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