sound/usb/endpoint.c

   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
  24 #include <sound/core.h>
  25 #include <sound/pcm.h>
  26
  27 #include "usbaudio.h"
  28 #include "helper.h"
  29 #include "card.h"
  30 #include "endpoint.h"
  31 #include "pcm.h"
  32
  33 /*
  34  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
  35  * this will overflow at approx 524 kHz
  36  */
  37 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
  38 {
  39         return ((rate << 13) + 62) / 125;
  40 }
  41
  42 /*
  43  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
  44  * this will overflow at approx 4 MHz
  45  */
  46 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
  47 {
  48         return ((rate << 10) + 62) / 125;
  49 }
  50
  51 /*
  52  * unlink active urbs.
  53  */
  54 static int deactivate_urbs(struct snd_usb_substream *subs, int force, int can_sleep)
  55 {
  56         struct snd_usb_audio *chip = subs->stream->chip;
  57         unsigned int i;
  58         int async;
  59
  60         subs->running = 0;
  61
  62         if (!force && subs->stream->chip->shutdown) /* to be sure... */
  63                 return -EBADFD;
  64
  65         async = !can_sleep && chip->async_unlink;
  66
  67         if (!async && in_interrupt())
  68                 return 0;
  69
  70         for (i = 0; i < subs->nurbs; i++) {
  71                 if (test_bit(i, &subs->active_mask)) {
  72                         if (!test_and_set_bit(i, &subs->unlink_mask)) {
  73                                 struct urb *u = subs->dataurb[i].urb;
  74                                 if (async)
  75                                         usb_unlink_urb(u);
  76                                 else
  77                                         usb_kill_urb(u);
  78                         }
  79                 }
  80         }
  81         if (subs->syncpipe) {
  82                 for (i = 0; i < SYNC_URBS; i++) {
  83                         if (test_bit(i+16, &subs->active_mask)) {
  84                                 if (!test_and_set_bit(i+16, &subs->unlink_mask)) {
  85                                         struct urb *u = subs->syncurb[i].urb;
  86                                         if (async)
  87                                                 usb_unlink_urb(u);
  88                                         else
  89                                                 usb_kill_urb(u);
  90                                 }
  91                         }
  92                 }
  93         }
  94         return 0;
  95 }
  96
  97
  98 /*
  99  * release a urb data
 100  */
 101 static void release_urb_ctx(struct snd_urb_ctx *u)
 102 {
 103         if (u->urb) {
 104                 if (u->buffer_size)
 105                         usb_free_coherent(u->subs->dev, u->buffer_size,
 106                                         u->urb->transfer_buffer,
 107                                         u->urb->transfer_dma);
 108                 usb_free_urb(u->urb);
 109                 u->urb = NULL;
 110         }
 111 }
 112
 113 /*
 114  *  wait until all urbs are processed.
 115  */
 116 static int wait_clear_urbs(struct snd_usb_substream *subs)
 117 {
 118         unsigned long end_time = jiffies + msecs_to_jiffies(1000);
 119         unsigned int i;
 120         int alive;
 121
 122         do {
 123                 alive = 0;
 124                 for (i = 0; i < subs->nurbs; i++) {
 125                         if (test_bit(i, &subs->active_mask))
 126                                 alive++;
 127                 }
 128                 if (subs->syncpipe) {
 129                         for (i = 0; i < SYNC_URBS; i++) {
 130                                 if (test_bit(i + 16, &subs->active_mask))
 131                                         alive++;
 132                         }
 133                 }
 134                 if (! alive)
 135                         break;
 136                 schedule_timeout_uninterruptible(1);
 137         } while (time_before(jiffies, end_time));
 138         if (alive)
 139                 snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
 140         return 0;
 141 }
 142
 143 /*
 144  * release a substream
 145  */
 146 void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force)
 147 {
 148         int i;
 149
 150         /* stop urbs (to be sure) */
 151         if (!subs->stream->chip->shutdown) {
 152                 deactivate_urbs(subs, force, 1);
 153                 wait_clear_urbs(subs);
 154         }
 155
 156         for (i = 0; i < MAX_URBS; i++)
 157                 release_urb_ctx(&subs->dataurb[i]);
 158         for (i = 0; i < SYNC_URBS; i++)
 159                 release_urb_ctx(&subs->syncurb[i]);
 160         usb_free_coherent(subs->dev, SYNC_URBS * 4,
 161                         subs->syncbuf, subs->sync_dma);
 162         subs->syncbuf = NULL;
 163         subs->nurbs = 0;
 164 }
 165
 166 /*
 167  * complete callback from data urb
 168  */
 169 static void snd_complete_urb(struct urb *urb)
 170 {
 171         struct snd_urb_ctx *ctx = urb->context;
 172         struct snd_usb_substream *subs = ctx->subs;
 173         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
 174         int err = 0;
 175
 176         if ((subs->running && subs->ops.retire(subs, substream->runtime, urb)) ||
 177             !subs->running || /* can be stopped during retire callback */
 178             (err = subs->ops.prepare(subs, substream->runtime, urb)) < 0 ||
 179             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
 180                 clear_bit(ctx->index, &subs->active_mask);
 181                 if (err < 0) {
 182                         snd_printd(KERN_ERR "cannot submit urb (err = %d)\n", err);
 183                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 184                 }
 185         }
 186 }
 187
 188
 189 /*
 190  * complete callback from sync urb
 191  */
 192 static void snd_complete_sync_urb(struct urb *urb)
 193 {
 194         struct snd_urb_ctx *ctx = urb->context;
 195         struct snd_usb_substream *subs = ctx->subs;
 196         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
 197         int err = 0;
 198
 199         if ((subs->running && subs->ops.retire_sync(subs, substream->runtime, urb)) ||
 200             !subs->running || /* can be stopped during retire callback */
 201             (err = subs->ops.prepare_sync(subs, substream->runtime, urb)) < 0 ||
 202             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
 203                 clear_bit(ctx->index + 16, &subs->active_mask);
 204                 if (err < 0) {
 205                         snd_printd(KERN_ERR "cannot submit sync urb (err = %d)\n", err);
 206                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 207                 }
 208         }
 209 }
 210
 211
 212 /*
 213  * initialize a substream for plaback/capture
 214  */
 215 int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
 216                                 unsigned int period_bytes,
 217                                 unsigned int rate,
 218                                 unsigned int frame_bits)
 219 {
 220         unsigned int maxsize, i;
 221         int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
 222         unsigned int urb_packs, total_packs, packs_per_ms;
 223         struct snd_usb_audio *chip = subs->stream->chip;
 224
 225         /* calculate the frequency in 16.16 format */
 226         if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
 227                 subs->freqn = get_usb_full_speed_rate(rate);
 228         else
 229                 subs->freqn = get_usb_high_speed_rate(rate);
 230         subs->freqm = subs->freqn;
 231         subs->freqshift = INT_MIN;
 232         /* calculate max. frequency */
 233         if (subs->maxpacksize) {
 234                 /* whatever fits into a max. size packet */
 235                 maxsize = subs->maxpacksize;
 236                 subs->freqmax = (maxsize / (frame_bits >> 3))
 237                                 << (16 - subs->datainterval);
 238         } else {
 239                 /* no max. packet size: just take 25% higher than nominal */
 240                 subs->freqmax = subs->freqn + (subs->freqn >> 2);
 241                 maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3))
 242                                 >> (16 - subs->datainterval);
 243         }
 244         subs->phase = 0;
 245
 246         if (subs->fill_max)
 247                 subs->curpacksize = subs->maxpacksize;
 248         else
 249                 subs->curpacksize = maxsize;
 250
 251         if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL)
 252                 packs_per_ms = 8 >> subs->datainterval;
 253         else
 254                 packs_per_ms = 1;
 255
 256         if (is_playback) {
 257                 urb_packs = max(chip->nrpacks, 1);
 258                 urb_packs = min(urb_packs, (unsigned int)MAX_PACKS);
 259         } else
 260                 urb_packs = 1;
 261         urb_packs *= packs_per_ms;
 262         if (subs->syncpipe)
 263                 urb_packs = min(urb_packs, 1U << subs->syncinterval);
 264
 265         /* decide how many packets to be used */
 266         if (is_playback) {
 267                 unsigned int minsize, maxpacks;
 268                 /* determine how small a packet can be */
 269                 minsize = (subs->freqn >> (16 - subs->datainterval))
 270                           * (frame_bits >> 3);
 271                 /* with sync from device, assume it can be 12% lower */
 272                 if (subs->syncpipe)
 273                         minsize -= minsize >> 3;
 274                 minsize = max(minsize, 1u);
 275                 total_packs = (period_bytes + minsize - 1) / minsize;
 276                 /* we need at least two URBs for queueing */
 277                 if (total_packs < 2) {
 278                         total_packs = 2;
 279                 } else {
 280                         /* and we don't want too long a queue either */
 281                         maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2);
 282                         total_packs = min(total_packs, maxpacks);
 283                 }
 284         } else {
 285                 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
 286                         urb_packs >>= 1;
 287                 total_packs = MAX_URBS * urb_packs;
 288         }
 289         subs->nurbs = (total_packs + urb_packs - 1) / urb_packs;
 290         if (subs->nurbs > MAX_URBS) {
 291                 /* too much... */
 292                 subs->nurbs = MAX_URBS;
 293                 total_packs = MAX_URBS * urb_packs;
 294         } else if (subs->nurbs < 2) {
 295                 /* too little - we need at least two packets
 296                  * to ensure contiguous playback/capture
 297                  */
 298                 subs->nurbs = 2;
 299         }
 300
 301         /* allocate and initialize data urbs */
 302         for (i = 0; i < subs->nurbs; i++) {
 303                 struct snd_urb_ctx *u = &subs->dataurb[i];
 304                 u->index = i;
 305                 u->subs = subs;
 306                 u->packets = (i + 1) * total_packs / subs->nurbs
 307                         - i * total_packs / subs->nurbs;
 308                 u->buffer_size = maxsize * u->packets;
 309                 if (subs->fmt_type == UAC_FORMAT_TYPE_II)
 310                         u->packets++; /* for transfer delimiter */
 311                 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
 312                 if (!u->urb)
 313                         goto out_of_memory;
 314                 u->urb->transfer_buffer =
 315                         usb_alloc_coherent(subs->dev, u->buffer_size,
 316                                            GFP_KERNEL, &u->urb->transfer_dma);
 317                 if (!u->urb->transfer_buffer)
 318                         goto out_of_memory;
 319                 u->urb->pipe = subs->datapipe;
 320                 u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 321                 u->urb->interval = 1 << subs->datainterval;
 322                 u->urb->context = u;
 323                 u->urb->complete = snd_complete_urb;
 324         }
 325
 326         if (subs->syncpipe) {
 327                 /* allocate and initialize sync urbs */
 328                 subs->syncbuf = usb_alloc_coherent(subs->dev, SYNC_URBS * 4,
 329                                                  GFP_KERNEL, &subs->sync_dma);
 330                 if (!subs->syncbuf)
 331                         goto out_of_memory;
 332                 for (i = 0; i < SYNC_URBS; i++) {
 333                         struct snd_urb_ctx *u = &subs->syncurb[i];
 334                         u->index = i;
 335                         u->subs = subs;
 336                         u->packets = 1;
 337                         u->urb = usb_alloc_urb(1, GFP_KERNEL);
 338                         if (!u->urb)
 339                                 goto out_of_memory;
 340                         u->urb->transfer_buffer = subs->syncbuf + i * 4;
 341                         u->urb->transfer_dma = subs->sync_dma + i * 4;
 342                         u->urb->transfer_buffer_length = 4;
 343                         u->urb->pipe = subs->syncpipe;
 344                         u->urb->transfer_flags = URB_ISO_ASAP |
 345                                                  URB_NO_TRANSFER_DMA_MAP;
 346                         u->urb->number_of_packets = 1;
 347                         u->urb->interval = 1 << subs->syncinterval;
 348                         u->urb->context = u;
 349                         u->urb->complete = snd_complete_sync_urb;
 350                 }
 351         }
 352         return 0;
 353
 354 out_of_memory:
 355         snd_usb_release_substream_urbs(subs, 0);
 356         return -ENOMEM;
 357 }
 358
 359 /*
 360  * prepare urb for full speed capture sync pipe
 361  *
 362  * fill the length and offset of each urb descriptor.
 363  * the fixed 10.14 frequency is passed through the pipe.
 364  */
 365 static int prepare_capture_sync_urb(struct snd_usb_substream *subs,
 366                                     struct snd_pcm_runtime *runtime,
 367                                     struct urb *urb)
 368 {
 369         unsigned char *cp = urb->transfer_buffer;
 370         struct snd_urb_ctx *ctx = urb->context;
 371
 372         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 373         urb->iso_frame_desc[0].length = 3;
 374         urb->iso_frame_desc[0].offset = 0;
 375         cp[0] = subs->freqn >> 2;
 376         cp[1] = subs->freqn >> 10;
 377         cp[2] = subs->freqn >> 18;
 378         return 0;
 379 }
 380
 381 /*
 382  * prepare urb for high speed capture sync pipe
 383  *
 384  * fill the length and offset of each urb descriptor.
 385  * the fixed 12.13 frequency is passed as 16.16 through the pipe.
 386  */
 387 static int prepare_capture_sync_urb_hs(struct snd_usb_substream *subs,
 388                                        struct snd_pcm_runtime *runtime,
 389                                        struct urb *urb)
 390 {
 391         unsigned char *cp = urb->transfer_buffer;
 392         struct snd_urb_ctx *ctx = urb->context;
 393
 394         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 395         urb->iso_frame_desc[0].length = 4;
 396         urb->iso_frame_desc[0].offset = 0;
 397         cp[0] = subs->freqn;
 398         cp[1] = subs->freqn >> 8;
 399         cp[2] = subs->freqn >> 16;
 400         cp[3] = subs->freqn >> 24;
 401         return 0;
 402 }
 403
 404 /*
 405  * process after capture sync complete
 406  * - nothing to do
 407  */
 408 static int retire_capture_sync_urb(struct snd_usb_substream *subs,
 409                                    struct snd_pcm_runtime *runtime,
 410                                    struct urb *urb)
 411 {
 412         return 0;
 413 }
 414
 415 /*
 416  * prepare urb for capture data pipe
 417  *
 418  * fill the offset and length of each descriptor.
 419  *
 420  * we use a temporary buffer to write the captured data.
 421  * since the length of written data is determined by host, we cannot
 422  * write onto the pcm buffer directly...  the data is thus copied
 423  * later at complete callback to the global buffer.
 424  */
 425 static int prepare_capture_urb(struct snd_usb_substream *subs,
 426                                struct snd_pcm_runtime *runtime,
 427                                struct urb *urb)
 428 {
 429         int i, offs;
 430         struct snd_urb_ctx *ctx = urb->context;
 431
 432         offs = 0;
 433         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 434         for (i = 0; i < ctx->packets; i++) {
 435                 urb->iso_frame_desc[i].offset = offs;
 436                 urb->iso_frame_desc[i].length = subs->curpacksize;
 437                 offs += subs->curpacksize;
 438         }
 439         urb->transfer_buffer_length = offs;
 440         urb->number_of_packets = ctx->packets;
 441         return 0;
 442 }
 443
 444 /*
 445  * process after capture complete
 446  *
 447  * copy the data from each desctiptor to the pcm buffer, and
 448  * update the current position.
 449  */
 450 static int retire_capture_urb(struct snd_usb_substream *subs,
 451                               struct snd_pcm_runtime *runtime,
 452                               struct urb *urb)
 453 {
 454         unsigned long flags;
 455         unsigned char *cp;
 456         int i;
 457         unsigned int stride, frames, bytes, oldptr;
 458         int period_elapsed = 0;
 459
 460         stride = runtime->frame_bits >> 3;
 461
 462         for (i = 0; i < urb->number_of_packets; i++) {
 463                 cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 464                 if (urb->iso_frame_desc[i].status && printk_ratelimit()) {
 465                         snd_printdd("frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
 466                         // continue;
 467                 }
 468                 bytes = urb->iso_frame_desc[i].actual_length;
 469                 frames = bytes / stride;
 470                 if (!subs->txfr_quirk)
 471                         bytes = frames * stride;
 472                 if (bytes % (runtime->sample_bits >> 3) != 0) {
 473 #ifdef CONFIG_SND_DEBUG_VERBOSE
 474                         int oldbytes = bytes;
 475 #endif
 476                         bytes = frames * stride;
 477                         snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
 478                                                         oldbytes, bytes);
 479                 }
 480                 /* update the current pointer */
 481                 spin_lock_irqsave(&subs->lock, flags);
 482                 oldptr = subs->hwptr_done;
 483                 subs->hwptr_done += bytes;
 484                 if (subs->hwptr_done >= runtime->buffer_size * stride)
 485                         subs->hwptr_done -= runtime->buffer_size * stride;
 486                 frames = (bytes + (oldptr % stride)) / stride;
 487                 subs->transfer_done += frames;
 488                 if (subs->transfer_done >= runtime->period_size) {
 489                         subs->transfer_done -= runtime->period_size;
 490                         period_elapsed = 1;
 491                 }
 492                 spin_unlock_irqrestore(&subs->lock, flags);
 493                 /* copy a data chunk */
 494                 if (oldptr + bytes > runtime->buffer_size * stride) {
 495                         unsigned int bytes1 =
 496                                         runtime->buffer_size * stride - oldptr;
 497                         memcpy(runtime->dma_area + oldptr, cp, bytes1);
 498                         memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
 499                 } else {
 500                         memcpy(runtime->dma_area + oldptr, cp, bytes);
 501                 }
 502         }
 503         if (period_elapsed)
 504                 snd_pcm_period_elapsed(subs->pcm_substream);
 505         return 0;
 506 }
 507
 508 /*
 509  * Process after capture complete when paused.  Nothing to do.
 510  */
 511 static int retire_paused_capture_urb(struct snd_usb_substream *subs,
 512                                      struct snd_pcm_runtime *runtime,
 513                                      struct urb *urb)
 514 {
 515         return 0;
 516 }
 517
 518
 519 /*
 520  * prepare urb for playback sync pipe
 521  *
 522  * set up the offset and length to receive the current frequency.
 523  */
 524 static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
 525                                      struct snd_pcm_runtime *runtime,
 526                                      struct urb *urb)
 527 {
 528         struct snd_urb_ctx *ctx = urb->context;
 529
 530         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 531         urb->iso_frame_desc[0].length = min(4u, ctx->subs->syncmaxsize);
 532         urb->iso_frame_desc[0].offset = 0;
 533         return 0;
 534 }
 535
 536 /*
 537  * process after playback sync complete
 538  *
 539  * Full speed devices report feedback values in 10.14 format as samples per
 540  * frame, high speed devices in 16.16 format as samples per microframe.
 541  * Because the Audio Class 1 spec was written before USB 2.0, many high speed
 542  * devices use a wrong interpretation, some others use an entirely different
 543  * format.  Therefore, we cannot predict what format any particular device uses
 544  * and must detect it automatically.
 545  */
 546 static int retire_playback_sync_urb(struct snd_usb_substream *subs,
 547                                     struct snd_pcm_runtime *runtime,
 548                                     struct urb *urb)
 549 {
 550         unsigned int f;
 551         int shift;
 552         unsigned long flags;
 553
 554         if (urb->iso_frame_desc[0].status != 0 ||
 555             urb->iso_frame_desc[0].actual_length < 3)
 556                 return 0;
 557
 558         f = le32_to_cpup(urb->transfer_buffer);
 559         if (urb->iso_frame_desc[0].actual_length == 3)
 560                 f &= 0x00ffffff;
 561         else
 562                 f &= 0x0fffffff;
 563         if (f == 0)
 564                 return 0;
 565
 566         if (unlikely(subs->freqshift == INT_MIN)) {
 567                 /*
 568                  * The first time we see a feedback value, determine its format
 569                  * by shifting it left or right until it matches the nominal
 570                  * frequency value.  This assumes that the feedback does not
 571                  * differ from the nominal value more than +50% or -25%.
 572                  */
 573                 shift = 0;
 574                 while (f < subs->freqn - subs->freqn / 4) {
 575                         f <<= 1;
 576                         shift++;
 577                 }
 578                 while (f > subs->freqn + subs->freqn / 2) {
 579                         f >>= 1;
 580                         shift--;
 581                 }
 582                 subs->freqshift = shift;
 583         }
 584         else if (subs->freqshift >= 0)
 585                 f <<= subs->freqshift;
 586         else
 587                 f >>= -subs->freqshift;
 588
 589         if (likely(f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax)) {
 590                 /*
 591                  * If the frequency looks valid, set it.
 592                  * This value is referred to in prepare_playback_urb().
 593                  */
 594                 spin_lock_irqsave(&subs->lock, flags);
 595                 subs->freqm = f;
 596                 spin_unlock_irqrestore(&subs->lock, flags);
 597         } else {
 598                 /*
 599                  * Out of range; maybe the shift value is wrong.
 600                  * Reset it so that we autodetect again the next time.
 601                  */
 602                 subs->freqshift = INT_MIN;
 603         }
 604
 605         return 0;
 606 }
 607
 608 /* determine the number of frames in the next packet */
 609 static int snd_usb_audio_next_packet_size(struct snd_usb_substream *subs)
 610 {
 611         if (subs->fill_max)
 612                 return subs->maxframesize;
 613         else {
 614                 subs->phase = (subs->phase & 0xffff)
 615                         + (subs->freqm << subs->datainterval);
 616                 return min(subs->phase >> 16, subs->maxframesize);
 617         }
 618 }
 619
 620 /*
 621  * Prepare urb for streaming before playback starts or when paused.
 622  *
 623  * We don't have any data, so we send silence.
 624  */
 625 static int prepare_nodata_playback_urb(struct snd_usb_substream *subs,
 626                                        struct snd_pcm_runtime *runtime,
 627                                        struct urb *urb)
 628 {
 629         unsigned int i, offs, counts;
 630         struct snd_urb_ctx *ctx = urb->context;
 631         int stride = runtime->frame_bits >> 3;
 632
 633         offs = 0;
 634         urb->dev = ctx->subs->dev;
 635         for (i = 0; i < ctx->packets; ++i) {
 636                 counts = snd_usb_audio_next_packet_size(subs);
 637                 urb->iso_frame_desc[i].offset = offs * stride;
 638                 urb->iso_frame_desc[i].length = counts * stride;
 639                 offs += counts;
 640         }
 641         urb->number_of_packets = ctx->packets;
 642         urb->transfer_buffer_length = offs * stride;
 643         memset(urb->transfer_buffer,
 644                runtime->format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0,
 645                offs * stride);
 646         return 0;
 647 }
 648
 649 /*
 650  * prepare urb for playback data pipe
 651  *
 652  * Since a URB can handle only a single linear buffer, we must use double
 653  * buffering when the data to be transferred overflows the buffer boundary.
 654  * To avoid inconsistencies when updating hwptr_done, we use double buffering
 655  * for all URBs.
 656  */
 657 static int prepare_playback_urb(struct snd_usb_substream *subs,
 658                                 struct snd_pcm_runtime *runtime,
 659                                 struct urb *urb)
 660 {
 661         int i, stride;
 662         unsigned int counts, frames, bytes;
 663         unsigned long flags;
 664         int period_elapsed = 0;
 665         struct snd_urb_ctx *ctx = urb->context;
 666
 667         stride = runtime->frame_bits >> 3;
 668
 669         frames = 0;
 670         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 671         urb->number_of_packets = 0;
 672         spin_lock_irqsave(&subs->lock, flags);
 673         for (i = 0; i < ctx->packets; i++) {
 674                 counts = snd_usb_audio_next_packet_size(subs);
 675                 /* set up descriptor */
 676                 urb->iso_frame_desc[i].offset = frames * stride;
 677                 urb->iso_frame_desc[i].length = counts * stride;
 678                 frames += counts;
 679                 urb->number_of_packets++;
 680                 subs->transfer_done += counts;
 681                 if (subs->transfer_done >= runtime->period_size) {
 682                         subs->transfer_done -= runtime->period_size;
 683                         period_elapsed = 1;
 684                         if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
 685                                 if (subs->transfer_done > 0) {
 686                                         /* FIXME: fill-max mode is not
 687                                          * supported yet */
 688                                         frames -= subs->transfer_done;
 689                                         counts -= subs->transfer_done;
 690                                         urb->iso_frame_desc[i].length =
 691                                                 counts * stride;
 692                                         subs->transfer_done = 0;
 693                                 }
 694                                 i++;
 695                                 if (i < ctx->packets) {
 696                                         /* add a transfer delimiter */
 697                                         urb->iso_frame_desc[i].offset =
 698                                                 frames * stride;
 699                                         urb->iso_frame_desc[i].length = 0;
 700                                         urb->number_of_packets++;
 701                                 }
 702                                 break;
 703                         }
 704                 }
 705                 if (period_elapsed) /* finish at the period boundary */
 706                         break;
 707         }
 708         bytes = frames * stride;
 709         if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
 710                 /* err, the transferred area goes over buffer boundary. */
 711                 unsigned int bytes1 =
 712                         runtime->buffer_size * stride - subs->hwptr_done;
 713                 memcpy(urb->transfer_buffer,
 714                        runtime->dma_area + subs->hwptr_done, bytes1);
 715                 memcpy(urb->transfer_buffer + bytes1,
 716                        runtime->dma_area, bytes - bytes1);
 717         } else {
 718                 memcpy(urb->transfer_buffer,
 719                        runtime->dma_area + subs->hwptr_done, bytes);
 720         }
 721         subs->hwptr_done += bytes;
 722         if (subs->hwptr_done >= runtime->buffer_size * stride)
 723                 subs->hwptr_done -= runtime->buffer_size * stride;
 724
 725         /* update delay with exact number of samples queued */
 726         runtime->delay = subs->last_delay;
 727         runtime->delay += frames;
 728         subs->last_delay = runtime->delay;
 729
 730         /* realign last_frame_number */
 731         subs->last_frame_number = usb_get_current_frame_number(subs->dev);
 732         subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
 733
 734         spin_unlock_irqrestore(&subs->lock, flags);
 735         urb->transfer_buffer_length = bytes;
 736         if (period_elapsed)
 737                 snd_pcm_period_elapsed(subs->pcm_substream);
 738         return 0;
 739 }
 740
 741 /*
 742  * process after playback data complete
 743  * - decrease the delay count again
 744  */
 745 static int retire_playback_urb(struct snd_usb_substream *subs,
 746                                struct snd_pcm_runtime *runtime,
 747                                struct urb *urb)
 748 {
 749         unsigned long flags;
 750         int stride = runtime->frame_bits >> 3;
 751         int processed = urb->transfer_buffer_length / stride;
 752         int est_delay;
 753
 754         spin_lock_irqsave(&subs->lock, flags);
 755
 756         est_delay = snd_usb_pcm_delay(subs, runtime->rate);
 757         /* update delay with exact number of samples played */
 758         if (processed > subs->last_delay)
 759                 subs->last_delay = 0;
 760         else
 761                 subs->last_delay -= processed;
 762         runtime->delay = subs->last_delay;
 763
 764         /*
 765          * Report when delay estimate is off by more than 2ms.
 766          * The error should be lower than 2ms since the estimate relies
 767          * on two reads of a counter updated every ms.
 768          */
 769         if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
 770                 snd_printk(KERN_DEBUG "delay: estimated %d, actual %d\n",
 771                         est_delay, subs->last_delay);
 772
 773         spin_unlock_irqrestore(&subs->lock, flags);
 774         return 0;
 775 }
 776
 777 static const char *usb_error_string(int err)
 778 {
 779         switch (err) {
 780         case -ENODEV:
 781                 return "no device";
 782         case -ENOENT:
 783                 return "endpoint not enabled";
 784         case -EPIPE:
 785                 return "endpoint stalled";
 786         case -ENOSPC:
 787                 return "not enough bandwidth";
 788         case -ESHUTDOWN:
 789                 return "device disabled";
 790         case -EHOSTUNREACH:
 791                 return "device suspended";
 792         case -EINVAL:
 793         case -EAGAIN:
 794         case -EFBIG:
 795         case -EMSGSIZE:
 796                 return "internal error";
 797         default:
 798                 return "unknown error";
 799         }
 800 }
 801
 802 /*
 803  * set up and start data/sync urbs
 804  */
 805 static int start_urbs(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime)
 806 {
 807         unsigned int i;
 808         int err;
 809
 810         if (subs->stream->chip->shutdown)
 811                 return -EBADFD;
 812
 813         for (i = 0; i < subs->nurbs; i++) {
 814                 if (snd_BUG_ON(!subs->dataurb[i].urb))
 815                         return -EINVAL;
 816                 if (subs->ops.prepare(subs, runtime, subs->dataurb[i].urb) < 0) {
 817                         snd_printk(KERN_ERR "cannot prepare datapipe for urb %d\n", i);
 818                         goto __error;
 819                 }
 820         }
 821         if (subs->syncpipe) {
 822                 for (i = 0; i < SYNC_URBS; i++) {
 823                         if (snd_BUG_ON(!subs->syncurb[i].urb))
 824                                 return -EINVAL;
 825                         if (subs->ops.prepare_sync(subs, runtime, subs->syncurb[i].urb) < 0) {
 826                                 snd_printk(KERN_ERR "cannot prepare syncpipe for urb %d\n", i);
 827                                 goto __error;
 828                         }
 829                 }
 830         }
 831
 832         subs->active_mask = 0;
 833         subs->unlink_mask = 0;
 834         subs->running = 1;
 835         for (i = 0; i < subs->nurbs; i++) {
 836                 err = usb_submit_urb(subs->dataurb[i].urb, GFP_ATOMIC);
 837                 if (err < 0) {
 838                         snd_printk(KERN_ERR "cannot submit datapipe "
 839                                    "for urb %d, error %d: %s\n",
 840                                    i, err, usb_error_string(err));
 841                         goto __error;
 842                 }
 843                 set_bit(i, &subs->active_mask);
 844         }
 845         if (subs->syncpipe) {
 846                 for (i = 0; i < SYNC_URBS; i++) {
 847                         err = usb_submit_urb(subs->syncurb[i].urb, GFP_ATOMIC);
 848                         if (err < 0) {
 849                                 snd_printk(KERN_ERR "cannot submit syncpipe "
 850                                            "for urb %d, error %d: %s\n",
 851                                            i, err, usb_error_string(err));
 852                                 goto __error;
 853                         }
 854                         set_bit(i + 16, &subs->active_mask);
 855                 }
 856         }
 857         return 0;
 858
 859  __error:
 860         // snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
 861         deactivate_urbs(subs, 0, 0);
 862         return -EPIPE;
 863 }
 864
 865
 866 /*
 867  */
 868 static struct snd_urb_ops audio_urb_ops[2] = {
 869         {
 870                 .prepare =      prepare_nodata_playback_urb,
 871                 .retire =       retire_playback_urb,
 872                 .prepare_sync = prepare_playback_sync_urb,
 873                 .retire_sync =  retire_playback_sync_urb,
 874         },
 875         {
 876                 .prepare =      prepare_capture_urb,
 877                 .retire =       retire_capture_urb,
 878                 .prepare_sync = prepare_capture_sync_urb,
 879                 .retire_sync =  retire_capture_sync_urb,
 880         },
 881 };
 882
 883 /*
 884  * initialize the substream instance.
 885  */
 886
 887 void snd_usb_init_substream(struct snd_usb_stream *as,
 888                             int stream, struct audioformat *fp)
 889 {
 890         struct snd_usb_substream *subs = &as->substream[stream];
 891
 892         INIT_LIST_HEAD(&subs->fmt_list);
 893         spin_lock_init(&subs->lock);
 894
 895         subs->stream = as;
 896         subs->direction = stream;
 897         subs->dev = as->chip->dev;
 898         subs->txfr_quirk = as->chip->txfr_quirk;
 899         subs->ops = audio_urb_ops[stream];
 900         subs->speed = snd_usb_get_speed(subs->dev);
 901         if (subs->speed >= USB_SPEED_HIGH)
 902                 subs->ops.prepare_sync = prepare_capture_sync_urb_hs;
 903
 904         snd_usb_set_pcm_ops(as->pcm, stream);
 905
 906         list_add_tail(&fp->list, &subs->fmt_list);
 907         subs->formats |= fp->formats;
 908         subs->endpoint = fp->endpoint;
 909         subs->num_formats++;
 910         subs->fmt_type = fp->fmt_type;
 911 }
 912
 913 int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd)
 914 {
 915         struct snd_usb_substream *subs = substream->runtime->private_data;
 916
 917         switch (cmd) {
 918         case SNDRV_PCM_TRIGGER_START:
 919         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 920                 subs->ops.prepare = prepare_playback_urb;
 921                 return 0;
 922         case SNDRV_PCM_TRIGGER_STOP:
 923                 return deactivate_urbs(subs, 0, 0);
 924         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 925                 subs->ops.prepare = prepare_nodata_playback_urb;
 926                 return 0;
 927         }
 928
 929         return -EINVAL;
 930 }
 931
 932 int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd)
 933 {
 934         struct snd_usb_substream *subs = substream->runtime->private_data;
 935
 936         switch (cmd) {
 937         case SNDRV_PCM_TRIGGER_START:
 938                 subs->ops.retire = retire_capture_urb;
 939                 return start_urbs(subs, substream->runtime);
 940         case SNDRV_PCM_TRIGGER_STOP:
 941                 return deactivate_urbs(subs, 0, 0);
 942         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 943                 subs->ops.retire = retire_paused_capture_urb;
 944                 return 0;
 945         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 946                 subs->ops.retire = retire_capture_urb;
 947                 return 0;
 948         }
 949
 950         return -EINVAL;
 951 }
 952
 953 int snd_usb_substream_prepare(struct snd_usb_substream *subs,
 954                               struct snd_pcm_runtime *runtime)
 955 {
 956         /* clear urbs (to be sure) */
 957         deactivate_urbs(subs, 0, 1);
 958         wait_clear_urbs(subs);
 959
 960         /* for playback, submit the URBs now; otherwise, the first hwptr_done
 961          * updates for all URBs would happen at the same time when starting */
 962         if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
 963                 subs->ops.prepare = prepare_nodata_playback_urb;
 964                 return start_urbs(subs, runtime);
 965         }
 966
 967         return 0;
 968 }
 969