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