sound/core/pcm_lib.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *                   Abramo Bagnara <abramo@alsa-project.org>
   5  *
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  *
  21  */
  22
  23 #include <linux/slab.h>
  24 #include <linux/time.h>
  25 #include <linux/math64.h>
  26 #include <linux/export.h>
  27 #include <sound/core.h>
  28 #include <sound/control.h>
  29 #include <sound/tlv.h>
  30 #include <sound/info.h>
  31 #include <sound/pcm.h>
  32 #include <sound/pcm_params.h>
  33 #include <sound/timer.h>
  34
  35 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  36 #define CREATE_TRACE_POINTS
  37 #include "pcm_trace.h"
  38 #else
  39 #define trace_hwptr(substream, pos, in_interrupt)
  40 #define trace_xrun(substream)
  41 #define trace_hw_ptr_error(substream, reason)
  42 #endif
  43
  44 /*
  45  * fill ring buffer with silence
  46  * runtime->silence_start: starting pointer to silence area
  47  * runtime->silence_filled: size filled with silence
  48  * runtime->silence_threshold: threshold from application
  49  * runtime->silence_size: maximal size from application
  50  *
  51  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
  52  */
  53 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
  54 {
  55         struct snd_pcm_runtime *runtime = substream->runtime;
  56         snd_pcm_uframes_t frames, ofs, transfer;
  57
  58         if (runtime->silence_size < runtime->boundary) {
  59                 snd_pcm_sframes_t noise_dist, n;
  60                 if (runtime->silence_start != runtime->control->appl_ptr) {
  61                         n = runtime->control->appl_ptr - runtime->silence_start;
  62                         if (n < 0)
  63                                 n += runtime->boundary;
  64                         if ((snd_pcm_uframes_t)n < runtime->silence_filled)
  65                                 runtime->silence_filled -= n;
  66                         else
  67                                 runtime->silence_filled = 0;
  68                         runtime->silence_start = runtime->control->appl_ptr;
  69                 }
  70                 if (runtime->silence_filled >= runtime->buffer_size)
  71                         return;
  72                 noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
  73                 if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
  74                         return;
  75                 frames = runtime->silence_threshold - noise_dist;
  76                 if (frames > runtime->silence_size)
  77                         frames = runtime->silence_size;
  78         } else {
  79                 if (new_hw_ptr == ULONG_MAX) {  /* initialization */
  80                         snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
  81                         if (avail > runtime->buffer_size)
  82                                 avail = runtime->buffer_size;
  83                         runtime->silence_filled = avail > 0 ? avail : 0;
  84                         runtime->silence_start = (runtime->status->hw_ptr +
  85                                                   runtime->silence_filled) %
  86                                                  runtime->boundary;
  87                 } else {
  88                         ofs = runtime->status->hw_ptr;
  89                         frames = new_hw_ptr - ofs;
  90                         if ((snd_pcm_sframes_t)frames < 0)
  91                                 frames += runtime->boundary;
  92                         runtime->silence_filled -= frames;
  93                         if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
  94                                 runtime->silence_filled = 0;
  95                                 runtime->silence_start = new_hw_ptr;
  96                         } else {
  97                                 runtime->silence_start = ofs;
  98                         }
  99                 }
 100                 frames = runtime->buffer_size - runtime->silence_filled;
 101         }
 102         if (snd_BUG_ON(frames > runtime->buffer_size))
 103                 return;
 104         if (frames == 0)
 105                 return;
 106         ofs = runtime->silence_start % runtime->buffer_size;
 107         while (frames > 0) {
 108                 transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
 109                 if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
 110                     runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
 111                         if (substream->ops->silence) {
 112                                 int err;
 113                                 err = substream->ops->silence(substream, -1, ofs, transfer);
 114                                 snd_BUG_ON(err < 0);
 115                         } else {
 116                                 char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
 117                                 snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
 118                         }
 119                 } else {
 120                         unsigned int c;
 121                         unsigned int channels = runtime->channels;
 122                         if (substream->ops->silence) {
 123                                 for (c = 0; c < channels; ++c) {
 124                                         int err;
 125                                         err = substream->ops->silence(substream, c, ofs, transfer);
 126                                         snd_BUG_ON(err < 0);
 127                                 }
 128                         } else {
 129                                 size_t dma_csize = runtime->dma_bytes / channels;
 130                                 for (c = 0; c < channels; ++c) {
 131                                         char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
 132                                         snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
 133                                 }
 134                         }
 135                 }
 136                 runtime->silence_filled += transfer;
 137                 frames -= transfer;
 138                 ofs = 0;
 139         }
 140 }
 141
 142 #ifdef CONFIG_SND_DEBUG
 143 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
 144                            char *name, size_t len)
 145 {
 146         snprintf(name, len, "pcmC%dD%d%c:%d",
 147                  substream->pcm->card->number,
 148                  substream->pcm->device,
 149                  substream->stream ? 'c' : 'p',
 150                  substream->number);
 151 }
 152 EXPORT_SYMBOL(snd_pcm_debug_name);
 153 #endif
 154
 155 #define XRUN_DEBUG_BASIC        (1<<0)
 156 #define XRUN_DEBUG_STACK        (1<<1)  /* dump also stack */
 157 #define XRUN_DEBUG_JIFFIESCHECK (1<<2)  /* do jiffies check */
 158
 159 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 160
 161 #define xrun_debug(substream, mask) \
 162                         ((substream)->pstr->xrun_debug & (mask))
 163 #else
 164 #define xrun_debug(substream, mask)     0
 165 #endif
 166
 167 #define dump_stack_on_xrun(substream) do {                      \
 168                 if (xrun_debug(substream, XRUN_DEBUG_STACK))    \
 169                         dump_stack();                           \
 170         } while (0)
 171
 172 static void xrun(struct snd_pcm_substream *substream)
 173 {
 174         struct snd_pcm_runtime *runtime = substream->runtime;
 175
 176         trace_xrun(substream);
 177         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
 178                 snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
 179         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 180         if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
 181                 char name[16];
 182                 snd_pcm_debug_name(substream, name, sizeof(name));
 183                 pcm_warn(substream->pcm, "XRUN: %s\n", name);
 184                 dump_stack_on_xrun(substream);
 185         }
 186 }
 187
 188 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 189 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)     \
 190         do {                                                            \
 191                 trace_hw_ptr_error(substream, reason);  \
 192                 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {          \
 193                         pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
 194                                            (in_interrupt) ? 'Q' : 'P', ##args); \
 195                         dump_stack_on_xrun(substream);                  \
 196                 }                                                       \
 197         } while (0)
 198
 199 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
 200
 201 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
 202
 203 #endif
 204
 205 int snd_pcm_update_state(struct snd_pcm_substream *substream,
 206                          struct snd_pcm_runtime *runtime)
 207 {
 208         snd_pcm_uframes_t avail;
 209
 210         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 211                 avail = snd_pcm_playback_avail(runtime);
 212         else
 213                 avail = snd_pcm_capture_avail(runtime);
 214         if (avail > runtime->avail_max)
 215                 runtime->avail_max = avail;
 216         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
 217                 if (avail >= runtime->buffer_size) {
 218                         snd_pcm_drain_done(substream);
 219                         return -EPIPE;
 220                 }
 221         } else {
 222                 if (avail >= runtime->stop_threshold) {
 223                         xrun(substream);
 224                         return -EPIPE;
 225                 }
 226         }
 227         if (runtime->twake) {
 228                 if (avail >= runtime->twake)
 229                         wake_up(&runtime->tsleep);
 230         } else if (avail >= runtime->control->avail_min)
 231                 wake_up(&runtime->sleep);
 232         return 0;
 233 }
 234
 235 static void update_audio_tstamp(struct snd_pcm_substream *substream,
 236                                 struct timespec *curr_tstamp,
 237                                 struct timespec *audio_tstamp)
 238 {
 239         struct snd_pcm_runtime *runtime = substream->runtime;
 240         u64 audio_frames, audio_nsecs;
 241         struct timespec driver_tstamp;
 242
 243         if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
 244                 return;
 245
 246         if (!(substream->ops->get_time_info) ||
 247                 (runtime->audio_tstamp_report.actual_type ==
 248                         SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 249
 250                 /*
 251                  * provide audio timestamp derived from pointer position
 252                  * add delay only if requested
 253                  */
 254
 255                 audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
 256
 257                 if (runtime->audio_tstamp_config.report_delay) {
 258                         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 259                                 audio_frames -=  runtime->delay;
 260                         else
 261                                 audio_frames +=  runtime->delay;
 262                 }
 263                 audio_nsecs = div_u64(audio_frames * 1000000000LL,
 264                                 runtime->rate);
 265                 *audio_tstamp = ns_to_timespec(audio_nsecs);
 266         }
 267         runtime->status->audio_tstamp = *audio_tstamp;
 268         runtime->status->tstamp = *curr_tstamp;
 269
 270         /*
 271          * re-take a driver timestamp to let apps detect if the reference tstamp
 272          * read by low-level hardware was provided with a delay
 273          */
 274         snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
 275         runtime->driver_tstamp = driver_tstamp;
 276 }
 277
 278 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 279                                   unsigned int in_interrupt)
 280 {
 281         struct snd_pcm_runtime *runtime = substream->runtime;
 282         snd_pcm_uframes_t pos;
 283         snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
 284         snd_pcm_sframes_t hdelta, delta;
 285         unsigned long jdelta;
 286         unsigned long curr_jiffies;
 287         struct timespec curr_tstamp;
 288         struct timespec audio_tstamp;
 289         int crossed_boundary = 0;
 290
 291         old_hw_ptr = runtime->status->hw_ptr;
 292
 293         /*
 294          * group pointer, time and jiffies reads to allow for more
 295          * accurate correlations/corrections.
 296          * The values are stored at the end of this routine after
 297          * corrections for hw_ptr position
 298          */
 299         pos = substream->ops->pointer(substream);
 300         curr_jiffies = jiffies;
 301         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
 302                 if ((substream->ops->get_time_info) &&
 303                         (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 304                         substream->ops->get_time_info(substream, &curr_tstamp,
 305                                                 &audio_tstamp,
 306                                                 &runtime->audio_tstamp_config,
 307                                                 &runtime->audio_tstamp_report);
 308
 309                         /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
 310                         if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
 311                                 snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 312                 } else
 313                         snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 314         }
 315
 316         if (pos == SNDRV_PCM_POS_XRUN) {
 317                 xrun(substream);
 318                 return -EPIPE;
 319         }
 320         if (pos >= runtime->buffer_size) {
 321                 if (printk_ratelimit()) {
 322                         char name[16];
 323                         snd_pcm_debug_name(substream, name, sizeof(name));
 324                         pcm_err(substream->pcm,
 325                                 "BUG: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
 326                                 name, pos, runtime->buffer_size,
 327                                 runtime->period_size);
 328                 }
 329                 pos = 0;
 330         }
 331         pos -= pos % runtime->min_align;
 332         trace_hwptr(substream, pos, in_interrupt);
 333         hw_base = runtime->hw_ptr_base;
 334         new_hw_ptr = hw_base + pos;
 335         if (in_interrupt) {
 336                 /* we know that one period was processed */
 337                 /* delta = "expected next hw_ptr" for in_interrupt != 0 */
 338                 delta = runtime->hw_ptr_interrupt + runtime->period_size;
 339                 if (delta > new_hw_ptr) {
 340                         /* check for double acknowledged interrupts */
 341                         hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 342                         if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
 343                                 hw_base += runtime->buffer_size;
 344                                 if (hw_base >= runtime->boundary) {
 345                                         hw_base = 0;
 346                                         crossed_boundary++;
 347                                 }
 348                                 new_hw_ptr = hw_base + pos;
 349                                 goto __delta;
 350                         }
 351                 }
 352         }
 353         /* new_hw_ptr might be lower than old_hw_ptr in case when */
 354         /* pointer crosses the end of the ring buffer */
 355         if (new_hw_ptr < old_hw_ptr) {
 356                 hw_base += runtime->buffer_size;
 357                 if (hw_base >= runtime->boundary) {
 358                         hw_base = 0;
 359                         crossed_boundary++;
 360                 }
 361                 new_hw_ptr = hw_base + pos;
 362         }
 363       __delta:
 364         delta = new_hw_ptr - old_hw_ptr;
 365         if (delta < 0)
 366                 delta += runtime->boundary;
 367
 368         if (runtime->no_period_wakeup) {
 369                 snd_pcm_sframes_t xrun_threshold;
 370                 /*
 371                  * Without regular period interrupts, we have to check
 372                  * the elapsed time to detect xruns.
 373                  */
 374                 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 375                 if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
 376                         goto no_delta_check;
 377                 hdelta = jdelta - delta * HZ / runtime->rate;
 378                 xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
 379                 while (hdelta > xrun_threshold) {
 380                         delta += runtime->buffer_size;
 381                         hw_base += runtime->buffer_size;
 382                         if (hw_base >= runtime->boundary) {
 383                                 hw_base = 0;
 384                                 crossed_boundary++;
 385                         }
 386                         new_hw_ptr = hw_base + pos;
 387                         hdelta -= runtime->hw_ptr_buffer_jiffies;
 388                 }
 389                 goto no_delta_check;
 390         }
 391
 392         /* something must be really wrong */
 393         if (delta >= runtime->buffer_size + runtime->period_size) {
 394                 hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
 395                              "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 396                              substream->stream, (long)pos,
 397                              (long)new_hw_ptr, (long)old_hw_ptr);
 398                 return 0;
 399         }
 400
 401         /* Do jiffies check only in xrun_debug mode */
 402         if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
 403                 goto no_jiffies_check;
 404
 405         /* Skip the jiffies check for hardwares with BATCH flag.
 406          * Such hardware usually just increases the position at each IRQ,
 407          * thus it can't give any strange position.
 408          */
 409         if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
 410                 goto no_jiffies_check;
 411         hdelta = delta;
 412         if (hdelta < runtime->delay)
 413                 goto no_jiffies_check;
 414         hdelta -= runtime->delay;
 415         jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 416         if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
 417                 delta = jdelta /
 418                         (((runtime->period_size * HZ) / runtime->rate)
 419                                                                 + HZ/100);
 420                 /* move new_hw_ptr according jiffies not pos variable */
 421                 new_hw_ptr = old_hw_ptr;
 422                 hw_base = delta;
 423                 /* use loop to avoid checks for delta overflows */
 424                 /* the delta value is small or zero in most cases */
 425                 while (delta > 0) {
 426                         new_hw_ptr += runtime->period_size;
 427                         if (new_hw_ptr >= runtime->boundary) {
 428                                 new_hw_ptr -= runtime->boundary;
 429                                 crossed_boundary--;
 430                         }
 431                         delta--;
 432                 }
 433                 /* align hw_base to buffer_size */
 434                 hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
 435                              "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
 436                              (long)pos, (long)hdelta,
 437                              (long)runtime->period_size, jdelta,
 438                              ((hdelta * HZ) / runtime->rate), hw_base,
 439                              (unsigned long)old_hw_ptr,
 440                              (unsigned long)new_hw_ptr);
 441                 /* reset values to proper state */
 442                 delta = 0;
 443                 hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
 444         }
 445  no_jiffies_check:
 446         if (delta > runtime->period_size + runtime->period_size / 2) {
 447                 hw_ptr_error(substream, in_interrupt,
 448                              "Lost interrupts?",
 449                              "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 450                              substream->stream, (long)delta,
 451                              (long)new_hw_ptr,
 452                              (long)old_hw_ptr);
 453         }
 454
 455  no_delta_check:
 456         if (runtime->status->hw_ptr == new_hw_ptr) {
 457                 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 458                 return 0;
 459         }
 460
 461         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 462             runtime->silence_size > 0)
 463                 snd_pcm_playback_silence(substream, new_hw_ptr);
 464
 465         if (in_interrupt) {
 466                 delta = new_hw_ptr - runtime->hw_ptr_interrupt;
 467                 if (delta < 0)
 468                         delta += runtime->boundary;
 469                 delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
 470                 runtime->hw_ptr_interrupt += delta;
 471                 if (runtime->hw_ptr_interrupt >= runtime->boundary)
 472                         runtime->hw_ptr_interrupt -= runtime->boundary;
 473         }
 474         runtime->hw_ptr_base = hw_base;
 475         runtime->status->hw_ptr = new_hw_ptr;
 476         runtime->hw_ptr_jiffies = curr_jiffies;
 477         if (crossed_boundary) {
 478                 snd_BUG_ON(crossed_boundary != 1);
 479                 runtime->hw_ptr_wrap += runtime->boundary;
 480         }
 481
 482         update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 483
 484         return snd_pcm_update_state(substream, runtime);
 485 }
 486
 487 /* CAUTION: call it with irq disabled */
 488 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 489 {
 490         return snd_pcm_update_hw_ptr0(substream, 0);
 491 }
 492
 493 /**
 494  * snd_pcm_set_ops - set the PCM operators
 495  * @pcm: the pcm instance
 496  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
 497  * @ops: the operator table
 498  *
 499  * Sets the given PCM operators to the pcm instance.
 500  */
 501 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
 502                      const struct snd_pcm_ops *ops)
 503 {
 504         struct snd_pcm_str *stream = &pcm->streams[direction];
 505         struct snd_pcm_substream *substream;
 506
 507         for (substream = stream->substream; substream != NULL; substream = substream->next)
 508                 substream->ops = ops;
 509 }
 510
 511 EXPORT_SYMBOL(snd_pcm_set_ops);
 512
 513 /**
 514  * snd_pcm_sync - set the PCM sync id
 515  * @substream: the pcm substream
 516  *
 517  * Sets the PCM sync identifier for the card.
 518  */
 519 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
 520 {
 521         struct snd_pcm_runtime *runtime = substream->runtime;
 522
 523         runtime->sync.id32[0] = substream->pcm->card->number;
 524         runtime->sync.id32[1] = -1;
 525         runtime->sync.id32[2] = -1;
 526         runtime->sync.id32[3] = -1;
 527 }
 528
 529 EXPORT_SYMBOL(snd_pcm_set_sync);
 530
 531 /*
 532  *  Standard ioctl routine
 533  */
 534
 535 static inline unsigned int div32(unsigned int a, unsigned int b,
 536                                  unsigned int *r)
 537 {
 538         if (b == 0) {
 539                 *r = 0;
 540                 return UINT_MAX;
 541         }
 542         *r = a % b;
 543         return a / b;
 544 }
 545
 546 static inline unsigned int div_down(unsigned int a, unsigned int b)
 547 {
 548         if (b == 0)
 549                 return UINT_MAX;
 550         return a / b;
 551 }
 552
 553 static inline unsigned int div_up(unsigned int a, unsigned int b)
 554 {
 555         unsigned int r;
 556         unsigned int q;
 557         if (b == 0)
 558                 return UINT_MAX;
 559         q = div32(a, b, &r);
 560         if (r)
 561                 ++q;
 562         return q;
 563 }
 564
 565 static inline unsigned int mul(unsigned int a, unsigned int b)
 566 {
 567         if (a == 0)
 568                 return 0;
 569         if (div_down(UINT_MAX, a) < b)
 570                 return UINT_MAX;
 571         return a * b;
 572 }
 573
 574 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
 575                                     unsigned int c, unsigned int *r)
 576 {
 577         u_int64_t n = (u_int64_t) a * b;
 578         if (c == 0) {
 579                 snd_BUG_ON(!n);
 580                 *r = 0;
 581                 return UINT_MAX;
 582         }
 583         n = div_u64_rem(n, c, r);
 584         if (n >= UINT_MAX) {
 585                 *r = 0;
 586                 return UINT_MAX;
 587         }
 588         return n;
 589 }
 590
 591 /**
 592  * snd_interval_refine - refine the interval value of configurator
 593  * @i: the interval value to refine
 594  * @v: the interval value to refer to
 595  *
 596  * Refines the interval value with the reference value.
 597  * The interval is changed to the range satisfying both intervals.
 598  * The interval status (min, max, integer, etc.) are evaluated.
 599  *
 600  * Return: Positive if the value is changed, zero if it's not changed, or a
 601  * negative error code.
 602  */
 603 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
 604 {
 605         int changed = 0;
 606         if (snd_BUG_ON(snd_interval_empty(i)))
 607                 return -EINVAL;
 608         if (i->min < v->min) {
 609                 i->min = v->min;
 610                 i->openmin = v->openmin;
 611                 changed = 1;
 612         } else if (i->min == v->min && !i->openmin && v->openmin) {
 613                 i->openmin = 1;
 614                 changed = 1;
 615         }
 616         if (i->max > v->max) {
 617                 i->max = v->max;
 618                 i->openmax = v->openmax;
 619                 changed = 1;
 620         } else if (i->max == v->max && !i->openmax && v->openmax) {
 621                 i->openmax = 1;
 622                 changed = 1;
 623         }
 624         if (!i->integer && v->integer) {
 625                 i->integer = 1;
 626                 changed = 1;
 627         }
 628         if (i->integer) {
 629                 if (i->openmin) {
 630                         i->min++;
 631                         i->openmin = 0;
 632                 }
 633                 if (i->openmax) {
 634                         i->max--;
 635                         i->openmax = 0;
 636                 }
 637         } else if (!i->openmin && !i->openmax && i->min == i->max)
 638                 i->integer = 1;
 639         if (snd_interval_checkempty(i)) {
 640                 snd_interval_none(i);
 641                 return -EINVAL;
 642         }
 643         return changed;
 644 }
 645
 646 EXPORT_SYMBOL(snd_interval_refine);
 647
 648 static int snd_interval_refine_first(struct snd_interval *i)
 649 {
 650         if (snd_BUG_ON(snd_interval_empty(i)))
 651                 return -EINVAL;
 652         if (snd_interval_single(i))
 653                 return 0;
 654         i->max = i->min;
 655         i->openmax = i->openmin;
 656         if (i->openmax)
 657                 i->max++;
 658         return 1;
 659 }
 660
 661 static int snd_interval_refine_last(struct snd_interval *i)
 662 {
 663         if (snd_BUG_ON(snd_interval_empty(i)))
 664                 return -EINVAL;
 665         if (snd_interval_single(i))
 666                 return 0;
 667         i->min = i->max;
 668         i->openmin = i->openmax;
 669         if (i->openmin)
 670                 i->min--;
 671         return 1;
 672 }
 673
 674 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 675 {
 676         if (a->empty || b->empty) {
 677                 snd_interval_none(c);
 678                 return;
 679         }
 680         c->empty = 0;
 681         c->min = mul(a->min, b->min);
 682         c->openmin = (a->openmin || b->openmin);
 683         c->max = mul(a->max,  b->max);
 684         c->openmax = (a->openmax || b->openmax);
 685         c->integer = (a->integer && b->integer);
 686 }
 687
 688 /**
 689  * snd_interval_div - refine the interval value with division
 690  * @a: dividend
 691  * @b: divisor
 692  * @c: quotient
 693  *
 694  * c = a / b
 695  *
 696  * Returns non-zero if the value is changed, zero if not changed.
 697  */
 698 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 699 {
 700         unsigned int r;
 701         if (a->empty || b->empty) {
 702                 snd_interval_none(c);
 703                 return;
 704         }
 705         c->empty = 0;
 706         c->min = div32(a->min, b->max, &r);
 707         c->openmin = (r || a->openmin || b->openmax);
 708         if (b->min > 0) {
 709                 c->max = div32(a->max, b->min, &r);
 710                 if (r) {
 711                         c->max++;
 712                         c->openmax = 1;
 713                 } else
 714                         c->openmax = (a->openmax || b->openmin);
 715         } else {
 716                 c->max = UINT_MAX;
 717                 c->openmax = 0;
 718         }
 719         c->integer = 0;
 720 }
 721
 722 /**
 723  * snd_interval_muldivk - refine the interval value
 724  * @a: dividend 1
 725  * @b: dividend 2
 726  * @k: divisor (as integer)
 727  * @c: result
 728   *
 729  * c = a * b / k
 730  *
 731  * Returns non-zero if the value is changed, zero if not changed.
 732  */
 733 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
 734                       unsigned int k, struct snd_interval *c)
 735 {
 736         unsigned int r;
 737         if (a->empty || b->empty) {
 738                 snd_interval_none(c);
 739                 return;
 740         }
 741         c->empty = 0;
 742         c->min = muldiv32(a->min, b->min, k, &r);
 743         c->openmin = (r || a->openmin || b->openmin);
 744         c->max = muldiv32(a->max, b->max, k, &r);
 745         if (r) {
 746                 c->max++;
 747                 c->openmax = 1;
 748         } else
 749                 c->openmax = (a->openmax || b->openmax);
 750         c->integer = 0;
 751 }
 752
 753 /**
 754  * snd_interval_mulkdiv - refine the interval value
 755  * @a: dividend 1
 756  * @k: dividend 2 (as integer)
 757  * @b: divisor
 758  * @c: result
 759  *
 760  * c = a * k / b
 761  *
 762  * Returns non-zero if the value is changed, zero if not changed.
 763  */
 764 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
 765                       const struct snd_interval *b, struct snd_interval *c)
 766 {
 767         unsigned int r;
 768         if (a->empty || b->empty) {
 769                 snd_interval_none(c);
 770                 return;
 771         }
 772         c->empty = 0;
 773         c->min = muldiv32(a->min, k, b->max, &r);
 774         c->openmin = (r || a->openmin || b->openmax);
 775         if (b->min > 0) {
 776                 c->max = muldiv32(a->max, k, b->min, &r);
 777                 if (r) {
 778                         c->max++;
 779                         c->openmax = 1;
 780                 } else
 781                         c->openmax = (a->openmax || b->openmin);
 782         } else {
 783                 c->max = UINT_MAX;
 784                 c->openmax = 0;
 785         }
 786         c->integer = 0;
 787 }
 788
 789 /* ---- */
 790
 791
 792 /**
 793  * snd_interval_ratnum - refine the interval value
 794  * @i: interval to refine
 795  * @rats_count: number of ratnum_t
 796  * @rats: ratnum_t array
 797  * @nump: pointer to store the resultant numerator
 798  * @denp: pointer to store the resultant denominator
 799  *
 800  * Return: Positive if the value is changed, zero if it's not changed, or a
 801  * negative error code.
 802  */
 803 int snd_interval_ratnum(struct snd_interval *i,
 804                         unsigned int rats_count, const struct snd_ratnum *rats,
 805                         unsigned int *nump, unsigned int *denp)
 806 {
 807         unsigned int best_num, best_den;
 808         int best_diff;
 809         unsigned int k;
 810         struct snd_interval t;
 811         int err;
 812         unsigned int result_num, result_den;
 813         int result_diff;
 814
 815         best_num = best_den = best_diff = 0;
 816         for (k = 0; k < rats_count; ++k) {
 817                 unsigned int num = rats[k].num;
 818                 unsigned int den;
 819                 unsigned int q = i->min;
 820                 int diff;
 821                 if (q == 0)
 822                         q = 1;
 823                 den = div_up(num, q);
 824                 if (den < rats[k].den_min)
 825                         continue;
 826                 if (den > rats[k].den_max)
 827                         den = rats[k].den_max;
 828                 else {
 829                         unsigned int r;
 830                         r = (den - rats[k].den_min) % rats[k].den_step;
 831                         if (r != 0)
 832                                 den -= r;
 833                 }
 834                 diff = num - q * den;
 835                 if (diff < 0)
 836                         diff = -diff;
 837                 if (best_num == 0 ||
 838                     diff * best_den < best_diff * den) {
 839                         best_diff = diff;
 840                         best_den = den;
 841                         best_num = num;
 842                 }
 843         }
 844         if (best_den == 0) {
 845                 i->empty = 1;
 846                 return -EINVAL;
 847         }
 848         t.min = div_down(best_num, best_den);
 849         t.openmin = !!(best_num % best_den);
 850
 851         result_num = best_num;
 852         result_diff = best_diff;
 853         result_den = best_den;
 854         best_num = best_den = best_diff = 0;
 855         for (k = 0; k < rats_count; ++k) {
 856                 unsigned int num = rats[k].num;
 857                 unsigned int den;
 858                 unsigned int q = i->max;
 859                 int diff;
 860                 if (q == 0) {
 861                         i->empty = 1;
 862                         return -EINVAL;
 863                 }
 864                 den = div_down(num, q);
 865                 if (den > rats[k].den_max)
 866                         continue;
 867                 if (den < rats[k].den_min)
 868                         den = rats[k].den_min;
 869                 else {
 870                         unsigned int r;
 871                         r = (den - rats[k].den_min) % rats[k].den_step;
 872                         if (r != 0)
 873                                 den += rats[k].den_step - r;
 874                 }
 875                 diff = q * den - num;
 876                 if (diff < 0)
 877                         diff = -diff;
 878                 if (best_num == 0 ||
 879                     diff * best_den < best_diff * den) {
 880                         best_diff = diff;
 881                         best_den = den;
 882                         best_num = num;
 883                 }
 884         }
 885         if (best_den == 0) {
 886                 i->empty = 1;
 887                 return -EINVAL;
 888         }
 889         t.max = div_up(best_num, best_den);
 890         t.openmax = !!(best_num % best_den);
 891         t.integer = 0;
 892         err = snd_interval_refine(i, &t);
 893         if (err < 0)
 894                 return err;
 895
 896         if (snd_interval_single(i)) {
 897                 if (best_diff * result_den < result_diff * best_den) {
 898                         result_num = best_num;
 899                         result_den = best_den;
 900                 }
 901                 if (nump)
 902                         *nump = result_num;
 903                 if (denp)
 904                         *denp = result_den;
 905         }
 906         return err;
 907 }
 908
 909 EXPORT_SYMBOL(snd_interval_ratnum);
 910
 911 /**
 912  * snd_interval_ratden - refine the interval value
 913  * @i: interval to refine
 914  * @rats_count: number of struct ratden
 915  * @rats: struct ratden array
 916  * @nump: pointer to store the resultant numerator
 917  * @denp: pointer to store the resultant denominator
 918  *
 919  * Return: Positive if the value is changed, zero if it's not changed, or a
 920  * negative error code.
 921  */
 922 static int snd_interval_ratden(struct snd_interval *i,
 923                                unsigned int rats_count,
 924                                const struct snd_ratden *rats,
 925                                unsigned int *nump, unsigned int *denp)
 926 {
 927         unsigned int best_num, best_diff, best_den;
 928         unsigned int k;
 929         struct snd_interval t;
 930         int err;
 931
 932         best_num = best_den = best_diff = 0;
 933         for (k = 0; k < rats_count; ++k) {
 934                 unsigned int num;
 935                 unsigned int den = rats[k].den;
 936                 unsigned int q = i->min;
 937                 int diff;
 938                 num = mul(q, den);
 939                 if (num > rats[k].num_max)
 940                         continue;
 941                 if (num < rats[k].num_min)
 942                         num = rats[k].num_max;
 943                 else {
 944                         unsigned int r;
 945                         r = (num - rats[k].num_min) % rats[k].num_step;
 946                         if (r != 0)
 947                                 num += rats[k].num_step - r;
 948                 }
 949                 diff = num - q * den;
 950                 if (best_num == 0 ||
 951                     diff * best_den < best_diff * den) {
 952                         best_diff = diff;
 953                         best_den = den;
 954                         best_num = num;
 955                 }
 956         }
 957         if (best_den == 0) {
 958                 i->empty = 1;
 959                 return -EINVAL;
 960         }
 961         t.min = div_down(best_num, best_den);
 962         t.openmin = !!(best_num % best_den);
 963
 964         best_num = best_den = best_diff = 0;
 965         for (k = 0; k < rats_count; ++k) {
 966                 unsigned int num;
 967                 unsigned int den = rats[k].den;
 968                 unsigned int q = i->max;
 969                 int diff;
 970                 num = mul(q, den);
 971                 if (num < rats[k].num_min)
 972                         continue;
 973                 if (num > rats[k].num_max)
 974                         num = rats[k].num_max;
 975                 else {
 976                         unsigned int r;
 977                         r = (num - rats[k].num_min) % rats[k].num_step;
 978                         if (r != 0)
 979                                 num -= r;
 980                 }
 981                 diff = q * den - num;
 982                 if (best_num == 0 ||
 983                     diff * best_den < best_diff * den) {
 984                         best_diff = diff;
 985                         best_den = den;
 986                         best_num = num;
 987                 }
 988         }
 989         if (best_den == 0) {
 990                 i->empty = 1;
 991                 return -EINVAL;
 992         }
 993         t.max = div_up(best_num, best_den);
 994         t.openmax = !!(best_num % best_den);
 995         t.integer = 0;
 996         err = snd_interval_refine(i, &t);
 997         if (err < 0)
 998                 return err;
 999
1000         if (snd_interval_single(i)) {
1001                 if (nump)
1002                         *nump = best_num;
1003                 if (denp)
1004                         *denp = best_den;
1005         }
1006         return err;
1007 }
1008
1009 /**
1010  * snd_interval_list - refine the interval value from the list
1011  * @i: the interval value to refine
1012  * @count: the number of elements in the list
1013  * @list: the value list
1014  * @mask: the bit-mask to evaluate
1015  *
1016  * Refines the interval value from the list.
1017  * When mask is non-zero, only the elements corresponding to bit 1 are
1018  * evaluated.
1019  *
1020  * Return: Positive if the value is changed, zero if it's not changed, or a
1021  * negative error code.
1022  */
1023 int snd_interval_list(struct snd_interval *i, unsigned int count,
1024                       const unsigned int *list, unsigned int mask)
1025 {
1026         unsigned int k;
1027         struct snd_interval list_range;
1028
1029         if (!count) {
1030                 i->empty = 1;
1031                 return -EINVAL;
1032         }
1033         snd_interval_any(&list_range);
1034         list_range.min = UINT_MAX;
1035         list_range.max = 0;
1036         for (k = 0; k < count; k++) {
1037                 if (mask && !(mask & (1 << k)))
1038                         continue;
1039                 if (!snd_interval_test(i, list[k]))
1040                         continue;
1041                 list_range.min = min(list_range.min, list[k]);
1042                 list_range.max = max(list_range.max, list[k]);
1043         }
1044         return snd_interval_refine(i, &list_range);
1045 }
1046
1047 EXPORT_SYMBOL(snd_interval_list);
1048
1049 /**
1050  * snd_interval_ranges - refine the interval value from the list of ranges
1051  * @i: the interval value to refine
1052  * @count: the number of elements in the list of ranges
1053  * @ranges: the ranges list
1054  * @mask: the bit-mask to evaluate
1055  *
1056  * Refines the interval value from the list of ranges.
1057  * When mask is non-zero, only the elements corresponding to bit 1 are
1058  * evaluated.
1059  *
1060  * Return: Positive if the value is changed, zero if it's not changed, or a
1061  * negative error code.
1062  */
1063 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1064                         const struct snd_interval *ranges, unsigned int mask)
1065 {
1066         unsigned int k;
1067         struct snd_interval range_union;
1068         struct snd_interval range;
1069
1070         if (!count) {
1071                 snd_interval_none(i);
1072                 return -EINVAL;
1073         }
1074         snd_interval_any(&range_union);
1075         range_union.min = UINT_MAX;
1076         range_union.max = 0;
1077         for (k = 0; k < count; k++) {
1078                 if (mask && !(mask & (1 << k)))
1079                         continue;
1080                 snd_interval_copy(&range, &ranges[k]);
1081                 if (snd_interval_refine(&range, i) < 0)
1082                         continue;
1083                 if (snd_interval_empty(&range))
1084                         continue;
1085
1086                 if (range.min < range_union.min) {
1087                         range_union.min = range.min;
1088                         range_union.openmin = 1;
1089                 }
1090                 if (range.min == range_union.min && !range.openmin)
1091                         range_union.openmin = 0;
1092                 if (range.max > range_union.max) {
1093                         range_union.max = range.max;
1094                         range_union.openmax = 1;
1095                 }
1096                 if (range.max == range_union.max && !range.openmax)
1097                         range_union.openmax = 0;
1098         }
1099         return snd_interval_refine(i, &range_union);
1100 }
1101 EXPORT_SYMBOL(snd_interval_ranges);
1102
1103 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1104 {
1105         unsigned int n;
1106         int changed = 0;
1107         n = i->min % step;
1108         if (n != 0 || i->openmin) {
1109                 i->min += step - n;
1110                 i->openmin = 0;
1111                 changed = 1;
1112         }
1113         n = i->max % step;
1114         if (n != 0 || i->openmax) {
1115                 i->max -= n;
1116                 i->openmax = 0;
1117                 changed = 1;
1118         }
1119         if (snd_interval_checkempty(i)) {
1120                 i->empty = 1;
1121                 return -EINVAL;
1122         }
1123         return changed;
1124 }
1125
1126 /* Info constraints helpers */
1127
1128 /**
1129  * snd_pcm_hw_rule_add - add the hw-constraint rule
1130  * @runtime: the pcm runtime instance
1131  * @cond: condition bits
1132  * @var: the variable to evaluate
1133  * @func: the evaluation function
1134  * @private: the private data pointer passed to function
1135  * @dep: the dependent variables
1136  *
1137  * Return: Zero if successful, or a negative error code on failure.
1138  */
1139 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1140                         int var,
1141                         snd_pcm_hw_rule_func_t func, void *private,
1142                         int dep, ...)
1143 {
1144         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1145         struct snd_pcm_hw_rule *c;
1146         unsigned int k;
1147         va_list args;
1148         va_start(args, dep);
1149         if (constrs->rules_num >= constrs->rules_all) {
1150                 struct snd_pcm_hw_rule *new;
1151                 unsigned int new_rules = constrs->rules_all + 16;
1152                 new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1153                 if (!new) {
1154                         va_end(args);
1155                         return -ENOMEM;
1156                 }
1157                 if (constrs->rules) {
1158                         memcpy(new, constrs->rules,
1159                                constrs->rules_num * sizeof(*c));
1160                         kfree(constrs->rules);
1161                 }
1162                 constrs->rules = new;
1163                 constrs->rules_all = new_rules;
1164         }
1165         c = &constrs->rules[constrs->rules_num];
1166         c->cond = cond;
1167         c->func = func;
1168         c->var = var;
1169         c->private = private;
1170         k = 0;
1171         while (1) {
1172                 if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1173                         va_end(args);
1174                         return -EINVAL;
1175                 }
1176                 c->deps[k++] = dep;
1177                 if (dep < 0)
1178                         break;
1179                 dep = va_arg(args, int);
1180         }
1181         constrs->rules_num++;
1182         va_end(args);
1183         return 0;
1184 }
1185
1186 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1187
1188 /**
1189  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1190  * @runtime: PCM runtime instance
1191  * @var: hw_params variable to apply the mask
1192  * @mask: the bitmap mask
1193  *
1194  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1195  *
1196  * Return: Zero if successful, or a negative error code on failure.
1197  */
1198 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1199                                u_int32_t mask)
1200 {
1201         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1202         struct snd_mask *maskp = constrs_mask(constrs, var);
1203         *maskp->bits &= mask;
1204         memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1205         if (*maskp->bits == 0)
1206                 return -EINVAL;
1207         return 0;
1208 }
1209
1210 /**
1211  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1212  * @runtime: PCM runtime instance
1213  * @var: hw_params variable to apply the mask
1214  * @mask: the 64bit bitmap mask
1215  *
1216  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1217  *
1218  * Return: Zero if successful, or a negative error code on failure.
1219  */
1220 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1221                                  u_int64_t mask)
1222 {
1223         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1224         struct snd_mask *maskp = constrs_mask(constrs, var);
1225         maskp->bits[0] &= (u_int32_t)mask;
1226         maskp->bits[1] &= (u_int32_t)(mask >> 32);
1227         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1228         if (! maskp->bits[0] && ! maskp->bits[1])
1229                 return -EINVAL;
1230         return 0;
1231 }
1232 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1233
1234 /**
1235  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1236  * @runtime: PCM runtime instance
1237  * @var: hw_params variable to apply the integer constraint
1238  *
1239  * Apply the constraint of integer to an interval parameter.
1240  *
1241  * Return: Positive if the value is changed, zero if it's not changed, or a
1242  * negative error code.
1243  */
1244 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1245 {
1246         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1247         return snd_interval_setinteger(constrs_interval(constrs, var));
1248 }
1249
1250 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1251
1252 /**
1253  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1254  * @runtime: PCM runtime instance
1255  * @var: hw_params variable to apply the range
1256  * @min: the minimal value
1257  * @max: the maximal value
1258  *
1259  * Apply the min/max range constraint to an interval parameter.
1260  *
1261  * Return: Positive if the value is changed, zero if it's not changed, or a
1262  * negative error code.
1263  */
1264 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1265                                  unsigned int min, unsigned int max)
1266 {
1267         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1268         struct snd_interval t;
1269         t.min = min;
1270         t.max = max;
1271         t.openmin = t.openmax = 0;
1272         t.integer = 0;
1273         return snd_interval_refine(constrs_interval(constrs, var), &t);
1274 }
1275
1276 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1277
1278 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1279                                 struct snd_pcm_hw_rule *rule)
1280 {
1281         struct snd_pcm_hw_constraint_list *list = rule->private;
1282         return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1283 }
1284
1285
1286 /**
1287  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1288  * @runtime: PCM runtime instance
1289  * @cond: condition bits
1290  * @var: hw_params variable to apply the list constraint
1291  * @l: list
1292  *
1293  * Apply the list of constraints to an interval parameter.
1294  *
1295  * Return: Zero if successful, or a negative error code on failure.
1296  */
1297 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1298                                unsigned int cond,
1299                                snd_pcm_hw_param_t var,
1300                                const struct snd_pcm_hw_constraint_list *l)
1301 {
1302         return snd_pcm_hw_rule_add(runtime, cond, var,
1303                                    snd_pcm_hw_rule_list, (void *)l,
1304                                    var, -1);
1305 }
1306
1307 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1308
1309 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1310                                   struct snd_pcm_hw_rule *rule)
1311 {
1312         struct snd_pcm_hw_constraint_ranges *r = rule->private;
1313         return snd_interval_ranges(hw_param_interval(params, rule->var),
1314                                    r->count, r->ranges, r->mask);
1315 }
1316
1317
1318 /**
1319  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1320  * @runtime: PCM runtime instance
1321  * @cond: condition bits
1322  * @var: hw_params variable to apply the list of range constraints
1323  * @r: ranges
1324  *
1325  * Apply the list of range constraints to an interval parameter.
1326  *
1327  * Return: Zero if successful, or a negative error code on failure.
1328  */
1329 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1330                                  unsigned int cond,
1331                                  snd_pcm_hw_param_t var,
1332                                  const struct snd_pcm_hw_constraint_ranges *r)
1333 {
1334         return snd_pcm_hw_rule_add(runtime, cond, var,
1335                                    snd_pcm_hw_rule_ranges, (void *)r,
1336                                    var, -1);
1337 }
1338 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1339
1340 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1341                                    struct snd_pcm_hw_rule *rule)
1342 {
1343         const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1344         unsigned int num = 0, den = 0;
1345         int err;
1346         err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1347                                   r->nrats, r->rats, &num, &den);
1348         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1349                 params->rate_num = num;
1350                 params->rate_den = den;
1351         }
1352         return err;
1353 }
1354
1355 /**
1356  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1357  * @runtime: PCM runtime instance
1358  * @cond: condition bits
1359  * @var: hw_params variable to apply the ratnums constraint
1360  * @r: struct snd_ratnums constriants
1361  *
1362  * Return: Zero if successful, or a negative error code on failure.
1363  */
1364 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1365                                   unsigned int cond,
1366                                   snd_pcm_hw_param_t var,
1367                                   const struct snd_pcm_hw_constraint_ratnums *r)
1368 {
1369         return snd_pcm_hw_rule_add(runtime, cond, var,
1370                                    snd_pcm_hw_rule_ratnums, (void *)r,
1371                                    var, -1);
1372 }
1373
1374 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1375
1376 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1377                                    struct snd_pcm_hw_rule *rule)
1378 {
1379         const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1380         unsigned int num = 0, den = 0;
1381         int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1382                                   r->nrats, r->rats, &num, &den);
1383         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1384                 params->rate_num = num;
1385                 params->rate_den = den;
1386         }
1387         return err;
1388 }
1389
1390 /**
1391  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1392  * @runtime: PCM runtime instance
1393  * @cond: condition bits
1394  * @var: hw_params variable to apply the ratdens constraint
1395  * @r: struct snd_ratdens constriants
1396  *
1397  * Return: Zero if successful, or a negative error code on failure.
1398  */
1399 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1400                                   unsigned int cond,
1401                                   snd_pcm_hw_param_t var,
1402                                   const struct snd_pcm_hw_constraint_ratdens *r)
1403 {
1404         return snd_pcm_hw_rule_add(runtime, cond, var,
1405                                    snd_pcm_hw_rule_ratdens, (void *)r,
1406                                    var, -1);
1407 }
1408
1409 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1410
1411 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1412                                   struct snd_pcm_hw_rule *rule)
1413 {
1414         unsigned int l = (unsigned long) rule->private;
1415         int width = l & 0xffff;
1416         unsigned int msbits = l >> 16;
1417         struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1418
1419         if (!snd_interval_single(i))
1420                 return 0;
1421
1422         if ((snd_interval_value(i) == width) ||
1423             (width == 0 && snd_interval_value(i) > msbits))
1424                 params->msbits = min_not_zero(params->msbits, msbits);
1425
1426         return 0;
1427 }
1428
1429 /**
1430  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1431  * @runtime: PCM runtime instance
1432  * @cond: condition bits
1433  * @width: sample bits width
1434  * @msbits: msbits width
1435  *
1436  * This constraint will set the number of most significant bits (msbits) if a
1437  * sample format with the specified width has been select. If width is set to 0
1438  * the msbits will be set for any sample format with a width larger than the
1439  * specified msbits.
1440  *
1441  * Return: Zero if successful, or a negative error code on failure.
1442  */
1443 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1444                                  unsigned int cond,
1445                                  unsigned int width,
1446                                  unsigned int msbits)
1447 {
1448         unsigned long l = (msbits << 16) | width;
1449         return snd_pcm_hw_rule_add(runtime, cond, -1,
1450                                     snd_pcm_hw_rule_msbits,
1451                                     (void*) l,
1452                                     SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1453 }
1454
1455 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1456
1457 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1458                                 struct snd_pcm_hw_rule *rule)
1459 {
1460         unsigned long step = (unsigned long) rule->private;
1461         return snd_interval_step(hw_param_interval(params, rule->var), step);
1462 }
1463
1464 /**
1465  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1466  * @runtime: PCM runtime instance
1467  * @cond: condition bits
1468  * @var: hw_params variable to apply the step constraint
1469  * @step: step size
1470  *
1471  * Return: Zero if successful, or a negative error code on failure.
1472  */
1473 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1474                                unsigned int cond,
1475                                snd_pcm_hw_param_t var,
1476                                unsigned long step)
1477 {
1478         return snd_pcm_hw_rule_add(runtime, cond, var,
1479                                    snd_pcm_hw_rule_step, (void *) step,
1480                                    var, -1);
1481 }
1482
1483 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1484
1485 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1486 {
1487         static unsigned int pow2_sizes[] = {
1488                 1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1489                 1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1490                 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1491                 1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1492         };
1493         return snd_interval_list(hw_param_interval(params, rule->var),
1494                                  ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1495 }
1496
1497 /**
1498  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1499  * @runtime: PCM runtime instance
1500  * @cond: condition bits
1501  * @var: hw_params variable to apply the power-of-2 constraint
1502  *
1503  * Return: Zero if successful, or a negative error code on failure.
1504  */
1505 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1506                                unsigned int cond,
1507                                snd_pcm_hw_param_t var)
1508 {
1509         return snd_pcm_hw_rule_add(runtime, cond, var,
1510                                    snd_pcm_hw_rule_pow2, NULL,
1511                                    var, -1);
1512 }
1513
1514 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1515
1516 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1517                                            struct snd_pcm_hw_rule *rule)
1518 {
1519         unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1520         struct snd_interval *rate;
1521
1522         rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1523         return snd_interval_list(rate, 1, &base_rate, 0);
1524 }
1525
1526 /**
1527  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1528  * @runtime: PCM runtime instance
1529  * @base_rate: the rate at which the hardware does not resample
1530  *
1531  * Return: Zero if successful, or a negative error code on failure.
1532  */
1533 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1534                                unsigned int base_rate)
1535 {
1536         return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1537                                    SNDRV_PCM_HW_PARAM_RATE,
1538                                    snd_pcm_hw_rule_noresample_func,
1539                                    (void *)(uintptr_t)base_rate,
1540                                    SNDRV_PCM_HW_PARAM_RATE, -1);
1541 }
1542 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1543
1544 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1545                                   snd_pcm_hw_param_t var)
1546 {
1547         if (hw_is_mask(var)) {
1548                 snd_mask_any(hw_param_mask(params, var));
1549                 params->cmask |= 1 << var;
1550                 params->rmask |= 1 << var;
1551                 return;
1552         }
1553         if (hw_is_interval(var)) {
1554                 snd_interval_any(hw_param_interval(params, var));
1555                 params->cmask |= 1 << var;
1556                 params->rmask |= 1 << var;
1557                 return;
1558         }
1559         snd_BUG();
1560 }
1561
1562 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1563 {
1564         unsigned int k;
1565         memset(params, 0, sizeof(*params));
1566         for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1567                 _snd_pcm_hw_param_any(params, k);
1568         for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1569                 _snd_pcm_hw_param_any(params, k);
1570         params->info = ~0U;
1571 }
1572
1573 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1574
1575 /**
1576  * snd_pcm_hw_param_value - return @params field @var value
1577  * @params: the hw_params instance
1578  * @var: parameter to retrieve
1579  * @dir: pointer to the direction (-1,0,1) or %NULL
1580  *
1581  * Return: The value for field @var if it's fixed in configuration space
1582  * defined by @params. -%EINVAL otherwise.
1583  */
1584 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1585                            snd_pcm_hw_param_t var, int *dir)
1586 {
1587         if (hw_is_mask(var)) {
1588                 const struct snd_mask *mask = hw_param_mask_c(params, var);
1589                 if (!snd_mask_single(mask))
1590                         return -EINVAL;
1591                 if (dir)
1592                         *dir = 0;
1593                 return snd_mask_value(mask);
1594         }
1595         if (hw_is_interval(var)) {
1596                 const struct snd_interval *i = hw_param_interval_c(params, var);
1597                 if (!snd_interval_single(i))
1598                         return -EINVAL;
1599                 if (dir)
1600                         *dir = i->openmin;
1601                 return snd_interval_value(i);
1602         }
1603         return -EINVAL;
1604 }
1605
1606 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1607
1608 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1609                                 snd_pcm_hw_param_t var)
1610 {
1611         if (hw_is_mask(var)) {
1612                 snd_mask_none(hw_param_mask(params, var));
1613                 params->cmask |= 1 << var;
1614                 params->rmask |= 1 << var;
1615         } else if (hw_is_interval(var)) {
1616                 snd_interval_none(hw_param_interval(params, var));
1617                 params->cmask |= 1 << var;
1618                 params->rmask |= 1 << var;
1619         } else {
1620                 snd_BUG();
1621         }
1622 }
1623
1624 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1625
1626 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1627                                    snd_pcm_hw_param_t var)
1628 {
1629         int changed;
1630         if (hw_is_mask(var))
1631                 changed = snd_mask_refine_first(hw_param_mask(params, var));
1632         else if (hw_is_interval(var))
1633                 changed = snd_interval_refine_first(hw_param_interval(params, var));
1634         else
1635                 return -EINVAL;
1636         if (changed) {
1637                 params->cmask |= 1 << var;
1638                 params->rmask |= 1 << var;
1639         }
1640         return changed;
1641 }
1642
1643
1644 /**
1645  * snd_pcm_hw_param_first - refine config space and return minimum value
1646  * @pcm: PCM instance
1647  * @params: the hw_params instance
1648  * @var: parameter to retrieve
1649  * @dir: pointer to the direction (-1,0,1) or %NULL
1650  *
1651  * Inside configuration space defined by @params remove from @var all
1652  * values > minimum. Reduce configuration space accordingly.
1653  *
1654  * Return: The minimum, or a negative error code on failure.
1655  */
1656 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1657                            struct snd_pcm_hw_params *params,
1658                            snd_pcm_hw_param_t var, int *dir)
1659 {
1660         int changed = _snd_pcm_hw_param_first(params, var);
1661         if (changed < 0)
1662                 return changed;
1663         if (params->rmask) {
1664                 int err = snd_pcm_hw_refine(pcm, params);
1665                 if (snd_BUG_ON(err < 0))
1666                         return err;
1667         }
1668         return snd_pcm_hw_param_value(params, var, dir);
1669 }
1670
1671 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1672
1673 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1674                                   snd_pcm_hw_param_t var)
1675 {
1676         int changed;
1677         if (hw_is_mask(var))
1678                 changed = snd_mask_refine_last(hw_param_mask(params, var));
1679         else if (hw_is_interval(var))
1680                 changed = snd_interval_refine_last(hw_param_interval(params, var));
1681         else
1682                 return -EINVAL;
1683         if (changed) {
1684                 params->cmask |= 1 << var;
1685                 params->rmask |= 1 << var;
1686         }
1687         return changed;
1688 }
1689
1690
1691 /**
1692  * snd_pcm_hw_param_last - refine config space and return maximum value
1693  * @pcm: PCM instance
1694  * @params: the hw_params instance
1695  * @var: parameter to retrieve
1696  * @dir: pointer to the direction (-1,0,1) or %NULL
1697  *
1698  * Inside configuration space defined by @params remove from @var all
1699  * values < maximum. Reduce configuration space accordingly.
1700  *
1701  * Return: The maximum, or a negative error code on failure.
1702  */
1703 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1704                           struct snd_pcm_hw_params *params,
1705                           snd_pcm_hw_param_t var, int *dir)
1706 {
1707         int changed = _snd_pcm_hw_param_last(params, var);
1708         if (changed < 0)
1709                 return changed;
1710         if (params->rmask) {
1711                 int err = snd_pcm_hw_refine(pcm, params);
1712                 if (snd_BUG_ON(err < 0))
1713                         return err;
1714         }
1715         return snd_pcm_hw_param_value(params, var, dir);
1716 }
1717
1718 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1719
1720 /**
1721  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1722  * @pcm: PCM instance
1723  * @params: the hw_params instance
1724  *
1725  * Choose one configuration from configuration space defined by @params.
1726  * The configuration chosen is that obtained fixing in this order:
1727  * first access, first format, first subformat, min channels,
1728  * min rate, min period time, max buffer size, min tick time
1729  *
1730  * Return: Zero if successful, or a negative error code on failure.
1731  */
1732 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1733                              struct snd_pcm_hw_params *params)
1734 {
1735         static int vars[] = {
1736                 SNDRV_PCM_HW_PARAM_ACCESS,
1737                 SNDRV_PCM_HW_PARAM_FORMAT,
1738                 SNDRV_PCM_HW_PARAM_SUBFORMAT,
1739                 SNDRV_PCM_HW_PARAM_CHANNELS,
1740                 SNDRV_PCM_HW_PARAM_RATE,
1741                 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1742                 SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1743                 SNDRV_PCM_HW_PARAM_TICK_TIME,
1744                 -1
1745         };
1746         int err, *v;
1747
1748         for (v = vars; *v != -1; v++) {
1749                 if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1750                         err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1751                 else
1752                         err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1753                 if (snd_BUG_ON(err < 0))
1754                         return err;
1755         }
1756         return 0;
1757 }
1758
1759 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1760                                    void *arg)
1761 {
1762         struct snd_pcm_runtime *runtime = substream->runtime;
1763         unsigned long flags;
1764         snd_pcm_stream_lock_irqsave(substream, flags);
1765         if (snd_pcm_running(substream) &&
1766             snd_pcm_update_hw_ptr(substream) >= 0)
1767                 runtime->status->hw_ptr %= runtime->buffer_size;
1768         else {
1769                 runtime->status->hw_ptr = 0;
1770                 runtime->hw_ptr_wrap = 0;
1771         }
1772         snd_pcm_stream_unlock_irqrestore(substream, flags);
1773         return 0;
1774 }
1775
1776 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1777                                           void *arg)
1778 {
1779         struct snd_pcm_channel_info *info = arg;
1780         struct snd_pcm_runtime *runtime = substream->runtime;
1781         int width;
1782         if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1783                 info->offset = -1;
1784                 return 0;
1785         }
1786         width = snd_pcm_format_physical_width(runtime->format);
1787         if (width < 0)
1788                 return width;
1789         info->offset = 0;
1790         switch (runtime->access) {
1791         case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1792         case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1793                 info->first = info->channel * width;
1794                 info->step = runtime->channels * width;
1795                 break;
1796         case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1797         case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1798         {
1799                 size_t size = runtime->dma_bytes / runtime->channels;
1800                 info->first = info->channel * size * 8;
1801                 info->step = width;
1802                 break;
1803         }
1804         default:
1805                 snd_BUG();
1806                 break;
1807         }
1808         return 0;
1809 }
1810
1811 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1812                                        void *arg)
1813 {
1814         struct snd_pcm_hw_params *params = arg;
1815         snd_pcm_format_t format;
1816         int channels;
1817         ssize_t frame_size;
1818
1819         params->fifo_size = substream->runtime->hw.fifo_size;
1820         if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1821                 format = params_format(params);
1822                 channels = params_channels(params);
1823                 frame_size = snd_pcm_format_size(format, channels);
1824                 if (frame_size > 0)
1825                         params->fifo_size /= (unsigned)frame_size;
1826         }
1827         return 0;
1828 }
1829
1830 /**
1831  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1832  * @substream: the pcm substream instance
1833  * @cmd: ioctl command
1834  * @arg: ioctl argument
1835  *
1836  * Processes the generic ioctl commands for PCM.
1837  * Can be passed as the ioctl callback for PCM ops.
1838  *
1839  * Return: Zero if successful, or a negative error code on failure.
1840  */
1841 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1842                       unsigned int cmd, void *arg)
1843 {
1844         switch (cmd) {
1845         case SNDRV_PCM_IOCTL1_INFO:
1846                 return 0;
1847         case SNDRV_PCM_IOCTL1_RESET:
1848                 return snd_pcm_lib_ioctl_reset(substream, arg);
1849         case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1850                 return snd_pcm_lib_ioctl_channel_info(substream, arg);
1851         case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1852                 return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1853         }
1854         return -ENXIO;
1855 }
1856
1857 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1858
1859 /**
1860  * snd_pcm_period_elapsed - update the pcm status for the next period
1861  * @substream: the pcm substream instance
1862  *
1863  * This function is called from the interrupt handler when the
1864  * PCM has processed the period size.  It will update the current
1865  * pointer, wake up sleepers, etc.
1866  *
1867  * Even if more than one periods have elapsed since the last call, you
1868  * have to call this only once.
1869  */
1870 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1871 {
1872         struct snd_pcm_runtime *runtime;
1873         unsigned long flags;
1874
1875         if (PCM_RUNTIME_CHECK(substream))
1876                 return;
1877         runtime = substream->runtime;
1878
1879         snd_pcm_stream_lock_irqsave(substream, flags);
1880         if (!snd_pcm_running(substream) ||
1881             snd_pcm_update_hw_ptr0(substream, 1) < 0)
1882                 goto _end;
1883
1884 #ifdef CONFIG_SND_PCM_TIMER
1885         if (substream->timer_running)
1886                 snd_timer_interrupt(substream->timer, 1);
1887 #endif
1888  _end:
1889         snd_pcm_stream_unlock_irqrestore(substream, flags);
1890         kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1891 }
1892
1893 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1894
1895 /*
1896  * Wait until avail_min data becomes available
1897  * Returns a negative error code if any error occurs during operation.
1898  * The available space is stored on availp.  When err = 0 and avail = 0
1899  * on the capture stream, it indicates the stream is in DRAINING state.
1900  */
1901 static int wait_for_avail(struct snd_pcm_substream *substream,
1902                               snd_pcm_uframes_t *availp)
1903 {
1904         struct snd_pcm_runtime *runtime = substream->runtime;
1905         int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1906         wait_queue_t wait;
1907         int err = 0;
1908         snd_pcm_uframes_t avail = 0;
1909         long wait_time, tout;
1910
1911         init_waitqueue_entry(&wait, current);
1912         set_current_state(TASK_INTERRUPTIBLE);
1913         add_wait_queue(&runtime->tsleep, &wait);
1914
1915         if (runtime->no_period_wakeup)
1916                 wait_time = MAX_SCHEDULE_TIMEOUT;
1917         else {
1918                 wait_time = 10;
1919                 if (runtime->rate) {
1920                         long t = runtime->period_size * 2 / runtime->rate;
1921                         wait_time = max(t, wait_time);
1922                 }
1923                 wait_time = msecs_to_jiffies(wait_time * 1000);
1924         }
1925
1926         for (;;) {
1927                 if (signal_pending(current)) {
1928                         err = -ERESTARTSYS;
1929                         break;
1930                 }
1931
1932                 /*
1933                  * We need to check if space became available already
1934                  * (and thus the wakeup happened already) first to close
1935                  * the race of space already having become available.
1936                  * This check must happen after been added to the waitqueue
1937                  * and having current state be INTERRUPTIBLE.
1938                  */
1939                 if (is_playback)
1940                         avail = snd_pcm_playback_avail(runtime);
1941                 else
1942                         avail = snd_pcm_capture_avail(runtime);
1943                 if (avail >= runtime->twake)
1944                         break;
1945                 snd_pcm_stream_unlock_irq(substream);
1946
1947                 tout = schedule_timeout(wait_time);
1948
1949                 snd_pcm_stream_lock_irq(substream);
1950                 set_current_state(TASK_INTERRUPTIBLE);
1951                 switch (runtime->status->state) {
1952                 case SNDRV_PCM_STATE_SUSPENDED:
1953                         err = -ESTRPIPE;
1954                         goto _endloop;
1955                 case SNDRV_PCM_STATE_XRUN:
1956                         err = -EPIPE;
1957                         goto _endloop;
1958                 case SNDRV_PCM_STATE_DRAINING:
1959                         if (is_playback)
1960                                 err = -EPIPE;
1961                         else
1962                                 avail = 0; /* indicate draining */
1963                         goto _endloop;
1964                 case SNDRV_PCM_STATE_OPEN:
1965                 case SNDRV_PCM_STATE_SETUP:
1966                 case SNDRV_PCM_STATE_DISCONNECTED:
1967                         err = -EBADFD;
1968                         goto _endloop;
1969                 case SNDRV_PCM_STATE_PAUSED:
1970                         continue;
1971                 }
1972                 if (!tout) {
1973                         pcm_dbg(substream->pcm,
1974                                 "%s write error (DMA or IRQ trouble?)\n",
1975                                 is_playback ? "playback" : "capture");
1976                         err = -EIO;
1977                         break;
1978                 }
1979         }
1980  _endloop:
1981         set_current_state(TASK_RUNNING);
1982         remove_wait_queue(&runtime->tsleep, &wait);
1983         *availp = avail;
1984         return err;
1985 }
1986
1987 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1988                                       unsigned int hwoff,
1989                                       unsigned long data, unsigned int off,
1990                                       snd_pcm_uframes_t frames)
1991 {
1992         struct snd_pcm_runtime *runtime = substream->runtime;
1993         int err;
1994         char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1995         if (substream->ops->copy) {
1996                 if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1997                         return err;
1998         } else {
1999                 char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2000                 if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
2001                         return -EFAULT;
2002         }
2003         return 0;
2004 }
2005
2006 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
2007                           unsigned long data, unsigned int off,
2008                           snd_pcm_uframes_t size);
2009
2010 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
2011                                             unsigned long data,
2012                                             snd_pcm_uframes_t size,
2013                                             int nonblock,
2014                                             transfer_f transfer)
2015 {
2016         struct snd_pcm_runtime *runtime = substream->runtime;
2017         snd_pcm_uframes_t xfer = 0;
2018         snd_pcm_uframes_t offset = 0;
2019         snd_pcm_uframes_t avail;
2020         int err = 0;
2021
2022         if (size == 0)
2023                 return 0;
2024
2025         snd_pcm_stream_lock_irq(substream);
2026         switch (runtime->status->state) {
2027         case SNDRV_PCM_STATE_PREPARED:
2028         case SNDRV_PCM_STATE_RUNNING:
2029         case SNDRV_PCM_STATE_PAUSED:
2030                 break;
2031         case SNDRV_PCM_STATE_XRUN:
2032                 err = -EPIPE;
2033                 goto _end_unlock;
2034         case SNDRV_PCM_STATE_SUSPENDED:
2035                 err = -ESTRPIPE;
2036                 goto _end_unlock;
2037         default:
2038                 err = -EBADFD;
2039                 goto _end_unlock;
2040         }
2041
2042         runtime->twake = runtime->control->avail_min ? : 1;
2043         if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2044                 snd_pcm_update_hw_ptr(substream);
2045         avail = snd_pcm_playback_avail(runtime);
2046         while (size > 0) {
2047                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2048                 snd_pcm_uframes_t cont;
2049                 if (!avail) {
2050                         if (nonblock) {
2051                                 err = -EAGAIN;
2052                                 goto _end_unlock;
2053                         }
2054                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2055                                         runtime->control->avail_min ? : 1);
2056                         err = wait_for_avail(substream, &avail);
2057                         if (err < 0)
2058                                 goto _end_unlock;
2059                 }
2060                 frames = size > avail ? avail : size;
2061                 cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2062                 if (frames > cont)
2063                         frames = cont;
2064                 if (snd_BUG_ON(!frames)) {
2065                         runtime->twake = 0;
2066                         snd_pcm_stream_unlock_irq(substream);
2067                         return -EINVAL;
2068                 }
2069                 appl_ptr = runtime->control->appl_ptr;
2070                 appl_ofs = appl_ptr % runtime->buffer_size;
2071                 snd_pcm_stream_unlock_irq(substream);
2072                 err = transfer(substream, appl_ofs, data, offset, frames);
2073                 snd_pcm_stream_lock_irq(substream);
2074                 if (err < 0)
2075                         goto _end_unlock;
2076                 switch (runtime->status->state) {
2077                 case SNDRV_PCM_STATE_XRUN:
2078                         err = -EPIPE;
2079                         goto _end_unlock;
2080                 case SNDRV_PCM_STATE_SUSPENDED:
2081                         err = -ESTRPIPE;
2082                         goto _end_unlock;
2083                 default:
2084                         break;
2085                 }
2086                 appl_ptr += frames;
2087                 if (appl_ptr >= runtime->boundary)
2088                         appl_ptr -= runtime->boundary;
2089                 runtime->control->appl_ptr = appl_ptr;
2090                 if (substream->ops->ack)
2091                         substream->ops->ack(substream);
2092
2093                 offset += frames;
2094                 size -= frames;
2095                 xfer += frames;
2096                 avail -= frames;
2097                 if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2098                     snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2099                         err = snd_pcm_start(substream);
2100                         if (err < 0)
2101                                 goto _end_unlock;
2102                 }
2103         }
2104  _end_unlock:
2105         runtime->twake = 0;
2106         if (xfer > 0 && err >= 0)
2107                 snd_pcm_update_state(substream, runtime);
2108         snd_pcm_stream_unlock_irq(substream);
2109         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2110 }
2111
2112 /* sanity-check for read/write methods */
2113 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2114 {
2115         struct snd_pcm_runtime *runtime;
2116         if (PCM_RUNTIME_CHECK(substream))
2117                 return -ENXIO;
2118         runtime = substream->runtime;
2119         if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2120                 return -EINVAL;
2121         if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2122                 return -EBADFD;
2123         return 0;
2124 }
2125
2126 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2127 {
2128         struct snd_pcm_runtime *runtime;
2129         int nonblock;
2130         int err;
2131
2132         err = pcm_sanity_check(substream);
2133         if (err < 0)
2134                 return err;
2135         runtime = substream->runtime;
2136         nonblock = !!(substream->f_flags & O_NONBLOCK);
2137
2138         if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2139             runtime->channels > 1)
2140                 return -EINVAL;
2141         return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2142                                   snd_pcm_lib_write_transfer);
2143 }
2144
2145 EXPORT_SYMBOL(snd_pcm_lib_write);
2146
2147 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2148                                        unsigned int hwoff,
2149                                        unsigned long data, unsigned int off,
2150                                        snd_pcm_uframes_t frames)
2151 {
2152         struct snd_pcm_runtime *runtime = substream->runtime;
2153         int err;
2154         void __user **bufs = (void __user **)data;
2155         int channels = runtime->channels;
2156         int c;
2157         if (substream->ops->copy) {
2158                 if (snd_BUG_ON(!substream->ops->silence))
2159                         return -EINVAL;
2160                 for (c = 0; c < channels; ++c, ++bufs) {
2161                         if (*bufs == NULL) {
2162                                 if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2163                                         return err;
2164                         } else {
2165                                 char __user *buf = *bufs + samples_to_bytes(runtime, off);
2166                                 if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2167                                         return err;
2168                         }
2169                 }
2170         } else {
2171                 /* default transfer behaviour */
2172                 size_t dma_csize = runtime->dma_bytes / channels;
2173                 for (c = 0; c < channels; ++c, ++bufs) {
2174                         char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2175                         if (*bufs == NULL) {
2176                                 snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2177                         } else {
2178                                 char __user *buf = *bufs + samples_to_bytes(runtime, off);
2179                                 if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2180                                         return -EFAULT;
2181                         }
2182                 }
2183         }
2184         return 0;
2185 }
2186
2187 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2188                                      void __user **bufs,
2189                                      snd_pcm_uframes_t frames)
2190 {
2191         struct snd_pcm_runtime *runtime;
2192         int nonblock;
2193         int err;
2194
2195         err = pcm_sanity_check(substream);
2196         if (err < 0)
2197                 return err;
2198         runtime = substream->runtime;
2199         nonblock = !!(substream->f_flags & O_NONBLOCK);
2200
2201         if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2202                 return -EINVAL;
2203         return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2204                                   nonblock, snd_pcm_lib_writev_transfer);
2205 }
2206
2207 EXPORT_SYMBOL(snd_pcm_lib_writev);
2208
2209 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2210                                      unsigned int hwoff,
2211                                      unsigned long data, unsigned int off,
2212                                      snd_pcm_uframes_t frames)
2213 {
2214         struct snd_pcm_runtime *runtime = substream->runtime;
2215         int err;
2216         char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2217         if (substream->ops->copy) {
2218                 if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2219                         return err;
2220         } else {
2221                 char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2222                 if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2223                         return -EFAULT;
2224         }
2225         return 0;
2226 }
2227
2228 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2229                                            unsigned long data,
2230                                            snd_pcm_uframes_t size,
2231                                            int nonblock,
2232                                            transfer_f transfer)
2233 {
2234         struct snd_pcm_runtime *runtime = substream->runtime;
2235         snd_pcm_uframes_t xfer = 0;
2236         snd_pcm_uframes_t offset = 0;
2237         snd_pcm_uframes_t avail;
2238         int err = 0;
2239
2240         if (size == 0)
2241                 return 0;
2242
2243         snd_pcm_stream_lock_irq(substream);
2244         switch (runtime->status->state) {
2245         case SNDRV_PCM_STATE_PREPARED:
2246                 if (size >= runtime->start_threshold) {
2247                         err = snd_pcm_start(substream);
2248                         if (err < 0)
2249                                 goto _end_unlock;
2250                 }
2251                 break;
2252         case SNDRV_PCM_STATE_DRAINING:
2253         case SNDRV_PCM_STATE_RUNNING:
2254         case SNDRV_PCM_STATE_PAUSED:
2255                 break;
2256         case SNDRV_PCM_STATE_XRUN:
2257                 err = -EPIPE;
2258                 goto _end_unlock;
2259         case SNDRV_PCM_STATE_SUSPENDED:
2260                 err = -ESTRPIPE;
2261                 goto _end_unlock;
2262         default:
2263                 err = -EBADFD;
2264                 goto _end_unlock;
2265         }
2266
2267         runtime->twake = runtime->control->avail_min ? : 1;
2268         if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2269                 snd_pcm_update_hw_ptr(substream);
2270         avail = snd_pcm_capture_avail(runtime);
2271         while (size > 0) {
2272                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2273                 snd_pcm_uframes_t cont;
2274                 if (!avail) {
2275                         if (runtime->status->state ==
2276                             SNDRV_PCM_STATE_DRAINING) {
2277                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2278                                 goto _end_unlock;
2279                         }
2280                         if (nonblock) {
2281                                 err = -EAGAIN;
2282                                 goto _end_unlock;
2283                         }
2284                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2285                                         runtime->control->avail_min ? : 1);
2286                         err = wait_for_avail(substream, &avail);
2287                         if (err < 0)
2288                                 goto _end_unlock;
2289                         if (!avail)
2290                                 continue; /* draining */
2291                 }
2292                 frames = size > avail ? avail : size;
2293                 cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2294                 if (frames > cont)
2295                         frames = cont;
2296                 if (snd_BUG_ON(!frames)) {
2297                         runtime->twake = 0;
2298                         snd_pcm_stream_unlock_irq(substream);
2299                         return -EINVAL;
2300                 }
2301                 appl_ptr = runtime->control->appl_ptr;
2302                 appl_ofs = appl_ptr % runtime->buffer_size;
2303                 snd_pcm_stream_unlock_irq(substream);
2304                 err = transfer(substream, appl_ofs, data, offset, frames);
2305                 snd_pcm_stream_lock_irq(substream);
2306                 if (err < 0)
2307                         goto _end_unlock;
2308                 switch (runtime->status->state) {
2309                 case SNDRV_PCM_STATE_XRUN:
2310                         err = -EPIPE;
2311                         goto _end_unlock;
2312                 case SNDRV_PCM_STATE_SUSPENDED:
2313                         err = -ESTRPIPE;
2314                         goto _end_unlock;
2315                 default:
2316                         break;
2317                 }
2318                 appl_ptr += frames;
2319                 if (appl_ptr >= runtime->boundary)
2320                         appl_ptr -= runtime->boundary;
2321                 runtime->control->appl_ptr = appl_ptr;
2322                 if (substream->ops->ack)
2323                         substream->ops->ack(substream);
2324
2325                 offset += frames;
2326                 size -= frames;
2327                 xfer += frames;
2328                 avail -= frames;
2329         }
2330  _end_unlock:
2331         runtime->twake = 0;
2332         if (xfer > 0 && err >= 0)
2333                 snd_pcm_update_state(substream, runtime);
2334         snd_pcm_stream_unlock_irq(substream);
2335         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2336 }
2337
2338 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2339 {
2340         struct snd_pcm_runtime *runtime;
2341         int nonblock;
2342         int err;
2343
2344         err = pcm_sanity_check(substream);
2345         if (err < 0)
2346                 return err;
2347         runtime = substream->runtime;
2348         nonblock = !!(substream->f_flags & O_NONBLOCK);
2349         if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2350                 return -EINVAL;
2351         return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2352 }
2353
2354 EXPORT_SYMBOL(snd_pcm_lib_read);
2355
2356 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2357                                       unsigned int hwoff,
2358                                       unsigned long data, unsigned int off,
2359                                       snd_pcm_uframes_t frames)
2360 {
2361         struct snd_pcm_runtime *runtime = substream->runtime;
2362         int err;
2363         void __user **bufs = (void __user **)data;
2364         int channels = runtime->channels;
2365         int c;
2366         if (substream->ops->copy) {
2367                 for (c = 0; c < channels; ++c, ++bufs) {
2368                         char __user *buf;
2369                         if (*bufs == NULL)
2370                                 continue;
2371                         buf = *bufs + samples_to_bytes(runtime, off);
2372                         if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2373                                 return err;
2374                 }
2375         } else {
2376                 snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2377                 for (c = 0; c < channels; ++c, ++bufs) {
2378                         char *hwbuf;
2379                         char __user *buf;
2380                         if (*bufs == NULL)
2381                                 continue;
2382
2383                         hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2384                         buf = *bufs + samples_to_bytes(runtime, off);
2385                         if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2386                                 return -EFAULT;
2387                 }
2388         }
2389         return 0;
2390 }
2391
2392 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2393                                     void __user **bufs,
2394                                     snd_pcm_uframes_t frames)
2395 {
2396         struct snd_pcm_runtime *runtime;
2397         int nonblock;
2398         int err;
2399
2400         err = pcm_sanity_check(substream);
2401         if (err < 0)
2402                 return err;
2403         runtime = substream->runtime;
2404         if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2405                 return -EBADFD;
2406
2407         nonblock = !!(substream->f_flags & O_NONBLOCK);
2408         if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2409                 return -EINVAL;
2410         return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2411 }
2412
2413 EXPORT_SYMBOL(snd_pcm_lib_readv);
2414
2415 /*
2416  * standard channel mapping helpers
2417  */
2418
2419 /* default channel maps for multi-channel playbacks, up to 8 channels */
2420 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2421         { .channels = 1,
2422           .map = { SNDRV_CHMAP_MONO } },
2423         { .channels = 2,
2424           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2425         { .channels = 4,
2426           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2427                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2428         { .channels = 6,
2429           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2430                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2431                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2432         { .channels = 8,
2433           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2434                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2435                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2436                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2437         { }
2438 };
2439 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2440
2441 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2442 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2443         { .channels = 1,
2444           .map = { SNDRV_CHMAP_MONO } },
2445         { .channels = 2,
2446           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2447         { .channels = 4,
2448           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2449                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2450         { .channels = 6,
2451           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2452                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2453                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2454         { .channels = 8,
2455           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2456                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2457                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2458                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2459         { }
2460 };
2461 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2462
2463 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2464 {
2465         if (ch > info->max_channels)
2466                 return false;
2467         return !info->channel_mask || (info->channel_mask & (1U << ch));
2468 }
2469
2470 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2471                               struct snd_ctl_elem_info *uinfo)
2472 {
2473         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2474
2475         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2476         uinfo->count = 0;
2477         uinfo->count = info->max_channels;
2478         uinfo->value.integer.min = 0;
2479         uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2480         return 0;
2481 }
2482
2483 /* get callback for channel map ctl element
2484  * stores the channel position firstly matching with the current channels
2485  */
2486 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2487                              struct snd_ctl_elem_value *ucontrol)
2488 {
2489         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2490         unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2491         struct snd_pcm_substream *substream;
2492         const struct snd_pcm_chmap_elem *map;
2493
2494         if (snd_BUG_ON(!info->chmap))
2495                 return -EINVAL;
2496         substream = snd_pcm_chmap_substream(info, idx);
2497         if (!substream)
2498                 return -ENODEV;
2499         memset(ucontrol->value.integer.value, 0,
2500                sizeof(ucontrol->value.integer.value));
2501         if (!substream->runtime)
2502                 return 0; /* no channels set */
2503         for (map = info->chmap; map->channels; map++) {
2504                 int i;
2505                 if (map->channels == substream->runtime->channels &&
2506                     valid_chmap_channels(info, map->channels)) {
2507                         for (i = 0; i < map->channels; i++)
2508                                 ucontrol->value.integer.value[i] = map->map[i];
2509                         return 0;
2510                 }
2511         }
2512         return -EINVAL;
2513 }
2514
2515 /* tlv callback for channel map ctl element
2516  * expands the pre-defined channel maps in a form of TLV
2517  */
2518 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2519                              unsigned int size, unsigned int __user *tlv)
2520 {
2521         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2522         const struct snd_pcm_chmap_elem *map;
2523         unsigned int __user *dst;
2524         int c, count = 0;
2525
2526         if (snd_BUG_ON(!info->chmap))
2527                 return -EINVAL;
2528         if (size < 8)
2529                 return -ENOMEM;
2530         if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2531                 return -EFAULT;
2532         size -= 8;
2533         dst = tlv + 2;
2534         for (map = info->chmap; map->channels; map++) {
2535                 int chs_bytes = map->channels * 4;
2536                 if (!valid_chmap_channels(info, map->channels))
2537                         continue;
2538                 if (size < 8)
2539                         return -ENOMEM;
2540                 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2541                     put_user(chs_bytes, dst + 1))
2542                         return -EFAULT;
2543                 dst += 2;
2544                 size -= 8;
2545                 count += 8;
2546                 if (size < chs_bytes)
2547                         return -ENOMEM;
2548                 size -= chs_bytes;
2549                 count += chs_bytes;
2550                 for (c = 0; c < map->channels; c++) {
2551                         if (put_user(map->map[c], dst))
2552                                 return -EFAULT;
2553                         dst++;
2554                 }
2555         }
2556         if (put_user(count, tlv + 1))
2557                 return -EFAULT;
2558         return 0;
2559 }
2560
2561 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2562 {
2563         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2564         info->pcm->streams[info->stream].chmap_kctl = NULL;
2565         kfree(info);
2566 }
2567
2568 /**
2569  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2570  * @pcm: the assigned PCM instance
2571  * @stream: stream direction
2572  * @chmap: channel map elements (for query)
2573  * @max_channels: the max number of channels for the stream
2574  * @private_value: the value passed to each kcontrol's private_value field
2575  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2576  *
2577  * Create channel-mapping control elements assigned to the given PCM stream(s).
2578  * Return: Zero if successful, or a negative error value.
2579  */
2580 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2581                            const struct snd_pcm_chmap_elem *chmap,
2582                            int max_channels,
2583                            unsigned long private_value,
2584                            struct snd_pcm_chmap **info_ret)
2585 {
2586         struct snd_pcm_chmap *info;
2587         struct snd_kcontrol_new knew = {
2588                 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
2589                 .access = SNDRV_CTL_ELEM_ACCESS_READ |
2590                         SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2591                         SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2592                 .info = pcm_chmap_ctl_info,
2593                 .get = pcm_chmap_ctl_get,
2594                 .tlv.c = pcm_chmap_ctl_tlv,
2595         };
2596         int err;
2597
2598         info = kzalloc(sizeof(*info), GFP_KERNEL);
2599         if (!info)
2600                 return -ENOMEM;
2601         info->pcm = pcm;
2602         info->stream = stream;
2603         info->chmap = chmap;
2604         info->max_channels = max_channels;
2605         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2606                 knew.name = "Playback Channel Map";
2607         else
2608                 knew.name = "Capture Channel Map";
2609         knew.device = pcm->device;
2610         knew.count = pcm->streams[stream].substream_count;
2611         knew.private_value = private_value;
2612         info->kctl = snd_ctl_new1(&knew, info);
2613         if (!info->kctl) {
2614                 kfree(info);
2615                 return -ENOMEM;
2616         }
2617         info->kctl->private_free = pcm_chmap_ctl_private_free;
2618         err = snd_ctl_add(pcm->card, info->kctl);
2619         if (err < 0)
2620                 return err;
2621         pcm->streams[stream].chmap_kctl = info->kctl;
2622         if (info_ret)
2623                 *info_ret = info;
2624         return 0;
2625 }
2626 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);