summaryrefslogtreecommitdiffstats
path: root/arch/sparc64/kernel/time.c
blob: cd8c740cba1da72fccf69c78736b662383e8539b (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
/* $Id: time.c,v 1.42 2002/01/23 14:33:55 davem Exp $
 * time.c: UltraSparc timer and TOD clock support.
 *
 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1998 Eddie C. Dost   (ecd@skynet.be)
 *
 * Based largely on code which is:
 *
 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/mc146818rtc.h>
#include <linux/delay.h>
#include <linux/profile.h>
#include <linux/bcd.h>
#include <linux/jiffies.h>
#include <linux/cpufreq.h>
#include <linux/percpu.h>
#include <linux/profile.h>
#include <linux/miscdevice.h>
#include <linux/rtc.h>
#include <linux/kernel_stat.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>

#include <asm/oplib.h>
#include <asm/mostek.h>
#include <asm/timer.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/of_device.h>
#include <asm/starfire.h>
#include <asm/smp.h>
#include <asm/sections.h>
#include <asm/cpudata.h>
#include <asm/uaccess.h>
#include <asm/prom.h>
#include <asm/irq_regs.h>

DEFINE_SPINLOCK(mostek_lock);
DEFINE_SPINLOCK(rtc_lock);
void __iomem *mstk48t02_regs = NULL;
#ifdef CONFIG_PCI
unsigned long ds1287_regs = 0UL;
static void __iomem *bq4802_regs;
#endif

static void __iomem *mstk48t08_regs;
static void __iomem *mstk48t59_regs;

static int set_rtc_mmss(unsigned long);

#define TICK_PRIV_BIT	(1UL << 63)
#define TICKCMP_IRQ_BIT	(1UL << 63)

#ifdef CONFIG_SMP
unsigned long profile_pc(struct pt_regs *regs)
{
	unsigned long pc = instruction_pointer(regs);

	if (in_lock_functions(pc))
		return regs->u_regs[UREG_RETPC];
	return pc;
}
EXPORT_SYMBOL(profile_pc);
#endif

static void tick_disable_protection(void)
{
	/* Set things up so user can access tick register for profiling
	 * purposes.  Also workaround BB_ERRATA_1 by doing a dummy
	 * read back of %tick after writing it.
	 */
	__asm__ __volatile__(
	"	ba,pt	%%xcc, 1f\n"
	"	 nop\n"
	"	.align	64\n"
	"1:	rd	%%tick, %%g2\n"
	"	add	%%g2, 6, %%g2\n"
	"	andn	%%g2, %0, %%g2\n"
	"	wrpr	%%g2, 0, %%tick\n"
	"	rdpr	%%tick, %%g0"
	: /* no outputs */
	: "r" (TICK_PRIV_BIT)
	: "g2");
}

static void tick_disable_irq(void)
{
	__asm__ __volatile__(
	"	ba,pt	%%xcc, 1f\n"
	"	 nop\n"
	"	.align	64\n"
	"1:	wr	%0, 0x0, %%tick_cmpr\n"
	"	rd	%%tick_cmpr, %%g0"
	: /* no outputs */
	: "r" (TICKCMP_IRQ_BIT));
}

static void tick_init_tick(void)
{
	tick_disable_protection();
	tick_disable_irq();
}

static unsigned long tick_get_tick(void)
{
	unsigned long ret;

	__asm__ __volatile__("rd	%%tick, %0\n\t"
			     "mov	%0, %0"
			     : "=r" (ret));

	return ret & ~TICK_PRIV_BIT;
}

static int tick_add_compare(unsigned long adj)
{
	unsigned long orig_tick, new_tick, new_compare;

	__asm__ __volatile__("rd	%%tick, %0"
			     : "=r" (orig_tick));

	orig_tick &= ~TICKCMP_IRQ_BIT;

	/* Workaround for Spitfire Errata (#54 I think??), I discovered
	 * this via Sun BugID 4008234, mentioned in Solaris-2.5.1 patch
	 * number 103640.
	 *
	 * On Blackbird writes to %tick_cmpr can fail, the
	 * workaround seems to be to execute the wr instruction
	 * at the start of an I-cache line, and perform a dummy
	 * read back from %tick_cmpr right after writing to it. -DaveM
	 */
	__asm__ __volatile__("ba,pt	%%xcc, 1f\n\t"
			     " add	%1, %2, %0\n\t"
			     ".align	64\n"
			     "1:\n\t"
			     "wr	%0, 0, %%tick_cmpr\n\t"
			     "rd	%%tick_cmpr, %%g0\n\t"
			     : "=r" (new_compare)
			     : "r" (orig_tick), "r" (adj));

	__asm__ __volatile__("rd	%%tick, %0"
			     : "=r" (new_tick));
	new_tick &= ~TICKCMP_IRQ_BIT;

	return ((long)(new_tick - (orig_tick+adj))) > 0L;
}

static unsigned long tick_add_tick(unsigned long adj)
{
	unsigned long new_tick;

	/* Also need to handle Blackbird bug here too. */
	__asm__ __volatile__("rd	%%tick, %0\n\t"
			     "add	%0, %1, %0\n\t"
			     "wrpr	%0, 0, %%tick\n\t"
			     : "=&r" (new_tick)
			     : "r" (adj));

	return new_tick;
}

static struct sparc64_tick_ops tick_operations __read_mostly = {
	.name		=	"tick",
	.init_tick	=	tick_init_tick,
	.disable_irq	=	tick_disable_irq,
	.get_tick	=	tick_get_tick,
	.add_tick	=	tick_add_tick,
	.add_compare	=	tick_add_compare,
	.softint_mask	=	1UL << 0,
};

struct sparc64_tick_ops *tick_ops __read_mostly = &tick_operations;

static void stick_disable_irq(void)
{
	__asm__ __volatile__(
	"wr	%0, 0x0, %%asr25"
	: /* no outputs */
	: "r" (TICKCMP_IRQ_BIT));
}

static void stick_init_tick(void)
{
	/* Writes to the %tick and %stick register are not
	 * allowed on sun4v.  The Hypervisor controls that
	 * bit, per-strand.
	 */
	if (tlb_type != hypervisor) {
		tick_disable_protection();
		tick_disable_irq();

		/* Let the user get at STICK too. */
		__asm__ __volatile__(
		"	rd	%%asr24, %%g2\n"
		"	andn	%%g2, %0, %%g2\n"
		"	wr	%%g2, 0, %%asr24"
		: /* no outputs */
		: "r" (TICK_PRIV_BIT)
		: "g1", "g2");
	}

	stick_disable_irq();
}

static unsigned long stick_get_tick(void)
{
	unsigned long ret;

	__asm__ __volatile__("rd	%%asr24, %0"
			     : "=r" (ret));

	return ret & ~TICK_PRIV_BIT;
}

static unsigned long stick_add_tick(unsigned long adj)
{
	unsigned long new_tick;

	__asm__ __volatile__("rd	%%asr24, %0\n\t"
			     "add	%0, %1, %0\n\t"
			     "wr	%0, 0, %%asr24\n\t"
			     : "=&r" (new_tick)
			     : "r" (adj));

	return new_tick;
}

static int stick_add_compare(unsigned long adj)
{
	unsigned long orig_tick, new_tick;

	__asm__ __volatile__("rd	%%asr24, %0"
			     : "=r" (orig_tick));
	orig_tick &= ~TICKCMP_IRQ_BIT;

	__asm__ __volatile__("wr	%0, 0, %%asr25"
			     : /* no outputs */
			     : "r" (orig_tick + adj));

	__asm__ __volatile__("rd	%%asr24, %0"
			     : "=r" (new_tick));
	new_tick &= ~TICKCMP_IRQ_BIT;

	return ((long)(new_tick - (orig_tick+adj))) > 0L;
}

static struct sparc64_tick_ops stick_operations __read_mostly = {
	.name		=	"stick",
	.init_tick	=	stick_init_tick,
	.disable_irq	=	stick_disable_irq,
	.get_tick	=	stick_get_tick,
	.add_tick	=	stick_add_tick,
	.add_compare	=	stick_add_compare,
	.softint_mask	=	1UL << 16,
};

/* On Hummingbird the STICK/STICK_CMPR register is implemented
 * in I/O space.  There are two 64-bit registers each, the
 * first holds the low 32-bits of the value and the second holds
 * the high 32-bits.
 *
 * Since STICK is constantly updating, we have to access it carefully.
 *
 * The sequence we use to read is:
 * 1) read high
 * 2) read low
 * 3) read high again, if it rolled re-read both low and high again.
 *
 * Writing STICK safely is also tricky:
 * 1) write low to zero
 * 2) write high
 * 3) write low
 */
#define HBIRD_STICKCMP_ADDR	0x1fe0000f060UL
#define HBIRD_STICK_ADDR	0x1fe0000f070UL

static unsigned long __hbird_read_stick(void)
{
	unsigned long ret, tmp1, tmp2, tmp3;
	unsigned long addr = HBIRD_STICK_ADDR+8;

	__asm__ __volatile__("ldxa	[%1] %5, %2\n"
			     "1:\n\t"
			     "sub	%1, 0x8, %1\n\t"
			     "ldxa	[%1] %5, %3\n\t"
			     "add	%1, 0x8, %1\n\t"
			     "ldxa	[%1] %5, %4\n\t"
			     "cmp	%4, %2\n\t"
			     "bne,a,pn	%%xcc, 1b\n\t"
			     " mov	%4, %2\n\t"
			     "sllx	%4, 32, %4\n\t"
			     "or	%3, %4, %0\n\t"
			     : "=&r" (ret), "=&r" (addr),
			       "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3)
			     : "i" (ASI_PHYS_BYPASS_EC_E), "1" (addr));

	return ret;
}

static void __hbird_write_stick(unsigned long val)
{
	unsigned long low = (val & 0xffffffffUL);
	unsigned long high = (val >> 32UL);
	unsigned long addr = HBIRD_STICK_ADDR;

	__asm__ __volatile__("stxa	%%g0, [%0] %4\n\t"
			     "add	%0, 0x8, %0\n\t"
			     "stxa	%3, [%0] %4\n\t"
			     "sub	%0, 0x8, %0\n\t"
			     "stxa	%2, [%0] %4"
			     : "=&r" (addr)
			     : "0" (addr), "r" (low), "r" (high),
			       "i" (ASI_PHYS_BYPASS_EC_E));
}

static void __hbird_write_compare(unsigned long val)
{
	unsigned long low = (val & 0xffffffffUL);
	unsigned long high = (val >> 32UL);
	unsigned long addr = HBIRD_STICKCMP_ADDR + 0x8UL;

	__asm__ __volatile__("stxa	%3, [%0] %4\n\t"
			     "sub	%0, 0x8, %0\n\t"
			     "stxa	%2, [%0] %4"
			     : "=&r" (addr)
			     : "0" (addr), "r" (low), "r" (high),
			       "i" (ASI_PHYS_BYPASS_EC_E));
}

static void hbtick_disable_irq(void)
{
	__hbird_write_compare(TICKCMP_IRQ_BIT);
}

static void hbtick_init_tick(void)
{
	tick_disable_protection();

	/* XXX This seems to be necessary to 'jumpstart' Hummingbird
	 * XXX into actually sending STICK interrupts.  I think because
	 * XXX of how we store %tick_cmpr in head.S this somehow resets the
	 * XXX {TICK + STICK} interrupt mux.  -DaveM
	 */
	__hbird_write_stick(__hbird_read_stick());

	hbtick_disable_irq();
}

static unsigned long hbtick_get_tick(void)
{
	return __hbird_read_stick() & ~TICK_PRIV_BIT;
}

static unsigned long hbtick_add_tick(unsigned long adj)
{
	unsigned long val;

	val = __hbird_read_stick() + adj;
	__hbird_write_stick(val);

	return val;
}

static int hbtick_add_compare(unsigned long adj)
{
	unsigned long val = __hbird_read_stick();
	unsigned long val2;

	val &= ~TICKCMP_IRQ_BIT;
	val += adj;
	__hbird_write_compare(val);

	val2 = __hbird_read_stick() & ~TICKCMP_IRQ_BIT;

	return ((long)(val2 - val)) > 0L;
}

static struct sparc64_tick_ops hbtick_operations __read_mostly = {
	.name		=	"hbtick",
	.init_tick	=	hbtick_init_tick,
	.disable_irq	=	hbtick_disable_irq,
	.get_tick	=	hbtick_get_tick,
	.add_tick	=	hbtick_add_tick,
	.add_compare	=	hbtick_add_compare,
	.softint_mask	=	1UL << 0,
};

static unsigned long timer_ticks_per_nsec_quotient __read_mostly;

int update_persistent_clock(struct timespec now)
{
	return set_rtc_mmss(now.tv_sec);
}

/* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
static void __init kick_start_clock(void)
{
	void __iomem *regs = mstk48t02_regs;
	u8 sec, tmp;
	int i, count;

	prom_printf("CLOCK: Clock was stopped. Kick start ");

	spin_lock_irq(&mostek_lock);

	/* Turn on the kick start bit to start the oscillator. */
	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp |= MSTK_CREG_WRITE;
	mostek_write(regs + MOSTEK_CREG, tmp);
	tmp = mostek_read(regs + MOSTEK_SEC);
	tmp &= ~MSTK_STOP;
	mostek_write(regs + MOSTEK_SEC, tmp);
	tmp = mostek_read(regs + MOSTEK_HOUR);
	tmp |= MSTK_KICK_START;
	mostek_write(regs + MOSTEK_HOUR, tmp);
	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp &= ~MSTK_CREG_WRITE;
	mostek_write(regs + MOSTEK_CREG, tmp);

	spin_unlock_irq(&mostek_lock);

	/* Delay to allow the clock oscillator to start. */
	sec = MSTK_REG_SEC(regs);
	for (i = 0; i < 3; i++) {
		while (sec == MSTK_REG_SEC(regs))
			for (count = 0; count < 100000; count++)
				/* nothing */ ;
		prom_printf(".");
		sec = MSTK_REG_SEC(regs);
	}
	prom_printf("\n");

	spin_lock_irq(&mostek_lock);

	/* Turn off kick start and set a "valid" time and date. */
	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp |= MSTK_CREG_WRITE;
	mostek_write(regs + MOSTEK_CREG, tmp);
	tmp = mostek_read(regs + MOSTEK_HOUR);
	tmp &= ~MSTK_KICK_START;
	mostek_write(regs + MOSTEK_HOUR, tmp);
	MSTK_SET_REG_SEC(regs,0);
	MSTK_SET_REG_MIN(regs,0);
	MSTK_SET_REG_HOUR(regs,0);
	MSTK_SET_REG_DOW(regs,5);
	MSTK_SET_REG_DOM(regs,1);
	MSTK_SET_REG_MONTH(regs,8);
	MSTK_SET_REG_YEAR(regs,1996 - MSTK_YEAR_ZERO);
	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp &= ~MSTK_CREG_WRITE;
	mostek_write(regs + MOSTEK_CREG, tmp);

	spin_unlock_irq(&mostek_lock);

	/* Ensure the kick start bit is off. If it isn't, turn it off. */
	while (mostek_read(regs + MOSTEK_HOUR) & MSTK_KICK_START) {
		prom_printf("CLOCK: Kick start still on!\n");

		spin_lock_irq(&mostek_lock);

		tmp = mostek_read(regs + MOSTEK_CREG);
		tmp |= MSTK_CREG_WRITE;
		mostek_write(regs + MOSTEK_CREG, tmp);

		tmp = mostek_read(regs + MOSTEK_HOUR);
		tmp &= ~MSTK_KICK_START;
		mostek_write(regs + MOSTEK_HOUR, tmp);

		tmp = mostek_read(regs + MOSTEK_CREG);
		tmp &= ~MSTK_CREG_WRITE;
		mostek_write(regs + MOSTEK_CREG, tmp);

		spin_unlock_irq(&mostek_lock);
	}

	prom_printf("CLOCK: Kick start procedure successful.\n");
}

/* Return nonzero if the clock chip battery is low. */
static int __init has_low_battery(void)
{
	void __iomem *regs = mstk48t02_regs;
	u8 data1, data2;

	spin_lock_irq(&mostek_lock);

	data1 = mostek_read(regs + MOSTEK_EEPROM);	/* Read some data. */
	mostek_write(regs + MOSTEK_EEPROM, ~data1);	/* Write back the complement. */
	data2 = mostek_read(regs + MOSTEK_EEPROM);	/* Read back the complement. */
	mostek_write(regs + MOSTEK_EEPROM, data1);	/* Restore original value. */

	spin_unlock_irq(&mostek_lock);

	return (data1 == data2);	/* Was the write blocked? */
}

/* Probe for the real time clock chip. */
static void __init set_system_time(void)
{
	unsigned int year, mon, day, hour, min, sec;
	void __iomem *mregs = mstk48t02_regs;
#ifdef CONFIG_PCI
	unsigned long dregs = ds1287_regs;
	void __iomem *bregs = bq4802_regs;
#else
	unsigned long dregs = 0UL;
	void __iomem *bregs = 0UL;
#endif
	u8 tmp;

	if (!mregs && !dregs && !bregs) {
		prom_printf("Something wrong, clock regs not mapped yet.\n");
		prom_halt();
	}		

	if (mregs) {
		spin_lock_irq(&mostek_lock);

		/* Traditional Mostek chip. */
		tmp = mostek_read(mregs + MOSTEK_CREG);
		tmp |= MSTK_CREG_READ;
		mostek_write(mregs + MOSTEK_CREG, tmp);

		sec = MSTK_REG_SEC(mregs);
		min = MSTK_REG_MIN(mregs);
		hour = MSTK_REG_HOUR(mregs);
		day = MSTK_REG_DOM(mregs);
		mon = MSTK_REG_MONTH(mregs);
		year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
	} else if (bregs) {
		unsigned char val = readb(bregs + 0x0e);
		unsigned int century;

		/* BQ4802 RTC chip. */

		writeb(val | 0x08, bregs + 0x0e);

		sec  = readb(bregs + 0x00);
		min  = readb(bregs + 0x02);
		hour = readb(bregs + 0x04);
		day  = readb(bregs + 0x06);
		mon  = readb(bregs + 0x09);
		year = readb(bregs + 0x0a);
		century = readb(bregs + 0x0f);

		writeb(val, bregs + 0x0e);

		BCD_TO_BIN(sec);
		BCD_TO_BIN(min);
		BCD_TO_BIN(hour);
		BCD_TO_BIN(day);
		BCD_TO_BIN(mon);
		BCD_TO_BIN(year);
		BCD_TO_BIN(century);

		year += (century * 100);
	} else {
		/* Dallas 12887 RTC chip. */

		do {
			sec  = CMOS_READ(RTC_SECONDS);
			min  = CMOS_READ(RTC_MINUTES);
			hour = CMOS_READ(RTC_HOURS);
			day  = CMOS_READ(RTC_DAY_OF_MONTH);
			mon  = CMOS_READ(RTC_MONTH);
			year = CMOS_READ(RTC_YEAR);
		} while (sec != CMOS_READ(RTC_SECONDS));

		if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
			BCD_TO_BIN(sec);
			BCD_TO_BIN(min);
			BCD_TO_BIN(hour);
			BCD_TO_BIN(day);
			BCD_TO_BIN(mon);
			BCD_TO_BIN(year);
		}
		if ((year += 1900) < 1970)
			year += 100;
	}

	xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
	xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
	set_normalized_timespec(&wall_to_monotonic,
 	                        -xtime.tv_sec, -xtime.tv_nsec);

	if (mregs) {
		tmp = mostek_read(mregs + MOSTEK_CREG);
		tmp &= ~MSTK_CREG_READ;
		mostek_write(mregs + MOSTEK_CREG, tmp);

		spin_unlock_irq(&mostek_lock);
	}
}

/* davem suggests we keep this within the 4M locked kernel image */
static u32 starfire_get_time(void)
{
	static char obp_gettod[32];
	static u32 unix_tod;

	sprintf(obp_gettod, "h# %08x unix-gettod",
		(unsigned int) (long) &unix_tod);
	prom_feval(obp_gettod);

	return unix_tod;
}

static int starfire_set_time(u32 val)
{
	/* Do nothing, time is set using the service processor
	 * console on this platform.
	 */
	return 0;
}

static u32 hypervisor_get_time(void)
{
	unsigned long ret, time;
	int retries = 10000;

retry:
	ret = sun4v_tod_get(&time);
	if (ret == HV_EOK)
		return time;
	if (ret == HV_EWOULDBLOCK) {
		if (--retries > 0) {
			udelay(100);
			goto retry;
		}
		printk(KERN_WARNING "SUN4V: tod_get() timed out.\n");
		return 0;
	}
	printk(KERN_WARNING "SUN4V: tod_get() not supported.\n");
	return 0;
}

static int hypervisor_set_time(u32 secs)
{
	unsigned long ret;
	int retries = 10000;

retry:
	ret = sun4v_tod_set(secs);
	if (ret == HV_EOK)
		return 0;
	if (ret == HV_EWOULDBLOCK) {
		if (--retries > 0) {
			udelay(100);
			goto retry;
		}
		printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
		return -EAGAIN;
	}
	printk(KERN_WARNING "SUN4V: tod_set() not supported.\n");
	return -EOPNOTSUPP;
}

static int __init clock_model_matches(const char *model)
{
	if (strcmp(model, "mk48t02") &&
	    strcmp(model, "mk48t08") &&
	    strcmp(model, "mk48t59") &&
	    strcmp(model, "m5819") &&
	    strcmp(model, "m5819p") &&
	    strcmp(model, "m5823") &&
	    strcmp(model, "ds1287") &&
	    strcmp(model, "bq4802"))
		return 0;

	return 1;
}

static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
{
	struct device_node *dp = op->node;
	const char *model = of_get_property(dp, "model", NULL);
	const char *compat = of_get_property(dp, "compatible", NULL);
	unsigned long size, flags;
	void __iomem *regs;

	if (!model)
		model = compat;

	if (!model || !clock_model_matches(model))
		return -ENODEV;

	/* On an Enterprise system there can be multiple mostek clocks.
	 * We should only match the one that is on the central FHC bus.
	 */
	if (!strcmp(dp->parent->name, "fhc") &&
	    strcmp(dp->parent->parent->name, "central") != 0)
		return -ENODEV;

	size = (op->resource[0].end - op->resource[0].start) + 1;
	regs = of_ioremap(&op->resource[0], 0, size, "clock");
	if (!regs)
		return -ENOMEM;

#ifdef CONFIG_PCI
	if (!strcmp(model, "ds1287") ||
	    !strcmp(model, "m5819") ||
	    !strcmp(model, "m5819p") ||
	    !strcmp(model, "m5823")) {
		ds1287_regs = (unsigned long) regs;
	} else if (!strcmp(model, "bq4802")) {
		bq4802_regs = regs;
	} else
#endif
	if (model[5] == '0' && model[6] == '2') {
		mstk48t02_regs = regs;
	} else if(model[5] == '0' && model[6] == '8') {
		mstk48t08_regs = regs;
		mstk48t02_regs = mstk48t08_regs + MOSTEK_48T08_48T02;
	} else {
		mstk48t59_regs = regs;
		mstk48t02_regs = mstk48t59_regs + MOSTEK_48T59_48T02;
	}

	printk(KERN_INFO "%s: Clock regs at %p\n", dp->full_name, regs);

	local_irq_save(flags);

	if (mstk48t02_regs != NULL) {
		/* Report a low battery voltage condition. */
		if (has_low_battery())
			prom_printf("NVRAM: Low battery voltage!\n");

		/* Kick start the clock if it is completely stopped. */
		if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
			kick_start_clock();
	}

	set_system_time();
	
	local_irq_restore(flags);

	return 0;
}

static struct of_device_id clock_match[] = {
	{
		.name = "eeprom",
	},
	{
		.name = "rtc",
	},
	{},
};

static struct of_platform_driver clock_driver = {
	.match_table	= clock_match,
	.probe		= clock_probe,
	.driver		= {
		.name	= "clock",
	},
};

static int __init clock_init(void)
{
	if (this_is_starfire) {
		xtime.tv_sec = starfire_get_time();
		xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
		set_normalized_timespec(&wall_to_monotonic,
		                        -xtime.tv_sec, -xtime.tv_nsec);
		return 0;
	}
	if (tlb_type == hypervisor) {
		xtime.tv_sec = hypervisor_get_time();
		xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
		set_normalized_timespec(&wall_to_monotonic,
		                        -xtime.tv_sec, -xtime.tv_nsec);
		return 0;
	}

	return of_register_driver(&clock_driver, &of_platform_bus_type);
}

/* Must be after subsys_initcall() so that busses are probed.  Must
 * be before device_initcall() because things like the RTC driver
 * need to see the clock registers.
 */
fs_initcall(clock_init);

/* This is gets the master TICK_INT timer going. */
static unsigned long sparc64_init_timers(void)
{
	struct device_node *dp;
	unsigned long clock;

	dp = of_find_node_by_path("/");
	if (tlb_type == spitfire) {
		unsigned long ver, manuf, impl;

		__asm__ __volatile__ ("rdpr %%ver, %0"
				      : "=&r" (ver));
		manuf = ((ver >> 48) & 0xffff);
		impl = ((ver >> 32) & 0xffff);
		if (manuf == 0x17 && impl == 0x13) {
			/* Hummingbird, aka Ultra-IIe */
			tick_ops = &hbtick_operations;
			clock = of_getintprop_default(dp, "stick-frequency", 0);
		} else {
			tick_ops = &tick_operations;
			clock = local_cpu_data().clock_tick;
		}
	} else {
		tick_ops = &stick_operations;
		clock = of_getintprop_default(dp, "stick-frequency", 0);
	}

	return clock;
}

struct freq_table {
	unsigned long clock_tick_ref;
	unsigned int ref_freq;
};
static DEFINE_PER_CPU(struct freq_table, sparc64_freq_table) = { 0, 0 };

unsigned long sparc64_get_clock_tick(unsigned int cpu)
{
	struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);

	if (ft->clock_tick_ref)
		return ft->clock_tick_ref;
	return cpu_data(cpu).clock_tick;
}

#ifdef CONFIG_CPU_FREQ

static int sparc64_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
				    void *data)
{
	struct cpufreq_freqs *freq = data;
	unsigned int cpu = freq->cpu;
	struct freq_table *ft = &per_cpu(sparc64_freq_table, cpu);

	if (!ft->ref_freq) {
		ft->ref_freq = freq->old;
		ft->clock_tick_ref = cpu_data(cpu).clock_tick;
	}
	if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
	    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
	    (val == CPUFREQ_RESUMECHANGE)) {
		cpu_data(cpu).clock_tick =
			cpufreq_scale(ft->clock_tick_ref,
				      ft->ref_freq,
				      freq->new);
	}

	return 0;
}

static struct notifier_block sparc64_cpufreq_notifier_block = {
	.notifier_call	= sparc64_cpufreq_notifier
};

#endif /* CONFIG_CPU_FREQ */

static int sparc64_next_event(unsigned long delta,
			      struct clock_event_device *evt)
{
	return tick_ops->add_compare(delta) ? -ETIME : 0;
}

static void sparc64_timer_setup(enum clock_event_mode mode,
				struct clock_event_device *evt)
{
	switch (mode) {
	case CLOCK_EVT_MODE_ONESHOT:
	case CLOCK_EVT_MODE_RESUME:
		break;

	case CLOCK_EVT_MODE_SHUTDOWN:
		tick_ops->disable_irq();
		break;

	case CLOCK_EVT_MODE_PERIODIC:
	case CLOCK_EVT_MODE_UNUSED:
		WARN_ON(1);
		break;
	};
}

static struct clock_event_device sparc64_clockevent = {
	.features	= CLOCK_EVT_FEAT_ONESHOT,
	.set_mode	= sparc64_timer_setup,
	.set_next_event	= sparc64_next_event,
	.rating		= 100,
	.shift		= 30,
	.irq		= -1,
};
static DEFINE_PER_CPU(struct clock_event_device, sparc64_events);

void timer_interrupt(int irq, struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);
	unsigned long tick_mask = tick_ops->softint_mask;
	int cpu = smp_processor_id();
	struct clock_event_device *evt = &per_cpu(sparc64_events, cpu);

	clear_softint(tick_mask);

	irq_enter();

	kstat_this_cpu.irqs[0]++;

	if (unlikely(!evt->event_handler)) {
		printk(KERN_WARNING
		       "Spurious SPARC64 timer interrupt on cpu %d\n", cpu);
	} else
		evt->event_handler(evt);

	irq_exit();

	set_irq_regs(old_regs);
}

void __devinit setup_sparc64_timer(void)
{
	struct clock_event_device *sevt;
	unsigned long pstate;

	/* Guarantee that the following sequences execute
	 * uninterrupted.
	 */
	__asm__ __volatile__("rdpr	%%pstate, %0\n\t"
			     "wrpr	%0, %1, %%pstate"
			     : "=r" (pstate)
			     : "i" (PSTATE_IE));

	tick_ops->init_tick();

	/* Restore PSTATE_IE. */
	__asm__ __volatile__("wrpr	%0, 0x0, %%pstate"
			     : /* no outputs */
			     : "r" (pstate));

	sevt = &__get_cpu_var(sparc64_events);

	memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
	sevt->cpumask = cpumask_of_cpu(smp_processor_id());

	clockevents_register_device(sevt);
}

#define SPARC64_NSEC_PER_CYC_SHIFT	10UL

static struct clocksource clocksource_tick = {
	.rating		= 100,
	.mask		= CLOCKSOURCE_MASK(64),
	.shift		= 16,
	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
};

static void __init setup_clockevent_multiplier(unsigned long hz)
{
	unsigned long mult, shift = 32;

	while (1) {
		mult = div_sc(hz, NSEC_PER_SEC, shift);
		if (mult && (mult >> 32UL) == 0UL)
			break;

		shift--;
	}

	sparc64_clockevent.shift = shift;
	sparc64_clockevent.mult = mult;
}

static unsigned long tb_ticks_per_usec __read_mostly;

void __delay(unsigned long loops)
{
	unsigned long bclock, now;

	bclock = tick_ops->get_tick();
	do {
		now = tick_ops->get_tick();
	} while ((now-bclock) < loops);
}
EXPORT_SYMBOL(__delay);

void udelay(unsigned long usecs)
{
	__delay(tb_ticks_per_usec * usecs);
}
EXPORT_SYMBOL(udelay);

void __init time_init(void)
{
	unsigned long clock = sparc64_init_timers();

	tb_ticks_per_usec = clock / USEC_PER_SEC;

	timer_ticks_per_nsec_quotient =
		clocksource_hz2mult(clock, SPARC64_NSEC_PER_CYC_SHIFT);

	clocksource_tick.name = tick_ops->name;
	clocksource_tick.mult =
		clocksource_hz2mult(clock,
				    clocksource_tick.shift);
	clocksource_tick.read = tick_ops->get_tick;

	printk("clocksource: mult[%x] shift[%d]\n",
	       clocksource_tick.mult, clocksource_tick.shift);

	clocksource_register(&clocksource_tick);

	sparc64_clockevent.name = tick_ops->name;

	setup_clockevent_multiplier(clock);

	sparc64_clockevent.max_delta_ns =
		clockevent_delta2ns(0x7fffffffffffffff, &sparc64_clockevent);
	sparc64_clockevent.min_delta_ns =
		clockevent_delta2ns(0xF, &sparc64_clockevent);

	printk("clockevent: mult[%lx] shift[%d]\n",
	       sparc64_clockevent.mult, sparc64_clockevent.shift);

	setup_sparc64_timer();

#ifdef CONFIG_CPU_FREQ
	cpufreq_register_notifier(&sparc64_cpufreq_notifier_block,
				  CPUFREQ_TRANSITION_NOTIFIER);
#endif
}

unsigned long long sched_clock(void)
{
	unsigned long ticks = tick_ops->get_tick();

	return (ticks * timer_ticks_per_nsec_quotient)
		>> SPARC64_NSEC_PER_CYC_SHIFT;
}

static int set_rtc_mmss(unsigned long nowtime)
{
	int real_seconds, real_minutes, chip_minutes;
	void __iomem *mregs = mstk48t02_regs;
#ifdef CONFIG_PCI
	unsigned long dregs = ds1287_regs;
	void __iomem *bregs = bq4802_regs;
#else
	unsigned long dregs = 0UL;
	void __iomem *bregs = 0UL;
#endif
	unsigned long flags;
	u8 tmp;

	/* 
	 * Not having a register set can lead to trouble.
	 * Also starfire doesn't have a tod clock.
	 */
	if (!mregs && !dregs & !bregs)
		return -1;

	if (mregs) {
		spin_lock_irqsave(&mostek_lock, flags);

		/* Read the current RTC minutes. */
		tmp = mostek_read(mregs + MOSTEK_CREG);
		tmp |= MSTK_CREG_READ;
		mostek_write(mregs + MOSTEK_CREG, tmp);

		chip_minutes = MSTK_REG_MIN(mregs);

		tmp = mostek_read(mregs + MOSTEK_CREG);
		tmp &= ~MSTK_CREG_READ;
		mostek_write(mregs + MOSTEK_CREG, tmp);

		/*
		 * since we're only adjusting minutes and seconds,
		 * don't interfere with hour overflow. This avoids
		 * messing with unknown time zones but requires your
		 * RTC not to be off by more than 15 minutes
		 */
		real_seconds = nowtime % 60;
		real_minutes = nowtime / 60;
		if (((abs(real_minutes - chip_minutes) + 15)/30) & 1)
			real_minutes += 30;	/* correct for half hour time zone */
		real_minutes %= 60;

		if (abs(real_minutes - chip_minutes) < 30) {
			tmp = mostek_read(mregs + MOSTEK_CREG);
			tmp |= MSTK_CREG_WRITE;
			mostek_write(mregs + MOSTEK_CREG, tmp);

			MSTK_SET_REG_SEC(mregs,real_seconds);
			MSTK_SET_REG_MIN(mregs,real_minutes);

			tmp = mostek_read(mregs + MOSTEK_CREG);
			tmp &= ~MSTK_CREG_WRITE;
			mostek_write(mregs + MOSTEK_CREG, tmp);

			spin_unlock_irqrestore(&mostek_lock, flags);

			return 0;
		} else {
			spin_unlock_irqrestore(&mostek_lock, flags);

			return -1;
		}
	} else if (bregs) {
		int retval = 0;
		unsigned char val = readb(bregs + 0x0e);

		/* BQ4802 RTC chip. */

		writeb(val | 0x08, bregs + 0x0e);

		chip_minutes = readb(bregs + 0x02);
		BCD_TO_BIN(chip_minutes);
		real_seconds = nowtime % 60;
		real_minutes = nowtime / 60;
		if (((abs(real_minutes - chip_minutes) + 15)/30) & 1)
			real_minutes += 30;
		real_minutes %= 60;

		if (abs(real_minutes - chip_minutes) < 30) {
			BIN_TO_BCD(real_seconds);
			BIN_TO_BCD(real_minutes);
			writeb(real_seconds, bregs + 0x00);
			writeb(real_minutes, bregs + 0x02);
		} else {
			printk(KERN_WARNING
			       "set_rtc_mmss: can't update from %d to %d\n",
			       chip_minutes, real_minutes);
			retval = -1;
		}

		writeb(val, bregs + 0x0e);

		return retval;
	} else {
		int retval = 0;
		unsigned char save_control, save_freq_select;

		/* Stolen from arch/i386/kernel/time.c, see there for
		 * credits and descriptive comments.
		 */
		spin_lock_irqsave(&rtc_lock, flags);
		save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */
		CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);

		save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */
		CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);

		chip_minutes = CMOS_READ(RTC_MINUTES);
		if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
			BCD_TO_BIN(chip_minutes);
		real_seconds = nowtime % 60;
		real_minutes = nowtime / 60;
		if (((abs(real_minutes - chip_minutes) + 15)/30) & 1)
			real_minutes += 30;
		real_minutes %= 60;

		if (abs(real_minutes - chip_minutes) < 30) {
			if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
				BIN_TO_BCD(real_seconds);
				BIN_TO_BCD(real_minutes);
			}
			CMOS_WRITE(real_seconds,RTC_SECONDS);
			CMOS_WRITE(real_minutes,RTC_MINUTES);
		} else {
			printk(KERN_WARNING
			       "set_rtc_mmss: can't update from %d to %d\n",
			       chip_minutes, real_minutes);
			retval = -1;
		}

		CMOS_WRITE(save_control, RTC_CONTROL);
		CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
		spin_unlock_irqrestore(&rtc_lock, flags);

		return retval;
	}
}

#define RTC_IS_OPEN		0x01	/* means /dev/rtc is in use	*/
static unsigned char mini_rtc_status;	/* bitmapped status byte.	*/

#define FEBRUARY	2
#define	STARTOFTIME	1970
#define SECDAY		86400L
#define SECYR		(SECDAY * 365)
#define	leapyear(year)		((year) % 4 == 0 && \
				 ((year) % 100 != 0 || (year) % 400 == 0))
#define	days_in_year(a) 	(leapyear(a) ? 366 : 365)
#define	days_in_month(a) 	(month_days[(a) - 1])

static int month_days[12] = {
	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

/*
 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
 */
static void GregorianDay(struct rtc_time * tm)
{
	int leapsToDate;
	int lastYear;
	int day;
	int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };

	lastYear = tm->tm_year - 1;

	/*
	 * Number of leap corrections to apply up to end of last year
	 */
	leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;

	/*
	 * This year is a leap year if it is divisible by 4 except when it is
	 * divisible by 100 unless it is divisible by 400
	 *
	 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
	 */
	day = tm->tm_mon > 2 && leapyear(tm->tm_year);

	day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
		   tm->tm_mday;

	tm->tm_wday = day % 7;
}

static void to_tm(int tim, struct rtc_time *tm)
{
	register int    i;
	register long   hms, day;

	day = tim / SECDAY;
	hms = tim % SECDAY;

	/* Hours, minutes, seconds are easy */
	tm->tm_hour = hms / 3600;
	tm->tm_min = (hms % 3600) / 60;
	tm->tm_sec = (hms % 3600) % 60;

	/* Number of years in days */
	for (i = STARTOFTIME; day >= days_in_year(i); i++)
		day -= days_in_year(i);
	tm->tm_year = i;

	/* Number of months in days left */
	if (leapyear(tm->tm_year))
		days_in_month(FEBRUARY) = 29;
	for (i = 1; day >= days_in_month(i); i++)
		day -= days_in_month(i);
	days_in_month(FEBRUARY) = 28;
	tm->tm_mon = i;

	/* Days are what is left over (+1) from all that. */
	tm->tm_mday = day + 1;

	/*
	 * Determine the day of week
	 */
	GregorianDay(tm);
}

/* Both Starfire and SUN4V give us seconds since Jan 1st, 1970,
 * aka Unix time.  So we have to convert to/from rtc_time.
 */
static void starfire_get_rtc_time(struct rtc_time *time)
{
	u32 seconds = starfire_get_time();

	to_tm(seconds, time);
	time->tm_year -= 1900;
	time->tm_mon -= 1;
}

static int starfire_set_rtc_time(struct rtc_time *time)
{
	u32 seconds = mktime(time->tm_year + 1900, time->tm_mon + 1,
			     time->tm_mday, time->tm_hour,
			     time->tm_min, time->tm_sec);

	return starfire_set_time(seconds);
}

static void hypervisor_get_rtc_time(struct rtc_time *time)
{
	u32 seconds = hypervisor_get_time();

	to_tm(seconds, time);
	time->tm_year -= 1900;
	time->tm_mon -= 1;
}

static int hypervisor_set_rtc_time(struct rtc_time *time)
{
	u32 seconds = mktime(time->tm_year + 1900, time->tm_mon + 1,
			     time->tm_mday, time->tm_hour,
			     time->tm_min, time->tm_sec);

	return hypervisor_set_time(seconds);
}

#ifdef CONFIG_PCI
static void bq4802_get_rtc_time(struct rtc_time *time)
{
	unsigned char val = readb(bq4802_regs + 0x0e);
	unsigned int century;

	writeb(val | 0x08, bq4802_regs + 0x0e);

	time->tm_sec = readb(bq4802_regs + 0x00);
	time->tm_min = readb(bq4802_regs + 0x02);
	time->tm_hour = readb(bq4802_regs + 0x04);
	time->tm_mday = readb(bq4802_regs + 0x06);
	time->tm_mon = readb(bq4802_regs + 0x09);
	time->tm_year = readb(bq4802_regs + 0x0a);
	time->tm_wday = readb(bq4802_regs + 0x08);
	century = readb(bq4802_regs + 0x0f);

	writeb(val, bq4802_regs + 0x0e);

	BCD_TO_BIN(time->tm_sec);
	BCD_TO_BIN(time->tm_min);
	BCD_TO_BIN(time->tm_hour);
	BCD_TO_BIN(time->tm_mday);
	BCD_TO_BIN(time->tm_mon);
	BCD_TO_BIN(time->tm_year);
	BCD_TO_BIN(time->tm_wday);
	BCD_TO_BIN(century);

	time->tm_year += (century * 100);
	time->tm_year -= 1900;

	time->tm_mon--;
}

static int bq4802_set_rtc_time(struct rtc_time *time)
{
	unsigned char val = readb(bq4802_regs + 0x0e);
	unsigned char sec, min, hrs, day, mon, yrs, century;
	unsigned int year;

	year = time->tm_year + 1900;
	century = year / 100;
	yrs = year % 100;

	mon = time->tm_mon + 1;   /* tm_mon starts at zero */
	day = time->tm_mday;
	hrs = time->tm_hour;
	min = time->tm_min;
	sec = time->tm_sec;

	BIN_TO_BCD(sec);
	BIN_TO_BCD(min);
	BIN_TO_BCD(hrs);
	BIN_TO_BCD(day);
	BIN_TO_BCD(mon);
	BIN_TO_BCD(yrs);
	BIN_TO_BCD(century);

	writeb(val | 0x08, bq4802_regs + 0x0e);

	writeb(sec, bq4802_regs + 0x00);
	writeb(min, bq4802_regs + 0x02);
	writeb(hrs, bq4802_regs + 0x04);
	writeb(day, bq4802_regs + 0x06);
	writeb(mon, bq4802_regs + 0x09);
	writeb(yrs, bq4802_regs + 0x0a);
	writeb(century, bq4802_regs + 0x0f);

	writeb(val, bq4802_regs + 0x0e);

	return 0;
}

static void cmos_get_rtc_time(struct rtc_time *rtc_tm)
{
	unsigned char ctrl;

	rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
	rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
	rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
	rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
	rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
	rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
	rtc_tm->tm_wday = CMOS_READ(RTC_DAY_OF_WEEK);

	ctrl = CMOS_READ(RTC_CONTROL);
	if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
		BCD_TO_BIN(rtc_tm->tm_sec);
		BCD_TO_BIN(rtc_tm->tm_min);
		BCD_TO_BIN(rtc_tm->tm_hour);
		BCD_TO_BIN(rtc_tm->tm_mday);
		BCD_TO_BIN(rtc_tm->tm_mon);
		BCD_TO_BIN(rtc_tm->tm_year);
		BCD_TO_BIN(rtc_tm->tm_wday);
	}

	if (rtc_tm->tm_year <= 69)
		rtc_tm->tm_year += 100;

	rtc_tm->tm_mon--;
}

static int cmos_set_rtc_time(struct rtc_time *rtc_tm)
{
	unsigned char mon, day, hrs, min, sec;
	unsigned char save_control, save_freq_select;
	unsigned int yrs;

	yrs = rtc_tm->tm_year;
	mon = rtc_tm->tm_mon + 1;
	day = rtc_tm->tm_mday;
	hrs = rtc_tm->tm_hour;
	min = rtc_tm->tm_min;
	sec = rtc_tm->tm_sec;

	if (yrs >= 100)
		yrs -= 100;

	if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
		BIN_TO_BCD(sec);
		BIN_TO_BCD(min);
		BIN_TO_BCD(hrs);
		BIN_TO_BCD(day);
		BIN_TO_BCD(mon);
		BIN_TO_BCD(yrs);
	}

	save_control = CMOS_READ(RTC_CONTROL);
	CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
	CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);

	CMOS_WRITE(yrs, RTC_YEAR);
	CMOS_WRITE(mon, RTC_MONTH);
	CMOS_WRITE(day, RTC_DAY_OF_MONTH);
	CMOS_WRITE(hrs, RTC_HOURS);
	CMOS_WRITE(min, RTC_MINUTES);
	CMOS_WRITE(sec, RTC_SECONDS);

	CMOS_WRITE(save_control, RTC_CONTROL);
	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);

	return 0;
}
#endif /* CONFIG_PCI */

static void mostek_get_rtc_time(struct rtc_time *rtc_tm)
{
	void __iomem *regs = mstk48t02_regs;
	u8 tmp;

	spin_lock_irq(&mostek_lock);

	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp |= MSTK_CREG_READ;
	mostek_write(regs + MOSTEK_CREG, tmp);

	rtc_tm->tm_sec = MSTK_REG_SEC(regs);
	rtc_tm->tm_min = MSTK_REG_MIN(regs);
	rtc_tm->tm_hour = MSTK_REG_HOUR(regs);
	rtc_tm->tm_mday = MSTK_REG_DOM(regs);
	rtc_tm->tm_mon = MSTK_REG_MONTH(regs);
	rtc_tm->tm_year = MSTK_CVT_YEAR( MSTK_REG_YEAR(regs) );
	rtc_tm->tm_wday = MSTK_REG_DOW(regs);

	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp &= ~MSTK_CREG_READ;
	mostek_write(regs + MOSTEK_CREG, tmp);

	spin_unlock_irq(&mostek_lock);

	rtc_tm->tm_mon--;
	rtc_tm->tm_wday--;
	rtc_tm->tm_year -= 1900;
}

static int mostek_set_rtc_time(struct rtc_time *rtc_tm)
{
	unsigned char mon, day, hrs, min, sec, wday;
	void __iomem *regs = mstk48t02_regs;
	unsigned int yrs;
	u8 tmp;

	yrs = rtc_tm->tm_year + 1900;
	mon = rtc_tm->tm_mon + 1;
	day = rtc_tm->tm_mday;
	wday = rtc_tm->tm_wday + 1;
	hrs = rtc_tm->tm_hour;
	min = rtc_tm->tm_min;
	sec = rtc_tm->tm_sec;

	spin_lock_irq(&mostek_lock);

	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp |= MSTK_CREG_WRITE;
	mostek_write(regs + MOSTEK_CREG, tmp);

	MSTK_SET_REG_SEC(regs, sec);
	MSTK_SET_REG_MIN(regs, min);
	MSTK_SET_REG_HOUR(regs, hrs);
	MSTK_SET_REG_DOW(regs, wday);
	MSTK_SET_REG_DOM(regs, day);
	MSTK_SET_REG_MONTH(regs, mon);
	MSTK_SET_REG_YEAR(regs, yrs - MSTK_YEAR_ZERO);

	tmp = mostek_read(regs + MOSTEK_CREG);
	tmp &= ~MSTK_CREG_WRITE;
	mostek_write(regs + MOSTEK_CREG, tmp);

	spin_unlock_irq(&mostek_lock);

	return 0;
}

struct mini_rtc_ops {
	void (*get_rtc_time)(struct rtc_time *);
	int (*set_rtc_time)(struct rtc_time *);
};

static struct mini_rtc_ops starfire_rtc_ops = {
	.get_rtc_time = starfire_get_rtc_time,
	.set_rtc_time = starfire_set_rtc_time,
};

static struct mini_rtc_ops hypervisor_rtc_ops = {
	.get_rtc_time = hypervisor_get_rtc_time,
	.set_rtc_time = hypervisor_set_rtc_time,
};

#ifdef CONFIG_PCI
static struct mini_rtc_ops bq4802_rtc_ops = {
	.get_rtc_time = bq4802_get_rtc_time,
	.set_rtc_time = bq4802_set_rtc_time,
};

static struct mini_rtc_ops cmos_rtc_ops = {
	.get_rtc_time = cmos_get_rtc_time,
	.set_rtc_time = cmos_set_rtc_time,
};
#endif /* CONFIG_PCI */

static struct mini_rtc_ops mostek_rtc_ops = {
	.get_rtc_time = mostek_get_rtc_time,
	.set_rtc_time = mostek_set_rtc_time,
};

static struct mini_rtc_ops *mini_rtc_ops;

static inline void mini_get_rtc_time(struct rtc_time *time)
{
	unsigned long flags;

	spin_lock_irqsave(&rtc_lock, flags);
	mini_rtc_ops->get_rtc_time(time);
	spin_unlock_irqrestore(&rtc_lock, flags);
}

static inline int mini_set_rtc_time(struct rtc_time *time)
{
	unsigned long flags;
	int err;

	spin_lock_irqsave(&rtc_lock, flags);
	err = mini_rtc_ops->set_rtc_time(time);
	spin_unlock_irqrestore(&rtc_lock, flags);

	return err;
}

static int mini_rtc_ioctl(struct inode *inode, struct file *file,
			  unsigned int cmd, unsigned long arg)
{
	struct rtc_time wtime;
	void __user *argp = (void __user *)arg;

	switch (cmd) {

	case RTC_PLL_GET:
		return -EINVAL;

	case RTC_PLL_SET:
		return -EINVAL;

	case RTC_UIE_OFF:	/* disable ints from RTC updates.	*/
		return 0;

	case RTC_UIE_ON:	/* enable ints for RTC updates.	*/
	        return -EINVAL;

	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
		/* this doesn't get week-day, who cares */
		memset(&wtime, 0, sizeof(wtime));
		mini_get_rtc_time(&wtime);

		return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0;

	case RTC_SET_TIME:	/* Set the RTC */
	    {
		int year, days;

		if (!capable(CAP_SYS_TIME))
			return -EACCES;

		if (copy_from_user(&wtime, argp, sizeof(wtime)))
			return -EFAULT;

		year = wtime.tm_year + 1900;
		days = month_days[wtime.tm_mon] +
		       ((wtime.tm_mon == 1) && leapyear(year));

		if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) ||
		    (wtime.tm_mday < 1))
			return -EINVAL;

		if (wtime.tm_mday < 0 || wtime.tm_mday > days)
			return -EINVAL;

		if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
		    wtime.tm_min < 0 || wtime.tm_min >= 60 ||
		    wtime.tm_sec < 0 || wtime.tm_sec >= 60)
			return -EINVAL;

		return mini_set_rtc_time(&wtime);
	    }
	}

	return -EINVAL;
}

static int mini_rtc_open(struct inode *inode, struct file *file)
{
	if (mini_rtc_status & RTC_IS_OPEN)
		return -EBUSY;

	mini_rtc_status |= RTC_IS_OPEN;

	return 0;
}

static int mini_rtc_release(struct inode *inode, struct file *file)
{
	mini_rtc_status &= ~RTC_IS_OPEN;
	return 0;
}


static const struct file_operations mini_rtc_fops = {
	.owner		= THIS_MODULE,
	.ioctl		= mini_rtc_ioctl,
	.open		= mini_rtc_open,
	.release	= mini_rtc_release,
};

static struct miscdevice rtc_mini_dev =
{
	.minor		= RTC_MINOR,
	.name		= "rtc",
	.fops		= &mini_rtc_fops,
};

static int __init rtc_mini_init(void)
{
	int retval;

	if (tlb_type == hypervisor)
		mini_rtc_ops = &hypervisor_rtc_ops;
	else if (this_is_starfire)
		mini_rtc_ops = &starfire_rtc_ops;
#ifdef CONFIG_PCI
	else if (bq4802_regs)
		mini_rtc_ops = &bq4802_rtc_ops;
	else if (ds1287_regs)
		mini_rtc_ops = &cmos_rtc_ops;
#endif /* CONFIG_PCI */
	else if (mstk48t02_regs)
		mini_rtc_ops = &mostek_rtc_ops;
	else
		return -ENODEV;

	printk(KERN_INFO "Mini RTC Driver\n");

	retval = misc_register(&rtc_mini_dev);
	if (retval < 0)
		return retval;

	return 0;
}

static void __exit rtc_mini_exit(void)
{
	misc_deregister(&rtc_mini_dev);
}


module_init(rtc_mini_init);
module_exit(rtc_mini_exit);