed_block((u8 *)edid, do_inferred_modes,
1019 					    &closure);
1020 
1021 	return closure.modes;
1022 }
1023 
1024 static int
1025 drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
1026 {
1027 	int i, j, m, modes = 0;
1028 	struct drm_display_mode *mode;
1029 	u8 *est = ((u8 *)timing) + 5;
1030 
1031 	for (i = 0; i < 6; i++) {
1032 		for (j = 7; j > 0; j--) {
1033 			m = (i * 8) + (7 - j);
1034 			if (m >= ARRAY_SIZE(est3_modes))
1035 				break;
1036 			if (est[i] & (1 << j)) {
1037 				mode = drm_mode_find_dmt(connector->dev,
1038 							 est3_modes[m].w,
1039 							 est3_modes[m].h,
1040 							 est3_modes[m].r
1041 							 /*, est3_modes[m].rb */);
1042 				if (mode) {
1043 					drm_mode_probed_add(connector, mode);
1044 					modes++;
1045 				}
1046 			}
1047 		}
1048 	}
1049 
1050 	return modes;
1051 }
1052 
1053 static void
1054 do_established_modes(struct detailed_timing *timing, void *c)
1055 {
1056 	struct detailed_mode_closure *closure = c;
1057 	struct detailed_non_pixel *data = &timing->data.other_data;
1058 
1059 	if (data->type == EDID_DETAIL_EST_TIMINGS)
1060 		closure->modes += drm_est3_modes(closure->connector, timing);
1061 }
1062 
1063 /**
1064  * add_established_modes - get est. modes from EDID and add them
1065  * @edid: EDID block to scan
1066  *
1067  * Each EDID block contains a bitmap of the supported "established modes" list
1068  * (defined above).  Tease them out and add them to the global modes list.
1069  */
1070 static int
1071 add_established_modes(struct drm_connector *connector, struct edid *edid)
1072 {
1073 	struct drm_device *dev = connector->dev;
1074 	unsigned long est_bits = edid->established_timings.t1 |
1075 		(edid->established_timings.t2 << 8) |
1076 		((edid->established_timings.mfg_rsvd & 0x80) << 9);
1077 	int i, modes = 0;
1078 	struct detailed_mode_closure closure = {
1079 		connector, edid, 0, 0, 0
1080 	};
1081 
1082 	for (i = 0; i <= EDID_EST_TIMINGS; i++) {
1083 		if (est_bits & (1<<i)) {
1084 			struct drm_display_mode *newmode;
1085 			newmode = drm_mode_duplicate(dev, &edid_est_modes[i]);
1086 			if (newmode) {
1087 				drm_mode_probed_add(connector, newmode);
1088 				modes++;
1089 			}
1090 		}
1091 	}
1092 
1093 	if (version_greater(edid, 1, 0))
1094 		    drm_for_each_detailed_block((u8 *)edid,
1095 						do_established_modes, &closure);
1096 
1097 	return modes + closure.modes;
1098 }
1099 
1100 static void
1101 do_standard_modes(struct detailed_timing *timing, void *c)
1102 {
1103 	struct detailed_mode_closure *closure = c;
1104 	struct detailed_non_pixel *data = &timing->data.other_data;
1105 	struct drm_connector *connector = closure->connector;
1106 	struct edid *edid = closure->edid;
1107 
1108 	if (data->type == EDID_DETAIL_STD_MODES) {
1109 		int i;
1110 		for (i = 0; i < 6; i++) {
1111 			struct std_timing *std;
1112 			struct drm_display_mode *newmode;
1113 
1114 			std = &data->data.timings[i];
1115 			newmode = drm_mode_std(connector, edid, std,
1116 					       edid->revision);
1117 			if (newmode) {
1118 				drm_mode_probed_add(connector, newmode);
1119 				closure->modes++;
1120 			}
1121 		}
1122 	}
1123 }
1124 
1125 /**
1126  * add_standard_modes - get std. modes from EDID and add them
1127  * @edid: EDID block to scan
1128  *
1129  * Standard modes can be calculated using the appropriate standard (DMT,
1130  * GTF or CVT. Grab them from @edid and add them to the list.
1131  */
1132 static int
1133 add_standard_modes(struct drm_connector *connector, struct edid *edid)
1134 {
1135 	int i, modes = 0;
1136 	struct detailed_mode_closure closure = {
1137 		connector, edid, 0, 0, 0
1138 	};
1139 
1140 	for (i = 0; i < EDID_STD_TIMINGS; i++) {
1141 		struct drm_display_mode *newmode;
1142 
1143 		newmode = drm_mode_std(connector, edid,
1144 				       &edid->standard_timings[i],
1145 				       edid->revision);
1146 		if (newmode) {
1147 			drm_mode_probed_add(connector, newmode);
1148 			modes++;
1149 		}
1150 	}
1151 
1152 	if (version_greater(edid, 1, 0))
1153 		drm_for_each_detailed_block((u8 *)edid, do_standard_modes,
1154 					    &closure);
1155 
1156 	/* XXX should also look for standard codes in VTB blocks */
1157 
1158 	return modes + closure.modes;
1159 }
1160 
1161 static int drm_cvt_modes(struct drm_connector *connector,
1162 			 struct detailed_timing *timing)
1163 {
1164 	int i, j, modes = 0;
1165 	struct drm_display_mode *newmode;
1166 	struct drm_device *dev = connector->dev;
1167 	struct cvt_timing *cvt;
1168 	const int rates[] = { 60, 85, 75, 60, 50 };
1169 	const u8 empty[3] = { 0, 0, 0 };
1170 
1171 	for (i = 0; i < 4; i++) {
1172 		int uninitialized_var(width), height;
1173 		cvt = &(timing->data.other_data.data.cvt[i]);
1174 
1175 		if (!memcmp(cvt->code, empty, 3))
1176 			continue;
1177 
1178 		height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 4) + 1) * 2;
1179 		switch (cvt->code[1] & 0x0c) {
1180 		case 0x00:
1181 			width = height * 4 / 3;
1182 			break;
1183 		case 0x04:
1184 			width = height * 16 / 9;
1185 			break;
1186 		case 0x08:
1187 			width = height * 16 / 10;
1188 			break;
1189 		case 0x0c:
1190 			width = height * 15 / 9;
1191 			break;
1192 		}
1193 
1194 		for (j = 1; j < 5; j++) {
1195 			if (cvt->code[2] & (1 << j)) {
1196 				newmode = drm_cvt_mode(dev, width, height,
1197 						       rates[j], j == 0,
1198 						       false, false);
1199 				if (newmode) {
1200 					drm_mode_probed_add(connector, newmode);
1201 					modes++;
1202 				}
1203 			}
1204 		}
1205 	}
1206 
1207 	return modes;
1208 }
1209 
1210 static void
1211 do_cvt_mode(struct detailed_timing *timing, void *c)
1212 {
1213 	struct detailed_mode_closure *closure = c;
1214 	struct detailed_non_pixel *data = &timing->data.other_data;
1215 
1216 	if (data->type == EDID_DETAIL_CVT_3BYTE)
1217 		closure->modes += drm_cvt_modes(closure->connector, timing);
1218 }
1219 
1220 static int
1221 add_cvt_modes(struct drm_connector *connector, struct edid *edid)
1222 {
1223 	struct detailed_mode_closure closure = {
1224 		connector, edid, 0, 0, 0
1225 	};
1226 
1227 	if (version_greater(edid, 1, 2))
1228 		drm_for_each_detailed_block((u8 *)edid, do_cvt_mode, &closure);
1229 
1230 	/* XXX should also look for CVT codes in VTB blocks */
1231 
1232 	return closure.modes;
1233 }
1234 
1235 static void
1236 do_detailed_mode(struct detailed_timing *timing, void *c)
1237 {
1238 	struct detailed_mode_closure *closure = c;
1239 	struct drm_display_mode *newmode;
1240 
1241 	if (timing->pixel_clock) {
1242 		newmode = drm_mode_detailed(closure->connector->dev,
1243 					    closure->edid, timing,
1244 					    closure->quirks);
1245 		if (!newmode)
1246 			return;
1247 
1248 		if (closure->preferred)
1249 			newmode->type |= DRM_MODE_TYPE_PREFERRED;
1250 
1251 		drm_mode_probed_add(closure->connector, newmode);
1252 		closure->modes++;
1253 		closure->preferred = 0;
1254 	}
1255 }
1256 
1257 /*
1258  * add_detailed_modes - Add modes from detailed timings
1259  * @connector: attached connector
1260  * @edid: EDID block to scan
1261  * @quirks: quirks to apply
1262  */
1263 static int
1264 add_detailed_modes(struct drm_connector *connector, struct edid *edid,
1265 		   u32 quirks)
1266 {
1267 	struct detailed_mode_closure closure = {
1268 		connector,
1269 		edid,
1270 		1,
1271 		quirks,
1272 		0
1273 	};
1274 
1275 	if (closure.preferred && !version_greater(edid, 1, 3))
1276 		closure.preferred =
1277 		    (edid->features & DRM_EDID_FEATURE_PREFERRED_TIMING);
1278 
1279 	drm_for_each_detailed_block((u8 *)edid, do_detailed_mode, &closure);
1280 
1281 	return closure.modes;
1282 }
1283 
1284 #define HDMI_IDENTIFIER 0x000C03
1285 #define AUDIO_BLOCK	0x01
1286 #define VENDOR_BLOCK    0x03
1287 #define EDID_BASIC_AUDIO	(1 << 6)
1288 
1289 /**
1290  * Search EDID for CEA extension block.
1291  */
1292 static u8 *drm_find_cea_extension(struct edid *edid)
1293 {
1294 	u8 *edid_ext = NULL;
1295 	int i;
1296 
1297 	/* No EDID or EDID extensions */
1298 	if (edid == NULL || edid->extensions == 0)
1299 		return NULL;
1300 
1301 	/* Find CEA extension */
1302 	for (i = 0; i < edid->extensions; i++) {
1303 		edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
1304 		if (edid_ext[0] == CEA_EXT)
1305 			break;
1306 	}
1307 
1308 	if (i == edid->extensions)
1309 		return NULL;
1310 
1311 	return edid_ext;
1312 }
1313 
1314 /**
1315  * drm_detect_hdmi_monitor - detect whether monitor is hdmi.
1316  * @edid: monitor EDID information
1317  *
1318  * Parse the CEA extension according to CEA-861-B.
1319  * Return true if HDMI, false if not or unknown.
1320  */
1321 bool drm_detect_hdmi_monitor(struct edid *edid)
1322 {
1323 	u8 *edid_ext;
1324 	int i, hdmi_id;
1325 	int start_offset, end_offset;
1326 	bool is_hdmi = false;
1327 
1328 	edid_ext = drm_find_cea_extension(edid);
1329 	if (!edid_ext)
1330 		goto end;
1331 
1332 	/* Data block offset in CEA extension block */
1333 	start_offset = 4;
1334 	end_offset = edid_ext[2];
1335 
1336 	/*
1337 	 * Because HDMI identifier is in Vendor Specific Block,
1338 	 * search it from all data blocks of CEA extension.
1339 	 */
1340 	for (i = start_offset; i < end_offset;
1341 		/* Increased by data block len */
1342 		i += ((edid_ext[i] & 0x1f) + 1)) {
1343 		/* Find vendor specific block */
1344 		if ((edid_ext[i] >> 5) == VENDOR_BLOCK) {
1345 			hdmi_id = edid_ext[i + 1] | (edid_ext[i + 2] << 8) |
1346 				  edid_ext[i + 3] << 16;
1347 			/* Find HDMI identifier */
1348 			if (hdmi_id == HDMI_IDENTIFIER)
1349 				is_hdmi = true;
1350 			break;
1351 		}
1352 	}
1353 
1354 end:
1355 	return is_hdmi;
1356 }
1357 EXPORT_SYMBOL(drm_detect_hdmi_monitor);
1358 
1359 /**
1360  * drm_detect_monitor_audio - check monitor audio capability
1361  *
1362  * Monitor should have CEA extension block.
1363  * If monitor has 'basic audio', but no CEA audio blocks, it's 'basic
1364  * audio' only. If there is any audio extension block and supported
1365  * audio format, assume at least 'basic audio' support, even if 'basic
1366  * audio' is not defined in EDID.
1367  *
1368  */
1369 bool drm_detect_monitor_audio(struct edid *edid)
1370 {
1371 	u8 *edid_ext;
1372 	int i, j;
1373 	bool has_audio = false;
1374 	int start_offset, end_offset;
1375 
1376 	edid_ext = drm_find_cea_extension(edid);
1377 	if (!edid_ext)
1378 		goto end;
1379 
1380 	has_audio = ((edid_ext[3] & EDID_BASIC_AUDIO) != 0);
1381 
1382 	if (has_audio) {
1383 		DRM_DEBUG_KMS("Monitor has basic audio support\n");
1384 		goto end;
1385 	}
1386 
1387 	/* Data block offset in CEA extension block */
1388 	start_offset = 4;
1389 	end_offset = edid_ext[2];
1390 
1391 	for (i = start_offset; i < end_offset;
1392 			i += ((edid_ext[i] & 0x1f) + 1)) {
1393 		if ((edid_ext[i] >> 5) == AUDIO_BLOCK) {
1394 			has_audio = true;
1395 			for (j = 1; j < (edid_ext[i] & 0x1f); j += 3)
1396 				DRM_DEBUG_KMS("CEA audio format %d\n",
1397 					      (edid_ext[i + j] >> 3) & 0xf);
1398 			goto end;
1399 		}
1400 	}
1401 end:
1402 	return has_audio;
1403 }
1404 EXPORT_SYMBOL(drm_detect_monitor_audio);
1405 
1406 /**
1407  * drm_add_edid_modes - add modes from EDID data, if available
1408  * @connector: connector we're probing
1409  * @edid: edid data
1410  *
1411  * Add the specified modes to the connector's mode list.
1412  *
1413  * Return number of modes added or 0 if we couldn't find any.
1414  */
1415 int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
1416 {
1417 	int num_modes = 0;
1418 	u32 quirks;
1419 
1420 	if (edid == NULL) {
1421 		return 0;
1422 	}
1423 	if (!drm_edid_is_valid(edid)) {
1424 		dev_warn(connector->dev->dev, "%s: EDID invalid.\n",
1425 			 drm_get_connector_name(connector));
1426 		return 0;
1427 	}
1428 
1429 	quirks = edid_get_quirks(edid);
1430 
1431 	/*
1432 	 * EDID spec says modes should be preferred in this order:
1433 	 * - preferred detailed mode
1434 	 * - other detailed modes from base block
1435 	 * - detailed modes from extension blocks
1436 	 * - CVT 3-byte code modes
1437 	 * - standard timing codes
1438 	 * - established timing codes
1439 	 * - modes inferred from GTF or CVT range information
1440 	 *
1441 	 * We get this pretty much right.
1442 	 *
1443 	 * XXX order for additional mode types in extension blocks?
1444 	 */
1445 	num_modes += add_detailed_modes(connector, edid, quirks);
1446 	num_modes += add_cvt_modes(connector, edid);
1447 	num_modes += add_standard_modes(connector, edid);
1448 	num_modes += add_established_modes(connector, edid);
1449 	num_modes += add_inferred_modes(connector, edid);
1450 
1451 	if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
1452 		edid_fixup_preferred(connector, quirks);
1453 
1454 	connector->display_info.width_mm = edid->width_cm * 10;
1455 	connector->display_info.height_mm = edid->height_cm * 10;
1456 
1457 	return num_modes;
1458 }
1459 EXPORT_SYMBOL(drm_add_edid_modes);
1460 
1461 /**
1462  * drm_add_modes_noedid - add modes for the connectors without EDID
1463  * @connector: connector we're probing
1464  * @hdisplay: the horizontal display limit
1465  * @vdisplay: the vertical display limit
1466  *
1467  * Add the specified modes to the connector's mode list. Only when the
1468  * hdisplay/vdisplay is not beyond the given limit, it will be added.
1469  *
1470  * Return number of modes added or 0 if we couldn't find any.
1471  */
1472 int drm_add_modes_noedid(struct drm_connector *connector,
1473 			int hdisplay, int vdisplay)
1474 {
1475 	int i, count, num_modes = 0;
1476 	struct drm_display_mode *mode;
1477 	struct drm_device *dev = connector->dev;
1478 
1479 	count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
1480 	if (hdisplay < 0)
1481 		hdisplay = 0;
1482 	if (vdisplay < 0)
1483 		vdisplay = 0;
1484 
1485 	for (i = 0; i < count; i++) {
1486 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
1487 		if (hdisplay && vdisplay) {
1488 			/*
1489 			 * Only when two are valid, they will be used to check
1490 			 * whether the mode should be added to the mode list of
1491 			 * the connector.
1492 			 */
1493 			if (ptr->hdisplay > hdisplay ||
1494 					ptr->vdisplay > vdisplay)
1495 				continue;
1496 		}
1497 		if (drm_mode_vrefresh(ptr) > 61)
1498 			continue;
1499 		mode = drm_mode_duplicate(dev, ptr);
1500 		if (mode) {
1501 			drm_mode_probed_add(connector, mode);
1502 			num_modes++;
1503 		}
1504 	}
1505 	return num_modes;
1506 }
1507 EXPORT_SYMBOL(drm_add_modes_noedid);
1508