summaryrefslogtreecommitdiff
path: root/drivers/dma/stm32-mdma.c
blob: e28acbcb53f4c701f70542e359830d42368580d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
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
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Copyright (C) STMicroelectronics SA 2017
 * Author(s): M'boumba Cedric Madianga <cedric.madianga@gmail.com>
 *            Pierre-Yves Mordret <pierre-yves.mordret@st.com>
 *
 * Driver for STM32 MDMA controller
 *
 * Inspired by stm32-dma.c and dma-jz4780.c
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/iopoll.h>
#include <linux/jiffies.h>
#include <linux/list.h>
#include <linux/log2.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/slab.h>

#include "virt-dma.h"

#define STM32_MDMA_GISR0		0x0000 /* MDMA Int Status Reg 1 */

/* MDMA Channel x interrupt/status register */
#define STM32_MDMA_CISR(x)		(0x40 + 0x40 * (x)) /* x = 0..62 */
#define STM32_MDMA_CISR_CRQA		BIT(16)
#define STM32_MDMA_CISR_TCIF		BIT(4)
#define STM32_MDMA_CISR_BTIF		BIT(3)
#define STM32_MDMA_CISR_BRTIF		BIT(2)
#define STM32_MDMA_CISR_CTCIF		BIT(1)
#define STM32_MDMA_CISR_TEIF		BIT(0)

/* MDMA Channel x interrupt flag clear register */
#define STM32_MDMA_CIFCR(x)		(0x44 + 0x40 * (x))
#define STM32_MDMA_CIFCR_CLTCIF		BIT(4)
#define STM32_MDMA_CIFCR_CBTIF		BIT(3)
#define STM32_MDMA_CIFCR_CBRTIF		BIT(2)
#define STM32_MDMA_CIFCR_CCTCIF		BIT(1)
#define STM32_MDMA_CIFCR_CTEIF		BIT(0)
#define STM32_MDMA_CIFCR_CLEAR_ALL	(STM32_MDMA_CIFCR_CLTCIF \
					| STM32_MDMA_CIFCR_CBTIF \
					| STM32_MDMA_CIFCR_CBRTIF \
					| STM32_MDMA_CIFCR_CCTCIF \
					| STM32_MDMA_CIFCR_CTEIF)

/* MDMA Channel x error status register */
#define STM32_MDMA_CESR(x)		(0x48 + 0x40 * (x))
#define STM32_MDMA_CESR_BSE		BIT(11)
#define STM32_MDMA_CESR_ASR		BIT(10)
#define STM32_MDMA_CESR_TEMD		BIT(9)
#define STM32_MDMA_CESR_TELD		BIT(8)
#define STM32_MDMA_CESR_TED		BIT(7)
#define STM32_MDMA_CESR_TEA_MASK	GENMASK(6, 0)

/* MDMA Channel x control register */
#define STM32_MDMA_CCR(x)		(0x4C + 0x40 * (x))
#define STM32_MDMA_CCR_SWRQ		BIT(16)
#define STM32_MDMA_CCR_WEX		BIT(14)
#define STM32_MDMA_CCR_HEX		BIT(13)
#define STM32_MDMA_CCR_BEX		BIT(12)
#define STM32_MDMA_CCR_SM		BIT(8)
#define STM32_MDMA_CCR_PL_MASK		GENMASK(7, 6)
#define STM32_MDMA_CCR_PL(n)		FIELD_PREP(STM32_MDMA_CCR_PL_MASK, (n))
#define STM32_MDMA_CCR_TCIE		BIT(5)
#define STM32_MDMA_CCR_BTIE		BIT(4)
#define STM32_MDMA_CCR_BRTIE		BIT(3)
#define STM32_MDMA_CCR_CTCIE		BIT(2)
#define STM32_MDMA_CCR_TEIE		BIT(1)
#define STM32_MDMA_CCR_EN		BIT(0)
#define STM32_MDMA_CCR_IRQ_MASK		(STM32_MDMA_CCR_TCIE \
					| STM32_MDMA_CCR_BTIE \
					| STM32_MDMA_CCR_BRTIE \
					| STM32_MDMA_CCR_CTCIE \
					| STM32_MDMA_CCR_TEIE)

/* MDMA Channel x transfer configuration register */
#define STM32_MDMA_CTCR(x)		(0x50 + 0x40 * (x))
#define STM32_MDMA_CTCR_BWM		BIT(31)
#define STM32_MDMA_CTCR_SWRM		BIT(30)
#define STM32_MDMA_CTCR_TRGM_MSK	GENMASK(29, 28)
#define STM32_MDMA_CTCR_TRGM(n)		FIELD_PREP(STM32_MDMA_CTCR_TRGM_MSK, (n))
#define STM32_MDMA_CTCR_TRGM_GET(n)	FIELD_GET(STM32_MDMA_CTCR_TRGM_MSK, (n))
#define STM32_MDMA_CTCR_PAM_MASK	GENMASK(27, 26)
#define STM32_MDMA_CTCR_PAM(n)		FIELD_PREP(STM32_MDMA_CTCR_PAM_MASK, (n))
#define STM32_MDMA_CTCR_PKE		BIT(25)
#define STM32_MDMA_CTCR_TLEN_MSK	GENMASK(24, 18)
#define STM32_MDMA_CTCR_TLEN(n)		FIELD_PREP(STM32_MDMA_CTCR_TLEN_MSK, (n))
#define STM32_MDMA_CTCR_TLEN_GET(n)	FIELD_GET(STM32_MDMA_CTCR_TLEN_MSK, (n))
#define STM32_MDMA_CTCR_LEN2_MSK	GENMASK(25, 18)
#define STM32_MDMA_CTCR_LEN2(n)		FIELD_PREP(STM32_MDMA_CTCR_LEN2_MSK, (n))
#define STM32_MDMA_CTCR_LEN2_GET(n)	FIELD_GET(STM32_MDMA_CTCR_LEN2_MSK, (n))
#define STM32_MDMA_CTCR_DBURST_MASK	GENMASK(17, 15)
#define STM32_MDMA_CTCR_DBURST(n)	FIELD_PREP(STM32_MDMA_CTCR_DBURST_MASK, (n))
#define STM32_MDMA_CTCR_SBURST_MASK	GENMASK(14, 12)
#define STM32_MDMA_CTCR_SBURST(n)	FIELD_PREP(STM32_MDMA_CTCR_SBURST_MASK, (n))
#define STM32_MDMA_CTCR_DINCOS_MASK	GENMASK(11, 10)
#define STM32_MDMA_CTCR_DINCOS(n)	FIELD_PREP(STM32_MDMA_CTCR_DINCOS_MASK, (n))
#define STM32_MDMA_CTCR_SINCOS_MASK	GENMASK(9, 8)
#define STM32_MDMA_CTCR_SINCOS(n)	FIELD_PREP(STM32_MDMA_CTCR_SINCOS_MASK, (n))
#define STM32_MDMA_CTCR_DSIZE_MASK	GENMASK(7, 6)
#define STM32_MDMA_CTCR_DSIZE(n)	FIELD_PREP(STM32_MDMA_CTCR_DSIZE_MASK, (n))
#define STM32_MDMA_CTCR_SSIZE_MASK	GENMASK(5, 4)
#define STM32_MDMA_CTCR_SSIZE(n)	FIELD_PREP(STM32_MDMA_CTCR_SSIZE_MASK, (n))
#define STM32_MDMA_CTCR_DINC_MASK	GENMASK(3, 2)
#define STM32_MDMA_CTCR_DINC(n)		FIELD_PREP(STM32_MDMA_CTCR_DINC_MASK, (n))
#define STM32_MDMA_CTCR_SINC_MASK	GENMASK(1, 0)
#define STM32_MDMA_CTCR_SINC(n)		FIELD_PREP(STM32_MDMA_CTCR_SINC_MASK, (n))
#define STM32_MDMA_CTCR_CFG_MASK	(STM32_MDMA_CTCR_SINC_MASK \
					| STM32_MDMA_CTCR_DINC_MASK \
					| STM32_MDMA_CTCR_SINCOS_MASK \
					| STM32_MDMA_CTCR_DINCOS_MASK \
					| STM32_MDMA_CTCR_LEN2_MSK \
					| STM32_MDMA_CTCR_TRGM_MSK)

/* MDMA Channel x block number of data register */
#define STM32_MDMA_CBNDTR(x)		(0x54 + 0x40 * (x))
#define STM32_MDMA_CBNDTR_BRC_MK	GENMASK(31, 20)
#define STM32_MDMA_CBNDTR_BRC(n)	FIELD_PREP(STM32_MDMA_CBNDTR_BRC_MK, (n))
#define STM32_MDMA_CBNDTR_BRC_GET(n)	FIELD_GET(STM32_MDMA_CBNDTR_BRC_MK, (n))

#define STM32_MDMA_CBNDTR_BRDUM		BIT(19)
#define STM32_MDMA_CBNDTR_BRSUM		BIT(18)
#define STM32_MDMA_CBNDTR_BNDT_MASK	GENMASK(16, 0)
#define STM32_MDMA_CBNDTR_BNDT(n)	FIELD_PREP(STM32_MDMA_CBNDTR_BNDT_MASK, (n))

/* MDMA Channel x source address register */
#define STM32_MDMA_CSAR(x)		(0x58 + 0x40 * (x))

/* MDMA Channel x destination address register */
#define STM32_MDMA_CDAR(x)		(0x5C + 0x40 * (x))

/* MDMA Channel x block repeat address update register */
#define STM32_MDMA_CBRUR(x)		(0x60 + 0x40 * (x))
#define STM32_MDMA_CBRUR_DUV_MASK	GENMASK(31, 16)
#define STM32_MDMA_CBRUR_DUV(n)		FIELD_PREP(STM32_MDMA_CBRUR_DUV_MASK, (n))
#define STM32_MDMA_CBRUR_SUV_MASK	GENMASK(15, 0)
#define STM32_MDMA_CBRUR_SUV(n)		FIELD_PREP(STM32_MDMA_CBRUR_SUV_MASK, (n))

/* MDMA Channel x link address register */
#define STM32_MDMA_CLAR(x)		(0x64 + 0x40 * (x))

/* MDMA Channel x trigger and bus selection register */
#define STM32_MDMA_CTBR(x)		(0x68 + 0x40 * (x))
#define STM32_MDMA_CTBR_DBUS		BIT(17)
#define STM32_MDMA_CTBR_SBUS		BIT(16)
#define STM32_MDMA_CTBR_TSEL_MASK	GENMASK(5, 0)
#define STM32_MDMA_CTBR_TSEL(n)		FIELD_PREP(STM32_MDMA_CTBR_TSEL_MASK, (n))

/* MDMA Channel x mask address register */
#define STM32_MDMA_CMAR(x)		(0x70 + 0x40 * (x))

/* MDMA Channel x mask data register */
#define STM32_MDMA_CMDR(x)		(0x74 + 0x40 * (x))

#define STM32_MDMA_MAX_BUF_LEN		128
#define STM32_MDMA_MAX_BLOCK_LEN	65536
#define STM32_MDMA_MAX_CHANNELS		32
#define STM32_MDMA_MAX_REQUESTS		256
#define STM32_MDMA_MAX_BURST		128
#define STM32_MDMA_VERY_HIGH_PRIORITY	0x3

enum stm32_mdma_trigger_mode {
	STM32_MDMA_BUFFER,
	STM32_MDMA_BLOCK,
	STM32_MDMA_BLOCK_REP,
	STM32_MDMA_LINKED_LIST,
};

enum stm32_mdma_width {
	STM32_MDMA_BYTE,
	STM32_MDMA_HALF_WORD,
	STM32_MDMA_WORD,
	STM32_MDMA_DOUBLE_WORD,
};

enum stm32_mdma_inc_mode {
	STM32_MDMA_FIXED = 0,
	STM32_MDMA_INC = 2,
	STM32_MDMA_DEC = 3,
};

struct stm32_mdma_chan_config {
	u32 request;
	u32 priority_level;
	u32 transfer_config;
	u32 mask_addr;
	u32 mask_data;
	bool m2m_hw; /* True when MDMA is triggered by STM32 DMA */
};

struct stm32_mdma_hwdesc {
	u32 ctcr;
	u32 cbndtr;
	u32 csar;
	u32 cdar;
	u32 cbrur;
	u32 clar;
	u32 ctbr;
	u32 dummy;
	u32 cmar;
	u32 cmdr;
} __aligned(64);

struct stm32_mdma_desc_node {
	struct stm32_mdma_hwdesc *hwdesc;
	dma_addr_t hwdesc_phys;
};

struct stm32_mdma_desc {
	struct virt_dma_desc vdesc;
	u32 ccr;
	bool cyclic;
	u32 count;
	struct stm32_mdma_desc_node node[];
};

struct stm32_mdma_dma_config {
	u32 request;	/* STM32 DMA channel stream id, triggering MDMA */
	u32 cmar;	/* STM32 DMA interrupt flag clear register address */
	u32 cmdr;	/* STM32 DMA Transfer Complete flag */
};

struct stm32_mdma_chan {
	struct virt_dma_chan vchan;
	struct dma_pool *desc_pool;
	u32 id;
	struct stm32_mdma_desc *desc;
	u32 curr_hwdesc;
	struct dma_slave_config dma_config;
	struct stm32_mdma_chan_config chan_config;
	bool busy;
	u32 mem_burst;
	u32 mem_width;
};

struct stm32_mdma_device {
	struct dma_device ddev;
	void __iomem *base;
	struct clk *clk;
	int irq;
	u32 nr_channels;
	u32 nr_requests;
	u32 nr_ahb_addr_masks;
	u32 chan_reserved;
	struct stm32_mdma_chan chan[STM32_MDMA_MAX_CHANNELS];
	u32 ahb_addr_masks[];
};

static struct stm32_mdma_device *stm32_mdma_get_dev(
	struct stm32_mdma_chan *chan)
{
	return container_of(chan->vchan.chan.device, struct stm32_mdma_device,
			    ddev);
}

static struct stm32_mdma_chan *to_stm32_mdma_chan(struct dma_chan *c)
{
	return container_of(c, struct stm32_mdma_chan, vchan.chan);
}

static struct stm32_mdma_desc *to_stm32_mdma_desc(struct virt_dma_desc *vdesc)
{
	return container_of(vdesc, struct stm32_mdma_desc, vdesc);
}

static struct device *chan2dev(struct stm32_mdma_chan *chan)
{
	return &chan->vchan.chan.dev->device;
}

static struct device *mdma2dev(struct stm32_mdma_device *mdma_dev)
{
	return mdma_dev->ddev.dev;
}

static u32 stm32_mdma_read(struct stm32_mdma_device *dmadev, u32 reg)
{
	return readl_relaxed(dmadev->base + reg);
}

static void stm32_mdma_write(struct stm32_mdma_device *dmadev, u32 reg, u32 val)
{
	writel_relaxed(val, dmadev->base + reg);
}

static void stm32_mdma_set_bits(struct stm32_mdma_device *dmadev, u32 reg,
				u32 mask)
{
	void __iomem *addr = dmadev->base + reg;

	writel_relaxed(readl_relaxed(addr) | mask, addr);
}

static void stm32_mdma_clr_bits(struct stm32_mdma_device *dmadev, u32 reg,
				u32 mask)
{
	void __iomem *addr = dmadev->base + reg;

	writel_relaxed(readl_relaxed(addr) & ~mask, addr);
}

static struct stm32_mdma_desc *stm32_mdma_alloc_desc(
		struct stm32_mdma_chan *chan, u32 count)
{
	struct stm32_mdma_desc *desc;
	int i;

	desc = kzalloc(struct_size(desc, node, count), GFP_NOWAIT);
	if (!desc)
		return NULL;

	for (i = 0; i < count; i++) {
		desc->node[i].hwdesc =
			dma_pool_alloc(chan->desc_pool, GFP_NOWAIT,
				       &desc->node[i].hwdesc_phys);
		if (!desc->node[i].hwdesc)
			goto err;
	}

	desc->count = count;

	return desc;

err:
	dev_err(chan2dev(chan), "Failed to allocate descriptor\n");
	while (--i >= 0)
		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
			      desc->node[i].hwdesc_phys);
	kfree(desc);
	return NULL;
}

static void stm32_mdma_desc_free(struct virt_dma_desc *vdesc)
{
	struct stm32_mdma_desc *desc = to_stm32_mdma_desc(vdesc);
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(vdesc->tx.chan);
	int i;

	for (i = 0; i < desc->count; i++)
		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
			      desc->node[i].hwdesc_phys);
	kfree(desc);
}

static int stm32_mdma_get_width(struct stm32_mdma_chan *chan,
				enum dma_slave_buswidth width)
{
	switch (width) {
	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(width) - 1;
	default:
		dev_err(chan2dev(chan), "Dma bus width %i not supported\n",
			width);
		return -EINVAL;
	}
}

static enum dma_slave_buswidth stm32_mdma_get_max_width(dma_addr_t addr,
							u32 buf_len, u32 tlen)
{
	enum dma_slave_buswidth max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;

	for (max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
	     max_width > DMA_SLAVE_BUSWIDTH_1_BYTE;
	     max_width >>= 1) {
		/*
		 * Address and buffer length both have to be aligned on
		 * bus width
		 */
		if ((((buf_len | addr) & (max_width - 1)) == 0) &&
		    tlen >= max_width)
			break;
	}

	return max_width;
}

static u32 stm32_mdma_get_best_burst(u32 buf_len, u32 tlen, u32 max_burst,
				     enum dma_slave_buswidth width)
{
	u32 best_burst;

	best_burst = min((u32)1 << __ffs(tlen | buf_len),
			 max_burst * width) / width;

	return (best_burst > 0) ? best_burst : 1;
}

static int stm32_mdma_disable_chan(struct stm32_mdma_chan *chan)
{
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	u32 ccr, cisr, id, reg;
	int ret;

	id = chan->id;
	reg = STM32_MDMA_CCR(id);

	/* Disable interrupts */
	stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_IRQ_MASK);

	ccr = stm32_mdma_read(dmadev, reg);
	if (ccr & STM32_MDMA_CCR_EN) {
		stm32_mdma_clr_bits(dmadev, reg, STM32_MDMA_CCR_EN);

		/* Ensure that any ongoing transfer has been completed */
		ret = readl_relaxed_poll_timeout_atomic(
				dmadev->base + STM32_MDMA_CISR(id), cisr,
				(cisr & STM32_MDMA_CISR_CTCIF), 10, 1000);
		if (ret) {
			dev_err(chan2dev(chan), "%s: timeout!\n", __func__);
			return -EBUSY;
		}
	}

	return 0;
}

static void stm32_mdma_stop(struct stm32_mdma_chan *chan)
{
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	u32 status;
	int ret;

	/* Disable DMA */
	ret = stm32_mdma_disable_chan(chan);
	if (ret < 0)
		return;

	/* Clear interrupt status if it is there */
	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
	if (status) {
		dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n",
			__func__, status);
		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);
	}

	chan->busy = false;
}

static void stm32_mdma_set_bus(struct stm32_mdma_device *dmadev, u32 *ctbr,
			       u32 ctbr_mask, u32 src_addr)
{
	u32 mask;
	int i;

	/* Check if memory device is on AHB or AXI */
	*ctbr &= ~ctbr_mask;
	mask = src_addr & 0xF0000000;
	for (i = 0; i < dmadev->nr_ahb_addr_masks; i++) {
		if (mask == dmadev->ahb_addr_masks[i]) {
			*ctbr |= ctbr_mask;
			break;
		}
	}
}

static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
				     enum dma_transfer_direction direction,
				     u32 *mdma_ccr, u32 *mdma_ctcr,
				     u32 *mdma_ctbr, dma_addr_t addr,
				     u32 buf_len)
{
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
	enum dma_slave_buswidth src_addr_width, dst_addr_width;
	phys_addr_t src_addr, dst_addr;
	int src_bus_width, dst_bus_width;
	u32 src_maxburst, dst_maxburst, src_best_burst, dst_best_burst;
	u32 ccr, ctcr, ctbr, tlen;

	src_addr_width = chan->dma_config.src_addr_width;
	dst_addr_width = chan->dma_config.dst_addr_width;
	src_maxburst = chan->dma_config.src_maxburst;
	dst_maxburst = chan->dma_config.dst_maxburst;

	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));

	/* Enable HW request mode */
	ctcr &= ~STM32_MDMA_CTCR_SWRM;

	/* Set DINC, SINC, DINCOS, SINCOS, TRGM and TLEN retrieve from DT */
	ctcr &= ~STM32_MDMA_CTCR_CFG_MASK;
	ctcr |= chan_config->transfer_config & STM32_MDMA_CTCR_CFG_MASK;

	/*
	 * For buffer transfer length (TLEN) we have to set
	 * the number of bytes - 1 in CTCR register
	 */
	tlen = STM32_MDMA_CTCR_LEN2_GET(ctcr);
	ctcr &= ~STM32_MDMA_CTCR_LEN2_MSK;
	ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));

	/* Disable Pack Enable */
	ctcr &= ~STM32_MDMA_CTCR_PKE;

	/* Check burst size constraints */
	if (src_maxburst * src_addr_width > STM32_MDMA_MAX_BURST ||
	    dst_maxburst * dst_addr_width > STM32_MDMA_MAX_BURST) {
		dev_err(chan2dev(chan),
			"burst size * bus width higher than %d bytes\n",
			STM32_MDMA_MAX_BURST);
		return -EINVAL;
	}

	if ((!is_power_of_2(src_maxburst) && src_maxburst > 0) ||
	    (!is_power_of_2(dst_maxburst) && dst_maxburst > 0)) {
		dev_err(chan2dev(chan), "burst size must be a power of 2\n");
		return -EINVAL;
	}

	/*
	 * Configure channel control:
	 * - Clear SW request as in this case this is a HW one
	 * - Clear WEX, HEX and BEX bits
	 * - Set priority level
	 */
	ccr &= ~(STM32_MDMA_CCR_SWRQ | STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK);
	ccr |= STM32_MDMA_CCR_PL(chan_config->priority_level);

	/* Configure Trigger selection */
	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;
	ctbr |= STM32_MDMA_CTBR_TSEL(chan_config->request);

	switch (direction) {
	case DMA_MEM_TO_DEV:
		dst_addr = chan->dma_config.dst_addr;

		/* Set device data size */
		if (chan_config->m2m_hw)
			dst_addr_width = stm32_mdma_get_max_width(dst_addr, buf_len,
								  STM32_MDMA_MAX_BUF_LEN);
		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
		if (dst_bus_width < 0)
			return dst_bus_width;
		ctcr &= ~STM32_MDMA_CTCR_DSIZE_MASK;
		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width);
		if (chan_config->m2m_hw) {
			ctcr &= ~STM32_MDMA_CTCR_DINCOS_MASK;
			ctcr |= STM32_MDMA_CTCR_DINCOS(dst_bus_width);
		}

		/* Set device burst value */
		if (chan_config->m2m_hw)
			dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;

		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
							   dst_maxburst,
							   dst_addr_width);
		chan->mem_burst = dst_best_burst;
		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));

		/* Set memory data size */
		src_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
		chan->mem_width = src_addr_width;
		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
		if (src_bus_width < 0)
			return src_bus_width;
		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK |
			STM32_MDMA_CTCR_SINCOS_MASK;
		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width) |
			STM32_MDMA_CTCR_SINCOS(src_bus_width);

		/* Set memory burst value */
		src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;
		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
							   src_maxburst,
							   src_addr_width);
		chan->mem_burst = src_best_burst;
		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));

		/* Select bus */
		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
				   dst_addr);

		if (dst_bus_width != src_bus_width)
			ctcr |= STM32_MDMA_CTCR_PKE;

		/* Set destination address */
		stm32_mdma_write(dmadev, STM32_MDMA_CDAR(chan->id), dst_addr);
		break;

	case DMA_DEV_TO_MEM:
		src_addr = chan->dma_config.src_addr;

		/* Set device data size */
		if (chan_config->m2m_hw)
			src_addr_width = stm32_mdma_get_max_width(src_addr, buf_len,
								  STM32_MDMA_MAX_BUF_LEN);

		src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
		if (src_bus_width < 0)
			return src_bus_width;
		ctcr &= ~STM32_MDMA_CTCR_SSIZE_MASK;
		ctcr |= STM32_MDMA_CTCR_SSIZE(src_bus_width);
		if (chan_config->m2m_hw) {
			ctcr &= ~STM32_MDMA_CTCR_SINCOS_MASK;
			ctcr |= STM32_MDMA_CTCR_SINCOS(src_bus_width);
		}

		/* Set device burst value */
		if (chan_config->m2m_hw)
			src_maxburst = STM32_MDMA_MAX_BUF_LEN / src_addr_width;

		src_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
							   src_maxburst,
							   src_addr_width);
		ctcr &= ~STM32_MDMA_CTCR_SBURST_MASK;
		ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));

		/* Set memory data size */
		dst_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
		chan->mem_width = dst_addr_width;
		dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
		if (dst_bus_width < 0)
			return dst_bus_width;
		ctcr &= ~(STM32_MDMA_CTCR_DSIZE_MASK |
			STM32_MDMA_CTCR_DINCOS_MASK);
		ctcr |= STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
			STM32_MDMA_CTCR_DINCOS(dst_bus_width);

		/* Set memory burst value */
		dst_maxburst = STM32_MDMA_MAX_BUF_LEN / dst_addr_width;
		dst_best_burst = stm32_mdma_get_best_burst(buf_len, tlen,
							   dst_maxburst,
							   dst_addr_width);
		ctcr &= ~STM32_MDMA_CTCR_DBURST_MASK;
		ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));

		/* Select bus */
		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
				   src_addr);

		if (dst_bus_width != src_bus_width)
			ctcr |= STM32_MDMA_CTCR_PKE;

		/* Set source address */
		stm32_mdma_write(dmadev, STM32_MDMA_CSAR(chan->id), src_addr);
		break;

	default:
		dev_err(chan2dev(chan), "Dma direction is not supported\n");
		return -EINVAL;
	}

	*mdma_ccr = ccr;
	*mdma_ctcr = ctcr;
	*mdma_ctbr = ctbr;

	return 0;
}

static void stm32_mdma_dump_hwdesc(struct stm32_mdma_chan *chan,
				   struct stm32_mdma_desc_node *node)
{
	dev_dbg(chan2dev(chan), "hwdesc:  %pad\n", &node->hwdesc_phys);
	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n", node->hwdesc->ctcr);
	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n", node->hwdesc->cbndtr);
	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n", node->hwdesc->csar);
	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n", node->hwdesc->cdar);
	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n", node->hwdesc->cbrur);
	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n", node->hwdesc->clar);
	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n", node->hwdesc->ctbr);
	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n", node->hwdesc->cmar);
	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n\n", node->hwdesc->cmdr);
}

static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
				    struct stm32_mdma_desc *desc,
				    enum dma_transfer_direction dir, u32 count,
				    dma_addr_t src_addr, dma_addr_t dst_addr,
				    u32 len, u32 ctcr, u32 ctbr, bool is_last,
				    bool is_first, bool is_cyclic)
{
	struct stm32_mdma_chan_config *config = &chan->chan_config;
	struct stm32_mdma_hwdesc *hwdesc;
	u32 next = count + 1;

	hwdesc = desc->node[count].hwdesc;
	hwdesc->ctcr = ctcr;
	hwdesc->cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK |
			STM32_MDMA_CBNDTR_BRDUM |
			STM32_MDMA_CBNDTR_BRSUM |
			STM32_MDMA_CBNDTR_BNDT_MASK);
	hwdesc->cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
	hwdesc->csar = src_addr;
	hwdesc->cdar = dst_addr;
	hwdesc->cbrur = 0;
	hwdesc->ctbr = ctbr;
	hwdesc->cmar = config->mask_addr;
	hwdesc->cmdr = config->mask_data;

	if (is_last) {
		if (is_cyclic)
			hwdesc->clar = desc->node[0].hwdesc_phys;
		else
			hwdesc->clar = 0;
	} else {
		hwdesc->clar = desc->node[next].hwdesc_phys;
	}

	stm32_mdma_dump_hwdesc(chan, &desc->node[count]);
}

static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
				 struct stm32_mdma_desc *desc,
				 struct scatterlist *sgl, u32 sg_len,
				 enum dma_transfer_direction direction)
{
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	struct dma_slave_config *dma_config = &chan->dma_config;
	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
	struct scatterlist *sg;
	dma_addr_t src_addr, dst_addr;
	u32 m2m_hw_period, ccr, ctcr, ctbr;
	int i, ret = 0;

	if (chan_config->m2m_hw)
		m2m_hw_period = sg_dma_len(sgl);

	for_each_sg(sgl, sg, sg_len, i) {
		if (sg_dma_len(sg) > STM32_MDMA_MAX_BLOCK_LEN) {
			dev_err(chan2dev(chan), "Invalid block len\n");
			return -EINVAL;
		}

		if (direction == DMA_MEM_TO_DEV) {
			src_addr = sg_dma_address(sg);
			dst_addr = dma_config->dst_addr;
			if (chan_config->m2m_hw && (i & 1))
				dst_addr += m2m_hw_period;
			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
							&ctcr, &ctbr, src_addr,
							sg_dma_len(sg));
			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
					   src_addr);
		} else {
			src_addr = dma_config->src_addr;
			if (chan_config->m2m_hw && (i & 1))
				src_addr += m2m_hw_period;
			dst_addr = sg_dma_address(sg);
			ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
							&ctcr, &ctbr, dst_addr,
							sg_dma_len(sg));
			stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
					   dst_addr);
		}

		if (ret < 0)
			return ret;

		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
					dst_addr, sg_dma_len(sg), ctcr, ctbr,
					i == sg_len - 1, i == 0, false);
	}

	/* Enable interrupts */
	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE;
	if (sg_len > 1)
		ccr |= STM32_MDMA_CCR_BTIE;
	desc->ccr = ccr;

	return 0;
}

static struct dma_async_tx_descriptor *
stm32_mdma_prep_slave_sg(struct dma_chan *c, struct scatterlist *sgl,
			 u32 sg_len, enum dma_transfer_direction direction,
			 unsigned long flags, void *context)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
	struct stm32_mdma_desc *desc;
	int i, ret;

	/*
	 * Once DMA is in setup cyclic mode the channel we cannot assign this
	 * channel anymore. The DMA channel needs to be aborted or terminated
	 * for allowing another request.
	 */
	if (chan->desc && chan->desc->cyclic) {
		dev_err(chan2dev(chan),
			"Request not allowed when dma in cyclic mode\n");
		return NULL;
	}

	desc = stm32_mdma_alloc_desc(chan, sg_len);
	if (!desc)
		return NULL;

	ret = stm32_mdma_setup_xfer(chan, desc, sgl, sg_len, direction);
	if (ret < 0)
		goto xfer_setup_err;

	/*
	 * In case of M2M HW transfer triggered by STM32 DMA, we do not have to clear the
	 * transfer complete flag by hardware in order to let the CPU rearm the STM32 DMA
	 * with the next sg element and update some data in dmaengine framework.
	 */
	if (chan_config->m2m_hw && direction == DMA_MEM_TO_DEV) {
		struct stm32_mdma_hwdesc *hwdesc;

		for (i = 0; i < sg_len; i++) {
			hwdesc = desc->node[i].hwdesc;
			hwdesc->cmar = 0;
			hwdesc->cmdr = 0;
		}
	}

	desc->cyclic = false;

	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);

xfer_setup_err:
	for (i = 0; i < desc->count; i++)
		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
			      desc->node[i].hwdesc_phys);
	kfree(desc);
	return NULL;
}

static struct dma_async_tx_descriptor *
stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
			   size_t buf_len, size_t period_len,
			   enum dma_transfer_direction direction,
			   unsigned long flags)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	struct dma_slave_config *dma_config = &chan->dma_config;
	struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
	struct stm32_mdma_desc *desc;
	dma_addr_t src_addr, dst_addr;
	u32 ccr, ctcr, ctbr, count;
	int i, ret;

	/*
	 * Once DMA is in setup cyclic mode the channel we cannot assign this
	 * channel anymore. The DMA channel needs to be aborted or terminated
	 * for allowing another request.
	 */
	if (chan->desc && chan->desc->cyclic) {
		dev_err(chan2dev(chan),
			"Request not allowed when dma in cyclic mode\n");
		return NULL;
	}

	if (!buf_len || !period_len || period_len > STM32_MDMA_MAX_BLOCK_LEN) {
		dev_err(chan2dev(chan), "Invalid buffer/period len\n");
		return NULL;
	}

	if (buf_len % period_len) {
		dev_err(chan2dev(chan), "buf_len not multiple of period_len\n");
		return NULL;
	}

	count = buf_len / period_len;

	desc = stm32_mdma_alloc_desc(chan, count);
	if (!desc)
		return NULL;

	/* Select bus */
	if (direction == DMA_MEM_TO_DEV) {
		src_addr = buf_addr;
		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
						&ctbr, src_addr, period_len);
		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
				   src_addr);
	} else {
		dst_addr = buf_addr;
		ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
						&ctbr, dst_addr, period_len);
		stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
				   dst_addr);
	}

	if (ret < 0)
		goto xfer_setup_err;

	/* Enable interrupts */
	ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
	ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
	desc->ccr = ccr;

	/* Configure hwdesc list */
	for (i = 0; i < count; i++) {
		if (direction == DMA_MEM_TO_DEV) {
			src_addr = buf_addr + i * period_len;
			dst_addr = dma_config->dst_addr;
			if (chan_config->m2m_hw && (i & 1))
				dst_addr += period_len;
		} else {
			src_addr = dma_config->src_addr;
			if (chan_config->m2m_hw && (i & 1))
				src_addr += period_len;
			dst_addr = buf_addr + i * period_len;
		}

		stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
					dst_addr, period_len, ctcr, ctbr,
					i == count - 1, i == 0, true);
	}

	desc->cyclic = true;

	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);

xfer_setup_err:
	for (i = 0; i < desc->count; i++)
		dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
			      desc->node[i].hwdesc_phys);
	kfree(desc);
	return NULL;
}

static struct dma_async_tx_descriptor *
stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
			   size_t len, unsigned long flags)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	enum dma_slave_buswidth max_width;
	struct stm32_mdma_desc *desc;
	struct stm32_mdma_hwdesc *hwdesc;
	u32 ccr, ctcr, ctbr, cbndtr, count, max_burst, mdma_burst;
	u32 best_burst, tlen;
	size_t xfer_count, offset;
	int src_bus_width, dst_bus_width;
	int i;

	/*
	 * Once DMA is in setup cyclic mode the channel we cannot assign this
	 * channel anymore. The DMA channel needs to be aborted or terminated
	 * to allow another request
	 */
	if (chan->desc && chan->desc->cyclic) {
		dev_err(chan2dev(chan),
			"Request not allowed when dma in cyclic mode\n");
		return NULL;
	}

	count = DIV_ROUND_UP(len, STM32_MDMA_MAX_BLOCK_LEN);
	desc = stm32_mdma_alloc_desc(chan, count);
	if (!desc)
		return NULL;

	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
	ctcr = stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id));
	ctbr = stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id));
	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));

	/* Enable sw req, some interrupts and clear other bits */
	ccr &= ~(STM32_MDMA_CCR_WEX | STM32_MDMA_CCR_HEX |
		 STM32_MDMA_CCR_BEX | STM32_MDMA_CCR_PL_MASK |
		 STM32_MDMA_CCR_IRQ_MASK);
	ccr |= STM32_MDMA_CCR_TEIE;

	/* Enable SW request mode, dest/src inc and clear other bits */
	ctcr &= ~(STM32_MDMA_CTCR_BWM | STM32_MDMA_CTCR_TRGM_MSK |
		  STM32_MDMA_CTCR_PAM_MASK | STM32_MDMA_CTCR_PKE |
		  STM32_MDMA_CTCR_TLEN_MSK | STM32_MDMA_CTCR_DBURST_MASK |
		  STM32_MDMA_CTCR_SBURST_MASK | STM32_MDMA_CTCR_DINCOS_MASK |
		  STM32_MDMA_CTCR_SINCOS_MASK | STM32_MDMA_CTCR_DSIZE_MASK |
		  STM32_MDMA_CTCR_SSIZE_MASK | STM32_MDMA_CTCR_DINC_MASK |
		  STM32_MDMA_CTCR_SINC_MASK);
	ctcr |= STM32_MDMA_CTCR_SWRM | STM32_MDMA_CTCR_SINC(STM32_MDMA_INC) |
		STM32_MDMA_CTCR_DINC(STM32_MDMA_INC);

	/* Reset HW request */
	ctbr &= ~STM32_MDMA_CTBR_TSEL_MASK;

	/* Select bus */
	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS, src);
	stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS, dest);

	/* Clear CBNDTR registers */
	cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK | STM32_MDMA_CBNDTR_BRDUM |
			STM32_MDMA_CBNDTR_BRSUM | STM32_MDMA_CBNDTR_BNDT_MASK);

	if (len <= STM32_MDMA_MAX_BLOCK_LEN) {
		cbndtr |= STM32_MDMA_CBNDTR_BNDT(len);
		if (len <= STM32_MDMA_MAX_BUF_LEN) {
			/* Setup a buffer transfer */
			ccr |= STM32_MDMA_CCR_TCIE | STM32_MDMA_CCR_CTCIE;
			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BUFFER);
		} else {
			/* Setup a block transfer */
			ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
			ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_BLOCK);
		}

		tlen = STM32_MDMA_MAX_BUF_LEN;
		ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));

		/* Set source best burst size */
		max_width = stm32_mdma_get_max_width(src, len, tlen);
		src_bus_width = stm32_mdma_get_width(chan, max_width);

		max_burst = tlen / max_width;
		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
						       max_width);
		mdma_burst = ilog2(best_burst);

		ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
			STM32_MDMA_CTCR_SSIZE(src_bus_width) |
			STM32_MDMA_CTCR_SINCOS(src_bus_width);

		/* Set destination best burst size */
		max_width = stm32_mdma_get_max_width(dest, len, tlen);
		dst_bus_width = stm32_mdma_get_width(chan, max_width);

		max_burst = tlen / max_width;
		best_burst = stm32_mdma_get_best_burst(len, tlen, max_burst,
						       max_width);
		mdma_burst = ilog2(best_burst);

		ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
			STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
			STM32_MDMA_CTCR_DINCOS(dst_bus_width);

		if (dst_bus_width != src_bus_width)
			ctcr |= STM32_MDMA_CTCR_PKE;

		/* Prepare hardware descriptor */
		hwdesc = desc->node[0].hwdesc;
		hwdesc->ctcr = ctcr;
		hwdesc->cbndtr = cbndtr;
		hwdesc->csar = src;
		hwdesc->cdar = dest;
		hwdesc->cbrur = 0;
		hwdesc->clar = 0;
		hwdesc->ctbr = ctbr;
		hwdesc->cmar = 0;
		hwdesc->cmdr = 0;

		stm32_mdma_dump_hwdesc(chan, &desc->node[0]);
	} else {
		/* Setup a LLI transfer */
		ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_LINKED_LIST) |
			STM32_MDMA_CTCR_TLEN((STM32_MDMA_MAX_BUF_LEN - 1));
		ccr |= STM32_MDMA_CCR_BTIE | STM32_MDMA_CCR_CTCIE;
		tlen = STM32_MDMA_MAX_BUF_LEN;

		for (i = 0, offset = 0; offset < len;
		     i++, offset += xfer_count) {
			xfer_count = min_t(size_t, len - offset,
					   STM32_MDMA_MAX_BLOCK_LEN);

			/* Set source best burst size */
			max_width = stm32_mdma_get_max_width(src, len, tlen);
			src_bus_width = stm32_mdma_get_width(chan, max_width);

			max_burst = tlen / max_width;
			best_burst = stm32_mdma_get_best_burst(len, tlen,
							       max_burst,
							       max_width);
			mdma_burst = ilog2(best_burst);

			ctcr |= STM32_MDMA_CTCR_SBURST(mdma_burst) |
				STM32_MDMA_CTCR_SSIZE(src_bus_width) |
				STM32_MDMA_CTCR_SINCOS(src_bus_width);

			/* Set destination best burst size */
			max_width = stm32_mdma_get_max_width(dest, len, tlen);
			dst_bus_width = stm32_mdma_get_width(chan, max_width);

			max_burst = tlen / max_width;
			best_burst = stm32_mdma_get_best_burst(len, tlen,
							       max_burst,
							       max_width);
			mdma_burst = ilog2(best_burst);

			ctcr |= STM32_MDMA_CTCR_DBURST(mdma_burst) |
				STM32_MDMA_CTCR_DSIZE(dst_bus_width) |
				STM32_MDMA_CTCR_DINCOS(dst_bus_width);

			if (dst_bus_width != src_bus_width)
				ctcr |= STM32_MDMA_CTCR_PKE;

			/* Prepare hardware descriptor */
			stm32_mdma_setup_hwdesc(chan, desc, DMA_MEM_TO_MEM, i,
						src + offset, dest + offset,
						xfer_count, ctcr, ctbr,
						i == count - 1, i == 0, false);
		}
	}

	desc->ccr = ccr;

	desc->cyclic = false;

	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}

static void stm32_mdma_dump_reg(struct stm32_mdma_chan *chan)
{
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);

	dev_dbg(chan2dev(chan), "CCR:     0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id)));
	dev_dbg(chan2dev(chan), "CTCR:    0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CTCR(chan->id)));
	dev_dbg(chan2dev(chan), "CBNDTR:  0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id)));
	dev_dbg(chan2dev(chan), "CSAR:    0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CSAR(chan->id)));
	dev_dbg(chan2dev(chan), "CDAR:    0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CDAR(chan->id)));
	dev_dbg(chan2dev(chan), "CBRUR:   0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CBRUR(chan->id)));
	dev_dbg(chan2dev(chan), "CLAR:    0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CLAR(chan->id)));
	dev_dbg(chan2dev(chan), "CTBR:    0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CTBR(chan->id)));
	dev_dbg(chan2dev(chan), "CMAR:    0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CMAR(chan->id)));
	dev_dbg(chan2dev(chan), "CMDR:    0x%08x\n",
		stm32_mdma_read(dmadev, STM32_MDMA_CMDR(chan->id)));
}

static void stm32_mdma_start_transfer(struct stm32_mdma_chan *chan)
{
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	struct virt_dma_desc *vdesc;
	struct stm32_mdma_hwdesc *hwdesc;
	u32 id = chan->id;
	u32 status, reg;

	vdesc = vchan_next_desc(&chan->vchan);
	if (!vdesc) {
		chan->desc = NULL;
		return;
	}

	list_del(&vdesc->node);

	chan->desc = to_stm32_mdma_desc(vdesc);
	hwdesc = chan->desc->node[0].hwdesc;
	chan->curr_hwdesc = 0;

	stm32_mdma_write(dmadev, STM32_MDMA_CCR(id), chan->desc->ccr);
	stm32_mdma_write(dmadev, STM32_MDMA_CTCR(id), hwdesc->ctcr);
	stm32_mdma_write(dmadev, STM32_MDMA_CBNDTR(id), hwdesc->cbndtr);
	stm32_mdma_write(dmadev, STM32_MDMA_CSAR(id), hwdesc->csar);
	stm32_mdma_write(dmadev, STM32_MDMA_CDAR(id), hwdesc->cdar);
	stm32_mdma_write(dmadev, STM32_MDMA_CBRUR(id), hwdesc->cbrur);
	stm32_mdma_write(dmadev, STM32_MDMA_CLAR(id), hwdesc->clar);
	stm32_mdma_write(dmadev, STM32_MDMA_CTBR(id), hwdesc->ctbr);
	stm32_mdma_write(dmadev, STM32_MDMA_CMAR(id), hwdesc->cmar);
	stm32_mdma_write(dmadev, STM32_MDMA_CMDR(id), hwdesc->cmdr);

	/* Clear interrupt status if it is there */
	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
	if (status)
		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(id), status);

	stm32_mdma_dump_reg(chan);

	/* Start DMA */
	stm32_mdma_set_bits(dmadev, STM32_MDMA_CCR(id), STM32_MDMA_CCR_EN);

	/* Set SW request in case of MEM2MEM transfer */
	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM) {
		reg = STM32_MDMA_CCR(id);
		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);
	}

	chan->busy = true;

	dev_dbg(chan2dev(chan), "vchan %pK: started\n", &chan->vchan);
}

static void stm32_mdma_issue_pending(struct dma_chan *c)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	unsigned long flags;

	spin_lock_irqsave(&chan->vchan.lock, flags);

	if (!vchan_issue_pending(&chan->vchan))
		goto end;

	dev_dbg(chan2dev(chan), "vchan %pK: issued\n", &chan->vchan);

	if (!chan->desc && !chan->busy)
		stm32_mdma_start_transfer(chan);

end:
	spin_unlock_irqrestore(&chan->vchan.lock, flags);
}

static int stm32_mdma_pause(struct dma_chan *c)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	unsigned long flags;
	int ret;

	spin_lock_irqsave(&chan->vchan.lock, flags);
	ret = stm32_mdma_disable_chan(chan);
	spin_unlock_irqrestore(&chan->vchan.lock, flags);

	if (!ret)
		dev_dbg(chan2dev(chan), "vchan %pK: pause\n", &chan->vchan);

	return ret;
}

static int stm32_mdma_resume(struct dma_chan *c)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	struct stm32_mdma_hwdesc *hwdesc;
	unsigned long flags;
	u32 status, reg;

	hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc;

	spin_lock_irqsave(&chan->vchan.lock, flags);

	/* Re-configure control register */
	stm32_mdma_write(dmadev, STM32_MDMA_CCR(chan->id), chan->desc->ccr);

	/* Clear interrupt status if it is there */
	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
	if (status)
		stm32_mdma_set_bits(dmadev, STM32_MDMA_CIFCR(chan->id), status);

	stm32_mdma_dump_reg(chan);

	/* Re-start DMA */
	reg = STM32_MDMA_CCR(chan->id);
	stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_EN);

	/* Set SW request in case of MEM2MEM transfer */
	if (hwdesc->ctcr & STM32_MDMA_CTCR_SWRM)
		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CCR_SWRQ);

	spin_unlock_irqrestore(&chan->vchan.lock, flags);

	dev_dbg(chan2dev(chan), "vchan %pK: resume\n", &chan->vchan);

	return 0;
}

static int stm32_mdma_terminate_all(struct dma_chan *c)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&chan->vchan.lock, flags);
	if (chan->desc) {
		vchan_terminate_vdesc(&chan->desc->vdesc);
		if (chan->busy)
			stm32_mdma_stop(chan);
		chan->desc = NULL;
	}
	vchan_get_all_descriptors(&chan->vchan, &head);
	spin_unlock_irqrestore(&chan->vchan.lock, flags);

	vchan_dma_desc_free_list(&chan->vchan, &head);

	return 0;
}

static void stm32_mdma_synchronize(struct dma_chan *c)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);

	vchan_synchronize(&chan->vchan);
}

static int stm32_mdma_slave_config(struct dma_chan *c,
				   struct dma_slave_config *config)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);

	memcpy(&chan->dma_config, config, sizeof(*config));

	/* Check if user is requesting STM32 DMA to trigger MDMA */
	if (config->peripheral_size) {
		struct stm32_mdma_dma_config *mdma_config;

		mdma_config = (struct stm32_mdma_dma_config *)chan->dma_config.peripheral_config;
		chan->chan_config.request = mdma_config->request;
		chan->chan_config.mask_addr = mdma_config->cmar;
		chan->chan_config.mask_data = mdma_config->cmdr;
		chan->chan_config.m2m_hw = true;
	}

	return 0;
}

static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
				      struct stm32_mdma_desc *desc,
				      u32 curr_hwdesc)
{
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	struct stm32_mdma_hwdesc *hwdesc;
	u32 cbndtr, residue, modulo, burst_size;
	int i;

	residue = 0;
	for (i = curr_hwdesc + 1; i < desc->count; i++) {
		hwdesc = desc->node[i].hwdesc;
		residue += STM32_MDMA_CBNDTR_BNDT(hwdesc->cbndtr);
	}
	cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
	residue += cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;

	if (!chan->mem_burst)
		return residue;

	burst_size = chan->mem_burst * chan->mem_width;
	modulo = residue % burst_size;
	if (modulo)
		residue = residue - modulo + burst_size;

	return residue;
}

static enum dma_status stm32_mdma_tx_status(struct dma_chan *c,
					    dma_cookie_t cookie,
					    struct dma_tx_state *state)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct virt_dma_desc *vdesc;
	enum dma_status status;
	unsigned long flags;
	u32 residue = 0;

	status = dma_cookie_status(c, cookie, state);
	if ((status == DMA_COMPLETE) || (!state))
		return status;

	spin_lock_irqsave(&chan->vchan.lock, flags);

	vdesc = vchan_find_desc(&chan->vchan, cookie);
	if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
		residue = stm32_mdma_desc_residue(chan, chan->desc,
						  chan->curr_hwdesc);
	else if (vdesc)
		residue = stm32_mdma_desc_residue(chan,
						  to_stm32_mdma_desc(vdesc), 0);
	dma_set_residue(state, residue);

	spin_unlock_irqrestore(&chan->vchan.lock, flags);

	return status;
}

static void stm32_mdma_xfer_end(struct stm32_mdma_chan *chan)
{
	vchan_cookie_complete(&chan->desc->vdesc);
	chan->desc = NULL;
	chan->busy = false;

	/* Start the next transfer if this driver has a next desc */
	stm32_mdma_start_transfer(chan);
}

static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)
{
	struct stm32_mdma_device *dmadev = devid;
	struct stm32_mdma_chan *chan;
	u32 reg, id, ccr, ien, status;

	/* Find out which channel generates the interrupt */
	status = readl_relaxed(dmadev->base + STM32_MDMA_GISR0);
	if (!status) {
		dev_dbg(mdma2dev(dmadev), "spurious it\n");
		return IRQ_NONE;
	}
	id = __ffs(status);
	chan = &dmadev->chan[id];

	/* Handle interrupt for the channel */
	spin_lock(&chan->vchan.lock);
	status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
	/* Mask Channel ReQuest Active bit which can be set in case of MEM2MEM */
	status &= ~STM32_MDMA_CISR_CRQA;
	ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
	ien = (ccr & STM32_MDMA_CCR_IRQ_MASK) >> 1;

	if (!(status & ien)) {
		spin_unlock(&chan->vchan.lock);
		if (chan->busy)
			dev_warn(chan2dev(chan),
				 "spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
		else
			dev_dbg(chan2dev(chan),
				"spurious it (status=0x%04x, ien=0x%04x)\n", status, ien);
		return IRQ_NONE;
	}

	reg = STM32_MDMA_CIFCR(id);

	if (status & STM32_MDMA_CISR_TEIF) {
		dev_err(chan2dev(chan), "Transfer Err: stat=0x%08x\n",
			readl_relaxed(dmadev->base + STM32_MDMA_CESR(id)));
		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CTEIF);
		status &= ~STM32_MDMA_CISR_TEIF;
	}

	if (status & STM32_MDMA_CISR_CTCIF) {
		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CCTCIF);
		status &= ~STM32_MDMA_CISR_CTCIF;
		stm32_mdma_xfer_end(chan);
	}

	if (status & STM32_MDMA_CISR_BRTIF) {
		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBRTIF);
		status &= ~STM32_MDMA_CISR_BRTIF;
	}

	if (status & STM32_MDMA_CISR_BTIF) {
		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBTIF);
		status &= ~STM32_MDMA_CISR_BTIF;
		chan->curr_hwdesc++;
		if (chan->desc && chan->desc->cyclic) {
			if (chan->curr_hwdesc == chan->desc->count)
				chan->curr_hwdesc = 0;
			vchan_cyclic_callback(&chan->desc->vdesc);
		}
	}

	if (status & STM32_MDMA_CISR_TCIF) {
		stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CLTCIF);
		status &= ~STM32_MDMA_CISR_TCIF;
	}

	if (status) {
		stm32_mdma_set_bits(dmadev, reg, status);
		dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
		if (!(ccr & STM32_MDMA_CCR_EN))
			dev_err(chan2dev(chan), "chan disabled by HW\n");
	}

	spin_unlock(&chan->vchan.lock);

	return IRQ_HANDLED;
}

static int stm32_mdma_alloc_chan_resources(struct dma_chan *c)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	int ret;

	chan->desc_pool = dmam_pool_create(dev_name(&c->dev->device),
					   c->device->dev,
					   sizeof(struct stm32_mdma_hwdesc),
					  __alignof__(struct stm32_mdma_hwdesc),
					   0);
	if (!chan->desc_pool) {
		dev_err(chan2dev(chan), "failed to allocate descriptor pool\n");
		return -ENOMEM;
	}

	ret = pm_runtime_resume_and_get(dmadev->ddev.dev);
	if (ret < 0)
		return ret;

	ret = stm32_mdma_disable_chan(chan);
	if (ret < 0)
		pm_runtime_put(dmadev->ddev.dev);

	return ret;
}

static void stm32_mdma_free_chan_resources(struct dma_chan *c)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
	unsigned long flags;

	dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id);

	if (chan->busy) {
		spin_lock_irqsave(&chan->vchan.lock, flags);
		stm32_mdma_stop(chan);
		chan->desc = NULL;
		spin_unlock_irqrestore(&chan->vchan.lock, flags);
	}

	pm_runtime_put(dmadev->ddev.dev);
	vchan_free_chan_resources(to_virt_chan(c));
	dmam_pool_destroy(chan->desc_pool);
	chan->desc_pool = NULL;
}

static bool stm32_mdma_filter_fn(struct dma_chan *c, void *fn_param)
{
	struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
	struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);

	/* Check if chan is marked Secure */
	if (dmadev->chan_reserved & BIT(chan->id))
		return false;

	return true;
}

static struct dma_chan *stm32_mdma_of_xlate(struct of_phandle_args *dma_spec,
					    struct of_dma *ofdma)
{
	struct stm32_mdma_device *dmadev = ofdma->of_dma_data;
	dma_cap_mask_t mask = dmadev->ddev.cap_mask;
	struct stm32_mdma_chan *chan;
	struct dma_chan *c;
	struct stm32_mdma_chan_config config;

	if (dma_spec->args_count < 5) {
		dev_err(mdma2dev(dmadev), "Bad number of args\n");
		return NULL;
	}

	config.request = dma_spec->args[0];
	config.priority_level = dma_spec->args[1];
	config.transfer_config = dma_spec->args[2];
	config.mask_addr = dma_spec->args[3];
	config.mask_data = dma_spec->args[4];

	if (config.request >= dmadev->nr_requests) {
		dev_err(mdma2dev(dmadev), "Bad request line\n");
		return NULL;
	}

	if (config.priority_level > STM32_MDMA_VERY_HIGH_PRIORITY) {
		dev_err(mdma2dev(dmadev), "Priority level not supported\n");
		return NULL;
	}

	c = __dma_request_channel(&mask, stm32_mdma_filter_fn, &config, ofdma->of_node);
	if (!c) {
		dev_err(mdma2dev(dmadev), "No more channels available\n");
		return NULL;
	}

	chan = to_stm32_mdma_chan(c);
	chan->chan_config = config;

	return c;
}

static const struct of_device_id stm32_mdma_of_match[] = {
	{ .compatible = "st,stm32h7-mdma", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, stm32_mdma_of_match);

static int stm32_mdma_probe(struct platform_device *pdev)
{
	struct stm32_mdma_chan *chan;
	struct stm32_mdma_device *dmadev;
	struct dma_device *dd;
	struct device_node *of_node;
	struct resource *res;
	struct reset_control *rst;
	u32 nr_channels, nr_requests;
	int i, count, ret;

	of_node = pdev->dev.of_node;
	if (!of_node)
		return -ENODEV;

	ret = device_property_read_u32(&pdev->dev, "dma-channels",
				       &nr_channels);
	if (ret) {
		nr_channels = STM32_MDMA_MAX_CHANNELS;
		dev_warn(&pdev->dev, "MDMA defaulting on %i channels\n",
			 nr_channels);
	}

	ret = device_property_read_u32(&pdev->dev, "dma-requests",
				       &nr_requests);
	if (ret) {
		nr_requests = STM32_MDMA_MAX_REQUESTS;
		dev_warn(&pdev->dev, "MDMA defaulting on %i request lines\n",
			 nr_requests);
	}

	count = device_property_count_u32(&pdev->dev, "st,ahb-addr-masks");
	if (count < 0)
		count = 0;

	dmadev = devm_kzalloc(&pdev->dev,
			      struct_size(dmadev, ahb_addr_masks, count),
			      GFP_KERNEL);
	if (!dmadev)
		return -ENOMEM;

	dmadev->nr_channels = nr_channels;
	dmadev->nr_requests = nr_requests;
	device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks",
				       dmadev->ahb_addr_masks,
				       count);
	dmadev->nr_ahb_addr_masks = count;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	dmadev->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(dmadev->base))
		return PTR_ERR(dmadev->base);

	dmadev->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(dmadev->clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(dmadev->clk),
				     "Missing clock controller\n");

	ret = clk_prepare_enable(dmadev->clk);
	if (ret < 0) {
		dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret);
		return ret;
	}

	rst = devm_reset_control_get(&pdev->dev, NULL);
	if (IS_ERR(rst)) {
		ret = PTR_ERR(rst);
		if (ret == -EPROBE_DEFER)
			goto err_clk;
	} else {
		reset_control_assert(rst);
		udelay(2);
		reset_control_deassert(rst);
	}

	dd = &dmadev->ddev;
	dma_cap_set(DMA_SLAVE, dd->cap_mask);
	dma_cap_set(DMA_PRIVATE, dd->cap_mask);
	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
	dd->device_alloc_chan_resources = stm32_mdma_alloc_chan_resources;
	dd->device_free_chan_resources = stm32_mdma_free_chan_resources;
	dd->device_tx_status = stm32_mdma_tx_status;
	dd->device_issue_pending = stm32_mdma_issue_pending;
	dd->device_prep_slave_sg = stm32_mdma_prep_slave_sg;
	dd->device_prep_dma_cyclic = stm32_mdma_prep_dma_cyclic;
	dd->device_prep_dma_memcpy = stm32_mdma_prep_dma_memcpy;
	dd->device_config = stm32_mdma_slave_config;
	dd->device_pause = stm32_mdma_pause;
	dd->device_resume = stm32_mdma_resume;
	dd->device_terminate_all = stm32_mdma_terminate_all;
	dd->device_synchronize = stm32_mdma_synchronize;
	dd->descriptor_reuse = true;

	dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
	dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
		BIT(DMA_MEM_TO_MEM);
	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
	dd->max_burst = STM32_MDMA_MAX_BURST;
	dd->dev = &pdev->dev;
	INIT_LIST_HEAD(&dd->channels);

	for (i = 0; i < dmadev->nr_channels; i++) {
		chan = &dmadev->chan[i];
		chan->id = i;

		if (stm32_mdma_read(dmadev, STM32_MDMA_CCR(i)) & STM32_MDMA_CCR_SM)
			dmadev->chan_reserved |= BIT(i);

		chan->vchan.desc_free = stm32_mdma_desc_free;
		vchan_init(&chan->vchan, dd);
	}

	dmadev->irq = platform_get_irq(pdev, 0);
	if (dmadev->irq < 0) {
		ret = dmadev->irq;
		goto err_clk;
	}

	ret = devm_request_irq(&pdev->dev, dmadev->irq, stm32_mdma_irq_handler,
			       0, dev_name(&pdev->dev), dmadev);
	if (ret) {
		dev_err(&pdev->dev, "failed to request IRQ\n");
		goto err_clk;
	}

	ret = dmaenginem_async_device_register(dd);
	if (ret)
		goto err_clk;

	ret = of_dma_controller_register(of_node, stm32_mdma_of_xlate, dmadev);
	if (ret < 0) {
		dev_err(&pdev->dev,
			"STM32 MDMA DMA OF registration failed %d\n", ret);
		goto err_clk;
	}

	platform_set_drvdata(pdev, dmadev);
	pm_runtime_set_active(&pdev->dev);
	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_noresume(&pdev->dev);
	pm_runtime_put(&pdev->dev);

	dev_info(&pdev->dev, "STM32 MDMA driver registered\n");

	return 0;

err_clk:
	clk_disable_unprepare(dmadev->clk);

	return ret;
}

#ifdef CONFIG_PM
static int stm32_mdma_runtime_suspend(struct device *dev)
{
	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);

	clk_disable_unprepare(dmadev->clk);

	return 0;
}

static int stm32_mdma_runtime_resume(struct device *dev)
{
	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
	int ret;

	ret = clk_prepare_enable(dmadev->clk);
	if (ret) {
		dev_err(dev, "failed to prepare_enable clock\n");
		return ret;
	}

	return 0;
}
#endif

#ifdef CONFIG_PM_SLEEP
static int stm32_mdma_pm_suspend(struct device *dev)
{
	struct stm32_mdma_device *dmadev = dev_get_drvdata(dev);
	u32 ccr, id;
	int ret;

	ret = pm_runtime_resume_and_get(dev);
	if (ret < 0)
		return ret;

	for (id = 0; id < dmadev->nr_channels; id++) {
		ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
		if (ccr & STM32_MDMA_CCR_EN) {
			dev_warn(dev, "Suspend is prevented by Chan %i\n", id);
			return -EBUSY;
		}
	}

	pm_runtime_put_sync(dev);

	pm_runtime_force_suspend(dev);

	return 0;
}

static int stm32_mdma_pm_resume(struct device *dev)
{
	return pm_runtime_force_resume(dev);
}
#endif

static const struct dev_pm_ops stm32_mdma_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(stm32_mdma_pm_suspend, stm32_mdma_pm_resume)
	SET_RUNTIME_PM_OPS(stm32_mdma_runtime_suspend,
			   stm32_mdma_runtime_resume, NULL)
};

static struct platform_driver stm32_mdma_driver = {
	.probe = stm32_mdma_probe,
	.driver = {
		.name = "stm32-mdma",
		.of_match_table = stm32_mdma_of_match,
		.pm = &stm32_mdma_pm_ops,
	},
};

static int __init stm32_mdma_init(void)
{
	return platform_driver_register(&stm32_mdma_driver);
}

subsys_initcall(stm32_mdma_init);

MODULE_DESCRIPTION("Driver for STM32 MDMA controller");
MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
MODULE_AUTHOR("Pierre-Yves Mordret <pierre-yves.mordret@st.com>");
MODULE_LICENSE("GPL v2");