summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/goku_udc.c
blob: 1088d08c7ed8fac07146bd8d6fbde9d59a1897ca (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
/*
 * Toshiba TC86C001 ("Goku-S") USB Device Controller driver
 *
 * Copyright (C) 2000-2002 Lineo
 *      by Stuart Lynne, Tom Rushworth, and Bruce Balden
 * Copyright (C) 2002 Toshiba Corporation
 * Copyright (C) 2003 MontaVista Software (source@mvista.com)
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

/*
 * This device has ep0 and three semi-configurable bulk/interrupt endpoints.
 *
 *  - Endpoint numbering is fixed: ep{1,2,3}-bulk
 *  - Gadget drivers can choose ep maxpacket (8/16/32/64)
 *  - Gadget drivers can choose direction (IN, OUT)
 *  - DMA works with ep1 (OUT transfers) and ep2 (IN transfers).
 */

// #define	VERBOSE		/* extra debug messages (success too) */
// #define	USB_TRACE	/* packet-level success messages */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/unaligned.h>


#include "goku_udc.h"

#define	DRIVER_DESC		"TC86C001 USB Device Controller"
#define	DRIVER_VERSION		"30-Oct 2003"

#define	DMA_ADDR_INVALID	(~(dma_addr_t)0)

static const char driver_name [] = "goku_udc";
static const char driver_desc [] = DRIVER_DESC;

MODULE_AUTHOR("source@mvista.com");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");


/*
 * IN dma behaves ok under testing, though the IN-dma abort paths don't
 * seem to behave quite as expected.  Used by default.
 *
 * OUT dma documents design problems handling the common "short packet"
 * transfer termination policy; it couldn't be enabled by default, even
 * if the OUT-dma abort problems had a resolution.
 */
static unsigned use_dma = 1;

#if 0
//#include <linux/moduleparam.h>
/* "modprobe goku_udc use_dma=1" etc
 *	0 to disable dma
 *	1 to use IN dma only (normal operation)
 *	2 to use IN and OUT dma
 */
module_param(use_dma, uint, S_IRUGO);
#endif

/*-------------------------------------------------------------------------*/

static void nuke(struct goku_ep *, int status);

static inline void
command(struct goku_udc_regs __iomem *regs, int command, unsigned epnum)
{
	writel(COMMAND_EP(epnum) | command, &regs->Command);
	udelay(300);
}

static int
goku_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
	struct goku_udc	*dev;
	struct goku_ep	*ep;
	u32		mode;
	u16		max;
	unsigned long	flags;

	ep = container_of(_ep, struct goku_ep, ep);
	if (!_ep || !desc || ep->desc
			|| desc->bDescriptorType != USB_DT_ENDPOINT)
		return -EINVAL;
	dev = ep->dev;
	if (ep == &dev->ep[0])
		return -EINVAL;
	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;
	if (ep->num != usb_endpoint_num(desc))
		return -EINVAL;

	switch (usb_endpoint_type(desc)) {
	case USB_ENDPOINT_XFER_BULK:
	case USB_ENDPOINT_XFER_INT:
		break;
	default:
		return -EINVAL;
	}

	if ((readl(ep->reg_status) & EPxSTATUS_EP_MASK)
			!= EPxSTATUS_EP_INVALID)
		return -EBUSY;

	/* enabling the no-toggle interrupt mode would need an api hook */
	mode = 0;
	max = get_unaligned_le16(&desc->wMaxPacketSize);
	switch (max) {
	case 64:	mode++;
	case 32:	mode++;
	case 16:	mode++;
	case 8:		mode <<= 3;
			break;
	default:
		return -EINVAL;
	}
	mode |= 2 << 1;		/* bulk, or intr-with-toggle */

	/* ep1/ep2 dma direction is chosen early; it works in the other
	 * direction, with pio.  be cautious with out-dma.
	 */
	ep->is_in = usb_endpoint_dir_in(desc);
	if (ep->is_in) {
		mode |= 1;
		ep->dma = (use_dma != 0) && (ep->num == UDC_MSTRD_ENDPOINT);
	} else {
		ep->dma = (use_dma == 2) && (ep->num == UDC_MSTWR_ENDPOINT);
		if (ep->dma)
			DBG(dev, "%s out-dma hides short packets\n",
				ep->ep.name);
	}

	spin_lock_irqsave(&ep->dev->lock, flags);

	/* ep1 and ep2 can do double buffering and/or dma */
	if (ep->num < 3) {
		struct goku_udc_regs __iomem	*regs = ep->dev->regs;
		u32				tmp;

		/* double buffer except (for now) with pio in */
		tmp = ((ep->dma || !ep->is_in)
				? 0x10	/* double buffered */
				: 0x11	/* single buffer */
			) << ep->num;
		tmp |= readl(&regs->EPxSingle);
		writel(tmp, &regs->EPxSingle);

		tmp = (ep->dma ? 0x10/*dma*/ : 0x11/*pio*/) << ep->num;
		tmp |= readl(&regs->EPxBCS);
		writel(tmp, &regs->EPxBCS);
	}
	writel(mode, ep->reg_mode);
	command(ep->dev->regs, COMMAND_RESET, ep->num);
	ep->ep.maxpacket = max;
	ep->stopped = 0;
	ep->desc = desc;
	spin_unlock_irqrestore(&ep->dev->lock, flags);

	DBG(dev, "enable %s %s %s maxpacket %u\n", ep->ep.name,
		ep->is_in ? "IN" : "OUT",
		ep->dma ? "dma" : "pio",
		max);

	return 0;
}

static void ep_reset(struct goku_udc_regs __iomem *regs, struct goku_ep *ep)
{
	struct goku_udc		*dev = ep->dev;

	if (regs) {
		command(regs, COMMAND_INVALID, ep->num);
		if (ep->num) {
			if (ep->num == UDC_MSTWR_ENDPOINT)
				dev->int_enable &= ~(INT_MSTWREND
							|INT_MSTWRTMOUT);
			else if (ep->num == UDC_MSTRD_ENDPOINT)
				dev->int_enable &= ~INT_MSTRDEND;
			dev->int_enable &= ~INT_EPxDATASET (ep->num);
		} else
			dev->int_enable &= ~INT_EP0;
		writel(dev->int_enable, &regs->int_enable);
		readl(&regs->int_enable);
		if (ep->num < 3) {
			struct goku_udc_regs __iomem	*r = ep->dev->regs;
			u32				tmp;

			tmp = readl(&r->EPxSingle);
			tmp &= ~(0x11 << ep->num);
			writel(tmp, &r->EPxSingle);

			tmp = readl(&r->EPxBCS);
			tmp &= ~(0x11 << ep->num);
			writel(tmp, &r->EPxBCS);
		}
		/* reset dma in case we're still using it */
		if (ep->dma) {
			u32	master;

			master = readl(&regs->dma_master) & MST_RW_BITS;
			if (ep->num == UDC_MSTWR_ENDPOINT) {
				master &= ~MST_W_BITS;
				master |= MST_WR_RESET;
			} else {
				master &= ~MST_R_BITS;
				master |= MST_RD_RESET;
			}
			writel(master, &regs->dma_master);
		}
	}

	ep->ep.maxpacket = MAX_FIFO_SIZE;
	ep->desc = NULL;
	ep->stopped = 1;
	ep->irqs = 0;
	ep->dma = 0;
}

static int goku_ep_disable(struct usb_ep *_ep)
{
	struct goku_ep	*ep;
	struct goku_udc	*dev;
	unsigned long	flags;

	ep = container_of(_ep, struct goku_ep, ep);
	if (!_ep || !ep->desc)
		return -ENODEV;
	dev = ep->dev;
	if (dev->ep0state == EP0_SUSPEND)
		return -EBUSY;

	VDBG(dev, "disable %s\n", _ep->name);

	spin_lock_irqsave(&dev->lock, flags);
	nuke(ep, -ESHUTDOWN);
	ep_reset(dev->regs, ep);
	spin_unlock_irqrestore(&dev->lock, flags);

	return 0;
}

/*-------------------------------------------------------------------------*/

static struct usb_request *
goku_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
	struct goku_request	*req;

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

	req->req.dma = DMA_ADDR_INVALID;
	INIT_LIST_HEAD(&req->queue);
	return &req->req;
}

static void
goku_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
	struct goku_request	*req;

	if (!_ep || !_req)
		return;

	req = container_of(_req, struct goku_request, req);
	WARN_ON(!list_empty(&req->queue));
	kfree(req);
}

/*-------------------------------------------------------------------------*/

static void
done(struct goku_ep *ep, struct goku_request *req, int status)
{
	struct goku_udc		*dev;
	unsigned		stopped = ep->stopped;

	list_del_init(&req->queue);

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

	dev = ep->dev;
	if (req->mapped) {
		pci_unmap_single(dev->pdev, req->req.dma, req->req.length,
			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
		req->req.dma = DMA_ADDR_INVALID;
		req->mapped = 0;
	}

#ifndef USB_TRACE
	if (status && status != -ESHUTDOWN)
#endif
		VDBG(dev, "complete %s req %p stat %d len %u/%u\n",
			ep->ep.name, &req->req, status,
			req->req.actual, req->req.length);

	/* don't modify queue heads during completion callback */
	ep->stopped = 1;
	spin_unlock(&dev->lock);
	req->req.complete(&ep->ep, &req->req);
	spin_lock(&dev->lock);
	ep->stopped = stopped;
}

/*-------------------------------------------------------------------------*/

static inline int
write_packet(u32 __iomem *fifo, u8 *buf, struct goku_request *req, unsigned max)
{
	unsigned	length, count;

	length = min(req->req.length - req->req.actual, max);
	req->req.actual += length;

	count = length;
	while (likely(count--))
		writel(*buf++, fifo);
	return length;
}

// return:  0 = still running, 1 = completed, negative = errno
static int write_fifo(struct goku_ep *ep, struct goku_request *req)
{
	struct goku_udc	*dev = ep->dev;
	u32		tmp;
	u8		*buf;
	unsigned	count;
	int		is_last;

	tmp = readl(&dev->regs->DataSet);
	buf = req->req.buf + req->req.actual;
	prefetch(buf);

	dev = ep->dev;
	if (unlikely(ep->num == 0 && dev->ep0state != EP0_IN))
		return -EL2HLT;

	/* NOTE:  just single-buffered PIO-IN for now.  */
	if (unlikely((tmp & DATASET_A(ep->num)) != 0))
		return 0;

	/* clear our "packet available" irq */
	if (ep->num != 0)
		writel(~INT_EPxDATASET(ep->num), &dev->regs->int_status);

	count = write_packet(ep->reg_fifo, buf, req, ep->ep.maxpacket);

	/* last packet often short (sometimes a zlp, especially on ep0) */
	if (unlikely(count != ep->ep.maxpacket)) {
		writel(~(1<<ep->num), &dev->regs->EOP);
		if (ep->num == 0) {
			dev->ep[0].stopped = 1;
			dev->ep0state = EP0_STATUS;
		}
		is_last = 1;
	} else {
		if (likely(req->req.length != req->req.actual)
				|| req->req.zero)
			is_last = 0;
		else
			is_last = 1;
	}
#if 0		/* printk seemed to trash is_last...*/
//#ifdef USB_TRACE
	VDBG(dev, "wrote %s %u bytes%s IN %u left %p\n",
		ep->ep.name, count, is_last ? "/last" : "",
		req->req.length - req->req.actual, req);
#endif

	/* requests complete when all IN data is in the FIFO,
	 * or sometimes later, if a zlp was needed.
	 */
	if (is_last) {
		done(ep, req, 0);
		return 1;
	}

	return 0;
}

static int read_fifo(struct goku_ep *ep, struct goku_request *req)
{
	struct goku_udc_regs __iomem	*regs;
	u32				size, set;
	u8				*buf;
	unsigned			bufferspace, is_short, dbuff;

	regs = ep->dev->regs;
top:
	buf = req->req.buf + req->req.actual;
	prefetchw(buf);

	if (unlikely(ep->num == 0 && ep->dev->ep0state != EP0_OUT))
		return -EL2HLT;

	dbuff = (ep->num == 1 || ep->num == 2);
	do {
		/* ack dataset irq matching the status we'll handle */
		if (ep->num != 0)
			writel(~INT_EPxDATASET(ep->num), &regs->int_status);

		set = readl(&regs->DataSet) & DATASET_AB(ep->num);
		size = readl(&regs->EPxSizeLA[ep->num]);
		bufferspace = req->req.length - req->req.actual;

		/* usually do nothing without an OUT packet */
		if (likely(ep->num != 0 || bufferspace != 0)) {
			if (unlikely(set == 0))
				break;
			/* use ep1/ep2 double-buffering for OUT */
			if (!(size & PACKET_ACTIVE))
				size = readl(&regs->EPxSizeLB[ep->num]);
			if (!(size & PACKET_ACTIVE))	/* "can't happen" */
				break;
			size &= DATASIZE;	/* EPxSizeH == 0 */

		/* ep0out no-out-data case for set_config, etc */
		} else
			size = 0;

		/* read all bytes from this packet */
		req->req.actual += size;
		is_short = (size < ep->ep.maxpacket);
#ifdef USB_TRACE
		VDBG(ep->dev, "read %s %u bytes%s OUT req %p %u/%u\n",
			ep->ep.name, size, is_short ? "/S" : "",
			req, req->req.actual, req->req.length);
#endif
		while (likely(size-- != 0)) {
			u8	byte = (u8) readl(ep->reg_fifo);

			if (unlikely(bufferspace == 0)) {
				/* this happens when the driver's buffer
				 * is smaller than what the host sent.
				 * discard the extra data in this packet.
				 */
				if (req->req.status != -EOVERFLOW)
					DBG(ep->dev, "%s overflow %u\n",
						ep->ep.name, size);
				req->req.status = -EOVERFLOW;
			} else {
				*buf++ = byte;
				bufferspace--;
			}
		}

		/* completion */
		if (unlikely(is_short || req->req.actual == req->req.length)) {
			if (unlikely(ep->num == 0)) {
				/* non-control endpoints now usable? */
				if (ep->dev->req_config)
					writel(ep->dev->configured
							? USBSTATE_CONFIGURED
							: 0,
						&regs->UsbState);
				/* ep0out status stage */
				writel(~(1<<0), &regs->EOP);
				ep->stopped = 1;
				ep->dev->ep0state = EP0_STATUS;
			}
			done(ep, req, 0);

			/* empty the second buffer asap */
			if (dbuff && !list_empty(&ep->queue)) {
				req = list_entry(ep->queue.next,
						struct goku_request, queue);
				goto top;
			}
			return 1;
		}
	} while (dbuff);
	return 0;
}

static inline void
pio_irq_enable(struct goku_udc *dev,
		struct goku_udc_regs __iomem *regs, int epnum)
{
	dev->int_enable |= INT_EPxDATASET (epnum);
	writel(dev->int_enable, &regs->int_enable);
	/* write may still be posted */
}

static inline void
pio_irq_disable(struct goku_udc *dev,
		struct goku_udc_regs __iomem *regs, int epnum)
{
	dev->int_enable &= ~INT_EPxDATASET (epnum);
	writel(dev->int_enable, &regs->int_enable);
	/* write may still be posted */
}

static inline void
pio_advance(struct goku_ep *ep)
{
	struct goku_request	*req;

	if (unlikely(list_empty (&ep->queue)))
		return;
	req = list_entry(ep->queue.next, struct goku_request, queue);
	(ep->is_in ? write_fifo : read_fifo)(ep, req);
}


/*-------------------------------------------------------------------------*/

// return:  0 = q running, 1 = q stopped, negative = errno
static int start_dma(struct goku_ep *ep, struct goku_request *req)
{
	struct goku_udc_regs __iomem	*regs = ep->dev->regs;
	u32				master;
	u32				start = req->req.dma;
	u32				end = start + req->req.length - 1;

	master = readl(&regs->dma_master) & MST_RW_BITS;

	/* re-init the bits affecting IN dma; careful with zlps */
	if (likely(ep->is_in)) {
		if (unlikely(master & MST_RD_ENA)) {
			DBG (ep->dev, "start, IN active dma %03x!!\n",
				master);
//			return -EL2HLT;
		}
		writel(end, &regs->in_dma_end);
		writel(start, &regs->in_dma_start);

		master &= ~MST_R_BITS;
		if (unlikely(req->req.length == 0))
			master = MST_RD_ENA | MST_RD_EOPB;
		else if ((req->req.length % ep->ep.maxpacket) != 0
					|| req->req.zero)
			master = MST_RD_ENA | MST_EOPB_ENA;
		else
			master = MST_RD_ENA | MST_EOPB_DIS;

		ep->dev->int_enable |= INT_MSTRDEND;

	/* Goku DMA-OUT merges short packets, which plays poorly with
	 * protocols where short packets mark the transfer boundaries.
	 * The chip supports a nonstandard policy with INT_MSTWRTMOUT,
	 * ending transfers after 3 SOFs; we don't turn it on.
	 */
	} else {
		if (unlikely(master & MST_WR_ENA)) {
			DBG (ep->dev, "start, OUT active dma %03x!!\n",
				master);
//			return -EL2HLT;
		}
		writel(end, &regs->out_dma_end);
		writel(start, &regs->out_dma_start);

		master &= ~MST_W_BITS;
		master |= MST_WR_ENA | MST_TIMEOUT_DIS;

		ep->dev->int_enable |= INT_MSTWREND|INT_MSTWRTMOUT;
	}

	writel(master, &regs->dma_master);
	writel(ep->dev->int_enable, &regs->int_enable);
	return 0;
}

static void dma_advance(struct goku_udc *dev, struct goku_ep *ep)
{
	struct goku_request		*req;
	struct goku_udc_regs __iomem	*regs = ep->dev->regs;
	u32				master;

	master = readl(&regs->dma_master);

	if (unlikely(list_empty(&ep->queue))) {
stop:
		if (ep->is_in)
			dev->int_enable &= ~INT_MSTRDEND;
		else
			dev->int_enable &= ~(INT_MSTWREND|INT_MSTWRTMOUT);
		writel(dev->int_enable, &regs->int_enable);
		return;
	}
	req = list_entry(ep->queue.next, struct goku_request, queue);

	/* normal hw dma completion (not abort) */
	if (likely(ep->is_in)) {
		if (unlikely(master & MST_RD_ENA))
			return;
		req->req.actual = readl(&regs->in_dma_current);
	} else {
		if (unlikely(master & MST_WR_ENA))
			return;

		/* hardware merges short packets, and also hides packet
		 * overruns.  a partial packet MAY be in the fifo here.
		 */
		req->req.actual = readl(&regs->out_dma_current);
	}
	req->req.actual -= req->req.dma;
	req->req.actual++;

#ifdef USB_TRACE
	VDBG(dev, "done %s %s dma, %u/%u bytes, req %p\n",
		ep->ep.name, ep->is_in ? "IN" : "OUT",
		req->req.actual, req->req.length, req);
#endif
	done(ep, req, 0);
	if (list_empty(&ep->queue))
		goto stop;
	req = list_entry(ep->queue.next, struct goku_request, queue);
	(void) start_dma(ep, req);
}

static void abort_dma(struct goku_ep *ep, int status)
{
	struct goku_udc_regs __iomem	*regs = ep->dev->regs;
	struct goku_request		*req;
	u32				curr, master;

	/* NAK future host requests, hoping the implicit delay lets the
	 * dma engine finish reading (or writing) its latest packet and
	 * empty the dma buffer (up to 16 bytes).
	 *
	 * This avoids needing to clean up a partial packet in the fifo;
	 * we can't do that for IN without side effects to HALT and TOGGLE.
	 */
	command(regs, COMMAND_FIFO_DISABLE, ep->num);
	req = list_entry(ep->queue.next, struct goku_request, queue);
	master = readl(&regs->dma_master) & MST_RW_BITS;

	/* FIXME using these resets isn't usably documented. this may
	 * not work unless it's followed by disabling the endpoint.
	 *
	 * FIXME the OUT reset path doesn't even behave consistently.
	 */
	if (ep->is_in) {
		if (unlikely((readl(&regs->dma_master) & MST_RD_ENA) == 0))
			goto finished;
		curr = readl(&regs->in_dma_current);

		writel(curr, &regs->in_dma_end);
		writel(curr, &regs->in_dma_start);

		master &= ~MST_R_BITS;
		master |= MST_RD_RESET;
		writel(master, &regs->dma_master);

		if (readl(&regs->dma_master) & MST_RD_ENA)
			DBG(ep->dev, "IN dma active after reset!\n");

	} else {
		if (unlikely((readl(&regs->dma_master) & MST_WR_ENA) == 0))
			goto finished;
		curr = readl(&regs->out_dma_current);

		writel(curr, &regs->out_dma_end);
		writel(curr, &regs->out_dma_start);

		master &= ~MST_W_BITS;
		master |= MST_WR_RESET;
		writel(master, &regs->dma_master);

		if (readl(&regs->dma_master) & MST_WR_ENA)
			DBG(ep->dev, "OUT dma active after reset!\n");
	}
	req->req.actual = (curr - req->req.dma) + 1;
	req->req.status = status;

	VDBG(ep->dev, "%s %s %s %d/%d\n", __func__, ep->ep.name,
		ep->is_in ? "IN" : "OUT",
		req->req.actual, req->req.length);

	command(regs, COMMAND_FIFO_ENABLE, ep->num);

	return;

finished:
	/* dma already completed; no abort needed */
	command(regs, COMMAND_FIFO_ENABLE, ep->num);
	req->req.actual = req->req.length;
	req->req.status = 0;
}

/*-------------------------------------------------------------------------*/

static int
goku_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
	struct goku_request	*req;
	struct goku_ep		*ep;
	struct goku_udc		*dev;
	unsigned long		flags;
	int			status;

	/* always require a cpu-view buffer so pio works */
	req = container_of(_req, struct goku_request, req);
	if (unlikely(!_req || !_req->complete
			|| !_req->buf || !list_empty(&req->queue)))
		return -EINVAL;
	ep = container_of(_ep, struct goku_ep, ep);
	if (unlikely(!_ep || (!ep->desc && ep->num != 0)))
		return -EINVAL;
	dev = ep->dev;
	if (unlikely(!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN))
		return -ESHUTDOWN;

	/* can't touch registers when suspended */
	if (dev->ep0state == EP0_SUSPEND)
		return -EBUSY;

	/* set up dma mapping in case the caller didn't */
	if (ep->dma && _req->dma == DMA_ADDR_INVALID) {
		_req->dma = pci_map_single(dev->pdev, _req->buf, _req->length,
			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
		req->mapped = 1;
	}

#ifdef USB_TRACE
	VDBG(dev, "%s queue req %p, len %u buf %p\n",
			_ep->name, _req, _req->length, _req->buf);
#endif

	spin_lock_irqsave(&dev->lock, flags);

	_req->status = -EINPROGRESS;
	_req->actual = 0;

	/* for ep0 IN without premature status, zlp is required and
	 * writing EOP starts the status stage (OUT).
	 */
	if (unlikely(ep->num == 0 && ep->is_in))
		_req->zero = 1;

	/* kickstart this i/o queue? */
	status = 0;
	if (list_empty(&ep->queue) && likely(!ep->stopped)) {
		/* dma:  done after dma completion IRQ (or error)
		 * pio:  done after last fifo operation
		 */
		if (ep->dma)
			status = start_dma(ep, req);
		else
			status = (ep->is_in ? write_fifo : read_fifo)(ep, req);

		if (unlikely(status != 0)) {
			if (status > 0)
				status = 0;
			req = NULL;
		}

	} /* else pio or dma irq handler advances the queue. */

	if (likely(req != 0))
		list_add_tail(&req->queue, &ep->queue);

	if (likely(!list_empty(&ep->queue))
			&& likely(ep->num != 0)
			&& !ep->dma
			&& !(dev->int_enable & INT_EPxDATASET (ep->num)))
		pio_irq_enable(dev, dev->regs, ep->num);

	spin_unlock_irqrestore(&dev->lock, flags);

	/* pci writes may still be posted */
	return status;
}

/* dequeue ALL requests */
static void nuke(struct goku_ep *ep, int status)
{
	struct goku_request	*req;

	ep->stopped = 1;
	if (list_empty(&ep->queue))
		return;
	if (ep->dma)
		abort_dma(ep, status);
	while (!list_empty(&ep->queue)) {
		req = list_entry(ep->queue.next, struct goku_request, queue);
		done(ep, req, status);
	}
}

/* dequeue JUST ONE request */
static int goku_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
	struct goku_request	*req;
	struct goku_ep		*ep;
	struct goku_udc		*dev;
	unsigned long		flags;

	ep = container_of(_ep, struct goku_ep, ep);
	if (!_ep || !_req || (!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 == EP0_SUSPEND)
		return -EBUSY;

	VDBG(dev, "%s %s %s %s %p\n", __func__, _ep->name,
		ep->is_in ? "IN" : "OUT",
		ep->dma ? "dma" : "pio",
		_req);

	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) {
		spin_unlock_irqrestore (&dev->lock, flags);
		return -EINVAL;
	}

	if (ep->dma && ep->queue.next == &req->queue && !ep->stopped) {
		abort_dma(ep, -ECONNRESET);
		done(ep, req, -ECONNRESET);
		dma_advance(dev, ep);
	} else if (!list_empty(&req->queue))
		done(ep, req, -ECONNRESET);
	else
		req = NULL;
	spin_unlock_irqrestore(&dev->lock, flags);

	return req ? 0 : -EOPNOTSUPP;
}

/*-------------------------------------------------------------------------*/

static void goku_clear_halt(struct goku_ep *ep)
{
	// assert (ep->num !=0)
	VDBG(ep->dev, "%s clear halt\n", ep->ep.name);
	command(ep->dev->regs, COMMAND_SETDATA0, ep->num);
	command(ep->dev->regs, COMMAND_STALL_CLEAR, ep->num);
	if (ep->stopped) {
		ep->stopped = 0;
		if (ep->dma) {
			struct goku_request	*req;

			if (list_empty(&ep->queue))
				return;
			req = list_entry(ep->queue.next, struct goku_request,
						queue);
			(void) start_dma(ep, req);
		} else
			pio_advance(ep);
	}
}

static int goku_set_halt(struct usb_ep *_ep, int value)
{
	struct goku_ep	*ep;
	unsigned long	flags;
	int		retval = 0;

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

	if (ep->num == 0) {
		if (value) {
			ep->dev->ep0state = EP0_STALL;
			ep->dev->ep[0].stopped = 1;
		} else
			return -EINVAL;

	/* don't change EPxSTATUS_EP_INVALID to READY */
	} else if (!ep->desc) {
		DBG(ep->dev, "%s %s inactive?\n", __func__, ep->ep.name);
		return -EINVAL;
	}

	spin_lock_irqsave(&ep->dev->lock, flags);
	if (!list_empty(&ep->queue))
		retval = -EAGAIN;
	else if (ep->is_in && value
			/* data in (either) packet buffer? */
			&& (readl(&ep->dev->regs->DataSet)
					& DATASET_AB(ep->num)))
		retval = -EAGAIN;
	else if (!value)
		goku_clear_halt(ep);
	else {
		ep->stopped = 1;
		VDBG(ep->dev, "%s set halt\n", ep->ep.name);
		command(ep->dev->regs, COMMAND_STALL, ep->num);
		readl(ep->reg_status);
	}
	spin_unlock_irqrestore(&ep->dev->lock, flags);
	return retval;
}

static int goku_fifo_status(struct usb_ep *_ep)
{
	struct goku_ep			*ep;
	struct goku_udc_regs __iomem	*regs;
	u32				size;

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

	/* size is only reported sanely for OUT */
	if (ep->is_in)
		return -EOPNOTSUPP;

	/* ignores 16-byte dma buffer; SizeH == 0 */
	regs = ep->dev->regs;
	size = readl(&regs->EPxSizeLA[ep->num]) & DATASIZE;
	size += readl(&regs->EPxSizeLB[ep->num]) & DATASIZE;
	VDBG(ep->dev, "%s %s %u\n", __func__, ep->ep.name, size);
	return size;
}

static void goku_fifo_flush(struct usb_ep *_ep)
{
	struct goku_ep			*ep;
	struct goku_udc_regs __iomem	*regs;
	u32				size;

	if (!_ep)
		return;
	ep = container_of(_ep, struct goku_ep, ep);
	VDBG(ep->dev, "%s %s\n", __func__, ep->ep.name);

	/* don't change EPxSTATUS_EP_INVALID to READY */
	if (!ep->desc && ep->num != 0) {
		DBG(ep->dev, "%s %s inactive?\n", __func__, ep->ep.name);
		return;
	}

	regs = ep->dev->regs;
	size = readl(&regs->EPxSizeLA[ep->num]);
	size &= DATASIZE;

	/* Non-desirable behavior:  FIFO_CLEAR also clears the
	 * endpoint halt feature.  For OUT, we _could_ just read
	 * the bytes out (PIO, if !ep->dma); for in, no choice.
	 */
	if (size)
		command(regs, COMMAND_FIFO_CLEAR, ep->num);
}

static struct usb_ep_ops goku_ep_ops = {
	.enable		= goku_ep_enable,
	.disable	= goku_ep_disable,

	.alloc_request	= goku_alloc_request,
	.free_request	= goku_free_request,

	.queue		= goku_queue,
	.dequeue	= goku_dequeue,

	.set_halt	= goku_set_halt,
	.fifo_status	= goku_fifo_status,
	.fifo_flush	= goku_fifo_flush,
};

/*-------------------------------------------------------------------------*/

static int goku_get_frame(struct usb_gadget *_gadget)
{
	return -EOPNOTSUPP;
}

static const struct usb_gadget_ops goku_ops = {
	.get_frame	= goku_get_frame,
	// no remote wakeup
	// not selfpowered
};

/*-------------------------------------------------------------------------*/

static inline char *dmastr(void)
{
	if (use_dma == 0)
		return "(dma disabled)";
	else if (use_dma == 2)
		return "(dma IN and OUT)";
	else
		return "(dma IN)";
}

#ifdef CONFIG_USB_GADGET_DEBUG_FILES

static const char proc_node_name [] = "driver/udc";

#define FOURBITS "%s%s%s%s"
#define EIGHTBITS FOURBITS FOURBITS

static void
dump_intmask(const char *label, u32 mask, char **next, unsigned *size)
{
	int t;

	/* int_status is the same format ... */
	t = scnprintf(*next, *size,
		"%s %05X =" FOURBITS EIGHTBITS EIGHTBITS "\n",
		label, mask,
		(mask & INT_PWRDETECT) ? " power" : "",
		(mask & INT_SYSERROR) ? " sys" : "",
		(mask & INT_MSTRDEND) ? " in-dma" : "",
		(mask & INT_MSTWRTMOUT) ? " wrtmo" : "",

		(mask & INT_MSTWREND) ? " out-dma" : "",
		(mask & INT_MSTWRSET) ? " wrset" : "",
		(mask & INT_ERR) ? " err" : "",
		(mask & INT_SOF) ? " sof" : "",

		(mask & INT_EP3NAK) ? " ep3nak" : "",
		(mask & INT_EP2NAK) ? " ep2nak" : "",
		(mask & INT_EP1NAK) ? " ep1nak" : "",
		(mask & INT_EP3DATASET) ? " ep3" : "",

		(mask & INT_EP2DATASET) ? " ep2" : "",
		(mask & INT_EP1DATASET) ? " ep1" : "",
		(mask & INT_STATUSNAK) ? " ep0snak" : "",
		(mask & INT_STATUS) ? " ep0status" : "",

		(mask & INT_SETUP) ? " setup" : "",
		(mask & INT_ENDPOINT0) ? " ep0" : "",
		(mask & INT_USBRESET) ? " reset" : "",
		(mask & INT_SUSPEND) ? " suspend" : "");
	*size -= t;
	*next += t;
}


static int
udc_proc_read(char *buffer, char **start, off_t off, int count,
		int *eof, void *_dev)
{
	char				*buf = buffer;
	struct goku_udc			*dev = _dev;
	struct goku_udc_regs __iomem	*regs = dev->regs;
	char				*next = buf;
	unsigned			size = count;
	unsigned long			flags;
	int				i, t, is_usb_connected;
	u32				tmp;

	if (off != 0)
		return 0;

	local_irq_save(flags);

	/* basic device status */
	tmp = readl(&regs->power_detect);
	is_usb_connected = tmp & PW_DETECT;
	t = scnprintf(next, size,
		"%s - %s\n"
		"%s version: %s %s\n"
		"Gadget driver: %s\n"
		"Host %s, %s\n"
		"\n",
		pci_name(dev->pdev), driver_desc,
		driver_name, DRIVER_VERSION, dmastr(),
		dev->driver ? dev->driver->driver.name : "(none)",
		is_usb_connected
			? ((tmp & PW_PULLUP) ? "full speed" : "powered")
			: "disconnected",
		({char *state;
		switch(dev->ep0state){
		case EP0_DISCONNECT:	state = "ep0_disconnect"; break;
		case EP0_IDLE:		state = "ep0_idle"; break;
		case EP0_IN:		state = "ep0_in"; break;
		case EP0_OUT:		state = "ep0_out"; break;
		case EP0_STATUS:	state = "ep0_status"; break;
		case EP0_STALL:		state = "ep0_stall"; break;
		case EP0_SUSPEND:	state = "ep0_suspend"; break;
		default:		state = "ep0_?"; break;
		} state; })
		);
	size -= t;
	next += t;

	dump_intmask("int_status", readl(&regs->int_status), &next, &size);
	dump_intmask("int_enable", readl(&regs->int_enable), &next, &size);

	if (!is_usb_connected || !dev->driver || (tmp & PW_PULLUP) == 0)
		goto done;

	/* registers for (active) device and ep0 */
	t = scnprintf(next, size, "\nirqs %lu\ndataset %02x "
			"single.bcs %02x.%02x state %x addr %u\n",
			dev->irqs, readl(&regs->DataSet),
			readl(&regs->EPxSingle), readl(&regs->EPxBCS),
			readl(&regs->UsbState),
			readl(&regs->address));
	size -= t;
	next += t;

	tmp = readl(&regs->dma_master);
	t = scnprintf(next, size,
		"dma %03X =" EIGHTBITS "%s %s\n", tmp,
		(tmp & MST_EOPB_DIS) ? " eopb-" : "",
		(tmp & MST_EOPB_ENA) ? " eopb+" : "",
		(tmp & MST_TIMEOUT_DIS) ? " tmo-" : "",
		(tmp & MST_TIMEOUT_ENA) ? " tmo+" : "",

		(tmp & MST_RD_EOPB) ? " eopb" : "",
		(tmp & MST_RD_RESET) ? " in_reset" : "",
		(tmp & MST_WR_RESET) ? " out_reset" : "",
		(tmp & MST_RD_ENA) ? " IN" : "",

		(tmp & MST_WR_ENA) ? " OUT" : "",
		(tmp & MST_CONNECTION)
			? "ep1in/ep2out"
			: "ep1out/ep2in");
	size -= t;
	next += t;

	/* dump endpoint queues */
	for (i = 0; i < 4; i++) {
		struct goku_ep		*ep = &dev->ep [i];
		struct goku_request	*req;

		if (i && !ep->desc)
			continue;

		tmp = readl(ep->reg_status);
		t = scnprintf(next, size,
			"%s %s max %u %s, irqs %lu, "
			"status %02x (%s) " FOURBITS "\n",
			ep->ep.name,
			ep->is_in ? "in" : "out",
			ep->ep.maxpacket,
			ep->dma ? "dma" : "pio",
			ep->irqs,
			tmp, ({ char *s;
			switch (tmp & EPxSTATUS_EP_MASK) {
			case EPxSTATUS_EP_READY:
				s = "ready"; break;
			case EPxSTATUS_EP_DATAIN:
				s = "packet"; break;
			case EPxSTATUS_EP_FULL:
				s = "full"; break;
			case EPxSTATUS_EP_TX_ERR:	// host will retry
				s = "tx_err"; break;
			case EPxSTATUS_EP_RX_ERR:
				s = "rx_err"; break;
			case EPxSTATUS_EP_BUSY:		/* ep0 only */
				s = "busy"; break;
			case EPxSTATUS_EP_STALL:
				s = "stall"; break;
			case EPxSTATUS_EP_INVALID:	// these "can't happen"
				s = "invalid"; break;
			default:
				s = "?"; break;
			}; s; }),
			(tmp & EPxSTATUS_TOGGLE) ? "data1" : "data0",
			(tmp & EPxSTATUS_SUSPEND) ? " suspend" : "",
			(tmp & EPxSTATUS_FIFO_DISABLE) ? " disable" : "",
			(tmp & EPxSTATUS_STAGE_ERROR) ? " ep0stat" : ""
			);
		if (t <= 0 || t > size)
			goto done;
		size -= t;
		next += t;

		if (list_empty(&ep->queue)) {
			t = scnprintf(next, size, "\t(nothing queued)\n");
			if (t <= 0 || t > size)
				goto done;
			size -= t;
			next += t;
			continue;
		}
		list_for_each_entry(req, &ep->queue, queue) {
			if (ep->dma && req->queue.prev == &ep->queue) {
				if (i == UDC_MSTRD_ENDPOINT)
					tmp = readl(&regs->in_dma_current);
				else
					tmp = readl(&regs->out_dma_current);
				tmp -= req->req.dma;
				tmp++;
			} else
				tmp = req->req.actual;

			t = scnprintf(next, size,
				"\treq %p len %u/%u buf %p\n",
				&req->req, tmp, req->req.length,
				req->req.buf);
			if (t <= 0 || t > size)
				goto done;
			size -= t;
			next += t;
		}
	}

done:
	local_irq_restore(flags);
	*eof = 1;
	return count - size;
}

#endif	/* CONFIG_USB_GADGET_DEBUG_FILES */

/*-------------------------------------------------------------------------*/

static void udc_reinit (struct goku_udc *dev)
{
	static char *names [] = { "ep0", "ep1-bulk", "ep2-bulk", "ep3-bulk" };

	unsigned i;

	INIT_LIST_HEAD (&dev->gadget.ep_list);
	dev->gadget.ep0 = &dev->ep [0].ep;
	dev->gadget.speed = USB_SPEED_UNKNOWN;
	dev->ep0state = EP0_DISCONNECT;
	dev->irqs = 0;

	for (i = 0; i < 4; i++) {
		struct goku_ep	*ep = &dev->ep[i];

		ep->num = i;
		ep->ep.name = names[i];
		ep->reg_fifo = &dev->regs->ep_fifo [i];
		ep->reg_status = &dev->regs->ep_status [i];
		ep->reg_mode = &dev->regs->ep_mode[i];

		ep->ep.ops = &goku_ep_ops;
		list_add_tail (&ep->ep.ep_list, &dev->gadget.ep_list);
		ep->dev = dev;
		INIT_LIST_HEAD (&ep->queue);

		ep_reset(NULL, ep);
	}

	dev->ep[0].reg_mode = NULL;
	dev->ep[0].ep.maxpacket = MAX_EP0_SIZE;
	list_del_init (&dev->ep[0].ep.ep_list);
}

static void udc_reset(struct goku_udc *dev)
{
	struct goku_udc_regs __iomem	*regs = dev->regs;

	writel(0, &regs->power_detect);
	writel(0, &regs->int_enable);
	readl(&regs->int_enable);
	dev->int_enable = 0;

	/* deassert reset, leave USB D+ at hi-Z (no pullup)
	 * don't let INT_PWRDETECT sequence begin
	 */
	udelay(250);
	writel(PW_RESETB, &regs->power_detect);
	readl(&regs->int_enable);
}

static void ep0_start(struct goku_udc *dev)
{
	struct goku_udc_regs __iomem	*regs = dev->regs;
	unsigned			i;

	VDBG(dev, "%s\n", __func__);

	udc_reset(dev);
	udc_reinit (dev);
	//writel(MST_EOPB_ENA | MST_TIMEOUT_ENA, &regs->dma_master);

	/* hw handles set_address, set_feature, get_status; maybe more */
	writel(   G_REQMODE_SET_INTF | G_REQMODE_GET_INTF
		| G_REQMODE_SET_CONF | G_REQMODE_GET_CONF
		| G_REQMODE_GET_DESC
		| G_REQMODE_CLEAR_FEAT
		, &regs->reqmode);

	for (i = 0; i < 4; i++)
		dev->ep[i].irqs = 0;

	/* can't modify descriptors after writing UsbReady */
	for (i = 0; i < DESC_LEN; i++)
		writel(0, &regs->descriptors[i]);
	writel(0, &regs->UsbReady);

	/* expect ep0 requests when the host drops reset */
	writel(PW_RESETB | PW_PULLUP, &regs->power_detect);
	dev->int_enable = INT_DEVWIDE | INT_EP0;
	writel(dev->int_enable, &dev->regs->int_enable);
	readl(&regs->int_enable);
	dev->gadget.speed = USB_SPEED_FULL;
	dev->ep0state = EP0_IDLE;
}

static void udc_enable(struct goku_udc *dev)
{
	/* start enumeration now, or after power detect irq */
	if (readl(&dev->regs->power_detect) & PW_DETECT)
		ep0_start(dev);
	else {
		DBG(dev, "%s\n", __func__);
		dev->int_enable = INT_PWRDETECT;
		writel(dev->int_enable, &dev->regs->int_enable);
	}
}

/*-------------------------------------------------------------------------*/

/* keeping it simple:
 * - one bus driver, initted first;
 * - one function driver, initted second
 */

static struct goku_udc	*the_controller;

/* when a driver is successfully registered, it will receive
 * control requests including set_configuration(), which enables
 * non-control requests.  then usb traffic follows until a
 * disconnect is reported.  then a host may connect again, or
 * the driver might get unbound.
 */
int usb_gadget_register_driver(struct usb_gadget_driver *driver)
{
	struct goku_udc	*dev = the_controller;
	int			retval;

	if (!driver
			|| driver->speed < USB_SPEED_FULL
			|| !driver->bind
			|| !driver->disconnect
			|| !driver->setup)
		return -EINVAL;
	if (!dev)
		return -ENODEV;
	if (dev->driver)
		return -EBUSY;

	/* hook up the driver */
	driver->driver.bus = NULL;
	dev->driver = driver;
	dev->gadget.dev.driver = &driver->driver;
	retval = driver->bind(&dev->gadget);
	if (retval) {
		DBG(dev, "bind to driver %s --> error %d\n",
				driver->driver.name, retval);
		dev->driver = NULL;
		dev->gadget.dev.driver = NULL;
		return retval;
	}

	/* then enable host detection and ep0; and we're ready
	 * for set_configuration as well as eventual disconnect.
	 */
	udc_enable(dev);

	DBG(dev, "registered gadget driver '%s'\n", driver->driver.name);
	return 0;
}
EXPORT_SYMBOL(usb_gadget_register_driver);

static void
stop_activity(struct goku_udc *dev, struct usb_gadget_driver *driver)
{
	unsigned	i;

	DBG (dev, "%s\n", __func__);

	if (dev->gadget.speed == USB_SPEED_UNKNOWN)
		driver = NULL;

	/* disconnect gadget driver after quiesceing hw and the driver */
	udc_reset (dev);
	for (i = 0; i < 4; i++)
		nuke(&dev->ep [i], -ESHUTDOWN);
	if (driver) {
		spin_unlock(&dev->lock);
		driver->disconnect(&dev->gadget);
		spin_lock(&dev->lock);
	}

	if (dev->driver)
		udc_enable(dev);
}

int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
{
	struct goku_udc	*dev = the_controller;
	unsigned long	flags;

	if (!dev)
		return -ENODEV;
	if (!driver || driver != dev->driver || !driver->unbind)
		return -EINVAL;

	spin_lock_irqsave(&dev->lock, flags);
	dev->driver = NULL;
	stop_activity(dev, driver);
	spin_unlock_irqrestore(&dev->lock, flags);

	driver->unbind(&dev->gadget);
	dev->gadget.dev.driver = NULL;

	DBG(dev, "unregistered driver '%s'\n", driver->driver.name);
	return 0;
}
EXPORT_SYMBOL(usb_gadget_unregister_driver);


/*-------------------------------------------------------------------------*/

static void ep0_setup(struct goku_udc *dev)
{
	struct goku_udc_regs __iomem	*regs = dev->regs;
	struct usb_ctrlrequest		ctrl;
	int				tmp;

	/* read SETUP packet and enter DATA stage */
	ctrl.bRequestType = readl(&regs->bRequestType);
	ctrl.bRequest = readl(&regs->bRequest);
	ctrl.wValue  = cpu_to_le16((readl(&regs->wValueH)  << 8)
					| readl(&regs->wValueL));
	ctrl.wIndex  = cpu_to_le16((readl(&regs->wIndexH)  << 8)
					| readl(&regs->wIndexL));
	ctrl.wLength = cpu_to_le16((readl(&regs->wLengthH) << 8)
					| readl(&regs->wLengthL));
	writel(0, &regs->SetupRecv);

	nuke(&dev->ep[0], 0);
	dev->ep[0].stopped = 0;
	if (likely(ctrl.bRequestType & USB_DIR_IN)) {
		dev->ep[0].is_in = 1;
		dev->ep0state = EP0_IN;
		/* detect early status stages */
		writel(ICONTROL_STATUSNAK, &dev->regs->IntControl);
	} else {
		dev->ep[0].is_in = 0;
		dev->ep0state = EP0_OUT;

		/* NOTE:  CLEAR_FEATURE is done in software so that we can
		 * synchronize transfer restarts after bulk IN stalls.  data
		 * won't even enter the fifo until the halt is cleared.
		 */
		switch (ctrl.bRequest) {
		case USB_REQ_CLEAR_FEATURE:
			switch (ctrl.bRequestType) {
			case USB_RECIP_ENDPOINT:
				tmp = le16_to_cpu(ctrl.wIndex) & 0x0f;
				/* active endpoint */
				if (tmp > 3 || (!dev->ep[tmp].desc && tmp != 0))
					goto stall;
				if (ctrl.wIndex & cpu_to_le16(
						USB_DIR_IN)) {
					if (!dev->ep[tmp].is_in)
						goto stall;
				} else {
					if (dev->ep[tmp].is_in)
						goto stall;
				}
				if (ctrl.wValue != cpu_to_le16(
						USB_ENDPOINT_HALT))
					goto stall;
				if (tmp)
					goku_clear_halt(&dev->ep[tmp]);
succeed:
				/* start ep0out status stage */
				writel(~(1<<0), &regs->EOP);
				dev->ep[0].stopped = 1;
				dev->ep0state = EP0_STATUS;
				return;
			case USB_RECIP_DEVICE:
				/* device remote wakeup: always clear */
				if (ctrl.wValue != cpu_to_le16(1))
					goto stall;
				VDBG(dev, "clear dev remote wakeup\n");
				goto succeed;
			case USB_RECIP_INTERFACE:
				goto stall;
			default:		/* pass to gadget driver */
				break;
			}
			break;
		default:
			break;
		}
	}

#ifdef USB_TRACE
	VDBG(dev, "SETUP %02x.%02x v%04x i%04x l%04x\n",
		ctrl.bRequestType, ctrl.bRequest,
		le16_to_cpu(ctrl.wValue), le16_to_cpu(ctrl.wIndex),
		le16_to_cpu(ctrl.wLength));
#endif

	/* hw wants to know when we're configured (or not) */
	dev->req_config = (ctrl.bRequest == USB_REQ_SET_CONFIGURATION
				&& ctrl.bRequestType == USB_RECIP_DEVICE);
	if (unlikely(dev->req_config))
		dev->configured = (ctrl.wValue != cpu_to_le16(0));

	/* delegate everything to the gadget driver.
	 * it may respond after this irq handler returns.
	 */
	spin_unlock (&dev->lock);
	tmp = dev->driver->setup(&dev->gadget, &ctrl);
	spin_lock (&dev->lock);
	if (unlikely(tmp < 0)) {
stall:
#ifdef USB_TRACE
		VDBG(dev, "req %02x.%02x protocol STALL; err %d\n",
				ctrl.bRequestType, ctrl.bRequest, tmp);
#endif
		command(regs, COMMAND_STALL, 0);
		dev->ep[0].stopped = 1;
		dev->ep0state = EP0_STALL;
	}

	/* expect at least one data or status stage irq */
}

#define ACK(irqbit) { \
		stat &= ~irqbit; \
		writel(~irqbit, &regs->int_status); \
		handled = 1; \
		}

static irqreturn_t goku_irq(int irq, void *_dev)
{
	struct goku_udc			*dev = _dev;
	struct goku_udc_regs __iomem	*regs = dev->regs;
	struct goku_ep			*ep;
	u32				stat, handled = 0;
	unsigned			i, rescans = 5;

	spin_lock(&dev->lock);

rescan:
	stat = readl(&regs->int_status) & dev->int_enable;
        if (!stat)
		goto done;
	dev->irqs++;

	/* device-wide irqs */
	if (unlikely(stat & INT_DEVWIDE)) {
		if (stat & INT_SYSERROR) {
			ERROR(dev, "system error\n");
			stop_activity(dev, dev->driver);
			stat = 0;
			handled = 1;
			// FIXME have a neater way to prevent re-enumeration
			dev->driver = NULL;
			goto done;
		}
		if (stat & INT_PWRDETECT) {
			writel(~stat, &regs->int_status);
			if (readl(&dev->regs->power_detect) & PW_DETECT) {
				VDBG(dev, "connect\n");
				ep0_start(dev);
			} else {
				DBG(dev, "disconnect\n");
				if (dev->gadget.speed == USB_SPEED_FULL)
					stop_activity(dev, dev->driver);
				dev->ep0state = EP0_DISCONNECT;
				dev->int_enable = INT_DEVWIDE;
				writel(dev->int_enable, &dev->regs->int_enable);
			}
			stat = 0;
			handled = 1;
			goto done;
		}
		if (stat & INT_SUSPEND) {
			ACK(INT_SUSPEND);
			if (readl(&regs->ep_status[0]) & EPxSTATUS_SUSPEND) {
				switch (dev->ep0state) {
				case EP0_DISCONNECT:
				case EP0_SUSPEND:
					goto pm_next;
				default:
					break;
				}
				DBG(dev, "USB suspend\n");
				dev->ep0state = EP0_SUSPEND;
				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);
				}
			} else {
				if (dev->ep0state != EP0_SUSPEND) {
					DBG(dev, "bogus USB resume %d\n",
						dev->ep0state);
					goto pm_next;
				}
				DBG(dev, "USB resume\n");
				dev->ep0state = EP0_IDLE;
				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);
				}
			}
		}
pm_next:
		if (stat & INT_USBRESET) {		/* hub reset done */
			ACK(INT_USBRESET);
			INFO(dev, "USB reset done, gadget %s\n",
				dev->driver->driver.name);
		}
		// and INT_ERR on some endpoint's crc/bitstuff/... problem
	}

	/* progress ep0 setup, data, or status stages.
	 * no transition {EP0_STATUS, EP0_STALL} --> EP0_IDLE; saves irqs
	 */
	if (stat & INT_SETUP) {
		ACK(INT_SETUP);
		dev->ep[0].irqs++;
		ep0_setup(dev);
	}
        if (stat & INT_STATUSNAK) {
		ACK(INT_STATUSNAK|INT_ENDPOINT0);
		if (dev->ep0state == EP0_IN) {
			ep = &dev->ep[0];
			ep->irqs++;
			nuke(ep, 0);
			writel(~(1<<0), &regs->EOP);
			dev->ep0state = EP0_STATUS;
		}
	}
        if (stat & INT_ENDPOINT0) {
		ACK(INT_ENDPOINT0);
		ep = &dev->ep[0];
		ep->irqs++;
		pio_advance(ep);
        }

	/* dma completion */
        if (stat & INT_MSTRDEND) {	/* IN */
		ACK(INT_MSTRDEND);
		ep = &dev->ep[UDC_MSTRD_ENDPOINT];
		ep->irqs++;
		dma_advance(dev, ep);
        }
        if (stat & INT_MSTWREND) {	/* OUT */
		ACK(INT_MSTWREND);
		ep = &dev->ep[UDC_MSTWR_ENDPOINT];
		ep->irqs++;
		dma_advance(dev, ep);
        }
        if (stat & INT_MSTWRTMOUT) {	/* OUT */
		ACK(INT_MSTWRTMOUT);
		ep = &dev->ep[UDC_MSTWR_ENDPOINT];
		ep->irqs++;
		ERROR(dev, "%s write timeout ?\n", ep->ep.name);
		// reset dma? then dma_advance()
        }

	/* pio */
	for (i = 1; i < 4; i++) {
		u32		tmp = INT_EPxDATASET(i);

		if (!(stat & tmp))
			continue;
		ep = &dev->ep[i];
		pio_advance(ep);
		if (list_empty (&ep->queue))
			pio_irq_disable(dev, regs, i);
		stat &= ~tmp;
		handled = 1;
		ep->irqs++;
	}

	if (rescans--)
		goto rescan;

done:
	(void)readl(&regs->int_enable);
	spin_unlock(&dev->lock);
	if (stat)
		DBG(dev, "unhandled irq status: %05x (%05x, %05x)\n", stat,
				readl(&regs->int_status), dev->int_enable);
	return IRQ_RETVAL(handled);
}

#undef ACK

/*-------------------------------------------------------------------------*/

static void gadget_release(struct device *_dev)
{
	struct goku_udc	*dev = dev_get_drvdata(_dev);

	kfree(dev);
}

/* tear down the binding between this driver and the pci device */

static void goku_remove(struct pci_dev *pdev)
{
	struct goku_udc		*dev = pci_get_drvdata(pdev);

	DBG(dev, "%s\n", __func__);

	BUG_ON(dev->driver);

#ifdef CONFIG_USB_GADGET_DEBUG_FILES
	remove_proc_entry(proc_node_name, NULL);
#endif
	if (dev->regs)
		udc_reset(dev);
	if (dev->got_irq)
		free_irq(pdev->irq, dev);
	if (dev->regs)
		iounmap(dev->regs);
	if (dev->got_region)
		release_mem_region(pci_resource_start (pdev, 0),
				pci_resource_len (pdev, 0));
	if (dev->enabled)
		pci_disable_device(pdev);
	device_unregister(&dev->gadget.dev);

	pci_set_drvdata(pdev, NULL);
	dev->regs = NULL;
	the_controller = NULL;

	INFO(dev, "unbind\n");
}

/* wrap this driver around the specified pci device, but
 * don't respond over USB until a gadget driver binds to us.
 */

static int goku_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	struct goku_udc		*dev = NULL;
	unsigned long		resource, len;
	void __iomem		*base = NULL;
	int			retval;

	/* if you want to support more than one controller in a system,
	 * usb_gadget_driver_{register,unregister}() must change.
	 */
	if (the_controller) {
		pr_warning("ignoring %s\n", pci_name(pdev));
		return -EBUSY;
	}
	if (!pdev->irq) {
		printk(KERN_ERR "Check PCI %s IRQ setup!\n", pci_name(pdev));
		retval = -ENODEV;
		goto done;
	}

	/* alloc, and start init */
	dev = kzalloc (sizeof *dev, GFP_KERNEL);
	if (dev == NULL){
		pr_debug("enomem %s\n", pci_name(pdev));
		retval = -ENOMEM;
		goto done;
	}

	spin_lock_init(&dev->lock);
	dev->pdev = pdev;
	dev->gadget.ops = &goku_ops;

	/* the "gadget" abstracts/virtualizes the controller */
	dev_set_name(&dev->gadget.dev, "gadget");
	dev->gadget.dev.parent = &pdev->dev;
	dev->gadget.dev.dma_mask = pdev->dev.dma_mask;
	dev->gadget.dev.release = gadget_release;
	dev->gadget.name = driver_name;

	/* now all the pci goodies ... */
	retval = pci_enable_device(pdev);
	if (retval < 0) {
		DBG(dev, "can't enable, %d\n", retval);
		goto done;
	}
	dev->enabled = 1;

	resource = pci_resource_start(pdev, 0);
	len = pci_resource_len(pdev, 0);
	if (!request_mem_region(resource, len, driver_name)) {
		DBG(dev, "controller already in use\n");
		retval = -EBUSY;
		goto done;
	}
	dev->got_region = 1;

	base = ioremap_nocache(resource, len);
	if (base == NULL) {
		DBG(dev, "can't map memory\n");
		retval = -EFAULT;
		goto done;
	}
	dev->regs = (struct goku_udc_regs __iomem *) base;

	pci_set_drvdata(pdev, dev);
	INFO(dev, "%s\n", driver_desc);
	INFO(dev, "version: " DRIVER_VERSION " %s\n", dmastr());
	INFO(dev, "irq %d, pci mem %p\n", pdev->irq, base);

	/* init to known state, then setup irqs */
	udc_reset(dev);
	udc_reinit (dev);
	if (request_irq(pdev->irq, goku_irq, IRQF_SHARED/*|IRQF_SAMPLE_RANDOM*/,
			driver_name, dev) != 0) {
		DBG(dev, "request interrupt %d failed\n", pdev->irq);
		retval = -EBUSY;
		goto done;
	}
	dev->got_irq = 1;
	if (use_dma)
		pci_set_master(pdev);


#ifdef CONFIG_USB_GADGET_DEBUG_FILES
	create_proc_read_entry(proc_node_name, 0, NULL, udc_proc_read, dev);
#endif

	/* done */
	the_controller = dev;
	retval = device_register(&dev->gadget.dev);
	if (retval == 0)
		return 0;

done:
	if (dev)
		goku_remove (pdev);
	return retval;
}


/*-------------------------------------------------------------------------*/

static const struct pci_device_id pci_ids[] = { {
	.class =	((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
	.class_mask =	~0,
	.vendor =	0x102f,		/* Toshiba */
	.device =	0x0107,		/* this UDC */
	.subvendor =	PCI_ANY_ID,
	.subdevice =	PCI_ANY_ID,

}, { /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE (pci, pci_ids);

static struct pci_driver goku_pci_driver = {
	.name =		(char *) driver_name,
	.id_table =	pci_ids,

	.probe =	goku_probe,
	.remove =	goku_remove,

	/* FIXME add power management support */
};

static int __init init (void)
{
	return pci_register_driver (&goku_pci_driver);
}
module_init (init);

static void __exit cleanup (void)
{
	pci_unregister_driver (&goku_pci_driver);
}
module_exit (cleanup);
OpenPOWER on IntegriCloud