summaryrefslogtreecommitdiff
path: root/src/i830_display.c
blob: 39f36376d11a84670a7c827a5e97cc31355d93fb (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
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
/* -*- c-basic-offset: 4 -*- */
/*
 * 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>
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include <math.h>

#include "xf86.h"
#include "i830.h"
#include "i830_bios.h"
#include "i830_display.h"
#include "i830_debug.h"
#include "xf86Modes.h"

typedef struct {
    /* given values */    
    int n;
    int m1, m2;
    int p1, p2;
    /* derived values */
    int	dot;
    int	vco;
    int	m;
    int	p;
} intel_clock_t;

typedef struct {
    int	min, max;
} intel_range_t;

typedef struct {
    int	dot_limit;
    int	p2_slow, p2_fast;
} intel_p2_t;

#define INTEL_P2_NUM		      2

typedef struct {
    intel_range_t   dot, vco, n, m, m1, m2, p, p1;
    intel_p2_t	    p2;
} intel_limit_t;

#define I8XX_DOT_MIN		  25000
#define I8XX_DOT_MAX		 350000
#define I8XX_VCO_MIN		 930000
#define I8XX_VCO_MAX		1400000
#define I8XX_N_MIN		      3
#define I8XX_N_MAX		     16
#define I8XX_M_MIN		     96
#define I8XX_M_MAX		    140
#define I8XX_M1_MIN		     18
#define I8XX_M1_MAX		     26
#define I8XX_M2_MIN		      6
#define I8XX_M2_MAX		     16
#define I8XX_P_MIN		      4
#define I8XX_P_MAX		    128
#define I8XX_P1_MIN		      2
#define I8XX_P1_MAX		     33
#define I8XX_P1_LVDS_MIN	      1
#define I8XX_P1_LVDS_MAX	      6
#define I8XX_P2_SLOW		      4
#define I8XX_P2_FAST		      2
#define I8XX_P2_LVDS_SLOW	      14
#define I8XX_P2_LVDS_FAST	      7
#define I8XX_P2_SLOW_LIMIT	 165000

#define I9XX_DOT_MIN		  20000
#define I9XX_DOT_MAX		 400000
#define I9XX_VCO_MIN		1400000
#define I9XX_VCO_MAX		2800000

/* Haven't found any reason to go this fast, but newer chips support it */
#define I96X_VCO_MAX		3200000

/*
 * These values are taken from the broadwater/crestline PLL spreadsheet.
 * All of the defines here are for the programmed register value, not
 * the 'counter' value (e.g. Ncounter = Nregister + 2)
 */
#define I9XX_N_MIN		      1
#define I9XX_N_MAX		      6
#define I9XX_M_MIN		     70
#define I9XX_M_MAX		    120

/* these two come from the calm1 macro */
#define I9XX_M1_MIN		     10
#define I9XX_M1_MAX		     22
#define I9XX_M2_MIN		      5
#define I9XX_M2_MAX		      9

#define I9XX_P_SDVO_DAC_MIN	      5
#define I9XX_P_SDVO_DAC_MAX	     80
#define I9XX_P_LVDS_MIN		      7
#define I9XX_P_LVDS_MAX		     98
#define I9XX_P1_MIN		      1
#define I9XX_P1_MAX		      8
#define I9XX_P2_SDVO_DAC_SLOW		     10
#define I9XX_P2_SDVO_DAC_FAST		      5
#define I9XX_P2_SDVO_DAC_SLOW_LIMIT	 200000
#define I9XX_P2_LVDS_SLOW		     14
#define I9XX_P2_LVDS_FAST		      7
#define I9XX_P2_LVDS_SLOW_LIMIT		 112000

#define INTEL_LIMIT_I8XX_DVO_DAC    0
#define INTEL_LIMIT_I8XX_LVDS	    1
#define INTEL_LIMIT_I9XX_SDVO_DAC   2
#define INTEL_LIMIT_I9XX_LVDS	    3

static const intel_limit_t intel_limits[] = {
    { /* INTEL_LIMIT_I8XX_DVO_DAC */
        .dot = { .min = I8XX_DOT_MIN,		.max = I8XX_DOT_MAX },
        .vco = { .min = I8XX_VCO_MIN,		.max = I8XX_VCO_MAX },
        .n   = { .min = I8XX_N_MIN,		.max = I8XX_N_MAX },
        .m   = { .min = I8XX_M_MIN,		.max = I8XX_M_MAX },
        .m1  = { .min = I8XX_M1_MIN,		.max = I8XX_M1_MAX },
        .m2  = { .min = I8XX_M2_MIN,		.max = I8XX_M2_MAX },
        .p   = { .min = I8XX_P_MIN,		.max = I8XX_P_MAX },
        .p1  = { .min = I8XX_P1_MIN,		.max = I8XX_P1_MAX },
	.p2  = { .dot_limit = I8XX_P2_SLOW_LIMIT,
		 .p2_slow = I8XX_P2_SLOW,	.p2_fast = I8XX_P2_FAST },
    },
    { /* INTEL_LIMIT_I8XX_LVDS */
        .dot = { .min = I8XX_DOT_MIN,		.max = I8XX_DOT_MAX },
        .vco = { .min = I8XX_VCO_MIN,		.max = I8XX_VCO_MAX },
        .n   = { .min = I8XX_N_MIN,		.max = I8XX_N_MAX },
        .m   = { .min = I8XX_M_MIN,		.max = I8XX_M_MAX },
        .m1  = { .min = I8XX_M1_MIN,		.max = I8XX_M1_MAX },
        .m2  = { .min = I8XX_M2_MIN,		.max = I8XX_M2_MAX },
        .p   = { .min = I8XX_P_MIN,		.max = I8XX_P_MAX },
        .p1  = { .min = I8XX_P1_LVDS_MIN,	.max = I8XX_P1_LVDS_MAX },
	.p2  = { .dot_limit = I8XX_P2_SLOW_LIMIT,
		 .p2_slow = I8XX_P2_LVDS_SLOW,	.p2_fast = I8XX_P2_LVDS_FAST },
    },
    { /* INTEL_LIMIT_I9XX_SDVO_DAC */
        .dot = { .min = I9XX_DOT_MIN,		.max = I9XX_DOT_MAX },
        .vco = { .min = I9XX_VCO_MIN,		.max = I9XX_VCO_MAX },
        .n   = { .min = I9XX_N_MIN,		.max = I9XX_N_MAX },
        .m   = { .min = I9XX_M_MIN,		.max = I9XX_M_MAX },
        .m1  = { .min = I9XX_M1_MIN,		.max = I9XX_M1_MAX },
        .m2  = { .min = I9XX_M2_MIN,		.max = I9XX_M2_MAX },
        .p   = { .min = I9XX_P_SDVO_DAC_MIN,	.max = I9XX_P_SDVO_DAC_MAX },
        .p1  = { .min = I9XX_P1_MIN,		.max = I9XX_P1_MAX },
	.p2  = { .dot_limit = I9XX_P2_SDVO_DAC_SLOW_LIMIT,
		 .p2_slow = I9XX_P2_SDVO_DAC_SLOW,	.p2_fast = I9XX_P2_SDVO_DAC_FAST },
    },
    { /* INTEL_LIMIT_I9XX_LVDS */
        .dot = { .min = I9XX_DOT_MIN,		.max = I9XX_DOT_MAX },
        .vco = { .min = I9XX_VCO_MIN,		.max = I9XX_VCO_MAX },
        .n   = { .min = I9XX_N_MIN,		.max = I9XX_N_MAX },
        .m   = { .min = I9XX_M_MIN,		.max = I9XX_M_MAX },
        .m1  = { .min = I9XX_M1_MIN,		.max = I9XX_M1_MAX },
        .m2  = { .min = I9XX_M2_MIN,		.max = I9XX_M2_MAX },
        .p   = { .min = I9XX_P_LVDS_MIN,	.max = I9XX_P_LVDS_MAX },
        .p1  = { .min = I9XX_P1_MIN,		.max = I9XX_P1_MAX },
	/* The single-channel range is 25-112Mhz, and dual-channel
	 * is 80-224Mhz.  Prefer single channel as much as possible.
	 */
	.p2  = { .dot_limit = I9XX_P2_LVDS_SLOW_LIMIT,
		 .p2_slow = I9XX_P2_LVDS_SLOW,	.p2_fast = I9XX_P2_LVDS_FAST },
    },
};

static const intel_limit_t *intel_limit (xf86CrtcPtr crtc)
{
    ScrnInfoPtr	pScrn = crtc->scrn;
    I830Ptr	pI830 = I830PTR(pScrn);
    const intel_limit_t *limit;

    if (IS_I9XX(pI830)) {
	if (i830PipeHasType (crtc, I830_OUTPUT_LVDS))
	    limit = &intel_limits[INTEL_LIMIT_I9XX_LVDS];
	else
	    limit = &intel_limits[INTEL_LIMIT_I9XX_SDVO_DAC];
    } else {
	if (i830PipeHasType (crtc, I830_OUTPUT_LVDS))
	    limit = &intel_limits[INTEL_LIMIT_I8XX_LVDS];
	else
	    limit = &intel_limits[INTEL_LIMIT_I8XX_DVO_DAC];
    }

    return limit;
}

/** Derive the pixel clock for the given refclk and divisors for 8xx chips. */

static void i8xx_clock(int refclk, intel_clock_t *clock)
{
    clock->m = 5 * (clock->m1 + 2) + (clock->m2 + 2);
    clock->p = clock->p1 * clock->p2;
    clock->vco = refclk * clock->m / (clock->n + 2);
    clock->dot = clock->vco / clock->p;
}

/** Derive the pixel clock for the given refclk and divisors for 9xx chips. */

static void i9xx_clock(int refclk, intel_clock_t *clock)
{
    clock->m = 5 * (clock->m1 + 2) + (clock->m2 + 2);
    clock->p = clock->p1 * clock->p2;
    clock->vco = refclk * clock->m / (clock->n + 2);
    clock->dot = clock->vco / clock->p;
}

static void intel_clock(I830Ptr pI830, int refclk, intel_clock_t *clock)
{
    if (IS_I9XX(pI830))
	i9xx_clock (refclk, clock);
    else
	i8xx_clock (refclk, clock);
}

static void
i830PrintPll(char *prefix, intel_clock_t *clock)
{
    ErrorF("%s: dotclock %d vco %d ((m %d, m1 %d, m2 %d), n %d, (p %d, p1 %d, p2 %d))\n",
	   prefix, clock->dot, clock->vco,
	   clock->m, clock->m1, clock->m2,
	   clock->n, 
	   clock->p, clock->p1, clock->p2);
}

/**
 * Returns whether any output on the specified pipe is of the specified type
 */
Bool
i830PipeHasType (xf86CrtcPtr crtc, int type)
{
    ScrnInfoPtr	pScrn = crtc->scrn;
    xf86CrtcConfigPtr   xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
    int		i;

    for (i = 0; i < xf86_config->num_output; i++)
    {
	xf86OutputPtr  output = xf86_config->output[i];
	if (output->crtc == crtc)
	{
	    I830OutputPrivatePtr    intel_output = output->driver_private;
	    if (intel_output->type == type)
		return TRUE;
	}
    }
    return FALSE;
}

#define i830PllInvalid(s)   { /* ErrorF (s) */; return FALSE; }
/**
 * Returns whether the given set of divisors are valid for a given refclk with
 * the given outputs.
 */

static Bool
i830PllIsValid(xf86CrtcPtr crtc, intel_clock_t *clock)
{
    const intel_limit_t *limit = intel_limit (crtc);

    if (clock->p1  < limit->p1.min  || limit->p1.max  < clock->p1)
	i830PllInvalid ("p1 out of range\n");
    if (clock->p   < limit->p.min   || limit->p.max   < clock->p)
	i830PllInvalid ("p out of range\n");
    if (clock->m2  < limit->m2.min  || limit->m2.max  < clock->m2)
	i830PllInvalid ("m2 out of range\n");
    if (clock->m1  < limit->m1.min  || limit->m1.max  < clock->m1)
	i830PllInvalid ("m1 out of range\n");
    if (clock->m1 <= clock->m2)
	i830PllInvalid ("m1 <= m2\n");
    if (clock->m   < limit->m.min   || limit->m.max   < clock->m)
	i830PllInvalid ("m out of range\n");
    if (clock->n   < limit->n.min   || limit->n.max   < clock->n)
	i830PllInvalid ("n out of range\n");
    if (clock->vco < limit->vco.min || limit->vco.max < clock->vco)
	i830PllInvalid ("vco out of range\n");
    /* XXX: We may need to be checking "Dot clock" depending on the multiplier,
     * output, etc., rather than just a single range.
     */
    if (clock->dot < limit->dot.min || limit->dot.max < clock->dot)
	i830PllInvalid ("dot out of range\n");

    return TRUE;
}

/**
 * Returns a set of divisors for the desired target clock with the given
 * refclk, or FALSE.  The returned values represent the clock equation:
 * reflck * (5 * (m1 + 2) + (m2 + 2)) / (n + 2) / p1 / p2.
 */
static Bool
i830FindBestPLL(xf86CrtcPtr crtc, int target, int refclk, intel_clock_t *best_clock)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    intel_clock_t   clock;
    const intel_limit_t   *limit = intel_limit (crtc);
    int err = target;

    if (i830PipeHasType(crtc, I830_OUTPUT_LVDS))
    {
	/* For LVDS, if the panel is on, just rely on its current settings for
	 * dual-channel.  We haven't figured out how to reliably set up
	 * different single/dual channel state, if we even can.
	 */
	if ((INREG(LVDS) & LVDS_CLKB_POWER_MASK) == LVDS_CLKB_POWER_UP)
	    clock.p2 = limit->p2.p2_fast;
	else
	    clock.p2 = limit->p2.p2_slow;
    } else {
	if (target < limit->p2.dot_limit)
	    clock.p2 = limit->p2.p2_slow;
	else
	    clock.p2 = limit->p2.p2_fast;
    }

    memset (best_clock, 0, sizeof (*best_clock));

    for (clock.m1 = limit->m1.min; clock.m1 <= limit->m1.max; clock.m1++) 
    {
	for (clock.m2 = limit->m2.min; clock.m2 < clock.m1 && clock.m2 <= limit->m2.max; clock.m2++) 
	{
	    for (clock.n = limit->n.min; clock.n <= limit->n.max; clock.n++) 
	    {
		for (clock.p1 = limit->p1.min; clock.p1 <= limit->p1.max; clock.p1++) 
		{
		    int this_err;

		    intel_clock (pI830, refclk, &clock);
		    
		    if (!i830PllIsValid(crtc, &clock))
			continue;

		    this_err = abs(clock.dot - target);
		    if (this_err < err) {
			*best_clock = clock;
			err = this_err;
		    }
		}
	    }
	}
    }
    return (err != target);
}

void
i830WaitForVblank(ScrnInfoPtr pScreen)
{
    /* Wait for 20ms, i.e. one cycle at 50hz. */
    usleep(30000);
}

void
i830PipeSetBase(xf86CrtcPtr crtc, int x, int y)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr	intel_crtc = crtc->driver_private;
    int pipe = intel_crtc->pipe;
    int plane = intel_crtc->plane;
    unsigned long Start, Offset;
    int dspbase = (plane == 0 ? DSPABASE : DSPBBASE);
    int dspsurf = (plane == 0 ? DSPASURF : DSPBSURF);
    int dsptileoff = (plane == 0 ? DSPATILEOFF : DSPBTILEOFF);

    Offset = ((y * pScrn->displayWidth + x) * pI830->cpp);
    if (pI830->front_buffer == NULL) {
	/* During startup we may be called as part of monitor detection while
	 * there is no memory allocation done, so just supply a dummy base
	 * address.
	 */
	Start = 0;
    } else if (crtc->rotatedData != NULL) {
	/* offset is done by shadow painting code, not here */
	Start = (char *)crtc->rotatedData - (char *)pI830->FbBase;
	Offset = 0;
    } else if (I830IsPrimary(pScrn)) {
	Start = pI830->front_buffer->offset;
    } else {
	I830Ptr pI8301 = I830PTR(pI830->entityPrivate->pScrn_1);
	Start = pI8301->front_buffer_2->offset;
    }

    if (IS_I965G(pI830)) {
        OUTREG(dspbase, Offset);
	POSTING_READ(dspbase);
        OUTREG(dspsurf, Start);
	POSTING_READ(dspsurf);
	OUTREG(dsptileoff, (y << 16) | x);
    } else {
	OUTREG(dspbase, Start + Offset);
	POSTING_READ(dspbase);
    }

#ifdef XF86DRI
    if (pI830->directRenderingEnabled) {
	drmI830Sarea *sPriv = (drmI830Sarea *) DRIGetSAREAPrivate(pScrn->pScreen);

	if (!sPriv)
	    return;

	switch (plane) {
	case 0:
	    sPriv->planeA_x = x;
	    sPriv->planeA_y = y;
	    break;
	case 1:
	    sPriv->planeB_x = x;
	    sPriv->planeB_y = y;
	    break;
	default:
	    xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
		       "Can't update pipe %d in SAREA\n", pipe);
	    break;
	}
    }
#endif
}

/*
 * Both crtc activation and video overlay enablement on pipe B
 * will fail on i830 if pipe A is not running. This function
 * makes sure pipe A is active for these cases
 */

int
i830_crtc_pipe (xf86CrtcPtr crtc)
{
    if (crtc == NULL)
	return 0;
    return ((I830CrtcPrivatePtr) crtc->driver_private)->pipe;
}

static xf86CrtcPtr
i830_crtc_for_pipe (ScrnInfoPtr scrn, int pipe)
{
    xf86CrtcConfigPtr   xf86_config = XF86_CRTC_CONFIG_PTR(scrn);
    int			c;

    for (c = 0; c < xf86_config->num_crtc; c++)
    {
	xf86CrtcPtr crtc = xf86_config->crtc[c];
	if (i830_crtc_pipe (crtc) == pipe)
	    return crtc;
    }
    return NULL;
}

Bool
i830_pipe_a_require_activate (ScrnInfoPtr scrn)
{
    xf86CrtcPtr	crtc = i830_crtc_for_pipe (scrn, 0);
    /* VESA 640x480x72Hz mode to set on the pipe */
    static DisplayModeRec   mode = {
	NULL, NULL, "640x480", MODE_OK, M_T_DEFAULT,
	31500,
	640, 664, 704, 832, 0,
	480, 489, 491, 520, 0,
	V_NHSYNC | V_NVSYNC,
	0, 0,
	0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0,
	FALSE, FALSE, 0, NULL, 0, 0.0, 0.0
    };

    if (!crtc)
	return FALSE;
    if (crtc->enabled)
	return FALSE;
    xf86SetModeCrtc (&mode, INTERLACE_HALVE_V);
    crtc->funcs->mode_set (crtc, &mode, &mode, 0, 0);
    crtc->funcs->dpms (crtc, DPMSModeOn);
    return TRUE;
}

void
i830_pipe_a_require_deactivate (ScrnInfoPtr scrn)
{
    xf86CrtcPtr	crtc = i830_crtc_for_pipe (scrn, 0);

    if (!crtc)
	return;
    if (crtc->enabled)
	return;
    crtc->funcs->dpms (crtc, DPMSModeOff);
    return;
}

/* FIXME: use pixmap private instead if possible */
static Bool
i830_display_tiled(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);

    /* Rotated data is currently linear, allocated either via XAA or EXA */
    if (crtc->rotatedData)
	return FALSE;

    if (pI830->front_buffer && pI830->front_buffer->tiling != TILE_NONE)
	return TRUE;

    return FALSE;
}

static Bool
i830_use_fb_compression(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr	intel_crtc = crtc->driver_private;
    int plane = (intel_crtc->plane == 0 ? FBC_CTL_PLANEA : FBC_CTL_PLANEB);

    if (!pI830->fb_compression)
	return FALSE;

    if (!i830_display_tiled(crtc))
	return FALSE;

    /* Pre-965 only supports plane A */
    if (!IS_I965GM(pI830) && plane != FBC_CTL_PLANEA)
	return FALSE;

    /* Need 15, 16, or 32 (w/alpha) pixel format */
    if (!(pScrn->bitsPerPixel == 16 || /* covers 15 bit mode as well */
	  pScrn->bitsPerPixel == 32)) /* mode_set dtrt if fbc is in use */
	return FALSE;

    /*
     * No checks for pixel multiply, incl. horizontal, or interlaced modes
     * since they're currently unused.
     */
    return TRUE;
}

/*
 * Several restrictions:
 *   - DSP[AB]CNTR - no line duplication && no pixel multiplier
 *   - pixel format == 15 bit, 16 bit, or 32 bit xRGB_8888
 *   - no alpha buffer discard
 *   - no dual wide display
 *   - progressive mode only (DSP[AB]CNTR)
 *   - uncompressed fb is <= 2048 in width, 0 mod 8
 *   - uncompressed fb is <= 1536 in height, 0 mod 2
 *   - SR display watermarks must be equal between 16bpp and 32bpp?
 *
 * FIXME: verify above conditions are true
 *
 * Enable 8xx style FB compression
 */
static void
i830_enable_fb_compression_8xx(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr	intel_crtc = crtc->driver_private;
    uint32_t fbc_ctl = 0;
    unsigned long compressed_stride;
    int plane = (intel_crtc->plane == 0 ? FBC_CTL_PLANEA : FBC_CTL_PLANEB);
    unsigned long uncompressed_stride = pScrn->displayWidth * pI830->cpp;
    unsigned long interval = 1000;

    if (INREG(FBC_CONTROL) & FBC_CTL_EN) {
	char cur_plane = (INREG(FBC_CONTROL2) & 1) ? 'b' : 'a';
	xf86DrvMsg(pScrn->scrnIndex, X_WARNING, "fbc already enabled on "
		   "plane %c, not enabling on plane %c\n", cur_plane,
		   plane ? 'b' : 'a');
	return;
    }

    compressed_stride = pI830->compressed_front_buffer->size /
	FBC_LL_SIZE;

    if (uncompressed_stride < compressed_stride)
	compressed_stride = uncompressed_stride;

    /* FBC_CTL wants 64B units */
    compressed_stride = (compressed_stride / 64) - 1;

    /* Set it up... */
    /* Wait for compressing bit to clear */
    while (INREG(FBC_STATUS) & FBC_STAT_COMPRESSING)
	; /* nothing */
    i830WaitForVblank(pScrn);
    OUTREG(FBC_CFB_BASE, pI830->compressed_front_buffer->bus_addr);
    OUTREG(FBC_LL_BASE, pI830->compressed_ll_buffer->bus_addr + 6);
    OUTREG(FBC_CONTROL2, FBC_CTL_FENCE_DBL | FBC_CTL_IDLE_FULL |
	   FBC_CTL_CPU_FENCE | plane);

    /* Zero buffers */
    memset(pI830->FbBase + pI830->compressed_front_buffer->offset, 0,
	   pI830->compressed_front_buffer->size);
    memset(pI830->FbBase + pI830->compressed_ll_buffer->offset, 0,
	   pI830->compressed_ll_buffer->size);

    /* enable it... */
    fbc_ctl |= FBC_CTL_EN | FBC_CTL_PERIODIC;
    fbc_ctl |= (compressed_stride & 0xff) << FBC_CTL_STRIDE_SHIFT;
    fbc_ctl |= (interval & 0x2fff) << FBC_CTL_INTERVAL_SHIFT;
    fbc_ctl |= FBC_CTL_UNCOMPRESSIBLE;
    fbc_ctl |= pI830->front_buffer->fence_nr;
    OUTREG(FBC_CONTROL, fbc_ctl);

    xf86DrvMsg(pScrn->scrnIndex, X_INFO, "fbc enabled on plane %c\n", plane ?
	       'b' : 'a');
}

/*
 * Disable 8xx style FB compression
 */
static void
i830_disable_fb_compression_8xx(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    uint32_t fbc_ctl;
    char plane = (INREG(FBC_CONTROL2) & 1) ? 'b' : 'a';

    /* Disable compression */
    fbc_ctl = INREG(FBC_CONTROL);
    fbc_ctl &= ~FBC_CTL_EN;
    OUTREG(FBC_CONTROL, fbc_ctl);

    /* Wait for compressing bit to clear */
    while (INREG(FBC_STATUS) & FBC_STAT_COMPRESSING)
	; /* nothing */
    xf86DrvMsg(pScrn->scrnIndex, X_INFO, "fbc disabled on plane %c\n", plane);
}

static void
i830_disable_fb_compression2(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    uint32_t dpfc_ctl;
    char plane = (INREG(DPFC_CONTROL) & DPFC_CTL_PLANEB) ? 'b' : 'a';

    /* Disable compression */
    dpfc_ctl = INREG(DPFC_CONTROL);
    dpfc_ctl &= ~DPFC_CTL_EN;
    OUTREG(DPFC_CONTROL, dpfc_ctl);
    i830WaitForVblank(pScrn);

    xf86DrvMsg(pScrn->scrnIndex, X_INFO, "fbc2 disabled on plane %c\n", plane);
}

static void
i830_enable_fb_compression2(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr	intel_crtc = crtc->driver_private;
    int plane = (intel_crtc->plane == 0 ? DPFC_CTL_PLANEA : DPFC_CTL_PLANEB);
    unsigned long stall_watermark = 200, frames = 50;

    if (INREG(DPFC_CONTROL) & DPFC_CTL_EN) {
	char cur_plane = (INREG(DPFC_CONTROL) & DPFC_CTL_PLANEB) ? 'b' : 'a';
	xf86DrvMsg(pScrn->scrnIndex, X_WARNING, "fbc2 already enabled on "
		   "plane %c, not enabling on plane %c\n", cur_plane,
		   plane ? 'b' : 'a');
	return;
    }

    /* Set it up... */
    i830_disable_fb_compression2(crtc);
    OUTREG(DPFC_CB_BASE, pI830->compressed_front_buffer->offset);
    /* Update i830_memory.c too if compression ratio changes */
    OUTREG(DPFC_CONTROL, plane | DPFC_CTL_FENCE_EN | DPFC_CTL_LIMIT_4X |
	   pI830->front_buffer->fence_nr);
    OUTREG(DPFC_RECOMP_CTL, DPFC_RECOMP_STALL_EN |
	   (stall_watermark << DPFC_RECOMP_STALL_WM_SHIFT) |
	   (frames << DPFC_RECOMP_TIMER_COUNT_SHIFT));
    OUTREG(DPFC_FENCE_YOFF, crtc->y);

    /* Zero buffers */
    memset(pI830->FbBase + pI830->compressed_front_buffer->offset, 0,
	   pI830->compressed_front_buffer->size);

    /* enable it... */
    OUTREG(DPFC_CONTROL, INREG(DPFC_CONTROL) | DPFC_CTL_EN);

    xf86DrvMsg(pScrn->scrnIndex, X_INFO, "fbc2 enabled on plane %c\n", plane ?
	       'b' : 'a');
}

static void
i830_enable_fb_compression(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);

    if (IS_IGD_GM(pI830))
	return i830_enable_fb_compression2(crtc);

    i830_enable_fb_compression_8xx(crtc);
}

static void
i830_disable_fb_compression(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);

    if (IS_IGD_GM(pI830))
	return i830_disable_fb_compression2(crtc);

    i830_disable_fb_compression_8xx(crtc);
}

/**
 * Sets the power management mode of the pipe and plane.
 *
 * This code should probably grow support for turning the cursor off and back
 * on appropriately at the same time as we're turning the pipe off/on.
 */
static void
i830_crtc_dpms(xf86CrtcPtr crtc, int mode)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr intel_crtc = crtc->driver_private;
    int pipe = intel_crtc->pipe;
    int plane = intel_crtc->plane;
    int dpll_reg = (pipe == 0) ? DPLL_A : DPLL_B;
    int pipeconf_reg = (pipe == 0) ? PIPEACONF : PIPEBCONF;
    int dspcntr_reg = (plane == 0) ? DSPACNTR : DSPBCNTR;
    int dspbase_reg = (plane == 0) ? DSPABASE : DSPBBASE;
    CARD32 temp;

    /* XXX: When our outputs are all unaware of DPMS modes other than off and
     * on, we should map those modes to DPMSModeOff in the CRTC.
     */
    switch (mode) {
    case DPMSModeOn:
    case DPMSModeStandby:
    case DPMSModeSuspend:
	/* Enable the DPLL */
	temp = INREG(dpll_reg);
	if ((temp & DPLL_VCO_ENABLE) == 0)
	{
	    OUTREG(dpll_reg, temp);
	    POSTING_READ(dpll_reg);
	    /* Wait for the clocks to stabilize. */
	    usleep(150);
	    OUTREG(dpll_reg, temp | DPLL_VCO_ENABLE);
	    POSTING_READ(dpll_reg);
	    /* Wait for the clocks to stabilize. */
	    usleep(150);
	    OUTREG(dpll_reg, temp | DPLL_VCO_ENABLE);
	    POSTING_READ(dpll_reg);
	    /* Wait for the clocks to stabilize. */
	    usleep(150);
	}

	/* Enable the pipe */
	temp = INREG(pipeconf_reg);
	if ((temp & PIPEACONF_ENABLE) == 0)
	    OUTREG(pipeconf_reg, temp | PIPEACONF_ENABLE);

	/* Enable the plane */
	temp = INREG(dspcntr_reg);
	if ((temp & DISPLAY_PLANE_ENABLE) == 0)
	{
	    OUTREG(dspcntr_reg, temp | DISPLAY_PLANE_ENABLE);
	    /* Flush the plane changes */
	    OUTREG(dspbase_reg, INREG(dspbase_reg));
	}

	i830_crtc_load_lut(crtc);

	/* Give the overlay scaler a chance to enable if it's on this pipe */
	i830_crtc_dpms_video(crtc, TRUE);

	/* Reenable compression if needed */
	if (i830_use_fb_compression(crtc))
	    i830_enable_fb_compression(crtc);
	break;
    case DPMSModeOff:
	/* Shut off compression if in use */
	if (i830_use_fb_compression(crtc))
	    i830_disable_fb_compression(crtc);

	/* Give the overlay scaler a chance to disable if it's on this pipe */
	i830_crtc_dpms_video(crtc, FALSE);

	/* May need to leave pipe A on */
	if ((pipe == 0) && (pI830->quirk_flag & QUIRK_PIPEA_FORCE))
	    return;

	/* Disable the VGA plane that we never use */
	OUTREG(VGACNTRL, VGA_DISP_DISABLE);

	/* Disable display plane */
	temp = INREG(dspcntr_reg);
	if ((temp & DISPLAY_PLANE_ENABLE) != 0)
	{
	    OUTREG(dspcntr_reg, temp & ~DISPLAY_PLANE_ENABLE);
	    /* Flush the plane changes */
	    OUTREG(dspbase_reg, INREG(dspbase_reg));
	    POSTING_READ(dspbase_reg);
	}

	if (!IS_I9XX(pI830)) {
	    /* Wait for vblank for the disable to take effect */
	    i830WaitForVblank(pScrn);
	}

	/* Next, disable display pipes */
	temp = INREG(pipeconf_reg);
	if ((temp & PIPEACONF_ENABLE) != 0) {
	    OUTREG(pipeconf_reg, temp & ~PIPEACONF_ENABLE);
	    POSTING_READ(pipeconf_reg);
	}

	/* Wait for vblank for the disable to take effect. */
	i830WaitForVblank(pScrn);

	temp = INREG(dpll_reg);
	if ((temp & DPLL_VCO_ENABLE) != 0) {
	    OUTREG(dpll_reg, temp & ~DPLL_VCO_ENABLE);
	    POSTING_READ(dpll_reg);
	}

	/* Wait for the clocks to turn off. */
	usleep(150);
	break;
    }

    intel_crtc->dpms_mode = mode;

#ifdef XF86DRI
    if (pI830->directRenderingEnabled) {
	drmI830Sarea *sPriv = (drmI830Sarea *) DRIGetSAREAPrivate(pScrn->pScreen);
	Bool enabled = crtc->enabled && mode != DPMSModeOff;

	I830DRISetVBlankInterrupt (pScrn, TRUE);

	if (!sPriv)
	    return;

	switch (plane) {
	case 0:
	    sPriv->planeA_w = enabled ? crtc->mode.HDisplay : 0;
	    sPriv->planeA_h = enabled ? crtc->mode.VDisplay : 0;
	    break;
	case 1:
	    sPriv->planeB_w = enabled ? crtc->mode.HDisplay : 0;
	    sPriv->planeB_h = enabled ? crtc->mode.VDisplay : 0;
	    break;
	default:
	    xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
		       "Can't update pipe %d in SAREA\n", pipe);
	    break;
	}
    }
#endif
}

static Bool
i830_crtc_lock (xf86CrtcPtr crtc)
{
   /* Sync the engine before mode switch */
   i830WaitSync(crtc->scrn);

#ifdef XF86DRI
    return I830DRILock(crtc->scrn);
#else
    return FALSE;
#endif
}

static void
i830_crtc_unlock (xf86CrtcPtr crtc)
{
#ifdef XF86DRI
    I830DRIUnlock (crtc->scrn);
#endif
}

static void
i830_crtc_prepare (xf86CrtcPtr crtc)
{
    /* Temporarily turn off FB compression during modeset */
    if (i830_use_fb_compression(crtc))
        i830_disable_fb_compression(crtc);
    crtc->funcs->dpms (crtc, DPMSModeOff);
}

static void
i830_crtc_commit (xf86CrtcPtr crtc)
{
    I830CrtcPrivatePtr	intel_crtc = crtc->driver_private;
    Bool		deactivate = FALSE;

    if (!intel_crtc->enabled && intel_crtc->pipe != 0)
	deactivate = i830_pipe_a_require_activate (crtc->scrn);
    
    intel_crtc->enabled = TRUE;
    
    crtc->funcs->dpms (crtc, DPMSModeOn);
    if (crtc->scrn->pScreen != NULL)
	xf86_reload_cursors (crtc->scrn->pScreen);
    if (deactivate)
	i830_pipe_a_require_deactivate (crtc->scrn);

    /* Reenable FB compression if possible */
    if (i830_use_fb_compression(crtc))
	i830_enable_fb_compression(crtc);
}

void
i830_output_prepare (xf86OutputPtr output)
{
    output->funcs->dpms (output, DPMSModeOff);
}

void
i830_output_commit (xf86OutputPtr output)
{
    output->funcs->dpms (output, DPMSModeOn);
}

static Bool
i830_crtc_mode_fixup(xf86CrtcPtr crtc, DisplayModePtr mode,
		     DisplayModePtr adjusted_mode)
{
    return TRUE;
}

/** Returns the core display clock speed for i830 - i945 */
static int
i830_get_core_clock_speed(ScrnInfoPtr pScrn)
{
    I830Ptr pI830 = I830PTR(pScrn);

    /* Core clock values taken from the published datasheets.
     * The 830 may go up to 166 Mhz, which we should check.
     */
    if (IS_I945G(pI830) || IS_G33CLASS(pI830))
	return 400000;
    else if (IS_I915G(pI830))
	return 333000;
    else if (IS_I945GM(pI830) || IS_845G(pI830))
	return 200000;
    else if (IS_I915GM(pI830)) {
	uint16_t gcfgc;

#if XSERVER_LIBPCIACCESS
      pci_device_cfg_read_u16 (pI830->PciInfo, &gcfgc, I915_GCFGC);
#else
      gcfgc = pciReadWord(pI830->PciTag, I915_GCFGC);
#endif
      if (gcfgc & I915_LOW_FREQUENCY_ENABLE)
	    return 133000;
	else {
	    switch (gcfgc & I915_DISPLAY_CLOCK_MASK) {
	    case I915_DISPLAY_CLOCK_333_MHZ:
		return 333000;
	    default:
	    case I915_DISPLAY_CLOCK_190_200_MHZ:
		return 190000;
	    }
	}
    } else if (IS_I865G(pI830))
	return 266000;
    else if (IS_I855(pI830)) {
#if XSERVER_LIBPCIACCESS
        struct pci_device *bridge = intel_host_bridge ();
	uint16_t hpllcc;
	pci_device_cfg_read_u16 (bridge, &hpllcc, I855_HPLLCC);
#else
	PCITAG bridge = pciTag(0, 0, 0); /* This is always the host bridge */
	CARD16 hpllcc = pciReadWord(bridge, I855_HPLLCC);
#endif

	/* Assume that the hardware is in the high speed state.  This
	 * should be the default.
	 */
	switch (hpllcc & I855_CLOCK_CONTROL_MASK) {
	case I855_CLOCK_133_200:
	case I855_CLOCK_100_200:
	    return 200000;
	case I855_CLOCK_166_250:
	    return 250000;
	case I855_CLOCK_100_133:
	    return 133000;
	}
    } else /* 852, 830 */
	return 133000;

    return 0; /* Silence gcc warning */
}

/**
 * Return the pipe currently connected to the panel fitter,
 * or -1 if the panel fitter is not present or not in use
 */
static int
i830_panel_fitter_pipe(I830Ptr pI830)
{
    CARD32  pfit_control;

    /* i830 doesn't have a panel fitter */
    if (IS_I830(pI830))
	return -1;

    pfit_control = INREG(PFIT_CONTROL);

    /* See if the panel fitter is in use */
    if ((pfit_control & PFIT_ENABLE) == 0)
	return -1;

    /* 965 can place panel fitter on either pipe */
    if (IS_I965G(pI830))
	return (pfit_control & PFIT_PIPE_MASK) >> PFIT_PIPE_SHIFT;

    /* older chips can only use pipe 1 */
    return 1;
}

/**
 * Sets up registers for the given mode/adjusted_mode pair.
 *
 * The clocks, CRTCs and outputs attached to this CRTC must be off.
 *
 * This shouldn't enable any clocks, CRTCs, or outputs, but they should
 * be easily turned on/off after this.
 */
static void
i830_crtc_mode_set(xf86CrtcPtr crtc, DisplayModePtr mode,
		   DisplayModePtr adjusted_mode,
		   int x, int y)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    xf86CrtcConfigPtr   xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr intel_crtc = crtc->driver_private;
    int pipe = intel_crtc->pipe;
    int plane = intel_crtc->plane;
    int fp_reg = (pipe == 0) ? FPA0 : FPB0;
    int dpll_reg = (pipe == 0) ? DPLL_A : DPLL_B;
    int dpll_md_reg = (pipe == 0) ? DPLL_A_MD : DPLL_B_MD;
    int pipeconf_reg = (pipe == 0) ? PIPEACONF : PIPEBCONF;
    int htot_reg = (pipe == 0) ? HTOTAL_A : HTOTAL_B;
    int hblank_reg = (pipe == 0) ? HBLANK_A : HBLANK_B;
    int hsync_reg = (pipe == 0) ? HSYNC_A : HSYNC_B;
    int vtot_reg = (pipe == 0) ? VTOTAL_A : VTOTAL_B;
    int vblank_reg = (pipe == 0) ? VBLANK_A : VBLANK_B;
    int vsync_reg = (pipe == 0) ? VSYNC_A : VSYNC_B;
    int pipesrc_reg = (pipe == 0) ? PIPEASRC : PIPEBSRC;
    int dspcntr_reg = (plane == 0) ? DSPACNTR : DSPBCNTR;
    int dspstride_reg = (plane == 0) ? DSPASTRIDE : DSPBSTRIDE;
    int dsppos_reg = (plane == 0) ? DSPAPOS : DSPBPOS;
    int dspsize_reg = (plane == 0) ? DSPASIZE : DSPBSIZE;
    int i;
    int refclk;
    intel_clock_t clock;
    CARD32 dpll = 0, fp = 0, dspcntr, pipeconf;
    Bool ok, is_sdvo = FALSE, is_dvo = FALSE;
    Bool is_crt = FALSE, is_lvds = FALSE, is_tv = FALSE;

    /* Set up some convenient bools for what outputs are connected to
     * our pipe, used in DPLL setup.
     */
    for (i = 0; i < xf86_config->num_output; i++) {
	xf86OutputPtr  output = xf86_config->output[i];
	I830OutputPrivatePtr intel_output = output->driver_private;

	if (output->crtc != crtc)
	    continue;

	switch (intel_output->type) {
	case I830_OUTPUT_LVDS:
	    is_lvds = TRUE;
	    break;
	case I830_OUTPUT_SDVO:
	    is_sdvo = TRUE;
	    break;
	case I830_OUTPUT_DVO_TMDS:
	case I830_OUTPUT_DVO_LVDS:
	case I830_OUTPUT_DVO_TVOUT:
	    is_dvo = TRUE;
	    break;
	case I830_OUTPUT_TVOUT:
	    is_tv = TRUE;
	    break;
	case I830_OUTPUT_ANALOG:
	    is_crt = TRUE;
	    break;
	}
    }

    if (IS_I9XX(pI830)) {
	refclk = 96000;
    } else {
	refclk = 48000;
    }

    ok = i830FindBestPLL(crtc, adjusted_mode->Clock, refclk, &clock);
    if (!ok)
	FatalError("Couldn't find PLL settings for mode!\n");

    if (fabs(adjusted_mode->Clock - clock.dot) / clock.dot > .02) {
	xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
		   "Chosen PLL clock of %.1f Mhz more than 2%% away from "
		   "desired %.1f Mhz\n",
		   (float)clock.dot / 1000,
		   (float)adjusted_mode->Clock / 1000);
    }

    fp = clock.n << 16 | clock.m1 << 8 | clock.m2;

    dpll = DPLL_VGA_MODE_DIS;
    if (IS_I9XX(pI830)) {
	if (is_lvds)
	    dpll |= DPLLB_MODE_LVDS;
	else
	    dpll |= DPLLB_MODE_DAC_SERIAL;
	if (is_sdvo)
	{
	    dpll |= DPLL_DVO_HIGH_SPEED;
	    if (IS_I945G(pI830) || IS_I945GM(pI830) || IS_G33CLASS(pI830))
	    {
		int sdvo_pixel_multiply = adjusted_mode->Clock / mode->Clock;
		dpll |= (sdvo_pixel_multiply - 1) << SDVO_MULTIPLIER_SHIFT_HIRES;
	    }
	}
	
	/* compute bitmask from p1 value */
	dpll |= (1 << (clock.p1 - 1)) << 16;
	switch (clock.p2) {
	case 5:
	    dpll |= DPLL_DAC_SERIAL_P2_CLOCK_DIV_5;
	    break;
	case 7:
	    dpll |= DPLLB_LVDS_P2_CLOCK_DIV_7;
	    break;
	case 10:
	    dpll |= DPLL_DAC_SERIAL_P2_CLOCK_DIV_10;
	    break;
	case 14:
	    dpll |= DPLLB_LVDS_P2_CLOCK_DIV_14;
	    break;
	}
	if (IS_I965G(pI830))
	    dpll |= (6 << PLL_LOAD_PULSE_PHASE_SHIFT);
    } else {
	if (is_lvds) {
	    dpll |= (1 << (clock.p1 - 1)) << DPLL_FPA01_P1_POST_DIV_SHIFT;
	} else {
	    if (clock.p1 == 2)
		dpll |= PLL_P1_DIVIDE_BY_TWO;
	    else
		dpll |= (clock.p1 - 2) << DPLL_FPA01_P1_POST_DIV_SHIFT;
	    if (clock.p2 == 4)
		dpll |= PLL_P2_DIVIDE_BY_4;
	}
    }

    if (is_tv)
    {
	/* XXX: just matching BIOS for now */
/*	dpll |= PLL_REF_INPUT_TVCLKINBC; */
	dpll |= 3;
    }
#if 0
    else if (is_lvds)
	dpll |= PLLB_REF_INPUT_SPREADSPECTRUMIN;
#endif
    else
	dpll |= PLL_REF_INPUT_DREFCLK;

    /* Set up the display plane register */
    dspcntr = DISPPLANE_GAMMA_ENABLE;
    switch (pScrn->bitsPerPixel) {
    case 8:
	dspcntr |= DISPPLANE_8BPP;
	break;
    case 16:
	if (pScrn->depth == 15)
	    dspcntr |= DISPPLANE_15_16BPP;
	else
	    dspcntr |= DISPPLANE_16BPP;
	break;
    case 32:
	dspcntr |= DISPPLANE_32BPP_NO_ALPHA;
	break;
    default:
	FatalError("unknown display bpp\n");
    }

    if (pipe == 0)
	dspcntr |= DISPPLANE_SEL_PIPE_A;
    else
	dspcntr |= DISPPLANE_SEL_PIPE_B;

    if (IS_I965G(pI830) && i830_display_tiled(crtc))
	dspcntr |= DISPLAY_PLANE_TILED;

    pipeconf = INREG(pipeconf_reg);
    if (pipe == 0 && !IS_I965G(pI830))
    {
	/* Enable pixel doubling when the dot clock is > 90% of the (display)
	 * core speed.
	 *
	 * XXX: No double-wide on 915GM pipe B. Is that the only reason for the
	 * pipe == 0 check?
	 */
	if (mode->Clock > i830_get_core_clock_speed(pScrn) * 9 / 10)
	    pipeconf |= PIPEACONF_DOUBLE_WIDE;
	else
	    pipeconf &= ~PIPEACONF_DOUBLE_WIDE;
    }
    /*
     * This "shouldn't" be needed as the dpms on code
     * will be run after the mode is set. On 9xx, it helps.
     * On 855, it can lock up the chip (and the entire machine)
     */
    if (!IS_I85X (pI830))
    {
	dspcntr |= DISPLAY_PLANE_ENABLE;
	pipeconf |= PIPEACONF_ENABLE;
	dpll |= DPLL_VCO_ENABLE;
    }
    
    /* Disable the panel fitter if it was on our pipe */
    if (i830_panel_fitter_pipe (pI830) == pipe)
	OUTREG(PFIT_CONTROL, 0);

    if (pI830->debug_modes) {
	xf86DrvMsg(pScrn->scrnIndex, X_INFO,
		   "Mode for pipe %c:\n", pipe == 0 ? 'A' : 'B');
	xf86PrintModeline(pScrn->scrnIndex, mode);
	if (!xf86ModesEqual(mode, adjusted_mode)) {
	    xf86DrvMsg(pScrn->scrnIndex, X_INFO,
		       "Adjusted mode for pipe %c:\n", pipe == 0 ? 'A' : 'B');
	    xf86PrintModeline(pScrn->scrnIndex, mode);
	}
	i830PrintPll("chosen", &clock);
    }

    /* The LVDS pin pair needs to be on before the DPLLs are enabled.
     * This is an exception to the general rule that mode_set doesn't turn
     * things on.
     */
    if (is_lvds)
    {
	CARD32 lvds = INREG(LVDS);

	if (dpll & DPLL_VCO_ENABLE)
	{
	    OUTREG(fp_reg, fp);
	    OUTREG(dpll_reg, dpll & ~DPLL_VCO_ENABLE);
	    POSTING_READ(dpll_reg);
	    usleep(150);
	}

	lvds |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP | LVDS_PIPEB_SELECT;
	/* Set the B0-B3 data pairs corresponding to whether we're going to
	 * set the DPLLs for dual-channel mode or not.
	 */
	if (clock.p2 == I9XX_P2_LVDS_FAST)
	    lvds |= LVDS_B0B3_POWER_UP | LVDS_CLKB_POWER_UP;
	else
	    lvds &= ~(LVDS_B0B3_POWER_UP | LVDS_CLKB_POWER_UP);

	/* It would be nice to set 24 vs 18-bit mode (LVDS_A3_POWER_UP)
	 * appropriately here, but we need to look more thoroughly into how
	 * panels behave in the two modes.
	 */

	/* Enable dithering if we're in 18-bit mode. */
	if (IS_I965G(pI830))
	{
	    if ((lvds & LVDS_A3_POWER_MASK) == LVDS_A3_POWER_UP)
		lvds &= ~LVDS_DITHER_ENABLE;
	    else
		lvds |= LVDS_DITHER_ENABLE;
	}

	OUTREG(LVDS, lvds);
	POSTING_READ(LVDS);
    }

    OUTREG(fp_reg, fp);
    OUTREG(dpll_reg, dpll);
    POSTING_READ(dpll_reg);
    /* Wait for the clocks to stabilize. */
    usleep(150);
    
    if (IS_I965G(pI830)) {
	int sdvo_pixel_multiply = adjusted_mode->Clock / mode->Clock;
	OUTREG(dpll_md_reg, (0 << DPLL_MD_UDI_DIVIDER_SHIFT) |
	       ((sdvo_pixel_multiply - 1) << DPLL_MD_UDI_MULTIPLIER_SHIFT));
    } else {
	/* write it again -- the BIOS does, after all */
	OUTREG(dpll_reg, dpll);
    }
    POSTING_READ(dpll_reg);
    /* Wait for the clocks to stabilize. */
    usleep(150);

    OUTREG(htot_reg, (adjusted_mode->CrtcHDisplay - 1) |
	((adjusted_mode->CrtcHTotal - 1) << 16));
    OUTREG(hblank_reg, (adjusted_mode->CrtcHBlankStart - 1) |
	((adjusted_mode->CrtcHBlankEnd - 1) << 16));
    OUTREG(hsync_reg, (adjusted_mode->CrtcHSyncStart - 1) |
	((adjusted_mode->CrtcHSyncEnd - 1) << 16));
    OUTREG(vtot_reg, (adjusted_mode->CrtcVDisplay - 1) |
	((adjusted_mode->CrtcVTotal - 1) << 16));
    
    OUTREG(vblank_reg, (adjusted_mode->CrtcVBlankStart - 1) |
	((adjusted_mode->CrtcVBlankEnd - 1) << 16));
    OUTREG(vsync_reg, (adjusted_mode->CrtcVSyncStart - 1) |
	((adjusted_mode->CrtcVSyncEnd - 1) << 16));
    OUTREG(dspstride_reg, pScrn->displayWidth * pI830->cpp);
    /* pipesrc and dspsize control the size that is scaled from, which should
     * always be the user's requested size.
     */
    OUTREG(dspsize_reg, ((mode->VDisplay - 1) << 16) | (mode->HDisplay - 1));
    OUTREG(dsppos_reg, 0);
    OUTREG(pipesrc_reg, ((mode->HDisplay - 1) << 16) | (mode->VDisplay - 1));
    OUTREG(pipeconf_reg, pipeconf);
    POSTING_READ(pipeconf_reg);
    i830WaitForVblank(pScrn);

    OUTREG(dspcntr_reg, dspcntr);
    /* Flush the plane changes */
    i830PipeSetBase(crtc, x, y);
#ifdef XF86DRI
   I830DRISetVBlankInterrupt (pScrn, TRUE);
#endif
    
    i830WaitForVblank(pScrn);
}


/** Loads the palette/gamma unit for the CRTC with the prepared values */
void
i830_crtc_load_lut(xf86CrtcPtr crtc)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr intel_crtc = crtc->driver_private;
    int palreg = (intel_crtc->pipe == 0) ? PALETTE_A : PALETTE_B;
    int i;

    /* The clocks have to be on to load the palette. */
    if (!crtc->enabled)
	return;

    for (i = 0; i < 256; i++) {
	OUTREG(palreg + 4 * i,
	       (intel_crtc->lut_r[i] << 16) |
	       (intel_crtc->lut_g[i] << 8) |
	       intel_crtc->lut_b[i]);
    }
}

/** Sets the color ramps on behalf of RandR */
static void
i830_crtc_gamma_set(xf86CrtcPtr crtc, CARD16 *red, CARD16 *green, CARD16 *blue,
		    int size)
{
    I830CrtcPrivatePtr intel_crtc = crtc->driver_private;
    int i;

    assert(size == 256);

    for (i = 0; i < 256; i++) {
	intel_crtc->lut_r[i] = red[i] >> 8;
	intel_crtc->lut_g[i] = green[i] >> 8;
	intel_crtc->lut_b[i] = blue[i] >> 8;
    }

    i830_crtc_load_lut(crtc);
}

/**
 * Allocates memory for a locked-in-framebuffer shadow of the given
 * width and height for this CRTC's rotated shadow framebuffer.
 */
 
static void *
i830_crtc_shadow_allocate (xf86CrtcPtr crtc, int width, int height)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr intel_crtc = crtc->driver_private;
    unsigned long rotate_pitch;
    int align = KB(4), size;

    rotate_pitch = pScrn->displayWidth * pI830->cpp;
    size = rotate_pitch * height;

    assert(intel_crtc->rotate_mem == NULL);
    intel_crtc->rotate_mem = i830_allocate_memory(pScrn, "rotated crtc",
						  size, align, 0);
    if (intel_crtc->rotate_mem == NULL) {
	xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
		   "Couldn't allocate shadow memory for rotated CRTC\n");
	return NULL;
    }
    memset(pI830->FbBase + intel_crtc->rotate_mem->offset, 0, size);

    return pI830->FbBase + intel_crtc->rotate_mem->offset;
}
    
/**
 * Creates a pixmap for this CRTC's rotated shadow framebuffer.
 */
static PixmapPtr
i830_crtc_shadow_create(xf86CrtcPtr crtc, void *data, int width, int height)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830Ptr pI830 = I830PTR(pScrn);
    unsigned long rotate_pitch;
    PixmapPtr rotate_pixmap;

    if (!data)
	data = i830_crtc_shadow_allocate (crtc, width, height);
    
    rotate_pitch = pScrn->displayWidth * pI830->cpp;

    rotate_pixmap = GetScratchPixmapHeader(pScrn->pScreen,
					   width, height,
					   pScrn->depth,
					   pScrn->bitsPerPixel,
					   rotate_pitch,
					   data);

    if (rotate_pixmap == NULL) {
	xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
		   "Couldn't allocate shadow pixmap for rotated CRTC\n");
    }
    return rotate_pixmap;
}

static void
i830_crtc_shadow_destroy(xf86CrtcPtr crtc, PixmapPtr rotate_pixmap, void *data)
{
    ScrnInfoPtr pScrn = crtc->scrn;
    I830CrtcPrivatePtr intel_crtc = crtc->driver_private;

    if (rotate_pixmap)
	FreeScratchPixmapHeader(rotate_pixmap);

    if (data) {
	/* Be sure to sync acceleration before the memory gets unbound. */
	I830Sync(pScrn);
	i830_free_memory(pScrn, intel_crtc->rotate_mem);
	intel_crtc->rotate_mem = NULL;
    }
}


void
i830DescribeOutputConfiguration(ScrnInfoPtr pScrn)
{
    xf86CrtcConfigPtr   xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
    I830Ptr pI830 = I830PTR(pScrn);
    int i;

    xf86DrvMsg(pScrn->scrnIndex, X_INFO, "Output configuration:\n");

    for (i = 0; i < xf86_config->num_crtc; i++) {
	xf86CrtcPtr crtc = xf86_config->crtc[i];
	I830CrtcPrivatePtr intel_crtc = crtc ? crtc->driver_private : NULL;
	CARD32 dspcntr = intel_crtc->plane == 0 ? INREG(DSPACNTR) :
	    INREG(DSPBCNTR);
	CARD32 pipeconf = i == 0 ? INREG(PIPEACONF) :
	    INREG(PIPEBCONF);
	Bool hw_plane_enable = (dspcntr & DISPLAY_PLANE_ENABLE) != 0;
	Bool hw_pipe_enable = (pipeconf & PIPEACONF_ENABLE) != 0;

	xf86DrvMsg(pScrn->scrnIndex, X_INFO,
		   "  Pipe %c is %s\n",
		   'A' + i, crtc->enabled ? "on" : "off");
	xf86DrvMsg(pScrn->scrnIndex, X_INFO,
		   "  Display plane %c is now %s and connected to pipe %c.\n",
		   'A' + intel_crtc->plane,
		   hw_plane_enable ? "enabled" : "disabled",
		   dspcntr & DISPPLANE_SEL_PIPE_MASK ? 'B' : 'A');
	if (hw_pipe_enable != crtc->enabled) {
	    xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
		       "  Hardware claims pipe %c is %s while software "
		       "believes it is %s\n",
		       'A' + i, hw_pipe_enable ? "on" : "off",
		       crtc->enabled ? "on" : "off");
	}
	if (hw_plane_enable != crtc->enabled) {
	    xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
		       "  Hardware claims plane %c is %s while software "
		       "believes it is %s\n",
		       'A' + i, hw_plane_enable ? "on" : "off",
		       crtc->enabled ? "on" : "off");
	}
    }

    for (i = 0; i < xf86_config->num_output; i++) {
	xf86OutputPtr	output = xf86_config->output[i];
	xf86CrtcPtr	crtc = output->crtc;
	I830CrtcPrivatePtr	intel_crtc = crtc ? crtc->driver_private : NULL;
	
	xf86DrvMsg(pScrn->scrnIndex, X_INFO,
		   "  Output %s is connected to pipe %s\n",
		   output->name, intel_crtc == NULL ? "none" :
		   (intel_crtc->pipe == 0 ? "A" : "B"));
    }
}

/**
 * Get a pipe with a simple mode set on it for doing load-based monitor
 * detection.
 *
 * It will be up to the load-detect code to adjust the pipe as appropriate for
 * its requirements.  The pipe will be connected to no other outputs.
 *
 * Currently this code will only succeed if there is a pipe with no outputs
 * configured for it.  In the future, it could choose to temporarily disable
 * some outputs to free up a pipe for its use.
 *
 * \return crtc, or NULL if no pipes are available.
 */
    
/* VESA 640x480x72Hz mode to set on the pipe */
static DisplayModeRec   load_detect_mode = {
    NULL, NULL, "640x480", MODE_OK, M_T_DEFAULT,
    31500,
    640, 664, 704, 832, 0,
    480, 489, 491, 520, 0,
    V_NHSYNC | V_NVSYNC,
    0, 0,

    640, 640, 664, 704, 832, 832, 0,
    480, 489, 489, 491, 520, 520,
    FALSE, FALSE, 0, NULL, 0, 0.0, 0.0
};

xf86CrtcPtr
i830GetLoadDetectPipe(xf86OutputPtr output, DisplayModePtr mode, int *dpms_mode)
{
    ScrnInfoPtr		    pScrn = output->scrn;
    xf86CrtcConfigPtr	    xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
    I830OutputPrivatePtr    intel_output = output->driver_private;
    I830CrtcPrivatePtr	    intel_crtc;
    xf86CrtcPtr		    supported_crtc =NULL;
    xf86CrtcPtr		    crtc = NULL;
    int			    i;

    if (output->crtc) 
    {
	crtc = output->crtc;
	/*
	 * Make sure the crtc and output are running
	 */
	intel_crtc = crtc->driver_private;
	*dpms_mode = intel_crtc->dpms_mode;
	if (intel_crtc->dpms_mode != DPMSModeOn)
	{
	    crtc->funcs->dpms (crtc, DPMSModeOn);
	    output->funcs->dpms (output, DPMSModeOn);
	}
	return crtc;
    }

    for (i = 0; i < xf86_config->num_crtc; i++)
    {
	xf86CrtcPtr possible_crtc;
	if (!(output->possible_crtcs & (1 << i)))
	    continue;
	possible_crtc = xf86_config->crtc[i];
	if (!possible_crtc->enabled)
	{
	    crtc = possible_crtc;
	    break;
	}
	if (!supported_crtc)
	    supported_crtc = possible_crtc;
    }
    if (!crtc)
    {
	crtc = supported_crtc;
	if (!crtc)
	    return NULL;
    }

    output->crtc = crtc;
    intel_output->load_detect_temp = TRUE;
    
    intel_crtc = crtc->driver_private;
    *dpms_mode = intel_crtc->dpms_mode;

    if (!crtc->enabled)
    {
	if (!mode)
	    mode = &load_detect_mode;
	xf86CrtcSetMode (crtc, mode, RR_Rotate_0, 0, 0);
    }
    else
    {
	if (intel_crtc->dpms_mode != DPMSModeOn)
	    crtc->funcs->dpms (crtc, DPMSModeOn);

	/* Add this output to the crtc */
	output->funcs->mode_set (output, &crtc->mode, &crtc->mode);
	output->funcs->commit (output);
    }
    /* let the output get through one full cycle before testing */
    i830WaitForVblank (pScrn);

    return crtc;
}

void
i830ReleaseLoadDetectPipe(xf86OutputPtr output, int dpms_mode)
{
    ScrnInfoPtr		    pScrn = output->scrn;
    I830OutputPrivatePtr    intel_output = output->driver_private;
    xf86CrtcPtr		    crtc = output->crtc;
    
    if (intel_output->load_detect_temp) 
    {
	output->crtc = NULL;
	intel_output->load_detect_temp = FALSE;
	crtc->enabled = xf86CrtcInUse (crtc);
	xf86DisableUnusedFunctions(pScrn);
    }
    /*
     * Switch crtc and output back off if necessary
     */
    if (crtc->enabled && dpms_mode != DPMSModeOn)
    {
	if (output->crtc == crtc)
	    output->funcs->dpms (output, dpms_mode);
	crtc->funcs->dpms (crtc, dpms_mode);
    }
}

/* Returns the clock of the currently programmed mode of the given pipe. */
static int
i830_crtc_clock_get(ScrnInfoPtr pScrn, xf86CrtcPtr crtc)
{
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr	intel_crtc = crtc->driver_private;
    int pipe = intel_crtc->pipe;
    CARD32 dpll = INREG((pipe == 0) ? DPLL_A : DPLL_B);
    CARD32 fp;
    intel_clock_t clock;

    if ((dpll & DISPLAY_RATE_SELECT_FPA1) == 0)
	fp = INREG((pipe == 0) ? FPA0 : FPB0);
    else
	fp = INREG((pipe == 0) ? FPA1 : FPB1);

    clock.m1 = (fp & FP_M1_DIV_MASK) >> FP_M1_DIV_SHIFT;
    clock.m2 = (fp & FP_M2_DIV_MASK) >> FP_M2_DIV_SHIFT;
    clock.n = (fp & FP_N_DIV_MASK) >> FP_N_DIV_SHIFT;
    if (IS_I9XX(pI830)) {
	clock.p1 = ffs((dpll & DPLL_FPA01_P1_POST_DIV_MASK) >>
		       DPLL_FPA01_P1_POST_DIV_SHIFT);

	switch (dpll & DPLL_MODE_MASK) {
	case DPLLB_MODE_DAC_SERIAL:
	    clock.p2 = dpll & DPLL_DAC_SERIAL_P2_CLOCK_DIV_5 ? 5 : 10;
	    break;
	case DPLLB_MODE_LVDS:
	    clock.p2 = dpll & DPLLB_LVDS_P2_CLOCK_DIV_7 ? 7 : 14;
	    break;
	default:
	    xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
		       "Unknown DPLL mode %08x in programmed mode\n",
		       (int)(dpll & DPLL_MODE_MASK));
	    return 0;
	}

	/* XXX: Handle the 100Mhz refclk */
	i9xx_clock(96000, &clock);
    } else {
	Bool is_lvds = (pipe == 1) && (INREG(LVDS) & LVDS_PORT_EN);

	if (is_lvds) {
	    clock.p1 = ffs((dpll & DPLL_FPA01_P1_POST_DIV_MASK_I830_LVDS) >>
			   DPLL_FPA01_P1_POST_DIV_SHIFT);
	    clock.p2 = 14;

	    if ((dpll & PLL_REF_INPUT_MASK) == PLLB_REF_INPUT_SPREADSPECTRUMIN)
		i8xx_clock(66000, &clock); /* XXX: might not be 66MHz */
	    else
		i8xx_clock(48000, &clock);		
	} else {
	    if (dpll & PLL_P1_DIVIDE_BY_TWO) {
		clock.p1 = 2;
	    } else {
		clock.p1 = ((dpll & DPLL_FPA01_P1_POST_DIV_MASK_I830) >>
		    DPLL_FPA01_P1_POST_DIV_SHIFT) + 2;
	    }
	    if (dpll & PLL_P2_DIVIDE_BY_4)
		clock.p2 = 4;
	    else
		clock.p2 = 2;

	    i8xx_clock(48000, &clock);
	}
    }

    /* XXX: It would be nice to validate the clocks, but we can't reuse
     * i830PllIsValid() because it relies on the xf86_config output
     * configuration being accurate, which it isn't necessarily.
     */
    if (0)
	i830PrintPll("probed", &clock);

    return clock.dot;
}

/** Returns the currently programmed mode of the given pipe. */
DisplayModePtr
i830_crtc_mode_get(ScrnInfoPtr pScrn, xf86CrtcPtr crtc)
{
    I830Ptr pI830 = I830PTR(pScrn);
    I830CrtcPrivatePtr	intel_crtc = crtc->driver_private;
    int pipe = intel_crtc->pipe;
    DisplayModePtr mode;
    int htot = INREG((pipe == 0) ? HTOTAL_A : HTOTAL_B);
    int hsync = INREG((pipe == 0) ? HSYNC_A : HSYNC_B);
    int vtot = INREG((pipe == 0) ? VTOTAL_A : VTOTAL_B);
    int vsync = INREG((pipe == 0) ? VSYNC_A : VSYNC_B);

    mode = xcalloc(1, sizeof(DisplayModeRec));
    if (mode == NULL)
	return NULL;

    mode->Clock = i830_crtc_clock_get(pScrn, crtc);
    mode->HDisplay = (htot & 0xffff) + 1;
    mode->HTotal = ((htot & 0xffff0000) >> 16) + 1;
    mode->HSyncStart = (hsync & 0xffff) + 1;
    mode->HSyncEnd = ((hsync & 0xffff0000) >> 16) + 1;
    mode->VDisplay = (vtot & 0xffff) + 1;
    mode->VTotal = ((vtot & 0xffff0000) >> 16) + 1;
    mode->VSyncStart = (vsync & 0xffff) + 1;
    mode->VSyncEnd = ((vsync & 0xffff0000) >> 16) + 1;
    xf86SetModeDefaultName(mode);
    xf86SetModeCrtc(mode, 0);

    return mode;
}

static const xf86CrtcFuncsRec i830_crtc_funcs = {
    .dpms = i830_crtc_dpms,
    .save = NULL, /* XXX */
    .restore = NULL, /* XXX */
    .lock = i830_crtc_lock,
    .unlock = i830_crtc_unlock,
    .mode_fixup = i830_crtc_mode_fixup,
    .prepare = i830_crtc_prepare,
    .mode_set = i830_crtc_mode_set,
    .commit = i830_crtc_commit,
    .gamma_set = i830_crtc_gamma_set,
    .shadow_create = i830_crtc_shadow_create,
    .shadow_allocate = i830_crtc_shadow_allocate,
    .shadow_destroy = i830_crtc_shadow_destroy,
    .set_cursor_colors = i830_crtc_set_cursor_colors,
    .set_cursor_position = i830_crtc_set_cursor_position,
    .show_cursor = i830_crtc_show_cursor,
    .hide_cursor = i830_crtc_hide_cursor,
/*    .load_cursor_image = i830_crtc_load_cursor_image, */
    .load_cursor_argb = i830_crtc_load_cursor_argb,
    .destroy = NULL, /* XXX */
};

void
i830_crtc_init(ScrnInfoPtr pScrn, int pipe)
{
    xf86CrtcPtr crtc;
    I830CrtcPrivatePtr intel_crtc;
    int i;

    crtc = xf86CrtcCreate (pScrn, &i830_crtc_funcs);
    if (crtc == NULL)
	return;

    intel_crtc = xnfcalloc (sizeof (I830CrtcPrivateRec), 1);
    intel_crtc->pipe = pipe;
    intel_crtc->dpms_mode = DPMSModeOff;
    intel_crtc->plane = pipe;

    /* Initialize the LUTs for when we turn on the CRTC. */
    for (i = 0; i < 256; i++) {
	intel_crtc->lut_r[i] = i;
	intel_crtc->lut_g[i] = i;
	intel_crtc->lut_b[i] = i;
    }
    crtc->driver_private = intel_crtc;
}