summaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/udc/gr_udc.c
blob: 1f9941145746ee4d8b8130d4721e2fb2720fae54 (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
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
/*
 * USB Peripheral Controller driver for Aeroflex Gaisler GRUSBDC.
 *
 * 2013 (c) Aeroflex Gaisler AB
 *
 * This driver supports GRUSBDC USB Device Controller cores available in the
 * GRLIB VHDL IP core library.
 *
 * Full documentation of the GRUSBDC core can be found here:
 * http://www.gaisler.com/products/grlib/grip.pdf
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * Contributors:
 * - Andreas Larsson <andreas@gaisler.com>
 * - Marko Isomaki
 */

/*
 * A GRUSBDC core can have up to 16 IN endpoints and 16 OUT endpoints each
 * individually configurable to any of the four USB transfer types. This driver
 * only supports cores in DMA mode.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/of_platform.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>

#include <asm/byteorder.h>

#include "gr_udc.h"

#define	DRIVER_NAME	"gr_udc"
#define	DRIVER_DESC	"Aeroflex Gaisler GRUSBDC USB Peripheral Controller"

static const char driver_name[] = DRIVER_NAME;
static const char driver_desc[] = DRIVER_DESC;

#define gr_read32(x) (ioread32be((x)))
#define gr_write32(x, v) (iowrite32be((v), (x)))

/* USB speed and corresponding string calculated from status register value */
#define GR_SPEED(status) \
	((status & GR_STATUS_SP) ? USB_SPEED_FULL : USB_SPEED_HIGH)
#define GR_SPEED_STR(status) usb_speed_string(GR_SPEED(status))

/* Size of hardware buffer calculated from epctrl register value */
#define GR_BUFFER_SIZE(epctrl)					      \
	((((epctrl) & GR_EPCTRL_BUFSZ_MASK) >> GR_EPCTRL_BUFSZ_POS) * \
	 GR_EPCTRL_BUFSZ_SCALER)

/* ---------------------------------------------------------------------- */
/* Debug printout functionality */

static const char * const gr_modestring[] = {"control", "iso", "bulk", "int"};

static const char *gr_ep0state_string(enum gr_ep0state state)
{
	static const char *const names[] = {
		[GR_EP0_DISCONNECT] = "disconnect",
		[GR_EP0_SETUP] = "setup",
		[GR_EP0_IDATA] = "idata",
		[GR_EP0_ODATA] = "odata",
		[GR_EP0_ISTATUS] = "istatus",
		[GR_EP0_OSTATUS] = "ostatus",
		[GR_EP0_STALL] = "stall",
		[GR_EP0_SUSPEND] = "suspend",
	};

	if (state < 0 || state >= ARRAY_SIZE(names))
		return "UNKNOWN";

	return names[state];
}

#ifdef VERBOSE_DEBUG

static void gr_dbgprint_request(const char *str, struct gr_ep *ep,
				struct gr_request *req)
{
	int buflen = ep->is_in ? req->req.length : req->req.actual;
	int rowlen = 32;
	int plen = min(rowlen, buflen);

	dev_dbg(ep->dev->dev, "%s: 0x%p, %d bytes data%s:\n", str, req, buflen,
		(buflen > plen ? " (truncated)" : ""));
	print_hex_dump_debug("   ", DUMP_PREFIX_NONE,
			     rowlen, 4, req->req.buf, plen, false);
}

static void gr_dbgprint_devreq(struct gr_udc *dev, u8 type, u8 request,
			       u16 value, u16 index, u16 length)
{
	dev_vdbg(dev->dev, "REQ: %02x.%02x v%04x i%04x l%04x\n",
		 type, request, value, index, length);
}
#else /* !VERBOSE_DEBUG */

static void gr_dbgprint_request(const char *str, struct gr_ep *ep,
				struct gr_request *req) {}

static void gr_dbgprint_devreq(struct gr_udc *dev, u8 type, u8 request,
			       u16 value, u16 index, u16 length) {}

#endif /* VERBOSE_DEBUG */

/* ---------------------------------------------------------------------- */
/* Debugfs functionality */

#ifdef CONFIG_USB_GADGET_DEBUG_FS

static void gr_seq_ep_show(struct seq_file *seq, struct gr_ep *ep)
{
	u32 epctrl = gr_read32(&ep->regs->epctrl);
	u32 epstat = gr_read32(&ep->regs->epstat);
	int mode = (epctrl & GR_EPCTRL_TT_MASK) >> GR_EPCTRL_TT_POS;
	struct gr_request *req;

	seq_printf(seq, "%s:\n", ep->ep.name);
	seq_printf(seq, "  mode = %s\n", gr_modestring[mode]);
	seq_printf(seq, "  halted: %d\n", !!(epctrl & GR_EPCTRL_EH));
	seq_printf(seq, "  disabled: %d\n", !!(epctrl & GR_EPCTRL_ED));
	seq_printf(seq, "  valid: %d\n", !!(epctrl & GR_EPCTRL_EV));
	seq_printf(seq, "  dma_start = %d\n", ep->dma_start);
	seq_printf(seq, "  stopped = %d\n", ep->stopped);
	seq_printf(seq, "  wedged = %d\n", ep->wedged);
	seq_printf(seq, "  callback = %d\n", ep->callback);
	seq_printf(seq, "  maxpacket = %d\n", ep->ep.maxpacket);
	seq_printf(seq, "  maxpacket_limit = %d\n", ep->ep.maxpacket_limit);
	seq_printf(seq, "  bytes_per_buffer = %d\n", ep->bytes_per_buffer);
	if (mode == 1 || mode == 3)
		seq_printf(seq, "  nt = %d\n",
			   (epctrl & GR_EPCTRL_NT_MASK) >> GR_EPCTRL_NT_POS);

	seq_printf(seq, "  Buffer 0: %s %s%d\n",
		   epstat & GR_EPSTAT_B0 ? "valid" : "invalid",
		   epstat & GR_EPSTAT_BS ? " " : "selected ",
		   (epstat & GR_EPSTAT_B0CNT_MASK) >> GR_EPSTAT_B0CNT_POS);
	seq_printf(seq, "  Buffer 1: %s %s%d\n",
		   epstat & GR_EPSTAT_B1 ? "valid" : "invalid",
		   epstat & GR_EPSTAT_BS ? "selected " : " ",
		   (epstat & GR_EPSTAT_B1CNT_MASK) >> GR_EPSTAT_B1CNT_POS);

	if (list_empty(&ep->queue)) {
		seq_puts(seq, "  Queue: empty\n\n");
		return;
	}

	seq_puts(seq, "  Queue:\n");
	list_for_each_entry(req, &ep->queue, queue) {
		struct gr_dma_desc *desc;
		struct gr_dma_desc *next;

		seq_printf(seq, "    0x%p: 0x%p %d %d\n", req,
			   &req->req.buf, req->req.actual, req->req.length);

		next = req->first_desc;
		do {
			desc = next;
			next = desc->next_desc;
			seq_printf(seq, "    %c 0x%p (0x%08x): 0x%05x 0x%08x\n",
				   desc == req->curr_desc ? 'c' : ' ',
				   desc, desc->paddr, desc->ctrl, desc->data);
		} while (desc != req->last_desc);
	}
	seq_puts(seq, "\n");
}


static int gr_seq_show(struct seq_file *seq, void *v)
{
	struct gr_udc *dev = seq->private;
	u32 control = gr_read32(&dev->regs->control);
	u32 status = gr_read32(&dev->regs->status);
	struct gr_ep *ep;

	seq_printf(seq, "usb state = %s\n",
		   usb_state_string(dev->gadget.state));
	seq_printf(seq, "address = %d\n",
		   (control & GR_CONTROL_UA_MASK) >> GR_CONTROL_UA_POS);
	seq_printf(seq, "speed = %s\n", GR_SPEED_STR(status));
	seq_printf(seq, "ep0state = %s\n", gr_ep0state_string(dev->ep0state));
	seq_printf(seq, "irq_enabled = %d\n", dev->irq_enabled);
	seq_printf(seq, "remote_wakeup = %d\n", dev->remote_wakeup);
	seq_printf(seq, "test_mode = %d\n", dev->test_mode);
	seq_puts(seq, "\n");

	list_for_each_entry(ep, &dev->ep_list, ep_list)
		gr_seq_ep_show(seq, ep);

	return 0;
}

static int gr_dfs_open(struct inode *inode, struct file *file)
{
	return single_open(file, gr_seq_show, inode->i_private);
}

static const struct file_operations gr_dfs_fops = {
	.owner		= THIS_MODULE,
	.open		= gr_dfs_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static void gr_dfs_create(struct gr_udc *dev)
{
	const char *name = "gr_udc_state";

	dev->dfs_root = debugfs_create_dir(dev_name(dev->dev), NULL);
	dev->dfs_state = debugfs_create_file(name, 0444, dev->dfs_root, dev,
					     &gr_dfs_fops);
}

static void gr_dfs_delete(struct gr_udc *dev)
{
	/* Handles NULL and ERR pointers internally */
	debugfs_remove(dev->dfs_state);
	debugfs_remove(dev->dfs_root);
}

#else /* !CONFIG_USB_GADGET_DEBUG_FS */

static void gr_dfs_create(struct gr_udc *dev) {}
static void gr_dfs_delete(struct gr_udc *dev) {}

#endif /* CONFIG_USB_GADGET_DEBUG_FS */

/* ---------------------------------------------------------------------- */
/* DMA and request handling */

/* Allocates a new struct gr_dma_desc, sets paddr and zeroes the rest */
static struct gr_dma_desc *gr_alloc_dma_desc(struct gr_ep *ep, gfp_t gfp_flags)
{
	dma_addr_t paddr;
	struct gr_dma_desc *dma_desc;

	dma_desc = dma_pool_zalloc(ep->dev->desc_pool, gfp_flags, &paddr);
	if (!dma_desc) {
		dev_err(ep->dev->dev, "Could not allocate from DMA pool\n");
		return NULL;
	}

	dma_desc->paddr = paddr;

	return dma_desc;
}

static inline void gr_free_dma_desc(struct gr_udc *dev,
				    struct gr_dma_desc *desc)
{
	dma_pool_free(dev->desc_pool, desc, (dma_addr_t)desc->paddr);
}

/* Frees the chain of struct gr_dma_desc for the given request */
static void gr_free_dma_desc_chain(struct gr_udc *dev, struct gr_request *req)
{
	struct gr_dma_desc *desc;
	struct gr_dma_desc *next;

	next = req->first_desc;
	if (!next)
		return;

	do {
		desc = next;
		next = desc->next_desc;
		gr_free_dma_desc(dev, desc);
	} while (desc != req->last_desc);

	req->first_desc = NULL;
	req->curr_desc = NULL;
	req->last_desc = NULL;
}

static void gr_ep0_setup(struct gr_udc *dev, struct gr_request *req);

/*
 * Frees allocated resources and calls the appropriate completion function/setup
 * package handler for a finished request.
 *
 * Must be called with dev->lock held and irqs disabled.
 */
static void gr_finish_request(struct gr_ep *ep, struct gr_request *req,
			      int status)
	__releases(&dev->lock)
	__acquires(&dev->lock)
{
	struct gr_udc *dev;

	list_del_init(&req->queue);

	if (likely(req->req.status == -EINPROGRESS))
		req->req.status = status;
	else
		status = req->req.status;

	dev = ep->dev;
	usb_gadget_unmap_request(&dev->gadget, &req->req, ep->is_in);
	gr_free_dma_desc_chain(dev, req);

	if (ep->is_in) { /* For OUT, req->req.actual gets updated bit by bit */
		req->req.actual = req->req.length;
	} else if (req->oddlen && req->req.actual > req->evenlen) {
		/*
		 * Copy to user buffer in this case where length was not evenly
		 * divisible by ep->ep.maxpacket and the last descriptor was
		 * actually used.
		 */
		char *buftail = ((char *)req->req.buf + req->evenlen);

		memcpy(buftail, ep->tailbuf, req->oddlen);

		if (req->req.actual > req->req.length) {
			/* We got more data than was requested */
			dev_dbg(ep->dev->dev, "Overflow for ep %s\n",
				ep->ep.name);
			gr_dbgprint_request("OVFL", ep, req);
			req->req.status = -EOVERFLOW;
		}
	}

	if (!status) {
		if (ep->is_in)
			gr_dbgprint_request("SENT", ep, req);
		else
			gr_dbgprint_request("RECV", ep, req);
	}

	/* Prevent changes to ep->queue during callback */
	ep->callback = 1;
	if (req == dev->ep0reqo && !status) {
		if (req->setup)
			gr_ep0_setup(dev, req);
		else
			dev_err(dev->dev,
				"Unexpected non setup packet on ep0in\n");
	} else if (req->req.complete) {
		spin_unlock(&dev->lock);

		usb_gadget_giveback_request(&ep->ep, &req->req);

		spin_lock(&dev->lock);
	}
	ep->callback = 0;
}

static struct usb_request *gr_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
	struct gr_request *req;

	req = kzalloc(sizeof(*req), gfp_flags);
	if (!req)
		return NULL;

	INIT_LIST_HEAD(&req->queue);

	return &req->req;
}

/*
 * Starts DMA for endpoint ep if there are requests in the queue.
 *
 * Must be called with dev->lock held and with !ep->stopped.
 */
static void gr_start_dma(struct gr_ep *ep)
{
	struct gr_request *req;
	u32 dmactrl;

	if (list_empty(&ep->queue)) {
		ep->dma_start = 0;
		return;
	}

	req = list_first_entry(&ep->queue, struct gr_request, queue);

	/* A descriptor should already have been allocated */
	BUG_ON(!req->curr_desc);

	/*
	 * The DMA controller can not handle smaller OUT buffers than
	 * ep->ep.maxpacket. It could lead to buffer overruns if an unexpectedly
	 * long packet are received. Therefore an internal bounce buffer gets
	 * used when such a request gets enabled.
	 */
	if (!ep->is_in && req->oddlen)
		req->last_desc->data = ep->tailbuf_paddr;

	wmb(); /* Make sure all is settled before handing it over to DMA */

	/* Set the descriptor pointer in the hardware */
	gr_write32(&ep->regs->dmaaddr, req->curr_desc->paddr);

	/* Announce available descriptors */
	dmactrl = gr_read32(&ep->regs->dmactrl);
	gr_write32(&ep->regs->dmactrl, dmactrl | GR_DMACTRL_DA);

	ep->dma_start = 1;
}

/*
 * Finishes the first request in the ep's queue and, if available, starts the
 * next request in queue.
 *
 * Must be called with dev->lock held, irqs disabled and with !ep->stopped.
 */
static void gr_dma_advance(struct gr_ep *ep, int status)
{
	struct gr_request *req;

	req = list_first_entry(&ep->queue, struct gr_request, queue);
	gr_finish_request(ep, req, status);
	gr_start_dma(ep); /* Regardless of ep->dma_start */
}

/*
 * Abort DMA for an endpoint. Sets the abort DMA bit which causes an ongoing DMA
 * transfer to be canceled and clears GR_DMACTRL_DA.
 *
 * Must be called with dev->lock held.
 */
static void gr_abort_dma(struct gr_ep *ep)
{
	u32 dmactrl;

	dmactrl = gr_read32(&ep->regs->dmactrl);
	gr_write32(&ep->regs->dmactrl, dmactrl | GR_DMACTRL_AD);
}

/*
 * Allocates and sets up a struct gr_dma_desc and putting it on the descriptor
 * chain.
 *
 * Size is not used for OUT endpoints. Hardware can not be instructed to handle
 * smaller buffer than MAXPL in the OUT direction.
 */
static int gr_add_dma_desc(struct gr_ep *ep, struct gr_request *req,
			   dma_addr_t data, unsigned size, gfp_t gfp_flags)
{
	struct gr_dma_desc *desc;

	desc = gr_alloc_dma_desc(ep, gfp_flags);
	if (!desc)
		return -ENOMEM;

	desc->data = data;
	if (ep->is_in)
		desc->ctrl =
			(GR_DESC_IN_CTRL_LEN_MASK & size) | GR_DESC_IN_CTRL_EN;
	else
		desc->ctrl = GR_DESC_OUT_CTRL_IE;

	if (!req->first_desc) {
		req->first_desc = desc;
		req->curr_desc = desc;
	} else {
		req->last_desc->next_desc = desc;
		req->last_desc->next = desc->paddr;
		req->last_desc->ctrl |= GR_DESC_OUT_CTRL_NX;
	}
	req->last_desc = desc;

	return 0;
}

/*
 * Sets up a chain of struct gr_dma_descriptors pointing to buffers that
 * together covers req->req.length bytes of the buffer at DMA address
 * req->req.dma for the OUT direction.
 *
 * The first descriptor in the chain is enabled, the rest disabled. The
 * interrupt handler will later enable them one by one when needed so we can
 * find out when the transfer is finished. For OUT endpoints, all descriptors
 * therefore generate interrutps.
 */
static int gr_setup_out_desc_list(struct gr_ep *ep, struct gr_request *req,
				  gfp_t gfp_flags)
{
	u16 bytes_left; /* Bytes left to provide descriptors for */
	u16 bytes_used; /* Bytes accommodated for */
	int ret = 0;

	req->first_desc = NULL; /* Signals that no allocation is done yet */
	bytes_left = req->req.length;
	bytes_used = 0;
	while (bytes_left > 0) {
		dma_addr_t start = req->req.dma + bytes_used;
		u16 size = min(bytes_left, ep->bytes_per_buffer);

		if (size < ep->bytes_per_buffer) {
			/* Prepare using bounce buffer */
			req->evenlen = req->req.length - bytes_left;
			req->oddlen = size;
		}

		ret = gr_add_dma_desc(ep, req, start, size, gfp_flags);
		if (ret)
			goto alloc_err;

		bytes_left -= size;
		bytes_used += size;
	}

	req->first_desc->ctrl |= GR_DESC_OUT_CTRL_EN;

	return 0;

alloc_err:
	gr_free_dma_desc_chain(ep->dev, req);

	return ret;
}

/*
 * Sets up a chain of struct gr_dma_descriptors pointing to buffers that
 * together covers req->req.length bytes of the buffer at DMA address
 * req->req.dma for the IN direction.
 *
 * When more data is provided than the maximum payload size, the hardware splits
 * this up into several payloads automatically. Moreover, ep->bytes_per_buffer
 * is always set to a multiple of the maximum payload (restricted to the valid
 * number of maximum payloads during high bandwidth isochronous or interrupt
 * transfers)
 *
 * All descriptors are enabled from the beginning and we only generate an
 * interrupt for the last one indicating that the entire request has been pushed
 * to hardware.
 */
static int gr_setup_in_desc_list(struct gr_ep *ep, struct gr_request *req,
				 gfp_t gfp_flags)
{
	u16 bytes_left; /* Bytes left in req to provide descriptors for */
	u16 bytes_used; /* Bytes in req accommodated for */
	int ret = 0;

	req->first_desc = NULL; /* Signals that no allocation is done yet */
	bytes_left = req->req.length;
	bytes_used = 0;
	do { /* Allow for zero length packets */
		dma_addr_t start = req->req.dma + bytes_used;
		u16 size = min(bytes_left, ep->bytes_per_buffer);

		ret = gr_add_dma_desc(ep, req, start, size, gfp_flags);
		if (ret)
			goto alloc_err;

		bytes_left -= size;
		bytes_used += size;
	} while (bytes_left > 0);

	/*
	 * Send an extra zero length packet to indicate that no more data is
	 * available when req->req.zero is set and the data length is even
	 * multiples of ep->ep.maxpacket.
	 */
	if (req->req.zero && (req->req.length % ep->ep.maxpacket == 0)) {
		ret = gr_add_dma_desc(ep, req, 0, 0, gfp_flags);
		if (ret)
			goto alloc_err;
	}

	/*
	 * For IN packets we only want to know when the last packet has been
	 * transmitted (not just put into internal buffers).
	 */
	req->last_desc->ctrl |= GR_DESC_IN_CTRL_PI;

	return 0;

alloc_err:
	gr_free_dma_desc_chain(ep->dev, req);

	return ret;
}

/* Must be called with dev->lock held */
static int gr_queue(struct gr_ep *ep, struct gr_request *req, gfp_t gfp_flags)
{
	struct gr_udc *dev = ep->dev;
	int ret;

	if (unlikely(!ep->ep.desc && ep->num != 0)) {
		dev_err(dev->dev, "No ep descriptor for %s\n", ep->ep.name);
		return -EINVAL;
	}

	if (unlikely(!req->req.buf || !list_empty(&req->queue))) {
		dev_err(dev->dev,
			"Invalid request for %s: buf=%p list_empty=%d\n",
			ep->ep.name, req->req.buf, list_empty(&req->queue));
		return -EINVAL;
	}

	if (unlikely(!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)) {
		dev_err(dev->dev, "-ESHUTDOWN");
		return -ESHUTDOWN;
	}

	/* Can't touch registers when suspended */
	if (dev->ep0state == GR_EP0_SUSPEND) {
		dev_err(dev->dev, "-EBUSY");
		return -EBUSY;
	}

	/* Set up DMA mapping in case the caller didn't */
	ret = usb_gadget_map_request(&dev->gadget, &req->req, ep->is_in);
	if (ret) {
		dev_err(dev->dev, "usb_gadget_map_request");
		return ret;
	}

	if (ep->is_in)
		ret = gr_setup_in_desc_list(ep, req, gfp_flags);
	else
		ret = gr_setup_out_desc_list(ep, req, gfp_flags);
	if (ret)
		return ret;

	req->req.status = -EINPROGRESS;
	req->req.actual = 0;
	list_add_tail(&req->queue, &ep->queue);

	/* Start DMA if not started, otherwise interrupt handler handles it */
	if (!ep->dma_start && likely(!ep->stopped))
		gr_start_dma(ep);

	return 0;
}

/*
 * Queue a request from within the driver.
 *
 * Must be called with dev->lock held.
 */
static inline int gr_queue_int(struct gr_ep *ep, struct gr_request *req,
			       gfp_t gfp_flags)
{
	if (ep->is_in)
		gr_dbgprint_request("RESP", ep, req);

	return gr_queue(ep, req, gfp_flags);
}

/* ---------------------------------------------------------------------- */
/* General helper functions */

/*
 * Dequeue ALL requests.
 *
 * Must be called with dev->lock held and irqs disabled.
 */
static void gr_ep_nuke(struct gr_ep *ep)
{
	struct gr_request *req;

	ep->stopped = 1;
	ep->dma_start = 0;
	gr_abort_dma(ep);

	while (!list_empty(&ep->queue)) {
		req = list_first_entry(&ep->queue, struct gr_request, queue);
		gr_finish_request(ep, req, -ESHUTDOWN);
	}
}

/*
 * Reset the hardware state of this endpoint.
 *
 * Must be called with dev->lock held.
 */
static void gr_ep_reset(struct gr_ep *ep)
{
	gr_write32(&ep->regs->epctrl, 0);
	gr_write32(&ep->regs->dmactrl, 0);

	ep->ep.maxpacket = MAX_CTRL_PL_SIZE;
	ep->ep.desc = NULL;
	ep->stopped = 1;
	ep->dma_start = 0;
}

/*
 * Generate STALL on ep0in/out.
 *
 * Must be called with dev->lock held.
 */
static void gr_control_stall(struct gr_udc *dev)
{
	u32 epctrl;

	epctrl = gr_read32(&dev->epo[0].regs->epctrl);
	gr_write32(&dev->epo[0].regs->epctrl, epctrl | GR_EPCTRL_CS);
	epctrl = gr_read32(&dev->epi[0].regs->epctrl);
	gr_write32(&dev->epi[0].regs->epctrl, epctrl | GR_EPCTRL_CS);

	dev->ep0state = GR_EP0_STALL;
}

/*
 * Halts, halts and wedges, or clears halt for an endpoint.
 *
 * Must be called with dev->lock held.
 */
static int gr_ep_halt_wedge(struct gr_ep *ep, int halt, int wedge, int fromhost)
{
	u32 epctrl;
	int retval = 0;

	if (ep->num && !ep->ep.desc)
		return -EINVAL;

	if (ep->num && ep->ep.desc->bmAttributes == USB_ENDPOINT_XFER_ISOC)
		return -EOPNOTSUPP;

	/* Never actually halt ep0, and therefore never clear halt for ep0 */
	if (!ep->num) {
		if (halt && !fromhost) {
			/* ep0 halt from gadget - generate protocol stall */
			gr_control_stall(ep->dev);
			dev_dbg(ep->dev->dev, "EP: stall ep0\n");
			return 0;
		}
		return -EINVAL;
	}

	dev_dbg(ep->dev->dev, "EP: %s halt %s\n",
		(halt ? (wedge ? "wedge" : "set") : "clear"), ep->ep.name);

	epctrl = gr_read32(&ep->regs->epctrl);
	if (halt) {
		/* Set HALT */
		gr_write32(&ep->regs->epctrl, epctrl | GR_EPCTRL_EH);
		ep->stopped = 1;
		if (wedge)
			ep->wedged = 1;
	} else {
		gr_write32(&ep->regs->epctrl, epctrl & ~GR_EPCTRL_EH);
		ep->stopped = 0;
		ep->wedged = 0;

		/* Things might have been queued up in the meantime */
		if (!ep->dma_start)
			gr_start_dma(ep);
	}

	return retval;
}

/* Must be called with dev->lock held */
static inline void gr_set_ep0state(struct gr_udc *dev, enum gr_ep0state value)
{
	if (dev->ep0state != value)
		dev_vdbg(dev->dev, "STATE:  ep0state=%s\n",
			 gr_ep0state_string(value));
	dev->ep0state = value;
}

/*
 * Should only be called when endpoints can not generate interrupts.
 *
 * Must be called with dev->lock held.
 */
static void gr_disable_interrupts_and_pullup(struct gr_udc *dev)
{
	gr_write32(&dev->regs->control, 0);
	wmb(); /* Make sure that we do not deny one of our interrupts */
	dev->irq_enabled = 0;
}

/*
 * Stop all device activity and disable data line pullup.
 *
 * Must be called with dev->lock held and irqs disabled.
 */
static void gr_stop_activity(struct gr_udc *dev)
{
	struct gr_ep *ep;

	list_for_each_entry(ep, &dev->ep_list, ep_list)
		gr_ep_nuke(ep);

	gr_disable_interrupts_and_pullup(dev);

	gr_set_ep0state(dev, GR_EP0_DISCONNECT);
	usb_gadget_set_state(&dev->gadget, USB_STATE_NOTATTACHED);
}

/* ---------------------------------------------------------------------- */
/* ep0 setup packet handling */

static void gr_ep0_testmode_complete(struct usb_ep *_ep,
				     struct usb_request *_req)
{
	struct gr_ep *ep;
	struct gr_udc *dev;
	u32 control;

	ep = container_of(_ep, struct gr_ep, ep);
	dev = ep->dev;

	spin_lock(&dev->lock);

	control = gr_read32(&dev->regs->control);
	control |= GR_CONTROL_TM | (dev->test_mode << GR_CONTROL_TS_POS);
	gr_write32(&dev->regs->control, control);

	spin_unlock(&dev->lock);
}

static void gr_ep0_dummy_complete(struct usb_ep *_ep, struct usb_request *_req)
{
	/* Nothing needs to be done here */
}

/*
 * Queue a response on ep0in.
 *
 * Must be called with dev->lock held.
 */
static int gr_ep0_respond(struct gr_udc *dev, u8 *buf, int length,
			  void (*complete)(struct usb_ep *ep,
					   struct usb_request *req))
{
	u8 *reqbuf = dev->ep0reqi->req.buf;
	int status;
	int i;

	for (i = 0; i < length; i++)
		reqbuf[i] = buf[i];
	dev->ep0reqi->req.length = length;
	dev->ep0reqi->req.complete = complete;

	status = gr_queue_int(&dev->epi[0], dev->ep0reqi, GFP_ATOMIC);
	if (status < 0)
		dev_err(dev->dev,
			"Could not queue ep0in setup response: %d\n", status);

	return status;
}

/*
 * Queue a 2 byte response on ep0in.
 *
 * Must be called with dev->lock held.
 */
static inline int gr_ep0_respond_u16(struct gr_udc *dev, u16 response)
{
	__le16 le_response = cpu_to_le16(response);

	return gr_ep0_respond(dev, (u8 *)&le_response, 2,
			      gr_ep0_dummy_complete);
}

/*
 * Queue a ZLP response on ep0in.
 *
 * Must be called with dev->lock held.
 */
static inline int gr_ep0_respond_empty(struct gr_udc *dev)
{
	return gr_ep0_respond(dev, NULL, 0, gr_ep0_dummy_complete);
}

/*
 * This is run when a SET_ADDRESS request is received. First writes
 * the new address to the control register which is updated internally
 * when the next IN packet is ACKED.
 *
 * Must be called with dev->lock held.
 */
static void gr_set_address(struct gr_udc *dev, u8 address)
{
	u32 control;

	control = gr_read32(&dev->regs->control) & ~GR_CONTROL_UA_MASK;
	control |= (address << GR_CONTROL_UA_POS) & GR_CONTROL_UA_MASK;
	control |= GR_CONTROL_SU;
	gr_write32(&dev->regs->control, control);
}

/*
 * Returns negative for STALL, 0 for successful handling and positive for
 * delegation.
 *
 * Must be called with dev->lock held.
 */
static int gr_device_request(struct gr_udc *dev, u8 type, u8 request,
			     u16 value, u16 index)
{
	u16 response;
	u8 test;

	switch (request) {
	case USB_REQ_SET_ADDRESS:
		dev_dbg(dev->dev, "STATUS: address %d\n", value & 0xff);
		gr_set_address(dev, value & 0xff);
		if (value)
			usb_gadget_set_state(&dev->gadget, USB_STATE_ADDRESS);
		else
			usb_gadget_set_state(&dev->gadget, USB_STATE_DEFAULT);
		return gr_ep0_respond_empty(dev);

	case USB_REQ_GET_STATUS:
		/* Self powered | remote wakeup */
		response = 0x0001 | (dev->remote_wakeup ? 0x0002 : 0);
		return gr_ep0_respond_u16(dev, response);

	case USB_REQ_SET_FEATURE:
		switch (value) {
		case USB_DEVICE_REMOTE_WAKEUP:
			/* Allow remote wakeup */
			dev->remote_wakeup = 1;
			return gr_ep0_respond_empty(dev);

		case USB_DEVICE_TEST_MODE:
			/* The hardware does not support TEST_FORCE_EN */
			test = index >> 8;
			if (test >= TEST_J && test <= TEST_PACKET) {
				dev->test_mode = test;
				return gr_ep0_respond(dev, NULL, 0,
						      gr_ep0_testmode_complete);
			}
		}
		break;

	case USB_REQ_CLEAR_FEATURE:
		switch (value) {
		case USB_DEVICE_REMOTE_WAKEUP:
			/* Disallow remote wakeup */
			dev->remote_wakeup = 0;
			return gr_ep0_respond_empty(dev);
		}
		break;
	}

	return 1; /* Delegate the rest */
}

/*
 * Returns negative for STALL, 0 for successful handling and positive for
 * delegation.
 *
 * Must be called with dev->lock held.
 */
static int gr_interface_request(struct gr_udc *dev, u8 type, u8 request,
				u16 value, u16 index)
{
	if (dev->gadget.state != USB_STATE_CONFIGURED)
		return -1;

	/*
	 * Should return STALL for invalid interfaces, but udc driver does not
	 * know anything about that. However, many gadget drivers do not handle
	 * GET_STATUS so we need to take care of that.
	 */

	switch (request) {
	case USB_REQ_GET_STATUS:
		return gr_ep0_respond_u16(dev, 0x0000);

	case USB_REQ_SET_FEATURE:
	case USB_REQ_CLEAR_FEATURE:
		/*
		 * No possible valid standard requests. Still let gadget drivers
		 * have a go at it.
		 */
		break;
	}

	return 1; /* Delegate the rest */
}

/*
 * Returns negative for STALL, 0 for successful handling and positive for
 * delegation.
 *
 * Must be called with dev->lock held.
 */
static int gr_endpoint_request(struct gr_udc *dev, u8 type, u8 request,
			       u16 value, u16 index)
{
	struct gr_ep *ep;
	int status;
	int halted;
	u8 epnum = index & USB_ENDPOINT_NUMBER_MASK;
	u8 is_in = index & USB_ENDPOINT_DIR_MASK;

	if ((is_in && epnum >= dev->nepi) || (!is_in && epnum >= dev->nepo))
		return -1;

	if (dev->gadget.state != USB_STATE_CONFIGURED && epnum != 0)
		return -1;

	ep = (is_in ? &dev->epi[epnum] : &dev->epo[epnum]);

	switch (request) {
	case USB_REQ_GET_STATUS:
		halted = gr_read32(&ep->regs->epctrl) & GR_EPCTRL_EH;
		return gr_ep0_respond_u16(dev, halted ? 0x0001 : 0);

	case USB_REQ_SET_FEATURE:
		switch (value) {
		case USB_ENDPOINT_HALT:
			status = gr_ep_halt_wedge(ep, 1, 0, 1);
			if (status >= 0)
				status = gr_ep0_respond_empty(dev);
			return status;
		}
		break;

	case USB_REQ_CLEAR_FEATURE:
		switch (value) {
		case USB_ENDPOINT_HALT:
			if (ep->wedged)
				return -1;
			status = gr_ep_halt_wedge(ep, 0, 0, 1);
			if (status >= 0)
				status = gr_ep0_respond_empty(dev);
			return status;
		}
		break;
	}

	return 1; /* Delegate the rest */
}

/* Must be called with dev->lock held */
static void gr_ep0out_requeue(struct gr_udc *dev)
{
	int ret = gr_queue_int(&dev->epo[0], dev->ep0reqo, GFP_ATOMIC);

	if (ret)
		dev_err(dev->dev, "Could not queue ep0out setup request: %d\n",
			ret);
}

/*
 * The main function dealing with setup requests on ep0.
 *
 * Must be called with dev->lock held and irqs disabled
 */
static void gr_ep0_setup(struct gr_udc *dev, struct gr_request *req)
	__releases(&dev->lock)
	__acquires(&dev->lock)
{
	union {
		struct usb_ctrlrequest ctrl;
		u8 raw[8];
		u32 word[2];
	} u;
	u8 type;
	u8 request;
	u16 value;
	u16 index;
	u16 length;
	int i;
	int status;

	/* Restore from ep0 halt */
	if (dev->ep0state == GR_EP0_STALL) {
		gr_set_ep0state(dev, GR_EP0_SETUP);
		if (!req->req.actual)
			goto out;
	}

	if (dev->ep0state == GR_EP0_ISTATUS) {
		gr_set_ep0state(dev, GR_EP0_SETUP);
		if (req->req.actual > 0)
			dev_dbg(dev->dev,
				"Unexpected setup packet at state %s\n",
				gr_ep0state_string(GR_EP0_ISTATUS));
		else
			goto out; /* Got expected ZLP */
	} else if (dev->ep0state != GR_EP0_SETUP) {
		dev_info(dev->dev,
			 "Unexpected ep0out request at state %s - stalling\n",
			 gr_ep0state_string(dev->ep0state));
		gr_control_stall(dev);
		gr_set_ep0state(dev, GR_EP0_SETUP);
		goto out;
	} else if (!req->req.actual) {
		dev_dbg(dev->dev, "Unexpected ZLP at state %s\n",
			gr_ep0state_string(dev->ep0state));
		goto out;
	}

	/* Handle SETUP packet */
	for (i = 0; i < req->req.actual; i++)
		u.raw[i] = ((u8 *)req->req.buf)[i];

	type = u.ctrl.bRequestType;
	request = u.ctrl.bRequest;
	value = le16_to_cpu(u.ctrl.wValue);
	index = le16_to_cpu(u.ctrl.wIndex);
	length = le16_to_cpu(u.ctrl.wLength);

	gr_dbgprint_devreq(dev, type, request, value, index, length);

	/* Check for data stage */
	if (length) {
		if (type & USB_DIR_IN)
			gr_set_ep0state(dev, GR_EP0_IDATA);
		else
			gr_set_ep0state(dev, GR_EP0_ODATA);
	}

	status = 1; /* Positive status flags delegation */
	if ((type & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
		switch (type & USB_RECIP_MASK) {
		case USB_RECIP_DEVICE:
			status = gr_device_request(dev, type, request,
						   value, index);
			break;
		case USB_RECIP_ENDPOINT:
			status =  gr_endpoint_request(dev, type, request,
						      value, index);
			break;
		case USB_RECIP_INTERFACE:
			status = gr_interface_request(dev, type, request,
						      value, index);
			break;
		}
	}

	if (status > 0) {
		spin_unlock(&dev->lock);

		dev_vdbg(dev->dev, "DELEGATE\n");
		status = dev->driver->setup(&dev->gadget, &u.ctrl);

		spin_lock(&dev->lock);
	}

	/* Generate STALL on both ep0out and ep0in if requested */
	if (unlikely(status < 0)) {
		dev_vdbg(dev->dev, "STALL\n");
		gr_control_stall(dev);
	}

	if ((type & USB_TYPE_MASK) == USB_TYPE_STANDARD &&
	    request == USB_REQ_SET_CONFIGURATION) {
		if (!value) {
			dev_dbg(dev->dev, "STATUS: deconfigured\n");
			usb_gadget_set_state(&dev->gadget, USB_STATE_ADDRESS);
		} else if (status >= 0) {
			/* Not configured unless gadget OK:s it */
			dev_dbg(dev->dev, "STATUS: configured: %d\n", value);
			usb_gadget_set_state(&dev->gadget,
					     USB_STATE_CONFIGURED);
		}
	}

	/* Get ready for next stage */
	if (dev->ep0state == GR_EP0_ODATA)
		gr_set_ep0state(dev, GR_EP0_OSTATUS);
	else if (dev->ep0state == GR_EP0_IDATA)
		gr_set_ep0state(dev, GR_EP0_ISTATUS);
	else
		gr_set_ep0state(dev, GR_EP0_SETUP);

out:
	gr_ep0out_requeue(dev);
}

/* ---------------------------------------------------------------------- */
/* VBUS and USB reset handling */

/* Must be called with dev->lock held and irqs disabled  */
static void gr_vbus_connected(struct gr_udc *dev, u32 status)
{
	u32 control;

	dev->gadget.speed = GR_SPEED(status);
	usb_gadget_set_state(&dev->gadget, USB_STATE_POWERED);

	/* Turn on full interrupts and pullup */
	control = (GR_CONTROL_SI | GR_CONTROL_UI | GR_CONTROL_VI |
		   GR_CONTROL_SP | GR_CONTROL_EP);
	gr_write32(&dev->regs->control, control);
}

/* Must be called with dev->lock held */
static void gr_enable_vbus_detect(struct gr_udc *dev)
{
	u32 status;

	dev->irq_enabled = 1;
	wmb(); /* Make sure we do not ignore an interrupt */
	gr_write32(&dev->regs->control, GR_CONTROL_VI);

	/* Take care of the case we are already plugged in at this point */
	status = gr_read32(&dev->regs->status);
	if (status & GR_STATUS_VB)
		gr_vbus_connected(dev, status);
}

/* Must be called with dev->lock held and irqs disabled */
static void gr_vbus_disconnected(struct gr_udc *dev)
{
	gr_stop_activity(dev);

	/* Report disconnect */
	if (dev->driver && dev->driver->disconnect) {
		spin_unlock(&dev->lock);

		dev->driver->disconnect(&dev->gadget);

		spin_lock(&dev->lock);
	}

	gr_enable_vbus_detect(dev);
}

/* Must be called with dev->lock held and irqs disabled */
static void gr_udc_usbreset(struct gr_udc *dev, u32 status)
{
	gr_set_address(dev, 0);
	gr_set_ep0state(dev, GR_EP0_SETUP);
	usb_gadget_set_state(&dev->gadget, USB_STATE_DEFAULT);
	dev->gadget.speed = GR_SPEED(status);

	gr_ep_nuke(&dev->epo[0]);
	gr_ep_nuke(&dev->epi[0]);
	dev->epo[0].stopped = 0;
	dev->epi[0].stopped = 0;
	gr_ep0out_requeue(dev);
}

/* ---------------------------------------------------------------------- */
/* Irq handling */

/*
 * Handles interrupts from in endpoints. Returns whether something was handled.
 *
 * Must be called with dev->lock held, irqs disabled and with !ep->stopped.
 */
static int gr_handle_in_ep(struct gr_ep *ep)
{
	struct gr_request *req;

	req = list_first_entry(&ep->queue, struct gr_request, queue);
	if (!req->last_desc)
		return 0;

	if (ACCESS_ONCE(req->last_desc->ctrl) & GR_DESC_IN_CTRL_EN)
		return 0; /* Not put in hardware buffers yet */

	if (gr_read32(&ep->regs->epstat) & (GR_EPSTAT_B1 | GR_EPSTAT_B0))
		return 0; /* Not transmitted yet, still in hardware buffers */

	/* Write complete */
	gr_dma_advance(ep, 0);

	return 1;
}

/*
 * Handles interrupts from out endpoints. Returns whether something was handled.
 *
 * Must be called with dev->lock held, irqs disabled and with !ep->stopped.
 */
static int gr_handle_out_ep(struct gr_ep *ep)
{
	u32 ep_dmactrl;
	u32 ctrl;
	u16 len;
	struct gr_request *req;
	struct gr_udc *dev = ep->dev;

	req = list_first_entry(&ep->queue, struct gr_request, queue);
	if (!req->curr_desc)
		return 0;

	ctrl = ACCESS_ONCE(req->curr_desc->ctrl);
	if (ctrl & GR_DESC_OUT_CTRL_EN)
		return 0; /* Not received yet */

	/* Read complete */
	len = ctrl & GR_DESC_OUT_CTRL_LEN_MASK;
	req->req.actual += len;
	if (ctrl & GR_DESC_OUT_CTRL_SE)
		req->setup = 1;

	if (len < ep->ep.maxpacket || req->req.actual >= req->req.length) {
		/* Short packet or >= expected size - we are done */

		if ((ep == &dev->epo[0]) && (dev->ep0state == GR_EP0_OSTATUS)) {
			/*
			 * Send a status stage ZLP to ack the DATA stage in the
			 * OUT direction. This needs to be done before
			 * gr_dma_advance as that can lead to a call to
			 * ep0_setup that can change dev->ep0state.
			 */
			gr_ep0_respond_empty(dev);
			gr_set_ep0state(dev, GR_EP0_SETUP);
		}

		gr_dma_advance(ep, 0);
	} else {
		/* Not done yet. Enable the next descriptor to receive more. */
		req->curr_desc = req->curr_desc->next_desc;
		req->curr_desc->ctrl |= GR_DESC_OUT_CTRL_EN;

		ep_dmactrl = gr_read32(&ep->regs->dmactrl);
		gr_write32(&ep->regs->dmactrl, ep_dmactrl | GR_DMACTRL_DA);
	}

	return 1;
}

/*
 * Handle state changes. Returns whether something was handled.
 *
 * Must be called with dev->lock held and irqs disabled.
 */
static int gr_handle_state_changes(struct gr_udc *dev)
{
	u32 status = gr_read32(&dev->regs->status);
	int handled = 0;
	int powstate = !(dev->gadget.state == USB_STATE_NOTATTACHED ||
			 dev->gadget.state == USB_STATE_ATTACHED);

	/* VBUS valid detected */
	if (!powstate && (status & GR_STATUS_VB)) {
		dev_dbg(dev->dev, "STATUS: vbus valid detected\n");
		gr_vbus_connected(dev, status);
		handled = 1;
	}

	/* Disconnect */
	if (powstate && !(status & GR_STATUS_VB)) {
		dev_dbg(dev->dev, "STATUS: vbus invalid detected\n");
		gr_vbus_disconnected(dev);
		handled = 1;
	}

	/* USB reset detected */
	if (status & GR_STATUS_UR) {
		dev_dbg(dev->dev, "STATUS: USB reset - speed is %s\n",
			GR_SPEED_STR(status));
		gr_write32(&dev->regs->status, GR_STATUS_UR);
		gr_udc_usbreset(dev, status);
		handled = 1;
	}

	/* Speed change */
	if (dev->gadget.speed != GR_SPEED(status)) {
		dev_dbg(dev->dev, "STATUS: USB Speed change to %s\n",
			GR_SPEED_STR(status));
		dev->gadget.speed = GR_SPEED(status);
		handled = 1;
	}

	/* Going into suspend */
	if ((dev->ep0state != GR_EP0_SUSPEND) && !(status & GR_STATUS_SU)) {
		dev_dbg(dev->dev, "STATUS: USB suspend\n");
		gr_set_ep0state(dev, GR_EP0_SUSPEND);
		dev->suspended_from = dev->gadget.state;
		usb_gadget_set_state(&dev->gadget, USB_STATE_SUSPENDED);

		if ((dev->gadget.speed != USB_SPEED_UNKNOWN) &&
		    dev->driver && dev->driver->suspend) {
			spin_unlock(&dev->lock);

			dev->driver->suspend(&dev->gadget);

			spin_lock(&dev->lock);
		}
		handled = 1;
	}

	/* Coming out of suspend */
	if ((dev->ep0state == GR_EP0_SUSPEND) && (status & GR_STATUS_SU)) {
		dev_dbg(dev->dev, "STATUS: USB resume\n");
		if (dev->suspended_from == USB_STATE_POWERED)
			gr_set_ep0state(dev, GR_EP0_DISCONNECT);
		else
			gr_set_ep0state(dev, GR_EP0_SETUP);
		usb_gadget_set_state(&dev->gadget, dev->suspended_from);

		if ((dev->gadget.speed != USB_SPEED_UNKNOWN) &&
		    dev->driver && dev->driver->resume) {
			spin_unlock(&dev->lock);

			dev->driver->resume(&dev->gadget);

			spin_lock(&dev->lock);
		}
		handled = 1;
	}

	return handled;
}

/* Non-interrupt context irq handler */
static irqreturn_t gr_irq_handler(int irq, void *_dev)
{
	struct gr_udc *dev = _dev;
	struct gr_ep *ep;
	int handled = 0;
	int i;
	unsigned long flags;

	spin_lock_irqsave(&dev->lock, flags);

	if (!dev->irq_enabled)
		goto out;

	/*
	 * Check IN ep interrupts. We check these before the OUT eps because
	 * some gadgets reuse the request that might already be currently
	 * outstanding and needs to be completed (mainly setup requests).
	 */
	for (i = 0; i < dev->nepi; i++) {
		ep = &dev->epi[i];
		if (!ep->stopped && !ep->callback && !list_empty(&ep->queue))
			handled = gr_handle_in_ep(ep) || handled;
	}

	/* Check OUT ep interrupts */
	for (i = 0; i < dev->nepo; i++) {
		ep = &dev->epo[i];
		if (!ep->stopped && !ep->callback && !list_empty(&ep->queue))
			handled = gr_handle_out_ep(ep) || handled;
	}

	/* Check status interrupts */
	handled = gr_handle_state_changes(dev) || handled;

	/*
	 * Check AMBA DMA errors. Only check if we didn't find anything else to
	 * handle because this shouldn't happen if we did everything right.
	 */
	if (!handled) {
		list_for_each_entry(ep, &dev->ep_list, ep_list) {
			if (gr_read32(&ep->regs->dmactrl) & GR_DMACTRL_AE) {
				dev_err(dev->dev,
					"AMBA Error occurred for %s\n",
					ep->ep.name);
				handled = 1;
			}
		}
	}

out:
	spin_unlock_irqrestore(&dev->lock, flags);

	return handled ? IRQ_HANDLED : IRQ_NONE;
}

/* Interrupt context irq handler */
static irqreturn_t gr_irq(int irq, void *_dev)
{
	struct gr_udc *dev = _dev;

	if (!dev->irq_enabled)
		return IRQ_NONE;

	return IRQ_WAKE_THREAD;
}

/* ---------------------------------------------------------------------- */
/* USB ep ops */

/* Enable endpoint. Not for ep0in and ep0out that are handled separately. */
static int gr_ep_enable(struct usb_ep *_ep,
			const struct usb_endpoint_descriptor *desc)
{
	struct gr_udc *dev;
	struct gr_ep *ep;
	u8 mode;
	u8 nt;
	u16 max;
	u16 buffer_size = 0;
	u32 epctrl;

	ep = container_of(_ep, struct gr_ep, ep);
	if (!_ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT)
		return -EINVAL;

	dev = ep->dev;

	/* 'ep0' IN and OUT are reserved */
	if (ep == &dev->epo[0] || ep == &dev->epi[0])
		return -EINVAL;

	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;

	/* Make sure we are clear for enabling */
	epctrl = gr_read32(&ep->regs->epctrl);
	if (epctrl & GR_EPCTRL_EV)
		return -EBUSY;

	/* Check that directions match */
	if (!ep->is_in != !usb_endpoint_dir_in(desc))
		return -EINVAL;

	/* Check ep num */
	if ((!ep->is_in && ep->num >= dev->nepo) ||
	    (ep->is_in && ep->num >= dev->nepi))
		return -EINVAL;

	if (usb_endpoint_xfer_control(desc)) {
		mode = 0;
	} else if (usb_endpoint_xfer_isoc(desc)) {
		mode = 1;
	} else if (usb_endpoint_xfer_bulk(desc)) {
		mode = 2;
	} else if (usb_endpoint_xfer_int(desc)) {
		mode = 3;
	} else {
		dev_err(dev->dev, "Unknown transfer type for %s\n",
			ep->ep.name);
		return -EINVAL;
	}

	/*
	 * Bits 10-0 set the max payload. 12-11 set the number of
	 * additional transactions.
	 */
	max = 0x7ff & usb_endpoint_maxp(desc);
	nt = usb_endpoint_maxp_mult(desc) - 1;
	buffer_size = GR_BUFFER_SIZE(epctrl);
	if (nt && (mode == 0 || mode == 2)) {
		dev_err(dev->dev,
			"%s mode: multiple trans./microframe not valid\n",
			(mode == 2 ? "Bulk" : "Control"));
		return -EINVAL;
	} else if (nt == 0x3) {
		dev_err(dev->dev,
			"Invalid value 0x3 for additional trans./microframe\n");
		return -EINVAL;
	} else if ((nt + 1) * max > buffer_size) {
		dev_err(dev->dev, "Hw buffer size %d < max payload %d * %d\n",
			buffer_size, (nt + 1), max);
		return -EINVAL;
	} else if (max == 0) {
		dev_err(dev->dev, "Max payload cannot be set to 0\n");
		return -EINVAL;
	} else if (max > ep->ep.maxpacket_limit) {
		dev_err(dev->dev, "Requested max payload %d > limit %d\n",
			max, ep->ep.maxpacket_limit);
		return -EINVAL;
	}

	spin_lock(&ep->dev->lock);

	if (!ep->stopped) {
		spin_unlock(&ep->dev->lock);
		return -EBUSY;
	}

	ep->stopped = 0;
	ep->wedged = 0;
	ep->ep.desc = desc;
	ep->ep.maxpacket = max;
	ep->dma_start = 0;


	if (nt) {
		/*
		 * Maximum possible size of all payloads in one microframe
		 * regardless of direction when using high-bandwidth mode.
		 */
		ep->bytes_per_buffer = (nt + 1) * max;
	} else if (ep->is_in) {
		/*
		 * The biggest multiple of maximum packet size that fits into
		 * the buffer. The hardware will split up into many packets in
		 * the IN direction.
		 */
		ep->bytes_per_buffer = (buffer_size / max) * max;
	} else {
		/*
		 * Only single packets will be placed the buffers in the OUT
		 * direction.
		 */
		ep->bytes_per_buffer = max;
	}

	epctrl = (max << GR_EPCTRL_MAXPL_POS)
		| (nt << GR_EPCTRL_NT_POS)
		| (mode << GR_EPCTRL_TT_POS)
		| GR_EPCTRL_EV;
	if (ep->is_in)
		epctrl |= GR_EPCTRL_PI;
	gr_write32(&ep->regs->epctrl, epctrl);

	gr_write32(&ep->regs->dmactrl, GR_DMACTRL_IE | GR_DMACTRL_AI);

	spin_unlock(&ep->dev->lock);

	dev_dbg(ep->dev->dev, "EP: %s enabled - %s with %d bytes/buffer\n",
		ep->ep.name, gr_modestring[mode], ep->bytes_per_buffer);
	return 0;
}

/* Disable endpoint. Not for ep0in and ep0out that are handled separately. */
static int gr_ep_disable(struct usb_ep *_ep)
{
	struct gr_ep *ep;
	struct gr_udc *dev;
	unsigned long flags;

	ep = container_of(_ep, struct gr_ep, ep);
	if (!_ep || !ep->ep.desc)
		return -ENODEV;

	dev = ep->dev;

	/* 'ep0' IN and OUT are reserved */
	if (ep == &dev->epo[0] || ep == &dev->epi[0])
		return -EINVAL;

	if (dev->ep0state == GR_EP0_SUSPEND)
		return -EBUSY;

	dev_dbg(ep->dev->dev, "EP: disable %s\n", ep->ep.name);

	spin_lock_irqsave(&dev->lock, flags);

	gr_ep_nuke(ep);
	gr_ep_reset(ep);
	ep->ep.desc = NULL;

	spin_unlock_irqrestore(&dev->lock, flags);

	return 0;
}

/*
 * Frees a request, but not any DMA buffers associated with it
 * (gr_finish_request should already have taken care of that).
 */
static void gr_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
	struct gr_request *req;

	if (!_ep || !_req)
		return;
	req = container_of(_req, struct gr_request, req);

	/* Leads to memory leak */
	WARN(!list_empty(&req->queue),
	     "request not dequeued properly before freeing\n");

	kfree(req);
}

/* Queue a request from the gadget */
static int gr_queue_ext(struct usb_ep *_ep, struct usb_request *_req,
			gfp_t gfp_flags)
{
	struct gr_ep *ep;
	struct gr_request *req;
	struct gr_udc *dev;
	int ret;

	if (unlikely(!_ep || !_req))
		return -EINVAL;

	ep = container_of(_ep, struct gr_ep, ep);
	req = container_of(_req, struct gr_request, req);
	dev = ep->dev;

	spin_lock(&ep->dev->lock);

	/*
	 * The ep0 pointer in the gadget struct is used both for ep0in and
	 * ep0out. In a data stage in the out direction ep0out needs to be used
	 * instead of the default ep0in. Completion functions might use
	 * driver_data, so that needs to be copied as well.
	 */
	if ((ep == &dev->epi[0]) && (dev->ep0state == GR_EP0_ODATA)) {
		ep = &dev->epo[0];
		ep->ep.driver_data = dev->epi[0].ep.driver_data;
	}

	if (ep->is_in)
		gr_dbgprint_request("EXTERN", ep, req);

	ret = gr_queue(ep, req, GFP_ATOMIC);

	spin_unlock(&ep->dev->lock);

	return ret;
}

/* Dequeue JUST ONE request */
static int gr_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
	struct gr_request *req;
	struct gr_ep *ep;
	struct gr_udc *dev;
	int ret = 0;
	unsigned long flags;

	ep = container_of(_ep, struct gr_ep, ep);
	if (!_ep || !_req || (!ep->ep.desc && ep->num != 0))
		return -EINVAL;
	dev = ep->dev;
	if (!dev->driver)
		return -ESHUTDOWN;

	/* We can't touch (DMA) registers when suspended */
	if (dev->ep0state == GR_EP0_SUSPEND)
		return -EBUSY;

	spin_lock_irqsave(&dev->lock, flags);

	/* Make sure it's actually queued on this endpoint */
	list_for_each_entry(req, &ep->queue, queue) {
		if (&req->req == _req)
			break;
	}
	if (&req->req != _req) {
		ret = -EINVAL;
		goto out;
	}

	if (list_first_entry(&ep->queue, struct gr_request, queue) == req) {
		/* This request is currently being processed */
		gr_abort_dma(ep);
		if (ep->stopped)
			gr_finish_request(ep, req, -ECONNRESET);
		else
			gr_dma_advance(ep, -ECONNRESET);
	} else if (!list_empty(&req->queue)) {
		/* Not being processed - gr_finish_request dequeues it */
		gr_finish_request(ep, req, -ECONNRESET);
	} else {
		ret = -EOPNOTSUPP;
	}

out:
	spin_unlock_irqrestore(&dev->lock, flags);

	return ret;
}

/* Helper for gr_set_halt and gr_set_wedge */
static int gr_set_halt_wedge(struct usb_ep *_ep, int halt, int wedge)
{
	int ret;
	struct gr_ep *ep;

	if (!_ep)
		return -ENODEV;
	ep = container_of(_ep, struct gr_ep, ep);

	spin_lock(&ep->dev->lock);

	/* Halting an IN endpoint should fail if queue is not empty */
	if (halt && ep->is_in && !list_empty(&ep->queue)) {
		ret = -EAGAIN;
		goto out;
	}

	ret = gr_ep_halt_wedge(ep, halt, wedge, 0);

out:
	spin_unlock(&ep->dev->lock);

	return ret;
}

/* Halt endpoint */
static int gr_set_halt(struct usb_ep *_ep, int halt)
{
	return gr_set_halt_wedge(_ep, halt, 0);
}

/* Halt and wedge endpoint */
static int gr_set_wedge(struct usb_ep *_ep)
{
	return gr_set_halt_wedge(_ep, 1, 1);
}

/*
 * Return the total number of bytes currently stored in the internal buffers of
 * the endpoint.
 */
static int gr_fifo_status(struct usb_ep *_ep)
{
	struct gr_ep *ep;
	u32 epstat;
	u32 bytes = 0;

	if (!_ep)
		return -ENODEV;
	ep = container_of(_ep, struct gr_ep, ep);

	epstat = gr_read32(&ep->regs->epstat);

	if (epstat & GR_EPSTAT_B0)
		bytes += (epstat & GR_EPSTAT_B0CNT_MASK) >> GR_EPSTAT_B0CNT_POS;
	if (epstat & GR_EPSTAT_B1)
		bytes += (epstat & GR_EPSTAT_B1CNT_MASK) >> GR_EPSTAT_B1CNT_POS;

	return bytes;
}


/* Empty data from internal buffers of an endpoint. */
static void gr_fifo_flush(struct usb_ep *_ep)
{
	struct gr_ep *ep;
	u32 epctrl;

	if (!_ep)
		return;
	ep = container_of(_ep, struct gr_ep, ep);
	dev_vdbg(ep->dev->dev, "EP: flush fifo %s\n", ep->ep.name);

	spin_lock(&ep->dev->lock);

	epctrl = gr_read32(&ep->regs->epctrl);
	epctrl |= GR_EPCTRL_CB;
	gr_write32(&ep->regs->epctrl, epctrl);

	spin_unlock(&ep->dev->lock);
}

static const struct usb_ep_ops gr_ep_ops = {
	.enable		= gr_ep_enable,
	.disable	= gr_ep_disable,

	.alloc_request	= gr_alloc_request,
	.free_request	= gr_free_request,

	.queue		= gr_queue_ext,
	.dequeue	= gr_dequeue,

	.set_halt	= gr_set_halt,
	.set_wedge	= gr_set_wedge,
	.fifo_status	= gr_fifo_status,
	.fifo_flush	= gr_fifo_flush,
};

/* ---------------------------------------------------------------------- */
/* USB Gadget ops */

static int gr_get_frame(struct usb_gadget *_gadget)
{
	struct gr_udc *dev;

	if (!_gadget)
		return -ENODEV;
	dev = container_of(_gadget, struct gr_udc, gadget);
	return gr_read32(&dev->regs->status) & GR_STATUS_FN_MASK;
}

static int gr_wakeup(struct usb_gadget *_gadget)
{
	struct gr_udc *dev;

	if (!_gadget)
		return -ENODEV;
	dev = container_of(_gadget, struct gr_udc, gadget);

	/* Remote wakeup feature not enabled by host*/
	if (!dev->remote_wakeup)
		return -EINVAL;

	spin_lock(&dev->lock);

	gr_write32(&dev->regs->control,
		   gr_read32(&dev->regs->control) | GR_CONTROL_RW);

	spin_unlock(&dev->lock);

	return 0;
}

static int gr_pullup(struct usb_gadget *_gadget, int is_on)
{
	struct gr_udc *dev;
	u32 control;

	if (!_gadget)
		return -ENODEV;
	dev = container_of(_gadget, struct gr_udc, gadget);

	spin_lock(&dev->lock);

	control = gr_read32(&dev->regs->control);
	if (is_on)
		control |= GR_CONTROL_EP;
	else
		control &= ~GR_CONTROL_EP;
	gr_write32(&dev->regs->control, control);

	spin_unlock(&dev->lock);

	return 0;
}

static int gr_udc_start(struct usb_gadget *gadget,
			struct usb_gadget_driver *driver)
{
	struct gr_udc *dev = to_gr_udc(gadget);

	spin_lock(&dev->lock);

	/* Hook up the driver */
	driver->driver.bus = NULL;
	dev->driver = driver;

	/* Get ready for host detection */
	gr_enable_vbus_detect(dev);

	spin_unlock(&dev->lock);

	return 0;
}

static int gr_udc_stop(struct usb_gadget *gadget)
{
	struct gr_udc *dev = to_gr_udc(gadget);
	unsigned long flags;

	spin_lock_irqsave(&dev->lock, flags);

	dev->driver = NULL;
	gr_stop_activity(dev);

	spin_unlock_irqrestore(&dev->lock, flags);

	return 0;
}

static const struct usb_gadget_ops gr_ops = {
	.get_frame	= gr_get_frame,
	.wakeup         = gr_wakeup,
	.pullup         = gr_pullup,
	.udc_start	= gr_udc_start,
	.udc_stop	= gr_udc_stop,
	/* Other operations not supported */
};

/* ---------------------------------------------------------------------- */
/* Module probe, removal and of-matching */

static const char * const onames[] = {
	"ep0out", "ep1out", "ep2out", "ep3out", "ep4out", "ep5out",
	"ep6out", "ep7out", "ep8out", "ep9out", "ep10out", "ep11out",
	"ep12out", "ep13out", "ep14out", "ep15out"
};

static const char * const inames[] = {
	"ep0in", "ep1in", "ep2in", "ep3in", "ep4in", "ep5in",
	"ep6in", "ep7in", "ep8in", "ep9in", "ep10in", "ep11in",
	"ep12in", "ep13in", "ep14in", "ep15in"
};

/* Must be called with dev->lock held */
static int gr_ep_init(struct gr_udc *dev, int num, int is_in, u32 maxplimit)
{
	struct gr_ep *ep;
	struct gr_request *req;
	struct usb_request *_req;
	void *buf;

	if (is_in) {
		ep = &dev->epi[num];
		ep->ep.name = inames[num];
		ep->regs = &dev->regs->epi[num];
	} else {
		ep = &dev->epo[num];
		ep->ep.name = onames[num];
		ep->regs = &dev->regs->epo[num];
	}

	gr_ep_reset(ep);
	ep->num = num;
	ep->is_in = is_in;
	ep->dev = dev;
	ep->ep.ops = &gr_ep_ops;
	INIT_LIST_HEAD(&ep->queue);

	if (num == 0) {
		_req = gr_alloc_request(&ep->ep, GFP_ATOMIC);
		buf = devm_kzalloc(dev->dev, PAGE_SIZE, GFP_DMA | GFP_ATOMIC);
		if (!_req || !buf) {
			/* possible _req freed by gr_probe via gr_remove */
			return -ENOMEM;
		}

		req = container_of(_req, struct gr_request, req);
		req->req.buf = buf;
		req->req.length = MAX_CTRL_PL_SIZE;

		if (is_in)
			dev->ep0reqi = req; /* Complete gets set as used */
		else
			dev->ep0reqo = req; /* Completion treated separately */

		usb_ep_set_maxpacket_limit(&ep->ep, MAX_CTRL_PL_SIZE);
		ep->bytes_per_buffer = MAX_CTRL_PL_SIZE;

		ep->ep.caps.type_control = true;
	} else {
		usb_ep_set_maxpacket_limit(&ep->ep, (u16)maxplimit);
		list_add_tail(&ep->ep.ep_list, &dev->gadget.ep_list);

		ep->ep.caps.type_iso = true;
		ep->ep.caps.type_bulk = true;
		ep->ep.caps.type_int = true;
	}
	list_add_tail(&ep->ep_list, &dev->ep_list);

	if (is_in)
		ep->ep.caps.dir_in = true;
	else
		ep->ep.caps.dir_out = true;

	ep->tailbuf = dma_alloc_coherent(dev->dev, ep->ep.maxpacket_limit,
					 &ep->tailbuf_paddr, GFP_ATOMIC);
	if (!ep->tailbuf)
		return -ENOMEM;

	return 0;
}

/* Must be called with dev->lock held */
static int gr_udc_init(struct gr_udc *dev)
{
	struct device_node *np = dev->dev->of_node;
	u32 epctrl_val;
	u32 dmactrl_val;
	int i;
	int ret = 0;
	u32 bufsize;

	gr_set_address(dev, 0);

	INIT_LIST_HEAD(&dev->gadget.ep_list);
	dev->gadget.speed = USB_SPEED_UNKNOWN;
	dev->gadget.ep0 = &dev->epi[0].ep;

	INIT_LIST_HEAD(&dev->ep_list);
	gr_set_ep0state(dev, GR_EP0_DISCONNECT);

	for (i = 0; i < dev->nepo; i++) {
		if (of_property_read_u32_index(np, "epobufsizes", i, &bufsize))
			bufsize = 1024;
		ret = gr_ep_init(dev, i, 0, bufsize);
		if (ret)
			return ret;
	}

	for (i = 0; i < dev->nepi; i++) {
		if (of_property_read_u32_index(np, "epibufsizes", i, &bufsize))
			bufsize = 1024;
		ret = gr_ep_init(dev, i, 1, bufsize);
		if (ret)
			return ret;
	}

	/* Must be disabled by default */
	dev->remote_wakeup = 0;

	/* Enable ep0out and ep0in */
	epctrl_val = (MAX_CTRL_PL_SIZE << GR_EPCTRL_MAXPL_POS) | GR_EPCTRL_EV;
	dmactrl_val = GR_DMACTRL_IE | GR_DMACTRL_AI;
	gr_write32(&dev->epo[0].regs->epctrl, epctrl_val);
	gr_write32(&dev->epi[0].regs->epctrl, epctrl_val | GR_EPCTRL_PI);
	gr_write32(&dev->epo[0].regs->dmactrl, dmactrl_val);
	gr_write32(&dev->epi[0].regs->dmactrl, dmactrl_val);

	return 0;
}

static void gr_ep_remove(struct gr_udc *dev, int num, int is_in)
{
	struct gr_ep *ep;

	if (is_in)
		ep = &dev->epi[num];
	else
		ep = &dev->epo[num];

	if (ep->tailbuf)
		dma_free_coherent(dev->dev, ep->ep.maxpacket_limit,
				  ep->tailbuf, ep->tailbuf_paddr);
}

static int gr_remove(struct platform_device *pdev)
{
	struct gr_udc *dev = platform_get_drvdata(pdev);
	int i;

	if (dev->added)
		usb_del_gadget_udc(&dev->gadget); /* Shuts everything down */
	if (dev->driver)
		return -EBUSY;

	gr_dfs_delete(dev);
	dma_pool_destroy(dev->desc_pool);
	platform_set_drvdata(pdev, NULL);

	gr_free_request(&dev->epi[0].ep, &dev->ep0reqi->req);
	gr_free_request(&dev->epo[0].ep, &dev->ep0reqo->req);

	for (i = 0; i < dev->nepo; i++)
		gr_ep_remove(dev, i, 0);
	for (i = 0; i < dev->nepi; i++)
		gr_ep_remove(dev, i, 1);

	return 0;
}
static int gr_request_irq(struct gr_udc *dev, int irq)
{
	return devm_request_threaded_irq(dev->dev, irq, gr_irq, gr_irq_handler,
					 IRQF_SHARED, driver_name, dev);
}

static int gr_probe(struct platform_device *pdev)
{
	struct gr_udc *dev;
	struct resource *res;
	struct gr_regs __iomem *regs;
	int retval;
	u32 status;

	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;
	dev->dev = &pdev->dev;

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

	dev->irq = platform_get_irq(pdev, 0);
	if (dev->irq <= 0) {
		dev_err(dev->dev, "No irq found\n");
		return -ENODEV;
	}

	/* Some core configurations has separate irqs for IN and OUT events */
	dev->irqi = platform_get_irq(pdev, 1);
	if (dev->irqi > 0) {
		dev->irqo = platform_get_irq(pdev, 2);
		if (dev->irqo <= 0) {
			dev_err(dev->dev, "Found irqi but not irqo\n");
			return -ENODEV;
		}
	} else {
		dev->irqi = 0;
	}

	dev->gadget.name = driver_name;
	dev->gadget.max_speed = USB_SPEED_HIGH;
	dev->gadget.ops = &gr_ops;

	spin_lock_init(&dev->lock);
	dev->regs = regs;

	platform_set_drvdata(pdev, dev);

	/* Determine number of endpoints and data interface mode */
	status = gr_read32(&dev->regs->status);
	dev->nepi = ((status & GR_STATUS_NEPI_MASK) >> GR_STATUS_NEPI_POS) + 1;
	dev->nepo = ((status & GR_STATUS_NEPO_MASK) >> GR_STATUS_NEPO_POS) + 1;

	if (!(status & GR_STATUS_DM)) {
		dev_err(dev->dev, "Slave mode cores are not supported\n");
		return -ENODEV;
	}

	/* --- Effects of the following calls might need explicit cleanup --- */

	/* Create DMA pool for descriptors */
	dev->desc_pool = dma_pool_create("desc_pool", dev->dev,
					 sizeof(struct gr_dma_desc), 4, 0);
	if (!dev->desc_pool) {
		dev_err(dev->dev, "Could not allocate DMA pool");
		return -ENOMEM;
	}

	spin_lock(&dev->lock);

	/* Inside lock so that no gadget can use this udc until probe is done */
	retval = usb_add_gadget_udc(dev->dev, &dev->gadget);
	if (retval) {
		dev_err(dev->dev, "Could not add gadget udc");
		goto out;
	}
	dev->added = 1;

	retval = gr_udc_init(dev);
	if (retval)
		goto out;

	gr_dfs_create(dev);

	/* Clear all interrupt enables that might be left on since last boot */
	gr_disable_interrupts_and_pullup(dev);

	retval = gr_request_irq(dev, dev->irq);
	if (retval) {
		dev_err(dev->dev, "Failed to request irq %d\n", dev->irq);
		goto out;
	}

	if (dev->irqi) {
		retval = gr_request_irq(dev, dev->irqi);
		if (retval) {
			dev_err(dev->dev, "Failed to request irqi %d\n",
				dev->irqi);
			goto out;
		}
		retval = gr_request_irq(dev, dev->irqo);
		if (retval) {
			dev_err(dev->dev, "Failed to request irqo %d\n",
				dev->irqo);
			goto out;
		}
	}

	if (dev->irqi)
		dev_info(dev->dev, "regs: %p, irqs %d, %d, %d\n", dev->regs,
			 dev->irq, dev->irqi, dev->irqo);
	else
		dev_info(dev->dev, "regs: %p, irq %d\n", dev->regs, dev->irq);

out:
	spin_unlock(&dev->lock);

	if (retval)
		gr_remove(pdev);

	return retval;
}

static const struct of_device_id gr_match[] = {
	{.name = "GAISLER_USBDC"},
	{.name = "01_021"},
	{},
};
MODULE_DEVICE_TABLE(of, gr_match);

static struct platform_driver gr_driver = {
	.driver = {
		.name = DRIVER_NAME,
		.of_match_table = gr_match,
	},
	.probe = gr_probe,
	.remove = gr_remove,
};
module_platform_driver(gr_driver);

MODULE_AUTHOR("Aeroflex Gaisler AB.");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");