xref: /linux/drivers/gpu/drm/drm_edid.c (revision 424f0750edd5af866f80f5e65998e0610503cb5c)
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 static bool
153 drm_edid_block_valid(u8 *raw_edid)
154 {
155 	int i;
156 	u8 csum = 0;
157 	struct edid *edid = (struct edid *)raw_edid;
158 
159 	if (raw_edid[0] == 0x00) {
160 		int score = drm_edid_header_is_valid(raw_edid);
161 		if (score == 8) ;
162 		else if (score >= 6) {
163 			DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
164 			memcpy(raw_edid, edid_header, sizeof(edid_header));
165 		} else {
166 			goto bad;
167 		}
168 	}
169 
170 	for (i = 0; i < EDID_LENGTH; i++)
171 		csum += raw_edid[i];
172 	if (csum) {
173 		DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
174 
175 		/* allow CEA to slide through, switches mangle this */
176 		if (raw_edid[0] != 0x02)
177 			goto bad;
178 	}
179 
180 	/* per-block-type checks */
181 	switch (raw_edid[0]) {
182 	case 0: /* base */
183 		if (edid->version != 1) {
184 			DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
185 			goto bad;
186 		}
187 
188 		if (edid->revision > 4)
189 			DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
190 		break;
191 
192 	default:
193 		break;
194 	}
195 
196 	return 1;
197 
198 bad:
199 	if (raw_edid) {
200 		printk(KERN_ERR "Raw EDID:\n");
201 		print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
202 			       raw_edid, EDID_LENGTH, false);
203 	}
204 	return 0;
205 }
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_ADDR 0x50
230 #define DDC_SEGMENT_ADDR 0x30
231 /**
232  * Get EDID information via I2C.
233  *
234  * \param adapter : i2c device adaptor
235  * \param buf     : EDID data buffer to be filled
236  * \param len     : EDID data buffer length
237  * \return 0 on success or -1 on failure.
238  *
239  * Try to fetch EDID information by calling i2c driver function.
240  */
241 static int
242 drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
243 		      int block, int len)
244 {
245 	unsigned char start = block * EDID_LENGTH;
246 	int ret, retries = 5;
247 
248 	/* The core i2c driver will automatically retry the transfer if the
249 	 * adapter reports EAGAIN. However, we find that bit-banging transfers
250 	 * are susceptible to errors under a heavily loaded machine and
251 	 * generate spurious NAKs and timeouts. Retrying the transfer
252 	 * of the individual block a few times seems to overcome this.
253 	 */
254 	do {
255 		struct i2c_msg msgs[] = {
256 			{
257 				.addr	= DDC_ADDR,
258 				.flags	= 0,
259 				.len	= 1,
260 				.buf	= &start,
261 			}, {
262 				.addr	= DDC_ADDR,
263 				.flags	= I2C_M_RD,
264 				.len	= len,
265 				.buf	= buf,
266 			}
267 		};
268 		ret = i2c_transfer(adapter, msgs, 2);
269 	} while (ret != 2 && --retries);
270 
271 	return ret == 2 ? 0 : -1;
272 }
273 
274 static bool drm_edid_is_zero(u8 *in_edid, int length)
275 {
276 	int i;
277 	u32 *raw_edid = (u32 *)in_edid;
278 
279 	for (i = 0; i < length / 4; i++)
280 		if (*(raw_edid + i) != 0)
281 			return false;
282 	return true;
283 }
284 
285 static u8 *
286 drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
287 {
288 	int i, j = 0, valid_extensions = 0;
289 	u8 *block, *new;
290 
291 	if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
292 		return NULL;
293 
294 	/* base block fetch */
295 	for (i = 0; i < 4; i++) {
296 		if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
297 			goto out;
298 		if (drm_edid_block_valid(block))
299 			break;
300 		if (i == 0 && drm_edid_is_zero(block, EDID_LENGTH)) {
301 			connector->null_edid_counter++;
302 			goto carp;
303 		}
304 	}
305 	if (i == 4)
306 		goto carp;
307 
308 	/* if there's no extensions, we're done */
309 	if (block[0x7e] == 0)
310 		return block;
311 
312 	new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);
313 	if (!new)
314 		goto out;
315 	block = new;
316 
317 	for (j = 1; j <= block[0x7e]; j++) {
318 		for (i = 0; i < 4; i++) {
319 			if (drm_do_probe_ddc_edid(adapter,
320 				  block + (valid_extensions + 1) * EDID_LENGTH,
321 				  j, EDID_LENGTH))
322 				goto out;
323 			if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH)) {
324 				valid_extensions++;
325 				break;
326 			}
327 		}
328 		if (i == 4)
329 			dev_warn(connector->dev->dev,
330 			 "%s: Ignoring invalid EDID block %d.\n",
331 			 drm_get_connector_name(connector), j);
332 	}
333 
334 	if (valid_extensions != block[0x7e]) {
335 		block[EDID_LENGTH-1] += block[0x7e] - valid_extensions;
336 		block[0x7e] = valid_extensions;
337 		new = krealloc(block, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
338 		if (!new)
339 			goto out;
340 		block = new;
341 	}
342 
343 	return block;
344 
345 carp:
346 	dev_warn(connector->dev->dev, "%s: EDID block %d invalid.\n",
347 		 drm_get_connector_name(connector), j);
348 
349 out:
350 	kfree(block);
351 	return NULL;
352 }
353 
354 /**
355  * Probe DDC presence.
356  *
357  * \param adapter : i2c device adaptor
358  * \return 1 on success
359  */
360 static bool
361 drm_probe_ddc(struct i2c_adapter *adapter)
362 {
363 	unsigned char out;
364 
365 	return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
366 }
367 
368 /**
369  * drm_get_edid - get EDID data, if available
370  * @connector: connector we're probing
371  * @adapter: i2c adapter to use for DDC
372  *
373  * Poke the given i2c channel to grab EDID data if possible.  If found,
374  * attach it to the connector.
375  *
376  * Return edid data or NULL if we couldn't find any.
377  */
378 struct edid *drm_get_edid(struct drm_connector *connector,
379 			  struct i2c_adapter *adapter)
380 {
381 	struct edid *edid = NULL;
382 
383 	if (drm_probe_ddc(adapter))
384 		edid = (struct edid *)drm_do_get_edid(connector, adapter);
385 
386 	connector->display_info.raw_edid = (char *)edid;
387 
388 	return edid;
389 
390 }
391 EXPORT_SYMBOL(drm_get_edid);
392 
393 /*** EDID parsing ***/
394 
395 /**
396  * edid_vendor - match a string against EDID's obfuscated vendor field
397  * @edid: EDID to match
398  * @vendor: vendor string
399  *
400  * Returns true if @vendor is in @edid, false otherwise
401  */
402 static bool edid_vendor(struct edid *edid, char *vendor)
403 {
404 	char edid_vendor[3];
405 
406 	edid_vendor[0] = ((edid->mfg_id[0] & 0x7c) >> 2) + '@';
407 	edid_vendor[1] = (((edid->mfg_id[0] & 0x3) << 3) |
408 			  ((edid->mfg_id[1] & 0xe0) >> 5)) + '@';
409 	edid_vendor[2] = (edid->mfg_id[1] & 0x1f) + '@';
410 
411 	return !strncmp(edid_vendor, vendor, 3);
412 }
413 
414 /**
415  * edid_get_quirks - return quirk flags for a given EDID
416  * @edid: EDID to process
417  *
418  * This tells subsequent routines what fixes they need to apply.
419  */
420 static u32 edid_get_quirks(struct edid *edid)
421 {
422 	struct edid_quirk *quirk;
423 	int i;
424 
425 	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
426 		quirk = &edid_quirk_list[i];
427 
428 		if (edid_vendor(edid, quirk->vendor) &&
429 		    (EDID_PRODUCT_ID(edid) == quirk->product_id))
430 			return quirk->quirks;
431 	}
432 
433 	return 0;
434 }
435 
436 #define MODE_SIZE(m) ((m)->hdisplay * (m)->vdisplay)
437 #define MODE_REFRESH_DIFF(m,r) (abs((m)->vrefresh - target_refresh))
438 
439 /**
440  * edid_fixup_preferred - set preferred modes based on quirk list
441  * @connector: has mode list to fix up
442  * @quirks: quirks list
443  *
444  * Walk the mode list for @connector, clearing the preferred status
445  * on existing modes and setting it anew for the right mode ala @quirks.
446  */
447 static void edid_fixup_preferred(struct drm_connector *connector,
448 				 u32 quirks)
449 {
450 	struct drm_display_mode *t, *cur_mode, *preferred_mode;
451 	int target_refresh = 0;
452 
453 	if (list_empty(&connector->probed_modes))
454 		return;
455 
456 	if (quirks & EDID_QUIRK_PREFER_LARGE_60)
457 		target_refresh = 60;
458 	if (quirks & EDID_QUIRK_PREFER_LARGE_75)
459 		target_refresh = 75;
460 
461 	preferred_mode = list_first_entry(&connector->probed_modes,
462 					  struct drm_display_mode, head);
463 
464 	list_for_each_entry_safe(cur_mode, t, &connector->probed_modes, head) {
465 		cur_mode->type &= ~DRM_MODE_TYPE_PREFERRED;
466 
467 		if (cur_mode == preferred_mode)
468 			continue;
469 
470 		/* Largest mode is preferred */
471 		if (MODE_SIZE(cur_mode) > MODE_SIZE(preferred_mode))
472 			preferred_mode = cur_mode;
473 
474 		/* At a given size, try to get closest to target refresh */
475 		if ((MODE_SIZE(cur_mode) == MODE_SIZE(preferred_mode)) &&
476 		    MODE_REFRESH_DIFF(cur_mode, target_refresh) <
477 		    MODE_REFRESH_DIFF(preferred_mode, target_refresh)) {
478 			preferred_mode = cur_mode;
479 		}
480 	}
481 
482 	preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
483 }
484 
485 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
486 					   int hsize, int vsize, int fresh)
487 {
488 	struct drm_display_mode *mode = NULL;
489 	int i;
490 
491 	for (i = 0; i < drm_num_dmt_modes; i++) {
492 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
493 		if (hsize == ptr->hdisplay &&
494 			vsize == ptr->vdisplay &&
495 			fresh == drm_mode_vrefresh(ptr)) {
496 			/* get the expected default mode */
497 			mode = drm_mode_duplicate(dev, ptr);
498 			break;
499 		}
500 	}
501 	return mode;
502 }
503 EXPORT_SYMBOL(drm_mode_find_dmt);
504 
505 typedef void detailed_cb(struct detailed_timing *timing, void *closure);
506 
507 static void
508 cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
509 {
510 	int i, n = 0;
511 	u8 rev = ext[0x01], d = ext[0x02];
512 	u8 *det_base = ext + d;
513 
514 	switch (rev) {
515 	case 0:
516 		/* can't happen */
517 		return;
518 	case 1:
519 		/* have to infer how many blocks we have, check pixel clock */
520 		for (i = 0; i < 6; i++)
521 			if (det_base[18*i] || det_base[18*i+1])
522 				n++;
523 		break;
524 	default:
525 		/* explicit count */
526 		n = min(ext[0x03] & 0x0f, 6);
527 		break;
528 	}
529 
530 	for (i = 0; i < n; i++)
531 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
532 }
533 
534 static void
535 vtb_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
536 {
537 	unsigned int i, n = min((int)ext[0x02], 6);
538 	u8 *det_base = ext + 5;
539 
540 	if (ext[0x01] != 1)
541 		return; /* unknown version */
542 
543 	for (i = 0; i < n; i++)
544 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
545 }
546 
547 static void
548 drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
549 {
550 	int i;
551 	struct edid *edid = (struct edid *)raw_edid;
552 
553 	if (edid == NULL)
554 		return;
555 
556 	for (i = 0; i < EDID_DETAILED_TIMINGS; i++)
557 		cb(&(edid->detailed_timings[i]), closure);
558 
559 	for (i = 1; i <= raw_edid[0x7e]; i++) {
560 		u8 *ext = raw_edid + (i * EDID_LENGTH);
561 		switch (*ext) {
562 		case CEA_EXT:
563 			cea_for_each_detailed_block(ext, cb, closure);
564 			break;
565 		case VTB_EXT:
566 			vtb_for_each_detailed_block(ext, cb, closure);
567 			break;
568 		default:
569 			break;
570 		}
571 	}
572 }
573 
574 static void
575 is_rb(struct detailed_timing *t, void *data)
576 {
577 	u8 *r = (u8 *)t;
578 	if (r[3] == EDID_DETAIL_MONITOR_RANGE)
579 		if (r[15] & 0x10)
580 			*(bool *)data = true;
581 }
582 
583 /* EDID 1.4 defines this explicitly.  For EDID 1.3, we guess, badly. */
584 static bool
585 drm_monitor_supports_rb(struct edid *edid)
586 {
587 	if (edid->revision >= 4) {
588 		bool ret;
589 		drm_for_each_detailed_block((u8 *)edid, is_rb, &ret);
590 		return ret;
591 	}
592 
593 	return ((edid->input & DRM_EDID_INPUT_DIGITAL) != 0);
594 }
595 
596 static void
597 find_gtf2(struct detailed_timing *t, void *data)
598 {
599 	u8 *r = (u8 *)t;
600 	if (r[3] == EDID_DETAIL_MONITOR_RANGE && r[10] == 0x02)
601 		*(u8 **)data = r;
602 }
603 
604 /* Secondary GTF curve kicks in above some break frequency */
605 static int
606 drm_gtf2_hbreak(struct edid *edid)
607 {
608 	u8 *r = NULL;
609 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
610 	return r ? (r[12] * 2) : 0;
611 }
612 
613 static int
614 drm_gtf2_2c(struct edid *edid)
615 {
616 	u8 *r = NULL;
617 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
618 	return r ? r[13] : 0;
619 }
620 
621 static int
622 drm_gtf2_m(struct edid *edid)
623 {
624 	u8 *r = NULL;
625 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
626 	return r ? (r[15] << 8) + r[14] : 0;
627 }
628 
629 static int
630 drm_gtf2_k(struct edid *edid)
631 {
632 	u8 *r = NULL;
633 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
634 	return r ? r[16] : 0;
635 }
636 
637 static int
638 drm_gtf2_2j(struct edid *edid)
639 {
640 	u8 *r = NULL;
641 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
642 	return r ? r[17] : 0;
643 }
644 
645 /**
646  * standard_timing_level - get std. timing level(CVT/GTF/DMT)
647  * @edid: EDID block to scan
648  */
649 static int standard_timing_level(struct edid *edid)
650 {
651 	if (edid->revision >= 2) {
652 		if (edid->revision >= 4 && (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF))
653 			return LEVEL_CVT;
654 		if (drm_gtf2_hbreak(edid))
655 			return LEVEL_GTF2;
656 		return LEVEL_GTF;
657 	}
658 	return LEVEL_DMT;
659 }
660 
661 /*
662  * 0 is reserved.  The spec says 0x01 fill for unused timings.  Some old
663  * monitors fill with ascii space (0x20) instead.
664  */
665 static int
666 bad_std_timing(u8 a, u8 b)
667 {
668 	return (a == 0x00 && b == 0x00) ||
669 	       (a == 0x01 && b == 0x01) ||
670 	       (a == 0x20 && b == 0x20);
671 }
672 
673 /**
674  * drm_mode_std - convert standard mode info (width, height, refresh) into mode
675  * @t: standard timing params
676  * @timing_level: standard timing level
677  *
678  * Take the standard timing params (in this case width, aspect, and refresh)
679  * and convert them into a real mode using CVT/GTF/DMT.
680  */
681 static struct drm_display_mode *
682 drm_mode_std(struct drm_connector *connector, struct edid *edid,
683 	     struct std_timing *t, int revision)
684 {
685 	struct drm_device *dev = connector->dev;
686 	struct drm_display_mode *m, *mode = NULL;
687 	int hsize, vsize;
688 	int vrefresh_rate;
689 	unsigned aspect_ratio = (t->vfreq_aspect & EDID_TIMING_ASPECT_MASK)
690 		>> EDID_TIMING_ASPECT_SHIFT;
691 	unsigned vfreq = (t->vfreq_aspect & EDID_TIMING_VFREQ_MASK)
692 		>> EDID_TIMING_VFREQ_SHIFT;
693 	int timing_level = standard_timing_level(edid);
694 
695 	if (bad_std_timing(t->hsize, t->vfreq_aspect))
696 		return NULL;
697 
698 	/* According to the EDID spec, the hdisplay = hsize * 8 + 248 */
699 	hsize = t->hsize * 8 + 248;
700 	/* vrefresh_rate = vfreq + 60 */
701 	vrefresh_rate = vfreq + 60;
702 	/* the vdisplay is calculated based on the aspect ratio */
703 	if (aspect_ratio == 0) {
704 		if (revision < 3)
705 			vsize = hsize;
706 		else
707 			vsize = (hsize * 10) / 16;
708 	} else if (aspect_ratio == 1)
709 		vsize = (hsize * 3) / 4;
710 	else if (aspect_ratio == 2)
711 		vsize = (hsize * 4) / 5;
712 	else
713 		vsize = (hsize * 9) / 16;
714 
715 	/* HDTV hack, part 1 */
716 	if (vrefresh_rate == 60 &&
717 	    ((hsize == 1360 && vsize == 765) ||
718 	     (hsize == 1368 && vsize == 769))) {
719 		hsize = 1366;
720 		vsize = 768;
721 	}
722 
723 	/*
724 	 * If this connector already has a mode for this size and refresh
725 	 * rate (because it came from detailed or CVT info), use that
726 	 * instead.  This way we don't have to guess at interlace or
727 	 * reduced blanking.
728 	 */
729 	list_for_each_entry(m, &connector->probed_modes, head)
730 		if (m->hdisplay == hsize && m->vdisplay == vsize &&
731 		    drm_mode_vrefresh(m) == vrefresh_rate)
732 			return NULL;
733 
734 	/* HDTV hack, part 2 */
735 	if (hsize == 1366 && vsize == 768 && vrefresh_rate == 60) {
736 		mode = drm_cvt_mode(dev, 1366, 768, vrefresh_rate, 0, 0,
737 				    false);
738 		mode->hdisplay = 1366;
739 		mode->hsync_start = mode->hsync_start - 1;
740 		mode->hsync_end = mode->hsync_end - 1;
741 		return mode;
742 	}
743 
744 	/* check whether it can be found in default mode table */
745 	mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate);
746 	if (mode)
747 		return mode;
748 
749 	switch (timing_level) {
750 	case LEVEL_DMT:
751 		break;
752 	case LEVEL_GTF:
753 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
754 		break;
755 	case LEVEL_GTF2:
756 		/*
757 		 * This is potentially wrong if there's ever a monitor with
758 		 * more than one ranges section, each claiming a different
759 		 * secondary GTF curve.  Please don't do that.
760 		 */
761 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
762 		if (drm_mode_hsync(mode) > drm_gtf2_hbreak(edid)) {
763 			kfree(mode);
764 			mode = drm_gtf_mode_complex(dev, hsize, vsize,
765 						    vrefresh_rate, 0, 0,
766 						    drm_gtf2_m(edid),
767 						    drm_gtf2_2c(edid),
768 						    drm_gtf2_k(edid),
769 						    drm_gtf2_2j(edid));
770 		}
771 		break;
772 	case LEVEL_CVT:
773 		mode = drm_cvt_mode(dev, hsize, vsize, vrefresh_rate, 0, 0,
774 				    false);
775 		break;
776 	}
777 	return mode;
778 }
779 
780 /*
781  * EDID is delightfully ambiguous about how interlaced modes are to be
782  * encoded.  Our internal representation is of frame height, but some
783  * HDTV detailed timings are encoded as field height.
784  *
785  * The format list here is from CEA, in frame size.  Technically we
786  * should be checking refresh rate too.  Whatever.
787  */
788 static void
789 drm_mode_do_interlace_quirk(struct drm_display_mode *mode,
790 			    struct detailed_pixel_timing *pt)
791 {
792 	int i;
793 	static const struct {
794 		int w, h;
795 	} cea_interlaced[] = {
796 		{ 1920, 1080 },
797 		{  720,  480 },
798 		{ 1440,  480 },
799 		{ 2880,  480 },
800 		{  720,  576 },
801 		{ 1440,  576 },
802 		{ 2880,  576 },
803 	};
804 
805 	if (!(pt->misc & DRM_EDID_PT_INTERLACED))
806 		return;
807 
808 	for (i = 0; i < ARRAY_SIZE(cea_interlaced); i++) {
809 		if ((mode->hdisplay == cea_interlaced[i].w) &&
810 		    (mode->vdisplay == cea_interlaced[i].h / 2)) {
811 			mode->vdisplay *= 2;
812 			mode->vsync_start *= 2;
813 			mode->vsync_end *= 2;
814 			mode->vtotal *= 2;
815 			mode->vtotal |= 1;
816 		}
817 	}
818 
819 	mode->flags |= DRM_MODE_FLAG_INTERLACE;
820 }
821 
822 /**
823  * drm_mode_detailed - create a new mode from an EDID detailed timing section
824  * @dev: DRM device (needed to create new mode)
825  * @edid: EDID block
826  * @timing: EDID detailed timing info
827  * @quirks: quirks to apply
828  *
829  * An EDID detailed timing block contains enough info for us to create and
830  * return a new struct drm_display_mode.
831  */
832 static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
833 						  struct edid *edid,
834 						  struct detailed_timing *timing,
835 						  u32 quirks)
836 {
837 	struct drm_display_mode *mode;
838 	struct detailed_pixel_timing *pt = &timing->data.pixel_data;
839 	unsigned hactive = (pt->hactive_hblank_hi & 0xf0) << 4 | pt->hactive_lo;
840 	unsigned vactive = (pt->vactive_vblank_hi & 0xf0) << 4 | pt->vactive_lo;
841 	unsigned hblank = (pt->hactive_hblank_hi & 0xf) << 8 | pt->hblank_lo;
842 	unsigned vblank = (pt->vactive_vblank_hi & 0xf) << 8 | pt->vblank_lo;
843 	unsigned hsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc0) << 2 | pt->hsync_offset_lo;
844 	unsigned hsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x30) << 4 | pt->hsync_pulse_width_lo;
845 	unsigned vsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc) >> 2 | pt->vsync_offset_pulse_width_lo >> 4;
846 	unsigned vsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x3) << 4 | (pt->vsync_offset_pulse_width_lo & 0xf);
847 
848 	/* ignore tiny modes */
849 	if (hactive < 64 || vactive < 64)
850 		return NULL;
851 
852 	if (pt->misc & DRM_EDID_PT_STEREO) {
853 		printk(KERN_WARNING "stereo mode not supported\n");
854 		return NULL;
855 	}
856 	if (!(pt->misc & DRM_EDID_PT_SEPARATE_SYNC)) {
857 		printk(KERN_WARNING "composite sync not supported\n");
858 	}
859 
860 	/* it is incorrect if hsync/vsync width is zero */
861 	if (!hsync_pulse_width || !vsync_pulse_width) {
862 		DRM_DEBUG_KMS("Incorrect Detailed timing. "
863 				"Wrong Hsync/Vsync pulse width\n");
864 		return NULL;
865 	}
866 	mode = drm_mode_create(dev);
867 	if (!mode)
868 		return NULL;
869 
870 	mode->type = DRM_MODE_TYPE_DRIVER;
871 
872 	if (quirks & EDID_QUIRK_135_CLOCK_TOO_HIGH)
873 		timing->pixel_clock = cpu_to_le16(1088);
874 
875 	mode->clock = le16_to_cpu(timing->pixel_clock) * 10;
876 
877 	mode->hdisplay = hactive;
878 	mode->hsync_start = mode->hdisplay + hsync_offset;
879 	mode->hsync_end = mode->hsync_start + hsync_pulse_width;
880 	mode->htotal = mode->hdisplay + hblank;
881 
882 	mode->vdisplay = vactive;
883 	mode->vsync_start = mode->vdisplay + vsync_offset;
884 	mode->vsync_end = mode->vsync_start + vsync_pulse_width;
885 	mode->vtotal = mode->vdisplay + vblank;
886 
887 	/* Some EDIDs have bogus h/vtotal values */
888 	if (mode->hsync_end > mode->htotal)
889 		mode->htotal = mode->hsync_end + 1;
890 	if (mode->vsync_end > mode->vtotal)
891 		mode->vtotal = mode->vsync_end + 1;
892 
893 	drm_mode_do_interlace_quirk(mode, pt);
894 
895 	drm_mode_set_name(mode);
896 
897 	if (quirks & EDID_QUIRK_DETAILED_SYNC_PP) {
898 		pt->misc |= DRM_EDID_PT_HSYNC_POSITIVE | DRM_EDID_PT_VSYNC_POSITIVE;
899 	}
900 
901 	mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
902 		DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
903 	mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
904 		DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
905 
906 	mode->width_mm = pt->width_mm_lo | (pt->width_height_mm_hi & 0xf0) << 4;
907 	mode->height_mm = pt->height_mm_lo | (pt->width_height_mm_hi & 0xf) << 8;
908 
909 	if (quirks & EDID_QUIRK_DETAILED_IN_CM) {
910 		mode->width_mm *= 10;
911 		mode->height_mm *= 10;
912 	}
913 
914 	if (quirks & EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE) {
915 		mode->width_mm = edid->width_cm * 10;
916 		mode->height_mm = edid->height_cm * 10;
917 	}
918 
919 	return mode;
920 }
921 
922 static bool
923 mode_is_rb(const struct drm_display_mode *mode)
924 {
925 	return (mode->htotal - mode->hdisplay == 160) &&
926 	       (mode->hsync_end - mode->hdisplay == 80) &&
927 	       (mode->hsync_end - mode->hsync_start == 32) &&
928 	       (mode->vsync_start - mode->vdisplay == 3);
929 }
930 
931 static bool
932 mode_in_hsync_range(const struct drm_display_mode *mode,
933 		    struct edid *edid, u8 *t)
934 {
935 	int hsync, hmin, hmax;
936 
937 	hmin = t[7];
938 	if (edid->revision >= 4)
939 	    hmin += ((t[4] & 0x04) ? 255 : 0);
940 	hmax = t[8];
941 	if (edid->revision >= 4)
942 	    hmax += ((t[4] & 0x08) ? 255 : 0);
943 	hsync = drm_mode_hsync(mode);
944 
945 	return (hsync <= hmax && hsync >= hmin);
946 }
947 
948 static bool
949 mode_in_vsync_range(const struct drm_display_mode *mode,
950 		    struct edid *edid, u8 *t)
951 {
952 	int vsync, vmin, vmax;
953 
954 	vmin = t[5];
955 	if (edid->revision >= 4)
956 	    vmin += ((t[4] & 0x01) ? 255 : 0);
957 	vmax = t[6];
958 	if (edid->revision >= 4)
959 	    vmax += ((t[4] & 0x02) ? 255 : 0);
960 	vsync = drm_mode_vrefresh(mode);
961 
962 	return (vsync <= vmax && vsync >= vmin);
963 }
964 
965 static u32
966 range_pixel_clock(struct edid *edid, u8 *t)
967 {
968 	/* unspecified */
969 	if (t[9] == 0 || t[9] == 255)
970 		return 0;
971 
972 	/* 1.4 with CVT support gives us real precision, yay */
973 	if (edid->revision >= 4 && t[10] == 0x04)
974 		return (t[9] * 10000) - ((t[12] >> 2) * 250);
975 
976 	/* 1.3 is pathetic, so fuzz up a bit */
977 	return t[9] * 10000 + 5001;
978 }
979 
980 static bool
981 mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
982 	      struct detailed_timing *timing)
983 {
984 	u32 max_clock;
985 	u8 *t = (u8 *)timing;
986 
987 	if (!mode_in_hsync_range(mode, edid, t))
988 		return false;
989 
990 	if (!mode_in_vsync_range(mode, edid, t))
991 		return false;
992 
993 	if ((max_clock = range_pixel_clock(edid, t)))
994 		if (mode->clock > max_clock)
995 			return false;
996 
997 	/* 1.4 max horizontal check */
998 	if (edid->revision >= 4 && t[10] == 0x04)
999 		if (t[13] && mode->hdisplay > 8 * (t[13] + (256 * (t[12]&0x3))))
1000 			return false;
1001 
1002 	if (mode_is_rb(mode) && !drm_monitor_supports_rb(edid))
1003 		return false;
1004 
1005 	return true;
1006 }
1007 
1008 /*
1009  * XXX If drm_dmt_modes ever regrows the CVT-R modes (and it will) this will
1010  * need to account for them.
1011  */
1012 static int
1013 drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
1014 			struct detailed_timing *timing)
1015 {
1016 	int i, modes = 0;
1017 	struct drm_display_mode *newmode;
1018 	struct drm_device *dev = connector->dev;
1019 
1020 	for (i = 0; i < drm_num_dmt_modes; i++) {
1021 		if (mode_in_range(drm_dmt_modes + i, edid, timing)) {
1022 			newmode = drm_mode_duplicate(dev, &drm_dmt_modes[i]);
1023 			if (newmode) {
1024 				drm_mode_probed_add(connector, newmode);
1025 				modes++;
1026 			}
1027 		}
1028 	}
1029 
1030 	return modes;
1031 }
1032 
1033 static void
1034 do_inferred_modes(struct detailed_timing *timing, void *c)
1035 {
1036 	struct detailed_mode_closure *closure = c;
1037 	struct detailed_non_pixel *data = &timing->data.other_data;
1038 	int gtf = (closure->edid->features & DRM_EDID_FEATURE_DEFAULT_GTF);
1039 
1040 	if (gtf && data->type == EDID_DETAIL_MONITOR_RANGE)
1041 		closure->modes += drm_gtf_modes_for_range(closure->connector,
1042 							  closure->edid,
1043 							  timing);
1044 }
1045 
1046 static int
1047 add_inferred_modes(struct drm_connector *connector, struct edid *edid)
1048 {
1049 	struct detailed_mode_closure closure = {
1050 		connector, edid, 0, 0, 0
1051 	};
1052 
1053 	if (version_greater(edid, 1, 0))
1054 		drm_for_each_detailed_block((u8 *)edid, do_inferred_modes,
1055 					    &closure);
1056 
1057 	return closure.modes;
1058 }
1059 
1060 static int
1061 drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
1062 {
1063 	int i, j, m, modes = 0;
1064 	struct drm_display_mode *mode;
1065 	u8 *est = ((u8 *)timing) + 5;
1066 
1067 	for (i = 0; i < 6; i++) {
1068 		for (j = 7; j > 0; j--) {
1069 			m = (i * 8) + (7 - j);
1070 			if (m >= ARRAY_SIZE(est3_modes))
1071 				break;
1072 			if (est[i] & (1 << j)) {
1073 				mode = drm_mode_find_dmt(connector->dev,
1074 							 est3_modes[m].w,
1075 							 est3_modes[m].h,
1076 							 est3_modes[m].r
1077 							 /*, est3_modes[m].rb */);
1078 				if (mode) {
1079 					drm_mode_probed_add(connector, mode);
1080 					modes++;
1081 				}
1082 			}
1083 		}
1084 	}
1085 
1086 	return modes;
1087 }
1088 
1089 static void
1090 do_established_modes(struct detailed_timing *timing, void *c)
1091 {
1092 	struct detailed_mode_closure *closure = c;
1093 	struct detailed_non_pixel *data = &timing->data.other_data;
1094 
1095 	if (data->type == EDID_DETAIL_EST_TIMINGS)
1096 		closure->modes += drm_est3_modes(closure->connector, timing);
1097 }
1098 
1099 /**
1100  * add_established_modes - get est. modes from EDID and add them
1101  * @edid: EDID block to scan
1102  *
1103  * Each EDID block contains a bitmap of the supported "established modes" list
1104  * (defined above).  Tease them out and add them to the global modes list.
1105  */
1106 static int
1107 add_established_modes(struct drm_connector *connector, struct edid *edid)
1108 {
1109 	struct drm_device *dev = connector->dev;
1110 	unsigned long est_bits = edid->established_timings.t1 |
1111 		(edid->established_timings.t2 << 8) |
1112 		((edid->established_timings.mfg_rsvd & 0x80) << 9);
1113 	int i, modes = 0;
1114 	struct detailed_mode_closure closure = {
1115 		connector, edid, 0, 0, 0
1116 	};
1117 
1118 	for (i = 0; i <= EDID_EST_TIMINGS; i++) {
1119 		if (est_bits & (1<<i)) {
1120 			struct drm_display_mode *newmode;
1121 			newmode = drm_mode_duplicate(dev, &edid_est_modes[i]);
1122 			if (newmode) {
1123 				drm_mode_probed_add(connector, newmode);
1124 				modes++;
1125 			}
1126 		}
1127 	}
1128 
1129 	if (version_greater(edid, 1, 0))
1130 		    drm_for_each_detailed_block((u8 *)edid,
1131 						do_established_modes, &closure);
1132 
1133 	return modes + closure.modes;
1134 }
1135 
1136 static void
1137 do_standard_modes(struct detailed_timing *timing, void *c)
1138 {
1139 	struct detailed_mode_closure *closure = c;
1140 	struct detailed_non_pixel *data = &timing->data.other_data;
1141 	struct drm_connector *connector = closure->connector;
1142 	struct edid *edid = closure->edid;
1143 
1144 	if (data->type == EDID_DETAIL_STD_MODES) {
1145 		int i;
1146 		for (i = 0; i < 6; i++) {
1147 			struct std_timing *std;
1148 			struct drm_display_mode *newmode;
1149 
1150 			std = &data->data.timings[i];
1151 			newmode = drm_mode_std(connector, edid, std,
1152 					       edid->revision);
1153 			if (newmode) {
1154 				drm_mode_probed_add(connector, newmode);
1155 				closure->modes++;
1156 			}
1157 		}
1158 	}
1159 }
1160 
1161 /**
1162  * add_standard_modes - get std. modes from EDID and add them
1163  * @edid: EDID block to scan
1164  *
1165  * Standard modes can be calculated using the appropriate standard (DMT,
1166  * GTF or CVT. Grab them from @edid and add them to the list.
1167  */
1168 static int
1169 add_standard_modes(struct drm_connector *connector, struct edid *edid)
1170 {
1171 	int i, modes = 0;
1172 	struct detailed_mode_closure closure = {
1173 		connector, edid, 0, 0, 0
1174 	};
1175 
1176 	for (i = 0; i < EDID_STD_TIMINGS; i++) {
1177 		struct drm_display_mode *newmode;
1178 
1179 		newmode = drm_mode_std(connector, edid,
1180 				       &edid->standard_timings[i],
1181 				       edid->revision);
1182 		if (newmode) {
1183 			drm_mode_probed_add(connector, newmode);
1184 			modes++;
1185 		}
1186 	}
1187 
1188 	if (version_greater(edid, 1, 0))
1189 		drm_for_each_detailed_block((u8 *)edid, do_standard_modes,
1190 					    &closure);
1191 
1192 	/* XXX should also look for standard codes in VTB blocks */
1193 
1194 	return modes + closure.modes;
1195 }
1196 
1197 static int drm_cvt_modes(struct drm_connector *connector,
1198 			 struct detailed_timing *timing)
1199 {
1200 	int i, j, modes = 0;
1201 	struct drm_display_mode *newmode;
1202 	struct drm_device *dev = connector->dev;
1203 	struct cvt_timing *cvt;
1204 	const int rates[] = { 60, 85, 75, 60, 50 };
1205 	const u8 empty[3] = { 0, 0, 0 };
1206 
1207 	for (i = 0; i < 4; i++) {
1208 		int uninitialized_var(width), height;
1209 		cvt = &(timing->data.other_data.data.cvt[i]);
1210 
1211 		if (!memcmp(cvt->code, empty, 3))
1212 			continue;
1213 
1214 		height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 4) + 1) * 2;
1215 		switch (cvt->code[1] & 0x0c) {
1216 		case 0x00:
1217 			width = height * 4 / 3;
1218 			break;
1219 		case 0x04:
1220 			width = height * 16 / 9;
1221 			break;
1222 		case 0x08:
1223 			width = height * 16 / 10;
1224 			break;
1225 		case 0x0c:
1226 			width = height * 15 / 9;
1227 			break;
1228 		}
1229 
1230 		for (j = 1; j < 5; j++) {
1231 			if (cvt->code[2] & (1 << j)) {
1232 				newmode = drm_cvt_mode(dev, width, height,
1233 						       rates[j], j == 0,
1234 						       false, false);
1235 				if (newmode) {
1236 					drm_mode_probed_add(connector, newmode);
1237 					modes++;
1238 				}
1239 			}
1240 		}
1241 	}
1242 
1243 	return modes;
1244 }
1245 
1246 static void
1247 do_cvt_mode(struct detailed_timing *timing, void *c)
1248 {
1249 	struct detailed_mode_closure *closure = c;
1250 	struct detailed_non_pixel *data = &timing->data.other_data;
1251 
1252 	if (data->type == EDID_DETAIL_CVT_3BYTE)
1253 		closure->modes += drm_cvt_modes(closure->connector, timing);
1254 }
1255 
1256 static int
1257 add_cvt_modes(struct drm_connector *connector, struct edid *edid)
1258 {
1259 	struct detailed_mode_closure closure = {
1260 		connector, edid, 0, 0, 0
1261 	};
1262 
1263 	if (version_greater(edid, 1, 2))
1264 		drm_for_each_detailed_block((u8 *)edid, do_cvt_mode, &closure);
1265 
1266 	/* XXX should also look for CVT codes in VTB blocks */
1267 
1268 	return closure.modes;
1269 }
1270 
1271 static void
1272 do_detailed_mode(struct detailed_timing *timing, void *c)
1273 {
1274 	struct detailed_mode_closure *closure = c;
1275 	struct drm_display_mode *newmode;
1276 
1277 	if (timing->pixel_clock) {
1278 		newmode = drm_mode_detailed(closure->connector->dev,
1279 					    closure->edid, timing,
1280 					    closure->quirks);
1281 		if (!newmode)
1282 			return;
1283 
1284 		if (closure->preferred)
1285 			newmode->type |= DRM_MODE_TYPE_PREFERRED;
1286 
1287 		drm_mode_probed_add(closure->connector, newmode);
1288 		closure->modes++;
1289 		closure->preferred = 0;
1290 	}
1291 }
1292 
1293 /*
1294  * add_detailed_modes - Add modes from detailed timings
1295  * @connector: attached connector
1296  * @edid: EDID block to scan
1297  * @quirks: quirks to apply
1298  */
1299 static int
1300 add_detailed_modes(struct drm_connector *connector, struct edid *edid,
1301 		   u32 quirks)
1302 {
1303 	struct detailed_mode_closure closure = {
1304 		connector,
1305 		edid,
1306 		1,
1307 		quirks,
1308 		0
1309 	};
1310 
1311 	if (closure.preferred && !version_greater(edid, 1, 3))
1312 		closure.preferred =
1313 		    (edid->features & DRM_EDID_FEATURE_PREFERRED_TIMING);
1314 
1315 	drm_for_each_detailed_block((u8 *)edid, do_detailed_mode, &closure);
1316 
1317 	return closure.modes;
1318 }
1319 
1320 #define HDMI_IDENTIFIER 0x000C03
1321 #define AUDIO_BLOCK	0x01
1322 #define VENDOR_BLOCK    0x03
1323 #define SPEAKER_BLOCK	0x04
1324 #define EDID_BASIC_AUDIO	(1 << 6)
1325 
1326 /**
1327  * Search EDID for CEA extension block.
1328  */
1329 u8 *drm_find_cea_extension(struct edid *edid)
1330 {
1331 	u8 *edid_ext = NULL;
1332 	int i;
1333 
1334 	/* No EDID or EDID extensions */
1335 	if (edid == NULL || edid->extensions == 0)
1336 		return NULL;
1337 
1338 	/* Find CEA extension */
1339 	for (i = 0; i < edid->extensions; i++) {
1340 		edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
1341 		if (edid_ext[0] == CEA_EXT)
1342 			break;
1343 	}
1344 
1345 	if (i == edid->extensions)
1346 		return NULL;
1347 
1348 	return edid_ext;
1349 }
1350 EXPORT_SYMBOL(drm_find_cea_extension);
1351 
1352 static void
1353 parse_hdmi_vsdb(struct drm_connector *connector, uint8_t *db)
1354 {
1355 	connector->eld[5] |= (db[6] >> 7) << 1;  /* Supports_AI */
1356 
1357 	connector->dvi_dual = db[6] & 1;
1358 	connector->max_tmds_clock = db[7] * 5;
1359 
1360 	connector->latency_present[0] = db[8] >> 7;
1361 	connector->latency_present[1] = (db[8] >> 6) & 1;
1362 	connector->video_latency[0] = db[9];
1363 	connector->audio_latency[0] = db[10];
1364 	connector->video_latency[1] = db[11];
1365 	connector->audio_latency[1] = db[12];
1366 
1367 	DRM_LOG_KMS("HDMI: DVI dual %d, "
1368 		    "max TMDS clock %d, "
1369 		    "latency present %d %d, "
1370 		    "video latency %d %d, "
1371 		    "audio latency %d %d\n",
1372 		    connector->dvi_dual,
1373 		    connector->max_tmds_clock,
1374 	      (int) connector->latency_present[0],
1375 	      (int) connector->latency_present[1],
1376 		    connector->video_latency[0],
1377 		    connector->video_latency[1],
1378 		    connector->audio_latency[0],
1379 		    connector->audio_latency[1]);
1380 }
1381 
1382 static void
1383 monitor_name(struct detailed_timing *t, void *data)
1384 {
1385 	if (t->data.other_data.type == EDID_DETAIL_MONITOR_NAME)
1386 		*(u8 **)data = t->data.other_data.data.str.str;
1387 }
1388 
1389 /**
1390  * drm_edid_to_eld - build ELD from EDID
1391  * @connector: connector corresponding to the HDMI/DP sink
1392  * @edid: EDID to parse
1393  *
1394  * Fill the ELD (EDID-Like Data) buffer for passing to the audio driver.
1395  * Some ELD fields are left to the graphics driver caller:
1396  * - Conn_Type
1397  * - HDCP
1398  * - Port_ID
1399  */
1400 void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
1401 {
1402 	uint8_t *eld = connector->eld;
1403 	u8 *cea;
1404 	u8 *name;
1405 	u8 *db;
1406 	int sad_count = 0;
1407 	int mnl;
1408 	int dbl;
1409 
1410 	memset(eld, 0, sizeof(connector->eld));
1411 
1412 	cea = drm_find_cea_extension(edid);
1413 	if (!cea) {
1414 		DRM_DEBUG_KMS("ELD: no CEA Extension found\n");
1415 		return;
1416 	}
1417 
1418 	name = NULL;
1419 	drm_for_each_detailed_block((u8 *)edid, monitor_name, &name);
1420 	for (mnl = 0; name && mnl < 13; mnl++) {
1421 		if (name[mnl] == 0x0a)
1422 			break;
1423 		eld[20 + mnl] = name[mnl];
1424 	}
1425 	eld[4] = (cea[1] << 5) | mnl;
1426 	DRM_DEBUG_KMS("ELD monitor %s\n", eld + 20);
1427 
1428 	eld[0] = 2 << 3;		/* ELD version: 2 */
1429 
1430 	eld[16] = edid->mfg_id[0];
1431 	eld[17] = edid->mfg_id[1];
1432 	eld[18] = edid->prod_code[0];
1433 	eld[19] = edid->prod_code[1];
1434 
1435 	for (db = cea + 4; db < cea + cea[2]; db += dbl + 1) {
1436 		dbl = db[0] & 0x1f;
1437 
1438 		switch ((db[0] & 0xe0) >> 5) {
1439 		case AUDIO_BLOCK:	/* Audio Data Block, contains SADs */
1440 			sad_count = dbl / 3;
1441 			memcpy(eld + 20 + mnl, &db[1], dbl);
1442 			break;
1443 		case SPEAKER_BLOCK:	/* Speaker Allocation Data Block */
1444 			eld[7] = db[1];
1445 			break;
1446 		case VENDOR_BLOCK:
1447 			/* HDMI Vendor-Specific Data Block */
1448 			if (db[1] == 0x03 && db[2] == 0x0c && db[3] == 0)
1449 				parse_hdmi_vsdb(connector, db);
1450 			break;
1451 		default:
1452 			break;
1453 		}
1454 	}
1455 	eld[5] |= sad_count << 4;
1456 	eld[2] = (20 + mnl + sad_count * 3 + 3) / 4;
1457 
1458 	DRM_DEBUG_KMS("ELD size %d, SAD count %d\n", (int)eld[2], sad_count);
1459 }
1460 EXPORT_SYMBOL(drm_edid_to_eld);
1461 
1462 /**
1463  * drm_av_sync_delay - HDMI/DP sink audio-video sync delay in millisecond
1464  * @connector: connector associated with the HDMI/DP sink
1465  * @mode: the display mode
1466  */
1467 int drm_av_sync_delay(struct drm_connector *connector,
1468 		      struct drm_display_mode *mode)
1469 {
1470 	int i = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
1471 	int a, v;
1472 
1473 	if (!connector->latency_present[0])
1474 		return 0;
1475 	if (!connector->latency_present[1])
1476 		i = 0;
1477 
1478 	a = connector->audio_latency[i];
1479 	v = connector->video_latency[i];
1480 
1481 	/*
1482 	 * HDMI/DP sink doesn't support audio or video?
1483 	 */
1484 	if (a == 255 || v == 255)
1485 		return 0;
1486 
1487 	/*
1488 	 * Convert raw EDID values to millisecond.
1489 	 * Treat unknown latency as 0ms.
1490 	 */
1491 	if (a)
1492 		a = min(2 * (a - 1), 500);
1493 	if (v)
1494 		v = min(2 * (v - 1), 500);
1495 
1496 	return max(v - a, 0);
1497 }
1498 EXPORT_SYMBOL(drm_av_sync_delay);
1499 
1500 /**
1501  * drm_select_eld - select one ELD from multiple HDMI/DP sinks
1502  * @encoder: the encoder just changed display mode
1503  * @mode: the adjusted display mode
1504  *
1505  * It's possible for one encoder to be associated with multiple HDMI/DP sinks.
1506  * The policy is now hard coded to simply use the first HDMI/DP sink's ELD.
1507  */
1508 struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
1509 				     struct drm_display_mode *mode)
1510 {
1511 	struct drm_connector *connector;
1512 	struct drm_device *dev = encoder->dev;
1513 
1514 	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
1515 		if (connector->encoder == encoder && connector->eld[0])
1516 			return connector;
1517 
1518 	return NULL;
1519 }
1520 EXPORT_SYMBOL(drm_select_eld);
1521 
1522 /**
1523  * drm_detect_hdmi_monitor - detect whether monitor is hdmi.
1524  * @edid: monitor EDID information
1525  *
1526  * Parse the CEA extension according to CEA-861-B.
1527  * Return true if HDMI, false if not or unknown.
1528  */
1529 bool drm_detect_hdmi_monitor(struct edid *edid)
1530 {
1531 	u8 *edid_ext;
1532 	int i, hdmi_id;
1533 	int start_offset, end_offset;
1534 	bool is_hdmi = false;
1535 
1536 	edid_ext = drm_find_cea_extension(edid);
1537 	if (!edid_ext)
1538 		goto end;
1539 
1540 	/* Data block offset in CEA extension block */
1541 	start_offset = 4;
1542 	end_offset = edid_ext[2];
1543 
1544 	/*
1545 	 * Because HDMI identifier is in Vendor Specific Block,
1546 	 * search it from all data blocks of CEA extension.
1547 	 */
1548 	for (i = start_offset; i < end_offset;
1549 		/* Increased by data block len */
1550 		i += ((edid_ext[i] & 0x1f) + 1)) {
1551 		/* Find vendor specific block */
1552 		if ((edid_ext[i] >> 5) == VENDOR_BLOCK) {
1553 			hdmi_id = edid_ext[i + 1] | (edid_ext[i + 2] << 8) |
1554 				  edid_ext[i + 3] << 16;
1555 			/* Find HDMI identifier */
1556 			if (hdmi_id == HDMI_IDENTIFIER)
1557 				is_hdmi = true;
1558 			break;
1559 		}
1560 	}
1561 
1562 end:
1563 	return is_hdmi;
1564 }
1565 EXPORT_SYMBOL(drm_detect_hdmi_monitor);
1566 
1567 /**
1568  * drm_detect_monitor_audio - check monitor audio capability
1569  *
1570  * Monitor should have CEA extension block.
1571  * If monitor has 'basic audio', but no CEA audio blocks, it's 'basic
1572  * audio' only. If there is any audio extension block and supported
1573  * audio format, assume at least 'basic audio' support, even if 'basic
1574  * audio' is not defined in EDID.
1575  *
1576  */
1577 bool drm_detect_monitor_audio(struct edid *edid)
1578 {
1579 	u8 *edid_ext;
1580 	int i, j;
1581 	bool has_audio = false;
1582 	int start_offset, end_offset;
1583 
1584 	edid_ext = drm_find_cea_extension(edid);
1585 	if (!edid_ext)
1586 		goto end;
1587 
1588 	has_audio = ((edid_ext[3] & EDID_BASIC_AUDIO) != 0);
1589 
1590 	if (has_audio) {
1591 		DRM_DEBUG_KMS("Monitor has basic audio support\n");
1592 		goto end;
1593 	}
1594 
1595 	/* Data block offset in CEA extension block */
1596 	start_offset = 4;
1597 	end_offset = edid_ext[2];
1598 
1599 	for (i = start_offset; i < end_offset;
1600 			i += ((edid_ext[i] & 0x1f) + 1)) {
1601 		if ((edid_ext[i] >> 5) == AUDIO_BLOCK) {
1602 			has_audio = true;
1603 			for (j = 1; j < (edid_ext[i] & 0x1f); j += 3)
1604 				DRM_DEBUG_KMS("CEA audio format %d\n",
1605 					      (edid_ext[i + j] >> 3) & 0xf);
1606 			goto end;
1607 		}
1608 	}
1609 end:
1610 	return has_audio;
1611 }
1612 EXPORT_SYMBOL(drm_detect_monitor_audio);
1613 
1614 /**
1615  * drm_add_display_info - pull display info out if present
1616  * @edid: EDID data
1617  * @info: display info (attached to connector)
1618  *
1619  * Grab any available display info and stuff it into the drm_display_info
1620  * structure that's part of the connector.  Useful for tracking bpp and
1621  * color spaces.
1622  */
1623 static void drm_add_display_info(struct edid *edid,
1624 				 struct drm_display_info *info)
1625 {
1626 	u8 *edid_ext;
1627 
1628 	info->width_mm = edid->width_cm * 10;
1629 	info->height_mm = edid->height_cm * 10;
1630 
1631 	/* driver figures it out in this case */
1632 	info->bpc = 0;
1633 	info->color_formats = 0;
1634 
1635 	/* Only defined for 1.4 with digital displays */
1636 	if (edid->revision < 4)
1637 		return;
1638 
1639 	if (!(edid->input & DRM_EDID_INPUT_DIGITAL))
1640 		return;
1641 
1642 	switch (edid->input & DRM_EDID_DIGITAL_DEPTH_MASK) {
1643 	case DRM_EDID_DIGITAL_DEPTH_6:
1644 		info->bpc = 6;
1645 		break;
1646 	case DRM_EDID_DIGITAL_DEPTH_8:
1647 		info->bpc = 8;
1648 		break;
1649 	case DRM_EDID_DIGITAL_DEPTH_10:
1650 		info->bpc = 10;
1651 		break;
1652 	case DRM_EDID_DIGITAL_DEPTH_12:
1653 		info->bpc = 12;
1654 		break;
1655 	case DRM_EDID_DIGITAL_DEPTH_14:
1656 		info->bpc = 14;
1657 		break;
1658 	case DRM_EDID_DIGITAL_DEPTH_16:
1659 		info->bpc = 16;
1660 		break;
1661 	case DRM_EDID_DIGITAL_DEPTH_UNDEF:
1662 	default:
1663 		info->bpc = 0;
1664 		break;
1665 	}
1666 
1667 	info->color_formats = DRM_COLOR_FORMAT_RGB444;
1668 	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB444)
1669 		info->color_formats = DRM_COLOR_FORMAT_YCRCB444;
1670 	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB422)
1671 		info->color_formats = DRM_COLOR_FORMAT_YCRCB422;
1672 
1673 	/* Get data from CEA blocks if present */
1674 	edid_ext = drm_find_cea_extension(edid);
1675 	if (!edid_ext)
1676 		return;
1677 
1678 	info->cea_rev = edid_ext[1];
1679 }
1680 
1681 /**
1682  * drm_add_edid_modes - add modes from EDID data, if available
1683  * @connector: connector we're probing
1684  * @edid: edid data
1685  *
1686  * Add the specified modes to the connector's mode list.
1687  *
1688  * Return number of modes added or 0 if we couldn't find any.
1689  */
1690 int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
1691 {
1692 	int num_modes = 0;
1693 	u32 quirks;
1694 
1695 	if (edid == NULL) {
1696 		return 0;
1697 	}
1698 	if (!drm_edid_is_valid(edid)) {
1699 		dev_warn(connector->dev->dev, "%s: EDID invalid.\n",
1700 			 drm_get_connector_name(connector));
1701 		return 0;
1702 	}
1703 
1704 	quirks = edid_get_quirks(edid);
1705 
1706 	/*
1707 	 * EDID spec says modes should be preferred in this order:
1708 	 * - preferred detailed mode
1709 	 * - other detailed modes from base block
1710 	 * - detailed modes from extension blocks
1711 	 * - CVT 3-byte code modes
1712 	 * - standard timing codes
1713 	 * - established timing codes
1714 	 * - modes inferred from GTF or CVT range information
1715 	 *
1716 	 * We get this pretty much right.
1717 	 *
1718 	 * XXX order for additional mode types in extension blocks?
1719 	 */
1720 	num_modes += add_detailed_modes(connector, edid, quirks);
1721 	num_modes += add_cvt_modes(connector, edid);
1722 	num_modes += add_standard_modes(connector, edid);
1723 	num_modes += add_established_modes(connector, edid);
1724 	num_modes += add_inferred_modes(connector, edid);
1725 
1726 	if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
1727 		edid_fixup_preferred(connector, quirks);
1728 
1729 	drm_add_display_info(edid, &connector->display_info);
1730 
1731 	return num_modes;
1732 }
1733 EXPORT_SYMBOL(drm_add_edid_modes);
1734 
1735 /**
1736  * drm_add_modes_noedid - add modes for the connectors without EDID
1737  * @connector: connector we're probing
1738  * @hdisplay: the horizontal display limit
1739  * @vdisplay: the vertical display limit
1740  *
1741  * Add the specified modes to the connector's mode list. Only when the
1742  * hdisplay/vdisplay is not beyond the given limit, it will be added.
1743  *
1744  * Return number of modes added or 0 if we couldn't find any.
1745  */
1746 int drm_add_modes_noedid(struct drm_connector *connector,
1747 			int hdisplay, int vdisplay)
1748 {
1749 	int i, count, num_modes = 0;
1750 	struct drm_display_mode *mode;
1751 	struct drm_device *dev = connector->dev;
1752 
1753 	count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
1754 	if (hdisplay < 0)
1755 		hdisplay = 0;
1756 	if (vdisplay < 0)
1757 		vdisplay = 0;
1758 
1759 	for (i = 0; i < count; i++) {
1760 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
1761 		if (hdisplay && vdisplay) {
1762 			/*
1763 			 * Only when two are valid, they will be used to check
1764 			 * whether the mode should be added to the mode list of
1765 			 * the connector.
1766 			 */
1767 			if (ptr->hdisplay > hdisplay ||
1768 					ptr->vdisplay > vdisplay)
1769 				continue;
1770 		}
1771 		if (drm_mode_vrefresh(ptr) > 61)
1772 			continue;
1773 		mode = drm_mode_duplicate(dev, ptr);
1774 		if (mode) {
1775 			drm_mode_probed_add(connector, mode);
1776 			num_modes++;
1777 		}
1778 	}
1779 	return num_modes;
1780 }
1781 EXPORT_SYMBOL(drm_add_modes_noedid);
1782