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