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); 112 113 DECLARE_UAC_AC_HEADER_DESCRIPTOR(1); 114 DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1); 115 DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16); 116 117 /* B.3.1 Standard AC Interface Descriptor */ 118 static 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 */ 129 static 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 */ 140 static 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 */ 151 static 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 */ 160 static 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 }; 166 167 static 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 */ 175 static 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 */ 184 static 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 }; 190 191 static 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 */ 199 static 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 0 210 211 static struct usb_string midi_string_defs[] = { 212 [STRING_FUNC_IDX].s = "MIDI function", 213 { } /* end of list */ 214 }; 215 216 static struct usb_gadget_strings midi_stringtab = { 217 .language = 0x0409, /* en-us */ 218 .strings = midi_string_defs, 219 }; 220 221 static struct usb_gadget_strings *midi_strings[] = { 222 &midi_stringtab, 223 NULL, 224 }; 225 226 static inline struct usb_request *midi_alloc_ep_req(struct usb_ep *ep, 227 unsigned length) 228 { 229 return alloc_ep_req(ep, length); 230 } 231 232 static 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 */ 239 static 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 } 254 255 static 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 } 267 268 static void 269 f_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 } 322 323 static 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 } 335 336 static 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 } 361 362 static 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 free_ep_req(midi->out_ep, req); 408 return err; 409 } 410 } 411 412 return 0; 413 } 414 415 static void f_midi_disable(struct usb_function *f) 416 { 417 struct f_midi *midi = func_to_midi(f); 418 struct usb_composite_dev *cdev = f->config->cdev; 419 struct usb_request *req = NULL; 420 421 DBG(cdev, "disable\n"); 422 423 /* 424 * just disable endpoints, forcing completion of pending i/o. 425 * all our completion handlers free their requests in this case. 426 */ 427 usb_ep_disable(midi->in_ep); 428 usb_ep_disable(midi->out_ep); 429 430 /* release IN requests */ 431 while (kfifo_get(&midi->in_req_fifo, &req)) 432 free_ep_req(midi->in_ep, req); 433 434 f_midi_drop_out_substreams(midi); 435 } 436 437 static int f_midi_snd_free(struct snd_device *device) 438 { 439 return 0; 440 } 441 442 /* 443 * Converts MIDI commands to USB MIDI packets. 444 */ 445 static void f_midi_transmit_byte(struct usb_request *req, 446 struct gmidi_in_port *port, uint8_t b) 447 { 448 uint8_t p[4] = { port->cable << 4, 0, 0, 0 }; 449 uint8_t next_state = STATE_INITIAL; 450 451 switch (b) { 452 case 0xf8 ... 0xff: 453 /* System Real-Time Messages */ 454 p[0] |= 0x0f; 455 p[1] = b; 456 next_state = port->state; 457 port->state = STATE_REAL_TIME; 458 break; 459 460 case 0xf7: 461 /* End of SysEx */ 462 switch (port->state) { 463 case STATE_SYSEX_0: 464 p[0] |= 0x05; 465 p[1] = 0xf7; 466 next_state = STATE_FINISHED; 467 break; 468 case STATE_SYSEX_1: 469 p[0] |= 0x06; 470 p[1] = port->data[0]; 471 p[2] = 0xf7; 472 next_state = STATE_FINISHED; 473 break; 474 case STATE_SYSEX_2: 475 p[0] |= 0x07; 476 p[1] = port->data[0]; 477 p[2] = port->data[1]; 478 p[3] = 0xf7; 479 next_state = STATE_FINISHED; 480 break; 481 default: 482 /* Ignore byte */ 483 next_state = port->state; 484 port->state = STATE_INITIAL; 485 } 486 break; 487 488 case 0xf0 ... 0xf6: 489 /* System Common Messages */ 490 port->data[0] = port->data[1] = 0; 491 port->state = STATE_INITIAL; 492 switch (b) { 493 case 0xf0: 494 port->data[0] = b; 495 port->data[1] = 0; 496 next_state = STATE_SYSEX_1; 497 break; 498 case 0xf1: 499 case 0xf3: 500 port->data[0] = b; 501 next_state = STATE_1PARAM; 502 break; 503 case 0xf2: 504 port->data[0] = b; 505 next_state = STATE_2PARAM_1; 506 break; 507 case 0xf4: 508 case 0xf5: 509 next_state = STATE_INITIAL; 510 break; 511 case 0xf6: 512 p[0] |= 0x05; 513 p[1] = 0xf6; 514 next_state = STATE_FINISHED; 515 break; 516 } 517 break; 518 519 case 0x80 ... 0xef: 520 /* 521 * Channel Voice Messages, Channel Mode Messages 522 * and Control Change Messages. 523 */ 524 port->data[0] = b; 525 port->data[1] = 0; 526 port->state = STATE_INITIAL; 527 if (b >= 0xc0 && b <= 0xdf) 528 next_state = STATE_1PARAM; 529 else 530 next_state = STATE_2PARAM_1; 531 break; 532 533 case 0x00 ... 0x7f: 534 /* Message parameters */ 535 switch (port->state) { 536 case STATE_1PARAM: 537 if (port->data[0] < 0xf0) 538 p[0] |= port->data[0] >> 4; 539 else 540 p[0] |= 0x02; 541 542 p[1] = port->data[0]; 543 p[2] = b; 544 /* This is to allow Running State Messages */ 545 next_state = STATE_1PARAM; 546 break; 547 case STATE_2PARAM_1: 548 port->data[1] = b; 549 next_state = STATE_2PARAM_2; 550 break; 551 case STATE_2PARAM_2: 552 if (port->data[0] < 0xf0) 553 p[0] |= port->data[0] >> 4; 554 else 555 p[0] |= 0x03; 556 557 p[1] = port->data[0]; 558 p[2] = port->data[1]; 559 p[3] = b; 560 /* This is to allow Running State Messages */ 561 next_state = STATE_2PARAM_1; 562 break; 563 case STATE_SYSEX_0: 564 port->data[0] = b; 565 next_state = STATE_SYSEX_1; 566 break; 567 case STATE_SYSEX_1: 568 port->data[1] = b; 569 next_state = STATE_SYSEX_2; 570 break; 571 case STATE_SYSEX_2: 572 p[0] |= 0x04; 573 p[1] = port->data[0]; 574 p[2] = port->data[1]; 575 p[3] = b; 576 next_state = STATE_SYSEX_0; 577 break; 578 } 579 break; 580 } 581 582 /* States where we have to write into the USB request */ 583 if (next_state == STATE_FINISHED || 584 port->state == STATE_SYSEX_2 || 585 port->state == STATE_1PARAM || 586 port->state == STATE_2PARAM_2 || 587 port->state == STATE_REAL_TIME) { 588 589 unsigned int length = req->length; 590 u8 *buf = (u8 *)req->buf + length; 591 592 memcpy(buf, p, sizeof(p)); 593 req->length = length + sizeof(p); 594 595 if (next_state == STATE_FINISHED) { 596 next_state = STATE_INITIAL; 597 port->data[0] = port->data[1] = 0; 598 } 599 } 600 601 port->state = next_state; 602 } 603 604 static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep) 605 { 606 struct usb_request *req = NULL; 607 unsigned int len, i; 608 bool active = false; 609 int err; 610 611 /* 612 * We peek the request in order to reuse it if it fails to enqueue on 613 * its endpoint 614 */ 615 len = kfifo_peek(&midi->in_req_fifo, &req); 616 if (len != 1) { 617 ERROR(midi, "%s: Couldn't get usb request\n", __func__); 618 return -1; 619 } 620 621 /* 622 * If buffer overrun, then we ignore this transmission. 623 * IMPORTANT: This will cause the user-space rawmidi device to block 624 * until a) usb requests have been completed or b) snd_rawmidi_write() 625 * times out. 626 */ 627 if (req->length > 0) 628 return 0; 629 630 for (i = midi->in_last_port; i < midi->in_ports; ++i) { 631 struct gmidi_in_port *port = midi->in_ports_array + i; 632 struct snd_rawmidi_substream *substream = port->substream; 633 634 if (!port->active || !substream) 635 continue; 636 637 while (req->length + 3 < midi->buflen) { 638 uint8_t b; 639 640 if (snd_rawmidi_transmit(substream, &b, 1) != 1) { 641 port->active = 0; 642 break; 643 } 644 f_midi_transmit_byte(req, port, b); 645 } 646 647 active = !!port->active; 648 if (active) 649 break; 650 } 651 midi->in_last_port = active ? i : 0; 652 653 if (req->length <= 0) 654 goto done; 655 656 err = usb_ep_queue(ep, req, GFP_ATOMIC); 657 if (err < 0) { 658 ERROR(midi, "%s failed to queue req: %d\n", 659 midi->in_ep->name, err); 660 req->length = 0; /* Re-use request next time. */ 661 } else { 662 /* Upon success, put request at the back of the queue. */ 663 kfifo_skip(&midi->in_req_fifo); 664 kfifo_put(&midi->in_req_fifo, req); 665 } 666 667 done: 668 return active; 669 } 670 671 static void f_midi_transmit(struct f_midi *midi) 672 { 673 struct usb_ep *ep = midi->in_ep; 674 int ret; 675 unsigned long flags; 676 677 /* We only care about USB requests if IN endpoint is enabled */ 678 if (!ep || !ep->enabled) 679 goto drop_out; 680 681 spin_lock_irqsave(&midi->transmit_lock, flags); 682 683 do { 684 ret = f_midi_do_transmit(midi, ep); 685 if (ret < 0) { 686 spin_unlock_irqrestore(&midi->transmit_lock, flags); 687 goto drop_out; 688 } 689 } while (ret); 690 691 spin_unlock_irqrestore(&midi->transmit_lock, flags); 692 693 return; 694 695 drop_out: 696 f_midi_drop_out_substreams(midi); 697 } 698 699 static void f_midi_in_tasklet(unsigned long data) 700 { 701 struct f_midi *midi = (struct f_midi *) data; 702 f_midi_transmit(midi); 703 } 704 705 static int f_midi_in_open(struct snd_rawmidi_substream *substream) 706 { 707 struct f_midi *midi = substream->rmidi->private_data; 708 struct gmidi_in_port *port; 709 710 if (substream->number >= midi->in_ports) 711 return -EINVAL; 712 713 VDBG(midi, "%s()\n", __func__); 714 port = midi->in_ports_array + substream->number; 715 port->substream = substream; 716 port->state = STATE_INITIAL; 717 return 0; 718 } 719 720 static int f_midi_in_close(struct snd_rawmidi_substream *substream) 721 { 722 struct f_midi *midi = substream->rmidi->private_data; 723 724 VDBG(midi, "%s()\n", __func__); 725 return 0; 726 } 727 728 static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up) 729 { 730 struct f_midi *midi = substream->rmidi->private_data; 731 732 if (substream->number >= midi->in_ports) 733 return; 734 735 VDBG(midi, "%s() %d\n", __func__, up); 736 midi->in_ports_array[substream->number].active = up; 737 if (up) 738 tasklet_hi_schedule(&midi->tasklet); 739 } 740 741 static int f_midi_out_open(struct snd_rawmidi_substream *substream) 742 { 743 struct f_midi *midi = substream->rmidi->private_data; 744 745 if (substream->number >= MAX_PORTS) 746 return -EINVAL; 747 748 VDBG(midi, "%s()\n", __func__); 749 midi->out_substream[substream->number] = substream; 750 return 0; 751 } 752 753 static int f_midi_out_close(struct snd_rawmidi_substream *substream) 754 { 755 struct f_midi *midi = substream->rmidi->private_data; 756 757 VDBG(midi, "%s()\n", __func__); 758 return 0; 759 } 760 761 static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up) 762 { 763 struct f_midi *midi = substream->rmidi->private_data; 764 765 VDBG(midi, "%s()\n", __func__); 766 767 if (up) 768 set_bit(substream->number, &midi->out_triggered); 769 else 770 clear_bit(substream->number, &midi->out_triggered); 771 } 772 773 static const struct snd_rawmidi_ops gmidi_in_ops = { 774 .open = f_midi_in_open, 775 .close = f_midi_in_close, 776 .trigger = f_midi_in_trigger, 777 }; 778 779 static const struct snd_rawmidi_ops gmidi_out_ops = { 780 .open = f_midi_out_open, 781 .close = f_midi_out_close, 782 .trigger = f_midi_out_trigger 783 }; 784 785 static inline void f_midi_unregister_card(struct f_midi *midi) 786 { 787 if (midi->card) { 788 snd_card_free(midi->card); 789 midi->card = NULL; 790 } 791 } 792 793 /* register as a sound "card" */ 794 static int f_midi_register_card(struct f_midi *midi) 795 { 796 struct snd_card *card; 797 struct snd_rawmidi *rmidi; 798 int err; 799 static struct snd_device_ops ops = { 800 .dev_free = f_midi_snd_free, 801 }; 802 803 err = snd_card_new(&midi->gadget->dev, midi->index, midi->id, 804 THIS_MODULE, 0, &card); 805 if (err < 0) { 806 ERROR(midi, "snd_card_new() failed\n"); 807 goto fail; 808 } 809 midi->card = card; 810 811 err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops); 812 if (err < 0) { 813 ERROR(midi, "snd_device_new() failed: error %d\n", err); 814 goto fail; 815 } 816 817 strcpy(card->driver, f_midi_longname); 818 strcpy(card->longname, f_midi_longname); 819 strcpy(card->shortname, f_midi_shortname); 820 821 /* Set up rawmidi */ 822 snd_component_add(card, "MIDI"); 823 err = snd_rawmidi_new(card, card->longname, 0, 824 midi->out_ports, midi->in_ports, &rmidi); 825 if (err < 0) { 826 ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err); 827 goto fail; 828 } 829 midi->rmidi = rmidi; 830 midi->in_last_port = 0; 831 strcpy(rmidi->name, card->shortname); 832 rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT | 833 SNDRV_RAWMIDI_INFO_INPUT | 834 SNDRV_RAWMIDI_INFO_DUPLEX; 835 rmidi->private_data = midi; 836 rmidi->private_free = f_midi_rmidi_free; 837 midi->free_ref++; 838 839 /* 840 * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT. 841 * It's an upside-down world being a gadget. 842 */ 843 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops); 844 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops); 845 846 /* register it - we're ready to go */ 847 err = snd_card_register(card); 848 if (err < 0) { 849 ERROR(midi, "snd_card_register() failed\n"); 850 goto fail; 851 } 852 853 VDBG(midi, "%s() finished ok\n", __func__); 854 return 0; 855 856 fail: 857 f_midi_unregister_card(midi); 858 return err; 859 } 860 861 /* MIDI function driver setup/binding */ 862 863 static int f_midi_bind(struct usb_configuration *c, struct usb_function *f) 864 { 865 struct usb_descriptor_header **midi_function; 866 struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS]; 867 struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS]; 868 struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS]; 869 struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS]; 870 struct usb_composite_dev *cdev = c->cdev; 871 struct f_midi *midi = func_to_midi(f); 872 struct usb_string *us; 873 int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0; 874 875 midi->gadget = cdev->gadget; 876 tasklet_init(&midi->tasklet, f_midi_in_tasklet, (unsigned long) midi); 877 status = f_midi_register_card(midi); 878 if (status < 0) 879 goto fail_register; 880 881 /* maybe allocate device-global string ID */ 882 us = usb_gstrings_attach(c->cdev, midi_strings, 883 ARRAY_SIZE(midi_string_defs)); 884 if (IS_ERR(us)) { 885 status = PTR_ERR(us); 886 goto fail; 887 } 888 ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id; 889 890 /* We have two interfaces, AudioControl and MIDIStreaming */ 891 status = usb_interface_id(c, f); 892 if (status < 0) 893 goto fail; 894 ac_interface_desc.bInterfaceNumber = status; 895 896 status = usb_interface_id(c, f); 897 if (status < 0) 898 goto fail; 899 ms_interface_desc.bInterfaceNumber = status; 900 ac_header_desc.baInterfaceNr[0] = status; 901 midi->ms_id = status; 902 903 status = -ENODEV; 904 905 /* allocate instance-specific endpoints */ 906 midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc); 907 if (!midi->in_ep) 908 goto fail; 909 910 midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc); 911 if (!midi->out_ep) 912 goto fail; 913 914 /* allocate temporary function list */ 915 midi_function = kcalloc((MAX_PORTS * 4) + 11, sizeof(*midi_function), 916 GFP_KERNEL); 917 if (!midi_function) { 918 status = -ENOMEM; 919 goto fail; 920 } 921 922 /* 923 * construct the function's descriptor set. As the number of 924 * input and output MIDI ports is configurable, we have to do 925 * it that way. 926 */ 927 928 /* add the headers - these are always the same */ 929 midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc; 930 midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc; 931 midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc; 932 933 /* calculate the header's wTotalLength */ 934 n = USB_DT_MS_HEADER_SIZE 935 + (midi->in_ports + midi->out_ports) * 936 (USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1)); 937 ms_header_desc.wTotalLength = cpu_to_le16(n); 938 939 midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc; 940 941 /* configure the external IN jacks, each linked to an embedded OUT jack */ 942 for (n = 0; n < midi->in_ports; n++) { 943 struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n]; 944 struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n]; 945 946 in_ext->bLength = USB_DT_MIDI_IN_SIZE; 947 in_ext->bDescriptorType = USB_DT_CS_INTERFACE; 948 in_ext->bDescriptorSubtype = USB_MS_MIDI_IN_JACK; 949 in_ext->bJackType = USB_MS_EXTERNAL; 950 in_ext->bJackID = jack++; 951 in_ext->iJack = 0; 952 midi_function[i++] = (struct usb_descriptor_header *) in_ext; 953 954 out_emb->bLength = USB_DT_MIDI_OUT_SIZE(1); 955 out_emb->bDescriptorType = USB_DT_CS_INTERFACE; 956 out_emb->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK; 957 out_emb->bJackType = USB_MS_EMBEDDED; 958 out_emb->bJackID = jack++; 959 out_emb->bNrInputPins = 1; 960 out_emb->pins[0].baSourcePin = 1; 961 out_emb->pins[0].baSourceID = in_ext->bJackID; 962 out_emb->iJack = 0; 963 midi_function[i++] = (struct usb_descriptor_header *) out_emb; 964 965 /* link it to the endpoint */ 966 ms_in_desc.baAssocJackID[n] = out_emb->bJackID; 967 } 968 969 /* configure the external OUT jacks, each linked to an embedded IN jack */ 970 for (n = 0; n < midi->out_ports; n++) { 971 struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n]; 972 struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n]; 973 974 in_emb->bLength = USB_DT_MIDI_IN_SIZE; 975 in_emb->bDescriptorType = USB_DT_CS_INTERFACE; 976 in_emb->bDescriptorSubtype = USB_MS_MIDI_IN_JACK; 977 in_emb->bJackType = USB_MS_EMBEDDED; 978 in_emb->bJackID = jack++; 979 in_emb->iJack = 0; 980 midi_function[i++] = (struct usb_descriptor_header *) in_emb; 981 982 out_ext->bLength = USB_DT_MIDI_OUT_SIZE(1); 983 out_ext->bDescriptorType = USB_DT_CS_INTERFACE; 984 out_ext->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK; 985 out_ext->bJackType = USB_MS_EXTERNAL; 986 out_ext->bJackID = jack++; 987 out_ext->bNrInputPins = 1; 988 out_ext->iJack = 0; 989 out_ext->pins[0].baSourceID = in_emb->bJackID; 990 out_ext->pins[0].baSourcePin = 1; 991 midi_function[i++] = (struct usb_descriptor_header *) out_ext; 992 993 /* link it to the endpoint */ 994 ms_out_desc.baAssocJackID[n] = in_emb->bJackID; 995 } 996 997 /* configure the endpoint descriptors ... */ 998 ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports); 999 ms_out_desc.bNumEmbMIDIJack = midi->in_ports; 1000 1001 ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports); 1002 ms_in_desc.bNumEmbMIDIJack = midi->out_ports; 1003 1004 /* ... and add them to the list */ 1005 endpoint_descriptor_index = i; 1006 midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc; 1007 midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc; 1008 midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc; 1009 midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc; 1010 midi_function[i++] = NULL; 1011 1012 /* 1013 * support all relevant hardware speeds... we expect that when 1014 * hardware is dual speed, all bulk-capable endpoints work at 1015 * both speeds 1016 */ 1017 /* copy descriptors, and track endpoint copies */ 1018 f->fs_descriptors = usb_copy_descriptors(midi_function); 1019 if (!f->fs_descriptors) 1020 goto fail_f_midi; 1021 1022 if (gadget_is_dualspeed(c->cdev->gadget)) { 1023 bulk_in_desc.wMaxPacketSize = cpu_to_le16(512); 1024 bulk_out_desc.wMaxPacketSize = cpu_to_le16(512); 1025 f->hs_descriptors = usb_copy_descriptors(midi_function); 1026 if (!f->hs_descriptors) 1027 goto fail_f_midi; 1028 } 1029 1030 if (gadget_is_superspeed(c->cdev->gadget)) { 1031 bulk_in_desc.wMaxPacketSize = cpu_to_le16(1024); 1032 bulk_out_desc.wMaxPacketSize = cpu_to_le16(1024); 1033 i = endpoint_descriptor_index; 1034 midi_function[i++] = (struct usb_descriptor_header *) 1035 &bulk_out_desc; 1036 midi_function[i++] = (struct usb_descriptor_header *) 1037 &bulk_out_ss_comp_desc; 1038 midi_function[i++] = (struct usb_descriptor_header *) 1039 &ms_out_desc; 1040 midi_function[i++] = (struct usb_descriptor_header *) 1041 &bulk_in_desc; 1042 midi_function[i++] = (struct usb_descriptor_header *) 1043 &bulk_in_ss_comp_desc; 1044 midi_function[i++] = (struct usb_descriptor_header *) 1045 &ms_in_desc; 1046 f->ss_descriptors = usb_copy_descriptors(midi_function); 1047 if (!f->ss_descriptors) 1048 goto fail_f_midi; 1049 } 1050 1051 kfree(midi_function); 1052 1053 return 0; 1054 1055 fail_f_midi: 1056 kfree(midi_function); 1057 usb_free_all_descriptors(f); 1058 fail: 1059 f_midi_unregister_card(midi); 1060 fail_register: 1061 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); 1062 1063 return status; 1064 } 1065 1066 static 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 1072 static 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 1079 static struct configfs_item_operations midi_item_ops = { 1080 .release = midi_attr_release, 1081 }; 1082 1083 #define F_MIDI_OPT(name, test_limit, limit) \ 1084 static 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, "%d\n", opts->name); \ 1091 mutex_unlock(&opts->lock); \ 1092 \ 1093 return result; \ 1094 } \ 1095 \ 1096 static 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) { \ 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 \ 1120 end: \ 1121 mutex_unlock(&opts->lock); \ 1122 return ret; \ 1123 } \ 1124 \ 1125 CONFIGFS_ATTR(f_midi_opts_, name); 1126 1127 F_MIDI_OPT(index, true, SNDRV_CARDS); 1128 F_MIDI_OPT(buflen, false, 0); 1129 F_MIDI_OPT(qlen, false, 0); 1130 F_MIDI_OPT(in_ports, true, MAX_PORTS); 1131 F_MIDI_OPT(out_ports, true, MAX_PORTS); 1132 1133 static ssize_t f_midi_opts_id_show(struct config_item *item, char *page) 1134 { 1135 struct f_midi_opts *opts = to_f_midi_opts(item); 1136 int result; 1137 1138 mutex_lock(&opts->lock); 1139 if (opts->id) { 1140 result = strlcpy(page, opts->id, PAGE_SIZE); 1141 } else { 1142 page[0] = 0; 1143 result = 0; 1144 } 1145 1146 mutex_unlock(&opts->lock); 1147 1148 return result; 1149 } 1150 1151 static ssize_t f_midi_opts_id_store(struct config_item *item, 1152 const char *page, size_t len) 1153 { 1154 struct f_midi_opts *opts = to_f_midi_opts(item); 1155 int ret; 1156 char *c; 1157 1158 mutex_lock(&opts->lock); 1159 if (opts->refcnt) { 1160 ret = -EBUSY; 1161 goto end; 1162 } 1163 1164 c = kstrndup(page, len, GFP_KERNEL); 1165 if (!c) { 1166 ret = -ENOMEM; 1167 goto end; 1168 } 1169 if (opts->id_allocated) 1170 kfree(opts->id); 1171 opts->id = c; 1172 opts->id_allocated = true; 1173 ret = len; 1174 end: 1175 mutex_unlock(&opts->lock); 1176 return ret; 1177 } 1178 1179 CONFIGFS_ATTR(f_midi_opts_, id); 1180 1181 static struct configfs_attribute *midi_attrs[] = { 1182 &f_midi_opts_attr_index, 1183 &f_midi_opts_attr_buflen, 1184 &f_midi_opts_attr_qlen, 1185 &f_midi_opts_attr_in_ports, 1186 &f_midi_opts_attr_out_ports, 1187 &f_midi_opts_attr_id, 1188 NULL, 1189 }; 1190 1191 static const struct config_item_type midi_func_type = { 1192 .ct_item_ops = &midi_item_ops, 1193 .ct_attrs = midi_attrs, 1194 .ct_owner = THIS_MODULE, 1195 }; 1196 1197 static void f_midi_free_inst(struct usb_function_instance *f) 1198 { 1199 struct f_midi_opts *opts; 1200 1201 opts = container_of(f, struct f_midi_opts, func_inst); 1202 1203 if (opts->id_allocated) 1204 kfree(opts->id); 1205 1206 kfree(opts); 1207 } 1208 1209 static struct usb_function_instance *f_midi_alloc_inst(void) 1210 { 1211 struct f_midi_opts *opts; 1212 1213 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 1214 if (!opts) 1215 return ERR_PTR(-ENOMEM); 1216 1217 mutex_init(&opts->lock); 1218 opts->func_inst.free_func_inst = f_midi_free_inst; 1219 opts->index = SNDRV_DEFAULT_IDX1; 1220 opts->id = SNDRV_DEFAULT_STR1; 1221 opts->buflen = 512; 1222 opts->qlen = 32; 1223 opts->in_ports = 1; 1224 opts->out_ports = 1; 1225 1226 config_group_init_type_name(&opts->func_inst.group, "", 1227 &midi_func_type); 1228 1229 return &opts->func_inst; 1230 } 1231 1232 static void f_midi_free(struct usb_function *f) 1233 { 1234 struct f_midi *midi; 1235 struct f_midi_opts *opts; 1236 1237 midi = func_to_midi(f); 1238 opts = container_of(f->fi, struct f_midi_opts, func_inst); 1239 mutex_lock(&opts->lock); 1240 if (!--midi->free_ref) { 1241 kfree(midi->id); 1242 kfifo_free(&midi->in_req_fifo); 1243 kfree(midi); 1244 --opts->refcnt; 1245 } 1246 mutex_unlock(&opts->lock); 1247 } 1248 1249 static void f_midi_rmidi_free(struct snd_rawmidi *rmidi) 1250 { 1251 f_midi_free(rmidi->private_data); 1252 } 1253 1254 static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f) 1255 { 1256 struct usb_composite_dev *cdev = f->config->cdev; 1257 struct f_midi *midi = func_to_midi(f); 1258 struct snd_card *card; 1259 1260 DBG(cdev, "unbind\n"); 1261 1262 /* just to be sure */ 1263 f_midi_disable(f); 1264 1265 card = midi->card; 1266 midi->card = NULL; 1267 if (card) 1268 snd_card_free_when_closed(card); 1269 1270 usb_free_all_descriptors(f); 1271 } 1272 1273 static struct usb_function *f_midi_alloc(struct usb_function_instance *fi) 1274 { 1275 struct f_midi *midi = NULL; 1276 struct f_midi_opts *opts; 1277 int status, i; 1278 1279 opts = container_of(fi, struct f_midi_opts, func_inst); 1280 1281 mutex_lock(&opts->lock); 1282 /* sanity check */ 1283 if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) { 1284 status = -EINVAL; 1285 goto setup_fail; 1286 } 1287 1288 /* allocate and initialize one new instance */ 1289 midi = kzalloc( 1290 sizeof(*midi) + opts->in_ports * sizeof(*midi->in_ports_array), 1291 GFP_KERNEL); 1292 if (!midi) { 1293 status = -ENOMEM; 1294 goto setup_fail; 1295 } 1296 1297 for (i = 0; i < opts->in_ports; i++) 1298 midi->in_ports_array[i].cable = i; 1299 1300 /* set up ALSA midi devices */ 1301 midi->id = kstrdup(opts->id, GFP_KERNEL); 1302 if (opts->id && !midi->id) { 1303 status = -ENOMEM; 1304 goto setup_fail; 1305 } 1306 midi->in_ports = opts->in_ports; 1307 midi->out_ports = opts->out_ports; 1308 midi->index = opts->index; 1309 midi->buflen = opts->buflen; 1310 midi->qlen = opts->qlen; 1311 midi->in_last_port = 0; 1312 midi->free_ref = 1; 1313 1314 status = kfifo_alloc(&midi->in_req_fifo, midi->qlen, GFP_KERNEL); 1315 if (status) 1316 goto setup_fail; 1317 1318 spin_lock_init(&midi->transmit_lock); 1319 1320 ++opts->refcnt; 1321 mutex_unlock(&opts->lock); 1322 1323 midi->func.name = "gmidi function"; 1324 midi->func.bind = f_midi_bind; 1325 midi->func.unbind = f_midi_unbind; 1326 midi->func.set_alt = f_midi_set_alt; 1327 midi->func.disable = f_midi_disable; 1328 midi->func.free_func = f_midi_free; 1329 1330 return &midi->func; 1331 1332 setup_fail: 1333 mutex_unlock(&opts->lock); 1334 kfree(midi); 1335 return ERR_PTR(status); 1336 } 1337 1338 DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc); 1339