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/usb.h>
  21 #include <linux/usb/audio.h>
  22
  23 #include <sound/core.h>
  24 #include <sound/pcm.h>
  25
  26 #include "usbaudio.h"
  27 #include "helper.h"
  28 #include "card.h"
  29 #include "endpoint.h"
  30 #include "pcm.h"
  31
  32 /*
  33  * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
  34  * this will overflow at approx 524 kHz
  35  */
  36 static inline unsigned get_usb_full_speed_rate(unsigned int rate)
  37 {
  38         return ((rate << 13) + 62) / 125;
  39 }
  40
  41 /*
  42  * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
  43  * this will overflow at approx 4 MHz
  44  */
  45 static inline unsigned get_usb_high_speed_rate(unsigned int rate)
  46 {
  47         return ((rate << 10) + 62) / 125;
  48 }
  49
  50 /*
  51  * unlink active urbs.
  52  */
  53 static int deactivate_urbs(struct snd_usb_substream *subs, int force, int can_sleep)
  54 {
  55         struct snd_usb_audio *chip = subs->stream->chip;
  56         unsigned int i;
  57         int async;
  58
  59         subs->running = 0;
  60
  61         if (!force && subs->stream->chip->shutdown) /* to be sure... */
  62                 return -EBADFD;
  63
  64         async = !can_sleep && chip->async_unlink;
  65
  66         if (!async && in_interrupt())
  67                 return 0;
  68
  69         for (i = 0; i < subs->nurbs; i++) {
  70                 if (test_bit(i, &subs->active_mask)) {
  71                         if (!test_and_set_bit(i, &subs->unlink_mask)) {
  72                                 struct urb *u = subs->dataurb[i].urb;
  73                                 if (async)
  74                                         usb_unlink_urb(u);
  75                                 else
  76                                         usb_kill_urb(u);
  77                         }
  78                 }
  79         }
  80         if (subs->syncpipe) {
  81                 for (i = 0; i < SYNC_URBS; i++) {
  82                         if (test_bit(i+16, &subs->active_mask)) {
  83                                 if (!test_and_set_bit(i+16, &subs->unlink_mask)) {
  84                                         struct urb *u = subs->syncurb[i].urb;
  85                                         if (async)
  86                                                 usb_unlink_urb(u);
  87                                         else
  88                                                 usb_kill_urb(u);
  89                                 }
  90                         }
  91                 }
  92         }
  93         return 0;
  94 }
  95
  96
  97 /*
  98  * release a urb data
  99  */
 100 static void release_urb_ctx(struct snd_urb_ctx *u)
 101 {
 102         if (u->urb) {
 103                 if (u->buffer_size)
 104                         usb_free_coherent(u->subs->dev, u->buffer_size,
 105                                         u->urb->transfer_buffer,
 106                                         u->urb->transfer_dma);
 107                 usb_free_urb(u->urb);
 108                 u->urb = NULL;
 109         }
 110 }
 111
 112 /*
 113  *  wait until all urbs are processed.
 114  */
 115 static int wait_clear_urbs(struct snd_usb_substream *subs)
 116 {
 117         unsigned long end_time = jiffies + msecs_to_jiffies(1000);
 118         unsigned int i;
 119         int alive;
 120
 121         do {
 122                 alive = 0;
 123                 for (i = 0; i < subs->nurbs; i++) {
 124                         if (test_bit(i, &subs->active_mask))
 125                                 alive++;
 126                 }
 127                 if (subs->syncpipe) {
 128                         for (i = 0; i < SYNC_URBS; i++) {
 129                                 if (test_bit(i + 16, &subs->active_mask))
 130                                         alive++;
 131                         }
 132                 }
 133                 if (! alive)
 134                         break;
 135                 schedule_timeout_uninterruptible(1);
 136         } while (time_before(jiffies, end_time));
 137         if (alive)
 138                 snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
 139         return 0;
 140 }
 141
 142 /*
 143  * release a substream
 144  */
 145 void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force)
 146 {
 147         int i;
 148
 149         /* stop urbs (to be sure) */
 150         deactivate_urbs(subs, force, 1);
 151         wait_clear_urbs(subs);
 152
 153         for (i = 0; i < MAX_URBS; i++)
 154                 release_urb_ctx(&subs->dataurb[i]);
 155         for (i = 0; i < SYNC_URBS; i++)
 156                 release_urb_ctx(&subs->syncurb[i]);
 157         usb_free_coherent(subs->dev, SYNC_URBS * 4,
 158                         subs->syncbuf, subs->sync_dma);
 159         subs->syncbuf = NULL;
 160         subs->nurbs = 0;
 161 }
 162
 163 /*
 164  * complete callback from data urb
 165  */
 166 static void snd_complete_urb(struct urb *urb)
 167 {
 168         struct snd_urb_ctx *ctx = urb->context;
 169         struct snd_usb_substream *subs = ctx->subs;
 170         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
 171         int err = 0;
 172
 173         if ((subs->running && subs->ops.retire(subs, substream->runtime, urb)) ||
 174             !subs->running || /* can be stopped during retire callback */
 175             (err = subs->ops.prepare(subs, substream->runtime, urb)) < 0 ||
 176             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
 177                 clear_bit(ctx->index, &subs->active_mask);
 178                 if (err < 0) {
 179                         snd_printd(KERN_ERR "cannot submit urb (err = %d)\n", err);
 180                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 181                 }
 182         }
 183 }
 184
 185
 186 /*
 187  * complete callback from sync urb
 188  */
 189 static void snd_complete_sync_urb(struct urb *urb)
 190 {
 191         struct snd_urb_ctx *ctx = urb->context;
 192         struct snd_usb_substream *subs = ctx->subs;
 193         struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
 194         int err = 0;
 195
 196         if ((subs->running && subs->ops.retire_sync(subs, substream->runtime, urb)) ||
 197             !subs->running || /* can be stopped during retire callback */
 198             (err = subs->ops.prepare_sync(subs, substream->runtime, urb)) < 0 ||
 199             (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
 200                 clear_bit(ctx->index + 16, &subs->active_mask);
 201                 if (err < 0) {
 202                         snd_printd(KERN_ERR "cannot submit sync urb (err = %d)\n", err);
 203                         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 204                 }
 205         }
 206 }
 207
 208
 209 /*
 210  * initialize a substream for plaback/capture
 211  */
 212 int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
 213                                 unsigned int period_bytes,
 214                                 unsigned int rate,
 215                                 unsigned int frame_bits)
 216 {
 217         unsigned int maxsize, i;
 218         int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
 219         unsigned int urb_packs, total_packs, packs_per_ms;
 220         struct snd_usb_audio *chip = subs->stream->chip;
 221
 222         /* calculate the frequency in 16.16 format */
 223         if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
 224                 subs->freqn = get_usb_full_speed_rate(rate);
 225         else
 226                 subs->freqn = get_usb_high_speed_rate(rate);
 227         subs->freqm = subs->freqn;
 228         subs->freqshift = INT_MIN;
 229         /* calculate max. frequency */
 230         if (subs->maxpacksize) {
 231                 /* whatever fits into a max. size packet */
 232                 maxsize = subs->maxpacksize;
 233                 subs->freqmax = (maxsize / (frame_bits >> 3))
 234                                 << (16 - subs->datainterval);
 235         } else {
 236                 /* no max. packet size: just take 25% higher than nominal */
 237                 subs->freqmax = subs->freqn + (subs->freqn >> 2);
 238                 maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3))
 239                                 >> (16 - subs->datainterval);
 240         }
 241         subs->phase = 0;
 242
 243         if (subs->fill_max)
 244                 subs->curpacksize = subs->maxpacksize;
 245         else
 246                 subs->curpacksize = maxsize;
 247
 248         if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL)
 249                 packs_per_ms = 8 >> subs->datainterval;
 250         else
 251                 packs_per_ms = 1;
 252
 253         if (is_playback) {
 254                 urb_packs = max(chip->nrpacks, 1);
 255                 urb_packs = min(urb_packs, (unsigned int)MAX_PACKS);
 256         } else
 257                 urb_packs = 1;
 258         urb_packs *= packs_per_ms;
 259         if (subs->syncpipe)
 260                 urb_packs = min(urb_packs, 1U << subs->syncinterval);
 261
 262         /* decide how many packets to be used */
 263         if (is_playback) {
 264                 unsigned int minsize, maxpacks;
 265                 /* determine how small a packet can be */
 266                 minsize = (subs->freqn >> (16 - subs->datainterval))
 267                           * (frame_bits >> 3);
 268                 /* with sync from device, assume it can be 12% lower */
 269                 if (subs->syncpipe)
 270                         minsize -= minsize >> 3;
 271                 minsize = max(minsize, 1u);
 272                 total_packs = (period_bytes + minsize - 1) / minsize;
 273                 /* we need at least two URBs for queueing */
 274                 if (total_packs < 2) {
 275                         total_packs = 2;
 276                 } else {
 277                         /* and we don't want too long a queue either */
 278                         maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2);
 279                         total_packs = min(total_packs, maxpacks);
 280                 }
 281         } else {
 282                 while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
 283                         urb_packs >>= 1;
 284                 total_packs = MAX_URBS * urb_packs;
 285         }
 286         subs->nurbs = (total_packs + urb_packs - 1) / urb_packs;
 287         if (subs->nurbs > MAX_URBS) {
 288                 /* too much... */
 289                 subs->nurbs = MAX_URBS;
 290                 total_packs = MAX_URBS * urb_packs;
 291         } else if (subs->nurbs < 2) {
 292                 /* too little - we need at least two packets
 293                  * to ensure contiguous playback/capture
 294                  */
 295                 subs->nurbs = 2;
 296         }
 297
 298         /* allocate and initialize data urbs */
 299         for (i = 0; i < subs->nurbs; i++) {
 300                 struct snd_urb_ctx *u = &subs->dataurb[i];
 301                 u->index = i;
 302                 u->subs = subs;
 303                 u->packets = (i + 1) * total_packs / subs->nurbs
 304                         - i * total_packs / subs->nurbs;
 305                 u->buffer_size = maxsize * u->packets;
 306                 if (subs->fmt_type == UAC_FORMAT_TYPE_II)
 307                         u->packets++; /* for transfer delimiter */
 308                 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
 309                 if (!u->urb)
 310                         goto out_of_memory;
 311                 u->urb->transfer_buffer =
 312                         usb_alloc_coherent(subs->dev, u->buffer_size,
 313                                            GFP_KERNEL, &u->urb->transfer_dma);
 314                 if (!u->urb->transfer_buffer)
 315                         goto out_of_memory;
 316                 u->urb->pipe = subs->datapipe;
 317                 u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
 318                 u->urb->interval = 1 << subs->datainterval;
 319                 u->urb->context = u;
 320                 u->urb->complete = snd_complete_urb;
 321         }
 322
 323         if (subs->syncpipe) {
 324                 /* allocate and initialize sync urbs */
 325                 subs->syncbuf = usb_alloc_coherent(subs->dev, SYNC_URBS * 4,
 326                                                  GFP_KERNEL, &subs->sync_dma);
 327                 if (!subs->syncbuf)
 328                         goto out_of_memory;
 329                 for (i = 0; i < SYNC_URBS; i++) {
 330                         struct snd_urb_ctx *u = &subs->syncurb[i];
 331                         u->index = i;
 332                         u->subs = subs;
 333                         u->packets = 1;
 334                         u->urb = usb_alloc_urb(1, GFP_KERNEL);
 335                         if (!u->urb)
 336                                 goto out_of_memory;
 337                         u->urb->transfer_buffer = subs->syncbuf + i * 4;
 338                         u->urb->transfer_dma = subs->sync_dma + i * 4;
 339                         u->urb->transfer_buffer_length = 4;
 340                         u->urb->pipe = subs->syncpipe;
 341                         u->urb->transfer_flags = URB_ISO_ASAP |
 342                                                  URB_NO_TRANSFER_DMA_MAP;
 343                         u->urb->number_of_packets = 1;
 344                         u->urb->interval = 1 << subs->syncinterval;
 345                         u->urb->context = u;
 346                         u->urb->complete = snd_complete_sync_urb;
 347                 }
 348         }
 349         return 0;
 350
 351 out_of_memory:
 352         snd_usb_release_substream_urbs(subs, 0);
 353         return -ENOMEM;
 354 }
 355
 356 /*
 357  * prepare urb for full speed capture sync pipe
 358  *
 359  * fill the length and offset of each urb descriptor.
 360  * the fixed 10.14 frequency is passed through the pipe.
 361  */
 362 static int prepare_capture_sync_urb(struct snd_usb_substream *subs,
 363                                     struct snd_pcm_runtime *runtime,
 364                                     struct urb *urb)
 365 {
 366         unsigned char *cp = urb->transfer_buffer;
 367         struct snd_urb_ctx *ctx = urb->context;
 368
 369         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 370         urb->iso_frame_desc[0].length = 3;
 371         urb->iso_frame_desc[0].offset = 0;
 372         cp[0] = subs->freqn >> 2;
 373         cp[1] = subs->freqn >> 10;
 374         cp[2] = subs->freqn >> 18;
 375         return 0;
 376 }
 377
 378 /*
 379  * prepare urb for high speed capture sync pipe
 380  *
 381  * fill the length and offset of each urb descriptor.
 382  * the fixed 12.13 frequency is passed as 16.16 through the pipe.
 383  */
 384 static int prepare_capture_sync_urb_hs(struct snd_usb_substream *subs,
 385                                        struct snd_pcm_runtime *runtime,
 386                                        struct urb *urb)
 387 {
 388         unsigned char *cp = urb->transfer_buffer;
 389         struct snd_urb_ctx *ctx = urb->context;
 390
 391         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 392         urb->iso_frame_desc[0].length = 4;
 393         urb->iso_frame_desc[0].offset = 0;
 394         cp[0] = subs->freqn;
 395         cp[1] = subs->freqn >> 8;
 396         cp[2] = subs->freqn >> 16;
 397         cp[3] = subs->freqn >> 24;
 398         return 0;
 399 }
 400
 401 /*
 402  * process after capture sync complete
 403  * - nothing to do
 404  */
 405 static int retire_capture_sync_urb(struct snd_usb_substream *subs,
 406                                    struct snd_pcm_runtime *runtime,
 407                                    struct urb *urb)
 408 {
 409         return 0;
 410 }
 411
 412 /*
 413  * prepare urb for capture data pipe
 414  *
 415  * fill the offset and length of each descriptor.
 416  *
 417  * we use a temporary buffer to write the captured data.
 418  * since the length of written data is determined by host, we cannot
 419  * write onto the pcm buffer directly...  the data is thus copied
 420  * later at complete callback to the global buffer.
 421  */
 422 static int prepare_capture_urb(struct snd_usb_substream *subs,
 423                                struct snd_pcm_runtime *runtime,
 424                                struct urb *urb)
 425 {
 426         int i, offs;
 427         struct snd_urb_ctx *ctx = urb->context;
 428
 429         offs = 0;
 430         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 431         for (i = 0; i < ctx->packets; i++) {
 432                 urb->iso_frame_desc[i].offset = offs;
 433                 urb->iso_frame_desc[i].length = subs->curpacksize;
 434                 offs += subs->curpacksize;
 435         }
 436         urb->transfer_buffer_length = offs;
 437         urb->number_of_packets = ctx->packets;
 438         return 0;
 439 }
 440
 441 /*
 442  * process after capture complete
 443  *
 444  * copy the data from each desctiptor to the pcm buffer, and
 445  * update the current position.
 446  */
 447 static int retire_capture_urb(struct snd_usb_substream *subs,
 448                               struct snd_pcm_runtime *runtime,
 449                               struct urb *urb)
 450 {
 451         unsigned long flags;
 452         unsigned char *cp;
 453         int i;
 454         unsigned int stride, frames, bytes, oldptr;
 455         int period_elapsed = 0;
 456
 457         stride = runtime->frame_bits >> 3;
 458
 459         for (i = 0; i < urb->number_of_packets; i++) {
 460                 cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
 461                 if (urb->iso_frame_desc[i].status) {
 462                         snd_printd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
 463                         // continue;
 464                 }
 465                 bytes = urb->iso_frame_desc[i].actual_length;
 466                 frames = bytes / stride;
 467                 if (!subs->txfr_quirk)
 468                         bytes = frames * stride;
 469                 if (bytes % (runtime->sample_bits >> 3) != 0) {
 470 #ifdef CONFIG_SND_DEBUG_VERBOSE
 471                         int oldbytes = bytes;
 472 #endif
 473                         bytes = frames * stride;
 474                         snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
 475                                                         oldbytes, bytes);
 476                 }
 477                 /* update the current pointer */
 478                 spin_lock_irqsave(&subs->lock, flags);
 479                 oldptr = subs->hwptr_done;
 480                 subs->hwptr_done += bytes;
 481                 if (subs->hwptr_done >= runtime->buffer_size * stride)
 482                         subs->hwptr_done -= runtime->buffer_size * stride;
 483                 frames = (bytes + (oldptr % stride)) / stride;
 484                 subs->transfer_done += frames;
 485                 if (subs->transfer_done >= runtime->period_size) {
 486                         subs->transfer_done -= runtime->period_size;
 487                         period_elapsed = 1;
 488                 }
 489                 spin_unlock_irqrestore(&subs->lock, flags);
 490                 /* copy a data chunk */
 491                 if (oldptr + bytes > runtime->buffer_size * stride) {
 492                         unsigned int bytes1 =
 493                                         runtime->buffer_size * stride - oldptr;
 494                         memcpy(runtime->dma_area + oldptr, cp, bytes1);
 495                         memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
 496                 } else {
 497                         memcpy(runtime->dma_area + oldptr, cp, bytes);
 498                 }
 499         }
 500         if (period_elapsed)
 501                 snd_pcm_period_elapsed(subs->pcm_substream);
 502         return 0;
 503 }
 504
 505 /*
 506  * Process after capture complete when paused.  Nothing to do.
 507  */
 508 static int retire_paused_capture_urb(struct snd_usb_substream *subs,
 509                                      struct snd_pcm_runtime *runtime,
 510                                      struct urb *urb)
 511 {
 512         return 0;
 513 }
 514
 515
 516 /*
 517  * prepare urb for playback sync pipe
 518  *
 519  * set up the offset and length to receive the current frequency.
 520  */
 521 static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
 522                                      struct snd_pcm_runtime *runtime,
 523                                      struct urb *urb)
 524 {
 525         struct snd_urb_ctx *ctx = urb->context;
 526
 527         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 528         urb->iso_frame_desc[0].length = min(4u, ctx->subs->syncmaxsize);
 529         urb->iso_frame_desc[0].offset = 0;
 530         return 0;
 531 }
 532
 533 /*
 534  * process after playback sync complete
 535  *
 536  * Full speed devices report feedback values in 10.14 format as samples per
 537  * frame, high speed devices in 16.16 format as samples per microframe.
 538  * Because the Audio Class 1 spec was written before USB 2.0, many high speed
 539  * devices use a wrong interpretation, some others use an entirely different
 540  * format.  Therefore, we cannot predict what format any particular device uses
 541  * and must detect it automatically.
 542  */
 543 static int retire_playback_sync_urb(struct snd_usb_substream *subs,
 544                                     struct snd_pcm_runtime *runtime,
 545                                     struct urb *urb)
 546 {
 547         unsigned int f;
 548         int shift;
 549         unsigned long flags;
 550
 551         if (urb->iso_frame_desc[0].status != 0 ||
 552             urb->iso_frame_desc[0].actual_length < 3)
 553                 return 0;
 554
 555         f = le32_to_cpup(urb->transfer_buffer);
 556         if (urb->iso_frame_desc[0].actual_length == 3)
 557                 f &= 0x00ffffff;
 558         else
 559                 f &= 0x0fffffff;
 560         if (f == 0)
 561                 return 0;
 562
 563         if (unlikely(subs->freqshift == INT_MIN)) {
 564                 /*
 565                  * The first time we see a feedback value, determine its format
 566                  * by shifting it left or right until it matches the nominal
 567                  * frequency value.  This assumes that the feedback does not
 568                  * differ from the nominal value more than +50% or -25%.
 569                  */
 570                 shift = 0;
 571                 while (f < subs->freqn - subs->freqn / 4) {
 572                         f <<= 1;
 573                         shift++;
 574                 }
 575                 while (f > subs->freqn + subs->freqn / 2) {
 576                         f >>= 1;
 577                         shift--;
 578                 }
 579                 subs->freqshift = shift;
 580         }
 581         else if (subs->freqshift >= 0)
 582                 f <<= subs->freqshift;
 583         else
 584                 f >>= -subs->freqshift;
 585
 586         if (likely(f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax)) {
 587                 /*
 588                  * If the frequency looks valid, set it.
 589                  * This value is referred to in prepare_playback_urb().
 590                  */
 591                 spin_lock_irqsave(&subs->lock, flags);
 592                 subs->freqm = f;
 593                 spin_unlock_irqrestore(&subs->lock, flags);
 594         } else {
 595                 /*
 596                  * Out of range; maybe the shift value is wrong.
 597                  * Reset it so that we autodetect again the next time.
 598                  */
 599                 subs->freqshift = INT_MIN;
 600         }
 601
 602         return 0;
 603 }
 604
 605 /* determine the number of frames in the next packet */
 606 static int snd_usb_audio_next_packet_size(struct snd_usb_substream *subs)
 607 {
 608         if (subs->fill_max)
 609                 return subs->maxframesize;
 610         else {
 611                 subs->phase = (subs->phase & 0xffff)
 612                         + (subs->freqm << subs->datainterval);
 613                 return min(subs->phase >> 16, subs->maxframesize);
 614         }
 615 }
 616
 617 /*
 618  * Prepare urb for streaming before playback starts or when paused.
 619  *
 620  * We don't have any data, so we send silence.
 621  */
 622 static int prepare_nodata_playback_urb(struct snd_usb_substream *subs,
 623                                        struct snd_pcm_runtime *runtime,
 624                                        struct urb *urb)
 625 {
 626         unsigned int i, offs, counts;
 627         struct snd_urb_ctx *ctx = urb->context;
 628         int stride = runtime->frame_bits >> 3;
 629
 630         offs = 0;
 631         urb->dev = ctx->subs->dev;
 632         for (i = 0; i < ctx->packets; ++i) {
 633                 counts = snd_usb_audio_next_packet_size(subs);
 634                 urb->iso_frame_desc[i].offset = offs * stride;
 635                 urb->iso_frame_desc[i].length = counts * stride;
 636                 offs += counts;
 637         }
 638         urb->number_of_packets = ctx->packets;
 639         urb->transfer_buffer_length = offs * stride;
 640         memset(urb->transfer_buffer,
 641                runtime->format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0,
 642                offs * stride);
 643         return 0;
 644 }
 645
 646 /*
 647  * prepare urb for playback data pipe
 648  *
 649  * Since a URB can handle only a single linear buffer, we must use double
 650  * buffering when the data to be transferred overflows the buffer boundary.
 651  * To avoid inconsistencies when updating hwptr_done, we use double buffering
 652  * for all URBs.
 653  */
 654 static int prepare_playback_urb(struct snd_usb_substream *subs,
 655                                 struct snd_pcm_runtime *runtime,
 656                                 struct urb *urb)
 657 {
 658         int i, stride;
 659         unsigned int counts, frames, bytes;
 660         unsigned long flags;
 661         int period_elapsed = 0;
 662         struct snd_urb_ctx *ctx = urb->context;
 663
 664         stride = runtime->frame_bits >> 3;
 665
 666         frames = 0;
 667         urb->dev = ctx->subs->dev; /* we need to set this at each time */
 668         urb->number_of_packets = 0;
 669         spin_lock_irqsave(&subs->lock, flags);
 670         for (i = 0; i < ctx->packets; i++) {
 671                 counts = snd_usb_audio_next_packet_size(subs);
 672                 /* set up descriptor */
 673                 urb->iso_frame_desc[i].offset = frames * stride;
 674                 urb->iso_frame_desc[i].length = counts * stride;
 675                 frames += counts;
 676                 urb->number_of_packets++;
 677                 subs->transfer_done += counts;
 678                 if (subs->transfer_done >= runtime->period_size) {
 679                         subs->transfer_done -= runtime->period_size;
 680                         period_elapsed = 1;
 681                         if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
 682                                 if (subs->transfer_done > 0) {
 683                                         /* FIXME: fill-max mode is not
 684                                          * supported yet */
 685                                         frames -= subs->transfer_done;
 686                                         counts -= subs->transfer_done;
 687                                         urb->iso_frame_desc[i].length =
 688                                                 counts * stride;
 689                                         subs->transfer_done = 0;
 690                                 }
 691                                 i++;
 692                                 if (i < ctx->packets) {
 693                                         /* add a transfer delimiter */
 694                                         urb->iso_frame_desc[i].offset =
 695                                                 frames * stride;
 696                                         urb->iso_frame_desc[i].length = 0;
 697                                         urb->number_of_packets++;
 698                                 }
 699                                 break;
 700                         }
 701                 }
 702                 if (period_elapsed) /* finish at the period boundary */
 703                         break;
 704         }
 705         bytes = frames * stride;
 706         if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
 707                 /* err, the transferred area goes over buffer boundary. */
 708                 unsigned int bytes1 =
 709                         runtime->buffer_size * stride - subs->hwptr_done;
 710                 memcpy(urb->transfer_buffer,
 711                        runtime->dma_area + subs->hwptr_done, bytes1);
 712                 memcpy(urb->transfer_buffer + bytes1,
 713                        runtime->dma_area, bytes - bytes1);
 714         } else {
 715                 memcpy(urb->transfer_buffer,
 716                        runtime->dma_area + subs->hwptr_done, bytes);
 717         }
 718         subs->hwptr_done += bytes;
 719         if (subs->hwptr_done >= runtime->buffer_size * stride)
 720                 subs->hwptr_done -= runtime->buffer_size * stride;
 721
 722         /* update delay with exact number of samples queued */
 723         runtime->delay = subs->last_delay;
 724         runtime->delay += frames;
 725         subs->last_delay = runtime->delay;
 726
 727         /* realign last_frame_number */
 728         subs->last_frame_number = usb_get_current_frame_number(subs->dev);
 729         subs->last_frame_number &= 0xFF; /* keep 8 LSBs */
 730
 731         spin_unlock_irqrestore(&subs->lock, flags);
 732         urb->transfer_buffer_length = bytes;
 733         if (period_elapsed)
 734                 snd_pcm_period_elapsed(subs->pcm_substream);
 735         return 0;
 736 }
 737
 738 /*
 739  * process after playback data complete
 740  * - decrease the delay count again
 741  */
 742 static int retire_playback_urb(struct snd_usb_substream *subs,
 743                                struct snd_pcm_runtime *runtime,
 744                                struct urb *urb)
 745 {
 746         unsigned long flags;
 747         int stride = runtime->frame_bits >> 3;
 748         int processed = urb->transfer_buffer_length / stride;
 749         int est_delay;
 750
 751         spin_lock_irqsave(&subs->lock, flags);
 752
 753         est_delay = snd_usb_pcm_delay(subs, runtime->rate);
 754         /* update delay with exact number of samples played */
 755         if (processed > subs->last_delay)
 756                 subs->last_delay = 0;
 757         else
 758                 subs->last_delay -= processed;
 759         runtime->delay = subs->last_delay;
 760
 761         /*
 762          * Report when delay estimate is off by more than 2ms.
 763          * The error should be lower than 2ms since the estimate relies
 764          * on two reads of a counter updated every ms.
 765          */
 766         if (abs(est_delay - subs->last_delay) * 1000 > runtime->rate * 2)
 767                 snd_printk(KERN_DEBUG "delay: estimated %d, actual %d\n",
 768                         est_delay, subs->last_delay);
 769
 770         spin_unlock_irqrestore(&subs->lock, flags);
 771         return 0;
 772 }
 773
 774 static const char *usb_error_string(int err)
 775 {
 776         switch (err) {
 777         case -ENODEV:
 778                 return "no device";
 779         case -ENOENT:
 780                 return "endpoint not enabled";
 781         case -EPIPE:
 782                 return "endpoint stalled";
 783         case -ENOSPC:
 784                 return "not enough bandwidth";
 785         case -ESHUTDOWN:
 786                 return "device disabled";
 787         case -EHOSTUNREACH:
 788                 return "device suspended";
 789         case -EINVAL:
 790         case -EAGAIN:
 791         case -EFBIG:
 792         case -EMSGSIZE:
 793                 return "internal error";
 794         default:
 795                 return "unknown error";
 796         }
 797 }
 798
 799 /*
 800  * set up and start data/sync urbs
 801  */
 802 static int start_urbs(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime)
 803 {
 804         unsigned int i;
 805         int err;
 806
 807         if (subs->stream->chip->shutdown)
 808                 return -EBADFD;
 809
 810         for (i = 0; i < subs->nurbs; i++) {
 811                 if (snd_BUG_ON(!subs->dataurb[i].urb))
 812                         return -EINVAL;
 813                 if (subs->ops.prepare(subs, runtime, subs->dataurb[i].urb) < 0) {
 814                         snd_printk(KERN_ERR "cannot prepare datapipe for urb %d\n", i);
 815                         goto __error;
 816                 }
 817         }
 818         if (subs->syncpipe) {
 819                 for (i = 0; i < SYNC_URBS; i++) {
 820                         if (snd_BUG_ON(!subs->syncurb[i].urb))
 821                                 return -EINVAL;
 822                         if (subs->ops.prepare_sync(subs, runtime, subs->syncurb[i].urb) < 0) {
 823                                 snd_printk(KERN_ERR "cannot prepare syncpipe for urb %d\n", i);
 824                                 goto __error;
 825                         }
 826                 }
 827         }
 828
 829         subs->active_mask = 0;
 830         subs->unlink_mask = 0;
 831         subs->running = 1;
 832         for (i = 0; i < subs->nurbs; i++) {
 833                 err = usb_submit_urb(subs->dataurb[i].urb, GFP_ATOMIC);
 834                 if (err < 0) {
 835                         snd_printk(KERN_ERR "cannot submit datapipe "
 836                                    "for urb %d, error %d: %s\n",
 837                                    i, err, usb_error_string(err));
 838                         goto __error;
 839                 }
 840                 set_bit(i, &subs->active_mask);
 841         }
 842         if (subs->syncpipe) {
 843                 for (i = 0; i < SYNC_URBS; i++) {
 844                         err = usb_submit_urb(subs->syncurb[i].urb, GFP_ATOMIC);
 845                         if (err < 0) {
 846                                 snd_printk(KERN_ERR "cannot submit syncpipe "
 847                                            "for urb %d, error %d: %s\n",
 848                                            i, err, usb_error_string(err));
 849                                 goto __error;
 850                         }
 851                         set_bit(i + 16, &subs->active_mask);
 852                 }
 853         }
 854         return 0;
 855
 856  __error:
 857         // snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
 858         deactivate_urbs(subs, 0, 0);
 859         return -EPIPE;
 860 }
 861
 862
 863 /*
 864  */
 865 static struct snd_urb_ops audio_urb_ops[2] = {
 866         {
 867                 .prepare =      prepare_nodata_playback_urb,
 868                 .retire =       retire_playback_urb,
 869                 .prepare_sync = prepare_playback_sync_urb,
 870                 .retire_sync =  retire_playback_sync_urb,
 871         },
 872         {
 873                 .prepare =      prepare_capture_urb,
 874                 .retire =       retire_capture_urb,
 875                 .prepare_sync = prepare_capture_sync_urb,
 876                 .retire_sync =  retire_capture_sync_urb,
 877         },
 878 };
 879
 880 /*
 881  * initialize the substream instance.
 882  */
 883
 884 void snd_usb_init_substream(struct snd_usb_stream *as,
 885                             int stream, struct audioformat *fp)
 886 {
 887         struct snd_usb_substream *subs = &as->substream[stream];
 888
 889         INIT_LIST_HEAD(&subs->fmt_list);
 890         spin_lock_init(&subs->lock);
 891
 892         subs->stream = as;
 893         subs->direction = stream;
 894         subs->dev = as->chip->dev;
 895         subs->txfr_quirk = as->chip->txfr_quirk;
 896         subs->ops = audio_urb_ops[stream];
 897         if (snd_usb_get_speed(subs->dev) >= USB_SPEED_HIGH)
 898                 subs->ops.prepare_sync = prepare_capture_sync_urb_hs;
 899
 900         snd_usb_set_pcm_ops(as->pcm, stream);
 901
 902         list_add_tail(&fp->list, &subs->fmt_list);
 903         subs->formats |= fp->formats;
 904         subs->endpoint = fp->endpoint;
 905         subs->num_formats++;
 906         subs->fmt_type = fp->fmt_type;
 907 }
 908
 909 int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd)
 910 {
 911         struct snd_usb_substream *subs = substream->runtime->private_data;
 912
 913         switch (cmd) {
 914         case SNDRV_PCM_TRIGGER_START:
 915         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 916                 subs->ops.prepare = prepare_playback_urb;
 917                 return 0;
 918         case SNDRV_PCM_TRIGGER_STOP:
 919                 return deactivate_urbs(subs, 0, 0);
 920         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 921                 subs->ops.prepare = prepare_nodata_playback_urb;
 922                 return 0;
 923         }
 924
 925         return -EINVAL;
 926 }
 927
 928 int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd)
 929 {
 930         struct snd_usb_substream *subs = substream->runtime->private_data;
 931
 932         switch (cmd) {
 933         case SNDRV_PCM_TRIGGER_START:
 934                 subs->ops.retire = retire_capture_urb;
 935                 return start_urbs(subs, substream->runtime);
 936         case SNDRV_PCM_TRIGGER_STOP:
 937                 return deactivate_urbs(subs, 0, 0);
 938         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 939                 subs->ops.retire = retire_paused_capture_urb;
 940                 return 0;
 941         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 942                 subs->ops.retire = retire_capture_urb;
 943                 return 0;
 944         }
 945
 946         return -EINVAL;
 947 }
 948
 949 int snd_usb_substream_prepare(struct snd_usb_substream *subs,
 950                               struct snd_pcm_runtime *runtime)
 951 {
 952         /* clear urbs (to be sure) */
 953         deactivate_urbs(subs, 0, 1);
 954         wait_clear_urbs(subs);
 955
 956         /* for playback, submit the URBs now; otherwise, the first hwptr_done
 957          * updates for all URBs would happen at the same time when starting */
 958         if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
 959                 subs->ops.prepare = prepare_nodata_playback_urb;
 960                 return start_urbs(subs, runtime);
 961         }
 962
 963         return 0;
 964 }
 965