Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
   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
/*
 * SH RSPI driver
 *
 * Copyright (C) 2012, 2013  Renesas Solutions Corp.
 * Copyright (C) 2014 Glider bvba
 *
 * Based on spi-sh.c:
 * Copyright (C) 2011 Renesas Solutions Corp.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/of_device.h>
#include <linux/pm_runtime.h>
#include <linux/sh_dma.h>
#include <linux/spi/spi.h>
#include <linux/spi/rspi.h>

#define RSPI_SPCR		0x00	/* Control Register */
#define RSPI_SSLP		0x01	/* Slave Select Polarity Register */
#define RSPI_SPPCR		0x02	/* Pin Control Register */
#define RSPI_SPSR		0x03	/* Status Register */
#define RSPI_SPDR		0x04	/* Data Register */
#define RSPI_SPSCR		0x08	/* Sequence Control Register */
#define RSPI_SPSSR		0x09	/* Sequence Status Register */
#define RSPI_SPBR		0x0a	/* Bit Rate Register */
#define RSPI_SPDCR		0x0b	/* Data Control Register */
#define RSPI_SPCKD		0x0c	/* Clock Delay Register */
#define RSPI_SSLND		0x0d	/* Slave Select Negation Delay Register */
#define RSPI_SPND		0x0e	/* Next-Access Delay Register */
#define RSPI_SPCR2		0x0f	/* Control Register 2 (SH only) */
#define RSPI_SPCMD0		0x10	/* Command Register 0 */
#define RSPI_SPCMD1		0x12	/* Command Register 1 */
#define RSPI_SPCMD2		0x14	/* Command Register 2 */
#define RSPI_SPCMD3		0x16	/* Command Register 3 */
#define RSPI_SPCMD4		0x18	/* Command Register 4 */
#define RSPI_SPCMD5		0x1a	/* Command Register 5 */
#define RSPI_SPCMD6		0x1c	/* Command Register 6 */
#define RSPI_SPCMD7		0x1e	/* Command Register 7 */
#define RSPI_SPCMD(i)		(RSPI_SPCMD0 + (i) * 2)
#define RSPI_NUM_SPCMD		8
#define RSPI_RZ_NUM_SPCMD	4
#define QSPI_NUM_SPCMD		4

/* RSPI on RZ only */
#define RSPI_SPBFCR		0x20	/* Buffer Control Register */
#define RSPI_SPBFDR		0x22	/* Buffer Data Count Setting Register */

/* QSPI only */
#define QSPI_SPBFCR		0x18	/* Buffer Control Register */
#define QSPI_SPBDCR		0x1a	/* Buffer Data Count Register */
#define QSPI_SPBMUL0		0x1c	/* Transfer Data Length Multiplier Setting Register 0 */
#define QSPI_SPBMUL1		0x20	/* Transfer Data Length Multiplier Setting Register 1 */
#define QSPI_SPBMUL2		0x24	/* Transfer Data Length Multiplier Setting Register 2 */
#define QSPI_SPBMUL3		0x28	/* Transfer Data Length Multiplier Setting Register 3 */
#define QSPI_SPBMUL(i)		(QSPI_SPBMUL0 + (i) * 4)

/* SPCR - Control Register */
#define SPCR_SPRIE		0x80	/* Receive Interrupt Enable */
#define SPCR_SPE		0x40	/* Function Enable */
#define SPCR_SPTIE		0x20	/* Transmit Interrupt Enable */
#define SPCR_SPEIE		0x10	/* Error Interrupt Enable */
#define SPCR_MSTR		0x08	/* Master/Slave Mode Select */
#define SPCR_MODFEN		0x04	/* Mode Fault Error Detection Enable */
/* RSPI on SH only */
#define SPCR_TXMD		0x02	/* TX Only Mode (vs. Full Duplex) */
#define SPCR_SPMS		0x01	/* 3-wire Mode (vs. 4-wire) */
/* QSPI on R-Car Gen2 only */
#define SPCR_WSWAP		0x02	/* Word Swap of read-data for DMAC */
#define SPCR_BSWAP		0x01	/* Byte Swap of read-data for DMAC */

/* SSLP - Slave Select Polarity Register */
#define SSLP_SSL1P		0x02	/* SSL1 Signal Polarity Setting */
#define SSLP_SSL0P		0x01	/* SSL0 Signal Polarity Setting */

/* SPPCR - Pin Control Register */
#define SPPCR_MOIFE		0x20	/* MOSI Idle Value Fixing Enable */
#define SPPCR_MOIFV		0x10	/* MOSI Idle Fixed Value */
#define SPPCR_SPOM		0x04
#define SPPCR_SPLP2		0x02	/* Loopback Mode 2 (non-inverting) */
#define SPPCR_SPLP		0x01	/* Loopback Mode (inverting) */

#define SPPCR_IO3FV		0x04	/* Single-/Dual-SPI Mode IO3 Output Fixed Value */
#define SPPCR_IO2FV		0x04	/* Single-/Dual-SPI Mode IO2 Output Fixed Value */

/* SPSR - Status Register */
#define SPSR_SPRF		0x80	/* Receive Buffer Full Flag */
#define SPSR_TEND		0x40	/* Transmit End */
#define SPSR_SPTEF		0x20	/* Transmit Buffer Empty Flag */
#define SPSR_PERF		0x08	/* Parity Error Flag */
#define SPSR_MODF		0x04	/* Mode Fault Error Flag */
#define SPSR_IDLNF		0x02	/* RSPI Idle Flag */
#define SPSR_OVRF		0x01	/* Overrun Error Flag (RSPI only) */

/* SPSCR - Sequence Control Register */
#define SPSCR_SPSLN_MASK	0x07	/* Sequence Length Specification */

/* SPSSR - Sequence Status Register */
#define SPSSR_SPECM_MASK	0x70	/* Command Error Mask */
#define SPSSR_SPCP_MASK		0x07	/* Command Pointer Mask */

/* SPDCR - Data Control Register */
#define SPDCR_TXDMY		0x80	/* Dummy Data Transmission Enable */
#define SPDCR_SPLW1		0x40	/* Access Width Specification (RZ) */
#define SPDCR_SPLW0		0x20	/* Access Width Specification (RZ) */
#define SPDCR_SPLLWORD		(SPDCR_SPLW1 | SPDCR_SPLW0)
#define SPDCR_SPLWORD		SPDCR_SPLW1
#define SPDCR_SPLBYTE		SPDCR_SPLW0
#define SPDCR_SPLW		0x20	/* Access Width Specification (SH) */
#define SPDCR_SPRDTD		0x10	/* Receive Transmit Data Select (SH) */
#define SPDCR_SLSEL1		0x08
#define SPDCR_SLSEL0		0x04
#define SPDCR_SLSEL_MASK	0x0c	/* SSL1 Output Select (SH) */
#define SPDCR_SPFC1		0x02
#define SPDCR_SPFC0		0x01
#define SPDCR_SPFC_MASK		0x03	/* Frame Count Setting (1-4) (SH) */

/* SPCKD - Clock Delay Register */
#define SPCKD_SCKDL_MASK	0x07	/* Clock Delay Setting (1-8) */

/* SSLND - Slave Select Negation Delay Register */
#define SSLND_SLNDL_MASK	0x07	/* SSL Negation Delay Setting (1-8) */

/* SPND - Next-Access Delay Register */
#define SPND_SPNDL_MASK		0x07	/* Next-Access Delay Setting (1-8) */

/* SPCR2 - Control Register 2 */
#define SPCR2_PTE		0x08	/* Parity Self-Test Enable */
#define SPCR2_SPIE		0x04	/* Idle Interrupt Enable */
#define SPCR2_SPOE		0x02	/* Odd Parity Enable (vs. Even) */
#define SPCR2_SPPE		0x01	/* Parity Enable */

/* SPCMDn - Command Registers */
#define SPCMD_SCKDEN		0x8000	/* Clock Delay Setting Enable */
#define SPCMD_SLNDEN		0x4000	/* SSL Negation Delay Setting Enable */
#define SPCMD_SPNDEN		0x2000	/* Next-Access Delay Enable */
#define SPCMD_LSBF		0x1000	/* LSB First */
#define SPCMD_SPB_MASK		0x0f00	/* Data Length Setting */
#define SPCMD_SPB_8_TO_16(bit)	(((bit - 1) << 8) & SPCMD_SPB_MASK)
#define SPCMD_SPB_8BIT		0x0000	/* QSPI only */
#define SPCMD_SPB_16BIT		0x0100
#define SPCMD_SPB_20BIT		0x0000
#define SPCMD_SPB_24BIT		0x0100
#define SPCMD_SPB_32BIT		0x0200
#define SPCMD_SSLKP		0x0080	/* SSL Signal Level Keeping */
#define SPCMD_SPIMOD_MASK	0x0060	/* SPI Operating Mode (QSPI only) */
#define SPCMD_SPIMOD1		0x0040
#define SPCMD_SPIMOD0		0x0020
#define SPCMD_SPIMOD_SINGLE	0
#define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
#define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
#define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
#define SPCMD_SSLA_MASK		0x0030	/* SSL Assert Signal Setting (RSPI) */
#define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
#define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
#define SPCMD_CPHA		0x0001	/* Clock Phase Setting */

/* SPBFCR - Buffer Control Register */
#define SPBFCR_TXRST		0x80	/* Transmit Buffer Data Reset */
#define SPBFCR_RXRST		0x40	/* Receive Buffer Data Reset */
#define SPBFCR_TXTRG_MASK	0x30	/* Transmit Buffer Data Triggering Number */
#define SPBFCR_RXTRG_MASK	0x07	/* Receive Buffer Data Triggering Number */
/* QSPI on R-Car Gen2 */
#define SPBFCR_TXTRG_1B		0x00	/* 31 bytes (1 byte available) */
#define SPBFCR_TXTRG_32B	0x30	/* 0 byte (32 bytes available) */
#define SPBFCR_RXTRG_1B		0x00	/* 1 byte (31 bytes available) */
#define SPBFCR_RXTRG_32B	0x07	/* 32 bytes (0 byte available) */

#define QSPI_BUFFER_SIZE        32u

struct rspi_data {
	void __iomem *addr;
	u32 max_speed_hz;
	struct spi_master *master;
	wait_queue_head_t wait;
	struct clk *clk;
	u16 spcmd;
	u8 spsr;
	u8 sppcr;
	int rx_irq, tx_irq;
	const struct spi_ops *ops;

	unsigned dma_callbacked:1;
	unsigned byte_access:1;
};

static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
{
	iowrite8(data, rspi->addr + offset);
}

static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
{
	iowrite16(data, rspi->addr + offset);
}

static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
{
	iowrite32(data, rspi->addr + offset);
}

static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
{
	return ioread8(rspi->addr + offset);
}

static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
{
	return ioread16(rspi->addr + offset);
}

static void rspi_write_data(const struct rspi_data *rspi, u16 data)
{
	if (rspi->byte_access)
		rspi_write8(rspi, data, RSPI_SPDR);
	else /* 16 bit */
		rspi_write16(rspi, data, RSPI_SPDR);
}

static u16 rspi_read_data(const struct rspi_data *rspi)
{
	if (rspi->byte_access)
		return rspi_read8(rspi, RSPI_SPDR);
	else /* 16 bit */
		return rspi_read16(rspi, RSPI_SPDR);
}

/* optional functions */
struct spi_ops {
	int (*set_config_register)(struct rspi_data *rspi, int access_size);
	int (*transfer_one)(struct spi_master *master, struct spi_device *spi,
			    struct spi_transfer *xfer);
	u16 mode_bits;
	u16 flags;
	u16 fifo_size;
};

/*
 * functions for RSPI on legacy SH
 */
static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
{
	int spbr;

	/* Sets output mode, MOSI signal, and (optionally) loopback */
	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);

	/* Sets transfer bit rate */
	spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk),
			    2 * rspi->max_speed_hz) - 1;
	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);

	/* Disable dummy transmission, set 16-bit word access, 1 frame */
	rspi_write8(rspi, 0, RSPI_SPDCR);
	rspi->byte_access = 0;

	/* Sets RSPCK, SSL, next-access delay value */
	rspi_write8(rspi, 0x00, RSPI_SPCKD);
	rspi_write8(rspi, 0x00, RSPI_SSLND);
	rspi_write8(rspi, 0x00, RSPI_SPND);

	/* Sets parity, interrupt mask */
	rspi_write8(rspi, 0x00, RSPI_SPCR2);

	/* Resets sequencer */
	rspi_write8(rspi, 0, RSPI_SPSCR);
	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);

	/* Sets RSPI mode */
	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);

	return 0;
}

/*
 * functions for RSPI on RZ
 */
static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
{
	int spbr;
	int div = 0;
	unsigned long clksrc;

	/* Sets output mode, MOSI signal, and (optionally) loopback */
	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);

	clksrc = clk_get_rate(rspi->clk);
	while (div < 3) {
		if (rspi->max_speed_hz >= clksrc/4) /* 4=(CLK/2)/2 */
			break;
		div++;
		clksrc /= 2;
	}

	/* Sets transfer bit rate */
	spbr = DIV_ROUND_UP(clksrc, 2 * rspi->max_speed_hz) - 1;
	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
	rspi->spcmd |= div << 2;

	/* Disable dummy transmission, set byte access */
	rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
	rspi->byte_access = 1;

	/* Sets RSPCK, SSL, next-access delay value */
	rspi_write8(rspi, 0x00, RSPI_SPCKD);
	rspi_write8(rspi, 0x00, RSPI_SSLND);
	rspi_write8(rspi, 0x00, RSPI_SPND);

	/* Resets sequencer */
	rspi_write8(rspi, 0, RSPI_SPSCR);
	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);

	/* Sets RSPI mode */
	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);

	return 0;
}

/*
 * functions for QSPI
 */
static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
{
	int spbr;

	/* Sets output mode, MOSI signal, and (optionally) loopback */
	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);

	/* Sets transfer bit rate */
	spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk), 2 * rspi->max_speed_hz);
	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);

	/* Disable dummy transmission, set byte access */
	rspi_write8(rspi, 0, RSPI_SPDCR);
	rspi->byte_access = 1;

	/* Sets RSPCK, SSL, next-access delay value */
	rspi_write8(rspi, 0x00, RSPI_SPCKD);
	rspi_write8(rspi, 0x00, RSPI_SSLND);
	rspi_write8(rspi, 0x00, RSPI_SPND);

	/* Data Length Setting */
	if (access_size == 8)
		rspi->spcmd |= SPCMD_SPB_8BIT;
	else if (access_size == 16)
		rspi->spcmd |= SPCMD_SPB_16BIT;
	else
		rspi->spcmd |= SPCMD_SPB_32BIT;

	rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;

	/* Resets transfer data length */
	rspi_write32(rspi, 0, QSPI_SPBMUL0);

	/* Resets transmit and receive buffer */
	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
	/* Sets buffer to allow normal operation */
	rspi_write8(rspi, 0x00, QSPI_SPBFCR);

	/* Resets sequencer */
	rspi_write8(rspi, 0, RSPI_SPSCR);
	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);

	/* Enables SPI function in master mode */
	rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);

	return 0;
}

static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg)
{
	u8 data;

	data = rspi_read8(rspi, reg);
	data &= ~mask;
	data |= (val & mask);
	rspi_write8(rspi, data, reg);
}

static unsigned int qspi_set_send_trigger(struct rspi_data *rspi,
					  unsigned int len)
{
	unsigned int n;

	n = min(len, QSPI_BUFFER_SIZE);

	if (len >= QSPI_BUFFER_SIZE) {
		/* sets triggering number to 32 bytes */
		qspi_update(rspi, SPBFCR_TXTRG_MASK,
			     SPBFCR_TXTRG_32B, QSPI_SPBFCR);
	} else {
		/* sets triggering number to 1 byte */
		qspi_update(rspi, SPBFCR_TXTRG_MASK,
			     SPBFCR_TXTRG_1B, QSPI_SPBFCR);
	}

	return n;
}

static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
{
	unsigned int n;

	n = min(len, QSPI_BUFFER_SIZE);

	if (len >= QSPI_BUFFER_SIZE) {
		/* sets triggering number to 32 bytes */
		qspi_update(rspi, SPBFCR_RXTRG_MASK,
			     SPBFCR_RXTRG_32B, QSPI_SPBFCR);
	} else {
		/* sets triggering number to 1 byte */
		qspi_update(rspi, SPBFCR_RXTRG_MASK,
			     SPBFCR_RXTRG_1B, QSPI_SPBFCR);
	}
	return n;
}

#define set_config_register(spi, n) spi->ops->set_config_register(spi, n)

static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
{
	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
}

static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
{
	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
}

static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
				   u8 enable_bit)
{
	int ret;

	rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
	if (rspi->spsr & wait_mask)
		return 0;

	rspi_enable_irq(rspi, enable_bit);
	ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
	if (ret == 0 && !(rspi->spsr & wait_mask))
		return -ETIMEDOUT;

	return 0;
}

static inline int rspi_wait_for_tx_empty(struct rspi_data *rspi)
{
	return rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
}

static inline int rspi_wait_for_rx_full(struct rspi_data *rspi)
{
	return rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE);
}

static int rspi_data_out(struct rspi_data *rspi, u8 data)
{
	int error = rspi_wait_for_tx_empty(rspi);
	if (error < 0) {
		dev_err(&rspi->master->dev, "transmit timeout\n");
		return error;
	}
	rspi_write_data(rspi, data);
	return 0;
}

static int rspi_data_in(struct rspi_data *rspi)
{
	int error;
	u8 data;

	error = rspi_wait_for_rx_full(rspi);
	if (error < 0) {
		dev_err(&rspi->master->dev, "receive timeout\n");
		return error;
	}
	data = rspi_read_data(rspi);
	return data;
}

static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
			     unsigned int n)
{
	while (n-- > 0) {
		if (tx) {
			int ret = rspi_data_out(rspi, *tx++);
			if (ret < 0)
				return ret;
		}
		if (rx) {
			int ret = rspi_data_in(rspi);
			if (ret < 0)
				return ret;
			*rx++ = ret;
		}
	}

	return 0;
}

static void rspi_dma_complete(void *arg)
{
	struct rspi_data *rspi = arg;

	rspi->dma_callbacked = 1;
	wake_up_interruptible(&rspi->wait);
}

static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
			     struct sg_table *rx)
{
	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
	u8 irq_mask = 0;
	unsigned int other_irq = 0;
	dma_cookie_t cookie;
	int ret;

	/* First prepare and submit the DMA request(s), as this may fail */
	if (rx) {
		desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx,
					rx->sgl, rx->nents, DMA_FROM_DEVICE,
					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
		if (!desc_rx) {
			ret = -EAGAIN;
			goto no_dma_rx;
		}

		desc_rx->callback = rspi_dma_complete;
		desc_rx->callback_param = rspi;
		cookie = dmaengine_submit(desc_rx);
		if (dma_submit_error(cookie)) {
			ret = cookie;
			goto no_dma_rx;
		}

		irq_mask |= SPCR_SPRIE;
	}

	if (tx) {
		desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx,
					tx->sgl, tx->nents, 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 = rspi_dma_complete;
			desc_tx->callback_param = rspi;
		}
		cookie = dmaengine_submit(desc_tx);
		if (dma_submit_error(cookie)) {
			ret = cookie;
			goto no_dma_tx;
		}

		irq_mask |= SPCR_SPTIE;
	}

	/*
	 * DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
	 * called. So, this driver disables the IRQ while DMA transfer.
	 */
	if (tx)
		disable_irq(other_irq = rspi->tx_irq);
	if (rx && rspi->rx_irq != other_irq)
		disable_irq(rspi->rx_irq);

	rspi_enable_irq(rspi, irq_mask);
	rspi->dma_callbacked = 0;

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

	ret = wait_event_interruptible_timeout(rspi->wait,
					       rspi->dma_callbacked, HZ);
	if (ret > 0 && rspi->dma_callbacked) {
		ret = 0;
	} else {
		if (!ret) {
			dev_err(&rspi->master->dev, "DMA timeout\n");
			ret = -ETIMEDOUT;
		}
		if (tx)
			dmaengine_terminate_all(rspi->master->dma_tx);
		if (rx)
			dmaengine_terminate_all(rspi->master->dma_rx);
	}

	rspi_disable_irq(rspi, irq_mask);

	if (tx)
		enable_irq(rspi->tx_irq);
	if (rx && rspi->rx_irq != other_irq)
		enable_irq(rspi->rx_irq);

	return ret;

no_dma_tx:
	if (rx)
		dmaengine_terminate_all(rspi->master->dma_rx);
no_dma_rx:
	if (ret == -EAGAIN) {
		pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
			     dev_driver_string(&rspi->master->dev),
			     dev_name(&rspi->master->dev));
	}
	return ret;
}

static void rspi_receive_init(const struct rspi_data *rspi)
{
	u8 spsr;

	spsr = rspi_read8(rspi, RSPI_SPSR);
	if (spsr & SPSR_SPRF)
		rspi_read_data(rspi);	/* dummy read */
	if (spsr & SPSR_OVRF)
		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
			    RSPI_SPSR);
}

static void rspi_rz_receive_init(const struct rspi_data *rspi)
{
	rspi_receive_init(rspi);
	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
	rspi_write8(rspi, 0, RSPI_SPBFCR);
}

static void qspi_receive_init(const struct rspi_data *rspi)
{
	u8 spsr;

	spsr = rspi_read8(rspi, RSPI_SPSR);
	if (spsr & SPSR_SPRF)
		rspi_read_data(rspi);   /* dummy read */
	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
	rspi_write8(rspi, 0, QSPI_SPBFCR);
}

static bool __rspi_can_dma(const struct rspi_data *rspi,
			   const struct spi_transfer *xfer)
{
	return xfer->len > rspi->ops->fifo_size;
}

static bool rspi_can_dma(struct spi_master *master, struct spi_device *spi,
			 struct spi_transfer *xfer)
{
	struct rspi_data *rspi = spi_master_get_devdata(master);

	return __rspi_can_dma(rspi, xfer);
}

static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
					 struct spi_transfer *xfer)
{
	if (!rspi->master->can_dma || !__rspi_can_dma(rspi, xfer))
		return -EAGAIN;

	/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
	return rspi_dma_transfer(rspi, &xfer->tx_sg,
				xfer->rx_buf ? &xfer->rx_sg : NULL);
}

static int rspi_common_transfer(struct rspi_data *rspi,
				struct spi_transfer *xfer)
{
	int ret;

	ret = rspi_dma_check_then_transfer(rspi, xfer);
	if (ret != -EAGAIN)
		return ret;

	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
	if (ret < 0)
		return ret;

	/* Wait for the last transmission */
	rspi_wait_for_tx_empty(rspi);

	return 0;
}

static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
			     struct spi_transfer *xfer)
{
	struct rspi_data *rspi = spi_master_get_devdata(master);
	u8 spcr;

	spcr = rspi_read8(rspi, RSPI_SPCR);
	if (xfer->rx_buf) {
		rspi_receive_init(rspi);
		spcr &= ~SPCR_TXMD;
	} else {
		spcr |= SPCR_TXMD;
	}
	rspi_write8(rspi, spcr, RSPI_SPCR);

	return rspi_common_transfer(rspi, xfer);
}

static int rspi_rz_transfer_one(struct spi_master *master,
				struct spi_device *spi,
				struct spi_transfer *xfer)
{
	struct rspi_data *rspi = spi_master_get_devdata(master);

	rspi_rz_receive_init(rspi);

	return rspi_common_transfer(rspi, xfer);
}

static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
					u8 *rx, unsigned int len)
{
	unsigned int i, n;
	int ret;

	while (len > 0) {
		n = qspi_set_send_trigger(rspi, len);
		qspi_set_receive_trigger(rspi, len);
		if (n == QSPI_BUFFER_SIZE) {
			ret = rspi_wait_for_tx_empty(rspi);
			if (ret < 0) {
				dev_err(&rspi->master->dev, "transmit timeout\n");
				return ret;
			}
			for (i = 0; i < n; i++)
				rspi_write_data(rspi, *tx++);

			ret = rspi_wait_for_rx_full(rspi);
			if (ret < 0) {
				dev_err(&rspi->master->dev, "receive timeout\n");
				return ret;
			}
			for (i = 0; i < n; i++)
				*rx++ = rspi_read_data(rspi);
		} else {
			ret = rspi_pio_transfer(rspi, tx, rx, n);
			if (ret < 0)
				return ret;
		}
		len -= n;
	}

	return 0;
}

static int qspi_transfer_out_in(struct rspi_data *rspi,
				struct spi_transfer *xfer)
{
	int ret;

	qspi_receive_init(rspi);

	ret = rspi_dma_check_then_transfer(rspi, xfer);
	if (ret != -EAGAIN)
		return ret;

	return qspi_trigger_transfer_out_in(rspi, xfer->tx_buf,
					    xfer->rx_buf, xfer->len);
}

static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
{
	const u8 *tx = xfer->tx_buf;
	unsigned int n = xfer->len;
	unsigned int i, len;
	int ret;

	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
		ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
		if (ret != -EAGAIN)
			return ret;
	}

	while (n > 0) {
		len = qspi_set_send_trigger(rspi, n);
		if (len == QSPI_BUFFER_SIZE) {
			ret = rspi_wait_for_tx_empty(rspi);
			if (ret < 0) {
				dev_err(&rspi->master->dev, "transmit timeout\n");
				return ret;
			}
			for (i = 0; i < len; i++)
				rspi_write_data(rspi, *tx++);
		} else {
			ret = rspi_pio_transfer(rspi, tx, NULL, len);
			if (ret < 0)
				return ret;
		}
		n -= len;
	}

	/* Wait for the last transmission */
	rspi_wait_for_tx_empty(rspi);

	return 0;
}

static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
{
	u8 *rx = xfer->rx_buf;
	unsigned int n = xfer->len;
	unsigned int i, len;
	int ret;

	if (rspi->master->can_dma && __rspi_can_dma(rspi, xfer)) {
		int ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
		if (ret != -EAGAIN)
			return ret;
	}

	while (n > 0) {
		len = qspi_set_receive_trigger(rspi, n);
		if (len == QSPI_BUFFER_SIZE) {
			ret = rspi_wait_for_rx_full(rspi);
			if (ret < 0) {
				dev_err(&rspi->master->dev, "receive timeout\n");
				return ret;
			}
			for (i = 0; i < len; i++)
				*rx++ = rspi_read_data(rspi);
		} else {
			ret = rspi_pio_transfer(rspi, NULL, rx, len);
			if (ret < 0)
				return ret;
		}
		n -= len;
	}

	return 0;
}

static int qspi_transfer_one(struct spi_master *master, struct spi_device *spi,
			     struct spi_transfer *xfer)
{
	struct rspi_data *rspi = spi_master_get_devdata(master);

	if (spi->mode & SPI_LOOP) {
		return qspi_transfer_out_in(rspi, xfer);
	} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
		/* Quad or Dual SPI Write */
		return qspi_transfer_out(rspi, xfer);
	} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
		/* Quad or Dual SPI Read */
		return qspi_transfer_in(rspi, xfer);
	} else {
		/* Single SPI Transfer */
		return qspi_transfer_out_in(rspi, xfer);
	}
}

static int rspi_setup(struct spi_device *spi)
{
	struct rspi_data *rspi = spi_master_get_devdata(spi->master);

	rspi->max_speed_hz = spi->max_speed_hz;

	rspi->spcmd = SPCMD_SSLKP;
	if (spi->mode & SPI_CPOL)
		rspi->spcmd |= SPCMD_CPOL;
	if (spi->mode & SPI_CPHA)
		rspi->spcmd |= SPCMD_CPHA;

	/* CMOS output mode and MOSI signal from previous transfer */
	rspi->sppcr = 0;
	if (spi->mode & SPI_LOOP)
		rspi->sppcr |= SPPCR_SPLP;

	set_config_register(rspi, 8);

	return 0;
}

static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
{
	if (xfer->tx_buf)
		switch (xfer->tx_nbits) {
		case SPI_NBITS_QUAD:
			return SPCMD_SPIMOD_QUAD;
		case SPI_NBITS_DUAL:
			return SPCMD_SPIMOD_DUAL;
		default:
			return 0;
		}
	if (xfer->rx_buf)
		switch (xfer->rx_nbits) {
		case SPI_NBITS_QUAD:
			return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
		case SPI_NBITS_DUAL:
			return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
		default:
			return 0;
		}

	return 0;
}

static int qspi_setup_sequencer(struct rspi_data *rspi,
				const struct spi_message *msg)
{
	const struct spi_transfer *xfer;
	unsigned int i = 0, len = 0;
	u16 current_mode = 0xffff, mode;

	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
		mode = qspi_transfer_mode(xfer);
		if (mode == current_mode) {
			len += xfer->len;
			continue;
		}

		/* Transfer mode change */
		if (i) {
			/* Set transfer data length of previous transfer */
			rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
		}

		if (i >= QSPI_NUM_SPCMD) {
			dev_err(&msg->spi->dev,
				"Too many different transfer modes");
			return -EINVAL;
		}

		/* Program transfer mode for this transfer */
		rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
		current_mode = mode;
		len = xfer->len;
		i++;
	}
	if (i) {
		/* Set final transfer data length and sequence length */
		rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
		rspi_write8(rspi, i - 1, RSPI_SPSCR);
	}

	return 0;
}

static int rspi_prepare_message(struct spi_master *master,
				struct spi_message *msg)
{
	struct rspi_data *rspi = spi_master_get_devdata(master);
	int ret;

	if (msg->spi->mode &
	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
		/* Setup sequencer for messages with multiple transfer modes */
		ret = qspi_setup_sequencer(rspi, msg);
		if (ret < 0)
			return ret;
	}

	/* Enable SPI function in master mode */
	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
	return 0;
}

static int rspi_unprepare_message(struct spi_master *master,
				  struct spi_message *msg)
{
	struct rspi_data *rspi = spi_master_get_devdata(master);

	/* Disable SPI function */
	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);

	/* Reset sequencer for Single SPI Transfers */
	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
	rspi_write8(rspi, 0, RSPI_SPSCR);
	return 0;
}

static irqreturn_t rspi_irq_mux(int irq, void *_sr)
{
	struct rspi_data *rspi = _sr;
	u8 spsr;
	irqreturn_t ret = IRQ_NONE;
	u8 disable_irq = 0;

	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
	if (spsr & SPSR_SPRF)
		disable_irq |= SPCR_SPRIE;
	if (spsr & SPSR_SPTEF)
		disable_irq |= SPCR_SPTIE;

	if (disable_irq) {
		ret = IRQ_HANDLED;
		rspi_disable_irq(rspi, disable_irq);
		wake_up(&rspi->wait);
	}

	return ret;
}

static irqreturn_t rspi_irq_rx(int irq, void *_sr)
{
	struct rspi_data *rspi = _sr;
	u8 spsr;

	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
	if (spsr & SPSR_SPRF) {
		rspi_disable_irq(rspi, SPCR_SPRIE);
		wake_up(&rspi->wait);
		return IRQ_HANDLED;
	}

	return 0;
}

static irqreturn_t rspi_irq_tx(int irq, void *_sr)
{
	struct rspi_data *rspi = _sr;
	u8 spsr;

	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
	if (spsr & SPSR_SPTEF) {
		rspi_disable_irq(rspi, SPCR_SPTIE);
		wake_up(&rspi->wait);
		return IRQ_HANDLED;
	}

	return 0;
}

static struct dma_chan *rspi_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_1_BYTE;
	} else {
		cfg.src_addr = port_addr;
		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
	}

	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 rspi_request_dma(struct device *dev, struct spi_master *master,
			    const struct resource *res)
{
	const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
	unsigned int dma_tx_id, dma_rx_id;

	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 (rspi_pd && rspi_pd->dma_tx_id && rspi_pd->dma_rx_id) {
		dma_tx_id = rspi_pd->dma_tx_id;
		dma_rx_id = rspi_pd->dma_rx_id;
	} else {
		/* The driver assumes no error. */
		return 0;
	}

	master->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
					       res->start + RSPI_SPDR);
	if (!master->dma_tx)
		return -ENODEV;

	master->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
					       res->start + RSPI_SPDR);
	if (!master->dma_rx) {
		dma_release_channel(master->dma_tx);
		master->dma_tx = NULL;
		return -ENODEV;
	}

	master->can_dma = rspi_can_dma;
	dev_info(dev, "DMA available");
	return 0;
}

static void rspi_release_dma(struct spi_master *master)
{
	if (master->dma_tx)
		dma_release_channel(master->dma_tx);
	if (master->dma_rx)
		dma_release_channel(master->dma_rx);
}

static int rspi_remove(struct platform_device *pdev)
{
	struct rspi_data *rspi = platform_get_drvdata(pdev);

	rspi_release_dma(rspi->master);
	pm_runtime_disable(&pdev->dev);

	return 0;
}

static const struct spi_ops rspi_ops = {
	.set_config_register =	rspi_set_config_register,
	.transfer_one =		rspi_transfer_one,
	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
	.flags =		SPI_MASTER_MUST_TX,
	.fifo_size =		8,
};

static const struct spi_ops rspi_rz_ops = {
	.set_config_register =	rspi_rz_set_config_register,
	.transfer_one =		rspi_rz_transfer_one,
	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP,
	.flags =		SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
	.fifo_size =		8,	/* 8 for TX, 32 for RX */
};

static const struct spi_ops qspi_ops = {
	.set_config_register =	qspi_set_config_register,
	.transfer_one =		qspi_transfer_one,
	.mode_bits =		SPI_CPHA | SPI_CPOL | SPI_LOOP |
				SPI_TX_DUAL | SPI_TX_QUAD |
				SPI_RX_DUAL | SPI_RX_QUAD,
	.flags =		SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
	.fifo_size =		32,
};

#ifdef CONFIG_OF
static const struct of_device_id rspi_of_match[] = {
	/* RSPI on legacy SH */
	{ .compatible = "renesas,rspi", .data = &rspi_ops },
	/* RSPI on RZ/A1H */
	{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
	/* QSPI on R-Car Gen2 */
	{ .compatible = "renesas,qspi", .data = &qspi_ops },
	{ /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, rspi_of_match);

static int rspi_parse_dt(struct device *dev, struct spi_master *master)
{
	u32 num_cs;
	int error;

	/* Parse DT properties */
	error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
	if (error) {
		dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
		return error;
	}

	master->num_chipselect = num_cs;
	return 0;
}
#else
#define rspi_of_match	NULL
static inline int rspi_parse_dt(struct device *dev, struct spi_master *master)
{
	return -EINVAL;
}
#endif /* CONFIG_OF */

static int rspi_request_irq(struct device *dev, unsigned int irq,
			    irq_handler_t handler, const char *suffix,
			    void *dev_id)
{
	const char *name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
					  dev_name(dev), suffix);
	if (!name)
		return -ENOMEM;

	return devm_request_irq(dev, irq, handler, 0, name, dev_id);
}

static int rspi_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct spi_master *master;
	struct rspi_data *rspi;
	int ret;
	const struct of_device_id *of_id;
	const struct rspi_plat_data *rspi_pd;
	const struct spi_ops *ops;

	master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
	if (master == NULL)
		return -ENOMEM;

	of_id = of_match_device(rspi_of_match, &pdev->dev);
	if (of_id) {
		ops = of_id->data;
		ret = rspi_parse_dt(&pdev->dev, master);
		if (ret)
			goto error1;
	} else {
		ops = (struct spi_ops *)pdev->id_entry->driver_data;
		rspi_pd = dev_get_platdata(&pdev->dev);
		if (rspi_pd && rspi_pd->num_chipselect)
			master->num_chipselect = rspi_pd->num_chipselect;
		else
			master->num_chipselect = 2; /* default */
	}

	/* ops parameter check */
	if (!ops->set_config_register) {
		dev_err(&pdev->dev, "there is no set_config_register\n");
		ret = -ENODEV;
		goto error1;
	}

	rspi = spi_master_get_devdata(master);
	platform_set_drvdata(pdev, rspi);
	rspi->ops = ops;
	rspi->master = master;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	rspi->addr = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(rspi->addr)) {
		ret = PTR_ERR(rspi->addr);
		goto error1;
	}

	rspi->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(rspi->clk)) {
		dev_err(&pdev->dev, "cannot get clock\n");
		ret = PTR_ERR(rspi->clk);
		goto error1;
	}

	pm_runtime_enable(&pdev->dev);

	init_waitqueue_head(&rspi->wait);

	master->bus_num = pdev->id;
	master->setup = rspi_setup;
	master->auto_runtime_pm = true;
	master->transfer_one = ops->transfer_one;
	master->prepare_message = rspi_prepare_message;
	master->unprepare_message = rspi_unprepare_message;
	master->mode_bits = ops->mode_bits;
	master->flags = ops->flags;
	master->dev.of_node = pdev->dev.of_node;

	ret = platform_get_irq_byname(pdev, "rx");
	if (ret < 0) {
		ret = platform_get_irq_byname(pdev, "mux");
		if (ret < 0)
			ret = platform_get_irq(pdev, 0);
		if (ret >= 0)
			rspi->rx_irq = rspi->tx_irq = ret;
	} else {
		rspi->rx_irq = ret;
		ret = platform_get_irq_byname(pdev, "tx");
		if (ret >= 0)
			rspi->tx_irq = ret;
	}
	if (ret < 0) {
		dev_err(&pdev->dev, "platform_get_irq error\n");
		goto error2;
	}

	if (rspi->rx_irq == rspi->tx_irq) {
		/* Single multiplexed interrupt */
		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
				       "mux", rspi);
	} else {
		/* Multi-interrupt mode, only SPRI and SPTI are used */
		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
				       "rx", rspi);
		if (!ret)
			ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
					       rspi_irq_tx, "tx", rspi);
	}
	if (ret < 0) {
		dev_err(&pdev->dev, "request_irq error\n");
		goto error2;
	}

	ret = rspi_request_dma(&pdev->dev, master, res);
	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 error3;
	}

	dev_info(&pdev->dev, "probed\n");

	return 0;

error3:
	rspi_release_dma(master);
error2:
	pm_runtime_disable(&pdev->dev);
error1:
	spi_master_put(master);

	return ret;
}

static const struct platform_device_id spi_driver_ids[] = {
	{ "rspi",	(kernel_ulong_t)&rspi_ops },
	{ "rspi-rz",	(kernel_ulong_t)&rspi_rz_ops },
	{ "qspi",	(kernel_ulong_t)&qspi_ops },
	{},
};

MODULE_DEVICE_TABLE(platform, spi_driver_ids);

#ifdef CONFIG_PM_SLEEP
static int rspi_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rspi_data *rspi = platform_get_drvdata(pdev);

	return spi_master_suspend(rspi->master);
}

static int rspi_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct rspi_data *rspi = platform_get_drvdata(pdev);

	return spi_master_resume(rspi->master);
}

static SIMPLE_DEV_PM_OPS(rspi_pm_ops, rspi_suspend, rspi_resume);
#define DEV_PM_OPS	&rspi_pm_ops
#else
#define DEV_PM_OPS	NULL
#endif /* CONFIG_PM_SLEEP */

static struct platform_driver rspi_driver = {
	.probe =	rspi_probe,
	.remove =	rspi_remove,
	.id_table =	spi_driver_ids,
	.driver		= {
		.name = "renesas_spi",
		.pm = DEV_PM_OPS,
		.of_match_table = of_match_ptr(rspi_of_match),
	},
};
module_platform_driver(rspi_driver);

MODULE_DESCRIPTION("Renesas RSPI bus driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Yoshihiro Shimoda");
MODULE_ALIAS("platform:rspi");