summaryrefslogtreecommitdiff
path: root/drivers/usb/storage/sddr09.c
blob: 79224fcf9b592120253d132c34d9e3d764fe635a (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
/* Driver for SanDisk SDDR-09 SmartMedia reader
 *
 *   (c) 2000, 2001 Robert Baruch (autophile@starband.net)
 *   (c) 2002 Andries Brouwer (aeb@cwi.nl)
 * Developed with the assistance of:
 *   (c) 2002 Alan Stern <stern@rowland.org>
 *
 * The SanDisk SDDR-09 SmartMedia reader uses the Shuttle EUSB-01 chip.
 * This chip is a programmable USB controller. In the SDDR-09, it has
 * been programmed to obey a certain limited set of SCSI commands.
 * This driver translates the "real" SCSI commands to the SDDR-09 SCSI
 * commands.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * Known vendor commands: 12 bytes, first byte is opcode
 *
 * E7: read scatter gather
 * E8: read
 * E9: write
 * EA: erase
 * EB: reset
 * EC: read status
 * ED: read ID
 * EE: write CIS (?)
 * EF: compute checksum (?)
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>

#include "usb.h"
#include "transport.h"
#include "protocol.h"
#include "debug.h"
#include "scsiglue.h"

#define DRV_NAME "ums-sddr09"

MODULE_DESCRIPTION("Driver for SanDisk SDDR-09 SmartMedia reader");
MODULE_AUTHOR("Andries Brouwer <aeb@cwi.nl>, Robert Baruch <autophile@starband.net>");
MODULE_LICENSE("GPL");

static int usb_stor_sddr09_dpcm_init(struct us_data *us);
static int sddr09_transport(struct scsi_cmnd *srb, struct us_data *us);
static int usb_stor_sddr09_init(struct us_data *us);


/*
 * The table of devices
 */
#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
		    vendorName, productName, useProtocol, useTransport, \
		    initFunction, flags) \
{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
  .driver_info = (flags) }

static struct usb_device_id sddr09_usb_ids[] = {
#	include "unusual_sddr09.h"
	{ }		/* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, sddr09_usb_ids);

#undef UNUSUAL_DEV

/*
 * The flags table
 */
#define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
		    vendor_name, product_name, use_protocol, use_transport, \
		    init_function, Flags) \
{ \
	.vendorName = vendor_name,	\
	.productName = product_name,	\
	.useProtocol = use_protocol,	\
	.useTransport = use_transport,	\
	.initFunction = init_function,	\
}

static struct us_unusual_dev sddr09_unusual_dev_list[] = {
#	include "unusual_sddr09.h"
	{ }		/* Terminating entry */
};

#undef UNUSUAL_DEV


#define short_pack(lsb,msb) ( ((u16)(lsb)) | ( ((u16)(msb))<<8 ) )
#define LSB_of(s) ((s)&0xFF)
#define MSB_of(s) ((s)>>8)

/*
 * First some stuff that does not belong here:
 * data on SmartMedia and other cards, completely
 * unrelated to this driver.
 * Similar stuff occurs in <linux/mtd/nand_ids.h>.
 */

struct nand_flash_dev {
	int model_id;
	int chipshift;		/* 1<<cs bytes total capacity */
	char pageshift;		/* 1<<ps bytes in a page */
	char blockshift;	/* 1<<bs pages in an erase block */
	char zoneshift;		/* 1<<zs blocks in a zone */
				/* # of logical blocks is 125/128 of this */
	char pageadrlen;	/* length of an address in bytes - 1 */
};

/*
 * NAND Flash Manufacturer ID Codes
 */
#define NAND_MFR_AMD		0x01
#define NAND_MFR_NATSEMI	0x8f
#define NAND_MFR_TOSHIBA	0x98
#define NAND_MFR_SAMSUNG	0xec

static inline char *nand_flash_manufacturer(int manuf_id) {
	switch(manuf_id) {
	case NAND_MFR_AMD:
		return "AMD";
	case NAND_MFR_NATSEMI:
		return "NATSEMI";
	case NAND_MFR_TOSHIBA:
		return "Toshiba";
	case NAND_MFR_SAMSUNG:
		return "Samsung";
	default:
		return "unknown";
	}
}

/*
 * It looks like it is unnecessary to attach manufacturer to the
 * remaining data: SSFDC prescribes manufacturer-independent id codes.
 *
 * 256 MB NAND flash has a 5-byte ID with 2nd byte 0xaa, 0xba, 0xca or 0xda.
 */

static struct nand_flash_dev nand_flash_ids[] = {
	/* NAND flash */
	{ 0x6e, 20, 8, 4, 8, 2},	/* 1 MB */
	{ 0xe8, 20, 8, 4, 8, 2},	/* 1 MB */
	{ 0xec, 20, 8, 4, 8, 2},	/* 1 MB */
	{ 0x64, 21, 8, 4, 9, 2}, 	/* 2 MB */
	{ 0xea, 21, 8, 4, 9, 2},	/* 2 MB */
	{ 0x6b, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xe3, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xe5, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xe6, 23, 9, 4, 10, 2},	/* 8 MB */
	{ 0x73, 24, 9, 5, 10, 2},	/* 16 MB */
	{ 0x75, 25, 9, 5, 10, 2},	/* 32 MB */
	{ 0x76, 26, 9, 5, 10, 3},	/* 64 MB */
	{ 0x79, 27, 9, 5, 10, 3},	/* 128 MB */

	/* MASK ROM */
	{ 0x5d, 21, 9, 4, 8, 2},	/* 2 MB */
	{ 0xd5, 22, 9, 4, 9, 2},	/* 4 MB */
	{ 0xd6, 23, 9, 4, 10, 2},	/* 8 MB */
	{ 0x57, 24, 9, 4, 11, 2},	/* 16 MB */
	{ 0x58, 25, 9, 4, 12, 2},	/* 32 MB */
	{ 0,}
};

static struct nand_flash_dev *
nand_find_id(unsigned char id) {
	int i;

	for (i = 0; i < ARRAY_SIZE(nand_flash_ids); i++)
		if (nand_flash_ids[i].model_id == id)
			return &(nand_flash_ids[i]);
	return NULL;
}

/*
 * ECC computation.
 */
static unsigned char parity[256];
static unsigned char ecc2[256];

static void nand_init_ecc(void) {
	int i, j, a;

	parity[0] = 0;
	for (i = 1; i < 256; i++)
		parity[i] = (parity[i&(i-1)] ^ 1);

	for (i = 0; i < 256; i++) {
		a = 0;
		for (j = 0; j < 8; j++) {
			if (i & (1<<j)) {
				if ((j & 1) == 0)
					a ^= 0x04;
				if ((j & 2) == 0)
					a ^= 0x10;
				if ((j & 4) == 0)
					a ^= 0x40;
			}
		}
		ecc2[i] = ~(a ^ (a<<1) ^ (parity[i] ? 0xa8 : 0));
	}
}

/* compute 3-byte ecc on 256 bytes */
static void nand_compute_ecc(unsigned char *data, unsigned char *ecc) {
	int i, j, a;
	unsigned char par = 0, bit, bits[8] = {0};

	/* collect 16 checksum bits */
	for (i = 0; i < 256; i++) {
		par ^= data[i];
		bit = parity[data[i]];
		for (j = 0; j < 8; j++)
			if ((i & (1<<j)) == 0)
				bits[j] ^= bit;
	}

	/* put 4+4+4 = 12 bits in the ecc */
	a = (bits[3] << 6) + (bits[2] << 4) + (bits[1] << 2) + bits[0];
	ecc[0] = ~(a ^ (a<<1) ^ (parity[par] ? 0xaa : 0));

	a = (bits[7] << 6) + (bits[6] << 4) + (bits[5] << 2) + bits[4];
	ecc[1] = ~(a ^ (a<<1) ^ (parity[par] ? 0xaa : 0));

	ecc[2] = ecc2[par];
}

static int nand_compare_ecc(unsigned char *data, unsigned char *ecc) {
	return (data[0] == ecc[0] && data[1] == ecc[1] && data[2] == ecc[2]);
}

static void nand_store_ecc(unsigned char *data, unsigned char *ecc) {
	memcpy(data, ecc, 3);
}

/*
 * The actual driver starts here.
 */

struct sddr09_card_info {
	unsigned long	capacity;	/* Size of card in bytes */
	int		pagesize;	/* Size of page in bytes */
	int		pageshift;	/* log2 of pagesize */
	int		blocksize;	/* Size of block in pages */
	int		blockshift;	/* log2 of blocksize */
	int		blockmask;	/* 2^blockshift - 1 */
	int		*lba_to_pba;	/* logical to physical map */
	int		*pba_to_lba;	/* physical to logical map */
	int		lbact;		/* number of available pages */
	int		flags;
#define	SDDR09_WP	1		/* write protected */
};

/*
 * On my 16MB card, control blocks have size 64 (16 real control bytes,
 * and 48 junk bytes). In reality of course the card uses 16 control bytes,
 * so the reader makes up the remaining 48. Don't know whether these numbers
 * depend on the card. For now a constant.
 */
#define CONTROL_SHIFT 6

/*
 * On my Combo CF/SM reader, the SM reader has LUN 1.
 * (and things fail with LUN 0).
 * It seems LUN is irrelevant for others.
 */
#define LUN	1
#define	LUNBITS	(LUN << 5)

/*
 * LBA and PBA are unsigned ints. Special values.
 */
#define UNDEF    0xffffffff
#define SPARE    0xfffffffe
#define UNUSABLE 0xfffffffd

static const int erase_bad_lba_entries = 0;

/* send vendor interface command (0x41) */
/* called for requests 0, 1, 8 */
static int
sddr09_send_command(struct us_data *us,
		    unsigned char request,
		    unsigned char direction,
		    unsigned char *xfer_data,
		    unsigned int xfer_len) {
	unsigned int pipe;
	unsigned char requesttype = (0x41 | direction);
	int rc;

	// Get the receive or send control pipe number

	if (direction == USB_DIR_IN)
		pipe = us->recv_ctrl_pipe;
	else
		pipe = us->send_ctrl_pipe;

	rc = usb_stor_ctrl_transfer(us, pipe, request, requesttype,
				   0, 0, xfer_data, xfer_len);
	switch (rc) {
		case USB_STOR_XFER_GOOD:	return 0;
		case USB_STOR_XFER_STALLED:	return -EPIPE;
		default:			return -EIO;
	}
}

static int
sddr09_send_scsi_command(struct us_data *us,
			 unsigned char *command,
			 unsigned int command_len) {
	return sddr09_send_command(us, 0, USB_DIR_OUT, command, command_len);
}

#if 0
/*
 * Test Unit Ready Command: 12 bytes.
 * byte 0: opcode: 00
 */
static int
sddr09_test_unit_ready(struct us_data *us) {
	unsigned char *command = us->iobuf;
	int result;

	memset(command, 0, 6);
	command[1] = LUNBITS;

	result = sddr09_send_scsi_command(us, command, 6);

	usb_stor_dbg(us, "sddr09_test_unit_ready returns %d\n", result);

	return result;
}
#endif

/*
 * Request Sense Command: 12 bytes.
 * byte 0: opcode: 03
 * byte 4: data length
 */
static int
sddr09_request_sense(struct us_data *us, unsigned char *sensebuf, int buflen) {
	unsigned char *command = us->iobuf;
	int result;

	memset(command, 0, 12);
	command[0] = 0x03;
	command[1] = LUNBITS;
	command[4] = buflen;

	result = sddr09_send_scsi_command(us, command, 12);
	if (result)
		return result;

	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
			sensebuf, buflen, NULL);
	return (result == USB_STOR_XFER_GOOD ? 0 : -EIO);
}

/*
 * Read Command: 12 bytes.
 * byte 0: opcode: E8
 * byte 1: last two bits: 00: read data, 01: read blockwise control,
 *			10: read both, 11: read pagewise control.
 *	 It turns out we need values 20, 21, 22, 23 here (LUN 1).
 * bytes 2-5: address (interpretation depends on byte 1, see below)
 * bytes 10-11: count (idem)
 *
 * A page has 512 data bytes and 64 control bytes (16 control and 48 junk).
 * A read data command gets data in 512-byte pages.
 * A read control command gets control in 64-byte chunks.
 * A read both command gets data+control in 576-byte chunks.
 *
 * Blocks are groups of 32 pages, and read blockwise control jumps to the
 * next block, while read pagewise control jumps to the next page after
 * reading a group of 64 control bytes.
 * [Here 512 = 1<<pageshift, 32 = 1<<blockshift, 64 is constant?]
 *
 * (1 MB and 2 MB cards are a bit different, but I have only a 16 MB card.)
 */

static int
sddr09_readX(struct us_data *us, int x, unsigned long fromaddress,
	     int nr_of_pages, int bulklen, unsigned char *buf,
	     int use_sg) {

	unsigned char *command = us->iobuf;
	int result;

	command[0] = 0xE8;
	command[1] = LUNBITS | x;
	command[2] = MSB_of(fromaddress>>16);
	command[3] = LSB_of(fromaddress>>16); 
	command[4] = MSB_of(fromaddress & 0xFFFF);
	command[5] = LSB_of(fromaddress & 0xFFFF); 
	command[6] = 0;
	command[7] = 0;
	command[8] = 0;
	command[9] = 0;
	command[10] = MSB_of(nr_of_pages);
	command[11] = LSB_of(nr_of_pages);

	result = sddr09_send_scsi_command(us, command, 12);

	if (result) {
		usb_stor_dbg(us, "Result for send_control in sddr09_read2%d %d\n",
			     x, result);
		return result;
	}

	result = usb_stor_bulk_transfer_sg(us, us->recv_bulk_pipe,
				       buf, bulklen, use_sg, NULL);

	if (result != USB_STOR_XFER_GOOD) {
		usb_stor_dbg(us, "Result for bulk_transfer in sddr09_read2%d %d\n",
			     x, result);
		return -EIO;
	}
	return 0;
}

/*
 * Read Data
 *
 * fromaddress counts data shorts:
 * increasing it by 256 shifts the bytestream by 512 bytes;
 * the last 8 bits are ignored.
 *
 * nr_of_pages counts pages of size (1 << pageshift).
 */
static int
sddr09_read20(struct us_data *us, unsigned long fromaddress,
	      int nr_of_pages, int pageshift, unsigned char *buf, int use_sg) {
	int bulklen = nr_of_pages << pageshift;

	/* The last 8 bits of fromaddress are ignored. */
	return sddr09_readX(us, 0, fromaddress, nr_of_pages, bulklen,
			    buf, use_sg);
}

/*
 * Read Blockwise Control
 *
 * fromaddress gives the starting position (as in read data;
 * the last 8 bits are ignored); increasing it by 32*256 shifts
 * the output stream by 64 bytes.
 *
 * count counts control groups of size (1 << controlshift).
 * For me, controlshift = 6. Is this constant?
 *
 * After getting one control group, jump to the next block
 * (fromaddress += 8192).
 */
static int
sddr09_read21(struct us_data *us, unsigned long fromaddress,
	      int count, int controlshift, unsigned char *buf, int use_sg) {

	int bulklen = (count << controlshift);
	return sddr09_readX(us, 1, fromaddress, count, bulklen,
			    buf, use_sg);
}

/*
 * Read both Data and Control
 *
 * fromaddress counts data shorts, ignoring control:
 * increasing it by 256 shifts the bytestream by 576 = 512+64 bytes;
 * the last 8 bits are ignored.
 *
 * nr_of_pages counts pages of size (1 << pageshift) + (1 << controlshift).
 */
static int
sddr09_read22(struct us_data *us, unsigned long fromaddress,
	      int nr_of_pages, int pageshift, unsigned char *buf, int use_sg) {

	int bulklen = (nr_of_pages << pageshift) + (nr_of_pages << CONTROL_SHIFT);
	usb_stor_dbg(us, "reading %d pages, %d bytes\n", nr_of_pages, bulklen);
	return sddr09_readX(us, 2, fromaddress, nr_of_pages, bulklen,
			    buf, use_sg);
}

#if 0
/*
 * Read Pagewise Control
 *
 * fromaddress gives the starting position (as in read data;
 * the last 8 bits are ignored); increasing it by 256 shifts
 * the output stream by 64 bytes.
 *
 * count counts control groups of size (1 << controlshift).
 * For me, controlshift = 6. Is this constant?
 *
 * After getting one control group, jump to the next page
 * (fromaddress += 256).
 */
static int
sddr09_read23(struct us_data *us, unsigned long fromaddress,
	      int count, int controlshift, unsigned char *buf, int use_sg) {

	int bulklen = (count << controlshift);
	return sddr09_readX(us, 3, fromaddress, count, bulklen,
			    buf, use_sg);
}
#endif

/*
 * Erase Command: 12 bytes.
 * byte 0: opcode: EA
 * bytes 6-9: erase address (big-endian, counting shorts, sector aligned).
 * 
 * Always precisely one block is erased; bytes 2-5 and 10-11 are ignored.
 * The byte address being erased is 2*Eaddress.
 * The CIS cannot be erased.
 */
static int
sddr09_erase(struct us_data *us, unsigned long Eaddress) {
	unsigned char *command = us->iobuf;
	int result;

	usb_stor_dbg(us, "erase address %lu\n", Eaddress);

	memset(command, 0, 12);
	command[0] = 0xEA;
	command[1] = LUNBITS;
	command[6] = MSB_of(Eaddress>>16);
	command[7] = LSB_of(Eaddress>>16);
	command[8] = MSB_of(Eaddress & 0xFFFF);
	command[9] = LSB_of(Eaddress & 0xFFFF);

	result = sddr09_send_scsi_command(us, command, 12);

	if (result)
		usb_stor_dbg(us, "Result for send_control in sddr09_erase %d\n",
			     result);

	return result;
}

/*
 * Write CIS Command: 12 bytes.
 * byte 0: opcode: EE
 * bytes 2-5: write address in shorts
 * bytes 10-11: sector count
 *
 * This writes at the indicated address. Don't know how it differs
 * from E9. Maybe it does not erase? However, it will also write to
 * the CIS.
 *
 * When two such commands on the same page follow each other directly,
 * the second one is not done.
 */

/*
 * Write Command: 12 bytes.
 * byte 0: opcode: E9
 * bytes 2-5: write address (big-endian, counting shorts, sector aligned).
 * bytes 6-9: erase address (big-endian, counting shorts, sector aligned).
 * bytes 10-11: sector count (big-endian, in 512-byte sectors).
 *
 * If write address equals erase address, the erase is done first,
 * otherwise the write is done first. When erase address equals zero
 * no erase is done?
 */
static int
sddr09_writeX(struct us_data *us,
	      unsigned long Waddress, unsigned long Eaddress,
	      int nr_of_pages, int bulklen, unsigned char *buf, int use_sg) {

	unsigned char *command = us->iobuf;
	int result;

	command[0] = 0xE9;
	command[1] = LUNBITS;

	command[2] = MSB_of(Waddress>>16);
	command[3] = LSB_of(Waddress>>16);
	command[4] = MSB_of(Waddress & 0xFFFF);
	command[5] = LSB_of(Waddress & 0xFFFF);

	command[6] = MSB_of(Eaddress>>16);
	command[7] = LSB_of(Eaddress>>16);
	command[8] = MSB_of(Eaddress & 0xFFFF);
	command[9] = LSB_of(Eaddress & 0xFFFF);

	command[10] = MSB_of(nr_of_pages);
	command[11] = LSB_of(nr_of_pages);

	result = sddr09_send_scsi_command(us, command, 12);

	if (result) {
		usb_stor_dbg(us, "Result for send_control in sddr09_writeX %d\n",
			     result);
		return result;
	}

	result = usb_stor_bulk_transfer_sg(us, us->send_bulk_pipe,
				       buf, bulklen, use_sg, NULL);

	if (result != USB_STOR_XFER_GOOD) {
		usb_stor_dbg(us, "Result for bulk_transfer in sddr09_writeX %d\n",
			     result);
		return -EIO;
	}
	return 0;
}

/* erase address, write same address */
static int
sddr09_write_inplace(struct us_data *us, unsigned long address,
		     int nr_of_pages, int pageshift, unsigned char *buf,
		     int use_sg) {
	int bulklen = (nr_of_pages << pageshift) + (nr_of_pages << CONTROL_SHIFT);
	return sddr09_writeX(us, address, address, nr_of_pages, bulklen,
			     buf, use_sg);
}

#if 0
/*
 * Read Scatter Gather Command: 3+4n bytes.
 * byte 0: opcode E7
 * byte 2: n
 * bytes 4i-1,4i,4i+1: page address
 * byte 4i+2: page count
 * (i=1..n)
 *
 * This reads several pages from the card to a single memory buffer.
 * The last two bits of byte 1 have the same meaning as for E8.
 */
static int
sddr09_read_sg_test_only(struct us_data *us) {
	unsigned char *command = us->iobuf;
	int result, bulklen, nsg, ct;
	unsigned char *buf;
	unsigned long address;

	nsg = bulklen = 0;
	command[0] = 0xE7;
	command[1] = LUNBITS;
	command[2] = 0;
	address = 040000; ct = 1;
	nsg++;
	bulklen += (ct << 9);
	command[4*nsg+2] = ct;
	command[4*nsg+1] = ((address >> 9) & 0xFF);
	command[4*nsg+0] = ((address >> 17) & 0xFF);
	command[4*nsg-1] = ((address >> 25) & 0xFF);

	address = 0340000; ct = 1;
	nsg++;
	bulklen += (ct << 9);
	command[4*nsg+2] = ct;
	command[4*nsg+1] = ((address >> 9) & 0xFF);
	command[4*nsg+0] = ((address >> 17) & 0xFF);
	command[4*nsg-1] = ((address >> 25) & 0xFF);

	address = 01000000; ct = 2;
	nsg++;
	bulklen += (ct << 9);
	command[4*nsg+2] = ct;
	command[4*nsg+1] = ((address >> 9) & 0xFF);
	command[4*nsg+0] = ((address >> 17) & 0xFF);
	command[4*nsg-1] = ((address >> 25) & 0xFF);

	command[2] = nsg;

	result = sddr09_send_scsi_command(us, command, 4*nsg+3);

	if (result) {
		usb_stor_dbg(us, "Result for send_control in sddr09_read_sg %d\n",
			     result);
		return result;
	}

	buf = kmalloc(bulklen, GFP_NOIO);
	if (!buf)
		return -ENOMEM;

	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
				       buf, bulklen, NULL);
	kfree(buf);
	if (result != USB_STOR_XFER_GOOD) {
		usb_stor_dbg(us, "Result for bulk_transfer in sddr09_read_sg %d\n",
			     result);
		return -EIO;
	}

	return 0;
}
#endif

/*
 * Read Status Command: 12 bytes.
 * byte 0: opcode: EC
 *
 * Returns 64 bytes, all zero except for the first.
 * bit 0: 1: Error
 * bit 5: 1: Suspended
 * bit 6: 1: Ready
 * bit 7: 1: Not write-protected
 */

static int
sddr09_read_status(struct us_data *us, unsigned char *status) {

	unsigned char *command = us->iobuf;
	unsigned char *data = us->iobuf;
	int result;

	usb_stor_dbg(us, "Reading status...\n");

	memset(command, 0, 12);
	command[0] = 0xEC;
	command[1] = LUNBITS;

	result = sddr09_send_scsi_command(us, command, 12);
	if (result)
		return result;

	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
				       data, 64, NULL);
	*status = data[0];
	return (result == USB_STOR_XFER_GOOD ? 0 : -EIO);
}

static int
sddr09_read_data(struct us_data *us,
		 unsigned long address,
		 unsigned int sectors) {

	struct sddr09_card_info *info = (struct sddr09_card_info *) us->extra;
	unsigned char *buffer;
	unsigned int lba, maxlba, pba;
	unsigned int page, pages;
	unsigned int len, offset;
	struct scatterlist *sg;
	int result;

	// Figure out the initial LBA and page
	lba = address >> info->blockshift;
	page = (address & info->blockmask);
	maxlba = info->capacity >> (info->pageshift + info->blockshift);
	if (lba >= maxlba)
		return -EIO;

	// Since we only read in one block at a time, we have to create
	// a bounce buffer and move the data a piece at a time between the
	// bounce buffer and the actual transfer buffer.

	len = min(sectors, (unsigned int) info->blocksize) * info->pagesize;
	buffer = kmalloc(len, GFP_NOIO);
	if (buffer == NULL) {
		printk(KERN_WARNING "sddr09_read_data: Out of memory\n");
		return -ENOMEM;
	}

	// This could be made much more efficient by checking for
	// contiguous LBA's. Another exercise left to the student.

	result = 0;
	offset = 0;
	sg = NULL;

	while (sectors > 0) {

		/* Find number of pages we can read in this block */
		pages = min(sectors, info->blocksize - page);
		len = pages << info->pageshift;

		/* Not overflowing capacity? */
		if (lba >= maxlba) {
			usb_stor_dbg(us, "Error: Requested lba %u exceeds maximum %u\n",
				     lba, maxlba);
			result = -EIO;
			break;
		}

		/* Find where this lba lives on disk */
		pba = info->lba_to_pba[lba];

		if (pba == UNDEF) {	/* this lba was never written */

			usb_stor_dbg(us, "Read %d zero pages (LBA %d) page %d\n",
				     pages, lba, page);

			/* This is not really an error. It just means
			   that the block has never been written.
			   Instead of returning an error
			   it is better to return all zero data. */

			memset(buffer, 0, len);

		} else {
			usb_stor_dbg(us, "Read %d pages, from PBA %d (LBA %d) page %d\n",
				     pages, pba, lba, page);

			address = ((pba << info->blockshift) + page) << 
				info->pageshift;

			result = sddr09_read20(us, address>>1,
					pages, info->pageshift, buffer, 0);
			if (result)
				break;
		}

		// Store the data in the transfer buffer
		usb_stor_access_xfer_buf(buffer, len, us->srb,
				&sg, &offset, TO_XFER_BUF);

		page = 0;
		lba++;
		sectors -= pages;
	}

	kfree(buffer);
	return result;
}

static unsigned int
sddr09_find_unused_pba(struct sddr09_card_info *info, unsigned int lba) {
	static unsigned int lastpba = 1;
	int zonestart, end, i;

	zonestart = (lba/1000) << 10;
	end = info->capacity >> (info->blockshift + info->pageshift);
	end -= zonestart;
	if (end > 1024)
		end = 1024;

	for (i = lastpba+1; i < end; i++) {
		if (info->pba_to_lba[zonestart+i] == UNDEF) {
			lastpba = i;
			return zonestart+i;
		}
	}
	for (i = 0; i <= lastpba; i++) {
		if (info->pba_to_lba[zonestart+i] == UNDEF) {
			lastpba = i;
			return zonestart+i;
		}
	}
	return 0;
}

static int
sddr09_write_lba(struct us_data *us, unsigned int lba,
		 unsigned int page, unsigned int pages,
		 unsigned char *ptr, unsigned char *blockbuffer) {

	struct sddr09_card_info *info = (struct sddr09_card_info *) us->extra;
	unsigned long address;
	unsigned int pba, lbap;
	unsigned int pagelen;
	unsigned char *bptr, *cptr, *xptr;
	unsigned char ecc[3];
	int i, result, isnew;

	lbap = ((lba % 1000) << 1) | 0x1000;
	if (parity[MSB_of(lbap) ^ LSB_of(lbap)])
		lbap ^= 1;
	pba = info->lba_to_pba[lba];
	isnew = 0;

	if (pba == UNDEF) {
		pba = sddr09_find_unused_pba(info, lba);
		if (!pba) {
			printk(KERN_WARNING
			       "sddr09_write_lba: Out of unused blocks\n");
			return -ENOSPC;
		}
		info->pba_to_lba[pba] = lba;
		info->lba_to_pba[lba] = pba;
		isnew = 1;
	}

	if (pba == 1) {
		/* Maybe it is impossible to write to PBA 1.
		   Fake success, but don't do anything. */
		printk(KERN_WARNING "sddr09: avoid writing to pba 1\n");
		return 0;
	}

	pagelen = (1 << info->pageshift) + (1 << CONTROL_SHIFT);

	/* read old contents */
	address = (pba << (info->pageshift + info->blockshift));
	result = sddr09_read22(us, address>>1, info->blocksize,
			       info->pageshift, blockbuffer, 0);
	if (result)
		return result;

	/* check old contents and fill lba */
	for (i = 0; i < info->blocksize; i++) {
		bptr = blockbuffer + i*pagelen;
		cptr = bptr + info->pagesize;
		nand_compute_ecc(bptr, ecc);
		if (!nand_compare_ecc(cptr+13, ecc)) {
			usb_stor_dbg(us, "Warning: bad ecc in page %d- of pba %d\n",
				     i, pba);
			nand_store_ecc(cptr+13, ecc);
		}
		nand_compute_ecc(bptr+(info->pagesize / 2), ecc);
		if (!nand_compare_ecc(cptr+8, ecc)) {
			usb_stor_dbg(us, "Warning: bad ecc in page %d+ of pba %d\n",
				     i, pba);
			nand_store_ecc(cptr+8, ecc);
		}
		cptr[6] = cptr[11] = MSB_of(lbap);
		cptr[7] = cptr[12] = LSB_of(lbap);
	}

	/* copy in new stuff and compute ECC */
	xptr = ptr;
	for (i = page; i < page+pages; i++) {
		bptr = blockbuffer + i*pagelen;
		cptr = bptr + info->pagesize;
		memcpy(bptr, xptr, info->pagesize);
		xptr += info->pagesize;
		nand_compute_ecc(bptr, ecc);
		nand_store_ecc(cptr+13, ecc);
		nand_compute_ecc(bptr+(info->pagesize / 2), ecc);
		nand_store_ecc(cptr+8, ecc);
	}

	usb_stor_dbg(us, "Rewrite PBA %d (LBA %d)\n", pba, lba);

	result = sddr09_write_inplace(us, address>>1, info->blocksize,
				      info->pageshift, blockbuffer, 0);

	usb_stor_dbg(us, "sddr09_write_inplace returns %d\n", result);

#if 0
	{
		unsigned char status = 0;
		int result2 = sddr09_read_status(us, &status);
		if (result2)
			usb_stor_dbg(us, "cannot read status\n");
		else if (status != 0xc0)
			usb_stor_dbg(us, "status after write: 0x%x\n", status);
	}
#endif

#if 0
	{
		int result2 = sddr09_test_unit_ready(us);
	}
#endif

	return result;
}

static int
sddr09_write_data(struct us_data *us,
		  unsigned long address,
		  unsigned int sectors) {

	struct sddr09_card_info *info = (struct sddr09_card_info *) us->extra;
	unsigned int lba, maxlba, page, pages;
	unsigned int pagelen, blocklen;
	unsigned char *blockbuffer;
	unsigned char *buffer;
	unsigned int len, offset;
	struct scatterlist *sg;
	int result;

	// Figure out the initial LBA and page
	lba = address >> info->blockshift;
	page = (address & info->blockmask);
	maxlba = info->capacity >> (info->pageshift + info->blockshift);
	if (lba >= maxlba)
		return -EIO;

	// blockbuffer is used for reading in the old data, overwriting
	// with the new data, and performing ECC calculations

	/* TODO: instead of doing kmalloc/kfree for each write,
	   add a bufferpointer to the info structure */

	pagelen = (1 << info->pageshift) + (1 << CONTROL_SHIFT);
	blocklen = (pagelen << info->blockshift);
	blockbuffer = kmalloc(blocklen, GFP_NOIO);
	if (!blockbuffer) {
		printk(KERN_WARNING "sddr09_write_data: Out of memory\n");
		return -ENOMEM;
	}

	// Since we don't write the user data directly to the device,
	// we have to create a bounce buffer and move the data a piece
	// at a time between the bounce buffer and the actual transfer buffer.

	len = min(sectors, (unsigned int) info->blocksize) * info->pagesize;
	buffer = kmalloc(len, GFP_NOIO);
	if (buffer == NULL) {
		printk(KERN_WARNING "sddr09_write_data: Out of memory\n");
		kfree(blockbuffer);
		return -ENOMEM;
	}

	result = 0;
	offset = 0;
	sg = NULL;

	while (sectors > 0) {

		// Write as many sectors as possible in this block

		pages = min(sectors, info->blocksize - page);
		len = (pages << info->pageshift);

		/* Not overflowing capacity? */
		if (lba >= maxlba) {
			usb_stor_dbg(us, "Error: Requested lba %u exceeds maximum %u\n",
				     lba, maxlba);
			result = -EIO;
			break;
		}

		// Get the data from the transfer buffer
		usb_stor_access_xfer_buf(buffer, len, us->srb,
				&sg, &offset, FROM_XFER_BUF);

		result = sddr09_write_lba(us, lba, page, pages,
				buffer, blockbuffer);
		if (result)
			break;

		page = 0;
		lba++;
		sectors -= pages;
	}

	kfree(buffer);
	kfree(blockbuffer);

	return result;
}

static int
sddr09_read_control(struct us_data *us,
		unsigned long address,
		unsigned int blocks,
		unsigned char *content,
		int use_sg) {

	usb_stor_dbg(us, "Read control address %lu, blocks %d\n",
		     address, blocks);

	return sddr09_read21(us, address, blocks,
			     CONTROL_SHIFT, content, use_sg);
}

/*
 * Read Device ID Command: 12 bytes.
 * byte 0: opcode: ED
 *
 * Returns 2 bytes: Manufacturer ID and Device ID.
 * On more recent cards 3 bytes: the third byte is an option code A5
 * signifying that the secret command to read an 128-bit ID is available.
 * On still more recent cards 4 bytes: the fourth byte C0 means that
 * a second read ID cmd is available.
 */
static int
sddr09_read_deviceID(struct us_data *us, unsigned char *deviceID) {
	unsigned char *command = us->iobuf;
	unsigned char *content = us->iobuf;
	int result, i;

	memset(command, 0, 12);
	command[0] = 0xED;
	command[1] = LUNBITS;

	result = sddr09_send_scsi_command(us, command, 12);
	if (result)
		return result;

	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
			content, 64, NULL);

	for (i = 0; i < 4; i++)
		deviceID[i] = content[i];

	return (result == USB_STOR_XFER_GOOD ? 0 : -EIO);
}

static int
sddr09_get_wp(struct us_data *us, struct sddr09_card_info *info) {
	int result;
	unsigned char status;
	const char *wp_fmt;

	result = sddr09_read_status(us, &status);
	if (result) {
		usb_stor_dbg(us, "read_status fails\n");
		return result;
	}
	if ((status & 0x80) == 0) {
		info->flags |= SDDR09_WP;	/* write protected */
		wp_fmt = " WP";
	} else {
		wp_fmt = "";
	}
	usb_stor_dbg(us, "status 0x%02X%s%s%s%s\n", status, wp_fmt,
		     status & 0x40 ? " Ready" : "",
		     status & LUNBITS ? " Suspended" : "",
		     status & 0x01 ? " Error" : "");

	return 0;
}

#if 0
/*
 * Reset Command: 12 bytes.
 * byte 0: opcode: EB
 */
static int
sddr09_reset(struct us_data *us) {

	unsigned char *command = us->iobuf;

	memset(command, 0, 12);
	command[0] = 0xEB;
	command[1] = LUNBITS;

	return sddr09_send_scsi_command(us, command, 12);
}
#endif

static struct nand_flash_dev *
sddr09_get_cardinfo(struct us_data *us, unsigned char flags) {
	struct nand_flash_dev *cardinfo;
	unsigned char deviceID[4];
	char blurbtxt[256];
	int result;

	usb_stor_dbg(us, "Reading capacity...\n");

	result = sddr09_read_deviceID(us, deviceID);

	if (result) {
		usb_stor_dbg(us, "Result of read_deviceID is %d\n", result);
		printk(KERN_WARNING "sddr09: could not read card info\n");
		return NULL;
	}

	sprintf(blurbtxt, "sddr09: Found Flash card, ID = %4ph", deviceID);

	/* Byte 0 is the manufacturer */
	sprintf(blurbtxt + strlen(blurbtxt),
		": Manuf. %s",
		nand_flash_manufacturer(deviceID[0]));

	/* Byte 1 is the device type */
	cardinfo = nand_find_id(deviceID[1]);
	if (cardinfo) {
		/* MB or MiB? It is neither. A 16 MB card has
		   17301504 raw bytes, of which 16384000 are
		   usable for user data. */
		sprintf(blurbtxt + strlen(blurbtxt),
			", %d MB", 1<<(cardinfo->chipshift - 20));
	} else {
		sprintf(blurbtxt + strlen(blurbtxt),
			", type unrecognized");
	}

	/* Byte 2 is code to signal availability of 128-bit ID */
	if (deviceID[2] == 0xa5) {
		sprintf(blurbtxt + strlen(blurbtxt),
			", 128-bit ID");
	}

	/* Byte 3 announces the availability of another read ID command */
	if (deviceID[3] == 0xc0) {
		sprintf(blurbtxt + strlen(blurbtxt),
			", extra cmd");
	}

	if (flags & SDDR09_WP)
		sprintf(blurbtxt + strlen(blurbtxt),
			", WP");

	printk(KERN_WARNING "%s\n", blurbtxt);

	return cardinfo;
}

static int
sddr09_read_map(struct us_data *us) {

	struct sddr09_card_info *info = (struct sddr09_card_info *) us->extra;
	int numblocks, alloc_len, alloc_blocks;
	int i, j, result;
	unsigned char *buffer, *buffer_end, *ptr;
	unsigned int lba, lbact;

	if (!info->capacity)
		return -1;

	// size of a block is 1 << (blockshift + pageshift) bytes
	// divide into the total capacity to get the number of blocks

	numblocks = info->capacity >> (info->blockshift + info->pageshift);

	// read 64 bytes for every block (actually 1 << CONTROL_SHIFT)
	// but only use a 64 KB buffer
	// buffer size used must be a multiple of (1 << CONTROL_SHIFT)
#define SDDR09_READ_MAP_BUFSZ 65536

	alloc_blocks = min(numblocks, SDDR09_READ_MAP_BUFSZ >> CONTROL_SHIFT);
	alloc_len = (alloc_blocks << CONTROL_SHIFT);
	buffer = kmalloc(alloc_len, GFP_NOIO);
	if (buffer == NULL) {
		printk(KERN_WARNING "sddr09_read_map: out of memory\n");
		result = -1;
		goto done;
	}
	buffer_end = buffer + alloc_len;

#undef SDDR09_READ_MAP_BUFSZ

	kfree(info->lba_to_pba);
	kfree(info->pba_to_lba);
	info->lba_to_pba = kmalloc(numblocks*sizeof(int), GFP_NOIO);
	info->pba_to_lba = kmalloc(numblocks*sizeof(int), GFP_NOIO);

	if (info->lba_to_pba == NULL || info->pba_to_lba == NULL) {
		printk(KERN_WARNING "sddr09_read_map: out of memory\n");
		result = -1;
		goto done;
	}

	for (i = 0; i < numblocks; i++)
		info->lba_to_pba[i] = info->pba_to_lba[i] = UNDEF;

	/*
	 * Define lba-pba translation table
	 */

	ptr = buffer_end;
	for (i = 0; i < numblocks; i++) {
		ptr += (1 << CONTROL_SHIFT);
		if (ptr >= buffer_end) {
			unsigned long address;

			address = i << (info->pageshift + info->blockshift);
			result = sddr09_read_control(
				us, address>>1,
				min(alloc_blocks, numblocks - i),
				buffer, 0);
			if (result) {
				result = -1;
				goto done;
			}
			ptr = buffer;
		}

		if (i == 0 || i == 1) {
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		/* special PBAs have control field 0^16 */
		for (j = 0; j < 16; j++)
			if (ptr[j] != 0)
				goto nonz;
		info->pba_to_lba[i] = UNUSABLE;
		printk(KERN_WARNING "sddr09: PBA %d has no logical mapping\n",
		       i);
		continue;

	nonz:
		/* unwritten PBAs have control field FF^16 */
		for (j = 0; j < 16; j++)
			if (ptr[j] != 0xff)
				goto nonff;
		continue;

	nonff:
		/* normal PBAs start with six FFs */
		if (j < 6) {
			printk(KERN_WARNING
			       "sddr09: PBA %d has no logical mapping: "
			       "reserved area = %02X%02X%02X%02X "
			       "data status %02X block status %02X\n",
			       i, ptr[0], ptr[1], ptr[2], ptr[3],
			       ptr[4], ptr[5]);
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		if ((ptr[6] >> 4) != 0x01) {
			printk(KERN_WARNING
			       "sddr09: PBA %d has invalid address field "
			       "%02X%02X/%02X%02X\n",
			       i, ptr[6], ptr[7], ptr[11], ptr[12]);
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		/* check even parity */
		if (parity[ptr[6] ^ ptr[7]]) {
			printk(KERN_WARNING
			       "sddr09: Bad parity in LBA for block %d"
			       " (%02X %02X)\n", i, ptr[6], ptr[7]);
			info->pba_to_lba[i] = UNUSABLE;
			continue;
		}

		lba = short_pack(ptr[7], ptr[6]);
		lba = (lba & 0x07FF) >> 1;

		/*
		 * Every 1024 physical blocks ("zone"), the LBA numbers
		 * go back to zero, but are within a higher block of LBA's.
		 * Also, there is a maximum of 1000 LBA's per zone.
		 * In other words, in PBA 1024-2047 you will find LBA 0-999
		 * which are really LBA 1000-1999. This allows for 24 bad
		 * or special physical blocks per zone.
		 */

		if (lba >= 1000) {
			printk(KERN_WARNING
			       "sddr09: Bad low LBA %d for block %d\n",
			       lba, i);
			goto possibly_erase;
		}

		lba += 1000*(i/0x400);

		if (info->lba_to_pba[lba] != UNDEF) {
			printk(KERN_WARNING
			       "sddr09: LBA %d seen for PBA %d and %d\n",
			       lba, info->lba_to_pba[lba], i);
			goto possibly_erase;
		}

		info->pba_to_lba[i] = lba;
		info->lba_to_pba[lba] = i;
		continue;

	possibly_erase:
		if (erase_bad_lba_entries) {
			unsigned long address;

			address = (i << (info->pageshift + info->blockshift));
			sddr09_erase(us, address>>1);
			info->pba_to_lba[i] = UNDEF;
		} else
			info->pba_to_lba[i] = UNUSABLE;
	}

	/*
	 * Approximate capacity. This is not entirely correct yet,
	 * since a zone with less than 1000 usable pages leads to
	 * missing LBAs. Especially if it is the last zone, some
	 * LBAs can be past capacity.
	 */
	lbact = 0;
	for (i = 0; i < numblocks; i += 1024) {
		int ct = 0;

		for (j = 0; j < 1024 && i+j < numblocks; j++) {
			if (info->pba_to_lba[i+j] != UNUSABLE) {
				if (ct >= 1000)
					info->pba_to_lba[i+j] = SPARE;
				else
					ct++;
			}
		}
		lbact += ct;
	}
	info->lbact = lbact;
	usb_stor_dbg(us, "Found %d LBA's\n", lbact);
	result = 0;

 done:
	if (result != 0) {
		kfree(info->lba_to_pba);
		kfree(info->pba_to_lba);
		info->lba_to_pba = NULL;
		info->pba_to_lba = NULL;
	}
	kfree(buffer);
	return result;
}

static void
sddr09_card_info_destructor(void *extra) {
	struct sddr09_card_info *info = (struct sddr09_card_info *)extra;

	if (!info)
		return;

	kfree(info->lba_to_pba);
	kfree(info->pba_to_lba);
}

static int
sddr09_common_init(struct us_data *us) {
	int result;

	/* set the configuration -- STALL is an acceptable response here */
	if (us->pusb_dev->actconfig->desc.bConfigurationValue != 1) {
		usb_stor_dbg(us, "active config #%d != 1 ??\n",
			     us->pusb_dev->actconfig->desc.bConfigurationValue);
		return -EINVAL;
	}

	result = usb_reset_configuration(us->pusb_dev);
	usb_stor_dbg(us, "Result of usb_reset_configuration is %d\n", result);
	if (result == -EPIPE) {
		usb_stor_dbg(us, "-- stall on control interface\n");
	} else if (result != 0) {
		/* it's not a stall, but another error -- time to bail */
		usb_stor_dbg(us, "-- Unknown error.  Rejecting device\n");
		return -EINVAL;
	}

	us->extra = kzalloc(sizeof(struct sddr09_card_info), GFP_NOIO);
	if (!us->extra)
		return -ENOMEM;
	us->extra_destructor = sddr09_card_info_destructor;

	nand_init_ecc();
	return 0;
}


/*
 * This is needed at a very early stage. If this is not listed in the
 * unusual devices list but called from here then LUN 0 of the combo reader
 * is not recognized. But I do not know what precisely these calls do.
 */
static int
usb_stor_sddr09_dpcm_init(struct us_data *us) {
	int result;
	unsigned char *data = us->iobuf;

	result = sddr09_common_init(us);
	if (result)
		return result;

	result = sddr09_send_command(us, 0x01, USB_DIR_IN, data, 2);
	if (result) {
		usb_stor_dbg(us, "send_command fails\n");
		return result;
	}

	usb_stor_dbg(us, "%02X %02X\n", data[0], data[1]);
	// get 07 02

	result = sddr09_send_command(us, 0x08, USB_DIR_IN, data, 2);
	if (result) {
		usb_stor_dbg(us, "2nd send_command fails\n");
		return result;
	}

	usb_stor_dbg(us, "%02X %02X\n", data[0], data[1]);
	// get 07 00

	result = sddr09_request_sense(us, data, 18);
	if (result == 0 && data[2] != 0) {
		int j;
		for (j=0; j<18; j++)
			printk(" %02X", data[j]);
		printk("\n");
		// get 70 00 00 00 00 00 00 * 00 00 00 00 00 00
		// 70: current command
		// sense key 0, sense code 0, extd sense code 0
		// additional transfer length * = sizeof(data) - 7
		// Or: 70 00 06 00 00 00 00 0b 00 00 00 00 28 00 00 00 00 00
		// sense key 06, sense code 28: unit attention,
		// not ready to ready transition
	}

	// test unit ready

	return 0;		/* not result */
}

/*
 * Transport for the Microtech DPCM-USB
 */
static int dpcm_transport(struct scsi_cmnd *srb, struct us_data *us)
{
	int ret;

	usb_stor_dbg(us, "LUN=%d\n", (u8)srb->device->lun);

	switch (srb->device->lun) {
	case 0:

		/*
		 * LUN 0 corresponds to the CompactFlash card reader.
		 */
		ret = usb_stor_CB_transport(srb, us);
		break;

	case 1:

		/*
		 * LUN 1 corresponds to the SmartMedia card reader.
		 */

		/*
		 * Set the LUN to 0 (just in case).
		 */
		srb->device->lun = 0;
		ret = sddr09_transport(srb, us);
		srb->device->lun = 1;
		break;

	default:
	    usb_stor_dbg(us, "Invalid LUN %d\n", (u8)srb->device->lun);
		ret = USB_STOR_TRANSPORT_ERROR;
		break;
	}
	return ret;
}


/*
 * Transport for the Sandisk SDDR-09
 */
static int sddr09_transport(struct scsi_cmnd *srb, struct us_data *us)
{
	static unsigned char sensekey = 0, sensecode = 0;
	static unsigned char havefakesense = 0;
	int result, i;
	unsigned char *ptr = us->iobuf;
	unsigned long capacity;
	unsigned int page, pages;

	struct sddr09_card_info *info;

	static unsigned char inquiry_response[8] = {
		0x00, 0x80, 0x00, 0x02, 0x1F, 0x00, 0x00, 0x00
	};

	/* note: no block descriptor support */
	static unsigned char mode_page_01[19] = {
		0x00, 0x0F, 0x00, 0x0, 0x0, 0x0, 0x00,
		0x01, 0x0A,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	};

	info = (struct sddr09_card_info *)us->extra;

	if (srb->cmnd[0] == REQUEST_SENSE && havefakesense) {
		/* for a faked command, we have to follow with a faked sense */
		memset(ptr, 0, 18);
		ptr[0] = 0x70;
		ptr[2] = sensekey;
		ptr[7] = 11;
		ptr[12] = sensecode;
		usb_stor_set_xfer_buf(ptr, 18, srb);
		sensekey = sensecode = havefakesense = 0;
		return USB_STOR_TRANSPORT_GOOD;
	}

	havefakesense = 1;

	/* Dummy up a response for INQUIRY since SDDR09 doesn't
	   respond to INQUIRY commands */

	if (srb->cmnd[0] == INQUIRY) {
		memcpy(ptr, inquiry_response, 8);
		fill_inquiry_response(us, ptr, 36);
		return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == READ_CAPACITY) {
		struct nand_flash_dev *cardinfo;

		sddr09_get_wp(us, info);	/* read WP bit */

		cardinfo = sddr09_get_cardinfo(us, info->flags);
		if (!cardinfo) {
			/* probably no media */
		init_error:
			sensekey = 0x02;	/* not ready */
			sensecode = 0x3a;	/* medium not present */
			return USB_STOR_TRANSPORT_FAILED;
		}

		info->capacity = (1 << cardinfo->chipshift);
		info->pageshift = cardinfo->pageshift;
		info->pagesize = (1 << info->pageshift);
		info->blockshift = cardinfo->blockshift;
		info->blocksize = (1 << info->blockshift);
		info->blockmask = info->blocksize - 1;

		// map initialization, must follow get_cardinfo()
		if (sddr09_read_map(us)) {
			/* probably out of memory */
			goto init_error;
		}

		// Report capacity

		capacity = (info->lbact << info->blockshift) - 1;

		((__be32 *) ptr)[0] = cpu_to_be32(capacity);

		// Report page size

		((__be32 *) ptr)[1] = cpu_to_be32(info->pagesize);
		usb_stor_set_xfer_buf(ptr, 8, srb);

		return USB_STOR_TRANSPORT_GOOD;
	}

	if (srb->cmnd[0] == MODE_SENSE_10) {
		int modepage = (srb->cmnd[2] & 0x3F);

		/* They ask for the Read/Write error recovery page,
		   or for all pages. */
		/* %% We should check DBD %% */
		if (modepage == 0x01 || modepage == 0x3F) {
			usb_stor_dbg(us, "Dummy up request for mode page 0x%x\n",
				     modepage);

			memcpy(ptr, mode_page_01, sizeof(mode_page_01));
			((__be16*)ptr)[0] = cpu_to_be16(sizeof(mode_page_01) - 2);
			ptr[3] = (info->flags & SDDR09_WP) ? 0x80 : 0;
			usb_stor_set_xfer_buf(ptr, sizeof(mode_page_01), srb);
			return USB_STOR_TRANSPORT_GOOD;
		}

		sensekey = 0x05;	/* illegal request */
		sensecode = 0x24;	/* invalid field in CDB */
		return USB_STOR_TRANSPORT_FAILED;
	}

	if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL)
		return USB_STOR_TRANSPORT_GOOD;

	havefakesense = 0;

	if (srb->cmnd[0] == READ_10) {

		page = short_pack(srb->cmnd[3], srb->cmnd[2]);
		page <<= 16;
		page |= short_pack(srb->cmnd[5], srb->cmnd[4]);
		pages = short_pack(srb->cmnd[8], srb->cmnd[7]);

		usb_stor_dbg(us, "READ_10: read page %d pagect %d\n",
			     page, pages);

		result = sddr09_read_data(us, page, pages);
		return (result == 0 ? USB_STOR_TRANSPORT_GOOD :
				USB_STOR_TRANSPORT_ERROR);
	}

	if (srb->cmnd[0] == WRITE_10) {

		page = short_pack(srb->cmnd[3], srb->cmnd[2]);
		page <<= 16;
		page |= short_pack(srb->cmnd[5], srb->cmnd[4]);
		pages = short_pack(srb->cmnd[8], srb->cmnd[7]);

		usb_stor_dbg(us, "WRITE_10: write page %d pagect %d\n",
			     page, pages);

		result = sddr09_write_data(us, page, pages);
		return (result == 0 ? USB_STOR_TRANSPORT_GOOD :
				USB_STOR_TRANSPORT_ERROR);
	}

	/* catch-all for all other commands, except
	 * pass TEST_UNIT_READY and REQUEST_SENSE through
	 */
	if (srb->cmnd[0] != TEST_UNIT_READY &&
	    srb->cmnd[0] != REQUEST_SENSE) {
		sensekey = 0x05;	/* illegal request */
		sensecode = 0x20;	/* invalid command */
		havefakesense = 1;
		return USB_STOR_TRANSPORT_FAILED;
	}

	for (; srb->cmd_len<12; srb->cmd_len++)
		srb->cmnd[srb->cmd_len] = 0;

	srb->cmnd[1] = LUNBITS;

	ptr[0] = 0;
	for (i=0; i<12; i++)
		sprintf(ptr+strlen(ptr), "%02X ", srb->cmnd[i]);

	usb_stor_dbg(us, "Send control for command %s\n", ptr);

	result = sddr09_send_scsi_command(us, srb->cmnd, 12);
	if (result) {
		usb_stor_dbg(us, "sddr09_send_scsi_command returns %d\n",
			     result);
		return USB_STOR_TRANSPORT_ERROR;
	}

	if (scsi_bufflen(srb) == 0)
		return USB_STOR_TRANSPORT_GOOD;

	if (srb->sc_data_direction == DMA_TO_DEVICE ||
	    srb->sc_data_direction == DMA_FROM_DEVICE) {
		unsigned int pipe = (srb->sc_data_direction == DMA_TO_DEVICE)
				? us->send_bulk_pipe : us->recv_bulk_pipe;

		usb_stor_dbg(us, "%s %d bytes\n",
			     (srb->sc_data_direction == DMA_TO_DEVICE) ?
			     "sending" : "receiving",
			     scsi_bufflen(srb));

		result = usb_stor_bulk_srb(us, pipe, srb);

		return (result == USB_STOR_XFER_GOOD ?
			USB_STOR_TRANSPORT_GOOD : USB_STOR_TRANSPORT_ERROR);
	} 

	return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Initialization routine for the sddr09 subdriver
 */
static int
usb_stor_sddr09_init(struct us_data *us) {
	return sddr09_common_init(us);
}

static struct scsi_host_template sddr09_host_template;

static int sddr09_probe(struct usb_interface *intf,
			 const struct usb_device_id *id)
{
	struct us_data *us;
	int result;

	result = usb_stor_probe1(&us, intf, id,
			(id - sddr09_usb_ids) + sddr09_unusual_dev_list,
			&sddr09_host_template);
	if (result)
		return result;

	if (us->protocol == USB_PR_DPCM_USB) {
		us->transport_name = "Control/Bulk-EUSB/SDDR09";
		us->transport = dpcm_transport;
		us->transport_reset = usb_stor_CB_reset;
		us->max_lun = 1;
	} else {
		us->transport_name = "EUSB/SDDR09";
		us->transport = sddr09_transport;
		us->transport_reset = usb_stor_CB_reset;
		us->max_lun = 0;
	}

	result = usb_stor_probe2(us);
	return result;
}

static struct usb_driver sddr09_driver = {
	.name =		DRV_NAME,
	.probe =	sddr09_probe,
	.disconnect =	usb_stor_disconnect,
	.suspend =	usb_stor_suspend,
	.resume =	usb_stor_resume,
	.reset_resume =	usb_stor_reset_resume,
	.pre_reset =	usb_stor_pre_reset,
	.post_reset =	usb_stor_post_reset,
	.id_table =	sddr09_usb_ids,
	.soft_unbind =	1,
	.no_dynamic_id = 1,
};

module_usb_stor_driver(sddr09_driver, sddr09_host_template, DRV_NAME);