aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/intel_bios.c
blob: 55ffba1f5818d933227c0ea5344afb491da295a9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
/*
 * Copyright © 2006 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *
 */
#include <linux/dmi.h>
#include <drm/drm_dp_helper.h>
#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include "intel_bios.h"

#define	SLAVE_ADDR1	0x70
#define	SLAVE_ADDR2	0x72

static int panel_type;

static void *
find_section(struct bdb_header *bdb, int section_id)
{
	u8 *base = (u8 *)bdb;
	int index = 0;
	u16 total, current_size;
	u8 current_id;

	/* skip to first section */
	index += bdb->header_size;
	total = bdb->bdb_size;

	/* walk the sections looking for section_id */
	while (index < total) {
		current_id = *(base + index);
		index++;
		current_size = *((u16 *)(base + index));
		index += 2;
		if (current_id == section_id)
			return base + index;
		index += current_size;
	}

	return NULL;
}

static u16
get_blocksize(void *p)
{
	u16 *block_ptr, block_size;

	block_ptr = (u16 *)((char *)p - 2);
	block_size = *block_ptr;
	return block_size;
}

static void
fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
			const struct lvds_dvo_timing *dvo_timing)
{
	panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
		dvo_timing->hactive_lo;
	panel_fixed_mode->hsync_start = panel_fixed_mode->hdisplay +
		((dvo_timing->hsync_off_hi << 8) | dvo_timing->hsync_off_lo);
	panel_fixed_mode->hsync_end = panel_fixed_mode->hsync_start +
		dvo_timing->hsync_pulse_width;
	panel_fixed_mode->htotal = panel_fixed_mode->hdisplay +
		((dvo_timing->hblank_hi << 8) | dvo_timing->hblank_lo);

	panel_fixed_mode->vdisplay = (dvo_timing->vactive_hi << 8) |
		dvo_timing->vactive_lo;
	panel_fixed_mode->vsync_start = panel_fixed_mode->vdisplay +
		dvo_timing->vsync_off;
	panel_fixed_mode->vsync_end = panel_fixed_mode->vsync_start +
		dvo_timing->vsync_pulse_width;
	panel_fixed_mode->vtotal = panel_fixed_mode->vdisplay +
		((dvo_timing->vblank_hi << 8) | dvo_timing->vblank_lo);
	panel_fixed_mode->clock = dvo_timing->clock * 10;
	panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;

	if (dvo_timing->hsync_positive)
		panel_fixed_mode->flags |= DRM_MODE_FLAG_PHSYNC;
	else
		panel_fixed_mode->flags |= DRM_MODE_FLAG_NHSYNC;

	if (dvo_timing->vsync_positive)
		panel_fixed_mode->flags |= DRM_MODE_FLAG_PVSYNC;
	else
		panel_fixed_mode->flags |= DRM_MODE_FLAG_NVSYNC;

	/* Some VBTs have bogus h/vtotal values */
	if (panel_fixed_mode->hsync_end > panel_fixed_mode->htotal)
		panel_fixed_mode->htotal = panel_fixed_mode->hsync_end + 1;
	if (panel_fixed_mode->vsync_end > panel_fixed_mode->vtotal)
		panel_fixed_mode->vtotal = panel_fixed_mode->vsync_end + 1;

	drm_mode_set_name(panel_fixed_mode);
}

static bool
lvds_dvo_timing_equal_size(const struct lvds_dvo_timing *a,
			   const struct lvds_dvo_timing *b)
{
	if (a->hactive_hi != b->hactive_hi ||
	    a->hactive_lo != b->hactive_lo)
		return false;

	if (a->hsync_off_hi != b->hsync_off_hi ||
	    a->hsync_off_lo != b->hsync_off_lo)
		return false;

	if (a->hsync_pulse_width != b->hsync_pulse_width)
		return false;

	if (a->hblank_hi != b->hblank_hi ||
	    a->hblank_lo != b->hblank_lo)
		return false;

	if (a->vactive_hi != b->vactive_hi ||
	    a->vactive_lo != b->vactive_lo)
		return false;

	if (a->vsync_off != b->vsync_off)
		return false;

	if (a->vsync_pulse_width != b->vsync_pulse_width)
		return false;

	if (a->vblank_hi != b->vblank_hi ||
	    a->vblank_lo != b->vblank_lo)
		return false;

	return true;
}

static const struct lvds_dvo_timing *
get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
		    const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
		    int index)
{
	/*
	 * the size of fp_timing varies on the different platform.
	 * So calculate the DVO timing relative offset in LVDS data
	 * entry to get the DVO timing entry
	 */

	int lfp_data_size =
		lvds_lfp_data_ptrs->ptr[1].dvo_timing_offset -
		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset;
	int dvo_timing_offset =
		lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset -
		lvds_lfp_data_ptrs->ptr[0].fp_timing_offset;
	char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;

	return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);
}

/* get lvds_fp_timing entry
 * this function may return NULL if the corresponding entry is invalid
 */
static const struct lvds_fp_timing *
get_lvds_fp_timing(const struct bdb_header *bdb,
		   const struct bdb_lvds_lfp_data *data,
		   const struct bdb_lvds_lfp_data_ptrs *ptrs,
		   int index)
{
	size_t data_ofs = (const u8 *)data - (const u8 *)bdb;
	u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
	size_t ofs;

	if (index >= ARRAY_SIZE(ptrs->ptr))
		return NULL;
	ofs = ptrs->ptr[index].fp_timing_offset;
	if (ofs < data_ofs ||
	    ofs + sizeof(struct lvds_fp_timing) > data_ofs + data_size)
		return NULL;
	return (const struct lvds_fp_timing *)((const u8 *)bdb + ofs);
}

/* Try to find integrated panel data */
static void
parse_lfp_panel_data(struct drm_i915_private *dev_priv,
			    struct bdb_header *bdb)
{
	const struct bdb_lvds_options *lvds_options;
	const struct bdb_lvds_lfp_data *lvds_lfp_data;
	const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
	const struct lvds_dvo_timing *panel_dvo_timing;
	const struct lvds_fp_timing *fp_timing;
	struct drm_display_mode *panel_fixed_mode;
	int i, downclock;

	lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
	if (!lvds_options)
		return;

	dev_priv->lvds_dither = lvds_options->pixel_dither;
	if (lvds_options->panel_type == 0xff)
		return;

	panel_type = lvds_options->panel_type;

	lvds_lfp_data = find_section(bdb, BDB_LVDS_LFP_DATA);
	if (!lvds_lfp_data)
		return;

	lvds_lfp_data_ptrs = find_section(bdb, BDB_LVDS_LFP_DATA_PTRS);
	if (!lvds_lfp_data_ptrs)
		return;

	dev_priv->lvds_vbt = 1;

	panel_dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
					       lvds_lfp_data_ptrs,
					       lvds_options->panel_type);

	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
	if (!panel_fixed_mode)
		return;

	fill_detail_timing_data(panel_fixed_mode, panel_dvo_timing);

	dev_priv->lfp_lvds_vbt_mode = panel_fixed_mode;

	DRM_DEBUG_KMS("Found panel mode in BIOS VBT tables:\n");
	drm_mode_debug_printmodeline(panel_fixed_mode);

	/*
	 * Iterate over the LVDS panel timing info to find the lowest clock
	 * for the native resolution.
	 */
	downclock = panel_dvo_timing->clock;
	for (i = 0; i < 16; i++) {
		const struct lvds_dvo_timing *dvo_timing;

		dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
						 lvds_lfp_data_ptrs,
						 i);
		if (lvds_dvo_timing_equal_size(dvo_timing, panel_dvo_timing) &&
		    dvo_timing->clock < downclock)
			downclock = dvo_timing->clock;
	}

	if (downclock < panel_dvo_timing->clock && i915_lvds_downclock) {
		dev_priv->lvds_downclock_avail = 1;
		dev_priv->lvds_downclock = downclock * 10;
		DRM_DEBUG_KMS("LVDS downclock is found in VBT. "
			      "Normal Clock %dKHz, downclock %dKHz\n",
			      panel_fixed_mode->clock, 10*downclock);
	}

	fp_timing = get_lvds_fp_timing(bdb, lvds_lfp_data,
				       lvds_lfp_data_ptrs,
				       lvds_options->panel_type);
	if (fp_timing) {
		/* check the resolution, just to be sure */
		if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
		    fp_timing->y_res == panel_fixed_mode->vdisplay) {
			dev_priv->bios_lvds_val = fp_timing->lvds_reg_val;
			DRM_DEBUG_KMS("VBT initial LVDS value %x\n",
				      dev_priv->bios_lvds_val);
		}
	}
}

/* Try to find sdvo panel data */
static void
parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
		      struct bdb_header *bdb)
{
	struct lvds_dvo_timing *dvo_timing;
	struct drm_display_mode *panel_fixed_mode;
	int index;

	index = i915_vbt_sdvo_panel_type;
	if (index == -2) {
		DRM_DEBUG_KMS("Ignore SDVO panel mode from BIOS VBT tables.\n");
		return;
	}

	if (index == -1) {
		struct bdb_sdvo_lvds_options *sdvo_lvds_options;

		sdvo_lvds_options = find_section(bdb, BDB_SDVO_LVDS_OPTIONS);
		if (!sdvo_lvds_options)
			return;

		index = sdvo_lvds_options->panel_type;
	}

	dvo_timing = find_section(bdb, BDB_SDVO_PANEL_DTDS);
	if (!dvo_timing)
		return;

	panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
	if (!panel_fixed_mode)
		return;

	fill_detail_timing_data(panel_fixed_mode, dvo_timing + index);

	dev_priv->sdvo_lvds_vbt_mode = panel_fixed_mode;

	DRM_DEBUG_KMS("Found SDVO panel mode in BIOS VBT tables:\n");
	drm_mode_debug_printmodeline(panel_fixed_mode);
}

static int intel_bios_ssc_frequency(struct drm_device *dev,
				    bool alternate)
{
	switch (INTEL_INFO(dev)->gen) {
	case 2:
		return alternate ? 66 : 48;
	case 3:
	case 4:
		return alternate ? 100 : 96;
	default:
		return alternate ? 100 : 120;
	}
}

static void
parse_general_features(struct drm_i915_private *dev_priv,
		       struct bdb_header *bdb)
{
	struct drm_device *dev = dev_priv->dev;
	struct bdb_general_features *general;

	general = find_section(bdb, BDB_GENERAL_FEATURES);
	if (general) {
		dev_priv->int_tv_support = general->int_tv_support;
		dev_priv->int_crt_support = general->int_crt_support;
		dev_priv->lvds_use_ssc = general->enable_ssc;
		dev_priv->lvds_ssc_freq =
			intel_bios_ssc_frequency(dev, general->ssc_freq);
		dev_priv->display_clock_mode = general->display_clock_mode;
		DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d display_clock_mode %d\n",
			      dev_priv->int_tv_support,
			      dev_priv->int_crt_support,
			      dev_priv->lvds_use_ssc,
			      dev_priv->lvds_ssc_freq,
			      dev_priv->display_clock_mode);
	}
}

static void
parse_general_definitions(struct drm_i915_private *dev_priv,
			  struct bdb_header *bdb)
{
	struct bdb_general_definitions *general;

	general = find_section(bdb, BDB_GENERAL_DEFINITIONS);
	if (general) {
		u16 block_size = get_blocksize(general);
		if (block_size >= sizeof(*general)) {
			int bus_pin = general->crt_ddc_gmbus_pin;
			DRM_DEBUG_KMS("crt_ddc_bus_pin: %d\n", bus_pin);
			if (intel_gmbus_is_port_valid(bus_pin))
				dev_priv->crt_ddc_pin = bus_pin;
		} else {
			DRM_DEBUG_KMS("BDB_GD too small (%d). Invalid.\n",
				      block_size);
		}
	}
}

static void
parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
			  struct bdb_header *bdb)
{
	struct sdvo_device_mapping *p_mapping;
	struct bdb_general_definitions *p_defs;
	struct child_device_config *p_child;
	int i, child_device_num, count;
	u16	block_size;

	p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
	if (!p_defs) {
		DRM_DEBUG_KMS("No general definition block is found, unable to construct sdvo mapping.\n");
		return;
	}
	/* judge whether the size of child device meets the requirements.
	 * If the child device size obtained from general definition block
	 * is different with sizeof(struct child_device_config), skip the
	 * parsing of sdvo device info
	 */
	if (p_defs->child_dev_size != sizeof(*p_child)) {
		/* different child dev size . Ignore it */
		DRM_DEBUG_KMS("different child size is found. Invalid.\n");
		return;
	}
	/* get the block size of general definitions */
	block_size = get_blocksize(p_defs);
	/* get the number of child device */
	child_device_num = (block_size - sizeof(*p_defs)) /
				sizeof(*p_child);
	count = 0;
	for (i = 0; i < child_device_num; i++) {
		p_child = &(p_defs->devices[i]);
		if (!p_child->device_type) {
			/* skip the device block if device type is invalid */
			continue;
		}
		if (p_child->slave_addr != SLAVE_ADDR1 &&
			p_child->slave_addr != SLAVE_ADDR2) {
			/*
			 * If the slave address is neither 0x70 nor 0x72,
			 * it is not a SDVO device. Skip it.
			 */
			continue;
		}
		if (p_child->dvo_port != DEVICE_PORT_DVOB &&
			p_child->dvo_port != DEVICE_PORT_DVOC) {
			/* skip the incorrect SDVO port */
			DRM_DEBUG_KMS("Incorrect SDVO port. Skip it\n");
			continue;
		}
		DRM_DEBUG_KMS("the SDVO device with slave addr %2x is found on"
				" %s port\n",
				p_child->slave_addr,
				(p_child->dvo_port == DEVICE_PORT_DVOB) ?
					"SDVOB" : "SDVOC");
		p_mapping = &(dev_priv->sdvo_mappings[p_child->dvo_port - 1]);
		if (!p_mapping->initialized) {
			p_mapping->dvo_port = p_child->dvo_port;
			p_mapping->slave_addr = p_child->slave_addr;
			p_mapping->dvo_wiring = p_child->dvo_wiring;
			p_mapping->ddc_pin = p_child->ddc_pin;
			p_mapping->i2c_pin = p_child->i2c_pin;
			p_mapping->initialized = 1;
			DRM_DEBUG_KMS("SDVO device: dvo=%x, addr=%x, wiring=%d, ddc_pin=%d, i2c_pin=%d\n",
				      p_mapping->dvo_port,
				      p_mapping->slave_addr,
				      p_mapping->dvo_wiring,
				      p_mapping->ddc_pin,
				      p_mapping->i2c_pin);
		} else {
			DRM_DEBUG_KMS("Maybe one SDVO port is shared by "
					 "two SDVO device.\n");
		}
		if (p_child->slave2_addr) {
			/* Maybe this is a SDVO device with multiple inputs */
			/* And the mapping info is not added */
			DRM_DEBUG_KMS("there exists the slave2_addr. Maybe this"
				" is a SDVO device with multiple inputs.\n");
		}
		count++;
	}

	if (!count) {
		/* No SDVO device info is found */
		DRM_DEBUG_KMS("No SDVO device info is found in VBT\n");
	}
	return;
}

static void
parse_driver_features(struct drm_i915_private *dev_priv,
		       struct bdb_header *bdb)
{
	struct drm_device *dev = dev_priv->dev;
	struct bdb_driver_features *driver;

	driver = find_section(bdb, BDB_DRIVER_FEATURES);
	if (!driver)
		return;

	if (SUPPORTS_EDP(dev) &&
	    driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
		dev_priv->edp.support = 1;

	if (driver->dual_frequency)
		dev_priv->render_reclock_avail = true;
}

static void
parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
{
	struct bdb_edp *edp;
	struct edp_power_seq *edp_pps;
	struct edp_link_params *edp_link_params;

	edp = find_section(bdb, BDB_EDP);
	if (!edp) {
		if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp.support)
			DRM_DEBUG_KMS("No eDP BDB found but eDP panel supported.\n");
		return;
	}

	switch ((edp->color_depth >> (panel_type * 2)) & 3) {
	case EDP_18BPP:
		dev_priv->edp.bpp = 18;
		break;
	case EDP_24BPP:
		dev_priv->edp.bpp = 24;
		break;
	case EDP_30BPP:
		dev_priv->edp.bpp = 30;
		break;
	}

	/* Get the eDP sequencing and link info */
	edp_pps = &edp->power_seqs[panel_type];
	edp_link_params = &edp->link_params[panel_type];

	dev_priv->edp.pps = *edp_pps;

	dev_priv->edp.rate = edp_link_params->rate ? DP_LINK_BW_2_7 :
		DP_LINK_BW_1_62;
	switch (edp_link_params->lanes) {
	case 0:
		dev_priv->edp.lanes = 1;
		break;
	case 1:
		dev_priv->edp.lanes = 2;
		break;
	case 3:
	default:
		dev_priv->edp.lanes = 4;
		break;
	}
	switch (edp_link_params->preemphasis) {
	case 0:
		dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_0;
		break;
	case 1:
		dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_3_5;
		break;
	case 2:
		dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_6;
		break;
	case 3:
		dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_9_5;
		break;
	}
	switch (edp_link_params->vswing) {
	case 0:
		dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_400;
		break;
	case 1:
		dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_600;
		break;
	case 2:
		dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_800;
		break;
	case 3:
		dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_1200;
		break;
	}
}

static void
parse_device_mapping(struct drm_i915_private *dev_priv,
		       struct bdb_header *bdb)
{
	struct bdb_general_definitions *p_defs;
	struct child_device_config *p_child, *child_dev_ptr;
	int i, child_device_num, count;
	u16	block_size;

	p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
	if (!p_defs) {
		DRM_DEBUG_KMS("No general definition block is found, no devices defined.\n");
		return;
	}
	/* judge whether the size of child device meets the requirements.
	 * If the child device size obtained from general definition block
	 * is different with sizeof(struct child_device_config), skip the
	 * parsing of sdvo device info
	 */
	if (p_defs->child_dev_size != sizeof(*p_child)) {
		/* different child dev size . Ignore it */
		DRM_DEBUG_KMS("different child size is found. Invalid.\n");
		return;
	}
	/* get the block size of general definitions */
	block_size = get_blocksize(p_defs);
	/* get the number of child device */
	child_device_num = (block_size - sizeof(*p_defs)) /
				sizeof(*p_child);
	count = 0;
	/* get the number of child device that is present */
	for (i = 0; i < child_device_num; i++) {
		p_child = &(p_defs->devices[i]);
		if (!p_child->device_type) {
			/* skip the device block if device type is invalid */
			continue;
		}
		count++;
	}
	if (!count) {
		DRM_DEBUG_KMS("no child dev is parsed from VBT\n");
		return;
	}
	dev_priv->child_dev = kcalloc(count, sizeof(*p_child), GFP_KERNEL);
	if (!dev_priv->child_dev) {
		DRM_DEBUG_KMS("No memory space for child device\n");
		return;
	}

	dev_priv->child_dev_num = count;
	count = 0;
	for (i = 0; i < child_device_num; i++) {
		p_child = &(p_defs->devices[i]);
		if (!p_child->device_type) {
			/* skip the device block if device type is invalid */
			continue;
		}
		child_dev_ptr = dev_priv->child_dev + count;
		count++;
		memcpy((void *)child_dev_ptr, (void *)p_child,
					sizeof(*p_child));
	}
	return;
}

static void
init_vbt_defaults(struct drm_i915_private *dev_priv)
{
	struct drm_device *dev = dev_priv->dev;

	dev_priv->crt_ddc_pin = GMBUS_PORT_VGADDC;

	/* LFP panel data */
	dev_priv->lvds_dither = 1;
	dev_priv->lvds_vbt = 0;

	/* SDVO panel data */
	dev_priv->sdvo_lvds_vbt_mode = NULL;

	/* general features */
	dev_priv->int_tv_support = 1;
	dev_priv->int_crt_support = 1;

	/* Default to using SSC */
	dev_priv->lvds_use_ssc = 1;
	dev_priv->lvds_ssc_freq = intel_bios_ssc_frequency(dev, 1);
	DRM_DEBUG_KMS("Set default to SSC at %dMHz\n", dev_priv->lvds_ssc_freq);
}

static int __init intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
{
	DRM_DEBUG_KMS("Falling back to manually reading VBT from "
		      "VBIOS ROM for %s\n",
		      id->ident);
	return 1;
}

static const struct dmi_system_id intel_no_opregion_vbt[] = {
	{
		.callback = intel_no_opregion_vbt_callback,
		.ident = "ThinkCentre A57",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
			DMI_MATCH(DMI_PRODUCT_NAME, "97027RG"),
		},
	},
	{ }
};

/**
 * intel_parse_bios - find VBT and initialize settings from the BIOS
 * @dev: DRM device
 *
 * Loads the Video BIOS and checks that the VBT exists.  Sets scratch registers
 * to appropriate values.
 *
 * Returns 0 on success, nonzero on failure.
 */
int
intel_parse_bios(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct pci_dev *pdev = dev->pdev;
	struct bdb_header *bdb = NULL;
	u8 __iomem *bios = NULL;

	init_vbt_defaults(dev_priv);

	/* XXX Should this validation be moved to intel_opregion.c? */
	if (!dmi_check_system(intel_no_opregion_vbt) && dev_priv->opregion.vbt) {
		struct vbt_header *vbt = dev_priv->opregion.vbt;
		if (memcmp(vbt->signature, "$VBT", 4) == 0) {
			DRM_DEBUG_KMS("Using VBT from OpRegion: %20s\n",
					 vbt->signature);
			bdb = (struct bdb_header *)((char *)vbt + vbt->bdb_offset);
		} else
			dev_priv->opregion.vbt = NULL;
	}

	if (bdb == NULL) {
		struct vbt_header *vbt = NULL;
		size_t size;
		int i;

		bios = pci_map_rom(pdev, &size);
		if (!bios)
			return -1;

		/* Scour memory looking for the VBT signature */
		for (i = 0; i + 4 < size; i++) {
			if (!memcmp(bios + i, "$VBT", 4)) {
				vbt = (struct vbt_header *)(bios + i);
				break;
			}
		}

		if (!vbt) {
			DRM_DEBUG_DRIVER("VBT signature missing\n");
			pci_unmap_rom(pdev, bios);
			return -1;
		}

		bdb = (struct bdb_header *)(bios + i + vbt->bdb_offset);
	}

	/* Grab useful general definitions */
	parse_general_features(dev_priv, bdb);
	parse_general_definitions(dev_priv, bdb);
	parse_lfp_panel_data(dev_priv, bdb);
	parse_sdvo_panel_data(dev_priv, bdb);
	parse_sdvo_device_mapping(dev_priv, bdb);
	parse_device_mapping(dev_priv, bdb);
	parse_driver_features(dev_priv, bdb);
	parse_edp(dev_priv, bdb);

	if (bios)
		pci_unmap_rom(pdev, bios);

	return 0;
}

/* Ensure that vital registers have been initialised, even if the BIOS
 * is absent or just failing to do its job.
 */
void intel_setup_bios(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	 /* Set the Panel Power On/Off timings if uninitialized. */
	if (!HAS_PCH_SPLIT(dev) &&
	    I915_READ(PP_ON_DELAYS) == 0 && I915_READ(PP_OFF_DELAYS) == 0) {
		/* Set T2 to 40ms and T5 to 200ms */
		I915_WRITE(PP_ON_DELAYS, 0x019007d0);

		/* Set T3 to 35ms and Tx to 200ms */
		I915_WRITE(PP_OFF_DELAYS, 0x015e07d0);
	}
}