summaryrefslogtreecommitdiff
path: root/drivers/video/fbmon.c
blob: 94ad0f71383c7fa71563332b3ab0fad9276dd2ab (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
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
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
/*
 * linux/drivers/video/fbmon.c
 *
 * Copyright (C) 2002 James Simmons <jsimmons@users.sf.net>
 *
 * Credits:
 *
 * The EDID Parser is a conglomeration from the following sources:
 *
 *   1. SciTech SNAP Graphics Architecture
 *      Copyright (C) 1991-2002 SciTech Software, Inc. All rights reserved.
 *
 *   2. XFree86 4.3.0, interpret_edid.c
 *      Copyright 1998 by Egbert Eich <Egbert.Eich@Physik.TU-Darmstadt.DE>
 *
 *   3. John Fremlin <vii@users.sourceforge.net> and
 *      Ani Joshi <ajoshi@unixbox.com>
 *
 * Generalized Timing Formula is derived from:
 *
 *      GTF Spreadsheet by Andy Morrish (1/5/97)
 *      available at http://www.vesa.org
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 */
#include <linux/fb.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <video/edid.h>
#include <video/of_videomode.h>
#include <video/videomode.h>
#ifdef CONFIG_PPC_OF
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#endif
#include "edid.h"

/*
 * EDID parser
 */

#undef DEBUG  /* define this for verbose EDID parsing output */

#ifdef DEBUG
#define DPRINTK(fmt, args...) printk(fmt,## args)
#else
#define DPRINTK(fmt, args...)
#endif

#define FBMON_FIX_HEADER  1
#define FBMON_FIX_INPUT   2
#define FBMON_FIX_TIMINGS 3

#ifdef CONFIG_FB_MODE_HELPERS
struct broken_edid {
	u8  manufacturer[4];
	u32 model;
	u32 fix;
};

static const struct broken_edid brokendb[] = {
	/* DEC FR-PCXAV-YZ */
	{
		.manufacturer = "DEC",
		.model        = 0x073a,
		.fix          = FBMON_FIX_HEADER,
	},
	/* ViewSonic PF775a */
	{
		.manufacturer = "VSC",
		.model        = 0x5a44,
		.fix          = FBMON_FIX_INPUT,
	},
	/* Sharp UXGA? */
	{
		.manufacturer = "SHP",
		.model        = 0x138e,
		.fix          = FBMON_FIX_TIMINGS,
	},
};

static const unsigned char edid_v1_header[] = { 0x00, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0x00
};

static void copy_string(unsigned char *c, unsigned char *s)
{
  int i;
  c = c + 5;
  for (i = 0; (i < 13 && *c != 0x0A); i++)
    *(s++) = *(c++);
  *s = 0;
  while (i-- && (*--s == 0x20)) *s = 0;
}

static int edid_is_serial_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xff) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_ascii_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xfe) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_limits_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xfd) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_monitor_block(unsigned char *block)
{
	if ((block[0] == 0x00) && (block[1] == 0x00) &&
	    (block[2] == 0x00) && (block[3] == 0xfc) &&
	    (block[4] == 0x00))
		return 1;
	else
		return 0;
}

static int edid_is_timing_block(unsigned char *block)
{
	if ((block[0] != 0x00) || (block[1] != 0x00) ||
	    (block[2] != 0x00) || (block[4] != 0x00))
		return 1;
	else
		return 0;
}

static int check_edid(unsigned char *edid)
{
	unsigned char *block = edid + ID_MANUFACTURER_NAME, manufacturer[4];
	unsigned char *b;
	u32 model;
	int i, fix = 0, ret = 0;

	manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
	manufacturer[1] = ((block[0] & 0x03) << 3) +
		((block[1] & 0xe0) >> 5) + '@';
	manufacturer[2] = (block[1] & 0x1f) + '@';
	manufacturer[3] = 0;
	model = block[2] + (block[3] << 8);

	for (i = 0; i < ARRAY_SIZE(brokendb); i++) {
		if (!strncmp(manufacturer, brokendb[i].manufacturer, 4) &&
			brokendb[i].model == model) {
			fix = brokendb[i].fix;
			break;
		}
	}

	switch (fix) {
	case FBMON_FIX_HEADER:
		for (i = 0; i < 8; i++) {
			if (edid[i] != edid_v1_header[i]) {
				ret = fix;
				break;
			}
		}
		break;
	case FBMON_FIX_INPUT:
		b = edid + EDID_STRUCT_DISPLAY;
		/* Only if display is GTF capable will
		   the input type be reset to analog */
		if (b[4] & 0x01 && b[0] & 0x80)
			ret = fix;
		break;
	case FBMON_FIX_TIMINGS:
		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
		ret = fix;

		for (i = 0; i < 4; i++) {
			if (edid_is_limits_block(b)) {
				ret = 0;
				break;
			}

			b += DETAILED_TIMING_DESCRIPTION_SIZE;
		}

		break;
	}

	if (ret)
		printk("fbmon: The EDID Block of "
		       "Manufacturer: %s Model: 0x%x is known to "
		       "be broken,\n",  manufacturer, model);

	return ret;
}

static void fix_edid(unsigned char *edid, int fix)
{
	int i;
	unsigned char *b, csum = 0;

	switch (fix) {
	case FBMON_FIX_HEADER:
		printk("fbmon: trying a header reconstruct\n");
		memcpy(edid, edid_v1_header, 8);
		break;
	case FBMON_FIX_INPUT:
		printk("fbmon: trying to fix input type\n");
		b = edid + EDID_STRUCT_DISPLAY;
		b[0] &= ~0x80;
		edid[127] += 0x80;
		break;
	case FBMON_FIX_TIMINGS:
		printk("fbmon: trying to fix monitor timings\n");
		b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
		for (i = 0; i < 4; i++) {
			if (!(edid_is_serial_block(b) ||
			      edid_is_ascii_block(b) ||
			      edid_is_monitor_block(b) ||
			      edid_is_timing_block(b))) {
				b[0] = 0x00;
				b[1] = 0x00;
				b[2] = 0x00;
				b[3] = 0xfd;
				b[4] = 0x00;
				b[5] = 60;   /* vfmin */
				b[6] = 60;   /* vfmax */
				b[7] = 30;   /* hfmin */
				b[8] = 75;   /* hfmax */
				b[9] = 17;   /* pixclock - 170 MHz*/
				b[10] = 0;   /* GTF */
				break;
			}

			b += DETAILED_TIMING_DESCRIPTION_SIZE;
		}

		for (i = 0; i < EDID_LENGTH - 1; i++)
			csum += edid[i];

		edid[127] = 256 - csum;
		break;
	}
}

static int edid_checksum(unsigned char *edid)
{
	unsigned char csum = 0, all_null = 0;
	int i, err = 0, fix = check_edid(edid);

	if (fix)
		fix_edid(edid, fix);

	for (i = 0; i < EDID_LENGTH; i++) {
		csum += edid[i];
		all_null |= edid[i];
	}

	if (csum == 0x00 && all_null) {
		/* checksum passed, everything's good */
		err = 1;
	}

	return err;
}

static int edid_check_header(unsigned char *edid)
{
	int i, err = 1, fix = check_edid(edid);

	if (fix)
		fix_edid(edid, fix);

	for (i = 0; i < 8; i++) {
		if (edid[i] != edid_v1_header[i])
			err = 0;
	}

	return err;
}

static void parse_vendor_block(unsigned char *block, struct fb_monspecs *specs)
{
	specs->manufacturer[0] = ((block[0] & 0x7c) >> 2) + '@';
	specs->manufacturer[1] = ((block[0] & 0x03) << 3) +
		((block[1] & 0xe0) >> 5) + '@';
	specs->manufacturer[2] = (block[1] & 0x1f) + '@';
	specs->manufacturer[3] = 0;
	specs->model = block[2] + (block[3] << 8);
	specs->serial = block[4] + (block[5] << 8) +
	       (block[6] << 16) + (block[7] << 24);
	specs->year = block[9] + 1990;
	specs->week = block[8];
	DPRINTK("   Manufacturer: %s\n", specs->manufacturer);
	DPRINTK("   Model: %x\n", specs->model);
	DPRINTK("   Serial#: %u\n", specs->serial);
	DPRINTK("   Year: %u Week %u\n", specs->year, specs->week);
}

static void get_dpms_capabilities(unsigned char flags,
				  struct fb_monspecs *specs)
{
	specs->dpms = 0;
	if (flags & DPMS_ACTIVE_OFF)
		specs->dpms |= FB_DPMS_ACTIVE_OFF;
	if (flags & DPMS_SUSPEND)
		specs->dpms |= FB_DPMS_SUSPEND;
	if (flags & DPMS_STANDBY)
		specs->dpms |= FB_DPMS_STANDBY;
	DPRINTK("      DPMS: Active %s, Suspend %s, Standby %s\n",
	       (flags & DPMS_ACTIVE_OFF) ? "yes" : "no",
	       (flags & DPMS_SUSPEND)    ? "yes" : "no",
	       (flags & DPMS_STANDBY)    ? "yes" : "no");
}

static void get_chroma(unsigned char *block, struct fb_monspecs *specs)
{
	int tmp;

	DPRINTK("      Chroma\n");
	/* Chromaticity data */
	tmp = ((block[5] & (3 << 6)) >> 6) | (block[0x7] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.redx = tmp/1024;
	DPRINTK("         RedX:     0.%03d ", specs->chroma.redx);

	tmp = ((block[5] & (3 << 4)) >> 4) | (block[0x8] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.redy = tmp/1024;
	DPRINTK("RedY:     0.%03d\n", specs->chroma.redy);

	tmp = ((block[5] & (3 << 2)) >> 2) | (block[0x9] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.greenx = tmp/1024;
	DPRINTK("         GreenX:   0.%03d ", specs->chroma.greenx);

	tmp = (block[5] & 3) | (block[0xa] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.greeny = tmp/1024;
	DPRINTK("GreenY:   0.%03d\n", specs->chroma.greeny);

	tmp = ((block[6] & (3 << 6)) >> 6) | (block[0xb] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.bluex = tmp/1024;
	DPRINTK("         BlueX:    0.%03d ", specs->chroma.bluex);

	tmp = ((block[6] & (3 << 4)) >> 4) | (block[0xc] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.bluey = tmp/1024;
	DPRINTK("BlueY:    0.%03d\n", specs->chroma.bluey);

	tmp = ((block[6] & (3 << 2)) >> 2) | (block[0xd] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.whitex = tmp/1024;
	DPRINTK("         WhiteX:   0.%03d ", specs->chroma.whitex);

	tmp = (block[6] & 3) | (block[0xe] << 2);
	tmp *= 1000;
	tmp += 512;
	specs->chroma.whitey = tmp/1024;
	DPRINTK("WhiteY:   0.%03d\n", specs->chroma.whitey);
}

static void calc_mode_timings(int xres, int yres, int refresh,
			      struct fb_videomode *mode)
{
	struct fb_var_screeninfo *var;

	var = kzalloc(sizeof(struct fb_var_screeninfo), GFP_KERNEL);

	if (var) {
		var->xres = xres;
		var->yres = yres;
		fb_get_mode(FB_VSYNCTIMINGS | FB_IGNOREMON,
			    refresh, var, NULL);
		mode->xres = xres;
		mode->yres = yres;
		mode->pixclock = var->pixclock;
		mode->refresh = refresh;
		mode->left_margin = var->left_margin;
		mode->right_margin = var->right_margin;
		mode->upper_margin = var->upper_margin;
		mode->lower_margin = var->lower_margin;
		mode->hsync_len = var->hsync_len;
		mode->vsync_len = var->vsync_len;
		mode->vmode = 0;
		mode->sync = 0;
		kfree(var);
	}
}

static int get_est_timing(unsigned char *block, struct fb_videomode *mode)
{
	int num = 0;
	unsigned char c;

	c = block[0];
	if (c&0x80) {
		calc_mode_timings(720, 400, 70, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      720x400@70Hz\n");
	}
	if (c&0x40) {
		calc_mode_timings(720, 400, 88, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      720x400@88Hz\n");
	}
	if (c&0x20) {
		mode[num++] = vesa_modes[3];
		DPRINTK("      640x480@60Hz\n");
	}
	if (c&0x10) {
		calc_mode_timings(640, 480, 67, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      640x480@67Hz\n");
	}
	if (c&0x08) {
		mode[num++] = vesa_modes[4];
		DPRINTK("      640x480@72Hz\n");
	}
	if (c&0x04) {
		mode[num++] = vesa_modes[5];
		DPRINTK("      640x480@75Hz\n");
	}
	if (c&0x02) {
		mode[num++] = vesa_modes[7];
		DPRINTK("      800x600@56Hz\n");
	}
	if (c&0x01) {
		mode[num++] = vesa_modes[8];
		DPRINTK("      800x600@60Hz\n");
	}

	c = block[1];
	if (c&0x80) {
		mode[num++] = vesa_modes[9];
		DPRINTK("      800x600@72Hz\n");
	}
	if (c&0x40) {
		mode[num++] = vesa_modes[10];
		DPRINTK("      800x600@75Hz\n");
	}
	if (c&0x20) {
		calc_mode_timings(832, 624, 75, &mode[num]);
		mode[num++].flag = FB_MODE_IS_CALCULATED;
		DPRINTK("      832x624@75Hz\n");
	}
	if (c&0x10) {
		mode[num++] = vesa_modes[12];
		DPRINTK("      1024x768@87Hz Interlaced\n");
	}
	if (c&0x08) {
		mode[num++] = vesa_modes[13];
		DPRINTK("      1024x768@60Hz\n");
	}
	if (c&0x04) {
		mode[num++] = vesa_modes[14];
		DPRINTK("      1024x768@70Hz\n");
	}
	if (c&0x02) {
		mode[num++] = vesa_modes[15];
		DPRINTK("      1024x768@75Hz\n");
	}
	if (c&0x01) {
		mode[num++] = vesa_modes[21];
		DPRINTK("      1280x1024@75Hz\n");
	}
	c = block[2];
	if (c&0x80) {
		mode[num++] = vesa_modes[17];
		DPRINTK("      1152x870@75Hz\n");
	}
	DPRINTK("      Manufacturer's mask: %x\n",c&0x7F);
	return num;
}

static int get_std_timing(unsigned char *block, struct fb_videomode *mode,
		int ver, int rev)
{
	int xres, yres = 0, refresh, ratio, i;

	xres = (block[0] + 31) * 8;
	if (xres <= 256)
		return 0;

	ratio = (block[1] & 0xc0) >> 6;
	switch (ratio) {
	case 0:
		/* in EDID 1.3 the meaning of 0 changed to 16:10 (prior 1:1) */
		if (ver < 1 || (ver == 1 && rev < 3))
			yres = xres;
		else
			yres = (xres * 10)/16;
		break;
	case 1:
		yres = (xres * 3)/4;
		break;
	case 2:
		yres = (xres * 4)/5;
		break;
	case 3:
		yres = (xres * 9)/16;
		break;
	}
	refresh = (block[1] & 0x3f) + 60;

	DPRINTK("      %dx%d@%dHz\n", xres, yres, refresh);
	for (i = 0; i < VESA_MODEDB_SIZE; i++) {
		if (vesa_modes[i].xres == xres &&
		    vesa_modes[i].yres == yres &&
		    vesa_modes[i].refresh == refresh) {
			*mode = vesa_modes[i];
			mode->flag |= FB_MODE_IS_STANDARD;
			return 1;
		}
	}
	calc_mode_timings(xres, yres, refresh, mode);
	return 1;
}

static int get_dst_timing(unsigned char *block,
			  struct fb_videomode *mode, int ver, int rev)
{
	int j, num = 0;

	for (j = 0; j < 6; j++, block += STD_TIMING_DESCRIPTION_SIZE)
		num += get_std_timing(block, &mode[num], ver, rev);

	return num;
}

static void get_detailed_timing(unsigned char *block,
				struct fb_videomode *mode)
{
	mode->xres = H_ACTIVE;
	mode->yres = V_ACTIVE;
	mode->pixclock = PIXEL_CLOCK;
	mode->pixclock /= 1000;
	mode->pixclock = KHZ2PICOS(mode->pixclock);
	mode->right_margin = H_SYNC_OFFSET;
	mode->left_margin = (H_ACTIVE + H_BLANKING) -
		(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
	mode->upper_margin = V_BLANKING - V_SYNC_OFFSET -
		V_SYNC_WIDTH;
	mode->lower_margin = V_SYNC_OFFSET;
	mode->hsync_len = H_SYNC_WIDTH;
	mode->vsync_len = V_SYNC_WIDTH;
	if (HSYNC_POSITIVE)
		mode->sync |= FB_SYNC_HOR_HIGH_ACT;
	if (VSYNC_POSITIVE)
		mode->sync |= FB_SYNC_VERT_HIGH_ACT;
	mode->refresh = PIXEL_CLOCK/((H_ACTIVE + H_BLANKING) *
				     (V_ACTIVE + V_BLANKING));
	if (INTERLACED) {
		mode->yres *= 2;
		mode->upper_margin *= 2;
		mode->lower_margin *= 2;
		mode->vsync_len *= 2;
		mode->vmode |= FB_VMODE_INTERLACED;
	}
	mode->flag = FB_MODE_IS_DETAILED;

	DPRINTK("      %d MHz ",  PIXEL_CLOCK/1000000);
	DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET,
	       H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
	DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET,
	       V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
	DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-",
	       (VSYNC_POSITIVE) ? "+" : "-");
}

/**
 * fb_create_modedb - create video mode database
 * @edid: EDID data
 * @dbsize: database size
 *
 * RETURNS: struct fb_videomode, @dbsize contains length of database
 *
 * DESCRIPTION:
 * This function builds a mode database using the contents of the EDID
 * data
 */
static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize)
{
	struct fb_videomode *mode, *m;
	unsigned char *block;
	int num = 0, i, first = 1;
	int ver, rev;

	ver = edid[EDID_STRUCT_VERSION];
	rev = edid[EDID_STRUCT_REVISION];

	mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
	if (mode == NULL)
		return NULL;

	if (edid == NULL || !edid_checksum(edid) ||
	    !edid_check_header(edid)) {
		kfree(mode);
		return NULL;
	}

	*dbsize = 0;

	DPRINTK("   Detailed Timings\n");
	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
		if (!(block[0] == 0x00 && block[1] == 0x00)) {
			get_detailed_timing(block, &mode[num]);
			if (first) {
			        mode[num].flag |= FB_MODE_IS_FIRST;
				first = 0;
			}
			num++;
		}
	}

	DPRINTK("   Supported VESA Modes\n");
	block = edid + ESTABLISHED_TIMING_1;
	num += get_est_timing(block, &mode[num]);

	DPRINTK("   Standard Timings\n");
	block = edid + STD_TIMING_DESCRIPTIONS_START;
	for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
		num += get_std_timing(block, &mode[num], ver, rev);

	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
	for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
		if (block[0] == 0x00 && block[1] == 0x00 && block[3] == 0xfa)
			num += get_dst_timing(block + 5, &mode[num], ver, rev);
	}

	/* Yikes, EDID data is totally useless */
	if (!num) {
		kfree(mode);
		return NULL;
	}

	*dbsize = num;
	m = kmalloc(num * sizeof(struct fb_videomode), GFP_KERNEL);
	if (!m)
		return mode;
	memmove(m, mode, num * sizeof(struct fb_videomode));
	kfree(mode);
	return m;
}

/**
 * fb_destroy_modedb - destroys mode database
 * @modedb: mode database to destroy
 *
 * DESCRIPTION:
 * Destroy mode database created by fb_create_modedb
 */
void fb_destroy_modedb(struct fb_videomode *modedb)
{
	kfree(modedb);
}

static int fb_get_monitor_limits(unsigned char *edid, struct fb_monspecs *specs)
{
	int i, retval = 1;
	unsigned char *block;

	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;

	DPRINTK("      Monitor Operating Limits: ");

	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
		if (edid_is_limits_block(block)) {
			specs->hfmin = H_MIN_RATE * 1000;
			specs->hfmax = H_MAX_RATE * 1000;
			specs->vfmin = V_MIN_RATE;
			specs->vfmax = V_MAX_RATE;
			specs->dclkmax = MAX_PIXEL_CLOCK * 1000000;
			specs->gtf = (GTF_SUPPORT) ? 1 : 0;
			retval = 0;
			DPRINTK("From EDID\n");
			break;
		}
	}

	/* estimate monitor limits based on modes supported */
	if (retval) {
		struct fb_videomode *modes, *mode;
		int num_modes, hz, hscan, pixclock;
		int vtotal, htotal;

		modes = fb_create_modedb(edid, &num_modes);
		if (!modes) {
			DPRINTK("None Available\n");
			return 1;
		}

		retval = 0;
		for (i = 0; i < num_modes; i++) {
			mode = &modes[i];
			pixclock = PICOS2KHZ(modes[i].pixclock) * 1000;
			htotal = mode->xres + mode->right_margin + mode->hsync_len
				+ mode->left_margin;
			vtotal = mode->yres + mode->lower_margin + mode->vsync_len
				+ mode->upper_margin;

			if (mode->vmode & FB_VMODE_INTERLACED)
				vtotal /= 2;

			if (mode->vmode & FB_VMODE_DOUBLE)
				vtotal *= 2;

			hscan = (pixclock + htotal / 2) / htotal;
			hscan = (hscan + 500) / 1000 * 1000;
			hz = (hscan + vtotal / 2) / vtotal;

			if (specs->dclkmax == 0 || specs->dclkmax < pixclock)
				specs->dclkmax = pixclock;

			if (specs->dclkmin == 0 || specs->dclkmin > pixclock)
				specs->dclkmin = pixclock;

			if (specs->hfmax == 0 || specs->hfmax < hscan)
				specs->hfmax = hscan;

			if (specs->hfmin == 0 || specs->hfmin > hscan)
				specs->hfmin = hscan;

			if (specs->vfmax == 0 || specs->vfmax < hz)
				specs->vfmax = hz;

			if (specs->vfmin == 0 || specs->vfmin > hz)
				specs->vfmin = hz;
		}
		DPRINTK("Extrapolated\n");
		fb_destroy_modedb(modes);
	}
	DPRINTK("           H: %d-%dKHz V: %d-%dHz DCLK: %dMHz\n",
		specs->hfmin/1000, specs->hfmax/1000, specs->vfmin,
		specs->vfmax, specs->dclkmax/1000000);
	return retval;
}

static void get_monspecs(unsigned char *edid, struct fb_monspecs *specs)
{
	unsigned char c, *block;

	block = edid + EDID_STRUCT_DISPLAY;

	fb_get_monitor_limits(edid, specs);

	c = block[0] & 0x80;
	specs->input = 0;
	if (c) {
		specs->input |= FB_DISP_DDI;
		DPRINTK("      Digital Display Input");
	} else {
		DPRINTK("      Analog Display Input: Input Voltage - ");
		switch ((block[0] & 0x60) >> 5) {
		case 0:
			DPRINTK("0.700V/0.300V");
			specs->input |= FB_DISP_ANA_700_300;
			break;
		case 1:
			DPRINTK("0.714V/0.286V");
			specs->input |= FB_DISP_ANA_714_286;
			break;
		case 2:
			DPRINTK("1.000V/0.400V");
			specs->input |= FB_DISP_ANA_1000_400;
			break;
		case 3:
			DPRINTK("0.700V/0.000V");
			specs->input |= FB_DISP_ANA_700_000;
			break;
		}
	}
	DPRINTK("\n      Sync: ");
	c = block[0] & 0x10;
	if (c)
		DPRINTK("      Configurable signal level\n");
	c = block[0] & 0x0f;
	specs->signal = 0;
	if (c & 0x10) {
		DPRINTK("Blank to Blank ");
		specs->signal |= FB_SIGNAL_BLANK_BLANK;
	}
	if (c & 0x08) {
		DPRINTK("Separate ");
		specs->signal |= FB_SIGNAL_SEPARATE;
	}
	if (c & 0x04) {
		DPRINTK("Composite ");
		specs->signal |= FB_SIGNAL_COMPOSITE;
	}
	if (c & 0x02) {
		DPRINTK("Sync on Green ");
		specs->signal |= FB_SIGNAL_SYNC_ON_GREEN;
	}
	if (c & 0x01) {
		DPRINTK("Serration on ");
		specs->signal |= FB_SIGNAL_SERRATION_ON;
	}
	DPRINTK("\n");
	specs->max_x = block[1];
	specs->max_y = block[2];
	DPRINTK("      Max H-size in cm: ");
	if (specs->max_x)
		DPRINTK("%d\n", specs->max_x);
	else
		DPRINTK("variable\n");
	DPRINTK("      Max V-size in cm: ");
	if (specs->max_y)
		DPRINTK("%d\n", specs->max_y);
	else
		DPRINTK("variable\n");

	c = block[3];
	specs->gamma = c+100;
	DPRINTK("      Gamma: ");
	DPRINTK("%d.%d\n", specs->gamma/100, specs->gamma % 100);

	get_dpms_capabilities(block[4], specs);

	switch ((block[4] & 0x18) >> 3) {
	case 0:
		DPRINTK("      Monochrome/Grayscale\n");
		specs->input |= FB_DISP_MONO;
		break;
	case 1:
		DPRINTK("      RGB Color Display\n");
		specs->input |= FB_DISP_RGB;
		break;
	case 2:
		DPRINTK("      Non-RGB Multicolor Display\n");
		specs->input |= FB_DISP_MULTI;
		break;
	default:
		DPRINTK("      Unknown\n");
		specs->input |= FB_DISP_UNKNOWN;
		break;
	}

	get_chroma(block, specs);

	specs->misc = 0;
	c = block[4] & 0x7;
	if (c & 0x04) {
		DPRINTK("      Default color format is primary\n");
		specs->misc |= FB_MISC_PRIM_COLOR;
	}
	if (c & 0x02) {
		DPRINTK("      First DETAILED Timing is preferred\n");
		specs->misc |= FB_MISC_1ST_DETAIL;
	}
	if (c & 0x01) {
		printk("      Display is GTF capable\n");
		specs->gtf = 1;
	}
}

int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
{
	int i;
	unsigned char *block;

	if (edid == NULL || var == NULL)
		return 1;

	if (!(edid_checksum(edid)))
		return 1;

	if (!(edid_check_header(edid)))
		return 1;

	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;

	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
		if (edid_is_timing_block(block)) {
			var->xres = var->xres_virtual = H_ACTIVE;
			var->yres = var->yres_virtual = V_ACTIVE;
			var->height = var->width = 0;
			var->right_margin = H_SYNC_OFFSET;
			var->left_margin = (H_ACTIVE + H_BLANKING) -
				(H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH);
			var->upper_margin = V_BLANKING - V_SYNC_OFFSET -
				V_SYNC_WIDTH;
			var->lower_margin = V_SYNC_OFFSET;
			var->hsync_len = H_SYNC_WIDTH;
			var->vsync_len = V_SYNC_WIDTH;
			var->pixclock = PIXEL_CLOCK;
			var->pixclock /= 1000;
			var->pixclock = KHZ2PICOS(var->pixclock);

			if (HSYNC_POSITIVE)
				var->sync |= FB_SYNC_HOR_HIGH_ACT;
			if (VSYNC_POSITIVE)
				var->sync |= FB_SYNC_VERT_HIGH_ACT;
			return 0;
		}
	}
	return 1;
}

void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
{
	unsigned char *block;
	int i, found = 0;

	if (edid == NULL)
		return;

	if (!(edid_checksum(edid)))
		return;

	if (!(edid_check_header(edid)))
		return;

	memset(specs, 0, sizeof(struct fb_monspecs));

	specs->version = edid[EDID_STRUCT_VERSION];
	specs->revision = edid[EDID_STRUCT_REVISION];

	DPRINTK("========================================\n");
	DPRINTK("Display Information (EDID)\n");
	DPRINTK("========================================\n");
	DPRINTK("   EDID Version %d.%d\n", (int) specs->version,
	       (int) specs->revision);

	parse_vendor_block(edid + ID_MANUFACTURER_NAME, specs);

	block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
	for (i = 0; i < 4; i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
		if (edid_is_serial_block(block)) {
			copy_string(block, specs->serial_no);
			DPRINTK("   Serial Number: %s\n", specs->serial_no);
		} else if (edid_is_ascii_block(block)) {
			copy_string(block, specs->ascii);
			DPRINTK("   ASCII Block: %s\n", specs->ascii);
		} else if (edid_is_monitor_block(block)) {
			copy_string(block, specs->monitor);
			DPRINTK("   Monitor Name: %s\n", specs->monitor);
		}
	}

	DPRINTK("   Display Characteristics:\n");
	get_monspecs(edid, specs);

	specs->modedb = fb_create_modedb(edid, &specs->modedb_len);

	/*
	 * Workaround for buggy EDIDs that sets that the first
	 * detailed timing is preferred but has not detailed
	 * timing specified
	 */
	for (i = 0; i < specs->modedb_len; i++) {
		if (specs->modedb[i].flag & FB_MODE_IS_DETAILED) {
			found = 1;
			break;
		}
	}

	if (!found)
		specs->misc &= ~FB_MISC_1ST_DETAIL;

	DPRINTK("========================================\n");
}

/**
 * fb_edid_add_monspecs() - add monitor video modes from E-EDID data
 * @edid:	128 byte array with an E-EDID block
 * @spacs:	monitor specs to be extended
 */
void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
{
	unsigned char *block;
	struct fb_videomode *m;
	int num = 0, i;
	u8 svd[64], edt[(128 - 4) / DETAILED_TIMING_DESCRIPTION_SIZE];
	u8 pos = 4, svd_n = 0;

	if (!edid)
		return;

	if (!edid_checksum(edid))
		return;

	if (edid[0] != 0x2 ||
	    edid[2] < 4 || edid[2] > 128 - DETAILED_TIMING_DESCRIPTION_SIZE)
		return;

	DPRINTK("  Short Video Descriptors\n");

	while (pos < edid[2]) {
		u8 len = edid[pos] & 0x1f, type = (edid[pos] >> 5) & 7;
		pr_debug("Data block %u of %u bytes\n", type, len);
		if (type == 2)
			for (i = pos; i < pos + len; i++) {
				u8 idx = edid[pos + i] & 0x7f;
				svd[svd_n++] = idx;
				pr_debug("N%sative mode #%d\n",
					 edid[pos + i] & 0x80 ? "" : "on-n", idx);
			}
		pos += len + 1;
	}

	block = edid + edid[2];

	DPRINTK("  Extended Detailed Timings\n");

	for (i = 0; i < (128 - edid[2]) / DETAILED_TIMING_DESCRIPTION_SIZE;
	     i++, block += DETAILED_TIMING_DESCRIPTION_SIZE)
		if (PIXEL_CLOCK)
			edt[num++] = block - edid;

	/* Yikes, EDID data is totally useless */
	if (!(num + svd_n))
		return;

	m = kzalloc((specs->modedb_len + num + svd_n) *
		       sizeof(struct fb_videomode), GFP_KERNEL);

	if (!m)
		return;

	memcpy(m, specs->modedb, specs->modedb_len * sizeof(struct fb_videomode));

	for (i = specs->modedb_len; i < specs->modedb_len + num; i++) {
		get_detailed_timing(edid + edt[i - specs->modedb_len], &m[i]);
		if (i == specs->modedb_len)
			m[i].flag |= FB_MODE_IS_FIRST;
		pr_debug("Adding %ux%u@%u\n", m[i].xres, m[i].yres, m[i].refresh);
	}

	for (i = specs->modedb_len + num; i < specs->modedb_len + num + svd_n; i++) {
		int idx = svd[i - specs->modedb_len - num];
		if (!idx || idx > 63) {
			pr_warning("Reserved SVD code %d\n", idx);
		} else if (idx > ARRAY_SIZE(cea_modes) || !cea_modes[idx].xres) {
			pr_warning("Unimplemented SVD code %d\n", idx);
		} else {
			memcpy(&m[i], cea_modes + idx, sizeof(m[i]));
			pr_debug("Adding SVD #%d: %ux%u@%u\n", idx,
				 m[i].xres, m[i].yres, m[i].refresh);
		}
	}

	kfree(specs->modedb);
	specs->modedb = m;
	specs->modedb_len = specs->modedb_len + num + svd_n;
}

/*
 * VESA Generalized Timing Formula (GTF)
 */

#define FLYBACK                     550
#define V_FRONTPORCH                1
#define H_OFFSET                    40
#define H_SCALEFACTOR               20
#define H_BLANKSCALE                128
#define H_GRADIENT                  600
#define C_VAL                       30
#define M_VAL                       300

struct __fb_timings {
	u32 dclk;
	u32 hfreq;
	u32 vfreq;
	u32 hactive;
	u32 vactive;
	u32 hblank;
	u32 vblank;
	u32 htotal;
	u32 vtotal;
};

/**
 * fb_get_vblank - get vertical blank time
 * @hfreq: horizontal freq
 *
 * DESCRIPTION:
 * vblank = right_margin + vsync_len + left_margin
 *
 *    given: right_margin = 1 (V_FRONTPORCH)
 *           vsync_len    = 3
 *           flyback      = 550
 *
 *                          flyback * hfreq
 *           left_margin  = --------------- - vsync_len
 *                           1000000
 */
static u32 fb_get_vblank(u32 hfreq)
{
	u32 vblank;

	vblank = (hfreq * FLYBACK)/1000;
	vblank = (vblank + 500)/1000;
	return (vblank + V_FRONTPORCH);
}

/**
 * fb_get_hblank_by_freq - get horizontal blank time given hfreq
 * @hfreq: horizontal freq
 * @xres: horizontal resolution in pixels
 *
 * DESCRIPTION:
 *
 *           xres * duty_cycle
 * hblank = ------------------
 *           100 - duty_cycle
 *
 * duty cycle = percent of htotal assigned to inactive display
 * duty cycle = C - (M/Hfreq)
 *
 * where: C = ((offset - scale factor) * blank_scale)
 *            -------------------------------------- + scale factor
 *                        256
 *        M = blank_scale * gradient
 *
 */
static u32 fb_get_hblank_by_hfreq(u32 hfreq, u32 xres)
{
	u32 c_val, m_val, duty_cycle, hblank;

	c_val = (((H_OFFSET - H_SCALEFACTOR) * H_BLANKSCALE)/256 +
		 H_SCALEFACTOR) * 1000;
	m_val = (H_BLANKSCALE * H_GRADIENT)/256;
	m_val = (m_val * 1000000)/hfreq;
	duty_cycle = c_val - m_val;
	hblank = (xres * duty_cycle)/(100000 - duty_cycle);
	return (hblank);
}

/**
 * fb_get_hblank_by_dclk - get horizontal blank time given pixelclock
 * @dclk: pixelclock in Hz
 * @xres: horizontal resolution in pixels
 *
 * DESCRIPTION:
 *
 *           xres * duty_cycle
 * hblank = ------------------
 *           100 - duty_cycle
 *
 * duty cycle = percent of htotal assigned to inactive display
 * duty cycle = C - (M * h_period)
 *
 * where: h_period = SQRT(100 - C + (0.4 * xres * M)/dclk) + C - 100
 *                   -----------------------------------------------
 *                                    2 * M
 *        M = 300;
 *        C = 30;

 */
static u32 fb_get_hblank_by_dclk(u32 dclk, u32 xres)
{
	u32 duty_cycle, h_period, hblank;

	dclk /= 1000;
	h_period = 100 - C_VAL;
	h_period *= h_period;
	h_period += (M_VAL * xres * 2 * 1000)/(5 * dclk);
	h_period *= 10000;

	h_period = int_sqrt(h_period);
	h_period -= (100 - C_VAL) * 100;
	h_period *= 1000;
	h_period /= 2 * M_VAL;

	duty_cycle = C_VAL * 1000 - (M_VAL * h_period)/100;
	hblank = (xres * duty_cycle)/(100000 - duty_cycle) + 8;
	hblank &= ~15;
	return (hblank);
}

/**
 * fb_get_hfreq - estimate hsync
 * @vfreq: vertical refresh rate
 * @yres: vertical resolution
 *
 * DESCRIPTION:
 *
 *          (yres + front_port) * vfreq * 1000000
 * hfreq = -------------------------------------
 *          (1000000 - (vfreq * FLYBACK)
 *
 */

static u32 fb_get_hfreq(u32 vfreq, u32 yres)
{
	u32 divisor, hfreq;

	divisor = (1000000 - (vfreq * FLYBACK))/1000;
	hfreq = (yres + V_FRONTPORCH) * vfreq  * 1000;
	return (hfreq/divisor);
}

static void fb_timings_vfreq(struct __fb_timings *timings)
{
	timings->hfreq = fb_get_hfreq(timings->vfreq, timings->vactive);
	timings->vblank = fb_get_vblank(timings->hfreq);
	timings->vtotal = timings->vactive + timings->vblank;
	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
						 timings->hactive);
	timings->htotal = timings->hactive + timings->hblank;
	timings->dclk = timings->htotal * timings->hfreq;
}

static void fb_timings_hfreq(struct __fb_timings *timings)
{
	timings->vblank = fb_get_vblank(timings->hfreq);
	timings->vtotal = timings->vactive + timings->vblank;
	timings->vfreq = timings->hfreq/timings->vtotal;
	timings->hblank = fb_get_hblank_by_hfreq(timings->hfreq,
						 timings->hactive);
	timings->htotal = timings->hactive + timings->hblank;
	timings->dclk = timings->htotal * timings->hfreq;
}

static void fb_timings_dclk(struct __fb_timings *timings)
{
	timings->hblank = fb_get_hblank_by_dclk(timings->dclk,
						timings->hactive);
	timings->htotal = timings->hactive + timings->hblank;
	timings->hfreq = timings->dclk/timings->htotal;
	timings->vblank = fb_get_vblank(timings->hfreq);
	timings->vtotal = timings->vactive + timings->vblank;
	timings->vfreq = timings->hfreq/timings->vtotal;
}

/*
 * fb_get_mode - calculates video mode using VESA GTF
 * @flags: if: 0 - maximize vertical refresh rate
 *             1 - vrefresh-driven calculation;
 *             2 - hscan-driven calculation;
 *             3 - pixelclock-driven calculation;
 * @val: depending on @flags, ignored, vrefresh, hsync or pixelclock
 * @var: pointer to fb_var_screeninfo
 * @info: pointer to fb_info
 *
 * DESCRIPTION:
 * Calculates video mode based on monitor specs using VESA GTF.
 * The GTF is best for VESA GTF compliant monitors but is
 * specifically formulated to work for older monitors as well.
 *
 * If @flag==0, the function will attempt to maximize the
 * refresh rate.  Otherwise, it will calculate timings based on
 * the flag and accompanying value.
 *
 * If FB_IGNOREMON bit is set in @flags, monitor specs will be
 * ignored and @var will be filled with the calculated timings.
 *
 * All calculations are based on the VESA GTF Spreadsheet
 * available at VESA's public ftp (http://www.vesa.org).
 *
 * NOTES:
 * The timings generated by the GTF will be different from VESA
 * DMT.  It might be a good idea to keep a table of standard
 * VESA modes as well.  The GTF may also not work for some displays,
 * such as, and especially, analog TV.
 *
 * REQUIRES:
 * A valid info->monspecs, otherwise 'safe numbers' will be used.
 */
int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct __fb_timings *timings;
	u32 interlace = 1, dscan = 1;
	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax, err = 0;


	timings = kzalloc(sizeof(struct __fb_timings), GFP_KERNEL);

	if (!timings)
		return -ENOMEM;

	/*
	 * If monspecs are invalid, use values that are enough
	 * for 640x480@60
	 */
	if (!info || !info->monspecs.hfmax || !info->monspecs.vfmax ||
	    !info->monspecs.dclkmax ||
	    info->monspecs.hfmax < info->monspecs.hfmin ||
	    info->monspecs.vfmax < info->monspecs.vfmin ||
	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
		hfmin = 29000; hfmax = 30000;
		vfmin = 60; vfmax = 60;
		dclkmin = 0; dclkmax = 25000000;
	} else {
		hfmin = info->monspecs.hfmin;
		hfmax = info->monspecs.hfmax;
		vfmin = info->monspecs.vfmin;
		vfmax = info->monspecs.vfmax;
		dclkmin = info->monspecs.dclkmin;
		dclkmax = info->monspecs.dclkmax;
	}

	timings->hactive = var->xres;
	timings->vactive = var->yres;
	if (var->vmode & FB_VMODE_INTERLACED) {
		timings->vactive /= 2;
		interlace = 2;
	}
	if (var->vmode & FB_VMODE_DOUBLE) {
		timings->vactive *= 2;
		dscan = 2;
	}

	switch (flags & ~FB_IGNOREMON) {
	case FB_MAXTIMINGS: /* maximize refresh rate */
		timings->hfreq = hfmax;
		fb_timings_hfreq(timings);
		if (timings->vfreq > vfmax) {
			timings->vfreq = vfmax;
			fb_timings_vfreq(timings);
		}
		if (timings->dclk > dclkmax) {
			timings->dclk = dclkmax;
			fb_timings_dclk(timings);
		}
		break;
	case FB_VSYNCTIMINGS: /* vrefresh driven */
		timings->vfreq = val;
		fb_timings_vfreq(timings);
		break;
	case FB_HSYNCTIMINGS: /* hsync driven */
		timings->hfreq = val;
		fb_timings_hfreq(timings);
		break;
	case FB_DCLKTIMINGS: /* pixelclock driven */
		timings->dclk = PICOS2KHZ(val) * 1000;
		fb_timings_dclk(timings);
		break;
	default:
		err = -EINVAL;

	}

	if (err || (!(flags & FB_IGNOREMON) &&
	    (timings->vfreq < vfmin || timings->vfreq > vfmax ||
	     timings->hfreq < hfmin || timings->hfreq > hfmax ||
	     timings->dclk < dclkmin || timings->dclk > dclkmax))) {
		err = -EINVAL;
	} else {
		var->pixclock = KHZ2PICOS(timings->dclk/1000);
		var->hsync_len = (timings->htotal * 8)/100;
		var->right_margin = (timings->hblank/2) - var->hsync_len;
		var->left_margin = timings->hblank - var->right_margin -
			var->hsync_len;
		var->vsync_len = (3 * interlace)/dscan;
		var->lower_margin = (1 * interlace)/dscan;
		var->upper_margin = (timings->vblank * interlace)/dscan -
			(var->vsync_len + var->lower_margin);
	}

	kfree(timings);
	return err;
}

#if IS_ENABLED(CONFIG_VIDEOMODE)
int fb_videomode_from_videomode(const struct videomode *vm,
				struct fb_videomode *fbmode)
{
	unsigned int htotal, vtotal;

	fbmode->xres = vm->hactive;
	fbmode->left_margin = vm->hback_porch;
	fbmode->right_margin = vm->hfront_porch;
	fbmode->hsync_len = vm->hsync_len;

	fbmode->yres = vm->vactive;
	fbmode->upper_margin = vm->vback_porch;
	fbmode->lower_margin = vm->vfront_porch;
	fbmode->vsync_len = vm->vsync_len;

	/* prevent division by zero in KHZ2PICOS macro */
	fbmode->pixclock = vm->pixelclock ?
			KHZ2PICOS(vm->pixelclock / 1000) : 0;

	fbmode->sync = 0;
	fbmode->vmode = 0;
	if (vm->dmt_flags & VESA_DMT_HSYNC_HIGH)
		fbmode->sync |= FB_SYNC_HOR_HIGH_ACT;
	if (vm->dmt_flags & VESA_DMT_HSYNC_HIGH)
		fbmode->sync |= FB_SYNC_VERT_HIGH_ACT;
	if (vm->data_flags & DISPLAY_FLAGS_INTERLACED)
		fbmode->vmode |= FB_VMODE_INTERLACED;
	if (vm->data_flags & DISPLAY_FLAGS_DOUBLESCAN)
		fbmode->vmode |= FB_VMODE_DOUBLE;
	fbmode->flag = 0;

	htotal = vm->hactive + vm->hfront_porch + vm->hback_porch +
		 vm->hsync_len;
	vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch +
		 vm->vsync_len;
	/* prevent division by zero */
	if (htotal && vtotal) {
		fbmode->refresh = vm->pixelclock / (htotal * vtotal);
	/* a mode must have htotal and vtotal != 0 or it is invalid */
	} else {
		fbmode->refresh = 0;
		return -EINVAL;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(fb_videomode_from_videomode);
#endif

#if IS_ENABLED(CONFIG_OF_VIDEOMODE)
static inline void dump_fb_videomode(const struct fb_videomode *m)
{
	pr_debug("fb_videomode = %ux%u@%uHz (%ukHz) %u %u %u %u %u %u %u %u %u\n",
		 m->xres, m->yres, m->refresh, m->pixclock, m->left_margin,
		 m->right_margin, m->upper_margin, m->lower_margin,
		 m->hsync_len, m->vsync_len, m->sync, m->vmode, m->flag);
}

/**
 * of_get_fb_videomode - get a fb_videomode from devicetree
 * @np: device_node with the timing specification
 * @fb: will be set to the return value
 * @index: index into the list of display timings in devicetree
 *
 * DESCRIPTION:
 * This function is expensive and should only be used, if only one mode is to be
 * read from DT. To get multiple modes start with of_get_display_timings ond
 * work with that instead.
 */
int of_get_fb_videomode(struct device_node *np, struct fb_videomode *fb,
			int index)
{
	struct videomode vm;
	int ret;

	ret = of_get_videomode(np, &vm, index);
	if (ret)
		return ret;

	fb_videomode_from_videomode(&vm, fb);

	pr_debug("%s: got %dx%d display mode from %s\n",
		of_node_full_name(np), vm.hactive, vm.vactive, np->name);
	dump_fb_videomode(fb);

	return 0;
}
EXPORT_SYMBOL_GPL(of_get_fb_videomode);
#endif

#else
int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
{
	return 1;
}
void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs)
{
	specs = NULL;
}
void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
{
}
void fb_destroy_modedb(struct fb_videomode *modedb)
{
}
int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var,
		struct fb_info *info)
{
	return -EINVAL;
}
#endif /* CONFIG_FB_MODE_HELPERS */

/*
 * fb_validate_mode - validates var against monitor capabilities
 * @var: pointer to fb_var_screeninfo
 * @info: pointer to fb_info
 *
 * DESCRIPTION:
 * Validates video mode against monitor capabilities specified in
 * info->monspecs.
 *
 * REQUIRES:
 * A valid info->monspecs.
 */
int fb_validate_mode(const struct fb_var_screeninfo *var, struct fb_info *info)
{
	u32 hfreq, vfreq, htotal, vtotal, pixclock;
	u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;

	/*
	 * If monspecs are invalid, use values that are enough
	 * for 640x480@60
	 */
	if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
	    !info->monspecs.dclkmax ||
	    info->monspecs.hfmax < info->monspecs.hfmin ||
	    info->monspecs.vfmax < info->monspecs.vfmin ||
	    info->monspecs.dclkmax < info->monspecs.dclkmin) {
		hfmin = 29000; hfmax = 30000;
		vfmin = 60; vfmax = 60;
		dclkmin = 0; dclkmax = 25000000;
	} else {
		hfmin = info->monspecs.hfmin;
		hfmax = info->monspecs.hfmax;
		vfmin = info->monspecs.vfmin;
		vfmax = info->monspecs.vfmax;
		dclkmin = info->monspecs.dclkmin;
		dclkmax = info->monspecs.dclkmax;
	}

	if (!var->pixclock)
		return -EINVAL;
	pixclock = PICOS2KHZ(var->pixclock) * 1000;

	htotal = var->xres + var->right_margin + var->hsync_len +
		var->left_margin;
	vtotal = var->yres + var->lower_margin + var->vsync_len +
		var->upper_margin;

	if (var->vmode & FB_VMODE_INTERLACED)
		vtotal /= 2;
	if (var->vmode & FB_VMODE_DOUBLE)
		vtotal *= 2;

	hfreq = pixclock/htotal;
	hfreq = (hfreq + 500) / 1000 * 1000;

	vfreq = hfreq/vtotal;

	return (vfreq < vfmin || vfreq > vfmax ||
		hfreq < hfmin || hfreq > hfmax ||
		pixclock < dclkmin || pixclock > dclkmax) ?
		-EINVAL : 0;
}

#if defined(CONFIG_FIRMWARE_EDID) && defined(CONFIG_X86)

/*
 * We need to ensure that the EDID block is only returned for
 * the primary graphics adapter.
 */

const unsigned char *fb_firmware_edid(struct device *device)
{
	struct pci_dev *dev = NULL;
	struct resource *res = NULL;
	unsigned char *edid = NULL;

	if (device)
		dev = to_pci_dev(device);

	if (dev)
		res = &dev->resource[PCI_ROM_RESOURCE];

	if (res && res->flags & IORESOURCE_ROM_SHADOW)
		edid = edid_info.dummy;

	return edid;
}
#else
const unsigned char *fb_firmware_edid(struct device *device)
{
	return NULL;
}
#endif
EXPORT_SYMBOL(fb_firmware_edid);

EXPORT_SYMBOL(fb_parse_edid);
EXPORT_SYMBOL(fb_edid_to_monspecs);
EXPORT_SYMBOL(fb_edid_add_monspecs);
EXPORT_SYMBOL(fb_get_mode);
EXPORT_SYMBOL(fb_validate_mode);
EXPORT_SYMBOL(fb_destroy_modedb);