summaryrefslogtreecommitdiffstats
path: root/drivers/spi/spi_bfin5xx.c
blob: d54058a903bec981be9688285b69b8c191c71f2e (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
/*
 * Blackfin On-Chip SPI Driver
 *
 * Copyright 2004-2007 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>

#include <asm/dma.h>
#include <asm/portmux.h>
#include <asm/bfin5xx_spi.h>
#include <asm/cacheflush.h>

#define DRV_NAME	"bfin-spi"
#define DRV_AUTHOR	"Bryan Wu, Luke Yang"
#define DRV_DESC	"Blackfin on-chip SPI Controller Driver"
#define DRV_VERSION	"1.0"

MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);
MODULE_LICENSE("GPL");

#define START_STATE	((void *)0)
#define RUNNING_STATE	((void *)1)
#define DONE_STATE	((void *)2)
#define ERROR_STATE	((void *)-1)
#define QUEUE_RUNNING	0
#define QUEUE_STOPPED	1

/* Value to send if no TX value is supplied */
#define SPI_IDLE_TXVAL 0x0000

struct driver_data {
	/* Driver model hookup */
	struct platform_device *pdev;

	/* SPI framework hookup */
	struct spi_master *master;

	/* Regs base of SPI controller */
	void __iomem *regs_base;

	/* Pin request list */
	u16 *pin_req;

	/* BFIN hookup */
	struct bfin5xx_spi_master *master_info;

	/* Driver message queue */
	struct workqueue_struct *workqueue;
	struct work_struct pump_messages;
	spinlock_t lock;
	struct list_head queue;
	int busy;
	int run;

	/* Message Transfer pump */
	struct tasklet_struct pump_transfers;

	/* Current message transfer state info */
	struct spi_message *cur_msg;
	struct spi_transfer *cur_transfer;
	struct chip_data *cur_chip;
	size_t len_in_bytes;
	size_t len;
	void *tx;
	void *tx_end;
	void *rx;
	void *rx_end;

	/* DMA stuffs */
	int dma_channel;
	int dma_mapped;
	int dma_requested;
	dma_addr_t rx_dma;
	dma_addr_t tx_dma;

	size_t rx_map_len;
	size_t tx_map_len;
	u8 n_bytes;
	int cs_change;
	void (*write) (struct driver_data *);
	void (*read) (struct driver_data *);
	void (*duplex) (struct driver_data *);
};

struct chip_data {
	u16 ctl_reg;
	u16 baud;
	u16 flag;

	u8 chip_select_num;
	u8 n_bytes;
	u8 width;		/* 0 or 1 */
	u8 enable_dma;
	u8 bits_per_word;	/* 8 or 16 */
	u8 cs_change_per_word;
	u16 cs_chg_udelay;	/* Some devices require > 255usec delay */
	u32 cs_gpio;
	u16 idle_tx_val;
	void (*write) (struct driver_data *);
	void (*read) (struct driver_data *);
	void (*duplex) (struct driver_data *);
};

#define DEFINE_SPI_REG(reg, off) \
static inline u16 read_##reg(struct driver_data *drv_data) \
	{ return bfin_read16(drv_data->regs_base + off); } \
static inline void write_##reg(struct driver_data *drv_data, u16 v) \
	{ bfin_write16(drv_data->regs_base + off, v); }

DEFINE_SPI_REG(CTRL, 0x00)
DEFINE_SPI_REG(FLAG, 0x04)
DEFINE_SPI_REG(STAT, 0x08)
DEFINE_SPI_REG(TDBR, 0x0C)
DEFINE_SPI_REG(RDBR, 0x10)
DEFINE_SPI_REG(BAUD, 0x14)
DEFINE_SPI_REG(SHAW, 0x18)

static void bfin_spi_enable(struct driver_data *drv_data)
{
	u16 cr;

	cr = read_CTRL(drv_data);
	write_CTRL(drv_data, (cr | BIT_CTL_ENABLE));
}

static void bfin_spi_disable(struct driver_data *drv_data)
{
	u16 cr;

	cr = read_CTRL(drv_data);
	write_CTRL(drv_data, (cr & (~BIT_CTL_ENABLE)));
}

/* Caculate the SPI_BAUD register value based on input HZ */
static u16 hz_to_spi_baud(u32 speed_hz)
{
	u_long sclk = get_sclk();
	u16 spi_baud = (sclk / (2 * speed_hz));

	if ((sclk % (2 * speed_hz)) > 0)
		spi_baud++;

	if (spi_baud < MIN_SPI_BAUD_VAL)
		spi_baud = MIN_SPI_BAUD_VAL;

	return spi_baud;
}

static int bfin_spi_flush(struct driver_data *drv_data)
{
	unsigned long limit = loops_per_jiffy << 1;

	/* wait for stop and clear stat */
	while (!(read_STAT(drv_data) & BIT_STAT_SPIF) && --limit)
		cpu_relax();

	write_STAT(drv_data, BIT_STAT_CLR);

	return limit;
}

/* Chip select operation functions for cs_change flag */
static void bfin_spi_cs_active(struct driver_data *drv_data, struct chip_data *chip)
{
	if (likely(chip->chip_select_num)) {
		u16 flag = read_FLAG(drv_data);

		flag |= chip->flag;
		flag &= ~(chip->flag << 8);

		write_FLAG(drv_data, flag);
	} else {
		gpio_set_value(chip->cs_gpio, 0);
	}
}

static void bfin_spi_cs_deactive(struct driver_data *drv_data, struct chip_data *chip)
{
	if (likely(chip->chip_select_num)) {
		u16 flag = read_FLAG(drv_data);

		flag &= ~chip->flag;
		flag |= (chip->flag << 8);

		write_FLAG(drv_data, flag);
	} else {
		gpio_set_value(chip->cs_gpio, 1);
	}

	/* Move delay here for consistency */
	if (chip->cs_chg_udelay)
		udelay(chip->cs_chg_udelay);
}

/* stop controller and re-config current chip*/
static void bfin_spi_restore_state(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;

	/* Clear status and disable clock */
	write_STAT(drv_data, BIT_STAT_CLR);
	bfin_spi_disable(drv_data);
	dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");

	/* Load the registers */
	write_CTRL(drv_data, chip->ctl_reg);
	write_BAUD(drv_data, chip->baud);

	bfin_spi_enable(drv_data);
	bfin_spi_cs_active(drv_data, chip);
}

/* used to kick off transfer in rx mode and read unwanted RX data */
static inline void bfin_spi_dummy_read(struct driver_data *drv_data)
{
	(void) read_RDBR(drv_data);
}

static void bfin_spi_null_writer(struct driver_data *drv_data)
{
	u8 n_bytes = drv_data->n_bytes;
	u16 tx_val = drv_data->cur_chip->idle_tx_val;

	/* clear RXS (we check for RXS inside the loop) */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->tx < drv_data->tx_end) {
		write_TDBR(drv_data, tx_val);
		drv_data->tx += n_bytes;
		/* wait until transfer finished.
		   checking SPIF or TXS may not guarantee transfer completion */
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		/* discard RX data and clear RXS */
		bfin_spi_dummy_read(drv_data);
	}
}

static void bfin_spi_null_reader(struct driver_data *drv_data)
{
	u8 n_bytes = drv_data->n_bytes;
	u16 tx_val = drv_data->cur_chip->idle_tx_val;

	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		write_TDBR(drv_data, tx_val);
		drv_data->rx += n_bytes;
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		bfin_spi_dummy_read(drv_data);
	}
}

static void bfin_spi_u8_writer(struct driver_data *drv_data)
{
	/* clear RXS (we check for RXS inside the loop) */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->tx < drv_data->tx_end) {
		write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
		/* wait until transfer finished.
		   checking SPIF or TXS may not guarantee transfer completion */
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		/* discard RX data and clear RXS */
		bfin_spi_dummy_read(drv_data);
	}
}

static void bfin_spi_u8_cs_chg_writer(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;

	/* clear RXS (we check for RXS inside the loop) */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->tx < drv_data->tx_end) {
		bfin_spi_cs_active(drv_data, chip);
		write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
		/* make sure transfer finished before deactiving CS */
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		bfin_spi_dummy_read(drv_data);
		bfin_spi_cs_deactive(drv_data, chip);
	}
}

static void bfin_spi_u8_reader(struct driver_data *drv_data)
{
	u16 tx_val = drv_data->cur_chip->idle_tx_val;

	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		write_TDBR(drv_data, tx_val);
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
	}
}

static void bfin_spi_u8_cs_chg_reader(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;
	u16 tx_val = chip->idle_tx_val;

	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		bfin_spi_cs_active(drv_data, chip);
		write_TDBR(drv_data, tx_val);
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
		bfin_spi_cs_deactive(drv_data, chip);
	}
}

static void bfin_spi_u8_duplex(struct driver_data *drv_data)
{
	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
	}
}

static void bfin_spi_u8_cs_chg_duplex(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;

	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		bfin_spi_cs_active(drv_data, chip);
		write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
		bfin_spi_cs_deactive(drv_data, chip);
	}
}

static void bfin_spi_u16_writer(struct driver_data *drv_data)
{
	/* clear RXS (we check for RXS inside the loop) */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->tx < drv_data->tx_end) {
		write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
		drv_data->tx += 2;
		/* wait until transfer finished.
		   checking SPIF or TXS may not guarantee transfer completion */
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		/* discard RX data and clear RXS */
		bfin_spi_dummy_read(drv_data);
	}
}

static void bfin_spi_u16_cs_chg_writer(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;

	/* clear RXS (we check for RXS inside the loop) */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->tx < drv_data->tx_end) {
		bfin_spi_cs_active(drv_data, chip);
		write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
		drv_data->tx += 2;
		/* make sure transfer finished before deactiving CS */
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		bfin_spi_dummy_read(drv_data);
		bfin_spi_cs_deactive(drv_data, chip);
	}
}

static void bfin_spi_u16_reader(struct driver_data *drv_data)
{
	u16 tx_val = drv_data->cur_chip->idle_tx_val;

	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		write_TDBR(drv_data, tx_val);
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
		drv_data->rx += 2;
	}
}

static void bfin_spi_u16_cs_chg_reader(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;
	u16 tx_val = chip->idle_tx_val;

	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		bfin_spi_cs_active(drv_data, chip);
		write_TDBR(drv_data, tx_val);
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
		drv_data->rx += 2;
		bfin_spi_cs_deactive(drv_data, chip);
	}
}

static void bfin_spi_u16_duplex(struct driver_data *drv_data)
{
	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
		drv_data->tx += 2;
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
		drv_data->rx += 2;
	}
}

static void bfin_spi_u16_cs_chg_duplex(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;

	/* discard old RX data and clear RXS */
	bfin_spi_dummy_read(drv_data);

	while (drv_data->rx < drv_data->rx_end) {
		bfin_spi_cs_active(drv_data, chip);
		write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
		drv_data->tx += 2;
		while (!(read_STAT(drv_data) & BIT_STAT_RXS))
			cpu_relax();
		*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
		drv_data->rx += 2;
		bfin_spi_cs_deactive(drv_data, chip);
	}
}

/* test if ther is more transfer to be done */
static void *bfin_spi_next_transfer(struct driver_data *drv_data)
{
	struct spi_message *msg = drv_data->cur_msg;
	struct spi_transfer *trans = drv_data->cur_transfer;

	/* Move to next transfer */
	if (trans->transfer_list.next != &msg->transfers) {
		drv_data->cur_transfer =
		    list_entry(trans->transfer_list.next,
			       struct spi_transfer, transfer_list);
		return RUNNING_STATE;
	} else
		return DONE_STATE;
}

/*
 * caller already set message->status;
 * dma and pio irqs are blocked give finished message back
 */
static void bfin_spi_giveback(struct driver_data *drv_data)
{
	struct chip_data *chip = drv_data->cur_chip;
	struct spi_transfer *last_transfer;
	unsigned long flags;
	struct spi_message *msg;

	spin_lock_irqsave(&drv_data->lock, flags);
	msg = drv_data->cur_msg;
	drv_data->cur_msg = NULL;
	drv_data->cur_transfer = NULL;
	drv_data->cur_chip = NULL;
	queue_work(drv_data->workqueue, &drv_data->pump_messages);
	spin_unlock_irqrestore(&drv_data->lock, flags);

	last_transfer = list_entry(msg->transfers.prev,
				   struct spi_transfer, transfer_list);

	msg->state = NULL;

	if (!drv_data->cs_change)
		bfin_spi_cs_deactive(drv_data, chip);

	/* Not stop spi in autobuffer mode */
	if (drv_data->tx_dma != 0xFFFF)
		bfin_spi_disable(drv_data);

	if (msg->complete)
		msg->complete(msg->context);
}

static irqreturn_t bfin_spi_dma_irq_handler(int irq, void *dev_id)
{
	struct driver_data *drv_data = dev_id;
	struct chip_data *chip = drv_data->cur_chip;
	struct spi_message *msg = drv_data->cur_msg;
	unsigned long timeout;
	unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel);
	u16 spistat = read_STAT(drv_data);

	dev_dbg(&drv_data->pdev->dev,
		"in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
		dmastat, spistat);

	clear_dma_irqstat(drv_data->dma_channel);

	/* Wait for DMA to complete */
	while (get_dma_curr_irqstat(drv_data->dma_channel) & DMA_RUN)
		cpu_relax();

	/*
	 * wait for the last transaction shifted out.  HRM states:
	 * at this point there may still be data in the SPI DMA FIFO waiting
	 * to be transmitted ... software needs to poll TXS in the SPI_STAT
	 * register until it goes low for 2 successive reads
	 */
	if (drv_data->tx != NULL) {
		while ((read_STAT(drv_data) & TXS) ||
		       (read_STAT(drv_data) & TXS))
			cpu_relax();
	}

	dev_dbg(&drv_data->pdev->dev,
		"in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
		dmastat, read_STAT(drv_data));

	timeout = jiffies + HZ;
	while (!(read_STAT(drv_data) & SPIF))
		if (!time_before(jiffies, timeout)) {
			dev_warn(&drv_data->pdev->dev, "timeout waiting for SPIF");
			break;
		} else
			cpu_relax();

	if ((dmastat & DMA_ERR) && (spistat & RBSY)) {
		msg->state = ERROR_STATE;
		dev_err(&drv_data->pdev->dev, "dma receive: fifo/buffer overflow\n");
	} else {
		msg->actual_length += drv_data->len_in_bytes;

		if (drv_data->cs_change)
			bfin_spi_cs_deactive(drv_data, chip);

		/* Move to next transfer */
		msg->state = bfin_spi_next_transfer(drv_data);
	}

	/* Schedule transfer tasklet */
	tasklet_schedule(&drv_data->pump_transfers);

	/* free the irq handler before next transfer */
	dev_dbg(&drv_data->pdev->dev,
		"disable dma channel irq%d\n",
		drv_data->dma_channel);
	dma_disable_irq(drv_data->dma_channel);

	return IRQ_HANDLED;
}

static void bfin_spi_pump_transfers(unsigned long data)
{
	struct driver_data *drv_data = (struct driver_data *)data;
	struct spi_message *message = NULL;
	struct spi_transfer *transfer = NULL;
	struct spi_transfer *previous = NULL;
	struct chip_data *chip = NULL;
	u8 width;
	u16 cr, dma_width, dma_config;
	u32 tranf_success = 1;
	u8 full_duplex = 0;

	/* Get current state information */
	message = drv_data->cur_msg;
	transfer = drv_data->cur_transfer;
	chip = drv_data->cur_chip;

	/*
	 * if msg is error or done, report it back using complete() callback
	 */

	 /* Handle for abort */
	if (message->state == ERROR_STATE) {
		dev_dbg(&drv_data->pdev->dev, "transfer: we've hit an error\n");
		message->status = -EIO;
		bfin_spi_giveback(drv_data);
		return;
	}

	/* Handle end of message */
	if (message->state == DONE_STATE) {
		dev_dbg(&drv_data->pdev->dev, "transfer: all done!\n");
		message->status = 0;
		bfin_spi_giveback(drv_data);
		return;
	}

	/* Delay if requested at end of transfer */
	if (message->state == RUNNING_STATE) {
		dev_dbg(&drv_data->pdev->dev, "transfer: still running ...\n");
		previous = list_entry(transfer->transfer_list.prev,
				      struct spi_transfer, transfer_list);
		if (previous->delay_usecs)
			udelay(previous->delay_usecs);
	}

	/* Setup the transfer state based on the type of transfer */
	if (bfin_spi_flush(drv_data) == 0) {
		dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
		message->status = -EIO;
		bfin_spi_giveback(drv_data);
		return;
	}

	if (transfer->len == 0) {
		/* Move to next transfer of this msg */
		message->state = bfin_spi_next_transfer(drv_data);
		/* Schedule next transfer tasklet */
		tasklet_schedule(&drv_data->pump_transfers);
	}

	if (transfer->tx_buf != NULL) {
		drv_data->tx = (void *)transfer->tx_buf;
		drv_data->tx_end = drv_data->tx + transfer->len;
		dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
			transfer->tx_buf, drv_data->tx_end);
	} else {
		drv_data->tx = NULL;
	}

	if (transfer->rx_buf != NULL) {
		full_duplex = transfer->tx_buf != NULL;
		drv_data->rx = transfer->rx_buf;
		drv_data->rx_end = drv_data->rx + transfer->len;
		dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
			transfer->rx_buf, drv_data->rx_end);
	} else {
		drv_data->rx = NULL;
	}

	drv_data->rx_dma = transfer->rx_dma;
	drv_data->tx_dma = transfer->tx_dma;
	drv_data->len_in_bytes = transfer->len;
	drv_data->cs_change = transfer->cs_change;

	/* Bits per word setup */
	switch (transfer->bits_per_word) {
	case 8:
		drv_data->n_bytes = 1;
		width = CFG_SPI_WORDSIZE8;
		drv_data->read = chip->cs_change_per_word ?
			bfin_spi_u8_cs_chg_reader : bfin_spi_u8_reader;
		drv_data->write = chip->cs_change_per_word ?
			bfin_spi_u8_cs_chg_writer : bfin_spi_u8_writer;
		drv_data->duplex = chip->cs_change_per_word ?
			bfin_spi_u8_cs_chg_duplex : bfin_spi_u8_duplex;
		break;

	case 16:
		drv_data->n_bytes = 2;
		width = CFG_SPI_WORDSIZE16;
		drv_data->read = chip->cs_change_per_word ?
			bfin_spi_u16_cs_chg_reader : bfin_spi_u16_reader;
		drv_data->write = chip->cs_change_per_word ?
			bfin_spi_u16_cs_chg_writer : bfin_spi_u16_writer;
		drv_data->duplex = chip->cs_change_per_word ?
			bfin_spi_u16_cs_chg_duplex : bfin_spi_u16_duplex;
		break;

	default:
		/* No change, the same as default setting */
		drv_data->n_bytes = chip->n_bytes;
		width = chip->width;
		drv_data->write = drv_data->tx ? chip->write : bfin_spi_null_writer;
		drv_data->read = drv_data->rx ? chip->read : bfin_spi_null_reader;
		drv_data->duplex = chip->duplex ? chip->duplex : bfin_spi_null_writer;
		break;
	}
	cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
	cr |= (width << 8);
	write_CTRL(drv_data, cr);

	if (width == CFG_SPI_WORDSIZE16) {
		drv_data->len = (transfer->len) >> 1;
	} else {
		drv_data->len = transfer->len;
	}
	dev_dbg(&drv_data->pdev->dev,
		"transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
		drv_data->write, chip->write, bfin_spi_null_writer);

	/* speed and width has been set on per message */
	message->state = RUNNING_STATE;
	dma_config = 0;

	/* Speed setup (surely valid because already checked) */
	if (transfer->speed_hz)
		write_BAUD(drv_data, hz_to_spi_baud(transfer->speed_hz));
	else
		write_BAUD(drv_data, chip->baud);

	write_STAT(drv_data, BIT_STAT_CLR);
	cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
	if (drv_data->cs_change)
		bfin_spi_cs_active(drv_data, chip);

	dev_dbg(&drv_data->pdev->dev,
		"now pumping a transfer: width is %d, len is %d\n",
		width, transfer->len);

	/*
	 * Try to map dma buffer and do a dma transfer.  If successful use,
	 * different way to r/w according to the enable_dma settings and if
	 * we are not doing a full duplex transfer (since the hardware does
	 * not support full duplex DMA transfers).
	 */
	if (!full_duplex && drv_data->cur_chip->enable_dma
				&& drv_data->len > 6) {

		unsigned long dma_start_addr, flags;

		disable_dma(drv_data->dma_channel);
		clear_dma_irqstat(drv_data->dma_channel);

		/* config dma channel */
		dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
		set_dma_x_count(drv_data->dma_channel, drv_data->len);
		if (width == CFG_SPI_WORDSIZE16) {
			set_dma_x_modify(drv_data->dma_channel, 2);
			dma_width = WDSIZE_16;
		} else {
			set_dma_x_modify(drv_data->dma_channel, 1);
			dma_width = WDSIZE_8;
		}

		/* poll for SPI completion before start */
		while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
			cpu_relax();

		/* dirty hack for autobuffer DMA mode */
		if (drv_data->tx_dma == 0xFFFF) {
			dev_dbg(&drv_data->pdev->dev,
				"doing autobuffer DMA out.\n");

			/* no irq in autobuffer mode */
			dma_config =
			    (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
			set_dma_config(drv_data->dma_channel, dma_config);
			set_dma_start_addr(drv_data->dma_channel,
					(unsigned long)drv_data->tx);
			enable_dma(drv_data->dma_channel);

			/* start SPI transfer */
			write_CTRL(drv_data, cr | BIT_CTL_TIMOD_DMA_TX);

			/* just return here, there can only be one transfer
			 * in this mode
			 */
			message->status = 0;
			bfin_spi_giveback(drv_data);
			return;
		}

		/* In dma mode, rx or tx must be NULL in one transfer */
		dma_config = (RESTART | dma_width | DI_EN);
		if (drv_data->rx != NULL) {
			/* set transfer mode, and enable SPI */
			dev_dbg(&drv_data->pdev->dev, "doing DMA in to %p (size %zx)\n",
				drv_data->rx, drv_data->len_in_bytes);

			/* invalidate caches, if needed */
			if (bfin_addr_dcacheable((unsigned long) drv_data->rx))
				invalidate_dcache_range((unsigned long) drv_data->rx,
							(unsigned long) (drv_data->rx +
							drv_data->len_in_bytes));

			dma_config |= WNR;
			dma_start_addr = (unsigned long)drv_data->rx;
			cr |= BIT_CTL_TIMOD_DMA_RX | BIT_CTL_SENDOPT;

		} else if (drv_data->tx != NULL) {
			dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");

			/* flush caches, if needed */
			if (bfin_addr_dcacheable((unsigned long) drv_data->tx))
				flush_dcache_range((unsigned long) drv_data->tx,
						(unsigned long) (drv_data->tx +
						drv_data->len_in_bytes));

			dma_start_addr = (unsigned long)drv_data->tx;
			cr |= BIT_CTL_TIMOD_DMA_TX;

		} else
			BUG();

		/* oh man, here there be monsters ... and i dont mean the
		 * fluffy cute ones from pixar, i mean the kind that'll eat
		 * your data, kick your dog, and love it all.  do *not* try
		 * and change these lines unless you (1) heavily test DMA
		 * with SPI flashes on a loaded system (e.g. ping floods),
		 * (2) know just how broken the DMA engine interaction with
		 * the SPI peripheral is, and (3) have someone else to blame
		 * when you screw it all up anyways.
		 */
		set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
		set_dma_config(drv_data->dma_channel, dma_config);
		local_irq_save(flags);
		SSYNC();
		write_CTRL(drv_data, cr);
		enable_dma(drv_data->dma_channel);
		dma_enable_irq(drv_data->dma_channel);
		local_irq_restore(flags);

	} else {
		/* IO mode write then read */
		dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");

		/* we always use SPI_WRITE mode. SPI_READ mode
		   seems to have problems with setting up the
		   output value in TDBR prior to the transfer. */
		write_CTRL(drv_data, (cr | CFG_SPI_WRITE));

		if (full_duplex) {
			/* full duplex mode */
			BUG_ON((drv_data->tx_end - drv_data->tx) !=
			       (drv_data->rx_end - drv_data->rx));
			dev_dbg(&drv_data->pdev->dev,
				"IO duplex: cr is 0x%x\n", cr);

			drv_data->duplex(drv_data);

			if (drv_data->tx != drv_data->tx_end)
				tranf_success = 0;
		} else if (drv_data->tx != NULL) {
			/* write only half duplex */
			dev_dbg(&drv_data->pdev->dev,
				"IO write: cr is 0x%x\n", cr);

			drv_data->write(drv_data);

			if (drv_data->tx != drv_data->tx_end)
				tranf_success = 0;
		} else if (drv_data->rx != NULL) {
			/* read only half duplex */
			dev_dbg(&drv_data->pdev->dev,
				"IO read: cr is 0x%x\n", cr);

			drv_data->read(drv_data);
			if (drv_data->rx != drv_data->rx_end)
				tranf_success = 0;
		}

		if (!tranf_success) {
			dev_dbg(&drv_data->pdev->dev,
				"IO write error!\n");
			message->state = ERROR_STATE;
		} else {
			/* Update total byte transfered */
			message->actual_length += drv_data->len_in_bytes;
			/* Move to next transfer of this msg */
			message->state = bfin_spi_next_transfer(drv_data);
			if (drv_data->cs_change)
				bfin_spi_cs_deactive(drv_data, chip);
		}
		/* Schedule next transfer tasklet */
		tasklet_schedule(&drv_data->pump_transfers);
	}
}

/* pop a msg from queue and kick off real transfer */
static void bfin_spi_pump_messages(struct work_struct *work)
{
	struct driver_data *drv_data;
	unsigned long flags;

	drv_data = container_of(work, struct driver_data, pump_messages);

	/* Lock queue and check for queue work */
	spin_lock_irqsave(&drv_data->lock, flags);
	if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
		/* pumper kicked off but no work to do */
		drv_data->busy = 0;
		spin_unlock_irqrestore(&drv_data->lock, flags);
		return;
	}

	/* Make sure we are not already running a message */
	if (drv_data->cur_msg) {
		spin_unlock_irqrestore(&drv_data->lock, flags);
		return;
	}

	/* Extract head of queue */
	drv_data->cur_msg = list_entry(drv_data->queue.next,
				       struct spi_message, queue);

	/* Setup the SSP using the per chip configuration */
	drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
	bfin_spi_restore_state(drv_data);

	list_del_init(&drv_data->cur_msg->queue);

	/* Initial message state */
	drv_data->cur_msg->state = START_STATE;
	drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
					    struct spi_transfer, transfer_list);

	dev_dbg(&drv_data->pdev->dev, "got a message to pump, "
		"state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
		drv_data->cur_chip->baud, drv_data->cur_chip->flag,
		drv_data->cur_chip->ctl_reg);

	dev_dbg(&drv_data->pdev->dev,
		"the first transfer len is %d\n",
		drv_data->cur_transfer->len);

	/* Mark as busy and launch transfers */
	tasklet_schedule(&drv_data->pump_transfers);

	drv_data->busy = 1;
	spin_unlock_irqrestore(&drv_data->lock, flags);
}

/*
 * got a msg to transfer, queue it in drv_data->queue.
 * And kick off message pumper
 */
static int bfin_spi_transfer(struct spi_device *spi, struct spi_message *msg)
{
	struct driver_data *drv_data = spi_master_get_devdata(spi->master);
	unsigned long flags;

	spin_lock_irqsave(&drv_data->lock, flags);

	if (drv_data->run == QUEUE_STOPPED) {
		spin_unlock_irqrestore(&drv_data->lock, flags);
		return -ESHUTDOWN;
	}

	msg->actual_length = 0;
	msg->status = -EINPROGRESS;
	msg->state = START_STATE;

	dev_dbg(&spi->dev, "adding an msg in transfer() \n");
	list_add_tail(&msg->queue, &drv_data->queue);

	if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
		queue_work(drv_data->workqueue, &drv_data->pump_messages);

	spin_unlock_irqrestore(&drv_data->lock, flags);

	return 0;
}

#define MAX_SPI_SSEL	7

static u16 ssel[][MAX_SPI_SSEL] = {
	{P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
	P_SPI0_SSEL4, P_SPI0_SSEL5,
	P_SPI0_SSEL6, P_SPI0_SSEL7},

	{P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
	P_SPI1_SSEL4, P_SPI1_SSEL5,
	P_SPI1_SSEL6, P_SPI1_SSEL7},

	{P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
	P_SPI2_SSEL4, P_SPI2_SSEL5,
	P_SPI2_SSEL6, P_SPI2_SSEL7},
};

/* first setup for new devices */
static int bfin_spi_setup(struct spi_device *spi)
{
	struct bfin5xx_spi_chip *chip_info = NULL;
	struct chip_data *chip;
	struct driver_data *drv_data = spi_master_get_devdata(spi->master);
	int ret;

	/* Abort device setup if requested features are not supported */
	if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
		dev_err(&spi->dev, "requested mode not fully supported\n");
		return -EINVAL;
	}

	if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
		return -EINVAL;

	/* Only alloc (or use chip_info) on first setup */
	chip = spi_get_ctldata(spi);
	if (chip == NULL) {
		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
		if (!chip)
			return -ENOMEM;

		chip->enable_dma = 0;
		chip_info = spi->controller_data;
	}

	/* chip_info isn't always needed */
	if (chip_info) {
		/* Make sure people stop trying to set fields via ctl_reg
		 * when they should actually be using common SPI framework.
		 * Currently we let through: WOM EMISO PSSE GM SZ TIMOD.
		 * Not sure if a user actually needs/uses any of these,
		 * but let's assume (for now) they do.
		 */
		if (chip_info->ctl_reg & (SPE|MSTR|CPOL|CPHA|LSBF|SIZE)) {
			dev_err(&spi->dev, "do not set bits in ctl_reg "
				"that the SPI framework manages\n");
			return -EINVAL;
		}

		chip->enable_dma = chip_info->enable_dma != 0
		    && drv_data->master_info->enable_dma;
		chip->ctl_reg = chip_info->ctl_reg;
		chip->bits_per_word = chip_info->bits_per_word;
		chip->cs_change_per_word = chip_info->cs_change_per_word;
		chip->cs_chg_udelay = chip_info->cs_chg_udelay;
		chip->cs_gpio = chip_info->cs_gpio;
		chip->idle_tx_val = chip_info->idle_tx_val;
	}

	/* translate common spi framework into our register */
	if (spi->mode & SPI_CPOL)
		chip->ctl_reg |= CPOL;
	if (spi->mode & SPI_CPHA)
		chip->ctl_reg |= CPHA;
	if (spi->mode & SPI_LSB_FIRST)
		chip->ctl_reg |= LSBF;
	/* we dont support running in slave mode (yet?) */
	chip->ctl_reg |= MSTR;

	/*
	 * if any one SPI chip is registered and wants DMA, request the
	 * DMA channel for it
	 */
	if (chip->enable_dma && !drv_data->dma_requested) {
		/* register dma irq handler */
		if (request_dma(drv_data->dma_channel, "BFIN_SPI_DMA") < 0) {
			dev_dbg(&spi->dev,
				"Unable to request BlackFin SPI DMA channel\n");
			return -ENODEV;
		}
		if (set_dma_callback(drv_data->dma_channel,
		    bfin_spi_dma_irq_handler, drv_data) < 0) {
			dev_dbg(&spi->dev, "Unable to set dma callback\n");
			return -EPERM;
		}
		dma_disable_irq(drv_data->dma_channel);
		drv_data->dma_requested = 1;
	}

	/*
	 * Notice: for blackfin, the speed_hz is the value of register
	 * SPI_BAUD, not the real baudrate
	 */
	chip->baud = hz_to_spi_baud(spi->max_speed_hz);
	chip->flag = 1 << (spi->chip_select);
	chip->chip_select_num = spi->chip_select;

	if (chip->chip_select_num == 0) {
		ret = gpio_request(chip->cs_gpio, spi->modalias);
		if (ret) {
			if (drv_data->dma_requested)
				free_dma(drv_data->dma_channel);
			return ret;
		}
		gpio_direction_output(chip->cs_gpio, 1);
	}

	switch (chip->bits_per_word) {
	case 8:
		chip->n_bytes = 1;
		chip->width = CFG_SPI_WORDSIZE8;
		chip->read = chip->cs_change_per_word ?
			bfin_spi_u8_cs_chg_reader : bfin_spi_u8_reader;
		chip->write = chip->cs_change_per_word ?
			bfin_spi_u8_cs_chg_writer : bfin_spi_u8_writer;
		chip->duplex = chip->cs_change_per_word ?
			bfin_spi_u8_cs_chg_duplex : bfin_spi_u8_duplex;
		break;

	case 16:
		chip->n_bytes = 2;
		chip->width = CFG_SPI_WORDSIZE16;
		chip->read = chip->cs_change_per_word ?
			bfin_spi_u16_cs_chg_reader : bfin_spi_u16_reader;
		chip->write = chip->cs_change_per_word ?
			bfin_spi_u16_cs_chg_writer : bfin_spi_u16_writer;
		chip->duplex = chip->cs_change_per_word ?
			bfin_spi_u16_cs_chg_duplex : bfin_spi_u16_duplex;
		break;

	default:
		dev_err(&spi->dev, "%d bits_per_word is not supported\n",
				chip->bits_per_word);
		if (chip_info)
			kfree(chip);
		return -ENODEV;
	}

	dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
			spi->modalias, chip->width, chip->enable_dma);
	dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
			chip->ctl_reg, chip->flag);

	spi_set_ctldata(spi, chip);

	dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
	if ((chip->chip_select_num > 0)
		&& (chip->chip_select_num <= spi->master->num_chipselect))
		peripheral_request(ssel[spi->master->bus_num]
			[chip->chip_select_num-1], spi->modalias);

	bfin_spi_cs_deactive(drv_data, chip);

	return 0;
}

/*
 * callback for spi framework.
 * clean driver specific data
 */
static void bfin_spi_cleanup(struct spi_device *spi)
{
	struct chip_data *chip = spi_get_ctldata(spi);

	if (!chip)
		return;

	if ((chip->chip_select_num > 0)
		&& (chip->chip_select_num <= spi->master->num_chipselect))
		peripheral_free(ssel[spi->master->bus_num]
					[chip->chip_select_num-1]);

	if (chip->chip_select_num == 0)
		gpio_free(chip->cs_gpio);

	kfree(chip);
}

static inline int bfin_spi_init_queue(struct driver_data *drv_data)
{
	INIT_LIST_HEAD(&drv_data->queue);
	spin_lock_init(&drv_data->lock);

	drv_data->run = QUEUE_STOPPED;
	drv_data->busy = 0;

	/* init transfer tasklet */
	tasklet_init(&drv_data->pump_transfers,
		     bfin_spi_pump_transfers, (unsigned long)drv_data);

	/* init messages workqueue */
	INIT_WORK(&drv_data->pump_messages, bfin_spi_pump_messages);
	drv_data->workqueue = create_singlethread_workqueue(
				dev_name(drv_data->master->dev.parent));
	if (drv_data->workqueue == NULL)
		return -EBUSY;

	return 0;
}

static inline int bfin_spi_start_queue(struct driver_data *drv_data)
{
	unsigned long flags;

	spin_lock_irqsave(&drv_data->lock, flags);

	if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
		spin_unlock_irqrestore(&drv_data->lock, flags);
		return -EBUSY;
	}

	drv_data->run = QUEUE_RUNNING;
	drv_data->cur_msg = NULL;
	drv_data->cur_transfer = NULL;
	drv_data->cur_chip = NULL;
	spin_unlock_irqrestore(&drv_data->lock, flags);

	queue_work(drv_data->workqueue, &drv_data->pump_messages);

	return 0;
}

static inline int bfin_spi_stop_queue(struct driver_data *drv_data)
{
	unsigned long flags;
	unsigned limit = 500;
	int status = 0;

	spin_lock_irqsave(&drv_data->lock, flags);

	/*
	 * This is a bit lame, but is optimized for the common execution path.
	 * A wait_queue on the drv_data->busy could be used, but then the common
	 * execution path (pump_messages) would be required to call wake_up or
	 * friends on every SPI message. Do this instead
	 */
	drv_data->run = QUEUE_STOPPED;
	while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
		spin_unlock_irqrestore(&drv_data->lock, flags);
		msleep(10);
		spin_lock_irqsave(&drv_data->lock, flags);
	}

	if (!list_empty(&drv_data->queue) || drv_data->busy)
		status = -EBUSY;

	spin_unlock_irqrestore(&drv_data->lock, flags);

	return status;
}

static inline int bfin_spi_destroy_queue(struct driver_data *drv_data)
{
	int status;

	status = bfin_spi_stop_queue(drv_data);
	if (status != 0)
		return status;

	destroy_workqueue(drv_data->workqueue);

	return 0;
}

static int __init bfin_spi_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct bfin5xx_spi_master *platform_info;
	struct spi_master *master;
	struct driver_data *drv_data = 0;
	struct resource *res;
	int status = 0;

	platform_info = dev->platform_data;

	/* Allocate master with space for drv_data */
	master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
	if (!master) {
		dev_err(&pdev->dev, "can not alloc spi_master\n");
		return -ENOMEM;
	}

	drv_data = spi_master_get_devdata(master);
	drv_data->master = master;
	drv_data->master_info = platform_info;
	drv_data->pdev = pdev;
	drv_data->pin_req = platform_info->pin_req;

	master->bus_num = pdev->id;
	master->num_chipselect = platform_info->num_chipselect;
	master->cleanup = bfin_spi_cleanup;
	master->setup = bfin_spi_setup;
	master->transfer = bfin_spi_transfer;

	/* Find and map our resources */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res == NULL) {
		dev_err(dev, "Cannot get IORESOURCE_MEM\n");
		status = -ENOENT;
		goto out_error_get_res;
	}

	drv_data->regs_base = ioremap(res->start, (res->end - res->start + 1));
	if (drv_data->regs_base == NULL) {
		dev_err(dev, "Cannot map IO\n");
		status = -ENXIO;
		goto out_error_ioremap;
	}

	drv_data->dma_channel = platform_get_irq(pdev, 0);
	if (drv_data->dma_channel < 0) {
		dev_err(dev, "No DMA channel specified\n");
		status = -ENOENT;
		goto out_error_no_dma_ch;
	}

	/* Initial and start queue */
	status = bfin_spi_init_queue(drv_data);
	if (status != 0) {
		dev_err(dev, "problem initializing queue\n");
		goto out_error_queue_alloc;
	}

	status = bfin_spi_start_queue(drv_data);
	if (status != 0) {
		dev_err(dev, "problem starting queue\n");
		goto out_error_queue_alloc;
	}

	status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
	if (status != 0) {
		dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
		goto out_error_queue_alloc;
	}

	/* Register with the SPI framework */
	platform_set_drvdata(pdev, drv_data);
	status = spi_register_master(master);
	if (status != 0) {
		dev_err(dev, "problem registering spi master\n");
		goto out_error_queue_alloc;
	}

	dev_info(dev, "%s, Version %s, regs_base@%p, dma channel@%d\n",
		DRV_DESC, DRV_VERSION, drv_data->regs_base,
		drv_data->dma_channel);
	return status;

out_error_queue_alloc:
	bfin_spi_destroy_queue(drv_data);
out_error_no_dma_ch:
	iounmap((void *) drv_data->regs_base);
out_error_ioremap:
out_error_get_res:
	spi_master_put(master);

	return status;
}

/* stop hardware and remove the driver */
static int __devexit bfin_spi_remove(struct platform_device *pdev)
{
	struct driver_data *drv_data = platform_get_drvdata(pdev);
	int status = 0;

	if (!drv_data)
		return 0;

	/* Remove the queue */
	status = bfin_spi_destroy_queue(drv_data);
	if (status != 0)
		return status;

	/* Disable the SSP at the peripheral and SOC level */
	bfin_spi_disable(drv_data);

	/* Release DMA */
	if (drv_data->master_info->enable_dma) {
		if (dma_channel_active(drv_data->dma_channel))
			free_dma(drv_data->dma_channel);
	}

	/* Disconnect from the SPI framework */
	spi_unregister_master(drv_data->master);

	peripheral_free_list(drv_data->pin_req);

	/* Prevent double remove */
	platform_set_drvdata(pdev, NULL);

	return 0;
}

#ifdef CONFIG_PM
static int bfin_spi_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct driver_data *drv_data = platform_get_drvdata(pdev);
	int status = 0;

	status = bfin_spi_stop_queue(drv_data);
	if (status != 0)
		return status;

	/* stop hardware */
	bfin_spi_disable(drv_data);

	return 0;
}

static int bfin_spi_resume(struct platform_device *pdev)
{
	struct driver_data *drv_data = platform_get_drvdata(pdev);
	int status = 0;

	/* Enable the SPI interface */
	bfin_spi_enable(drv_data);

	/* Start the queue running */
	status = bfin_spi_start_queue(drv_data);
	if (status != 0) {
		dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
		return status;
	}

	return 0;
}
#else
#define bfin_spi_suspend NULL
#define bfin_spi_resume NULL
#endif				/* CONFIG_PM */

MODULE_ALIAS("platform:bfin-spi");
static struct platform_driver bfin_spi_driver = {
	.driver	= {
		.name	= DRV_NAME,
		.owner	= THIS_MODULE,
	},
	.suspend	= bfin_spi_suspend,
	.resume		= bfin_spi_resume,
	.remove		= __devexit_p(bfin_spi_remove),
};

static int __init bfin_spi_init(void)
{
	return platform_driver_probe(&bfin_spi_driver, bfin_spi_probe);
}
module_init(bfin_spi_init);

static void __exit bfin_spi_exit(void)
{
	platform_driver_unregister(&bfin_spi_driver);
}
module_exit(bfin_spi_exit);