1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_midi.c -- USB MIDI class function driver
4 *
5 * Copyright (C) 2006 Thumtronics Pty Ltd.
6 * Developed for Thumtronics by Grey Innovation
7 * Ben Williamson <ben.williamson@greyinnovation.com>
8 *
9 * Rewritten for the composite framework
10 * Copyright (C) 2011 Daniel Mack <zonque@gmail.com>
11 *
12 * Based on drivers/usb/gadget/f_audio.c,
13 * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org>
14 * Copyright (C) 2008 Analog Devices, Inc
15 *
16 * and drivers/usb/gadget/midi.c,
17 * Copyright (C) 2006 Thumtronics Pty Ltd.
18 * Ben Williamson <ben.williamson@greyinnovation.com>
19 */
20
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/slab.h>
24#include <linux/device.h>
25#include <linux/kfifo.h>
26#include <linux/spinlock.h>
27
28#include <sound/core.h>
29#include <sound/initval.h>
30#include <sound/rawmidi.h>
31
32#include <linux/usb/ch9.h>
33#include <linux/usb/func_utils.h>
34#include <linux/usb/gadget.h>
35#include <linux/usb/audio.h>
36#include <linux/usb/midi.h>
37
38#include "u_midi.h"
39
40MODULE_AUTHOR("Ben Williamson");
41MODULE_DESCRIPTION("USB MIDI class function driver");
42MODULE_LICENSE("GPL v2");
43
44static const char f_midi_shortname[] = "f_midi";
45static const char f_midi_longname[] = "MIDI Gadget";
46
47/*
48 * We can only handle 16 cables on one single endpoint, as cable numbers are
49 * stored in 4-bit fields. And as the interface currently only holds one
50 * single endpoint, this is the maximum number of ports we can allow.
51 */
52#define MAX_PORTS 16
53
54/* MIDI message states */
55enum {
56 STATE_INITIAL = 0, /* pseudo state */
57 STATE_1PARAM,
58 STATE_2PARAM_1,
59 STATE_2PARAM_2,
60 STATE_SYSEX_0,
61 STATE_SYSEX_1,
62 STATE_SYSEX_2,
63 STATE_REAL_TIME,
64 STATE_FINISHED, /* pseudo state */
65};
66
67/*
68 * This is a gadget, and the IN/OUT naming is from the host's perspective.
69 * USB -> OUT endpoint -> rawmidi
70 * USB <- IN endpoint <- rawmidi
71 */
72struct gmidi_in_port {
73 struct snd_rawmidi_substream *substream;
74 int active;
75 uint8_t cable;
76 uint8_t state;
77 uint8_t data[2];
78};
79
80struct f_midi {
81 struct usb_function func;
82 struct usb_gadget *gadget;
83 struct usb_ep *in_ep, *out_ep;
84 struct snd_card *card;
85 struct snd_rawmidi *rmidi;
86 u8 ms_id;
87
88 struct snd_rawmidi_substream *out_substream[MAX_PORTS];
89
90 unsigned long out_triggered;
91 struct work_struct work;
92 unsigned int in_ports;
93 unsigned int out_ports;
94 int index;
95 char *id;
96 unsigned int buflen, qlen;
97 /* This fifo is used as a buffer ring for pre-allocated IN usb_requests */
98 DECLARE_KFIFO_PTR(in_req_fifo, struct usb_request *);
99 spinlock_t transmit_lock;
100 unsigned int in_last_port;
101 unsigned char free_ref;
102
103 struct gmidi_in_port in_ports_array[] __counted_by(in_ports);
104};
105
106static inline struct f_midi *func_to_midi(struct usb_function *f)
107{
108 return container_of(f, struct f_midi, func);
109}
110
111static void f_midi_transmit(struct f_midi *midi);
112static void f_midi_rmidi_free(struct snd_rawmidi *rmidi);
113static void f_midi_free_inst(struct usb_function_instance *f);
114
115DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
116DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
117DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
118
119/* B.3.1 Standard AC Interface Descriptor */
120static struct usb_interface_descriptor ac_interface_desc = {
121 .bLength = USB_DT_INTERFACE_SIZE,
122 .bDescriptorType = USB_DT_INTERFACE,
123 /* .bInterfaceNumber = DYNAMIC */
124 /* .bNumEndpoints = DYNAMIC */
125 .bInterfaceClass = USB_CLASS_AUDIO,
126 .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL,
127 /* .iInterface = DYNAMIC */
128};
129
130/* B.3.2 Class-Specific AC Interface Descriptor */
131static struct uac1_ac_header_descriptor_1 ac_header_desc = {
132 .bLength = UAC_DT_AC_HEADER_SIZE(1),
133 .bDescriptorType = USB_DT_CS_INTERFACE,
134 .bDescriptorSubtype = USB_MS_HEADER,
135 .bcdADC = cpu_to_le16(0x0100),
136 .wTotalLength = cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)),
137 .bInCollection = 1,
138 /* .baInterfaceNr = DYNAMIC */
139};
140
141/* B.4.1 Standard MS Interface Descriptor */
142static struct usb_interface_descriptor ms_interface_desc = {
143 .bLength = USB_DT_INTERFACE_SIZE,
144 .bDescriptorType = USB_DT_INTERFACE,
145 /* .bInterfaceNumber = DYNAMIC */
146 .bNumEndpoints = 2,
147 .bInterfaceClass = USB_CLASS_AUDIO,
148 .bInterfaceSubClass = USB_SUBCLASS_MIDISTREAMING,
149 /* .iInterface = DYNAMIC */
150};
151
152/* B.4.2 Class-Specific MS Interface Descriptor */
153static struct usb_ms_header_descriptor ms_header_desc = {
154 .bLength = USB_DT_MS_HEADER_SIZE,
155 .bDescriptorType = USB_DT_CS_INTERFACE,
156 .bDescriptorSubtype = USB_MS_HEADER,
157 .bcdMSC = cpu_to_le16(0x0100),
158 /* .wTotalLength = DYNAMIC */
159};
160
161/* B.5.1 Standard Bulk OUT Endpoint Descriptor */
162static struct usb_endpoint_descriptor bulk_out_desc = {
163 .bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
164 .bDescriptorType = USB_DT_ENDPOINT,
165 .bEndpointAddress = USB_DIR_OUT,
166 .bmAttributes = USB_ENDPOINT_XFER_BULK,
167};
168
169static struct usb_ss_ep_comp_descriptor bulk_out_ss_comp_desc = {
170 .bLength = sizeof(bulk_out_ss_comp_desc),
171 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
172 /* .bMaxBurst = 0, */
173 /* .bmAttributes = 0, */
174};
175
176/* B.5.2 Class-specific MS Bulk OUT Endpoint Descriptor */
177static struct usb_ms_endpoint_descriptor_16 ms_out_desc = {
178 /* .bLength = DYNAMIC */
179 .bDescriptorType = USB_DT_CS_ENDPOINT,
180 .bDescriptorSubtype = USB_MS_GENERAL,
181 /* .bNumEmbMIDIJack = DYNAMIC */
182 /* .baAssocJackID = DYNAMIC */
183};
184
185/* B.6.1 Standard Bulk IN Endpoint Descriptor */
186static struct usb_endpoint_descriptor bulk_in_desc = {
187 .bLength = USB_DT_ENDPOINT_AUDIO_SIZE,
188 .bDescriptorType = USB_DT_ENDPOINT,
189 .bEndpointAddress = USB_DIR_IN,
190 .bmAttributes = USB_ENDPOINT_XFER_BULK,
191};
192
193static struct usb_ss_ep_comp_descriptor bulk_in_ss_comp_desc = {
194 .bLength = sizeof(bulk_in_ss_comp_desc),
195 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
196 /* .bMaxBurst = 0, */
197 /* .bmAttributes = 0, */
198};
199
200/* B.6.2 Class-specific MS Bulk IN Endpoint Descriptor */
201static struct usb_ms_endpoint_descriptor_16 ms_in_desc = {
202 /* .bLength = DYNAMIC */
203 .bDescriptorType = USB_DT_CS_ENDPOINT,
204 .bDescriptorSubtype = USB_MS_GENERAL,
205 /* .bNumEmbMIDIJack = DYNAMIC */
206 /* .baAssocJackID = DYNAMIC */
207};
208
209/* string IDs are assigned dynamically */
210
211#define STRING_FUNC_IDX 0
212
213static struct usb_string midi_string_defs[] = {
214 [STRING_FUNC_IDX].s = "MIDI function",
215 { } /* end of list */
216};
217
218static struct usb_gadget_strings midi_stringtab = {
219 .language = 0x0409, /* en-us */
220 .strings = midi_string_defs,
221};
222
223static struct usb_gadget_strings *midi_strings[] = {
224 &midi_stringtab,
225 NULL,
226};
227
228static inline struct usb_request *midi_alloc_ep_req(struct usb_ep *ep,
229 unsigned length)
230{
231 return alloc_ep_req(ep, len: length);
232}
233
234static const uint8_t f_midi_cin_length[] = {
235 0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
236};
237
238/*
239 * Receives a chunk of MIDI data.
240 */
241static void f_midi_read_data(struct usb_ep *ep, int cable,
242 uint8_t *data, int length)
243{
244 struct f_midi *midi = ep->driver_data;
245 struct snd_rawmidi_substream *substream = midi->out_substream[cable];
246
247 if (!substream)
248 /* Nobody is listening - throw it on the floor. */
249 return;
250
251 if (!test_bit(cable, &midi->out_triggered))
252 return;
253
254 snd_rawmidi_receive(substream, buffer: data, count: length);
255}
256
257static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
258{
259 unsigned int i;
260 u8 *buf = req->buf;
261
262 for (i = 0; i + 3 < req->actual; i += 4)
263 if (buf[i] != 0) {
264 int cable = buf[i] >> 4;
265 int length = f_midi_cin_length[buf[i] & 0x0f];
266 f_midi_read_data(ep, cable, data: &buf[i + 1], length);
267 }
268}
269
270static void
271f_midi_complete(struct usb_ep *ep, struct usb_request *req)
272{
273 struct f_midi *midi = ep->driver_data;
274 struct usb_composite_dev *cdev = midi->func.config->cdev;
275 int status = req->status;
276
277 switch (status) {
278 case 0: /* normal completion */
279 if (ep == midi->out_ep) {
280 /* We received stuff. req is queued again, below */
281 f_midi_handle_out_data(ep, req);
282 } else if (ep == midi->in_ep) {
283 /* Our transmit completed. See if there's more to go.
284 * f_midi_transmit eats req, don't queue it again. */
285 req->length = 0;
286 queue_work(wq: system_highpri_wq, work: &midi->work);
287 return;
288 }
289 break;
290
291 /* this endpoint is normally active while we're configured */
292 case -ECONNABORTED: /* hardware forced ep reset */
293 case -ECONNRESET: /* request dequeued */
294 case -ESHUTDOWN: /* disconnect from host */
295 VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status,
296 req->actual, req->length);
297 if (ep == midi->out_ep) {
298 f_midi_handle_out_data(ep, req);
299 /* We don't need to free IN requests because it's handled
300 * by the midi->in_req_fifo. */
301 free_ep_req(ep, req);
302 }
303 return;
304
305 case -EOVERFLOW: /* buffer overrun on read means that
306 * we didn't provide a big enough buffer.
307 */
308 default:
309 DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name,
310 status, req->actual, req->length);
311 break;
312 case -EREMOTEIO: /* short read */
313 break;
314 }
315
316 status = usb_ep_queue(ep, req, GFP_ATOMIC);
317 if (status) {
318 ERROR(cdev, "kill %s: resubmit %d bytes --> %d\n",
319 ep->name, req->length, status);
320 usb_ep_set_halt(ep);
321 /* FIXME recover later ... somehow */
322 }
323}
324
325static void f_midi_drop_out_substreams(struct f_midi *midi)
326{
327 unsigned int i;
328
329 for (i = 0; i < midi->in_ports; i++) {
330 struct gmidi_in_port *port = midi->in_ports_array + i;
331 struct snd_rawmidi_substream *substream = port->substream;
332
333 if (port->active && substream)
334 snd_rawmidi_drop_output(substream);
335 }
336}
337
338static int f_midi_start_ep(struct f_midi *midi,
339 struct usb_function *f,
340 struct usb_ep *ep)
341{
342 int err;
343 struct usb_composite_dev *cdev = f->config->cdev;
344
345 usb_ep_disable(ep);
346
347 err = config_ep_by_speed(g: midi->gadget, f, ep: ep);
348 if (err) {
349 ERROR(cdev, "can't configure %s: %d\n", ep->name, err);
350 return err;
351 }
352
353 err = usb_ep_enable(ep);
354 if (err) {
355 ERROR(cdev, "can't start %s: %d\n", ep->name, err);
356 return err;
357 }
358
359 ep->driver_data = midi;
360
361 return 0;
362}
363
364static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
365{
366 struct f_midi *midi = func_to_midi(f);
367 unsigned i;
368 int err;
369
370 /* we only set alt for MIDIStreaming interface */
371 if (intf != midi->ms_id)
372 return 0;
373
374 err = f_midi_start_ep(midi, f, ep: midi->in_ep);
375 if (err)
376 return err;
377
378 err = f_midi_start_ep(midi, f, ep: midi->out_ep);
379 if (err)
380 return err;
381
382 /* pre-allocate write usb requests to use on f_midi_transmit. */
383 while (kfifo_avail(&midi->in_req_fifo)) {
384 struct usb_request *req =
385 midi_alloc_ep_req(ep: midi->in_ep, length: midi->buflen);
386
387 if (req == NULL)
388 return -ENOMEM;
389
390 req->length = 0;
391 req->complete = f_midi_complete;
392
393 kfifo_put(&midi->in_req_fifo, req);
394 }
395
396 /* allocate a bunch of read buffers and queue them all at once. */
397 for (i = 0; i < midi->qlen && err == 0; i++) {
398 struct usb_request *req =
399 midi_alloc_ep_req(ep: midi->out_ep, length: midi->buflen);
400
401 if (req == NULL)
402 return -ENOMEM;
403
404 req->complete = f_midi_complete;
405 err = usb_ep_queue(ep: midi->out_ep, req, GFP_ATOMIC);
406 if (err) {
407 ERROR(midi, "%s: couldn't enqueue request: %d\n",
408 midi->out_ep->name, err);
409 if (req->buf != NULL)
410 free_ep_req(ep: midi->out_ep, req);
411 return err;
412 }
413 }
414
415 return 0;
416}
417
418static void f_midi_disable(struct usb_function *f)
419{
420 struct f_midi *midi = func_to_midi(f);
421 struct usb_composite_dev *cdev = f->config->cdev;
422 struct usb_request *req = NULL;
423
424 DBG(cdev, "disable\n");
425
426 /*
427 * just disable endpoints, forcing completion of pending i/o.
428 * all our completion handlers free their requests in this case.
429 */
430 usb_ep_disable(ep: midi->in_ep);
431 usb_ep_disable(ep: midi->out_ep);
432
433 /* release IN requests */
434 while (kfifo_get(&midi->in_req_fifo, &req))
435 free_ep_req(ep: midi->in_ep, req);
436
437 f_midi_drop_out_substreams(midi);
438}
439
440static int f_midi_snd_free(struct snd_device *device)
441{
442 return 0;
443}
444
445/*
446 * Converts MIDI commands to USB MIDI packets.
447 */
448static void f_midi_transmit_byte(struct usb_request *req,
449 struct gmidi_in_port *port, uint8_t b)
450{
451 uint8_t p[4] = { port->cable << 4, 0, 0, 0 };
452 uint8_t next_state = STATE_INITIAL;
453
454 switch (b) {
455 case 0xf8 ... 0xff:
456 /* System Real-Time Messages */
457 p[0] |= 0x0f;
458 p[1] = b;
459 next_state = port->state;
460 port->state = STATE_REAL_TIME;
461 break;
462
463 case 0xf7:
464 /* End of SysEx */
465 switch (port->state) {
466 case STATE_SYSEX_0:
467 p[0] |= 0x05;
468 p[1] = 0xf7;
469 next_state = STATE_FINISHED;
470 break;
471 case STATE_SYSEX_1:
472 p[0] |= 0x06;
473 p[1] = port->data[0];
474 p[2] = 0xf7;
475 next_state = STATE_FINISHED;
476 break;
477 case STATE_SYSEX_2:
478 p[0] |= 0x07;
479 p[1] = port->data[0];
480 p[2] = port->data[1];
481 p[3] = 0xf7;
482 next_state = STATE_FINISHED;
483 break;
484 default:
485 /* Ignore byte */
486 next_state = port->state;
487 port->state = STATE_INITIAL;
488 }
489 break;
490
491 case 0xf0 ... 0xf6:
492 /* System Common Messages */
493 port->data[0] = port->data[1] = 0;
494 port->state = STATE_INITIAL;
495 switch (b) {
496 case 0xf0:
497 port->data[0] = b;
498 port->data[1] = 0;
499 next_state = STATE_SYSEX_1;
500 break;
501 case 0xf1:
502 case 0xf3:
503 port->data[0] = b;
504 next_state = STATE_1PARAM;
505 break;
506 case 0xf2:
507 port->data[0] = b;
508 next_state = STATE_2PARAM_1;
509 break;
510 case 0xf4:
511 case 0xf5:
512 next_state = STATE_INITIAL;
513 break;
514 case 0xf6:
515 p[0] |= 0x05;
516 p[1] = 0xf6;
517 next_state = STATE_FINISHED;
518 break;
519 }
520 break;
521
522 case 0x80 ... 0xef:
523 /*
524 * Channel Voice Messages, Channel Mode Messages
525 * and Control Change Messages.
526 */
527 port->data[0] = b;
528 port->data[1] = 0;
529 port->state = STATE_INITIAL;
530 if (b >= 0xc0 && b <= 0xdf)
531 next_state = STATE_1PARAM;
532 else
533 next_state = STATE_2PARAM_1;
534 break;
535
536 case 0x00 ... 0x7f:
537 /* Message parameters */
538 switch (port->state) {
539 case STATE_1PARAM:
540 if (port->data[0] < 0xf0)
541 p[0] |= port->data[0] >> 4;
542 else
543 p[0] |= 0x02;
544
545 p[1] = port->data[0];
546 p[2] = b;
547 /* This is to allow Running State Messages */
548 next_state = STATE_1PARAM;
549 break;
550 case STATE_2PARAM_1:
551 port->data[1] = b;
552 next_state = STATE_2PARAM_2;
553 break;
554 case STATE_2PARAM_2:
555 if (port->data[0] < 0xf0)
556 p[0] |= port->data[0] >> 4;
557 else
558 p[0] |= 0x03;
559
560 p[1] = port->data[0];
561 p[2] = port->data[1];
562 p[3] = b;
563 /* This is to allow Running State Messages */
564 next_state = STATE_2PARAM_1;
565 break;
566 case STATE_SYSEX_0:
567 port->data[0] = b;
568 next_state = STATE_SYSEX_1;
569 break;
570 case STATE_SYSEX_1:
571 port->data[1] = b;
572 next_state = STATE_SYSEX_2;
573 break;
574 case STATE_SYSEX_2:
575 p[0] |= 0x04;
576 p[1] = port->data[0];
577 p[2] = port->data[1];
578 p[3] = b;
579 next_state = STATE_SYSEX_0;
580 break;
581 }
582 break;
583 }
584
585 /* States where we have to write into the USB request */
586 if (next_state == STATE_FINISHED ||
587 port->state == STATE_SYSEX_2 ||
588 port->state == STATE_1PARAM ||
589 port->state == STATE_2PARAM_2 ||
590 port->state == STATE_REAL_TIME) {
591
592 unsigned int length = req->length;
593 u8 *buf = (u8 *)req->buf + length;
594
595 memcpy(buf, p, sizeof(p));
596 req->length = length + sizeof(p);
597
598 if (next_state == STATE_FINISHED) {
599 next_state = STATE_INITIAL;
600 port->data[0] = port->data[1] = 0;
601 }
602 }
603
604 port->state = next_state;
605}
606
607static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep)
608{
609 struct usb_request *req = NULL;
610 unsigned int len, i;
611 bool active = false;
612 int err;
613
614 /*
615 * We peek the request in order to reuse it if it fails to enqueue on
616 * its endpoint
617 */
618 len = kfifo_peek(&midi->in_req_fifo, &req);
619 if (len != 1) {
620 ERROR(midi, "%s: Couldn't get usb request\n", __func__);
621 return -1;
622 }
623
624 /*
625 * If buffer overrun, then we ignore this transmission.
626 * IMPORTANT: This will cause the user-space rawmidi device to block
627 * until a) usb requests have been completed or b) snd_rawmidi_write()
628 * times out.
629 */
630 if (req->length > 0)
631 return 0;
632
633 for (i = midi->in_last_port; i < midi->in_ports; ++i) {
634 struct gmidi_in_port *port = midi->in_ports_array + i;
635 struct snd_rawmidi_substream *substream = port->substream;
636
637 if (!port->active || !substream)
638 continue;
639
640 while (req->length + 3 < midi->buflen) {
641 uint8_t b;
642
643 if (snd_rawmidi_transmit(substream, buffer: &b, count: 1) != 1) {
644 port->active = 0;
645 break;
646 }
647 f_midi_transmit_byte(req, port, b);
648 }
649
650 active = !!port->active;
651 if (active)
652 break;
653 }
654 midi->in_last_port = active ? i : 0;
655
656 if (req->length <= 0)
657 goto done;
658
659 err = usb_ep_queue(ep, req, GFP_ATOMIC);
660 if (err < 0) {
661 ERROR(midi, "%s failed to queue req: %d\n",
662 midi->in_ep->name, err);
663 req->length = 0; /* Re-use request next time. */
664 } else {
665 /* Upon success, put request at the back of the queue. */
666 kfifo_skip(&midi->in_req_fifo);
667 kfifo_put(&midi->in_req_fifo, req);
668 }
669
670done:
671 return active;
672}
673
674static void f_midi_transmit(struct f_midi *midi)
675{
676 struct usb_ep *ep = midi->in_ep;
677 int ret;
678 unsigned long flags;
679
680 /* We only care about USB requests if IN endpoint is enabled */
681 if (!ep || !ep->enabled)
682 goto drop_out;
683
684 spin_lock_irqsave(&midi->transmit_lock, flags);
685
686 do {
687 ret = f_midi_do_transmit(midi, ep);
688 if (ret < 0) {
689 spin_unlock_irqrestore(lock: &midi->transmit_lock, flags);
690 goto drop_out;
691 }
692 } while (ret);
693
694 spin_unlock_irqrestore(lock: &midi->transmit_lock, flags);
695
696 return;
697
698drop_out:
699 f_midi_drop_out_substreams(midi);
700}
701
702static void f_midi_in_work(struct work_struct *work)
703{
704 struct f_midi *midi;
705
706 midi = container_of(work, struct f_midi, work);
707 f_midi_transmit(midi);
708}
709
710static int f_midi_in_open(struct snd_rawmidi_substream *substream)
711{
712 struct f_midi *midi = substream->rmidi->private_data;
713 struct gmidi_in_port *port;
714
715 if (substream->number >= midi->in_ports)
716 return -EINVAL;
717
718 VDBG(midi, "%s()\n", __func__);
719 port = midi->in_ports_array + substream->number;
720 port->substream = substream;
721 port->state = STATE_INITIAL;
722 return 0;
723}
724
725static int f_midi_in_close(struct snd_rawmidi_substream *substream)
726{
727 struct f_midi *midi = substream->rmidi->private_data;
728
729 VDBG(midi, "%s()\n", __func__);
730 return 0;
731}
732
733static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
734{
735 struct f_midi *midi = substream->rmidi->private_data;
736
737 if (substream->number >= midi->in_ports)
738 return;
739
740 VDBG(midi, "%s() %d\n", __func__, up);
741 midi->in_ports_array[substream->number].active = up;
742 if (up)
743 queue_work(wq: system_highpri_wq, work: &midi->work);
744}
745
746static int f_midi_out_open(struct snd_rawmidi_substream *substream)
747{
748 struct f_midi *midi = substream->rmidi->private_data;
749
750 if (substream->number >= MAX_PORTS)
751 return -EINVAL;
752
753 VDBG(midi, "%s()\n", __func__);
754 midi->out_substream[substream->number] = substream;
755 return 0;
756}
757
758static int f_midi_out_close(struct snd_rawmidi_substream *substream)
759{
760 struct f_midi *midi = substream->rmidi->private_data;
761
762 VDBG(midi, "%s()\n", __func__);
763 return 0;
764}
765
766static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
767{
768 struct f_midi *midi = substream->rmidi->private_data;
769
770 VDBG(midi, "%s()\n", __func__);
771
772 if (up)
773 set_bit(nr: substream->number, addr: &midi->out_triggered);
774 else
775 clear_bit(nr: substream->number, addr: &midi->out_triggered);
776}
777
778static const struct snd_rawmidi_ops gmidi_in_ops = {
779 .open = f_midi_in_open,
780 .close = f_midi_in_close,
781 .trigger = f_midi_in_trigger,
782};
783
784static const struct snd_rawmidi_ops gmidi_out_ops = {
785 .open = f_midi_out_open,
786 .close = f_midi_out_close,
787 .trigger = f_midi_out_trigger
788};
789
790static inline void f_midi_unregister_card(struct f_midi *midi)
791{
792 if (midi->card) {
793 snd_card_free(card: midi->card);
794 midi->card = NULL;
795 }
796}
797
798/* register as a sound "card" */
799static int f_midi_register_card(struct f_midi *midi)
800{
801 struct snd_card *card;
802 struct snd_rawmidi *rmidi;
803 int err;
804 static struct snd_device_ops ops = {
805 .dev_free = f_midi_snd_free,
806 };
807
808 err = snd_card_new(parent: &midi->gadget->dev, idx: midi->index, xid: midi->id,
809 THIS_MODULE, extra_size: 0, card_ret: &card);
810 if (err < 0) {
811 ERROR(midi, "snd_card_new() failed\n");
812 goto fail;
813 }
814 midi->card = card;
815
816 err = snd_device_new(card, type: SNDRV_DEV_LOWLEVEL, device_data: midi, ops: &ops);
817 if (err < 0) {
818 ERROR(midi, "snd_device_new() failed: error %d\n", err);
819 goto fail;
820 }
821
822 strscpy(card->driver, f_midi_longname);
823 strscpy(card->longname, f_midi_longname);
824 strscpy(card->shortname, f_midi_shortname);
825
826 /* Set up rawmidi */
827 snd_component_add(card, component: "MIDI");
828 err = snd_rawmidi_new(card, id: card->longname, device: 0,
829 output_count: midi->out_ports, input_count: midi->in_ports, rmidi: &rmidi);
830 if (err < 0) {
831 ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
832 goto fail;
833 }
834 midi->rmidi = rmidi;
835 midi->in_last_port = 0;
836 strscpy(rmidi->name, card->shortname);
837 rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
838 SNDRV_RAWMIDI_INFO_INPUT |
839 SNDRV_RAWMIDI_INFO_DUPLEX;
840 rmidi->private_data = midi;
841 rmidi->private_free = f_midi_rmidi_free;
842 midi->free_ref++;
843
844 /*
845 * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
846 * It's an upside-down world being a gadget.
847 */
848 snd_rawmidi_set_ops(rmidi, stream: SNDRV_RAWMIDI_STREAM_OUTPUT, ops: &gmidi_in_ops);
849 snd_rawmidi_set_ops(rmidi, stream: SNDRV_RAWMIDI_STREAM_INPUT, ops: &gmidi_out_ops);
850
851 /* register it - we're ready to go */
852 err = snd_card_register(card);
853 if (err < 0) {
854 ERROR(midi, "snd_card_register() failed\n");
855 goto fail;
856 }
857
858 VDBG(midi, "%s() finished ok\n", __func__);
859 return 0;
860
861fail:
862 f_midi_unregister_card(midi);
863 return err;
864}
865
866/* MIDI function driver setup/binding */
867
868static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
869{
870 struct usb_descriptor_header **midi_function;
871 struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
872 struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
873 struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
874 struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
875 struct usb_composite_dev *cdev = c->cdev;
876 struct f_midi *midi = func_to_midi(f);
877 struct usb_string *us;
878 int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0;
879
880 midi->gadget = cdev->gadget;
881 INIT_WORK(&midi->work, f_midi_in_work);
882 status = f_midi_register_card(midi);
883 if (status < 0)
884 goto fail_register;
885
886 /* maybe allocate device-global string ID */
887 us = usb_gstrings_attach(cdev: c->cdev, sp: midi_strings,
888 ARRAY_SIZE(midi_string_defs));
889 if (IS_ERR(ptr: us)) {
890 status = PTR_ERR(ptr: us);
891 goto fail;
892 }
893 ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id;
894
895 /* We have two interfaces, AudioControl and MIDIStreaming */
896 status = usb_interface_id(c, f);
897 if (status < 0)
898 goto fail;
899 ac_interface_desc.bInterfaceNumber = status;
900
901 status = usb_interface_id(c, f);
902 if (status < 0)
903 goto fail;
904 ms_interface_desc.bInterfaceNumber = status;
905 ac_header_desc.baInterfaceNr[0] = status;
906 midi->ms_id = status;
907
908 status = -ENODEV;
909
910 /*
911 * Reset wMaxPacketSize with maximum packet size of FS bulk transfer before
912 * endpoint claim. This ensures that the wMaxPacketSize does not exceed the
913 * limit during bind retries where configured dwc3 TX/RX FIFO's maxpacket
914 * size of 512 bytes for IN/OUT endpoints in support HS speed only.
915 */
916 bulk_in_desc.wMaxPacketSize = cpu_to_le16(64);
917 bulk_out_desc.wMaxPacketSize = cpu_to_le16(64);
918
919 /* allocate instance-specific endpoints */
920 midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
921 if (!midi->in_ep)
922 goto fail;
923
924 midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
925 if (!midi->out_ep)
926 goto fail;
927
928 /* allocate temporary function list */
929 midi_function = kcalloc((MAX_PORTS * 4) + 11, sizeof(*midi_function),
930 GFP_KERNEL);
931 if (!midi_function) {
932 status = -ENOMEM;
933 goto fail;
934 }
935
936 /*
937 * construct the function's descriptor set. As the number of
938 * input and output MIDI ports is configurable, we have to do
939 * it that way.
940 */
941
942 /* add the headers - these are always the same */
943 midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
944 midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
945 midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;
946
947 /* calculate the header's wTotalLength */
948 n = USB_DT_MS_HEADER_SIZE
949 + (midi->in_ports + midi->out_ports) *
950 (USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
951 ms_header_desc.wTotalLength = cpu_to_le16(n);
952
953 midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;
954
955 /* configure the external IN jacks, each linked to an embedded OUT jack */
956 for (n = 0; n < midi->in_ports; n++) {
957 struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
958 struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];
959
960 in_ext->bLength = USB_DT_MIDI_IN_SIZE;
961 in_ext->bDescriptorType = USB_DT_CS_INTERFACE;
962 in_ext->bDescriptorSubtype = USB_MS_MIDI_IN_JACK;
963 in_ext->bJackType = USB_MS_EXTERNAL;
964 in_ext->bJackID = jack++;
965 in_ext->iJack = 0;
966 midi_function[i++] = (struct usb_descriptor_header *) in_ext;
967
968 out_emb->bLength = USB_DT_MIDI_OUT_SIZE(1);
969 out_emb->bDescriptorType = USB_DT_CS_INTERFACE;
970 out_emb->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK;
971 out_emb->bJackType = USB_MS_EMBEDDED;
972 out_emb->bJackID = jack++;
973 out_emb->bNrInputPins = 1;
974 out_emb->pins[0].baSourcePin = 1;
975 out_emb->pins[0].baSourceID = in_ext->bJackID;
976 out_emb->iJack = 0;
977 midi_function[i++] = (struct usb_descriptor_header *) out_emb;
978
979 /* link it to the endpoint */
980 ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
981 }
982
983 /* configure the external OUT jacks, each linked to an embedded IN jack */
984 for (n = 0; n < midi->out_ports; n++) {
985 struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
986 struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];
987
988 in_emb->bLength = USB_DT_MIDI_IN_SIZE;
989 in_emb->bDescriptorType = USB_DT_CS_INTERFACE;
990 in_emb->bDescriptorSubtype = USB_MS_MIDI_IN_JACK;
991 in_emb->bJackType = USB_MS_EMBEDDED;
992 in_emb->bJackID = jack++;
993 in_emb->iJack = 0;
994 midi_function[i++] = (struct usb_descriptor_header *) in_emb;
995
996 out_ext->bLength = USB_DT_MIDI_OUT_SIZE(1);
997 out_ext->bDescriptorType = USB_DT_CS_INTERFACE;
998 out_ext->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK;
999 out_ext->bJackType = USB_MS_EXTERNAL;
1000 out_ext->bJackID = jack++;
1001 out_ext->bNrInputPins = 1;
1002 out_ext->iJack = 0;
1003 out_ext->pins[0].baSourceID = in_emb->bJackID;
1004 out_ext->pins[0].baSourcePin = 1;
1005 midi_function[i++] = (struct usb_descriptor_header *) out_ext;
1006
1007 /* link it to the endpoint */
1008 ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
1009 }
1010
1011 /* configure the endpoint descriptors ... */
1012 ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
1013 ms_out_desc.bNumEmbMIDIJack = midi->out_ports;
1014
1015 ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
1016 ms_in_desc.bNumEmbMIDIJack = midi->in_ports;
1017
1018 /* ... and add them to the list */
1019 endpoint_descriptor_index = i;
1020 midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
1021 midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
1022 midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
1023 midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
1024 midi_function[i++] = NULL;
1025
1026 /*
1027 * support all relevant hardware speeds... we expect that when
1028 * hardware is dual speed, all bulk-capable endpoints work at
1029 * both speeds
1030 */
1031 /* copy descriptors, and track endpoint copies */
1032 f->fs_descriptors = usb_copy_descriptors(midi_function);
1033 if (!f->fs_descriptors)
1034 goto fail_f_midi;
1035
1036 bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
1037 bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
1038 f->hs_descriptors = usb_copy_descriptors(midi_function);
1039 if (!f->hs_descriptors)
1040 goto fail_f_midi;
1041
1042 bulk_in_desc.wMaxPacketSize = cpu_to_le16(1024);
1043 bulk_out_desc.wMaxPacketSize = cpu_to_le16(1024);
1044 i = endpoint_descriptor_index;
1045 midi_function[i++] = (struct usb_descriptor_header *)
1046 &bulk_out_desc;
1047 midi_function[i++] = (struct usb_descriptor_header *)
1048 &bulk_out_ss_comp_desc;
1049 midi_function[i++] = (struct usb_descriptor_header *)
1050 &ms_out_desc;
1051 midi_function[i++] = (struct usb_descriptor_header *)
1052 &bulk_in_desc;
1053 midi_function[i++] = (struct usb_descriptor_header *)
1054 &bulk_in_ss_comp_desc;
1055 midi_function[i++] = (struct usb_descriptor_header *)
1056 &ms_in_desc;
1057 f->ss_descriptors = usb_copy_descriptors(midi_function);
1058 if (!f->ss_descriptors)
1059 goto fail_f_midi;
1060
1061 kfree(objp: midi_function);
1062
1063 return 0;
1064
1065fail_f_midi:
1066 kfree(objp: midi_function);
1067 usb_free_all_descriptors(f);
1068fail:
1069 f_midi_unregister_card(midi);
1070fail_register:
1071 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1072
1073 return status;
1074}
1075
1076static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item)
1077{
1078 return container_of(to_config_group(item), struct f_midi_opts,
1079 func_inst.group);
1080}
1081
1082static void midi_attr_release(struct config_item *item)
1083{
1084 struct f_midi_opts *opts = to_f_midi_opts(item);
1085
1086 usb_put_function_instance(fi: &opts->func_inst);
1087}
1088
1089static struct configfs_item_operations midi_item_ops = {
1090 .release = midi_attr_release,
1091};
1092
1093#define F_MIDI_OPT(name, test_limit, limit) \
1094static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \
1095{ \
1096 struct f_midi_opts *opts = to_f_midi_opts(item); \
1097 int result; \
1098 \
1099 mutex_lock(&opts->lock); \
1100 result = sprintf(page, "%u\n", opts->name); \
1101 mutex_unlock(&opts->lock); \
1102 \
1103 return result; \
1104} \
1105 \
1106static ssize_t f_midi_opts_##name##_store(struct config_item *item, \
1107 const char *page, size_t len) \
1108{ \
1109 struct f_midi_opts *opts = to_f_midi_opts(item); \
1110 int ret; \
1111 u32 num; \
1112 \
1113 mutex_lock(&opts->lock); \
1114 if (opts->refcnt > 1) { \
1115 ret = -EBUSY; \
1116 goto end; \
1117 } \
1118 \
1119 ret = kstrtou32(page, 0, &num); \
1120 if (ret) \
1121 goto end; \
1122 \
1123 if (test_limit && num > limit) { \
1124 ret = -EINVAL; \
1125 goto end; \
1126 } \
1127 opts->name = num; \
1128 ret = len; \
1129 \
1130end: \
1131 mutex_unlock(&opts->lock); \
1132 return ret; \
1133} \
1134 \
1135CONFIGFS_ATTR(f_midi_opts_, name);
1136
1137#define F_MIDI_OPT_SIGNED(name, test_limit, limit) \
1138static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \
1139{ \
1140 struct f_midi_opts *opts = to_f_midi_opts(item); \
1141 int result; \
1142 \
1143 mutex_lock(&opts->lock); \
1144 result = sprintf(page, "%d\n", opts->name); \
1145 mutex_unlock(&opts->lock); \
1146 \
1147 return result; \
1148} \
1149 \
1150static ssize_t f_midi_opts_##name##_store(struct config_item *item, \
1151 const char *page, size_t len) \
1152{ \
1153 struct f_midi_opts *opts = to_f_midi_opts(item); \
1154 int ret; \
1155 s32 num; \
1156 \
1157 mutex_lock(&opts->lock); \
1158 if (opts->refcnt > 1) { \
1159 ret = -EBUSY; \
1160 goto end; \
1161 } \
1162 \
1163 ret = kstrtos32(page, 0, &num); \
1164 if (ret) \
1165 goto end; \
1166 \
1167 if (test_limit && num > limit) { \
1168 ret = -EINVAL; \
1169 goto end; \
1170 } \
1171 opts->name = num; \
1172 ret = len; \
1173 \
1174end: \
1175 mutex_unlock(&opts->lock); \
1176 return ret; \
1177} \
1178 \
1179CONFIGFS_ATTR(f_midi_opts_, name);
1180
1181F_MIDI_OPT_SIGNED(index, true, SNDRV_CARDS);
1182F_MIDI_OPT(buflen, false, 0);
1183F_MIDI_OPT(qlen, false, 0);
1184F_MIDI_OPT(in_ports, true, MAX_PORTS);
1185F_MIDI_OPT(out_ports, true, MAX_PORTS);
1186
1187static ssize_t f_midi_opts_id_show(struct config_item *item, char *page)
1188{
1189 struct f_midi_opts *opts = to_f_midi_opts(item);
1190 ssize_t result;
1191
1192 mutex_lock(&opts->lock);
1193 if (opts->id) {
1194 result = strscpy(page, opts->id, PAGE_SIZE);
1195 } else {
1196 page[0] = 0;
1197 result = 0;
1198 }
1199
1200 mutex_unlock(lock: &opts->lock);
1201
1202 return result;
1203}
1204
1205static ssize_t f_midi_opts_id_store(struct config_item *item,
1206 const char *page, size_t len)
1207{
1208 struct f_midi_opts *opts = to_f_midi_opts(item);
1209 int ret;
1210 char *c;
1211
1212 mutex_lock(&opts->lock);
1213 if (opts->refcnt > 1) {
1214 ret = -EBUSY;
1215 goto end;
1216 }
1217
1218 c = kstrndup(s: page, len, GFP_KERNEL);
1219 if (!c) {
1220 ret = -ENOMEM;
1221 goto end;
1222 }
1223 if (opts->id_allocated)
1224 kfree(objp: opts->id);
1225 opts->id = c;
1226 opts->id_allocated = true;
1227 ret = len;
1228end:
1229 mutex_unlock(lock: &opts->lock);
1230 return ret;
1231}
1232
1233CONFIGFS_ATTR(f_midi_opts_, id);
1234
1235static struct configfs_attribute *midi_attrs[] = {
1236 &f_midi_opts_attr_index,
1237 &f_midi_opts_attr_buflen,
1238 &f_midi_opts_attr_qlen,
1239 &f_midi_opts_attr_in_ports,
1240 &f_midi_opts_attr_out_ports,
1241 &f_midi_opts_attr_id,
1242 NULL,
1243};
1244
1245static const struct config_item_type midi_func_type = {
1246 .ct_item_ops = &midi_item_ops,
1247 .ct_attrs = midi_attrs,
1248 .ct_owner = THIS_MODULE,
1249};
1250
1251static void f_midi_free_inst(struct usb_function_instance *f)
1252{
1253 struct f_midi_opts *opts;
1254 bool free = false;
1255
1256 opts = container_of(f, struct f_midi_opts, func_inst);
1257
1258 mutex_lock(&opts->lock);
1259 if (!--opts->refcnt) {
1260 free = true;
1261 }
1262 mutex_unlock(lock: &opts->lock);
1263
1264 if (free) {
1265 if (opts->id_allocated)
1266 kfree(objp: opts->id);
1267 kfree(objp: opts);
1268 }
1269}
1270
1271static struct usb_function_instance *f_midi_alloc_inst(void)
1272{
1273 struct f_midi_opts *opts;
1274
1275 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1276 if (!opts)
1277 return ERR_PTR(error: -ENOMEM);
1278
1279 mutex_init(&opts->lock);
1280 opts->func_inst.free_func_inst = f_midi_free_inst;
1281 opts->index = SNDRV_DEFAULT_IDX1;
1282 opts->id = SNDRV_DEFAULT_STR1;
1283 opts->buflen = 512;
1284 opts->qlen = 32;
1285 opts->in_ports = 1;
1286 opts->out_ports = 1;
1287 opts->refcnt = 1;
1288
1289 config_group_init_type_name(group: &opts->func_inst.group, name: "",
1290 type: &midi_func_type);
1291
1292 return &opts->func_inst;
1293}
1294
1295static void f_midi_free(struct usb_function *f)
1296{
1297 struct f_midi *midi;
1298 struct f_midi_opts *opts;
1299 bool free = false;
1300
1301 midi = func_to_midi(f);
1302 opts = container_of(f->fi, struct f_midi_opts, func_inst);
1303 mutex_lock(&opts->lock);
1304 if (!--midi->free_ref) {
1305 kfree(objp: midi->id);
1306 kfifo_free(&midi->in_req_fifo);
1307 kfree(objp: midi);
1308 free = true;
1309 }
1310 mutex_unlock(lock: &opts->lock);
1311
1312 if (free)
1313 f_midi_free_inst(f: &opts->func_inst);
1314}
1315
1316static void f_midi_rmidi_free(struct snd_rawmidi *rmidi)
1317{
1318 f_midi_free(f: rmidi->private_data);
1319}
1320
1321static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
1322{
1323 struct usb_composite_dev *cdev = f->config->cdev;
1324 struct f_midi *midi = func_to_midi(f);
1325 struct snd_card *card;
1326
1327 DBG(cdev, "unbind\n");
1328
1329 /* just to be sure */
1330 f_midi_disable(f);
1331
1332 card = midi->card;
1333 midi->card = NULL;
1334 if (card)
1335 snd_card_free_when_closed(card);
1336
1337 usb_free_all_descriptors(f);
1338}
1339
1340static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
1341{
1342 struct f_midi *midi = NULL;
1343 struct f_midi_opts *opts;
1344 int status, i;
1345
1346 opts = container_of(fi, struct f_midi_opts, func_inst);
1347
1348 mutex_lock(&opts->lock);
1349 /* sanity check */
1350 if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) {
1351 status = -EINVAL;
1352 goto setup_fail;
1353 }
1354
1355 /* allocate and initialize one new instance */
1356 midi = kzalloc(struct_size(midi, in_ports_array, opts->in_ports),
1357 GFP_KERNEL);
1358 if (!midi) {
1359 status = -ENOMEM;
1360 goto setup_fail;
1361 }
1362 midi->in_ports = opts->in_ports;
1363
1364 for (i = 0; i < opts->in_ports; i++)
1365 midi->in_ports_array[i].cable = i;
1366
1367 /* set up ALSA midi devices */
1368 midi->id = kstrdup(s: opts->id, GFP_KERNEL);
1369 if (opts->id && !midi->id) {
1370 status = -ENOMEM;
1371 goto midi_free;
1372 }
1373 midi->out_ports = opts->out_ports;
1374 midi->index = opts->index;
1375 midi->buflen = opts->buflen;
1376 midi->qlen = opts->qlen;
1377 midi->in_last_port = 0;
1378 midi->free_ref = 1;
1379
1380 status = kfifo_alloc(&midi->in_req_fifo, midi->qlen, GFP_KERNEL);
1381 if (status)
1382 goto midi_free;
1383
1384 spin_lock_init(&midi->transmit_lock);
1385
1386 ++opts->refcnt;
1387 mutex_unlock(lock: &opts->lock);
1388
1389 midi->func.name = "gmidi function";
1390 midi->func.bind = f_midi_bind;
1391 midi->func.unbind = f_midi_unbind;
1392 midi->func.set_alt = f_midi_set_alt;
1393 midi->func.disable = f_midi_disable;
1394 midi->func.free_func = f_midi_free;
1395
1396 return &midi->func;
1397
1398midi_free:
1399 if (midi)
1400 kfree(objp: midi->id);
1401 kfree(objp: midi);
1402setup_fail:
1403 mutex_unlock(lock: &opts->lock);
1404
1405 return ERR_PTR(error: status);
1406}
1407
1408DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc);
1409

source code of linux/drivers/usb/gadget/function/f_midi.c