aboutsummaryrefslogtreecommitdiffstats
path: root/sound/soc/fsl/fsl_ssi.c
blob: 0d48804218b1bdbc31198fbb6b0ce16bc09a4fc3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
/*
 * Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
 *
 * Author: Timur Tabi <timur@freescale.com>
 *
 * Copyright 2007-2010 Freescale Semiconductor, Inc.
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 *
 *
 * Some notes why imx-pcm-fiq is used instead of DMA on some boards:
 *
 * The i.MX SSI core has some nasty limitations in AC97 mode. While most
 * sane processor vendors have a FIFO per AC97 slot, the i.MX has only
 * one FIFO which combines all valid receive slots. We cannot even select
 * which slots we want to receive. The WM9712 with which this driver
 * was developed with always sends GPIO status data in slot 12 which
 * we receive in our (PCM-) data stream. The only chance we have is to
 * manually skip this data in the FIQ handler. With sampling rates different
 * from 48000Hz not every frame has valid receive data, so the ratio
 * between pcm data and GPIO status data changes. Our FIQ handler is not
 * able to handle this, hence this driver only works with 48000Hz sampling
 * rate.
 * Reading and writing AC97 registers is another challenge. The core
 * provides us status bits when the read register is updated with *another*
 * value. When we read the same register two times (and the register still
 * contains the same value) these status bits are not set. We work
 * around this by not polling these bits but only wait a fixed delay.
 */

#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>

#include "fsl_ssi.h"
#include "imx-pcm.h"

/**
 * FSLSSI_I2S_RATES: sample rates supported by the I2S
 *
 * This driver currently only supports the SSI running in I2S slave mode,
 * which means the codec determines the sample rate.  Therefore, we tell
 * ALSA that we support all rates and let the codec driver decide what rates
 * are really supported.
 */
#define FSLSSI_I2S_RATES SNDRV_PCM_RATE_CONTINUOUS

/**
 * FSLSSI_I2S_FORMATS: audio formats supported by the SSI
 *
 * The SSI has a limitation in that the samples must be in the same byte
 * order as the host CPU.  This is because when multiple bytes are written
 * to the STX register, the bytes and bits must be written in the same
 * order.  The STX is a shift register, so all the bits need to be aligned
 * (bit-endianness must match byte-endianness).  Processors typically write
 * the bits within a byte in the same order that the bytes of a word are
 * written in.  So if the host CPU is big-endian, then only big-endian
 * samples will be written to STX properly.
 */
#ifdef __BIG_ENDIAN
#define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE | \
	 SNDRV_PCM_FMTBIT_S18_3BE | SNDRV_PCM_FMTBIT_S20_3BE | \
	 SNDRV_PCM_FMTBIT_S24_3BE | SNDRV_PCM_FMTBIT_S24_BE)
#else
#define FSLSSI_I2S_FORMATS (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE | \
	 SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S20_3LE | \
	 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_LE)
#endif

#define FSLSSI_SIER_DBG_RX_FLAGS (CCSR_SSI_SIER_RFF0_EN | \
		CCSR_SSI_SIER_RLS_EN | CCSR_SSI_SIER_RFS_EN | \
		CCSR_SSI_SIER_ROE0_EN | CCSR_SSI_SIER_RFRC_EN)
#define FSLSSI_SIER_DBG_TX_FLAGS (CCSR_SSI_SIER_TFE0_EN | \
		CCSR_SSI_SIER_TLS_EN | CCSR_SSI_SIER_TFS_EN | \
		CCSR_SSI_SIER_TUE0_EN | CCSR_SSI_SIER_TFRC_EN)

enum fsl_ssi_type {
	FSL_SSI_MCP8610,
	FSL_SSI_MX21,
	FSL_SSI_MX35,
	FSL_SSI_MX51,
};

struct fsl_ssi_reg_val {
	u32 sier;
	u32 srcr;
	u32 stcr;
	u32 scr;
};

struct fsl_ssi_rxtx_reg_val {
	struct fsl_ssi_reg_val rx;
	struct fsl_ssi_reg_val tx;
};
static const struct regmap_config fsl_ssi_regconfig = {
	.max_register = CCSR_SSI_SACCDIS,
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.val_format_endian = REGMAP_ENDIAN_NATIVE,
};

struct fsl_ssi_soc_data {
	bool imx;
	bool offline_config;
	u32 sisr_write_mask;
};

/**
 * fsl_ssi_private: per-SSI private data
 *
 * @reg: Pointer to the regmap registers
 * @irq: IRQ of this SSI
 * @cpu_dai_drv: CPU DAI driver for this device
 *
 * @dai_fmt: DAI configuration this device is currently used with
 * @i2s_mode: i2s and network mode configuration of the device. Is used to
 * switch between normal and i2s/network mode
 * mode depending on the number of channels
 * @use_dma: DMA is used or FIQ with stream filter
 * @use_dual_fifo: DMA with support for both FIFOs used
 * @fifo_deph: Depth of the SSI FIFOs
 * @rxtx_reg_val: Specific register settings for receive/transmit configuration
 *
 * @clk: SSI clock
 * @baudclk: SSI baud clock for master mode
 * @baudclk_streams: Active streams that are using baudclk
 * @bitclk_freq: bitclock frequency set by .set_dai_sysclk
 *
 * @dma_params_tx: DMA transmit parameters
 * @dma_params_rx: DMA receive parameters
 * @ssi_phys: physical address of the SSI registers
 *
 * @fiq_params: FIQ stream filtering parameters
 *
 * @pdev: Pointer to pdev used for deprecated fsl-ssi sound card
 *
 * @dbg_stats: Debugging statistics
 *
 * @soc: SoC specifc data
 */
struct fsl_ssi_private {
	struct regmap *regs;
	int irq;
	struct snd_soc_dai_driver cpu_dai_drv;

	unsigned int dai_fmt;
	u8 i2s_mode;
	bool use_dma;
	bool use_dual_fifo;
	bool has_ipg_clk_name;
	unsigned int fifo_depth;
	struct fsl_ssi_rxtx_reg_val rxtx_reg_val;

	struct clk *clk;
	struct clk *baudclk;
	unsigned int baudclk_streams;
	unsigned int bitclk_freq;

	/* DMA params */
	struct snd_dmaengine_dai_dma_data dma_params_tx;
	struct snd_dmaengine_dai_dma_data dma_params_rx;
	dma_addr_t ssi_phys;

	/* params for non-dma FIQ stream filtered mode */
	struct imx_pcm_fiq_params fiq_params;

	/* Used when using fsl-ssi as sound-card. This is only used by ppc and
	 * should be replaced with simple-sound-card. */
	struct platform_device *pdev;

	struct fsl_ssi_dbg dbg_stats;

	const struct fsl_ssi_soc_data *soc;
};

/*
 * imx51 and later SoCs have a slightly different IP that allows the
 * SSI configuration while the SSI unit is running.
 *
 * More important, it is necessary on those SoCs to configure the
 * sperate TX/RX DMA bits just before starting the stream
 * (fsl_ssi_trigger). The SDMA unit has to be configured before fsl_ssi
 * sends any DMA requests to the SDMA unit, otherwise it is not defined
 * how the SDMA unit handles the DMA request.
 *
 * SDMA units are present on devices starting at imx35 but the imx35
 * reference manual states that the DMA bits should not be changed
 * while the SSI unit is running (SSIEN). So we support the necessary
 * online configuration of fsl-ssi starting at imx51.
 */

static struct fsl_ssi_soc_data fsl_ssi_mpc8610 = {
	.imx = false,
	.offline_config = true,
	.sisr_write_mask = CCSR_SSI_SISR_RFRC | CCSR_SSI_SISR_TFRC |
			CCSR_SSI_SISR_ROE0 | CCSR_SSI_SISR_ROE1 |
			CCSR_SSI_SISR_TUE0 | CCSR_SSI_SISR_TUE1,
};

static struct fsl_ssi_soc_data fsl_ssi_imx21 = {
	.imx = true,
	.offline_config = true,
	.sisr_write_mask = 0,
};

static struct fsl_ssi_soc_data fsl_ssi_imx35 = {
	.imx = true,
	.offline_config = true,
	.sisr_write_mask = CCSR_SSI_SISR_RFRC | CCSR_SSI_SISR_TFRC |
			CCSR_SSI_SISR_ROE0 | CCSR_SSI_SISR_ROE1 |
			CCSR_SSI_SISR_TUE0 | CCSR_SSI_SISR_TUE1,
};

static struct fsl_ssi_soc_data fsl_ssi_imx51 = {
	.imx = true,
	.offline_config = false,
	.sisr_write_mask = CCSR_SSI_SISR_ROE0 | CCSR_SSI_SISR_ROE1 |
		CCSR_SSI_SISR_TUE0 | CCSR_SSI_SISR_TUE1,
};

static const struct of_device_id fsl_ssi_ids[] = {
	{ .compatible = "fsl,mpc8610-ssi", .data = &fsl_ssi_mpc8610 },
	{ .compatible = "fsl,imx51-ssi", .data = &fsl_ssi_imx51 },
	{ .compatible = "fsl,imx35-ssi", .data = &fsl_ssi_imx35 },
	{ .compatible = "fsl,imx21-ssi", .data = &fsl_ssi_imx21 },
	{}
};
MODULE_DEVICE_TABLE(of, fsl_ssi_ids);

static bool fsl_ssi_is_ac97(struct fsl_ssi_private *ssi_private)
{
	return !!(ssi_private->dai_fmt & SND_SOC_DAIFMT_AC97);
}

static bool fsl_ssi_is_i2s_master(struct fsl_ssi_private *ssi_private)
{
	return (ssi_private->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
		SND_SOC_DAIFMT_CBS_CFS;
}

static bool fsl_ssi_is_i2s_cbm_cfs(struct fsl_ssi_private *ssi_private)
{
	return (ssi_private->dai_fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
		SND_SOC_DAIFMT_CBM_CFS;
}
/**
 * fsl_ssi_isr: SSI interrupt handler
 *
 * Although it's possible to use the interrupt handler to send and receive
 * data to/from the SSI, we use the DMA instead.  Programming is more
 * complicated, but the performance is much better.
 *
 * This interrupt handler is used only to gather statistics.
 *
 * @irq: IRQ of the SSI device
 * @dev_id: pointer to the ssi_private structure for this SSI device
 */
static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
{
	struct fsl_ssi_private *ssi_private = dev_id;
	struct regmap *regs = ssi_private->regs;
	__be32 sisr;
	__be32 sisr2;

	/* We got an interrupt, so read the status register to see what we
	   were interrupted for.  We mask it with the Interrupt Enable register
	   so that we only check for events that we're interested in.
	 */
	regmap_read(regs, CCSR_SSI_SISR, &sisr);

	sisr2 = sisr & ssi_private->soc->sisr_write_mask;
	/* Clear the bits that we set */
	if (sisr2)
		regmap_write(regs, CCSR_SSI_SISR, sisr2);

	fsl_ssi_dbg_isr(&ssi_private->dbg_stats, sisr);

	return IRQ_HANDLED;
}

/*
 * Enable/Disable all rx/tx config flags at once.
 */
static void fsl_ssi_rxtx_config(struct fsl_ssi_private *ssi_private,
		bool enable)
{
	struct regmap *regs = ssi_private->regs;
	struct fsl_ssi_rxtx_reg_val *vals = &ssi_private->rxtx_reg_val;

	if (enable) {
		regmap_update_bits(regs, CCSR_SSI_SIER,
				vals->rx.sier | vals->tx.sier,
				vals->rx.sier | vals->tx.sier);
		regmap_update_bits(regs, CCSR_SSI_SRCR,
				vals->rx.srcr | vals->tx.srcr,
				vals->rx.srcr | vals->tx.srcr);
		regmap_update_bits(regs, CCSR_SSI_STCR,
				vals->rx.stcr | vals->tx.stcr,
				vals->rx.stcr | vals->tx.stcr);
	} else {
		regmap_update_bits(regs, CCSR_SSI_SRCR,
				vals->rx.srcr | vals->tx.srcr, 0);
		regmap_update_bits(regs, CCSR_SSI_STCR,
				vals->rx.stcr | vals->tx.stcr, 0);
		regmap_update_bits(regs, CCSR_SSI_SIER,
				vals->rx.sier | vals->tx.sier, 0);
	}
}

/*
 * Calculate the bits that have to be disabled for the current stream that is
 * getting disabled. This keeps the bits enabled that are necessary for the
 * second stream to work if 'stream_active' is true.
 *
 * Detailed calculation:
 * These are the values that need to be active after disabling. For non-active
 * second stream, this is 0:
 *	vals_stream * !!stream_active
 *
 * The following computes the overall differences between the setup for the
 * to-disable stream and the active stream, a simple XOR:
 *	vals_disable ^ (vals_stream * !!(stream_active))
 *
 * The full expression adds a mask on all values we care about
 */
#define fsl_ssi_disable_val(vals_disable, vals_stream, stream_active) \
	((vals_disable) & \
	 ((vals_disable) ^ ((vals_stream) * (u32)!!(stream_active))))

/*
 * Enable/Disable a ssi configuration. You have to pass either
 * ssi_private->rxtx_reg_val.rx or tx as vals parameter.
 */
static void fsl_ssi_config(struct fsl_ssi_private *ssi_private, bool enable,
		struct fsl_ssi_reg_val *vals)
{
	struct regmap *regs = ssi_private->regs;
	struct fsl_ssi_reg_val *avals;
	int nr_active_streams;
	u32 scr_val;
	int keep_active;

	regmap_read(regs, CCSR_SSI_SCR, &scr_val);

	nr_active_streams = !!(scr_val & CCSR_SSI_SCR_TE) +
				!!(scr_val & CCSR_SSI_SCR_RE);

	if (nr_active_streams - 1 > 0)
		keep_active = 1;
	else
		keep_active = 0;

	/* Find the other direction values rx or tx which we do not want to
	 * modify */
	if (&ssi_private->rxtx_reg_val.rx == vals)
		avals = &ssi_private->rxtx_reg_val.tx;
	else
		avals = &ssi_private->rxtx_reg_val.rx;

	/* If vals should be disabled, start with disabling the unit */
	if (!enable) {
		u32 scr = fsl_ssi_disable_val(vals->scr, avals->scr,
				keep_active);
		regmap_update_bits(regs, CCSR_SSI_SCR, scr, 0);
	}

	/*
	 * We are running on a SoC which does not support online SSI
	 * reconfiguration, so we have to enable all necessary flags at once
	 * even if we do not use them later (capture and playback configuration)
	 */
	if (ssi_private->soc->offline_config) {
		if ((enable && !nr_active_streams) ||
				(!enable && !keep_active))
			fsl_ssi_rxtx_config(ssi_private, enable);

		goto config_done;
	}

	/*
	 * Configure single direction units while the SSI unit is running
	 * (online configuration)
	 */
	if (enable) {
		regmap_update_bits(regs, CCSR_SSI_SIER, vals->sier, vals->sier);
		regmap_update_bits(regs, CCSR_SSI_SRCR, vals->srcr, vals->srcr);
		regmap_update_bits(regs, CCSR_SSI_STCR, vals->stcr, vals->stcr);
	} else {
		u32 sier;
		u32 srcr;
		u32 stcr;

		/*
		 * Disabling the necessary flags for one of rx/tx while the
		 * other stream is active is a little bit more difficult. We
		 * have to disable only those flags that differ between both
		 * streams (rx XOR tx) and that are set in the stream that is
		 * disabled now. Otherwise we could alter flags of the other
		 * stream
		 */

		/* These assignments are simply vals without bits set in avals*/
		sier = fsl_ssi_disable_val(vals->sier, avals->sier,
				keep_active);
		srcr = fsl_ssi_disable_val(vals->srcr, avals->srcr,
				keep_active);
		stcr = fsl_ssi_disable_val(vals->stcr, avals->stcr,
				keep_active);

		regmap_update_bits(regs, CCSR_SSI_SRCR, srcr, 0);
		regmap_update_bits(regs, CCSR_SSI_STCR, stcr, 0);
		regmap_update_bits(regs, CCSR_SSI_SIER, sier, 0);
	}

config_done:
	/* Enabling of subunits is done after configuration */
	if (enable)
		regmap_update_bits(regs, CCSR_SSI_SCR, vals->scr, vals->scr);
}


static void fsl_ssi_rx_config(struct fsl_ssi_private *ssi_private, bool enable)
{
	fsl_ssi_config(ssi_private, enable, &ssi_private->rxtx_reg_val.rx);
}

static void fsl_ssi_tx_config(struct fsl_ssi_private *ssi_private, bool enable)
{
	fsl_ssi_config(ssi_private, enable, &ssi_private->rxtx_reg_val.tx);
}

/*
 * Setup rx/tx register values used to enable/disable the streams. These will
 * be used later in fsl_ssi_config to setup the streams without the need to
 * check for all different SSI modes.
 */
static void fsl_ssi_setup_reg_vals(struct fsl_ssi_private *ssi_private)
{
	struct fsl_ssi_rxtx_reg_val *reg = &ssi_private->rxtx_reg_val;

	reg->rx.sier = CCSR_SSI_SIER_RFF0_EN;
	reg->rx.srcr = CCSR_SSI_SRCR_RFEN0;
	reg->rx.scr = 0;
	reg->tx.sier = CCSR_SSI_SIER_TFE0_EN;
	reg->tx.stcr = CCSR_SSI_STCR_TFEN0;
	reg->tx.scr = 0;

	if (!fsl_ssi_is_ac97(ssi_private)) {
		reg->rx.scr = CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_RE;
		reg->rx.sier |= CCSR_SSI_SIER_RFF0_EN;
		reg->tx.scr = CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE;
		reg->tx.sier |= CCSR_SSI_SIER_TFE0_EN;
	}

	if (ssi_private->use_dma) {
		reg->rx.sier |= CCSR_SSI_SIER_RDMAE;
		reg->tx.sier |= CCSR_SSI_SIER_TDMAE;
	} else {
		reg->rx.sier |= CCSR_SSI_SIER_RIE;
		reg->tx.sier |= CCSR_SSI_SIER_TIE;
	}

	reg->rx.sier |= FSLSSI_SIER_DBG_RX_FLAGS;
	reg->tx.sier |= FSLSSI_SIER_DBG_TX_FLAGS;
}

static void fsl_ssi_setup_ac97(struct fsl_ssi_private *ssi_private)
{
	struct regmap *regs = ssi_private->regs;

	/*
	 * Setup the clock control register
	 */
	regmap_write(regs, CCSR_SSI_STCCR,
			CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13));
	regmap_write(regs, CCSR_SSI_SRCCR,
			CCSR_SSI_SxCCR_WL(17) | CCSR_SSI_SxCCR_DC(13));

	/*
	 * Enable AC97 mode and startup the SSI
	 */
	regmap_write(regs, CCSR_SSI_SACNT,
			CCSR_SSI_SACNT_AC97EN | CCSR_SSI_SACNT_FV);
	regmap_write(regs, CCSR_SSI_SACCDIS, 0xff);
	regmap_write(regs, CCSR_SSI_SACCEN, 0x300);

	/*
	 * Enable SSI, Transmit and Receive. AC97 has to communicate with the
	 * codec before a stream is started.
	 */
	regmap_update_bits(regs, CCSR_SSI_SCR,
			CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE,
			CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE | CCSR_SSI_SCR_RE);

	regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_WAIT(3));
}

/**
 * fsl_ssi_startup: create a new substream
 *
 * This is the first function called when a stream is opened.
 *
 * If this is the first stream open, then grab the IRQ and program most of
 * the SSI registers.
 */
static int fsl_ssi_startup(struct snd_pcm_substream *substream,
			   struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct fsl_ssi_private *ssi_private =
		snd_soc_dai_get_drvdata(rtd->cpu_dai);
	int ret;

	ret = clk_prepare_enable(ssi_private->clk);
	if (ret)
		return ret;

	/* When using dual fifo mode, it is safer to ensure an even period
	 * size. If appearing to an odd number while DMA always starts its
	 * task from fifo0, fifo1 would be neglected at the end of each
	 * period. But SSI would still access fifo1 with an invalid data.
	 */
	if (ssi_private->use_dual_fifo)
		snd_pcm_hw_constraint_step(substream->runtime, 0,
				SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 2);

	return 0;
}

/**
 * fsl_ssi_shutdown: shutdown the SSI
 *
 */
static void fsl_ssi_shutdown(struct snd_pcm_substream *substream,
				struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct fsl_ssi_private *ssi_private =
		snd_soc_dai_get_drvdata(rtd->cpu_dai);

	clk_disable_unprepare(ssi_private->clk);

}

/**
 * fsl_ssi_set_bclk - configure Digital Audio Interface bit clock
 *
 * Note: This function can be only called when using SSI as DAI master
 *
 * Quick instruction for parameters:
 * freq: Output BCLK frequency = samplerate * 32 (fixed) * channels
 * dir: SND_SOC_CLOCK_OUT -> TxBCLK, SND_SOC_CLOCK_IN -> RxBCLK.
 */
static int fsl_ssi_set_bclk(struct snd_pcm_substream *substream,
		struct snd_soc_dai *cpu_dai,
		struct snd_pcm_hw_params *hw_params)
{
	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
	struct regmap *regs = ssi_private->regs;
	int synchronous = ssi_private->cpu_dai_drv.symmetric_rates, ret;
	u32 pm = 999, div2, psr, stccr, mask, afreq, factor, i;
	unsigned long clkrate, baudrate, tmprate;
	u64 sub, savesub = 100000;
	unsigned int freq;
	bool baudclk_is_used;

	/* Prefer the explicitly set bitclock frequency */
	if (ssi_private->bitclk_freq)
		freq = ssi_private->bitclk_freq;
	else
		freq = params_channels(hw_params) * 32 * params_rate(hw_params);

	/* Don't apply it to any non-baudclk circumstance */
	if (IS_ERR(ssi_private->baudclk))
		return -EINVAL;

	baudclk_is_used = ssi_private->baudclk_streams & ~(BIT(substream->stream));

	/* It should be already enough to divide clock by setting pm alone */
	psr = 0;
	div2 = 0;

	factor = (div2 + 1) * (7 * psr + 1) * 2;

	for (i = 0; i < 255; i++) {
		tmprate = freq * factor * (i + 1);

		if (baudclk_is_used)
			clkrate = clk_get_rate(ssi_private->baudclk);
		else
			clkrate = clk_round_rate(ssi_private->baudclk, tmprate);

		/*
		 * Hardware limitation: The bclk rate must be
		 * never greater than 1/5 IPG clock rate
		 */
		if (clkrate * 5 > clk_get_rate(ssi_private->clk))
			continue;

		clkrate /= factor;
		afreq = clkrate / (i + 1);

		if (freq == afreq)
			sub = 0;
		else if (freq / afreq == 1)
			sub = freq - afreq;
		else if (afreq / freq == 1)
			sub = afreq - freq;
		else
			continue;

		/* Calculate the fraction */
		sub *= 100000;
		do_div(sub, freq);

		if (sub < savesub) {
			baudrate = tmprate;
			savesub = sub;
			pm = i;
		}

		/* We are lucky */
		if (savesub == 0)
			break;
	}

	/* No proper pm found if it is still remaining the initial value */
	if (pm == 999) {
		dev_err(cpu_dai->dev, "failed to handle the required sysclk\n");
		return -EINVAL;
	}

	stccr = CCSR_SSI_SxCCR_PM(pm + 1) | (div2 ? CCSR_SSI_SxCCR_DIV2 : 0) |
		(psr ? CCSR_SSI_SxCCR_PSR : 0);
	mask = CCSR_SSI_SxCCR_PM_MASK | CCSR_SSI_SxCCR_DIV2 |
		CCSR_SSI_SxCCR_PSR;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK || synchronous)
		regmap_update_bits(regs, CCSR_SSI_STCCR, mask, stccr);
	else
		regmap_update_bits(regs, CCSR_SSI_SRCCR, mask, stccr);

	if (!baudclk_is_used) {
		ret = clk_set_rate(ssi_private->baudclk, baudrate);
		if (ret) {
			dev_err(cpu_dai->dev, "failed to set baudclk rate\n");
			return -EINVAL;
		}
	}

	return 0;
}

static int fsl_ssi_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
		int clk_id, unsigned int freq, int dir)
{
	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);

	ssi_private->bitclk_freq = freq;

	return 0;
}

/**
 * fsl_ssi_hw_params - program the sample size
 *
 * Most of the SSI registers have been programmed in the startup function,
 * but the word length must be programmed here.  Unfortunately, programming
 * the SxCCR.WL bits requires the SSI to be temporarily disabled.  This can
 * cause a problem with supporting simultaneous playback and capture.  If
 * the SSI is already playing a stream, then that stream may be temporarily
 * stopped when you start capture.
 *
 * Note: The SxCCR.DC and SxCCR.PM bits are only used if the SSI is the
 * clock master.
 */
static int fsl_ssi_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *hw_params, struct snd_soc_dai *cpu_dai)
{
	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
	struct regmap *regs = ssi_private->regs;
	unsigned int channels = params_channels(hw_params);
	unsigned int sample_size =
		snd_pcm_format_width(params_format(hw_params));
	u32 wl = CCSR_SSI_SxCCR_WL(sample_size);
	int ret;
	u32 scr_val;
	int enabled;

	regmap_read(regs, CCSR_SSI_SCR, &scr_val);
	enabled = scr_val & CCSR_SSI_SCR_SSIEN;

	/*
	 * If we're in synchronous mode, and the SSI is already enabled,
	 * then STCCR is already set properly.
	 */
	if (enabled && ssi_private->cpu_dai_drv.symmetric_rates)
		return 0;

	if (fsl_ssi_is_i2s_master(ssi_private)) {
		ret = fsl_ssi_set_bclk(substream, cpu_dai, hw_params);
		if (ret)
			return ret;

		/* Do not enable the clock if it is already enabled */
		if (!(ssi_private->baudclk_streams & BIT(substream->stream))) {
			ret = clk_prepare_enable(ssi_private->baudclk);
			if (ret)
				return ret;

			ssi_private->baudclk_streams |= BIT(substream->stream);
		}
	}

	if (!fsl_ssi_is_ac97(ssi_private)) {
		u8 i2smode;
		/*
		 * Switch to normal net mode in order to have a frame sync
		 * signal every 32 bits instead of 16 bits
		 */
		if (fsl_ssi_is_i2s_cbm_cfs(ssi_private) && sample_size == 16)
			i2smode = CCSR_SSI_SCR_I2S_MODE_NORMAL |
				CCSR_SSI_SCR_NET;
		else
			i2smode = ssi_private->i2s_mode;

		regmap_update_bits(regs, CCSR_SSI_SCR,
				CCSR_SSI_SCR_NET | CCSR_SSI_SCR_I2S_MODE_MASK,
				channels == 1 ? 0 : i2smode);
	}

	/*
	 * FIXME: The documentation says that SxCCR[WL] should not be
	 * modified while the SSI is enabled.  The only time this can
	 * happen is if we're trying to do simultaneous playback and
	 * capture in asynchronous mode.  Unfortunately, I have been enable
	 * to get that to work at all on the P1022DS.  Therefore, we don't
	 * bother to disable/enable the SSI when setting SxCCR[WL], because
	 * the SSI will stop anyway.  Maybe one day, this will get fixed.
	 */

	/* In synchronous mode, the SSI uses STCCR for capture */
	if ((substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ||
	    ssi_private->cpu_dai_drv.symmetric_rates)
		regmap_update_bits(regs, CCSR_SSI_STCCR, CCSR_SSI_SxCCR_WL_MASK,
				wl);
	else
		regmap_update_bits(regs, CCSR_SSI_SRCCR, CCSR_SSI_SxCCR_WL_MASK,
				wl);

	return 0;
}

static int fsl_ssi_hw_free(struct snd_pcm_substream *substream,
		struct snd_soc_dai *cpu_dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct fsl_ssi_private *ssi_private =
		snd_soc_dai_get_drvdata(rtd->cpu_dai);

	if (fsl_ssi_is_i2s_master(ssi_private) &&
			ssi_private->baudclk_streams & BIT(substream->stream)) {
		clk_disable_unprepare(ssi_private->baudclk);
		ssi_private->baudclk_streams &= ~BIT(substream->stream);
	}

	return 0;
}

static int _fsl_ssi_set_dai_fmt(struct device *dev,
				struct fsl_ssi_private *ssi_private,
				unsigned int fmt)
{
	struct regmap *regs = ssi_private->regs;
	u32 strcr = 0, stcr, srcr, scr, mask;
	u8 wm;

	ssi_private->dai_fmt = fmt;

	if (fsl_ssi_is_i2s_master(ssi_private) && IS_ERR(ssi_private->baudclk)) {
		dev_err(dev, "baudclk is missing which is necessary for master mode\n");
		return -EINVAL;
	}

	fsl_ssi_setup_reg_vals(ssi_private);

	regmap_read(regs, CCSR_SSI_SCR, &scr);
	scr &= ~(CCSR_SSI_SCR_SYN | CCSR_SSI_SCR_I2S_MODE_MASK);
	scr |= CCSR_SSI_SCR_SYNC_TX_FS;

	mask = CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TFDIR | CCSR_SSI_STCR_TXDIR |
		CCSR_SSI_STCR_TSCKP | CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TFSL |
		CCSR_SSI_STCR_TEFS;
	regmap_read(regs, CCSR_SSI_STCR, &stcr);
	regmap_read(regs, CCSR_SSI_SRCR, &srcr);
	stcr &= ~mask;
	srcr &= ~mask;

	ssi_private->i2s_mode = CCSR_SSI_SCR_NET;
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_I2S:
		switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
		case SND_SOC_DAIFMT_CBM_CFS:
		case SND_SOC_DAIFMT_CBS_CFS:
			ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_MASTER;
			regmap_update_bits(regs, CCSR_SSI_STCCR,
					CCSR_SSI_SxCCR_DC_MASK,
					CCSR_SSI_SxCCR_DC(2));
			regmap_update_bits(regs, CCSR_SSI_SRCCR,
					CCSR_SSI_SxCCR_DC_MASK,
					CCSR_SSI_SxCCR_DC(2));
			break;
		case SND_SOC_DAIFMT_CBM_CFM:
			ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_SLAVE;
			break;
		default:
			return -EINVAL;
		}

		/* Data on rising edge of bclk, frame low, 1clk before data */
		strcr |= CCSR_SSI_STCR_TFSI | CCSR_SSI_STCR_TSCKP |
			CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TEFS;
		break;
	case SND_SOC_DAIFMT_LEFT_J:
		/* Data on rising edge of bclk, frame high */
		strcr |= CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TSCKP;
		break;
	case SND_SOC_DAIFMT_DSP_A:
		/* Data on rising edge of bclk, frame high, 1clk before data */
		strcr |= CCSR_SSI_STCR_TFSL | CCSR_SSI_STCR_TSCKP |
			CCSR_SSI_STCR_TXBIT0 | CCSR_SSI_STCR_TEFS;
		break;
	case SND_SOC_DAIFMT_DSP_B:
		/* Data on rising edge of bclk, frame high */
		strcr |= CCSR_SSI_STCR_TFSL | CCSR_SSI_STCR_TSCKP |
			CCSR_SSI_STCR_TXBIT0;
		break;
	case SND_SOC_DAIFMT_AC97:
		ssi_private->i2s_mode |= CCSR_SSI_SCR_I2S_MODE_NORMAL;
		break;
	default:
		return -EINVAL;
	}
	scr |= ssi_private->i2s_mode;

	/* DAI clock inversion */
	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_NB_NF:
		/* Nothing to do for both normal cases */
		break;
	case SND_SOC_DAIFMT_IB_NF:
		/* Invert bit clock */
		strcr ^= CCSR_SSI_STCR_TSCKP;
		break;
	case SND_SOC_DAIFMT_NB_IF:
		/* Invert frame clock */
		strcr ^= CCSR_SSI_STCR_TFSI;
		break;
	case SND_SOC_DAIFMT_IB_IF:
		/* Invert both clocks */
		strcr ^= CCSR_SSI_STCR_TSCKP;
		strcr ^= CCSR_SSI_STCR_TFSI;
		break;
	default:
		return -EINVAL;
	}

	/* DAI clock master masks */
	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBS_CFS:
		strcr |= CCSR_SSI_STCR_TFDIR | CCSR_SSI_STCR_TXDIR;
		scr |= CCSR_SSI_SCR_SYS_CLK_EN;
		break;
	case SND_SOC_DAIFMT_CBM_CFM:
		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
		break;
	case SND_SOC_DAIFMT_CBM_CFS:
		strcr &= ~CCSR_SSI_STCR_TXDIR;
		strcr |= CCSR_SSI_STCR_TFDIR;
		scr &= ~CCSR_SSI_SCR_SYS_CLK_EN;
		break;
	default:
		return -EINVAL;
	}

	stcr |= strcr;
	srcr |= strcr;

	if (ssi_private->cpu_dai_drv.symmetric_rates) {
		/* Need to clear RXDIR when using SYNC mode */
		srcr &= ~CCSR_SSI_SRCR_RXDIR;
		scr |= CCSR_SSI_SCR_SYN;
	}

	regmap_write(regs, CCSR_SSI_STCR, stcr);
	regmap_write(regs, CCSR_SSI_SRCR, srcr);
	regmap_write(regs, CCSR_SSI_SCR, scr);

	/*
	 * Set the watermark for transmit FIFI 0 and receive FIFO 0. We don't
	 * use FIFO 1. We program the transmit water to signal a DMA transfer
	 * if there are only two (or fewer) elements left in the FIFO. Two
	 * elements equals one frame (left channel, right channel). This value,
	 * however, depends on the depth of the transmit buffer.
	 *
	 * We set the watermark on the same level as the DMA burstsize.  For
	 * fiq it is probably better to use the biggest possible watermark
	 * size.
	 */
	if (ssi_private->use_dma)
		wm = ssi_private->fifo_depth - 2;
	else
		wm = ssi_private->fifo_depth;

	regmap_write(regs, CCSR_SSI_SFCSR,
			CCSR_SSI_SFCSR_TFWM0(wm) | CCSR_SSI_SFCSR_RFWM0(wm) |
			CCSR_SSI_SFCSR_TFWM1(wm) | CCSR_SSI_SFCSR_RFWM1(wm));

	if (ssi_private->use_dual_fifo) {
		regmap_update_bits(regs, CCSR_SSI_SRCR, CCSR_SSI_SRCR_RFEN1,
				CCSR_SSI_SRCR_RFEN1);
		regmap_update_bits(regs, CCSR_SSI_STCR, CCSR_SSI_STCR_TFEN1,
				CCSR_SSI_STCR_TFEN1);
		regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_TCH_EN,
				CCSR_SSI_SCR_TCH_EN);
	}

	if (fmt & SND_SOC_DAIFMT_AC97)
		fsl_ssi_setup_ac97(ssi_private);

	return 0;

}

/**
 * fsl_ssi_set_dai_fmt - configure Digital Audio Interface Format.
 */
static int fsl_ssi_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
{
	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);

	return _fsl_ssi_set_dai_fmt(cpu_dai->dev, ssi_private, fmt);
}

/**
 * fsl_ssi_set_dai_tdm_slot - set TDM slot number
 *
 * Note: This function can be only called when using SSI as DAI master
 */
static int fsl_ssi_set_dai_tdm_slot(struct snd_soc_dai *cpu_dai, u32 tx_mask,
				u32 rx_mask, int slots, int slot_width)
{
	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(cpu_dai);
	struct regmap *regs = ssi_private->regs;
	u32 val;

	/* The slot number should be >= 2 if using Network mode or I2S mode */
	regmap_read(regs, CCSR_SSI_SCR, &val);
	val &= CCSR_SSI_SCR_I2S_MODE_MASK | CCSR_SSI_SCR_NET;
	if (val && slots < 2) {
		dev_err(cpu_dai->dev, "slot number should be >= 2 in I2S or NET\n");
		return -EINVAL;
	}

	regmap_update_bits(regs, CCSR_SSI_STCCR, CCSR_SSI_SxCCR_DC_MASK,
			CCSR_SSI_SxCCR_DC(slots));
	regmap_update_bits(regs, CCSR_SSI_SRCCR, CCSR_SSI_SxCCR_DC_MASK,
			CCSR_SSI_SxCCR_DC(slots));

	/* The register SxMSKs needs SSI to provide essential clock due to
	 * hardware design. So we here temporarily enable SSI to set them.
	 */
	regmap_read(regs, CCSR_SSI_SCR, &val);
	val &= CCSR_SSI_SCR_SSIEN;
	regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_SSIEN,
			CCSR_SSI_SCR_SSIEN);

	regmap_write(regs, CCSR_SSI_STMSK, ~tx_mask);
	regmap_write(regs, CCSR_SSI_SRMSK, ~rx_mask);

	regmap_update_bits(regs, CCSR_SSI_SCR, CCSR_SSI_SCR_SSIEN, val);

	return 0;
}

/**
 * fsl_ssi_trigger: start and stop the DMA transfer.
 *
 * This function is called by ALSA to start, stop, pause, and resume the DMA
 * transfer of data.
 *
 * The DMA channel is in external master start and pause mode, which
 * means the SSI completely controls the flow of data.
 */
static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd,
			   struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(rtd->cpu_dai);
	struct regmap *regs = ssi_private->regs;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			fsl_ssi_tx_config(ssi_private, true);
		else
			fsl_ssi_rx_config(ssi_private, true);
		break;

	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			fsl_ssi_tx_config(ssi_private, false);
		else
			fsl_ssi_rx_config(ssi_private, false);
		break;

	default:
		return -EINVAL;
	}

	if (fsl_ssi_is_ac97(ssi_private)) {
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_TX_CLR);
		else
			regmap_write(regs, CCSR_SSI_SOR, CCSR_SSI_SOR_RX_CLR);
	}

	return 0;
}

static int fsl_ssi_dai_probe(struct snd_soc_dai *dai)
{
	struct fsl_ssi_private *ssi_private = snd_soc_dai_get_drvdata(dai);

	if (ssi_private->soc->imx && ssi_private->use_dma) {
		dai->playback_dma_data = &ssi_private->dma_params_tx;
		dai->capture_dma_data = &ssi_private->dma_params_rx;
	}

	return 0;
}

static const struct snd_soc_dai_ops fsl_ssi_dai_ops = {
	.startup	= fsl_ssi_startup,
	.shutdown       = fsl_ssi_shutdown,
	.hw_params	= fsl_ssi_hw_params,
	.hw_free	= fsl_ssi_hw_free,
	.set_fmt	= fsl_ssi_set_dai_fmt,
	.set_sysclk	= fsl_ssi_set_dai_sysclk,
	.set_tdm_slot	= fsl_ssi_set_dai_tdm_slot,
	.trigger	= fsl_ssi_trigger,
};

/* Template for the CPU dai driver structure */
static struct snd_soc_dai_driver fsl_ssi_dai_template = {
	.probe = fsl_ssi_dai_probe,
	.playback = {
		.stream_name = "CPU-Playback",
		.channels_min = 1,
		.channels_max = 2,
		.rates = FSLSSI_I2S_RATES,
		.formats = FSLSSI_I2S_FORMATS,
	},
	.capture = {
		.stream_name = "CPU-Capture",
		.channels_min = 1,
		.channels_max = 2,
		.rates = FSLSSI_I2S_RATES,
		.formats = FSLSSI_I2S_FORMATS,
	},
	.ops = &fsl_ssi_dai_ops,
};

static const struct snd_soc_component_driver fsl_ssi_component = {
	.name		= "fsl-ssi",
};

static struct snd_soc_dai_driver fsl_ssi_ac97_dai = {
	.bus_control = true,
	.playback = {
		.stream_name = "AC97 Playback",
		.channels_min = 2,
		.channels_max = 2,
		.rates = SNDRV_PCM_RATE_8000_48000,
		.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.capture = {
		.stream_name = "AC97 Capture",
		.channels_min = 2,
		.channels_max = 2,
		.rates = SNDRV_PCM_RATE_48000,
		.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	.ops = &fsl_ssi_dai_ops,
};


static struct fsl_ssi_private *fsl_ac97_data;

static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
		unsigned short val)
{
	struct regmap *regs = fsl_ac97_data->regs;
	unsigned int lreg;
	unsigned int lval;

	if (reg > 0x7f)
		return;


	lreg = reg <<  12;
	regmap_write(regs, CCSR_SSI_SACADD, lreg);

	lval = val << 4;
	regmap_write(regs, CCSR_SSI_SACDAT, lval);

	regmap_update_bits(regs, CCSR_SSI_SACNT, CCSR_SSI_SACNT_RDWR_MASK,
			CCSR_SSI_SACNT_WR);
	udelay(100);
}

static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97,
		unsigned short reg)
{
	struct regmap *regs = fsl_ac97_data->regs;

	unsigned short val = -1;
	u32 reg_val;
	unsigned int lreg;

	lreg = (reg & 0x7f) <<  12;
	regmap_write(regs, CCSR_SSI_SACADD, lreg);
	regmap_update_bits(regs, CCSR_SSI_SACNT, CCSR_SSI_SACNT_RDWR_MASK,
			CCSR_SSI_SACNT_RD);

	udelay(100);

	regmap_read(regs, CCSR_SSI_SACDAT, &reg_val);
	val = (reg_val >> 4) & 0xffff;

	return val;
}

static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
	.read		= fsl_ssi_ac97_read,
	.write		= fsl_ssi_ac97_write,
};

/**
 * Make every character in a string lower-case
 */
static void make_lowercase(char *s)
{
	char *p = s;
	char c;

	while ((c = *p)) {
		if ((c >= 'A') && (c <= 'Z'))
			*p = c + ('a' - 'A');
		p++;
	}
}

static int fsl_ssi_imx_probe(struct platform_device *pdev,
		struct fsl_ssi_private *ssi_private, void __iomem *iomem)
{
	struct device_node *np = pdev->dev.of_node;
	u32 dmas[4];
	int ret;

	if (ssi_private->has_ipg_clk_name)
		ssi_private->clk = devm_clk_get(&pdev->dev, "ipg");
	else
		ssi_private->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(ssi_private->clk)) {
		ret = PTR_ERR(ssi_private->clk);
		dev_err(&pdev->dev, "could not get clock: %d\n", ret);
		return ret;
	}

	if (!ssi_private->has_ipg_clk_name) {
		ret = clk_prepare_enable(ssi_private->clk);
		if (ret) {
			dev_err(&pdev->dev, "clk_prepare_enable failed: %d\n", ret);
			return ret;
		}
	}

	/* For those SLAVE implementations, we ingore non-baudclk cases
	 * and, instead, abandon MASTER mode that needs baud clock.
	 */
	ssi_private->baudclk = devm_clk_get(&pdev->dev, "baud");
	if (IS_ERR(ssi_private->baudclk))
		dev_dbg(&pdev->dev, "could not get baud clock: %ld\n",
			 PTR_ERR(ssi_private->baudclk));

	/*
	 * We have burstsize be "fifo_depth - 2" to match the SSI
	 * watermark setting in fsl_ssi_startup().
	 */
	ssi_private->dma_params_tx.maxburst = ssi_private->fifo_depth - 2;
	ssi_private->dma_params_rx.maxburst = ssi_private->fifo_depth - 2;
	ssi_private->dma_params_tx.addr = ssi_private->ssi_phys + CCSR_SSI_STX0;
	ssi_private->dma_params_rx.addr = ssi_private->ssi_phys + CCSR_SSI_SRX0;

	ret = of_property_read_u32_array(np, "dmas", dmas, 4);
	if (ssi_private->use_dma && !ret && dmas[2] == IMX_DMATYPE_SSI_DUAL) {
		ssi_private->use_dual_fifo = true;
		/* When using dual fifo mode, we need to keep watermark
		 * as even numbers due to dma script limitation.
		 */
		ssi_private->dma_params_tx.maxburst &= ~0x1;
		ssi_private->dma_params_rx.maxburst &= ~0x1;
	}

	if (!ssi_private->use_dma) {

		/*
		 * Some boards use an incompatible codec. To get it
		 * working, we are using imx-fiq-pcm-audio, that
		 * can handle those codecs. DMA is not possible in this
		 * situation.
		 */

		ssi_private->fiq_params.irq = ssi_private->irq;
		ssi_private->fiq_params.base = iomem;
		ssi_private->fiq_params.dma_params_rx =
			&ssi_private->dma_params_rx;
		ssi_private->fiq_params.dma_params_tx =
			&ssi_private->dma_params_tx;

		ret = imx_pcm_fiq_init(pdev, &ssi_private->fiq_params);
		if (ret)
			goto error_pcm;
	} else {
		ret = imx_pcm_dma_init(pdev);
		if (ret)
			goto error_pcm;
	}

	return 0;

error_pcm:

	if (!ssi_private->has_ipg_clk_name)
		clk_disable_unprepare(ssi_private->clk);
	return ret;
}

static void fsl_ssi_imx_clean(struct platform_device *pdev,
		struct fsl_ssi_private *ssi_private)
{
	if (!ssi_private->use_dma)
		imx_pcm_fiq_exit(pdev);
	if (!ssi_private->has_ipg_clk_name)
		clk_disable_unprepare(ssi_private->clk);
}

static int fsl_ssi_probe(struct platform_device *pdev)
{
	struct fsl_ssi_private *ssi_private;
	int ret = 0;
	struct device_node *np = pdev->dev.of_node;
	const struct of_device_id *of_id;
	const char *p, *sprop;
	const uint32_t *iprop;
	struct resource *res;
	void __iomem *iomem;
	char name[64];

	/* SSIs that are not connected on the board should have a
	 *      status = "disabled"
	 * property in their device tree nodes.
	 */
	if (!of_device_is_available(np))
		return -ENODEV;

	of_id = of_match_device(fsl_ssi_ids, &pdev->dev);
	if (!of_id || !of_id->data)
		return -EINVAL;

	ssi_private = devm_kzalloc(&pdev->dev, sizeof(*ssi_private),
			GFP_KERNEL);
	if (!ssi_private) {
		dev_err(&pdev->dev, "could not allocate DAI object\n");
		return -ENOMEM;
	}

	ssi_private->soc = of_id->data;

	sprop = of_get_property(np, "fsl,mode", NULL);
	if (sprop) {
		if (!strcmp(sprop, "ac97-slave"))
			ssi_private->dai_fmt = SND_SOC_DAIFMT_AC97;
	}

	ssi_private->use_dma = !of_property_read_bool(np,
			"fsl,fiq-stream-filter");

	if (fsl_ssi_is_ac97(ssi_private)) {
		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_ac97_dai,
				sizeof(fsl_ssi_ac97_dai));

		fsl_ac97_data = ssi_private;

		snd_soc_set_ac97_ops_of_reset(&fsl_ssi_ac97_ops, pdev);
	} else {
		/* Initialize this copy of the CPU DAI driver structure */
		memcpy(&ssi_private->cpu_dai_drv, &fsl_ssi_dai_template,
		       sizeof(fsl_ssi_dai_template));
	}
	ssi_private->cpu_dai_drv.name = dev_name(&pdev->dev);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	iomem = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(iomem))
		return PTR_ERR(iomem);
	ssi_private->ssi_phys = res->start;

	ret = of_property_match_string(np, "clock-names", "ipg");
	if (ret < 0) {
		ssi_private->has_ipg_clk_name = false;
		ssi_private->regs = devm_regmap_init_mmio(&pdev->dev, iomem,
			&fsl_ssi_regconfig);
	} else {
		ssi_private->has_ipg_clk_name = true;
		ssi_private->regs = devm_regmap_init_mmio_clk(&pdev->dev,
			"ipg", iomem, &fsl_ssi_regconfig);
	}
	if (IS_ERR(ssi_private->regs)) {
		dev_err(&pdev->dev, "Failed to init register map\n");
		return PTR_ERR(ssi_private->regs);
	}

	ssi_private->irq = platform_get_irq(pdev, 0);
	if (ssi_private->irq < 0) {
		dev_err(&pdev->dev, "no irq for node %s\n", pdev->name);
		return ssi_private->irq;
	}

	/* Are the RX and the TX clocks locked? */
	if (!of_find_property(np, "fsl,ssi-asynchronous", NULL)) {
		ssi_private->cpu_dai_drv.symmetric_rates = 1;
		ssi_private->cpu_dai_drv.symmetric_channels = 1;
		ssi_private->cpu_dai_drv.symmetric_samplebits = 1;
	}

	/* Determine the FIFO depth. */
	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
	if (iprop)
		ssi_private->fifo_depth = be32_to_cpup(iprop);
	else
                /* Older 8610 DTs didn't have the fifo-depth property */
		ssi_private->fifo_depth = 8;

	dev_set_drvdata(&pdev->dev, ssi_private);

	if (ssi_private->soc->imx) {
		ret = fsl_ssi_imx_probe(pdev, ssi_private, iomem);
		if (ret)
			return ret;
	}

	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_ssi_component,
					      &ssi_private->cpu_dai_drv, 1);
	if (ret) {
		dev_err(&pdev->dev, "failed to register DAI: %d\n", ret);
		goto error_asoc_register;
	}

	if (ssi_private->use_dma) {
		ret = devm_request_irq(&pdev->dev, ssi_private->irq,
					fsl_ssi_isr, 0, dev_name(&pdev->dev),
					ssi_private);
		if (ret < 0) {
			dev_err(&pdev->dev, "could not claim irq %u\n",
					ssi_private->irq);
			goto error_asoc_register;
		}
	}

	ret = fsl_ssi_debugfs_create(&ssi_private->dbg_stats, &pdev->dev);
	if (ret)
		goto error_asoc_register;

	/*
	 * If codec-handle property is missing from SSI node, we assume
	 * that the machine driver uses new binding which does not require
	 * SSI driver to trigger machine driver's probe.
	 */
	if (!of_get_property(np, "codec-handle", NULL))
		goto done;

	/* Trigger the machine driver's probe function.  The platform driver
	 * name of the machine driver is taken from /compatible property of the
	 * device tree.  We also pass the address of the CPU DAI driver
	 * structure.
	 */
	sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
	/* Sometimes the compatible name has a "fsl," prefix, so we strip it. */
	p = strrchr(sprop, ',');
	if (p)
		sprop = p + 1;
	snprintf(name, sizeof(name), "snd-soc-%s", sprop);
	make_lowercase(name);

	ssi_private->pdev =
		platform_device_register_data(&pdev->dev, name, 0, NULL, 0);
	if (IS_ERR(ssi_private->pdev)) {
		ret = PTR_ERR(ssi_private->pdev);
		dev_err(&pdev->dev, "failed to register platform: %d\n", ret);
		goto error_sound_card;
	}

done:
	if (ssi_private->dai_fmt)
		_fsl_ssi_set_dai_fmt(&pdev->dev, ssi_private,
				     ssi_private->dai_fmt);

	return 0;

error_sound_card:
	fsl_ssi_debugfs_remove(&ssi_private->dbg_stats);

error_asoc_register:
	if (ssi_private->soc->imx)
		fsl_ssi_imx_clean(pdev, ssi_private);

	return ret;
}

static int fsl_ssi_remove(struct platform_device *pdev)
{
	struct fsl_ssi_private *ssi_private = dev_get_drvdata(&pdev->dev);

	fsl_ssi_debugfs_remove(&ssi_private->dbg_stats);

	if (ssi_private->pdev)
		platform_device_unregister(ssi_private->pdev);

	if (ssi_private->soc->imx)
		fsl_ssi_imx_clean(pdev, ssi_private);

	return 0;
}

static struct platform_driver fsl_ssi_driver = {
	.driver = {
		.name = "fsl-ssi-dai",
		.of_match_table = fsl_ssi_ids,
	},
	.probe = fsl_ssi_probe,
	.remove = fsl_ssi_remove,
};

module_platform_driver(fsl_ssi_driver);

MODULE_ALIAS("platform:fsl-ssi-dai");
MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
MODULE_DESCRIPTION("Freescale Synchronous Serial Interface (SSI) ASoC Driver");
MODULE_LICENSE("GPL v2");