xref: /openbmc/linux/drivers/gpu/drm/drm_edid.c (revision 9c1f8594)
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 header of the base EDID block.  Return 8 if the header
132  * is perfect, down to 0 if it's totally wrong.
133  */
134 int drm_edid_header_is_valid(const u8 *raw_edid)
135 {
136 	int i, score = 0;
137 
138 	for (i = 0; i < sizeof(edid_header); i++)
139 		if (raw_edid[i] == edid_header[i])
140 			score++;
141 
142 	return score;
143 }
144 EXPORT_SYMBOL(drm_edid_header_is_valid);
145 
146 
147 /*
148  * Sanity check the EDID block (base or extension).  Return 0 if the block
149  * doesn't check out, or 1 if it's valid.
150  */
151 static bool
152 drm_edid_block_valid(u8 *raw_edid)
153 {
154 	int i;
155 	u8 csum = 0;
156 	struct edid *edid = (struct edid *)raw_edid;
157 
158 	if (raw_edid[0] == 0x00) {
159 		int score = drm_edid_header_is_valid(raw_edid);
160 		if (score == 8) ;
161 		else if (score >= 6) {
162 			DRM_DEBUG("Fixing EDID header, your hardware may be failing\n");
163 			memcpy(raw_edid, edid_header, sizeof(edid_header));
164 		} else {
165 			goto bad;
166 		}
167 	}
168 
169 	for (i = 0; i < EDID_LENGTH; i++)
170 		csum += raw_edid[i];
171 	if (csum) {
172 		DRM_ERROR("EDID checksum is invalid, remainder is %d\n", csum);
173 
174 		/* allow CEA to slide through, switches mangle this */
175 		if (raw_edid[0] != 0x02)
176 			goto bad;
177 	}
178 
179 	/* per-block-type checks */
180 	switch (raw_edid[0]) {
181 	case 0: /* base */
182 		if (edid->version != 1) {
183 			DRM_ERROR("EDID has major version %d, instead of 1\n", edid->version);
184 			goto bad;
185 		}
186 
187 		if (edid->revision > 4)
188 			DRM_DEBUG("EDID minor > 4, assuming backward compatibility\n");
189 		break;
190 
191 	default:
192 		break;
193 	}
194 
195 	return 1;
196 
197 bad:
198 	if (raw_edid) {
199 		printk(KERN_ERR "Raw EDID:\n");
200 		print_hex_dump(KERN_ERR, " \t", DUMP_PREFIX_NONE, 16, 1,
201 			       raw_edid, EDID_LENGTH, false);
202 	}
203 	return 0;
204 }
205 
206 /**
207  * drm_edid_is_valid - sanity check EDID data
208  * @edid: EDID data
209  *
210  * Sanity-check an entire EDID record (including extensions)
211  */
212 bool drm_edid_is_valid(struct edid *edid)
213 {
214 	int i;
215 	u8 *raw = (u8 *)edid;
216 
217 	if (!edid)
218 		return false;
219 
220 	for (i = 0; i <= edid->extensions; i++)
221 		if (!drm_edid_block_valid(raw + i * EDID_LENGTH))
222 			return false;
223 
224 	return true;
225 }
226 EXPORT_SYMBOL(drm_edid_is_valid);
227 
228 #define DDC_ADDR 0x50
229 #define DDC_SEGMENT_ADDR 0x30
230 /**
231  * Get EDID information via I2C.
232  *
233  * \param adapter : i2c device adaptor
234  * \param buf     : EDID data buffer to be filled
235  * \param len     : EDID data buffer length
236  * \return 0 on success or -1 on failure.
237  *
238  * Try to fetch EDID information by calling i2c driver function.
239  */
240 static int
241 drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
242 		      int block, int len)
243 {
244 	unsigned char start = block * EDID_LENGTH;
245 	int ret, retries = 5;
246 
247 	/* The core i2c driver will automatically retry the transfer if the
248 	 * adapter reports EAGAIN. However, we find that bit-banging transfers
249 	 * are susceptible to errors under a heavily loaded machine and
250 	 * generate spurious NAKs and timeouts. Retrying the transfer
251 	 * of the individual block a few times seems to overcome this.
252 	 */
253 	do {
254 		struct i2c_msg msgs[] = {
255 			{
256 				.addr	= DDC_ADDR,
257 				.flags	= 0,
258 				.len	= 1,
259 				.buf	= &start,
260 			}, {
261 				.addr	= DDC_ADDR,
262 				.flags	= I2C_M_RD,
263 				.len	= len,
264 				.buf	= buf,
265 			}
266 		};
267 		ret = i2c_transfer(adapter, msgs, 2);
268 	} while (ret != 2 && --retries);
269 
270 	return ret == 2 ? 0 : -1;
271 }
272 
273 static bool drm_edid_is_zero(u8 *in_edid, int length)
274 {
275 	int i;
276 	u32 *raw_edid = (u32 *)in_edid;
277 
278 	for (i = 0; i < length / 4; i++)
279 		if (*(raw_edid + i) != 0)
280 			return false;
281 	return true;
282 }
283 
284 static u8 *
285 drm_do_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter)
286 {
287 	int i, j = 0, valid_extensions = 0;
288 	u8 *block, *new;
289 
290 	if ((block = kmalloc(EDID_LENGTH, GFP_KERNEL)) == NULL)
291 		return NULL;
292 
293 	/* base block fetch */
294 	for (i = 0; i < 4; i++) {
295 		if (drm_do_probe_ddc_edid(adapter, block, 0, EDID_LENGTH))
296 			goto out;
297 		if (drm_edid_block_valid(block))
298 			break;
299 		if (i == 0 && drm_edid_is_zero(block, EDID_LENGTH)) {
300 			connector->null_edid_counter++;
301 			goto carp;
302 		}
303 	}
304 	if (i == 4)
305 		goto carp;
306 
307 	/* if there's no extensions, we're done */
308 	if (block[0x7e] == 0)
309 		return block;
310 
311 	new = krealloc(block, (block[0x7e] + 1) * EDID_LENGTH, GFP_KERNEL);
312 	if (!new)
313 		goto out;
314 	block = new;
315 
316 	for (j = 1; j <= block[0x7e]; j++) {
317 		for (i = 0; i < 4; i++) {
318 			if (drm_do_probe_ddc_edid(adapter,
319 				  block + (valid_extensions + 1) * EDID_LENGTH,
320 				  j, EDID_LENGTH))
321 				goto out;
322 			if (drm_edid_block_valid(block + (valid_extensions + 1) * EDID_LENGTH)) {
323 				valid_extensions++;
324 				break;
325 			}
326 		}
327 		if (i == 4)
328 			dev_warn(connector->dev->dev,
329 			 "%s: Ignoring invalid EDID block %d.\n",
330 			 drm_get_connector_name(connector), j);
331 	}
332 
333 	if (valid_extensions != block[0x7e]) {
334 		block[EDID_LENGTH-1] += block[0x7e] - valid_extensions;
335 		block[0x7e] = valid_extensions;
336 		new = krealloc(block, (valid_extensions + 1) * EDID_LENGTH, GFP_KERNEL);
337 		if (!new)
338 			goto out;
339 		block = new;
340 	}
341 
342 	return block;
343 
344 carp:
345 	dev_warn(connector->dev->dev, "%s: EDID block %d invalid.\n",
346 		 drm_get_connector_name(connector), j);
347 
348 out:
349 	kfree(block);
350 	return NULL;
351 }
352 
353 /**
354  * Probe DDC presence.
355  *
356  * \param adapter : i2c device adaptor
357  * \return 1 on success
358  */
359 static bool
360 drm_probe_ddc(struct i2c_adapter *adapter)
361 {
362 	unsigned char out;
363 
364 	return (drm_do_probe_ddc_edid(adapter, &out, 0, 1) == 0);
365 }
366 
367 /**
368  * drm_get_edid - get EDID data, if available
369  * @connector: connector we're probing
370  * @adapter: i2c adapter to use for DDC
371  *
372  * Poke the given i2c channel to grab EDID data if possible.  If found,
373  * attach it to the connector.
374  *
375  * Return edid data or NULL if we couldn't find any.
376  */
377 struct edid *drm_get_edid(struct drm_connector *connector,
378 			  struct i2c_adapter *adapter)
379 {
380 	struct edid *edid = NULL;
381 
382 	if (drm_probe_ddc(adapter))
383 		edid = (struct edid *)drm_do_get_edid(connector, adapter);
384 
385 	connector->display_info.raw_edid = (char *)edid;
386 
387 	return edid;
388 
389 }
390 EXPORT_SYMBOL(drm_get_edid);
391 
392 /*** EDID parsing ***/
393 
394 /**
395  * edid_vendor - match a string against EDID's obfuscated vendor field
396  * @edid: EDID to match
397  * @vendor: vendor string
398  *
399  * Returns true if @vendor is in @edid, false otherwise
400  */
401 static bool edid_vendor(struct edid *edid, char *vendor)
402 {
403 	char edid_vendor[3];
404 
405 	edid_vendor[0] = ((edid->mfg_id[0] & 0x7c) >> 2) + '@';
406 	edid_vendor[1] = (((edid->mfg_id[0] & 0x3) << 3) |
407 			  ((edid->mfg_id[1] & 0xe0) >> 5)) + '@';
408 	edid_vendor[2] = (edid->mfg_id[1] & 0x1f) + '@';
409 
410 	return !strncmp(edid_vendor, vendor, 3);
411 }
412 
413 /**
414  * edid_get_quirks - return quirk flags for a given EDID
415  * @edid: EDID to process
416  *
417  * This tells subsequent routines what fixes they need to apply.
418  */
419 static u32 edid_get_quirks(struct edid *edid)
420 {
421 	struct edid_quirk *quirk;
422 	int i;
423 
424 	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
425 		quirk = &edid_quirk_list[i];
426 
427 		if (edid_vendor(edid, quirk->vendor) &&
428 		    (EDID_PRODUCT_ID(edid) == quirk->product_id))
429 			return quirk->quirks;
430 	}
431 
432 	return 0;
433 }
434 
435 #define MODE_SIZE(m) ((m)->hdisplay * (m)->vdisplay)
436 #define MODE_REFRESH_DIFF(m,r) (abs((m)->vrefresh - target_refresh))
437 
438 /**
439  * edid_fixup_preferred - set preferred modes based on quirk list
440  * @connector: has mode list to fix up
441  * @quirks: quirks list
442  *
443  * Walk the mode list for @connector, clearing the preferred status
444  * on existing modes and setting it anew for the right mode ala @quirks.
445  */
446 static void edid_fixup_preferred(struct drm_connector *connector,
447 				 u32 quirks)
448 {
449 	struct drm_display_mode *t, *cur_mode, *preferred_mode;
450 	int target_refresh = 0;
451 
452 	if (list_empty(&connector->probed_modes))
453 		return;
454 
455 	if (quirks & EDID_QUIRK_PREFER_LARGE_60)
456 		target_refresh = 60;
457 	if (quirks & EDID_QUIRK_PREFER_LARGE_75)
458 		target_refresh = 75;
459 
460 	preferred_mode = list_first_entry(&connector->probed_modes,
461 					  struct drm_display_mode, head);
462 
463 	list_for_each_entry_safe(cur_mode, t, &connector->probed_modes, head) {
464 		cur_mode->type &= ~DRM_MODE_TYPE_PREFERRED;
465 
466 		if (cur_mode == preferred_mode)
467 			continue;
468 
469 		/* Largest mode is preferred */
470 		if (MODE_SIZE(cur_mode) > MODE_SIZE(preferred_mode))
471 			preferred_mode = cur_mode;
472 
473 		/* At a given size, try to get closest to target refresh */
474 		if ((MODE_SIZE(cur_mode) == MODE_SIZE(preferred_mode)) &&
475 		    MODE_REFRESH_DIFF(cur_mode, target_refresh) <
476 		    MODE_REFRESH_DIFF(preferred_mode, target_refresh)) {
477 			preferred_mode = cur_mode;
478 		}
479 	}
480 
481 	preferred_mode->type |= DRM_MODE_TYPE_PREFERRED;
482 }
483 
484 struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
485 					   int hsize, int vsize, int fresh)
486 {
487 	struct drm_display_mode *mode = NULL;
488 	int i;
489 
490 	for (i = 0; i < drm_num_dmt_modes; i++) {
491 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
492 		if (hsize == ptr->hdisplay &&
493 			vsize == ptr->vdisplay &&
494 			fresh == drm_mode_vrefresh(ptr)) {
495 			/* get the expected default mode */
496 			mode = drm_mode_duplicate(dev, ptr);
497 			break;
498 		}
499 	}
500 	return mode;
501 }
502 EXPORT_SYMBOL(drm_mode_find_dmt);
503 
504 typedef void detailed_cb(struct detailed_timing *timing, void *closure);
505 
506 static void
507 cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
508 {
509 	int i, n = 0;
510 	u8 rev = ext[0x01], d = ext[0x02];
511 	u8 *det_base = ext + d;
512 
513 	switch (rev) {
514 	case 0:
515 		/* can't happen */
516 		return;
517 	case 1:
518 		/* have to infer how many blocks we have, check pixel clock */
519 		for (i = 0; i < 6; i++)
520 			if (det_base[18*i] || det_base[18*i+1])
521 				n++;
522 		break;
523 	default:
524 		/* explicit count */
525 		n = min(ext[0x03] & 0x0f, 6);
526 		break;
527 	}
528 
529 	for (i = 0; i < n; i++)
530 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
531 }
532 
533 static void
534 vtb_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
535 {
536 	unsigned int i, n = min((int)ext[0x02], 6);
537 	u8 *det_base = ext + 5;
538 
539 	if (ext[0x01] != 1)
540 		return; /* unknown version */
541 
542 	for (i = 0; i < n; i++)
543 		cb((struct detailed_timing *)(det_base + 18 * i), closure);
544 }
545 
546 static void
547 drm_for_each_detailed_block(u8 *raw_edid, detailed_cb *cb, void *closure)
548 {
549 	int i;
550 	struct edid *edid = (struct edid *)raw_edid;
551 
552 	if (edid == NULL)
553 		return;
554 
555 	for (i = 0; i < EDID_DETAILED_TIMINGS; i++)
556 		cb(&(edid->detailed_timings[i]), closure);
557 
558 	for (i = 1; i <= raw_edid[0x7e]; i++) {
559 		u8 *ext = raw_edid + (i * EDID_LENGTH);
560 		switch (*ext) {
561 		case CEA_EXT:
562 			cea_for_each_detailed_block(ext, cb, closure);
563 			break;
564 		case VTB_EXT:
565 			vtb_for_each_detailed_block(ext, cb, closure);
566 			break;
567 		default:
568 			break;
569 		}
570 	}
571 }
572 
573 static void
574 is_rb(struct detailed_timing *t, void *data)
575 {
576 	u8 *r = (u8 *)t;
577 	if (r[3] == EDID_DETAIL_MONITOR_RANGE)
578 		if (r[15] & 0x10)
579 			*(bool *)data = true;
580 }
581 
582 /* EDID 1.4 defines this explicitly.  For EDID 1.3, we guess, badly. */
583 static bool
584 drm_monitor_supports_rb(struct edid *edid)
585 {
586 	if (edid->revision >= 4) {
587 		bool ret;
588 		drm_for_each_detailed_block((u8 *)edid, is_rb, &ret);
589 		return ret;
590 	}
591 
592 	return ((edid->input & DRM_EDID_INPUT_DIGITAL) != 0);
593 }
594 
595 static void
596 find_gtf2(struct detailed_timing *t, void *data)
597 {
598 	u8 *r = (u8 *)t;
599 	if (r[3] == EDID_DETAIL_MONITOR_RANGE && r[10] == 0x02)
600 		*(u8 **)data = r;
601 }
602 
603 /* Secondary GTF curve kicks in above some break frequency */
604 static int
605 drm_gtf2_hbreak(struct edid *edid)
606 {
607 	u8 *r = NULL;
608 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
609 	return r ? (r[12] * 2) : 0;
610 }
611 
612 static int
613 drm_gtf2_2c(struct edid *edid)
614 {
615 	u8 *r = NULL;
616 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
617 	return r ? r[13] : 0;
618 }
619 
620 static int
621 drm_gtf2_m(struct edid *edid)
622 {
623 	u8 *r = NULL;
624 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
625 	return r ? (r[15] << 8) + r[14] : 0;
626 }
627 
628 static int
629 drm_gtf2_k(struct edid *edid)
630 {
631 	u8 *r = NULL;
632 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
633 	return r ? r[16] : 0;
634 }
635 
636 static int
637 drm_gtf2_2j(struct edid *edid)
638 {
639 	u8 *r = NULL;
640 	drm_for_each_detailed_block((u8 *)edid, find_gtf2, &r);
641 	return r ? r[17] : 0;
642 }
643 
644 /**
645  * standard_timing_level - get std. timing level(CVT/GTF/DMT)
646  * @edid: EDID block to scan
647  */
648 static int standard_timing_level(struct edid *edid)
649 {
650 	if (edid->revision >= 2) {
651 		if (edid->revision >= 4 && (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF))
652 			return LEVEL_CVT;
653 		if (drm_gtf2_hbreak(edid))
654 			return LEVEL_GTF2;
655 		return LEVEL_GTF;
656 	}
657 	return LEVEL_DMT;
658 }
659 
660 /*
661  * 0 is reserved.  The spec says 0x01 fill for unused timings.  Some old
662  * monitors fill with ascii space (0x20) instead.
663  */
664 static int
665 bad_std_timing(u8 a, u8 b)
666 {
667 	return (a == 0x00 && b == 0x00) ||
668 	       (a == 0x01 && b == 0x01) ||
669 	       (a == 0x20 && b == 0x20);
670 }
671 
672 /**
673  * drm_mode_std - convert standard mode info (width, height, refresh) into mode
674  * @t: standard timing params
675  * @timing_level: standard timing level
676  *
677  * Take the standard timing params (in this case width, aspect, and refresh)
678  * and convert them into a real mode using CVT/GTF/DMT.
679  */
680 static struct drm_display_mode *
681 drm_mode_std(struct drm_connector *connector, struct edid *edid,
682 	     struct std_timing *t, int revision)
683 {
684 	struct drm_device *dev = connector->dev;
685 	struct drm_display_mode *m, *mode = NULL;
686 	int hsize, vsize;
687 	int vrefresh_rate;
688 	unsigned aspect_ratio = (t->vfreq_aspect & EDID_TIMING_ASPECT_MASK)
689 		>> EDID_TIMING_ASPECT_SHIFT;
690 	unsigned vfreq = (t->vfreq_aspect & EDID_TIMING_VFREQ_MASK)
691 		>> EDID_TIMING_VFREQ_SHIFT;
692 	int timing_level = standard_timing_level(edid);
693 
694 	if (bad_std_timing(t->hsize, t->vfreq_aspect))
695 		return NULL;
696 
697 	/* According to the EDID spec, the hdisplay = hsize * 8 + 248 */
698 	hsize = t->hsize * 8 + 248;
699 	/* vrefresh_rate = vfreq + 60 */
700 	vrefresh_rate = vfreq + 60;
701 	/* the vdisplay is calculated based on the aspect ratio */
702 	if (aspect_ratio == 0) {
703 		if (revision < 3)
704 			vsize = hsize;
705 		else
706 			vsize = (hsize * 10) / 16;
707 	} else if (aspect_ratio == 1)
708 		vsize = (hsize * 3) / 4;
709 	else if (aspect_ratio == 2)
710 		vsize = (hsize * 4) / 5;
711 	else
712 		vsize = (hsize * 9) / 16;
713 
714 	/* HDTV hack, part 1 */
715 	if (vrefresh_rate == 60 &&
716 	    ((hsize == 1360 && vsize == 765) ||
717 	     (hsize == 1368 && vsize == 769))) {
718 		hsize = 1366;
719 		vsize = 768;
720 	}
721 
722 	/*
723 	 * If this connector already has a mode for this size and refresh
724 	 * rate (because it came from detailed or CVT info), use that
725 	 * instead.  This way we don't have to guess at interlace or
726 	 * reduced blanking.
727 	 */
728 	list_for_each_entry(m, &connector->probed_modes, head)
729 		if (m->hdisplay == hsize && m->vdisplay == vsize &&
730 		    drm_mode_vrefresh(m) == vrefresh_rate)
731 			return NULL;
732 
733 	/* HDTV hack, part 2 */
734 	if (hsize == 1366 && vsize == 768 && vrefresh_rate == 60) {
735 		mode = drm_cvt_mode(dev, 1366, 768, vrefresh_rate, 0, 0,
736 				    false);
737 		mode->hdisplay = 1366;
738 		mode->hsync_start = mode->hsync_start - 1;
739 		mode->hsync_end = mode->hsync_end - 1;
740 		return mode;
741 	}
742 
743 	/* check whether it can be found in default mode table */
744 	mode = drm_mode_find_dmt(dev, hsize, vsize, vrefresh_rate);
745 	if (mode)
746 		return mode;
747 
748 	switch (timing_level) {
749 	case LEVEL_DMT:
750 		break;
751 	case LEVEL_GTF:
752 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
753 		break;
754 	case LEVEL_GTF2:
755 		/*
756 		 * This is potentially wrong if there's ever a monitor with
757 		 * more than one ranges section, each claiming a different
758 		 * secondary GTF curve.  Please don't do that.
759 		 */
760 		mode = drm_gtf_mode(dev, hsize, vsize, vrefresh_rate, 0, 0);
761 		if (drm_mode_hsync(mode) > drm_gtf2_hbreak(edid)) {
762 			kfree(mode);
763 			mode = drm_gtf_mode_complex(dev, hsize, vsize,
764 						    vrefresh_rate, 0, 0,
765 						    drm_gtf2_m(edid),
766 						    drm_gtf2_2c(edid),
767 						    drm_gtf2_k(edid),
768 						    drm_gtf2_2j(edid));
769 		}
770 		break;
771 	case LEVEL_CVT:
772 		mode = drm_cvt_mode(dev, hsize, vsize, vrefresh_rate, 0, 0,
773 				    false);
774 		break;
775 	}
776 	return mode;
777 }
778 
779 /*
780  * EDID is delightfully ambiguous about how interlaced modes are to be
781  * encoded.  Our internal representation is of frame height, but some
782  * HDTV detailed timings are encoded as field height.
783  *
784  * The format list here is from CEA, in frame size.  Technically we
785  * should be checking refresh rate too.  Whatever.
786  */
787 static void
788 drm_mode_do_interlace_quirk(struct drm_display_mode *mode,
789 			    struct detailed_pixel_timing *pt)
790 {
791 	int i;
792 	static const struct {
793 		int w, h;
794 	} cea_interlaced[] = {
795 		{ 1920, 1080 },
796 		{  720,  480 },
797 		{ 1440,  480 },
798 		{ 2880,  480 },
799 		{  720,  576 },
800 		{ 1440,  576 },
801 		{ 2880,  576 },
802 	};
803 
804 	if (!(pt->misc & DRM_EDID_PT_INTERLACED))
805 		return;
806 
807 	for (i = 0; i < ARRAY_SIZE(cea_interlaced); i++) {
808 		if ((mode->hdisplay == cea_interlaced[i].w) &&
809 		    (mode->vdisplay == cea_interlaced[i].h / 2)) {
810 			mode->vdisplay *= 2;
811 			mode->vsync_start *= 2;
812 			mode->vsync_end *= 2;
813 			mode->vtotal *= 2;
814 			mode->vtotal |= 1;
815 		}
816 	}
817 
818 	mode->flags |= DRM_MODE_FLAG_INTERLACE;
819 }
820 
821 /**
822  * drm_mode_detailed - create a new mode from an EDID detailed timing section
823  * @dev: DRM device (needed to create new mode)
824  * @edid: EDID block
825  * @timing: EDID detailed timing info
826  * @quirks: quirks to apply
827  *
828  * An EDID detailed timing block contains enough info for us to create and
829  * return a new struct drm_display_mode.
830  */
831 static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
832 						  struct edid *edid,
833 						  struct detailed_timing *timing,
834 						  u32 quirks)
835 {
836 	struct drm_display_mode *mode;
837 	struct detailed_pixel_timing *pt = &timing->data.pixel_data;
838 	unsigned hactive = (pt->hactive_hblank_hi & 0xf0) << 4 | pt->hactive_lo;
839 	unsigned vactive = (pt->vactive_vblank_hi & 0xf0) << 4 | pt->vactive_lo;
840 	unsigned hblank = (pt->hactive_hblank_hi & 0xf) << 8 | pt->hblank_lo;
841 	unsigned vblank = (pt->vactive_vblank_hi & 0xf) << 8 | pt->vblank_lo;
842 	unsigned hsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc0) << 2 | pt->hsync_offset_lo;
843 	unsigned hsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x30) << 4 | pt->hsync_pulse_width_lo;
844 	unsigned vsync_offset = (pt->hsync_vsync_offset_pulse_width_hi & 0xc) >> 2 | pt->vsync_offset_pulse_width_lo >> 4;
845 	unsigned vsync_pulse_width = (pt->hsync_vsync_offset_pulse_width_hi & 0x3) << 4 | (pt->vsync_offset_pulse_width_lo & 0xf);
846 
847 	/* ignore tiny modes */
848 	if (hactive < 64 || vactive < 64)
849 		return NULL;
850 
851 	if (pt->misc & DRM_EDID_PT_STEREO) {
852 		printk(KERN_WARNING "stereo mode not supported\n");
853 		return NULL;
854 	}
855 	if (!(pt->misc & DRM_EDID_PT_SEPARATE_SYNC)) {
856 		printk(KERN_WARNING "composite sync not supported\n");
857 	}
858 
859 	/* it is incorrect if hsync/vsync width is zero */
860 	if (!hsync_pulse_width || !vsync_pulse_width) {
861 		DRM_DEBUG_KMS("Incorrect Detailed timing. "
862 				"Wrong Hsync/Vsync pulse width\n");
863 		return NULL;
864 	}
865 	mode = drm_mode_create(dev);
866 	if (!mode)
867 		return NULL;
868 
869 	mode->type = DRM_MODE_TYPE_DRIVER;
870 
871 	if (quirks & EDID_QUIRK_135_CLOCK_TOO_HIGH)
872 		timing->pixel_clock = cpu_to_le16(1088);
873 
874 	mode->clock = le16_to_cpu(timing->pixel_clock) * 10;
875 
876 	mode->hdisplay = hactive;
877 	mode->hsync_start = mode->hdisplay + hsync_offset;
878 	mode->hsync_end = mode->hsync_start + hsync_pulse_width;
879 	mode->htotal = mode->hdisplay + hblank;
880 
881 	mode->vdisplay = vactive;
882 	mode->vsync_start = mode->vdisplay + vsync_offset;
883 	mode->vsync_end = mode->vsync_start + vsync_pulse_width;
884 	mode->vtotal = mode->vdisplay + vblank;
885 
886 	/* Some EDIDs have bogus h/vtotal values */
887 	if (mode->hsync_end > mode->htotal)
888 		mode->htotal = mode->hsync_end + 1;
889 	if (mode->vsync_end > mode->vtotal)
890 		mode->vtotal = mode->vsync_end + 1;
891 
892 	drm_mode_do_interlace_quirk(mode, pt);
893 
894 	drm_mode_set_name(mode);
895 
896 	if (quirks & EDID_QUIRK_DETAILED_SYNC_PP) {
897 		pt->misc |= DRM_EDID_PT_HSYNC_POSITIVE | DRM_EDID_PT_VSYNC_POSITIVE;
898 	}
899 
900 	mode->flags |= (pt->misc & DRM_EDID_PT_HSYNC_POSITIVE) ?
901 		DRM_MODE_FLAG_PHSYNC : DRM_MODE_FLAG_NHSYNC;
902 	mode->flags |= (pt->misc & DRM_EDID_PT_VSYNC_POSITIVE) ?
903 		DRM_MODE_FLAG_PVSYNC : DRM_MODE_FLAG_NVSYNC;
904 
905 	mode->width_mm = pt->width_mm_lo | (pt->width_height_mm_hi & 0xf0) << 4;
906 	mode->height_mm = pt->height_mm_lo | (pt->width_height_mm_hi & 0xf) << 8;
907 
908 	if (quirks & EDID_QUIRK_DETAILED_IN_CM) {
909 		mode->width_mm *= 10;
910 		mode->height_mm *= 10;
911 	}
912 
913 	if (quirks & EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE) {
914 		mode->width_mm = edid->width_cm * 10;
915 		mode->height_mm = edid->height_cm * 10;
916 	}
917 
918 	return mode;
919 }
920 
921 static bool
922 mode_is_rb(const struct drm_display_mode *mode)
923 {
924 	return (mode->htotal - mode->hdisplay == 160) &&
925 	       (mode->hsync_end - mode->hdisplay == 80) &&
926 	       (mode->hsync_end - mode->hsync_start == 32) &&
927 	       (mode->vsync_start - mode->vdisplay == 3);
928 }
929 
930 static bool
931 mode_in_hsync_range(const struct drm_display_mode *mode,
932 		    struct edid *edid, u8 *t)
933 {
934 	int hsync, hmin, hmax;
935 
936 	hmin = t[7];
937 	if (edid->revision >= 4)
938 	    hmin += ((t[4] & 0x04) ? 255 : 0);
939 	hmax = t[8];
940 	if (edid->revision >= 4)
941 	    hmax += ((t[4] & 0x08) ? 255 : 0);
942 	hsync = drm_mode_hsync(mode);
943 
944 	return (hsync <= hmax && hsync >= hmin);
945 }
946 
947 static bool
948 mode_in_vsync_range(const struct drm_display_mode *mode,
949 		    struct edid *edid, u8 *t)
950 {
951 	int vsync, vmin, vmax;
952 
953 	vmin = t[5];
954 	if (edid->revision >= 4)
955 	    vmin += ((t[4] & 0x01) ? 255 : 0);
956 	vmax = t[6];
957 	if (edid->revision >= 4)
958 	    vmax += ((t[4] & 0x02) ? 255 : 0);
959 	vsync = drm_mode_vrefresh(mode);
960 
961 	return (vsync <= vmax && vsync >= vmin);
962 }
963 
964 static u32
965 range_pixel_clock(struct edid *edid, u8 *t)
966 {
967 	/* unspecified */
968 	if (t[9] == 0 || t[9] == 255)
969 		return 0;
970 
971 	/* 1.4 with CVT support gives us real precision, yay */
972 	if (edid->revision >= 4 && t[10] == 0x04)
973 		return (t[9] * 10000) - ((t[12] >> 2) * 250);
974 
975 	/* 1.3 is pathetic, so fuzz up a bit */
976 	return t[9] * 10000 + 5001;
977 }
978 
979 static bool
980 mode_in_range(const struct drm_display_mode *mode, struct edid *edid,
981 	      struct detailed_timing *timing)
982 {
983 	u32 max_clock;
984 	u8 *t = (u8 *)timing;
985 
986 	if (!mode_in_hsync_range(mode, edid, t))
987 		return false;
988 
989 	if (!mode_in_vsync_range(mode, edid, t))
990 		return false;
991 
992 	if ((max_clock = range_pixel_clock(edid, t)))
993 		if (mode->clock > max_clock)
994 			return false;
995 
996 	/* 1.4 max horizontal check */
997 	if (edid->revision >= 4 && t[10] == 0x04)
998 		if (t[13] && mode->hdisplay > 8 * (t[13] + (256 * (t[12]&0x3))))
999 			return false;
1000 
1001 	if (mode_is_rb(mode) && !drm_monitor_supports_rb(edid))
1002 		return false;
1003 
1004 	return true;
1005 }
1006 
1007 /*
1008  * XXX If drm_dmt_modes ever regrows the CVT-R modes (and it will) this will
1009  * need to account for them.
1010  */
1011 static int
1012 drm_gtf_modes_for_range(struct drm_connector *connector, struct edid *edid,
1013 			struct detailed_timing *timing)
1014 {
1015 	int i, modes = 0;
1016 	struct drm_display_mode *newmode;
1017 	struct drm_device *dev = connector->dev;
1018 
1019 	for (i = 0; i < drm_num_dmt_modes; i++) {
1020 		if (mode_in_range(drm_dmt_modes + i, edid, timing)) {
1021 			newmode = drm_mode_duplicate(dev, &drm_dmt_modes[i]);
1022 			if (newmode) {
1023 				drm_mode_probed_add(connector, newmode);
1024 				modes++;
1025 			}
1026 		}
1027 	}
1028 
1029 	return modes;
1030 }
1031 
1032 static void
1033 do_inferred_modes(struct detailed_timing *timing, void *c)
1034 {
1035 	struct detailed_mode_closure *closure = c;
1036 	struct detailed_non_pixel *data = &timing->data.other_data;
1037 	int gtf = (closure->edid->features & DRM_EDID_FEATURE_DEFAULT_GTF);
1038 
1039 	if (gtf && data->type == EDID_DETAIL_MONITOR_RANGE)
1040 		closure->modes += drm_gtf_modes_for_range(closure->connector,
1041 							  closure->edid,
1042 							  timing);
1043 }
1044 
1045 static int
1046 add_inferred_modes(struct drm_connector *connector, struct edid *edid)
1047 {
1048 	struct detailed_mode_closure closure = {
1049 		connector, edid, 0, 0, 0
1050 	};
1051 
1052 	if (version_greater(edid, 1, 0))
1053 		drm_for_each_detailed_block((u8 *)edid, do_inferred_modes,
1054 					    &closure);
1055 
1056 	return closure.modes;
1057 }
1058 
1059 static int
1060 drm_est3_modes(struct drm_connector *connector, struct detailed_timing *timing)
1061 {
1062 	int i, j, m, modes = 0;
1063 	struct drm_display_mode *mode;
1064 	u8 *est = ((u8 *)timing) + 5;
1065 
1066 	for (i = 0; i < 6; i++) {
1067 		for (j = 7; j > 0; j--) {
1068 			m = (i * 8) + (7 - j);
1069 			if (m >= ARRAY_SIZE(est3_modes))
1070 				break;
1071 			if (est[i] & (1 << j)) {
1072 				mode = drm_mode_find_dmt(connector->dev,
1073 							 est3_modes[m].w,
1074 							 est3_modes[m].h,
1075 							 est3_modes[m].r
1076 							 /*, est3_modes[m].rb */);
1077 				if (mode) {
1078 					drm_mode_probed_add(connector, mode);
1079 					modes++;
1080 				}
1081 			}
1082 		}
1083 	}
1084 
1085 	return modes;
1086 }
1087 
1088 static void
1089 do_established_modes(struct detailed_timing *timing, void *c)
1090 {
1091 	struct detailed_mode_closure *closure = c;
1092 	struct detailed_non_pixel *data = &timing->data.other_data;
1093 
1094 	if (data->type == EDID_DETAIL_EST_TIMINGS)
1095 		closure->modes += drm_est3_modes(closure->connector, timing);
1096 }
1097 
1098 /**
1099  * add_established_modes - get est. modes from EDID and add them
1100  * @edid: EDID block to scan
1101  *
1102  * Each EDID block contains a bitmap of the supported "established modes" list
1103  * (defined above).  Tease them out and add them to the global modes list.
1104  */
1105 static int
1106 add_established_modes(struct drm_connector *connector, struct edid *edid)
1107 {
1108 	struct drm_device *dev = connector->dev;
1109 	unsigned long est_bits = edid->established_timings.t1 |
1110 		(edid->established_timings.t2 << 8) |
1111 		((edid->established_timings.mfg_rsvd & 0x80) << 9);
1112 	int i, modes = 0;
1113 	struct detailed_mode_closure closure = {
1114 		connector, edid, 0, 0, 0
1115 	};
1116 
1117 	for (i = 0; i <= EDID_EST_TIMINGS; i++) {
1118 		if (est_bits & (1<<i)) {
1119 			struct drm_display_mode *newmode;
1120 			newmode = drm_mode_duplicate(dev, &edid_est_modes[i]);
1121 			if (newmode) {
1122 				drm_mode_probed_add(connector, newmode);
1123 				modes++;
1124 			}
1125 		}
1126 	}
1127 
1128 	if (version_greater(edid, 1, 0))
1129 		    drm_for_each_detailed_block((u8 *)edid,
1130 						do_established_modes, &closure);
1131 
1132 	return modes + closure.modes;
1133 }
1134 
1135 static void
1136 do_standard_modes(struct detailed_timing *timing, void *c)
1137 {
1138 	struct detailed_mode_closure *closure = c;
1139 	struct detailed_non_pixel *data = &timing->data.other_data;
1140 	struct drm_connector *connector = closure->connector;
1141 	struct edid *edid = closure->edid;
1142 
1143 	if (data->type == EDID_DETAIL_STD_MODES) {
1144 		int i;
1145 		for (i = 0; i < 6; i++) {
1146 			struct std_timing *std;
1147 			struct drm_display_mode *newmode;
1148 
1149 			std = &data->data.timings[i];
1150 			newmode = drm_mode_std(connector, edid, std,
1151 					       edid->revision);
1152 			if (newmode) {
1153 				drm_mode_probed_add(connector, newmode);
1154 				closure->modes++;
1155 			}
1156 		}
1157 	}
1158 }
1159 
1160 /**
1161  * add_standard_modes - get std. modes from EDID and add them
1162  * @edid: EDID block to scan
1163  *
1164  * Standard modes can be calculated using the appropriate standard (DMT,
1165  * GTF or CVT. Grab them from @edid and add them to the list.
1166  */
1167 static int
1168 add_standard_modes(struct drm_connector *connector, struct edid *edid)
1169 {
1170 	int i, modes = 0;
1171 	struct detailed_mode_closure closure = {
1172 		connector, edid, 0, 0, 0
1173 	};
1174 
1175 	for (i = 0; i < EDID_STD_TIMINGS; i++) {
1176 		struct drm_display_mode *newmode;
1177 
1178 		newmode = drm_mode_std(connector, edid,
1179 				       &edid->standard_timings[i],
1180 				       edid->revision);
1181 		if (newmode) {
1182 			drm_mode_probed_add(connector, newmode);
1183 			modes++;
1184 		}
1185 	}
1186 
1187 	if (version_greater(edid, 1, 0))
1188 		drm_for_each_detailed_block((u8 *)edid, do_standard_modes,
1189 					    &closure);
1190 
1191 	/* XXX should also look for standard codes in VTB blocks */
1192 
1193 	return modes + closure.modes;
1194 }
1195 
1196 static int drm_cvt_modes(struct drm_connector *connector,
1197 			 struct detailed_timing *timing)
1198 {
1199 	int i, j, modes = 0;
1200 	struct drm_display_mode *newmode;
1201 	struct drm_device *dev = connector->dev;
1202 	struct cvt_timing *cvt;
1203 	const int rates[] = { 60, 85, 75, 60, 50 };
1204 	const u8 empty[3] = { 0, 0, 0 };
1205 
1206 	for (i = 0; i < 4; i++) {
1207 		int uninitialized_var(width), height;
1208 		cvt = &(timing->data.other_data.data.cvt[i]);
1209 
1210 		if (!memcmp(cvt->code, empty, 3))
1211 			continue;
1212 
1213 		height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 4) + 1) * 2;
1214 		switch (cvt->code[1] & 0x0c) {
1215 		case 0x00:
1216 			width = height * 4 / 3;
1217 			break;
1218 		case 0x04:
1219 			width = height * 16 / 9;
1220 			break;
1221 		case 0x08:
1222 			width = height * 16 / 10;
1223 			break;
1224 		case 0x0c:
1225 			width = height * 15 / 9;
1226 			break;
1227 		}
1228 
1229 		for (j = 1; j < 5; j++) {
1230 			if (cvt->code[2] & (1 << j)) {
1231 				newmode = drm_cvt_mode(dev, width, height,
1232 						       rates[j], j == 0,
1233 						       false, false);
1234 				if (newmode) {
1235 					drm_mode_probed_add(connector, newmode);
1236 					modes++;
1237 				}
1238 			}
1239 		}
1240 	}
1241 
1242 	return modes;
1243 }
1244 
1245 static void
1246 do_cvt_mode(struct detailed_timing *timing, void *c)
1247 {
1248 	struct detailed_mode_closure *closure = c;
1249 	struct detailed_non_pixel *data = &timing->data.other_data;
1250 
1251 	if (data->type == EDID_DETAIL_CVT_3BYTE)
1252 		closure->modes += drm_cvt_modes(closure->connector, timing);
1253 }
1254 
1255 static int
1256 add_cvt_modes(struct drm_connector *connector, struct edid *edid)
1257 {
1258 	struct detailed_mode_closure closure = {
1259 		connector, edid, 0, 0, 0
1260 	};
1261 
1262 	if (version_greater(edid, 1, 2))
1263 		drm_for_each_detailed_block((u8 *)edid, do_cvt_mode, &closure);
1264 
1265 	/* XXX should also look for CVT codes in VTB blocks */
1266 
1267 	return closure.modes;
1268 }
1269 
1270 static void
1271 do_detailed_mode(struct detailed_timing *timing, void *c)
1272 {
1273 	struct detailed_mode_closure *closure = c;
1274 	struct drm_display_mode *newmode;
1275 
1276 	if (timing->pixel_clock) {
1277 		newmode = drm_mode_detailed(closure->connector->dev,
1278 					    closure->edid, timing,
1279 					    closure->quirks);
1280 		if (!newmode)
1281 			return;
1282 
1283 		if (closure->preferred)
1284 			newmode->type |= DRM_MODE_TYPE_PREFERRED;
1285 
1286 		drm_mode_probed_add(closure->connector, newmode);
1287 		closure->modes++;
1288 		closure->preferred = 0;
1289 	}
1290 }
1291 
1292 /*
1293  * add_detailed_modes - Add modes from detailed timings
1294  * @connector: attached connector
1295  * @edid: EDID block to scan
1296  * @quirks: quirks to apply
1297  */
1298 static int
1299 add_detailed_modes(struct drm_connector *connector, struct edid *edid,
1300 		   u32 quirks)
1301 {
1302 	struct detailed_mode_closure closure = {
1303 		connector,
1304 		edid,
1305 		1,
1306 		quirks,
1307 		0
1308 	};
1309 
1310 	if (closure.preferred && !version_greater(edid, 1, 3))
1311 		closure.preferred =
1312 		    (edid->features & DRM_EDID_FEATURE_PREFERRED_TIMING);
1313 
1314 	drm_for_each_detailed_block((u8 *)edid, do_detailed_mode, &closure);
1315 
1316 	return closure.modes;
1317 }
1318 
1319 #define HDMI_IDENTIFIER 0x000C03
1320 #define AUDIO_BLOCK	0x01
1321 #define VENDOR_BLOCK    0x03
1322 #define EDID_BASIC_AUDIO	(1 << 6)
1323 
1324 /**
1325  * Search EDID for CEA extension block.
1326  */
1327 u8 *drm_find_cea_extension(struct edid *edid)
1328 {
1329 	u8 *edid_ext = NULL;
1330 	int i;
1331 
1332 	/* No EDID or EDID extensions */
1333 	if (edid == NULL || edid->extensions == 0)
1334 		return NULL;
1335 
1336 	/* Find CEA extension */
1337 	for (i = 0; i < edid->extensions; i++) {
1338 		edid_ext = (u8 *)edid + EDID_LENGTH * (i + 1);
1339 		if (edid_ext[0] == CEA_EXT)
1340 			break;
1341 	}
1342 
1343 	if (i == edid->extensions)
1344 		return NULL;
1345 
1346 	return edid_ext;
1347 }
1348 EXPORT_SYMBOL(drm_find_cea_extension);
1349 
1350 /**
1351  * drm_detect_hdmi_monitor - detect whether monitor is hdmi.
1352  * @edid: monitor EDID information
1353  *
1354  * Parse the CEA extension according to CEA-861-B.
1355  * Return true if HDMI, false if not or unknown.
1356  */
1357 bool drm_detect_hdmi_monitor(struct edid *edid)
1358 {
1359 	u8 *edid_ext;
1360 	int i, hdmi_id;
1361 	int start_offset, end_offset;
1362 	bool is_hdmi = false;
1363 
1364 	edid_ext = drm_find_cea_extension(edid);
1365 	if (!edid_ext)
1366 		goto end;
1367 
1368 	/* Data block offset in CEA extension block */
1369 	start_offset = 4;
1370 	end_offset = edid_ext[2];
1371 
1372 	/*
1373 	 * Because HDMI identifier is in Vendor Specific Block,
1374 	 * search it from all data blocks of CEA extension.
1375 	 */
1376 	for (i = start_offset; i < end_offset;
1377 		/* Increased by data block len */
1378 		i += ((edid_ext[i] & 0x1f) + 1)) {
1379 		/* Find vendor specific block */
1380 		if ((edid_ext[i] >> 5) == VENDOR_BLOCK) {
1381 			hdmi_id = edid_ext[i + 1] | (edid_ext[i + 2] << 8) |
1382 				  edid_ext[i + 3] << 16;
1383 			/* Find HDMI identifier */
1384 			if (hdmi_id == HDMI_IDENTIFIER)
1385 				is_hdmi = true;
1386 			break;
1387 		}
1388 	}
1389 
1390 end:
1391 	return is_hdmi;
1392 }
1393 EXPORT_SYMBOL(drm_detect_hdmi_monitor);
1394 
1395 /**
1396  * drm_detect_monitor_audio - check monitor audio capability
1397  *
1398  * Monitor should have CEA extension block.
1399  * If monitor has 'basic audio', but no CEA audio blocks, it's 'basic
1400  * audio' only. If there is any audio extension block and supported
1401  * audio format, assume at least 'basic audio' support, even if 'basic
1402  * audio' is not defined in EDID.
1403  *
1404  */
1405 bool drm_detect_monitor_audio(struct edid *edid)
1406 {
1407 	u8 *edid_ext;
1408 	int i, j;
1409 	bool has_audio = false;
1410 	int start_offset, end_offset;
1411 
1412 	edid_ext = drm_find_cea_extension(edid);
1413 	if (!edid_ext)
1414 		goto end;
1415 
1416 	has_audio = ((edid_ext[3] & EDID_BASIC_AUDIO) != 0);
1417 
1418 	if (has_audio) {
1419 		DRM_DEBUG_KMS("Monitor has basic audio support\n");
1420 		goto end;
1421 	}
1422 
1423 	/* Data block offset in CEA extension block */
1424 	start_offset = 4;
1425 	end_offset = edid_ext[2];
1426 
1427 	for (i = start_offset; i < end_offset;
1428 			i += ((edid_ext[i] & 0x1f) + 1)) {
1429 		if ((edid_ext[i] >> 5) == AUDIO_BLOCK) {
1430 			has_audio = true;
1431 			for (j = 1; j < (edid_ext[i] & 0x1f); j += 3)
1432 				DRM_DEBUG_KMS("CEA audio format %d\n",
1433 					      (edid_ext[i + j] >> 3) & 0xf);
1434 			goto end;
1435 		}
1436 	}
1437 end:
1438 	return has_audio;
1439 }
1440 EXPORT_SYMBOL(drm_detect_monitor_audio);
1441 
1442 /**
1443  * drm_add_display_info - pull display info out if present
1444  * @edid: EDID data
1445  * @info: display info (attached to connector)
1446  *
1447  * Grab any available display info and stuff it into the drm_display_info
1448  * structure that's part of the connector.  Useful for tracking bpp and
1449  * color spaces.
1450  */
1451 static void drm_add_display_info(struct edid *edid,
1452 				 struct drm_display_info *info)
1453 {
1454 	u8 *edid_ext;
1455 
1456 	info->width_mm = edid->width_cm * 10;
1457 	info->height_mm = edid->height_cm * 10;
1458 
1459 	/* driver figures it out in this case */
1460 	info->bpc = 0;
1461 	info->color_formats = 0;
1462 
1463 	/* Only defined for 1.4 with digital displays */
1464 	if (edid->revision < 4)
1465 		return;
1466 
1467 	if (!(edid->input & DRM_EDID_INPUT_DIGITAL))
1468 		return;
1469 
1470 	switch (edid->input & DRM_EDID_DIGITAL_DEPTH_MASK) {
1471 	case DRM_EDID_DIGITAL_DEPTH_6:
1472 		info->bpc = 6;
1473 		break;
1474 	case DRM_EDID_DIGITAL_DEPTH_8:
1475 		info->bpc = 8;
1476 		break;
1477 	case DRM_EDID_DIGITAL_DEPTH_10:
1478 		info->bpc = 10;
1479 		break;
1480 	case DRM_EDID_DIGITAL_DEPTH_12:
1481 		info->bpc = 12;
1482 		break;
1483 	case DRM_EDID_DIGITAL_DEPTH_14:
1484 		info->bpc = 14;
1485 		break;
1486 	case DRM_EDID_DIGITAL_DEPTH_16:
1487 		info->bpc = 16;
1488 		break;
1489 	case DRM_EDID_DIGITAL_DEPTH_UNDEF:
1490 	default:
1491 		info->bpc = 0;
1492 		break;
1493 	}
1494 
1495 	info->color_formats = DRM_COLOR_FORMAT_RGB444;
1496 	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB444)
1497 		info->color_formats = DRM_COLOR_FORMAT_YCRCB444;
1498 	if (info->color_formats & DRM_EDID_FEATURE_RGB_YCRCB422)
1499 		info->color_formats = DRM_COLOR_FORMAT_YCRCB422;
1500 
1501 	/* Get data from CEA blocks if present */
1502 	edid_ext = drm_find_cea_extension(edid);
1503 	if (!edid_ext)
1504 		return;
1505 
1506 	info->cea_rev = edid_ext[1];
1507 }
1508 
1509 /**
1510  * drm_add_edid_modes - add modes from EDID data, if available
1511  * @connector: connector we're probing
1512  * @edid: edid data
1513  *
1514  * Add the specified modes to the connector's mode list.
1515  *
1516  * Return number of modes added or 0 if we couldn't find any.
1517  */
1518 int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
1519 {
1520 	int num_modes = 0;
1521 	u32 quirks;
1522 
1523 	if (edid == NULL) {
1524 		return 0;
1525 	}
1526 	if (!drm_edid_is_valid(edid)) {
1527 		dev_warn(connector->dev->dev, "%s: EDID invalid.\n",
1528 			 drm_get_connector_name(connector));
1529 		return 0;
1530 	}
1531 
1532 	quirks = edid_get_quirks(edid);
1533 
1534 	/*
1535 	 * EDID spec says modes should be preferred in this order:
1536 	 * - preferred detailed mode
1537 	 * - other detailed modes from base block
1538 	 * - detailed modes from extension blocks
1539 	 * - CVT 3-byte code modes
1540 	 * - standard timing codes
1541 	 * - established timing codes
1542 	 * - modes inferred from GTF or CVT range information
1543 	 *
1544 	 * We get this pretty much right.
1545 	 *
1546 	 * XXX order for additional mode types in extension blocks?
1547 	 */
1548 	num_modes += add_detailed_modes(connector, edid, quirks);
1549 	num_modes += add_cvt_modes(connector, edid);
1550 	num_modes += add_standard_modes(connector, edid);
1551 	num_modes += add_established_modes(connector, edid);
1552 	num_modes += add_inferred_modes(connector, edid);
1553 
1554 	if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
1555 		edid_fixup_preferred(connector, quirks);
1556 
1557 	drm_add_display_info(edid, &connector->display_info);
1558 
1559 	return num_modes;
1560 }
1561 EXPORT_SYMBOL(drm_add_edid_modes);
1562 
1563 /**
1564  * drm_add_modes_noedid - add modes for the connectors without EDID
1565  * @connector: connector we're probing
1566  * @hdisplay: the horizontal display limit
1567  * @vdisplay: the vertical display limit
1568  *
1569  * Add the specified modes to the connector's mode list. Only when the
1570  * hdisplay/vdisplay is not beyond the given limit, it will be added.
1571  *
1572  * Return number of modes added or 0 if we couldn't find any.
1573  */
1574 int drm_add_modes_noedid(struct drm_connector *connector,
1575 			int hdisplay, int vdisplay)
1576 {
1577 	int i, count, num_modes = 0;
1578 	struct drm_display_mode *mode;
1579 	struct drm_device *dev = connector->dev;
1580 
1581 	count = sizeof(drm_dmt_modes) / sizeof(struct drm_display_mode);
1582 	if (hdisplay < 0)
1583 		hdisplay = 0;
1584 	if (vdisplay < 0)
1585 		vdisplay = 0;
1586 
1587 	for (i = 0; i < count; i++) {
1588 		const struct drm_display_mode *ptr = &drm_dmt_modes[i];
1589 		if (hdisplay && vdisplay) {
1590 			/*
1591 			 * Only when two are valid, they will be used to check
1592 			 * whether the mode should be added to the mode list of
1593 			 * the connector.
1594 			 */
1595 			if (ptr->hdisplay > hdisplay ||
1596 					ptr->vdisplay > vdisplay)
1597 				continue;
1598 		}
1599 		if (drm_mode_vrefresh(ptr) > 61)
1600 			continue;
1601 		mode = drm_mode_duplicate(dev, ptr);
1602 		if (mode) {
1603 			drm_mode_probed_add(connector, mode);
1604 			num_modes++;
1605 		}
1606 	}
1607 	return num_modes;
1608 }
1609 EXPORT_SYMBOL(drm_add_modes_noedid);
1610