aboutsummaryrefslogtreecommitdiff
path: root/drivers/macintosh/therm_pm72.c
blob: c987033714f6acbfcdf307c77e514c2c24baf8bb (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
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
/*
 * Device driver for the thermostats & fan controller of  the
 * Apple G5 "PowerMac7,2" desktop machines.
 *
 * (c) Copyright IBM Corp. 2003-2004
 *
 * Maintained by: Benjamin Herrenschmidt
 *                <benh@kernel.crashing.org>
 * 
 *
 * The algorithm used is the PID control algorithm, used the same
 * way the published Darwin code does, using the same values that
 * are present in the Darwin 7.0 snapshot property lists.
 *
 * As far as the CPUs control loops are concerned, I use the
 * calibration & PID constants provided by the EEPROM,
 * I do _not_ embed any value from the property lists, as the ones
 * provided by Darwin 7.0 seem to always have an older version that
 * what I've seen on the actual computers.
 * It would be interesting to verify that though. Darwin has a
 * version code of 1.0.0d11 for all control loops it seems, while
 * so far, the machines EEPROMs contain a dataset versioned 1.0.0f
 *
 * Darwin doesn't provide source to all parts, some missing
 * bits like the AppleFCU driver or the actual scale of some
 * of the values returned by sensors had to be "guessed" some
 * way... or based on what Open Firmware does.
 *
 * I didn't yet figure out how to get the slots power consumption
 * out of the FCU, so that part has not been implemented yet and
 * the slots fan is set to a fixed 50% PWM, hoping this value is
 * safe enough ...
 *
 * Note: I have observed strange oscillations of the CPU control
 * loop on a dual G5 here. When idle, the CPU exhaust fan tend to
 * oscillates slowly (over several minutes) between the minimum
 * of 300RPMs and approx. 1000 RPMs. I don't know what is causing
 * this, it could be some incorrect constant or an error in the
 * way I ported the algorithm, or it could be just normal. I
 * don't have full understanding on the way Apple tweaked the PID
 * algorithm for the CPU control, it is definitely not a standard
 * implementation...
 *
 * TODO:  - Check MPU structure version/signature
 *        - Add things like /sbin/overtemp for non-critical
 *          overtemp conditions so userland can take some policy
 *          decisions, like slewing down CPUs
 *	  - Deal with fan and i2c failures in a better way
 *	  - Maybe do a generic PID based on params used for
 *	    U3 and Drives ? Definitely need to factor code a bit
 *          bettter... also make sensor detection more robust using
 *          the device-tree to probe for them
 *        - Figure out how to get the slots consumption and set the
 *          slots fan accordingly
 *
 * History:
 *
 *  Nov. 13, 2003 : 0.5
 *	- First release
 *
 *  Nov. 14, 2003 : 0.6
 *	- Read fan speed from FCU, low level fan routines now deal
 *	  with errors & check fan status, though higher level don't
 *	  do much.
 *	- Move a bunch of definitions to .h file
 *
 *  Nov. 18, 2003 : 0.7
 *	- Fix build on ppc64 kernel
 *	- Move back statics definitions to .c file
 *	- Avoid calling schedule_timeout with a negative number
 *
 *  Dec. 18, 2003 : 0.8
 *	- Fix typo when reading back fan speed on 2 CPU machines
 *
 *  Mar. 11, 2004 : 0.9
 *	- Rework code accessing the ADC chips, make it more robust and
 *	  closer to the chip spec. Also make sure it is configured properly,
 *        I've seen yet unexplained cases where on startup, I would have stale
 *        values in the configuration register
 *	- Switch back to use of target fan speed for PID, thus lowering
 *        pressure on i2c
 *
 *  Oct. 20, 2004 : 1.1
 *	- Add device-tree lookup for fan IDs, should detect liquid cooling
 *        pumps when present
 *	- Enable driver for PowerMac7,3 machines
 *	- Split the U3/Backside cooling on U3 & U3H versions as Darwin does
 *	- Add new CPU cooling algorithm for machines with liquid cooling
 *	- Workaround for some PowerMac7,3 with empty "fan" node in the devtree
 *	- Fix a signed/unsigned compare issue in some PID loops
 *
 *  Mar. 10, 2005 : 1.2
 *	- Add basic support for Xserve G5
 *	- Retreive pumps min/max from EEPROM image in device-tree (broken)
 *	- Use min/max macros here or there
 *	- Latest darwin updated U3H min fan speed to 20% PWM
 *
 *  July. 06, 2006 : 1.3
 *	- Fix setting of RPM fans on Xserve G5 (they were going too fast)
 *      - Add missing slots fan control loop for Xserve G5
 *	- Lower fixed slots fan speed from 50% to 40% on desktop G5s. We
 *        still can't properly implement the control loop for these, so let's
 *        reduce the noise a little bit, it appears that 40% still gives us
 *        a pretty good air flow
 *	- Add code to "tickle" the FCU regulary so it doesn't think that
 *        we are gone while in fact, the machine just didn't need any fan
 *        speed change lately
 *
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/reboot.h>
#include <linux/kmod.h>
#include <linux/i2c.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/sections.h>
#include <asm/macio.h>

#include "therm_pm72.h"

#define VERSION "1.3"

#undef DEBUG

#ifdef DEBUG
#define DBG(args...)	printk(args)
#else
#define DBG(args...)	do { } while(0)
#endif


/*
 * Driver statics
 */

static struct platform_device *		of_dev;
static struct i2c_adapter *		u3_0;
static struct i2c_adapter *		u3_1;
static struct i2c_adapter *		k2;
static struct i2c_client *		fcu;
static struct cpu_pid_state		processor_state[2];
static struct basckside_pid_params	backside_params;
static struct backside_pid_state	backside_state;
static struct drives_pid_state		drives_state;
static struct dimm_pid_state		dimms_state;
static struct slots_pid_state		slots_state;
static int				state;
static int				cpu_count;
static int				cpu_pid_type;
static struct task_struct		*ctrl_task;
static struct completion		ctrl_complete;
static int				critical_state;
static int				rackmac;
static s32				dimm_output_clamp;
static int 				fcu_rpm_shift;
static int				fcu_tickle_ticks;
static DEFINE_MUTEX(driver_lock);

/*
 * We have 3 types of CPU PID control. One is "split" old style control
 * for intake & exhaust fans, the other is "combined" control for both
 * CPUs that also deals with the pumps when present. To be "compatible"
 * with OS X at this point, we only use "COMBINED" on the machines that
 * are identified as having the pumps (though that identification is at
 * least dodgy). Ultimately, we could probably switch completely to this
 * algorithm provided we hack it to deal with the UP case
 */
#define CPU_PID_TYPE_SPLIT	0
#define CPU_PID_TYPE_COMBINED	1
#define CPU_PID_TYPE_RACKMAC	2

/*
 * This table describes all fans in the FCU. The "id" and "type" values
 * are defaults valid for all earlier machines. Newer machines will
 * eventually override the table content based on the device-tree
 */
struct fcu_fan_table
{
	char*	loc;	/* location code */
	int	type;	/* 0 = rpm, 1 = pwm, 2 = pump */
	int	id;	/* id or -1 */
};

#define FCU_FAN_RPM		0
#define FCU_FAN_PWM		1

#define FCU_FAN_ABSENT_ID	-1

#define FCU_FAN_COUNT		ARRAY_SIZE(fcu_fans)

struct fcu_fan_table	fcu_fans[] = {
	[BACKSIDE_FAN_PWM_INDEX] = {
		.loc	= "BACKSIDE,SYS CTRLR FAN",
		.type	= FCU_FAN_PWM,
		.id	= BACKSIDE_FAN_PWM_DEFAULT_ID,
	},
	[DRIVES_FAN_RPM_INDEX] = {
		.loc	= "DRIVE BAY",
		.type	= FCU_FAN_RPM,
		.id	= DRIVES_FAN_RPM_DEFAULT_ID,
	},
	[SLOTS_FAN_PWM_INDEX] = {
		.loc	= "SLOT,PCI FAN",
		.type	= FCU_FAN_PWM,
		.id	= SLOTS_FAN_PWM_DEFAULT_ID,
	},
	[CPUA_INTAKE_FAN_RPM_INDEX] = {
		.loc	= "CPU A INTAKE",
		.type	= FCU_FAN_RPM,
		.id	= CPUA_INTAKE_FAN_RPM_DEFAULT_ID,
	},
	[CPUA_EXHAUST_FAN_RPM_INDEX] = {
		.loc	= "CPU A EXHAUST",
		.type	= FCU_FAN_RPM,
		.id	= CPUA_EXHAUST_FAN_RPM_DEFAULT_ID,
	},
	[CPUB_INTAKE_FAN_RPM_INDEX] = {
		.loc	= "CPU B INTAKE",
		.type	= FCU_FAN_RPM,
		.id	= CPUB_INTAKE_FAN_RPM_DEFAULT_ID,
	},
	[CPUB_EXHAUST_FAN_RPM_INDEX] = {
		.loc	= "CPU B EXHAUST",
		.type	= FCU_FAN_RPM,
		.id	= CPUB_EXHAUST_FAN_RPM_DEFAULT_ID,
	},
	/* pumps aren't present by default, have to be looked up in the
	 * device-tree
	 */
	[CPUA_PUMP_RPM_INDEX] = {
		.loc	= "CPU A PUMP",
		.type	= FCU_FAN_RPM,		
		.id	= FCU_FAN_ABSENT_ID,
	},
	[CPUB_PUMP_RPM_INDEX] = {
		.loc	= "CPU B PUMP",
		.type	= FCU_FAN_RPM,
		.id	= FCU_FAN_ABSENT_ID,
	},
	/* Xserve fans */
	[CPU_A1_FAN_RPM_INDEX] = {
		.loc	= "CPU A 1",
		.type	= FCU_FAN_RPM,
		.id	= FCU_FAN_ABSENT_ID,
	},
	[CPU_A2_FAN_RPM_INDEX] = {
		.loc	= "CPU A 2",
		.type	= FCU_FAN_RPM,
		.id	= FCU_FAN_ABSENT_ID,
	},
	[CPU_A3_FAN_RPM_INDEX] = {
		.loc	= "CPU A 3",
		.type	= FCU_FAN_RPM,
		.id	= FCU_FAN_ABSENT_ID,
	},
	[CPU_B1_FAN_RPM_INDEX] = {
		.loc	= "CPU B 1",
		.type	= FCU_FAN_RPM,
		.id	= FCU_FAN_ABSENT_ID,
	},
	[CPU_B2_FAN_RPM_INDEX] = {
		.loc	= "CPU B 2",
		.type	= FCU_FAN_RPM,
		.id	= FCU_FAN_ABSENT_ID,
	},
	[CPU_B3_FAN_RPM_INDEX] = {
		.loc	= "CPU B 3",
		.type	= FCU_FAN_RPM,
		.id	= FCU_FAN_ABSENT_ID,
	},
};

static struct i2c_driver therm_pm72_driver;

/*
 * Utility function to create an i2c_client structure and
 * attach it to one of u3 adapters
 */
static struct i2c_client *attach_i2c_chip(int id, const char *name)
{
	struct i2c_client *clt;
	struct i2c_adapter *adap;
	struct i2c_board_info info;

	if (id & 0x200)
		adap = k2;
	else if (id & 0x100)
		adap = u3_1;
	else
		adap = u3_0;
	if (adap == NULL)
		return NULL;

	memset(&info, 0, sizeof(struct i2c_board_info));
	info.addr = (id >> 1) & 0x7f;
	strlcpy(info.type, "therm_pm72", I2C_NAME_SIZE);
	clt = i2c_new_device(adap, &info);
	if (!clt) {
		printk(KERN_ERR "therm_pm72: Failed to attach to i2c ID 0x%x\n", id);
		return NULL;
	}

	/*
	 * Let i2c-core delete that device on driver removal.
	 * This is safe because i2c-core holds the core_lock mutex for us.
	 */
	list_add_tail(&clt->detected, &therm_pm72_driver.clients);
	return clt;
}

/*
 * Here are the i2c chip access wrappers
 */

static void initialize_adc(struct cpu_pid_state *state)
{
	int rc;
	u8 buf[2];

	/* Read ADC the configuration register and cache it. We
	 * also make sure Config2 contains proper values, I've seen
	 * cases where we got stale grabage in there, thus preventing
	 * proper reading of conv. values
	 */

	/* Clear Config2 */
	buf[0] = 5;
	buf[1] = 0;
	i2c_master_send(state->monitor, buf, 2);

	/* Read & cache Config1 */
	buf[0] = 1;
	rc = i2c_master_send(state->monitor, buf, 1);
	if (rc > 0) {
		rc = i2c_master_recv(state->monitor, buf, 1);
		if (rc > 0) {
			state->adc_config = buf[0];
			DBG("ADC config reg: %02x\n", state->adc_config);
			/* Disable shutdown mode */
		       	state->adc_config &= 0xfe;
			buf[0] = 1;
			buf[1] = state->adc_config;
			rc = i2c_master_send(state->monitor, buf, 2);
		}
	}
	if (rc <= 0)
		printk(KERN_ERR "therm_pm72: Error reading ADC config"
		       " register !\n");
}

static int read_smon_adc(struct cpu_pid_state *state, int chan)
{
	int rc, data, tries = 0;
	u8 buf[2];

	for (;;) {
		/* Set channel */
		buf[0] = 1;
		buf[1] = (state->adc_config & 0x1f) | (chan << 5);
		rc = i2c_master_send(state->monitor, buf, 2);
		if (rc <= 0)
			goto error;
		/* Wait for convertion */
		msleep(1);
		/* Switch to data register */
		buf[0] = 4;
		rc = i2c_master_send(state->monitor, buf, 1);
		if (rc <= 0)
			goto error;
		/* Read result */
		rc = i2c_master_recv(state->monitor, buf, 2);
		if (rc < 0)
			goto error;
		data = ((u16)buf[0]) << 8 | (u16)buf[1];
		return data >> 6;
	error:
		DBG("Error reading ADC, retrying...\n");
		if (++tries > 10) {
			printk(KERN_ERR "therm_pm72: Error reading ADC !\n");
			return -1;
		}
		msleep(10);
	}
}

static int read_lm87_reg(struct i2c_client * chip, int reg)
{
	int rc, tries = 0;
	u8 buf;

	for (;;) {
		/* Set address */
		buf = (u8)reg;
		rc = i2c_master_send(chip, &buf, 1);
		if (rc <= 0)
			goto error;
		rc = i2c_master_recv(chip, &buf, 1);
		if (rc <= 0)
			goto error;
		return (int)buf;
	error:
		DBG("Error reading LM87, retrying...\n");
		if (++tries > 10) {
			printk(KERN_ERR "therm_pm72: Error reading LM87 !\n");
			return -1;
		}
		msleep(10);
	}
}

static int fan_read_reg(int reg, unsigned char *buf, int nb)
{
	int tries, nr, nw;

	buf[0] = reg;
	tries = 0;
	for (;;) {
		nw = i2c_master_send(fcu, buf, 1);
		if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
			break;
		msleep(10);
		++tries;
	}
	if (nw <= 0) {
		printk(KERN_ERR "Failure writing address to FCU: %d", nw);
		return -EIO;
	}
	tries = 0;
	for (;;) {
		nr = i2c_master_recv(fcu, buf, nb);
		if (nr > 0 || (nr < 0 && nr != -ENODEV) || tries >= 100)
			break;
		msleep(10);
		++tries;
	}
	if (nr <= 0)
		printk(KERN_ERR "Failure reading data from FCU: %d", nw);
	return nr;
}

static int fan_write_reg(int reg, const unsigned char *ptr, int nb)
{
	int tries, nw;
	unsigned char buf[16];

	buf[0] = reg;
	memcpy(buf+1, ptr, nb);
	++nb;
	tries = 0;
	for (;;) {
		nw = i2c_master_send(fcu, buf, nb);
		if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
			break;
		msleep(10);
		++tries;
	}
	if (nw < 0)
		printk(KERN_ERR "Failure writing to FCU: %d", nw);
	return nw;
}

static int start_fcu(void)
{
	unsigned char buf = 0xff;
	int rc;

	rc = fan_write_reg(0xe, &buf, 1);
	if (rc < 0)
		return -EIO;
	rc = fan_write_reg(0x2e, &buf, 1);
	if (rc < 0)
		return -EIO;
	rc = fan_read_reg(0, &buf, 1);
	if (rc < 0)
		return -EIO;
	fcu_rpm_shift = (buf == 1) ? 2 : 3;
	printk(KERN_DEBUG "FCU Initialized, RPM fan shift is %d\n",
	       fcu_rpm_shift);

	return 0;
}

static int set_rpm_fan(int fan_index, int rpm)
{
	unsigned char buf[2];
	int rc, id, min, max;

	if (fcu_fans[fan_index].type != FCU_FAN_RPM)
		return -EINVAL;
	id = fcu_fans[fan_index].id; 
	if (id == FCU_FAN_ABSENT_ID)
		return -EINVAL;

	min = 2400 >> fcu_rpm_shift;
	max = 56000 >> fcu_rpm_shift;

	if (rpm < min)
		rpm = min;
	else if (rpm > max)
		rpm = max;
	buf[0] = rpm >> (8 - fcu_rpm_shift);
	buf[1] = rpm << fcu_rpm_shift;
	rc = fan_write_reg(0x10 + (id * 2), buf, 2);
	if (rc < 0)
		return -EIO;
	return 0;
}

static int get_rpm_fan(int fan_index, int programmed)
{
	unsigned char failure;
	unsigned char active;
	unsigned char buf[2];
	int rc, id, reg_base;

	if (fcu_fans[fan_index].type != FCU_FAN_RPM)
		return -EINVAL;
	id = fcu_fans[fan_index].id; 
	if (id == FCU_FAN_ABSENT_ID)
		return -EINVAL;

	rc = fan_read_reg(0xb, &failure, 1);
	if (rc != 1)
		return -EIO;
	if ((failure & (1 << id)) != 0)
		return -EFAULT;
	rc = fan_read_reg(0xd, &active, 1);
	if (rc != 1)
		return -EIO;
	if ((active & (1 << id)) == 0)
		return -ENXIO;

	/* Programmed value or real current speed */
	reg_base = programmed ? 0x10 : 0x11;
	rc = fan_read_reg(reg_base + (id * 2), buf, 2);
	if (rc != 2)
		return -EIO;

	return (buf[0] << (8 - fcu_rpm_shift)) | buf[1] >> fcu_rpm_shift;
}

static int set_pwm_fan(int fan_index, int pwm)
{
	unsigned char buf[2];
	int rc, id;

	if (fcu_fans[fan_index].type != FCU_FAN_PWM)
		return -EINVAL;
	id = fcu_fans[fan_index].id; 
	if (id == FCU_FAN_ABSENT_ID)
		return -EINVAL;

	if (pwm < 10)
		pwm = 10;
	else if (pwm > 100)
		pwm = 100;
	pwm = (pwm * 2559) / 1000;
	buf[0] = pwm;
	rc = fan_write_reg(0x30 + (id * 2), buf, 1);
	if (rc < 0)
		return rc;
	return 0;
}

static int get_pwm_fan(int fan_index)
{
	unsigned char failure;
	unsigned char active;
	unsigned char buf[2];
	int rc, id;

	if (fcu_fans[fan_index].type != FCU_FAN_PWM)
		return -EINVAL;
	id = fcu_fans[fan_index].id; 
	if (id == FCU_FAN_ABSENT_ID)
		return -EINVAL;

	rc = fan_read_reg(0x2b, &failure, 1);
	if (rc != 1)
		return -EIO;
	if ((failure & (1 << id)) != 0)
		return -EFAULT;
	rc = fan_read_reg(0x2d, &active, 1);
	if (rc != 1)
		return -EIO;
	if ((active & (1 << id)) == 0)
		return -ENXIO;

	/* Programmed value or real current speed */
	rc = fan_read_reg(0x30 + (id * 2), buf, 1);
	if (rc != 1)
		return -EIO;

	return (buf[0] * 1000) / 2559;
}

static void tickle_fcu(void)
{
	int pwm;

	pwm = get_pwm_fan(SLOTS_FAN_PWM_INDEX);

	DBG("FCU Tickle, slots fan is: %d\n", pwm);
	if (pwm < 0)
		pwm = 100;

	if (!rackmac) {
		pwm = SLOTS_FAN_DEFAULT_PWM;
	} else if (pwm < SLOTS_PID_OUTPUT_MIN)
		pwm = SLOTS_PID_OUTPUT_MIN;

	/* That is hopefully enough to make the FCU happy */
	set_pwm_fan(SLOTS_FAN_PWM_INDEX, pwm);
}


/*
 * Utility routine to read the CPU calibration EEPROM data
 * from the device-tree
 */
static int read_eeprom(int cpu, struct mpu_data *out)
{
	struct device_node *np;
	char nodename[64];
	const u8 *data;
	int len;

	/* prom.c routine for finding a node by path is a bit brain dead
	 * and requires exact @xxx unit numbers. This is a bit ugly but
	 * will work for these machines
	 */
	sprintf(nodename, "/u3@0,f8000000/i2c@f8001000/cpuid@a%d", cpu ? 2 : 0);
	np = of_find_node_by_path(nodename);
	if (np == NULL) {
		printk(KERN_ERR "therm_pm72: Failed to retrieve cpuid node from device-tree\n");
		return -ENODEV;
	}
	data = of_get_property(np, "cpuid", &len);
	if (data == NULL) {
		printk(KERN_ERR "therm_pm72: Failed to retrieve cpuid property from device-tree\n");
		of_node_put(np);
		return -ENODEV;
	}
	memcpy(out, data, sizeof(struct mpu_data));
	of_node_put(np);
	
	return 0;
}

static void fetch_cpu_pumps_minmax(void)
{
	struct cpu_pid_state *state0 = &processor_state[0];
	struct cpu_pid_state *state1 = &processor_state[1];
	u16 pump_min = 0, pump_max = 0xffff;
	u16 tmp[4];

	/* Try to fetch pumps min/max infos from eeprom */

	memcpy(&tmp, &state0->mpu.processor_part_num, 8);
	if (tmp[0] != 0xffff && tmp[1] != 0xffff) {
		pump_min = max(pump_min, tmp[0]);
		pump_max = min(pump_max, tmp[1]);
	}
	if (tmp[2] != 0xffff && tmp[3] != 0xffff) {
		pump_min = max(pump_min, tmp[2]);
		pump_max = min(pump_max, tmp[3]);
	}

	/* Double check the values, this _IS_ needed as the EEPROM on
	 * some dual 2.5Ghz G5s seem, at least, to have both min & max
	 * same to the same value ... (grrrr)
	 */
	if (pump_min == pump_max || pump_min == 0 || pump_max == 0xffff) {
		pump_min = CPU_PUMP_OUTPUT_MIN;
		pump_max = CPU_PUMP_OUTPUT_MAX;
	}

	state0->pump_min = state1->pump_min = pump_min;
	state0->pump_max = state1->pump_max = pump_max;
}

/* 
 * Now, unfortunately, sysfs doesn't give us a nice void * we could
 * pass around to the attribute functions, so we don't really have
 * choice but implement a bunch of them...
 *
 * That sucks a bit, we take the lock because FIX32TOPRINT evaluates
 * the input twice... I accept patches :)
 */
#define BUILD_SHOW_FUNC_FIX(name, data)				\
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
{								\
	ssize_t r;						\
	mutex_lock(&driver_lock);					\
	r = sprintf(buf, "%d.%03d", FIX32TOPRINT(data));	\
	mutex_unlock(&driver_lock);					\
	return r;						\
}
#define BUILD_SHOW_FUNC_INT(name, data)				\
static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
{								\
	return sprintf(buf, "%d", data);			\
}

BUILD_SHOW_FUNC_FIX(cpu0_temperature, processor_state[0].last_temp)
BUILD_SHOW_FUNC_FIX(cpu0_voltage, processor_state[0].voltage)
BUILD_SHOW_FUNC_FIX(cpu0_current, processor_state[0].current_a)
BUILD_SHOW_FUNC_INT(cpu0_exhaust_fan_rpm, processor_state[0].rpm)
BUILD_SHOW_FUNC_INT(cpu0_intake_fan_rpm, processor_state[0].intake_rpm)

BUILD_SHOW_FUNC_FIX(cpu1_temperature, processor_state[1].last_temp)
BUILD_SHOW_FUNC_FIX(cpu1_voltage, processor_state[1].voltage)
BUILD_SHOW_FUNC_FIX(cpu1_current, processor_state[1].current_a)
BUILD_SHOW_FUNC_INT(cpu1_exhaust_fan_rpm, processor_state[1].rpm)
BUILD_SHOW_FUNC_INT(cpu1_intake_fan_rpm, processor_state[1].intake_rpm)

BUILD_SHOW_FUNC_FIX(backside_temperature, backside_state.last_temp)
BUILD_SHOW_FUNC_INT(backside_fan_pwm, backside_state.pwm)

BUILD_SHOW_FUNC_FIX(drives_temperature, drives_state.last_temp)
BUILD_SHOW_FUNC_INT(drives_fan_rpm, drives_state.rpm)

BUILD_SHOW_FUNC_FIX(slots_temperature, slots_state.last_temp)
BUILD_SHOW_FUNC_INT(slots_fan_pwm, slots_state.pwm)

BUILD_SHOW_FUNC_FIX(dimms_temperature, dimms_state.last_temp)

static DEVICE_ATTR(cpu0_temperature,S_IRUGO,show_cpu0_temperature,NULL);
static DEVICE_ATTR(cpu0_voltage,S_IRUGO,show_cpu0_voltage,NULL);
static DEVICE_ATTR(cpu0_current,S_IRUGO,show_cpu0_current,NULL);
static DEVICE_ATTR(cpu0_exhaust_fan_rpm,S_IRUGO,show_cpu0_exhaust_fan_rpm,NULL);
static DEVICE_ATTR(cpu0_intake_fan_rpm,S_IRUGO,show_cpu0_intake_fan_rpm,NULL);

static DEVICE_ATTR(cpu1_temperature,S_IRUGO,show_cpu1_temperature,NULL);
static DEVICE_ATTR(cpu1_voltage,S_IRUGO,show_cpu1_voltage,NULL);
static DEVICE_ATTR(cpu1_current,S_IRUGO,show_cpu1_current,NULL);
static DEVICE_ATTR(cpu1_exhaust_fan_rpm,S_IRUGO,show_cpu1_exhaust_fan_rpm,NULL);
static DEVICE_ATTR(cpu1_intake_fan_rpm,S_IRUGO,show_cpu1_intake_fan_rpm,NULL);

static DEVICE_ATTR(backside_temperature,S_IRUGO,show_backside_temperature,NULL);
static DEVICE_ATTR(backside_fan_pwm,S_IRUGO,show_backside_fan_pwm,NULL);

static DEVICE_ATTR(drives_temperature,S_IRUGO,show_drives_temperature,NULL);
static DEVICE_ATTR(drives_fan_rpm,S_IRUGO,show_drives_fan_rpm,NULL);

static DEVICE_ATTR(slots_temperature,S_IRUGO,show_slots_temperature,NULL);
static DEVICE_ATTR(slots_fan_pwm,S_IRUGO,show_slots_fan_pwm,NULL);

static DEVICE_ATTR(dimms_temperature,S_IRUGO,show_dimms_temperature,NULL);

/*
 * CPUs fans control loop
 */

static int do_read_one_cpu_values(struct cpu_pid_state *state, s32 *temp, s32 *power)
{
	s32 ltemp, volts, amps;
	int index, rc = 0;

	/* Default (in case of error) */
	*temp = state->cur_temp;
	*power = state->cur_power;

	if (cpu_pid_type == CPU_PID_TYPE_RACKMAC)
		index = (state->index == 0) ?
			CPU_A1_FAN_RPM_INDEX : CPU_B1_FAN_RPM_INDEX;
	else
		index = (state->index == 0) ?
			CPUA_EXHAUST_FAN_RPM_INDEX : CPUB_EXHAUST_FAN_RPM_INDEX;

	/* Read current fan status */
	rc = get_rpm_fan(index, !RPM_PID_USE_ACTUAL_SPEED);
	if (rc < 0) {
		/* XXX What do we do now ? Nothing for now, keep old value, but
		 * return error upstream
		 */
		DBG("  cpu %d, fan reading error !\n", state->index);
	} else {
		state->rpm = rc;
		DBG("  cpu %d, exhaust RPM: %d\n", state->index, state->rpm);
	}

	/* Get some sensor readings and scale it */
	ltemp = read_smon_adc(state, 1);
	if (ltemp == -1) {
		/* XXX What do we do now ? */
		state->overtemp++;
		if (rc == 0)
			rc = -EIO;
		DBG("  cpu %d, temp reading error !\n", state->index);
	} else {
		/* Fixup temperature according to diode calibration
		 */
		DBG("  cpu %d, temp raw: %04x, m_diode: %04x, b_diode: %04x\n",
		    state->index,
		    ltemp, state->mpu.mdiode, state->mpu.bdiode);
		*temp = ((s32)ltemp * (s32)state->mpu.mdiode + ((s32)state->mpu.bdiode << 12)) >> 2;
		state->last_temp = *temp;
		DBG("  temp: %d.%03d\n", FIX32TOPRINT((*temp)));
	}

	/*
	 * Read voltage & current and calculate power
	 */
	volts = read_smon_adc(state, 3);
	amps = read_smon_adc(state, 4);

	/* Scale voltage and current raw sensor values according to fixed scales
	 * obtained in Darwin and calculate power from I and V
	 */
	volts *= ADC_CPU_VOLTAGE_SCALE;
	amps *= ADC_CPU_CURRENT_SCALE;
	*power = (((u64)volts) * ((u64)amps)) >> 16;
	state->voltage = volts;
	state->current_a = amps;
	state->last_power = *power;

	DBG("  cpu %d, current: %d.%03d, voltage: %d.%03d, power: %d.%03d W\n",
	    state->index, FIX32TOPRINT(state->current_a),
	    FIX32TOPRINT(state->voltage), FIX32TOPRINT(*power));

	return 0;
}

static void do_cpu_pid(struct cpu_pid_state *state, s32 temp, s32 power)
{
	s32 power_target, integral, derivative, proportional, adj_in_target, sval;
	s64 integ_p, deriv_p, prop_p, sum; 
	int i;

	/* Calculate power target value (could be done once for all)
	 * and convert to a 16.16 fp number
	 */
	power_target = ((u32)(state->mpu.pmaxh - state->mpu.padjmax)) << 16;
	DBG("  power target: %d.%03d, error: %d.%03d\n",
	    FIX32TOPRINT(power_target), FIX32TOPRINT(power_target - power));

	/* Store temperature and power in history array */
	state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
	state->temp_history[state->cur_temp] = temp;
	state->cur_power = (state->cur_power + 1) % state->count_power;
	state->power_history[state->cur_power] = power;
	state->error_history[state->cur_power] = power_target - power;
	
	/* If first loop, fill the history table */
	if (state->first) {
		for (i = 0; i < (state->count_power - 1); i++) {
			state->cur_power = (state->cur_power + 1) % state->count_power;
			state->power_history[state->cur_power] = power;
			state->error_history[state->cur_power] = power_target - power;
		}
		for (i = 0; i < (CPU_TEMP_HISTORY_SIZE - 1); i++) {
			state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
			state->temp_history[state->cur_temp] = temp;			
		}
		state->first = 0;
	}

	/* Calculate the integral term normally based on the "power" values */
	sum = 0;
	integral = 0;
	for (i = 0; i < state->count_power; i++)
		integral += state->error_history[i];
	integral *= CPU_PID_INTERVAL;
	DBG("  integral: %08x\n", integral);

	/* Calculate the adjusted input (sense value).
	 *   G_r is 12.20
	 *   integ is 16.16
	 *   so the result is 28.36
	 *
	 * input target is mpu.ttarget, input max is mpu.tmax
	 */
	integ_p = ((s64)state->mpu.pid_gr) * (s64)integral;
	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
	sval = (state->mpu.tmax << 16) - ((integ_p >> 20) & 0xffffffff);
	adj_in_target = (state->mpu.ttarget << 16);
	if (adj_in_target > sval)
		adj_in_target = sval;
	DBG("   adj_in_target: %d.%03d, ttarget: %d\n", FIX32TOPRINT(adj_in_target),
	    state->mpu.ttarget);

	/* Calculate the derivative term */
	derivative = state->temp_history[state->cur_temp] -
		state->temp_history[(state->cur_temp + CPU_TEMP_HISTORY_SIZE - 1)
				    % CPU_TEMP_HISTORY_SIZE];
	derivative /= CPU_PID_INTERVAL;
	deriv_p = ((s64)state->mpu.pid_gd) * (s64)derivative;
	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
	sum += deriv_p;

	/* Calculate the proportional term */
	proportional = temp - adj_in_target;
	prop_p = ((s64)state->mpu.pid_gp) * (s64)proportional;
	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
	sum += prop_p;

	/* Scale sum */
	sum >>= 36;

	DBG("   sum: %d\n", (int)sum);
	state->rpm += (s32)sum;
}

static void do_monitor_cpu_combined(void)
{
	struct cpu_pid_state *state0 = &processor_state[0];
	struct cpu_pid_state *state1 = &processor_state[1];
	s32 temp0, power0, temp1, power1;
	s32 temp_combi, power_combi;
	int rc, intake, pump;

	rc = do_read_one_cpu_values(state0, &temp0, &power0);
	if (rc < 0) {
		/* XXX What do we do now ? */
	}
	state1->overtemp = 0;
	rc = do_read_one_cpu_values(state1, &temp1, &power1);
	if (rc < 0) {
		/* XXX What do we do now ? */
	}
	if (state1->overtemp)
		state0->overtemp++;

	temp_combi = max(temp0, temp1);
	power_combi = max(power0, power1);

	/* Check tmax, increment overtemp if we are there. At tmax+8, we go
	 * full blown immediately and try to trigger a shutdown
	 */
	if (temp_combi >= ((state0->mpu.tmax + 8) << 16)) {
		printk(KERN_WARNING "Warning ! Temperature way above maximum (%d) !\n",
		       temp_combi >> 16);
		state0->overtemp += CPU_MAX_OVERTEMP / 4;
	} else if (temp_combi > (state0->mpu.tmax << 16)) {
		state0->overtemp++;
		printk(KERN_WARNING "Temperature %d above max %d. overtemp %d\n",
		       temp_combi >> 16, state0->mpu.tmax, state0->overtemp);
	} else {
		if (state0->overtemp)
			printk(KERN_WARNING "Temperature back down to %d\n",
			       temp_combi >> 16);
		state0->overtemp = 0;
	}
	if (state0->overtemp >= CPU_MAX_OVERTEMP)
		critical_state = 1;
	if (state0->overtemp > 0) {
		state0->rpm = state0->mpu.rmaxn_exhaust_fan;
		state0->intake_rpm = intake = state0->mpu.rmaxn_intake_fan;
		pump = state0->pump_max;
		goto do_set_fans;
	}

	/* Do the PID */
	do_cpu_pid(state0, temp_combi, power_combi);

	/* Range check */
	state0->rpm = max(state0->rpm, (int)state0->mpu.rminn_exhaust_fan);
	state0->rpm = min(state0->rpm, (int)state0->mpu.rmaxn_exhaust_fan);

	/* Calculate intake fan speed */
	intake = (state0->rpm * CPU_INTAKE_SCALE) >> 16;
	intake = max(intake, (int)state0->mpu.rminn_intake_fan);
	intake = min(intake, (int)state0->mpu.rmaxn_intake_fan);
	state0->intake_rpm = intake;

	/* Calculate pump speed */
	pump = (state0->rpm * state0->pump_max) /
		state0->mpu.rmaxn_exhaust_fan;
	pump = min(pump, state0->pump_max);
	pump = max(pump, state0->pump_min);
	
 do_set_fans:
	/* We copy values from state 0 to state 1 for /sysfs */
	state1->rpm = state0->rpm;
	state1->intake_rpm = state0->intake_rpm;

	DBG("** CPU %d RPM: %d Ex, %d, Pump: %d, In, overtemp: %d\n",
	    state1->index, (int)state1->rpm, intake, pump, state1->overtemp);

	/* We should check for errors, shouldn't we ? But then, what
	 * do we do once the error occurs ? For FCU notified fan
	 * failures (-EFAULT) we probably want to notify userland
	 * some way...
	 */
	set_rpm_fan(CPUA_INTAKE_FAN_RPM_INDEX, intake);
	set_rpm_fan(CPUA_EXHAUST_FAN_RPM_INDEX, state0->rpm);
	set_rpm_fan(CPUB_INTAKE_FAN_RPM_INDEX, intake);
	set_rpm_fan(CPUB_EXHAUST_FAN_RPM_INDEX, state0->rpm);

	if (fcu_fans[CPUA_PUMP_RPM_INDEX].id != FCU_FAN_ABSENT_ID)
		set_rpm_fan(CPUA_PUMP_RPM_INDEX, pump);
	if (fcu_fans[CPUB_PUMP_RPM_INDEX].id != FCU_FAN_ABSENT_ID)
		set_rpm_fan(CPUB_PUMP_RPM_INDEX, pump);
}

static void do_monitor_cpu_split(struct cpu_pid_state *state)
{
	s32 temp, power;
	int rc, intake;

	/* Read current fan status */
	rc = do_read_one_cpu_values(state, &temp, &power);
	if (rc < 0) {
		/* XXX What do we do now ? */
	}

	/* Check tmax, increment overtemp if we are there. At tmax+8, we go
	 * full blown immediately and try to trigger a shutdown
	 */
	if (temp >= ((state->mpu.tmax + 8) << 16)) {
		printk(KERN_WARNING "Warning ! CPU %d temperature way above maximum"
		       " (%d) !\n",
		       state->index, temp >> 16);
		state->overtemp += CPU_MAX_OVERTEMP / 4;
	} else if (temp > (state->mpu.tmax << 16)) {
		state->overtemp++;
		printk(KERN_WARNING "CPU %d temperature %d above max %d. overtemp %d\n",
		       state->index, temp >> 16, state->mpu.tmax, state->overtemp);
	} else {
		if (state->overtemp)
			printk(KERN_WARNING "CPU %d temperature back down to %d\n",
			       state->index, temp >> 16);
		state->overtemp = 0;
	}
	if (state->overtemp >= CPU_MAX_OVERTEMP)
		critical_state = 1;
	if (state->overtemp > 0) {
		state->rpm = state->mpu.rmaxn_exhaust_fan;
		state->intake_rpm = intake = state->mpu.rmaxn_intake_fan;
		goto do_set_fans;
	}

	/* Do the PID */
	do_cpu_pid(state, temp, power);

	/* Range check */
	state->rpm = max(state->rpm, (int)state->mpu.rminn_exhaust_fan);
	state->rpm = min(state->rpm, (int)state->mpu.rmaxn_exhaust_fan);

	/* Calculate intake fan */
	intake = (state->rpm * CPU_INTAKE_SCALE) >> 16;
	intake = max(intake, (int)state->mpu.rminn_intake_fan);
	intake = min(intake, (int)state->mpu.rmaxn_intake_fan);
	state->intake_rpm = intake;

 do_set_fans:
	DBG("** CPU %d RPM: %d Ex, %d In, overtemp: %d\n",
	    state->index, (int)state->rpm, intake, state->overtemp);

	/* We should check for errors, shouldn't we ? But then, what
	 * do we do once the error occurs ? For FCU notified fan
	 * failures (-EFAULT) we probably want to notify userland
	 * some way...
	 */
	if (state->index == 0) {
		set_rpm_fan(CPUA_INTAKE_FAN_RPM_INDEX, intake);
		set_rpm_fan(CPUA_EXHAUST_FAN_RPM_INDEX, state->rpm);
	} else {
		set_rpm_fan(CPUB_INTAKE_FAN_RPM_INDEX, intake);
		set_rpm_fan(CPUB_EXHAUST_FAN_RPM_INDEX, state->rpm);
	}
}

static void do_monitor_cpu_rack(struct cpu_pid_state *state)
{
	s32 temp, power, fan_min;
	int rc;

	/* Read current fan status */
	rc = do_read_one_cpu_values(state, &temp, &power);
	if (rc < 0) {
		/* XXX What do we do now ? */
	}

	/* Check tmax, increment overtemp if we are there. At tmax+8, we go
	 * full blown immediately and try to trigger a shutdown
	 */
	if (temp >= ((state->mpu.tmax + 8) << 16)) {
		printk(KERN_WARNING "Warning ! CPU %d temperature way above maximum"
		       " (%d) !\n",
		       state->index, temp >> 16);
		state->overtemp = CPU_MAX_OVERTEMP / 4;
	} else if (temp > (state->mpu.tmax << 16)) {
		state->overtemp++;
		printk(KERN_WARNING "CPU %d temperature %d above max %d. overtemp %d\n",
		       state->index, temp >> 16, state->mpu.tmax, state->overtemp);
	} else {
		if (state->overtemp)
			printk(KERN_WARNING "CPU %d temperature back down to %d\n",
			       state->index, temp >> 16);
		state->overtemp = 0;
	}
	if (state->overtemp >= CPU_MAX_OVERTEMP)
		critical_state = 1;
	if (state->overtemp > 0) {
		state->rpm = state->intake_rpm = state->mpu.rmaxn_intake_fan;
		goto do_set_fans;
	}

	/* Do the PID */
	do_cpu_pid(state, temp, power);

	/* Check clamp from dimms */
	fan_min = dimm_output_clamp;
	fan_min = max(fan_min, (int)state->mpu.rminn_intake_fan);

	DBG(" CPU min mpu = %d, min dimm = %d\n",
	    state->mpu.rminn_intake_fan, dimm_output_clamp);

	state->rpm = max(state->rpm, (int)fan_min);
	state->rpm = min(state->rpm, (int)state->mpu.rmaxn_intake_fan);
	state->intake_rpm = state->rpm;

 do_set_fans:
	DBG("** CPU %d RPM: %d overtemp: %d\n",
	    state->index, (int)state->rpm, state->overtemp);

	/* We should check for errors, shouldn't we ? But then, what
	 * do we do once the error occurs ? For FCU notified fan
	 * failures (-EFAULT) we probably want to notify userland
	 * some way...
	 */
	if (state->index == 0) {
		set_rpm_fan(CPU_A1_FAN_RPM_INDEX, state->rpm);
		set_rpm_fan(CPU_A2_FAN_RPM_INDEX, state->rpm);
		set_rpm_fan(CPU_A3_FAN_RPM_INDEX, state->rpm);
	} else {
		set_rpm_fan(CPU_B1_FAN_RPM_INDEX, state->rpm);
		set_rpm_fan(CPU_B2_FAN_RPM_INDEX, state->rpm);
		set_rpm_fan(CPU_B3_FAN_RPM_INDEX, state->rpm);
	}
}

/*
 * Initialize the state structure for one CPU control loop
 */
static int init_processor_state(struct cpu_pid_state *state, int index)
{
	int err;

	state->index = index;
	state->first = 1;
	state->rpm = (cpu_pid_type == CPU_PID_TYPE_RACKMAC) ? 4000 : 1000;
	state->overtemp = 0;
	state->adc_config = 0x00;


	if (index == 0)
		state->monitor = attach_i2c_chip(SUPPLY_MONITOR_ID, "CPU0_monitor");
	else if (index == 1)
		state->monitor = attach_i2c_chip(SUPPLY_MONITORB_ID, "CPU1_monitor");
	if (state->monitor == NULL)
		goto fail;

	if (read_eeprom(index, &state->mpu))
		goto fail;

	state->count_power = state->mpu.tguardband;
	if (state->count_power > CPU_POWER_HISTORY_SIZE) {
		printk(KERN_WARNING "Warning ! too many power history slots\n");
		state->count_power = CPU_POWER_HISTORY_SIZE;
	}
	DBG("CPU %d Using %d power history entries\n", index, state->count_power);

	if (index == 0) {
		err = device_create_file(&of_dev->dev, &dev_attr_cpu0_temperature);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu0_voltage);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu0_current);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
	} else {
		err = device_create_file(&of_dev->dev, &dev_attr_cpu1_temperature);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu1_voltage);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu1_current);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
		err |= device_create_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
	}
	if (err)
		printk(KERN_WARNING "Failed to create some of the atribute"
			"files for CPU %d\n", index);

	return 0;
 fail:
	state->monitor = NULL;
	
	return -ENODEV;
}

/*
 * Dispose of the state data for one CPU control loop
 */
static void dispose_processor_state(struct cpu_pid_state *state)
{
	if (state->monitor == NULL)
		return;

	if (state->index == 0) {
		device_remove_file(&of_dev->dev, &dev_attr_cpu0_temperature);
		device_remove_file(&of_dev->dev, &dev_attr_cpu0_voltage);
		device_remove_file(&of_dev->dev, &dev_attr_cpu0_current);
		device_remove_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
		device_remove_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
	} else {
		device_remove_file(&of_dev->dev, &dev_attr_cpu1_temperature);
		device_remove_file(&of_dev->dev, &dev_attr_cpu1_voltage);
		device_remove_file(&of_dev->dev, &dev_attr_cpu1_current);
		device_remove_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
		device_remove_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
	}

	state->monitor = NULL;
}

/*
 * Motherboard backside & U3 heatsink fan control loop
 */
static void do_monitor_backside(struct backside_pid_state *state)
{
	s32 temp, integral, derivative, fan_min;
	s64 integ_p, deriv_p, prop_p, sum; 
	int i, rc;

	if (--state->ticks != 0)
		return;
	state->ticks = backside_params.interval;

	DBG("backside:\n");

	/* Check fan status */
	rc = get_pwm_fan(BACKSIDE_FAN_PWM_INDEX);
	if (rc < 0) {
		printk(KERN_WARNING "Error %d reading backside fan !\n", rc);
		/* XXX What do we do now ? */
	} else
		state->pwm = rc;
	DBG("  current pwm: %d\n", state->pwm);

	/* Get some sensor readings */
	temp = i2c_smbus_read_byte_data(state->monitor, MAX6690_EXT_TEMP) << 16;
	state->last_temp = temp;
	DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
	    FIX32TOPRINT(backside_params.input_target));

	/* Store temperature and error in history array */
	state->cur_sample = (state->cur_sample + 1) % BACKSIDE_PID_HISTORY_SIZE;
	state->sample_history[state->cur_sample] = temp;
	state->error_history[state->cur_sample] = temp - backside_params.input_target;
	
	/* If first loop, fill the history table */
	if (state->first) {
		for (i = 0; i < (BACKSIDE_PID_HISTORY_SIZE - 1); i++) {
			state->cur_sample = (state->cur_sample + 1) %
				BACKSIDE_PID_HISTORY_SIZE;
			state->sample_history[state->cur_sample] = temp;
			state->error_history[state->cur_sample] =
				temp - backside_params.input_target;
		}
		state->first = 0;
	}

	/* Calculate the integral term */
	sum = 0;
	integral = 0;
	for (i = 0; i < BACKSIDE_PID_HISTORY_SIZE; i++)
		integral += state->error_history[i];
	integral *= backside_params.interval;
	DBG("  integral: %08x\n", integral);
	integ_p = ((s64)backside_params.G_r) * (s64)integral;
	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
	sum += integ_p;

	/* Calculate the derivative term */
	derivative = state->error_history[state->cur_sample] -
		state->error_history[(state->cur_sample + BACKSIDE_PID_HISTORY_SIZE - 1)
				    % BACKSIDE_PID_HISTORY_SIZE];
	derivative /= backside_params.interval;
	deriv_p = ((s64)backside_params.G_d) * (s64)derivative;
	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
	sum += deriv_p;

	/* Calculate the proportional term */
	prop_p = ((s64)backside_params.G_p) * (s64)(state->error_history[state->cur_sample]);
	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
	sum += prop_p;

	/* Scale sum */
	sum >>= 36;

	DBG("   sum: %d\n", (int)sum);
	if (backside_params.additive)
		state->pwm += (s32)sum;
	else
		state->pwm = sum;

	/* Check for clamp */
	fan_min = (dimm_output_clamp * 100) / 14000;
	fan_min = max(fan_min, backside_params.output_min);

	state->pwm = max(state->pwm, fan_min);
	state->pwm = min(state->pwm, backside_params.output_max);

	DBG("** BACKSIDE PWM: %d\n", (int)state->pwm);
	set_pwm_fan(BACKSIDE_FAN_PWM_INDEX, state->pwm);
}

/*
 * Initialize the state structure for the backside fan control loop
 */
static int init_backside_state(struct backside_pid_state *state)
{
	struct device_node *u3;
	int u3h = 1; /* conservative by default */
	int err;

	/*
	 * There are different PID params for machines with U3 and machines
	 * with U3H, pick the right ones now
	 */
	u3 = of_find_node_by_path("/u3@0,f8000000");
	if (u3 != NULL) {
		const u32 *vers = of_get_property(u3, "device-rev", NULL);
		if (vers)
			if (((*vers) & 0x3f) < 0x34)
				u3h = 0;
		of_node_put(u3);
	}

	if (rackmac) {
		backside_params.G_d = BACKSIDE_PID_RACK_G_d;
		backside_params.input_target = BACKSIDE_PID_RACK_INPUT_TARGET;
		backside_params.output_min = BACKSIDE_PID_U3H_OUTPUT_MIN;
		backside_params.interval = BACKSIDE_PID_RACK_INTERVAL;
		backside_params.G_p = BACKSIDE_PID_RACK_G_p;
		backside_params.G_r = BACKSIDE_PID_G_r;
		backside_params.output_max = BACKSIDE_PID_OUTPUT_MAX;
		backside_params.additive = 0;
	} else if (u3h) {
		backside_params.G_d = BACKSIDE_PID_U3H_G_d;
		backside_params.input_target = BACKSIDE_PID_U3H_INPUT_TARGET;
		backside_params.output_min = BACKSIDE_PID_U3H_OUTPUT_MIN;
		backside_params.interval = BACKSIDE_PID_INTERVAL;
		backside_params.G_p = BACKSIDE_PID_G_p;
		backside_params.G_r = BACKSIDE_PID_G_r;
		backside_params.output_max = BACKSIDE_PID_OUTPUT_MAX;
		backside_params.additive = 1;
	} else {
		backside_params.G_d = BACKSIDE_PID_U3_G_d;
		backside_params.input_target = BACKSIDE_PID_U3_INPUT_TARGET;
		backside_params.output_min = BACKSIDE_PID_U3_OUTPUT_MIN;
		backside_params.interval = BACKSIDE_PID_INTERVAL;
		backside_params.G_p = BACKSIDE_PID_G_p;
		backside_params.G_r = BACKSIDE_PID_G_r;
		backside_params.output_max = BACKSIDE_PID_OUTPUT_MAX;
		backside_params.additive = 1;
	}

	state->ticks = 1;
	state->first = 1;
	state->pwm = 50;

	state->monitor = attach_i2c_chip(BACKSIDE_MAX_ID, "backside_temp");
	if (state->monitor == NULL)
		return -ENODEV;

	err = device_create_file(&of_dev->dev, &dev_attr_backside_temperature);
	err |= device_create_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
	if (err)
		printk(KERN_WARNING "Failed to create attribute file(s)"
			" for backside fan\n");

	return 0;
}

/*
 * Dispose of the state data for the backside control loop
 */
static void dispose_backside_state(struct backside_pid_state *state)
{
	if (state->monitor == NULL)
		return;

	device_remove_file(&of_dev->dev, &dev_attr_backside_temperature);
	device_remove_file(&of_dev->dev, &dev_attr_backside_fan_pwm);

	state->monitor = NULL;
}
 
/*
 * Drives bay fan control loop
 */
static void do_monitor_drives(struct drives_pid_state *state)
{
	s32 temp, integral, derivative;
	s64 integ_p, deriv_p, prop_p, sum; 
	int i, rc;

	if (--state->ticks != 0)
		return;
	state->ticks = DRIVES_PID_INTERVAL;

	DBG("drives:\n");

	/* Check fan status */
	rc = get_rpm_fan(DRIVES_FAN_RPM_INDEX, !RPM_PID_USE_ACTUAL_SPEED);
	if (rc < 0) {
		printk(KERN_WARNING "Error %d reading drives fan !\n", rc);
		/* XXX What do we do now ? */
	} else
		state->rpm = rc;
	DBG("  current rpm: %d\n", state->rpm);

	/* Get some sensor readings */
	temp = le16_to_cpu(i2c_smbus_read_word_data(state->monitor,
						    DS1775_TEMP)) << 8;
	state->last_temp = temp;
	DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
	    FIX32TOPRINT(DRIVES_PID_INPUT_TARGET));

	/* Store temperature and error in history array */
	state->cur_sample = (state->cur_sample + 1) % DRIVES_PID_HISTORY_SIZE;
	state->sample_history[state->cur_sample] = temp;
	state->error_history[state->cur_sample] = temp - DRIVES_PID_INPUT_TARGET;
	
	/* If first loop, fill the history table */
	if (state->first) {
		for (i = 0; i < (DRIVES_PID_HISTORY_SIZE - 1); i++) {
			state->cur_sample = (state->cur_sample + 1) %
				DRIVES_PID_HISTORY_SIZE;
			state->sample_history[state->cur_sample] = temp;
			state->error_history[state->cur_sample] =
				temp - DRIVES_PID_INPUT_TARGET;
		}
		state->first = 0;
	}

	/* Calculate the integral term */
	sum = 0;
	integral = 0;
	for (i = 0; i < DRIVES_PID_HISTORY_SIZE; i++)
		integral += state->error_history[i];
	integral *= DRIVES_PID_INTERVAL;
	DBG("  integral: %08x\n", integral);
	integ_p = ((s64)DRIVES_PID_G_r) * (s64)integral;
	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
	sum += integ_p;

	/* Calculate the derivative term */
	derivative = state->error_history[state->cur_sample] -
		state->error_history[(state->cur_sample + DRIVES_PID_HISTORY_SIZE - 1)
				    % DRIVES_PID_HISTORY_SIZE];
	derivative /= DRIVES_PID_INTERVAL;
	deriv_p = ((s64)DRIVES_PID_G_d) * (s64)derivative;
	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
	sum += deriv_p;

	/* Calculate the proportional term */
	prop_p = ((s64)DRIVES_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
	sum += prop_p;

	/* Scale sum */
	sum >>= 36;

	DBG("   sum: %d\n", (int)sum);
	state->rpm += (s32)sum;

	state->rpm = max(state->rpm, DRIVES_PID_OUTPUT_MIN);
	state->rpm = min(state->rpm, DRIVES_PID_OUTPUT_MAX);

	DBG("** DRIVES RPM: %d\n", (int)state->rpm);
	set_rpm_fan(DRIVES_FAN_RPM_INDEX, state->rpm);
}

/*
 * Initialize the state structure for the drives bay fan control loop
 */
static int init_drives_state(struct drives_pid_state *state)
{
	int err;

	state->ticks = 1;
	state->first = 1;
	state->rpm = 1000;

	state->monitor = attach_i2c_chip(DRIVES_DALLAS_ID, "drives_temp");
	if (state->monitor == NULL)
		return -ENODEV;

	err = device_create_file(&of_dev->dev, &dev_attr_drives_temperature);
	err |= device_create_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
	if (err)
		printk(KERN_WARNING "Failed to create attribute file(s)"
			" for drives bay fan\n");

	return 0;
}

/*
 * Dispose of the state data for the drives control loop
 */
static void dispose_drives_state(struct drives_pid_state *state)
{
	if (state->monitor == NULL)
		return;

	device_remove_file(&of_dev->dev, &dev_attr_drives_temperature);
	device_remove_file(&of_dev->dev, &dev_attr_drives_fan_rpm);

	state->monitor = NULL;
}

/*
 * DIMMs temp control loop
 */
static void do_monitor_dimms(struct dimm_pid_state *state)
{
	s32 temp, integral, derivative, fan_min;
	s64 integ_p, deriv_p, prop_p, sum;
	int i;

	if (--state->ticks != 0)
		return;
	state->ticks = DIMM_PID_INTERVAL;

	DBG("DIMM:\n");

	DBG("  current value: %d\n", state->output);

	temp = read_lm87_reg(state->monitor, LM87_INT_TEMP);
	if (temp < 0)
		return;
	temp <<= 16;
	state->last_temp = temp;
	DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
	    FIX32TOPRINT(DIMM_PID_INPUT_TARGET));

	/* Store temperature and error in history array */
	state->cur_sample = (state->cur_sample + 1) % DIMM_PID_HISTORY_SIZE;
	state->sample_history[state->cur_sample] = temp;
	state->error_history[state->cur_sample] = temp - DIMM_PID_INPUT_TARGET;

	/* If first loop, fill the history table */
	if (state->first) {
		for (i = 0; i < (DIMM_PID_HISTORY_SIZE - 1); i++) {
			state->cur_sample = (state->cur_sample + 1) %
				DIMM_PID_HISTORY_SIZE;
			state->sample_history[state->cur_sample] = temp;
			state->error_history[state->cur_sample] =
				temp - DIMM_PID_INPUT_TARGET;
		}
		state->first = 0;
	}

	/* Calculate the integral term */
	sum = 0;
	integral = 0;
	for (i = 0; i < DIMM_PID_HISTORY_SIZE; i++)
		integral += state->error_history[i];
	integral *= DIMM_PID_INTERVAL;
	DBG("  integral: %08x\n", integral);
	integ_p = ((s64)DIMM_PID_G_r) * (s64)integral;
	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
	sum += integ_p;

	/* Calculate the derivative term */
	derivative = state->error_history[state->cur_sample] -
		state->error_history[(state->cur_sample + DIMM_PID_HISTORY_SIZE - 1)
				    % DIMM_PID_HISTORY_SIZE];
	derivative /= DIMM_PID_INTERVAL;
	deriv_p = ((s64)DIMM_PID_G_d) * (s64)derivative;
	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
	sum += deriv_p;

	/* Calculate the proportional term */
	prop_p = ((s64)DIMM_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
	sum += prop_p;

	/* Scale sum */
	sum >>= 36;

	DBG("   sum: %d\n", (int)sum);
	state->output = (s32)sum;
	state->output = max(state->output, DIMM_PID_OUTPUT_MIN);
	state->output = min(state->output, DIMM_PID_OUTPUT_MAX);
	dimm_output_clamp = state->output;

	DBG("** DIMM clamp value: %d\n", (int)state->output);

	/* Backside PID is only every 5 seconds, force backside fan clamping now */
	fan_min = (dimm_output_clamp * 100) / 14000;
	fan_min = max(fan_min, backside_params.output_min);
	if (backside_state.pwm < fan_min) {
		backside_state.pwm = fan_min;
		DBG(" -> applying clamp to backside fan now: %d  !\n", fan_min);
		set_pwm_fan(BACKSIDE_FAN_PWM_INDEX, fan_min);
	}
}

/*
 * Initialize the state structure for the DIMM temp control loop
 */
static int init_dimms_state(struct dimm_pid_state *state)
{
	state->ticks = 1;
	state->first = 1;
	state->output = 4000;

	state->monitor = attach_i2c_chip(XSERVE_DIMMS_LM87, "dimms_temp");
	if (state->monitor == NULL)
		return -ENODEV;

	if (device_create_file(&of_dev->dev, &dev_attr_dimms_temperature))
		printk(KERN_WARNING "Failed to create attribute file"
			" for DIMM temperature\n");

	return 0;
}

/*
 * Dispose of the state data for the DIMM control loop
 */
static void dispose_dimms_state(struct dimm_pid_state *state)
{
	if (state->monitor == NULL)
		return;

	device_remove_file(&of_dev->dev, &dev_attr_dimms_temperature);

	state->monitor = NULL;
}

/*
 * Slots fan control loop
 */
static void do_monitor_slots(struct slots_pid_state *state)
{
	s32 temp, integral, derivative;
	s64 integ_p, deriv_p, prop_p, sum;
	int i, rc;

	if (--state->ticks != 0)
		return;
	state->ticks = SLOTS_PID_INTERVAL;

	DBG("slots:\n");

	/* Check fan status */
	rc = get_pwm_fan(SLOTS_FAN_PWM_INDEX);
	if (rc < 0) {
		printk(KERN_WARNING "Error %d reading slots fan !\n", rc);
		/* XXX What do we do now ? */
	} else
		state->pwm = rc;
	DBG("  current pwm: %d\n", state->pwm);

	/* Get some sensor readings */
	temp = le16_to_cpu(i2c_smbus_read_word_data(state->monitor,
						    DS1775_TEMP)) << 8;
	state->last_temp = temp;
	DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
	    FIX32TOPRINT(SLOTS_PID_INPUT_TARGET));

	/* Store temperature and error in history array */
	state->cur_sample = (state->cur_sample + 1) % SLOTS_PID_HISTORY_SIZE;
	state->sample_history[state->cur_sample] = temp;
	state->error_history[state->cur_sample] = temp - SLOTS_PID_INPUT_TARGET;

	/* If first loop, fill the history table */
	if (state->first) {
		for (i = 0; i < (SLOTS_PID_HISTORY_SIZE - 1); i++) {
			state->cur_sample = (state->cur_sample + 1) %
				SLOTS_PID_HISTORY_SIZE;
			state->sample_history[state->cur_sample] = temp;
			state->error_history[state->cur_sample] =
				temp - SLOTS_PID_INPUT_TARGET;
		}
		state->first = 0;
	}

	/* Calculate the integral term */
	sum = 0;
	integral = 0;
	for (i = 0; i < SLOTS_PID_HISTORY_SIZE; i++)
		integral += state->error_history[i];
	integral *= SLOTS_PID_INTERVAL;
	DBG("  integral: %08x\n", integral);
	integ_p = ((s64)SLOTS_PID_G_r) * (s64)integral;
	DBG("   integ_p: %d\n", (int)(integ_p >> 36));
	sum += integ_p;

	/* Calculate the derivative term */
	derivative = state->error_history[state->cur_sample] -
		state->error_history[(state->cur_sample + SLOTS_PID_HISTORY_SIZE - 1)
				    % SLOTS_PID_HISTORY_SIZE];
	derivative /= SLOTS_PID_INTERVAL;
	deriv_p = ((s64)SLOTS_PID_G_d) * (s64)derivative;
	DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
	sum += deriv_p;

	/* Calculate the proportional term */
	prop_p = ((s64)SLOTS_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
	DBG("   prop_p: %d\n", (int)(prop_p >> 36));
	sum += prop_p;

	/* Scale sum */
	sum >>= 36;

	DBG("   sum: %d\n", (int)sum);
	state->pwm = (s32)sum;

	state->pwm = max(state->pwm, SLOTS_PID_OUTPUT_MIN);
	state->pwm = min(state->pwm, SLOTS_PID_OUTPUT_MAX);

	DBG("** DRIVES PWM: %d\n", (int)state->pwm);
	set_pwm_fan(SLOTS_FAN_PWM_INDEX, state->pwm);
}

/*
 * Initialize the state structure for the slots bay fan control loop
 */
static int init_slots_state(struct slots_pid_state *state)
{
	int err;

	state->ticks = 1;
	state->first = 1;
	state->pwm = 50;

	state->monitor = attach_i2c_chip(XSERVE_SLOTS_LM75, "slots_temp");
	if (state->monitor == NULL)
		return -ENODEV;

	err = device_create_file(&of_dev->dev, &dev_attr_slots_temperature);
	err |= device_create_file(&of_dev->dev, &dev_attr_slots_fan_pwm);
	if (err)
		printk(KERN_WARNING "Failed to create attribute file(s)"
			" for slots bay fan\n");

	return 0;
}

/*
 * Dispose of the state data for the slots control loop
 */
static void dispose_slots_state(struct slots_pid_state *state)
{
	if (state->monitor == NULL)
		return;

	device_remove_file(&of_dev->dev, &dev_attr_slots_temperature);
	device_remove_file(&of_dev->dev, &dev_attr_slots_fan_pwm);

	state->monitor = NULL;
}


static int call_critical_overtemp(void)
{
	char *argv[] = { critical_overtemp_path, NULL };
	static char *envp[] = { "HOME=/",
				"TERM=linux",
				"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
				NULL };

	return call_usermodehelper(critical_overtemp_path,
				   argv, envp, UMH_WAIT_EXEC);
}


/*
 * Here's the kernel thread that calls the various control loops
 */
static int main_control_loop(void *x)
{
	DBG("main_control_loop started\n");

	mutex_lock(&driver_lock);

	if (start_fcu() < 0) {
		printk(KERN_ERR "kfand: failed to start FCU\n");
		mutex_unlock(&driver_lock);
		goto out;
	}

	/* Set the PCI fan once for now on non-RackMac */
	if (!rackmac)
		set_pwm_fan(SLOTS_FAN_PWM_INDEX, SLOTS_FAN_DEFAULT_PWM);

	/* Initialize ADCs */
	initialize_adc(&processor_state[0]);
	if (processor_state[1].monitor != NULL)
		initialize_adc(&processor_state[1]);

	fcu_tickle_ticks = FCU_TICKLE_TICKS;

	mutex_unlock(&driver_lock);

	while (state == state_attached) {
		unsigned long elapsed, start;

		start = jiffies;

		mutex_lock(&driver_lock);

		/* Tickle the FCU just in case */
		if (--fcu_tickle_ticks < 0) {
			fcu_tickle_ticks = FCU_TICKLE_TICKS;
			tickle_fcu();
		}

		/* First, we always calculate the new DIMMs state on an Xserve */
		if (rackmac)
			do_monitor_dimms(&dimms_state);

		/* Then, the CPUs */
		if (cpu_pid_type == CPU_PID_TYPE_COMBINED)
			do_monitor_cpu_combined();
		else if (cpu_pid_type == CPU_PID_TYPE_RACKMAC) {
			do_monitor_cpu_rack(&processor_state[0]);
			if (processor_state[1].monitor != NULL)
				do_monitor_cpu_rack(&processor_state[1]);
			// better deal with UP
		} else {
			do_monitor_cpu_split(&processor_state[0]);
			if (processor_state[1].monitor != NULL)
				do_monitor_cpu_split(&processor_state[1]);
			// better deal with UP
		}
		/* Then, the rest */
		do_monitor_backside(&backside_state);
		if (rackmac)
			do_monitor_slots(&slots_state);
		else
			do_monitor_drives(&drives_state);
		mutex_unlock(&driver_lock);

		if (critical_state == 1) {
			printk(KERN_WARNING "Temperature control detected a critical condition\n");
			printk(KERN_WARNING "Attempting to shut down...\n");
			if (call_critical_overtemp()) {
				printk(KERN_WARNING "Can't call %s, power off now!\n",
				       critical_overtemp_path);
				machine_power_off();
			}
		}
		if (critical_state > 0)
			critical_state++;
		if (critical_state > MAX_CRITICAL_STATE) {
			printk(KERN_WARNING "Shutdown timed out, power off now !\n");
			machine_power_off();
		}

		// FIXME: Deal with signals
		elapsed = jiffies - start;
		if (elapsed < HZ)
			schedule_timeout_interruptible(HZ - elapsed);
	}

 out:
	DBG("main_control_loop ended\n");

	ctrl_task = 0;
	complete_and_exit(&ctrl_complete, 0);
}

/*
 * Dispose the control loops when tearing down
 */
static void dispose_control_loops(void)
{
	dispose_processor_state(&processor_state[0]);
	dispose_processor_state(&processor_state[1]);
	dispose_backside_state(&backside_state);
	dispose_drives_state(&drives_state);
	dispose_slots_state(&slots_state);
	dispose_dimms_state(&dimms_state);
}

/*
 * Create the control loops. U3-0 i2c bus is up, so we can now
 * get to the various sensors
 */
static int create_control_loops(void)
{
	struct device_node *np;

	/* Count CPUs from the device-tree, we don't care how many are
	 * actually used by Linux
	 */
	cpu_count = 0;
	for (np = NULL; NULL != (np = of_find_node_by_type(np, "cpu"));)
		cpu_count++;

	DBG("counted %d CPUs in the device-tree\n", cpu_count);

	/* Decide the type of PID algorithm to use based on the presence of
	 * the pumps, though that may not be the best way, that is good enough
	 * for now
	 */
	if (rackmac)
		cpu_pid_type = CPU_PID_TYPE_RACKMAC;
	else if (of_machine_is_compatible("PowerMac7,3")
	    && (cpu_count > 1)
	    && fcu_fans[CPUA_PUMP_RPM_INDEX].id != FCU_FAN_ABSENT_ID
	    && fcu_fans[CPUB_PUMP_RPM_INDEX].id != FCU_FAN_ABSENT_ID) {
		printk(KERN_INFO "Liquid cooling pumps detected, using new algorithm !\n");
		cpu_pid_type = CPU_PID_TYPE_COMBINED;
	} else
		cpu_pid_type = CPU_PID_TYPE_SPLIT;

	/* Create control loops for everything. If any fail, everything
	 * fails
	 */
	if (init_processor_state(&processor_state[0], 0))
		goto fail;
	if (cpu_pid_type == CPU_PID_TYPE_COMBINED)
		fetch_cpu_pumps_minmax();

	if (cpu_count > 1 && init_processor_state(&processor_state[1], 1))
		goto fail;
	if (init_backside_state(&backside_state))
		goto fail;
	if (rackmac && init_dimms_state(&dimms_state))
		goto fail;
	if (rackmac && init_slots_state(&slots_state))
		goto fail;
	if (!rackmac && init_drives_state(&drives_state))
		goto fail;

	DBG("all control loops up !\n");

	return 0;
	
 fail:
	DBG("failure creating control loops, disposing\n");

	dispose_control_loops();

	return -ENODEV;
}

/*
 * Start the control loops after everything is up, that is create
 * the thread that will make them run
 */
static void start_control_loops(void)
{
	init_completion(&ctrl_complete);

	ctrl_task = kthread_run(main_control_loop, NULL, "kfand");
}

/*
 * Stop the control loops when tearing down
 */
static void stop_control_loops(void)
{
	if (ctrl_task)
		wait_for_completion(&ctrl_complete);
}

/*
 * Attach to the i2c FCU after detecting U3-1 bus
 */
static int attach_fcu(void)
{
	fcu = attach_i2c_chip(FAN_CTRLER_ID, "fcu");
	if (fcu == NULL)
		return -ENODEV;

	DBG("FCU attached\n");

	return 0;
}

/*
 * Detach from the i2c FCU when tearing down
 */
static void detach_fcu(void)
{
	fcu = NULL;
}

/*
 * Attach to the i2c controller. We probe the various chips based
 * on the device-tree nodes and build everything for the driver to
 * run, we then kick the driver monitoring thread
 */
static int therm_pm72_attach(struct i2c_adapter *adapter)
{
	mutex_lock(&driver_lock);

	/* Check state */
	if (state == state_detached)
		state = state_attaching;
	if (state != state_attaching) {
		mutex_unlock(&driver_lock);
		return 0;
	}

	/* Check if we are looking for one of these */
	if (u3_0 == NULL && !strcmp(adapter->name, "u3 0")) {
		u3_0 = adapter;
		DBG("found U3-0\n");
		if (k2 || !rackmac)
			if (create_control_loops())
				u3_0 = NULL;
	} else if (u3_1 == NULL && !strcmp(adapter->name, "u3 1")) {
		u3_1 = adapter;
		DBG("found U3-1, attaching FCU\n");
		if (attach_fcu())
			u3_1 = NULL;
	} else if (k2 == NULL && !strcmp(adapter->name, "mac-io 0")) {
		k2 = adapter;
		DBG("Found K2\n");
		if (u3_0 && rackmac)
			if (create_control_loops())
				k2 = NULL;
	}
	/* We got all we need, start control loops */
	if (u3_0 != NULL && u3_1 != NULL && (k2 || !rackmac)) {
		DBG("everything up, starting control loops\n");
		state = state_attached;
		start_control_loops();
	}
	mutex_unlock(&driver_lock);

	return 0;
}

static int therm_pm72_probe(struct i2c_client *client,
			    const struct i2c_device_id *id)
{
	/* Always succeed, the real work was done in therm_pm72_attach() */
	return 0;
}

/*
 * Called when any of the devices which participates into thermal management
 * is going away.
 */
static int therm_pm72_remove(struct i2c_client *client)
{
	struct i2c_adapter *adapter = client->adapter;

	mutex_lock(&driver_lock);

	if (state != state_detached)
		state = state_detaching;

	/* Stop control loops if any */
	DBG("stopping control loops\n");
	mutex_unlock(&driver_lock);
	stop_control_loops();
	mutex_lock(&driver_lock);

	if (u3_0 != NULL && !strcmp(adapter->name, "u3 0")) {
		DBG("lost U3-0, disposing control loops\n");
		dispose_control_loops();
		u3_0 = NULL;
	}
	
	if (u3_1 != NULL && !strcmp(adapter->name, "u3 1")) {
		DBG("lost U3-1, detaching FCU\n");
		detach_fcu();
		u3_1 = NULL;
	}
	if (u3_0 == NULL && u3_1 == NULL)
		state = state_detached;

	mutex_unlock(&driver_lock);

	return 0;
}

/*
 * i2c_driver structure to attach to the host i2c controller
 */

static const struct i2c_device_id therm_pm72_id[] = {
	/*
	 * Fake device name, thermal management is done by several
	 * chips but we don't need to differentiate between them at
	 * this point.
	 */
	{ "therm_pm72", 0 },
	{ }
};

static struct i2c_driver therm_pm72_driver = {
	.driver = {
		.name	= "therm_pm72",
	},
	.attach_adapter	= therm_pm72_attach,
	.probe		= therm_pm72_probe,
	.remove		= therm_pm72_remove,
	.id_table	= therm_pm72_id,
};

static int fan_check_loc_match(const char *loc, int fan)
{
	char	tmp[64];
	char	*c, *e;

	strlcpy(tmp, fcu_fans[fan].loc, 64);

	c = tmp;
	for (;;) {
		e = strchr(c, ',');
		if (e)
			*e = 0;
		if (strcmp(loc, c) == 0)
			return 1;
		if (e == NULL)
			break;
		c = e + 1;
	}
	return 0;
}

static void fcu_lookup_fans(struct device_node *fcu_node)
{
	struct device_node *np = NULL;
	int i;

	/* The table is filled by default with values that are suitable
	 * for the old machines without device-tree informations. We scan
	 * the device-tree and override those values with whatever is
	 * there
	 */

	DBG("Looking up FCU controls in device-tree...\n");

	while ((np = of_get_next_child(fcu_node, np)) != NULL) {
		int type = -1;
		const char *loc;
		const u32 *reg;

		DBG(" control: %s, type: %s\n", np->name, np->type);

		/* Detect control type */
		if (!strcmp(np->type, "fan-rpm-control") ||
		    !strcmp(np->type, "fan-rpm"))
			type = FCU_FAN_RPM;
		if (!strcmp(np->type, "fan-pwm-control") ||
		    !strcmp(np->type, "fan-pwm"))
			type = FCU_FAN_PWM;
		/* Only care about fans for now */
		if (type == -1)
			continue;

		/* Lookup for a matching location */
		loc = of_get_property(np, "location", NULL);
		reg = of_get_property(np, "reg", NULL);
		if (loc == NULL || reg == NULL)
			continue;
		DBG(" matching location: %s, reg: 0x%08x\n", loc, *reg);

		for (i = 0; i < FCU_FAN_COUNT; i++) {
			int fan_id;

			if (!fan_check_loc_match(loc, i))
				continue;
			DBG(" location match, index: %d\n", i);
			fcu_fans[i].id = FCU_FAN_ABSENT_ID;
			if (type != fcu_fans[i].type) {
				printk(KERN_WARNING "therm_pm72: Fan type mismatch "
				       "in device-tree for %s\n", np->full_name);
				break;
			}
			if (type == FCU_FAN_RPM)
				fan_id = ((*reg) - 0x10) / 2;
			else
				fan_id = ((*reg) - 0x30) / 2;
			if (fan_id > 7) {
				printk(KERN_WARNING "therm_pm72: Can't parse "
				       "fan ID in device-tree for %s\n", np->full_name);
				break;
			}
			DBG(" fan id -> %d, type -> %d\n", fan_id, type);
			fcu_fans[i].id = fan_id;
		}
	}

	/* Now dump the array */
	printk(KERN_INFO "Detected fan controls:\n");
	for (i = 0; i < FCU_FAN_COUNT; i++) {
		if (fcu_fans[i].id == FCU_FAN_ABSENT_ID)
			continue;
		printk(KERN_INFO "  %d: %s fan, id %d, location: %s\n", i,
		       fcu_fans[i].type == FCU_FAN_RPM ? "RPM" : "PWM",
		       fcu_fans[i].id, fcu_fans[i].loc);
	}
}

static int fcu_of_probe(struct platform_device* dev)
{
	state = state_detached;
	of_dev = dev;

	dev_info(&dev->dev, "PowerMac G5 Thermal control driver %s\n", VERSION);

	/* Lookup the fans in the device tree */
	fcu_lookup_fans(dev->dev.of_node);

	/* Add the driver */
	return i2c_add_driver(&therm_pm72_driver);
}

static int fcu_of_remove(struct platform_device* dev)
{
	i2c_del_driver(&therm_pm72_driver);

	return 0;
}

static const struct of_device_id fcu_match[] = 
{
	{
	.type		= "fcu",
	},
	{},
};
MODULE_DEVICE_TABLE(of, fcu_match);

static struct platform_driver fcu_of_platform_driver = 
{
	.driver = {
		.name = "temperature",
		.owner = THIS_MODULE,
		.of_match_table = fcu_match,
	},
	.probe		= fcu_of_probe,
	.remove		= fcu_of_remove
};

/*
 * Check machine type, attach to i2c controller
 */
static int __init therm_pm72_init(void)
{
	rackmac = of_machine_is_compatible("RackMac3,1");

	if (!of_machine_is_compatible("PowerMac7,2") &&
	    !of_machine_is_compatible("PowerMac7,3") &&
	    !rackmac)
	    	return -ENODEV;

	return platform_driver_register(&fcu_of_platform_driver);
}

static void __exit therm_pm72_exit(void)
{
	platform_driver_unregister(&fcu_of_platform_driver);
}

module_init(therm_pm72_init);
module_exit(therm_pm72_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("Driver for Apple's PowerMac G5 thermal control");
MODULE_LICENSE("GPL");