1/*
2 * f_midi.c -- USB MIDI class function driver
3 *
4 * Copyright (C) 2006 Thumtronics Pty Ltd.
5 * Developed for Thumtronics by Grey Innovation
6 * Ben Williamson <ben.williamson@greyinnovation.com>
7 *
8 * Rewritten for the composite framework
9 *   Copyright (C) 2011 Daniel Mack <zonque@gmail.com>
10 *
11 * Based on drivers/usb/gadget/f_audio.c,
12 *   Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
13 *   Copyright (C) 2008 Analog Devices, Inc
14 *
15 * and drivers/usb/gadget/midi.c,
16 *   Copyright (C) 2006 Thumtronics Pty Ltd.
17 *   Ben Williamson <ben.williamson@greyinnovation.com>
18 *
19 * Licensed under the GPL-2 or later.
20 */
21
22#include <linux/kernel.h>
23#include <linux/slab.h>
24#include <linux/utsname.h>
25#include <linux/device.h>
26
27#include <sound/core.h>
28#include <sound/initval.h>
29#include <sound/rawmidi.h>
30
31#include <linux/usb/ch9.h>
32#include <linux/usb/gadget.h>
33#include <linux/usb/audio.h>
34#include <linux/usb/midi.h>
35
36MODULE_AUTHOR("Ben Williamson");
37MODULE_LICENSE("GPL v2");
38
39static const char f_midi_shortname[] = "f_midi";
40static const char f_midi_longname[] = "MIDI Gadget";
41
42/*
43 * We can only handle 16 cables on one single endpoint, as cable numbers are
44 * stored in 4-bit fields. And as the interface currently only holds one
45 * single endpoint, this is the maximum number of ports we can allow.
46 */
47#define MAX_PORTS 16
48
49/*
50 * This is a gadget, and the IN/OUT naming is from the host's perspective.
51 * USB -> OUT endpoint -> rawmidi
52 * USB <- IN endpoint  <- rawmidi
53 */
54struct gmidi_in_port {
55	struct f_midi *midi;
56	int active;
57	uint8_t cable;
58	uint8_t state;
59#define STATE_UNKNOWN	0
60#define STATE_1PARAM	1
61#define STATE_2PARAM_1	2
62#define STATE_2PARAM_2	3
63#define STATE_SYSEX_0	4
64#define STATE_SYSEX_1	5
65#define STATE_SYSEX_2	6
66	uint8_t data[2];
67};
68
69struct f_midi {
70	struct usb_function	func;
71	struct usb_gadget	*gadget;
72	struct usb_ep		*in_ep, *out_ep;
73	struct snd_card		*card;
74	struct snd_rawmidi	*rmidi;
75
76	struct snd_rawmidi_substream *in_substream[MAX_PORTS];
77	struct snd_rawmidi_substream *out_substream[MAX_PORTS];
78	struct gmidi_in_port	*in_port[MAX_PORTS];
79
80	unsigned long		out_triggered;
81	struct tasklet_struct	tasklet;
82	unsigned int in_ports;
83	unsigned int out_ports;
84	int index;
85	char *id;
86	unsigned int buflen, qlen;
87};
88
89static inline struct f_midi *func_to_midi(struct usb_function *f)
90{
91	return container_of(f, struct f_midi, func);
92}
93
94static void f_midi_transmit(struct f_midi *midi, struct usb_request *req);
95
96DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
97DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
98DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
99
100/* B.3.1  Standard AC Interface Descriptor */
101static struct usb_interface_descriptor ac_interface_desc __initdata = {
102	.bLength =		USB_DT_INTERFACE_SIZE,
103	.bDescriptorType =	USB_DT_INTERFACE,
104	/* .bInterfaceNumber =	DYNAMIC */
105	/* .bNumEndpoints =	DYNAMIC */
106	.bInterfaceClass =	USB_CLASS_AUDIO,
107	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
108	/* .iInterface =	DYNAMIC */
109};
110
111/* B.3.2  Class-Specific AC Interface Descriptor */
112static struct uac1_ac_header_descriptor_1 ac_header_desc __initdata = {
113	.bLength =		UAC_DT_AC_HEADER_SIZE(1),
114	.bDescriptorType =	USB_DT_CS_INTERFACE,
115	.bDescriptorSubtype =	USB_MS_HEADER,
116	.bcdADC =		cpu_to_le16(0x0100),
117	.wTotalLength =		cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)),
118	.bInCollection =	1,
119	/* .baInterfaceNr =	DYNAMIC */
120};
121
122/* B.4.1  Standard MS Interface Descriptor */
123static struct usb_interface_descriptor ms_interface_desc __initdata = {
124	.bLength =		USB_DT_INTERFACE_SIZE,
125	.bDescriptorType =	USB_DT_INTERFACE,
126	/* .bInterfaceNumber =	DYNAMIC */
127	.bNumEndpoints =	2,
128	.bInterfaceClass =	USB_CLASS_AUDIO,
129	.bInterfaceSubClass =	USB_SUBCLASS_MIDISTREAMING,
130	/* .iInterface =	DYNAMIC */
131};
132
133/* B.4.2  Class-Specific MS Interface Descriptor */
134static struct usb_ms_header_descriptor ms_header_desc __initdata = {
135	.bLength =		USB_DT_MS_HEADER_SIZE,
136	.bDescriptorType =	USB_DT_CS_INTERFACE,
137	.bDescriptorSubtype =	USB_MS_HEADER,
138	.bcdMSC =		cpu_to_le16(0x0100),
139	/* .wTotalLength =	DYNAMIC */
140};
141
142/* B.5.1  Standard Bulk OUT Endpoint Descriptor */
143static struct usb_endpoint_descriptor bulk_out_desc = {
144	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
145	.bDescriptorType =	USB_DT_ENDPOINT,
146	.bEndpointAddress =	USB_DIR_OUT,
147	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
148};
149
150/* B.5.2  Class-specific MS Bulk OUT Endpoint Descriptor */
151static struct usb_ms_endpoint_descriptor_16 ms_out_desc = {
152	/* .bLength =		DYNAMIC */
153	.bDescriptorType =	USB_DT_CS_ENDPOINT,
154	.bDescriptorSubtype =	USB_MS_GENERAL,
155	/* .bNumEmbMIDIJack =	DYNAMIC */
156	/* .baAssocJackID =	DYNAMIC */
157};
158
159/* B.6.1  Standard Bulk IN Endpoint Descriptor */
160static struct usb_endpoint_descriptor bulk_in_desc = {
161	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
162	.bDescriptorType =	USB_DT_ENDPOINT,
163	.bEndpointAddress =	USB_DIR_IN,
164	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
165};
166
167/* B.6.2  Class-specific MS Bulk IN Endpoint Descriptor */
168static struct usb_ms_endpoint_descriptor_16 ms_in_desc = {
169	/* .bLength =		DYNAMIC */
170	.bDescriptorType =	USB_DT_CS_ENDPOINT,
171	.bDescriptorSubtype =	USB_MS_GENERAL,
172	/* .bNumEmbMIDIJack =	DYNAMIC */
173	/* .baAssocJackID =	DYNAMIC */
174};
175
176/* string IDs are assigned dynamically */
177
178#define STRING_FUNC_IDX			0
179
180static struct usb_string midi_string_defs[] = {
181	[STRING_FUNC_IDX].s = "MIDI function",
182	{  } /* end of list */
183};
184
185static struct usb_gadget_strings midi_stringtab = {
186	.language	= 0x0409,	/* en-us */
187	.strings	= midi_string_defs,
188};
189
190static struct usb_gadget_strings *midi_strings[] = {
191	&midi_stringtab,
192	NULL,
193};
194
195static struct usb_request *alloc_ep_req(struct usb_ep *ep, unsigned length)
196{
197	struct usb_request *req;
198
199	req = usb_ep_alloc_request(ep, GFP_ATOMIC);
200	if (req) {
201		req->length = length;
202		req->buf = kmalloc(length, GFP_ATOMIC);
203		if (!req->buf) {
204			usb_ep_free_request(ep, req);
205			req = NULL;
206		}
207	}
208	return req;
209}
210
211static void free_ep_req(struct usb_ep *ep, struct usb_request *req)
212{
213	kfree(req->buf);
214	usb_ep_free_request(ep, req);
215}
216
217static const uint8_t f_midi_cin_length[] = {
218	0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
219};
220
221/*
222 * Receives a chunk of MIDI data.
223 */
224static void f_midi_read_data(struct usb_ep *ep, int cable,
225			     uint8_t *data, int length)
226{
227	struct f_midi *midi = ep->driver_data;
228	struct snd_rawmidi_substream *substream = midi->out_substream[cable];
229
230	if (!substream)
231		/* Nobody is listening - throw it on the floor. */
232		return;
233
234	if (!test_bit(cable, &midi->out_triggered))
235		return;
236
237	snd_rawmidi_receive(substream, data, length);
238}
239
240static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
241{
242	unsigned int i;
243	u8 *buf = req->buf;
244
245	for (i = 0; i + 3 < req->actual; i += 4)
246		if (buf[i] != 0) {
247			int cable = buf[i] >> 4;
248			int length = f_midi_cin_length[buf[i] & 0x0f];
249			f_midi_read_data(ep, cable, &buf[i + 1], length);
250		}
251}
252
253static void
254f_midi_complete(struct usb_ep *ep, struct usb_request *req)
255{
256	struct f_midi *midi = ep->driver_data;
257	struct usb_composite_dev *cdev = midi->func.config->cdev;
258	int status = req->status;
259
260	switch (status) {
261	case 0:			 /* normal completion */
262		if (ep == midi->out_ep) {
263			/* We received stuff. req is queued again, below */
264			f_midi_handle_out_data(ep, req);
265		} else if (ep == midi->in_ep) {
266			/* Our transmit completed. See if there's more to go.
267			 * f_midi_transmit eats req, don't queue it again. */
268			f_midi_transmit(midi, req);
269			return;
270		}
271		break;
272
273	/* this endpoint is normally active while we're configured */
274	case -ECONNABORTED:	/* hardware forced ep reset */
275	case -ECONNRESET:	/* request dequeued */
276	case -ESHUTDOWN:	/* disconnect from host */
277		VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
278				req->actual, req->length);
279		if (ep == midi->out_ep)
280			f_midi_handle_out_data(ep, req);
281
282		free_ep_req(ep, req);
283		return;
284
285	case -EOVERFLOW:	/* buffer overrun on read means that
286				 * we didn't provide a big enough buffer.
287				 */
288	default:
289		DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name,
290				status, req->actual, req->length);
291		break;
292	case -EREMOTEIO:	/* short read */
293		break;
294	}
295
296	status = usb_ep_queue(ep, req, GFP_ATOMIC);
297	if (status) {
298		ERROR(cdev, "kill %s:  resubmit %d bytes --> %d\n",
299				ep->name, req->length, status);
300		usb_ep_set_halt(ep);
301		/* FIXME recover later ... somehow */
302	}
303}
304
305static int f_midi_start_ep(struct f_midi *midi,
306			   struct usb_function *f,
307			   struct usb_ep *ep)
308{
309	int err;
310	struct usb_composite_dev *cdev = f->config->cdev;
311
312	if (ep->driver_data)
313		usb_ep_disable(ep);
314
315	err = config_ep_by_speed(midi->gadget, f, ep);
316	if (err) {
317		ERROR(cdev, "can't configure %s: %d\n", ep->name, err);
318		return err;
319	}
320
321	err = usb_ep_enable(ep);
322	if (err) {
323		ERROR(cdev, "can't start %s: %d\n", ep->name, err);
324		return err;
325	}
326
327	ep->driver_data = midi;
328
329	return 0;
330}
331
332static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
333{
334	struct f_midi *midi = func_to_midi(f);
335	struct usb_composite_dev *cdev = f->config->cdev;
336	unsigned i;
337	int err;
338
339	err = f_midi_start_ep(midi, f, midi->in_ep);
340	if (err)
341		return err;
342
343	err = f_midi_start_ep(midi, f, midi->out_ep);
344	if (err)
345		return err;
346
347	if (midi->out_ep->driver_data)
348		usb_ep_disable(midi->out_ep);
349
350	err = config_ep_by_speed(midi->gadget, f, midi->out_ep);
351	if (err) {
352		ERROR(cdev, "can't configure %s: %d\n",
353		      midi->out_ep->name, err);
354		return err;
355	}
356
357	err = usb_ep_enable(midi->out_ep);
358	if (err) {
359		ERROR(cdev, "can't start %s: %d\n",
360		      midi->out_ep->name, err);
361		return err;
362	}
363
364	midi->out_ep->driver_data = midi;
365
366	/* allocate a bunch of read buffers and queue them all at once. */
367	for (i = 0; i < midi->qlen && err == 0; i++) {
368		struct usb_request *req =
369			alloc_ep_req(midi->out_ep, midi->buflen);
370		if (req == NULL)
371			return -ENOMEM;
372
373		req->complete = f_midi_complete;
374		err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
375		if (err) {
376			ERROR(midi, "%s queue req: %d\n",
377				    midi->out_ep->name, err);
378		}
379	}
380
381	return 0;
382}
383
384static void f_midi_disable(struct usb_function *f)
385{
386	struct f_midi *midi = func_to_midi(f);
387	struct usb_composite_dev *cdev = f->config->cdev;
388
389	DBG(cdev, "disable\n");
390
391	/*
392	 * just disable endpoints, forcing completion of pending i/o.
393	 * all our completion handlers free their requests in this case.
394	 */
395	usb_ep_disable(midi->in_ep);
396	usb_ep_disable(midi->out_ep);
397}
398
399static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
400{
401	struct usb_composite_dev *cdev = f->config->cdev;
402	struct f_midi *midi = func_to_midi(f);
403	struct snd_card *card;
404
405	DBG(cdev, "unbind\n");
406
407	/* just to be sure */
408	f_midi_disable(f);
409
410	card = midi->card;
411	midi->card = NULL;
412	if (card)
413		snd_card_free(card);
414
415	kfree(midi->id);
416	midi->id = NULL;
417
418	usb_free_descriptors(f->descriptors);
419	kfree(midi);
420}
421
422static int f_midi_snd_free(struct snd_device *device)
423{
424	return 0;
425}
426
427static void f_midi_transmit_packet(struct usb_request *req, uint8_t p0,
428					uint8_t p1, uint8_t p2, uint8_t p3)
429{
430	unsigned length = req->length;
431	u8 *buf = (u8 *)req->buf + length;
432
433	buf[0] = p0;
434	buf[1] = p1;
435	buf[2] = p2;
436	buf[3] = p3;
437	req->length = length + 4;
438}
439
440/*
441 * Converts MIDI commands to USB MIDI packets.
442 */
443static void f_midi_transmit_byte(struct usb_request *req,
444				 struct gmidi_in_port *port, uint8_t b)
445{
446	uint8_t p0 = port->cable << 4;
447
448	if (b >= 0xf8) {
449		f_midi_transmit_packet(req, p0 | 0x0f, b, 0, 0);
450	} else if (b >= 0xf0) {
451		switch (b) {
452		case 0xf0:
453			port->data[0] = b;
454			port->state = STATE_SYSEX_1;
455			break;
456		case 0xf1:
457		case 0xf3:
458			port->data[0] = b;
459			port->state = STATE_1PARAM;
460			break;
461		case 0xf2:
462			port->data[0] = b;
463			port->state = STATE_2PARAM_1;
464			break;
465		case 0xf4:
466		case 0xf5:
467			port->state = STATE_UNKNOWN;
468			break;
469		case 0xf6:
470			f_midi_transmit_packet(req, p0 | 0x05, 0xf6, 0, 0);
471			port->state = STATE_UNKNOWN;
472			break;
473		case 0xf7:
474			switch (port->state) {
475			case STATE_SYSEX_0:
476				f_midi_transmit_packet(req,
477					p0 | 0x05, 0xf7, 0, 0);
478				break;
479			case STATE_SYSEX_1:
480				f_midi_transmit_packet(req,
481					p0 | 0x06, port->data[0], 0xf7, 0);
482				break;
483			case STATE_SYSEX_2:
484				f_midi_transmit_packet(req,
485					p0 | 0x07, port->data[0],
486					port->data[1], 0xf7);
487				break;
488			}
489			port->state = STATE_UNKNOWN;
490			break;
491		}
492	} else if (b >= 0x80) {
493		port->data[0] = b;
494		if (b >= 0xc0 && b <= 0xdf)
495			port->state = STATE_1PARAM;
496		else
497			port->state = STATE_2PARAM_1;
498	} else { /* b < 0x80 */
499		switch (port->state) {
500		case STATE_1PARAM:
501			if (port->data[0] < 0xf0) {
502				p0 |= port->data[0] >> 4;
503			} else {
504				p0 |= 0x02;
505				port->state = STATE_UNKNOWN;
506			}
507			f_midi_transmit_packet(req, p0, port->data[0], b, 0);
508			break;
509		case STATE_2PARAM_1:
510			port->data[1] = b;
511			port->state = STATE_2PARAM_2;
512			break;
513		case STATE_2PARAM_2:
514			if (port->data[0] < 0xf0) {
515				p0 |= port->data[0] >> 4;
516				port->state = STATE_2PARAM_1;
517			} else {
518				p0 |= 0x03;
519				port->state = STATE_UNKNOWN;
520			}
521			f_midi_transmit_packet(req,
522				p0, port->data[0], port->data[1], b);
523			break;
524		case STATE_SYSEX_0:
525			port->data[0] = b;
526			port->state = STATE_SYSEX_1;
527			break;
528		case STATE_SYSEX_1:
529			port->data[1] = b;
530			port->state = STATE_SYSEX_2;
531			break;
532		case STATE_SYSEX_2:
533			f_midi_transmit_packet(req,
534				p0 | 0x04, port->data[0], port->data[1], b);
535			port->state = STATE_SYSEX_0;
536			break;
537		}
538	}
539}
540
541static void f_midi_transmit(struct f_midi *midi, struct usb_request *req)
542{
543	struct usb_ep *ep = midi->in_ep;
544	int i;
545
546	if (!ep)
547		return;
548
549	if (!req)
550		req = alloc_ep_req(ep, midi->buflen);
551
552	if (!req) {
553		ERROR(midi, "gmidi_transmit: alloc_ep_request failed\n");
554		return;
555	}
556	req->length = 0;
557	req->complete = f_midi_complete;
558
559	for (i = 0; i < MAX_PORTS; i++) {
560		struct gmidi_in_port *port = midi->in_port[i];
561		struct snd_rawmidi_substream *substream = midi->in_substream[i];
562
563		if (!port || !port->active || !substream)
564			continue;
565
566		while (req->length + 3 < midi->buflen) {
567			uint8_t b;
568			if (snd_rawmidi_transmit(substream, &b, 1) != 1) {
569				port->active = 0;
570				break;
571			}
572			f_midi_transmit_byte(req, port, b);
573		}
574	}
575
576	if (req->length > 0)
577		usb_ep_queue(ep, req, GFP_ATOMIC);
578	else
579		free_ep_req(ep, req);
580}
581
582static void f_midi_in_tasklet(unsigned long data)
583{
584	struct f_midi *midi = (struct f_midi *) data;
585	f_midi_transmit(midi, NULL);
586}
587
588static int f_midi_in_open(struct snd_rawmidi_substream *substream)
589{
590	struct f_midi *midi = substream->rmidi->private_data;
591
592	if (!midi->in_port[substream->number])
593		return -EINVAL;
594
595	VDBG(midi, "%s()\n", __func__);
596	midi->in_substream[substream->number] = substream;
597	midi->in_port[substream->number]->state = STATE_UNKNOWN;
598	return 0;
599}
600
601static int f_midi_in_close(struct snd_rawmidi_substream *substream)
602{
603	struct f_midi *midi = substream->rmidi->private_data;
604
605	VDBG(midi, "%s()\n", __func__);
606	return 0;
607}
608
609static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
610{
611	struct f_midi *midi = substream->rmidi->private_data;
612
613	if (!midi->in_port[substream->number])
614		return;
615
616	VDBG(midi, "%s() %d\n", __func__, up);
617	midi->in_port[substream->number]->active = up;
618	if (up)
619		tasklet_hi_schedule(&midi->tasklet);
620}
621
622static int f_midi_out_open(struct snd_rawmidi_substream *substream)
623{
624	struct f_midi *midi = substream->rmidi->private_data;
625
626	if (substream->number >= MAX_PORTS)
627		return -EINVAL;
628
629	VDBG(midi, "%s()\n", __func__);
630	midi->out_substream[substream->number] = substream;
631	return 0;
632}
633
634static int f_midi_out_close(struct snd_rawmidi_substream *substream)
635{
636	struct f_midi *midi = substream->rmidi->private_data;
637
638	VDBG(midi, "%s()\n", __func__);
639	return 0;
640}
641
642static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
643{
644	struct f_midi *midi = substream->rmidi->private_data;
645
646	VDBG(midi, "%s()\n", __func__);
647
648	if (up)
649		set_bit(substream->number, &midi->out_triggered);
650	else
651		clear_bit(substream->number, &midi->out_triggered);
652}
653
654static struct snd_rawmidi_ops gmidi_in_ops = {
655	.open = f_midi_in_open,
656	.close = f_midi_in_close,
657	.trigger = f_midi_in_trigger,
658};
659
660static struct snd_rawmidi_ops gmidi_out_ops = {
661	.open = f_midi_out_open,
662	.close = f_midi_out_close,
663	.trigger = f_midi_out_trigger
664};
665
666/* register as a sound "card" */
667static int f_midi_register_card(struct f_midi *midi)
668{
669	struct snd_card *card;
670	struct snd_rawmidi *rmidi;
671	int err;
672	static struct snd_device_ops ops = {
673		.dev_free = f_midi_snd_free,
674	};
675
676	err = snd_card_create(midi->index, midi->id, THIS_MODULE, 0, &card);
677	if (err < 0) {
678		ERROR(midi, "snd_card_create() failed\n");
679		goto fail;
680	}
681	midi->card = card;
682
683	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops);
684	if (err < 0) {
685		ERROR(midi, "snd_device_new() failed: error %d\n", err);
686		goto fail;
687	}
688
689	strcpy(card->driver, f_midi_longname);
690	strcpy(card->longname, f_midi_longname);
691	strcpy(card->shortname, f_midi_shortname);
692
693	/* Set up rawmidi */
694	snd_component_add(card, "MIDI");
695	err = snd_rawmidi_new(card, card->longname, 0,
696			      midi->out_ports, midi->in_ports, &rmidi);
697	if (err < 0) {
698		ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
699		goto fail;
700	}
701	midi->rmidi = rmidi;
702	strcpy(rmidi->name, card->shortname);
703	rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
704			    SNDRV_RAWMIDI_INFO_INPUT |
705			    SNDRV_RAWMIDI_INFO_DUPLEX;
706	rmidi->private_data = midi;
707
708	/*
709	 * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
710	 * It's an upside-down world being a gadget.
711	 */
712	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
713	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
714
715	snd_card_set_dev(card, &midi->gadget->dev);
716
717	/* register it - we're ready to go */
718	err = snd_card_register(card);
719	if (err < 0) {
720		ERROR(midi, "snd_card_register() failed\n");
721		goto fail;
722	}
723
724	VDBG(midi, "%s() finished ok\n", __func__);
725	return 0;
726
727fail:
728	if (midi->card) {
729		snd_card_free(midi->card);
730		midi->card = NULL;
731	}
732	return err;
733}
734
735/* MIDI function driver setup/binding */
736
737static int __init
738f_midi_bind(struct usb_configuration *c, struct usb_function *f)
739{
740	struct usb_descriptor_header **midi_function;
741	struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
742	struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
743	struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
744	struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
745	struct usb_composite_dev *cdev = c->cdev;
746	struct f_midi *midi = func_to_midi(f);
747	int status, n, jack = 1, i = 0;
748
749	/* maybe allocate device-global string ID */
750	if (midi_string_defs[0].id == 0) {
751		status = usb_string_id(c->cdev);
752		if (status < 0)
753			goto fail;
754		midi_string_defs[0].id = status;
755	}
756
757	/* We have two interfaces, AudioControl and MIDIStreaming */
758	status = usb_interface_id(c, f);
759	if (status < 0)
760		goto fail;
761	ac_interface_desc.bInterfaceNumber = status;
762
763	status = usb_interface_id(c, f);
764	if (status < 0)
765		goto fail;
766	ms_interface_desc.bInterfaceNumber = status;
767	ac_header_desc.baInterfaceNr[0] = status;
768
769	status = -ENODEV;
770
771	/* allocate instance-specific endpoints */
772	midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
773	if (!midi->in_ep)
774		goto fail;
775	midi->in_ep->driver_data = cdev;	/* claim */
776
777	midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
778	if (!midi->out_ep)
779		goto fail;
780	midi->out_ep->driver_data = cdev;	/* claim */
781
782	/* allocate temporary function list */
783	midi_function = kcalloc((MAX_PORTS * 4) + 9, sizeof(*midi_function),
784				GFP_KERNEL);
785	if (!midi_function) {
786		status = -ENOMEM;
787		goto fail;
788	}
789
790	/*
791	 * construct the function's descriptor set. As the number of
792	 * input and output MIDI ports is configurable, we have to do
793	 * it that way.
794	 */
795
796	/* add the headers - these are always the same */
797	midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
798	midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
799	midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;
800
801	/* calculate the header's wTotalLength */
802	n = USB_DT_MS_HEADER_SIZE
803		+ (midi->in_ports + midi->out_ports) *
804			(USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
805	ms_header_desc.wTotalLength = cpu_to_le16(n);
806
807	midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;
808
809	/* configure the external IN jacks, each linked to an embedded OUT jack */
810	for (n = 0; n < midi->in_ports; n++) {
811		struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
812		struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];
813
814		in_ext->bLength			= USB_DT_MIDI_IN_SIZE;
815		in_ext->bDescriptorType		= USB_DT_CS_INTERFACE;
816		in_ext->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
817		in_ext->bJackType		= USB_MS_EXTERNAL;
818		in_ext->bJackID			= jack++;
819		in_ext->iJack			= 0;
820		midi_function[i++] = (struct usb_descriptor_header *) in_ext;
821
822		out_emb->bLength		= USB_DT_MIDI_OUT_SIZE(1);
823		out_emb->bDescriptorType	= USB_DT_CS_INTERFACE;
824		out_emb->bDescriptorSubtype	= USB_MS_MIDI_OUT_JACK;
825		out_emb->bJackType		= USB_MS_EMBEDDED;
826		out_emb->bJackID		= jack++;
827		out_emb->bNrInputPins		= 1;
828		out_emb->pins[0].baSourcePin	= 1;
829		out_emb->pins[0].baSourceID	= in_ext->bJackID;
830		out_emb->iJack			= 0;
831		midi_function[i++] = (struct usb_descriptor_header *) out_emb;
832
833		/* link it to the endpoint */
834		ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
835	}
836
837	/* configure the external OUT jacks, each linked to an embedded IN jack */
838	for (n = 0; n < midi->out_ports; n++) {
839		struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
840		struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];
841
842		in_emb->bLength			= USB_DT_MIDI_IN_SIZE;
843		in_emb->bDescriptorType		= USB_DT_CS_INTERFACE;
844		in_emb->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
845		in_emb->bJackType		= USB_MS_EMBEDDED;
846		in_emb->bJackID			= jack++;
847		in_emb->iJack			= 0;
848		midi_function[i++] = (struct usb_descriptor_header *) in_emb;
849
850		out_ext->bLength =		USB_DT_MIDI_OUT_SIZE(1);
851		out_ext->bDescriptorType =	USB_DT_CS_INTERFACE;
852		out_ext->bDescriptorSubtype =	USB_MS_MIDI_OUT_JACK;
853		out_ext->bJackType =		USB_MS_EXTERNAL;
854		out_ext->bJackID =		jack++;
855		out_ext->bNrInputPins =		1;
856		out_ext->iJack =		0;
857		out_ext->pins[0].baSourceID =	in_emb->bJackID;
858		out_ext->pins[0].baSourcePin =	1;
859		midi_function[i++] = (struct usb_descriptor_header *) out_ext;
860
861		/* link it to the endpoint */
862		ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
863	}
864
865	/* configure the endpoint descriptors ... */
866	ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
867	ms_out_desc.bNumEmbMIDIJack = midi->in_ports;
868
869	ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
870	ms_in_desc.bNumEmbMIDIJack = midi->out_ports;
871
872	/* ... and add them to the list */
873	midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
874	midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
875	midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
876	midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
877	midi_function[i++] = NULL;
878
879	/*
880	 * support all relevant hardware speeds... we expect that when
881	 * hardware is dual speed, all bulk-capable endpoints work at
882	 * both speeds
883	 */
884	/* copy descriptors, and track endpoint copies */
885	if (gadget_is_dualspeed(c->cdev->gadget)) {
886		c->highspeed = true;
887		bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
888		bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
889		f->hs_descriptors = usb_copy_descriptors(midi_function);
890	} else {
891		f->descriptors = usb_copy_descriptors(midi_function);
892	}
893
894	kfree(midi_function);
895
896	return 0;
897
898fail:
899	/* we might as well release our claims on endpoints */
900	if (midi->out_ep)
901		midi->out_ep->driver_data = NULL;
902	if (midi->in_ep)
903		midi->in_ep->driver_data = NULL;
904
905	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
906
907	return status;
908}
909
910/**
911 * f_midi_bind_config - add USB MIDI function to a configuration
912 * @c: the configuration to supcard the USB audio function
913 * @index: the soundcard index to use for the ALSA device creation
914 * @id: the soundcard id to use for the ALSA device creation
915 * @buflen: the buffer length to use
916 * @qlen the number of read requests to pre-allocate
917 * Context: single threaded during gadget setup
918 *
919 * Returns zero on success, else negative errno.
920 */
921int __init f_midi_bind_config(struct usb_configuration *c,
922			      int index, char *id,
923			      unsigned int in_ports,
924			      unsigned int out_ports,
925			      unsigned int buflen,
926			      unsigned int qlen)
927{
928	struct f_midi *midi;
929	int status, i;
930
931	/* sanity check */
932	if (in_ports > MAX_PORTS || out_ports > MAX_PORTS)
933		return -EINVAL;
934
935	/* allocate and initialize one new instance */
936	midi = kzalloc(sizeof *midi, GFP_KERNEL);
937	if (!midi) {
938		status = -ENOMEM;
939		goto fail;
940	}
941
942	for (i = 0; i < in_ports; i++) {
943		struct gmidi_in_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
944		if (!port) {
945			status = -ENOMEM;
946			goto setup_fail;
947		}
948
949		port->midi = midi;
950		port->active = 0;
951		port->cable = i;
952		midi->in_port[i] = port;
953	}
954
955	midi->gadget = c->cdev->gadget;
956	tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
957
958	/* set up ALSA midi devices */
959	midi->in_ports = in_ports;
960	midi->out_ports = out_ports;
961	status = f_midi_register_card(midi);
962	if (status < 0)
963		goto setup_fail;
964
965	midi->func.name        = "gmidi function";
966	midi->func.strings     = midi_strings;
967	midi->func.bind        = f_midi_bind;
968	midi->func.unbind      = f_midi_unbind;
969	midi->func.set_alt     = f_midi_set_alt;
970	midi->func.disable     = f_midi_disable;
971
972	midi->id = kstrdup(id, GFP_KERNEL);
973	midi->index = index;
974	midi->buflen = buflen;
975	midi->qlen = qlen;
976
977	status = usb_add_function(c, &midi->func);
978	if (status)
979		goto setup_fail;
980
981	return 0;
982
983setup_fail:
984	for (--i; i >= 0; i--)
985		kfree(midi->in_port[i]);
986	kfree(midi);
987fail:
988	return status;
989}
990
991