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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / usb / gadget / function / f_midi.c
blob46af0aa07e2e380d86b50e56ae5cd2d3d4297dfb
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
40 MODULE_AUTHOR("Ben Williamson");
41 MODULE_LICENSE("GPL v2");
42
43 static const char f_midi_shortname[] = "f_midi";
44 static 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 */
54 enum {
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 */
71 struct 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
79 struct 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
105 static inline struct f_midi *func_to_midi(struct usb_function *f)
106 {
107 return container_of(f, struct f_midi, func);
108 }
109
110 static void f_midi_transmit(struct f_midi *midi);
111 static void f_midi_rmidi_free(struct snd_rawmidi *rmidi);
112 static void f_midi_free_inst(struct usb_function_instance *f);
113
114 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1);
115 DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
116 DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16);
117
118 /* B.3.1 Standard AC Interface Descriptor */
119 static 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 */
130 static 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 */
141 static 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 */
152 static 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 */
161 static 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
168 static 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 */
176 static 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 */
185 static 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
192 static 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 */
200 static 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
212 static struct usb_string midi_string_defs[] = {
213 [STRING_FUNC_IDX].s = "MIDI function",
214 { } /* end of list */
215 };
216
217 static struct usb_gadget_strings midi_stringtab = {
218 .language = 0x0409, /* en-us */
219 .strings = midi_string_defs,
220 };
221
222 static struct usb_gadget_strings *midi_strings[] = {
223 &midi_stringtab,
224 NULL,
225 };
226
227 static 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
233 static 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 */
240 static 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
256 static 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
269 static void
270 f_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
324 static 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
337 static 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
363 static 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
417 static 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
439 static 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 */
447 static 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
606 static 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
669 done:
670 return active;
671 }
672
673 static 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
697 drop_out:
698 f_midi_drop_out_substreams(midi);
699 }
700
701 static void f_midi_in_tasklet(unsigned long data)
702 {
703 struct f_midi *midi = (struct f_midi *) data;
704 f_midi_transmit(midi);
705 }
706
707 static int f_midi_in_open(struct snd_rawmidi_substream *substream)
708 {
709 struct f_midi *midi = substream->rmidi->private_data;
710 struct gmidi_in_port *port;
711
712 if (substream->number >= midi->in_ports)
713 return -EINVAL;
714
715 VDBG(midi, "%s()\n", __func__);
716 port = midi->in_ports_array + substream->number;
717 port->substream = substream;
718 port->state = STATE_INITIAL;
719 return 0;
720 }
721
722 static int f_midi_in_close(struct snd_rawmidi_substream *substream)
723 {
724 struct f_midi *midi = substream->rmidi->private_data;
725
726 VDBG(midi, "%s()\n", __func__);
727 return 0;
728 }
729
730 static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up)
731 {
732 struct f_midi *midi = substream->rmidi->private_data;
733
734 if (substream->number >= midi->in_ports)
735 return;
736
737 VDBG(midi, "%s() %d\n", __func__, up);
738 midi->in_ports_array[substream->number].active = up;
739 if (up)
740 tasklet_hi_schedule(&midi->tasklet);
741 }
742
743 static int f_midi_out_open(struct snd_rawmidi_substream *substream)
744 {
745 struct f_midi *midi = substream->rmidi->private_data;
746
747 if (substream->number >= MAX_PORTS)
748 return -EINVAL;
749
750 VDBG(midi, "%s()\n", __func__);
751 midi->out_substream[substream->number] = substream;
752 return 0;
753 }
754
755 static int f_midi_out_close(struct snd_rawmidi_substream *substream)
756 {
757 struct f_midi *midi = substream->rmidi->private_data;
758
759 VDBG(midi, "%s()\n", __func__);
760 return 0;
761 }
762
763 static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up)
764 {
765 struct f_midi *midi = substream->rmidi->private_data;
766
767 VDBG(midi, "%s()\n", __func__);
768
769 if (up)
770 set_bit(substream->number, &midi->out_triggered);
771 else
772 clear_bit(substream->number, &midi->out_triggered);
773 }
774
775 static const struct snd_rawmidi_ops gmidi_in_ops = {
776 .open = f_midi_in_open,
777 .close = f_midi_in_close,
778 .trigger = f_midi_in_trigger,
779 };
780
781 static const struct snd_rawmidi_ops gmidi_out_ops = {
782 .open = f_midi_out_open,
783 .close = f_midi_out_close,
784 .trigger = f_midi_out_trigger
785 };
786
787 static inline void f_midi_unregister_card(struct f_midi *midi)
788 {
789 if (midi->card) {
790 snd_card_free(midi->card);
791 midi->card = NULL;
792 }
793 }
794
795 /* register as a sound "card" */
796 static int f_midi_register_card(struct f_midi *midi)
797 {
798 struct snd_card *card;
799 struct snd_rawmidi *rmidi;
800 int err;
801 static struct snd_device_ops ops = {
802 .dev_free = f_midi_snd_free,
803 };
804
805 err = snd_card_new(&midi->gadget->dev, midi->index, midi->id,
806 THIS_MODULE, 0, &card);
807 if (err < 0) {
808 ERROR(midi, "snd_card_new() failed\n");
809 goto fail;
810 }
811 midi->card = card;
812
813 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops);
814 if (err < 0) {
815 ERROR(midi, "snd_device_new() failed: error %d\n", err);
816 goto fail;
817 }
818
819 strcpy(card->driver, f_midi_longname);
820 strcpy(card->longname, f_midi_longname);
821 strcpy(card->shortname, f_midi_shortname);
822
823 /* Set up rawmidi */
824 snd_component_add(card, "MIDI");
825 err = snd_rawmidi_new(card, card->longname, 0,
826 midi->out_ports, midi->in_ports, &rmidi);
827 if (err < 0) {
828 ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err);
829 goto fail;
830 }
831 midi->rmidi = rmidi;
832 midi->in_last_port = 0;
833 strcpy(rmidi->name, card->shortname);
834 rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
835 SNDRV_RAWMIDI_INFO_INPUT |
836 SNDRV_RAWMIDI_INFO_DUPLEX;
837 rmidi->private_data = midi;
838 rmidi->private_free = f_midi_rmidi_free;
839 midi->free_ref++;
840
841 /*
842 * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
843 * It's an upside-down world being a gadget.
844 */
845 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
846 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
847
848 /* register it - we're ready to go */
849 err = snd_card_register(card);
850 if (err < 0) {
851 ERROR(midi, "snd_card_register() failed\n");
852 goto fail;
853 }
854
855 VDBG(midi, "%s() finished ok\n", __func__);
856 return 0;
857
858 fail:
859 f_midi_unregister_card(midi);
860 return err;
861 }
862
863 /* MIDI function driver setup/binding */
864
865 static int f_midi_bind(struct usb_configuration *c, struct usb_function *f)
866 {
867 struct usb_descriptor_header **midi_function;
868 struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS];
869 struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS];
870 struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS];
871 struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS];
872 struct usb_composite_dev *cdev = c->cdev;
873 struct f_midi *midi = func_to_midi(f);
874 struct usb_string *us;
875 int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0;
876
877 midi->gadget = cdev->gadget;
878 tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi);
879 status = f_midi_register_card(midi);
880 if (status < 0)
881 goto fail_register;
882
883 /* maybe allocate device-global string ID */
884 us = usb_gstrings_attach(c->cdev, midi_strings,
885 ARRAY_SIZE(midi_string_defs));
886 if (IS_ERR(us)) {
887 status = PTR_ERR(us);
888 goto fail;
889 }
890 ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id;
891
892 /* We have two interfaces, AudioControl and MIDIStreaming */
893 status = usb_interface_id(c, f);
894 if (status < 0)
895 goto fail;
896 ac_interface_desc.bInterfaceNumber = status;
897
898 status = usb_interface_id(c, f);
899 if (status < 0)
900 goto fail;
901 ms_interface_desc.bInterfaceNumber = status;
902 ac_header_desc.baInterfaceNr[0] = status;
903 midi->ms_id = status;
904
905 status = -ENODEV;
906
907 /* allocate instance-specific endpoints */
908 midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc);
909 if (!midi->in_ep)
910 goto fail;
911
912 midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc);
913 if (!midi->out_ep)
914 goto fail;
915
916 /* allocate temporary function list */
917 midi_function = kcalloc((MAX_PORTS * 4) + 11, sizeof(*midi_function),
918 GFP_KERNEL);
919 if (!midi_function) {
920 status = -ENOMEM;
921 goto fail;
922 }
923
924 /*
925 * construct the function's descriptor set. As the number of
926 * input and output MIDI ports is configurable, we have to do
927 * it that way.
928 */
929
930 /* add the headers - these are always the same */
931 midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc;
932 midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc;
933 midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc;
934
935 /* calculate the header's wTotalLength */
936 n = USB_DT_MS_HEADER_SIZE
937 + (midi->in_ports + midi->out_ports) *
938 (USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1));
939 ms_header_desc.wTotalLength = cpu_to_le16(n);
940
941 midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc;
942
943 /* configure the external IN jacks, each linked to an embedded OUT jack */
944 for (n = 0; n < midi->in_ports; n++) {
945 struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n];
946 struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n];
947
948 in_ext->bLength = USB_DT_MIDI_IN_SIZE;
949 in_ext->bDescriptorType = USB_DT_CS_INTERFACE;
950 in_ext->bDescriptorSubtype = USB_MS_MIDI_IN_JACK;
951 in_ext->bJackType = USB_MS_EXTERNAL;
952 in_ext->bJackID = jack++;
953 in_ext->iJack = 0;
954 midi_function[i++] = (struct usb_descriptor_header *) in_ext;
955
956 out_emb->bLength = USB_DT_MIDI_OUT_SIZE(1);
957 out_emb->bDescriptorType = USB_DT_CS_INTERFACE;
958 out_emb->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK;
959 out_emb->bJackType = USB_MS_EMBEDDED;
960 out_emb->bJackID = jack++;
961 out_emb->bNrInputPins = 1;
962 out_emb->pins[0].baSourcePin = 1;
963 out_emb->pins[0].baSourceID = in_ext->bJackID;
964 out_emb->iJack = 0;
965 midi_function[i++] = (struct usb_descriptor_header *) out_emb;
966
967 /* link it to the endpoint */
968 ms_in_desc.baAssocJackID[n] = out_emb->bJackID;
969 }
970
971 /* configure the external OUT jacks, each linked to an embedded IN jack */
972 for (n = 0; n < midi->out_ports; n++) {
973 struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n];
974 struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n];
975
976 in_emb->bLength = USB_DT_MIDI_IN_SIZE;
977 in_emb->bDescriptorType = USB_DT_CS_INTERFACE;
978 in_emb->bDescriptorSubtype = USB_MS_MIDI_IN_JACK;
979 in_emb->bJackType = USB_MS_EMBEDDED;
980 in_emb->bJackID = jack++;
981 in_emb->iJack = 0;
982 midi_function[i++] = (struct usb_descriptor_header *) in_emb;
983
984 out_ext->bLength = USB_DT_MIDI_OUT_SIZE(1);
985 out_ext->bDescriptorType = USB_DT_CS_INTERFACE;
986 out_ext->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK;
987 out_ext->bJackType = USB_MS_EXTERNAL;
988 out_ext->bJackID = jack++;
989 out_ext->bNrInputPins = 1;
990 out_ext->iJack = 0;
991 out_ext->pins[0].baSourceID = in_emb->bJackID;
992 out_ext->pins[0].baSourcePin = 1;
993 midi_function[i++] = (struct usb_descriptor_header *) out_ext;
994
995 /* link it to the endpoint */
996 ms_out_desc.baAssocJackID[n] = in_emb->bJackID;
997 }
998
999 /* configure the endpoint descriptors ... */
1000 ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports);
1001 ms_out_desc.bNumEmbMIDIJack = midi->in_ports;
1002
1003 ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports);
1004 ms_in_desc.bNumEmbMIDIJack = midi->out_ports;
1005
1006 /* ... and add them to the list */
1007 endpoint_descriptor_index = i;
1008 midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc;
1009 midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc;
1010 midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc;
1011 midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc;
1012 midi_function[i++] = NULL;
1013
1014 /*
1015 * support all relevant hardware speeds... we expect that when
1016 * hardware is dual speed, all bulk-capable endpoints work at
1017 * both speeds
1018 */
1019 /* copy descriptors, and track endpoint copies */
1020 f->fs_descriptors = usb_copy_descriptors(midi_function);
1021 if (!f->fs_descriptors)
1022 goto fail_f_midi;
1023
1024 if (gadget_is_dualspeed(c->cdev->gadget)) {
1025 bulk_in_desc.wMaxPacketSize = cpu_to_le16(512);
1026 bulk_out_desc.wMaxPacketSize = cpu_to_le16(512);
1027 f->hs_descriptors = usb_copy_descriptors(midi_function);
1028 if (!f->hs_descriptors)
1029 goto fail_f_midi;
1030 }
1031
1032 if (gadget_is_superspeed(c->cdev->gadget)) {
1033 bulk_in_desc.wMaxPacketSize = cpu_to_le16(1024);
1034 bulk_out_desc.wMaxPacketSize = cpu_to_le16(1024);
1035 i = endpoint_descriptor_index;
1036 midi_function[i++] = (struct usb_descriptor_header *)
1037 &bulk_out_desc;
1038 midi_function[i++] = (struct usb_descriptor_header *)
1039 &bulk_out_ss_comp_desc;
1040 midi_function[i++] = (struct usb_descriptor_header *)
1041 &ms_out_desc;
1042 midi_function[i++] = (struct usb_descriptor_header *)
1043 &bulk_in_desc;
1044 midi_function[i++] = (struct usb_descriptor_header *)
1045 &bulk_in_ss_comp_desc;
1046 midi_function[i++] = (struct usb_descriptor_header *)
1047 &ms_in_desc;
1048 f->ss_descriptors = usb_copy_descriptors(midi_function);
1049 if (!f->ss_descriptors)
1050 goto fail_f_midi;
1051 }
1052
1053 kfree(midi_function);
1054
1055 return 0;
1056
1057 fail_f_midi:
1058 kfree(midi_function);
1059 usb_free_all_descriptors(f);
1060 fail:
1061 f_midi_unregister_card(midi);
1062 fail_register:
1063 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1064
1065 return status;
1066 }
1067
1068 static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item)
1069 {
1070 return container_of(to_config_group(item), struct f_midi_opts,
1071 func_inst.group);
1072 }
1073
1074 static void midi_attr_release(struct config_item *item)
1075 {
1076 struct f_midi_opts *opts = to_f_midi_opts(item);
1077
1078 usb_put_function_instance(&opts->func_inst);
1079 }
1080
1081 static struct configfs_item_operations midi_item_ops = {
1082 .release = midi_attr_release,
1083 };
1084
1085 #define F_MIDI_OPT(name, test_limit, limit) \
1086 static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \
1087 { \
1088 struct f_midi_opts *opts = to_f_midi_opts(item); \
1089 int result; \
1090 \
1091 mutex_lock(&opts->lock); \
1092 result = sprintf(page, "%d\n", opts->name); \
1093 mutex_unlock(&opts->lock); \
1094 \
1095 return result; \
1096 } \
1097 \
1098 static ssize_t f_midi_opts_##name##_store(struct config_item *item, \
1099 const char *page, size_t len) \
1100 { \
1101 struct f_midi_opts *opts = to_f_midi_opts(item); \
1102 int ret; \
1103 u32 num; \
1104 \
1105 mutex_lock(&opts->lock); \
1106 if (opts->refcnt > 1) { \
1107 ret = -EBUSY; \
1108 goto end; \
1109 } \
1110 \
1111 ret = kstrtou32(page, 0, &num); \
1112 if (ret) \
1113 goto end; \
1114 \
1115 if (test_limit && num > limit) { \
1116 ret = -EINVAL; \
1117 goto end; \
1118 } \
1119 opts->name = num; \
1120 ret = len; \
1121 \
1122 end: \
1123 mutex_unlock(&opts->lock); \
1124 return ret; \
1125 } \
1126 \
1127 CONFIGFS_ATTR(f_midi_opts_, name);
1128
1129 F_MIDI_OPT(index, true, SNDRV_CARDS);
1130 F_MIDI_OPT(buflen, false, 0);
1131 F_MIDI_OPT(qlen, false, 0);
1132 F_MIDI_OPT(in_ports, true, MAX_PORTS);
1133 F_MIDI_OPT(out_ports, true, MAX_PORTS);
1134
1135 static ssize_t f_midi_opts_id_show(struct config_item *item, char *page)
1136 {
1137 struct f_midi_opts *opts = to_f_midi_opts(item);
1138 int result;
1139
1140 mutex_lock(&opts->lock);
1141 if (opts->id) {
1142 result = strlcpy(page, opts->id, PAGE_SIZE);
1143 } else {
1144 page[0] = 0;
1145 result = 0;
1146 }
1147
1148 mutex_unlock(&opts->lock);
1149
1150 return result;
1151 }
1152
1153 static ssize_t f_midi_opts_id_store(struct config_item *item,
1154 const char *page, size_t len)
1155 {
1156 struct f_midi_opts *opts = to_f_midi_opts(item);
1157 int ret;
1158 char *c;
1159
1160 mutex_lock(&opts->lock);
1161 if (opts->refcnt > 1) {
1162 ret = -EBUSY;
1163 goto end;
1164 }
1165
1166 c = kstrndup(page, len, GFP_KERNEL);
1167 if (!c) {
1168 ret = -ENOMEM;
1169 goto end;
1170 }
1171 if (opts->id_allocated)
1172 kfree(opts->id);
1173 opts->id = c;
1174 opts->id_allocated = true;
1175 ret = len;
1176 end:
1177 mutex_unlock(&opts->lock);
1178 return ret;
1179 }
1180
1181 CONFIGFS_ATTR(f_midi_opts_, id);
1182
1183 static struct configfs_attribute *midi_attrs[] = {
1184 &f_midi_opts_attr_index,
1185 &f_midi_opts_attr_buflen,
1186 &f_midi_opts_attr_qlen,
1187 &f_midi_opts_attr_in_ports,
1188 &f_midi_opts_attr_out_ports,
1189 &f_midi_opts_attr_id,
1190 NULL,
1191 };
1192
1193 static const struct config_item_type midi_func_type = {
1194 .ct_item_ops = &midi_item_ops,
1195 .ct_attrs = midi_attrs,
1196 .ct_owner = THIS_MODULE,
1197 };
1198
1199 static void f_midi_free_inst(struct usb_function_instance *f)
1200 {
1201 struct f_midi_opts *opts;
1202 bool free = false;
1203
1204 opts = container_of(f, struct f_midi_opts, func_inst);
1205
1206 mutex_lock(&opts->lock);
1207 if (!--opts->refcnt) {
1208 free = true;
1209 }
1210 mutex_unlock(&opts->lock);
1211
1212 if (free) {
1213 if (opts->id_allocated)
1214 kfree(opts->id);
1215 kfree(opts);
1216 }
1217 }
1218
1219 static struct usb_function_instance *f_midi_alloc_inst(void)
1220 {
1221 struct f_midi_opts *opts;
1222
1223 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1224 if (!opts)
1225 return ERR_PTR(-ENOMEM);
1226
1227 mutex_init(&opts->lock);
1228 opts->func_inst.free_func_inst = f_midi_free_inst;
1229 opts->index = SNDRV_DEFAULT_IDX1;
1230 opts->id = SNDRV_DEFAULT_STR1;
1231 opts->buflen = 512;
1232 opts->qlen = 32;
1233 opts->in_ports = 1;
1234 opts->out_ports = 1;
1235 opts->refcnt = 1;
1236
1237 config_group_init_type_name(&opts->func_inst.group, "",
1238 &midi_func_type);
1239
1240 return &opts->func_inst;
1241 }
1242
1243 static void f_midi_free(struct usb_function *f)
1244 {
1245 struct f_midi *midi;
1246 struct f_midi_opts *opts;
1247 bool free = false;
1248
1249 midi = func_to_midi(f);
1250 opts = container_of(f->fi, struct f_midi_opts, func_inst);
1251 mutex_lock(&opts->lock);
1252 if (!--midi->free_ref) {
1253 kfree(midi->id);
1254 kfifo_free(&midi->in_req_fifo);
1255 kfree(midi);
1256 free = true;
1257 }
1258 mutex_unlock(&opts->lock);
1259
1260 if (free)
1261 f_midi_free_inst(&opts->func_inst);
1262 }
1263
1264 static void f_midi_rmidi_free(struct snd_rawmidi *rmidi)
1265 {
1266 f_midi_free(rmidi->private_data);
1267 }
1268
1269 static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f)
1270 {
1271 struct usb_composite_dev *cdev = f->config->cdev;
1272 struct f_midi *midi = func_to_midi(f);
1273 struct snd_card *card;
1274
1275 DBG(cdev, "unbind\n");
1276
1277 /* just to be sure */
1278 f_midi_disable(f);
1279
1280 card = midi->card;
1281 midi->card = NULL;
1282 if (card)
1283 snd_card_free_when_closed(card);
1284
1285 usb_free_all_descriptors(f);
1286 }
1287
1288 static struct usb_function *f_midi_alloc(struct usb_function_instance *fi)
1289 {
1290 struct f_midi *midi = NULL;
1291 struct f_midi_opts *opts;
1292 int status, i;
1293
1294 opts = container_of(fi, struct f_midi_opts, func_inst);
1295
1296 mutex_lock(&opts->lock);
1297 /* sanity check */
1298 if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) {
1299 status = -EINVAL;
1300 goto setup_fail;
1301 }
1302
1303 /* allocate and initialize one new instance */
1304 midi = kzalloc(struct_size(midi, in_ports_array, opts->in_ports),
1305 GFP_KERNEL);
1306 if (!midi) {
1307 status = -ENOMEM;
1308 goto setup_fail;
1309 }
1310
1311 for (i = 0; i < opts->in_ports; i++)
1312 midi->in_ports_array[i].cable = i;
1313
1314 /* set up ALSA midi devices */
1315 midi->id = kstrdup(opts->id, GFP_KERNEL);
1316 if (opts->id && !midi->id) {
1317 status = -ENOMEM;
1318 goto setup_fail;
1319 }
1320 midi->in_ports = opts->in_ports;
1321 midi->out_ports = opts->out_ports;
1322 midi->index = opts->index;
1323 midi->buflen = opts->buflen;
1324 midi->qlen = opts->qlen;
1325 midi->in_last_port = 0;
1326 midi->free_ref = 1;
1327
1328 status = kfifo_alloc(&midi->in_req_fifo, midi->qlen, GFP_KERNEL);
1329 if (status)
1330 goto setup_fail;
1331
1332 spin_lock_init(&midi->transmit_lock);
1333
1334 ++opts->refcnt;
1335 mutex_unlock(&opts->lock);
1336
1337 midi->func.name = "gmidi function";
1338 midi->func.bind = f_midi_bind;
1339 midi->func.unbind = f_midi_unbind;
1340 midi->func.set_alt = f_midi_set_alt;
1341 midi->func.disable = f_midi_disable;
1342 midi->func.free_func = f_midi_free;
1343
1344 return &midi->func;
1345
1346 setup_fail:
1347 mutex_unlock(&opts->lock);
1348 kfree(midi);
1349 return ERR_PTR(status);
1350 }
1351
1352 DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc);
Linux with added FPC-III support