summaryrefslogtreecommitdiffstats
path: root/drivers/usb/gadget/f_midi.c
blob: 3797b3d6c622bd49ff709b33303a86e323294c44 (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
/*
 * f_midi.c -- USB MIDI class function driver
 *
 * Copyright (C) 2006 Thumtronics Pty Ltd.
 * Developed for Thumtronics by Grey Innovation
 * Ben Williamson <ben.williamson@greyinnovation.com>
 *
 * Rewritten for the composite framework
 *   Copyright (C) 2011 Daniel Mack <zonque@gmail.com>
 *
 * Based on drivers/usb/gadget/f_audio.c,
 *   Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
 *   Copyright (C) 2008 Analog Devices, Inc
 *
 * and drivers/usb/gadget/midi.c,
 *   Copyright (C) 2006 Thumtronics Pty Ltd.
 *   Ben Williamson <ben.williamson@greyinnovation.com>
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/kernel.h>
#include <linux/slab.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>

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

static const char f_midi_shortname[] = "f_midi";
static const char f_midi_longname[] = "MIDI Gadget";

/*
 * We can only handle 16 cables on one single endpoint, as cable numbers are
 * stored in 4-bit fields. And as the interface currently only holds one
 * single endpoint, this is the maximum number of ports we can allow.
 */
#define MAX_PORTS 16

/*
 * 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 f_midi *midi;
	int active;
	uint8_t cable;
	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 f_midi {
	struct usb_function	func;
	struct usb_gadget	*gadget;
	struct usb_ep		*in_ep, *out_ep;
	struct snd_card		*card;
	struct snd_rawmidi	*rmidi;

	struct snd_rawmidi_substream *in_substream[MAX_PORTS];
	struct snd_rawmidi_substream *out_substream[MAX_PORTS];
	struct gmidi_in_port	*in_port[MAX_PORTS];

	unsigned long		out_triggered;
	struct tasklet_struct	tasklet;
	unsigned int in_ports;
	unsigned int out_ports;
	int index;
	char *id;
	unsigned int buflen, qlen;
};

static inline struct f_midi *func_to_midi(struct usb_function *f)
{
	return container_of(f, struct f_midi, func);
}

static void f_midi_transmit(struct f_midi *midi, struct usb_request *req);

DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);

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

/* B.3.2  Class-Specific AC Interface Descriptor */
static struct uac1_ac_header_descriptor_1 ac_header_desc __initdata = {
	.bLength =		UAC_DT_AC_HEADER_SIZE(1),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_HEADER,
	.bcdADC =		cpu_to_le16(0x0100),
	.wTotalLength =		cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)),
	.bInCollection =	1,
	/* .baInterfaceNr =	DYNAMIC */
};

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

/* B.4.2  Class-Specific MS Interface Descriptor */
static struct usb_ms_header_descriptor ms_header_desc __initdata = {
	.bLength =		USB_DT_MS_HEADER_SIZE,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubtype =	USB_MS_HEADER,
	.bcdMSC =		cpu_to_le16(0x0100),
	/* .wTotalLength =	DYNAMIC */
};

/* 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 struct usb_ms_endpoint_descriptor_16 ms_out_desc = {
	/* .bLength =		DYNAMIC */
	.bDescriptorType =	USB_DT_CS_ENDPOINT,
	.bDescriptorSubtype =	USB_MS_GENERAL,
	/* .bNumEmbMIDIJack =	DYNAMIC */
	/* .baAssocJackID =	DYNAMIC */
};

/* 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 struct usb_ms_endpoint_descriptor_16 ms_in_desc = {
	/* .bLength =		DYNAMIC */
	.bDescriptorType =	USB_DT_CS_ENDPOINT,
	.bDescriptorSubtype =	USB_MS_GENERAL,
	/* .bNumEmbMIDIJack =	DYNAMIC */
	/* .baAssocJackID =	DYNAMIC */
};

/* string IDs are assigned dynamically */

#define STRING_FUNC_IDX			0

static struct usb_string midi_string_defs[] = {
	[STRING_FUNC_IDX].s = "MIDI function",
	{  } /* end of list */
};

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

static struct usb_gadget_strings *midi_strings[] = {
	&midi_stringtab,
	NULL,
};

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 f_midi_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 f_midi_read_data(struct usb_ep *ep, int cable,
			     uint8_t *data, int length)
{
	struct f_midi *midi = ep->driver_data;
	struct snd_rawmidi_substream *substream = midi->out_substream[cable];

	if (!substream)
		/* Nobody is listening - throw it on the floor. */
		return;

	if (!test_bit(cable, &midi->out_triggered))
		return;

	snd_rawmidi_receive(substream, data, length);
}

static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
{
	unsigned int 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 = f_midi_cin_length[buf[i] & 0x0f];
			f_midi_read_data(ep, cable, &buf[i + 1], length);
		}
}

static void
f_midi_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct f_midi *midi = ep->driver_data;
	struct usb_composite_dev *cdev = midi->func.config->cdev;
	int status = req->status;

	switch (status) {
	case 0:			 /* normal completion */
		if (ep == midi->out_ep) {
			/* We received stuff. req is queued again, below */
			f_midi_handle_out_data(ep, req);
		} else if (ep == midi->in_ep) {
			/* Our transmit completed. See if there's more to go.
			 * f_midi_transmit eats req, don't queue it again. */
			f_midi_transmit(midi, 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(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
				req->actual, req->length);
		if (ep == midi->out_ep)
			f_midi_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(cdev, "%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(cdev, "kill %s:  resubmit %d bytes --> %d\n",
				ep->name, req->length, status);
		usb_ep_set_halt(ep);
		/* FIXME recover later ... somehow */
	}
}

static int f_midi_start_ep(struct f_midi *midi,
			   struct usb_function *f,
			   struct usb_ep *ep)
{
	int err;
	struct usb_composite_dev *cdev = f->config->cdev;

	if (ep->driver_data)
		usb_ep_disable(ep);

	err = config_ep_by_speed(midi->gadget, f, ep);
	if (err) {
		ERROR(cdev, "can't configure %s: %d\n", ep->name, err);
		return err;
	}

	err = usb_ep_enable(ep);
	if (err) {
		ERROR(cdev, "can't start %s: %d\n", ep->name, err);
		return err;
	}

	ep->driver_data = midi;

	return 0;
}

static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
	struct f_midi *midi = func_to_midi(f);
	struct usb_composite_dev *cdev = f->config->cdev;
	unsigned i;
	int err;

	err = f_midi_start_ep(midi, f, midi->in_ep);
	if (err)
		return err;

	err = f_midi_start_ep(midi, f, midi->out_ep);
	if (err)
		return err;

	if (midi->out_ep->driver_data)
		usb_ep_disable(midi->out_ep);

	err = config_ep_by_speed(midi->gadget, f, midi->out_ep);
	if (err) {
		ERROR(cdev, "can't configure %s: %d\n",
		      midi->out_ep->name, err);
		return err;
	}

	err = usb_ep_enable(midi->out_ep);
	if (err) {
		ERROR(cdev, "can't start %s: %d\n",
		      midi->out_ep->name, err);
		return err;
	}

	midi->out_ep->driver_data = midi;

	/* allocate a bunch of read buffers and queue them all at once. */
	for (i = 0; i < midi->qlen && err == 0; i++) {
		struct usb_request *req =
			alloc_ep_req(midi->out_ep, midi->buflen);
		if (req == NULL)
			return -ENOMEM;

		req->complete = f_midi_complete;
		err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
		if (err) {
			ERROR(midi, "%s queue req: %d\n",
				    midi->out_ep->name, err);
		}
	}

	return 0;
}

static void f_midi_disable(struct usb_function *f)
{
	struct f_midi *midi = func_to_midi(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	DBG(cdev, "disable\n");

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

static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = f->config->cdev;
	struct f_midi *midi = func_to_midi(f);
	struct snd_card *card;

	DBG(cdev, "unbind\n");

	/* just to be sure */
	f_midi_disable(f);

	card = midi->card;
	midi->card = NULL;
	if (card)
		snd_card_free(card);

	kfree(midi->id);
	midi->id = NULL;

	usb_free_descriptors(f->descriptors);
	kfree(midi);
}

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

static void f_midi_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 f_midi_transmit_byte(struct usb_request *req,
				 struct gmidi_in_port *port, uint8_t b)
{
	uint8_t p0 = port->cable << 4;

	if (b >= 0xf8) {
		f_midi_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:
			f_midi_transmit_packet(req, p0 | 0x05, 0xf6, 0, 0);
			port->state = STATE_UNKNOWN;
			break;
		case 0xf7:
			switch (port->state) {
			case STATE_SYSEX_0:
				f_midi_transmit_packet(req,
					p0 | 0x05, 0xf7, 0, 0);
				break;
			case STATE_SYSEX_1:
				f_midi_transmit_packet(req,
					p0 | 0x06, port->data[0], 0xf7, 0);
				break;
			case STATE_SYSEX_2:
				f_midi_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;
			}
			f_midi_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;
			}
			f_midi_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:
			f_midi_transmit_packet(req,
				p0 | 0x04, port->data[0], port->data[1], b);
			port->state = STATE_SYSEX_0;
			break;
		}
	}
}

static void f_midi_transmit(struct f_midi *midi, struct usb_request *req)
{
	struct usb_ep *ep = midi->in_ep;
	int i;

	if (!ep)
		return;

	if (!req)
		req = alloc_ep_req(ep, midi->buflen);

	if (!req) {
		ERROR(midi, "gmidi_transmit: alloc_ep_request failed\n");
		return;
	}
	req->length = 0;
	req->complete = f_midi_complete;

	for (i = 0; i < MAX_PORTS; i++) {
		struct gmidi_in_port *port = midi->in_port[i];
		struct snd_rawmidi_substream *substream = midi->in_substream[i];

		if (!port || !port->active || !substream)
			continue;

		while (req->length + 3 < midi->buflen) {
			uint8_t b;
			if (snd_rawmidi_transmit(substream, &b, 1) != 1) {
				port->active = 0;
				break;
			}
			f_midi_transmit_byte(req, port, b);
		}
	}

	if (req->length > 0)
		usb_ep_queue(ep, req, GFP_ATOMIC);
	else
		free_ep_req(ep, req);
}

static void f_midi_in_tasklet(unsigned long data)
{
	struct f_midi *midi = (struct f_midi *) data;
	f_midi_transmit(midi, NULL);
}

static int f_midi_in_open(struct snd_rawmidi_substream *substream)
{
	struct f_midi *midi = substream->rmidi->private_data;

	if (!midi->in_port[substream->number])
		return -EINVAL;

	VDBG(midi, "%s()\n", __func__);
	midi->in_substream[substream->number] = substream;
	midi->in_port[substream->number]->state = STATE_UNKNOWN;
	return 0;
}

static int f_midi_in_close(struct snd_rawmidi_substream *substream)
{
	struct f_midi *midi = substream->rmidi->private_data;

	VDBG(midi, "%s()\n", __func__);
	return 0;
}

static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
{
	struct f_midi *midi = substream->rmidi->private_data;

	if (!midi->in_port[substream->number])
		return;

	VDBG(midi, "%s() %d\n", __func__, up);
	midi->in_port[substream->number]->active = up;
	if (up)
		tasklet_hi_schedule(&midi->tasklet);
}

static int f_midi_out_open(struct snd_rawmidi_substream *substream)
{
	struct f_midi *midi = substream->rmidi->private_data;

	if (substream->number >= MAX_PORTS)
		return -EINVAL;

	VDBG(midi, "%s()\n", __func__);
	midi->out_substream[substream->number] = substream;
	return 0;
}

static int f_midi_out_close(struct snd_rawmidi_substream *substream)
{
	struct f_midi *midi = substream->rmidi->private_data;

	VDBG(midi, "%s()\n", __func__);
	return 0;
}

static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
{
	struct f_midi *midi = substream->rmidi->private_data;

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

	if (up)
		set_bit(substream->number, &midi->out_triggered);
	else
		clear_bit(substream->number, &midi->out_triggered);
}

static struct snd_rawmidi_ops gmidi_in_ops = {
	.open = f_midi_in_open,
	.close = f_midi_in_close,
	.trigger = f_midi_in_trigger,
};

static struct snd_rawmidi_ops gmidi_out_ops = {
	.open = f_midi_out_open,
	.close = f_midi_out_close,
	.trigger = f_midi_out_trigger
};

/* register as a sound "card" */
static int f_midi_register_card(struct f_midi *midi)
{
	struct snd_card *card;
	struct snd_rawmidi *rmidi;
	int err;
	static struct snd_device_ops ops = {
		.dev_free = f_midi_snd_free,
	};

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

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

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

	/* Set up rawmidi */
	snd_component_add(card, "MIDI");
	err = snd_rawmidi_new(card, card->longname, 0,
			      midi->out_ports, midi->in_ports, &rmidi);
	if (err < 0) {
		ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
		goto fail;
	}
	midi->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 = midi;

	/*
	 * 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, &midi->gadget->dev);

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

	VDBG(midi, "%s() finished ok\n", __func__);
	return 0;

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

/* MIDI function driver setup/binding */

static int __init
f_midi_bind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_descriptor_header **midi_function;
	struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
	struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
	struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
	struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
	struct usb_composite_dev *cdev = c->cdev;
	struct f_midi *midi = func_to_midi(f);
	int status, n, jack = 1, i = 0;

	/* maybe allocate device-global string ID */
	if (midi_string_defs[0].id == 0) {
		status = usb_string_id(c->cdev);
		if (status < 0)
			goto fail;
		midi_string_defs[0].id = status;
	}

	/* We have two interfaces, AudioControl and MIDIStreaming */
	status = usb_interface_id(c, f);
	if (status < 0)
		goto fail;
	ac_interface_desc.bInterfaceNumber = status;

	status = usb_interface_id(c, f);
	if (status < 0)
		goto fail;
	ms_interface_desc.bInterfaceNumber = status;
	ac_header_desc.baInterfaceNr[0] = status;

	status = -ENODEV;

	/* allocate instance-specific endpoints */
	midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
	if (!midi->in_ep)
		goto fail;
	midi->in_ep->driver_data = cdev;	/* claim */

	midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
	if (!midi->out_ep)
		goto fail;
	midi->out_ep->driver_data = cdev;	/* claim */

	/* allocate temporary function list */
	midi_function = kcalloc((MAX_PORTS * 4) + 9, sizeof(midi_function),
				GFP_KERNEL);
	if (!midi_function) {
		status = -ENOMEM;
		goto fail;
	}

	/*
	 * construct the function's descriptor set. As the number of
	 * input and output MIDI ports is configurable, we have to do
	 * it that way.
	 */

	/* add the headers - these are always the same */
	midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
	midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
	midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;

	/* calculate the header's wTotalLength */
	n = USB_DT_MS_HEADER_SIZE
		+ (midi->in_ports + midi->out_ports) *
			(USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
	ms_header_desc.wTotalLength = cpu_to_le16(n);

	midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;

	/* configure the external IN jacks, each linked to an embedded OUT jack */
	for (n = 0; n < midi->in_ports; n++) {
		struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
		struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];

		in_ext->bLength			= USB_DT_MIDI_IN_SIZE;
		in_ext->bDescriptorType		= USB_DT_CS_INTERFACE;
		in_ext->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
		in_ext->bJackType		= USB_MS_EXTERNAL;
		in_ext->bJackID			= jack++;
		in_ext->iJack			= 0;
		midi_function[i++] = (struct usb_descriptor_header *) in_ext;

		out_emb->bLength		= USB_DT_MIDI_OUT_SIZE(1);
		out_emb->bDescriptorType	= USB_DT_CS_INTERFACE;
		out_emb->bDescriptorSubtype	= USB_MS_MIDI_OUT_JACK;
		out_emb->bJackType		= USB_MS_EMBEDDED;
		out_emb->bJackID		= jack++;
		out_emb->bNrInputPins		= 1;
		out_emb->pins[0].baSourcePin	= 1;
		out_emb->pins[0].baSourceID	= in_ext->bJackID;
		out_emb->iJack			= 0;
		midi_function[i++] = (struct usb_descriptor_header *) out_emb;

		/* link it to the endpoint */
		ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
	}

	/* configure the external OUT jacks, each linked to an embedded IN jack */
	for (n = 0; n < midi->out_ports; n++) {
		struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
		struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];

		in_emb->bLength			= USB_DT_MIDI_IN_SIZE;
		in_emb->bDescriptorType		= USB_DT_CS_INTERFACE;
		in_emb->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
		in_emb->bJackType		= USB_MS_EMBEDDED;
		in_emb->bJackID			= jack++;
		in_emb->iJack			= 0;
		midi_function[i++] = (struct usb_descriptor_header *) in_emb;

		out_ext->bLength =		USB_DT_MIDI_OUT_SIZE(1);
		out_ext->bDescriptorType =	USB_DT_CS_INTERFACE;
		out_ext->bDescriptorSubtype =	USB_MS_MIDI_OUT_JACK;
		out_ext->bJackType =		USB_MS_EXTERNAL;
		out_ext->bJackID =		jack++;
		out_ext->bNrInputPins =		1;
		out_ext->iJack =		0;
		out_ext->pins[0].baSourceID =	in_emb->bJackID;
		out_ext->pins[0].baSourcePin =	1;
		midi_function[i++] = (struct usb_descriptor_header *) out_ext;

		/* link it to the endpoint */
		ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
	}

	/* configure the endpoint descriptors ... */
	ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
	ms_out_desc.bNumEmbMIDIJack = midi->in_ports;

	ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
	ms_in_desc.bNumEmbMIDIJack = midi->out_ports;

	/* ... and add them to the list */
	midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
	midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
	midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
	midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
	midi_function[i++] = NULL;

	/*
	 * support all relevant hardware speeds... we expect that when
	 * hardware is dual speed, all bulk-capable endpoints work at
	 * both speeds
	 */
	/* copy descriptors, and track endpoint copies */
	if (gadget_is_dualspeed(c->cdev->gadget)) {
		c->highspeed = true;
		bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
		bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
		f->hs_descriptors = usb_copy_descriptors(midi_function);
	} else {
		f->descriptors = usb_copy_descriptors(midi_function);
	}

	kfree(midi_function);

	return 0;

fail:
	/* we might as well release our claims on endpoints */
	if (midi->out_ep)
		midi->out_ep->driver_data = NULL;
	if (midi->in_ep)
		midi->in_ep->driver_data = NULL;

	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);

	return status;
}

/**
 * f_midi_bind_config - add USB MIDI function to a configuration
 * @c: the configuration to supcard the USB audio function
 * @index: the soundcard index to use for the ALSA device creation
 * @id: the soundcard id to use for the ALSA device creation
 * @buflen: the buffer length to use
 * @qlen the number of read requests to pre-allocate
 * Context: single threaded during gadget setup
 *
 * Returns zero on success, else negative errno.
 */
int __init f_midi_bind_config(struct usb_configuration *c,
			      int index, char *id,
			      unsigned int in_ports,
			      unsigned int out_ports,
			      unsigned int buflen,
			      unsigned int qlen)
{
	struct f_midi *midi;
	int status, i;

	/* sanity check */
	if (in_ports > MAX_PORTS || out_ports > MAX_PORTS)
		return -EINVAL;

	/* allocate and initialize one new instance */
	midi = kzalloc(sizeof *midi, GFP_KERNEL);
	if (!midi) {
		status = -ENOMEM;
		goto fail;
	}

	for (i = 0; i < in_ports; i++) {
		struct gmidi_in_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
		if (!port) {
			status = -ENOMEM;
			goto setup_fail;
		}

		port->midi = midi;
		port->active = 0;
		port->cable = i;
		midi->in_port[i] = port;
	}

	midi->gadget = c->cdev->gadget;
	tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);

	/* set up ALSA midi devices */
	midi->in_ports = in_ports;
	midi->out_ports = out_ports;
	status = f_midi_register_card(midi);
	if (status < 0)
		goto setup_fail;

	midi->func.name        = "gmidi function";
	midi->func.strings     = midi_strings;
	midi->func.bind        = f_midi_bind;
	midi->func.unbind      = f_midi_unbind;
	midi->func.set_alt     = f_midi_set_alt;
	midi->func.disable     = f_midi_disable;

	midi->id = kstrdup(id, GFP_KERNEL);
	midi->index = index;
	midi->buflen = buflen;
	midi->qlen = qlen;

	status = usb_add_function(c, &midi->func);
	if (status)
		goto setup_fail;

	return 0;

setup_fail:
	for (--i; i >= 0; i--)
		kfree(midi->in_port[i]);
	kfree(midi);
fail:
	return status;
}

OpenPOWER on IntegriCloud