aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/nand/nand_base.c
blob: 055f6608a2ecefeaa65529a1e5d94cc1eb680762 (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
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
/*
 *  drivers/mtd/nand.c
 *
 *  Overview:
 *   This is the generic MTD driver for NAND flash devices. It should be
 *   capable of working with almost all NAND chips currently available.
 *   Basic support for AG-AND chips is provided.
 *
 *	Additional technical information is available on
 *	http://www.linux-mtd.infradead.org/tech/nand.html
 *
 *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
 * 		  2002 Thomas Gleixner (tglx@linutronix.de)
 *
 *  02-08-2004  tglx: support for strange chips, which cannot auto increment
 *		pages on read / read_oob
 *
 *  03-17-2004  tglx: Check ready before auto increment check. Simon Bayes
 *		pointed this out, as he marked an auto increment capable chip
 *		as NOAUTOINCR in the board driver.
 *		Make reads over block boundaries work too
 *
 *  04-14-2004	tglx: first working version for 2k page size chips
 *
 *  05-19-2004  tglx: Basic support for Renesas AG-AND chips
 *
 *  09-24-2004  tglx: add support for hardware controllers (e.g. ECC) shared
 *		among multiple independend devices. Suggestions and initial patch
 *		from Ben Dooks <ben-mtd@fluff.org>
 *
 *  12-05-2004	dmarlin: add workaround for Renesas AG-AND chips "disturb" issue.
 *		Basically, any block not rewritten may lose data when surrounding blocks
 *		are rewritten many times.  JFFS2 ensures this doesn't happen for blocks
 *		it uses, but the Bad Block Table(s) may not be rewritten.  To ensure they
 *		do not lose data, force them to be rewritten when some of the surrounding
 *		blocks are erased.  Rather than tracking a specific nearby block (which
 *		could itself go bad), use a page address 'mask' to select several blocks
 *		in the same area, and rewrite the BBT when any of them are erased.
 *
 *  01-03-2005	dmarlin: added support for the device recovery command sequence for Renesas
 *		AG-AND chips.  If there was a sudden loss of power during an erase operation,
 * 		a "device recovery" operation must be performed when power is restored
 * 		to ensure correct operation.
 *
 *  01-20-2005	dmarlin: added support for optional hardware specific callback routine to
 *		perform extra error status checks on erase and write failures.  This required
 *		adding a wrapper function for nand_read_ecc.
 *
 * 08-20-2005	vwool: suspend/resume added
 *
 * Credits:
 *	David Woodhouse for adding multichip support
 *
 *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
 *	rework for 2K page size chips
 *
 * TODO:
 *	Enable cached programming for 2k page size chips
 *	Check, if mtd->ecctype should be set to MTD_ECC_HW
 *	if we have HW ecc support.
 *	The AG-AND chips have nice features for speed improvement,
 *	which are not supported yet. Read / program 4 pages in one go.
 *
 * $Id: nand_base.c,v 1.150 2005/09/15 13:58:48 vwool Exp $
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/compatmac.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/leds.h>
#include <asm/io.h>

#ifdef CONFIG_MTD_PARTITIONS
#include <linux/mtd/partitions.h>
#endif

/* Define default oob placement schemes for large and small page devices */
static struct nand_oobinfo nand_oob_8 = {
	.useecc = MTD_NANDECC_AUTOPLACE,
	.eccbytes = 3,
	.eccpos = {0, 1, 2},
	.oobfree = {{3, 2}, {6, 2}}
};

static struct nand_oobinfo nand_oob_16 = {
	.useecc = MTD_NANDECC_AUTOPLACE,
	.eccbytes = 6,
	.eccpos = {0, 1, 2, 3, 6, 7},
	.oobfree = {{8, 8}}
};

static struct nand_oobinfo nand_oob_64 = {
	.useecc = MTD_NANDECC_AUTOPLACE,
	.eccbytes = 24,
	.eccpos = {
		   40, 41, 42, 43, 44, 45, 46, 47,
		   48, 49, 50, 51, 52, 53, 54, 55,
		   56, 57, 58, 59, 60, 61, 62, 63},
	.oobfree = {{2, 38}}
};

/* This is used for padding purposes in nand_write_oob */
static u_char ffchars[] = {
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};

/*
 * NAND low-level MTD interface functions
 */
static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len);
static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len);
static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len);

static int nand_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
static int nand_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
			 size_t *retlen, u_char *buf, u_char *eccbuf, struct nand_oobinfo *oobsel);
static int nand_read_oob(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
static int nand_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
static int nand_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
			  size_t *retlen, const u_char *buf, u_char *eccbuf, struct nand_oobinfo *oobsel);
static int nand_write_oob(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
static int nand_writev(struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen);
static int nand_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs,
			   unsigned long count, loff_t to, size_t *retlen, u_char *eccbuf,
			   struct nand_oobinfo *oobsel);
static int nand_erase(struct mtd_info *mtd, struct erase_info *instr);
static void nand_sync(struct mtd_info *mtd);

/* Some internal functions */
static int nand_write_page(struct mtd_info *mtd, struct nand_chip *this, int page, u_char * oob_buf,
			   struct nand_oobinfo *oobsel, int mode);
#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
static int nand_verify_pages(struct mtd_info *mtd, struct nand_chip *this, int page, int numpages,
			     u_char *oob_buf, struct nand_oobinfo *oobsel, int chipnr, int oobmode);
#else
#define nand_verify_pages(...) (0)
#endif

static int nand_get_device(struct nand_chip *this, struct mtd_info *mtd, int new_state);

/**
 * nand_release_device - [GENERIC] release chip
 * @mtd:	MTD device structure
 *
 * Deselect, release chip lock and wake up anyone waiting on the device
 */
static void nand_release_device(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;

	/* De-select the NAND device */
	this->select_chip(mtd, -1);

	if (this->controller) {
		/* Release the controller and the chip */
		spin_lock(&this->controller->lock);
		this->controller->active = NULL;
		this->state = FL_READY;
		wake_up(&this->controller->wq);
		spin_unlock(&this->controller->lock);
	} else {
		/* Release the chip */
		spin_lock(&this->chip_lock);
		this->state = FL_READY;
		wake_up(&this->wq);
		spin_unlock(&this->chip_lock);
	}
}

/**
 * nand_read_byte - [DEFAULT] read one byte from the chip
 * @mtd:	MTD device structure
 *
 * Default read function for 8bit buswith
 */
static u_char nand_read_byte(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	return readb(this->IO_ADDR_R);
}

/**
 * nand_write_byte - [DEFAULT] write one byte to the chip
 * @mtd:	MTD device structure
 * @byte:	pointer to data byte to write
 *
 * Default write function for 8it buswith
 */
static void nand_write_byte(struct mtd_info *mtd, u_char byte)
{
	struct nand_chip *this = mtd->priv;
	writeb(byte, this->IO_ADDR_W);
}

/**
 * nand_read_byte16 - [DEFAULT] read one byte endianess aware from the chip
 * @mtd:	MTD device structure
 *
 * Default read function for 16bit buswith with
 * endianess conversion
 */
static u_char nand_read_byte16(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	return (u_char) cpu_to_le16(readw(this->IO_ADDR_R));
}

/**
 * nand_write_byte16 - [DEFAULT] write one byte endianess aware to the chip
 * @mtd:	MTD device structure
 * @byte:	pointer to data byte to write
 *
 * Default write function for 16bit buswith with
 * endianess conversion
 */
static void nand_write_byte16(struct mtd_info *mtd, u_char byte)
{
	struct nand_chip *this = mtd->priv;
	writew(le16_to_cpu((u16) byte), this->IO_ADDR_W);
}

/**
 * nand_read_word - [DEFAULT] read one word from the chip
 * @mtd:	MTD device structure
 *
 * Default read function for 16bit buswith without
 * endianess conversion
 */
static u16 nand_read_word(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	return readw(this->IO_ADDR_R);
}

/**
 * nand_write_word - [DEFAULT] write one word to the chip
 * @mtd:	MTD device structure
 * @word:	data word to write
 *
 * Default write function for 16bit buswith without
 * endianess conversion
 */
static void nand_write_word(struct mtd_info *mtd, u16 word)
{
	struct nand_chip *this = mtd->priv;
	writew(word, this->IO_ADDR_W);
}

/**
 * nand_select_chip - [DEFAULT] control CE line
 * @mtd:	MTD device structure
 * @chip:	chipnumber to select, -1 for deselect
 *
 * Default select function for 1 chip devices.
 */
static void nand_select_chip(struct mtd_info *mtd, int chip)
{
	struct nand_chip *this = mtd->priv;
	switch (chip) {
	case -1:
		this->hwcontrol(mtd, NAND_CTL_CLRNCE);
		break;
	case 0:
		this->hwcontrol(mtd, NAND_CTL_SETNCE);
		break;

	default:
		BUG();
	}
}

/**
 * nand_write_buf - [DEFAULT] write buffer to chip
 * @mtd:	MTD device structure
 * @buf:	data buffer
 * @len:	number of bytes to write
 *
 * Default write function for 8bit buswith
 */
static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;

	for (i = 0; i < len; i++)
		writeb(buf[i], this->IO_ADDR_W);
}

/**
 * nand_read_buf - [DEFAULT] read chip data into buffer
 * @mtd:	MTD device structure
 * @buf:	buffer to store date
 * @len:	number of bytes to read
 *
 * Default read function for 8bit buswith
 */
static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;

	for (i = 0; i < len; i++)
		buf[i] = readb(this->IO_ADDR_R);
}

/**
 * nand_verify_buf - [DEFAULT] Verify chip data against buffer
 * @mtd:	MTD device structure
 * @buf:	buffer containing the data to compare
 * @len:	number of bytes to compare
 *
 * Default verify function for 8bit buswith
 */
static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;

	for (i = 0; i < len; i++)
		if (buf[i] != readb(this->IO_ADDR_R))
			return -EFAULT;

	return 0;
}

/**
 * nand_write_buf16 - [DEFAULT] write buffer to chip
 * @mtd:	MTD device structure
 * @buf:	data buffer
 * @len:	number of bytes to write
 *
 * Default write function for 16bit buswith
 */
static void nand_write_buf16(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	u16 *p = (u16 *) buf;
	len >>= 1;

	for (i = 0; i < len; i++)
		writew(p[i], this->IO_ADDR_W);

}

/**
 * nand_read_buf16 - [DEFAULT] read chip data into buffer
 * @mtd:	MTD device structure
 * @buf:	buffer to store date
 * @len:	number of bytes to read
 *
 * Default read function for 16bit buswith
 */
static void nand_read_buf16(struct mtd_info *mtd, u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	u16 *p = (u16 *) buf;
	len >>= 1;

	for (i = 0; i < len; i++)
		p[i] = readw(this->IO_ADDR_R);
}

/**
 * nand_verify_buf16 - [DEFAULT] Verify chip data against buffer
 * @mtd:	MTD device structure
 * @buf:	buffer containing the data to compare
 * @len:	number of bytes to compare
 *
 * Default verify function for 16bit buswith
 */
static int nand_verify_buf16(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	u16 *p = (u16 *) buf;
	len >>= 1;

	for (i = 0; i < len; i++)
		if (p[i] != readw(this->IO_ADDR_R))
			return -EFAULT;

	return 0;
}

/**
 * nand_block_bad - [DEFAULT] Read bad block marker from the chip
 * @mtd:	MTD device structure
 * @ofs:	offset from device start
 * @getchip:	0, if the chip is already selected
 *
 * Check, if the block is bad.
 */
static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
{
	int page, chipnr, res = 0;
	struct nand_chip *this = mtd->priv;
	u16 bad;

	if (getchip) {
		page = (int)(ofs >> this->page_shift);
		chipnr = (int)(ofs >> this->chip_shift);

		/* Grab the lock and see if the device is available */
		nand_get_device(this, mtd, FL_READING);

		/* Select the NAND device */
		this->select_chip(mtd, chipnr);
	} else
		page = (int)ofs;

	if (this->options & NAND_BUSWIDTH_16) {
		this->cmdfunc(mtd, NAND_CMD_READOOB, this->badblockpos & 0xFE, page & this->pagemask);
		bad = cpu_to_le16(this->read_word(mtd));
		if (this->badblockpos & 0x1)
			bad >>= 8;
		if ((bad & 0xFF) != 0xff)
			res = 1;
	} else {
		this->cmdfunc(mtd, NAND_CMD_READOOB, this->badblockpos, page & this->pagemask);
		if (this->read_byte(mtd) != 0xff)
			res = 1;
	}

	if (getchip) {
		/* Deselect and wake up anyone waiting on the device */
		nand_release_device(mtd);
	}

	return res;
}

/**
 * nand_default_block_markbad - [DEFAULT] mark a block bad
 * @mtd:	MTD device structure
 * @ofs:	offset from device start
 *
 * This is the default implementation, which can be overridden by
 * a hardware specific driver.
*/
static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
	struct nand_chip *this = mtd->priv;
	u_char buf[2] = { 0, 0 };
	size_t retlen;
	int block;

	/* Get block number */
	block = ((int)ofs) >> this->bbt_erase_shift;
	if (this->bbt)
		this->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);

	/* Do we have a flash based bad block table ? */
	if (this->options & NAND_USE_FLASH_BBT)
		return nand_update_bbt(mtd, ofs);

	/* We write two bytes, so we dont have to mess with 16 bit access */
	ofs += mtd->oobsize + (this->badblockpos & ~0x01);
	return nand_write_oob(mtd, ofs, 2, &retlen, buf);
}

/**
 * nand_check_wp - [GENERIC] check if the chip is write protected
 * @mtd:	MTD device structure
 * Check, if the device is write protected
 *
 * The function expects, that the device is already selected
 */
static int nand_check_wp(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	/* Check the WP bit */
	this->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
	return (this->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1;
}

/**
 * nand_block_checkbad - [GENERIC] Check if a block is marked bad
 * @mtd:	MTD device structure
 * @ofs:	offset from device start
 * @getchip:	0, if the chip is already selected
 * @allowbbt:	1, if its allowed to access the bbt area
 *
 * Check, if the block is bad. Either by reading the bad block table or
 * calling of the scan function.
 */
static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip, int allowbbt)
{
	struct nand_chip *this = mtd->priv;

	if (!this->bbt)
		return this->block_bad(mtd, ofs, getchip);

	/* Return info from the table */
	return nand_isbad_bbt(mtd, ofs, allowbbt);
}

DEFINE_LED_TRIGGER(nand_led_trigger);

/*
 * Wait for the ready pin, after a command
 * The timeout is catched later.
 */
static void nand_wait_ready(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	unsigned long timeo = jiffies + 2;

	led_trigger_event(nand_led_trigger, LED_FULL);
	/* wait until command is processed or timeout occures */
	do {
		if (this->dev_ready(mtd))
			break;
		touch_softlockup_watchdog();
	} while (time_before(jiffies, timeo));
	led_trigger_event(nand_led_trigger, LED_OFF);
}

/**
 * nand_command - [DEFAULT] Send command to NAND device
 * @mtd:	MTD device structure
 * @command:	the command to be sent
 * @column:	the column address for this command, -1 if none
 * @page_addr:	the page address for this command, -1 if none
 *
 * Send command to NAND device. This function is used for small page
 * devices (256/512 Bytes per page)
 */
static void nand_command(struct mtd_info *mtd, unsigned command, int column, int page_addr)
{
	register struct nand_chip *this = mtd->priv;

	/* Begin command latch cycle */
	this->hwcontrol(mtd, NAND_CTL_SETCLE);
	/*
	 * Write out the command to the device.
	 */
	if (command == NAND_CMD_SEQIN) {
		int readcmd;

		if (column >= mtd->writesize) {
			/* OOB area */
			column -= mtd->writesize;
			readcmd = NAND_CMD_READOOB;
		} else if (column < 256) {
			/* First 256 bytes --> READ0 */
			readcmd = NAND_CMD_READ0;
		} else {
			column -= 256;
			readcmd = NAND_CMD_READ1;
		}
		this->write_byte(mtd, readcmd);
	}
	this->write_byte(mtd, command);

	/* Set ALE and clear CLE to start address cycle */
	this->hwcontrol(mtd, NAND_CTL_CLRCLE);

	if (column != -1 || page_addr != -1) {
		this->hwcontrol(mtd, NAND_CTL_SETALE);

		/* Serially input address */
		if (column != -1) {
			/* Adjust columns for 16 bit buswidth */
			if (this->options & NAND_BUSWIDTH_16)
				column >>= 1;
			this->write_byte(mtd, column);
		}
		if (page_addr != -1) {
			this->write_byte(mtd, (unsigned char)(page_addr & 0xff));
			this->write_byte(mtd, (unsigned char)((page_addr >> 8) & 0xff));
			/* One more address cycle for devices > 32MiB */
			if (this->chipsize > (32 << 20))
				this->write_byte(mtd, (unsigned char)((page_addr >> 16) & 0x0f));
		}
		/* Latch in address */
		this->hwcontrol(mtd, NAND_CTL_CLRALE);
	}

	/*
	 * program and erase have their own busy handlers
	 * status and sequential in needs no delay
	 */
	switch (command) {

	case NAND_CMD_PAGEPROG:
	case NAND_CMD_ERASE1:
	case NAND_CMD_ERASE2:
	case NAND_CMD_SEQIN:
	case NAND_CMD_STATUS:
		return;

	case NAND_CMD_RESET:
		if (this->dev_ready)
			break;
		udelay(this->chip_delay);
		this->hwcontrol(mtd, NAND_CTL_SETCLE);
		this->write_byte(mtd, NAND_CMD_STATUS);
		this->hwcontrol(mtd, NAND_CTL_CLRCLE);
		while (!(this->read_byte(mtd) & NAND_STATUS_READY)) ;
		return;

		/* This applies to read commands */
	default:
		/*
		 * If we don't have access to the busy pin, we apply the given
		 * command delay
		 */
		if (!this->dev_ready) {
			udelay(this->chip_delay);
			return;
		}
	}
	/* Apply this short delay always to ensure that we do wait tWB in
	 * any case on any machine. */
	ndelay(100);

	nand_wait_ready(mtd);
}

/**
 * nand_command_lp - [DEFAULT] Send command to NAND large page device
 * @mtd:	MTD device structure
 * @command:	the command to be sent
 * @column:	the column address for this command, -1 if none
 * @page_addr:	the page address for this command, -1 if none
 *
 * Send command to NAND device. This is the version for the new large page devices
 * We dont have the separate regions as we have in the small page devices.
 * We must emulate NAND_CMD_READOOB to keep the code compatible.
 *
 */
static void nand_command_lp(struct mtd_info *mtd, unsigned command, int column, int page_addr)
{
	register struct nand_chip *this = mtd->priv;

	/* Emulate NAND_CMD_READOOB */
	if (command == NAND_CMD_READOOB) {
		column += mtd->writesize;
		command = NAND_CMD_READ0;
	}

	/* Begin command latch cycle */
	this->hwcontrol(mtd, NAND_CTL_SETCLE);
	/* Write out the command to the device. */
	this->write_byte(mtd, (command & 0xff));
	/* End command latch cycle */
	this->hwcontrol(mtd, NAND_CTL_CLRCLE);

	if (column != -1 || page_addr != -1) {
		this->hwcontrol(mtd, NAND_CTL_SETALE);

		/* Serially input address */
		if (column != -1) {
			/* Adjust columns for 16 bit buswidth */
			if (this->options & NAND_BUSWIDTH_16)
				column >>= 1;
			this->write_byte(mtd, column & 0xff);
			this->write_byte(mtd, column >> 8);
		}
		if (page_addr != -1) {
			this->write_byte(mtd, (unsigned char)(page_addr & 0xff));
			this->write_byte(mtd, (unsigned char)((page_addr >> 8) & 0xff));
			/* One more address cycle for devices > 128MiB */
			if (this->chipsize > (128 << 20))
				this->write_byte(mtd, (unsigned char)((page_addr >> 16) & 0xff));
		}
		/* Latch in address */
		this->hwcontrol(mtd, NAND_CTL_CLRALE);
	}

	/*
	 * program and erase have their own busy handlers
	 * status, sequential in, and deplete1 need no delay
	 */
	switch (command) {

	case NAND_CMD_CACHEDPROG:
	case NAND_CMD_PAGEPROG:
	case NAND_CMD_ERASE1:
	case NAND_CMD_ERASE2:
	case NAND_CMD_SEQIN:
	case NAND_CMD_STATUS:
	case NAND_CMD_DEPLETE1:
		return;

		/*
		 * read error status commands require only a short delay
		 */
	case NAND_CMD_STATUS_ERROR:
	case NAND_CMD_STATUS_ERROR0:
	case NAND_CMD_STATUS_ERROR1:
	case NAND_CMD_STATUS_ERROR2:
	case NAND_CMD_STATUS_ERROR3:
		udelay(this->chip_delay);
		return;

	case NAND_CMD_RESET:
		if (this->dev_ready)
			break;
		udelay(this->chip_delay);
		this->hwcontrol(mtd, NAND_CTL_SETCLE);
		this->write_byte(mtd, NAND_CMD_STATUS);
		this->hwcontrol(mtd, NAND_CTL_CLRCLE);
		while (!(this->read_byte(mtd) & NAND_STATUS_READY)) ;
		return;

	case NAND_CMD_READ0:
		/* Begin command latch cycle */
		this->hwcontrol(mtd, NAND_CTL_SETCLE);
		/* Write out the start read command */
		this->write_byte(mtd, NAND_CMD_READSTART);
		/* End command latch cycle */
		this->hwcontrol(mtd, NAND_CTL_CLRCLE);
		/* Fall through into ready check */

		/* This applies to read commands */
	default:
		/*
		 * If we don't have access to the busy pin, we apply the given
		 * command delay
		 */
		if (!this->dev_ready) {
			udelay(this->chip_delay);
			return;
		}
	}

	/* Apply this short delay always to ensure that we do wait tWB in
	 * any case on any machine. */
	ndelay(100);

	nand_wait_ready(mtd);
}

/**
 * nand_get_device - [GENERIC] Get chip for selected access
 * @this:	the nand chip descriptor
 * @mtd:	MTD device structure
 * @new_state:	the state which is requested
 *
 * Get the device and lock it for exclusive access
 */
static int nand_get_device(struct nand_chip *this, struct mtd_info *mtd, int new_state)
{
	struct nand_chip *active;
	spinlock_t *lock;
	wait_queue_head_t *wq;
	DECLARE_WAITQUEUE(wait, current);

	lock = (this->controller) ? &this->controller->lock : &this->chip_lock;
	wq = (this->controller) ? &this->controller->wq : &this->wq;
 retry:
	active = this;
	spin_lock(lock);

	/* Hardware controller shared among independend devices */
	if (this->controller) {
		if (this->controller->active)
			active = this->controller->active;
		else
			this->controller->active = this;
	}
	if (active == this && this->state == FL_READY) {
		this->state = new_state;
		spin_unlock(lock);
		return 0;
	}
	if (new_state == FL_PM_SUSPENDED) {
		spin_unlock(lock);
		return (this->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;
	}
	set_current_state(TASK_UNINTERRUPTIBLE);
	add_wait_queue(wq, &wait);
	spin_unlock(lock);
	schedule();
	remove_wait_queue(wq, &wait);
	goto retry;
}

/**
 * nand_wait - [DEFAULT]  wait until the command is done
 * @mtd:	MTD device structure
 * @this:	NAND chip structure
 * @state:	state to select the max. timeout value
 *
 * Wait for command done. This applies to erase and program only
 * Erase can take up to 400ms and program up to 20ms according to
 * general NAND and SmartMedia specs
 *
*/
static int nand_wait(struct mtd_info *mtd, struct nand_chip *this, int state)
{

	unsigned long timeo = jiffies;
	int status;

	if (state == FL_ERASING)
		timeo += (HZ * 400) / 1000;
	else
		timeo += (HZ * 20) / 1000;

	led_trigger_event(nand_led_trigger, LED_FULL);

	/* Apply this short delay always to ensure that we do wait tWB in
	 * any case on any machine. */
	ndelay(100);

	if ((state == FL_ERASING) && (this->options & NAND_IS_AND))
		this->cmdfunc(mtd, NAND_CMD_STATUS_MULTI, -1, -1);
	else
		this->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);

	while (time_before(jiffies, timeo)) {
		/* Check, if we were interrupted */
		if (this->state != state)
			return 0;

		if (this->dev_ready) {
			if (this->dev_ready(mtd))
				break;
		} else {
			if (this->read_byte(mtd) & NAND_STATUS_READY)
				break;
		}
		cond_resched();
	}
	led_trigger_event(nand_led_trigger, LED_OFF);

	status = (int)this->read_byte(mtd);
	return status;
}

/**
 * nand_write_page - [GENERIC] write one page
 * @mtd:	MTD device structure
 * @this:	NAND chip structure
 * @page: 	startpage inside the chip, must be called with (page & this->pagemask)
 * @oob_buf:	out of band data buffer
 * @oobsel:	out of band selecttion structre
 * @cached:	1 = enable cached programming if supported by chip
 *
 * Nand_page_program function is used for write and writev !
 * This function will always program a full page of data
 * If you call it with a non page aligned buffer, you're lost :)
 *
 * Cached programming is not supported yet.
 */
static int nand_write_page(struct mtd_info *mtd, struct nand_chip *this, int page,
			   u_char *oob_buf, struct nand_oobinfo *oobsel, int cached)
{
	int i, status;
	u_char ecc_code[32];
	int eccmode = oobsel->useecc ? this->eccmode : NAND_ECC_NONE;
	int *oob_config = oobsel->eccpos;
	int datidx = 0, eccidx = 0, eccsteps = this->eccsteps;
	int eccbytes = 0;

	/* FIXME: Enable cached programming */
	cached = 0;

	/* Send command to begin auto page programming */
	this->cmdfunc(mtd, NAND_CMD_SEQIN, 0x00, page);

	/* Write out complete page of data, take care of eccmode */
	switch (eccmode) {
		/* No ecc, write all */
	case NAND_ECC_NONE:
		printk(KERN_WARNING "Writing data without ECC to NAND-FLASH is not recommended\n");
		this->write_buf(mtd, this->data_poi, mtd->writesize);
		break;

		/* Software ecc 3/256, write all */
	case NAND_ECC_SOFT:
		for (; eccsteps; eccsteps--) {
			this->calculate_ecc(mtd, &this->data_poi[datidx], ecc_code);
			for (i = 0; i < 3; i++, eccidx++)
				oob_buf[oob_config[eccidx]] = ecc_code[i];
			datidx += this->eccsize;
		}
		this->write_buf(mtd, this->data_poi, mtd->writesize);
		break;
	default:
		eccbytes = this->eccbytes;
		for (; eccsteps; eccsteps--) {
			/* enable hardware ecc logic for write */
			this->enable_hwecc(mtd, NAND_ECC_WRITE);
			this->write_buf(mtd, &this->data_poi[datidx], this->eccsize);
			this->calculate_ecc(mtd, &this->data_poi[datidx], ecc_code);
			for (i = 0; i < eccbytes; i++, eccidx++)
				oob_buf[oob_config[eccidx]] = ecc_code[i];
			/* If the hardware ecc provides syndromes then
			 * the ecc code must be written immidiately after
			 * the data bytes (words) */
			if (this->options & NAND_HWECC_SYNDROME)
				this->write_buf(mtd, ecc_code, eccbytes);
			datidx += this->eccsize;
		}
		break;
	}

	/* Write out OOB data */
	if (this->options & NAND_HWECC_SYNDROME)
		this->write_buf(mtd, &oob_buf[oobsel->eccbytes], mtd->oobsize - oobsel->eccbytes);
	else
		this->write_buf(mtd, oob_buf, mtd->oobsize);

	/* Send command to actually program the data */
	this->cmdfunc(mtd, cached ? NAND_CMD_CACHEDPROG : NAND_CMD_PAGEPROG, -1, -1);

	if (!cached) {
		/* call wait ready function */
		status = this->waitfunc(mtd, this, FL_WRITING);

		/* See if operation failed and additional status checks are available */
		if ((status & NAND_STATUS_FAIL) && (this->errstat)) {
			status = this->errstat(mtd, this, FL_WRITING, status, page);
		}

		/* See if device thinks it succeeded */
		if (status & NAND_STATUS_FAIL) {
			DEBUG(MTD_DEBUG_LEVEL0, "%s: " "Failed write, page 0x%08x, ", __FUNCTION__, page);
			return -EIO;
		}
	} else {
		/* FIXME: Implement cached programming ! */
		/* wait until cache is ready */
		// status = this->waitfunc (mtd, this, FL_CACHEDRPG);
	}
	return 0;
}

#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
/**
 * nand_verify_pages - [GENERIC] verify the chip contents after a write
 * @mtd:	MTD device structure
 * @this:	NAND chip structure
 * @page: 	startpage inside the chip, must be called with (page & this->pagemask)
 * @numpages:	number of pages to verify
 * @oob_buf:	out of band data buffer
 * @oobsel:	out of band selecttion structre
 * @chipnr:	number of the current chip
 * @oobmode:	1 = full buffer verify, 0 = ecc only
 *
 * The NAND device assumes that it is always writing to a cleanly erased page.
 * Hence, it performs its internal write verification only on bits that
 * transitioned from 1 to 0. The device does NOT verify the whole page on a
 * byte by byte basis. It is possible that the page was not completely erased
 * or the page is becoming unusable due to wear. The read with ECC would catch
 * the error later when the ECC page check fails, but we would rather catch
 * it early in the page write stage. Better to write no data than invalid data.
 */
static int nand_verify_pages(struct mtd_info *mtd, struct nand_chip *this, int page, int numpages,
			     u_char *oob_buf, struct nand_oobinfo *oobsel, int chipnr, int oobmode)
{
	int i, j, datidx = 0, oobofs = 0, res = -EIO;
	int eccsteps = this->eccsteps;
	int hweccbytes;
	u_char oobdata[64];

	hweccbytes = (this->options & NAND_HWECC_SYNDROME) ? (oobsel->eccbytes / eccsteps) : 0;

	/* Send command to read back the first page */
	this->cmdfunc(mtd, NAND_CMD_READ0, 0, page);

	for (;;) {
		for (j = 0; j < eccsteps; j++) {
			/* Loop through and verify the data */
			if (this->verify_buf(mtd, &this->data_poi[datidx], mtd->eccsize)) {
				DEBUG(MTD_DEBUG_LEVEL0, "%s: " "Failed write verify, page 0x%08x ", __FUNCTION__, page);
				goto out;
			}
			datidx += mtd->eccsize;
			/* Have we a hw generator layout ? */
			if (!hweccbytes)
				continue;
			if (this->verify_buf(mtd, &this->oob_buf[oobofs], hweccbytes)) {
				DEBUG(MTD_DEBUG_LEVEL0, "%s: " "Failed write verify, page 0x%08x ", __FUNCTION__, page);
				goto out;
			}
			oobofs += hweccbytes;
		}

		/* check, if we must compare all data or if we just have to
		 * compare the ecc bytes
		 */
		if (oobmode) {
			if (this->verify_buf(mtd, &oob_buf[oobofs], mtd->oobsize - hweccbytes * eccsteps)) {
				DEBUG(MTD_DEBUG_LEVEL0, "%s: " "Failed write verify, page 0x%08x ", __FUNCTION__, page);
				goto out;
			}
		} else {
			/* Read always, else autoincrement fails */
			this->read_buf(mtd, oobdata, mtd->oobsize - hweccbytes * eccsteps);

			if (oobsel->useecc != MTD_NANDECC_OFF && !hweccbytes) {
				int ecccnt = oobsel->eccbytes;

				for (i = 0; i < ecccnt; i++) {
					int idx = oobsel->eccpos[i];
					if (oobdata[idx] != oob_buf[oobofs + idx]) {
						DEBUG(MTD_DEBUG_LEVEL0, "%s: Failed ECC write verify, page 0x%08x, %6i bytes were succesful\n",
						      __FUNCTION__, page, i);
						goto out;
					}
				}
			}
		}
		oobofs += mtd->oobsize - hweccbytes * eccsteps;
		page++;
		numpages--;

		/* Apply delay or wait for ready/busy pin
		 * Do this before the AUTOINCR check, so no problems
		 * arise if a chip which does auto increment
		 * is marked as NOAUTOINCR by the board driver.
		 * Do this also before returning, so the chip is
		 * ready for the next command.
		 */
		if (!this->dev_ready)
			udelay(this->chip_delay);
		else
			nand_wait_ready(mtd);

		/* All done, return happy */
		if (!numpages)
			return 0;

		/* Check, if the chip supports auto page increment */
		if (!NAND_CANAUTOINCR(this))
			this->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
	}
	/*
	 * Terminate the read command. We come here in case of an error
	 * So we must issue a reset command.
	 */
 out:
	this->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
	return res;
}
#endif

/**
 * nand_read - [MTD Interface] MTD compability function for nand_do_read_ecc
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @len:	number of bytes to read
 * @retlen:	pointer to variable to store the number of read bytes
 * @buf:	the databuffer to put data
 *
 * This function simply calls nand_do_read_ecc with oob buffer and oobsel = NULL
 * and flags = 0xff
 */
static int nand_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
{
	return nand_do_read_ecc(mtd, from, len, retlen, buf, NULL, &mtd->oobinfo, 0xff);
}

/**
 * nand_read_ecc - [MTD Interface] MTD compability function for nand_do_read_ecc
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @len:	number of bytes to read
 * @retlen:	pointer to variable to store the number of read bytes
 * @buf:	the databuffer to put data
 * @oob_buf:	filesystem supplied oob data buffer
 * @oobsel:	oob selection structure
 *
 * This function simply calls nand_do_read_ecc with flags = 0xff
 */
static int nand_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
			 size_t *retlen, u_char *buf, u_char *oob_buf, struct nand_oobinfo *oobsel)
{
	/* use userspace supplied oobinfo, if zero */
	if (oobsel == NULL)
		oobsel = &mtd->oobinfo;
	return nand_do_read_ecc(mtd, from, len, retlen, buf, oob_buf, oobsel, 0xff);
}

/**
 * nand_do_read_ecc - [MTD Interface] Read data with ECC
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @len:	number of bytes to read
 * @retlen:	pointer to variable to store the number of read bytes
 * @buf:	the databuffer to put data
 * @oob_buf:	filesystem supplied oob data buffer (can be NULL)
 * @oobsel:	oob selection structure
 * @flags:	flag to indicate if nand_get_device/nand_release_device should be preformed
 *		and how many corrected error bits are acceptable:
 *		  bits 0..7 - number of tolerable errors
 *		  bit  8    - 0 == do not get/release chip, 1 == get/release chip
 *
 * NAND read with ECC
 */
int nand_do_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
		     size_t *retlen, u_char *buf, u_char *oob_buf, struct nand_oobinfo *oobsel, int flags)
{

	int i, j, col, realpage, page, end, ecc, chipnr, sndcmd = 1;
	int read = 0, oob = 0, ecc_status = 0, ecc_failed = 0;
	struct nand_chip *this = mtd->priv;
	u_char *data_poi, *oob_data = oob_buf;
	u_char ecc_calc[32];
	u_char ecc_code[32];
	int eccmode, eccsteps;
	int *oob_config, datidx;
	int blockcheck = (1 << (this->phys_erase_shift - this->page_shift)) - 1;
	int eccbytes;
	int compareecc = 1;
	int oobreadlen;

	DEBUG(MTD_DEBUG_LEVEL3, "nand_read_ecc: from = 0x%08x, len = %i\n", (unsigned int)from, (int)len);

	/* Do not allow reads past end of device */
	if ((from + len) > mtd->size) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_ecc: Attempt read beyond end of device\n");
		*retlen = 0;
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	if (flags & NAND_GET_DEVICE)
		nand_get_device(this, mtd, FL_READING);

	/* Autoplace of oob data ? Use the default placement scheme */
	if (oobsel->useecc == MTD_NANDECC_AUTOPLACE)
		oobsel = this->autooob;

	eccmode = oobsel->useecc ? this->eccmode : NAND_ECC_NONE;
	oob_config = oobsel->eccpos;

	/* Select the NAND device */
	chipnr = (int)(from >> this->chip_shift);
	this->select_chip(mtd, chipnr);

	/* First we calculate the starting page */
	realpage = (int)(from >> this->page_shift);
	page = realpage & this->pagemask;

	/* Get raw starting column */
	col = from & (mtd->writesize - 1);

	end = mtd->writesize;
	ecc = this->eccsize;
	eccbytes = this->eccbytes;

	if ((eccmode == NAND_ECC_NONE) || (this->options & NAND_HWECC_SYNDROME))
		compareecc = 0;

	oobreadlen = mtd->oobsize;
	if (this->options & NAND_HWECC_SYNDROME)
		oobreadlen -= oobsel->eccbytes;

	/* Loop until all data read */
	while (read < len) {

		int aligned = (!col && (len - read) >= end);
		/*
		 * If the read is not page aligned, we have to read into data buffer
		 * due to ecc, else we read into return buffer direct
		 */
		if (aligned)
			data_poi = &buf[read];
		else
			data_poi = this->data_buf;

		/* Check, if we have this page in the buffer
		 *
		 * FIXME: Make it work when we must provide oob data too,
		 * check the usage of data_buf oob field
		 */
		if (realpage == this->pagebuf && !oob_buf) {
			/* aligned read ? */
			if (aligned)
				memcpy(data_poi, this->data_buf, end);
			goto readdata;
		}

		/* Check, if we must send the read command */
		if (sndcmd) {
			this->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
			sndcmd = 0;
		}

		/* get oob area, if we have no oob buffer from fs-driver */
		if (!oob_buf || oobsel->useecc == MTD_NANDECC_AUTOPLACE ||
			oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
			oob_data = &this->data_buf[end];

		eccsteps = this->eccsteps;

		switch (eccmode) {
		case NAND_ECC_NONE:{
				/* No ECC, Read in a page */
				static unsigned long lastwhinge = 0;
				if ((lastwhinge / HZ) != (jiffies / HZ)) {
					printk(KERN_WARNING
					       "Reading data from NAND FLASH without ECC is not recommended\n");
					lastwhinge = jiffies;
				}
				this->read_buf(mtd, data_poi, end);
				break;
			}

		case NAND_ECC_SOFT:	/* Software ECC 3/256: Read in a page + oob data */
			this->read_buf(mtd, data_poi, end);
			for (i = 0, datidx = 0; eccsteps; eccsteps--, i += 3, datidx += ecc)
				this->calculate_ecc(mtd, &data_poi[datidx], &ecc_calc[i]);
			break;

		default:
			for (i = 0, datidx = 0; eccsteps; eccsteps--, i += eccbytes, datidx += ecc) {
				this->enable_hwecc(mtd, NAND_ECC_READ);
				this->read_buf(mtd, &data_poi[datidx], ecc);

				/* HW ecc with syndrome calculation must read the
				 * syndrome from flash immidiately after the data */
				if (!compareecc) {
					/* Some hw ecc generators need to know when the
					 * syndrome is read from flash */
					this->enable_hwecc(mtd, NAND_ECC_READSYN);
					this->read_buf(mtd, &oob_data[i], eccbytes);
					/* We calc error correction directly, it checks the hw
					 * generator for an error, reads back the syndrome and
					 * does the error correction on the fly */
					ecc_status = this->correct_data(mtd, &data_poi[datidx], &oob_data[i], &ecc_code[i]);
					if ((ecc_status == -1) || (ecc_status > (flags && 0xff))) {
						DEBUG(MTD_DEBUG_LEVEL0, "nand_read_ecc: "
						      "Failed ECC read, page 0x%08x on chip %d\n", page, chipnr);
						ecc_failed++;
					}
				} else {
					this->calculate_ecc(mtd, &data_poi[datidx], &ecc_calc[i]);
				}
			}
			break;
		}

		/* read oobdata */
		this->read_buf(mtd, &oob_data[mtd->oobsize - oobreadlen], oobreadlen);

		/* Skip ECC check, if not requested (ECC_NONE or HW_ECC with syndromes) */
		if (!compareecc)
			goto readoob;

		/* Pick the ECC bytes out of the oob data */
		for (j = 0; j < oobsel->eccbytes; j++)
			ecc_code[j] = oob_data[oob_config[j]];

		/* correct data, if necessary */
		for (i = 0, j = 0, datidx = 0; i < this->eccsteps; i++, datidx += ecc) {
			ecc_status = this->correct_data(mtd, &data_poi[datidx], &ecc_code[j], &ecc_calc[j]);

			/* Get next chunk of ecc bytes */
			j += eccbytes;

			/* Check, if we have a fs supplied oob-buffer,
			 * This is the legacy mode. Used by YAFFS1
			 * Should go away some day
			 */
			if (oob_buf && oobsel->useecc == MTD_NANDECC_PLACE) {
				int *p = (int *)(&oob_data[mtd->oobsize]);
				p[i] = ecc_status;
			}

			if ((ecc_status == -1) || (ecc_status > (flags && 0xff))) {
				DEBUG(MTD_DEBUG_LEVEL0, "nand_read_ecc: " "Failed ECC read, page 0x%08x\n", page);
				ecc_failed++;
			}
		}

	      readoob:
		/* check, if we have a fs supplied oob-buffer */
		if (oob_buf) {
			/* without autoplace. Legacy mode used by YAFFS1 */
			switch (oobsel->useecc) {
			case MTD_NANDECC_AUTOPLACE:
			case MTD_NANDECC_AUTOPL_USR:
				/* Walk through the autoplace chunks */
				for (i = 0; oobsel->oobfree[i][1]; i++) {
					int from = oobsel->oobfree[i][0];
					int num = oobsel->oobfree[i][1];
					memcpy(&oob_buf[oob], &oob_data[from], num);
					oob += num;
				}
				break;
			case MTD_NANDECC_PLACE:
				/* YAFFS1 legacy mode */
				oob_data += this->eccsteps * sizeof(int);
			default:
				oob_data += mtd->oobsize;
			}
		}
	readdata:
		/* Partial page read, transfer data into fs buffer */
		if (!aligned) {
			for (j = col; j < end && read < len; j++)
				buf[read++] = data_poi[j];
			this->pagebuf = realpage;
		} else
			read += mtd->writesize;

		/* Apply delay or wait for ready/busy pin
		 * Do this before the AUTOINCR check, so no problems
		 * arise if a chip which does auto increment
		 * is marked as NOAUTOINCR by the board driver.
		 */
		if (!this->dev_ready)
			udelay(this->chip_delay);
		else
			nand_wait_ready(mtd);

		if (read == len)
			break;

		/* For subsequent reads align to page boundary. */
		col = 0;
		/* Increment page address */
		realpage++;

		page = realpage & this->pagemask;
		/* Check, if we cross a chip boundary */
		if (!page) {
			chipnr++;
			this->select_chip(mtd, -1);
			this->select_chip(mtd, chipnr);
		}
		/* Check, if the chip supports auto page increment
		 * or if we have hit a block boundary.
		 */
		if (!NAND_CANAUTOINCR(this) || !(page & blockcheck))
			sndcmd = 1;
	}

	/* Deselect and wake up anyone waiting on the device */
	if (flags & NAND_GET_DEVICE)
		nand_release_device(mtd);

	/*
	 * Return success, if no ECC failures, else -EBADMSG
	 * fs driver will take care of that, because
	 * retlen == desired len and result == -EBADMSG
	 */
	*retlen = read;
	return ecc_failed ? -EBADMSG : 0;
}

/**
 * nand_read_oob - [MTD Interface] NAND read out-of-band
 * @mtd:	MTD device structure
 * @from:	offset to read from
 * @len:	number of bytes to read
 * @retlen:	pointer to variable to store the number of read bytes
 * @buf:	the databuffer to put data
 *
 * NAND read out-of-band data from the spare area
 */
static int nand_read_oob(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
{
	int i, col, page, chipnr;
	struct nand_chip *this = mtd->priv;
	int blockcheck = (1 << (this->phys_erase_shift - this->page_shift)) - 1;

	DEBUG(MTD_DEBUG_LEVEL3, "nand_read_oob: from = 0x%08x, len = %i\n", (unsigned int)from, (int)len);

	/* Shift to get page */
	page = (int)(from >> this->page_shift);
	chipnr = (int)(from >> this->chip_shift);

	/* Mask to get column */
	col = from & (mtd->oobsize - 1);

	/* Initialize return length value */
	*retlen = 0;

	/* Do not allow reads past end of device */
	if ((from + len) > mtd->size) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_oob: Attempt read beyond end of device\n");
		*retlen = 0;
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device(this, mtd, FL_READING);

	/* Select the NAND device */
	this->select_chip(mtd, chipnr);

	/* Send the read command */
	this->cmdfunc(mtd, NAND_CMD_READOOB, col, page & this->pagemask);
	/*
	 * Read the data, if we read more than one page
	 * oob data, let the device transfer the data !
	 */
	i = 0;
	while (i < len) {
		int thislen = mtd->oobsize - col;
		thislen = min_t(int, thislen, len);
		this->read_buf(mtd, &buf[i], thislen);
		i += thislen;

		/* Read more ? */
		if (i < len) {
			page++;
			col = 0;

			/* Check, if we cross a chip boundary */
			if (!(page & this->pagemask)) {
				chipnr++;
				this->select_chip(mtd, -1);
				this->select_chip(mtd, chipnr);
			}

			/* Apply delay or wait for ready/busy pin
			 * Do this before the AUTOINCR check, so no problems
			 * arise if a chip which does auto increment
			 * is marked as NOAUTOINCR by the board driver.
			 */
			if (!this->dev_ready)
				udelay(this->chip_delay);
			else
				nand_wait_ready(mtd);

			/* Check, if the chip supports auto page increment
			 * or if we have hit a block boundary.
			 */
			if (!NAND_CANAUTOINCR(this) || !(page & blockcheck)) {
				/* For subsequent page reads set offset to 0 */
				this->cmdfunc(mtd, NAND_CMD_READOOB, 0x0, page & this->pagemask);
			}
		}
	}

	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);

	/* Return happy */
	*retlen = len;
	return 0;
}

/**
 * nand_read_raw - [GENERIC] Read raw data including oob into buffer
 * @mtd:	MTD device structure
 * @buf:	temporary buffer
 * @from:	offset to read from
 * @len:	number of bytes to read
 * @ooblen:	number of oob data bytes to read
 *
 * Read raw data including oob into buffer
 */
int nand_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t from, size_t len, size_t ooblen)
{
	struct nand_chip *this = mtd->priv;
	int page = (int)(from >> this->page_shift);
	int chip = (int)(from >> this->chip_shift);
	int sndcmd = 1;
	int cnt = 0;
	int pagesize = mtd->writesize + mtd->oobsize;
	int blockcheck = (1 << (this->phys_erase_shift - this->page_shift)) - 1;

	/* Do not allow reads past end of device */
	if ((from + len) > mtd->size) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_read_raw: Attempt read beyond end of device\n");
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device(this, mtd, FL_READING);

	this->select_chip(mtd, chip);

	/* Add requested oob length */
	len += ooblen;

	while (len) {
		if (sndcmd)
			this->cmdfunc(mtd, NAND_CMD_READ0, 0, page & this->pagemask);
		sndcmd = 0;

		this->read_buf(mtd, &buf[cnt], pagesize);

		len -= pagesize;
		cnt += pagesize;
		page++;

		if (!this->dev_ready)
			udelay(this->chip_delay);
		else
			nand_wait_ready(mtd);

		/* Check, if the chip supports auto page increment */
		if (!NAND_CANAUTOINCR(this) || !(page & blockcheck))
			sndcmd = 1;
	}

	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);
	return 0;
}

/**
 * nand_prepare_oobbuf - [GENERIC] Prepare the out of band buffer
 * @mtd:	MTD device structure
 * @fsbuf:	buffer given by fs driver
 * @oobsel:	out of band selection structre
 * @autoplace:	1 = place given buffer into the oob bytes
 * @numpages:	number of pages to prepare
 *
 * Return:
 * 1. Filesystem buffer available and autoplacement is off,
 *    return filesystem buffer
 * 2. No filesystem buffer or autoplace is off, return internal
 *    buffer
 * 3. Filesystem buffer is given and autoplace selected
 *    put data from fs buffer into internal buffer and
 *    retrun internal buffer
 *
 * Note: The internal buffer is filled with 0xff. This must
 * be done only once, when no autoplacement happens
 * Autoplacement sets the buffer dirty flag, which
 * forces the 0xff fill before using the buffer again.
 *
*/
static u_char *nand_prepare_oobbuf(struct mtd_info *mtd, u_char *fsbuf, struct nand_oobinfo *oobsel,
				   int autoplace, int numpages)
{
	struct nand_chip *this = mtd->priv;
	int i, len, ofs;

	/* Zero copy fs supplied buffer */
	if (fsbuf && !autoplace)
		return fsbuf;

	/* Check, if the buffer must be filled with ff again */
	if (this->oobdirty) {
		memset(this->oob_buf, 0xff, mtd->oobsize << (this->phys_erase_shift - this->page_shift));
		this->oobdirty = 0;
	}

	/* If we have no autoplacement or no fs buffer use the internal one */
	if (!autoplace || !fsbuf)
		return this->oob_buf;

	/* Walk through the pages and place the data */
	this->oobdirty = 1;
	ofs = 0;
	while (numpages--) {
		for (i = 0, len = 0; len < mtd->oobavail; i++) {
			int to = ofs + oobsel->oobfree[i][0];
			int num = oobsel->oobfree[i][1];
			memcpy(&this->oob_buf[to], fsbuf, num);
			len += num;
			fsbuf += num;
		}
		ofs += mtd->oobavail;
	}
	return this->oob_buf;
}

#define NOTALIGNED(x) (x & (mtd->writesize-1)) != 0

/**
 * nand_write - [MTD Interface] compability function for nand_write_ecc
 * @mtd:	MTD device structure
 * @to:		offset to write to
 * @len:	number of bytes to write
 * @retlen:	pointer to variable to store the number of written bytes
 * @buf:	the data to write
 *
 * This function simply calls nand_write_ecc with oob buffer and oobsel = NULL
 *
*/
static int nand_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
{
	return (nand_write_ecc(mtd, to, len, retlen, buf, NULL, NULL));
}

/**
 * nand_write_ecc - [MTD Interface] NAND write with ECC
 * @mtd:	MTD device structure
 * @to:		offset to write to
 * @len:	number of bytes to write
 * @retlen:	pointer to variable to store the number of written bytes
 * @buf:	the data to write
 * @eccbuf:	filesystem supplied oob data buffer
 * @oobsel:	oob selection structure
 *
 * NAND write with ECC
 */
static int nand_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
			  size_t *retlen, const u_char *buf, u_char *eccbuf,
			  struct nand_oobinfo *oobsel)
{
	int startpage, page, ret = -EIO, oob = 0, written = 0, chipnr;
	int autoplace = 0, numpages, totalpages;
	struct nand_chip *this = mtd->priv;
	u_char *oobbuf, *bufstart;
	int ppblock = (1 << (this->phys_erase_shift - this->page_shift));

	DEBUG(MTD_DEBUG_LEVEL3, "nand_write_ecc: to = 0x%08x, len = %i\n", (unsigned int)to, (int)len);

	/* Initialize retlen, in case of early exit */
	*retlen = 0;

	/* Do not allow write past end of device */
	if ((to + len) > mtd->size) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_write_ecc: Attempt to write past end of page\n");
		return -EINVAL;
	}

	/* reject writes, which are not page aligned */
	if (NOTALIGNED(to) || NOTALIGNED(len)) {
		printk(KERN_NOTICE "nand_write_ecc: Attempt to write not page aligned data\n");
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device(this, mtd, FL_WRITING);

	/* Calculate chipnr */
	chipnr = (int)(to >> this->chip_shift);
	/* Select the NAND device */
	this->select_chip(mtd, chipnr);

	/* Check, if it is write protected */
	if (nand_check_wp(mtd))
		goto out;

	/* if oobsel is NULL, use chip defaults */
	if (oobsel == NULL)
		oobsel = &mtd->oobinfo;

	/* Autoplace of oob data ? Use the default placement scheme */
	if (oobsel->useecc == MTD_NANDECC_AUTOPLACE) {
		oobsel = this->autooob;
		autoplace = 1;
	}
	if (oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
		autoplace = 1;

	/* Setup variables and oob buffer */
	totalpages = len >> this->page_shift;
	page = (int)(to >> this->page_shift);
	/* Invalidate the page cache, if we write to the cached page */
	if (page <= this->pagebuf && this->pagebuf < (page + totalpages))
		this->pagebuf = -1;

	/* Set it relative to chip */
	page &= this->pagemask;
	startpage = page;
	/* Calc number of pages we can write in one go */
	numpages = min(ppblock - (startpage & (ppblock - 1)), totalpages);
	oobbuf = nand_prepare_oobbuf(mtd, eccbuf, oobsel, autoplace, numpages);
	bufstart = (u_char *) buf;

	/* Loop until all data is written */
	while (written < len) {

		this->data_poi = (u_char *) &buf[written];
		/* Write one page. If this is the last page to write
		 * or the last page in this block, then use the
		 * real pageprogram command, else select cached programming
		 * if supported by the chip.
		 */
		ret = nand_write_page(mtd, this, page, &oobbuf[oob], oobsel, (--numpages > 0));
		if (ret) {
			DEBUG(MTD_DEBUG_LEVEL0, "nand_write_ecc: write_page failed %d\n", ret);
			goto out;
		}
		/* Next oob page */
		oob += mtd->oobsize;
		/* Update written bytes count */
		written += mtd->writesize;
		if (written == len)
			goto cmp;

		/* Increment page address */
		page++;

		/* Have we hit a block boundary ? Then we have to verify and
		 * if verify is ok, we have to setup the oob buffer for
		 * the next pages.
		 */
		if (!(page & (ppblock - 1))) {
			int ofs;
			this->data_poi = bufstart;
			ret = nand_verify_pages(mtd, this, startpage, page - startpage,
						oobbuf, oobsel, chipnr, (eccbuf != NULL));
			if (ret) {
				DEBUG(MTD_DEBUG_LEVEL0, "nand_write_ecc: verify_pages failed %d\n", ret);
				goto out;
			}
			*retlen = written;

			ofs = autoplace ? mtd->oobavail : mtd->oobsize;
			if (eccbuf)
				eccbuf += (page - startpage) * ofs;
			totalpages -= page - startpage;
			numpages = min(totalpages, ppblock);
			page &= this->pagemask;
			startpage = page;
			oobbuf = nand_prepare_oobbuf(mtd, eccbuf, oobsel, autoplace, numpages);
			oob = 0;
			/* Check, if we cross a chip boundary */
			if (!page) {
				chipnr++;
				this->select_chip(mtd, -1);
				this->select_chip(mtd, chipnr);
			}
		}
	}
	/* Verify the remaining pages */
 cmp:
	this->data_poi = bufstart;
	ret = nand_verify_pages(mtd, this, startpage, totalpages, oobbuf, oobsel, chipnr, (eccbuf != NULL));
	if (!ret)
		*retlen = written;
	else
		DEBUG(MTD_DEBUG_LEVEL0, "nand_write_ecc: verify_pages failed %d\n", ret);

 out:
	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);

	return ret;
}

/**
 * nand_write_oob - [MTD Interface] NAND write out-of-band
 * @mtd:	MTD device structure
 * @to:		offset to write to
 * @len:	number of bytes to write
 * @retlen:	pointer to variable to store the number of written bytes
 * @buf:	the data to write
 *
 * NAND write out-of-band
 */
static int nand_write_oob(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
{
	int column, page, status, ret = -EIO, chipnr;
	struct nand_chip *this = mtd->priv;

	DEBUG(MTD_DEBUG_LEVEL3, "nand_write_oob: to = 0x%08x, len = %i\n", (unsigned int)to, (int)len);

	/* Shift to get page */
	page = (int)(to >> this->page_shift);
	chipnr = (int)(to >> this->chip_shift);

	/* Mask to get column */
	column = to & (mtd->oobsize - 1);

	/* Initialize return length value */
	*retlen = 0;

	/* Do not allow write past end of page */
	if ((column + len) > mtd->oobsize) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: Attempt to write past end of page\n");
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device(this, mtd, FL_WRITING);

	/* Select the NAND device */
	this->select_chip(mtd, chipnr);

	/* Reset the chip. Some chips (like the Toshiba TC5832DC found
	   in one of my DiskOnChip 2000 test units) will clear the whole
	   data page too if we don't do this. I have no clue why, but
	   I seem to have 'fixed' it in the doc2000 driver in
	   August 1999.  dwmw2. */
	this->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);

	/* Check, if it is write protected */
	if (nand_check_wp(mtd))
		goto out;

	/* Invalidate the page cache, if we write to the cached page */
	if (page == this->pagebuf)
		this->pagebuf = -1;

	if (NAND_MUST_PAD(this)) {
		/* Write out desired data */
		this->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, page & this->pagemask);
		/* prepad 0xff for partial programming */
		this->write_buf(mtd, ffchars, column);
		/* write data */
		this->write_buf(mtd, buf, len);
		/* postpad 0xff for partial programming */
		this->write_buf(mtd, ffchars, mtd->oobsize - (len + column));
	} else {
		/* Write out desired data */
		this->cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize + column, page & this->pagemask);
		/* write data */
		this->write_buf(mtd, buf, len);
	}
	/* Send command to program the OOB data */
	this->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);

	status = this->waitfunc(mtd, this, FL_WRITING);

	/* See if device thinks it succeeded */
	if (status & NAND_STATUS_FAIL) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: " "Failed write, page 0x%08x\n", page);
		ret = -EIO;
		goto out;
	}
	/* Return happy */
	*retlen = len;

#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
	/* Send command to read back the data */
	this->cmdfunc(mtd, NAND_CMD_READOOB, column, page & this->pagemask);

	if (this->verify_buf(mtd, buf, len)) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_write_oob: " "Failed write verify, page 0x%08x\n", page);
		ret = -EIO;
		goto out;
	}
#endif
	ret = 0;
 out:
	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);

	return ret;
}

/**
 * nand_writev - [MTD Interface] compabilty function for nand_writev_ecc
 * @mtd:	MTD device structure
 * @vecs:	the iovectors to write
 * @count:	number of vectors
 * @to:		offset to write to
 * @retlen:	pointer to variable to store the number of written bytes
 *
 * NAND write with kvec. This just calls the ecc function
 */
static int nand_writev(struct mtd_info *mtd, const struct kvec *vecs, unsigned long count,
		       loff_t to, size_t *retlen)
{
	return (nand_writev_ecc(mtd, vecs, count, to, retlen, NULL, NULL));
}

/**
 * nand_writev_ecc - [MTD Interface] write with iovec with ecc
 * @mtd:	MTD device structure
 * @vecs:	the iovectors to write
 * @count:	number of vectors
 * @to:		offset to write to
 * @retlen:	pointer to variable to store the number of written bytes
 * @eccbuf:	filesystem supplied oob data buffer
 * @oobsel:	oob selection structure
 *
 * NAND write with iovec with ecc
 */
static int nand_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs, unsigned long count,
			   loff_t to, size_t *retlen, u_char *eccbuf, struct nand_oobinfo *oobsel)
{
	int i, page, len, total_len, ret = -EIO, written = 0, chipnr;
	int oob, numpages, autoplace = 0, startpage;
	struct nand_chip *this = mtd->priv;
	int ppblock = (1 << (this->phys_erase_shift - this->page_shift));
	u_char *oobbuf, *bufstart;

	/* Preset written len for early exit */
	*retlen = 0;

	/* Calculate total length of data */
	total_len = 0;
	for (i = 0; i < count; i++)
		total_len += (int)vecs[i].iov_len;

	DEBUG(MTD_DEBUG_LEVEL3, "nand_writev: to = 0x%08x, len = %i, count = %ld\n", (unsigned int)to, (unsigned int)total_len, count);

	/* Do not allow write past end of page */
	if ((to + total_len) > mtd->size) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_writev: Attempted write past end of device\n");
		return -EINVAL;
	}

	/* reject writes, which are not page aligned */
	if (NOTALIGNED(to) || NOTALIGNED(total_len)) {
		printk(KERN_NOTICE "nand_write_ecc: Attempt to write not page aligned data\n");
		return -EINVAL;
	}

	/* Grab the lock and see if the device is available */
	nand_get_device(this, mtd, FL_WRITING);

	/* Get the current chip-nr */
	chipnr = (int)(to >> this->chip_shift);
	/* Select the NAND device */
	this->select_chip(mtd, chipnr);

	/* Check, if it is write protected */
	if (nand_check_wp(mtd))
		goto out;

	/* if oobsel is NULL, use chip defaults */
	if (oobsel == NULL)
		oobsel = &mtd->oobinfo;

	/* Autoplace of oob data ? Use the default placement scheme */
	if (oobsel->useecc == MTD_NANDECC_AUTOPLACE) {
		oobsel = this->autooob;
		autoplace = 1;
	}
	if (oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
		autoplace = 1;

	/* Setup start page */
	page = (int)(to >> this->page_shift);
	/* Invalidate the page cache, if we write to the cached page */
	if (page <= this->pagebuf && this->pagebuf < ((to + total_len) >> this->page_shift))
		this->pagebuf = -1;

	startpage = page & this->pagemask;

	/* Loop until all kvec' data has been written */
	len = 0;
	while (count) {
		/* If the given tuple is >= pagesize then
		 * write it out from the iov
		 */
		if ((vecs->iov_len - len) >= mtd->writesize) {
			/* Calc number of pages we can write
			 * out of this iov in one go */
			numpages = (vecs->iov_len - len) >> this->page_shift;
			/* Do not cross block boundaries */
			numpages = min(ppblock - (startpage & (ppblock - 1)), numpages);
			oobbuf = nand_prepare_oobbuf(mtd, NULL, oobsel, autoplace, numpages);
			bufstart = (u_char *) vecs->iov_base;
			bufstart += len;
			this->data_poi = bufstart;
			oob = 0;
			for (i = 1; i <= numpages; i++) {
				/* Write one page. If this is the last page to write
				 * then use the real pageprogram command, else select
				 * cached programming if supported by the chip.
				 */
				ret = nand_write_page(mtd, this, page & this->pagemask,
						      &oobbuf[oob], oobsel, i != numpages);
				if (ret)
					goto out;
				this->data_poi += mtd->writesize;
				len += mtd->writesize;
				oob += mtd->oobsize;
				page++;
			}
			/* Check, if we have to switch to the next tuple */
			if (len >= (int)vecs->iov_len) {
				vecs++;
				len = 0;
				count--;
			}
		} else {
			/* We must use the internal buffer, read data out of each
			 * tuple until we have a full page to write
			 */
			int cnt = 0;
			while (cnt < mtd->writesize) {
				if (vecs->iov_base != NULL && vecs->iov_len)
					this->data_buf[cnt++] = ((u_char *) vecs->iov_base)[len++];
				/* Check, if we have to switch to the next tuple */
				if (len >= (int)vecs->iov_len) {
					vecs++;
					len = 0;
					count--;
				}
			}
			this->pagebuf = page;
			this->data_poi = this->data_buf;
			bufstart = this->data_poi;
			numpages = 1;
			oobbuf = nand_prepare_oobbuf(mtd, NULL, oobsel, autoplace, numpages);
			ret = nand_write_page(mtd, this, page & this->pagemask, oobbuf, oobsel, 0);
			if (ret)
				goto out;
			page++;
		}

		this->data_poi = bufstart;
		ret = nand_verify_pages(mtd, this, startpage, numpages, oobbuf, oobsel, chipnr, 0);
		if (ret)
			goto out;

		written += mtd->writesize * numpages;
		/* All done ? */
		if (!count)
			break;

		startpage = page & this->pagemask;
		/* Check, if we cross a chip boundary */
		if (!startpage) {
			chipnr++;
			this->select_chip(mtd, -1);
			this->select_chip(mtd, chipnr);
		}
	}
	ret = 0;
 out:
	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);

	*retlen = written;
	return ret;
}

/**
 * single_erease_cmd - [GENERIC] NAND standard block erase command function
 * @mtd:	MTD device structure
 * @page:	the page address of the block which will be erased
 *
 * Standard erase command for NAND chips
 */
static void single_erase_cmd(struct mtd_info *mtd, int page)
{
	struct nand_chip *this = mtd->priv;
	/* Send commands to erase a block */
	this->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
	this->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
}

/**
 * multi_erease_cmd - [GENERIC] AND specific block erase command function
 * @mtd:	MTD device structure
 * @page:	the page address of the block which will be erased
 *
 * AND multi block erase command function
 * Erase 4 consecutive blocks
 */
static void multi_erase_cmd(struct mtd_info *mtd, int page)
{
	struct nand_chip *this = mtd->priv;
	/* Send commands to erase a block */
	this->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
	this->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
	this->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page++);
	this->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
	this->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
}

/**
 * nand_erase - [MTD Interface] erase block(s)
 * @mtd:	MTD device structure
 * @instr:	erase instruction
 *
 * Erase one ore more blocks
 */
static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	return nand_erase_nand(mtd, instr, 0);
}

#define BBT_PAGE_MASK	0xffffff3f
/**
 * nand_erase_intern - [NAND Interface] erase block(s)
 * @mtd:	MTD device structure
 * @instr:	erase instruction
 * @allowbbt:	allow erasing the bbt area
 *
 * Erase one ore more blocks
 */
int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr, int allowbbt)
{
	int page, len, status, pages_per_block, ret, chipnr;
	struct nand_chip *this = mtd->priv;
	int rewrite_bbt[NAND_MAX_CHIPS]={0};	/* flags to indicate the page, if bbt needs to be rewritten. */
	unsigned int bbt_masked_page;		/* bbt mask to compare to page being erased. */
						/* It is used to see if the current page is in the same */
						/*   256 block group and the same bank as the bbt. */

	DEBUG(MTD_DEBUG_LEVEL3, "nand_erase: start = 0x%08x, len = %i\n", (unsigned int)instr->addr, (unsigned int)instr->len);

	/* Start address must align on block boundary */
	if (instr->addr & ((1 << this->phys_erase_shift) - 1)) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: Unaligned address\n");
		return -EINVAL;
	}

	/* Length must align on block boundary */
	if (instr->len & ((1 << this->phys_erase_shift) - 1)) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: Length not block aligned\n");
		return -EINVAL;
	}

	/* Do not allow erase past end of device */
	if ((instr->len + instr->addr) > mtd->size) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: Erase past end of device\n");
		return -EINVAL;
	}

	instr->fail_addr = 0xffffffff;

	/* Grab the lock and see if the device is available */
	nand_get_device(this, mtd, FL_ERASING);

	/* Shift to get first page */
	page = (int)(instr->addr >> this->page_shift);
	chipnr = (int)(instr->addr >> this->chip_shift);

	/* Calculate pages in each block */
	pages_per_block = 1 << (this->phys_erase_shift - this->page_shift);

	/* Select the NAND device */
	this->select_chip(mtd, chipnr);

	/* Check the WP bit */
	/* Check, if it is write protected */
	if (nand_check_wp(mtd)) {
		DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: Device is write protected!!!\n");
		instr->state = MTD_ERASE_FAILED;
		goto erase_exit;
	}

	/* if BBT requires refresh, set the BBT page mask to see if the BBT should be rewritten */
	if (this->options & BBT_AUTO_REFRESH) {
		bbt_masked_page = this->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
	} else {
		bbt_masked_page = 0xffffffff;	/* should not match anything */
	}

	/* Loop through the pages */
	len = instr->len;

	instr->state = MTD_ERASING;

	while (len) {
		/* Check if we have a bad block, we do not erase bad blocks ! */
		if (nand_block_checkbad(mtd, ((loff_t) page) << this->page_shift, 0, allowbbt)) {
			printk(KERN_WARNING "nand_erase: attempt to erase a bad block at page 0x%08x\n", page);
			instr->state = MTD_ERASE_FAILED;
			goto erase_exit;
		}

		/* Invalidate the page cache, if we erase the block which contains
		   the current cached page */
		if (page <= this->pagebuf && this->pagebuf < (page + pages_per_block))
			this->pagebuf = -1;

		this->erase_cmd(mtd, page & this->pagemask);

		status = this->waitfunc(mtd, this, FL_ERASING);

		/* See if operation failed and additional status checks are available */
		if ((status & NAND_STATUS_FAIL) && (this->errstat)) {
			status = this->errstat(mtd, this, FL_ERASING, status, page);
		}

		/* See if block erase succeeded */
		if (status & NAND_STATUS_FAIL) {
			DEBUG(MTD_DEBUG_LEVEL0, "nand_erase: " "Failed erase, page 0x%08x\n", page);
			instr->state = MTD_ERASE_FAILED;
			instr->fail_addr = (page << this->page_shift);
			goto erase_exit;
		}

		/* if BBT requires refresh, set the BBT rewrite flag to the page being erased */
		if (this->options & BBT_AUTO_REFRESH) {
			if (((page & BBT_PAGE_MASK) == bbt_masked_page) &&
			     (page != this->bbt_td->pages[chipnr])) {
				rewrite_bbt[chipnr] = (page << this->page_shift);
			}
		}

		/* Increment page address and decrement length */
		len -= (1 << this->phys_erase_shift);
		page += pages_per_block;

		/* Check, if we cross a chip boundary */
		if (len && !(page & this->pagemask)) {
			chipnr++;
			this->select_chip(mtd, -1);
			this->select_chip(mtd, chipnr);

			/* if BBT requires refresh and BBT-PERCHIP,
			 *   set the BBT page mask to see if this BBT should be rewritten */
			if ((this->options & BBT_AUTO_REFRESH) && (this->bbt_td->options & NAND_BBT_PERCHIP)) {
				bbt_masked_page = this->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
			}

		}
	}
	instr->state = MTD_ERASE_DONE;

 erase_exit:

	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
	/* Do call back function */
	if (!ret)
		mtd_erase_callback(instr);

	/* Deselect and wake up anyone waiting on the device */
	nand_release_device(mtd);

	/* if BBT requires refresh and erase was successful, rewrite any selected bad block tables */
	if ((this->options & BBT_AUTO_REFRESH) && (!ret)) {
		for (chipnr = 0; chipnr < this->numchips; chipnr++) {
			if (rewrite_bbt[chipnr]) {
				/* update the BBT for chip */
				DEBUG(MTD_DEBUG_LEVEL0, "nand_erase_nand: nand_update_bbt (%d:0x%0x 0x%0x)\n",
				      chipnr, rewrite_bbt[chipnr], this->bbt_td->pages[chipnr]);
				nand_update_bbt(mtd, rewrite_bbt[chipnr]);
			}
		}
	}

	/* Return more or less happy */
	return ret;
}

/**
 * nand_sync - [MTD Interface] sync
 * @mtd:	MTD device structure
 *
 * Sync is actually a wait for chip ready function
 */
static void nand_sync(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;

	DEBUG(MTD_DEBUG_LEVEL3, "nand_sync: called\n");

	/* Grab the lock and see if the device is available */
	nand_get_device(this, mtd, FL_SYNCING);
	/* Release it and go back */
	nand_release_device(mtd);
}

/**
 * nand_block_isbad - [MTD Interface] Check whether the block at the given offset is bad
 * @mtd:	MTD device structure
 * @ofs:	offset relative to mtd start
 */
static int nand_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
	/* Check for invalid offset */
	if (ofs > mtd->size)
		return -EINVAL;

	return nand_block_checkbad(mtd, ofs, 1, 0);
}

/**
 * nand_block_markbad - [MTD Interface] Mark the block at the given offset as bad
 * @mtd:	MTD device structure
 * @ofs:	offset relative to mtd start
 */
static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
	struct nand_chip *this = mtd->priv;
	int ret;

	if ((ret = nand_block_isbad(mtd, ofs))) {
		/* If it was bad already, return success and do nothing. */
		if (ret > 0)
			return 0;
		return ret;
	}

	return this->block_markbad(mtd, ofs);
}

/**
 * nand_suspend - [MTD Interface] Suspend the NAND flash
 * @mtd:	MTD device structure
 */
static int nand_suspend(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;

	return nand_get_device(this, mtd, FL_PM_SUSPENDED);
}

/**
 * nand_resume - [MTD Interface] Resume the NAND flash
 * @mtd:	MTD device structure
 */
static void nand_resume(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;

	if (this->state == FL_PM_SUSPENDED)
		nand_release_device(mtd);
	else
		printk(KERN_ERR "resume() called for the chip which is not in suspended state\n");

}

/* module_text_address() isn't exported, and it's mostly a pointless
   test if this is a module _anyway_ -- they'd have to try _really_ hard
   to call us from in-kernel code if the core NAND support is modular. */
#ifdef MODULE
#define caller_is_module() (1)
#else
#define caller_is_module() module_text_address((unsigned long)__builtin_return_address(0))
#endif

/**
 * nand_scan - [NAND Interface] Scan for the NAND device
 * @mtd:	MTD device structure
 * @maxchips:	Number of chips to scan for
 *
 * This fills out all the uninitialized function pointers
 * with the defaults.
 * The flash ID is read and the mtd/chip structures are
 * filled with the appropriate values. Buffers are allocated if
 * they are not provided by the board driver
 * The mtd->owner field must be set to the module of the caller
 *
 */
int nand_scan(struct mtd_info *mtd, int maxchips)
{
	int i, nand_maf_id, nand_dev_id, busw, maf_id;
	struct nand_chip *this = mtd->priv;

	/* Many callers got this wrong, so check for it for a while... */
	if (!mtd->owner && caller_is_module()) {
		printk(KERN_CRIT "nand_scan() called with NULL mtd->owner!\n");
		BUG();
	}

	/* Get buswidth to select the correct functions */
	busw = this->options & NAND_BUSWIDTH_16;

	/* check for proper chip_delay setup, set 20us if not */
	if (!this->chip_delay)
		this->chip_delay = 20;

	/* check, if a user supplied command function given */
	if (this->cmdfunc == NULL)
		this->cmdfunc = nand_command;

	/* check, if a user supplied wait function given */
	if (this->waitfunc == NULL)
		this->waitfunc = nand_wait;

	if (!this->select_chip)
		this->select_chip = nand_select_chip;
	if (!this->write_byte)
		this->write_byte = busw ? nand_write_byte16 : nand_write_byte;
	if (!this->read_byte)
		this->read_byte = busw ? nand_read_byte16 : nand_read_byte;
	if (!this->write_word)
		this->write_word = nand_write_word;
	if (!this->read_word)
		this->read_word = nand_read_word;
	if (!this->block_bad)
		this->block_bad = nand_block_bad;
	if (!this->block_markbad)
		this->block_markbad = nand_default_block_markbad;
	if (!this->write_buf)
		this->write_buf = busw ? nand_write_buf16 : nand_write_buf;
	if (!this->read_buf)
		this->read_buf = busw ? nand_read_buf16 : nand_read_buf;
	if (!this->verify_buf)
		this->verify_buf = busw ? nand_verify_buf16 : nand_verify_buf;
	if (!this->scan_bbt)
		this->scan_bbt = nand_default_bbt;

	/* Select the device */
	this->select_chip(mtd, 0);

	/* Send the command for reading device ID */
	this->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);

	/* Read manufacturer and device IDs */
	nand_maf_id = this->read_byte(mtd);
	nand_dev_id = this->read_byte(mtd);

	/* Print and store flash device information */
	for (i = 0; nand_flash_ids[i].name != NULL; i++) {

		if (nand_dev_id != nand_flash_ids[i].id)
			continue;

		if (!mtd->name)
			mtd->name = nand_flash_ids[i].name;
		this->chipsize = nand_flash_ids[i].chipsize << 20;

		/* New devices have all the information in additional id bytes */
		if (!nand_flash_ids[i].pagesize) {
			int extid;
			/* The 3rd id byte contains non relevant data ATM */
			extid = this->read_byte(mtd);
			/* The 4th id byte is the important one */
			extid = this->read_byte(mtd);
			/* Calc pagesize */
			mtd->writesize = 1024 << (extid & 0x3);
			extid >>= 2;
			/* Calc oobsize */
			mtd->oobsize = (8 << (extid & 0x01)) * (mtd->writesize >> 9);
			extid >>= 2;
			/* Calc blocksize. Blocksize is multiples of 64KiB */
			mtd->erasesize = (64 * 1024) << (extid & 0x03);
			extid >>= 2;
			/* Get buswidth information */
			busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;

		} else {
			/* Old devices have this data hardcoded in the
			 * device id table */
			mtd->erasesize = nand_flash_ids[i].erasesize;
			mtd->writesize = nand_flash_ids[i].pagesize;
			mtd->oobsize = mtd->writesize / 32;
			busw = nand_flash_ids[i].options & NAND_BUSWIDTH_16;
		}

		/* Try to identify manufacturer */
		for (maf_id = 0; nand_manuf_ids[maf_id].id != 0x0; maf_id++) {
			if (nand_manuf_ids[maf_id].id == nand_maf_id)
				break;
		}

		/* Check, if buswidth is correct. Hardware drivers should set
		 * this correct ! */
		if (busw != (this->options & NAND_BUSWIDTH_16)) {
			printk(KERN_INFO "NAND device: Manufacturer ID:"
			       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", nand_maf_id, nand_dev_id,
			       nand_manuf_ids[maf_id].name, mtd->name);
			printk(KERN_WARNING
			       "NAND bus width %d instead %d bit\n",
			       (this->options & NAND_BUSWIDTH_16) ? 16 : 8, busw ? 16 : 8);
			this->select_chip(mtd, -1);
			return 1;
		}

		/* Calculate the address shift from the page size */
		this->page_shift = ffs(mtd->writesize) - 1;
		this->bbt_erase_shift = this->phys_erase_shift = ffs(mtd->erasesize) - 1;
		this->chip_shift = ffs(this->chipsize) - 1;

		/* Set the bad block position */
		this->badblockpos = mtd->writesize > 512 ? NAND_LARGE_BADBLOCK_POS : NAND_SMALL_BADBLOCK_POS;

		/* Get chip options, preserve non chip based options */
		this->options &= ~NAND_CHIPOPTIONS_MSK;
		this->options |= nand_flash_ids[i].options & NAND_CHIPOPTIONS_MSK;
		/* Set this as a default. Board drivers can override it, if necessary */
		this->options |= NAND_NO_AUTOINCR;
		/* Check if this is a not a samsung device. Do not clear the options
		 * for chips which are not having an extended id.
		 */
		if (nand_maf_id != NAND_MFR_SAMSUNG && !nand_flash_ids[i].pagesize)
			this->options &= ~NAND_SAMSUNG_LP_OPTIONS;

		/* Check for AND chips with 4 page planes */
		if (this->options & NAND_4PAGE_ARRAY)
			this->erase_cmd = multi_erase_cmd;
		else
			this->erase_cmd = single_erase_cmd;

		/* Do not replace user supplied command function ! */
		if (mtd->writesize > 512 && this->cmdfunc == nand_command)
			this->cmdfunc = nand_command_lp;

		printk(KERN_INFO "NAND device: Manufacturer ID:"
		       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", nand_maf_id, nand_dev_id,
		       nand_manuf_ids[maf_id].name, nand_flash_ids[i].name);
		break;
	}

	if (!nand_flash_ids[i].name) {
		printk(KERN_WARNING "No NAND device found!!!\n");
		this->select_chip(mtd, -1);
		return 1;
	}

	for (i = 1; i < maxchips; i++) {
		this->select_chip(mtd, i);

		/* Send the command for reading device ID */
		this->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);

		/* Read manufacturer and device IDs */
		if (nand_maf_id != this->read_byte(mtd) ||
		    nand_dev_id != this->read_byte(mtd))
			break;
	}
	if (i > 1)
		printk(KERN_INFO "%d NAND chips detected\n", i);

	/* Allocate buffers, if necessary */
	if (!this->oob_buf) {
		size_t len;
		len = mtd->oobsize << (this->phys_erase_shift - this->page_shift);
		this->oob_buf = kmalloc(len, GFP_KERNEL);
		if (!this->oob_buf) {
			printk(KERN_ERR "nand_scan(): Cannot allocate oob_buf\n");
			return -ENOMEM;
		}
		this->options |= NAND_OOBBUF_ALLOC;
	}

	if (!this->data_buf) {
		size_t len;
		len = mtd->writesize + mtd->oobsize;
		this->data_buf = kmalloc(len, GFP_KERNEL);
		if (!this->data_buf) {
			if (this->options & NAND_OOBBUF_ALLOC)
				kfree(this->oob_buf);
			printk(KERN_ERR "nand_scan(): Cannot allocate data_buf\n");
			return -ENOMEM;
		}
		this->options |= NAND_DATABUF_ALLOC;
	}

	/* Store the number of chips and calc total size for mtd */
	this->numchips = i;
	mtd->size = i * this->chipsize;
	/* Convert chipsize to number of pages per chip -1. */
	this->pagemask = (this->chipsize >> this->page_shift) - 1;
	/* Preset the internal oob buffer */
	memset(this->oob_buf, 0xff, mtd->oobsize << (this->phys_erase_shift - this->page_shift));

	/* If no default placement scheme is given, select an
	 * appropriate one */
	if (!this->autooob) {
		/* Select the appropriate default oob placement scheme for
		 * placement agnostic filesystems */
		switch (mtd->oobsize) {
		case 8:
			this->autooob = &nand_oob_8;
			break;
		case 16:
			this->autooob = &nand_oob_16;
			break;
		case 64:
			this->autooob = &nand_oob_64;
			break;
		default:
			printk(KERN_WARNING "No oob scheme defined for oobsize %d\n", mtd->oobsize);
			BUG();
		}
	}

	/* The number of bytes available for the filesystem to place fs dependend
	 * oob data */
	mtd->oobavail = 0;
	for (i = 0; this->autooob->oobfree[i][1]; i++)
		mtd->oobavail += this->autooob->oobfree[i][1];

	/*
	 * check ECC mode, default to software
	 * if 3byte/512byte hardware ECC is selected and we have 256 byte pagesize
	 * fallback to software ECC
	 */
	this->eccsize = 256;	/* set default eccsize */
	this->eccbytes = 3;

	switch (this->eccmode) {
	case NAND_ECC_HW12_2048:
		if (mtd->writesize < 2048) {
			printk(KERN_WARNING "2048 byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
			       mtd->writesize);
			this->eccmode = NAND_ECC_SOFT;
			this->calculate_ecc = nand_calculate_ecc;
			this->correct_data = nand_correct_data;
		} else
			this->eccsize = 2048;
		break;

	case NAND_ECC_HW3_512:
	case NAND_ECC_HW6_512:
	case NAND_ECC_HW8_512:
		if (mtd->writesize == 256) {
			printk(KERN_WARNING "512 byte HW ECC not possible on 256 Byte pagesize, fallback to SW ECC \n");
			this->eccmode = NAND_ECC_SOFT;
			this->calculate_ecc = nand_calculate_ecc;
			this->correct_data = nand_correct_data;
		} else
			this->eccsize = 512;	/* set eccsize to 512 */
		break;

	case NAND_ECC_HW3_256:
		break;

	case NAND_ECC_NONE:
		printk(KERN_WARNING "NAND_ECC_NONE selected by board driver. This is not recommended !!\n");
		this->eccmode = NAND_ECC_NONE;
		break;

	case NAND_ECC_SOFT:
		this->calculate_ecc = nand_calculate_ecc;
		this->correct_data = nand_correct_data;
		break;

	default:
		printk(KERN_WARNING "Invalid NAND_ECC_MODE %d\n", this->eccmode);
		BUG();
	}

	/* Check hardware ecc function availability and adjust number of ecc bytes per
	 * calculation step
	 */
	switch (this->eccmode) {
	case NAND_ECC_HW12_2048:
		this->eccbytes += 4;
	case NAND_ECC_HW8_512:
		this->eccbytes += 2;
	case NAND_ECC_HW6_512:
		this->eccbytes += 3;
	case NAND_ECC_HW3_512:
	case NAND_ECC_HW3_256:
		if (this->calculate_ecc && this->correct_data && this->enable_hwecc)
			break;
		printk(KERN_WARNING "No ECC functions supplied, Hardware ECC not possible\n");
		BUG();
	}

	mtd->eccsize = this->eccsize;

	/* Set the number of read / write steps for one page to ensure ECC generation */
	switch (this->eccmode) {
	case NAND_ECC_HW12_2048:
		this->eccsteps = mtd->writesize / 2048;
		break;
	case NAND_ECC_HW3_512:
	case NAND_ECC_HW6_512:
	case NAND_ECC_HW8_512:
		this->eccsteps = mtd->writesize / 512;
		break;
	case NAND_ECC_HW3_256:
	case NAND_ECC_SOFT:
		this->eccsteps = mtd->writesize / 256;
		break;

	case NAND_ECC_NONE:
		this->eccsteps = 1;
		break;
	}

	/* Initialize state, waitqueue and spinlock */
	this->state = FL_READY;
	init_waitqueue_head(&this->wq);
	spin_lock_init(&this->chip_lock);

	/* De-select the device */
	this->select_chip(mtd, -1);

	/* Invalidate the pagebuffer reference */
	this->pagebuf = -1;

	/* Fill in remaining MTD driver data */
	mtd->type = MTD_NANDFLASH;
	mtd->flags = MTD_CAP_NANDFLASH | MTD_ECC;
	mtd->ecctype = MTD_ECC_SW;
	mtd->erase = nand_erase;
	mtd->point = NULL;
	mtd->unpoint = NULL;
	mtd->read = nand_read;
	mtd->write = nand_write;
	mtd->read_ecc = nand_read_ecc;
	mtd->write_ecc = nand_write_ecc;
	mtd->read_oob = nand_read_oob;
	mtd->write_oob = nand_write_oob;
	mtd->readv = NULL;
	mtd->writev = nand_writev;
	mtd->writev_ecc = nand_writev_ecc;
	mtd->sync = nand_sync;
	mtd->lock = NULL;
	mtd->unlock = NULL;
	mtd->suspend = nand_suspend;
	mtd->resume = nand_resume;
	mtd->block_isbad = nand_block_isbad;
	mtd->block_markbad = nand_block_markbad;

	/* and make the autooob the default one */
	memcpy(&mtd->oobinfo, this->autooob, sizeof(mtd->oobinfo));

	/* Check, if we should skip the bad block table scan */
	if (this->options & NAND_SKIP_BBTSCAN)
		return 0;

	/* Build bad block table */
	return this->scan_bbt(mtd);
}

/**
 * nand_release - [NAND Interface] Free resources held by the NAND device
 * @mtd:	MTD device structure
*/
void nand_release(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;

#ifdef CONFIG_MTD_PARTITIONS
	/* Deregister partitions */
	del_mtd_partitions(mtd);
#endif
	/* Deregister the device */
	del_mtd_device(mtd);

	/* Free bad block table memory */
	kfree(this->bbt);
	/* Buffer allocated by nand_scan ? */
	if (this->options & NAND_OOBBUF_ALLOC)
		kfree(this->oob_buf);
	/* Buffer allocated by nand_scan ? */
	if (this->options & NAND_DATABUF_ALLOC)
		kfree(this->data_buf);
}

EXPORT_SYMBOL_GPL(nand_scan);
EXPORT_SYMBOL_GPL(nand_release);

static int __init nand_base_init(void)
{
	led_trigger_register_simple("nand-disk", &nand_led_trigger);
	return 0;
}

static void __exit nand_base_exit(void)
{
	led_trigger_unregister_simple(nand_led_trigger);
}

module_init(nand_base_init);
module_exit(nand_base_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>, Thomas Gleixner <tglx@linutronix.de>");
MODULE_DESCRIPTION("Generic NAND flash driver code");