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/module.h>
24#include <linux/slab.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
36#include "u_f.h"
37#include "u_midi.h"
38
39MODULE_AUTHOR("Ben Williamson");
40MODULE_LICENSE("GPL v2");
41
42static const char f_midi_shortname[] = "f_midi";
43static const char f_midi_longname[] = "MIDI Gadget";
44
45/*
46 * We can only handle 16 cables on one single endpoint, as cable numbers are
47 * stored in 4-bit fields. And as the interface currently only holds one
48 * single endpoint, this is the maximum number of ports we can allow.
49 */
50#define MAX_PORTS 16
51
52/*
53 * This is a gadget, and the IN/OUT naming is from the host's perspective.
54 * USB -> OUT endpoint -> rawmidi
55 * USB <- IN endpoint  <- rawmidi
56 */
57struct gmidi_in_port {
58	struct f_midi *midi;
59	int active;
60	uint8_t cable;
61	uint8_t state;
62#define STATE_UNKNOWN	0
63#define STATE_1PARAM	1
64#define STATE_2PARAM_1	2
65#define STATE_2PARAM_2	3
66#define STATE_SYSEX_0	4
67#define STATE_SYSEX_1	5
68#define STATE_SYSEX_2	6
69	uint8_t data[2];
70};
71
72struct f_midi {
73	struct usb_function	func;
74	struct usb_gadget	*gadget;
75	struct usb_ep		*in_ep, *out_ep;
76	struct snd_card		*card;
77	struct snd_rawmidi	*rmidi;
78
79	struct snd_rawmidi_substream *in_substream[MAX_PORTS];
80	struct snd_rawmidi_substream *out_substream[MAX_PORTS];
81	struct gmidi_in_port	*in_port[MAX_PORTS];
82
83	unsigned long		out_triggered;
84	struct tasklet_struct	tasklet;
85	unsigned int in_ports;
86	unsigned int out_ports;
87	int index;
88	char *id;
89	unsigned int buflen, qlen;
90};
91
92static inline struct f_midi *func_to_midi(struct usb_function *f)
93{
94	return container_of(f, struct f_midi, func);
95}
96
97static void f_midi_transmit(struct f_midi *midi, struct usb_request *req);
98
99DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
100DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
101DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
102
103/* B.3.1  Standard AC Interface Descriptor */
104static struct usb_interface_descriptor ac_interface_desc = {
105	.bLength =		USB_DT_INTERFACE_SIZE,
106	.bDescriptorType =	USB_DT_INTERFACE,
107	/* .bInterfaceNumber =	DYNAMIC */
108	/* .bNumEndpoints =	DYNAMIC */
109	.bInterfaceClass =	USB_CLASS_AUDIO,
110	.bInterfaceSubClass =	USB_SUBCLASS_AUDIOCONTROL,
111	/* .iInterface =	DYNAMIC */
112};
113
114/* B.3.2  Class-Specific AC Interface Descriptor */
115static struct uac1_ac_header_descriptor_1 ac_header_desc = {
116	.bLength =		UAC_DT_AC_HEADER_SIZE(1),
117	.bDescriptorType =	USB_DT_CS_INTERFACE,
118	.bDescriptorSubtype =	USB_MS_HEADER,
119	.bcdADC =		cpu_to_le16(0x0100),
120	.wTotalLength =		cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)),
121	.bInCollection =	1,
122	/* .baInterfaceNr =	DYNAMIC */
123};
124
125/* B.4.1  Standard MS Interface Descriptor */
126static struct usb_interface_descriptor ms_interface_desc = {
127	.bLength =		USB_DT_INTERFACE_SIZE,
128	.bDescriptorType =	USB_DT_INTERFACE,
129	/* .bInterfaceNumber =	DYNAMIC */
130	.bNumEndpoints =	2,
131	.bInterfaceClass =	USB_CLASS_AUDIO,
132	.bInterfaceSubClass =	USB_SUBCLASS_MIDISTREAMING,
133	/* .iInterface =	DYNAMIC */
134};
135
136/* B.4.2  Class-Specific MS Interface Descriptor */
137static struct usb_ms_header_descriptor ms_header_desc = {
138	.bLength =		USB_DT_MS_HEADER_SIZE,
139	.bDescriptorType =	USB_DT_CS_INTERFACE,
140	.bDescriptorSubtype =	USB_MS_HEADER,
141	.bcdMSC =		cpu_to_le16(0x0100),
142	/* .wTotalLength =	DYNAMIC */
143};
144
145/* B.5.1  Standard Bulk OUT Endpoint Descriptor */
146static struct usb_endpoint_descriptor bulk_out_desc = {
147	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
148	.bDescriptorType =	USB_DT_ENDPOINT,
149	.bEndpointAddress =	USB_DIR_OUT,
150	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
151};
152
153/* B.5.2  Class-specific MS Bulk OUT Endpoint Descriptor */
154static struct usb_ms_endpoint_descriptor_16 ms_out_desc = {
155	/* .bLength =		DYNAMIC */
156	.bDescriptorType =	USB_DT_CS_ENDPOINT,
157	.bDescriptorSubtype =	USB_MS_GENERAL,
158	/* .bNumEmbMIDIJack =	DYNAMIC */
159	/* .baAssocJackID =	DYNAMIC */
160};
161
162/* B.6.1  Standard Bulk IN Endpoint Descriptor */
163static struct usb_endpoint_descriptor bulk_in_desc = {
164	.bLength =		USB_DT_ENDPOINT_AUDIO_SIZE,
165	.bDescriptorType =	USB_DT_ENDPOINT,
166	.bEndpointAddress =	USB_DIR_IN,
167	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
168};
169
170/* B.6.2  Class-specific MS Bulk IN Endpoint Descriptor */
171static struct usb_ms_endpoint_descriptor_16 ms_in_desc = {
172	/* .bLength =		DYNAMIC */
173	.bDescriptorType =	USB_DT_CS_ENDPOINT,
174	.bDescriptorSubtype =	USB_MS_GENERAL,
175	/* .bNumEmbMIDIJack =	DYNAMIC */
176	/* .baAssocJackID =	DYNAMIC */
177};
178
179/* string IDs are assigned dynamically */
180
181#define STRING_FUNC_IDX			0
182
183static struct usb_string midi_string_defs[] = {
184	[STRING_FUNC_IDX].s = "MIDI function",
185	{  } /* end of list */
186};
187
188static struct usb_gadget_strings midi_stringtab = {
189	.language	= 0x0409,	/* en-us */
190	.strings	= midi_string_defs,
191};
192
193static struct usb_gadget_strings *midi_strings[] = {
194	&midi_stringtab,
195	NULL,
196};
197
198static inline struct usb_request *midi_alloc_ep_req(struct usb_ep *ep,
199						    unsigned length)
200{
201	return alloc_ep_req(ep, length, length);
202}
203
204static void free_ep_req(struct usb_ep *ep, struct usb_request *req)
205{
206	kfree(req->buf);
207	usb_ep_free_request(ep, req);
208}
209
210static const uint8_t f_midi_cin_length[] = {
211	0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
212};
213
214/*
215 * Receives a chunk of MIDI data.
216 */
217static void f_midi_read_data(struct usb_ep *ep, int cable,
218			     uint8_t *data, int length)
219{
220	struct f_midi *midi = ep->driver_data;
221	struct snd_rawmidi_substream *substream = midi->out_substream[cable];
222
223	if (!substream)
224		/* Nobody is listening - throw it on the floor. */
225		return;
226
227	if (!test_bit(cable, &midi->out_triggered))
228		return;
229
230	snd_rawmidi_receive(substream, data, length);
231}
232
233static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
234{
235	unsigned int i;
236	u8 *buf = req->buf;
237
238	for (i = 0; i + 3 < req->actual; i += 4)
239		if (buf[i] != 0) {
240			int cable = buf[i] >> 4;
241			int length = f_midi_cin_length[buf[i] & 0x0f];
242			f_midi_read_data(ep, cable, &buf[i + 1], length);
243		}
244}
245
246static void
247f_midi_complete(struct usb_ep *ep, struct usb_request *req)
248{
249	struct f_midi *midi = ep->driver_data;
250	struct usb_composite_dev *cdev = midi->func.config->cdev;
251	int status = req->status;
252
253	switch (status) {
254	case 0:			 /* normal completion */
255		if (ep == midi->out_ep) {
256			/* We received stuff. req is queued again, below */
257			f_midi_handle_out_data(ep, req);
258		} else if (ep == midi->in_ep) {
259			/* Our transmit completed. See if there's more to go.
260			 * f_midi_transmit eats req, don't queue it again. */
261			f_midi_transmit(midi, req);
262			return;
263		}
264		break;
265
266	/* this endpoint is normally active while we're configured */
267	case -ECONNABORTED:	/* hardware forced ep reset */
268	case -ECONNRESET:	/* request dequeued */
269	case -ESHUTDOWN:	/* disconnect from host */
270		VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
271				req->actual, req->length);
272		if (ep == midi->out_ep)
273			f_midi_handle_out_data(ep, req);
274
275		free_ep_req(ep, req);
276		return;
277
278	case -EOVERFLOW:	/* buffer overrun on read means that
279				 * we didn't provide a big enough buffer.
280				 */
281	default:
282		DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name,
283				status, req->actual, req->length);
284		break;
285	case -EREMOTEIO:	/* short read */
286		break;
287	}
288
289	status = usb_ep_queue(ep, req, GFP_ATOMIC);
290	if (status) {
291		ERROR(cdev, "kill %s:  resubmit %d bytes --> %d\n",
292				ep->name, req->length, status);
293		usb_ep_set_halt(ep);
294		/* FIXME recover later ... somehow */
295	}
296}
297
298static int f_midi_start_ep(struct f_midi *midi,
299			   struct usb_function *f,
300			   struct usb_ep *ep)
301{
302	int err;
303	struct usb_composite_dev *cdev = f->config->cdev;
304
305	if (ep->driver_data)
306		usb_ep_disable(ep);
307
308	err = config_ep_by_speed(midi->gadget, f, ep);
309	if (err) {
310		ERROR(cdev, "can't configure %s: %d\n", ep->name, err);
311		return err;
312	}
313
314	err = usb_ep_enable(ep);
315	if (err) {
316		ERROR(cdev, "can't start %s: %d\n", ep->name, err);
317		return err;
318	}
319
320	ep->driver_data = midi;
321
322	return 0;
323}
324
325static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
326{
327	struct f_midi *midi = func_to_midi(f);
328	struct usb_composite_dev *cdev = f->config->cdev;
329	unsigned i;
330	int err;
331
332	err = f_midi_start_ep(midi, f, midi->in_ep);
333	if (err)
334		return err;
335
336	err = f_midi_start_ep(midi, f, midi->out_ep);
337	if (err)
338		return err;
339
340	if (midi->out_ep->driver_data)
341		usb_ep_disable(midi->out_ep);
342
343	err = config_ep_by_speed(midi->gadget, f, midi->out_ep);
344	if (err) {
345		ERROR(cdev, "can't configure %s: %d\n",
346		      midi->out_ep->name, err);
347		return err;
348	}
349
350	err = usb_ep_enable(midi->out_ep);
351	if (err) {
352		ERROR(cdev, "can't start %s: %d\n",
353		      midi->out_ep->name, err);
354		return err;
355	}
356
357	midi->out_ep->driver_data = midi;
358
359	/* allocate a bunch of read buffers and queue them all at once. */
360	for (i = 0; i < midi->qlen && err == 0; i++) {
361		struct usb_request *req =
362			midi_alloc_ep_req(midi->out_ep, midi->buflen);
363		if (req == NULL)
364			return -ENOMEM;
365
366		req->complete = f_midi_complete;
367		err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
368		if (err) {
369			ERROR(midi, "%s queue req: %d\n",
370				    midi->out_ep->name, err);
371		}
372	}
373
374	return 0;
375}
376
377static void f_midi_disable(struct usb_function *f)
378{
379	struct f_midi *midi = func_to_midi(f);
380	struct usb_composite_dev *cdev = f->config->cdev;
381
382	DBG(cdev, "disable\n");
383
384	/*
385	 * just disable endpoints, forcing completion of pending i/o.
386	 * all our completion handlers free their requests in this case.
387	 */
388	usb_ep_disable(midi->in_ep);
389	usb_ep_disable(midi->out_ep);
390}
391
392static int f_midi_snd_free(struct snd_device *device)
393{
394	return 0;
395}
396
397static void f_midi_transmit_packet(struct usb_request *req, uint8_t p0,
398					uint8_t p1, uint8_t p2, uint8_t p3)
399{
400	unsigned length = req->length;
401	u8 *buf = (u8 *)req->buf + length;
402
403	buf[0] = p0;
404	buf[1] = p1;
405	buf[2] = p2;
406	buf[3] = p3;
407	req->length = length + 4;
408}
409
410/*
411 * Converts MIDI commands to USB MIDI packets.
412 */
413static void f_midi_transmit_byte(struct usb_request *req,
414				 struct gmidi_in_port *port, uint8_t b)
415{
416	uint8_t p0 = port->cable << 4;
417
418	if (b >= 0xf8) {
419		f_midi_transmit_packet(req, p0 | 0x0f, b, 0, 0);
420	} else if (b >= 0xf0) {
421		switch (b) {
422		case 0xf0:
423			port->data[0] = b;
424			port->state = STATE_SYSEX_1;
425			break;
426		case 0xf1:
427		case 0xf3:
428			port->data[0] = b;
429			port->state = STATE_1PARAM;
430			break;
431		case 0xf2:
432			port->data[0] = b;
433			port->state = STATE_2PARAM_1;
434			break;
435		case 0xf4:
436		case 0xf5:
437			port->state = STATE_UNKNOWN;
438			break;
439		case 0xf6:
440			f_midi_transmit_packet(req, p0 | 0x05, 0xf6, 0, 0);
441			port->state = STATE_UNKNOWN;
442			break;
443		case 0xf7:
444			switch (port->state) {
445			case STATE_SYSEX_0:
446				f_midi_transmit_packet(req,
447					p0 | 0x05, 0xf7, 0, 0);
448				break;
449			case STATE_SYSEX_1:
450				f_midi_transmit_packet(req,
451					p0 | 0x06, port->data[0], 0xf7, 0);
452				break;
453			case STATE_SYSEX_2:
454				f_midi_transmit_packet(req,
455					p0 | 0x07, port->data[0],
456					port->data[1], 0xf7);
457				break;
458			}
459			port->state = STATE_UNKNOWN;
460			break;
461		}
462	} else if (b >= 0x80) {
463		port->data[0] = b;
464		if (b >= 0xc0 && b <= 0xdf)
465			port->state = STATE_1PARAM;
466		else
467			port->state = STATE_2PARAM_1;
468	} else { /* b < 0x80 */
469		switch (port->state) {
470		case STATE_1PARAM:
471			if (port->data[0] < 0xf0) {
472				p0 |= port->data[0] >> 4;
473			} else {
474				p0 |= 0x02;
475				port->state = STATE_UNKNOWN;
476			}
477			f_midi_transmit_packet(req, p0, port->data[0], b, 0);
478			break;
479		case STATE_2PARAM_1:
480			port->data[1] = b;
481			port->state = STATE_2PARAM_2;
482			break;
483		case STATE_2PARAM_2:
484			if (port->data[0] < 0xf0) {
485				p0 |= port->data[0] >> 4;
486				port->state = STATE_2PARAM_1;
487			} else {
488				p0 |= 0x03;
489				port->state = STATE_UNKNOWN;
490			}
491			f_midi_transmit_packet(req,
492				p0, port->data[0], port->data[1], b);
493			break;
494		case STATE_SYSEX_0:
495			port->data[0] = b;
496			port->state = STATE_SYSEX_1;
497			break;
498		case STATE_SYSEX_1:
499			port->data[1] = b;
500			port->state = STATE_SYSEX_2;
501			break;
502		case STATE_SYSEX_2:
503			f_midi_transmit_packet(req,
504				p0 | 0x04, port->data[0], port->data[1], b);
505			port->state = STATE_SYSEX_0;
506			break;
507		}
508	}
509}
510
511static void f_midi_transmit(struct f_midi *midi, struct usb_request *req)
512{
513	struct usb_ep *ep = midi->in_ep;
514	int i;
515
516	if (!ep)
517		return;
518
519	if (!req)
520		req = midi_alloc_ep_req(ep, midi->buflen);
521
522	if (!req) {
523		ERROR(midi, "%s: alloc_ep_request failed\n", __func__);
524		return;
525	}
526	req->length = 0;
527	req->complete = f_midi_complete;
528
529	for (i = 0; i < MAX_PORTS; i++) {
530		struct gmidi_in_port *port = midi->in_port[i];
531		struct snd_rawmidi_substream *substream = midi->in_substream[i];
532
533		if (!port || !port->active || !substream)
534			continue;
535
536		while (req->length + 3 < midi->buflen) {
537			uint8_t b;
538			if (snd_rawmidi_transmit(substream, &b, 1) != 1) {
539				port->active = 0;
540				break;
541			}
542			f_midi_transmit_byte(req, port, b);
543		}
544	}
545
546	if (req->length > 0)
547		usb_ep_queue(ep, req, GFP_ATOMIC);
548	else
549		free_ep_req(ep, req);
550}
551
552static void f_midi_in_tasklet(unsigned long data)
553{
554	struct f_midi *midi = (struct f_midi *) data;
555	f_midi_transmit(midi, NULL);
556}
557
558static int f_midi_in_open(struct snd_rawmidi_substream *substream)
559{
560	struct f_midi *midi = substream->rmidi->private_data;
561
562	if (!midi->in_port[substream->number])
563		return -EINVAL;
564
565	VDBG(midi, "%s()\n", __func__);
566	midi->in_substream[substream->number] = substream;
567	midi->in_port[substream->number]->state = STATE_UNKNOWN;
568	return 0;
569}
570
571static int f_midi_in_close(struct snd_rawmidi_substream *substream)
572{
573	struct f_midi *midi = substream->rmidi->private_data;
574
575	VDBG(midi, "%s()\n", __func__);
576	return 0;
577}
578
579static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
580{
581	struct f_midi *midi = substream->rmidi->private_data;
582
583	if (!midi->in_port[substream->number])
584		return;
585
586	VDBG(midi, "%s() %d\n", __func__, up);
587	midi->in_port[substream->number]->active = up;
588	if (up)
589		tasklet_hi_schedule(&midi->tasklet);
590}
591
592static int f_midi_out_open(struct snd_rawmidi_substream *substream)
593{
594	struct f_midi *midi = substream->rmidi->private_data;
595
596	if (substream->number >= MAX_PORTS)
597		return -EINVAL;
598
599	VDBG(midi, "%s()\n", __func__);
600	midi->out_substream[substream->number] = substream;
601	return 0;
602}
603
604static int f_midi_out_close(struct snd_rawmidi_substream *substream)
605{
606	struct f_midi *midi = substream->rmidi->private_data;
607
608	VDBG(midi, "%s()\n", __func__);
609	return 0;
610}
611
612static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
613{
614	struct f_midi *midi = substream->rmidi->private_data;
615
616	VDBG(midi, "%s()\n", __func__);
617
618	if (up)
619		set_bit(substream->number, &midi->out_triggered);
620	else
621		clear_bit(substream->number, &midi->out_triggered);
622}
623
624static struct snd_rawmidi_ops gmidi_in_ops = {
625	.open = f_midi_in_open,
626	.close = f_midi_in_close,
627	.trigger = f_midi_in_trigger,
628};
629
630static struct snd_rawmidi_ops gmidi_out_ops = {
631	.open = f_midi_out_open,
632	.close = f_midi_out_close,
633	.trigger = f_midi_out_trigger
634};
635
636static inline void f_midi_unregister_card(struct f_midi *midi)
637{
638	if (midi->card) {
639		snd_card_free(midi->card);
640		midi->card = NULL;
641	}
642}
643
644/* register as a sound "card" */
645static int f_midi_register_card(struct f_midi *midi)
646{
647	struct snd_card *card;
648	struct snd_rawmidi *rmidi;
649	int err;
650	static struct snd_device_ops ops = {
651		.dev_free = f_midi_snd_free,
652	};
653
654	err = snd_card_new(&midi->gadget->dev, midi->index, midi->id,
655			   THIS_MODULE, 0, &card);
656	if (err < 0) {
657		ERROR(midi, "snd_card_new() failed\n");
658		goto fail;
659	}
660	midi->card = card;
661
662	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops);
663	if (err < 0) {
664		ERROR(midi, "snd_device_new() failed: error %d\n", err);
665		goto fail;
666	}
667
668	strcpy(card->driver, f_midi_longname);
669	strcpy(card->longname, f_midi_longname);
670	strcpy(card->shortname, f_midi_shortname);
671
672	/* Set up rawmidi */
673	snd_component_add(card, "MIDI");
674	err = snd_rawmidi_new(card, card->longname, 0,
675			      midi->out_ports, midi->in_ports, &rmidi);
676	if (err < 0) {
677		ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
678		goto fail;
679	}
680	midi->rmidi = rmidi;
681	strcpy(rmidi->name, card->shortname);
682	rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
683			    SNDRV_RAWMIDI_INFO_INPUT |
684			    SNDRV_RAWMIDI_INFO_DUPLEX;
685	rmidi->private_data = midi;
686
687	/*
688	 * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
689	 * It's an upside-down world being a gadget.
690	 */
691	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
692	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
693
694	/* register it - we're ready to go */
695	err = snd_card_register(card);
696	if (err < 0) {
697		ERROR(midi, "snd_card_register() failed\n");
698		goto fail;
699	}
700
701	VDBG(midi, "%s() finished ok\n", __func__);
702	return 0;
703
704fail:
705	f_midi_unregister_card(midi);
706	return err;
707}
708
709/* MIDI function driver setup/binding */
710
711static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
712{
713	struct usb_descriptor_header **midi_function;
714	struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
715	struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
716	struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
717	struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
718	struct usb_composite_dev *cdev = c->cdev;
719	struct f_midi *midi = func_to_midi(f);
720	struct usb_string *us;
721	int status, n, jack = 1, i = 0;
722
723	midi->gadget = cdev->gadget;
724	tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
725	status = f_midi_register_card(midi);
726	if (status < 0)
727		goto fail_register;
728
729	/* maybe allocate device-global string ID */
730	us = usb_gstrings_attach(c->cdev, midi_strings,
731				 ARRAY_SIZE(midi_string_defs));
732	if (IS_ERR(us)) {
733		status = PTR_ERR(us);
734		goto fail;
735	}
736	ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id;
737
738	/* We have two interfaces, AudioControl and MIDIStreaming */
739	status = usb_interface_id(c, f);
740	if (status < 0)
741		goto fail;
742	ac_interface_desc.bInterfaceNumber = status;
743
744	status = usb_interface_id(c, f);
745	if (status < 0)
746		goto fail;
747	ms_interface_desc.bInterfaceNumber = status;
748	ac_header_desc.baInterfaceNr[0] = status;
749
750	status = -ENODEV;
751
752	/* allocate instance-specific endpoints */
753	midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
754	if (!midi->in_ep)
755		goto fail;
756	midi->in_ep->driver_data = cdev;	/* claim */
757
758	midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
759	if (!midi->out_ep)
760		goto fail;
761	midi->out_ep->driver_data = cdev;	/* claim */
762
763	/* allocate temporary function list */
764	midi_function = kcalloc((MAX_PORTS * 4) + 9, sizeof(*midi_function),
765				GFP_KERNEL);
766	if (!midi_function) {
767		status = -ENOMEM;
768		goto fail;
769	}
770
771	/*
772	 * construct the function's descriptor set. As the number of
773	 * input and output MIDI ports is configurable, we have to do
774	 * it that way.
775	 */
776
777	/* add the headers - these are always the same */
778	midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
779	midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
780	midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;
781
782	/* calculate the header's wTotalLength */
783	n = USB_DT_MS_HEADER_SIZE
784		+ (midi->in_ports + midi->out_ports) *
785			(USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
786	ms_header_desc.wTotalLength = cpu_to_le16(n);
787
788	midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;
789
790	/* configure the external IN jacks, each linked to an embedded OUT jack */
791	for (n = 0; n < midi->in_ports; n++) {
792		struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
793		struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];
794
795		in_ext->bLength			= USB_DT_MIDI_IN_SIZE;
796		in_ext->bDescriptorType		= USB_DT_CS_INTERFACE;
797		in_ext->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
798		in_ext->bJackType		= USB_MS_EXTERNAL;
799		in_ext->bJackID			= jack++;
800		in_ext->iJack			= 0;
801		midi_function[i++] = (struct usb_descriptor_header *) in_ext;
802
803		out_emb->bLength		= USB_DT_MIDI_OUT_SIZE(1);
804		out_emb->bDescriptorType	= USB_DT_CS_INTERFACE;
805		out_emb->bDescriptorSubtype	= USB_MS_MIDI_OUT_JACK;
806		out_emb->bJackType		= USB_MS_EMBEDDED;
807		out_emb->bJackID		= jack++;
808		out_emb->bNrInputPins		= 1;
809		out_emb->pins[0].baSourcePin	= 1;
810		out_emb->pins[0].baSourceID	= in_ext->bJackID;
811		out_emb->iJack			= 0;
812		midi_function[i++] = (struct usb_descriptor_header *) out_emb;
813
814		/* link it to the endpoint */
815		ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
816	}
817
818	/* configure the external OUT jacks, each linked to an embedded IN jack */
819	for (n = 0; n < midi->out_ports; n++) {
820		struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
821		struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];
822
823		in_emb->bLength			= USB_DT_MIDI_IN_SIZE;
824		in_emb->bDescriptorType		= USB_DT_CS_INTERFACE;
825		in_emb->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
826		in_emb->bJackType		= USB_MS_EMBEDDED;
827		in_emb->bJackID			= jack++;
828		in_emb->iJack			= 0;
829		midi_function[i++] = (struct usb_descriptor_header *) in_emb;
830
831		out_ext->bLength =		USB_DT_MIDI_OUT_SIZE(1);
832		out_ext->bDescriptorType =	USB_DT_CS_INTERFACE;
833		out_ext->bDescriptorSubtype =	USB_MS_MIDI_OUT_JACK;
834		out_ext->bJackType =		USB_MS_EXTERNAL;
835		out_ext->bJackID =		jack++;
836		out_ext->bNrInputPins =		1;
837		out_ext->iJack =		0;
838		out_ext->pins[0].baSourceID =	in_emb->bJackID;
839		out_ext->pins[0].baSourcePin =	1;
840		midi_function[i++] = (struct usb_descriptor_header *) out_ext;
841
842		/* link it to the endpoint */
843		ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
844	}
845
846	/* configure the endpoint descriptors ... */
847	ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
848	ms_out_desc.bNumEmbMIDIJack = midi->in_ports;
849
850	ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
851	ms_in_desc.bNumEmbMIDIJack = midi->out_ports;
852
853	/* ... and add them to the list */
854	midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
855	midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
856	midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
857	midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
858	midi_function[i++] = NULL;
859
860	/*
861	 * support all relevant hardware speeds... we expect that when
862	 * hardware is dual speed, all bulk-capable endpoints work at
863	 * both speeds
864	 */
865	/* copy descriptors, and track endpoint copies */
866	f->fs_descriptors = usb_copy_descriptors(midi_function);
867	if (!f->fs_descriptors)
868		goto fail_f_midi;
869
870	if (gadget_is_dualspeed(c->cdev->gadget)) {
871		bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
872		bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
873		f->hs_descriptors = usb_copy_descriptors(midi_function);
874		if (!f->hs_descriptors)
875			goto fail_f_midi;
876	}
877
878	kfree(midi_function);
879
880	return 0;
881
882fail_f_midi:
883	kfree(midi_function);
884	usb_free_descriptors(f->hs_descriptors);
885fail:
886	f_midi_unregister_card(midi);
887fail_register:
888	/* we might as well release our claims on endpoints */
889	if (midi->out_ep)
890		midi->out_ep->driver_data = NULL;
891	if (midi->in_ep)
892		midi->in_ep->driver_data = NULL;
893
894	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
895
896	return status;
897}
898
899static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item)
900{
901	return container_of(to_config_group(item), struct f_midi_opts,
902			    func_inst.group);
903}
904
905CONFIGFS_ATTR_STRUCT(f_midi_opts);
906CONFIGFS_ATTR_OPS(f_midi_opts);
907
908static void midi_attr_release(struct config_item *item)
909{
910	struct f_midi_opts *opts = to_f_midi_opts(item);
911
912	usb_put_function_instance(&opts->func_inst);
913}
914
915static struct configfs_item_operations midi_item_ops = {
916	.release	= midi_attr_release,
917	.show_attribute	= f_midi_opts_attr_show,
918	.store_attribute = f_midi_opts_attr_store,
919};
920
921#define F_MIDI_OPT(name, test_limit, limit)				\
922static ssize_t f_midi_opts_##name##_show(struct f_midi_opts *opts, char *page) \
923{									\
924	int result;							\
925									\
926	mutex_lock(&opts->lock);					\
927	result = sprintf(page, "%d\n", opts->name);			\
928	mutex_unlock(&opts->lock);					\
929									\
930	return result;							\
931}									\
932									\
933static ssize_t f_midi_opts_##name##_store(struct f_midi_opts *opts,	\
934					 const char *page, size_t len)	\
935{									\
936	int ret;							\
937	u32 num;							\
938									\
939	mutex_lock(&opts->lock);					\
940	if (opts->refcnt) {						\
941		ret = -EBUSY;						\
942		goto end;						\
943	}								\
944									\
945	ret = kstrtou32(page, 0, &num);					\
946	if (ret)							\
947		goto end;						\
948									\
949	if (test_limit && num > limit) {				\
950		ret = -EINVAL;						\
951		goto end;						\
952	}								\
953	opts->name = num;						\
954	ret = len;							\
955									\
956end:									\
957	mutex_unlock(&opts->lock);					\
958	return ret;							\
959}									\
960									\
961static struct f_midi_opts_attribute f_midi_opts_##name =		\
962	__CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_midi_opts_##name##_show, \
963			f_midi_opts_##name##_store)
964
965F_MIDI_OPT(index, true, SNDRV_CARDS);
966F_MIDI_OPT(buflen, false, 0);
967F_MIDI_OPT(qlen, false, 0);
968F_MIDI_OPT(in_ports, true, MAX_PORTS);
969F_MIDI_OPT(out_ports, true, MAX_PORTS);
970
971static ssize_t f_midi_opts_id_show(struct f_midi_opts *opts, char *page)
972{
973	int result;
974
975	mutex_lock(&opts->lock);
976	if (opts->id) {
977		result = strlcpy(page, opts->id, PAGE_SIZE);
978	} else {
979		page[0] = 0;
980		result = 0;
981	}
982
983	mutex_unlock(&opts->lock);
984
985	return result;
986}
987
988static ssize_t f_midi_opts_id_store(struct f_midi_opts *opts,
989				    const char *page, size_t len)
990{
991	int ret;
992	char *c;
993
994	mutex_lock(&opts->lock);
995	if (opts->refcnt) {
996		ret = -EBUSY;
997		goto end;
998	}
999
1000	c = kstrndup(page, len, GFP_KERNEL);
1001	if (!c) {
1002		ret = -ENOMEM;
1003		goto end;
1004	}
1005	if (opts->id_allocated)
1006		kfree(opts->id);
1007	opts->id = c;
1008	opts->id_allocated = true;
1009	ret = len;
1010end:
1011	mutex_unlock(&opts->lock);
1012	return ret;
1013}
1014
1015static struct f_midi_opts_attribute f_midi_opts_id =
1016	__CONFIGFS_ATTR(id, S_IRUGO | S_IWUSR, f_midi_opts_id_show,
1017			f_midi_opts_id_store);
1018
1019static struct configfs_attribute *midi_attrs[] = {
1020	&f_midi_opts_index.attr,
1021	&f_midi_opts_buflen.attr,
1022	&f_midi_opts_qlen.attr,
1023	&f_midi_opts_in_ports.attr,
1024	&f_midi_opts_out_ports.attr,
1025	&f_midi_opts_id.attr,
1026	NULL,
1027};
1028
1029static struct config_item_type midi_func_type = {
1030	.ct_item_ops	= &midi_item_ops,
1031	.ct_attrs	= midi_attrs,
1032	.ct_owner	= THIS_MODULE,
1033};
1034
1035static void f_midi_free_inst(struct usb_function_instance *f)
1036{
1037	struct f_midi_opts *opts;
1038
1039	opts = container_of(f, struct f_midi_opts, func_inst);
1040
1041	if (opts->id_allocated)
1042		kfree(opts->id);
1043
1044	kfree(opts);
1045}
1046
1047static struct usb_function_instance *f_midi_alloc_inst(void)
1048{
1049	struct f_midi_opts *opts;
1050
1051	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1052	if (!opts)
1053		return ERR_PTR(-ENOMEM);
1054
1055	mutex_init(&opts->lock);
1056	opts->func_inst.free_func_inst = f_midi_free_inst;
1057	opts->index = SNDRV_DEFAULT_IDX1;
1058	opts->id = SNDRV_DEFAULT_STR1;
1059	opts->buflen = 256;
1060	opts->qlen = 32;
1061	opts->in_ports = 1;
1062	opts->out_ports = 1;
1063
1064	config_group_init_type_name(&opts->func_inst.group, "",
1065				    &midi_func_type);
1066
1067	return &opts->func_inst;
1068}
1069
1070static void f_midi_free(struct usb_function *f)
1071{
1072	struct f_midi *midi;
1073	struct f_midi_opts *opts;
1074	int i;
1075
1076	midi = func_to_midi(f);
1077	opts = container_of(f->fi, struct f_midi_opts, func_inst);
1078	kfree(midi->id);
1079	mutex_lock(&opts->lock);
1080	for (i = opts->in_ports - 1; i >= 0; --i)
1081		kfree(midi->in_port[i]);
1082	kfree(midi);
1083	--opts->refcnt;
1084	mutex_unlock(&opts->lock);
1085}
1086
1087static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
1088{
1089	struct usb_composite_dev *cdev = f->config->cdev;
1090	struct f_midi *midi = func_to_midi(f);
1091	struct snd_card *card;
1092
1093	DBG(cdev, "unbind\n");
1094
1095	/* just to be sure */
1096	f_midi_disable(f);
1097
1098	card = midi->card;
1099	midi->card = NULL;
1100	if (card)
1101		snd_card_free(card);
1102
1103	usb_free_all_descriptors(f);
1104}
1105
1106static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
1107{
1108	struct f_midi *midi;
1109	struct f_midi_opts *opts;
1110	int status, i;
1111
1112	opts = container_of(fi, struct f_midi_opts, func_inst);
1113
1114	mutex_lock(&opts->lock);
1115	/* sanity check */
1116	if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) {
1117		mutex_unlock(&opts->lock);
1118		return ERR_PTR(-EINVAL);
1119	}
1120
1121	/* allocate and initialize one new instance */
1122	midi = kzalloc(sizeof(*midi), GFP_KERNEL);
1123	if (!midi) {
1124		mutex_unlock(&opts->lock);
1125		return ERR_PTR(-ENOMEM);
1126	}
1127
1128	for (i = 0; i < opts->in_ports; i++) {
1129		struct gmidi_in_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
1130
1131		if (!port) {
1132			status = -ENOMEM;
1133			mutex_unlock(&opts->lock);
1134			goto setup_fail;
1135		}
1136
1137		port->midi = midi;
1138		port->active = 0;
1139		port->cable = i;
1140		midi->in_port[i] = port;
1141	}
1142
1143	/* set up ALSA midi devices */
1144	midi->id = kstrdup(opts->id, GFP_KERNEL);
1145	if (opts->id && !midi->id) {
1146		status = -ENOMEM;
1147		mutex_unlock(&opts->lock);
1148		goto kstrdup_fail;
1149	}
1150	midi->in_ports = opts->in_ports;
1151	midi->out_ports = opts->out_ports;
1152	midi->index = opts->index;
1153	midi->buflen = opts->buflen;
1154	midi->qlen = opts->qlen;
1155	++opts->refcnt;
1156	mutex_unlock(&opts->lock);
1157
1158	midi->func.name		= "gmidi function";
1159	midi->func.bind		= f_midi_bind;
1160	midi->func.unbind	= f_midi_unbind;
1161	midi->func.set_alt	= f_midi_set_alt;
1162	midi->func.disable	= f_midi_disable;
1163	midi->func.free_func	= f_midi_free;
1164
1165	return &midi->func;
1166
1167kstrdup_fail:
1168	f_midi_unregister_card(midi);
1169setup_fail:
1170	for (--i; i >= 0; i--)
1171		kfree(midi->in_port[i]);
1172	kfree(midi);
1173	return ERR_PTR(status);
1174}
1175
1176DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc);
1177