summaryrefslogtreecommitdiffstats
path: root/drivers/spi/spi-sh-msiof.c
blob: c304c7167866d2dbc9fdfcff902729eefb2db78e (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
/*
 * SuperH MSIOF SPI Master Interface
 *
 * Copyright (c) 2009 Magnus Damm
 * Copyright (C) 2014 Renesas Electronics Corporation
 * Copyright (C) 2014-2017 Glider bvba
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/bitmap.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>

#include <linux/spi/sh_msiof.h>
#include <linux/spi/spi.h>

#include <asm/unaligned.h>

struct sh_msiof_chipdata {
	u16 tx_fifo_size;
	u16 rx_fifo_size;
	u16 master_flags;
};

struct sh_msiof_spi_priv {
	struct spi_master *master;
	void __iomem *mapbase;
	struct clk *clk;
	struct platform_device *pdev;
	struct sh_msiof_spi_info *info;
	struct completion done;
	unsigned int tx_fifo_size;
	unsigned int rx_fifo_size;
	void *tx_dma_page;
	void *rx_dma_page;
	dma_addr_t tx_dma_addr;
	dma_addr_t rx_dma_addr;
	bool slave_aborted;
};

#define TMDR1	0x00	/* Transmit Mode Register 1 */
#define TMDR2	0x04	/* Transmit Mode Register 2 */
#define TMDR3	0x08	/* Transmit Mode Register 3 */
#define RMDR1	0x10	/* Receive Mode Register 1 */
#define RMDR2	0x14	/* Receive Mode Register 2 */
#define RMDR3	0x18	/* Receive Mode Register 3 */
#define TSCR	0x20	/* Transmit Clock Select Register */
#define RSCR	0x22	/* Receive Clock Select Register (SH, A1, APE6) */
#define CTR	0x28	/* Control Register */
#define FCTR	0x30	/* FIFO Control Register */
#define STR	0x40	/* Status Register */
#define IER	0x44	/* Interrupt Enable Register */
#define TDR1	0x48	/* Transmit Control Data Register 1 (SH, A1) */
#define TDR2	0x4c	/* Transmit Control Data Register 2 (SH, A1) */
#define TFDR	0x50	/* Transmit FIFO Data Register */
#define RDR1	0x58	/* Receive Control Data Register 1 (SH, A1) */
#define RDR2	0x5c	/* Receive Control Data Register 2 (SH, A1) */
#define RFDR	0x60	/* Receive FIFO Data Register */

/* TMDR1 and RMDR1 */
#define MDR1_TRMD	 0x80000000 /* Transfer Mode (1 = Master mode) */
#define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */
#define MDR1_SYNCMD_SPI	 0x20000000 /*   Level mode/SPI */
#define MDR1_SYNCMD_LR	 0x30000000 /*   L/R mode */
#define MDR1_SYNCAC_SHIFT	 25 /* Sync Polarity (1 = Active-low) */
#define MDR1_BITLSB_SHIFT	 24 /* MSB/LSB First (1 = LSB first) */
#define MDR1_DTDL_SHIFT		 20 /* Data Pin Bit Delay for MSIOF_SYNC */
#define MDR1_SYNCDL_SHIFT	 16 /* Frame Sync Signal Timing Delay */
#define MDR1_FLD_MASK	 0x0000000c /* Frame Sync Signal Interval (0-3) */
#define MDR1_FLD_SHIFT		  2
#define MDR1_XXSTP	 0x00000001 /* Transmission/Reception Stop on FIFO */
/* TMDR1 */
#define TMDR1_PCON	 0x40000000 /* Transfer Signal Connection */

/* TMDR2 and RMDR2 */
#define MDR2_BITLEN1(i)	(((i) - 1) << 24) /* Data Size (8-32 bits) */
#define MDR2_WDLEN1(i)	(((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */
#define MDR2_GRPMASK1	0x00000001 /* Group Output Mask 1 (SH, A1) */

/* TSCR and RSCR */
#define SCR_BRPS_MASK	    0x1f00 /* Prescaler Setting (1-32) */
#define SCR_BRPS(i)	(((i) - 1) << 8)
#define SCR_BRDV_MASK	    0x0007 /* Baud Rate Generator's Division Ratio */
#define SCR_BRDV_DIV_2	    0x0000
#define SCR_BRDV_DIV_4	    0x0001
#define SCR_BRDV_DIV_8	    0x0002
#define SCR_BRDV_DIV_16	    0x0003
#define SCR_BRDV_DIV_32	    0x0004
#define SCR_BRDV_DIV_1	    0x0007

/* CTR */
#define CTR_TSCKIZ_MASK	0xc0000000 /* Transmit Clock I/O Polarity Select */
#define CTR_TSCKIZ_SCK	0x80000000 /*   Disable SCK when TX disabled */
#define CTR_TSCKIZ_POL_SHIFT	30 /*   Transmit Clock Polarity */
#define CTR_RSCKIZ_MASK	0x30000000 /* Receive Clock Polarity Select */
#define CTR_RSCKIZ_SCK	0x20000000 /*   Must match CTR_TSCKIZ_SCK */
#define CTR_RSCKIZ_POL_SHIFT	28 /*   Receive Clock Polarity */
#define CTR_TEDG_SHIFT		27 /* Transmit Timing (1 = falling edge) */
#define CTR_REDG_SHIFT		26 /* Receive Timing (1 = falling edge) */
#define CTR_TXDIZ_MASK	0x00c00000 /* Pin Output When TX is Disabled */
#define CTR_TXDIZ_LOW	0x00000000 /*   0 */
#define CTR_TXDIZ_HIGH	0x00400000 /*   1 */
#define CTR_TXDIZ_HIZ	0x00800000 /*   High-impedance */
#define CTR_TSCKE	0x00008000 /* Transmit Serial Clock Output Enable */
#define CTR_TFSE	0x00004000 /* Transmit Frame Sync Signal Output Enable */
#define CTR_TXE		0x00000200 /* Transmit Enable */
#define CTR_RXE		0x00000100 /* Receive Enable */

/* FCTR */
#define FCTR_TFWM_MASK	0xe0000000 /* Transmit FIFO Watermark */
#define FCTR_TFWM_64	0x00000000 /*  Transfer Request when 64 empty stages */
#define FCTR_TFWM_32	0x20000000 /*  Transfer Request when 32 empty stages */
#define FCTR_TFWM_24	0x40000000 /*  Transfer Request when 24 empty stages */
#define FCTR_TFWM_16	0x60000000 /*  Transfer Request when 16 empty stages */
#define FCTR_TFWM_12	0x80000000 /*  Transfer Request when 12 empty stages */
#define FCTR_TFWM_8	0xa0000000 /*  Transfer Request when 8 empty stages */
#define FCTR_TFWM_4	0xc0000000 /*  Transfer Request when 4 empty stages */
#define FCTR_TFWM_1	0xe0000000 /*  Transfer Request when 1 empty stage */
#define FCTR_TFUA_MASK	0x07f00000 /* Transmit FIFO Usable Area */
#define FCTR_TFUA_SHIFT		20
#define FCTR_TFUA(i)	((i) << FCTR_TFUA_SHIFT)
#define FCTR_RFWM_MASK	0x0000e000 /* Receive FIFO Watermark */
#define FCTR_RFWM_1	0x00000000 /*  Transfer Request when 1 valid stages */
#define FCTR_RFWM_4	0x00002000 /*  Transfer Request when 4 valid stages */
#define FCTR_RFWM_8	0x00004000 /*  Transfer Request when 8 valid stages */
#define FCTR_RFWM_16	0x00006000 /*  Transfer Request when 16 valid stages */
#define FCTR_RFWM_32	0x00008000 /*  Transfer Request when 32 valid stages */
#define FCTR_RFWM_64	0x0000a000 /*  Transfer Request when 64 valid stages */
#define FCTR_RFWM_128	0x0000c000 /*  Transfer Request when 128 valid stages */
#define FCTR_RFWM_256	0x0000e000 /*  Transfer Request when 256 valid stages */
#define FCTR_RFUA_MASK	0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */
#define FCTR_RFUA_SHIFT		 4
#define FCTR_RFUA(i)	((i) << FCTR_RFUA_SHIFT)

/* STR */
#define STR_TFEMP	0x20000000 /* Transmit FIFO Empty */
#define STR_TDREQ	0x10000000 /* Transmit Data Transfer Request */
#define STR_TEOF	0x00800000 /* Frame Transmission End */
#define STR_TFSERR	0x00200000 /* Transmit Frame Synchronization Error */
#define STR_TFOVF	0x00100000 /* Transmit FIFO Overflow */
#define STR_TFUDF	0x00080000 /* Transmit FIFO Underflow */
#define STR_RFFUL	0x00002000 /* Receive FIFO Full */
#define STR_RDREQ	0x00001000 /* Receive Data Transfer Request */
#define STR_REOF	0x00000080 /* Frame Reception End */
#define STR_RFSERR	0x00000020 /* Receive Frame Synchronization Error */
#define STR_RFUDF	0x00000010 /* Receive FIFO Underflow */
#define STR_RFOVF	0x00000008 /* Receive FIFO Overflow */

/* IER */
#define IER_TDMAE	0x80000000 /* Transmit Data DMA Transfer Req. Enable */
#define IER_TFEMPE	0x20000000 /* Transmit FIFO Empty Enable */
#define IER_TDREQE	0x10000000 /* Transmit Data Transfer Request Enable */
#define IER_TEOFE	0x00800000 /* Frame Transmission End Enable */
#define IER_TFSERRE	0x00200000 /* Transmit Frame Sync Error Enable */
#define IER_TFOVFE	0x00100000 /* Transmit FIFO Overflow Enable */
#define IER_TFUDFE	0x00080000 /* Transmit FIFO Underflow Enable */
#define IER_RDMAE	0x00008000 /* Receive Data DMA Transfer Req. Enable */
#define IER_RFFULE	0x00002000 /* Receive FIFO Full Enable */
#define IER_RDREQE	0x00001000 /* Receive Data Transfer Request Enable */
#define IER_REOFE	0x00000080 /* Frame Reception End Enable */
#define IER_RFSERRE	0x00000020 /* Receive Frame Sync Error Enable */
#define IER_RFUDFE	0x00000010 /* Receive FIFO Underflow Enable */
#define IER_RFOVFE	0x00000008 /* Receive FIFO Overflow Enable */


static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs)
{
	switch (reg_offs) {
	case TSCR:
	case RSCR:
		return ioread16(p->mapbase + reg_offs);
	default:
		return ioread32(p->mapbase + reg_offs);
	}
}

static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs,
			   u32 value)
{
	switch (reg_offs) {
	case TSCR:
	case RSCR:
		iowrite16(value, p->mapbase + reg_offs);
		break;
	default:
		iowrite32(value, p->mapbase + reg_offs);
		break;
	}
}

static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p,
				    u32 clr, u32 set)
{
	u32 mask = clr | set;
	u32 data;
	int k;

	data = sh_msiof_read(p, CTR);
	data &= ~clr;
	data |= set;
	sh_msiof_write(p, CTR, data);

	for (k = 100; k > 0; k--) {
		if ((sh_msiof_read(p, CTR) & mask) == set)
			break;

		udelay(10);
	}

	return k > 0 ? 0 : -ETIMEDOUT;
}

static irqreturn_t sh_msiof_spi_irq(int irq, void *data)
{
	struct sh_msiof_spi_priv *p = data;

	/* just disable the interrupt and wake up */
	sh_msiof_write(p, IER, 0);
	complete(&p->done);

	return IRQ_HANDLED;
}

static struct {
	unsigned short div;
	unsigned short brdv;
} const sh_msiof_spi_div_table[] = {
	{ 1,	SCR_BRDV_DIV_1 },
	{ 2,	SCR_BRDV_DIV_2 },
	{ 4,	SCR_BRDV_DIV_4 },
	{ 8,	SCR_BRDV_DIV_8 },
	{ 16,	SCR_BRDV_DIV_16 },
	{ 32,	SCR_BRDV_DIV_32 },
};

static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p,
				      unsigned long parent_rate, u32 spi_hz)
{
	unsigned long div = 1024;
	u32 brps, scr;
	size_t k;

	if (!WARN_ON(!spi_hz || !parent_rate))
		div = DIV_ROUND_UP(parent_rate, spi_hz);

	for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) {
		brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div);
		/* SCR_BRDV_DIV_1 is valid only if BRPS is x 1/1 or x 1/2 */
		if (sh_msiof_spi_div_table[k].div == 1 && brps > 2)
			continue;
		if (brps <= 32) /* max of brdv is 32 */
			break;
	}

	k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1);

	scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps);
	sh_msiof_write(p, TSCR, scr);
	if (!(p->master->flags & SPI_MASTER_MUST_TX))
		sh_msiof_write(p, RSCR, scr);
}

static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl)
{
	/*
	 * DTDL/SYNCDL bit	: p->info->dtdl or p->info->syncdl
	 * b'000		: 0
	 * b'001		: 100
	 * b'010		: 200
	 * b'011 (SYNCDL only)	: 300
	 * b'101		: 50
	 * b'110		: 150
	 */
	if (dtdl_or_syncdl % 100)
		return dtdl_or_syncdl / 100 + 5;
	else
		return dtdl_or_syncdl / 100;
}

static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p)
{
	u32 val;

	if (!p->info)
		return 0;

	/* check if DTDL and SYNCDL is allowed value */
	if (p->info->dtdl > 200 || p->info->syncdl > 300) {
		dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n");
		return 0;
	}

	/* check if the sum of DTDL and SYNCDL becomes an integer value  */
	if ((p->info->dtdl + p->info->syncdl) % 100) {
		dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n");
		return 0;
	}

	val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT;
	val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT;

	return val;
}

static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p,
				      u32 cpol, u32 cpha,
				      u32 tx_hi_z, u32 lsb_first, u32 cs_high)
{
	u32 tmp;
	int edge;

	/*
	 * CPOL CPHA     TSCKIZ RSCKIZ TEDG REDG
	 *    0    0         10     10    1    1
	 *    0    1         10     10    0    0
	 *    1    0         11     11    0    0
	 *    1    1         11     11    1    1
	 */
	tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP;
	tmp |= !cs_high << MDR1_SYNCAC_SHIFT;
	tmp |= lsb_first << MDR1_BITLSB_SHIFT;
	tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p);
	if (spi_controller_is_slave(p->master))
		sh_msiof_write(p, TMDR1, tmp | TMDR1_PCON);
	else
		sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON);
	if (p->master->flags & SPI_MASTER_MUST_TX) {
		/* These bits are reserved if RX needs TX */
		tmp &= ~0x0000ffff;
	}
	sh_msiof_write(p, RMDR1, tmp);

	tmp = 0;
	tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT;
	tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT;

	edge = cpol ^ !cpha;

	tmp |= edge << CTR_TEDG_SHIFT;
	tmp |= edge << CTR_REDG_SHIFT;
	tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW;
	sh_msiof_write(p, CTR, tmp);
}

static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p,
				       const void *tx_buf, void *rx_buf,
				       u32 bits, u32 words)
{
	u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words);

	if (tx_buf || (p->master->flags & SPI_MASTER_MUST_TX))
		sh_msiof_write(p, TMDR2, dr2);
	else
		sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1);

	if (rx_buf)
		sh_msiof_write(p, RMDR2, dr2);
}

static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p)
{
	sh_msiof_write(p, STR, sh_msiof_read(p, STR));
}

static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p,
				      const void *tx_buf, int words, int fs)
{
	const u8 *buf_8 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, buf_8[k] << fs);
}

static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p,
				       const void *tx_buf, int words, int fs)
{
	const u16 *buf_16 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, buf_16[k] << fs);
}

static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p,
					const void *tx_buf, int words, int fs)
{
	const u16 *buf_16 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs);
}

static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p,
				       const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, buf_32[k] << fs);
}

static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p,
					const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs);
}

static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p,
					const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs));
}

static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p,
					 const void *tx_buf, int words, int fs)
{
	const u32 *buf_32 = tx_buf;
	int k;

	for (k = 0; k < words; k++)
		sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs));
}

static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p,
				     void *rx_buf, int words, int fs)
{
	u8 *buf_8 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_8[k] = sh_msiof_read(p, RFDR) >> fs;
}

static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p,
				      void *rx_buf, int words, int fs)
{
	u16 *buf_16 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_16[k] = sh_msiof_read(p, RFDR) >> fs;
}

static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u16 *buf_16 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]);
}

static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p,
				      void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_32[k] = sh_msiof_read(p, RFDR) >> fs;
}

static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]);
}

static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs);
}

static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p,
				       void *rx_buf, int words, int fs)
{
	u32 *buf_32 = rx_buf;
	int k;

	for (k = 0; k < words; k++)
		put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]);
}

static int sh_msiof_spi_setup(struct spi_device *spi)
{
	struct device_node	*np = spi->master->dev.of_node;
	struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master);

	pm_runtime_get_sync(&p->pdev->dev);

	if (!np) {
		/*
		 * Use spi->controller_data for CS (same strategy as spi_gpio),
		 * if any. otherwise let HW control CS
		 */
		spi->cs_gpio = (uintptr_t)spi->controller_data;
	}

	/* Configure pins before deasserting CS */
	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
				  !!(spi->mode & SPI_CPHA),
				  !!(spi->mode & SPI_3WIRE),
				  !!(spi->mode & SPI_LSB_FIRST),
				  !!(spi->mode & SPI_CS_HIGH));

	if (spi->cs_gpio >= 0)
		gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));


	pm_runtime_put(&p->pdev->dev);

	return 0;
}

static int sh_msiof_prepare_message(struct spi_master *master,
				    struct spi_message *msg)
{
	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
	const struct spi_device *spi = msg->spi;

	/* Configure pins before asserting CS */
	sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL),
				  !!(spi->mode & SPI_CPHA),
				  !!(spi->mode & SPI_3WIRE),
				  !!(spi->mode & SPI_LSB_FIRST),
				  !!(spi->mode & SPI_CS_HIGH));
	return 0;
}

static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf)
{
	bool slave = spi_controller_is_slave(p->master);
	int ret = 0;

	/* setup clock and rx/tx signals */
	if (!slave)
		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE);
	if (rx_buf && !ret)
		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE);
	if (!ret)
		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE);

	/* start by setting frame bit */
	if (!ret && !slave)
		ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE);

	return ret;
}

static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf)
{
	bool slave = spi_controller_is_slave(p->master);
	int ret = 0;

	/* shut down frame, rx/tx and clock signals */
	if (!slave)
		ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0);
	if (!ret)
		ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0);
	if (rx_buf && !ret)
		ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0);
	if (!ret && !slave)
		ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0);

	return ret;
}

static int sh_msiof_slave_abort(struct spi_master *master)
{
	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);

	p->slave_aborted = true;
	complete(&p->done);
	return 0;
}

static int sh_msiof_wait_for_completion(struct sh_msiof_spi_priv *p)
{
	if (spi_controller_is_slave(p->master)) {
		if (wait_for_completion_interruptible(&p->done) ||
		    p->slave_aborted) {
			dev_dbg(&p->pdev->dev, "interrupted\n");
			return -EINTR;
		}
	} else {
		if (!wait_for_completion_timeout(&p->done, HZ)) {
			dev_err(&p->pdev->dev, "timeout\n");
			return -ETIMEDOUT;
		}
	}

	return 0;
}

static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p,
				  void (*tx_fifo)(struct sh_msiof_spi_priv *,
						  const void *, int, int),
				  void (*rx_fifo)(struct sh_msiof_spi_priv *,
						  void *, int, int),
				  const void *tx_buf, void *rx_buf,
				  int words, int bits)
{
	int fifo_shift;
	int ret;

	/* limit maximum word transfer to rx/tx fifo size */
	if (tx_buf)
		words = min_t(int, words, p->tx_fifo_size);
	if (rx_buf)
		words = min_t(int, words, p->rx_fifo_size);

	/* the fifo contents need shifting */
	fifo_shift = 32 - bits;

	/* default FIFO watermarks for PIO */
	sh_msiof_write(p, FCTR, 0);

	/* setup msiof transfer mode registers */
	sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words);
	sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE);

	/* write tx fifo */
	if (tx_buf)
		tx_fifo(p, tx_buf, words, fifo_shift);

	reinit_completion(&p->done);
	p->slave_aborted = false;

	ret = sh_msiof_spi_start(p, rx_buf);
	if (ret) {
		dev_err(&p->pdev->dev, "failed to start hardware\n");
		goto stop_ier;
	}

	/* wait for tx fifo to be emptied / rx fifo to be filled */
	ret = sh_msiof_wait_for_completion(p);
	if (ret)
		goto stop_reset;

	/* read rx fifo */
	if (rx_buf)
		rx_fifo(p, rx_buf, words, fifo_shift);

	/* clear status bits */
	sh_msiof_reset_str(p);

	ret = sh_msiof_spi_stop(p, rx_buf);
	if (ret) {
		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
		return ret;
	}

	return words;

stop_reset:
	sh_msiof_reset_str(p);
	sh_msiof_spi_stop(p, rx_buf);
stop_ier:
	sh_msiof_write(p, IER, 0);
	return ret;
}

static void sh_msiof_dma_complete(void *arg)
{
	struct sh_msiof_spi_priv *p = arg;

	sh_msiof_write(p, IER, 0);
	complete(&p->done);
}

static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx,
			     void *rx, unsigned int len)
{
	u32 ier_bits = 0;
	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
	dma_cookie_t cookie;
	int ret;

	/* First prepare and submit the DMA request(s), as this may fail */
	if (rx) {
		ier_bits |= IER_RDREQE | IER_RDMAE;
		desc_rx = dmaengine_prep_slave_single(p->master->dma_rx,
					p->rx_dma_addr, len, DMA_FROM_DEVICE,
					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
		if (!desc_rx)
			return -EAGAIN;

		desc_rx->callback = sh_msiof_dma_complete;
		desc_rx->callback_param = p;
		cookie = dmaengine_submit(desc_rx);
		if (dma_submit_error(cookie))
			return cookie;
	}

	if (tx) {
		ier_bits |= IER_TDREQE | IER_TDMAE;
		dma_sync_single_for_device(p->master->dma_tx->device->dev,
					   p->tx_dma_addr, len, DMA_TO_DEVICE);
		desc_tx = dmaengine_prep_slave_single(p->master->dma_tx,
					p->tx_dma_addr, len, DMA_TO_DEVICE,
					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
		if (!desc_tx) {
			ret = -EAGAIN;
			goto no_dma_tx;
		}

		if (rx) {
			/* No callback */
			desc_tx->callback = NULL;
		} else {
			desc_tx->callback = sh_msiof_dma_complete;
			desc_tx->callback_param = p;
		}
		cookie = dmaengine_submit(desc_tx);
		if (dma_submit_error(cookie)) {
			ret = cookie;
			goto no_dma_tx;
		}
	}

	/* 1 stage FIFO watermarks for DMA */
	sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1);

	/* setup msiof transfer mode registers (32-bit words) */
	sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4);

	sh_msiof_write(p, IER, ier_bits);

	reinit_completion(&p->done);
	p->slave_aborted = false;

	/* Now start DMA */
	if (rx)
		dma_async_issue_pending(p->master->dma_rx);
	if (tx)
		dma_async_issue_pending(p->master->dma_tx);

	ret = sh_msiof_spi_start(p, rx);
	if (ret) {
		dev_err(&p->pdev->dev, "failed to start hardware\n");
		goto stop_dma;
	}

	/* wait for tx fifo to be emptied / rx fifo to be filled */
	ret = sh_msiof_wait_for_completion(p);
	if (ret)
		goto stop_reset;

	/* clear status bits */
	sh_msiof_reset_str(p);

	ret = sh_msiof_spi_stop(p, rx);
	if (ret) {
		dev_err(&p->pdev->dev, "failed to shut down hardware\n");
		return ret;
	}

	if (rx)
		dma_sync_single_for_cpu(p->master->dma_rx->device->dev,
					p->rx_dma_addr, len,
					DMA_FROM_DEVICE);

	return 0;

stop_reset:
	sh_msiof_reset_str(p);
	sh_msiof_spi_stop(p, rx);
stop_dma:
	if (tx)
		dmaengine_terminate_all(p->master->dma_tx);
no_dma_tx:
	if (rx)
		dmaengine_terminate_all(p->master->dma_rx);
	sh_msiof_write(p, IER, 0);
	return ret;
}

static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words)
{
	/* src or dst can be unaligned, but not both */
	if ((unsigned long)src & 3) {
		while (words--) {
			*dst++ = swab32(get_unaligned(src));
			src++;
		}
	} else if ((unsigned long)dst & 3) {
		while (words--) {
			put_unaligned(swab32(*src++), dst);
			dst++;
		}
	} else {
		while (words--)
			*dst++ = swab32(*src++);
	}
}

static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words)
{
	/* src or dst can be unaligned, but not both */
	if ((unsigned long)src & 3) {
		while (words--) {
			*dst++ = swahw32(get_unaligned(src));
			src++;
		}
	} else if ((unsigned long)dst & 3) {
		while (words--) {
			put_unaligned(swahw32(*src++), dst);
			dst++;
		}
	} else {
		while (words--)
			*dst++ = swahw32(*src++);
	}
}

static void copy_plain32(u32 *dst, const u32 *src, unsigned int words)
{
	memcpy(dst, src, words * 4);
}

static int sh_msiof_transfer_one(struct spi_master *master,
				 struct spi_device *spi,
				 struct spi_transfer *t)
{
	struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
	void (*copy32)(u32 *, const u32 *, unsigned int);
	void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
	void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
	const void *tx_buf = t->tx_buf;
	void *rx_buf = t->rx_buf;
	unsigned int len = t->len;
	unsigned int bits = t->bits_per_word;
	unsigned int bytes_per_word;
	unsigned int words;
	int n;
	bool swab;
	int ret;

	/* setup clocks (clock already enabled in chipselect()) */
	if (!spi_controller_is_slave(p->master))
		sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);

	while (master->dma_tx && len > 15) {
		/*
		 *  DMA supports 32-bit words only, hence pack 8-bit and 16-bit
		 *  words, with byte resp. word swapping.
		 */
		unsigned int l = 0;

		if (tx_buf)
			l = min(len, p->tx_fifo_size * 4);
		if (rx_buf)
			l = min(len, p->rx_fifo_size * 4);

		if (bits <= 8) {
			if (l & 3)
				break;
			copy32 = copy_bswap32;
		} else if (bits <= 16) {
			if (l & 1)
				break;
			copy32 = copy_wswap32;
		} else {
			copy32 = copy_plain32;
		}

		if (tx_buf)
			copy32(p->tx_dma_page, tx_buf, l / 4);

		ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l);
		if (ret == -EAGAIN) {
			pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
				     dev_driver_string(&p->pdev->dev),
				     dev_name(&p->pdev->dev));
			break;
		}
		if (ret)
			return ret;

		if (rx_buf) {
			copy32(rx_buf, p->rx_dma_page, l / 4);
			rx_buf += l;
		}
		if (tx_buf)
			tx_buf += l;

		len -= l;
		if (!len)
			return 0;
	}

	if (bits <= 8 && len > 15 && !(len & 3)) {
		bits = 32;
		swab = true;
	} else {
		swab = false;
	}

	/* setup bytes per word and fifo read/write functions */
	if (bits <= 8) {
		bytes_per_word = 1;
		tx_fifo = sh_msiof_spi_write_fifo_8;
		rx_fifo = sh_msiof_spi_read_fifo_8;
	} else if (bits <= 16) {
		bytes_per_word = 2;
		if ((unsigned long)tx_buf & 0x01)
			tx_fifo = sh_msiof_spi_write_fifo_16u;
		else
			tx_fifo = sh_msiof_spi_write_fifo_16;

		if ((unsigned long)rx_buf & 0x01)
			rx_fifo = sh_msiof_spi_read_fifo_16u;
		else
			rx_fifo = sh_msiof_spi_read_fifo_16;
	} else if (swab) {
		bytes_per_word = 4;
		if ((unsigned long)tx_buf & 0x03)
			tx_fifo = sh_msiof_spi_write_fifo_s32u;
		else
			tx_fifo = sh_msiof_spi_write_fifo_s32;

		if ((unsigned long)rx_buf & 0x03)
			rx_fifo = sh_msiof_spi_read_fifo_s32u;
		else
			rx_fifo = sh_msiof_spi_read_fifo_s32;
	} else {
		bytes_per_word = 4;
		if ((unsigned long)tx_buf & 0x03)
			tx_fifo = sh_msiof_spi_write_fifo_32u;
		else
			tx_fifo = sh_msiof_spi_write_fifo_32;

		if ((unsigned long)rx_buf & 0x03)
			rx_fifo = sh_msiof_spi_read_fifo_32u;
		else
			rx_fifo = sh_msiof_spi_read_fifo_32;
	}

	/* transfer in fifo sized chunks */
	words = len / bytes_per_word;

	while (words > 0) {
		n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
					   words, bits);
		if (n < 0)
			return n;

		if (tx_buf)
			tx_buf += n * bytes_per_word;
		if (rx_buf)
			rx_buf += n * bytes_per_word;
		words -= n;
	}

	return 0;
}

static const struct sh_msiof_chipdata sh_data = {
	.tx_fifo_size = 64,
	.rx_fifo_size = 64,
	.master_flags = 0,
};

static const struct sh_msiof_chipdata r8a779x_data = {
	.tx_fifo_size = 64,
	.rx_fifo_size = 64,
	.master_flags = SPI_MASTER_MUST_TX,
};

static const struct of_device_id sh_msiof_match[] = {
	{ .compatible = "renesas,sh-mobile-msiof", .data = &sh_data },
	{ .compatible = "renesas,msiof-r8a7790",   .data = &r8a779x_data },
	{ .compatible = "renesas,msiof-r8a7791",   .data = &r8a779x_data },
	{ .compatible = "renesas,msiof-r8a7792",   .data = &r8a779x_data },
	{ .compatible = "renesas,msiof-r8a7793",   .data = &r8a779x_data },
	{ .compatible = "renesas,msiof-r8a7794",   .data = &r8a779x_data },
	{ .compatible = "renesas,rcar-gen2-msiof", .data = &r8a779x_data },
	{ .compatible = "renesas,msiof-r8a7796",   .data = &r8a779x_data },
	{ .compatible = "renesas,rcar-gen3-msiof", .data = &r8a779x_data },
	{ .compatible = "renesas,sh-msiof",        .data = &sh_data }, /* Deprecated */
	{},
};
MODULE_DEVICE_TABLE(of, sh_msiof_match);

#ifdef CONFIG_OF
static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
{
	struct sh_msiof_spi_info *info;
	struct device_node *np = dev->of_node;
	u32 num_cs = 1;

	info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL);
	if (!info)
		return NULL;

	info->mode = of_property_read_bool(np, "spi-slave") ? MSIOF_SPI_SLAVE
							    : MSIOF_SPI_MASTER;

	/* Parse the MSIOF properties */
	if (info->mode == MSIOF_SPI_MASTER)
		of_property_read_u32(np, "num-cs", &num_cs);
	of_property_read_u32(np, "renesas,tx-fifo-size",
					&info->tx_fifo_override);
	of_property_read_u32(np, "renesas,rx-fifo-size",
					&info->rx_fifo_override);
	of_property_read_u32(np, "renesas,dtdl", &info->dtdl);
	of_property_read_u32(np, "renesas,syncdl", &info->syncdl);

	info->num_chipselect = num_cs;

	return info;
}
#else
static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev)
{
	return NULL;
}
#endif

static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev,
	enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr)
{
	dma_cap_mask_t mask;
	struct dma_chan *chan;
	struct dma_slave_config cfg;
	int ret;

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
				(void *)(unsigned long)id, dev,
				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
	if (!chan) {
		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
		return NULL;
	}

	memset(&cfg, 0, sizeof(cfg));
	cfg.direction = dir;
	if (dir == DMA_MEM_TO_DEV) {
		cfg.dst_addr = port_addr;
		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
	} else {
		cfg.src_addr = port_addr;
		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
	}

	ret = dmaengine_slave_config(chan, &cfg);
	if (ret) {
		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
		dma_release_channel(chan);
		return NULL;
	}

	return chan;
}

static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p)
{
	struct platform_device *pdev = p->pdev;
	struct device *dev = &pdev->dev;
	const struct sh_msiof_spi_info *info = dev_get_platdata(dev);
	unsigned int dma_tx_id, dma_rx_id;
	const struct resource *res;
	struct spi_master *master;
	struct device *tx_dev, *rx_dev;

	if (dev->of_node) {
		/* In the OF case we will get the slave IDs from the DT */
		dma_tx_id = 0;
		dma_rx_id = 0;
	} else if (info && info->dma_tx_id && info->dma_rx_id) {
		dma_tx_id = info->dma_tx_id;
		dma_rx_id = info->dma_rx_id;
	} else {
		/* The driver assumes no error */
		return 0;
	}

	/* The DMA engine uses the second register set, if present */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	if (!res)
		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	master = p->master;
	master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV,
						   dma_tx_id,
						   res->start + TFDR);
	if (!master->dma_tx)
		return -ENODEV;

	master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM,
						   dma_rx_id,
						   res->start + RFDR);
	if (!master->dma_rx)
		goto free_tx_chan;

	p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
	if (!p->tx_dma_page)
		goto free_rx_chan;

	p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
	if (!p->rx_dma_page)
		goto free_tx_page;

	tx_dev = master->dma_tx->device->dev;
	p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE,
					DMA_TO_DEVICE);
	if (dma_mapping_error(tx_dev, p->tx_dma_addr))
		goto free_rx_page;

	rx_dev = master->dma_rx->device->dev;
	p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE,
					DMA_FROM_DEVICE);
	if (dma_mapping_error(rx_dev, p->rx_dma_addr))
		goto unmap_tx_page;

	dev_info(dev, "DMA available");
	return 0;

unmap_tx_page:
	dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE);
free_rx_page:
	free_page((unsigned long)p->rx_dma_page);
free_tx_page:
	free_page((unsigned long)p->tx_dma_page);
free_rx_chan:
	dma_release_channel(master->dma_rx);
free_tx_chan:
	dma_release_channel(master->dma_tx);
	master->dma_tx = NULL;
	return -ENODEV;
}

static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p)
{
	struct spi_master *master = p->master;
	struct device *dev;

	if (!master->dma_tx)
		return;

	dev = &p->pdev->dev;
	dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr,
			 PAGE_SIZE, DMA_FROM_DEVICE);
	dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr,
			 PAGE_SIZE, DMA_TO_DEVICE);
	free_page((unsigned long)p->rx_dma_page);
	free_page((unsigned long)p->tx_dma_page);
	dma_release_channel(master->dma_rx);
	dma_release_channel(master->dma_tx);
}

static int sh_msiof_spi_probe(struct platform_device *pdev)
{
	struct resource	*r;
	struct spi_master *master;
	const struct sh_msiof_chipdata *chipdata;
	const struct of_device_id *of_id;
	struct sh_msiof_spi_info *info;
	struct sh_msiof_spi_priv *p;
	int i;
	int ret;

	of_id = of_match_device(sh_msiof_match, &pdev->dev);
	if (of_id) {
		chipdata = of_id->data;
		info = sh_msiof_spi_parse_dt(&pdev->dev);
	} else {
		chipdata = (const void *)pdev->id_entry->driver_data;
		info = dev_get_platdata(&pdev->dev);
	}

	if (!info) {
		dev_err(&pdev->dev, "failed to obtain device info\n");
		return -ENXIO;
	}

	if (info->mode == MSIOF_SPI_SLAVE)
		master = spi_alloc_slave(&pdev->dev,
					 sizeof(struct sh_msiof_spi_priv));
	else
		master = spi_alloc_master(&pdev->dev,
					  sizeof(struct sh_msiof_spi_priv));
	if (master == NULL)
		return -ENOMEM;

	p = spi_master_get_devdata(master);

	platform_set_drvdata(pdev, p);
	p->master = master;
	p->info = info;

	init_completion(&p->done);

	p->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(p->clk)) {
		dev_err(&pdev->dev, "cannot get clock\n");
		ret = PTR_ERR(p->clk);
		goto err1;
	}

	i = platform_get_irq(pdev, 0);
	if (i < 0) {
		dev_err(&pdev->dev, "cannot get platform IRQ\n");
		ret = -ENOENT;
		goto err1;
	}

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	p->mapbase = devm_ioremap_resource(&pdev->dev, r);
	if (IS_ERR(p->mapbase)) {
		ret = PTR_ERR(p->mapbase);
		goto err1;
	}

	ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0,
			       dev_name(&pdev->dev), p);
	if (ret) {
		dev_err(&pdev->dev, "unable to request irq\n");
		goto err1;
	}

	p->pdev = pdev;
	pm_runtime_enable(&pdev->dev);

	/* Platform data may override FIFO sizes */
	p->tx_fifo_size = chipdata->tx_fifo_size;
	p->rx_fifo_size = chipdata->rx_fifo_size;
	if (p->info->tx_fifo_override)
		p->tx_fifo_size = p->info->tx_fifo_override;
	if (p->info->rx_fifo_override)
		p->rx_fifo_size = p->info->rx_fifo_override;

	/* init master code */
	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
	master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE;
	master->flags = chipdata->master_flags;
	master->bus_num = pdev->id;
	master->dev.of_node = pdev->dev.of_node;
	master->num_chipselect = p->info->num_chipselect;
	master->setup = sh_msiof_spi_setup;
	master->prepare_message = sh_msiof_prepare_message;
	master->slave_abort = sh_msiof_slave_abort;
	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
	master->auto_runtime_pm = true;
	master->transfer_one = sh_msiof_transfer_one;

	ret = sh_msiof_request_dma(p);
	if (ret < 0)
		dev_warn(&pdev->dev, "DMA not available, using PIO\n");

	ret = devm_spi_register_master(&pdev->dev, master);
	if (ret < 0) {
		dev_err(&pdev->dev, "spi_register_master error.\n");
		goto err2;
	}

	return 0;

 err2:
	sh_msiof_release_dma(p);
	pm_runtime_disable(&pdev->dev);
 err1:
	spi_master_put(master);
	return ret;
}

static int sh_msiof_spi_remove(struct platform_device *pdev)
{
	struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev);

	sh_msiof_release_dma(p);
	pm_runtime_disable(&pdev->dev);
	return 0;
}

static const struct platform_device_id spi_driver_ids[] = {
	{ "spi_sh_msiof",	(kernel_ulong_t)&sh_data },
	{},
};
MODULE_DEVICE_TABLE(platform, spi_driver_ids);

static struct platform_driver sh_msiof_spi_drv = {
	.probe		= sh_msiof_spi_probe,
	.remove		= sh_msiof_spi_remove,
	.id_table	= spi_driver_ids,
	.driver		= {
		.name		= "spi_sh_msiof",
		.of_match_table = of_match_ptr(sh_msiof_match),
	},
};
module_platform_driver(sh_msiof_spi_drv);

MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver");
MODULE_AUTHOR("Magnus Damm");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:spi_sh_msiof");