1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License as published by 4 * the Free Software Foundation; either version 2 of the License, or 5 * (at your option) any later version. 6 * 7 * This program is distributed in the hope that it will be useful, 8 * but WITHOUT ANY WARRANTY; without even the implied warranty of 9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 * GNU General Public License for more details. 11 * 12 * You should have received a copy of the GNU General Public License 13 * along with this program; if not, write to the Free Software 14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 15 * 16 */ 17 18 #include <linux/gfp.h> 19 #include <linux/init.h> 20 #include <linux/ratelimit.h> 21 #include <linux/usb.h> 22 #include <linux/usb/audio.h> 23 #include <linux/slab.h> 24 25 #include <sound/core.h> 26 #include <sound/pcm.h> 27 #include <sound/pcm_params.h> 28 29 #include "usbaudio.h" 30 #include "helper.h" 31 #include "card.h" 32 #include "endpoint.h" 33 #include "pcm.h" 34 35 #define EP_FLAG_ACTIVATED 0 36 #define EP_FLAG_RUNNING 1 37 38 /* 39 * snd_usb_endpoint is a model that abstracts everything related to an 40 * USB endpoint and its streaming. 41 * 42 * There are functions to activate and deactivate the streaming URBs and 43 * optional callbacks to let the pcm logic handle the actual content of the 44 * packets for playback and record. Thus, the bus streaming and the audio 45 * handlers are fully decoupled. 46 * 47 * There are two different types of endpoints in audio applications. 48 * 49 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both 50 * inbound and outbound traffic. 51 * 52 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and 53 * expect the payload to carry Q10.14 / Q16.16 formatted sync information 54 * (3 or 4 bytes). 55 * 56 * Each endpoint has to be configured prior to being used by calling 57 * snd_usb_endpoint_set_params(). 58 * 59 * The model incorporates a reference counting, so that multiple users 60 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and 61 * only the first user will effectively start the URBs, and only the last 62 * one to stop it will tear the URBs down again. 63 */ 64 65 /* 66 * convert a sampling rate into our full speed format (fs/1000 in Q16.16) 67 * this will overflow at approx 524 kHz 68 */ 69 static inline unsigned get_usb_full_speed_rate(unsigned int rate) 70 { 71 return ((rate << 13) + 62) / 125; 72 } 73 74 /* 75 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16) 76 * this will overflow at approx 4 MHz 77 */ 78 static inline unsigned get_usb_high_speed_rate(unsigned int rate) 79 { 80 return ((rate << 10) + 62) / 125; 81 } 82 83 /* 84 * release a urb data 85 */ 86 static void release_urb_ctx(struct snd_urb_ctx *u) 87 { 88 if (u->buffer_size) 89 usb_free_coherent(u->ep->chip->dev, u->buffer_size, 90 u->urb->transfer_buffer, 91 u->urb->transfer_dma); 92 usb_free_urb(u->urb); 93 u->urb = NULL; 94 } 95 96 static const char *usb_error_string(int err) 97 { 98 switch (err) { 99 case -ENODEV: 100 return "no device"; 101 case -ENOENT: 102 return "endpoint not enabled"; 103 case -EPIPE: 104 return "endpoint stalled"; 105 case -ENOSPC: 106 return "not enough bandwidth"; 107 case -ESHUTDOWN: 108 return "device disabled"; 109 case -EHOSTUNREACH: 110 return "device suspended"; 111 case -EINVAL: 112 case -EAGAIN: 113 case -EFBIG: 114 case -EMSGSIZE: 115 return "internal error"; 116 default: 117 return "unknown error"; 118 } 119 } 120 121 /** 122 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type 123 * 124 * @ep: The snd_usb_endpoint 125 * 126 * Determine whether an endpoint is driven by an implicit feedback 127 * data endpoint source. 128 */ 129 int snd_usb_endpoint_implict_feedback_sink(struct snd_usb_endpoint *ep) 130 { 131 return ep->sync_master && 132 ep->sync_master->type == SND_USB_ENDPOINT_TYPE_DATA && 133 ep->type == SND_USB_ENDPOINT_TYPE_DATA && 134 usb_pipeout(ep->pipe); 135 } 136 137 /* 138 * For streaming based on information derived from sync endpoints, 139 * prepare_outbound_urb_sizes() will call next_packet_size() to 140 * determine the number of samples to be sent in the next packet. 141 * 142 * For implicit feedback, next_packet_size() is unused. 143 */ 144 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep) 145 { 146 unsigned long flags; 147 int ret; 148 149 if (ep->fill_max) 150 return ep->maxframesize; 151 152 spin_lock_irqsave(&ep->lock, flags); 153 ep->phase = (ep->phase & 0xffff) 154 + (ep->freqm << ep->datainterval); 155 ret = min(ep->phase >> 16, ep->maxframesize); 156 spin_unlock_irqrestore(&ep->lock, flags); 157 158 return ret; 159 } 160 161 static void retire_outbound_urb(struct snd_usb_endpoint *ep, 162 struct snd_urb_ctx *urb_ctx) 163 { 164 if (ep->retire_data_urb) 165 ep->retire_data_urb(ep->data_subs, urb_ctx->urb); 166 } 167 168 static void retire_inbound_urb(struct snd_usb_endpoint *ep, 169 struct snd_urb_ctx *urb_ctx) 170 { 171 struct urb *urb = urb_ctx->urb; 172 173 if (ep->sync_slave) 174 snd_usb_handle_sync_urb(ep->sync_slave, ep, urb); 175 176 if (ep->retire_data_urb) 177 ep->retire_data_urb(ep->data_subs, urb); 178 } 179 180 /* 181 * Prepare a PLAYBACK urb for submission to the bus. 182 */ 183 static void prepare_outbound_urb(struct snd_usb_endpoint *ep, 184 struct snd_urb_ctx *ctx) 185 { 186 int i; 187 struct urb *urb = ctx->urb; 188 unsigned char *cp = urb->transfer_buffer; 189 190 urb->dev = ep->chip->dev; /* we need to set this at each time */ 191 192 switch (ep->type) { 193 case SND_USB_ENDPOINT_TYPE_DATA: 194 if (ep->prepare_data_urb) { 195 ep->prepare_data_urb(ep->data_subs, urb); 196 } else { 197 /* no data provider, so send silence */ 198 unsigned int offs = 0; 199 for (i = 0; i < ctx->packets; ++i) { 200 int counts; 201 202 if (ctx->packet_size[i]) 203 counts = ctx->packet_size[i]; 204 else 205 counts = snd_usb_endpoint_next_packet_size(ep); 206 207 urb->iso_frame_desc[i].offset = offs * ep->stride; 208 urb->iso_frame_desc[i].length = counts * ep->stride; 209 offs += counts; 210 } 211 212 urb->number_of_packets = ctx->packets; 213 urb->transfer_buffer_length = offs * ep->stride; 214 memset(urb->transfer_buffer, ep->silence_value, 215 offs * ep->stride); 216 } 217 break; 218 219 case SND_USB_ENDPOINT_TYPE_SYNC: 220 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) { 221 /* 222 * fill the length and offset of each urb descriptor. 223 * the fixed 12.13 frequency is passed as 16.16 through the pipe. 224 */ 225 urb->iso_frame_desc[0].length = 4; 226 urb->iso_frame_desc[0].offset = 0; 227 cp[0] = ep->freqn; 228 cp[1] = ep->freqn >> 8; 229 cp[2] = ep->freqn >> 16; 230 cp[3] = ep->freqn >> 24; 231 } else { 232 /* 233 * fill the length and offset of each urb descriptor. 234 * the fixed 10.14 frequency is passed through the pipe. 235 */ 236 urb->iso_frame_desc[0].length = 3; 237 urb->iso_frame_desc[0].offset = 0; 238 cp[0] = ep->freqn >> 2; 239 cp[1] = ep->freqn >> 10; 240 cp[2] = ep->freqn >> 18; 241 } 242 243 break; 244 } 245 } 246 247 /* 248 * Prepare a CAPTURE or SYNC urb for submission to the bus. 249 */ 250 static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep, 251 struct snd_urb_ctx *urb_ctx) 252 { 253 int i, offs; 254 struct urb *urb = urb_ctx->urb; 255 256 urb->dev = ep->chip->dev; /* we need to set this at each time */ 257 258 switch (ep->type) { 259 case SND_USB_ENDPOINT_TYPE_DATA: 260 offs = 0; 261 for (i = 0; i < urb_ctx->packets; i++) { 262 urb->iso_frame_desc[i].offset = offs; 263 urb->iso_frame_desc[i].length = ep->curpacksize; 264 offs += ep->curpacksize; 265 } 266 267 urb->transfer_buffer_length = offs; 268 urb->number_of_packets = urb_ctx->packets; 269 break; 270 271 case SND_USB_ENDPOINT_TYPE_SYNC: 272 urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize); 273 urb->iso_frame_desc[0].offset = 0; 274 break; 275 } 276 } 277 278 /* 279 * Send output urbs that have been prepared previously. URBs are dequeued 280 * from ep->ready_playback_urbs and in case there there aren't any available 281 * or there are no packets that have been prepared, this function does 282 * nothing. 283 * 284 * The reason why the functionality of sending and preparing URBs is separated 285 * is that host controllers don't guarantee the order in which they return 286 * inbound and outbound packets to their submitters. 287 * 288 * This function is only used for implicit feedback endpoints. For endpoints 289 * driven by dedicated sync endpoints, URBs are immediately re-submitted 290 * from their completion handler. 291 */ 292 static void queue_pending_output_urbs(struct snd_usb_endpoint *ep) 293 { 294 while (test_bit(EP_FLAG_RUNNING, &ep->flags)) { 295 296 unsigned long flags; 297 struct snd_usb_packet_info *uninitialized_var(packet); 298 struct snd_urb_ctx *ctx = NULL; 299 struct urb *urb; 300 int err, i; 301 302 spin_lock_irqsave(&ep->lock, flags); 303 if (ep->next_packet_read_pos != ep->next_packet_write_pos) { 304 packet = ep->next_packet + ep->next_packet_read_pos; 305 ep->next_packet_read_pos++; 306 ep->next_packet_read_pos %= MAX_URBS; 307 308 /* take URB out of FIFO */ 309 if (!list_empty(&ep->ready_playback_urbs)) 310 ctx = list_first_entry(&ep->ready_playback_urbs, 311 struct snd_urb_ctx, ready_list); 312 } 313 spin_unlock_irqrestore(&ep->lock, flags); 314 315 if (ctx == NULL) 316 return; 317 318 list_del_init(&ctx->ready_list); 319 urb = ctx->urb; 320 321 /* copy over the length information */ 322 for (i = 0; i < packet->packets; i++) 323 ctx->packet_size[i] = packet->packet_size[i]; 324 325 /* call the data handler to fill in playback data */ 326 prepare_outbound_urb(ep, ctx); 327 328 err = usb_submit_urb(ctx->urb, GFP_ATOMIC); 329 if (err < 0) 330 snd_printk(KERN_ERR "Unable to submit urb #%d: %d (urb %p)\n", 331 ctx->index, err, ctx->urb); 332 else 333 set_bit(ctx->index, &ep->active_mask); 334 } 335 } 336 337 /* 338 * complete callback for urbs 339 */ 340 static void snd_complete_urb(struct urb *urb) 341 { 342 struct snd_urb_ctx *ctx = urb->context; 343 struct snd_usb_endpoint *ep = ctx->ep; 344 int err; 345 346 if (unlikely(urb->status == -ENOENT || /* unlinked */ 347 urb->status == -ENODEV || /* device removed */ 348 urb->status == -ECONNRESET || /* unlinked */ 349 urb->status == -ESHUTDOWN || /* device disabled */ 350 ep->chip->shutdown)) /* device disconnected */ 351 goto exit_clear; 352 353 if (usb_pipeout(ep->pipe)) { 354 retire_outbound_urb(ep, ctx); 355 /* can be stopped during retire callback */ 356 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) 357 goto exit_clear; 358 359 if (snd_usb_endpoint_implict_feedback_sink(ep)) { 360 unsigned long flags; 361 362 spin_lock_irqsave(&ep->lock, flags); 363 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); 364 spin_unlock_irqrestore(&ep->lock, flags); 365 queue_pending_output_urbs(ep); 366 367 goto exit_clear; 368 } 369 370 prepare_outbound_urb(ep, ctx); 371 } else { 372 retire_inbound_urb(ep, ctx); 373 /* can be stopped during retire callback */ 374 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) 375 goto exit_clear; 376 377 prepare_inbound_urb(ep, ctx); 378 } 379 380 err = usb_submit_urb(urb, GFP_ATOMIC); 381 if (err == 0) 382 return; 383 384 snd_printk(KERN_ERR "cannot submit urb (err = %d)\n", err); 385 //snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN); 386 387 exit_clear: 388 clear_bit(ctx->index, &ep->active_mask); 389 } 390 391 /** 392 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip 393 * 394 * @chip: The chip 395 * @alts: The USB host interface 396 * @ep_num: The number of the endpoint to use 397 * @direction: SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE 398 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC 399 * 400 * If the requested endpoint has not been added to the given chip before, 401 * a new instance is created. Otherwise, a pointer to the previoulsy 402 * created instance is returned. In case of any error, NULL is returned. 403 * 404 * New endpoints will be added to chip->ep_list and must be freed by 405 * calling snd_usb_endpoint_free(). 406 */ 407 struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip, 408 struct usb_host_interface *alts, 409 int ep_num, int direction, int type) 410 { 411 struct list_head *p; 412 struct snd_usb_endpoint *ep; 413 int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK; 414 415 mutex_lock(&chip->mutex); 416 417 list_for_each(p, &chip->ep_list) { 418 ep = list_entry(p, struct snd_usb_endpoint, list); 419 if (ep->ep_num == ep_num && 420 ep->iface == alts->desc.bInterfaceNumber && 421 ep->alt_idx == alts->desc.bAlternateSetting) { 422 snd_printdd(KERN_DEBUG "Re-using EP %x in iface %d,%d @%p\n", 423 ep_num, ep->iface, ep->alt_idx, ep); 424 goto __exit_unlock; 425 } 426 } 427 428 snd_printdd(KERN_DEBUG "Creating new %s %s endpoint #%x\n", 429 is_playback ? "playback" : "capture", 430 type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync", 431 ep_num); 432 433 ep = kzalloc(sizeof(*ep), GFP_KERNEL); 434 if (!ep) 435 goto __exit_unlock; 436 437 ep->chip = chip; 438 spin_lock_init(&ep->lock); 439 ep->type = type; 440 ep->ep_num = ep_num; 441 ep->iface = alts->desc.bInterfaceNumber; 442 ep->alt_idx = alts->desc.bAlternateSetting; 443 INIT_LIST_HEAD(&ep->ready_playback_urbs); 444 ep_num &= USB_ENDPOINT_NUMBER_MASK; 445 446 if (is_playback) 447 ep->pipe = usb_sndisocpipe(chip->dev, ep_num); 448 else 449 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num); 450 451 if (type == SND_USB_ENDPOINT_TYPE_SYNC) { 452 if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE && 453 get_endpoint(alts, 1)->bRefresh >= 1 && 454 get_endpoint(alts, 1)->bRefresh <= 9) 455 ep->syncinterval = get_endpoint(alts, 1)->bRefresh; 456 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) 457 ep->syncinterval = 1; 458 else if (get_endpoint(alts, 1)->bInterval >= 1 && 459 get_endpoint(alts, 1)->bInterval <= 16) 460 ep->syncinterval = get_endpoint(alts, 1)->bInterval - 1; 461 else 462 ep->syncinterval = 3; 463 464 ep->syncmaxsize = le16_to_cpu(get_endpoint(alts, 1)->wMaxPacketSize); 465 } 466 467 list_add_tail(&ep->list, &chip->ep_list); 468 469 __exit_unlock: 470 mutex_unlock(&chip->mutex); 471 472 return ep; 473 } 474 475 /* 476 * wait until all urbs are processed. 477 */ 478 static int wait_clear_urbs(struct snd_usb_endpoint *ep) 479 { 480 unsigned long end_time = jiffies + msecs_to_jiffies(1000); 481 unsigned int i; 482 int alive; 483 484 do { 485 alive = 0; 486 for (i = 0; i < ep->nurbs; i++) 487 if (test_bit(i, &ep->active_mask)) 488 alive++; 489 490 if (!alive) 491 break; 492 493 schedule_timeout_uninterruptible(1); 494 } while (time_before(jiffies, end_time)); 495 496 if (alive) 497 snd_printk(KERN_ERR "timeout: still %d active urbs on EP #%x\n", 498 alive, ep->ep_num); 499 500 return 0; 501 } 502 503 /* 504 * unlink active urbs. 505 */ 506 static int deactivate_urbs(struct snd_usb_endpoint *ep, int force, int can_sleep) 507 { 508 unsigned int i; 509 int async; 510 511 if (!force && ep->chip->shutdown) /* to be sure... */ 512 return -EBADFD; 513 514 async = !can_sleep && ep->chip->async_unlink; 515 516 clear_bit(EP_FLAG_RUNNING, &ep->flags); 517 518 INIT_LIST_HEAD(&ep->ready_playback_urbs); 519 ep->next_packet_read_pos = 0; 520 ep->next_packet_write_pos = 0; 521 522 if (!async && in_interrupt()) 523 return 0; 524 525 for (i = 0; i < ep->nurbs; i++) { 526 if (test_bit(i, &ep->active_mask)) { 527 if (!test_and_set_bit(i, &ep->unlink_mask)) { 528 struct urb *u = ep->urb[i].urb; 529 if (async) 530 usb_unlink_urb(u); 531 else 532 usb_kill_urb(u); 533 } 534 } 535 } 536 537 return 0; 538 } 539 540 /* 541 * release an endpoint's urbs 542 */ 543 static void release_urbs(struct snd_usb_endpoint *ep, int force) 544 { 545 int i; 546 547 /* route incoming urbs to nirvana */ 548 ep->retire_data_urb = NULL; 549 ep->prepare_data_urb = NULL; 550 551 /* stop urbs */ 552 deactivate_urbs(ep, force, 1); 553 wait_clear_urbs(ep); 554 555 for (i = 0; i < ep->nurbs; i++) 556 release_urb_ctx(&ep->urb[i]); 557 558 if (ep->syncbuf) 559 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4, 560 ep->syncbuf, ep->sync_dma); 561 562 ep->syncbuf = NULL; 563 ep->nurbs = 0; 564 } 565 566 /* 567 * configure a data endpoint 568 */ 569 static int data_ep_set_params(struct snd_usb_endpoint *ep, 570 struct snd_pcm_hw_params *hw_params, 571 struct audioformat *fmt, 572 struct snd_usb_endpoint *sync_ep) 573 { 574 unsigned int maxsize, i, urb_packs, total_packs, packs_per_ms; 575 int period_bytes = params_period_bytes(hw_params); 576 int format = params_format(hw_params); 577 int is_playback = usb_pipeout(ep->pipe); 578 int frame_bits = snd_pcm_format_physical_width(params_format(hw_params)) * 579 params_channels(hw_params); 580 581 ep->datainterval = fmt->datainterval; 582 ep->stride = frame_bits >> 3; 583 ep->silence_value = format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0; 584 585 /* calculate max. frequency */ 586 if (ep->maxpacksize) { 587 /* whatever fits into a max. size packet */ 588 maxsize = ep->maxpacksize; 589 ep->freqmax = (maxsize / (frame_bits >> 3)) 590 << (16 - ep->datainterval); 591 } else { 592 /* no max. packet size: just take 25% higher than nominal */ 593 ep->freqmax = ep->freqn + (ep->freqn >> 2); 594 maxsize = ((ep->freqmax + 0xffff) * (frame_bits >> 3)) 595 >> (16 - ep->datainterval); 596 } 597 598 if (ep->fill_max) 599 ep->curpacksize = ep->maxpacksize; 600 else 601 ep->curpacksize = maxsize; 602 603 if (snd_usb_get_speed(ep->chip->dev) != USB_SPEED_FULL) 604 packs_per_ms = 8 >> ep->datainterval; 605 else 606 packs_per_ms = 1; 607 608 if (is_playback && !snd_usb_endpoint_implict_feedback_sink(ep)) { 609 urb_packs = max(ep->chip->nrpacks, 1); 610 urb_packs = min(urb_packs, (unsigned int) MAX_PACKS); 611 } else { 612 urb_packs = 1; 613 } 614 615 urb_packs *= packs_per_ms; 616 617 if (sync_ep && !snd_usb_endpoint_implict_feedback_sink(ep)) 618 urb_packs = min(urb_packs, 1U << sync_ep->syncinterval); 619 620 /* decide how many packets to be used */ 621 if (is_playback && !snd_usb_endpoint_implict_feedback_sink(ep)) { 622 unsigned int minsize, maxpacks; 623 /* determine how small a packet can be */ 624 minsize = (ep->freqn >> (16 - ep->datainterval)) 625 * (frame_bits >> 3); 626 /* with sync from device, assume it can be 12% lower */ 627 if (sync_ep) 628 minsize -= minsize >> 3; 629 minsize = max(minsize, 1u); 630 total_packs = (period_bytes + minsize - 1) / minsize; 631 /* we need at least two URBs for queueing */ 632 if (total_packs < 2) { 633 total_packs = 2; 634 } else { 635 /* and we don't want too long a queue either */ 636 maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2); 637 total_packs = min(total_packs, maxpacks); 638 } 639 } else { 640 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes) 641 urb_packs >>= 1; 642 total_packs = MAX_URBS * urb_packs; 643 } 644 645 ep->nurbs = (total_packs + urb_packs - 1) / urb_packs; 646 if (ep->nurbs > MAX_URBS) { 647 /* too much... */ 648 ep->nurbs = MAX_URBS; 649 total_packs = MAX_URBS * urb_packs; 650 } else if (ep->nurbs < 2) { 651 /* too little - we need at least two packets 652 * to ensure contiguous playback/capture 653 */ 654 ep->nurbs = 2; 655 } 656 657 /* allocate and initialize data urbs */ 658 for (i = 0; i < ep->nurbs; i++) { 659 struct snd_urb_ctx *u = &ep->urb[i]; 660 u->index = i; 661 u->ep = ep; 662 u->packets = (i + 1) * total_packs / ep->nurbs 663 - i * total_packs / ep->nurbs; 664 u->buffer_size = maxsize * u->packets; 665 666 if (fmt->fmt_type == UAC_FORMAT_TYPE_II) 667 u->packets++; /* for transfer delimiter */ 668 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL); 669 if (!u->urb) 670 goto out_of_memory; 671 672 u->urb->transfer_buffer = 673 usb_alloc_coherent(ep->chip->dev, u->buffer_size, 674 GFP_KERNEL, &u->urb->transfer_dma); 675 if (!u->urb->transfer_buffer) 676 goto out_of_memory; 677 u->urb->pipe = ep->pipe; 678 u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; 679 u->urb->interval = 1 << ep->datainterval; 680 u->urb->context = u; 681 u->urb->complete = snd_complete_urb; 682 INIT_LIST_HEAD(&u->ready_list); 683 } 684 685 return 0; 686 687 out_of_memory: 688 release_urbs(ep, 0); 689 return -ENOMEM; 690 } 691 692 /* 693 * configure a sync endpoint 694 */ 695 static int sync_ep_set_params(struct snd_usb_endpoint *ep, 696 struct snd_pcm_hw_params *hw_params, 697 struct audioformat *fmt) 698 { 699 int i; 700 701 ep->syncbuf = usb_alloc_coherent(ep->chip->dev, SYNC_URBS * 4, 702 GFP_KERNEL, &ep->sync_dma); 703 if (!ep->syncbuf) 704 return -ENOMEM; 705 706 for (i = 0; i < SYNC_URBS; i++) { 707 struct snd_urb_ctx *u = &ep->urb[i]; 708 u->index = i; 709 u->ep = ep; 710 u->packets = 1; 711 u->urb = usb_alloc_urb(1, GFP_KERNEL); 712 if (!u->urb) 713 goto out_of_memory; 714 u->urb->transfer_buffer = ep->syncbuf + i * 4; 715 u->urb->transfer_dma = ep->sync_dma + i * 4; 716 u->urb->transfer_buffer_length = 4; 717 u->urb->pipe = ep->pipe; 718 u->urb->transfer_flags = URB_ISO_ASAP | 719 URB_NO_TRANSFER_DMA_MAP; 720 u->urb->number_of_packets = 1; 721 u->urb->interval = 1 << ep->syncinterval; 722 u->urb->context = u; 723 u->urb->complete = snd_complete_urb; 724 } 725 726 ep->nurbs = SYNC_URBS; 727 728 return 0; 729 730 out_of_memory: 731 release_urbs(ep, 0); 732 return -ENOMEM; 733 } 734 735 /** 736 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint 737 * 738 * @ep: the snd_usb_endpoint to configure 739 * @hw_params: the hardware parameters 740 * @fmt: the USB audio format information 741 * @sync_ep: the sync endpoint to use, if any 742 * 743 * Determine the number of URBs to be used on this endpoint. 744 * An endpoint must be configured before it can be started. 745 * An endpoint that is already running can not be reconfigured. 746 */ 747 int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep, 748 struct snd_pcm_hw_params *hw_params, 749 struct audioformat *fmt, 750 struct snd_usb_endpoint *sync_ep) 751 { 752 int err; 753 754 if (ep->use_count != 0) { 755 snd_printk(KERN_WARNING "Unable to change format on ep #%x: already in use\n", 756 ep->ep_num); 757 return -EBUSY; 758 } 759 760 /* release old buffers, if any */ 761 release_urbs(ep, 0); 762 763 ep->datainterval = fmt->datainterval; 764 ep->maxpacksize = fmt->maxpacksize; 765 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX); 766 767 if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_FULL) 768 ep->freqn = get_usb_full_speed_rate(params_rate(hw_params)); 769 else 770 ep->freqn = get_usb_high_speed_rate(params_rate(hw_params)); 771 772 /* calculate the frequency in 16.16 format */ 773 ep->freqm = ep->freqn; 774 ep->freqshift = INT_MIN; 775 776 ep->phase = 0; 777 778 switch (ep->type) { 779 case SND_USB_ENDPOINT_TYPE_DATA: 780 err = data_ep_set_params(ep, hw_params, fmt, sync_ep); 781 break; 782 case SND_USB_ENDPOINT_TYPE_SYNC: 783 err = sync_ep_set_params(ep, hw_params, fmt); 784 break; 785 default: 786 err = -EINVAL; 787 } 788 789 snd_printdd(KERN_DEBUG "Setting params for ep #%x (type %d, %d urbs), ret=%d\n", 790 ep->ep_num, ep->type, ep->nurbs, err); 791 792 return err; 793 } 794 795 /** 796 * snd_usb_endpoint_start: start an snd_usb_endpoint 797 * 798 * @ep: the endpoint to start 799 * @can_sleep: flag indicating whether the operation is executed in 800 * non-atomic context 801 * 802 * A call to this function will increment the use count of the endpoint. 803 * In case it is not already running, the URBs for this endpoint will be 804 * submitted. Otherwise, this function does nothing. 805 * 806 * Must be balanced to calls of snd_usb_endpoint_stop(). 807 * 808 * Returns an error if the URB submission failed, 0 in all other cases. 809 */ 810 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, int can_sleep) 811 { 812 int err; 813 unsigned int i; 814 815 if (ep->chip->shutdown) 816 return -EBADFD; 817 818 /* already running? */ 819 if (++ep->use_count != 1) 820 return 0; 821 822 /* just to be sure */ 823 deactivate_urbs(ep, 0, can_sleep); 824 if (can_sleep) 825 wait_clear_urbs(ep); 826 827 ep->active_mask = 0; 828 ep->unlink_mask = 0; 829 ep->phase = 0; 830 831 /* 832 * If this endpoint has a data endpoint as implicit feedback source, 833 * don't start the urbs here. Instead, mark them all as available, 834 * wait for the record urbs to return and queue the playback urbs 835 * from that context. 836 */ 837 838 set_bit(EP_FLAG_RUNNING, &ep->flags); 839 840 if (snd_usb_endpoint_implict_feedback_sink(ep)) { 841 for (i = 0; i < ep->nurbs; i++) { 842 struct snd_urb_ctx *ctx = ep->urb + i; 843 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); 844 } 845 846 return 0; 847 } 848 849 for (i = 0; i < ep->nurbs; i++) { 850 struct urb *urb = ep->urb[i].urb; 851 852 if (snd_BUG_ON(!urb)) 853 goto __error; 854 855 if (usb_pipeout(ep->pipe)) { 856 prepare_outbound_urb(ep, urb->context); 857 } else { 858 prepare_inbound_urb(ep, urb->context); 859 } 860 861 err = usb_submit_urb(urb, GFP_ATOMIC); 862 if (err < 0) { 863 snd_printk(KERN_ERR "cannot submit urb %d, error %d: %s\n", 864 i, err, usb_error_string(err)); 865 goto __error; 866 } 867 set_bit(i, &ep->active_mask); 868 } 869 870 return 0; 871 872 __error: 873 clear_bit(EP_FLAG_RUNNING, &ep->flags); 874 ep->use_count--; 875 deactivate_urbs(ep, 0, 0); 876 return -EPIPE; 877 } 878 879 /** 880 * snd_usb_endpoint_stop: stop an snd_usb_endpoint 881 * 882 * @ep: the endpoint to stop (may be NULL) 883 * 884 * A call to this function will decrement the use count of the endpoint. 885 * In case the last user has requested the endpoint stop, the URBs will 886 * actually be deactivated. 887 * 888 * Must be balanced to calls of snd_usb_endpoint_start(). 889 */ 890 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, 891 int force, int can_sleep, int wait) 892 { 893 if (!ep) 894 return; 895 896 if (snd_BUG_ON(ep->use_count == 0)) 897 return; 898 899 if (--ep->use_count == 0) { 900 deactivate_urbs(ep, force, can_sleep); 901 ep->data_subs = NULL; 902 ep->sync_slave = NULL; 903 ep->retire_data_urb = NULL; 904 ep->prepare_data_urb = NULL; 905 906 if (wait) 907 wait_clear_urbs(ep); 908 } 909 } 910 911 /** 912 * snd_usb_endpoint_deactivate: deactivate an snd_usb_endpoint 913 * 914 * @ep: the endpoint to deactivate 915 * 916 * If the endpoint is not currently in use, this functions will select the 917 * alternate interface setting 0 for the interface of this endpoint. 918 * 919 * In case of any active users, this functions does nothing. 920 * 921 * Returns an error if usb_set_interface() failed, 0 in all other 922 * cases. 923 */ 924 int snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep) 925 { 926 if (!ep) 927 return -EINVAL; 928 929 deactivate_urbs(ep, 1, 1); 930 wait_clear_urbs(ep); 931 932 if (ep->use_count != 0) 933 return 0; 934 935 clear_bit(EP_FLAG_ACTIVATED, &ep->flags); 936 937 return 0; 938 } 939 940 /** 941 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint 942 * 943 * @ep: the list header of the endpoint to free 944 * 945 * This function does not care for the endpoint's use count but will tear 946 * down all the streaming URBs immediately and free all resources. 947 */ 948 void snd_usb_endpoint_free(struct list_head *head) 949 { 950 struct snd_usb_endpoint *ep; 951 952 ep = list_entry(head, struct snd_usb_endpoint, list); 953 release_urbs(ep, 1); 954 kfree(ep); 955 } 956 957 /** 958 * snd_usb_handle_sync_urb: parse an USB sync packet 959 * 960 * @ep: the endpoint to handle the packet 961 * @sender: the sending endpoint 962 * @urb: the received packet 963 * 964 * This function is called from the context of an endpoint that received 965 * the packet and is used to let another endpoint object handle the payload. 966 */ 967 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep, 968 struct snd_usb_endpoint *sender, 969 const struct urb *urb) 970 { 971 int shift; 972 unsigned int f; 973 unsigned long flags; 974 975 snd_BUG_ON(ep == sender); 976 977 /* 978 * In case the endpoint is operating in implicit feedback mode, prepare 979 * a new outbound URB that has the same layout as the received packet 980 * and add it to the list of pending urbs. queue_pending_output_urbs() 981 * will take care of them later. 982 */ 983 if (snd_usb_endpoint_implict_feedback_sink(ep) && 984 ep->use_count != 0) { 985 986 /* implicit feedback case */ 987 int i, bytes = 0; 988 struct snd_urb_ctx *in_ctx; 989 struct snd_usb_packet_info *out_packet; 990 991 in_ctx = urb->context; 992 993 /* Count overall packet size */ 994 for (i = 0; i < in_ctx->packets; i++) 995 if (urb->iso_frame_desc[i].status == 0) 996 bytes += urb->iso_frame_desc[i].actual_length; 997 998 /* 999 * skip empty packets. At least M-Audio's Fast Track Ultra stops 1000 * streaming once it received a 0-byte OUT URB 1001 */ 1002 if (bytes == 0) 1003 return; 1004 1005 spin_lock_irqsave(&ep->lock, flags); 1006 out_packet = ep->next_packet + ep->next_packet_write_pos; 1007 1008 /* 1009 * Iterate through the inbound packet and prepare the lengths 1010 * for the output packet. The OUT packet we are about to send 1011 * will have the same amount of payload bytes than the IN 1012 * packet we just received. 1013 */ 1014 1015 out_packet->packets = in_ctx->packets; 1016 for (i = 0; i < in_ctx->packets; i++) { 1017 if (urb->iso_frame_desc[i].status == 0) 1018 out_packet->packet_size[i] = 1019 urb->iso_frame_desc[i].actual_length / ep->stride; 1020 else 1021 out_packet->packet_size[i] = 0; 1022 } 1023 1024 ep->next_packet_write_pos++; 1025 ep->next_packet_write_pos %= MAX_URBS; 1026 spin_unlock_irqrestore(&ep->lock, flags); 1027 queue_pending_output_urbs(ep); 1028 1029 return; 1030 } 1031 1032 /* 1033 * process after playback sync complete 1034 * 1035 * Full speed devices report feedback values in 10.14 format as samples 1036 * per frame, high speed devices in 16.16 format as samples per 1037 * microframe. 1038 * 1039 * Because the Audio Class 1 spec was written before USB 2.0, many high 1040 * speed devices use a wrong interpretation, some others use an 1041 * entirely different format. 1042 * 1043 * Therefore, we cannot predict what format any particular device uses 1044 * and must detect it automatically. 1045 */ 1046 1047 if (urb->iso_frame_desc[0].status != 0 || 1048 urb->iso_frame_desc[0].actual_length < 3) 1049 return; 1050 1051 f = le32_to_cpup(urb->transfer_buffer); 1052 if (urb->iso_frame_desc[0].actual_length == 3) 1053 f &= 0x00ffffff; 1054 else 1055 f &= 0x0fffffff; 1056 1057 if (f == 0) 1058 return; 1059 1060 if (unlikely(ep->freqshift == INT_MIN)) { 1061 /* 1062 * The first time we see a feedback value, determine its format 1063 * by shifting it left or right until it matches the nominal 1064 * frequency value. This assumes that the feedback does not 1065 * differ from the nominal value more than +50% or -25%. 1066 */ 1067 shift = 0; 1068 while (f < ep->freqn - ep->freqn / 4) { 1069 f <<= 1; 1070 shift++; 1071 } 1072 while (f > ep->freqn + ep->freqn / 2) { 1073 f >>= 1; 1074 shift--; 1075 } 1076 ep->freqshift = shift; 1077 } else if (ep->freqshift >= 0) 1078 f <<= ep->freqshift; 1079 else 1080 f >>= -ep->freqshift; 1081 1082 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) { 1083 /* 1084 * If the frequency looks valid, set it. 1085 * This value is referred to in prepare_playback_urb(). 1086 */ 1087 spin_lock_irqsave(&ep->lock, flags); 1088 ep->freqm = f; 1089 spin_unlock_irqrestore(&ep->lock, flags); 1090 } else { 1091 /* 1092 * Out of range; maybe the shift value is wrong. 1093 * Reset it so that we autodetect again the next time. 1094 */ 1095 ep->freqshift = INT_MIN; 1096 } 1097 } 1098 1099