summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/intel_opregion.c
blob: 7acbbbf97833a36cff79bc27b479a9791d5cc574 (plain) (blame)
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
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
/*
 * Copyright 2008 Intel Corporation <hong.liu@intel.com>
 * Copyright 2008 Red Hat <mjg@redhat.com>
 *
 * 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, sub license, 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
 * NON-INFRINGEMENT.  IN NO EVENT SHALL INTEL AND/OR ITS SUPPLIERS 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.
 *
 */

#include <linux/acpi.h>
#include <linux/dmi.h>
#include <acpi/video.h>

#include <drm/drmP.h>
#include <drm/i915_drm.h>
#include "i915_drv.h"
#include "intel_drv.h"

#define OPREGION_HEADER_OFFSET 0
#define OPREGION_ACPI_OFFSET   0x100
#define   ACPI_CLID 0x01ac /* current lid state indicator */
#define   ACPI_CDCK 0x01b0 /* current docking state indicator */
#define OPREGION_SWSCI_OFFSET  0x200
#define OPREGION_ASLE_OFFSET   0x300
#define OPREGION_VBT_OFFSET    0x400
#define OPREGION_ASLE_EXT_OFFSET	0x1C00

#define OPREGION_SIGNATURE "IntelGraphicsMem"
#define MBOX_ACPI      (1<<0)
#define MBOX_SWSCI     (1<<1)
#define MBOX_ASLE      (1<<2)
#define MBOX_ASLE_EXT  (1<<4)

struct opregion_header {
	u8 signature[16];
	u32 size;
	u32 opregion_ver;
	u8 bios_ver[32];
	u8 vbios_ver[16];
	u8 driver_ver[16];
	u32 mboxes;
	u32 driver_model;
	u32 pcon;
	u8 dver[32];
	u8 rsvd[124];
} __packed;

/* OpRegion mailbox #1: public ACPI methods */
struct opregion_acpi {
	u32 drdy;       /* driver readiness */
	u32 csts;       /* notification status */
	u32 cevt;       /* current event */
	u8 rsvd1[20];
	u32 didl[8];    /* supported display devices ID list */
	u32 cpdl[8];    /* currently presented display list */
	u32 cadl[8];    /* currently active display list */
	u32 nadl[8];    /* next active devices list */
	u32 aslp;       /* ASL sleep time-out */
	u32 tidx;       /* toggle table index */
	u32 chpd;       /* current hotplug enable indicator */
	u32 clid;       /* current lid state*/
	u32 cdck;       /* current docking state */
	u32 sxsw;       /* Sx state resume */
	u32 evts;       /* ASL supported events */
	u32 cnot;       /* current OS notification */
	u32 nrdy;       /* driver status */
	u32 did2[7];	/* extended supported display devices ID list */
	u32 cpd2[7];	/* extended attached display devices list */
	u8 rsvd2[4];
} __packed;

/* OpRegion mailbox #2: SWSCI */
struct opregion_swsci {
	u32 scic;       /* SWSCI command|status|data */
	u32 parm;       /* command parameters */
	u32 dslp;       /* driver sleep time-out */
	u8 rsvd[244];
} __packed;

/* OpRegion mailbox #3: ASLE */
struct opregion_asle {
	u32 ardy;       /* driver readiness */
	u32 aslc;       /* ASLE interrupt command */
	u32 tche;       /* technology enabled indicator */
	u32 alsi;       /* current ALS illuminance reading */
	u32 bclp;       /* backlight brightness to set */
	u32 pfit;       /* panel fitting state */
	u32 cblv;       /* current brightness level */
	u16 bclm[20];   /* backlight level duty cycle mapping table */
	u32 cpfm;       /* current panel fitting mode */
	u32 epfm;       /* enabled panel fitting modes */
	u8 plut[74];    /* panel LUT and identifier */
	u32 pfmb;       /* PWM freq and min brightness */
	u32 cddv;       /* color correction default values */
	u32 pcft;       /* power conservation features */
	u32 srot;       /* supported rotation angles */
	u32 iuer;       /* IUER events */
	u64 fdss;
	u32 fdsp;
	u32 stat;
	u64 rvda;	/* Physical address of raw vbt data */
	u32 rvds;	/* Size of raw vbt data */
	u8 rsvd[58];
} __packed;

/* OpRegion mailbox #5: ASLE ext */
struct opregion_asle_ext {
	u32 phed;	/* Panel Header */
	u8 bddc[256];	/* Panel EDID */
	u8 rsvd[764];
} __packed;

/* Driver readiness indicator */
#define ASLE_ARDY_READY		(1 << 0)
#define ASLE_ARDY_NOT_READY	(0 << 0)

/* ASLE Interrupt Command (ASLC) bits */
#define ASLC_SET_ALS_ILLUM		(1 << 0)
#define ASLC_SET_BACKLIGHT		(1 << 1)
#define ASLC_SET_PFIT			(1 << 2)
#define ASLC_SET_PWM_FREQ		(1 << 3)
#define ASLC_SUPPORTED_ROTATION_ANGLES	(1 << 4)
#define ASLC_BUTTON_ARRAY		(1 << 5)
#define ASLC_CONVERTIBLE_INDICATOR	(1 << 6)
#define ASLC_DOCKING_INDICATOR		(1 << 7)
#define ASLC_ISCT_STATE_CHANGE		(1 << 8)
#define ASLC_REQ_MSK			0x1ff
/* response bits */
#define ASLC_ALS_ILLUM_FAILED		(1 << 10)
#define ASLC_BACKLIGHT_FAILED		(1 << 12)
#define ASLC_PFIT_FAILED		(1 << 14)
#define ASLC_PWM_FREQ_FAILED		(1 << 16)
#define ASLC_ROTATION_ANGLES_FAILED	(1 << 18)
#define ASLC_BUTTON_ARRAY_FAILED	(1 << 20)
#define ASLC_CONVERTIBLE_FAILED		(1 << 22)
#define ASLC_DOCKING_FAILED		(1 << 24)
#define ASLC_ISCT_STATE_FAILED		(1 << 26)

/* Technology enabled indicator */
#define ASLE_TCHE_ALS_EN	(1 << 0)
#define ASLE_TCHE_BLC_EN	(1 << 1)
#define ASLE_TCHE_PFIT_EN	(1 << 2)
#define ASLE_TCHE_PFMB_EN	(1 << 3)

/* ASLE backlight brightness to set */
#define ASLE_BCLP_VALID                (1<<31)
#define ASLE_BCLP_MSK          (~(1<<31))

/* ASLE panel fitting request */
#define ASLE_PFIT_VALID         (1<<31)
#define ASLE_PFIT_CENTER (1<<0)
#define ASLE_PFIT_STRETCH_TEXT (1<<1)
#define ASLE_PFIT_STRETCH_GFX (1<<2)

/* PWM frequency and minimum brightness */
#define ASLE_PFMB_BRIGHTNESS_MASK (0xff)
#define ASLE_PFMB_BRIGHTNESS_VALID (1<<8)
#define ASLE_PFMB_PWM_MASK (0x7ffffe00)
#define ASLE_PFMB_PWM_VALID (1<<31)

#define ASLE_CBLV_VALID         (1<<31)

/* IUER */
#define ASLE_IUER_DOCKING		(1 << 7)
#define ASLE_IUER_CONVERTIBLE		(1 << 6)
#define ASLE_IUER_ROTATION_LOCK_BTN	(1 << 4)
#define ASLE_IUER_VOLUME_DOWN_BTN	(1 << 3)
#define ASLE_IUER_VOLUME_UP_BTN		(1 << 2)
#define ASLE_IUER_WINDOWS_BTN		(1 << 1)
#define ASLE_IUER_POWER_BTN		(1 << 0)

/* Software System Control Interrupt (SWSCI) */
#define SWSCI_SCIC_INDICATOR		(1 << 0)
#define SWSCI_SCIC_MAIN_FUNCTION_SHIFT	1
#define SWSCI_SCIC_MAIN_FUNCTION_MASK	(0xf << 1)
#define SWSCI_SCIC_SUB_FUNCTION_SHIFT	8
#define SWSCI_SCIC_SUB_FUNCTION_MASK	(0xff << 8)
#define SWSCI_SCIC_EXIT_PARAMETER_SHIFT	8
#define SWSCI_SCIC_EXIT_PARAMETER_MASK	(0xff << 8)
#define SWSCI_SCIC_EXIT_STATUS_SHIFT	5
#define SWSCI_SCIC_EXIT_STATUS_MASK	(7 << 5)
#define SWSCI_SCIC_EXIT_STATUS_SUCCESS	1

#define SWSCI_FUNCTION_CODE(main, sub) \
	((main) << SWSCI_SCIC_MAIN_FUNCTION_SHIFT | \
	 (sub) << SWSCI_SCIC_SUB_FUNCTION_SHIFT)

/* SWSCI: Get BIOS Data (GBDA) */
#define SWSCI_GBDA			4
#define SWSCI_GBDA_SUPPORTED_CALLS	SWSCI_FUNCTION_CODE(SWSCI_GBDA, 0)
#define SWSCI_GBDA_REQUESTED_CALLBACKS	SWSCI_FUNCTION_CODE(SWSCI_GBDA, 1)
#define SWSCI_GBDA_BOOT_DISPLAY_PREF	SWSCI_FUNCTION_CODE(SWSCI_GBDA, 4)
#define SWSCI_GBDA_PANEL_DETAILS	SWSCI_FUNCTION_CODE(SWSCI_GBDA, 5)
#define SWSCI_GBDA_TV_STANDARD		SWSCI_FUNCTION_CODE(SWSCI_GBDA, 6)
#define SWSCI_GBDA_INTERNAL_GRAPHICS	SWSCI_FUNCTION_CODE(SWSCI_GBDA, 7)
#define SWSCI_GBDA_SPREAD_SPECTRUM	SWSCI_FUNCTION_CODE(SWSCI_GBDA, 10)

/* SWSCI: System BIOS Callbacks (SBCB) */
#define SWSCI_SBCB			6
#define SWSCI_SBCB_SUPPORTED_CALLBACKS	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 0)
#define SWSCI_SBCB_INIT_COMPLETION	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 1)
#define SWSCI_SBCB_PRE_HIRES_SET_MODE	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 3)
#define SWSCI_SBCB_POST_HIRES_SET_MODE	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 4)
#define SWSCI_SBCB_DISPLAY_SWITCH	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 5)
#define SWSCI_SBCB_SET_TV_FORMAT	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 6)
#define SWSCI_SBCB_ADAPTER_POWER_STATE	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 7)
#define SWSCI_SBCB_DISPLAY_POWER_STATE	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 8)
#define SWSCI_SBCB_SET_BOOT_DISPLAY	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 9)
#define SWSCI_SBCB_SET_PANEL_DETAILS	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 10)
#define SWSCI_SBCB_SET_INTERNAL_GFX	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 11)
#define SWSCI_SBCB_POST_HIRES_TO_DOS_FS	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 16)
#define SWSCI_SBCB_SUSPEND_RESUME	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 17)
#define SWSCI_SBCB_SET_SPREAD_SPECTRUM	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 18)
#define SWSCI_SBCB_POST_VBE_PM		SWSCI_FUNCTION_CODE(SWSCI_SBCB, 19)
#define SWSCI_SBCB_ENABLE_DISABLE_AUDIO	SWSCI_FUNCTION_CODE(SWSCI_SBCB, 21)

/*
 * ACPI Specification, Revision 5.0, Appendix B.3.2 _DOD (Enumerate All Devices
 * Attached to the Display Adapter).
 */
#define ACPI_DISPLAY_INDEX_SHIFT		0
#define ACPI_DISPLAY_INDEX_MASK			(0xf << 0)
#define ACPI_DISPLAY_PORT_ATTACHMENT_SHIFT	4
#define ACPI_DISPLAY_PORT_ATTACHMENT_MASK	(0xf << 4)
#define ACPI_DISPLAY_TYPE_SHIFT			8
#define ACPI_DISPLAY_TYPE_MASK			(0xf << 8)
#define ACPI_DISPLAY_TYPE_OTHER			(0 << 8)
#define ACPI_DISPLAY_TYPE_VGA			(1 << 8)
#define ACPI_DISPLAY_TYPE_TV			(2 << 8)
#define ACPI_DISPLAY_TYPE_EXTERNAL_DIGITAL	(3 << 8)
#define ACPI_DISPLAY_TYPE_INTERNAL_DIGITAL	(4 << 8)
#define ACPI_VENDOR_SPECIFIC_SHIFT		12
#define ACPI_VENDOR_SPECIFIC_MASK		(0xf << 12)
#define ACPI_BIOS_CAN_DETECT			(1 << 16)
#define ACPI_DEPENDS_ON_VGA			(1 << 17)
#define ACPI_PIPE_ID_SHIFT			18
#define ACPI_PIPE_ID_MASK			(7 << 18)
#define ACPI_DEVICE_ID_SCHEME			(1 << 31)

#define MAX_DSLP	1500

static int swsci(struct drm_i915_private *dev_priv,
		 u32 function, u32 parm, u32 *parm_out)
{
	struct opregion_swsci *swsci = dev_priv->opregion.swsci;
	struct pci_dev *pdev = dev_priv->drm.pdev;
	u32 main_function, sub_function, scic;
	u16 swsci_val;
	u32 dslp;

	if (!swsci)
		return -ENODEV;

	main_function = (function & SWSCI_SCIC_MAIN_FUNCTION_MASK) >>
		SWSCI_SCIC_MAIN_FUNCTION_SHIFT;
	sub_function = (function & SWSCI_SCIC_SUB_FUNCTION_MASK) >>
		SWSCI_SCIC_SUB_FUNCTION_SHIFT;

	/* Check if we can call the function. See swsci_setup for details. */
	if (main_function == SWSCI_SBCB) {
		if ((dev_priv->opregion.swsci_sbcb_sub_functions &
		     (1 << sub_function)) == 0)
			return -EINVAL;
	} else if (main_function == SWSCI_GBDA) {
		if ((dev_priv->opregion.swsci_gbda_sub_functions &
		     (1 << sub_function)) == 0)
			return -EINVAL;
	}

	/* Driver sleep timeout in ms. */
	dslp = swsci->dslp;
	if (!dslp) {
		/* The spec says 2ms should be the default, but it's too small
		 * for some machines. */
		dslp = 50;
	} else if (dslp > MAX_DSLP) {
		/* Hey bios, trust must be earned. */
		DRM_INFO_ONCE("ACPI BIOS requests an excessive sleep of %u ms, "
			      "using %u ms instead\n", dslp, MAX_DSLP);
		dslp = MAX_DSLP;
	}

	/* The spec tells us to do this, but we are the only user... */
	scic = swsci->scic;
	if (scic & SWSCI_SCIC_INDICATOR) {
		DRM_DEBUG_DRIVER("SWSCI request already in progress\n");
		return -EBUSY;
	}

	scic = function | SWSCI_SCIC_INDICATOR;

	swsci->parm = parm;
	swsci->scic = scic;

	/* Ensure SCI event is selected and event trigger is cleared. */
	pci_read_config_word(pdev, SWSCI, &swsci_val);
	if (!(swsci_val & SWSCI_SCISEL) || (swsci_val & SWSCI_GSSCIE)) {
		swsci_val |= SWSCI_SCISEL;
		swsci_val &= ~SWSCI_GSSCIE;
		pci_write_config_word(pdev, SWSCI, swsci_val);
	}

	/* Use event trigger to tell bios to check the mail. */
	swsci_val |= SWSCI_GSSCIE;
	pci_write_config_word(pdev, SWSCI, swsci_val);

	/* Poll for the result. */
#define C (((scic = swsci->scic) & SWSCI_SCIC_INDICATOR) == 0)
	if (wait_for(C, dslp)) {
		DRM_DEBUG_DRIVER("SWSCI request timed out\n");
		return -ETIMEDOUT;
	}

	scic = (scic & SWSCI_SCIC_EXIT_STATUS_MASK) >>
		SWSCI_SCIC_EXIT_STATUS_SHIFT;

	/* Note: scic == 0 is an error! */
	if (scic != SWSCI_SCIC_EXIT_STATUS_SUCCESS) {
		DRM_DEBUG_DRIVER("SWSCI request error %u\n", scic);
		return -EIO;
	}

	if (parm_out)
		*parm_out = swsci->parm;

	return 0;

#undef C
}

#define DISPLAY_TYPE_CRT			0
#define DISPLAY_TYPE_TV				1
#define DISPLAY_TYPE_EXTERNAL_FLAT_PANEL	2
#define DISPLAY_TYPE_INTERNAL_FLAT_PANEL	3

int intel_opregion_notify_encoder(struct intel_encoder *intel_encoder,
				  bool enable)
{
	struct drm_i915_private *dev_priv = to_i915(intel_encoder->base.dev);
	u32 parm = 0;
	u32 type = 0;
	u32 port;

	/* don't care about old stuff for now */
	if (!HAS_DDI(dev_priv))
		return 0;

	if (intel_encoder->type == INTEL_OUTPUT_DSI)
		port = 0;
	else
		port = intel_ddi_get_encoder_port(intel_encoder);

	if (port == PORT_E)  {
		port = 0;
	} else {
		parm |= 1 << port;
		port++;
	}

	if (!enable)
		parm |= 4 << 8;

	switch (intel_encoder->type) {
	case INTEL_OUTPUT_ANALOG:
		type = DISPLAY_TYPE_CRT;
		break;
	case INTEL_OUTPUT_UNKNOWN:
	case INTEL_OUTPUT_DP:
	case INTEL_OUTPUT_HDMI:
	case INTEL_OUTPUT_DP_MST:
		type = DISPLAY_TYPE_EXTERNAL_FLAT_PANEL;
		break;
	case INTEL_OUTPUT_EDP:
	case INTEL_OUTPUT_DSI:
		type = DISPLAY_TYPE_INTERNAL_FLAT_PANEL;
		break;
	default:
		WARN_ONCE(1, "unsupported intel_encoder type %d\n",
			  intel_encoder->type);
		return -EINVAL;
	}

	parm |= type << (16 + port * 3);

	return swsci(dev_priv, SWSCI_SBCB_DISPLAY_POWER_STATE, parm, NULL);
}

static const struct {
	pci_power_t pci_power_state;
	u32 parm;
} power_state_map[] = {
	{ PCI_D0,	0x00 },
	{ PCI_D1,	0x01 },
	{ PCI_D2,	0x02 },
	{ PCI_D3hot,	0x04 },
	{ PCI_D3cold,	0x04 },
};

int intel_opregion_notify_adapter(struct drm_i915_private *dev_priv,
				  pci_power_t state)
{
	int i;

	if (!HAS_DDI(dev_priv))
		return 0;

	for (i = 0; i < ARRAY_SIZE(power_state_map); i++) {
		if (state == power_state_map[i].pci_power_state)
			return swsci(dev_priv, SWSCI_SBCB_ADAPTER_POWER_STATE,
				     power_state_map[i].parm, NULL);
	}

	return -EINVAL;
}

static u32 asle_set_backlight(struct drm_i915_private *dev_priv, u32 bclp)
{
	struct intel_connector *connector;
	struct opregion_asle *asle = dev_priv->opregion.asle;
	struct drm_device *dev = &dev_priv->drm;

	DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);

	if (acpi_video_get_backlight_type() == acpi_backlight_native) {
		DRM_DEBUG_KMS("opregion backlight request ignored\n");
		return 0;
	}

	if (!(bclp & ASLE_BCLP_VALID))
		return ASLC_BACKLIGHT_FAILED;

	bclp &= ASLE_BCLP_MSK;
	if (bclp > 255)
		return ASLC_BACKLIGHT_FAILED;

	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);

	/*
	 * Update backlight on all connectors that support backlight (usually
	 * only one).
	 */
	DRM_DEBUG_KMS("updating opregion backlight %d/255\n", bclp);
	for_each_intel_connector(dev, connector)
		intel_panel_set_backlight_acpi(connector, bclp, 255);
	asle->cblv = DIV_ROUND_UP(bclp * 100, 255) | ASLE_CBLV_VALID;

	drm_modeset_unlock(&dev->mode_config.connection_mutex);


	return 0;
}

static u32 asle_set_als_illum(struct drm_i915_private *dev_priv, u32 alsi)
{
	/* alsi is the current ALS reading in lux. 0 indicates below sensor
	   range, 0xffff indicates above sensor range. 1-0xfffe are valid */
	DRM_DEBUG_DRIVER("Illum is not supported\n");
	return ASLC_ALS_ILLUM_FAILED;
}

static u32 asle_set_pwm_freq(struct drm_i915_private *dev_priv, u32 pfmb)
{
	DRM_DEBUG_DRIVER("PWM freq is not supported\n");
	return ASLC_PWM_FREQ_FAILED;
}

static u32 asle_set_pfit(struct drm_i915_private *dev_priv, u32 pfit)
{
	/* Panel fitting is currently controlled by the X code, so this is a
	   noop until modesetting support works fully */
	DRM_DEBUG_DRIVER("Pfit is not supported\n");
	return ASLC_PFIT_FAILED;
}

static u32 asle_set_supported_rotation_angles(struct drm_i915_private *dev_priv, u32 srot)
{
	DRM_DEBUG_DRIVER("SROT is not supported\n");
	return ASLC_ROTATION_ANGLES_FAILED;
}

static u32 asle_set_button_array(struct drm_i915_private *dev_priv, u32 iuer)
{
	if (!iuer)
		DRM_DEBUG_DRIVER("Button array event is not supported (nothing)\n");
	if (iuer & ASLE_IUER_ROTATION_LOCK_BTN)
		DRM_DEBUG_DRIVER("Button array event is not supported (rotation lock)\n");
	if (iuer & ASLE_IUER_VOLUME_DOWN_BTN)
		DRM_DEBUG_DRIVER("Button array event is not supported (volume down)\n");
	if (iuer & ASLE_IUER_VOLUME_UP_BTN)
		DRM_DEBUG_DRIVER("Button array event is not supported (volume up)\n");
	if (iuer & ASLE_IUER_WINDOWS_BTN)
		DRM_DEBUG_DRIVER("Button array event is not supported (windows)\n");
	if (iuer & ASLE_IUER_POWER_BTN)
		DRM_DEBUG_DRIVER("Button array event is not supported (power)\n");

	return ASLC_BUTTON_ARRAY_FAILED;
}

static u32 asle_set_convertible(struct drm_i915_private *dev_priv, u32 iuer)
{
	if (iuer & ASLE_IUER_CONVERTIBLE)
		DRM_DEBUG_DRIVER("Convertible is not supported (clamshell)\n");
	else
		DRM_DEBUG_DRIVER("Convertible is not supported (slate)\n");

	return ASLC_CONVERTIBLE_FAILED;
}

static u32 asle_set_docking(struct drm_i915_private *dev_priv, u32 iuer)
{
	if (iuer & ASLE_IUER_DOCKING)
		DRM_DEBUG_DRIVER("Docking is not supported (docked)\n");
	else
		DRM_DEBUG_DRIVER("Docking is not supported (undocked)\n");

	return ASLC_DOCKING_FAILED;
}

static u32 asle_isct_state(struct drm_i915_private *dev_priv)
{
	DRM_DEBUG_DRIVER("ISCT is not supported\n");
	return ASLC_ISCT_STATE_FAILED;
}

static void asle_work(struct work_struct *work)
{
	struct intel_opregion *opregion =
		container_of(work, struct intel_opregion, asle_work);
	struct drm_i915_private *dev_priv =
		container_of(opregion, struct drm_i915_private, opregion);
	struct opregion_asle *asle = dev_priv->opregion.asle;
	u32 aslc_stat = 0;
	u32 aslc_req;

	if (!asle)
		return;

	aslc_req = asle->aslc;

	if (!(aslc_req & ASLC_REQ_MSK)) {
		DRM_DEBUG_DRIVER("No request on ASLC interrupt 0x%08x\n",
				 aslc_req);
		return;
	}

	if (aslc_req & ASLC_SET_ALS_ILLUM)
		aslc_stat |= asle_set_als_illum(dev_priv, asle->alsi);

	if (aslc_req & ASLC_SET_BACKLIGHT)
		aslc_stat |= asle_set_backlight(dev_priv, asle->bclp);

	if (aslc_req & ASLC_SET_PFIT)
		aslc_stat |= asle_set_pfit(dev_priv, asle->pfit);

	if (aslc_req & ASLC_SET_PWM_FREQ)
		aslc_stat |= asle_set_pwm_freq(dev_priv, asle->pfmb);

	if (aslc_req & ASLC_SUPPORTED_ROTATION_ANGLES)
		aslc_stat |= asle_set_supported_rotation_angles(dev_priv,
							asle->srot);

	if (aslc_req & ASLC_BUTTON_ARRAY)
		aslc_stat |= asle_set_button_array(dev_priv, asle->iuer);

	if (aslc_req & ASLC_CONVERTIBLE_INDICATOR)
		aslc_stat |= asle_set_convertible(dev_priv, asle->iuer);

	if (aslc_req & ASLC_DOCKING_INDICATOR)
		aslc_stat |= asle_set_docking(dev_priv, asle->iuer);

	if (aslc_req & ASLC_ISCT_STATE_CHANGE)
		aslc_stat |= asle_isct_state(dev_priv);

	asle->aslc = aslc_stat;
}

void intel_opregion_asle_intr(struct drm_i915_private *dev_priv)
{
	if (dev_priv->opregion.asle)
		schedule_work(&dev_priv->opregion.asle_work);
}

#define ACPI_EV_DISPLAY_SWITCH (1<<0)
#define ACPI_EV_LID            (1<<1)
#define ACPI_EV_DOCK           (1<<2)

static struct intel_opregion *system_opregion;

static int intel_opregion_video_event(struct notifier_block *nb,
				      unsigned long val, void *data)
{
	/* The only video events relevant to opregion are 0x80. These indicate
	   either a docking event, lid switch or display switch request. In
	   Linux, these are handled by the dock, button and video drivers.
	*/

	struct acpi_bus_event *event = data;
	struct opregion_acpi *acpi;
	int ret = NOTIFY_OK;

	if (strcmp(event->device_class, ACPI_VIDEO_CLASS) != 0)
		return NOTIFY_DONE;

	if (!system_opregion)
		return NOTIFY_DONE;

	acpi = system_opregion->acpi;

	if (event->type == 0x80 && ((acpi->cevt & 1) == 0))
		ret = NOTIFY_BAD;

	acpi->csts = 0;

	return ret;
}

static struct notifier_block intel_opregion_notifier = {
	.notifier_call = intel_opregion_video_event,
};

/*
 * Initialise the DIDL field in opregion. This passes a list of devices to
 * the firmware. Values are defined by section B.4.2 of the ACPI specification
 * (version 3)
 */

static u32 get_did(struct intel_opregion *opregion, int i)
{
	u32 did;

	if (i < ARRAY_SIZE(opregion->acpi->didl)) {
		did = opregion->acpi->didl[i];
	} else {
		i -= ARRAY_SIZE(opregion->acpi->didl);

		if (WARN_ON(i >= ARRAY_SIZE(opregion->acpi->did2)))
			return 0;

		did = opregion->acpi->did2[i];
	}

	return did;
}

static void set_did(struct intel_opregion *opregion, int i, u32 val)
{
	if (i < ARRAY_SIZE(opregion->acpi->didl)) {
		opregion->acpi->didl[i] = val;
	} else {
		i -= ARRAY_SIZE(opregion->acpi->didl);

		if (WARN_ON(i >= ARRAY_SIZE(opregion->acpi->did2)))
			return;

		opregion->acpi->did2[i] = val;
	}
}

static u32 acpi_display_type(struct drm_connector *connector)
{
	u32 display_type;

	switch (connector->connector_type) {
	case DRM_MODE_CONNECTOR_VGA:
	case DRM_MODE_CONNECTOR_DVIA:
		display_type = ACPI_DISPLAY_TYPE_VGA;
		break;
	case DRM_MODE_CONNECTOR_Composite:
	case DRM_MODE_CONNECTOR_SVIDEO:
	case DRM_MODE_CONNECTOR_Component:
	case DRM_MODE_CONNECTOR_9PinDIN:
	case DRM_MODE_CONNECTOR_TV:
		display_type = ACPI_DISPLAY_TYPE_TV;
		break;
	case DRM_MODE_CONNECTOR_DVII:
	case DRM_MODE_CONNECTOR_DVID:
	case DRM_MODE_CONNECTOR_DisplayPort:
	case DRM_MODE_CONNECTOR_HDMIA:
	case DRM_MODE_CONNECTOR_HDMIB:
		display_type = ACPI_DISPLAY_TYPE_EXTERNAL_DIGITAL;
		break;
	case DRM_MODE_CONNECTOR_LVDS:
	case DRM_MODE_CONNECTOR_eDP:
	case DRM_MODE_CONNECTOR_DSI:
		display_type = ACPI_DISPLAY_TYPE_INTERNAL_DIGITAL;
		break;
	case DRM_MODE_CONNECTOR_Unknown:
	case DRM_MODE_CONNECTOR_VIRTUAL:
		display_type = ACPI_DISPLAY_TYPE_OTHER;
		break;
	default:
		MISSING_CASE(connector->connector_type);
		display_type = ACPI_DISPLAY_TYPE_OTHER;
		break;
	}

	return display_type;
}

static void intel_didl_outputs(struct drm_i915_private *dev_priv)
{
	struct intel_opregion *opregion = &dev_priv->opregion;
	struct pci_dev *pdev = dev_priv->drm.pdev;
	struct drm_connector *connector;
	acpi_handle handle;
	struct acpi_device *acpi_dev, *acpi_cdev, *acpi_video_bus = NULL;
	unsigned long long device_id;
	acpi_status status;
	u32 temp, max_outputs;
	int i = 0;

	handle = ACPI_HANDLE(&pdev->dev);
	if (!handle || acpi_bus_get_device(handle, &acpi_dev))
		return;

	if (acpi_is_video_device(handle))
		acpi_video_bus = acpi_dev;
	else {
		list_for_each_entry(acpi_cdev, &acpi_dev->children, node) {
			if (acpi_is_video_device(acpi_cdev->handle)) {
				acpi_video_bus = acpi_cdev;
				break;
			}
		}
	}

	if (!acpi_video_bus) {
		DRM_DEBUG_KMS("No ACPI video bus found\n");
		return;
	}

	/*
	 * In theory, did2, the extended didl, gets added at opregion version
	 * 3.0. In practice, however, we're supposed to set it for earlier
	 * versions as well, since a BIOS that doesn't understand did2 should
	 * not look at it anyway. Use a variable so we can tweak this if a need
	 * arises later.
	 */
	max_outputs = ARRAY_SIZE(opregion->acpi->didl) +
		ARRAY_SIZE(opregion->acpi->did2);

	list_for_each_entry(acpi_cdev, &acpi_video_bus->children, node) {
		if (i >= max_outputs) {
			DRM_DEBUG_KMS("More than %u outputs detected via ACPI\n",
				      max_outputs);
			return;
		}
		status = acpi_evaluate_integer(acpi_cdev->handle, "_ADR",
					       NULL, &device_id);
		if (ACPI_SUCCESS(status)) {
			if (!device_id)
				goto blind_set;
			set_did(opregion, i++, (u32)(device_id & 0x0f0f));
		}
	}

end:
	DRM_DEBUG_KMS("%d outputs detected\n", i);

	/* If fewer than max outputs, the list must be null terminated */
	if (i < max_outputs)
		set_did(opregion, i, 0);
	return;

blind_set:
	i = 0;
	list_for_each_entry(connector,
			    &dev_priv->drm.mode_config.connector_list, head) {
		int display_type = acpi_display_type(connector);

		if (i >= max_outputs) {
			DRM_DEBUG_KMS("More than %u outputs in connector list\n",
				      max_outputs);
			return;
		}

		temp = get_did(opregion, i);
		set_did(opregion, i, temp | (1 << 31) | display_type | i);
		i++;
	}
	goto end;
}

static void intel_setup_cadls(struct drm_i915_private *dev_priv)
{
	struct intel_opregion *opregion = &dev_priv->opregion;
	int i = 0;
	u32 disp_id;

	/* Initialize the CADL field by duplicating the DIDL values.
	 * Technically, this is not always correct as display outputs may exist,
	 * but not active. This initialization is necessary for some Clevo
	 * laptops that check this field before processing the brightness and
	 * display switching hotkeys. Just like DIDL, CADL is NULL-terminated if
	 * there are less than eight devices. */
	do {
		disp_id = get_did(opregion, i);
		opregion->acpi->cadl[i] = disp_id;
	} while (++i < 8 && disp_id != 0);
}

void intel_opregion_register(struct drm_i915_private *dev_priv)
{
	struct intel_opregion *opregion = &dev_priv->opregion;

	if (!opregion->header)
		return;

	if (opregion->acpi) {
		intel_didl_outputs(dev_priv);
		intel_setup_cadls(dev_priv);

		/* Notify BIOS we are ready to handle ACPI video ext notifs.
		 * Right now, all the events are handled by the ACPI video module.
		 * We don't actually need to do anything with them. */
		opregion->acpi->csts = 0;
		opregion->acpi->drdy = 1;

		system_opregion = opregion;
		register_acpi_notifier(&intel_opregion_notifier);
	}

	if (opregion->asle) {
		opregion->asle->tche = ASLE_TCHE_BLC_EN;
		opregion->asle->ardy = ASLE_ARDY_READY;
	}
}

void intel_opregion_unregister(struct drm_i915_private *dev_priv)
{
	struct intel_opregion *opregion = &dev_priv->opregion;

	if (!opregion->header)
		return;

	if (opregion->asle)
		opregion->asle->ardy = ASLE_ARDY_NOT_READY;

	cancel_work_sync(&dev_priv->opregion.asle_work);

	if (opregion->acpi) {
		opregion->acpi->drdy = 0;

		system_opregion = NULL;
		unregister_acpi_notifier(&intel_opregion_notifier);
	}

	/* just clear all opregion memory pointers now */
	memunmap(opregion->header);
	if (opregion->rvda) {
		memunmap(opregion->rvda);
		opregion->rvda = NULL;
	}
	opregion->header = NULL;
	opregion->acpi = NULL;
	opregion->swsci = NULL;
	opregion->asle = NULL;
	opregion->vbt = NULL;
	opregion->lid_state = NULL;
}

static void swsci_setup(struct drm_i915_private *dev_priv)
{
	struct intel_opregion *opregion = &dev_priv->opregion;
	bool requested_callbacks = false;
	u32 tmp;

	/* Sub-function code 0 is okay, let's allow them. */
	opregion->swsci_gbda_sub_functions = 1;
	opregion->swsci_sbcb_sub_functions = 1;

	/* We use GBDA to ask for supported GBDA calls. */
	if (swsci(dev_priv, SWSCI_GBDA_SUPPORTED_CALLS, 0, &tmp) == 0) {
		/* make the bits match the sub-function codes */
		tmp <<= 1;
		opregion->swsci_gbda_sub_functions |= tmp;
	}

	/*
	 * We also use GBDA to ask for _requested_ SBCB callbacks. The driver
	 * must not call interfaces that are not specifically requested by the
	 * bios.
	 */
	if (swsci(dev_priv, SWSCI_GBDA_REQUESTED_CALLBACKS, 0, &tmp) == 0) {
		/* here, the bits already match sub-function codes */
		opregion->swsci_sbcb_sub_functions |= tmp;
		requested_callbacks = true;
	}

	/*
	 * But we use SBCB to ask for _supported_ SBCB calls. This does not mean
	 * the callback is _requested_. But we still can't call interfaces that
	 * are not requested.
	 */
	if (swsci(dev_priv, SWSCI_SBCB_SUPPORTED_CALLBACKS, 0, &tmp) == 0) {
		/* make the bits match the sub-function codes */
		u32 low = tmp & 0x7ff;
		u32 high = tmp & ~0xfff; /* bit 11 is reserved */
		tmp = (high << 4) | (low << 1) | 1;

		/* best guess what to do with supported wrt requested */
		if (requested_callbacks) {
			u32 req = opregion->swsci_sbcb_sub_functions;
			if ((req & tmp) != req)
				DRM_DEBUG_DRIVER("SWSCI BIOS requested (%08x) SBCB callbacks that are not supported (%08x)\n", req, tmp);
			/* XXX: for now, trust the requested callbacks */
			/* opregion->swsci_sbcb_sub_functions &= tmp; */
		} else {
			opregion->swsci_sbcb_sub_functions |= tmp;
		}
	}

	DRM_DEBUG_DRIVER("SWSCI GBDA callbacks %08x, SBCB callbacks %08x\n",
			 opregion->swsci_gbda_sub_functions,
			 opregion->swsci_sbcb_sub_functions);
}

static int 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"),
		},
	},
	{ }
};

int intel_opregion_setup(struct drm_i915_private *dev_priv)
{
	struct intel_opregion *opregion = &dev_priv->opregion;
	struct pci_dev *pdev = dev_priv->drm.pdev;
	u32 asls, mboxes;
	char buf[sizeof(OPREGION_SIGNATURE)];
	int err = 0;
	void *base;

	BUILD_BUG_ON(sizeof(struct opregion_header) != 0x100);
	BUILD_BUG_ON(sizeof(struct opregion_acpi) != 0x100);
	BUILD_BUG_ON(sizeof(struct opregion_swsci) != 0x100);
	BUILD_BUG_ON(sizeof(struct opregion_asle) != 0x100);
	BUILD_BUG_ON(sizeof(struct opregion_asle_ext) != 0x400);

	pci_read_config_dword(pdev, ASLS, &asls);
	DRM_DEBUG_DRIVER("graphic opregion physical addr: 0x%x\n", asls);
	if (asls == 0) {
		DRM_DEBUG_DRIVER("ACPI OpRegion not supported!\n");
		return -ENOTSUPP;
	}

	INIT_WORK(&opregion->asle_work, asle_work);

	base = memremap(asls, OPREGION_SIZE, MEMREMAP_WB);
	if (!base)
		return -ENOMEM;

	memcpy(buf, base, sizeof(buf));

	if (memcmp(buf, OPREGION_SIGNATURE, 16)) {
		DRM_DEBUG_DRIVER("opregion signature mismatch\n");
		err = -EINVAL;
		goto err_out;
	}
	opregion->header = base;
	opregion->lid_state = base + ACPI_CLID;

	mboxes = opregion->header->mboxes;
	if (mboxes & MBOX_ACPI) {
		DRM_DEBUG_DRIVER("Public ACPI methods supported\n");
		opregion->acpi = base + OPREGION_ACPI_OFFSET;
	}

	if (mboxes & MBOX_SWSCI) {
		DRM_DEBUG_DRIVER("SWSCI supported\n");
		opregion->swsci = base + OPREGION_SWSCI_OFFSET;
		swsci_setup(dev_priv);
	}

	if (mboxes & MBOX_ASLE) {
		DRM_DEBUG_DRIVER("ASLE supported\n");
		opregion->asle = base + OPREGION_ASLE_OFFSET;

		opregion->asle->ardy = ASLE_ARDY_NOT_READY;
	}

	if (mboxes & MBOX_ASLE_EXT)
		DRM_DEBUG_DRIVER("ASLE extension supported\n");

	if (!dmi_check_system(intel_no_opregion_vbt)) {
		const void *vbt = NULL;
		u32 vbt_size = 0;

		if (opregion->header->opregion_ver >= 2 && opregion->asle &&
		    opregion->asle->rvda && opregion->asle->rvds) {
			opregion->rvda = memremap(opregion->asle->rvda,
						  opregion->asle->rvds,
						  MEMREMAP_WB);
			vbt = opregion->rvda;
			vbt_size = opregion->asle->rvds;
		}

		if (intel_bios_is_valid_vbt(vbt, vbt_size)) {
			DRM_DEBUG_KMS("Found valid VBT in ACPI OpRegion (RVDA)\n");
			opregion->vbt = vbt;
			opregion->vbt_size = vbt_size;
		} else {
			vbt = base + OPREGION_VBT_OFFSET;
			vbt_size = OPREGION_ASLE_EXT_OFFSET - OPREGION_VBT_OFFSET;
			if (intel_bios_is_valid_vbt(vbt, vbt_size)) {
				DRM_DEBUG_KMS("Found valid VBT in ACPI OpRegion (Mailbox #4)\n");
				opregion->vbt = vbt;
				opregion->vbt_size = vbt_size;
			}
		}
	}

	return 0;

err_out:
	memunmap(base);
	return err;
}

static int intel_use_opregion_panel_type_callback(const struct dmi_system_id *id)
{
	DRM_INFO("Using panel type from OpRegion on %s\n", id->ident);
	return 1;
}

static const struct dmi_system_id intel_use_opregion_panel_type[] = {
	{
		.callback = intel_use_opregion_panel_type_callback,
		.ident = "Conrac GmbH IX45GM2",
		.matches = {DMI_MATCH(DMI_SYS_VENDOR, "Conrac GmbH"),
			    DMI_MATCH(DMI_PRODUCT_NAME, "IX45GM2"),
		},
	},
	{ }
};

int
intel_opregion_get_panel_type(struct drm_i915_private *dev_priv)
{
	u32 panel_details;
	int ret;

	ret = swsci(dev_priv, SWSCI_GBDA_PANEL_DETAILS, 0x0, &panel_details);
	if (ret) {
		DRM_DEBUG_KMS("Failed to get panel details from OpRegion (%d)\n",
			      ret);
		return ret;
	}

	ret = (panel_details >> 8) & 0xff;
	if (ret > 0x10) {
		DRM_DEBUG_KMS("Invalid OpRegion panel type 0x%x\n", ret);
		return -EINVAL;
	}

	/* fall back to VBT panel type? */
	if (ret == 0x0) {
		DRM_DEBUG_KMS("No panel type in OpRegion\n");
		return -ENODEV;
	}

	/*
	 * So far we know that some machined must use it, others must not use it.
	 * There doesn't seem to be any way to determine which way to go, except
	 * via a quirk list :(
	 */
	if (!dmi_check_system(intel_use_opregion_panel_type)) {
		DRM_DEBUG_KMS("Ignoring OpRegion panel type (%d)\n", ret - 1);
		return -ENODEV;
	}

	/*
	 * FIXME On Dell XPS 13 9350 the OpRegion panel type (0) gives us
	 * low vswing for eDP, whereas the VBT panel type (2) gives us normal
	 * vswing instead. Low vswing results in some display flickers, so
	 * let's simply ignore the OpRegion panel type on SKL for now.
	 */
	if (IS_SKYLAKE(dev_priv)) {
		DRM_DEBUG_KMS("Ignoring OpRegion panel type (%d)\n", ret - 1);
		return -ENODEV;
	}

	return ret - 1;
}