aboutsummaryrefslogtreecommitdiff
path: root/drivers/dma/sprd-dma.c
blob: 0ef5ca81ba4d0009cecf2a45af08cc9c466fd06c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
/*
 * Copyright (C) 2017 Spreadtrum Communications Inc.
 *
 * SPDX-License-Identifier: GPL-2.0
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/dma/sprd-dma.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/of_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include "virt-dma.h"

#define SPRD_DMA_CHN_REG_OFFSET		0x1000
#define SPRD_DMA_CHN_REG_LENGTH		0x40
#define SPRD_DMA_MEMCPY_MIN_SIZE	64

/* DMA global registers definition */
#define SPRD_DMA_GLB_PAUSE		0x0
#define SPRD_DMA_GLB_FRAG_WAIT		0x4
#define SPRD_DMA_GLB_REQ_PEND0_EN	0x8
#define SPRD_DMA_GLB_REQ_PEND1_EN	0xc
#define SPRD_DMA_GLB_INT_RAW_STS	0x10
#define SPRD_DMA_GLB_INT_MSK_STS	0x14
#define SPRD_DMA_GLB_REQ_STS		0x18
#define SPRD_DMA_GLB_CHN_EN_STS		0x1c
#define SPRD_DMA_GLB_DEBUG_STS		0x20
#define SPRD_DMA_GLB_ARB_SEL_STS	0x24
#define SPRD_DMA_GLB_2STAGE_GRP1	0x28
#define SPRD_DMA_GLB_2STAGE_GRP2	0x2c
#define SPRD_DMA_GLB_REQ_UID(uid)	(0x4 * ((uid) - 1))
#define SPRD_DMA_GLB_REQ_UID_OFFSET	0x2000

/* DMA channel registers definition */
#define SPRD_DMA_CHN_PAUSE		0x0
#define SPRD_DMA_CHN_REQ		0x4
#define SPRD_DMA_CHN_CFG		0x8
#define SPRD_DMA_CHN_INTC		0xc
#define SPRD_DMA_CHN_SRC_ADDR		0x10
#define SPRD_DMA_CHN_DES_ADDR		0x14
#define SPRD_DMA_CHN_FRG_LEN		0x18
#define SPRD_DMA_CHN_BLK_LEN		0x1c
#define SPRD_DMA_CHN_TRSC_LEN		0x20
#define SPRD_DMA_CHN_TRSF_STEP		0x24
#define SPRD_DMA_CHN_WARP_PTR		0x28
#define SPRD_DMA_CHN_WARP_TO		0x2c
#define SPRD_DMA_CHN_LLIST_PTR		0x30
#define SPRD_DMA_CHN_FRAG_STEP		0x34
#define SPRD_DMA_CHN_SRC_BLK_STEP	0x38
#define SPRD_DMA_CHN_DES_BLK_STEP	0x3c

/* SPRD_DMA_GLB_2STAGE_GRP register definition */
#define SPRD_DMA_GLB_2STAGE_EN		BIT(24)
#define SPRD_DMA_GLB_CHN_INT_MASK	GENMASK(23, 20)
#define SPRD_DMA_GLB_DEST_INT		BIT(22)
#define SPRD_DMA_GLB_SRC_INT		BIT(20)
#define SPRD_DMA_GLB_LIST_DONE_TRG	BIT(19)
#define SPRD_DMA_GLB_TRANS_DONE_TRG	BIT(18)
#define SPRD_DMA_GLB_BLOCK_DONE_TRG	BIT(17)
#define SPRD_DMA_GLB_FRAG_DONE_TRG	BIT(16)
#define SPRD_DMA_GLB_TRG_OFFSET		16
#define SPRD_DMA_GLB_DEST_CHN_MASK	GENMASK(13, 8)
#define SPRD_DMA_GLB_DEST_CHN_OFFSET	8
#define SPRD_DMA_GLB_SRC_CHN_MASK	GENMASK(5, 0)

/* SPRD_DMA_CHN_INTC register definition */
#define SPRD_DMA_INT_MASK		GENMASK(4, 0)
#define SPRD_DMA_INT_CLR_OFFSET		24
#define SPRD_DMA_FRAG_INT_EN		BIT(0)
#define SPRD_DMA_BLK_INT_EN		BIT(1)
#define SPRD_DMA_TRANS_INT_EN		BIT(2)
#define SPRD_DMA_LIST_INT_EN		BIT(3)
#define SPRD_DMA_CFG_ERR_INT_EN		BIT(4)

/* SPRD_DMA_CHN_CFG register definition */
#define SPRD_DMA_CHN_EN			BIT(0)
#define SPRD_DMA_LINKLIST_EN		BIT(4)
#define SPRD_DMA_WAIT_BDONE_OFFSET	24
#define SPRD_DMA_DONOT_WAIT_BDONE	1

/* SPRD_DMA_CHN_REQ register definition */
#define SPRD_DMA_REQ_EN			BIT(0)

/* SPRD_DMA_CHN_PAUSE register definition */
#define SPRD_DMA_PAUSE_EN		BIT(0)
#define SPRD_DMA_PAUSE_STS		BIT(2)
#define SPRD_DMA_PAUSE_CNT		0x2000

/* DMA_CHN_WARP_* register definition */
#define SPRD_DMA_HIGH_ADDR_MASK		GENMASK(31, 28)
#define SPRD_DMA_LOW_ADDR_MASK		GENMASK(31, 0)
#define SPRD_DMA_WRAP_ADDR_MASK		GENMASK(27, 0)
#define SPRD_DMA_HIGH_ADDR_OFFSET	4

/* SPRD_DMA_CHN_INTC register definition */
#define SPRD_DMA_FRAG_INT_STS		BIT(16)
#define SPRD_DMA_BLK_INT_STS		BIT(17)
#define SPRD_DMA_TRSC_INT_STS		BIT(18)
#define SPRD_DMA_LIST_INT_STS		BIT(19)
#define SPRD_DMA_CFGERR_INT_STS		BIT(20)
#define SPRD_DMA_CHN_INT_STS					\
	(SPRD_DMA_FRAG_INT_STS | SPRD_DMA_BLK_INT_STS |		\
	 SPRD_DMA_TRSC_INT_STS | SPRD_DMA_LIST_INT_STS |	\
	 SPRD_DMA_CFGERR_INT_STS)

/* SPRD_DMA_CHN_FRG_LEN register definition */
#define SPRD_DMA_SRC_DATAWIDTH_OFFSET	30
#define SPRD_DMA_DES_DATAWIDTH_OFFSET	28
#define SPRD_DMA_SWT_MODE_OFFSET	26
#define SPRD_DMA_REQ_MODE_OFFSET	24
#define SPRD_DMA_REQ_MODE_MASK		GENMASK(1, 0)
#define SPRD_DMA_WRAP_SEL_DEST		BIT(23)
#define SPRD_DMA_WRAP_EN		BIT(22)
#define SPRD_DMA_FIX_SEL_OFFSET		21
#define SPRD_DMA_FIX_EN_OFFSET		20
#define SPRD_DMA_LLIST_END		BIT(19)
#define SPRD_DMA_FRG_LEN_MASK		GENMASK(16, 0)

/* SPRD_DMA_CHN_BLK_LEN register definition */
#define SPRD_DMA_BLK_LEN_MASK		GENMASK(16, 0)

/* SPRD_DMA_CHN_TRSC_LEN register definition */
#define SPRD_DMA_TRSC_LEN_MASK		GENMASK(27, 0)

/* SPRD_DMA_CHN_TRSF_STEP register definition */
#define SPRD_DMA_DEST_TRSF_STEP_OFFSET	16
#define SPRD_DMA_SRC_TRSF_STEP_OFFSET	0
#define SPRD_DMA_TRSF_STEP_MASK		GENMASK(15, 0)

/* SPRD DMA_SRC_BLK_STEP register definition */
#define SPRD_DMA_LLIST_HIGH_MASK	GENMASK(31, 28)
#define SPRD_DMA_LLIST_HIGH_SHIFT	28

/* define DMA channel mode & trigger mode mask */
#define SPRD_DMA_CHN_MODE_MASK		GENMASK(7, 0)
#define SPRD_DMA_TRG_MODE_MASK		GENMASK(7, 0)
#define SPRD_DMA_INT_TYPE_MASK		GENMASK(7, 0)

/* define the DMA transfer step type */
#define SPRD_DMA_NONE_STEP		0
#define SPRD_DMA_BYTE_STEP		1
#define SPRD_DMA_SHORT_STEP		2
#define SPRD_DMA_WORD_STEP		4
#define SPRD_DMA_DWORD_STEP		8

#define SPRD_DMA_SOFTWARE_UID		0

/* dma data width values */
enum sprd_dma_datawidth {
	SPRD_DMA_DATAWIDTH_1_BYTE,
	SPRD_DMA_DATAWIDTH_2_BYTES,
	SPRD_DMA_DATAWIDTH_4_BYTES,
	SPRD_DMA_DATAWIDTH_8_BYTES,
};

/* dma channel hardware configuration */
struct sprd_dma_chn_hw {
	u32 pause;
	u32 req;
	u32 cfg;
	u32 intc;
	u32 src_addr;
	u32 des_addr;
	u32 frg_len;
	u32 blk_len;
	u32 trsc_len;
	u32 trsf_step;
	u32 wrap_ptr;
	u32 wrap_to;
	u32 llist_ptr;
	u32 frg_step;
	u32 src_blk_step;
	u32 des_blk_step;
};

/* dma request description */
struct sprd_dma_desc {
	struct virt_dma_desc	vd;
	struct sprd_dma_chn_hw	chn_hw;
	enum dma_transfer_direction dir;
};

/* dma channel description */
struct sprd_dma_chn {
	struct virt_dma_chan	vc;
	void __iomem		*chn_base;
	struct sprd_dma_linklist	linklist;
	struct dma_slave_config	slave_cfg;
	u32			chn_num;
	u32			dev_id;
	enum sprd_dma_chn_mode	chn_mode;
	enum sprd_dma_trg_mode	trg_mode;
	enum sprd_dma_int_type	int_type;
	struct sprd_dma_desc	*cur_desc;
};

/* SPRD dma device */
struct sprd_dma_dev {
	struct dma_device	dma_dev;
	void __iomem		*glb_base;
	struct clk		*clk;
	struct clk		*ashb_clk;
	int			irq;
	u32			total_chns;
	struct sprd_dma_chn	channels[];
};

static void sprd_dma_free_desc(struct virt_dma_desc *vd);
static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param);
static struct of_dma_filter_info sprd_dma_info = {
	.filter_fn = sprd_dma_filter_fn,
};

static inline struct sprd_dma_chn *to_sprd_dma_chan(struct dma_chan *c)
{
	return container_of(c, struct sprd_dma_chn, vc.chan);
}

static inline struct sprd_dma_dev *to_sprd_dma_dev(struct dma_chan *c)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(c);

	return container_of(schan, struct sprd_dma_dev, channels[c->chan_id]);
}

static inline struct sprd_dma_desc *to_sprd_dma_desc(struct virt_dma_desc *vd)
{
	return container_of(vd, struct sprd_dma_desc, vd);
}

static void sprd_dma_glb_update(struct sprd_dma_dev *sdev, u32 reg,
				u32 mask, u32 val)
{
	u32 orig = readl(sdev->glb_base + reg);
	u32 tmp;

	tmp = (orig & ~mask) | val;
	writel(tmp, sdev->glb_base + reg);
}

static void sprd_dma_chn_update(struct sprd_dma_chn *schan, u32 reg,
				u32 mask, u32 val)
{
	u32 orig = readl(schan->chn_base + reg);
	u32 tmp;

	tmp = (orig & ~mask) | val;
	writel(tmp, schan->chn_base + reg);
}

static int sprd_dma_enable(struct sprd_dma_dev *sdev)
{
	int ret;

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

	/*
	 * The ashb_clk is optional and only for AGCP DMA controller, so we
	 * need add one condition to check if the ashb_clk need enable.
	 */
	if (!IS_ERR(sdev->ashb_clk))
		ret = clk_prepare_enable(sdev->ashb_clk);

	return ret;
}

static void sprd_dma_disable(struct sprd_dma_dev *sdev)
{
	clk_disable_unprepare(sdev->clk);

	/*
	 * Need to check if we need disable the optional ashb_clk for AGCP DMA.
	 */
	if (!IS_ERR(sdev->ashb_clk))
		clk_disable_unprepare(sdev->ashb_clk);
}

static void sprd_dma_set_uid(struct sprd_dma_chn *schan)
{
	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
	u32 dev_id = schan->dev_id;

	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
				 SPRD_DMA_GLB_REQ_UID(dev_id);

		writel(schan->chn_num + 1, sdev->glb_base + uid_offset);
	}
}

static void sprd_dma_unset_uid(struct sprd_dma_chn *schan)
{
	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
	u32 dev_id = schan->dev_id;

	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
				 SPRD_DMA_GLB_REQ_UID(dev_id);

		writel(0, sdev->glb_base + uid_offset);
	}
}

static void sprd_dma_clear_int(struct sprd_dma_chn *schan)
{
	sprd_dma_chn_update(schan, SPRD_DMA_CHN_INTC,
			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET,
			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET);
}

static void sprd_dma_enable_chn(struct sprd_dma_chn *schan)
{
	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN,
			    SPRD_DMA_CHN_EN);
}

static void sprd_dma_disable_chn(struct sprd_dma_chn *schan)
{
	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN, 0);
}

static void sprd_dma_soft_request(struct sprd_dma_chn *schan)
{
	sprd_dma_chn_update(schan, SPRD_DMA_CHN_REQ, SPRD_DMA_REQ_EN,
			    SPRD_DMA_REQ_EN);
}

static void sprd_dma_pause_resume(struct sprd_dma_chn *schan, bool enable)
{
	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
	u32 pause, timeout = SPRD_DMA_PAUSE_CNT;

	if (enable) {
		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
				    SPRD_DMA_PAUSE_EN, SPRD_DMA_PAUSE_EN);

		do {
			pause = readl(schan->chn_base + SPRD_DMA_CHN_PAUSE);
			if (pause & SPRD_DMA_PAUSE_STS)
				break;

			cpu_relax();
		} while (--timeout > 0);

		if (!timeout)
			dev_warn(sdev->dma_dev.dev,
				 "pause dma controller timeout\n");
	} else {
		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
				    SPRD_DMA_PAUSE_EN, 0);
	}
}

static void sprd_dma_stop_and_disable(struct sprd_dma_chn *schan)
{
	u32 cfg = readl(schan->chn_base + SPRD_DMA_CHN_CFG);

	if (!(cfg & SPRD_DMA_CHN_EN))
		return;

	sprd_dma_pause_resume(schan, true);
	sprd_dma_disable_chn(schan);
}

static unsigned long sprd_dma_get_src_addr(struct sprd_dma_chn *schan)
{
	unsigned long addr, addr_high;

	addr = readl(schan->chn_base + SPRD_DMA_CHN_SRC_ADDR);
	addr_high = readl(schan->chn_base + SPRD_DMA_CHN_WARP_PTR) &
		    SPRD_DMA_HIGH_ADDR_MASK;

	return addr | (addr_high << SPRD_DMA_HIGH_ADDR_OFFSET);
}

static unsigned long sprd_dma_get_dst_addr(struct sprd_dma_chn *schan)
{
	unsigned long addr, addr_high;

	addr = readl(schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
	addr_high = readl(schan->chn_base + SPRD_DMA_CHN_WARP_TO) &
		    SPRD_DMA_HIGH_ADDR_MASK;

	return addr | (addr_high << SPRD_DMA_HIGH_ADDR_OFFSET);
}

static enum sprd_dma_int_type sprd_dma_get_int_type(struct sprd_dma_chn *schan)
{
	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
	u32 intc_sts = readl(schan->chn_base + SPRD_DMA_CHN_INTC) &
		       SPRD_DMA_CHN_INT_STS;

	switch (intc_sts) {
	case SPRD_DMA_CFGERR_INT_STS:
		return SPRD_DMA_CFGERR_INT;

	case SPRD_DMA_LIST_INT_STS:
		return SPRD_DMA_LIST_INT;

	case SPRD_DMA_TRSC_INT_STS:
		return SPRD_DMA_TRANS_INT;

	case SPRD_DMA_BLK_INT_STS:
		return SPRD_DMA_BLK_INT;

	case SPRD_DMA_FRAG_INT_STS:
		return SPRD_DMA_FRAG_INT;

	default:
		dev_warn(sdev->dma_dev.dev, "incorrect dma interrupt type\n");
		return SPRD_DMA_NO_INT;
	}
}

static enum sprd_dma_req_mode sprd_dma_get_req_type(struct sprd_dma_chn *schan)
{
	u32 frag_reg = readl(schan->chn_base + SPRD_DMA_CHN_FRG_LEN);

	return (frag_reg >> SPRD_DMA_REQ_MODE_OFFSET) & SPRD_DMA_REQ_MODE_MASK;
}

static int sprd_dma_set_2stage_config(struct sprd_dma_chn *schan)
{
	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
	u32 val, chn = schan->chn_num + 1;

	switch (schan->chn_mode) {
	case SPRD_DMA_SRC_CHN0:
		val = chn & SPRD_DMA_GLB_SRC_CHN_MASK;
		val |= BIT(schan->trg_mode - 1) << SPRD_DMA_GLB_TRG_OFFSET;
		val |= SPRD_DMA_GLB_2STAGE_EN;
		if (schan->int_type != SPRD_DMA_NO_INT)
			val |= SPRD_DMA_GLB_SRC_INT;

		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP1, val, val);
		break;

	case SPRD_DMA_SRC_CHN1:
		val = chn & SPRD_DMA_GLB_SRC_CHN_MASK;
		val |= BIT(schan->trg_mode - 1) << SPRD_DMA_GLB_TRG_OFFSET;
		val |= SPRD_DMA_GLB_2STAGE_EN;
		if (schan->int_type != SPRD_DMA_NO_INT)
			val |= SPRD_DMA_GLB_SRC_INT;

		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP2, val, val);
		break;

	case SPRD_DMA_DST_CHN0:
		val = (chn << SPRD_DMA_GLB_DEST_CHN_OFFSET) &
			SPRD_DMA_GLB_DEST_CHN_MASK;
		val |= SPRD_DMA_GLB_2STAGE_EN;
		if (schan->int_type != SPRD_DMA_NO_INT)
			val |= SPRD_DMA_GLB_DEST_INT;

		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP1, val, val);
		break;

	case SPRD_DMA_DST_CHN1:
		val = (chn << SPRD_DMA_GLB_DEST_CHN_OFFSET) &
			SPRD_DMA_GLB_DEST_CHN_MASK;
		val |= SPRD_DMA_GLB_2STAGE_EN;
		if (schan->int_type != SPRD_DMA_NO_INT)
			val |= SPRD_DMA_GLB_DEST_INT;

		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP2, val, val);
		break;

	default:
		dev_err(sdev->dma_dev.dev, "invalid channel mode setting %d\n",
			schan->chn_mode);
		return -EINVAL;
	}

	return 0;
}

static void sprd_dma_set_pending(struct sprd_dma_chn *schan, bool enable)
{
	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
	u32 reg, val, req_id;

	if (schan->dev_id == SPRD_DMA_SOFTWARE_UID)
		return;

	/* The DMA request id always starts from 0. */
	req_id = schan->dev_id - 1;

	if (req_id < 32) {
		reg = SPRD_DMA_GLB_REQ_PEND0_EN;
		val = BIT(req_id);
	} else {
		reg = SPRD_DMA_GLB_REQ_PEND1_EN;
		val = BIT(req_id - 32);
	}

	sprd_dma_glb_update(sdev, reg, val, enable ? val : 0);
}

static void sprd_dma_set_chn_config(struct sprd_dma_chn *schan,
				    struct sprd_dma_desc *sdesc)
{
	struct sprd_dma_chn_hw *cfg = &sdesc->chn_hw;

	writel(cfg->pause, schan->chn_base + SPRD_DMA_CHN_PAUSE);
	writel(cfg->cfg, schan->chn_base + SPRD_DMA_CHN_CFG);
	writel(cfg->intc, schan->chn_base + SPRD_DMA_CHN_INTC);
	writel(cfg->src_addr, schan->chn_base + SPRD_DMA_CHN_SRC_ADDR);
	writel(cfg->des_addr, schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
	writel(cfg->frg_len, schan->chn_base + SPRD_DMA_CHN_FRG_LEN);
	writel(cfg->blk_len, schan->chn_base + SPRD_DMA_CHN_BLK_LEN);
	writel(cfg->trsc_len, schan->chn_base + SPRD_DMA_CHN_TRSC_LEN);
	writel(cfg->trsf_step, schan->chn_base + SPRD_DMA_CHN_TRSF_STEP);
	writel(cfg->wrap_ptr, schan->chn_base + SPRD_DMA_CHN_WARP_PTR);
	writel(cfg->wrap_to, schan->chn_base + SPRD_DMA_CHN_WARP_TO);
	writel(cfg->llist_ptr, schan->chn_base + SPRD_DMA_CHN_LLIST_PTR);
	writel(cfg->frg_step, schan->chn_base + SPRD_DMA_CHN_FRAG_STEP);
	writel(cfg->src_blk_step, schan->chn_base + SPRD_DMA_CHN_SRC_BLK_STEP);
	writel(cfg->des_blk_step, schan->chn_base + SPRD_DMA_CHN_DES_BLK_STEP);
	writel(cfg->req, schan->chn_base + SPRD_DMA_CHN_REQ);
}

static void sprd_dma_start(struct sprd_dma_chn *schan)
{
	struct virt_dma_desc *vd = vchan_next_desc(&schan->vc);

	if (!vd)
		return;

	list_del(&vd->node);
	schan->cur_desc = to_sprd_dma_desc(vd);

	/*
	 * Set 2-stage configuration if the channel starts one 2-stage
	 * transfer.
	 */
	if (schan->chn_mode && sprd_dma_set_2stage_config(schan))
		return;

	/*
	 * Copy the DMA configuration from DMA descriptor to this hardware
	 * channel.
	 */
	sprd_dma_set_chn_config(schan, schan->cur_desc);
	sprd_dma_set_uid(schan);
	sprd_dma_set_pending(schan, true);
	sprd_dma_enable_chn(schan);

	if (schan->dev_id == SPRD_DMA_SOFTWARE_UID &&
	    schan->chn_mode != SPRD_DMA_DST_CHN0 &&
	    schan->chn_mode != SPRD_DMA_DST_CHN1)
		sprd_dma_soft_request(schan);
}

static void sprd_dma_stop(struct sprd_dma_chn *schan)
{
	sprd_dma_stop_and_disable(schan);
	sprd_dma_set_pending(schan, false);
	sprd_dma_unset_uid(schan);
	sprd_dma_clear_int(schan);
	schan->cur_desc = NULL;
}

static bool sprd_dma_check_trans_done(struct sprd_dma_desc *sdesc,
				      enum sprd_dma_int_type int_type,
				      enum sprd_dma_req_mode req_mode)
{
	if (int_type == SPRD_DMA_NO_INT)
		return false;

	if (int_type >= req_mode + 1)
		return true;
	else
		return false;
}

static irqreturn_t dma_irq_handle(int irq, void *dev_id)
{
	struct sprd_dma_dev *sdev = (struct sprd_dma_dev *)dev_id;
	u32 irq_status = readl(sdev->glb_base + SPRD_DMA_GLB_INT_MSK_STS);
	struct sprd_dma_chn *schan;
	struct sprd_dma_desc *sdesc;
	enum sprd_dma_req_mode req_type;
	enum sprd_dma_int_type int_type;
	bool trans_done = false, cyclic = false;
	u32 i;

	while (irq_status) {
		i = __ffs(irq_status);
		irq_status &= (irq_status - 1);
		schan = &sdev->channels[i];

		spin_lock(&schan->vc.lock);

		sdesc = schan->cur_desc;
		if (!sdesc) {
			spin_unlock(&schan->vc.lock);
			return IRQ_HANDLED;
		}

		int_type = sprd_dma_get_int_type(schan);
		req_type = sprd_dma_get_req_type(schan);
		sprd_dma_clear_int(schan);

		/* cyclic mode schedule callback */
		cyclic = schan->linklist.phy_addr ? true : false;
		if (cyclic == true) {
			vchan_cyclic_callback(&sdesc->vd);
		} else {
			/* Check if the dma request descriptor is done. */
			trans_done = sprd_dma_check_trans_done(sdesc, int_type,
							       req_type);
			if (trans_done == true) {
				vchan_cookie_complete(&sdesc->vd);
				schan->cur_desc = NULL;
				sprd_dma_start(schan);
			}
		}
		spin_unlock(&schan->vc.lock);
	}

	return IRQ_HANDLED;
}

static int sprd_dma_alloc_chan_resources(struct dma_chan *chan)
{
	return pm_runtime_get_sync(chan->device->dev);
}

static void sprd_dma_free_chan_resources(struct dma_chan *chan)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	struct virt_dma_desc *cur_vd = NULL;
	unsigned long flags;

	spin_lock_irqsave(&schan->vc.lock, flags);
	if (schan->cur_desc)
		cur_vd = &schan->cur_desc->vd;

	sprd_dma_stop(schan);
	spin_unlock_irqrestore(&schan->vc.lock, flags);

	if (cur_vd)
		sprd_dma_free_desc(cur_vd);

	vchan_free_chan_resources(&schan->vc);
	pm_runtime_put(chan->device->dev);
}

static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
					  dma_cookie_t cookie,
					  struct dma_tx_state *txstate)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	struct virt_dma_desc *vd;
	unsigned long flags;
	enum dma_status ret;
	u32 pos;

	ret = dma_cookie_status(chan, cookie, txstate);
	if (ret == DMA_COMPLETE || !txstate)
		return ret;

	spin_lock_irqsave(&schan->vc.lock, flags);
	vd = vchan_find_desc(&schan->vc, cookie);
	if (vd) {
		struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
		struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;

		if (hw->trsc_len > 0)
			pos = hw->trsc_len;
		else if (hw->blk_len > 0)
			pos = hw->blk_len;
		else if (hw->frg_len > 0)
			pos = hw->frg_len;
		else
			pos = 0;
	} else if (schan->cur_desc && schan->cur_desc->vd.tx.cookie == cookie) {
		struct sprd_dma_desc *sdesc = schan->cur_desc;

		if (sdesc->dir == DMA_DEV_TO_MEM)
			pos = sprd_dma_get_dst_addr(schan);
		else
			pos = sprd_dma_get_src_addr(schan);
	} else {
		pos = 0;
	}
	spin_unlock_irqrestore(&schan->vc.lock, flags);

	dma_set_residue(txstate, pos);
	return ret;
}

static void sprd_dma_issue_pending(struct dma_chan *chan)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	unsigned long flags;

	spin_lock_irqsave(&schan->vc.lock, flags);
	if (vchan_issue_pending(&schan->vc) && !schan->cur_desc)
		sprd_dma_start(schan);
	spin_unlock_irqrestore(&schan->vc.lock, flags);
}

static int sprd_dma_get_datawidth(enum dma_slave_buswidth buswidth)
{
	switch (buswidth) {
	case DMA_SLAVE_BUSWIDTH_1_BYTE:
	case DMA_SLAVE_BUSWIDTH_2_BYTES:
	case DMA_SLAVE_BUSWIDTH_4_BYTES:
	case DMA_SLAVE_BUSWIDTH_8_BYTES:
		return ffs(buswidth) - 1;

	default:
		return -EINVAL;
	}
}

static int sprd_dma_get_step(enum dma_slave_buswidth buswidth)
{
	switch (buswidth) {
	case DMA_SLAVE_BUSWIDTH_1_BYTE:
	case DMA_SLAVE_BUSWIDTH_2_BYTES:
	case DMA_SLAVE_BUSWIDTH_4_BYTES:
	case DMA_SLAVE_BUSWIDTH_8_BYTES:
		return buswidth;

	default:
		return -EINVAL;
	}
}

static int sprd_dma_fill_desc(struct dma_chan *chan,
			      struct sprd_dma_chn_hw *hw,
			      unsigned int sglen, int sg_index,
			      dma_addr_t src, dma_addr_t dst, u32 len,
			      enum dma_transfer_direction dir,
			      unsigned long flags,
			      struct dma_slave_config *slave_cfg)
{
	struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	enum sprd_dma_chn_mode chn_mode = schan->chn_mode;
	u32 req_mode = (flags >> SPRD_DMA_REQ_SHIFT) & SPRD_DMA_REQ_MODE_MASK;
	u32 int_mode = flags & SPRD_DMA_INT_MASK;
	int src_datawidth, dst_datawidth, src_step, dst_step;
	u32 temp, fix_mode = 0, fix_en = 0;
	phys_addr_t llist_ptr;

	if (dir == DMA_MEM_TO_DEV) {
		src_step = sprd_dma_get_step(slave_cfg->src_addr_width);
		if (src_step < 0) {
			dev_err(sdev->dma_dev.dev, "invalid source step\n");
			return src_step;
		}

		/*
		 * For 2-stage transfer, destination channel step can not be 0,
		 * since destination device is AON IRAM.
		 */
		if (chn_mode == SPRD_DMA_DST_CHN0 ||
		    chn_mode == SPRD_DMA_DST_CHN1)
			dst_step = src_step;
		else
			dst_step = SPRD_DMA_NONE_STEP;
	} else {
		dst_step = sprd_dma_get_step(slave_cfg->dst_addr_width);
		if (dst_step < 0) {
			dev_err(sdev->dma_dev.dev, "invalid destination step\n");
			return dst_step;
		}
		src_step = SPRD_DMA_NONE_STEP;
	}

	src_datawidth = sprd_dma_get_datawidth(slave_cfg->src_addr_width);
	if (src_datawidth < 0) {
		dev_err(sdev->dma_dev.dev, "invalid source datawidth\n");
		return src_datawidth;
	}

	dst_datawidth = sprd_dma_get_datawidth(slave_cfg->dst_addr_width);
	if (dst_datawidth < 0) {
		dev_err(sdev->dma_dev.dev, "invalid destination datawidth\n");
		return dst_datawidth;
	}

	if (slave_cfg->slave_id)
		schan->dev_id = slave_cfg->slave_id;

	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;

	/*
	 * wrap_ptr and wrap_to will save the high 4 bits source address and
	 * destination address.
	 */
	hw->wrap_ptr = (src >> SPRD_DMA_HIGH_ADDR_OFFSET) & SPRD_DMA_HIGH_ADDR_MASK;
	hw->wrap_to = (dst >> SPRD_DMA_HIGH_ADDR_OFFSET) & SPRD_DMA_HIGH_ADDR_MASK;
	hw->src_addr = src & SPRD_DMA_LOW_ADDR_MASK;
	hw->des_addr = dst & SPRD_DMA_LOW_ADDR_MASK;

	/*
	 * If the src step and dst step both are 0 or both are not 0, that means
	 * we can not enable the fix mode. If one is 0 and another one is not,
	 * we can enable the fix mode.
	 */
	if ((src_step != 0 && dst_step != 0) || (src_step | dst_step) == 0) {
		fix_en = 0;
	} else {
		fix_en = 1;
		if (src_step)
			fix_mode = 1;
		else
			fix_mode = 0;
	}

	hw->intc = int_mode | SPRD_DMA_CFG_ERR_INT_EN;

	temp = src_datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET;
	temp |= dst_datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET;
	temp |= req_mode << SPRD_DMA_REQ_MODE_OFFSET;
	temp |= fix_mode << SPRD_DMA_FIX_SEL_OFFSET;
	temp |= fix_en << SPRD_DMA_FIX_EN_OFFSET;
	temp |= schan->linklist.wrap_addr ?
		SPRD_DMA_WRAP_EN | SPRD_DMA_WRAP_SEL_DEST : 0;
	temp |= slave_cfg->src_maxburst & SPRD_DMA_FRG_LEN_MASK;
	hw->frg_len = temp;

	hw->blk_len = slave_cfg->src_maxburst & SPRD_DMA_BLK_LEN_MASK;
	hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;

	temp = (dst_step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
	temp |= (src_step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_SRC_TRSF_STEP_OFFSET;
	hw->trsf_step = temp;

	/* link-list configuration */
	if (schan->linklist.phy_addr) {
		hw->cfg |= SPRD_DMA_LINKLIST_EN;

		/* link-list index */
		temp = sglen ? (sg_index + 1) % sglen : 0;

		/* Next link-list configuration's physical address offset */
		temp = temp * sizeof(*hw) + SPRD_DMA_CHN_SRC_ADDR;
		/*
		 * Set the link-list pointer point to next link-list
		 * configuration's physical address.
		 */
		llist_ptr = schan->linklist.phy_addr + temp;
		hw->llist_ptr = lower_32_bits(llist_ptr);
		hw->src_blk_step = (upper_32_bits(llist_ptr) << SPRD_DMA_LLIST_HIGH_SHIFT) &
			SPRD_DMA_LLIST_HIGH_MASK;

		if (schan->linklist.wrap_addr) {
			hw->wrap_ptr |= schan->linklist.wrap_addr &
				SPRD_DMA_WRAP_ADDR_MASK;
			hw->wrap_to |= dst & SPRD_DMA_WRAP_ADDR_MASK;
		}
	} else {
		hw->llist_ptr = 0;
		hw->src_blk_step = 0;
	}

	hw->frg_step = 0;
	hw->des_blk_step = 0;
	return 0;
}

static int sprd_dma_fill_linklist_desc(struct dma_chan *chan,
				       unsigned int sglen, int sg_index,
				       dma_addr_t src, dma_addr_t dst, u32 len,
				       enum dma_transfer_direction dir,
				       unsigned long flags,
				       struct dma_slave_config *slave_cfg)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	struct sprd_dma_chn_hw *hw;

	if (!schan->linklist.virt_addr)
		return -EINVAL;

	hw = (struct sprd_dma_chn_hw *)(schan->linklist.virt_addr +
					sg_index * sizeof(*hw));

	return sprd_dma_fill_desc(chan, hw, sglen, sg_index, src, dst, len,
				  dir, flags, slave_cfg);
}

static struct dma_async_tx_descriptor *
sprd_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
			 size_t len, unsigned long flags)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	struct sprd_dma_desc *sdesc;
	struct sprd_dma_chn_hw *hw;
	enum sprd_dma_datawidth datawidth;
	u32 step, temp;

	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
	if (!sdesc)
		return NULL;

	hw = &sdesc->chn_hw;

	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
	hw->intc = SPRD_DMA_TRANS_INT | SPRD_DMA_CFG_ERR_INT_EN;
	hw->src_addr = src & SPRD_DMA_LOW_ADDR_MASK;
	hw->des_addr = dest & SPRD_DMA_LOW_ADDR_MASK;
	hw->wrap_ptr = (src >> SPRD_DMA_HIGH_ADDR_OFFSET) &
		SPRD_DMA_HIGH_ADDR_MASK;
	hw->wrap_to = (dest >> SPRD_DMA_HIGH_ADDR_OFFSET) &
		SPRD_DMA_HIGH_ADDR_MASK;

	if (IS_ALIGNED(len, 8)) {
		datawidth = SPRD_DMA_DATAWIDTH_8_BYTES;
		step = SPRD_DMA_DWORD_STEP;
	} else if (IS_ALIGNED(len, 4)) {
		datawidth = SPRD_DMA_DATAWIDTH_4_BYTES;
		step = SPRD_DMA_WORD_STEP;
	} else if (IS_ALIGNED(len, 2)) {
		datawidth = SPRD_DMA_DATAWIDTH_2_BYTES;
		step = SPRD_DMA_SHORT_STEP;
	} else {
		datawidth = SPRD_DMA_DATAWIDTH_1_BYTE;
		step = SPRD_DMA_BYTE_STEP;
	}

	temp = datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET;
	temp |= datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET;
	temp |= SPRD_DMA_TRANS_REQ << SPRD_DMA_REQ_MODE_OFFSET;
	temp |= len & SPRD_DMA_FRG_LEN_MASK;
	hw->frg_len = temp;

	hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
	hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;

	temp = (step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
	temp |= (step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_SRC_TRSF_STEP_OFFSET;
	hw->trsf_step = temp;

	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
}

static struct dma_async_tx_descriptor *
sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
		       unsigned int sglen, enum dma_transfer_direction dir,
		       unsigned long flags, void *context)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	struct dma_slave_config *slave_cfg = &schan->slave_cfg;
	dma_addr_t src = 0, dst = 0;
	dma_addr_t start_src = 0, start_dst = 0;
	struct sprd_dma_desc *sdesc;
	struct scatterlist *sg;
	u32 len = 0;
	int ret, i;

	if (!is_slave_direction(dir))
		return NULL;

	if (context) {
		struct sprd_dma_linklist *ll_cfg =
			(struct sprd_dma_linklist *)context;

		schan->linklist.phy_addr = ll_cfg->phy_addr;
		schan->linklist.virt_addr = ll_cfg->virt_addr;
		schan->linklist.wrap_addr = ll_cfg->wrap_addr;
	} else {
		schan->linklist.phy_addr = 0;
		schan->linklist.virt_addr = 0;
		schan->linklist.wrap_addr = 0;
	}

	/*
	 * Set channel mode, interrupt mode and trigger mode for 2-stage
	 * transfer.
	 */
	schan->chn_mode =
		(flags >> SPRD_DMA_CHN_MODE_SHIFT) & SPRD_DMA_CHN_MODE_MASK;
	schan->trg_mode =
		(flags >> SPRD_DMA_TRG_MODE_SHIFT) & SPRD_DMA_TRG_MODE_MASK;
	schan->int_type = flags & SPRD_DMA_INT_TYPE_MASK;

	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
	if (!sdesc)
		return NULL;

	sdesc->dir = dir;

	for_each_sg(sgl, sg, sglen, i) {
		len = sg_dma_len(sg);

		if (dir == DMA_MEM_TO_DEV) {
			src = sg_dma_address(sg);
			dst = slave_cfg->dst_addr;
		} else {
			src = slave_cfg->src_addr;
			dst = sg_dma_address(sg);
		}

		if (!i) {
			start_src = src;
			start_dst = dst;
		}

		/*
		 * The link-list mode needs at least 2 link-list
		 * configurations. If there is only one sg, it doesn't
		 * need to fill the link-list configuration.
		 */
		if (sglen < 2)
			break;

		ret = sprd_dma_fill_linklist_desc(chan, sglen, i, src, dst, len,
						  dir, flags, slave_cfg);
		if (ret) {
			kfree(sdesc);
			return NULL;
		}
	}

	ret = sprd_dma_fill_desc(chan, &sdesc->chn_hw, 0, 0, start_src,
				 start_dst, len, dir, flags, slave_cfg);
	if (ret) {
		kfree(sdesc);
		return NULL;
	}

	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
}

static int sprd_dma_slave_config(struct dma_chan *chan,
				 struct dma_slave_config *config)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	struct dma_slave_config *slave_cfg = &schan->slave_cfg;

	memcpy(slave_cfg, config, sizeof(*config));
	return 0;
}

static int sprd_dma_pause(struct dma_chan *chan)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	unsigned long flags;

	spin_lock_irqsave(&schan->vc.lock, flags);
	sprd_dma_pause_resume(schan, true);
	spin_unlock_irqrestore(&schan->vc.lock, flags);

	return 0;
}

static int sprd_dma_resume(struct dma_chan *chan)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	unsigned long flags;

	spin_lock_irqsave(&schan->vc.lock, flags);
	sprd_dma_pause_resume(schan, false);
	spin_unlock_irqrestore(&schan->vc.lock, flags);

	return 0;
}

static int sprd_dma_terminate_all(struct dma_chan *chan)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	struct virt_dma_desc *cur_vd = NULL;
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&schan->vc.lock, flags);
	if (schan->cur_desc)
		cur_vd = &schan->cur_desc->vd;

	sprd_dma_stop(schan);

	vchan_get_all_descriptors(&schan->vc, &head);
	spin_unlock_irqrestore(&schan->vc.lock, flags);

	if (cur_vd)
		sprd_dma_free_desc(cur_vd);

	vchan_dma_desc_free_list(&schan->vc, &head);
	return 0;
}

static void sprd_dma_free_desc(struct virt_dma_desc *vd)
{
	struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);

	kfree(sdesc);
}

static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param)
{
	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
	u32 slave_id = *(u32 *)param;

	schan->dev_id = slave_id;
	return true;
}

static int sprd_dma_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct sprd_dma_dev *sdev;
	struct sprd_dma_chn *dma_chn;
	u32 chn_count;
	int ret, i;

	ret = device_property_read_u32(&pdev->dev, "#dma-channels", &chn_count);
	if (ret) {
		dev_err(&pdev->dev, "get dma channels count failed\n");
		return ret;
	}

	sdev = devm_kzalloc(&pdev->dev,
			    struct_size(sdev, channels, chn_count),
			    GFP_KERNEL);
	if (!sdev)
		return -ENOMEM;

	sdev->clk = devm_clk_get(&pdev->dev, "enable");
	if (IS_ERR(sdev->clk)) {
		dev_err(&pdev->dev, "get enable clock failed\n");
		return PTR_ERR(sdev->clk);
	}

	/* ashb clock is optional for AGCP DMA */
	sdev->ashb_clk = devm_clk_get(&pdev->dev, "ashb_eb");
	if (IS_ERR(sdev->ashb_clk))
		dev_warn(&pdev->dev, "no optional ashb eb clock\n");

	/*
	 * We have three DMA controllers: AP DMA, AON DMA and AGCP DMA. For AGCP
	 * DMA controller, it can or do not request the irq, which will save
	 * system power without resuming system by DMA interrupts if AGCP DMA
	 * does not request the irq. Thus the DMA interrupts property should
	 * be optional.
	 */
	sdev->irq = platform_get_irq(pdev, 0);
	if (sdev->irq > 0) {
		ret = devm_request_irq(&pdev->dev, sdev->irq, dma_irq_handle,
				       0, "sprd_dma", (void *)sdev);
		if (ret < 0) {
			dev_err(&pdev->dev, "request dma irq failed\n");
			return ret;
		}
	} else {
		dev_warn(&pdev->dev, "no interrupts for the dma controller\n");
	}

	sdev->glb_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(sdev->glb_base))
		return PTR_ERR(sdev->glb_base);

	dma_cap_set(DMA_MEMCPY, sdev->dma_dev.cap_mask);
	sdev->total_chns = chn_count;
	sdev->dma_dev.chancnt = chn_count;
	INIT_LIST_HEAD(&sdev->dma_dev.channels);
	INIT_LIST_HEAD(&sdev->dma_dev.global_node);
	sdev->dma_dev.dev = &pdev->dev;
	sdev->dma_dev.device_alloc_chan_resources = sprd_dma_alloc_chan_resources;
	sdev->dma_dev.device_free_chan_resources = sprd_dma_free_chan_resources;
	sdev->dma_dev.device_tx_status = sprd_dma_tx_status;
	sdev->dma_dev.device_issue_pending = sprd_dma_issue_pending;
	sdev->dma_dev.device_prep_dma_memcpy = sprd_dma_prep_dma_memcpy;
	sdev->dma_dev.device_prep_slave_sg = sprd_dma_prep_slave_sg;
	sdev->dma_dev.device_config = sprd_dma_slave_config;
	sdev->dma_dev.device_pause = sprd_dma_pause;
	sdev->dma_dev.device_resume = sprd_dma_resume;
	sdev->dma_dev.device_terminate_all = sprd_dma_terminate_all;

	for (i = 0; i < chn_count; i++) {
		dma_chn = &sdev->channels[i];
		dma_chn->chn_num = i;
		dma_chn->cur_desc = NULL;
		/* get each channel's registers base address. */
		dma_chn->chn_base = sdev->glb_base + SPRD_DMA_CHN_REG_OFFSET +
				    SPRD_DMA_CHN_REG_LENGTH * i;

		dma_chn->vc.desc_free = sprd_dma_free_desc;
		vchan_init(&dma_chn->vc, &sdev->dma_dev);
	}

	platform_set_drvdata(pdev, sdev);
	ret = sprd_dma_enable(sdev);
	if (ret)
		return ret;

	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);

	ret = pm_runtime_get_sync(&pdev->dev);
	if (ret < 0)
		goto err_rpm;

	ret = dma_async_device_register(&sdev->dma_dev);
	if (ret < 0) {
		dev_err(&pdev->dev, "register dma device failed:%d\n", ret);
		goto err_register;
	}

	sprd_dma_info.dma_cap = sdev->dma_dev.cap_mask;
	ret = of_dma_controller_register(np, of_dma_simple_xlate,
					 &sprd_dma_info);
	if (ret)
		goto err_of_register;

	pm_runtime_put(&pdev->dev);
	return 0;

err_of_register:
	dma_async_device_unregister(&sdev->dma_dev);
err_register:
	pm_runtime_put_noidle(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
err_rpm:
	sprd_dma_disable(sdev);
	return ret;
}

static int sprd_dma_remove(struct platform_device *pdev)
{
	struct sprd_dma_dev *sdev = platform_get_drvdata(pdev);
	struct sprd_dma_chn *c, *cn;
	int ret;

	ret = pm_runtime_get_sync(&pdev->dev);
	if (ret < 0)
		return ret;

	/* explicitly free the irq */
	if (sdev->irq > 0)
		devm_free_irq(&pdev->dev, sdev->irq, sdev);

	list_for_each_entry_safe(c, cn, &sdev->dma_dev.channels,
				 vc.chan.device_node) {
		list_del(&c->vc.chan.device_node);
		tasklet_kill(&c->vc.task);
	}

	of_dma_controller_free(pdev->dev.of_node);
	dma_async_device_unregister(&sdev->dma_dev);
	sprd_dma_disable(sdev);

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

static const struct of_device_id sprd_dma_match[] = {
	{ .compatible = "sprd,sc9860-dma", },
	{},
};

static int __maybe_unused sprd_dma_runtime_suspend(struct device *dev)
{
	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);

	sprd_dma_disable(sdev);
	return 0;
}

static int __maybe_unused sprd_dma_runtime_resume(struct device *dev)
{
	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
	int ret;

	ret = sprd_dma_enable(sdev);
	if (ret)
		dev_err(sdev->dma_dev.dev, "enable dma failed\n");

	return ret;
}

static const struct dev_pm_ops sprd_dma_pm_ops = {
	SET_RUNTIME_PM_OPS(sprd_dma_runtime_suspend,
			   sprd_dma_runtime_resume,
			   NULL)
};

static struct platform_driver sprd_dma_driver = {
	.probe = sprd_dma_probe,
	.remove = sprd_dma_remove,
	.driver = {
		.name = "sprd-dma",
		.of_match_table = sprd_dma_match,
		.pm = &sprd_dma_pm_ops,
	},
};
module_platform_driver(sprd_dma_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DMA driver for Spreadtrum");
MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
MODULE_AUTHOR("Eric Long <eric.long@spreadtrum.com>");
MODULE_ALIAS("platform:sprd-dma");