aboutsummaryrefslogtreecommitdiff
path: root/drivers/mtd/chips/cfi_cmdset_0020.c
blob: 85e80180b65b5131201d974e6946fdc658c2463b (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
/*
 * Common Flash Interface support:
 *   ST Advanced Architecture Command Set (ID 0x0020)
 *
 * (C) 2000 Red Hat. GPL'd
 *
 * 10/10/2000	Nicolas Pitre <nico@fluxnic.net>
 * 	- completely revamped method functions so they are aware and
 * 	  independent of the flash geometry (buswidth, interleave, etc.)
 * 	- scalability vs code size is completely set at compile-time
 * 	  (see include/linux/mtd/cfi.h for selection)
 *	- optimized write buffer method
 * 06/21/2002	Joern Engel <joern@wh.fh-wedel.de> and others
 *	- modified Intel Command Set 0x0001 to support ST Advanced Architecture
 *	  (command set 0x0020)
 *	- added a writev function
 * 07/13/2005	Joern Engel <joern@wh.fh-wedel.de>
 * 	- Plugged memory leak in cfi_staa_writev().
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/byteorder.h>

#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/mtd/map.h>
#include <linux/mtd/cfi.h>
#include <linux/mtd/mtd.h>


static int cfi_staa_read(struct mtd_info *, loff_t, size_t, size_t *, u_char *);
static int cfi_staa_write_buffers(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
static int cfi_staa_writev(struct mtd_info *mtd, const struct kvec *vecs,
		unsigned long count, loff_t to, size_t *retlen);
static int cfi_staa_erase_varsize(struct mtd_info *, struct erase_info *);
static void cfi_staa_sync (struct mtd_info *);
static int cfi_staa_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
static int cfi_staa_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
static int cfi_staa_suspend (struct mtd_info *);
static void cfi_staa_resume (struct mtd_info *);

static void cfi_staa_destroy(struct mtd_info *);

struct mtd_info *cfi_cmdset_0020(struct map_info *, int);

static struct mtd_info *cfi_staa_setup (struct map_info *);

static struct mtd_chip_driver cfi_staa_chipdrv = {
	.probe		= NULL, /* Not usable directly */
	.destroy	= cfi_staa_destroy,
	.name		= "cfi_cmdset_0020",
	.module		= THIS_MODULE
};

/* #define DEBUG_LOCK_BITS */
//#define DEBUG_CFI_FEATURES

#ifdef DEBUG_CFI_FEATURES
static void cfi_tell_features(struct cfi_pri_intelext *extp)
{
        int i;
        printk("  Feature/Command Support: %4.4X\n", extp->FeatureSupport);
	printk("     - Chip Erase:         %s\n", extp->FeatureSupport&1?"supported":"unsupported");
	printk("     - Suspend Erase:      %s\n", extp->FeatureSupport&2?"supported":"unsupported");
	printk("     - Suspend Program:    %s\n", extp->FeatureSupport&4?"supported":"unsupported");
	printk("     - Legacy Lock/Unlock: %s\n", extp->FeatureSupport&8?"supported":"unsupported");
	printk("     - Queued Erase:       %s\n", extp->FeatureSupport&16?"supported":"unsupported");
	printk("     - Instant block lock: %s\n", extp->FeatureSupport&32?"supported":"unsupported");
	printk("     - Protection Bits:    %s\n", extp->FeatureSupport&64?"supported":"unsupported");
	printk("     - Page-mode read:     %s\n", extp->FeatureSupport&128?"supported":"unsupported");
	printk("     - Synchronous read:   %s\n", extp->FeatureSupport&256?"supported":"unsupported");
	for (i=9; i<32; i++) {
		if (extp->FeatureSupport & (1<<i))
			printk("     - Unknown Bit %X:      supported\n", i);
	}

	printk("  Supported functions after Suspend: %2.2X\n", extp->SuspendCmdSupport);
	printk("     - Program after Erase Suspend: %s\n", extp->SuspendCmdSupport&1?"supported":"unsupported");
	for (i=1; i<8; i++) {
		if (extp->SuspendCmdSupport & (1<<i))
			printk("     - Unknown Bit %X:               supported\n", i);
	}

	printk("  Block Status Register Mask: %4.4X\n", extp->BlkStatusRegMask);
	printk("     - Lock Bit Active:      %s\n", extp->BlkStatusRegMask&1?"yes":"no");
	printk("     - Valid Bit Active:     %s\n", extp->BlkStatusRegMask&2?"yes":"no");
	for (i=2; i<16; i++) {
		if (extp->BlkStatusRegMask & (1<<i))
			printk("     - Unknown Bit %X Active: yes\n",i);
	}

	printk("  Vcc Logic Supply Optimum Program/Erase Voltage: %d.%d V\n",
	       extp->VccOptimal >> 8, extp->VccOptimal & 0xf);
	if (extp->VppOptimal)
		printk("  Vpp Programming Supply Optimum Program/Erase Voltage: %d.%d V\n",
		       extp->VppOptimal >> 8, extp->VppOptimal & 0xf);
}
#endif

/* This routine is made available to other mtd code via
 * inter_module_register.  It must only be accessed through
 * inter_module_get which will bump the use count of this module.  The
 * addresses passed back in cfi are valid as long as the use count of
 * this module is non-zero, i.e. between inter_module_get and
 * inter_module_put.  Keith Owens <kaos@ocs.com.au> 29 Oct 2000.
 */
struct mtd_info *cfi_cmdset_0020(struct map_info *map, int primary)
{
	struct cfi_private *cfi = map->fldrv_priv;
	int i;

	if (cfi->cfi_mode) {
		/*
		 * It's a real CFI chip, not one for which the probe
		 * routine faked a CFI structure. So we read the feature
		 * table from it.
		 */
		__u16 adr = primary?cfi->cfiq->P_ADR:cfi->cfiq->A_ADR;
		struct cfi_pri_intelext *extp;

		extp = (struct cfi_pri_intelext*)cfi_read_pri(map, adr, sizeof(*extp), "ST Microelectronics");
		if (!extp)
			return NULL;

		if (extp->MajorVersion != '1' ||
		    (extp->MinorVersion < '0' || extp->MinorVersion > '3')) {
			printk(KERN_ERR "  Unknown ST Microelectronics"
			       " Extended Query version %c.%c.\n",
			       extp->MajorVersion, extp->MinorVersion);
			kfree(extp);
			return NULL;
		}

		/* Do some byteswapping if necessary */
		extp->FeatureSupport = cfi32_to_cpu(map, extp->FeatureSupport);
		extp->BlkStatusRegMask = cfi32_to_cpu(map,
						extp->BlkStatusRegMask);

#ifdef DEBUG_CFI_FEATURES
		/* Tell the user about it in lots of lovely detail */
		cfi_tell_features(extp);
#endif

		/* Install our own private info structure */
		cfi->cmdset_priv = extp;
	}

	for (i=0; i< cfi->numchips; i++) {
		cfi->chips[i].word_write_time = 128;
		cfi->chips[i].buffer_write_time = 128;
		cfi->chips[i].erase_time = 1024;
		cfi->chips[i].ref_point_counter = 0;
		init_waitqueue_head(&(cfi->chips[i].wq));
	}

	return cfi_staa_setup(map);
}
EXPORT_SYMBOL_GPL(cfi_cmdset_0020);

static struct mtd_info *cfi_staa_setup(struct map_info *map)
{
	struct cfi_private *cfi = map->fldrv_priv;
	struct mtd_info *mtd;
	unsigned long offset = 0;
	int i,j;
	unsigned long devsize = (1<<cfi->cfiq->DevSize) * cfi->interleave;

	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
	//printk(KERN_DEBUG "number of CFI chips: %d\n", cfi->numchips);

	if (!mtd) {
		printk(KERN_ERR "Failed to allocate memory for MTD device\n");
		kfree(cfi->cmdset_priv);
		return NULL;
	}

	mtd->priv = map;
	mtd->type = MTD_NORFLASH;
	mtd->size = devsize * cfi->numchips;

	mtd->numeraseregions = cfi->cfiq->NumEraseRegions * cfi->numchips;
	mtd->eraseregions = kmalloc(sizeof(struct mtd_erase_region_info)
			* mtd->numeraseregions, GFP_KERNEL);
	if (!mtd->eraseregions) {
		printk(KERN_ERR "Failed to allocate memory for MTD erase region info\n");
		kfree(cfi->cmdset_priv);
		kfree(mtd);
		return NULL;
	}

	for (i=0; i<cfi->cfiq->NumEraseRegions; i++) {
		unsigned long ernum, ersize;
		ersize = ((cfi->cfiq->EraseRegionInfo[i] >> 8) & ~0xff) * cfi->interleave;
		ernum = (cfi->cfiq->EraseRegionInfo[i] & 0xffff) + 1;

		if (mtd->erasesize < ersize) {
			mtd->erasesize = ersize;
		}
		for (j=0; j<cfi->numchips; j++) {
			mtd->eraseregions[(j*cfi->cfiq->NumEraseRegions)+i].offset = (j*devsize)+offset;
			mtd->eraseregions[(j*cfi->cfiq->NumEraseRegions)+i].erasesize = ersize;
			mtd->eraseregions[(j*cfi->cfiq->NumEraseRegions)+i].numblocks = ernum;
		}
		offset += (ersize * ernum);
		}

		if (offset != devsize) {
			/* Argh */
			printk(KERN_WARNING "Sum of regions (%lx) != total size of set of interleaved chips (%lx)\n", offset, devsize);
			kfree(mtd->eraseregions);
			kfree(cfi->cmdset_priv);
			kfree(mtd);
			return NULL;
		}

		for (i=0; i<mtd->numeraseregions;i++){
			printk(KERN_DEBUG "%d: offset=0x%llx,size=0x%x,blocks=%d\n",
			       i, (unsigned long long)mtd->eraseregions[i].offset,
			       mtd->eraseregions[i].erasesize,
			       mtd->eraseregions[i].numblocks);
		}

	/* Also select the correct geometry setup too */
	mtd->erase = cfi_staa_erase_varsize;
	mtd->read = cfi_staa_read;
        mtd->write = cfi_staa_write_buffers;
	mtd->writev = cfi_staa_writev;
	mtd->sync = cfi_staa_sync;
	mtd->lock = cfi_staa_lock;
	mtd->unlock = cfi_staa_unlock;
	mtd->suspend = cfi_staa_suspend;
	mtd->resume = cfi_staa_resume;
	mtd->flags = MTD_CAP_NORFLASH & ~MTD_BIT_WRITEABLE;
	mtd->writesize = 8; /* FIXME: Should be 0 for STMicro flashes w/out ECC */
	mtd->writebufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
	map->fldrv = &cfi_staa_chipdrv;
	__module_get(THIS_MODULE);
	mtd->name = map->name;
	return mtd;
}


static inline int do_read_onechip(struct map_info *map, struct flchip *chip, loff_t adr, size_t len, u_char *buf)
{
	map_word status, status_OK;
	unsigned long timeo;
	DECLARE_WAITQUEUE(wait, current);
	int suspended = 0;
	unsigned long cmd_addr;
	struct cfi_private *cfi = map->fldrv_priv;

	adr += chip->start;

	/* Ensure cmd read/writes are aligned. */
	cmd_addr = adr & ~(map_bankwidth(map)-1);

	/* Let's determine this according to the interleave only once */
	status_OK = CMD(0x80);

	timeo = jiffies + HZ;
 retry:
	mutex_lock(&chip->mutex);

	/* Check that the chip's ready to talk to us.
	 * If it's in FL_ERASING state, suspend it and make it talk now.
	 */
	switch (chip->state) {
	case FL_ERASING:
		if (!(((struct cfi_pri_intelext *)cfi->cmdset_priv)->FeatureSupport & 2))
			goto sleep; /* We don't support erase suspend */

		map_write (map, CMD(0xb0), cmd_addr);
		/* If the flash has finished erasing, then 'erase suspend'
		 * appears to make some (28F320) flash devices switch to
		 * 'read' mode.  Make sure that we switch to 'read status'
		 * mode so we get the right data. --rmk
		 */
		map_write(map, CMD(0x70), cmd_addr);
		chip->oldstate = FL_ERASING;
		chip->state = FL_ERASE_SUSPENDING;
		//		printk("Erase suspending at 0x%lx\n", cmd_addr);
		for (;;) {
			status = map_read(map, cmd_addr);
			if (map_word_andequal(map, status, status_OK, status_OK))
				break;

			if (time_after(jiffies, timeo)) {
				/* Urgh */
				map_write(map, CMD(0xd0), cmd_addr);
				/* make sure we're in 'read status' mode */
				map_write(map, CMD(0x70), cmd_addr);
				chip->state = FL_ERASING;
				wake_up(&chip->wq);
				mutex_unlock(&chip->mutex);
				printk(KERN_ERR "Chip not ready after erase "
				       "suspended: status = 0x%lx\n", status.x[0]);
				return -EIO;
			}

			mutex_unlock(&chip->mutex);
			cfi_udelay(1);
			mutex_lock(&chip->mutex);
		}

		suspended = 1;
		map_write(map, CMD(0xff), cmd_addr);
		chip->state = FL_READY;
		break;

#if 0
	case FL_WRITING:
		/* Not quite yet */
#endif

	case FL_READY:
		break;

	case FL_CFI_QUERY:
	case FL_JEDEC_QUERY:
		map_write(map, CMD(0x70), cmd_addr);
		chip->state = FL_STATUS;

	case FL_STATUS:
		status = map_read(map, cmd_addr);
		if (map_word_andequal(map, status, status_OK, status_OK)) {
			map_write(map, CMD(0xff), cmd_addr);
			chip->state = FL_READY;
			break;
		}

		/* Urgh. Chip not yet ready to talk to us. */
		if (time_after(jiffies, timeo)) {
			mutex_unlock(&chip->mutex);
			printk(KERN_ERR "waiting for chip to be ready timed out in read. WSM status = %lx\n", status.x[0]);
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		goto retry;

	default:
	sleep:
		/* Stick ourselves on a wait queue to be woken when
		   someone changes the status */
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&chip->wq, &wait);
		mutex_unlock(&chip->mutex);
		schedule();
		remove_wait_queue(&chip->wq, &wait);
		timeo = jiffies + HZ;
		goto retry;
	}

	map_copy_from(map, buf, adr, len);

	if (suspended) {
		chip->state = chip->oldstate;
		/* What if one interleaved chip has finished and the
		   other hasn't? The old code would leave the finished
		   one in READY mode. That's bad, and caused -EROFS
		   errors to be returned from do_erase_oneblock because
		   that's the only bit it checked for at the time.
		   As the state machine appears to explicitly allow
		   sending the 0x70 (Read Status) command to an erasing
		   chip and expecting it to be ignored, that's what we
		   do. */
		map_write(map, CMD(0xd0), cmd_addr);
		map_write(map, CMD(0x70), cmd_addr);
	}

	wake_up(&chip->wq);
	mutex_unlock(&chip->mutex);
	return 0;
}

static int cfi_staa_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long ofs;
	int chipnum;
	int ret = 0;

	/* ofs: offset within the first chip that the first read should start */
	chipnum = (from >> cfi->chipshift);
	ofs = from - (chipnum <<  cfi->chipshift);

	*retlen = 0;

	while (len) {
		unsigned long thislen;

		if (chipnum >= cfi->numchips)
			break;

		if ((len + ofs -1) >> cfi->chipshift)
			thislen = (1<<cfi->chipshift) - ofs;
		else
			thislen = len;

		ret = do_read_onechip(map, &cfi->chips[chipnum], ofs, thislen, buf);
		if (ret)
			break;

		*retlen += thislen;
		len -= thislen;
		buf += thislen;

		ofs = 0;
		chipnum++;
	}
	return ret;
}

static inline int do_write_buffer(struct map_info *map, struct flchip *chip,
				  unsigned long adr, const u_char *buf, int len)
{
	struct cfi_private *cfi = map->fldrv_priv;
	map_word status, status_OK;
	unsigned long cmd_adr, timeo;
	DECLARE_WAITQUEUE(wait, current);
	int wbufsize, z;

        /* M58LW064A requires bus alignment for buffer wriets -- saw */
        if (adr & (map_bankwidth(map)-1))
            return -EINVAL;

        wbufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
        adr += chip->start;
	cmd_adr = adr & ~(wbufsize-1);

	/* Let's determine this according to the interleave only once */
        status_OK = CMD(0x80);

	timeo = jiffies + HZ;
 retry:

#ifdef DEBUG_CFI_FEATURES
       printk("%s: chip->state[%d]\n", __func__, chip->state);
#endif
	mutex_lock(&chip->mutex);

	/* Check that the chip's ready to talk to us.
	 * Later, we can actually think about interrupting it
	 * if it's in FL_ERASING state.
	 * Not just yet, though.
	 */
	switch (chip->state) {
	case FL_READY:
		break;

	case FL_CFI_QUERY:
	case FL_JEDEC_QUERY:
		map_write(map, CMD(0x70), cmd_adr);
                chip->state = FL_STATUS;
#ifdef DEBUG_CFI_FEATURES
	printk("%s: 1 status[%x]\n", __func__, map_read(map, cmd_adr));
#endif

	case FL_STATUS:
		status = map_read(map, cmd_adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;
		/* Urgh. Chip not yet ready to talk to us. */
		if (time_after(jiffies, timeo)) {
			mutex_unlock(&chip->mutex);
                        printk(KERN_ERR "waiting for chip to be ready timed out in buffer write Xstatus = %lx, status = %lx\n",
                               status.x[0], map_read(map, cmd_adr).x[0]);
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		goto retry;

	default:
		/* Stick ourselves on a wait queue to be woken when
		   someone changes the status */
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&chip->wq, &wait);
		mutex_unlock(&chip->mutex);
		schedule();
		remove_wait_queue(&chip->wq, &wait);
		timeo = jiffies + HZ;
		goto retry;
	}

	ENABLE_VPP(map);
	map_write(map, CMD(0xe8), cmd_adr);
	chip->state = FL_WRITING_TO_BUFFER;

	z = 0;
	for (;;) {
		status = map_read(map, cmd_adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		mutex_lock(&chip->mutex);

		if (++z > 100) {
			/* Argh. Not ready for write to buffer */
			DISABLE_VPP(map);
                        map_write(map, CMD(0x70), cmd_adr);
			chip->state = FL_STATUS;
			mutex_unlock(&chip->mutex);
			printk(KERN_ERR "Chip not ready for buffer write. Xstatus = %lx\n", status.x[0]);
			return -EIO;
		}
	}

	/* Write length of data to come */
	map_write(map, CMD(len/map_bankwidth(map)-1), cmd_adr );

	/* Write data */
	for (z = 0; z < len;
	     z += map_bankwidth(map), buf += map_bankwidth(map)) {
		map_word d;
		d = map_word_load(map, buf);
		map_write(map, d, adr+z);
	}
	/* GO GO GO */
	map_write(map, CMD(0xd0), cmd_adr);
	chip->state = FL_WRITING;

	mutex_unlock(&chip->mutex);
	cfi_udelay(chip->buffer_write_time);
	mutex_lock(&chip->mutex);

	timeo = jiffies + (HZ/2);
	z = 0;
	for (;;) {
		if (chip->state != FL_WRITING) {
			/* Someone's suspended the write. Sleep */
			set_current_state(TASK_UNINTERRUPTIBLE);
			add_wait_queue(&chip->wq, &wait);
			mutex_unlock(&chip->mutex);
			schedule();
			remove_wait_queue(&chip->wq, &wait);
			timeo = jiffies + (HZ / 2); /* FIXME */
			mutex_lock(&chip->mutex);
			continue;
		}

		status = map_read(map, cmd_adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		/* OK Still waiting */
		if (time_after(jiffies, timeo)) {
                        /* clear status */
                        map_write(map, CMD(0x50), cmd_adr);
                        /* put back into read status register mode */
                        map_write(map, CMD(0x70), adr);
			chip->state = FL_STATUS;
			DISABLE_VPP(map);
			mutex_unlock(&chip->mutex);
			printk(KERN_ERR "waiting for chip to be ready timed out in bufwrite\n");
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		z++;
		mutex_lock(&chip->mutex);
	}
	if (!z) {
		chip->buffer_write_time--;
		if (!chip->buffer_write_time)
			chip->buffer_write_time++;
	}
	if (z > 1)
		chip->buffer_write_time++;

	/* Done and happy. */
	DISABLE_VPP(map);
	chip->state = FL_STATUS;

        /* check for errors: 'lock bit', 'VPP', 'dead cell'/'unerased cell' or 'incorrect cmd' -- saw */
        if (map_word_bitsset(map, status, CMD(0x3a))) {
#ifdef DEBUG_CFI_FEATURES
		printk("%s: 2 status[%lx]\n", __func__, status.x[0]);
#endif
		/* clear status */
		map_write(map, CMD(0x50), cmd_adr);
		/* put back into read status register mode */
		map_write(map, CMD(0x70), adr);
		wake_up(&chip->wq);
		mutex_unlock(&chip->mutex);
		return map_word_bitsset(map, status, CMD(0x02)) ? -EROFS : -EIO;
	}
	wake_up(&chip->wq);
	mutex_unlock(&chip->mutex);

        return 0;
}

static int cfi_staa_write_buffers (struct mtd_info *mtd, loff_t to,
				       size_t len, size_t *retlen, const u_char *buf)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	int wbufsize = cfi_interleave(cfi) << cfi->cfiq->MaxBufWriteSize;
	int ret = 0;
	int chipnum;
	unsigned long ofs;

	*retlen = 0;
	if (!len)
		return 0;

	chipnum = to >> cfi->chipshift;
	ofs = to  - (chipnum << cfi->chipshift);

#ifdef DEBUG_CFI_FEATURES
	printk("%s: map_bankwidth(map)[%x]\n", __func__, map_bankwidth(map));
	printk("%s: chipnum[%x] wbufsize[%x]\n", __func__, chipnum, wbufsize);
	printk("%s: ofs[%x] len[%x]\n", __func__, ofs, len);
#endif

        /* Write buffer is worth it only if more than one word to write... */
        while (len > 0) {
		/* We must not cross write block boundaries */
		int size = wbufsize - (ofs & (wbufsize-1));

                if (size > len)
                    size = len;

                ret = do_write_buffer(map, &cfi->chips[chipnum],
				      ofs, buf, size);
		if (ret)
			return ret;

		ofs += size;
		buf += size;
		(*retlen) += size;
		len -= size;

		if (ofs >> cfi->chipshift) {
			chipnum ++;
			ofs = 0;
			if (chipnum == cfi->numchips)
				return 0;
		}
	}

	return 0;
}

/*
 * Writev for ECC-Flashes is a little more complicated. We need to maintain
 * a small buffer for this.
 * XXX: If the buffer size is not a multiple of 2, this will break
 */
#define ECCBUF_SIZE (mtd->writesize)
#define ECCBUF_DIV(x) ((x) & ~(ECCBUF_SIZE - 1))
#define ECCBUF_MOD(x) ((x) &  (ECCBUF_SIZE - 1))
static int
cfi_staa_writev(struct mtd_info *mtd, const struct kvec *vecs,
		unsigned long count, loff_t to, size_t *retlen)
{
	unsigned long i;
	size_t	 totlen = 0, thislen;
	int	 ret = 0;
	size_t	 buflen = 0;
	static char *buffer;

	if (!ECCBUF_SIZE) {
		/* We should fall back to a general writev implementation.
		 * Until that is written, just break.
		 */
		return -EIO;
	}
	buffer = kmalloc(ECCBUF_SIZE, GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	for (i=0; i<count; i++) {
		size_t elem_len = vecs[i].iov_len;
		void *elem_base = vecs[i].iov_base;
		if (!elem_len) /* FIXME: Might be unnecessary. Check that */
			continue;
		if (buflen) { /* cut off head */
			if (buflen + elem_len < ECCBUF_SIZE) { /* just accumulate */
				memcpy(buffer+buflen, elem_base, elem_len);
				buflen += elem_len;
				continue;
			}
			memcpy(buffer+buflen, elem_base, ECCBUF_SIZE-buflen);
			ret = mtd_write(mtd, to, ECCBUF_SIZE, &thislen,
					buffer);
			totlen += thislen;
			if (ret || thislen != ECCBUF_SIZE)
				goto write_error;
			elem_len -= thislen-buflen;
			elem_base += thislen-buflen;
			to += ECCBUF_SIZE;
		}
		if (ECCBUF_DIV(elem_len)) { /* write clean aligned data */
			ret = mtd_write(mtd, to, ECCBUF_DIV(elem_len),
					&thislen, elem_base);
			totlen += thislen;
			if (ret || thislen != ECCBUF_DIV(elem_len))
				goto write_error;
			to += thislen;
		}
		buflen = ECCBUF_MOD(elem_len); /* cut off tail */
		if (buflen) {
			memset(buffer, 0xff, ECCBUF_SIZE);
			memcpy(buffer, elem_base + thislen, buflen);
		}
	}
	if (buflen) { /* flush last page, even if not full */
		/* This is sometimes intended behaviour, really */
		ret = mtd_write(mtd, to, buflen, &thislen, buffer);
		totlen += thislen;
		if (ret || thislen != ECCBUF_SIZE)
			goto write_error;
	}
write_error:
	if (retlen)
		*retlen = totlen;
	kfree(buffer);
	return ret;
}


static inline int do_erase_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr)
{
	struct cfi_private *cfi = map->fldrv_priv;
	map_word status, status_OK;
	unsigned long timeo;
	int retries = 3;
	DECLARE_WAITQUEUE(wait, current);
	int ret = 0;

	adr += chip->start;

	/* Let's determine this according to the interleave only once */
	status_OK = CMD(0x80);

	timeo = jiffies + HZ;
retry:
	mutex_lock(&chip->mutex);

	/* Check that the chip's ready to talk to us. */
	switch (chip->state) {
	case FL_CFI_QUERY:
	case FL_JEDEC_QUERY:
	case FL_READY:
		map_write(map, CMD(0x70), adr);
		chip->state = FL_STATUS;

	case FL_STATUS:
		status = map_read(map, adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		/* Urgh. Chip not yet ready to talk to us. */
		if (time_after(jiffies, timeo)) {
			mutex_unlock(&chip->mutex);
			printk(KERN_ERR "waiting for chip to be ready timed out in erase\n");
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		goto retry;

	default:
		/* Stick ourselves on a wait queue to be woken when
		   someone changes the status */
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&chip->wq, &wait);
		mutex_unlock(&chip->mutex);
		schedule();
		remove_wait_queue(&chip->wq, &wait);
		timeo = jiffies + HZ;
		goto retry;
	}

	ENABLE_VPP(map);
	/* Clear the status register first */
	map_write(map, CMD(0x50), adr);

	/* Now erase */
	map_write(map, CMD(0x20), adr);
	map_write(map, CMD(0xD0), adr);
	chip->state = FL_ERASING;

	mutex_unlock(&chip->mutex);
	msleep(1000);
	mutex_lock(&chip->mutex);

	/* FIXME. Use a timer to check this, and return immediately. */
	/* Once the state machine's known to be working I'll do that */

	timeo = jiffies + (HZ*20);
	for (;;) {
		if (chip->state != FL_ERASING) {
			/* Someone's suspended the erase. Sleep */
			set_current_state(TASK_UNINTERRUPTIBLE);
			add_wait_queue(&chip->wq, &wait);
			mutex_unlock(&chip->mutex);
			schedule();
			remove_wait_queue(&chip->wq, &wait);
			timeo = jiffies + (HZ*20); /* FIXME */
			mutex_lock(&chip->mutex);
			continue;
		}

		status = map_read(map, adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		/* OK Still waiting */
		if (time_after(jiffies, timeo)) {
			map_write(map, CMD(0x70), adr);
			chip->state = FL_STATUS;
			printk(KERN_ERR "waiting for erase to complete timed out. Xstatus = %lx, status = %lx.\n", status.x[0], map_read(map, adr).x[0]);
			DISABLE_VPP(map);
			mutex_unlock(&chip->mutex);
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		mutex_lock(&chip->mutex);
	}

	DISABLE_VPP(map);
	ret = 0;

	/* We've broken this before. It doesn't hurt to be safe */
	map_write(map, CMD(0x70), adr);
	chip->state = FL_STATUS;
	status = map_read(map, adr);

	/* check for lock bit */
	if (map_word_bitsset(map, status, CMD(0x3a))) {
		unsigned char chipstatus = status.x[0];
		if (!map_word_equal(map, status, CMD(chipstatus))) {
			int i, w;
			for (w=0; w<map_words(map); w++) {
				for (i = 0; i<cfi_interleave(cfi); i++) {
					chipstatus |= status.x[w] >> (cfi->device_type * 8);
				}
			}
			printk(KERN_WARNING "Status is not identical for all chips: 0x%lx. Merging to give 0x%02x\n",
			       status.x[0], chipstatus);
		}
		/* Reset the error bits */
		map_write(map, CMD(0x50), adr);
		map_write(map, CMD(0x70), adr);

		if ((chipstatus & 0x30) == 0x30) {
			printk(KERN_NOTICE "Chip reports improper command sequence: status 0x%x\n", chipstatus);
			ret = -EIO;
		} else if (chipstatus & 0x02) {
			/* Protection bit set */
			ret = -EROFS;
		} else if (chipstatus & 0x8) {
			/* Voltage */
			printk(KERN_WARNING "Chip reports voltage low on erase: status 0x%x\n", chipstatus);
			ret = -EIO;
		} else if (chipstatus & 0x20) {
			if (retries--) {
				printk(KERN_DEBUG "Chip erase failed at 0x%08lx: status 0x%x. Retrying...\n", adr, chipstatus);
				timeo = jiffies + HZ;
				chip->state = FL_STATUS;
				mutex_unlock(&chip->mutex);
				goto retry;
			}
			printk(KERN_DEBUG "Chip erase failed at 0x%08lx: status 0x%x\n", adr, chipstatus);
			ret = -EIO;
		}
	}

	wake_up(&chip->wq);
	mutex_unlock(&chip->mutex);
	return ret;
}

static int cfi_staa_erase_varsize(struct mtd_info *mtd,
				  struct erase_info *instr)
{	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long adr, len;
	int chipnum, ret = 0;
	int i, first;
	struct mtd_erase_region_info *regions = mtd->eraseregions;

	if (instr->addr > mtd->size)
		return -EINVAL;

	if ((instr->len + instr->addr) > mtd->size)
		return -EINVAL;

	/* Check that both start and end of the requested erase are
	 * aligned with the erasesize at the appropriate addresses.
	 */

	i = 0;

	/* Skip all erase regions which are ended before the start of
	   the requested erase. Actually, to save on the calculations,
	   we skip to the first erase region which starts after the
	   start of the requested erase, and then go back one.
	*/

	while (i < mtd->numeraseregions && instr->addr >= regions[i].offset)
	       i++;
	i--;

	/* OK, now i is pointing at the erase region in which this
	   erase request starts. Check the start of the requested
	   erase range is aligned with the erase size which is in
	   effect here.
	*/

	if (instr->addr & (regions[i].erasesize-1))
		return -EINVAL;

	/* Remember the erase region we start on */
	first = i;

	/* Next, check that the end of the requested erase is aligned
	 * with the erase region at that address.
	 */

	while (i<mtd->numeraseregions && (instr->addr + instr->len) >= regions[i].offset)
		i++;

	/* As before, drop back one to point at the region in which
	   the address actually falls
	*/
	i--;

	if ((instr->addr + instr->len) & (regions[i].erasesize-1))
		return -EINVAL;

	chipnum = instr->addr >> cfi->chipshift;
	adr = instr->addr - (chipnum << cfi->chipshift);
	len = instr->len;

	i=first;

	while(len) {
		ret = do_erase_oneblock(map, &cfi->chips[chipnum], adr);

		if (ret)
			return ret;

		adr += regions[i].erasesize;
		len -= regions[i].erasesize;

		if (adr % (1<< cfi->chipshift) == (((unsigned long)regions[i].offset + (regions[i].erasesize * regions[i].numblocks)) %( 1<< cfi->chipshift)))
			i++;

		if (adr >> cfi->chipshift) {
			adr = 0;
			chipnum++;

			if (chipnum >= cfi->numchips)
			break;
		}
	}

	instr->state = MTD_ERASE_DONE;
	mtd_erase_callback(instr);

	return 0;
}

static void cfi_staa_sync (struct mtd_info *mtd)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	int i;
	struct flchip *chip;
	int ret = 0;
	DECLARE_WAITQUEUE(wait, current);

	for (i=0; !ret && i<cfi->numchips; i++) {
		chip = &cfi->chips[i];

	retry:
		mutex_lock(&chip->mutex);

		switch(chip->state) {
		case FL_READY:
		case FL_STATUS:
		case FL_CFI_QUERY:
		case FL_JEDEC_QUERY:
			chip->oldstate = chip->state;
			chip->state = FL_SYNCING;
			/* No need to wake_up() on this state change -
			 * as the whole point is that nobody can do anything
			 * with the chip now anyway.
			 */
		case FL_SYNCING:
			mutex_unlock(&chip->mutex);
			break;

		default:
			/* Not an idle state */
			set_current_state(TASK_UNINTERRUPTIBLE);
			add_wait_queue(&chip->wq, &wait);

			mutex_unlock(&chip->mutex);
			schedule();
		        remove_wait_queue(&chip->wq, &wait);

			goto retry;
		}
	}

	/* Unlock the chips again */

	for (i--; i >=0; i--) {
		chip = &cfi->chips[i];

		mutex_lock(&chip->mutex);

		if (chip->state == FL_SYNCING) {
			chip->state = chip->oldstate;
			wake_up(&chip->wq);
		}
		mutex_unlock(&chip->mutex);
	}
}

static inline int do_lock_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr)
{
	struct cfi_private *cfi = map->fldrv_priv;
	map_word status, status_OK;
	unsigned long timeo = jiffies + HZ;
	DECLARE_WAITQUEUE(wait, current);

	adr += chip->start;

	/* Let's determine this according to the interleave only once */
	status_OK = CMD(0x80);

	timeo = jiffies + HZ;
retry:
	mutex_lock(&chip->mutex);

	/* Check that the chip's ready to talk to us. */
	switch (chip->state) {
	case FL_CFI_QUERY:
	case FL_JEDEC_QUERY:
	case FL_READY:
		map_write(map, CMD(0x70), adr);
		chip->state = FL_STATUS;

	case FL_STATUS:
		status = map_read(map, adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		/* Urgh. Chip not yet ready to talk to us. */
		if (time_after(jiffies, timeo)) {
			mutex_unlock(&chip->mutex);
			printk(KERN_ERR "waiting for chip to be ready timed out in lock\n");
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		goto retry;

	default:
		/* Stick ourselves on a wait queue to be woken when
		   someone changes the status */
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&chip->wq, &wait);
		mutex_unlock(&chip->mutex);
		schedule();
		remove_wait_queue(&chip->wq, &wait);
		timeo = jiffies + HZ;
		goto retry;
	}

	ENABLE_VPP(map);
	map_write(map, CMD(0x60), adr);
	map_write(map, CMD(0x01), adr);
	chip->state = FL_LOCKING;

	mutex_unlock(&chip->mutex);
	msleep(1000);
	mutex_lock(&chip->mutex);

	/* FIXME. Use a timer to check this, and return immediately. */
	/* Once the state machine's known to be working I'll do that */

	timeo = jiffies + (HZ*2);
	for (;;) {

		status = map_read(map, adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		/* OK Still waiting */
		if (time_after(jiffies, timeo)) {
			map_write(map, CMD(0x70), adr);
			chip->state = FL_STATUS;
			printk(KERN_ERR "waiting for lock to complete timed out. Xstatus = %lx, status = %lx.\n", status.x[0], map_read(map, adr).x[0]);
			DISABLE_VPP(map);
			mutex_unlock(&chip->mutex);
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		mutex_lock(&chip->mutex);
	}

	/* Done and happy. */
	chip->state = FL_STATUS;
	DISABLE_VPP(map);
	wake_up(&chip->wq);
	mutex_unlock(&chip->mutex);
	return 0;
}
static int cfi_staa_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long adr;
	int chipnum, ret = 0;
#ifdef DEBUG_LOCK_BITS
	int ofs_factor = cfi->interleave * cfi->device_type;
#endif

	if (ofs & (mtd->erasesize - 1))
		return -EINVAL;

	if (len & (mtd->erasesize -1))
		return -EINVAL;

	if ((len + ofs) > mtd->size)
		return -EINVAL;

	chipnum = ofs >> cfi->chipshift;
	adr = ofs - (chipnum << cfi->chipshift);

	while(len) {

#ifdef DEBUG_LOCK_BITS
		cfi_send_gen_cmd(0x90, 0x55, 0, map, cfi, cfi->device_type, NULL);
		printk("before lock: block status register is %x\n",cfi_read_query(map, adr+(2*ofs_factor)));
		cfi_send_gen_cmd(0xff, 0x55, 0, map, cfi, cfi->device_type, NULL);
#endif

		ret = do_lock_oneblock(map, &cfi->chips[chipnum], adr);

#ifdef DEBUG_LOCK_BITS
		cfi_send_gen_cmd(0x90, 0x55, 0, map, cfi, cfi->device_type, NULL);
		printk("after lock: block status register is %x\n",cfi_read_query(map, adr+(2*ofs_factor)));
		cfi_send_gen_cmd(0xff, 0x55, 0, map, cfi, cfi->device_type, NULL);
#endif

		if (ret)
			return ret;

		adr += mtd->erasesize;
		len -= mtd->erasesize;

		if (adr >> cfi->chipshift) {
			adr = 0;
			chipnum++;

			if (chipnum >= cfi->numchips)
			break;
		}
	}
	return 0;
}
static inline int do_unlock_oneblock(struct map_info *map, struct flchip *chip, unsigned long adr)
{
	struct cfi_private *cfi = map->fldrv_priv;
	map_word status, status_OK;
	unsigned long timeo = jiffies + HZ;
	DECLARE_WAITQUEUE(wait, current);

	adr += chip->start;

	/* Let's determine this according to the interleave only once */
	status_OK = CMD(0x80);

	timeo = jiffies + HZ;
retry:
	mutex_lock(&chip->mutex);

	/* Check that the chip's ready to talk to us. */
	switch (chip->state) {
	case FL_CFI_QUERY:
	case FL_JEDEC_QUERY:
	case FL_READY:
		map_write(map, CMD(0x70), adr);
		chip->state = FL_STATUS;

	case FL_STATUS:
		status = map_read(map, adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		/* Urgh. Chip not yet ready to talk to us. */
		if (time_after(jiffies, timeo)) {
			mutex_unlock(&chip->mutex);
			printk(KERN_ERR "waiting for chip to be ready timed out in unlock\n");
			return -EIO;
		}

		/* Latency issues. Drop the lock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		goto retry;

	default:
		/* Stick ourselves on a wait queue to be woken when
		   someone changes the status */
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&chip->wq, &wait);
		mutex_unlock(&chip->mutex);
		schedule();
		remove_wait_queue(&chip->wq, &wait);
		timeo = jiffies + HZ;
		goto retry;
	}

	ENABLE_VPP(map);
	map_write(map, CMD(0x60), adr);
	map_write(map, CMD(0xD0), adr);
	chip->state = FL_UNLOCKING;

	mutex_unlock(&chip->mutex);
	msleep(1000);
	mutex_lock(&chip->mutex);

	/* FIXME. Use a timer to check this, and return immediately. */
	/* Once the state machine's known to be working I'll do that */

	timeo = jiffies + (HZ*2);
	for (;;) {

		status = map_read(map, adr);
		if (map_word_andequal(map, status, status_OK, status_OK))
			break;

		/* OK Still waiting */
		if (time_after(jiffies, timeo)) {
			map_write(map, CMD(0x70), adr);
			chip->state = FL_STATUS;
			printk(KERN_ERR "waiting for unlock to complete timed out. Xstatus = %lx, status = %lx.\n", status.x[0], map_read(map, adr).x[0]);
			DISABLE_VPP(map);
			mutex_unlock(&chip->mutex);
			return -EIO;
		}

		/* Latency issues. Drop the unlock, wait a while and retry */
		mutex_unlock(&chip->mutex);
		cfi_udelay(1);
		mutex_lock(&chip->mutex);
	}

	/* Done and happy. */
	chip->state = FL_STATUS;
	DISABLE_VPP(map);
	wake_up(&chip->wq);
	mutex_unlock(&chip->mutex);
	return 0;
}
static int cfi_staa_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	unsigned long adr;
	int chipnum, ret = 0;
#ifdef DEBUG_LOCK_BITS
	int ofs_factor = cfi->interleave * cfi->device_type;
#endif

	chipnum = ofs >> cfi->chipshift;
	adr = ofs - (chipnum << cfi->chipshift);

#ifdef DEBUG_LOCK_BITS
	{
		unsigned long temp_adr = adr;
		unsigned long temp_len = len;

		cfi_send_gen_cmd(0x90, 0x55, 0, map, cfi, cfi->device_type, NULL);
                while (temp_len) {
			printk("before unlock %x: block status register is %x\n",temp_adr,cfi_read_query(map, temp_adr+(2*ofs_factor)));
			temp_adr += mtd->erasesize;
			temp_len -= mtd->erasesize;
		}
		cfi_send_gen_cmd(0xff, 0x55, 0, map, cfi, cfi->device_type, NULL);
	}
#endif

	ret = do_unlock_oneblock(map, &cfi->chips[chipnum], adr);

#ifdef DEBUG_LOCK_BITS
	cfi_send_gen_cmd(0x90, 0x55, 0, map, cfi, cfi->device_type, NULL);
	printk("after unlock: block status register is %x\n",cfi_read_query(map, adr+(2*ofs_factor)));
	cfi_send_gen_cmd(0xff, 0x55, 0, map, cfi, cfi->device_type, NULL);
#endif

	return ret;
}

static int cfi_staa_suspend(struct mtd_info *mtd)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	int i;
	struct flchip *chip;
	int ret = 0;

	for (i=0; !ret && i<cfi->numchips; i++) {
		chip = &cfi->chips[i];

		mutex_lock(&chip->mutex);

		switch(chip->state) {
		case FL_READY:
		case FL_STATUS:
		case FL_CFI_QUERY:
		case FL_JEDEC_QUERY:
			chip->oldstate = chip->state;
			chip->state = FL_PM_SUSPENDED;
			/* No need to wake_up() on this state change -
			 * as the whole point is that nobody can do anything
			 * with the chip now anyway.
			 */
		case FL_PM_SUSPENDED:
			break;

		default:
			ret = -EAGAIN;
			break;
		}
		mutex_unlock(&chip->mutex);
	}

	/* Unlock the chips again */

	if (ret) {
		for (i--; i >=0; i--) {
			chip = &cfi->chips[i];

			mutex_lock(&chip->mutex);

			if (chip->state == FL_PM_SUSPENDED) {
				/* No need to force it into a known state here,
				   because we're returning failure, and it didn't
				   get power cycled */
				chip->state = chip->oldstate;
				wake_up(&chip->wq);
			}
			mutex_unlock(&chip->mutex);
		}
	}

	return ret;
}

static void cfi_staa_resume(struct mtd_info *mtd)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	int i;
	struct flchip *chip;

	for (i=0; i<cfi->numchips; i++) {

		chip = &cfi->chips[i];

		mutex_lock(&chip->mutex);

		/* Go to known state. Chip may have been power cycled */
		if (chip->state == FL_PM_SUSPENDED) {
			map_write(map, CMD(0xFF), 0);
			chip->state = FL_READY;
			wake_up(&chip->wq);
		}

		mutex_unlock(&chip->mutex);
	}
}

static void cfi_staa_destroy(struct mtd_info *mtd)
{
	struct map_info *map = mtd->priv;
	struct cfi_private *cfi = map->fldrv_priv;
	kfree(cfi->cmdset_priv);
	kfree(cfi);
}

MODULE_LICENSE("GPL");