sound/core/pcm_lib.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Digital Audio (PCM) abstract layer
   4  *  Copyright (c) by Jaroslav Kysela <[email protected]>
   5  *                   Abramo Bagnara <[email protected]>
   6  */
   7
   8 #include <linux/slab.h>
   9 #include <linux/sched/signal.h>
  10 #include <linux/time.h>
  11 #include <linux/math64.h>
  12 #include <linux/export.h>
  13 #include <sound/core.h>
  14 #include <sound/control.h>
  15 #include <sound/tlv.h>
  16 #include <sound/info.h>
  17 #include <sound/pcm.h>
  18 #include <sound/pcm_params.h>
  19 #include <sound/timer.h>
  20
  21 #include "pcm_local.h"
  22
  23 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  24 #define CREATE_TRACE_POINTS
  25 #include "pcm_trace.h"
  26 #else
  27 #define trace_hwptr(substream, pos, in_interrupt)
  28 #define trace_xrun(substream)
  29 #define trace_hw_ptr_error(substream, reason)
  30 #define trace_applptr(substream, prev, curr)
  31 #endif
  32
  33 static int fill_silence_frames(struct snd_pcm_substream *substream,
  34                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
  35
  36 /*
  37  * fill ring buffer with silence
  38  * runtime->silence_start: starting pointer to silence area
  39  * runtime->silence_filled: size filled with silence
  40  * runtime->silence_threshold: threshold from application
  41  * runtime->silence_size: maximal size from application
  42  *
  43  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
  44  */
  45 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
  46 {
  47         struct snd_pcm_runtime *runtime = substream->runtime;
  48         snd_pcm_uframes_t frames, ofs, transfer;
  49         int err;
  50
  51         if (runtime->silence_size < runtime->boundary) {
  52                 snd_pcm_sframes_t noise_dist, n;
  53                 snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr);
  54                 if (runtime->silence_start != appl_ptr) {
  55                         n = appl_ptr - runtime->silence_start;
  56                         if (n < 0)
  57                                 n += runtime->boundary;
  58                         if ((snd_pcm_uframes_t)n < runtime->silence_filled)
  59                                 runtime->silence_filled -= n;
  60                         else
  61                                 runtime->silence_filled = 0;
  62                         runtime->silence_start = appl_ptr;
  63                 }
  64                 if (runtime->silence_filled >= runtime->buffer_size)
  65                         return;
  66                 noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
  67                 if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
  68                         return;
  69                 frames = runtime->silence_threshold - noise_dist;
  70                 if (frames > runtime->silence_size)
  71                         frames = runtime->silence_size;
  72         } else {
  73                 if (new_hw_ptr == ULONG_MAX) {  /* initialization */
  74                         snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
  75                         if (avail > runtime->buffer_size)
  76                                 avail = runtime->buffer_size;
  77                         runtime->silence_filled = avail > 0 ? avail : 0;
  78                         runtime->silence_start = (runtime->status->hw_ptr +
  79                                                   runtime->silence_filled) %
  80                                                  runtime->boundary;
  81                 } else {
  82                         ofs = runtime->status->hw_ptr;
  83                         frames = new_hw_ptr - ofs;
  84                         if ((snd_pcm_sframes_t)frames < 0)
  85                                 frames += runtime->boundary;
  86                         runtime->silence_filled -= frames;
  87                         if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
  88                                 runtime->silence_filled = 0;
  89                                 runtime->silence_start = new_hw_ptr;
  90                         } else {
  91                                 runtime->silence_start = ofs;
  92                         }
  93                 }
  94                 frames = runtime->buffer_size - runtime->silence_filled;
  95         }
  96         if (snd_BUG_ON(frames > runtime->buffer_size))
  97                 return;
  98         if (frames == 0)
  99                 return;
 100         ofs = runtime->silence_start % runtime->buffer_size;
 101         while (frames > 0) {
 102                 transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
 103                 err = fill_silence_frames(substream, ofs, transfer);
 104                 snd_BUG_ON(err < 0);
 105                 runtime->silence_filled += transfer;
 106                 frames -= transfer;
 107                 ofs = 0;
 108         }
 109         snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
 110 }
 111
 112 #ifdef CONFIG_SND_DEBUG
 113 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
 114                            char *name, size_t len)
 115 {
 116         snprintf(name, len, "pcmC%dD%d%c:%d",
 117                  substream->pcm->card->number,
 118                  substream->pcm->device,
 119                  substream->stream ? 'c' : 'p',
 120                  substream->number);
 121 }
 122 EXPORT_SYMBOL(snd_pcm_debug_name);
 123 #endif
 124
 125 #define XRUN_DEBUG_BASIC        (1<<0)
 126 #define XRUN_DEBUG_STACK        (1<<1)  /* dump also stack */
 127 #define XRUN_DEBUG_JIFFIESCHECK (1<<2)  /* do jiffies check */
 128
 129 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 130
 131 #define xrun_debug(substream, mask) \
 132                         ((substream)->pstr->xrun_debug & (mask))
 133 #else
 134 #define xrun_debug(substream, mask)     0
 135 #endif
 136
 137 #define dump_stack_on_xrun(substream) do {                      \
 138                 if (xrun_debug(substream, XRUN_DEBUG_STACK))    \
 139                         dump_stack();                           \
 140         } while (0)
 141
 142 /* call with stream lock held */
 143 void __snd_pcm_xrun(struct snd_pcm_substream *substream)
 144 {
 145         struct snd_pcm_runtime *runtime = substream->runtime;
 146
 147         trace_xrun(substream);
 148         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
 149                 struct timespec64 tstamp;
 150
 151                 snd_pcm_gettime(runtime, &tstamp);
 152                 runtime->status->tstamp.tv_sec = tstamp.tv_sec;
 153                 runtime->status->tstamp.tv_nsec = tstamp.tv_nsec;
 154         }
 155         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 156         if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
 157                 char name[16];
 158                 snd_pcm_debug_name(substream, name, sizeof(name));
 159                 pcm_warn(substream->pcm, "XRUN: %s\n", name);
 160                 dump_stack_on_xrun(substream);
 161         }
 162 }
 163
 164 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 165 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)     \
 166         do {                                                            \
 167                 trace_hw_ptr_error(substream, reason);  \
 168                 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {          \
 169                         pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
 170                                            (in_interrupt) ? 'Q' : 'P', ##args); \
 171                         dump_stack_on_xrun(substream);                  \
 172                 }                                                       \
 173         } while (0)
 174
 175 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
 176
 177 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
 178
 179 #endif
 180
 181 int snd_pcm_update_state(struct snd_pcm_substream *substream,
 182                          struct snd_pcm_runtime *runtime)
 183 {
 184         snd_pcm_uframes_t avail;
 185
 186         avail = snd_pcm_avail(substream);
 187         if (avail > runtime->avail_max)
 188                 runtime->avail_max = avail;
 189         if (runtime->state == SNDRV_PCM_STATE_DRAINING) {
 190                 if (avail >= runtime->buffer_size) {
 191                         snd_pcm_drain_done(substream);
 192                         return -EPIPE;
 193                 }
 194         } else {
 195                 if (avail >= runtime->stop_threshold) {
 196                         __snd_pcm_xrun(substream);
 197                         return -EPIPE;
 198                 }
 199         }
 200         if (runtime->twake) {
 201                 if (avail >= runtime->twake)
 202                         wake_up(&runtime->tsleep);
 203         } else if (avail >= runtime->control->avail_min)
 204                 wake_up(&runtime->sleep);
 205         return 0;
 206 }
 207
 208 static void update_audio_tstamp(struct snd_pcm_substream *substream,
 209                                 struct timespec64 *curr_tstamp,
 210                                 struct timespec64 *audio_tstamp)
 211 {
 212         struct snd_pcm_runtime *runtime = substream->runtime;
 213         u64 audio_frames, audio_nsecs;
 214         struct timespec64 driver_tstamp;
 215
 216         if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
 217                 return;
 218
 219         if (!(substream->ops->get_time_info) ||
 220                 (runtime->audio_tstamp_report.actual_type ==
 221                         SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 222
 223                 /*
 224                  * provide audio timestamp derived from pointer position
 225                  * add delay only if requested
 226                  */
 227
 228                 audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
 229
 230                 if (runtime->audio_tstamp_config.report_delay) {
 231                         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 232                                 audio_frames -=  runtime->delay;
 233                         else
 234                                 audio_frames +=  runtime->delay;
 235                 }
 236                 audio_nsecs = div_u64(audio_frames * 1000000000LL,
 237                                 runtime->rate);
 238                 *audio_tstamp = ns_to_timespec64(audio_nsecs);
 239         }
 240
 241         if (runtime->status->audio_tstamp.tv_sec != audio_tstamp->tv_sec ||
 242             runtime->status->audio_tstamp.tv_nsec != audio_tstamp->tv_nsec) {
 243                 runtime->status->audio_tstamp.tv_sec = audio_tstamp->tv_sec;
 244                 runtime->status->audio_tstamp.tv_nsec = audio_tstamp->tv_nsec;
 245                 runtime->status->tstamp.tv_sec = curr_tstamp->tv_sec;
 246                 runtime->status->tstamp.tv_nsec = curr_tstamp->tv_nsec;
 247         }
 248
 249
 250         /*
 251          * re-take a driver timestamp to let apps detect if the reference tstamp
 252          * read by low-level hardware was provided with a delay
 253          */
 254         snd_pcm_gettime(substream->runtime, &driver_tstamp);
 255         runtime->driver_tstamp = driver_tstamp;
 256 }
 257
 258 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 259                                   unsigned int in_interrupt)
 260 {
 261         struct snd_pcm_runtime *runtime = substream->runtime;
 262         snd_pcm_uframes_t pos;
 263         snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
 264         snd_pcm_sframes_t hdelta, delta;
 265         unsigned long jdelta;
 266         unsigned long curr_jiffies;
 267         struct timespec64 curr_tstamp;
 268         struct timespec64 audio_tstamp;
 269         int crossed_boundary = 0;
 270
 271         old_hw_ptr = runtime->status->hw_ptr;
 272
 273         /*
 274          * group pointer, time and jiffies reads to allow for more
 275          * accurate correlations/corrections.
 276          * The values are stored at the end of this routine after
 277          * corrections for hw_ptr position
 278          */
 279         pos = substream->ops->pointer(substream);
 280         curr_jiffies = jiffies;
 281         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
 282                 if ((substream->ops->get_time_info) &&
 283                         (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 284                         substream->ops->get_time_info(substream, &curr_tstamp,
 285                                                 &audio_tstamp,
 286                                                 &runtime->audio_tstamp_config,
 287                                                 &runtime->audio_tstamp_report);
 288
 289                         /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
 290                         if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
 291                                 snd_pcm_gettime(runtime, &curr_tstamp);
 292                 } else
 293                         snd_pcm_gettime(runtime, &curr_tstamp);
 294         }
 295
 296         if (pos == SNDRV_PCM_POS_XRUN) {
 297                 __snd_pcm_xrun(substream);
 298                 return -EPIPE;
 299         }
 300         if (pos >= runtime->buffer_size) {
 301                 if (printk_ratelimit()) {
 302                         char name[16];
 303                         snd_pcm_debug_name(substream, name, sizeof(name));
 304                         pcm_err(substream->pcm,
 305                                 "invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
 306                                 name, pos, runtime->buffer_size,
 307                                 runtime->period_size);
 308                 }
 309                 pos = 0;
 310         }
 311         pos -= pos % runtime->min_align;
 312         trace_hwptr(substream, pos, in_interrupt);
 313         hw_base = runtime->hw_ptr_base;
 314         new_hw_ptr = hw_base + pos;
 315         if (in_interrupt) {
 316                 /* we know that one period was processed */
 317                 /* delta = "expected next hw_ptr" for in_interrupt != 0 */
 318                 delta = runtime->hw_ptr_interrupt + runtime->period_size;
 319                 if (delta > new_hw_ptr) {
 320                         /* check for double acknowledged interrupts */
 321                         hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 322                         if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
 323                                 hw_base += runtime->buffer_size;
 324                                 if (hw_base >= runtime->boundary) {
 325                                         hw_base = 0;
 326                                         crossed_boundary++;
 327                                 }
 328                                 new_hw_ptr = hw_base + pos;
 329                                 goto __delta;
 330                         }
 331                 }
 332         }
 333         /* new_hw_ptr might be lower than old_hw_ptr in case when */
 334         /* pointer crosses the end of the ring buffer */
 335         if (new_hw_ptr < old_hw_ptr) {
 336                 hw_base += runtime->buffer_size;
 337                 if (hw_base >= runtime->boundary) {
 338                         hw_base = 0;
 339                         crossed_boundary++;
 340                 }
 341                 new_hw_ptr = hw_base + pos;
 342         }
 343       __delta:
 344         delta = new_hw_ptr - old_hw_ptr;
 345         if (delta < 0)
 346                 delta += runtime->boundary;
 347
 348         if (runtime->no_period_wakeup) {
 349                 snd_pcm_sframes_t xrun_threshold;
 350                 /*
 351                  * Without regular period interrupts, we have to check
 352                  * the elapsed time to detect xruns.
 353                  */
 354                 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 355                 if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
 356                         goto no_delta_check;
 357                 hdelta = jdelta - delta * HZ / runtime->rate;
 358                 xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
 359                 while (hdelta > xrun_threshold) {
 360                         delta += runtime->buffer_size;
 361                         hw_base += runtime->buffer_size;
 362                         if (hw_base >= runtime->boundary) {
 363                                 hw_base = 0;
 364                                 crossed_boundary++;
 365                         }
 366                         new_hw_ptr = hw_base + pos;
 367                         hdelta -= runtime->hw_ptr_buffer_jiffies;
 368                 }
 369                 goto no_delta_check;
 370         }
 371
 372         /* something must be really wrong */
 373         if (delta >= runtime->buffer_size + runtime->period_size) {
 374                 hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
 375                              "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 376                              substream->stream, (long)pos,
 377                              (long)new_hw_ptr, (long)old_hw_ptr);
 378                 return 0;
 379         }
 380
 381         /* Do jiffies check only in xrun_debug mode */
 382         if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
 383                 goto no_jiffies_check;
 384
 385         /* Skip the jiffies check for hardwares with BATCH flag.
 386          * Such hardware usually just increases the position at each IRQ,
 387          * thus it can't give any strange position.
 388          */
 389         if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
 390                 goto no_jiffies_check;
 391         hdelta = delta;
 392         if (hdelta < runtime->delay)
 393                 goto no_jiffies_check;
 394         hdelta -= runtime->delay;
 395         jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 396         if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
 397                 delta = jdelta /
 398                         (((runtime->period_size * HZ) / runtime->rate)
 399                                                                 + HZ/100);
 400                 /* move new_hw_ptr according jiffies not pos variable */
 401                 new_hw_ptr = old_hw_ptr;
 402                 hw_base = delta;
 403                 /* use loop to avoid checks for delta overflows */
 404                 /* the delta value is small or zero in most cases */
 405                 while (delta > 0) {
 406                         new_hw_ptr += runtime->period_size;
 407                         if (new_hw_ptr >= runtime->boundary) {
 408                                 new_hw_ptr -= runtime->boundary;
 409                                 crossed_boundary--;
 410                         }
 411                         delta--;
 412                 }
 413                 /* align hw_base to buffer_size */
 414                 hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
 415                              "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
 416                              (long)pos, (long)hdelta,
 417                              (long)runtime->period_size, jdelta,
 418                              ((hdelta * HZ) / runtime->rate), hw_base,
 419                              (unsigned long)old_hw_ptr,
 420                              (unsigned long)new_hw_ptr);
 421                 /* reset values to proper state */
 422                 delta = 0;
 423                 hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
 424         }
 425  no_jiffies_check:
 426         if (delta > runtime->period_size + runtime->period_size / 2) {
 427                 hw_ptr_error(substream, in_interrupt,
 428                              "Lost interrupts?",
 429                              "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 430                              substream->stream, (long)delta,
 431                              (long)new_hw_ptr,
 432                              (long)old_hw_ptr);
 433         }
 434
 435  no_delta_check:
 436         if (runtime->status->hw_ptr == new_hw_ptr) {
 437                 runtime->hw_ptr_jiffies = curr_jiffies;
 438                 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 439                 return 0;
 440         }
 441
 442         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 443             runtime->silence_size > 0)
 444                 snd_pcm_playback_silence(substream, new_hw_ptr);
 445
 446         if (in_interrupt) {
 447                 delta = new_hw_ptr - runtime->hw_ptr_interrupt;
 448                 if (delta < 0)
 449                         delta += runtime->boundary;
 450                 delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
 451                 runtime->hw_ptr_interrupt += delta;
 452                 if (runtime->hw_ptr_interrupt >= runtime->boundary)
 453                         runtime->hw_ptr_interrupt -= runtime->boundary;
 454         }
 455         runtime->hw_ptr_base = hw_base;
 456         runtime->status->hw_ptr = new_hw_ptr;
 457         runtime->hw_ptr_jiffies = curr_jiffies;
 458         if (crossed_boundary) {
 459                 snd_BUG_ON(crossed_boundary != 1);
 460                 runtime->hw_ptr_wrap += runtime->boundary;
 461         }
 462
 463         update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 464
 465         return snd_pcm_update_state(substream, runtime);
 466 }
 467
 468 /* CAUTION: call it with irq disabled */
 469 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 470 {
 471         return snd_pcm_update_hw_ptr0(substream, 0);
 472 }
 473
 474 /**
 475  * snd_pcm_set_ops - set the PCM operators
 476  * @pcm: the pcm instance
 477  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
 478  * @ops: the operator table
 479  *
 480  * Sets the given PCM operators to the pcm instance.
 481  */
 482 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
 483                      const struct snd_pcm_ops *ops)
 484 {
 485         struct snd_pcm_str *stream = &pcm->streams[direction];
 486         struct snd_pcm_substream *substream;
 487
 488         for (substream = stream->substream; substream != NULL; substream = substream->next)
 489                 substream->ops = ops;
 490 }
 491 EXPORT_SYMBOL(snd_pcm_set_ops);
 492
 493 /**
 494  * snd_pcm_set_sync - set the PCM sync id
 495  * @substream: the pcm substream
 496  *
 497  * Sets the PCM sync identifier for the card.
 498  */
 499 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
 500 {
 501         struct snd_pcm_runtime *runtime = substream->runtime;
 502
 503         runtime->sync.id32[0] = substream->pcm->card->number;
 504         runtime->sync.id32[1] = -1;
 505         runtime->sync.id32[2] = -1;
 506         runtime->sync.id32[3] = -1;
 507 }
 508 EXPORT_SYMBOL(snd_pcm_set_sync);
 509
 510 /*
 511  *  Standard ioctl routine
 512  */
 513
 514 static inline unsigned int div32(unsigned int a, unsigned int b,
 515                                  unsigned int *r)
 516 {
 517         if (b == 0) {
 518                 *r = 0;
 519                 return UINT_MAX;
 520         }
 521         *r = a % b;
 522         return a / b;
 523 }
 524
 525 static inline unsigned int div_down(unsigned int a, unsigned int b)
 526 {
 527         if (b == 0)
 528                 return UINT_MAX;
 529         return a / b;
 530 }
 531
 532 static inline unsigned int div_up(unsigned int a, unsigned int b)
 533 {
 534         unsigned int r;
 535         unsigned int q;
 536         if (b == 0)
 537                 return UINT_MAX;
 538         q = div32(a, b, &r);
 539         if (r)
 540                 ++q;
 541         return q;
 542 }
 543
 544 static inline unsigned int mul(unsigned int a, unsigned int b)
 545 {
 546         if (a == 0)
 547                 return 0;
 548         if (div_down(UINT_MAX, a) < b)
 549                 return UINT_MAX;
 550         return a * b;
 551 }
 552
 553 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
 554                                     unsigned int c, unsigned int *r)
 555 {
 556         u_int64_t n = (u_int64_t) a * b;
 557         if (c == 0) {
 558                 *r = 0;
 559                 return UINT_MAX;
 560         }
 561         n = div_u64_rem(n, c, r);
 562         if (n >= UINT_MAX) {
 563                 *r = 0;
 564                 return UINT_MAX;
 565         }
 566         return n;
 567 }
 568
 569 /**
 570  * snd_interval_refine - refine the interval value of configurator
 571  * @i: the interval value to refine
 572  * @v: the interval value to refer to
 573  *
 574  * Refines the interval value with the reference value.
 575  * The interval is changed to the range satisfying both intervals.
 576  * The interval status (min, max, integer, etc.) are evaluated.
 577  *
 578  * Return: Positive if the value is changed, zero if it's not changed, or a
 579  * negative error code.
 580  */
 581 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
 582 {
 583         int changed = 0;
 584         if (snd_BUG_ON(snd_interval_empty(i)))
 585                 return -EINVAL;
 586         if (i->min < v->min) {
 587                 i->min = v->min;
 588                 i->openmin = v->openmin;
 589                 changed = 1;
 590         } else if (i->min == v->min && !i->openmin && v->openmin) {
 591                 i->openmin = 1;
 592                 changed = 1;
 593         }
 594         if (i->max > v->max) {
 595                 i->max = v->max;
 596                 i->openmax = v->openmax;
 597                 changed = 1;
 598         } else if (i->max == v->max && !i->openmax && v->openmax) {
 599                 i->openmax = 1;
 600                 changed = 1;
 601         }
 602         if (!i->integer && v->integer) {
 603                 i->integer = 1;
 604                 changed = 1;
 605         }
 606         if (i->integer) {
 607                 if (i->openmin) {
 608                         i->min++;
 609                         i->openmin = 0;
 610                 }
 611                 if (i->openmax) {
 612                         i->max--;
 613                         i->openmax = 0;
 614                 }
 615         } else if (!i->openmin && !i->openmax && i->min == i->max)
 616                 i->integer = 1;
 617         if (snd_interval_checkempty(i)) {
 618                 snd_interval_none(i);
 619                 return -EINVAL;
 620         }
 621         return changed;
 622 }
 623 EXPORT_SYMBOL(snd_interval_refine);
 624
 625 static int snd_interval_refine_first(struct snd_interval *i)
 626 {
 627         const unsigned int last_max = i->max;
 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         if (i->openmin)
 635                 i->max++;
 636         /* only exclude max value if also excluded before refine */
 637         i->openmax = (i->openmax && i->max >= last_max);
 638         return 1;
 639 }
 640
 641 static int snd_interval_refine_last(struct snd_interval *i)
 642 {
 643         const unsigned int last_min = i->min;
 644
 645         if (snd_BUG_ON(snd_interval_empty(i)))
 646                 return -EINVAL;
 647         if (snd_interval_single(i))
 648                 return 0;
 649         i->min = i->max;
 650         if (i->openmax)
 651                 i->min--;
 652         /* only exclude min value if also excluded before refine */
 653         i->openmin = (i->openmin && i->min <= last_min);
 654         return 1;
 655 }
 656
 657 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 658 {
 659         if (a->empty || b->empty) {
 660                 snd_interval_none(c);
 661                 return;
 662         }
 663         c->empty = 0;
 664         c->min = mul(a->min, b->min);
 665         c->openmin = (a->openmin || b->openmin);
 666         c->max = mul(a->max,  b->max);
 667         c->openmax = (a->openmax || b->openmax);
 668         c->integer = (a->integer && b->integer);
 669 }
 670
 671 /**
 672  * snd_interval_div - refine the interval value with division
 673  * @a: dividend
 674  * @b: divisor
 675  * @c: quotient
 676  *
 677  * c = a / b
 678  *
 679  * Returns non-zero if the value is changed, zero if not changed.
 680  */
 681 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 682 {
 683         unsigned int r;
 684         if (a->empty || b->empty) {
 685                 snd_interval_none(c);
 686                 return;
 687         }
 688         c->empty = 0;
 689         c->min = div32(a->min, b->max, &r);
 690         c->openmin = (r || a->openmin || b->openmax);
 691         if (b->min > 0) {
 692                 c->max = div32(a->max, b->min, &r);
 693                 if (r) {
 694                         c->max++;
 695                         c->openmax = 1;
 696                 } else
 697                         c->openmax = (a->openmax || b->openmin);
 698         } else {
 699                 c->max = UINT_MAX;
 700                 c->openmax = 0;
 701         }
 702         c->integer = 0;
 703 }
 704
 705 /**
 706  * snd_interval_muldivk - refine the interval value
 707  * @a: dividend 1
 708  * @b: dividend 2
 709  * @k: divisor (as integer)
 710  * @c: result
 711   *
 712  * c = a * b / k
 713  *
 714  * Returns non-zero if the value is changed, zero if not changed.
 715  */
 716 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
 717                       unsigned int k, struct snd_interval *c)
 718 {
 719         unsigned int r;
 720         if (a->empty || b->empty) {
 721                 snd_interval_none(c);
 722                 return;
 723         }
 724         c->empty = 0;
 725         c->min = muldiv32(a->min, b->min, k, &r);
 726         c->openmin = (r || a->openmin || b->openmin);
 727         c->max = muldiv32(a->max, b->max, k, &r);
 728         if (r) {
 729                 c->max++;
 730                 c->openmax = 1;
 731         } else
 732                 c->openmax = (a->openmax || b->openmax);
 733         c->integer = 0;
 734 }
 735
 736 /**
 737  * snd_interval_mulkdiv - refine the interval value
 738  * @a: dividend 1
 739  * @k: dividend 2 (as integer)
 740  * @b: divisor
 741  * @c: result
 742  *
 743  * c = a * k / b
 744  *
 745  * Returns non-zero if the value is changed, zero if not changed.
 746  */
 747 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
 748                       const struct snd_interval *b, struct snd_interval *c)
 749 {
 750         unsigned int r;
 751         if (a->empty || b->empty) {
 752                 snd_interval_none(c);
 753                 return;
 754         }
 755         c->empty = 0;
 756         c->min = muldiv32(a->min, k, b->max, &r);
 757         c->openmin = (r || a->openmin || b->openmax);
 758         if (b->min > 0) {
 759                 c->max = muldiv32(a->max, k, b->min, &r);
 760                 if (r) {
 761                         c->max++;
 762                         c->openmax = 1;
 763                 } else
 764                         c->openmax = (a->openmax || b->openmin);
 765         } else {
 766                 c->max = UINT_MAX;
 767                 c->openmax = 0;
 768         }
 769         c->integer = 0;
 770 }
 771
 772 /* ---- */
 773
 774
 775 /**
 776  * snd_interval_ratnum - refine the interval value
 777  * @i: interval to refine
 778  * @rats_count: number of ratnum_t
 779  * @rats: ratnum_t array
 780  * @nump: pointer to store the resultant numerator
 781  * @denp: pointer to store the resultant denominator
 782  *
 783  * Return: Positive if the value is changed, zero if it's not changed, or a
 784  * negative error code.
 785  */
 786 int snd_interval_ratnum(struct snd_interval *i,
 787                         unsigned int rats_count, const struct snd_ratnum *rats,
 788                         unsigned int *nump, unsigned int *denp)
 789 {
 790         unsigned int best_num, best_den;
 791         int best_diff;
 792         unsigned int k;
 793         struct snd_interval t;
 794         int err;
 795         unsigned int result_num, result_den;
 796         int result_diff;
 797
 798         best_num = best_den = best_diff = 0;
 799         for (k = 0; k < rats_count; ++k) {
 800                 unsigned int num = rats[k].num;
 801                 unsigned int den;
 802                 unsigned int q = i->min;
 803                 int diff;
 804                 if (q == 0)
 805                         q = 1;
 806                 den = div_up(num, q);
 807                 if (den < rats[k].den_min)
 808                         continue;
 809                 if (den > rats[k].den_max)
 810                         den = rats[k].den_max;
 811                 else {
 812                         unsigned int r;
 813                         r = (den - rats[k].den_min) % rats[k].den_step;
 814                         if (r != 0)
 815                                 den -= r;
 816                 }
 817                 diff = num - q * den;
 818                 if (diff < 0)
 819                         diff = -diff;
 820                 if (best_num == 0 ||
 821                     diff * best_den < best_diff * den) {
 822                         best_diff = diff;
 823                         best_den = den;
 824                         best_num = num;
 825                 }
 826         }
 827         if (best_den == 0) {
 828                 i->empty = 1;
 829                 return -EINVAL;
 830         }
 831         t.min = div_down(best_num, best_den);
 832         t.openmin = !!(best_num % best_den);
 833
 834         result_num = best_num;
 835         result_diff = best_diff;
 836         result_den = best_den;
 837         best_num = best_den = best_diff = 0;
 838         for (k = 0; k < rats_count; ++k) {
 839                 unsigned int num = rats[k].num;
 840                 unsigned int den;
 841                 unsigned int q = i->max;
 842                 int diff;
 843                 if (q == 0) {
 844                         i->empty = 1;
 845                         return -EINVAL;
 846                 }
 847                 den = div_down(num, q);
 848                 if (den > rats[k].den_max)
 849                         continue;
 850                 if (den < rats[k].den_min)
 851                         den = rats[k].den_min;
 852                 else {
 853                         unsigned int r;
 854                         r = (den - rats[k].den_min) % rats[k].den_step;
 855                         if (r != 0)
 856                                 den += rats[k].den_step - r;
 857                 }
 858                 diff = q * den - num;
 859                 if (diff < 0)
 860                         diff = -diff;
 861                 if (best_num == 0 ||
 862                     diff * best_den < best_diff * den) {
 863                         best_diff = diff;
 864                         best_den = den;
 865                         best_num = num;
 866                 }
 867         }
 868         if (best_den == 0) {
 869                 i->empty = 1;
 870                 return -EINVAL;
 871         }
 872         t.max = div_up(best_num, best_den);
 873         t.openmax = !!(best_num % best_den);
 874         t.integer = 0;
 875         err = snd_interval_refine(i, &t);
 876         if (err < 0)
 877                 return err;
 878
 879         if (snd_interval_single(i)) {
 880                 if (best_diff * result_den < result_diff * best_den) {
 881                         result_num = best_num;
 882                         result_den = best_den;
 883                 }
 884                 if (nump)
 885                         *nump = result_num;
 886                 if (denp)
 887                         *denp = result_den;
 888         }
 889         return err;
 890 }
 891 EXPORT_SYMBOL(snd_interval_ratnum);
 892
 893 /**
 894  * snd_interval_ratden - refine the interval value
 895  * @i: interval to refine
 896  * @rats_count: number of struct ratden
 897  * @rats: struct ratden array
 898  * @nump: pointer to store the resultant numerator
 899  * @denp: pointer to store the resultant denominator
 900  *
 901  * Return: Positive if the value is changed, zero if it's not changed, or a
 902  * negative error code.
 903  */
 904 static int snd_interval_ratden(struct snd_interval *i,
 905                                unsigned int rats_count,
 906                                const struct snd_ratden *rats,
 907                                unsigned int *nump, unsigned int *denp)
 908 {
 909         unsigned int best_num, best_diff, best_den;
 910         unsigned int k;
 911         struct snd_interval t;
 912         int err;
 913
 914         best_num = best_den = best_diff = 0;
 915         for (k = 0; k < rats_count; ++k) {
 916                 unsigned int num;
 917                 unsigned int den = rats[k].den;
 918                 unsigned int q = i->min;
 919                 int diff;
 920                 num = mul(q, den);
 921                 if (num > rats[k].num_max)
 922                         continue;
 923                 if (num < rats[k].num_min)
 924                         num = rats[k].num_max;
 925                 else {
 926                         unsigned int r;
 927                         r = (num - rats[k].num_min) % rats[k].num_step;
 928                         if (r != 0)
 929                                 num += rats[k].num_step - r;
 930                 }
 931                 diff = num - q * den;
 932                 if (best_num == 0 ||
 933                     diff * best_den < best_diff * den) {
 934                         best_diff = diff;
 935                         best_den = den;
 936                         best_num = num;
 937                 }
 938         }
 939         if (best_den == 0) {
 940                 i->empty = 1;
 941                 return -EINVAL;
 942         }
 943         t.min = div_down(best_num, best_den);
 944         t.openmin = !!(best_num % best_den);
 945
 946         best_num = best_den = best_diff = 0;
 947         for (k = 0; k < rats_count; ++k) {
 948                 unsigned int num;
 949                 unsigned int den = rats[k].den;
 950                 unsigned int q = i->max;
 951                 int diff;
 952                 num = mul(q, den);
 953                 if (num < rats[k].num_min)
 954                         continue;
 955                 if (num > rats[k].num_max)
 956                         num = rats[k].num_max;
 957                 else {
 958                         unsigned int r;
 959                         r = (num - rats[k].num_min) % rats[k].num_step;
 960                         if (r != 0)
 961                                 num -= r;
 962                 }
 963                 diff = q * den - num;
 964                 if (best_num == 0 ||
 965                     diff * best_den < best_diff * den) {
 966                         best_diff = diff;
 967                         best_den = den;
 968                         best_num = num;
 969                 }
 970         }
 971         if (best_den == 0) {
 972                 i->empty = 1;
 973                 return -EINVAL;
 974         }
 975         t.max = div_up(best_num, best_den);
 976         t.openmax = !!(best_num % best_den);
 977         t.integer = 0;
 978         err = snd_interval_refine(i, &t);
 979         if (err < 0)
 980                 return err;
 981
 982         if (snd_interval_single(i)) {
 983                 if (nump)
 984                         *nump = best_num;
 985                 if (denp)
 986                         *denp = best_den;
 987         }
 988         return err;
 989 }
 990
 991 /**
 992  * snd_interval_list - refine the interval value from the list
 993  * @i: the interval value to refine
 994  * @count: the number of elements in the list
 995  * @list: the value list
 996  * @mask: the bit-mask to evaluate
 997  *
 998  * Refines the interval value from the list.
 999  * When mask is non-zero, only the elements corresponding to bit 1 are
1000  * evaluated.
1001  *
1002  * Return: Positive if the value is changed, zero if it's not changed, or a
1003  * negative error code.
1004  */
1005 int snd_interval_list(struct snd_interval *i, unsigned int count,
1006                       const unsigned int *list, unsigned int mask)
1007 {
1008         unsigned int k;
1009         struct snd_interval list_range;
1010
1011         if (!count) {
1012                 i->empty = 1;
1013                 return -EINVAL;
1014         }
1015         snd_interval_any(&list_range);
1016         list_range.min = UINT_MAX;
1017         list_range.max = 0;
1018         for (k = 0; k < count; k++) {
1019                 if (mask && !(mask & (1 << k)))
1020                         continue;
1021                 if (!snd_interval_test(i, list[k]))
1022                         continue;
1023                 list_range.min = min(list_range.min, list[k]);
1024                 list_range.max = max(list_range.max, list[k]);
1025         }
1026         return snd_interval_refine(i, &list_range);
1027 }
1028 EXPORT_SYMBOL(snd_interval_list);
1029
1030 /**
1031  * snd_interval_ranges - refine the interval value from the list of ranges
1032  * @i: the interval value to refine
1033  * @count: the number of elements in the list of ranges
1034  * @ranges: the ranges list
1035  * @mask: the bit-mask to evaluate
1036  *
1037  * Refines the interval value from the list of ranges.
1038  * When mask is non-zero, only the elements corresponding to bit 1 are
1039  * evaluated.
1040  *
1041  * Return: Positive if the value is changed, zero if it's not changed, or a
1042  * negative error code.
1043  */
1044 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1045                         const struct snd_interval *ranges, unsigned int mask)
1046 {
1047         unsigned int k;
1048         struct snd_interval range_union;
1049         struct snd_interval range;
1050
1051         if (!count) {
1052                 snd_interval_none(i);
1053                 return -EINVAL;
1054         }
1055         snd_interval_any(&range_union);
1056         range_union.min = UINT_MAX;
1057         range_union.max = 0;
1058         for (k = 0; k < count; k++) {
1059                 if (mask && !(mask & (1 << k)))
1060                         continue;
1061                 snd_interval_copy(&range, &ranges[k]);
1062                 if (snd_interval_refine(&range, i) < 0)
1063                         continue;
1064                 if (snd_interval_empty(&range))
1065                         continue;
1066
1067                 if (range.min < range_union.min) {
1068                         range_union.min = range.min;
1069                         range_union.openmin = 1;
1070                 }
1071                 if (range.min == range_union.min && !range.openmin)
1072                         range_union.openmin = 0;
1073                 if (range.max > range_union.max) {
1074                         range_union.max = range.max;
1075                         range_union.openmax = 1;
1076                 }
1077                 if (range.max == range_union.max && !range.openmax)
1078                         range_union.openmax = 0;
1079         }
1080         return snd_interval_refine(i, &range_union);
1081 }
1082 EXPORT_SYMBOL(snd_interval_ranges);
1083
1084 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1085 {
1086         unsigned int n;
1087         int changed = 0;
1088         n = i->min % step;
1089         if (n != 0 || i->openmin) {
1090                 i->min += step - n;
1091                 i->openmin = 0;
1092                 changed = 1;
1093         }
1094         n = i->max % step;
1095         if (n != 0 || i->openmax) {
1096                 i->max -= n;
1097                 i->openmax = 0;
1098                 changed = 1;
1099         }
1100         if (snd_interval_checkempty(i)) {
1101                 i->empty = 1;
1102                 return -EINVAL;
1103         }
1104         return changed;
1105 }
1106
1107 /* Info constraints helpers */
1108
1109 /**
1110  * snd_pcm_hw_rule_add - add the hw-constraint rule
1111  * @runtime: the pcm runtime instance
1112  * @cond: condition bits
1113  * @var: the variable to evaluate
1114  * @func: the evaluation function
1115  * @private: the private data pointer passed to function
1116  * @dep: the dependent variables
1117  *
1118  * Return: Zero if successful, or a negative error code on failure.
1119  */
1120 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1121                         int var,
1122                         snd_pcm_hw_rule_func_t func, void *private,
1123                         int dep, ...)
1124 {
1125         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1126         struct snd_pcm_hw_rule *c;
1127         unsigned int k;
1128         va_list args;
1129         va_start(args, dep);
1130         if (constrs->rules_num >= constrs->rules_all) {
1131                 struct snd_pcm_hw_rule *new;
1132                 unsigned int new_rules = constrs->rules_all + 16;
1133                 new = krealloc_array(constrs->rules, new_rules,
1134                                      sizeof(*c), GFP_KERNEL);
1135                 if (!new) {
1136                         va_end(args);
1137                         return -ENOMEM;
1138                 }
1139                 constrs->rules = new;
1140                 constrs->rules_all = new_rules;
1141         }
1142         c = &constrs->rules[constrs->rules_num];
1143         c->cond = cond;
1144         c->func = func;
1145         c->var = var;
1146         c->private = private;
1147         k = 0;
1148         while (1) {
1149                 if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1150                         va_end(args);
1151                         return -EINVAL;
1152                 }
1153                 c->deps[k++] = dep;
1154                 if (dep < 0)
1155                         break;
1156                 dep = va_arg(args, int);
1157         }
1158         constrs->rules_num++;
1159         va_end(args);
1160         return 0;
1161 }
1162 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1163
1164 /**
1165  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1166  * @runtime: PCM runtime instance
1167  * @var: hw_params variable to apply the mask
1168  * @mask: the bitmap mask
1169  *
1170  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1171  *
1172  * Return: Zero if successful, or a negative error code on failure.
1173  */
1174 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1175                                u_int32_t mask)
1176 {
1177         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1178         struct snd_mask *maskp = constrs_mask(constrs, var);
1179         *maskp->bits &= mask;
1180         memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1181         if (*maskp->bits == 0)
1182                 return -EINVAL;
1183         return 0;
1184 }
1185
1186 /**
1187  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1188  * @runtime: PCM runtime instance
1189  * @var: hw_params variable to apply the mask
1190  * @mask: the 64bit bitmap mask
1191  *
1192  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1193  *
1194  * Return: Zero if successful, or a negative error code on failure.
1195  */
1196 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1197                                  u_int64_t mask)
1198 {
1199         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1200         struct snd_mask *maskp = constrs_mask(constrs, var);
1201         maskp->bits[0] &= (u_int32_t)mask;
1202         maskp->bits[1] &= (u_int32_t)(mask >> 32);
1203         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1204         if (! maskp->bits[0] && ! maskp->bits[1])
1205                 return -EINVAL;
1206         return 0;
1207 }
1208 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1209
1210 /**
1211  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1212  * @runtime: PCM runtime instance
1213  * @var: hw_params variable to apply the integer constraint
1214  *
1215  * Apply the constraint of integer to an interval parameter.
1216  *
1217  * Return: Positive if the value is changed, zero if it's not changed, or a
1218  * negative error code.
1219  */
1220 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1221 {
1222         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1223         return snd_interval_setinteger(constrs_interval(constrs, var));
1224 }
1225 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1226
1227 /**
1228  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1229  * @runtime: PCM runtime instance
1230  * @var: hw_params variable to apply the range
1231  * @min: the minimal value
1232  * @max: the maximal value
1233  *
1234  * Apply the min/max range constraint to an interval parameter.
1235  *
1236  * Return: Positive if the value is changed, zero if it's not changed, or a
1237  * negative error code.
1238  */
1239 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1240                                  unsigned int min, unsigned int max)
1241 {
1242         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1243         struct snd_interval t;
1244         t.min = min;
1245         t.max = max;
1246         t.openmin = t.openmax = 0;
1247         t.integer = 0;
1248         return snd_interval_refine(constrs_interval(constrs, var), &t);
1249 }
1250 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1251
1252 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1253                                 struct snd_pcm_hw_rule *rule)
1254 {
1255         struct snd_pcm_hw_constraint_list *list = rule->private;
1256         return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1257 }
1258
1259
1260 /**
1261  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1262  * @runtime: PCM runtime instance
1263  * @cond: condition bits
1264  * @var: hw_params variable to apply the list constraint
1265  * @l: list
1266  *
1267  * Apply the list of constraints to an interval parameter.
1268  *
1269  * Return: Zero if successful, or a negative error code on failure.
1270  */
1271 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1272                                unsigned int cond,
1273                                snd_pcm_hw_param_t var,
1274                                const struct snd_pcm_hw_constraint_list *l)
1275 {
1276         return snd_pcm_hw_rule_add(runtime, cond, var,
1277                                    snd_pcm_hw_rule_list, (void *)l,
1278                                    var, -1);
1279 }
1280 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1281
1282 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1283                                   struct snd_pcm_hw_rule *rule)
1284 {
1285         struct snd_pcm_hw_constraint_ranges *r = rule->private;
1286         return snd_interval_ranges(hw_param_interval(params, rule->var),
1287                                    r->count, r->ranges, r->mask);
1288 }
1289
1290
1291 /**
1292  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1293  * @runtime: PCM runtime instance
1294  * @cond: condition bits
1295  * @var: hw_params variable to apply the list of range constraints
1296  * @r: ranges
1297  *
1298  * Apply the list of range constraints to an interval parameter.
1299  *
1300  * Return: Zero if successful, or a negative error code on failure.
1301  */
1302 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1303                                  unsigned int cond,
1304                                  snd_pcm_hw_param_t var,
1305                                  const struct snd_pcm_hw_constraint_ranges *r)
1306 {
1307         return snd_pcm_hw_rule_add(runtime, cond, var,
1308                                    snd_pcm_hw_rule_ranges, (void *)r,
1309                                    var, -1);
1310 }
1311 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1312
1313 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1314                                    struct snd_pcm_hw_rule *rule)
1315 {
1316         const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1317         unsigned int num = 0, den = 0;
1318         int err;
1319         err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1320                                   r->nrats, r->rats, &num, &den);
1321         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1322                 params->rate_num = num;
1323                 params->rate_den = den;
1324         }
1325         return err;
1326 }
1327
1328 /**
1329  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1330  * @runtime: PCM runtime instance
1331  * @cond: condition bits
1332  * @var: hw_params variable to apply the ratnums constraint
1333  * @r: struct snd_ratnums constriants
1334  *
1335  * Return: Zero if successful, or a negative error code on failure.
1336  */
1337 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1338                                   unsigned int cond,
1339                                   snd_pcm_hw_param_t var,
1340                                   const struct snd_pcm_hw_constraint_ratnums *r)
1341 {
1342         return snd_pcm_hw_rule_add(runtime, cond, var,
1343                                    snd_pcm_hw_rule_ratnums, (void *)r,
1344                                    var, -1);
1345 }
1346 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1347
1348 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1349                                    struct snd_pcm_hw_rule *rule)
1350 {
1351         const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1352         unsigned int num = 0, den = 0;
1353         int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1354                                   r->nrats, r->rats, &num, &den);
1355         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1356                 params->rate_num = num;
1357                 params->rate_den = den;
1358         }
1359         return err;
1360 }
1361
1362 /**
1363  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1364  * @runtime: PCM runtime instance
1365  * @cond: condition bits
1366  * @var: hw_params variable to apply the ratdens constraint
1367  * @r: struct snd_ratdens constriants
1368  *
1369  * Return: Zero if successful, or a negative error code on failure.
1370  */
1371 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1372                                   unsigned int cond,
1373                                   snd_pcm_hw_param_t var,
1374                                   const struct snd_pcm_hw_constraint_ratdens *r)
1375 {
1376         return snd_pcm_hw_rule_add(runtime, cond, var,
1377                                    snd_pcm_hw_rule_ratdens, (void *)r,
1378                                    var, -1);
1379 }
1380 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1381
1382 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1383                                   struct snd_pcm_hw_rule *rule)
1384 {
1385         unsigned int l = (unsigned long) rule->private;
1386         int width = l & 0xffff;
1387         unsigned int msbits = l >> 16;
1388         const struct snd_interval *i =
1389                 hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1390
1391         if (!snd_interval_single(i))
1392                 return 0;
1393
1394         if ((snd_interval_value(i) == width) ||
1395             (width == 0 && snd_interval_value(i) > msbits))
1396                 params->msbits = min_not_zero(params->msbits, msbits);
1397
1398         return 0;
1399 }
1400
1401 /**
1402  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1403  * @runtime: PCM runtime instance
1404  * @cond: condition bits
1405  * @width: sample bits width
1406  * @msbits: msbits width
1407  *
1408  * This constraint will set the number of most significant bits (msbits) if a
1409  * sample format with the specified width has been select. If width is set to 0
1410  * the msbits will be set for any sample format with a width larger than the
1411  * specified msbits.
1412  *
1413  * Return: Zero if successful, or a negative error code on failure.
1414  */
1415 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1416                                  unsigned int cond,
1417                                  unsigned int width,
1418                                  unsigned int msbits)
1419 {
1420         unsigned long l = (msbits << 16) | width;
1421         return snd_pcm_hw_rule_add(runtime, cond, -1,
1422                                     snd_pcm_hw_rule_msbits,
1423                                     (void*) l,
1424                                     SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1425 }
1426 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1427
1428 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1429                                 struct snd_pcm_hw_rule *rule)
1430 {
1431         unsigned long step = (unsigned long) rule->private;
1432         return snd_interval_step(hw_param_interval(params, rule->var), step);
1433 }
1434
1435 /**
1436  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1437  * @runtime: PCM runtime instance
1438  * @cond: condition bits
1439  * @var: hw_params variable to apply the step constraint
1440  * @step: step size
1441  *
1442  * Return: Zero if successful, or a negative error code on failure.
1443  */
1444 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1445                                unsigned int cond,
1446                                snd_pcm_hw_param_t var,
1447                                unsigned long step)
1448 {
1449         return snd_pcm_hw_rule_add(runtime, cond, var,
1450                                    snd_pcm_hw_rule_step, (void *) step,
1451                                    var, -1);
1452 }
1453 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1454
1455 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1456 {
1457         static const unsigned int pow2_sizes[] = {
1458                 1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1459                 1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1460                 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1461                 1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1462         };
1463         return snd_interval_list(hw_param_interval(params, rule->var),
1464                                  ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1465 }
1466
1467 /**
1468  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1469  * @runtime: PCM runtime instance
1470  * @cond: condition bits
1471  * @var: hw_params variable to apply the power-of-2 constraint
1472  *
1473  * Return: Zero if successful, or a negative error code on failure.
1474  */
1475 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1476                                unsigned int cond,
1477                                snd_pcm_hw_param_t var)
1478 {
1479         return snd_pcm_hw_rule_add(runtime, cond, var,
1480                                    snd_pcm_hw_rule_pow2, NULL,
1481                                    var, -1);
1482 }
1483 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1484
1485 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1486                                            struct snd_pcm_hw_rule *rule)
1487 {
1488         unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1489         struct snd_interval *rate;
1490
1491         rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1492         return snd_interval_list(rate, 1, &base_rate, 0);
1493 }
1494
1495 /**
1496  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1497  * @runtime: PCM runtime instance
1498  * @base_rate: the rate at which the hardware does not resample
1499  *
1500  * Return: Zero if successful, or a negative error code on failure.
1501  */
1502 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1503                                unsigned int base_rate)
1504 {
1505         return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1506                                    SNDRV_PCM_HW_PARAM_RATE,
1507                                    snd_pcm_hw_rule_noresample_func,
1508                                    (void *)(uintptr_t)base_rate,
1509                                    SNDRV_PCM_HW_PARAM_RATE, -1);
1510 }
1511 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1512
1513 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1514                                   snd_pcm_hw_param_t var)
1515 {
1516         if (hw_is_mask(var)) {
1517                 snd_mask_any(hw_param_mask(params, var));
1518                 params->cmask |= 1 << var;
1519                 params->rmask |= 1 << var;
1520                 return;
1521         }
1522         if (hw_is_interval(var)) {
1523                 snd_interval_any(hw_param_interval(params, var));
1524                 params->cmask |= 1 << var;
1525                 params->rmask |= 1 << var;
1526                 return;
1527         }
1528         snd_BUG();
1529 }
1530
1531 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1532 {
1533         unsigned int k;
1534         memset(params, 0, sizeof(*params));
1535         for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1536                 _snd_pcm_hw_param_any(params, k);
1537         for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1538                 _snd_pcm_hw_param_any(params, k);
1539         params->info = ~0U;
1540 }
1541 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1542
1543 /**
1544  * snd_pcm_hw_param_value - return @params field @var value
1545  * @params: the hw_params instance
1546  * @var: parameter to retrieve
1547  * @dir: pointer to the direction (-1,0,1) or %NULL
1548  *
1549  * Return: The value for field @var if it's fixed in configuration space
1550  * defined by @params. -%EINVAL otherwise.
1551  */
1552 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1553                            snd_pcm_hw_param_t var, int *dir)
1554 {
1555         if (hw_is_mask(var)) {
1556                 const struct snd_mask *mask = hw_param_mask_c(params, var);
1557                 if (!snd_mask_single(mask))
1558                         return -EINVAL;
1559                 if (dir)
1560                         *dir = 0;
1561                 return snd_mask_value(mask);
1562         }
1563         if (hw_is_interval(var)) {
1564                 const struct snd_interval *i = hw_param_interval_c(params, var);
1565                 if (!snd_interval_single(i))
1566                         return -EINVAL;
1567                 if (dir)
1568                         *dir = i->openmin;
1569                 return snd_interval_value(i);
1570         }
1571         return -EINVAL;
1572 }
1573 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1574
1575 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1576                                 snd_pcm_hw_param_t var)
1577 {
1578         if (hw_is_mask(var)) {
1579                 snd_mask_none(hw_param_mask(params, var));
1580                 params->cmask |= 1 << var;
1581                 params->rmask |= 1 << var;
1582         } else if (hw_is_interval(var)) {
1583                 snd_interval_none(hw_param_interval(params, var));
1584                 params->cmask |= 1 << var;
1585                 params->rmask |= 1 << var;
1586         } else {
1587                 snd_BUG();
1588         }
1589 }
1590 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1591
1592 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1593                                    snd_pcm_hw_param_t var)
1594 {
1595         int changed;
1596         if (hw_is_mask(var))
1597                 changed = snd_mask_refine_first(hw_param_mask(params, var));
1598         else if (hw_is_interval(var))
1599                 changed = snd_interval_refine_first(hw_param_interval(params, var));
1600         else
1601                 return -EINVAL;
1602         if (changed > 0) {
1603                 params->cmask |= 1 << var;
1604                 params->rmask |= 1 << var;
1605         }
1606         return changed;
1607 }
1608
1609
1610 /**
1611  * snd_pcm_hw_param_first - refine config space and return minimum value
1612  * @pcm: PCM instance
1613  * @params: the hw_params instance
1614  * @var: parameter to retrieve
1615  * @dir: pointer to the direction (-1,0,1) or %NULL
1616  *
1617  * Inside configuration space defined by @params remove from @var all
1618  * values > minimum. Reduce configuration space accordingly.
1619  *
1620  * Return: The minimum, or a negative error code on failure.
1621  */
1622 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1623                            struct snd_pcm_hw_params *params,
1624                            snd_pcm_hw_param_t var, int *dir)
1625 {
1626         int changed = _snd_pcm_hw_param_first(params, var);
1627         if (changed < 0)
1628                 return changed;
1629         if (params->rmask) {
1630                 int err = snd_pcm_hw_refine(pcm, params);
1631                 if (err < 0)
1632                         return err;
1633         }
1634         return snd_pcm_hw_param_value(params, var, dir);
1635 }
1636 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1637
1638 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1639                                   snd_pcm_hw_param_t var)
1640 {
1641         int changed;
1642         if (hw_is_mask(var))
1643                 changed = snd_mask_refine_last(hw_param_mask(params, var));
1644         else if (hw_is_interval(var))
1645                 changed = snd_interval_refine_last(hw_param_interval(params, var));
1646         else
1647                 return -EINVAL;
1648         if (changed > 0) {
1649                 params->cmask |= 1 << var;
1650                 params->rmask |= 1 << var;
1651         }
1652         return changed;
1653 }
1654
1655
1656 /**
1657  * snd_pcm_hw_param_last - refine config space and return maximum value
1658  * @pcm: PCM instance
1659  * @params: the hw_params instance
1660  * @var: parameter to retrieve
1661  * @dir: pointer to the direction (-1,0,1) or %NULL
1662  *
1663  * Inside configuration space defined by @params remove from @var all
1664  * values < maximum. Reduce configuration space accordingly.
1665  *
1666  * Return: The maximum, or a negative error code on failure.
1667  */
1668 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1669                           struct snd_pcm_hw_params *params,
1670                           snd_pcm_hw_param_t var, int *dir)
1671 {
1672         int changed = _snd_pcm_hw_param_last(params, var);
1673         if (changed < 0)
1674                 return changed;
1675         if (params->rmask) {
1676                 int err = snd_pcm_hw_refine(pcm, params);
1677                 if (err < 0)
1678                         return err;
1679         }
1680         return snd_pcm_hw_param_value(params, var, dir);
1681 }
1682 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1683
1684 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1685                                    void *arg)
1686 {
1687         struct snd_pcm_runtime *runtime = substream->runtime;
1688         unsigned long flags;
1689         snd_pcm_stream_lock_irqsave(substream, flags);
1690         if (snd_pcm_running(substream) &&
1691             snd_pcm_update_hw_ptr(substream) >= 0)
1692                 runtime->status->hw_ptr %= runtime->buffer_size;
1693         else {
1694                 runtime->status->hw_ptr = 0;
1695                 runtime->hw_ptr_wrap = 0;
1696         }
1697         snd_pcm_stream_unlock_irqrestore(substream, flags);
1698         return 0;
1699 }
1700
1701 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1702                                           void *arg)
1703 {
1704         struct snd_pcm_channel_info *info = arg;
1705         struct snd_pcm_runtime *runtime = substream->runtime;
1706         int width;
1707         if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1708                 info->offset = -1;
1709                 return 0;
1710         }
1711         width = snd_pcm_format_physical_width(runtime->format);
1712         if (width < 0)
1713                 return width;
1714         info->offset = 0;
1715         switch (runtime->access) {
1716         case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1717         case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1718                 info->first = info->channel * width;
1719                 info->step = runtime->channels * width;
1720                 break;
1721         case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1722         case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1723         {
1724                 size_t size = runtime->dma_bytes / runtime->channels;
1725                 info->first = info->channel * size * 8;
1726                 info->step = width;
1727                 break;
1728         }
1729         default:
1730                 snd_BUG();
1731                 break;
1732         }
1733         return 0;
1734 }
1735
1736 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1737                                        void *arg)
1738 {
1739         struct snd_pcm_hw_params *params = arg;
1740         snd_pcm_format_t format;
1741         int channels;
1742         ssize_t frame_size;
1743
1744         params->fifo_size = substream->runtime->hw.fifo_size;
1745         if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1746                 format = params_format(params);
1747                 channels = params_channels(params);
1748                 frame_size = snd_pcm_format_size(format, channels);
1749                 if (frame_size > 0)
1750                         params->fifo_size /= frame_size;
1751         }
1752         return 0;
1753 }
1754
1755 /**
1756  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1757  * @substream: the pcm substream instance
1758  * @cmd: ioctl command
1759  * @arg: ioctl argument
1760  *
1761  * Processes the generic ioctl commands for PCM.
1762  * Can be passed as the ioctl callback for PCM ops.
1763  *
1764  * Return: Zero if successful, or a negative error code on failure.
1765  */
1766 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1767                       unsigned int cmd, void *arg)
1768 {
1769         switch (cmd) {
1770         case SNDRV_PCM_IOCTL1_RESET:
1771                 return snd_pcm_lib_ioctl_reset(substream, arg);
1772         case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1773                 return snd_pcm_lib_ioctl_channel_info(substream, arg);
1774         case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1775                 return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1776         }
1777         return -ENXIO;
1778 }
1779 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1780
1781 /**
1782  * snd_pcm_period_elapsed_under_stream_lock() - update the status of runtime for the next period
1783  *                                              under acquired lock of PCM substream.
1784  * @substream: the instance of pcm substream.
1785  *
1786  * This function is called when the batch of audio data frames as the same size as the period of
1787  * buffer is already processed in audio data transmission.
1788  *
1789  * The call of function updates the status of runtime with the latest position of audio data
1790  * transmission, checks overrun and underrun over buffer, awaken user processes from waiting for
1791  * available audio data frames, sampling audio timestamp, and performs stop or drain the PCM
1792  * substream according to configured threshold.
1793  *
1794  * The function is intended to use for the case that PCM driver operates audio data frames under
1795  * acquired lock of PCM substream; e.g. in callback of any operation of &snd_pcm_ops in process
1796  * context. In any interrupt context, it's preferrable to use ``snd_pcm_period_elapsed()`` instead
1797  * since lock of PCM substream should be acquired in advance.
1798  *
1799  * Developer should pay enough attention that some callbacks in &snd_pcm_ops are done by the call of
1800  * function:
1801  *
1802  * - .pointer - to retrieve current position of audio data transmission by frame count or XRUN state.
1803  * - .trigger - with SNDRV_PCM_TRIGGER_STOP at XRUN or DRAINING state.
1804  * - .get_time_info - to retrieve audio time stamp if needed.
1805  *
1806  * Even if more than one periods have elapsed since the last call, you have to call this only once.
1807  */
1808 void snd_pcm_period_elapsed_under_stream_lock(struct snd_pcm_substream *substream)
1809 {
1810         struct snd_pcm_runtime *runtime;
1811
1812         if (PCM_RUNTIME_CHECK(substream))
1813                 return;
1814         runtime = substream->runtime;
1815
1816         if (!snd_pcm_running(substream) ||
1817             snd_pcm_update_hw_ptr0(substream, 1) < 0)
1818                 goto _end;
1819
1820 #ifdef CONFIG_SND_PCM_TIMER
1821         if (substream->timer_running)
1822                 snd_timer_interrupt(substream->timer, 1);
1823 #endif
1824  _end:
1825         snd_kill_fasync(runtime->fasync, SIGIO, POLL_IN);
1826 }
1827 EXPORT_SYMBOL(snd_pcm_period_elapsed_under_stream_lock);
1828
1829 /**
1830  * snd_pcm_period_elapsed() - update the status of runtime for the next period by acquiring lock of
1831  *                            PCM substream.
1832  * @substream: the instance of PCM substream.
1833  *
1834  * This function is mostly similar to ``snd_pcm_period_elapsed_under_stream_lock()`` except for
1835  * acquiring lock of PCM substream voluntarily.
1836  *
1837  * It's typically called by any type of IRQ handler when hardware IRQ occurs to notify event that
1838  * the batch of audio data frames as the same size as the period of buffer is already processed in
1839  * audio data transmission.
1840  */
1841 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1842 {
1843         unsigned long flags;
1844
1845         if (snd_BUG_ON(!substream))
1846                 return;
1847
1848         snd_pcm_stream_lock_irqsave(substream, flags);
1849         snd_pcm_period_elapsed_under_stream_lock(substream);
1850         snd_pcm_stream_unlock_irqrestore(substream, flags);
1851 }
1852 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1853
1854 /*
1855  * Wait until avail_min data becomes available
1856  * Returns a negative error code if any error occurs during operation.
1857  * The available space is stored on availp.  When err = 0 and avail = 0
1858  * on the capture stream, it indicates the stream is in DRAINING state.
1859  */
1860 static int wait_for_avail(struct snd_pcm_substream *substream,
1861                               snd_pcm_uframes_t *availp)
1862 {
1863         struct snd_pcm_runtime *runtime = substream->runtime;
1864         int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1865         wait_queue_entry_t wait;
1866         int err = 0;
1867         snd_pcm_uframes_t avail = 0;
1868         long wait_time, tout;
1869
1870         init_waitqueue_entry(&wait, current);
1871         set_current_state(TASK_INTERRUPTIBLE);
1872         add_wait_queue(&runtime->tsleep, &wait);
1873
1874         if (runtime->no_period_wakeup)
1875                 wait_time = MAX_SCHEDULE_TIMEOUT;
1876         else {
1877                 /* use wait time from substream if available */
1878                 if (substream->wait_time) {
1879                         wait_time = substream->wait_time;
1880                 } else {
1881                         wait_time = 10;
1882
1883                         if (runtime->rate) {
1884                                 long t = runtime->period_size * 2 /
1885                                          runtime->rate;
1886                                 wait_time = max(t, wait_time);
1887                         }
1888                         wait_time = msecs_to_jiffies(wait_time * 1000);
1889                 }
1890         }
1891
1892         for (;;) {
1893                 if (signal_pending(current)) {
1894                         err = -ERESTARTSYS;
1895                         break;
1896                 }
1897
1898                 /*
1899                  * We need to check if space became available already
1900                  * (and thus the wakeup happened already) first to close
1901                  * the race of space already having become available.
1902                  * This check must happen after been added to the waitqueue
1903                  * and having current state be INTERRUPTIBLE.
1904                  */
1905                 avail = snd_pcm_avail(substream);
1906                 if (avail >= runtime->twake)
1907                         break;
1908                 snd_pcm_stream_unlock_irq(substream);
1909
1910                 tout = schedule_timeout(wait_time);
1911
1912                 snd_pcm_stream_lock_irq(substream);
1913                 set_current_state(TASK_INTERRUPTIBLE);
1914                 switch (runtime->state) {
1915                 case SNDRV_PCM_STATE_SUSPENDED:
1916                         err = -ESTRPIPE;
1917                         goto _endloop;
1918                 case SNDRV_PCM_STATE_XRUN:
1919                         err = -EPIPE;
1920                         goto _endloop;
1921                 case SNDRV_PCM_STATE_DRAINING:
1922                         if (is_playback)
1923                                 err = -EPIPE;
1924                         else
1925                                 avail = 0; /* indicate draining */
1926                         goto _endloop;
1927                 case SNDRV_PCM_STATE_OPEN:
1928                 case SNDRV_PCM_STATE_SETUP:
1929                 case SNDRV_PCM_STATE_DISCONNECTED:
1930                         err = -EBADFD;
1931                         goto _endloop;
1932                 case SNDRV_PCM_STATE_PAUSED:
1933                         continue;
1934                 }
1935                 if (!tout) {
1936                         pcm_dbg(substream->pcm,
1937                                 "%s write error (DMA or IRQ trouble?)\n",
1938                                 is_playback ? "playback" : "capture");
1939                         err = -EIO;
1940                         break;
1941                 }
1942         }
1943  _endloop:
1944         set_current_state(TASK_RUNNING);
1945         remove_wait_queue(&runtime->tsleep, &wait);
1946         *availp = avail;
1947         return err;
1948 }
1949
1950 typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
1951                               int channel, unsigned long hwoff,
1952                               void *buf, unsigned long bytes);
1953
1954 typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
1955                           snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
1956
1957 /* calculate the target DMA-buffer position to be written/read */
1958 static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
1959                            int channel, unsigned long hwoff)
1960 {
1961         return runtime->dma_area + hwoff +
1962                 channel * (runtime->dma_bytes / runtime->channels);
1963 }
1964
1965 /* default copy_user ops for write; used for both interleaved and non- modes */
1966 static int default_write_copy(struct snd_pcm_substream *substream,
1967                               int channel, unsigned long hwoff,
1968                               void *buf, unsigned long bytes)
1969 {
1970         if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
1971                            (void __user *)buf, bytes))
1972                 return -EFAULT;
1973         return 0;
1974 }
1975
1976 /* default copy_kernel ops for write */
1977 static int default_write_copy_kernel(struct snd_pcm_substream *substream,
1978                                      int channel, unsigned long hwoff,
1979                                      void *buf, unsigned long bytes)
1980 {
1981         memcpy(get_dma_ptr(substream->runtime, channel, hwoff), buf, bytes);
1982         return 0;
1983 }
1984
1985 /* fill silence instead of copy data; called as a transfer helper
1986  * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
1987  * a NULL buffer is passed
1988  */
1989 static int fill_silence(struct snd_pcm_substream *substream, int channel,
1990                         unsigned long hwoff, void *buf, unsigned long bytes)
1991 {
1992         struct snd_pcm_runtime *runtime = substream->runtime;
1993
1994         if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
1995                 return 0;
1996         if (substream->ops->fill_silence)
1997                 return substream->ops->fill_silence(substream, channel,
1998                                                     hwoff, bytes);
1999
2000         snd_pcm_format_set_silence(runtime->format,
2001                                    get_dma_ptr(runtime, channel, hwoff),
2002                                    bytes_to_samples(runtime, bytes));
2003         return 0;
2004 }
2005
2006 /* default copy_user ops for read; used for both interleaved and non- modes */
2007 static int default_read_copy(struct snd_pcm_substream *substream,
2008                              int channel, unsigned long hwoff,
2009                              void *buf, unsigned long bytes)
2010 {
2011         if (copy_to_user((void __user *)buf,
2012                          get_dma_ptr(substream->runtime, channel, hwoff),
2013                          bytes))
2014                 return -EFAULT;
2015         return 0;
2016 }
2017
2018 /* default copy_kernel ops for read */
2019 static int default_read_copy_kernel(struct snd_pcm_substream *substream,
2020                                     int channel, unsigned long hwoff,
2021                                     void *buf, unsigned long bytes)
2022 {
2023         memcpy(buf, get_dma_ptr(substream->runtime, channel, hwoff), bytes);
2024         return 0;
2025 }
2026
2027 /* call transfer function with the converted pointers and sizes;
2028  * for interleaved mode, it's one shot for all samples
2029  */
2030 static int interleaved_copy(struct snd_pcm_substream *substream,
2031                             snd_pcm_uframes_t hwoff, void *data,
2032                             snd_pcm_uframes_t off,
2033                             snd_pcm_uframes_t frames,
2034                             pcm_transfer_f transfer)
2035 {
2036         struct snd_pcm_runtime *runtime = substream->runtime;
2037
2038         /* convert to bytes */
2039         hwoff = frames_to_bytes(runtime, hwoff);
2040         off = frames_to_bytes(runtime, off);
2041         frames = frames_to_bytes(runtime, frames);
2042         return transfer(substream, 0, hwoff, data + off, frames);
2043 }
2044
2045 /* call transfer function with the converted pointers and sizes for each
2046  * non-interleaved channel; when buffer is NULL, silencing instead of copying
2047  */
2048 static int noninterleaved_copy(struct snd_pcm_substream *substream,
2049                                snd_pcm_uframes_t hwoff, void *data,
2050                                snd_pcm_uframes_t off,
2051                                snd_pcm_uframes_t frames,
2052                                pcm_transfer_f transfer)
2053 {
2054         struct snd_pcm_runtime *runtime = substream->runtime;
2055         int channels = runtime->channels;
2056         void **bufs = data;
2057         int c, err;
2058
2059         /* convert to bytes; note that it's not frames_to_bytes() here.
2060          * in non-interleaved mode, we copy for each channel, thus
2061          * each copy is n_samples bytes x channels = whole frames.
2062          */
2063         off = samples_to_bytes(runtime, off);
2064         frames = samples_to_bytes(runtime, frames);
2065         hwoff = samples_to_bytes(runtime, hwoff);
2066         for (c = 0; c < channels; ++c, ++bufs) {
2067                 if (!data || !*bufs)
2068                         err = fill_silence(substream, c, hwoff, NULL, frames);
2069                 else
2070                         err = transfer(substream, c, hwoff, *bufs + off,
2071                                        frames);
2072                 if (err < 0)
2073                         return err;
2074         }
2075         return 0;
2076 }
2077
2078 /* fill silence on the given buffer position;
2079  * called from snd_pcm_playback_silence()
2080  */
2081 static int fill_silence_frames(struct snd_pcm_substream *substream,
2082                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
2083 {
2084         if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
2085             substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
2086                 return interleaved_copy(substream, off, NULL, 0, frames,
2087                                         fill_silence);
2088         else
2089                 return noninterleaved_copy(substream, off, NULL, 0, frames,
2090                                            fill_silence);
2091 }
2092
2093 /* sanity-check for read/write methods */
2094 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2095 {
2096         struct snd_pcm_runtime *runtime;
2097         if (PCM_RUNTIME_CHECK(substream))
2098                 return -ENXIO;
2099         runtime = substream->runtime;
2100         if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area))
2101                 return -EINVAL;
2102         if (runtime->state == SNDRV_PCM_STATE_OPEN)
2103                 return -EBADFD;
2104         return 0;
2105 }
2106
2107 static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
2108 {
2109         switch (runtime->state) {
2110         case SNDRV_PCM_STATE_PREPARED:
2111         case SNDRV_PCM_STATE_RUNNING:
2112         case SNDRV_PCM_STATE_PAUSED:
2113                 return 0;
2114         case SNDRV_PCM_STATE_XRUN:
2115                 return -EPIPE;
2116         case SNDRV_PCM_STATE_SUSPENDED:
2117                 return -ESTRPIPE;
2118         default:
2119                 return -EBADFD;
2120         }
2121 }
2122
2123 /* update to the given appl_ptr and call ack callback if needed;
2124  * when an error is returned, take back to the original value
2125  */
2126 int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
2127                            snd_pcm_uframes_t appl_ptr)
2128 {
2129         struct snd_pcm_runtime *runtime = substream->runtime;
2130         snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
2131         snd_pcm_sframes_t diff;
2132         int ret;
2133
2134         if (old_appl_ptr == appl_ptr)
2135                 return 0;
2136
2137         if (appl_ptr >= runtime->boundary)
2138                 return -EINVAL;
2139         /*
2140          * check if a rewind is requested by the application
2141          */
2142         if (substream->runtime->info & SNDRV_PCM_INFO_NO_REWINDS) {
2143                 diff = appl_ptr - old_appl_ptr;
2144                 if (diff >= 0) {
2145                         if (diff > runtime->buffer_size)
2146                                 return -EINVAL;
2147                 } else {
2148                         if (runtime->boundary + diff > runtime->buffer_size)
2149                                 return -EINVAL;
2150                 }
2151         }
2152
2153         runtime->control->appl_ptr = appl_ptr;
2154         if (substream->ops->ack) {
2155                 ret = substream->ops->ack(substream);
2156                 if (ret < 0) {
2157                         runtime->control->appl_ptr = old_appl_ptr;
2158                         return ret;
2159                 }
2160         }
2161
2162         trace_applptr(substream, old_appl_ptr, appl_ptr);
2163
2164         return 0;
2165 }
2166
2167 /* the common loop for read/write data */
2168 snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
2169                                      void *data, bool interleaved,
2170                                      snd_pcm_uframes_t size, bool in_kernel)
2171 {
2172         struct snd_pcm_runtime *runtime = substream->runtime;
2173         snd_pcm_uframes_t xfer = 0;
2174         snd_pcm_uframes_t offset = 0;
2175         snd_pcm_uframes_t avail;
2176         pcm_copy_f writer;
2177         pcm_transfer_f transfer;
2178         bool nonblock;
2179         bool is_playback;
2180         int err;
2181
2182         err = pcm_sanity_check(substream);
2183         if (err < 0)
2184                 return err;
2185
2186         is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
2187         if (interleaved) {
2188                 if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2189                     runtime->channels > 1)
2190                         return -EINVAL;
2191                 writer = interleaved_copy;
2192         } else {
2193                 if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2194                         return -EINVAL;
2195                 writer = noninterleaved_copy;
2196         }
2197
2198         if (!data) {
2199                 if (is_playback)
2200                         transfer = fill_silence;
2201                 else
2202                         return -EINVAL;
2203         } else if (in_kernel) {
2204                 if (substream->ops->copy_kernel)
2205                         transfer = substream->ops->copy_kernel;
2206                 else
2207                         transfer = is_playback ?
2208                                 default_write_copy_kernel : default_read_copy_kernel;
2209         } else {
2210                 if (substream->ops->copy_user)
2211                         transfer = (pcm_transfer_f)substream->ops->copy_user;
2212                 else
2213                         transfer = is_playback ?
2214                                 default_write_copy : default_read_copy;
2215         }
2216
2217         if (size == 0)
2218                 return 0;
2219
2220         nonblock = !!(substream->f_flags & O_NONBLOCK);
2221
2222         snd_pcm_stream_lock_irq(substream);
2223         err = pcm_accessible_state(runtime);
2224         if (err < 0)
2225                 goto _end_unlock;
2226
2227         runtime->twake = runtime->control->avail_min ? : 1;
2228         if (runtime->state == SNDRV_PCM_STATE_RUNNING)
2229                 snd_pcm_update_hw_ptr(substream);
2230
2231         /*
2232          * If size < start_threshold, wait indefinitely. Another
2233          * thread may start capture
2234          */
2235         if (!is_playback &&
2236             runtime->state == SNDRV_PCM_STATE_PREPARED &&
2237             size >= runtime->start_threshold) {
2238                 err = snd_pcm_start(substream);
2239                 if (err < 0)
2240                         goto _end_unlock;
2241         }
2242
2243         avail = snd_pcm_avail(substream);
2244
2245         while (size > 0) {
2246                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2247                 snd_pcm_uframes_t cont;
2248                 if (!avail) {
2249                         if (!is_playback &&
2250                             runtime->state == SNDRV_PCM_STATE_DRAINING) {
2251                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2252                                 goto _end_unlock;
2253                         }
2254                         if (nonblock) {
2255                                 err = -EAGAIN;
2256                                 goto _end_unlock;
2257                         }
2258                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2259                                         runtime->control->avail_min ? : 1);
2260                         err = wait_for_avail(substream, &avail);
2261                         if (err < 0)
2262                                 goto _end_unlock;
2263                         if (!avail)
2264                                 continue; /* draining */
2265                 }
2266                 frames = size > avail ? avail : size;
2267                 appl_ptr = READ_ONCE(runtime->control->appl_ptr);
2268                 appl_ofs = appl_ptr % runtime->buffer_size;
2269                 cont = runtime->buffer_size - appl_ofs;
2270                 if (frames > cont)
2271                         frames = cont;
2272                 if (snd_BUG_ON(!frames)) {
2273                         err = -EINVAL;
2274                         goto _end_unlock;
2275                 }
2276                 if (!atomic_inc_unless_negative(&runtime->buffer_accessing)) {
2277                         err = -EBUSY;
2278                         goto _end_unlock;
2279                 }
2280                 snd_pcm_stream_unlock_irq(substream);
2281                 if (!is_playback)
2282                         snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU);
2283                 err = writer(substream, appl_ofs, data, offset, frames,
2284                              transfer);
2285                 if (is_playback)
2286                         snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
2287                 snd_pcm_stream_lock_irq(substream);
2288                 atomic_dec(&runtime->buffer_accessing);
2289                 if (err < 0)
2290                         goto _end_unlock;
2291                 err = pcm_accessible_state(runtime);
2292                 if (err < 0)
2293                         goto _end_unlock;
2294                 appl_ptr += frames;
2295                 if (appl_ptr >= runtime->boundary)
2296                         appl_ptr -= runtime->boundary;
2297                 err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
2298                 if (err < 0)
2299                         goto _end_unlock;
2300
2301                 offset += frames;
2302                 size -= frames;
2303                 xfer += frames;
2304                 avail -= frames;
2305                 if (is_playback &&
2306                     runtime->state == SNDRV_PCM_STATE_PREPARED &&
2307                     snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2308                         err = snd_pcm_start(substream);
2309                         if (err < 0)
2310                                 goto _end_unlock;
2311                 }
2312         }
2313  _end_unlock:
2314         runtime->twake = 0;
2315         if (xfer > 0 && err >= 0)
2316                 snd_pcm_update_state(substream, runtime);
2317         snd_pcm_stream_unlock_irq(substream);
2318         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2319 }
2320 EXPORT_SYMBOL(__snd_pcm_lib_xfer);
2321
2322 /*
2323  * standard channel mapping helpers
2324  */
2325
2326 /* default channel maps for multi-channel playbacks, up to 8 channels */
2327 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2328         { .channels = 1,
2329           .map = { SNDRV_CHMAP_MONO } },
2330         { .channels = 2,
2331           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2332         { .channels = 4,
2333           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2334                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2335         { .channels = 6,
2336           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2337                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2338                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2339         { .channels = 8,
2340           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2341                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2342                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2343                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2344         { }
2345 };
2346 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2347
2348 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2349 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2350         { .channels = 1,
2351           .map = { SNDRV_CHMAP_MONO } },
2352         { .channels = 2,
2353           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2354         { .channels = 4,
2355           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2356                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2357         { .channels = 6,
2358           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2359                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2360                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2361         { .channels = 8,
2362           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2363                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2364                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2365                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2366         { }
2367 };
2368 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2369
2370 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2371 {
2372         if (ch > info->max_channels)
2373                 return false;
2374         return !info->channel_mask || (info->channel_mask & (1U << ch));
2375 }
2376
2377 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2378                               struct snd_ctl_elem_info *uinfo)
2379 {
2380         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2381
2382         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2383         uinfo->count = info->max_channels;
2384         uinfo->value.integer.min = 0;
2385         uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2386         return 0;
2387 }
2388
2389 /* get callback for channel map ctl element
2390  * stores the channel position firstly matching with the current channels
2391  */
2392 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2393                              struct snd_ctl_elem_value *ucontrol)
2394 {
2395         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2396         unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2397         struct snd_pcm_substream *substream;
2398         const struct snd_pcm_chmap_elem *map;
2399
2400         if (!info->chmap)
2401                 return -EINVAL;
2402         substream = snd_pcm_chmap_substream(info, idx);
2403         if (!substream)
2404                 return -ENODEV;
2405         memset(ucontrol->value.integer.value, 0,
2406                sizeof(long) * info->max_channels);
2407         if (!substream->runtime)
2408                 return 0; /* no channels set */
2409         for (map = info->chmap; map->channels; map++) {
2410                 int i;
2411                 if (map->channels == substream->runtime->channels &&
2412                     valid_chmap_channels(info, map->channels)) {
2413                         for (i = 0; i < map->channels; i++)
2414                                 ucontrol->value.integer.value[i] = map->map[i];
2415                         return 0;
2416                 }
2417         }
2418         return -EINVAL;
2419 }
2420
2421 /* tlv callback for channel map ctl element
2422  * expands the pre-defined channel maps in a form of TLV
2423  */
2424 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2425                              unsigned int size, unsigned int __user *tlv)
2426 {
2427         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2428         const struct snd_pcm_chmap_elem *map;
2429         unsigned int __user *dst;
2430         int c, count = 0;
2431
2432         if (!info->chmap)
2433                 return -EINVAL;
2434         if (size < 8)
2435                 return -ENOMEM;
2436         if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2437                 return -EFAULT;
2438         size -= 8;
2439         dst = tlv + 2;
2440         for (map = info->chmap; map->channels; map++) {
2441                 int chs_bytes = map->channels * 4;
2442                 if (!valid_chmap_channels(info, map->channels))
2443                         continue;
2444                 if (size < 8)
2445                         return -ENOMEM;
2446                 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2447                     put_user(chs_bytes, dst + 1))
2448                         return -EFAULT;
2449                 dst += 2;
2450                 size -= 8;
2451                 count += 8;
2452                 if (size < chs_bytes)
2453                         return -ENOMEM;
2454                 size -= chs_bytes;
2455                 count += chs_bytes;
2456                 for (c = 0; c < map->channels; c++) {
2457                         if (put_user(map->map[c], dst))
2458                                 return -EFAULT;
2459                         dst++;
2460                 }
2461         }
2462         if (put_user(count, tlv + 1))
2463                 return -EFAULT;
2464         return 0;
2465 }
2466
2467 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2468 {
2469         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2470         info->pcm->streams[info->stream].chmap_kctl = NULL;
2471         kfree(info);
2472 }
2473
2474 /**
2475  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2476  * @pcm: the assigned PCM instance
2477  * @stream: stream direction
2478  * @chmap: channel map elements (for query)
2479  * @max_channels: the max number of channels for the stream
2480  * @private_value: the value passed to each kcontrol's private_value field
2481  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2482  *
2483  * Create channel-mapping control elements assigned to the given PCM stream(s).
2484  * Return: Zero if successful, or a negative error value.
2485  */
2486 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2487                            const struct snd_pcm_chmap_elem *chmap,
2488                            int max_channels,
2489                            unsigned long private_value,
2490                            struct snd_pcm_chmap **info_ret)
2491 {
2492         struct snd_pcm_chmap *info;
2493         struct snd_kcontrol_new knew = {
2494                 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
2495                 .access = SNDRV_CTL_ELEM_ACCESS_READ |
2496                         SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2497                         SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2498                 .info = pcm_chmap_ctl_info,
2499                 .get = pcm_chmap_ctl_get,
2500                 .tlv.c = pcm_chmap_ctl_tlv,
2501         };
2502         int err;
2503
2504         if (WARN_ON(pcm->streams[stream].chmap_kctl))
2505                 return -EBUSY;
2506         info = kzalloc(sizeof(*info), GFP_KERNEL);
2507         if (!info)
2508                 return -ENOMEM;
2509         info->pcm = pcm;
2510         info->stream = stream;
2511         info->chmap = chmap;
2512         info->max_channels = max_channels;
2513         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2514                 knew.name = "Playback Channel Map";
2515         else
2516                 knew.name = "Capture Channel Map";
2517         knew.device = pcm->device;
2518         knew.count = pcm->streams[stream].substream_count;
2519         knew.private_value = private_value;
2520         info->kctl = snd_ctl_new1(&knew, info);
2521         if (!info->kctl) {
2522                 kfree(info);
2523                 return -ENOMEM;
2524         }
2525         info->kctl->private_free = pcm_chmap_ctl_private_free;
2526         err = snd_ctl_add(pcm->card, info->kctl);
2527         if (err < 0)
2528                 return err;
2529         pcm->streams[stream].chmap_kctl = info->kctl;
2530         if (info_ret)
2531                 *info_ret = info;
2532         return 0;
2533 }
2534 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);