sound/core/pcm_lib.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *                   Abramo Bagnara <abramo@alsa-project.org>
   5  *
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  *
  21  */
  22
  23 #include <linux/slab.h>
  24 #include <linux/sched/signal.h>
  25 #include <linux/time.h>
  26 #include <linux/math64.h>
  27 #include <linux/export.h>
  28 #include <sound/core.h>
  29 #include <sound/control.h>
  30 #include <sound/tlv.h>
  31 #include <sound/info.h>
  32 #include <sound/pcm.h>
  33 #include <sound/pcm_params.h>
  34 #include <sound/timer.h>
  35
  36 #include "pcm_local.h"
  37
  38 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  39 #define CREATE_TRACE_POINTS
  40 #include "pcm_trace.h"
  41 #else
  42 #define trace_hwptr(substream, pos, in_interrupt)
  43 #define trace_xrun(substream)
  44 #define trace_hw_ptr_error(substream, reason)
  45 #define trace_applptr(substream, prev, curr)
  46 #endif
  47
  48 static int fill_silence_frames(struct snd_pcm_substream *substream,
  49                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
  50
  51 /*
  52  * fill ring buffer with silence
  53  * runtime->silence_start: starting pointer to silence area
  54  * runtime->silence_filled: size filled with silence
  55  * runtime->silence_threshold: threshold from application
  56  * runtime->silence_size: maximal size from application
  57  *
  58  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
  59  */
  60 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
  61 {
  62         struct snd_pcm_runtime *runtime = substream->runtime;
  63         snd_pcm_uframes_t frames, ofs, transfer;
  64         int err;
  65
  66         if (runtime->silence_size < runtime->boundary) {
  67                 snd_pcm_sframes_t noise_dist, n;
  68                 snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr);
  69                 if (runtime->silence_start != appl_ptr) {
  70                         n = appl_ptr - runtime->silence_start;
  71                         if (n < 0)
  72                                 n += runtime->boundary;
  73                         if ((snd_pcm_uframes_t)n < runtime->silence_filled)
  74                                 runtime->silence_filled -= n;
  75                         else
  76                                 runtime->silence_filled = 0;
  77                         runtime->silence_start = appl_ptr;
  78                 }
  79                 if (runtime->silence_filled >= runtime->buffer_size)
  80                         return;
  81                 noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
  82                 if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
  83                         return;
  84                 frames = runtime->silence_threshold - noise_dist;
  85                 if (frames > runtime->silence_size)
  86                         frames = runtime->silence_size;
  87         } else {
  88                 if (new_hw_ptr == ULONG_MAX) {  /* initialization */
  89                         snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
  90                         if (avail > runtime->buffer_size)
  91                                 avail = runtime->buffer_size;
  92                         runtime->silence_filled = avail > 0 ? avail : 0;
  93                         runtime->silence_start = (runtime->status->hw_ptr +
  94                                                   runtime->silence_filled) %
  95                                                  runtime->boundary;
  96                 } else {
  97                         ofs = runtime->status->hw_ptr;
  98                         frames = new_hw_ptr - ofs;
  99                         if ((snd_pcm_sframes_t)frames < 0)
 100                                 frames += runtime->boundary;
 101                         runtime->silence_filled -= frames;
 102                         if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
 103                                 runtime->silence_filled = 0;
 104                                 runtime->silence_start = new_hw_ptr;
 105                         } else {
 106                                 runtime->silence_start = ofs;
 107                         }
 108                 }
 109                 frames = runtime->buffer_size - runtime->silence_filled;
 110         }
 111         if (snd_BUG_ON(frames > runtime->buffer_size))
 112                 return;
 113         if (frames == 0)
 114                 return;
 115         ofs = runtime->silence_start % runtime->buffer_size;
 116         while (frames > 0) {
 117                 transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
 118                 err = fill_silence_frames(substream, ofs, transfer);
 119                 snd_BUG_ON(err < 0);
 120                 runtime->silence_filled += transfer;
 121                 frames -= transfer;
 122                 ofs = 0;
 123         }
 124 }
 125
 126 #ifdef CONFIG_SND_DEBUG
 127 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
 128                            char *name, size_t len)
 129 {
 130         snprintf(name, len, "pcmC%dD%d%c:%d",
 131                  substream->pcm->card->number,
 132                  substream->pcm->device,
 133                  substream->stream ? 'c' : 'p',
 134                  substream->number);
 135 }
 136 EXPORT_SYMBOL(snd_pcm_debug_name);
 137 #endif
 138
 139 #define XRUN_DEBUG_BASIC        (1<<0)
 140 #define XRUN_DEBUG_STACK        (1<<1)  /* dump also stack */
 141 #define XRUN_DEBUG_JIFFIESCHECK (1<<2)  /* do jiffies check */
 142
 143 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 144
 145 #define xrun_debug(substream, mask) \
 146                         ((substream)->pstr->xrun_debug & (mask))
 147 #else
 148 #define xrun_debug(substream, mask)     0
 149 #endif
 150
 151 #define dump_stack_on_xrun(substream) do {                      \
 152                 if (xrun_debug(substream, XRUN_DEBUG_STACK))    \
 153                         dump_stack();                           \
 154         } while (0)
 155
 156 /* call with stream lock held */
 157 void __snd_pcm_xrun(struct snd_pcm_substream *substream)
 158 {
 159         struct snd_pcm_runtime *runtime = substream->runtime;
 160
 161         trace_xrun(substream);
 162         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
 163                 snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
 164         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 165         if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
 166                 char name[16];
 167                 snd_pcm_debug_name(substream, name, sizeof(name));
 168                 pcm_warn(substream->pcm, "XRUN: %s\n", name);
 169                 dump_stack_on_xrun(substream);
 170         }
 171 }
 172
 173 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 174 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)     \
 175         do {                                                            \
 176                 trace_hw_ptr_error(substream, reason);  \
 177                 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {          \
 178                         pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
 179                                            (in_interrupt) ? 'Q' : 'P', ##args); \
 180                         dump_stack_on_xrun(substream);                  \
 181                 }                                                       \
 182         } while (0)
 183
 184 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
 185
 186 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
 187
 188 #endif
 189
 190 int snd_pcm_update_state(struct snd_pcm_substream *substream,
 191                          struct snd_pcm_runtime *runtime)
 192 {
 193         snd_pcm_uframes_t avail;
 194
 195         avail = snd_pcm_avail(substream);
 196         if (avail > runtime->avail_max)
 197                 runtime->avail_max = avail;
 198         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
 199                 if (avail >= runtime->buffer_size) {
 200                         snd_pcm_drain_done(substream);
 201                         return -EPIPE;
 202                 }
 203         } else {
 204                 if (avail >= runtime->stop_threshold) {
 205                         __snd_pcm_xrun(substream);
 206                         return -EPIPE;
 207                 }
 208         }
 209         if (runtime->twake) {
 210                 if (avail >= runtime->twake)
 211                         wake_up(&runtime->tsleep);
 212         } else if (avail >= runtime->control->avail_min)
 213                 wake_up(&runtime->sleep);
 214         return 0;
 215 }
 216
 217 static void update_audio_tstamp(struct snd_pcm_substream *substream,
 218                                 struct timespec *curr_tstamp,
 219                                 struct timespec *audio_tstamp)
 220 {
 221         struct snd_pcm_runtime *runtime = substream->runtime;
 222         u64 audio_frames, audio_nsecs;
 223         struct timespec driver_tstamp;
 224
 225         if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
 226                 return;
 227
 228         if (!(substream->ops->get_time_info) ||
 229                 (runtime->audio_tstamp_report.actual_type ==
 230                         SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 231
 232                 /*
 233                  * provide audio timestamp derived from pointer position
 234                  * add delay only if requested
 235                  */
 236
 237                 audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
 238
 239                 if (runtime->audio_tstamp_config.report_delay) {
 240                         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 241                                 audio_frames -=  runtime->delay;
 242                         else
 243                                 audio_frames +=  runtime->delay;
 244                 }
 245                 audio_nsecs = div_u64(audio_frames * 1000000000LL,
 246                                 runtime->rate);
 247                 *audio_tstamp = ns_to_timespec(audio_nsecs);
 248         }
 249         if (!timespec_equal(&runtime->status->audio_tstamp, audio_tstamp)) {
 250                 runtime->status->audio_tstamp = *audio_tstamp;
 251                 runtime->status->tstamp = *curr_tstamp;
 252         }
 253
 254         /*
 255          * re-take a driver timestamp to let apps detect if the reference tstamp
 256          * read by low-level hardware was provided with a delay
 257          */
 258         snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
 259         runtime->driver_tstamp = driver_tstamp;
 260 }
 261
 262 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 263                                   unsigned int in_interrupt)
 264 {
 265         struct snd_pcm_runtime *runtime = substream->runtime;
 266         snd_pcm_uframes_t pos;
 267         snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
 268         snd_pcm_sframes_t hdelta, delta;
 269         unsigned long jdelta;
 270         unsigned long curr_jiffies;
 271         struct timespec curr_tstamp;
 272         struct timespec audio_tstamp;
 273         int crossed_boundary = 0;
 274
 275         old_hw_ptr = runtime->status->hw_ptr;
 276
 277         /*
 278          * group pointer, time and jiffies reads to allow for more
 279          * accurate correlations/corrections.
 280          * The values are stored at the end of this routine after
 281          * corrections for hw_ptr position
 282          */
 283         pos = substream->ops->pointer(substream);
 284         curr_jiffies = jiffies;
 285         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
 286                 if ((substream->ops->get_time_info) &&
 287                         (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 288                         substream->ops->get_time_info(substream, &curr_tstamp,
 289                                                 &audio_tstamp,
 290                                                 &runtime->audio_tstamp_config,
 291                                                 &runtime->audio_tstamp_report);
 292
 293                         /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
 294                         if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
 295                                 snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 296                 } else
 297                         snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 298         }
 299
 300         if (pos == SNDRV_PCM_POS_XRUN) {
 301                 __snd_pcm_xrun(substream);
 302                 return -EPIPE;
 303         }
 304         if (pos >= runtime->buffer_size) {
 305                 if (printk_ratelimit()) {
 306                         char name[16];
 307                         snd_pcm_debug_name(substream, name, sizeof(name));
 308                         pcm_err(substream->pcm,
 309                                 "invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
 310                                 name, pos, runtime->buffer_size,
 311                                 runtime->period_size);
 312                 }
 313                 pos = 0;
 314         }
 315         pos -= pos % runtime->min_align;
 316         trace_hwptr(substream, pos, in_interrupt);
 317         hw_base = runtime->hw_ptr_base;
 318         new_hw_ptr = hw_base + pos;
 319         if (in_interrupt) {
 320                 /* we know that one period was processed */
 321                 /* delta = "expected next hw_ptr" for in_interrupt != 0 */
 322                 delta = runtime->hw_ptr_interrupt + runtime->period_size;
 323                 if (delta > new_hw_ptr) {
 324                         /* check for double acknowledged interrupts */
 325                         hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 326                         if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
 327                                 hw_base += runtime->buffer_size;
 328                                 if (hw_base >= runtime->boundary) {
 329                                         hw_base = 0;
 330                                         crossed_boundary++;
 331                                 }
 332                                 new_hw_ptr = hw_base + pos;
 333                                 goto __delta;
 334                         }
 335                 }
 336         }
 337         /* new_hw_ptr might be lower than old_hw_ptr in case when */
 338         /* pointer crosses the end of the ring buffer */
 339         if (new_hw_ptr < old_hw_ptr) {
 340                 hw_base += runtime->buffer_size;
 341                 if (hw_base >= runtime->boundary) {
 342                         hw_base = 0;
 343                         crossed_boundary++;
 344                 }
 345                 new_hw_ptr = hw_base + pos;
 346         }
 347       __delta:
 348         delta = new_hw_ptr - old_hw_ptr;
 349         if (delta < 0)
 350                 delta += runtime->boundary;
 351
 352         if (runtime->no_period_wakeup) {
 353                 snd_pcm_sframes_t xrun_threshold;
 354                 /*
 355                  * Without regular period interrupts, we have to check
 356                  * the elapsed time to detect xruns.
 357                  */
 358                 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 359                 if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
 360                         goto no_delta_check;
 361                 hdelta = jdelta - delta * HZ / runtime->rate;
 362                 xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
 363                 while (hdelta > xrun_threshold) {
 364                         delta += runtime->buffer_size;
 365                         hw_base += runtime->buffer_size;
 366                         if (hw_base >= runtime->boundary) {
 367                                 hw_base = 0;
 368                                 crossed_boundary++;
 369                         }
 370                         new_hw_ptr = hw_base + pos;
 371                         hdelta -= runtime->hw_ptr_buffer_jiffies;
 372                 }
 373                 goto no_delta_check;
 374         }
 375
 376         /* something must be really wrong */
 377         if (delta >= runtime->buffer_size + runtime->period_size) {
 378                 hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
 379                              "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 380                              substream->stream, (long)pos,
 381                              (long)new_hw_ptr, (long)old_hw_ptr);
 382                 return 0;
 383         }
 384
 385         /* Do jiffies check only in xrun_debug mode */
 386         if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
 387                 goto no_jiffies_check;
 388
 389         /* Skip the jiffies check for hardwares with BATCH flag.
 390          * Such hardware usually just increases the position at each IRQ,
 391          * thus it can't give any strange position.
 392          */
 393         if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
 394                 goto no_jiffies_check;
 395         hdelta = delta;
 396         if (hdelta < runtime->delay)
 397                 goto no_jiffies_check;
 398         hdelta -= runtime->delay;
 399         jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 400         if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
 401                 delta = jdelta /
 402                         (((runtime->period_size * HZ) / runtime->rate)
 403                                                                 + HZ/100);
 404                 /* move new_hw_ptr according jiffies not pos variable */
 405                 new_hw_ptr = old_hw_ptr;
 406                 hw_base = delta;
 407                 /* use loop to avoid checks for delta overflows */
 408                 /* the delta value is small or zero in most cases */
 409                 while (delta > 0) {
 410                         new_hw_ptr += runtime->period_size;
 411                         if (new_hw_ptr >= runtime->boundary) {
 412                                 new_hw_ptr -= runtime->boundary;
 413                                 crossed_boundary--;
 414                         }
 415                         delta--;
 416                 }
 417                 /* align hw_base to buffer_size */
 418                 hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
 419                              "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
 420                              (long)pos, (long)hdelta,
 421                              (long)runtime->period_size, jdelta,
 422                              ((hdelta * HZ) / runtime->rate), hw_base,
 423                              (unsigned long)old_hw_ptr,
 424                              (unsigned long)new_hw_ptr);
 425                 /* reset values to proper state */
 426                 delta = 0;
 427                 hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
 428         }
 429  no_jiffies_check:
 430         if (delta > runtime->period_size + runtime->period_size / 2) {
 431                 hw_ptr_error(substream, in_interrupt,
 432                              "Lost interrupts?",
 433                              "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 434                              substream->stream, (long)delta,
 435                              (long)new_hw_ptr,
 436                              (long)old_hw_ptr);
 437         }
 438
 439  no_delta_check:
 440         if (runtime->status->hw_ptr == new_hw_ptr) {
 441                 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 442                 return 0;
 443         }
 444
 445         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 446             runtime->silence_size > 0)
 447                 snd_pcm_playback_silence(substream, new_hw_ptr);
 448
 449         if (in_interrupt) {
 450                 delta = new_hw_ptr - runtime->hw_ptr_interrupt;
 451                 if (delta < 0)
 452                         delta += runtime->boundary;
 453                 delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
 454                 runtime->hw_ptr_interrupt += delta;
 455                 if (runtime->hw_ptr_interrupt >= runtime->boundary)
 456                         runtime->hw_ptr_interrupt -= runtime->boundary;
 457         }
 458         runtime->hw_ptr_base = hw_base;
 459         runtime->status->hw_ptr = new_hw_ptr;
 460         runtime->hw_ptr_jiffies = curr_jiffies;
 461         if (crossed_boundary) {
 462                 snd_BUG_ON(crossed_boundary != 1);
 463                 runtime->hw_ptr_wrap += runtime->boundary;
 464         }
 465
 466         update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 467
 468         return snd_pcm_update_state(substream, runtime);
 469 }
 470
 471 /* CAUTION: call it with irq disabled */
 472 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 473 {
 474         return snd_pcm_update_hw_ptr0(substream, 0);
 475 }
 476
 477 /**
 478  * snd_pcm_set_ops - set the PCM operators
 479  * @pcm: the pcm instance
 480  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
 481  * @ops: the operator table
 482  *
 483  * Sets the given PCM operators to the pcm instance.
 484  */
 485 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
 486                      const struct snd_pcm_ops *ops)
 487 {
 488         struct snd_pcm_str *stream = &pcm->streams[direction];
 489         struct snd_pcm_substream *substream;
 490
 491         for (substream = stream->substream; substream != NULL; substream = substream->next)
 492                 substream->ops = ops;
 493 }
 494 EXPORT_SYMBOL(snd_pcm_set_ops);
 495
 496 /**
 497  * snd_pcm_sync - set the PCM sync id
 498  * @substream: the pcm substream
 499  *
 500  * Sets the PCM sync identifier for the card.
 501  */
 502 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
 503 {
 504         struct snd_pcm_runtime *runtime = substream->runtime;
 505
 506         runtime->sync.id32[0] = substream->pcm->card->number;
 507         runtime->sync.id32[1] = -1;
 508         runtime->sync.id32[2] = -1;
 509         runtime->sync.id32[3] = -1;
 510 }
 511 EXPORT_SYMBOL(snd_pcm_set_sync);
 512
 513 /*
 514  *  Standard ioctl routine
 515  */
 516
 517 static inline unsigned int div32(unsigned int a, unsigned int b,
 518                                  unsigned int *r)
 519 {
 520         if (b == 0) {
 521                 *r = 0;
 522                 return UINT_MAX;
 523         }
 524         *r = a % b;
 525         return a / b;
 526 }
 527
 528 static inline unsigned int div_down(unsigned int a, unsigned int b)
 529 {
 530         if (b == 0)
 531                 return UINT_MAX;
 532         return a / b;
 533 }
 534
 535 static inline unsigned int div_up(unsigned int a, unsigned int b)
 536 {
 537         unsigned int r;
 538         unsigned int q;
 539         if (b == 0)
 540                 return UINT_MAX;
 541         q = div32(a, b, &r);
 542         if (r)
 543                 ++q;
 544         return q;
 545 }
 546
 547 static inline unsigned int mul(unsigned int a, unsigned int b)
 548 {
 549         if (a == 0)
 550                 return 0;
 551         if (div_down(UINT_MAX, a) < b)
 552                 return UINT_MAX;
 553         return a * b;
 554 }
 555
 556 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
 557                                     unsigned int c, unsigned int *r)
 558 {
 559         u_int64_t n = (u_int64_t) a * b;
 560         if (c == 0) {
 561                 *r = 0;
 562                 return UINT_MAX;
 563         }
 564         n = div_u64_rem(n, c, r);
 565         if (n >= UINT_MAX) {
 566                 *r = 0;
 567                 return UINT_MAX;
 568         }
 569         return n;
 570 }
 571
 572 /**
 573  * snd_interval_refine - refine the interval value of configurator
 574  * @i: the interval value to refine
 575  * @v: the interval value to refer to
 576  *
 577  * Refines the interval value with the reference value.
 578  * The interval is changed to the range satisfying both intervals.
 579  * The interval status (min, max, integer, etc.) are evaluated.
 580  *
 581  * Return: Positive if the value is changed, zero if it's not changed, or a
 582  * negative error code.
 583  */
 584 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
 585 {
 586         int changed = 0;
 587         if (snd_BUG_ON(snd_interval_empty(i)))
 588                 return -EINVAL;
 589         if (i->min < v->min) {
 590                 i->min = v->min;
 591                 i->openmin = v->openmin;
 592                 changed = 1;
 593         } else if (i->min == v->min && !i->openmin && v->openmin) {
 594                 i->openmin = 1;
 595                 changed = 1;
 596         }
 597         if (i->max > v->max) {
 598                 i->max = v->max;
 599                 i->openmax = v->openmax;
 600                 changed = 1;
 601         } else if (i->max == v->max && !i->openmax && v->openmax) {
 602                 i->openmax = 1;
 603                 changed = 1;
 604         }
 605         if (!i->integer && v->integer) {
 606                 i->integer = 1;
 607                 changed = 1;
 608         }
 609         if (i->integer) {
 610                 if (i->openmin) {
 611                         i->min++;
 612                         i->openmin = 0;
 613                 }
 614                 if (i->openmax) {
 615                         i->max--;
 616                         i->openmax = 0;
 617                 }
 618         } else if (!i->openmin && !i->openmax && i->min == i->max)
 619                 i->integer = 1;
 620         if (snd_interval_checkempty(i)) {
 621                 snd_interval_none(i);
 622                 return -EINVAL;
 623         }
 624         return changed;
 625 }
 626 EXPORT_SYMBOL(snd_interval_refine);
 627
 628 static int snd_interval_refine_first(struct snd_interval *i)
 629 {
 630         const unsigned int last_max = i->max;
 631
 632         if (snd_BUG_ON(snd_interval_empty(i)))
 633                 return -EINVAL;
 634         if (snd_interval_single(i))
 635                 return 0;
 636         i->max = i->min;
 637         if (i->openmin)
 638                 i->max++;
 639         /* only exclude max value if also excluded before refine */
 640         i->openmax = (i->openmax && i->max >= last_max);
 641         return 1;
 642 }
 643
 644 static int snd_interval_refine_last(struct snd_interval *i)
 645 {
 646         const unsigned int last_min = i->min;
 647
 648         if (snd_BUG_ON(snd_interval_empty(i)))
 649                 return -EINVAL;
 650         if (snd_interval_single(i))
 651                 return 0;
 652         i->min = i->max;
 653         if (i->openmax)
 654                 i->min--;
 655         /* only exclude min value if also excluded before refine */
 656         i->openmin = (i->openmin && i->min <= last_min);
 657         return 1;
 658 }
 659
 660 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 661 {
 662         if (a->empty || b->empty) {
 663                 snd_interval_none(c);
 664                 return;
 665         }
 666         c->empty = 0;
 667         c->min = mul(a->min, b->min);
 668         c->openmin = (a->openmin || b->openmin);
 669         c->max = mul(a->max,  b->max);
 670         c->openmax = (a->openmax || b->openmax);
 671         c->integer = (a->integer && b->integer);
 672 }
 673
 674 /**
 675  * snd_interval_div - refine the interval value with division
 676  * @a: dividend
 677  * @b: divisor
 678  * @c: quotient
 679  *
 680  * c = a / b
 681  *
 682  * Returns non-zero if the value is changed, zero if not changed.
 683  */
 684 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 685 {
 686         unsigned int r;
 687         if (a->empty || b->empty) {
 688                 snd_interval_none(c);
 689                 return;
 690         }
 691         c->empty = 0;
 692         c->min = div32(a->min, b->max, &r);
 693         c->openmin = (r || a->openmin || b->openmax);
 694         if (b->min > 0) {
 695                 c->max = div32(a->max, b->min, &r);
 696                 if (r) {
 697                         c->max++;
 698                         c->openmax = 1;
 699                 } else
 700                         c->openmax = (a->openmax || b->openmin);
 701         } else {
 702                 c->max = UINT_MAX;
 703                 c->openmax = 0;
 704         }
 705         c->integer = 0;
 706 }
 707
 708 /**
 709  * snd_interval_muldivk - refine the interval value
 710  * @a: dividend 1
 711  * @b: dividend 2
 712  * @k: divisor (as integer)
 713  * @c: result
 714   *
 715  * c = a * b / k
 716  *
 717  * Returns non-zero if the value is changed, zero if not changed.
 718  */
 719 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
 720                       unsigned int k, struct snd_interval *c)
 721 {
 722         unsigned int r;
 723         if (a->empty || b->empty) {
 724                 snd_interval_none(c);
 725                 return;
 726         }
 727         c->empty = 0;
 728         c->min = muldiv32(a->min, b->min, k, &r);
 729         c->openmin = (r || a->openmin || b->openmin);
 730         c->max = muldiv32(a->max, b->max, k, &r);
 731         if (r) {
 732                 c->max++;
 733                 c->openmax = 1;
 734         } else
 735                 c->openmax = (a->openmax || b->openmax);
 736         c->integer = 0;
 737 }
 738
 739 /**
 740  * snd_interval_mulkdiv - refine the interval value
 741  * @a: dividend 1
 742  * @k: dividend 2 (as integer)
 743  * @b: divisor
 744  * @c: result
 745  *
 746  * c = a * k / b
 747  *
 748  * Returns non-zero if the value is changed, zero if not changed.
 749  */
 750 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
 751                       const struct snd_interval *b, struct snd_interval *c)
 752 {
 753         unsigned int r;
 754         if (a->empty || b->empty) {
 755                 snd_interval_none(c);
 756                 return;
 757         }
 758         c->empty = 0;
 759         c->min = muldiv32(a->min, k, b->max, &r);
 760         c->openmin = (r || a->openmin || b->openmax);
 761         if (b->min > 0) {
 762                 c->max = muldiv32(a->max, k, b->min, &r);
 763                 if (r) {
 764                         c->max++;
 765                         c->openmax = 1;
 766                 } else
 767                         c->openmax = (a->openmax || b->openmin);
 768         } else {
 769                 c->max = UINT_MAX;
 770                 c->openmax = 0;
 771         }
 772         c->integer = 0;
 773 }
 774
 775 /* ---- */
 776
 777
 778 /**
 779  * snd_interval_ratnum - refine the interval value
 780  * @i: interval to refine
 781  * @rats_count: number of ratnum_t
 782  * @rats: ratnum_t array
 783  * @nump: pointer to store the resultant numerator
 784  * @denp: pointer to store the resultant denominator
 785  *
 786  * Return: Positive if the value is changed, zero if it's not changed, or a
 787  * negative error code.
 788  */
 789 int snd_interval_ratnum(struct snd_interval *i,
 790                         unsigned int rats_count, const struct snd_ratnum *rats,
 791                         unsigned int *nump, unsigned int *denp)
 792 {
 793         unsigned int best_num, best_den;
 794         int best_diff;
 795         unsigned int k;
 796         struct snd_interval t;
 797         int err;
 798         unsigned int result_num, result_den;
 799         int result_diff;
 800
 801         best_num = best_den = best_diff = 0;
 802         for (k = 0; k < rats_count; ++k) {
 803                 unsigned int num = rats[k].num;
 804                 unsigned int den;
 805                 unsigned int q = i->min;
 806                 int diff;
 807                 if (q == 0)
 808                         q = 1;
 809                 den = div_up(num, q);
 810                 if (den < rats[k].den_min)
 811                         continue;
 812                 if (den > rats[k].den_max)
 813                         den = rats[k].den_max;
 814                 else {
 815                         unsigned int r;
 816                         r = (den - rats[k].den_min) % rats[k].den_step;
 817                         if (r != 0)
 818                                 den -= r;
 819                 }
 820                 diff = num - q * den;
 821                 if (diff < 0)
 822                         diff = -diff;
 823                 if (best_num == 0 ||
 824                     diff * best_den < best_diff * den) {
 825                         best_diff = diff;
 826                         best_den = den;
 827                         best_num = num;
 828                 }
 829         }
 830         if (best_den == 0) {
 831                 i->empty = 1;
 832                 return -EINVAL;
 833         }
 834         t.min = div_down(best_num, best_den);
 835         t.openmin = !!(best_num % best_den);
 836
 837         result_num = best_num;
 838         result_diff = best_diff;
 839         result_den = best_den;
 840         best_num = best_den = best_diff = 0;
 841         for (k = 0; k < rats_count; ++k) {
 842                 unsigned int num = rats[k].num;
 843                 unsigned int den;
 844                 unsigned int q = i->max;
 845                 int diff;
 846                 if (q == 0) {
 847                         i->empty = 1;
 848                         return -EINVAL;
 849                 }
 850                 den = div_down(num, q);
 851                 if (den > rats[k].den_max)
 852                         continue;
 853                 if (den < rats[k].den_min)
 854                         den = rats[k].den_min;
 855                 else {
 856                         unsigned int r;
 857                         r = (den - rats[k].den_min) % rats[k].den_step;
 858                         if (r != 0)
 859                                 den += rats[k].den_step - r;
 860                 }
 861                 diff = q * den - num;
 862                 if (diff < 0)
 863                         diff = -diff;
 864                 if (best_num == 0 ||
 865                     diff * best_den < best_diff * den) {
 866                         best_diff = diff;
 867                         best_den = den;
 868                         best_num = num;
 869                 }
 870         }
 871         if (best_den == 0) {
 872                 i->empty = 1;
 873                 return -EINVAL;
 874         }
 875         t.max = div_up(best_num, best_den);
 876         t.openmax = !!(best_num % best_den);
 877         t.integer = 0;
 878         err = snd_interval_refine(i, &t);
 879         if (err < 0)
 880                 return err;
 881
 882         if (snd_interval_single(i)) {
 883                 if (best_diff * result_den < result_diff * best_den) {
 884                         result_num = best_num;
 885                         result_den = best_den;
 886                 }
 887                 if (nump)
 888                         *nump = result_num;
 889                 if (denp)
 890                         *denp = result_den;
 891         }
 892         return err;
 893 }
 894 EXPORT_SYMBOL(snd_interval_ratnum);
 895
 896 /**
 897  * snd_interval_ratden - refine the interval value
 898  * @i: interval to refine
 899  * @rats_count: number of struct ratden
 900  * @rats: struct ratden array
 901  * @nump: pointer to store the resultant numerator
 902  * @denp: pointer to store the resultant denominator
 903  *
 904  * Return: Positive if the value is changed, zero if it's not changed, or a
 905  * negative error code.
 906  */
 907 static int snd_interval_ratden(struct snd_interval *i,
 908                                unsigned int rats_count,
 909                                const struct snd_ratden *rats,
 910                                unsigned int *nump, unsigned int *denp)
 911 {
 912         unsigned int best_num, best_diff, best_den;
 913         unsigned int k;
 914         struct snd_interval t;
 915         int err;
 916
 917         best_num = best_den = best_diff = 0;
 918         for (k = 0; k < rats_count; ++k) {
 919                 unsigned int num;
 920                 unsigned int den = rats[k].den;
 921                 unsigned int q = i->min;
 922                 int diff;
 923                 num = mul(q, den);
 924                 if (num > rats[k].num_max)
 925                         continue;
 926                 if (num < rats[k].num_min)
 927                         num = rats[k].num_max;
 928                 else {
 929                         unsigned int r;
 930                         r = (num - rats[k].num_min) % rats[k].num_step;
 931                         if (r != 0)
 932                                 num += rats[k].num_step - r;
 933                 }
 934                 diff = num - q * den;
 935                 if (best_num == 0 ||
 936                     diff * best_den < best_diff * den) {
 937                         best_diff = diff;
 938                         best_den = den;
 939                         best_num = num;
 940                 }
 941         }
 942         if (best_den == 0) {
 943                 i->empty = 1;
 944                 return -EINVAL;
 945         }
 946         t.min = div_down(best_num, best_den);
 947         t.openmin = !!(best_num % best_den);
 948
 949         best_num = best_den = best_diff = 0;
 950         for (k = 0; k < rats_count; ++k) {
 951                 unsigned int num;
 952                 unsigned int den = rats[k].den;
 953                 unsigned int q = i->max;
 954                 int diff;
 955                 num = mul(q, den);
 956                 if (num < rats[k].num_min)
 957                         continue;
 958                 if (num > rats[k].num_max)
 959                         num = rats[k].num_max;
 960                 else {
 961                         unsigned int r;
 962                         r = (num - rats[k].num_min) % rats[k].num_step;
 963                         if (r != 0)
 964                                 num -= r;
 965                 }
 966                 diff = q * den - num;
 967                 if (best_num == 0 ||
 968                     diff * best_den < best_diff * den) {
 969                         best_diff = diff;
 970                         best_den = den;
 971                         best_num = num;
 972                 }
 973         }
 974         if (best_den == 0) {
 975                 i->empty = 1;
 976                 return -EINVAL;
 977         }
 978         t.max = div_up(best_num, best_den);
 979         t.openmax = !!(best_num % best_den);
 980         t.integer = 0;
 981         err = snd_interval_refine(i, &t);
 982         if (err < 0)
 983                 return err;
 984
 985         if (snd_interval_single(i)) {
 986                 if (nump)
 987                         *nump = best_num;
 988                 if (denp)
 989                         *denp = best_den;
 990         }
 991         return err;
 992 }
 993
 994 /**
 995  * snd_interval_list - refine the interval value from the list
 996  * @i: the interval value to refine
 997  * @count: the number of elements in the list
 998  * @list: the value list
 999  * @mask: the bit-mask to evaluate
1000  *
1001  * Refines the interval value from the list.
1002  * When mask is non-zero, only the elements corresponding to bit 1 are
1003  * evaluated.
1004  *
1005  * Return: Positive if the value is changed, zero if it's not changed, or a
1006  * negative error code.
1007  */
1008 int snd_interval_list(struct snd_interval *i, unsigned int count,
1009                       const unsigned int *list, unsigned int mask)
1010 {
1011         unsigned int k;
1012         struct snd_interval list_range;
1013
1014         if (!count) {
1015                 i->empty = 1;
1016                 return -EINVAL;
1017         }
1018         snd_interval_any(&list_range);
1019         list_range.min = UINT_MAX;
1020         list_range.max = 0;
1021         for (k = 0; k < count; k++) {
1022                 if (mask && !(mask & (1 << k)))
1023                         continue;
1024                 if (!snd_interval_test(i, list[k]))
1025                         continue;
1026                 list_range.min = min(list_range.min, list[k]);
1027                 list_range.max = max(list_range.max, list[k]);
1028         }
1029         return snd_interval_refine(i, &list_range);
1030 }
1031 EXPORT_SYMBOL(snd_interval_list);
1032
1033 /**
1034  * snd_interval_ranges - refine the interval value from the list of ranges
1035  * @i: the interval value to refine
1036  * @count: the number of elements in the list of ranges
1037  * @ranges: the ranges list
1038  * @mask: the bit-mask to evaluate
1039  *
1040  * Refines the interval value from the list of ranges.
1041  * When mask is non-zero, only the elements corresponding to bit 1 are
1042  * evaluated.
1043  *
1044  * Return: Positive if the value is changed, zero if it's not changed, or a
1045  * negative error code.
1046  */
1047 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1048                         const struct snd_interval *ranges, unsigned int mask)
1049 {
1050         unsigned int k;
1051         struct snd_interval range_union;
1052         struct snd_interval range;
1053
1054         if (!count) {
1055                 snd_interval_none(i);
1056                 return -EINVAL;
1057         }
1058         snd_interval_any(&range_union);
1059         range_union.min = UINT_MAX;
1060         range_union.max = 0;
1061         for (k = 0; k < count; k++) {
1062                 if (mask && !(mask & (1 << k)))
1063                         continue;
1064                 snd_interval_copy(&range, &ranges[k]);
1065                 if (snd_interval_refine(&range, i) < 0)
1066                         continue;
1067                 if (snd_interval_empty(&range))
1068                         continue;
1069
1070                 if (range.min < range_union.min) {
1071                         range_union.min = range.min;
1072                         range_union.openmin = 1;
1073                 }
1074                 if (range.min == range_union.min && !range.openmin)
1075                         range_union.openmin = 0;
1076                 if (range.max > range_union.max) {
1077                         range_union.max = range.max;
1078                         range_union.openmax = 1;
1079                 }
1080                 if (range.max == range_union.max && !range.openmax)
1081                         range_union.openmax = 0;
1082         }
1083         return snd_interval_refine(i, &range_union);
1084 }
1085 EXPORT_SYMBOL(snd_interval_ranges);
1086
1087 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1088 {
1089         unsigned int n;
1090         int changed = 0;
1091         n = i->min % step;
1092         if (n != 0 || i->openmin) {
1093                 i->min += step - n;
1094                 i->openmin = 0;
1095                 changed = 1;
1096         }
1097         n = i->max % step;
1098         if (n != 0 || i->openmax) {
1099                 i->max -= n;
1100                 i->openmax = 0;
1101                 changed = 1;
1102         }
1103         if (snd_interval_checkempty(i)) {
1104                 i->empty = 1;
1105                 return -EINVAL;
1106         }
1107         return changed;
1108 }
1109
1110 /* Info constraints helpers */
1111
1112 /**
1113  * snd_pcm_hw_rule_add - add the hw-constraint rule
1114  * @runtime: the pcm runtime instance
1115  * @cond: condition bits
1116  * @var: the variable to evaluate
1117  * @func: the evaluation function
1118  * @private: the private data pointer passed to function
1119  * @dep: the dependent variables
1120  *
1121  * Return: Zero if successful, or a negative error code on failure.
1122  */
1123 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1124                         int var,
1125                         snd_pcm_hw_rule_func_t func, void *private,
1126                         int dep, ...)
1127 {
1128         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1129         struct snd_pcm_hw_rule *c;
1130         unsigned int k;
1131         va_list args;
1132         va_start(args, dep);
1133         if (constrs->rules_num >= constrs->rules_all) {
1134                 struct snd_pcm_hw_rule *new;
1135                 unsigned int new_rules = constrs->rules_all + 16;
1136                 new = krealloc(constrs->rules, new_rules * sizeof(*c),
1137                                GFP_KERNEL);
1138                 if (!new) {
1139                         va_end(args);
1140                         return -ENOMEM;
1141                 }
1142                 constrs->rules = new;
1143                 constrs->rules_all = new_rules;
1144         }
1145         c = &constrs->rules[constrs->rules_num];
1146         c->cond = cond;
1147         c->func = func;
1148         c->var = var;
1149         c->private = private;
1150         k = 0;
1151         while (1) {
1152                 if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1153                         va_end(args);
1154                         return -EINVAL;
1155                 }
1156                 c->deps[k++] = dep;
1157                 if (dep < 0)
1158                         break;
1159                 dep = va_arg(args, int);
1160         }
1161         constrs->rules_num++;
1162         va_end(args);
1163         return 0;
1164 }
1165 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1166
1167 /**
1168  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1169  * @runtime: PCM runtime instance
1170  * @var: hw_params variable to apply the mask
1171  * @mask: the bitmap mask
1172  *
1173  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1174  *
1175  * Return: Zero if successful, or a negative error code on failure.
1176  */
1177 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1178                                u_int32_t mask)
1179 {
1180         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1181         struct snd_mask *maskp = constrs_mask(constrs, var);
1182         *maskp->bits &= mask;
1183         memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1184         if (*maskp->bits == 0)
1185                 return -EINVAL;
1186         return 0;
1187 }
1188
1189 /**
1190  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1191  * @runtime: PCM runtime instance
1192  * @var: hw_params variable to apply the mask
1193  * @mask: the 64bit bitmap mask
1194  *
1195  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1196  *
1197  * Return: Zero if successful, or a negative error code on failure.
1198  */
1199 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1200                                  u_int64_t mask)
1201 {
1202         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1203         struct snd_mask *maskp = constrs_mask(constrs, var);
1204         maskp->bits[0] &= (u_int32_t)mask;
1205         maskp->bits[1] &= (u_int32_t)(mask >> 32);
1206         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1207         if (! maskp->bits[0] && ! maskp->bits[1])
1208                 return -EINVAL;
1209         return 0;
1210 }
1211 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1212
1213 /**
1214  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1215  * @runtime: PCM runtime instance
1216  * @var: hw_params variable to apply the integer constraint
1217  *
1218  * Apply the constraint of integer to an interval parameter.
1219  *
1220  * Return: Positive if the value is changed, zero if it's not changed, or a
1221  * negative error code.
1222  */
1223 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1224 {
1225         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1226         return snd_interval_setinteger(constrs_interval(constrs, var));
1227 }
1228 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1229
1230 /**
1231  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1232  * @runtime: PCM runtime instance
1233  * @var: hw_params variable to apply the range
1234  * @min: the minimal value
1235  * @max: the maximal value
1236  *
1237  * Apply the min/max range constraint to an interval parameter.
1238  *
1239  * Return: Positive if the value is changed, zero if it's not changed, or a
1240  * negative error code.
1241  */
1242 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1243                                  unsigned int min, unsigned int max)
1244 {
1245         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1246         struct snd_interval t;
1247         t.min = min;
1248         t.max = max;
1249         t.openmin = t.openmax = 0;
1250         t.integer = 0;
1251         return snd_interval_refine(constrs_interval(constrs, var), &t);
1252 }
1253 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1254
1255 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1256                                 struct snd_pcm_hw_rule *rule)
1257 {
1258         struct snd_pcm_hw_constraint_list *list = rule->private;
1259         return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1260 }
1261
1262
1263 /**
1264  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1265  * @runtime: PCM runtime instance
1266  * @cond: condition bits
1267  * @var: hw_params variable to apply the list constraint
1268  * @l: list
1269  *
1270  * Apply the list of constraints to an interval parameter.
1271  *
1272  * Return: Zero if successful, or a negative error code on failure.
1273  */
1274 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1275                                unsigned int cond,
1276                                snd_pcm_hw_param_t var,
1277                                const struct snd_pcm_hw_constraint_list *l)
1278 {
1279         return snd_pcm_hw_rule_add(runtime, cond, var,
1280                                    snd_pcm_hw_rule_list, (void *)l,
1281                                    var, -1);
1282 }
1283 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1284
1285 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1286                                   struct snd_pcm_hw_rule *rule)
1287 {
1288         struct snd_pcm_hw_constraint_ranges *r = rule->private;
1289         return snd_interval_ranges(hw_param_interval(params, rule->var),
1290                                    r->count, r->ranges, r->mask);
1291 }
1292
1293
1294 /**
1295  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1296  * @runtime: PCM runtime instance
1297  * @cond: condition bits
1298  * @var: hw_params variable to apply the list of range constraints
1299  * @r: ranges
1300  *
1301  * Apply the list of range constraints to an interval parameter.
1302  *
1303  * Return: Zero if successful, or a negative error code on failure.
1304  */
1305 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1306                                  unsigned int cond,
1307                                  snd_pcm_hw_param_t var,
1308                                  const struct snd_pcm_hw_constraint_ranges *r)
1309 {
1310         return snd_pcm_hw_rule_add(runtime, cond, var,
1311                                    snd_pcm_hw_rule_ranges, (void *)r,
1312                                    var, -1);
1313 }
1314 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1315
1316 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1317                                    struct snd_pcm_hw_rule *rule)
1318 {
1319         const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1320         unsigned int num = 0, den = 0;
1321         int err;
1322         err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1323                                   r->nrats, r->rats, &num, &den);
1324         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1325                 params->rate_num = num;
1326                 params->rate_den = den;
1327         }
1328         return err;
1329 }
1330
1331 /**
1332  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1333  * @runtime: PCM runtime instance
1334  * @cond: condition bits
1335  * @var: hw_params variable to apply the ratnums constraint
1336  * @r: struct snd_ratnums constriants
1337  *
1338  * Return: Zero if successful, or a negative error code on failure.
1339  */
1340 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1341                                   unsigned int cond,
1342                                   snd_pcm_hw_param_t var,
1343                                   const struct snd_pcm_hw_constraint_ratnums *r)
1344 {
1345         return snd_pcm_hw_rule_add(runtime, cond, var,
1346                                    snd_pcm_hw_rule_ratnums, (void *)r,
1347                                    var, -1);
1348 }
1349 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1350
1351 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1352                                    struct snd_pcm_hw_rule *rule)
1353 {
1354         const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1355         unsigned int num = 0, den = 0;
1356         int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1357                                   r->nrats, r->rats, &num, &den);
1358         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1359                 params->rate_num = num;
1360                 params->rate_den = den;
1361         }
1362         return err;
1363 }
1364
1365 /**
1366  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1367  * @runtime: PCM runtime instance
1368  * @cond: condition bits
1369  * @var: hw_params variable to apply the ratdens constraint
1370  * @r: struct snd_ratdens constriants
1371  *
1372  * Return: Zero if successful, or a negative error code on failure.
1373  */
1374 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1375                                   unsigned int cond,
1376                                   snd_pcm_hw_param_t var,
1377                                   const struct snd_pcm_hw_constraint_ratdens *r)
1378 {
1379         return snd_pcm_hw_rule_add(runtime, cond, var,
1380                                    snd_pcm_hw_rule_ratdens, (void *)r,
1381                                    var, -1);
1382 }
1383 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1384
1385 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1386                                   struct snd_pcm_hw_rule *rule)
1387 {
1388         unsigned int l = (unsigned long) rule->private;
1389         int width = l & 0xffff;
1390         unsigned int msbits = l >> 16;
1391         const struct snd_interval *i =
1392                 hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1393
1394         if (!snd_interval_single(i))
1395                 return 0;
1396
1397         if ((snd_interval_value(i) == width) ||
1398             (width == 0 && snd_interval_value(i) > msbits))
1399                 params->msbits = min_not_zero(params->msbits, msbits);
1400
1401         return 0;
1402 }
1403
1404 /**
1405  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1406  * @runtime: PCM runtime instance
1407  * @cond: condition bits
1408  * @width: sample bits width
1409  * @msbits: msbits width
1410  *
1411  * This constraint will set the number of most significant bits (msbits) if a
1412  * sample format with the specified width has been select. If width is set to 0
1413  * the msbits will be set for any sample format with a width larger than the
1414  * specified msbits.
1415  *
1416  * Return: Zero if successful, or a negative error code on failure.
1417  */
1418 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1419                                  unsigned int cond,
1420                                  unsigned int width,
1421                                  unsigned int msbits)
1422 {
1423         unsigned long l = (msbits << 16) | width;
1424         return snd_pcm_hw_rule_add(runtime, cond, -1,
1425                                     snd_pcm_hw_rule_msbits,
1426                                     (void*) l,
1427                                     SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1428 }
1429 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1430
1431 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1432                                 struct snd_pcm_hw_rule *rule)
1433 {
1434         unsigned long step = (unsigned long) rule->private;
1435         return snd_interval_step(hw_param_interval(params, rule->var), step);
1436 }
1437
1438 /**
1439  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1440  * @runtime: PCM runtime instance
1441  * @cond: condition bits
1442  * @var: hw_params variable to apply the step constraint
1443  * @step: step size
1444  *
1445  * Return: Zero if successful, or a negative error code on failure.
1446  */
1447 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1448                                unsigned int cond,
1449                                snd_pcm_hw_param_t var,
1450                                unsigned long step)
1451 {
1452         return snd_pcm_hw_rule_add(runtime, cond, var,
1453                                    snd_pcm_hw_rule_step, (void *) step,
1454                                    var, -1);
1455 }
1456 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1457
1458 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1459 {
1460         static unsigned int pow2_sizes[] = {
1461                 1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1462                 1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1463                 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1464                 1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1465         };
1466         return snd_interval_list(hw_param_interval(params, rule->var),
1467                                  ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1468 }
1469
1470 /**
1471  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1472  * @runtime: PCM runtime instance
1473  * @cond: condition bits
1474  * @var: hw_params variable to apply the power-of-2 constraint
1475  *
1476  * Return: Zero if successful, or a negative error code on failure.
1477  */
1478 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1479                                unsigned int cond,
1480                                snd_pcm_hw_param_t var)
1481 {
1482         return snd_pcm_hw_rule_add(runtime, cond, var,
1483                                    snd_pcm_hw_rule_pow2, NULL,
1484                                    var, -1);
1485 }
1486 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1487
1488 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1489                                            struct snd_pcm_hw_rule *rule)
1490 {
1491         unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1492         struct snd_interval *rate;
1493
1494         rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1495         return snd_interval_list(rate, 1, &base_rate, 0);
1496 }
1497
1498 /**
1499  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1500  * @runtime: PCM runtime instance
1501  * @base_rate: the rate at which the hardware does not resample
1502  *
1503  * Return: Zero if successful, or a negative error code on failure.
1504  */
1505 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1506                                unsigned int base_rate)
1507 {
1508         return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1509                                    SNDRV_PCM_HW_PARAM_RATE,
1510                                    snd_pcm_hw_rule_noresample_func,
1511                                    (void *)(uintptr_t)base_rate,
1512                                    SNDRV_PCM_HW_PARAM_RATE, -1);
1513 }
1514 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1515
1516 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1517                                   snd_pcm_hw_param_t var)
1518 {
1519         if (hw_is_mask(var)) {
1520                 snd_mask_any(hw_param_mask(params, var));
1521                 params->cmask |= 1 << var;
1522                 params->rmask |= 1 << var;
1523                 return;
1524         }
1525         if (hw_is_interval(var)) {
1526                 snd_interval_any(hw_param_interval(params, var));
1527                 params->cmask |= 1 << var;
1528                 params->rmask |= 1 << var;
1529                 return;
1530         }
1531         snd_BUG();
1532 }
1533
1534 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1535 {
1536         unsigned int k;
1537         memset(params, 0, sizeof(*params));
1538         for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1539                 _snd_pcm_hw_param_any(params, k);
1540         for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1541                 _snd_pcm_hw_param_any(params, k);
1542         params->info = ~0U;
1543 }
1544 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1545
1546 /**
1547  * snd_pcm_hw_param_value - return @params field @var value
1548  * @params: the hw_params instance
1549  * @var: parameter to retrieve
1550  * @dir: pointer to the direction (-1,0,1) or %NULL
1551  *
1552  * Return: The value for field @var if it's fixed in configuration space
1553  * defined by @params. -%EINVAL otherwise.
1554  */
1555 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1556                            snd_pcm_hw_param_t var, int *dir)
1557 {
1558         if (hw_is_mask(var)) {
1559                 const struct snd_mask *mask = hw_param_mask_c(params, var);
1560                 if (!snd_mask_single(mask))
1561                         return -EINVAL;
1562                 if (dir)
1563                         *dir = 0;
1564                 return snd_mask_value(mask);
1565         }
1566         if (hw_is_interval(var)) {
1567                 const struct snd_interval *i = hw_param_interval_c(params, var);
1568                 if (!snd_interval_single(i))
1569                         return -EINVAL;
1570                 if (dir)
1571                         *dir = i->openmin;
1572                 return snd_interval_value(i);
1573         }
1574         return -EINVAL;
1575 }
1576 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1577
1578 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1579                                 snd_pcm_hw_param_t var)
1580 {
1581         if (hw_is_mask(var)) {
1582                 snd_mask_none(hw_param_mask(params, var));
1583                 params->cmask |= 1 << var;
1584                 params->rmask |= 1 << var;
1585         } else if (hw_is_interval(var)) {
1586                 snd_interval_none(hw_param_interval(params, var));
1587                 params->cmask |= 1 << var;
1588                 params->rmask |= 1 << var;
1589         } else {
1590                 snd_BUG();
1591         }
1592 }
1593 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1594
1595 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1596                                    snd_pcm_hw_param_t var)
1597 {
1598         int changed;
1599         if (hw_is_mask(var))
1600                 changed = snd_mask_refine_first(hw_param_mask(params, var));
1601         else if (hw_is_interval(var))
1602                 changed = snd_interval_refine_first(hw_param_interval(params, var));
1603         else
1604                 return -EINVAL;
1605         if (changed > 0) {
1606                 params->cmask |= 1 << var;
1607                 params->rmask |= 1 << var;
1608         }
1609         return changed;
1610 }
1611
1612
1613 /**
1614  * snd_pcm_hw_param_first - refine config space and return minimum value
1615  * @pcm: PCM instance
1616  * @params: the hw_params instance
1617  * @var: parameter to retrieve
1618  * @dir: pointer to the direction (-1,0,1) or %NULL
1619  *
1620  * Inside configuration space defined by @params remove from @var all
1621  * values > minimum. Reduce configuration space accordingly.
1622  *
1623  * Return: The minimum, or a negative error code on failure.
1624  */
1625 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1626                            struct snd_pcm_hw_params *params,
1627                            snd_pcm_hw_param_t var, int *dir)
1628 {
1629         int changed = _snd_pcm_hw_param_first(params, var);
1630         if (changed < 0)
1631                 return changed;
1632         if (params->rmask) {
1633                 int err = snd_pcm_hw_refine(pcm, params);
1634                 if (err < 0)
1635                         return err;
1636         }
1637         return snd_pcm_hw_param_value(params, var, dir);
1638 }
1639 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1640
1641 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1642                                   snd_pcm_hw_param_t var)
1643 {
1644         int changed;
1645         if (hw_is_mask(var))
1646                 changed = snd_mask_refine_last(hw_param_mask(params, var));
1647         else if (hw_is_interval(var))
1648                 changed = snd_interval_refine_last(hw_param_interval(params, var));
1649         else
1650                 return -EINVAL;
1651         if (changed > 0) {
1652                 params->cmask |= 1 << var;
1653                 params->rmask |= 1 << var;
1654         }
1655         return changed;
1656 }
1657
1658
1659 /**
1660  * snd_pcm_hw_param_last - refine config space and return maximum value
1661  * @pcm: PCM instance
1662  * @params: the hw_params instance
1663  * @var: parameter to retrieve
1664  * @dir: pointer to the direction (-1,0,1) or %NULL
1665  *
1666  * Inside configuration space defined by @params remove from @var all
1667  * values < maximum. Reduce configuration space accordingly.
1668  *
1669  * Return: The maximum, or a negative error code on failure.
1670  */
1671 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1672                           struct snd_pcm_hw_params *params,
1673                           snd_pcm_hw_param_t var, int *dir)
1674 {
1675         int changed = _snd_pcm_hw_param_last(params, var);
1676         if (changed < 0)
1677                 return changed;
1678         if (params->rmask) {
1679                 int err = snd_pcm_hw_refine(pcm, params);
1680                 if (err < 0)
1681                         return err;
1682         }
1683         return snd_pcm_hw_param_value(params, var, dir);
1684 }
1685 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1686
1687 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1688                                    void *arg)
1689 {
1690         struct snd_pcm_runtime *runtime = substream->runtime;
1691         unsigned long flags;
1692         snd_pcm_stream_lock_irqsave(substream, flags);
1693         if (snd_pcm_running(substream) &&
1694             snd_pcm_update_hw_ptr(substream) >= 0)
1695                 runtime->status->hw_ptr %= runtime->buffer_size;
1696         else {
1697                 runtime->status->hw_ptr = 0;
1698                 runtime->hw_ptr_wrap = 0;
1699         }
1700         snd_pcm_stream_unlock_irqrestore(substream, flags);
1701         return 0;
1702 }
1703
1704 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1705                                           void *arg)
1706 {
1707         struct snd_pcm_channel_info *info = arg;
1708         struct snd_pcm_runtime *runtime = substream->runtime;
1709         int width;
1710         if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1711                 info->offset = -1;
1712                 return 0;
1713         }
1714         width = snd_pcm_format_physical_width(runtime->format);
1715         if (width < 0)
1716                 return width;
1717         info->offset = 0;
1718         switch (runtime->access) {
1719         case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1720         case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1721                 info->first = info->channel * width;
1722                 info->step = runtime->channels * width;
1723                 break;
1724         case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1725         case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1726         {
1727                 size_t size = runtime->dma_bytes / runtime->channels;
1728                 info->first = info->channel * size * 8;
1729                 info->step = width;
1730                 break;
1731         }
1732         default:
1733                 snd_BUG();
1734                 break;
1735         }
1736         return 0;
1737 }
1738
1739 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1740                                        void *arg)
1741 {
1742         struct snd_pcm_hw_params *params = arg;
1743         snd_pcm_format_t format;
1744         int channels;
1745         ssize_t frame_size;
1746
1747         params->fifo_size = substream->runtime->hw.fifo_size;
1748         if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1749                 format = params_format(params);
1750                 channels = params_channels(params);
1751                 frame_size = snd_pcm_format_size(format, channels);
1752                 if (frame_size > 0)
1753                         params->fifo_size /= (unsigned)frame_size;
1754         }
1755         return 0;
1756 }
1757
1758 /**
1759  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1760  * @substream: the pcm substream instance
1761  * @cmd: ioctl command
1762  * @arg: ioctl argument
1763  *
1764  * Processes the generic ioctl commands for PCM.
1765  * Can be passed as the ioctl callback for PCM ops.
1766  *
1767  * Return: Zero if successful, or a negative error code on failure.
1768  */
1769 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1770                       unsigned int cmd, void *arg)
1771 {
1772         switch (cmd) {
1773         case SNDRV_PCM_IOCTL1_RESET:
1774                 return snd_pcm_lib_ioctl_reset(substream, arg);
1775         case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1776                 return snd_pcm_lib_ioctl_channel_info(substream, arg);
1777         case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1778                 return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1779         }
1780         return -ENXIO;
1781 }
1782 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1783
1784 /**
1785  * snd_pcm_period_elapsed - update the pcm status for the next period
1786  * @substream: the pcm substream instance
1787  *
1788  * This function is called from the interrupt handler when the
1789  * PCM has processed the period size.  It will update the current
1790  * pointer, wake up sleepers, etc.
1791  *
1792  * Even if more than one periods have elapsed since the last call, you
1793  * have to call this only once.
1794  */
1795 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1796 {
1797         struct snd_pcm_runtime *runtime;
1798         unsigned long flags;
1799
1800         if (PCM_RUNTIME_CHECK(substream))
1801                 return;
1802         runtime = substream->runtime;
1803
1804         snd_pcm_stream_lock_irqsave(substream, flags);
1805         if (!snd_pcm_running(substream) ||
1806             snd_pcm_update_hw_ptr0(substream, 1) < 0)
1807                 goto _end;
1808
1809 #ifdef CONFIG_SND_PCM_TIMER
1810         if (substream->timer_running)
1811                 snd_timer_interrupt(substream->timer, 1);
1812 #endif
1813  _end:
1814         kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1815         snd_pcm_stream_unlock_irqrestore(substream, flags);
1816 }
1817 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1818
1819 /*
1820  * Wait until avail_min data becomes available
1821  * Returns a negative error code if any error occurs during operation.
1822  * The available space is stored on availp.  When err = 0 and avail = 0
1823  * on the capture stream, it indicates the stream is in DRAINING state.
1824  */
1825 static int wait_for_avail(struct snd_pcm_substream *substream,
1826                               snd_pcm_uframes_t *availp)
1827 {
1828         struct snd_pcm_runtime *runtime = substream->runtime;
1829         int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1830         wait_queue_entry_t wait;
1831         int err = 0;
1832         snd_pcm_uframes_t avail = 0;
1833         long wait_time, tout;
1834
1835         init_waitqueue_entry(&wait, current);
1836         set_current_state(TASK_INTERRUPTIBLE);
1837         add_wait_queue(&runtime->tsleep, &wait);
1838
1839         if (runtime->no_period_wakeup)
1840                 wait_time = MAX_SCHEDULE_TIMEOUT;
1841         else {
1842                 /* use wait time from substream if available */
1843                 if (substream->wait_time) {
1844                         wait_time = substream->wait_time;
1845                 } else {
1846                         wait_time = 10;
1847
1848                         if (runtime->rate) {
1849                                 long t = runtime->period_size * 2 /
1850                                          runtime->rate;
1851                                 wait_time = max(t, wait_time);
1852                         }
1853                         wait_time = msecs_to_jiffies(wait_time * 1000);
1854                 }
1855         }
1856
1857         for (;;) {
1858                 if (signal_pending(current)) {
1859                         err = -ERESTARTSYS;
1860                         break;
1861                 }
1862
1863                 /*
1864                  * We need to check if space became available already
1865                  * (and thus the wakeup happened already) first to close
1866                  * the race of space already having become available.
1867                  * This check must happen after been added to the waitqueue
1868                  * and having current state be INTERRUPTIBLE.
1869                  */
1870                 avail = snd_pcm_avail(substream);
1871                 if (avail >= runtime->twake)
1872                         break;
1873                 snd_pcm_stream_unlock_irq(substream);
1874
1875                 tout = schedule_timeout(wait_time);
1876
1877                 snd_pcm_stream_lock_irq(substream);
1878                 set_current_state(TASK_INTERRUPTIBLE);
1879                 switch (runtime->status->state) {
1880                 case SNDRV_PCM_STATE_SUSPENDED:
1881                         err = -ESTRPIPE;
1882                         goto _endloop;
1883                 case SNDRV_PCM_STATE_XRUN:
1884                         err = -EPIPE;
1885                         goto _endloop;
1886                 case SNDRV_PCM_STATE_DRAINING:
1887                         if (is_playback)
1888                                 err = -EPIPE;
1889                         else
1890                                 avail = 0; /* indicate draining */
1891                         goto _endloop;
1892                 case SNDRV_PCM_STATE_OPEN:
1893                 case SNDRV_PCM_STATE_SETUP:
1894                 case SNDRV_PCM_STATE_DISCONNECTED:
1895                         err = -EBADFD;
1896                         goto _endloop;
1897                 case SNDRV_PCM_STATE_PAUSED:
1898                         continue;
1899                 }
1900                 if (!tout) {
1901                         pcm_dbg(substream->pcm,
1902                                 "%s write error (DMA or IRQ trouble?)\n",
1903                                 is_playback ? "playback" : "capture");
1904                         err = -EIO;
1905                         break;
1906                 }
1907         }
1908  _endloop:
1909         set_current_state(TASK_RUNNING);
1910         remove_wait_queue(&runtime->tsleep, &wait);
1911         *availp = avail;
1912         return err;
1913 }
1914
1915 typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
1916                               int channel, unsigned long hwoff,
1917                               void *buf, unsigned long bytes);
1918
1919 typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
1920                           snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
1921
1922 /* calculate the target DMA-buffer position to be written/read */
1923 static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
1924                            int channel, unsigned long hwoff)
1925 {
1926         return runtime->dma_area + hwoff +
1927                 channel * (runtime->dma_bytes / runtime->channels);
1928 }
1929
1930 /* default copy_user ops for write; used for both interleaved and non- modes */
1931 static int default_write_copy(struct snd_pcm_substream *substream,
1932                               int channel, unsigned long hwoff,
1933                               void *buf, unsigned long bytes)
1934 {
1935         if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
1936                            (void __user *)buf, bytes))
1937                 return -EFAULT;
1938         return 0;
1939 }
1940
1941 /* default copy_kernel ops for write */
1942 static int default_write_copy_kernel(struct snd_pcm_substream *substream,
1943                                      int channel, unsigned long hwoff,
1944                                      void *buf, unsigned long bytes)
1945 {
1946         memcpy(get_dma_ptr(substream->runtime, channel, hwoff), buf, bytes);
1947         return 0;
1948 }
1949
1950 /* fill silence instead of copy data; called as a transfer helper
1951  * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
1952  * a NULL buffer is passed
1953  */
1954 static int fill_silence(struct snd_pcm_substream *substream, int channel,
1955                         unsigned long hwoff, void *buf, unsigned long bytes)
1956 {
1957         struct snd_pcm_runtime *runtime = substream->runtime;
1958
1959         if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
1960                 return 0;
1961         if (substream->ops->fill_silence)
1962                 return substream->ops->fill_silence(substream, channel,
1963                                                     hwoff, bytes);
1964
1965         snd_pcm_format_set_silence(runtime->format,
1966                                    get_dma_ptr(runtime, channel, hwoff),
1967                                    bytes_to_samples(runtime, bytes));
1968         return 0;
1969 }
1970
1971 /* default copy_user ops for read; used for both interleaved and non- modes */
1972 static int default_read_copy(struct snd_pcm_substream *substream,
1973                              int channel, unsigned long hwoff,
1974                              void *buf, unsigned long bytes)
1975 {
1976         if (copy_to_user((void __user *)buf,
1977                          get_dma_ptr(substream->runtime, channel, hwoff),
1978                          bytes))
1979                 return -EFAULT;
1980         return 0;
1981 }
1982
1983 /* default copy_kernel ops for read */
1984 static int default_read_copy_kernel(struct snd_pcm_substream *substream,
1985                                     int channel, unsigned long hwoff,
1986                                     void *buf, unsigned long bytes)
1987 {
1988         memcpy(buf, get_dma_ptr(substream->runtime, channel, hwoff), bytes);
1989         return 0;
1990 }
1991
1992 /* call transfer function with the converted pointers and sizes;
1993  * for interleaved mode, it's one shot for all samples
1994  */
1995 static int interleaved_copy(struct snd_pcm_substream *substream,
1996                             snd_pcm_uframes_t hwoff, void *data,
1997                             snd_pcm_uframes_t off,
1998                             snd_pcm_uframes_t frames,
1999                             pcm_transfer_f transfer)
2000 {
2001         struct snd_pcm_runtime *runtime = substream->runtime;
2002
2003         /* convert to bytes */
2004         hwoff = frames_to_bytes(runtime, hwoff);
2005         off = frames_to_bytes(runtime, off);
2006         frames = frames_to_bytes(runtime, frames);
2007         return transfer(substream, 0, hwoff, data + off, frames);
2008 }
2009
2010 /* call transfer function with the converted pointers and sizes for each
2011  * non-interleaved channel; when buffer is NULL, silencing instead of copying
2012  */
2013 static int noninterleaved_copy(struct snd_pcm_substream *substream,
2014                                snd_pcm_uframes_t hwoff, void *data,
2015                                snd_pcm_uframes_t off,
2016                                snd_pcm_uframes_t frames,
2017                                pcm_transfer_f transfer)
2018 {
2019         struct snd_pcm_runtime *runtime = substream->runtime;
2020         int channels = runtime->channels;
2021         void **bufs = data;
2022         int c, err;
2023
2024         /* convert to bytes; note that it's not frames_to_bytes() here.
2025          * in non-interleaved mode, we copy for each channel, thus
2026          * each copy is n_samples bytes x channels = whole frames.
2027          */
2028         off = samples_to_bytes(runtime, off);
2029         frames = samples_to_bytes(runtime, frames);
2030         hwoff = samples_to_bytes(runtime, hwoff);
2031         for (c = 0; c < channels; ++c, ++bufs) {
2032                 if (!data || !*bufs)
2033                         err = fill_silence(substream, c, hwoff, NULL, frames);
2034                 else
2035                         err = transfer(substream, c, hwoff, *bufs + off,
2036                                        frames);
2037                 if (err < 0)
2038                         return err;
2039         }
2040         return 0;
2041 }
2042
2043 /* fill silence on the given buffer position;
2044  * called from snd_pcm_playback_silence()
2045  */
2046 static int fill_silence_frames(struct snd_pcm_substream *substream,
2047                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
2048 {
2049         if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
2050             substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
2051                 return interleaved_copy(substream, off, NULL, 0, frames,
2052                                         fill_silence);
2053         else
2054                 return noninterleaved_copy(substream, off, NULL, 0, frames,
2055                                            fill_silence);
2056 }
2057
2058 /* sanity-check for read/write methods */
2059 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2060 {
2061         struct snd_pcm_runtime *runtime;
2062         if (PCM_RUNTIME_CHECK(substream))
2063                 return -ENXIO;
2064         runtime = substream->runtime;
2065         if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area))
2066                 return -EINVAL;
2067         if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2068                 return -EBADFD;
2069         return 0;
2070 }
2071
2072 static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
2073 {
2074         switch (runtime->status->state) {
2075         case SNDRV_PCM_STATE_PREPARED:
2076         case SNDRV_PCM_STATE_RUNNING:
2077         case SNDRV_PCM_STATE_PAUSED:
2078                 return 0;
2079         case SNDRV_PCM_STATE_XRUN:
2080                 return -EPIPE;
2081         case SNDRV_PCM_STATE_SUSPENDED:
2082                 return -ESTRPIPE;
2083         default:
2084                 return -EBADFD;
2085         }
2086 }
2087
2088 /* update to the given appl_ptr and call ack callback if needed;
2089  * when an error is returned, take back to the original value
2090  */
2091 int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
2092                            snd_pcm_uframes_t appl_ptr)
2093 {
2094         struct snd_pcm_runtime *runtime = substream->runtime;
2095         snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
2096         int ret;
2097
2098         if (old_appl_ptr == appl_ptr)
2099                 return 0;
2100
2101         runtime->control->appl_ptr = appl_ptr;
2102         if (substream->ops->ack) {
2103                 ret = substream->ops->ack(substream);
2104                 if (ret < 0) {
2105                         runtime->control->appl_ptr = old_appl_ptr;
2106                         return ret;
2107                 }
2108         }
2109
2110         trace_applptr(substream, old_appl_ptr, appl_ptr);
2111
2112         return 0;
2113 }
2114
2115 /* allow waiting for a capture stream that hasn't been started */
2116 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
2117 #define wait_capture_start(substream)   ((substream)->oss.oss)
2118 #else
2119 #define wait_capture_start(substream)   false
2120 #endif
2121
2122 /* the common loop for read/write data */
2123 snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
2124                                      void *data, bool interleaved,
2125                                      snd_pcm_uframes_t size, bool in_kernel)
2126 {
2127         struct snd_pcm_runtime *runtime = substream->runtime;
2128         snd_pcm_uframes_t xfer = 0;
2129         snd_pcm_uframes_t offset = 0;
2130         snd_pcm_uframes_t avail;
2131         pcm_copy_f writer;
2132         pcm_transfer_f transfer;
2133         bool nonblock;
2134         bool is_playback;
2135         int err;
2136
2137         err = pcm_sanity_check(substream);
2138         if (err < 0)
2139                 return err;
2140
2141         is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
2142         if (interleaved) {
2143                 if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2144                     runtime->channels > 1)
2145                         return -EINVAL;
2146                 writer = interleaved_copy;
2147         } else {
2148                 if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2149                         return -EINVAL;
2150                 writer = noninterleaved_copy;
2151         }
2152
2153         if (!data) {
2154                 if (is_playback)
2155                         transfer = fill_silence;
2156                 else
2157                         return -EINVAL;
2158         } else if (in_kernel) {
2159                 if (substream->ops->copy_kernel)
2160                         transfer = substream->ops->copy_kernel;
2161                 else
2162                         transfer = is_playback ?
2163                                 default_write_copy_kernel : default_read_copy_kernel;
2164         } else {
2165                 if (substream->ops->copy_user)
2166                         transfer = (pcm_transfer_f)substream->ops->copy_user;
2167                 else
2168                         transfer = is_playback ?
2169                                 default_write_copy : default_read_copy;
2170         }
2171
2172         if (size == 0)
2173                 return 0;
2174
2175         nonblock = !!(substream->f_flags & O_NONBLOCK);
2176
2177         snd_pcm_stream_lock_irq(substream);
2178         err = pcm_accessible_state(runtime);
2179         if (err < 0)
2180                 goto _end_unlock;
2181
2182         runtime->twake = runtime->control->avail_min ? : 1;
2183         if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2184                 snd_pcm_update_hw_ptr(substream);
2185
2186         if (!is_playback &&
2187             runtime->status->state == SNDRV_PCM_STATE_PREPARED) {
2188                 if (size >= runtime->start_threshold) {
2189                         err = snd_pcm_start(substream);
2190                         if (err < 0)
2191                                 goto _end_unlock;
2192                 } else if (!wait_capture_start(substream)) {
2193                         /* nothing to do */
2194                         err = 0;
2195                         goto _end_unlock;
2196                 }
2197         }
2198
2199         avail = snd_pcm_avail(substream);
2200
2201         while (size > 0) {
2202                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2203                 snd_pcm_uframes_t cont;
2204                 if (!avail) {
2205                         if (!is_playback &&
2206                             runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
2207                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2208                                 goto _end_unlock;
2209                         }
2210                         if (nonblock) {
2211                                 err = -EAGAIN;
2212                                 goto _end_unlock;
2213                         }
2214                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2215                                         runtime->control->avail_min ? : 1);
2216                         err = wait_for_avail(substream, &avail);
2217                         if (err < 0)
2218                                 goto _end_unlock;
2219                         if (!avail)
2220                                 continue; /* draining */
2221                 }
2222                 frames = size > avail ? avail : size;
2223                 appl_ptr = READ_ONCE(runtime->control->appl_ptr);
2224                 appl_ofs = appl_ptr % runtime->buffer_size;
2225                 cont = runtime->buffer_size - appl_ofs;
2226                 if (frames > cont)
2227                         frames = cont;
2228                 if (snd_BUG_ON(!frames)) {
2229                         runtime->twake = 0;
2230                         snd_pcm_stream_unlock_irq(substream);
2231                         return -EINVAL;
2232                 }
2233                 snd_pcm_stream_unlock_irq(substream);
2234                 err = writer(substream, appl_ofs, data, offset, frames,
2235                              transfer);
2236                 snd_pcm_stream_lock_irq(substream);
2237                 if (err < 0)
2238                         goto _end_unlock;
2239                 err = pcm_accessible_state(runtime);
2240                 if (err < 0)
2241                         goto _end_unlock;
2242                 appl_ptr += frames;
2243                 if (appl_ptr >= runtime->boundary)
2244                         appl_ptr -= runtime->boundary;
2245                 err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
2246                 if (err < 0)
2247                         goto _end_unlock;
2248
2249                 offset += frames;
2250                 size -= frames;
2251                 xfer += frames;
2252                 avail -= frames;
2253                 if (is_playback &&
2254                     runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2255                     snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2256                         err = snd_pcm_start(substream);
2257                         if (err < 0)
2258                                 goto _end_unlock;
2259                 }
2260         }
2261  _end_unlock:
2262         runtime->twake = 0;
2263         if (xfer > 0 && err >= 0)
2264                 snd_pcm_update_state(substream, runtime);
2265         snd_pcm_stream_unlock_irq(substream);
2266         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2267 }
2268 EXPORT_SYMBOL(__snd_pcm_lib_xfer);
2269
2270 /*
2271  * standard channel mapping helpers
2272  */
2273
2274 /* default channel maps for multi-channel playbacks, up to 8 channels */
2275 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2276         { .channels = 1,
2277           .map = { SNDRV_CHMAP_MONO } },
2278         { .channels = 2,
2279           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2280         { .channels = 4,
2281           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2282                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2283         { .channels = 6,
2284           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2285                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2286                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2287         { .channels = 8,
2288           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2289                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2290                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2291                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2292         { }
2293 };
2294 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2295
2296 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2297 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2298         { .channels = 1,
2299           .map = { SNDRV_CHMAP_MONO } },
2300         { .channels = 2,
2301           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2302         { .channels = 4,
2303           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2304                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2305         { .channels = 6,
2306           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2307                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2308                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2309         { .channels = 8,
2310           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2311                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2312                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2313                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2314         { }
2315 };
2316 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2317
2318 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2319 {
2320         if (ch > info->max_channels)
2321                 return false;
2322         return !info->channel_mask || (info->channel_mask & (1U << ch));
2323 }
2324
2325 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2326                               struct snd_ctl_elem_info *uinfo)
2327 {
2328         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2329
2330         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2331         uinfo->count = 0;
2332         uinfo->count = info->max_channels;
2333         uinfo->value.integer.min = 0;
2334         uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2335         return 0;
2336 }
2337
2338 /* get callback for channel map ctl element
2339  * stores the channel position firstly matching with the current channels
2340  */
2341 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2342                              struct snd_ctl_elem_value *ucontrol)
2343 {
2344         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2345         unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2346         struct snd_pcm_substream *substream;
2347         const struct snd_pcm_chmap_elem *map;
2348
2349         if (!info->chmap)
2350                 return -EINVAL;
2351         substream = snd_pcm_chmap_substream(info, idx);
2352         if (!substream)
2353                 return -ENODEV;
2354         memset(ucontrol->value.integer.value, 0,
2355                sizeof(ucontrol->value.integer.value));
2356         if (!substream->runtime)
2357                 return 0; /* no channels set */
2358         for (map = info->chmap; map->channels; map++) {
2359                 int i;
2360                 if (map->channels == substream->runtime->channels &&
2361                     valid_chmap_channels(info, map->channels)) {
2362                         for (i = 0; i < map->channels; i++)
2363                                 ucontrol->value.integer.value[i] = map->map[i];
2364                         return 0;
2365                 }
2366         }
2367         return -EINVAL;
2368 }
2369
2370 /* tlv callback for channel map ctl element
2371  * expands the pre-defined channel maps in a form of TLV
2372  */
2373 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2374                              unsigned int size, unsigned int __user *tlv)
2375 {
2376         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2377         const struct snd_pcm_chmap_elem *map;
2378         unsigned int __user *dst;
2379         int c, count = 0;
2380
2381         if (!info->chmap)
2382                 return -EINVAL;
2383         if (size < 8)
2384                 return -ENOMEM;
2385         if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2386                 return -EFAULT;
2387         size -= 8;
2388         dst = tlv + 2;
2389         for (map = info->chmap; map->channels; map++) {
2390                 int chs_bytes = map->channels * 4;
2391                 if (!valid_chmap_channels(info, map->channels))
2392                         continue;
2393                 if (size < 8)
2394                         return -ENOMEM;
2395                 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2396                     put_user(chs_bytes, dst + 1))
2397                         return -EFAULT;
2398                 dst += 2;
2399                 size -= 8;
2400                 count += 8;
2401                 if (size < chs_bytes)
2402                         return -ENOMEM;
2403                 size -= chs_bytes;
2404                 count += chs_bytes;
2405                 for (c = 0; c < map->channels; c++) {
2406                         if (put_user(map->map[c], dst))
2407                                 return -EFAULT;
2408                         dst++;
2409                 }
2410         }
2411         if (put_user(count, tlv + 1))
2412                 return -EFAULT;
2413         return 0;
2414 }
2415
2416 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2417 {
2418         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2419         info->pcm->streams[info->stream].chmap_kctl = NULL;
2420         kfree(info);
2421 }
2422
2423 /**
2424  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2425  * @pcm: the assigned PCM instance
2426  * @stream: stream direction
2427  * @chmap: channel map elements (for query)
2428  * @max_channels: the max number of channels for the stream
2429  * @private_value: the value passed to each kcontrol's private_value field
2430  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2431  *
2432  * Create channel-mapping control elements assigned to the given PCM stream(s).
2433  * Return: Zero if successful, or a negative error value.
2434  */
2435 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2436                            const struct snd_pcm_chmap_elem *chmap,
2437                            int max_channels,
2438                            unsigned long private_value,
2439                            struct snd_pcm_chmap **info_ret)
2440 {
2441         struct snd_pcm_chmap *info;
2442         struct snd_kcontrol_new knew = {
2443                 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
2444                 .access = SNDRV_CTL_ELEM_ACCESS_READ |
2445                         SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2446                         SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2447                 .info = pcm_chmap_ctl_info,
2448                 .get = pcm_chmap_ctl_get,
2449                 .tlv.c = pcm_chmap_ctl_tlv,
2450         };
2451         int err;
2452
2453         if (WARN_ON(pcm->streams[stream].chmap_kctl))
2454                 return -EBUSY;
2455         info = kzalloc(sizeof(*info), GFP_KERNEL);
2456         if (!info)
2457                 return -ENOMEM;
2458         info->pcm = pcm;
2459         info->stream = stream;
2460         info->chmap = chmap;
2461         info->max_channels = max_channels;
2462         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2463                 knew.name = "Playback Channel Map";
2464         else
2465                 knew.name = "Capture Channel Map";
2466         knew.device = pcm->device;
2467         knew.count = pcm->streams[stream].substream_count;
2468         knew.private_value = private_value;
2469         info->kctl = snd_ctl_new1(&knew, info);
2470         if (!info->kctl) {
2471                 kfree(info);
2472                 return -ENOMEM;
2473         }
2474         info->kctl->private_free = pcm_chmap_ctl_private_free;
2475         err = snd_ctl_add(pcm->card, info->kctl);
2476         if (err < 0)
2477                 return err;
2478         pcm->streams[stream].chmap_kctl = info->kctl;
2479         if (info_ret)
2480                 *info_ret = info;
2481         return 0;
2482 }
2483 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);