summaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/gmidi.c
blob: 14e09abbddfcb0463e701a08cc3ec48702686875 (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
/*
 * gmidi.c -- USB MIDI Gadget Driver
 *
 * Copyright (C) 2006 Thumtronics Pty Ltd.
 * Developed for Thumtronics by Grey Innovation
 * Ben Williamson <ben.williamson@greyinnovation.com>
 *
 * This software is distributed under the terms of the GNU General Public
 * License ("GPL") version 2, as published by the Free Software Foundation.
 *
 * This code is based in part on:
 *
 * Gadget Zero driver, Copyright (C) 2003-2004 David Brownell.
 * USB Audio driver, Copyright (C) 2002 by Takashi Iwai.
 * USB MIDI driver, Copyright (C) 2002-2005 Clemens Ladisch.
 *
 * Refer to the USB Device Class Definition for MIDI Devices:
 * http://www.usb.org/developers/devclass_docs/midi10.pdf
 */

/* #define VERBOSE_DEBUG */

#include <linux/kernel.h>
#include <linux/utsname.h>
#include <linux/device.h>

#include <sound/core.h>
#include <sound/initval.h>
#include <sound/rawmidi.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/audio.h>
#include <linux/usb/midi.h>

#include "gadget_chips.h"


/*
 * Kbuild is not very cooperative with respect to linking separately
 * compiled library objects into one module.  So for now we won't use
 * separate compilation ... ensuring init/exit sections work to shrink
 * the runtime footprint, and giving us at least some parts of what
 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 */
#include "usbstring.c"
#include "config.c"
#include "epautoconf.c"

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


MODULE_AUTHOR("Ben Williamson");
MODULE_LICENSE("GPL v2");

#define DRIVER_VERSION "25 Jul 2006"

static const char shortname[] = "g_midi";
static const char longname[] = "MIDI Gadget";

static int index = SNDRV_DEFAULT_IDX1;
static char *id = SNDRV_DEFAULT_STR1;

module_param(index, int, 0444);
MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");
module_param(id, charp, 0444);
MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");

/* Some systems will want different product identifers published in the
 * device descriptor, either numbers or strings or both.  These string
 * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
 */

static ushort idVendor;
module_param(idVendor, ushort, S_IRUGO);
MODULE_PARM_DESC(idVendor, "USB Vendor ID");

static ushort idProduct;
module_param(idProduct, ushort, S_IRUGO);
MODULE_PARM_DESC(idProduct, "USB Product ID");

static ushort bcdDevice;
module_param(bcdDevice, ushort, S_IRUGO);
MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");

static char *iManufacturer;
module_param(iManufacturer, charp, S_IRUGO);
MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");

static char *iProduct;
module_param(iProduct, charp, S_IRUGO);
MODULE_PARM_DESC(iProduct, "USB Product string");

static char *iSerialNumber;
module_param(iSerialNumber, charp, S_IRUGO);
MODULE_PARM_DESC(iSerialNumber, "SerialNumber");

/*
 * this version autoconfigures as much as possible,
 * which is reasonable for most "bulk-only" drivers.
 */
static const char *EP_IN_NAME;
static const char *EP_OUT_NAME;


/* big enough to hold our biggest descriptor */
#define USB_BUFSIZ 256


/* This is a gadget, and the IN/OUT naming is from the host's perspective.
   USB -> OUT endpoint -> rawmidi
   USB <- IN endpoint  <- rawmidi */
struct gmidi_in_port {
	struct gmidi_device* dev;
	int active;
	uint8_t cable;		/* cable number << 4 */
	uint8_t state;
#define STATE_UNKNOWN	0
#define STATE_1PARAM	1
#define STATE_2PARAM_1	2
#define STATE_2PARAM_2	3
#define STATE_SYSEX_0	4
#define STATE_SYSEX_1	5
#define STATE_SYSEX_2	6
	uint8_t data[2];
};

struct gmidi_device {
	spinlock_t		lock;
	struct usb_gadget	*gadget;
	struct usb_request	*req;		/* for control responses */
	u8			config;
	struct usb_ep		*in_ep, *out_ep;
	struct snd_card		*card;
	struct snd_rawmidi	*rmidi;
	struct snd_rawmidi_substream *in_substream;
	struct snd_rawmidi_substream *out_substream;

	/* For the moment we only support one port in
	   each direction, but in_port is kept as a
	   separate struct so we can have more later. */
	struct gmidi_in_port	in_port;
	unsigned long		out_triggered;
	struct tasklet_struct	tasklet;
};

static void gmidi_transmit(struct gmidi_device* dev, struct usb_request* req);


#define DBG(d, fmt, args...) \
	dev_dbg(&(d)->gadget->dev , fmt , ## args)
#define VDBG(d, fmt, args...) \
	dev_vdbg(&(d)->gadget->dev , fmt , ## args)
#define ERROR(d, fmt, args...) \
	dev_err(&(d)->gadget->dev , fmt , ## args)
#define INFO(d, fmt, args...) \
	dev_info(&(d)->gadget->dev , fmt , ## args)


static unsigned buflen = 256;
static unsigned qlen = 32;

module_param(buflen, uint, S_IRUGO);
module_param(qlen, uint, S_IRUGO);


/* Thanks to Grey Innovation for donating this product ID.
 *
 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 * Instead:  allocate your own, using normal USB-IF procedures.
 */
#define DRIVER_VENDOR_NUM	0x17b3		/* Grey Innovation */
#define DRIVER_PRODUCT_NUM	0x0004		/* Linux-USB "MIDI Gadget" */


/*
 * DESCRIPTORS ... most are static, but strings and (full)
 * configuration descriptors are built on demand.
 */

#define STRING_MANUFACTURER	25
#define STRING_PRODUCT		42
#define STRING_SERIAL		101
#define STRING_MIDI_GADGET	250

/* We only have the one configuration, it's number 1. */
#define	GMIDI_CONFIG		1

/* We have two interfaces- AudioControl and MIDIStreaming */
#define GMIDI_AC_INTERFACE	0
#define GMIDI_MS_INTERFACE	1
#define GMIDI_NUM_INTERFACES	2

DECLARE_USB_AC_HEADER_DESCRIPTOR(1);
DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(1);

/* B.1  Device Descriptor */
static struct usb_device_descriptor device_desc = {
	.bLength =		USB_DT_DEVICE_SIZE,
	.bDescriptorType =	USB_DT_DEVICE,
	.bcdUSB =		__constant_cpu_to_le16(0x0200),
	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
	.idVendor =		__constant_cpu_to_le16(DRIVER_VENDOR_NUM),
	.idProduct =		__constant_cpu_to_le16(DRIVER_PRODUCT_NUM),
	.iManufacturer =	STRING_MANUFACTURER,
	.iProduct =		STRING_PRODUCT,
	.bNumConfigurations =	1,
};

/* B.2  Configuration Descriptor */
static struct usb_config_descriptor config_desc = {
	.bLength =		USB_DT_CONFIG_SIZE,
	.bDescriptorType =	USB_DT_CONFIG,
	/* compute wTotalLength on the fly */
	.bNumInterfaces =	GMIDI_NUM_INTERFACES,
	.bConfigurationValue =	GMIDI_CONFIG,
	.iConfiguration =	STRING_MIDI_GADGET,
	/*
	 * FIXME: When embedding this driver in a device,
	 * these need to be set to reflect the actual
	 * power properties of the device. Is it selfpowered?
	 */
	.bmAttributes =		USB_CONFIG_ATT_ONE,
	.bMaxPower =		CONFIG_USB_GADGET_VBUS_DRAW / 2,
};

/* B.3.1  Standard AC Interface Descriptor */
static const struct usb_interface_descriptor ac_interface_desc = {
	.bLength =		USB_DT_INTERFACE_SIZE,
	.bDescriptorType =	USB_DT_INTERFACE,
	.bInterfaceNumber =	GMIDI_AC_INTERFACE,
	.bNumEndpoints =	0,
	.bInterfaceClass =	USB_CLASS_AUDIO,
	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
	.iInterface =		STRING_MIDI_GADGET,
};

/* B.3.2  Class-Specific AC Interface Descriptor */
static const struct usb_ac_header_descriptor_1 ac_header_desc = {
	.bLength =		USB_DT_AC_HEADER_SIZE(1),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_HEADER,
	.bcdADC =		__constant_cpu_to_le16(0x0100),
	.wTotalLength =		__constant_cpu_to_le16(USB_DT_AC_HEADER_SIZE(1)),
	.bInCollection =	1,
	.baInterfaceNr = {
		[0] =		GMIDI_MS_INTERFACE,
	}
};

/* B.4.1  Standard MS Interface Descriptor */
static const struct usb_interface_descriptor ms_interface_desc = {
	.bLength =		USB_DT_INTERFACE_SIZE,
	.bDescriptorType =	USB_DT_INTERFACE,
	.bInterfaceNumber =	GMIDI_MS_INTERFACE,
	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_AUDIO,
	.bInterfaceSubClass =	USB_SUBCLASS_MIDISTREAMING,
	.iInterface =		STRING_MIDI_GADGET,
};

/* B.4.2  Class-Specific MS Interface Descriptor */
static const struct usb_ms_header_descriptor ms_header_desc = {
	.bLength =		USB_DT_MS_HEADER_SIZE,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_HEADER,
	.bcdMSC =		__constant_cpu_to_le16(0x0100),
	.wTotalLength =		__constant_cpu_to_le16(USB_DT_MS_HEADER_SIZE
				+ 2*USB_DT_MIDI_IN_SIZE
				+ 2*USB_DT_MIDI_OUT_SIZE(1)),
};

#define JACK_IN_EMB	1
#define JACK_IN_EXT	2
#define JACK_OUT_EMB	3
#define JACK_OUT_EXT	4

/* B.4.3  MIDI IN Jack Descriptors */
static const struct usb_midi_in_jack_descriptor jack_in_emb_desc = {
	.bLength =		USB_DT_MIDI_IN_SIZE,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_MIDI_IN_JACK,
	.bJackType =		USB_MS_EMBEDDED,
	.bJackID =		JACK_IN_EMB,
};

static const struct usb_midi_in_jack_descriptor jack_in_ext_desc = {
	.bLength =		USB_DT_MIDI_IN_SIZE,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_MIDI_IN_JACK,
	.bJackType =		USB_MS_EXTERNAL,
	.bJackID =		JACK_IN_EXT,
};

/* B.4.4  MIDI OUT Jack Descriptors */
static const struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc = {
	.bLength =		USB_DT_MIDI_OUT_SIZE(1),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_MIDI_OUT_JACK,
	.bJackType =		USB_MS_EMBEDDED,
	.bJackID =		JACK_OUT_EMB,
	.bNrInputPins =		1,
	.pins = {
		[0] = {
			.baSourceID =	JACK_IN_EXT,
			.baSourcePin =	1,
		}
	}
};

static const struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc = {
	.bLength =		USB_DT_MIDI_OUT_SIZE(1),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_MIDI_OUT_JACK,
	.bJackType =		USB_MS_EXTERNAL,
	.bJackID =		JACK_OUT_EXT,
	.bNrInputPins =		1,
	.pins = {
		[0] = {
			.baSourceID =	JACK_IN_EMB,
			.baSourcePin =	1,
		}
	}
};

/* B.5.1  Standard Bulk OUT Endpoint Descriptor */
static struct usb_endpoint_descriptor bulk_out_desc = {
	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

/* B.5.2  Class-specific MS Bulk OUT Endpoint Descriptor */
static const struct usb_ms_endpoint_descriptor_1 ms_out_desc = {
	.bLength =		USB_DT_MS_ENDPOINT_SIZE(1),
	.bDescriptorType =	USB_DT_CS_ENDPOINT,
	.bDescriptorSubtype =	USB_MS_GENERAL,
	.bNumEmbMIDIJack =	1,
	.baAssocJackID = {
		[0] =		JACK_IN_EMB,
	}
};

/* B.6.1  Standard Bulk IN Endpoint Descriptor */
static struct usb_endpoint_descriptor bulk_in_desc = {
	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,
	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

/* B.6.2  Class-specific MS Bulk IN Endpoint Descriptor */
static const struct usb_ms_endpoint_descriptor_1 ms_in_desc = {
	.bLength =		USB_DT_MS_ENDPOINT_SIZE(1),
	.bDescriptorType =	USB_DT_CS_ENDPOINT,
	.bDescriptorSubtype =	USB_MS_GENERAL,
	.bNumEmbMIDIJack =	1,
	.baAssocJackID = {
		[0] =		JACK_OUT_EMB,
	}
};

static const struct usb_descriptor_header *gmidi_function [] = {
	(struct usb_descriptor_header *)&ac_interface_desc,
	(struct usb_descriptor_header *)&ac_header_desc,
	(struct usb_descriptor_header *)&ms_interface_desc,

	(struct usb_descriptor_header *)&ms_header_desc,
	(struct usb_descriptor_header *)&jack_in_emb_desc,
	(struct usb_descriptor_header *)&jack_in_ext_desc,
	(struct usb_descriptor_header *)&jack_out_emb_desc,
	(struct usb_descriptor_header *)&jack_out_ext_desc,
	/* If you add more jacks, update ms_header_desc.wTotalLength */

	(struct usb_descriptor_header *)&bulk_out_desc,
	(struct usb_descriptor_header *)&ms_out_desc,
	(struct usb_descriptor_header *)&bulk_in_desc,
	(struct usb_descriptor_header *)&ms_in_desc,
	NULL,
};

static char manufacturer[50];
static char product_desc[40] = "MIDI Gadget";
static char serial_number[20];

/* static strings, in UTF-8 */
static struct usb_string strings [] = {
	{ STRING_MANUFACTURER, manufacturer, },
	{ STRING_PRODUCT, product_desc, },
	{ STRING_SERIAL, serial_number, },
	{ STRING_MIDI_GADGET, longname, },
	{  }			/* end of list */
};

static struct usb_gadget_strings stringtab = {
	.language	= 0x0409,	/* en-us */
	.strings	= strings,
};

static int config_buf(struct usb_gadget *gadget,
		u8 *buf, u8 type, unsigned index)
{
	int len;

	/* only one configuration */
	if (index != 0) {
		return -EINVAL;
	}
	len = usb_gadget_config_buf(&config_desc,
			buf, USB_BUFSIZ, gmidi_function);
	if (len < 0) {
		return len;
	}
	((struct usb_config_descriptor *)buf)->bDescriptorType = type;
	return len;
}

static struct usb_request *alloc_ep_req(struct usb_ep *ep, unsigned length)
{
	struct usb_request	*req;

	req = usb_ep_alloc_request(ep, GFP_ATOMIC);
	if (req) {
		req->length = length;
		req->buf = kmalloc(length, GFP_ATOMIC);
		if (!req->buf) {
			usb_ep_free_request(ep, req);
			req = NULL;
		}
	}
	return req;
}

static void free_ep_req(struct usb_ep *ep, struct usb_request *req)
{
	kfree(req->buf);
	usb_ep_free_request(ep, req);
}

static const uint8_t gmidi_cin_length[] = {
	0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
};

/*
 * Receives a chunk of MIDI data.
 */
static void gmidi_read_data(struct usb_ep *ep, int cable,
				   uint8_t *data, int length)
{
	struct gmidi_device *dev = ep->driver_data;
	/* cable is ignored, because for now we only have one. */

	if (!dev->out_substream) {
		/* Nobody is listening - throw it on the floor. */
		return;
	}
	if (!test_bit(dev->out_substream->number, &dev->out_triggered)) {
		return;
	}
	snd_rawmidi_receive(dev->out_substream, data, length);
}

static void gmidi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
{
	unsigned i;
	u8 *buf = req->buf;

	for (i = 0; i + 3 < req->actual; i += 4) {
		if (buf[i] != 0) {
			int cable = buf[i] >> 4;
			int length = gmidi_cin_length[buf[i] & 0x0f];
			gmidi_read_data(ep, cable, &buf[i + 1], length);
		}
	}
}

static void gmidi_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct gmidi_device *dev = ep->driver_data;
	int status = req->status;

	switch (status) {
	case 0:				/* normal completion */
		if (ep == dev->out_ep) {
			/* we received stuff.
			   req is queued again, below */
			gmidi_handle_out_data(ep, req);
		} else if (ep == dev->in_ep) {
			/* our transmit completed.
			   see if there's more to go.
			   gmidi_transmit eats req, don't queue it again. */
			gmidi_transmit(dev, req);
			return;
		}
		break;

	/* this endpoint is normally active while we're configured */
	case -ECONNABORTED:		/* hardware forced ep reset */
	case -ECONNRESET:		/* request dequeued */
	case -ESHUTDOWN:		/* disconnect from host */
		VDBG(dev, "%s gone (%d), %d/%d\n", ep->name, status,
				req->actual, req->length);
		if (ep == dev->out_ep) {
			gmidi_handle_out_data(ep, req);
		}
		free_ep_req(ep, req);
		return;

	case -EOVERFLOW:		/* buffer overrun on read means that
					 * we didn't provide a big enough
					 * buffer.
					 */
	default:
		DBG(dev, "%s complete --> %d, %d/%d\n", ep->name,
				status, req->actual, req->length);
		break;
	case -EREMOTEIO:		/* short read */
		break;
	}

	status = usb_ep_queue(ep, req, GFP_ATOMIC);
	if (status) {
		ERROR(dev, "kill %s:  resubmit %d bytes --> %d\n",
				ep->name, req->length, status);
		usb_ep_set_halt(ep);
		/* FIXME recover later ... somehow */
	}
}

static int set_gmidi_config(struct gmidi_device *dev, gfp_t gfp_flags)
{
	int err = 0;
	struct usb_request *req;
	struct usb_ep *ep;
	unsigned i;

	err = usb_ep_enable(dev->in_ep, &bulk_in_desc);
	if (err) {
		ERROR(dev, "can't start %s: %d\n", dev->in_ep->name, err);
		goto fail;
	}
	dev->in_ep->driver_data = dev;

	err = usb_ep_enable(dev->out_ep, &bulk_out_desc);
	if (err) {
		ERROR(dev, "can't start %s: %d\n", dev->out_ep->name, err);
		goto fail;
	}
	dev->out_ep->driver_data = dev;

	/* allocate a bunch of read buffers and queue them all at once. */
	ep = dev->out_ep;
	for (i = 0; i < qlen && err == 0; i++) {
		req = alloc_ep_req(ep, buflen);
		if (req) {
			req->complete = gmidi_complete;
			err = usb_ep_queue(ep, req, GFP_ATOMIC);
			if (err) {
				DBG(dev, "%s queue req: %d\n", ep->name, err);
			}
		} else {
			err = -ENOMEM;
		}
	}
fail:
	/* caller is responsible for cleanup on error */
	return err;
}


static void gmidi_reset_config(struct gmidi_device *dev)
{
	if (dev->config == 0) {
		return;
	}

	DBG(dev, "reset config\n");

	/* just disable endpoints, forcing completion of pending i/o.
	 * all our completion handlers free their requests in this case.
	 */
	usb_ep_disable(dev->in_ep);
	usb_ep_disable(dev->out_ep);
	dev->config = 0;
}

/* change our operational config.  this code must agree with the code
 * that returns config descriptors, and altsetting code.
 *
 * it's also responsible for power management interactions. some
 * configurations might not work with our current power sources.
 *
 * note that some device controller hardware will constrain what this
 * code can do, perhaps by disallowing more than one configuration or
 * by limiting configuration choices (like the pxa2xx).
 */
static int
gmidi_set_config(struct gmidi_device *dev, unsigned number, gfp_t gfp_flags)
{
	int result = 0;
	struct usb_gadget *gadget = dev->gadget;

#if 0
	/* FIXME */
	/* Hacking this bit out fixes a bug where on receipt of two
	   USB_REQ_SET_CONFIGURATION messages, we end up with no
	   buffered OUT requests waiting for data. This is clearly
	   hiding a bug elsewhere, because if the config didn't
	   change then we really shouldn't do anything. */
	/* Having said that, when we do "change" from config 1
	   to config 1, we at least gmidi_reset_config() which
	   clears out any requests on endpoints, so it's not like
	   we leak or anything. */
	if (number == dev->config) {
		return 0;
	}
#endif

	if (gadget_is_sa1100(gadget) && dev->config) {
		/* tx fifo is full, but we can't clear it...*/
		ERROR(dev, "can't change configurations\n");
		return -ESPIPE;
	}
	gmidi_reset_config(dev);

	switch (number) {
	case GMIDI_CONFIG:
		result = set_gmidi_config(dev, gfp_flags);
		break;
	default:
		result = -EINVAL;
		/* FALL THROUGH */
	case 0:
		return result;
	}

	if (!result && (!dev->in_ep || !dev->out_ep)) {
		result = -ENODEV;
	}
	if (result) {
		gmidi_reset_config(dev);
	} else {
		char *speed;

		switch (gadget->speed) {
		case USB_SPEED_LOW:	speed = "low"; break;
		case USB_SPEED_FULL:	speed = "full"; break;
		case USB_SPEED_HIGH:	speed = "high"; break;
		default:		speed = "?"; break;
		}

		dev->config = number;
		INFO(dev, "%s speed\n", speed);
	}
	return result;
}


static void gmidi_setup_complete(struct usb_ep *ep, struct usb_request *req)
{
	if (req->status || req->actual != req->length) {
		DBG((struct gmidi_device *) ep->driver_data,
				"setup complete --> %d, %d/%d\n",
				req->status, req->actual, req->length);
	}
}

/*
 * The setup() callback implements all the ep0 functionality that's
 * not handled lower down, in hardware or the hardware driver (like
 * device and endpoint feature flags, and their status).  It's all
 * housekeeping for the gadget function we're implementing.  Most of
 * the work is in config-specific setup.
 */
static int gmidi_setup(struct usb_gadget *gadget,
			const struct usb_ctrlrequest *ctrl)
{
	struct gmidi_device *dev = get_gadget_data(gadget);
	struct usb_request *req = dev->req;
	int value = -EOPNOTSUPP;
	u16 w_index = le16_to_cpu(ctrl->wIndex);
	u16 w_value = le16_to_cpu(ctrl->wValue);
	u16 w_length = le16_to_cpu(ctrl->wLength);

	/* usually this stores reply data in the pre-allocated ep0 buffer,
	 * but config change events will reconfigure hardware.
	 */
	req->zero = 0;
	switch (ctrl->bRequest) {

	case USB_REQ_GET_DESCRIPTOR:
		if (ctrl->bRequestType != USB_DIR_IN) {
			goto unknown;
		}
		switch (w_value >> 8) {

		case USB_DT_DEVICE:
			value = min(w_length, (u16) sizeof(device_desc));
			memcpy(req->buf, &device_desc, value);
			break;
		case USB_DT_CONFIG:
			value = config_buf(gadget, req->buf,
					w_value >> 8,
					w_value & 0xff);
			if (value >= 0) {
				value = min(w_length, (u16)value);
			}
			break;

		case USB_DT_STRING:
			/* wIndex == language code.
			 * this driver only handles one language, you can
			 * add string tables for other languages, using
			 * any UTF-8 characters
			 */
			value = usb_gadget_get_string(&stringtab,
					w_value & 0xff, req->buf);
			if (value >= 0) {
				value = min(w_length, (u16)value);
			}
			break;
		}
		break;

	/* currently two configs, two speeds */
	case USB_REQ_SET_CONFIGURATION:
		if (ctrl->bRequestType != 0) {
			goto unknown;
		}
		if (gadget->a_hnp_support) {
			DBG(dev, "HNP available\n");
		} else if (gadget->a_alt_hnp_support) {
			DBG(dev, "HNP needs a different root port\n");
		} else {
			VDBG(dev, "HNP inactive\n");
		}
		spin_lock(&dev->lock);
		value = gmidi_set_config(dev, w_value, GFP_ATOMIC);
		spin_unlock(&dev->lock);
		break;
	case USB_REQ_GET_CONFIGURATION:
		if (ctrl->bRequestType != USB_DIR_IN) {
			goto unknown;
		}
		*(u8 *)req->buf = dev->config;
		value = min(w_length, (u16)1);
		break;

	/* until we add altsetting support, or other interfaces,
	 * only 0/0 are possible.  pxa2xx only supports 0/0 (poorly)
	 * and already killed pending endpoint I/O.
	 */
	case USB_REQ_SET_INTERFACE:
		if (ctrl->bRequestType != USB_RECIP_INTERFACE) {
			goto unknown;
		}
		spin_lock(&dev->lock);
		if (dev->config && w_index < GMIDI_NUM_INTERFACES
			&& w_value == 0)
		{
			u8 config = dev->config;

			/* resets interface configuration, forgets about
			 * previous transaction state (queued bufs, etc)
			 * and re-inits endpoint state (toggle etc)
			 * no response queued, just zero status == success.
			 * if we had more than one interface we couldn't
			 * use this "reset the config" shortcut.
			 */
			gmidi_reset_config(dev);
			gmidi_set_config(dev, config, GFP_ATOMIC);
			value = 0;
		}
		spin_unlock(&dev->lock);
		break;
	case USB_REQ_GET_INTERFACE:
		if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE)) {
			goto unknown;
		}
		if (!dev->config) {
			break;
		}
		if (w_index >= GMIDI_NUM_INTERFACES) {
			value = -EDOM;
			break;
		}
		*(u8 *)req->buf = 0;
		value = min(w_length, (u16)1);
		break;

	default:
unknown:
		VDBG(dev, "unknown control req%02x.%02x v%04x i%04x l%d\n",
			ctrl->bRequestType, ctrl->bRequest,
			w_value, w_index, w_length);
	}

	/* respond with data transfer before status phase? */
	if (value >= 0) {
		req->length = value;
		req->zero = value < w_length;
		value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
		if (value < 0) {
			DBG(dev, "ep_queue --> %d\n", value);
			req->status = 0;
			gmidi_setup_complete(gadget->ep0, req);
		}
	}

	/* device either stalls (value < 0) or reports success */
	return value;
}

static void gmidi_disconnect(struct usb_gadget *gadget)
{
	struct gmidi_device *dev = get_gadget_data(gadget);
	unsigned long flags;

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

	/* a more significant application might have some non-usb
	 * activities to quiesce here, saving resources like power
	 * or pushing the notification up a network stack.
	 */
	spin_unlock_irqrestore(&dev->lock, flags);

	/* next we may get setup() calls to enumerate new connections;
	 * or an unbind() during shutdown (including removing module).
	 */
}

static void /* __init_or_exit */ gmidi_unbind(struct usb_gadget *gadget)
{
	struct gmidi_device *dev = get_gadget_data(gadget);
	struct snd_card *card;

	DBG(dev, "unbind\n");

	card = dev->card;
	dev->card = NULL;
	if (card) {
		snd_card_free(card);
	}

	/* we've already been disconnected ... no i/o is active */
	if (dev->req) {
		dev->req->length = USB_BUFSIZ;
		free_ep_req(gadget->ep0, dev->req);
	}
	kfree(dev);
	set_gadget_data(gadget, NULL);
}

static int gmidi_snd_free(struct snd_device *device)
{
	return 0;
}

static void gmidi_transmit_packet(struct usb_request *req, uint8_t p0,
					uint8_t p1, uint8_t p2, uint8_t p3)
{
	unsigned length = req->length;
	u8 *buf = (u8 *)req->buf + length;

	buf[0] = p0;
	buf[1] = p1;
	buf[2] = p2;
	buf[3] = p3;
	req->length = length + 4;
}

/*
 * Converts MIDI commands to USB MIDI packets.
 */
static void gmidi_transmit_byte(struct usb_request *req,
				struct gmidi_in_port *port, uint8_t b)
{
	uint8_t p0 = port->cable;

	if (b >= 0xf8) {
		gmidi_transmit_packet(req, p0 | 0x0f, b, 0, 0);
	} else if (b >= 0xf0) {
		switch (b) {
		case 0xf0:
			port->data[0] = b;
			port->state = STATE_SYSEX_1;
			break;
		case 0xf1:
		case 0xf3:
			port->data[0] = b;
			port->state = STATE_1PARAM;
			break;
		case 0xf2:
			port->data[0] = b;
			port->state = STATE_2PARAM_1;
			break;
		case 0xf4:
		case 0xf5:
			port->state = STATE_UNKNOWN;
			break;
		case 0xf6:
			gmidi_transmit_packet(req, p0 | 0x05, 0xf6, 0, 0);
			port->state = STATE_UNKNOWN;
			break;
		case 0xf7:
			switch (port->state) {
			case STATE_SYSEX_0:
				gmidi_transmit_packet(req,
					p0 | 0x05, 0xf7, 0, 0);
				break;
			case STATE_SYSEX_1:
				gmidi_transmit_packet(req,
					p0 | 0x06, port->data[0], 0xf7, 0);
				break;
			case STATE_SYSEX_2:
				gmidi_transmit_packet(req,
					p0 | 0x07, port->data[0],
					port->data[1], 0xf7);
				break;
			}
			port->state = STATE_UNKNOWN;
			break;
		}
	} else if (b >= 0x80) {
		port->data[0] = b;
		if (b >= 0xc0 && b <= 0xdf)
			port->state = STATE_1PARAM;
		else
			port->state = STATE_2PARAM_1;
	} else { /* b < 0x80 */
		switch (port->state) {
		case STATE_1PARAM:
			if (port->data[0] < 0xf0) {
				p0 |= port->data[0] >> 4;
			} else {
				p0 |= 0x02;
				port->state = STATE_UNKNOWN;
			}
			gmidi_transmit_packet(req, p0, port->data[0], b, 0);
			break;
		case STATE_2PARAM_1:
			port->data[1] = b;
			port->state = STATE_2PARAM_2;
			break;
		case STATE_2PARAM_2:
			if (port->data[0] < 0xf0) {
				p0 |= port->data[0] >> 4;
				port->state = STATE_2PARAM_1;
			} else {
				p0 |= 0x03;
				port->state = STATE_UNKNOWN;
			}
			gmidi_transmit_packet(req,
				p0, port->data[0], port->data[1], b);
			break;
		case STATE_SYSEX_0:
			port->data[0] = b;
			port->state = STATE_SYSEX_1;
			break;
		case STATE_SYSEX_1:
			port->data[1] = b;
			port->state = STATE_SYSEX_2;
			break;
		case STATE_SYSEX_2:
			gmidi_transmit_packet(req,
				p0 | 0x04, port->data[0], port->data[1], b);
			port->state = STATE_SYSEX_0;
			break;
		}
	}
}

static void gmidi_transmit(struct gmidi_device *dev, struct usb_request *req)
{
	struct usb_ep *ep = dev->in_ep;
	struct gmidi_in_port *port = &dev->in_port;

	if (!ep) {
		return;
	}
	if (!req) {
		req = alloc_ep_req(ep, buflen);
	}
	if (!req) {
		ERROR(dev, "gmidi_transmit: alloc_ep_request failed\n");
		return;
	}
	req->length = 0;
	req->complete = gmidi_complete;

	if (port->active) {
		while (req->length + 3 < buflen) {
			uint8_t b;
			if (snd_rawmidi_transmit(dev->in_substream, &b, 1)
				!= 1)
			{
				port->active = 0;
				break;
			}
			gmidi_transmit_byte(req, port, b);
		}
	}
	if (req->length > 0) {
		usb_ep_queue(ep, req, GFP_ATOMIC);
	} else {
		free_ep_req(ep, req);
	}
}

static void gmidi_in_tasklet(unsigned long data)
{
	struct gmidi_device *dev = (struct gmidi_device *)data;

	gmidi_transmit(dev, NULL);
}

static int gmidi_in_open(struct snd_rawmidi_substream *substream)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	VDBG(dev, "gmidi_in_open\n");
	dev->in_substream = substream;
	dev->in_port.state = STATE_UNKNOWN;
	return 0;
}

static int gmidi_in_close(struct snd_rawmidi_substream *substream)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	VDBG(dev, "gmidi_in_close\n");
	return 0;
}

static void gmidi_in_trigger(struct snd_rawmidi_substream *substream, int up)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	VDBG(dev, "gmidi_in_trigger %d\n", up);
	dev->in_port.active = up;
	if (up) {
		tasklet_hi_schedule(&dev->tasklet);
	}
}

static int gmidi_out_open(struct snd_rawmidi_substream *substream)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	VDBG(dev, "gmidi_out_open\n");
	dev->out_substream = substream;
	return 0;
}

static int gmidi_out_close(struct snd_rawmidi_substream *substream)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	VDBG(dev, "gmidi_out_close\n");
	return 0;
}

static void gmidi_out_trigger(struct snd_rawmidi_substream *substream, int up)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	VDBG(dev, "gmidi_out_trigger %d\n", up);
	if (up) {
		set_bit(substream->number, &dev->out_triggered);
	} else {
		clear_bit(substream->number, &dev->out_triggered);
	}
}

static struct snd_rawmidi_ops gmidi_in_ops = {
	.open = gmidi_in_open,
	.close = gmidi_in_close,
	.trigger = gmidi_in_trigger,
};

static struct snd_rawmidi_ops gmidi_out_ops = {
	.open = gmidi_out_open,
	.close = gmidi_out_close,
	.trigger = gmidi_out_trigger
};

/* register as a sound "card" */
static int gmidi_register_card(struct gmidi_device *dev)
{
	struct snd_card *card;
	struct snd_rawmidi *rmidi;
	int err;
	int out_ports = 1;
	int in_ports = 1;
	static struct snd_device_ops ops = {
		.dev_free = gmidi_snd_free,
	};

	err = snd_card_create(index, id, THIS_MODULE, 0, &card);
	if (err < 0) {
		ERROR(dev, "snd_card_create failed\n");
		goto fail;
	}
	dev->card = card;

	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, dev, &ops);
	if (err < 0) {
		ERROR(dev, "snd_device_new failed: error %d\n", err);
		goto fail;
	}

	strcpy(card->driver, longname);
	strcpy(card->longname, longname);
	strcpy(card->shortname, shortname);

	/* Set up rawmidi */
	dev->in_port.dev = dev;
	dev->in_port.active = 0;
	snd_component_add(card, "MIDI");
	err = snd_rawmidi_new(card, "USB MIDI Gadget", 0,
			      out_ports, in_ports, &rmidi);
	if (err < 0) {
		ERROR(dev, "snd_rawmidi_new failed: error %d\n", err);
		goto fail;
	}
	dev->rmidi = rmidi;
	strcpy(rmidi->name, card->shortname);
	rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
			    SNDRV_RAWMIDI_INFO_INPUT |
			    SNDRV_RAWMIDI_INFO_DUPLEX;
	rmidi->private_data = dev;

	/* Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
	   It's an upside-down world being a gadget. */
	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);

	snd_card_set_dev(card, &dev->gadget->dev);

	/* register it - we're ready to go */
	err = snd_card_register(card);
	if (err < 0) {
		ERROR(dev, "snd_card_register failed\n");
		goto fail;
	}

	VDBG(dev, "gmidi_register_card finished ok\n");
	return 0;

fail:
	if (dev->card) {
		snd_card_free(dev->card);
		dev->card = NULL;
	}
	return err;
}

/*
 * Creates an output endpoint, and initializes output ports.
 */
static int __init gmidi_bind(struct usb_gadget *gadget)
{
	struct gmidi_device *dev;
	struct usb_ep *in_ep, *out_ep;
	int gcnum, err = 0;

	/* support optional vendor/distro customization */
	if (idVendor) {
		if (!idProduct) {
			pr_err("idVendor needs idProduct!\n");
			return -ENODEV;
		}
		device_desc.idVendor = cpu_to_le16(idVendor);
		device_desc.idProduct = cpu_to_le16(idProduct);
		if (bcdDevice) {
			device_desc.bcdDevice = cpu_to_le16(bcdDevice);
		}
	}
	if (iManufacturer) {
		strlcpy(manufacturer, iManufacturer, sizeof(manufacturer));
	} else {
		snprintf(manufacturer, sizeof(manufacturer), "%s %s with %s",
			init_utsname()->sysname, init_utsname()->release,
			gadget->name);
	}
	if (iProduct) {
		strlcpy(product_desc, iProduct, sizeof(product_desc));
	}
	if (iSerialNumber) {
		device_desc.iSerialNumber = STRING_SERIAL,
		strlcpy(serial_number, iSerialNumber, sizeof(serial_number));
	}

	/* Bulk-only drivers like this one SHOULD be able to
	 * autoconfigure on any sane usb controller driver,
	 * but there may also be important quirks to address.
	 */
	usb_ep_autoconfig_reset(gadget);
	in_ep = usb_ep_autoconfig(gadget, &bulk_in_desc);
	if (!in_ep) {
autoconf_fail:
		pr_err("%s: can't autoconfigure on %s\n",
			shortname, gadget->name);
		return -ENODEV;
	}
	EP_IN_NAME = in_ep->name;
	in_ep->driver_data = in_ep;	/* claim */

	out_ep = usb_ep_autoconfig(gadget, &bulk_out_desc);
	if (!out_ep) {
		goto autoconf_fail;
	}
	EP_OUT_NAME = out_ep->name;
	out_ep->driver_data = out_ep;	/* claim */

	gcnum = usb_gadget_controller_number(gadget);
	if (gcnum >= 0) {
		device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
	} else {
		/* gmidi is so simple (no altsettings) that
		 * it SHOULD NOT have problems with bulk-capable hardware.
		 * so warn about unrecognized controllers, don't panic.
		 */
		pr_warning("%s: controller '%s' not recognized\n",
			shortname, gadget->name);
		device_desc.bcdDevice = __constant_cpu_to_le16(0x9999);
	}


	/* ok, we made sense of the hardware ... */
	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev) {
		return -ENOMEM;
	}
	spin_lock_init(&dev->lock);
	dev->gadget = gadget;
	dev->in_ep = in_ep;
	dev->out_ep = out_ep;
	set_gadget_data(gadget, dev);
	tasklet_init(&dev->tasklet, gmidi_in_tasklet, (unsigned long)dev);

	/* preallocate control response and buffer */
	dev->req = alloc_ep_req(gadget->ep0, USB_BUFSIZ);
	if (!dev->req) {
		err = -ENOMEM;
		goto fail;
	}

	dev->req->complete = gmidi_setup_complete;

	device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;

	gadget->ep0->driver_data = dev;

	INFO(dev, "%s, version: " DRIVER_VERSION "\n", longname);
	INFO(dev, "using %s, OUT %s IN %s\n", gadget->name,
		EP_OUT_NAME, EP_IN_NAME);

	/* register as an ALSA sound card */
	err = gmidi_register_card(dev);
	if (err < 0) {
		goto fail;
	}

	VDBG(dev, "gmidi_bind finished ok\n");
	return 0;

fail:
	gmidi_unbind(gadget);
	return err;
}


static void gmidi_suspend(struct usb_gadget *gadget)
{
	struct gmidi_device *dev = get_gadget_data(gadget);

	if (gadget->speed == USB_SPEED_UNKNOWN) {
		return;
	}

	DBG(dev, "suspend\n");
}

static void gmidi_resume(struct usb_gadget *gadget)
{
	struct gmidi_device *dev = get_gadget_data(gadget);

	DBG(dev, "resume\n");
}


static struct usb_gadget_driver gmidi_driver = {
	.speed		= USB_SPEED_FULL,
	.function	= (char *)longname,
	.bind		= gmidi_bind,
	.unbind		= gmidi_unbind,

	.setup		= gmidi_setup,
	.disconnect	= gmidi_disconnect,

	.suspend	= gmidi_suspend,
	.resume		= gmidi_resume,

	.driver		= {
		.name		= (char *)shortname,
		.owner		= THIS_MODULE,
	},
};

static int __init gmidi_init(void)
{
	return usb_gadget_register_driver(&gmidi_driver);
}
module_init(gmidi_init);

static void __exit gmidi_cleanup(void)
{
	usb_gadget_unregister_driver(&gmidi_driver);
}
module_exit(gmidi_cleanup);