xref: /linux/drivers/usb/gadget/function/f_midi.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 
39 MODULE_AUTHOR("Ben Williamson");
40 MODULE_LICENSE("GPL v2");
41 
42 static const char f_midi_shortname[] = "f_midi";
43 static 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  */
57 struct 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 
72 struct 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 
92 static inline struct f_midi *func_to_midi(struct usb_function *f)
93 {
94 	return container_of(f, struct f_midi, func);
95 }
96 
97 static void f_midi_transmit(struct f_midi *midi, struct usb_request *req);
98 
99 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
100 DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
101 DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
102 
103 /* B.3.1  Standard AC Interface Descriptor */
104 static 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 */
115 static 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 */
126 static 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 */
137 static 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 */
146 static 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 */
154 static 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 */
163 static 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 */
171 static 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 
183 static struct usb_string midi_string_defs[] = {
184 	[STRING_FUNC_IDX].s = "MIDI function",
185 	{  } /* end of list */
186 };
187 
188 static struct usb_gadget_strings midi_stringtab = {
189 	.language	= 0x0409,	/* en-us */
190 	.strings	= midi_string_defs,
191 };
192 
193 static struct usb_gadget_strings *midi_strings[] = {
194 	&midi_stringtab,
195 	NULL,
196 };
197 
198 static 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 
204 static 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 
210 static 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  */
217 static 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 
233 static 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 
246 static void
247 f_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 
298 static 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 
325 static 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 	/* For Control Device interface we do nothing */
333 	if (intf == 0)
334 		return 0;
335 
336 	err = f_midi_start_ep(midi, f, midi->in_ep);
337 	if (err)
338 		return err;
339 
340 	err = f_midi_start_ep(midi, f, midi->out_ep);
341 	if (err)
342 		return err;
343 
344 	if (midi->out_ep->driver_data)
345 		usb_ep_disable(midi->out_ep);
346 
347 	err = config_ep_by_speed(midi->gadget, f, midi->out_ep);
348 	if (err) {
349 		ERROR(cdev, "can't configure %s: %d\n",
350 		      midi->out_ep->name, err);
351 		return err;
352 	}
353 
354 	err = usb_ep_enable(midi->out_ep);
355 	if (err) {
356 		ERROR(cdev, "can't start %s: %d\n",
357 		      midi->out_ep->name, err);
358 		return err;
359 	}
360 
361 	midi->out_ep->driver_data = midi;
362 
363 	/* allocate a bunch of read buffers and queue them all at once. */
364 	for (i = 0; i < midi->qlen && err == 0; i++) {
365 		struct usb_request *req =
366 			midi_alloc_ep_req(midi->out_ep, midi->buflen);
367 		if (req == NULL)
368 			return -ENOMEM;
369 
370 		req->complete = f_midi_complete;
371 		err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
372 		if (err) {
373 			ERROR(midi, "%s queue req: %d\n",
374 				    midi->out_ep->name, err);
375 		}
376 	}
377 
378 	return 0;
379 }
380 
381 static void f_midi_disable(struct usb_function *f)
382 {
383 	struct f_midi *midi = func_to_midi(f);
384 	struct usb_composite_dev *cdev = f->config->cdev;
385 
386 	DBG(cdev, "disable\n");
387 
388 	/*
389 	 * just disable endpoints, forcing completion of pending i/o.
390 	 * all our completion handlers free their requests in this case.
391 	 */
392 	usb_ep_disable(midi->in_ep);
393 	usb_ep_disable(midi->out_ep);
394 }
395 
396 static int f_midi_snd_free(struct snd_device *device)
397 {
398 	return 0;
399 }
400 
401 static void f_midi_transmit_packet(struct usb_request *req, uint8_t p0,
402 					uint8_t p1, uint8_t p2, uint8_t p3)
403 {
404 	unsigned length = req->length;
405 	u8 *buf = (u8 *)req->buf + length;
406 
407 	buf[0] = p0;
408 	buf[1] = p1;
409 	buf[2] = p2;
410 	buf[3] = p3;
411 	req->length = length + 4;
412 }
413 
414 /*
415  * Converts MIDI commands to USB MIDI packets.
416  */
417 static void f_midi_transmit_byte(struct usb_request *req,
418 				 struct gmidi_in_port *port, uint8_t b)
419 {
420 	uint8_t p0 = port->cable << 4;
421 
422 	if (b >= 0xf8) {
423 		f_midi_transmit_packet(req, p0 | 0x0f, b, 0, 0);
424 	} else if (b >= 0xf0) {
425 		switch (b) {
426 		case 0xf0:
427 			port->data[0] = b;
428 			port->state = STATE_SYSEX_1;
429 			break;
430 		case 0xf1:
431 		case 0xf3:
432 			port->data[0] = b;
433 			port->state = STATE_1PARAM;
434 			break;
435 		case 0xf2:
436 			port->data[0] = b;
437 			port->state = STATE_2PARAM_1;
438 			break;
439 		case 0xf4:
440 		case 0xf5:
441 			port->state = STATE_UNKNOWN;
442 			break;
443 		case 0xf6:
444 			f_midi_transmit_packet(req, p0 | 0x05, 0xf6, 0, 0);
445 			port->state = STATE_UNKNOWN;
446 			break;
447 		case 0xf7:
448 			switch (port->state) {
449 			case STATE_SYSEX_0:
450 				f_midi_transmit_packet(req,
451 					p0 | 0x05, 0xf7, 0, 0);
452 				break;
453 			case STATE_SYSEX_1:
454 				f_midi_transmit_packet(req,
455 					p0 | 0x06, port->data[0], 0xf7, 0);
456 				break;
457 			case STATE_SYSEX_2:
458 				f_midi_transmit_packet(req,
459 					p0 | 0x07, port->data[0],
460 					port->data[1], 0xf7);
461 				break;
462 			}
463 			port->state = STATE_UNKNOWN;
464 			break;
465 		}
466 	} else if (b >= 0x80) {
467 		port->data[0] = b;
468 		if (b >= 0xc0 && b <= 0xdf)
469 			port->state = STATE_1PARAM;
470 		else
471 			port->state = STATE_2PARAM_1;
472 	} else { /* b < 0x80 */
473 		switch (port->state) {
474 		case STATE_1PARAM:
475 			if (port->data[0] < 0xf0) {
476 				p0 |= port->data[0] >> 4;
477 			} else {
478 				p0 |= 0x02;
479 				port->state = STATE_UNKNOWN;
480 			}
481 			f_midi_transmit_packet(req, p0, port->data[0], b, 0);
482 			break;
483 		case STATE_2PARAM_1:
484 			port->data[1] = b;
485 			port->state = STATE_2PARAM_2;
486 			break;
487 		case STATE_2PARAM_2:
488 			if (port->data[0] < 0xf0) {
489 				p0 |= port->data[0] >> 4;
490 				port->state = STATE_2PARAM_1;
491 			} else {
492 				p0 |= 0x03;
493 				port->state = STATE_UNKNOWN;
494 			}
495 			f_midi_transmit_packet(req,
496 				p0, port->data[0], port->data[1], b);
497 			break;
498 		case STATE_SYSEX_0:
499 			port->data[0] = b;
500 			port->state = STATE_SYSEX_1;
501 			break;
502 		case STATE_SYSEX_1:
503 			port->data[1] = b;
504 			port->state = STATE_SYSEX_2;
505 			break;
506 		case STATE_SYSEX_2:
507 			f_midi_transmit_packet(req,
508 				p0 | 0x04, port->data[0], port->data[1], b);
509 			port->state = STATE_SYSEX_0;
510 			break;
511 		}
512 	}
513 }
514 
515 static void f_midi_transmit(struct f_midi *midi, struct usb_request *req)
516 {
517 	struct usb_ep *ep = midi->in_ep;
518 	int i;
519 
520 	if (!ep)
521 		return;
522 
523 	if (!req)
524 		req = midi_alloc_ep_req(ep, midi->buflen);
525 
526 	if (!req) {
527 		ERROR(midi, "%s: alloc_ep_request failed\n", __func__);
528 		return;
529 	}
530 	req->length = 0;
531 	req->complete = f_midi_complete;
532 
533 	for (i = 0; i < MAX_PORTS; i++) {
534 		struct gmidi_in_port *port = midi->in_port[i];
535 		struct snd_rawmidi_substream *substream = midi->in_substream[i];
536 
537 		if (!port || !port->active || !substream)
538 			continue;
539 
540 		while (req->length + 3 < midi->buflen) {
541 			uint8_t b;
542 			if (snd_rawmidi_transmit(substream, &b, 1) != 1) {
543 				port->active = 0;
544 				break;
545 			}
546 			f_midi_transmit_byte(req, port, b);
547 		}
548 	}
549 
550 	if (req->length > 0)
551 		usb_ep_queue(ep, req, GFP_ATOMIC);
552 	else
553 		free_ep_req(ep, req);
554 }
555 
556 static void f_midi_in_tasklet(unsigned long data)
557 {
558 	struct f_midi *midi = (struct f_midi *) data;
559 	f_midi_transmit(midi, NULL);
560 }
561 
562 static int f_midi_in_open(struct snd_rawmidi_substream *substream)
563 {
564 	struct f_midi *midi = substream->rmidi->private_data;
565 
566 	if (!midi->in_port[substream->number])
567 		return -EINVAL;
568 
569 	VDBG(midi, "%s()\n", __func__);
570 	midi->in_substream[substream->number] = substream;
571 	midi->in_port[substream->number]->state = STATE_UNKNOWN;
572 	return 0;
573 }
574 
575 static int f_midi_in_close(struct snd_rawmidi_substream *substream)
576 {
577 	struct f_midi *midi = substream->rmidi->private_data;
578 
579 	VDBG(midi, "%s()\n", __func__);
580 	return 0;
581 }
582 
583 static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
584 {
585 	struct f_midi *midi = substream->rmidi->private_data;
586 
587 	if (!midi->in_port[substream->number])
588 		return;
589 
590 	VDBG(midi, "%s() %d\n", __func__, up);
591 	midi->in_port[substream->number]->active = up;
592 	if (up)
593 		tasklet_hi_schedule(&midi->tasklet);
594 }
595 
596 static int f_midi_out_open(struct snd_rawmidi_substream *substream)
597 {
598 	struct f_midi *midi = substream->rmidi->private_data;
599 
600 	if (substream->number >= MAX_PORTS)
601 		return -EINVAL;
602 
603 	VDBG(midi, "%s()\n", __func__);
604 	midi->out_substream[substream->number] = substream;
605 	return 0;
606 }
607 
608 static int f_midi_out_close(struct snd_rawmidi_substream *substream)
609 {
610 	struct f_midi *midi = substream->rmidi->private_data;
611 
612 	VDBG(midi, "%s()\n", __func__);
613 	return 0;
614 }
615 
616 static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
617 {
618 	struct f_midi *midi = substream->rmidi->private_data;
619 
620 	VDBG(midi, "%s()\n", __func__);
621 
622 	if (up)
623 		set_bit(substream->number, &midi->out_triggered);
624 	else
625 		clear_bit(substream->number, &midi->out_triggered);
626 }
627 
628 static struct snd_rawmidi_ops gmidi_in_ops = {
629 	.open = f_midi_in_open,
630 	.close = f_midi_in_close,
631 	.trigger = f_midi_in_trigger,
632 };
633 
634 static struct snd_rawmidi_ops gmidi_out_ops = {
635 	.open = f_midi_out_open,
636 	.close = f_midi_out_close,
637 	.trigger = f_midi_out_trigger
638 };
639 
640 static inline void f_midi_unregister_card(struct f_midi *midi)
641 {
642 	if (midi->card) {
643 		snd_card_free(midi->card);
644 		midi->card = NULL;
645 	}
646 }
647 
648 /* register as a sound "card" */
649 static int f_midi_register_card(struct f_midi *midi)
650 {
651 	struct snd_card *card;
652 	struct snd_rawmidi *rmidi;
653 	int err;
654 	static struct snd_device_ops ops = {
655 		.dev_free = f_midi_snd_free,
656 	};
657 
658 	err = snd_card_new(&midi->gadget->dev, midi->index, midi->id,
659 			   THIS_MODULE, 0, &card);
660 	if (err < 0) {
661 		ERROR(midi, "snd_card_new() failed\n");
662 		goto fail;
663 	}
664 	midi->card = card;
665 
666 	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops);
667 	if (err < 0) {
668 		ERROR(midi, "snd_device_new() failed: error %d\n", err);
669 		goto fail;
670 	}
671 
672 	strcpy(card->driver, f_midi_longname);
673 	strcpy(card->longname, f_midi_longname);
674 	strcpy(card->shortname, f_midi_shortname);
675 
676 	/* Set up rawmidi */
677 	snd_component_add(card, "MIDI");
678 	err = snd_rawmidi_new(card, card->longname, 0,
679 			      midi->out_ports, midi->in_ports, &rmidi);
680 	if (err < 0) {
681 		ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
682 		goto fail;
683 	}
684 	midi->rmidi = rmidi;
685 	strcpy(rmidi->name, card->shortname);
686 	rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
687 			    SNDRV_RAWMIDI_INFO_INPUT |
688 			    SNDRV_RAWMIDI_INFO_DUPLEX;
689 	rmidi->private_data = midi;
690 
691 	/*
692 	 * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
693 	 * It's an upside-down world being a gadget.
694 	 */
695 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
696 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
697 
698 	/* register it - we're ready to go */
699 	err = snd_card_register(card);
700 	if (err < 0) {
701 		ERROR(midi, "snd_card_register() failed\n");
702 		goto fail;
703 	}
704 
705 	VDBG(midi, "%s() finished ok\n", __func__);
706 	return 0;
707 
708 fail:
709 	f_midi_unregister_card(midi);
710 	return err;
711 }
712 
713 /* MIDI function driver setup/binding */
714 
715 static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
716 {
717 	struct usb_descriptor_header **midi_function;
718 	struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
719 	struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
720 	struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
721 	struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
722 	struct usb_composite_dev *cdev = c->cdev;
723 	struct f_midi *midi = func_to_midi(f);
724 	struct usb_string *us;
725 	int status, n, jack = 1, i = 0;
726 
727 	midi->gadget = cdev->gadget;
728 	tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
729 	status = f_midi_register_card(midi);
730 	if (status < 0)
731 		goto fail_register;
732 
733 	/* maybe allocate device-global string ID */
734 	us = usb_gstrings_attach(c->cdev, midi_strings,
735 				 ARRAY_SIZE(midi_string_defs));
736 	if (IS_ERR(us)) {
737 		status = PTR_ERR(us);
738 		goto fail;
739 	}
740 	ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id;
741 
742 	/* We have two interfaces, AudioControl and MIDIStreaming */
743 	status = usb_interface_id(c, f);
744 	if (status < 0)
745 		goto fail;
746 	ac_interface_desc.bInterfaceNumber = status;
747 
748 	status = usb_interface_id(c, f);
749 	if (status < 0)
750 		goto fail;
751 	ms_interface_desc.bInterfaceNumber = status;
752 	ac_header_desc.baInterfaceNr[0] = status;
753 
754 	status = -ENODEV;
755 
756 	/* allocate instance-specific endpoints */
757 	midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
758 	if (!midi->in_ep)
759 		goto fail;
760 	midi->in_ep->driver_data = cdev;	/* claim */
761 
762 	midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
763 	if (!midi->out_ep)
764 		goto fail;
765 	midi->out_ep->driver_data = cdev;	/* claim */
766 
767 	/* allocate temporary function list */
768 	midi_function = kcalloc((MAX_PORTS * 4) + 9, sizeof(*midi_function),
769 				GFP_KERNEL);
770 	if (!midi_function) {
771 		status = -ENOMEM;
772 		goto fail;
773 	}
774 
775 	/*
776 	 * construct the function's descriptor set. As the number of
777 	 * input and output MIDI ports is configurable, we have to do
778 	 * it that way.
779 	 */
780 
781 	/* add the headers - these are always the same */
782 	midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
783 	midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
784 	midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;
785 
786 	/* calculate the header's wTotalLength */
787 	n = USB_DT_MS_HEADER_SIZE
788 		+ (midi->in_ports + midi->out_ports) *
789 			(USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
790 	ms_header_desc.wTotalLength = cpu_to_le16(n);
791 
792 	midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;
793 
794 	/* configure the external IN jacks, each linked to an embedded OUT jack */
795 	for (n = 0; n < midi->in_ports; n++) {
796 		struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
797 		struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];
798 
799 		in_ext->bLength			= USB_DT_MIDI_IN_SIZE;
800 		in_ext->bDescriptorType		= USB_DT_CS_INTERFACE;
801 		in_ext->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
802 		in_ext->bJackType		= USB_MS_EXTERNAL;
803 		in_ext->bJackID			= jack++;
804 		in_ext->iJack			= 0;
805 		midi_function[i++] = (struct usb_descriptor_header *) in_ext;
806 
807 		out_emb->bLength		= USB_DT_MIDI_OUT_SIZE(1);
808 		out_emb->bDescriptorType	= USB_DT_CS_INTERFACE;
809 		out_emb->bDescriptorSubtype	= USB_MS_MIDI_OUT_JACK;
810 		out_emb->bJackType		= USB_MS_EMBEDDED;
811 		out_emb->bJackID		= jack++;
812 		out_emb->bNrInputPins		= 1;
813 		out_emb->pins[0].baSourcePin	= 1;
814 		out_emb->pins[0].baSourceID	= in_ext->bJackID;
815 		out_emb->iJack			= 0;
816 		midi_function[i++] = (struct usb_descriptor_header *) out_emb;
817 
818 		/* link it to the endpoint */
819 		ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
820 	}
821 
822 	/* configure the external OUT jacks, each linked to an embedded IN jack */
823 	for (n = 0; n < midi->out_ports; n++) {
824 		struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
825 		struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];
826 
827 		in_emb->bLength			= USB_DT_MIDI_IN_SIZE;
828 		in_emb->bDescriptorType		= USB_DT_CS_INTERFACE;
829 		in_emb->bDescriptorSubtype	= USB_MS_MIDI_IN_JACK;
830 		in_emb->bJackType		= USB_MS_EMBEDDED;
831 		in_emb->bJackID			= jack++;
832 		in_emb->iJack			= 0;
833 		midi_function[i++] = (struct usb_descriptor_header *) in_emb;
834 
835 		out_ext->bLength =		USB_DT_MIDI_OUT_SIZE(1);
836 		out_ext->bDescriptorType =	USB_DT_CS_INTERFACE;
837 		out_ext->bDescriptorSubtype =	USB_MS_MIDI_OUT_JACK;
838 		out_ext->bJackType =		USB_MS_EXTERNAL;
839 		out_ext->bJackID =		jack++;
840 		out_ext->bNrInputPins =		1;
841 		out_ext->iJack =		0;
842 		out_ext->pins[0].baSourceID =	in_emb->bJackID;
843 		out_ext->pins[0].baSourcePin =	1;
844 		midi_function[i++] = (struct usb_descriptor_header *) out_ext;
845 
846 		/* link it to the endpoint */
847 		ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
848 	}
849 
850 	/* configure the endpoint descriptors ... */
851 	ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
852 	ms_out_desc.bNumEmbMIDIJack = midi->in_ports;
853 
854 	ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
855 	ms_in_desc.bNumEmbMIDIJack = midi->out_ports;
856 
857 	/* ... and add them to the list */
858 	midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
859 	midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
860 	midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
861 	midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
862 	midi_function[i++] = NULL;
863 
864 	/*
865 	 * support all relevant hardware speeds... we expect that when
866 	 * hardware is dual speed, all bulk-capable endpoints work at
867 	 * both speeds
868 	 */
869 	/* copy descriptors, and track endpoint copies */
870 	f->fs_descriptors = usb_copy_descriptors(midi_function);
871 	if (!f->fs_descriptors)
872 		goto fail_f_midi;
873 
874 	if (gadget_is_dualspeed(c->cdev->gadget)) {
875 		bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
876 		bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
877 		f->hs_descriptors = usb_copy_descriptors(midi_function);
878 		if (!f->hs_descriptors)
879 			goto fail_f_midi;
880 	}
881 
882 	kfree(midi_function);
883 
884 	return 0;
885 
886 fail_f_midi:
887 	kfree(midi_function);
888 	usb_free_descriptors(f->hs_descriptors);
889 fail:
890 	f_midi_unregister_card(midi);
891 fail_register:
892 	/* we might as well release our claims on endpoints */
893 	if (midi->out_ep)
894 		midi->out_ep->driver_data = NULL;
895 	if (midi->in_ep)
896 		midi->in_ep->driver_data = NULL;
897 
898 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
899 
900 	return status;
901 }
902 
903 static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item)
904 {
905 	return container_of(to_config_group(item), struct f_midi_opts,
906 			    func_inst.group);
907 }
908 
909 CONFIGFS_ATTR_STRUCT(f_midi_opts);
910 CONFIGFS_ATTR_OPS(f_midi_opts);
911 
912 static void midi_attr_release(struct config_item *item)
913 {
914 	struct f_midi_opts *opts = to_f_midi_opts(item);
915 
916 	usb_put_function_instance(&opts->func_inst);
917 }
918 
919 static struct configfs_item_operations midi_item_ops = {
920 	.release	= midi_attr_release,
921 	.show_attribute	= f_midi_opts_attr_show,
922 	.store_attribute = f_midi_opts_attr_store,
923 };
924 
925 #define F_MIDI_OPT(name, test_limit, limit)				\
926 static ssize_t f_midi_opts_##name##_show(struct f_midi_opts *opts, char *page) \
927 {									\
928 	int result;							\
929 									\
930 	mutex_lock(&opts->lock);					\
931 	result = sprintf(page, "%d\n", opts->name);			\
932 	mutex_unlock(&opts->lock);					\
933 									\
934 	return result;							\
935 }									\
936 									\
937 static ssize_t f_midi_opts_##name##_store(struct f_midi_opts *opts,	\
938 					 const char *page, size_t len)	\
939 {									\
940 	int ret;							\
941 	u32 num;							\
942 									\
943 	mutex_lock(&opts->lock);					\
944 	if (opts->refcnt) {						\
945 		ret = -EBUSY;						\
946 		goto end;						\
947 	}								\
948 									\
949 	ret = kstrtou32(page, 0, &num);					\
950 	if (ret)							\
951 		goto end;						\
952 									\
953 	if (test_limit && num > limit) {				\
954 		ret = -EINVAL;						\
955 		goto end;						\
956 	}								\
957 	opts->name = num;						\
958 	ret = len;							\
959 									\
960 end:									\
961 	mutex_unlock(&opts->lock);					\
962 	return ret;							\
963 }									\
964 									\
965 static struct f_midi_opts_attribute f_midi_opts_##name =		\
966 	__CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_midi_opts_##name##_show, \
967 			f_midi_opts_##name##_store)
968 
969 F_MIDI_OPT(index, true, SNDRV_CARDS);
970 F_MIDI_OPT(buflen, false, 0);
971 F_MIDI_OPT(qlen, false, 0);
972 F_MIDI_OPT(in_ports, true, MAX_PORTS);
973 F_MIDI_OPT(out_ports, true, MAX_PORTS);
974 
975 static ssize_t f_midi_opts_id_show(struct f_midi_opts *opts, char *page)
976 {
977 	int result;
978 
979 	mutex_lock(&opts->lock);
980 	if (opts->id) {
981 		result = strlcpy(page, opts->id, PAGE_SIZE);
982 	} else {
983 		page[0] = 0;
984 		result = 0;
985 	}
986 
987 	mutex_unlock(&opts->lock);
988 
989 	return result;
990 }
991 
992 static ssize_t f_midi_opts_id_store(struct f_midi_opts *opts,
993 				    const char *page, size_t len)
994 {
995 	int ret;
996 	char *c;
997 
998 	mutex_lock(&opts->lock);
999 	if (opts->refcnt) {
1000 		ret = -EBUSY;
1001 		goto end;
1002 	}
1003 
1004 	c = kstrndup(page, len, GFP_KERNEL);
1005 	if (!c) {
1006 		ret = -ENOMEM;
1007 		goto end;
1008 	}
1009 	if (opts->id_allocated)
1010 		kfree(opts->id);
1011 	opts->id = c;
1012 	opts->id_allocated = true;
1013 	ret = len;
1014 end:
1015 	mutex_unlock(&opts->lock);
1016 	return ret;
1017 }
1018 
1019 static struct f_midi_opts_attribute f_midi_opts_id =
1020 	__CONFIGFS_ATTR(id, S_IRUGO | S_IWUSR, f_midi_opts_id_show,
1021 			f_midi_opts_id_store);
1022 
1023 static struct configfs_attribute *midi_attrs[] = {
1024 	&f_midi_opts_index.attr,
1025 	&f_midi_opts_buflen.attr,
1026 	&f_midi_opts_qlen.attr,
1027 	&f_midi_opts_in_ports.attr,
1028 	&f_midi_opts_out_ports.attr,
1029 	&f_midi_opts_id.attr,
1030 	NULL,
1031 };
1032 
1033 static struct config_item_type midi_func_type = {
1034 	.ct_item_ops	= &midi_item_ops,
1035 	.ct_attrs	= midi_attrs,
1036 	.ct_owner	= THIS_MODULE,
1037 };
1038 
1039 static void f_midi_free_inst(struct usb_function_instance *f)
1040 {
1041 	struct f_midi_opts *opts;
1042 
1043 	opts = container_of(f, struct f_midi_opts, func_inst);
1044 
1045 	if (opts->id_allocated)
1046 		kfree(opts->id);
1047 
1048 	kfree(opts);
1049 }
1050 
1051 static struct usb_function_instance *f_midi_alloc_inst(void)
1052 {
1053 	struct f_midi_opts *opts;
1054 
1055 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1056 	if (!opts)
1057 		return ERR_PTR(-ENOMEM);
1058 
1059 	mutex_init(&opts->lock);
1060 	opts->func_inst.free_func_inst = f_midi_free_inst;
1061 	opts->index = SNDRV_DEFAULT_IDX1;
1062 	opts->id = SNDRV_DEFAULT_STR1;
1063 	opts->buflen = 256;
1064 	opts->qlen = 32;
1065 	opts->in_ports = 1;
1066 	opts->out_ports = 1;
1067 
1068 	config_group_init_type_name(&opts->func_inst.group, "",
1069 				    &midi_func_type);
1070 
1071 	return &opts->func_inst;
1072 }
1073 
1074 static void f_midi_free(struct usb_function *f)
1075 {
1076 	struct f_midi *midi;
1077 	struct f_midi_opts *opts;
1078 	int i;
1079 
1080 	midi = func_to_midi(f);
1081 	opts = container_of(f->fi, struct f_midi_opts, func_inst);
1082 	kfree(midi->id);
1083 	mutex_lock(&opts->lock);
1084 	for (i = opts->in_ports - 1; i >= 0; --i)
1085 		kfree(midi->in_port[i]);
1086 	kfree(midi);
1087 	--opts->refcnt;
1088 	mutex_unlock(&opts->lock);
1089 }
1090 
1091 static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
1092 {
1093 	struct usb_composite_dev *cdev = f->config->cdev;
1094 	struct f_midi *midi = func_to_midi(f);
1095 	struct snd_card *card;
1096 
1097 	DBG(cdev, "unbind\n");
1098 
1099 	/* just to be sure */
1100 	f_midi_disable(f);
1101 
1102 	card = midi->card;
1103 	midi->card = NULL;
1104 	if (card)
1105 		snd_card_free(card);
1106 
1107 	usb_free_all_descriptors(f);
1108 }
1109 
1110 static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
1111 {
1112 	struct f_midi *midi;
1113 	struct f_midi_opts *opts;
1114 	int status, i;
1115 
1116 	opts = container_of(fi, struct f_midi_opts, func_inst);
1117 
1118 	mutex_lock(&opts->lock);
1119 	/* sanity check */
1120 	if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) {
1121 		mutex_unlock(&opts->lock);
1122 		return ERR_PTR(-EINVAL);
1123 	}
1124 
1125 	/* allocate and initialize one new instance */
1126 	midi = kzalloc(sizeof(*midi), GFP_KERNEL);
1127 	if (!midi) {
1128 		mutex_unlock(&opts->lock);
1129 		return ERR_PTR(-ENOMEM);
1130 	}
1131 
1132 	for (i = 0; i < opts->in_ports; i++) {
1133 		struct gmidi_in_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
1134 
1135 		if (!port) {
1136 			status = -ENOMEM;
1137 			mutex_unlock(&opts->lock);
1138 			goto setup_fail;
1139 		}
1140 
1141 		port->midi = midi;
1142 		port->active = 0;
1143 		port->cable = i;
1144 		midi->in_port[i] = port;
1145 	}
1146 
1147 	/* set up ALSA midi devices */
1148 	midi->id = kstrdup(opts->id, GFP_KERNEL);
1149 	if (opts->id && !midi->id) {
1150 		status = -ENOMEM;
1151 		mutex_unlock(&opts->lock);
1152 		goto setup_fail;
1153 	}
1154 	midi->in_ports = opts->in_ports;
1155 	midi->out_ports = opts->out_ports;
1156 	midi->index = opts->index;
1157 	midi->buflen = opts->buflen;
1158 	midi->qlen = opts->qlen;
1159 	++opts->refcnt;
1160 	mutex_unlock(&opts->lock);
1161 
1162 	midi->func.name		= "gmidi function";
1163 	midi->func.bind		= f_midi_bind;
1164 	midi->func.unbind	= f_midi_unbind;
1165 	midi->func.set_alt	= f_midi_set_alt;
1166 	midi->func.disable	= f_midi_disable;
1167 	midi->func.free_func	= f_midi_free;
1168 
1169 	return &midi->func;
1170 
1171 setup_fail:
1172 	for (--i; i >= 0; i--)
1173 		kfree(midi->in_port[i]);
1174 	kfree(midi);
1175 	return ERR_PTR(status);
1176 }
1177 
1178 DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc);
1179