sound/core/pcm_lib.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *                   Abramo Bagnara <abramo@alsa-project.org>
   5  *
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  *
  21  */
  22
  23 #include <linux/slab.h>
  24 #include <linux/sched/signal.h>
  25 #include <linux/time.h>
  26 #include <linux/math64.h>
  27 #include <linux/export.h>
  28 #include <sound/core.h>
  29 #include <sound/control.h>
  30 #include <sound/tlv.h>
  31 #include <sound/info.h>
  32 #include <sound/pcm.h>
  33 #include <sound/pcm_params.h>
  34 #include <sound/timer.h>
  35
  36 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  37 #define CREATE_TRACE_POINTS
  38 #include "pcm_trace.h"
  39 #else
  40 #define trace_hwptr(substream, pos, in_interrupt)
  41 #define trace_xrun(substream)
  42 #define trace_hw_ptr_error(substream, reason)
  43 #endif
  44
  45 /*
  46  * fill ring buffer with silence
  47  * runtime->silence_start: starting pointer to silence area
  48  * runtime->silence_filled: size filled with silence
  49  * runtime->silence_threshold: threshold from application
  50  * runtime->silence_size: maximal size from application
  51  *
  52  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
  53  */
  54 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
  55 {
  56         struct snd_pcm_runtime *runtime = substream->runtime;
  57         snd_pcm_uframes_t frames, ofs, transfer;
  58
  59         if (runtime->silence_size < runtime->boundary) {
  60                 snd_pcm_sframes_t noise_dist, n;
  61                 if (runtime->silence_start != runtime->control->appl_ptr) {
  62                         n = runtime->control->appl_ptr - runtime->silence_start;
  63                         if (n < 0)
  64                                 n += runtime->boundary;
  65                         if ((snd_pcm_uframes_t)n < runtime->silence_filled)
  66                                 runtime->silence_filled -= n;
  67                         else
  68                                 runtime->silence_filled = 0;
  69                         runtime->silence_start = runtime->control->appl_ptr;
  70                 }
  71                 if (runtime->silence_filled >= runtime->buffer_size)
  72                         return;
  73                 noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
  74                 if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
  75                         return;
  76                 frames = runtime->silence_threshold - noise_dist;
  77                 if (frames > runtime->silence_size)
  78                         frames = runtime->silence_size;
  79         } else {
  80                 if (new_hw_ptr == ULONG_MAX) {  /* initialization */
  81                         snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
  82                         if (avail > runtime->buffer_size)
  83                                 avail = runtime->buffer_size;
  84                         runtime->silence_filled = avail > 0 ? avail : 0;
  85                         runtime->silence_start = (runtime->status->hw_ptr +
  86                                                   runtime->silence_filled) %
  87                                                  runtime->boundary;
  88                 } else {
  89                         ofs = runtime->status->hw_ptr;
  90                         frames = new_hw_ptr - ofs;
  91                         if ((snd_pcm_sframes_t)frames < 0)
  92                                 frames += runtime->boundary;
  93                         runtime->silence_filled -= frames;
  94                         if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
  95                                 runtime->silence_filled = 0;
  96                                 runtime->silence_start = new_hw_ptr;
  97                         } else {
  98                                 runtime->silence_start = ofs;
  99                         }
 100                 }
 101                 frames = runtime->buffer_size - runtime->silence_filled;
 102         }
 103         if (snd_BUG_ON(frames > runtime->buffer_size))
 104                 return;
 105         if (frames == 0)
 106                 return;
 107         ofs = runtime->silence_start % runtime->buffer_size;
 108         while (frames > 0) {
 109                 transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
 110                 if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
 111                     runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
 112                         if (substream->ops->silence) {
 113                                 int err;
 114                                 err = substream->ops->silence(substream, -1, ofs, transfer);
 115                                 snd_BUG_ON(err < 0);
 116                         } else {
 117                                 char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
 118                                 snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
 119                         }
 120                 } else {
 121                         unsigned int c;
 122                         unsigned int channels = runtime->channels;
 123                         if (substream->ops->silence) {
 124                                 for (c = 0; c < channels; ++c) {
 125                                         int err;
 126                                         err = substream->ops->silence(substream, c, ofs, transfer);
 127                                         snd_BUG_ON(err < 0);
 128                                 }
 129                         } else {
 130                                 size_t dma_csize = runtime->dma_bytes / channels;
 131                                 for (c = 0; c < channels; ++c) {
 132                                         char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
 133                                         snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
 134                                 }
 135                         }
 136                 }
 137                 runtime->silence_filled += transfer;
 138                 frames -= transfer;
 139                 ofs = 0;
 140         }
 141 }
 142
 143 #ifdef CONFIG_SND_DEBUG
 144 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
 145                            char *name, size_t len)
 146 {
 147         snprintf(name, len, "pcmC%dD%d%c:%d",
 148                  substream->pcm->card->number,
 149                  substream->pcm->device,
 150                  substream->stream ? 'c' : 'p',
 151                  substream->number);
 152 }
 153 EXPORT_SYMBOL(snd_pcm_debug_name);
 154 #endif
 155
 156 #define XRUN_DEBUG_BASIC        (1<<0)
 157 #define XRUN_DEBUG_STACK        (1<<1)  /* dump also stack */
 158 #define XRUN_DEBUG_JIFFIESCHECK (1<<2)  /* do jiffies check */
 159
 160 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 161
 162 #define xrun_debug(substream, mask) \
 163                         ((substream)->pstr->xrun_debug & (mask))
 164 #else
 165 #define xrun_debug(substream, mask)     0
 166 #endif
 167
 168 #define dump_stack_on_xrun(substream) do {                      \
 169                 if (xrun_debug(substream, XRUN_DEBUG_STACK))    \
 170                         dump_stack();                           \
 171         } while (0)
 172
 173 static void xrun(struct snd_pcm_substream *substream)
 174 {
 175         struct snd_pcm_runtime *runtime = substream->runtime;
 176
 177         trace_xrun(substream);
 178         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
 179                 snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
 180         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 181         if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
 182                 char name[16];
 183                 snd_pcm_debug_name(substream, name, sizeof(name));
 184                 pcm_warn(substream->pcm, "XRUN: %s\n", name);
 185                 dump_stack_on_xrun(substream);
 186         }
 187 }
 188
 189 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 190 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)     \
 191         do {                                                            \
 192                 trace_hw_ptr_error(substream, reason);  \
 193                 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {          \
 194                         pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
 195                                            (in_interrupt) ? 'Q' : 'P', ##args); \
 196                         dump_stack_on_xrun(substream);                  \
 197                 }                                                       \
 198         } while (0)
 199
 200 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
 201
 202 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
 203
 204 #endif
 205
 206 int snd_pcm_update_state(struct snd_pcm_substream *substream,
 207                          struct snd_pcm_runtime *runtime)
 208 {
 209         snd_pcm_uframes_t avail;
 210
 211         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 212                 avail = snd_pcm_playback_avail(runtime);
 213         else
 214                 avail = snd_pcm_capture_avail(runtime);
 215         if (avail > runtime->avail_max)
 216                 runtime->avail_max = avail;
 217         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
 218                 if (avail >= runtime->buffer_size) {
 219                         snd_pcm_drain_done(substream);
 220                         return -EPIPE;
 221                 }
 222         } else {
 223                 if (avail >= runtime->stop_threshold) {
 224                         xrun(substream);
 225                         return -EPIPE;
 226                 }
 227         }
 228         if (runtime->twake) {
 229                 if (avail >= runtime->twake)
 230                         wake_up(&runtime->tsleep);
 231         } else if (avail >= runtime->control->avail_min)
 232                 wake_up(&runtime->sleep);
 233         return 0;
 234 }
 235
 236 static void update_audio_tstamp(struct snd_pcm_substream *substream,
 237                                 struct timespec *curr_tstamp,
 238                                 struct timespec *audio_tstamp)
 239 {
 240         struct snd_pcm_runtime *runtime = substream->runtime;
 241         u64 audio_frames, audio_nsecs;
 242         struct timespec driver_tstamp;
 243
 244         if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
 245                 return;
 246
 247         if (!(substream->ops->get_time_info) ||
 248                 (runtime->audio_tstamp_report.actual_type ==
 249                         SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 250
 251                 /*
 252                  * provide audio timestamp derived from pointer position
 253                  * add delay only if requested
 254                  */
 255
 256                 audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
 257
 258                 if (runtime->audio_tstamp_config.report_delay) {
 259                         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 260                                 audio_frames -=  runtime->delay;
 261                         else
 262                                 audio_frames +=  runtime->delay;
 263                 }
 264                 audio_nsecs = div_u64(audio_frames * 1000000000LL,
 265                                 runtime->rate);
 266                 *audio_tstamp = ns_to_timespec(audio_nsecs);
 267         }
 268         runtime->status->audio_tstamp = *audio_tstamp;
 269         runtime->status->tstamp = *curr_tstamp;
 270
 271         /*
 272          * re-take a driver timestamp to let apps detect if the reference tstamp
 273          * read by low-level hardware was provided with a delay
 274          */
 275         snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
 276         runtime->driver_tstamp = driver_tstamp;
 277 }
 278
 279 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 280                                   unsigned int in_interrupt)
 281 {
 282         struct snd_pcm_runtime *runtime = substream->runtime;
 283         snd_pcm_uframes_t pos;
 284         snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
 285         snd_pcm_sframes_t hdelta, delta;
 286         unsigned long jdelta;
 287         unsigned long curr_jiffies;
 288         struct timespec curr_tstamp;
 289         struct timespec audio_tstamp;
 290         int crossed_boundary = 0;
 291
 292         old_hw_ptr = runtime->status->hw_ptr;
 293
 294         /*
 295          * group pointer, time and jiffies reads to allow for more
 296          * accurate correlations/corrections.
 297          * The values are stored at the end of this routine after
 298          * corrections for hw_ptr position
 299          */
 300         pos = substream->ops->pointer(substream);
 301         curr_jiffies = jiffies;
 302         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
 303                 if ((substream->ops->get_time_info) &&
 304                         (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 305                         substream->ops->get_time_info(substream, &curr_tstamp,
 306                                                 &audio_tstamp,
 307                                                 &runtime->audio_tstamp_config,
 308                                                 &runtime->audio_tstamp_report);
 309
 310                         /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
 311                         if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
 312                                 snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 313                 } else
 314                         snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 315         }
 316
 317         if (pos == SNDRV_PCM_POS_XRUN) {
 318                 xrun(substream);
 319                 return -EPIPE;
 320         }
 321         if (pos >= runtime->buffer_size) {
 322                 if (printk_ratelimit()) {
 323                         char name[16];
 324                         snd_pcm_debug_name(substream, name, sizeof(name));
 325                         pcm_err(substream->pcm,
 326                                 "invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
 327                                 name, pos, runtime->buffer_size,
 328                                 runtime->period_size);
 329                 }
 330                 pos = 0;
 331         }
 332         pos -= pos % runtime->min_align;
 333         trace_hwptr(substream, pos, in_interrupt);
 334         hw_base = runtime->hw_ptr_base;
 335         new_hw_ptr = hw_base + pos;
 336         if (in_interrupt) {
 337                 /* we know that one period was processed */
 338                 /* delta = "expected next hw_ptr" for in_interrupt != 0 */
 339                 delta = runtime->hw_ptr_interrupt + runtime->period_size;
 340                 if (delta > new_hw_ptr) {
 341                         /* check for double acknowledged interrupts */
 342                         hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 343                         if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
 344                                 hw_base += runtime->buffer_size;
 345                                 if (hw_base >= runtime->boundary) {
 346                                         hw_base = 0;
 347                                         crossed_boundary++;
 348                                 }
 349                                 new_hw_ptr = hw_base + pos;
 350                                 goto __delta;
 351                         }
 352                 }
 353         }
 354         /* new_hw_ptr might be lower than old_hw_ptr in case when */
 355         /* pointer crosses the end of the ring buffer */
 356         if (new_hw_ptr < old_hw_ptr) {
 357                 hw_base += runtime->buffer_size;
 358                 if (hw_base >= runtime->boundary) {
 359                         hw_base = 0;
 360                         crossed_boundary++;
 361                 }
 362                 new_hw_ptr = hw_base + pos;
 363         }
 364       __delta:
 365         delta = new_hw_ptr - old_hw_ptr;
 366         if (delta < 0)
 367                 delta += runtime->boundary;
 368
 369         if (runtime->no_period_wakeup) {
 370                 snd_pcm_sframes_t xrun_threshold;
 371                 /*
 372                  * Without regular period interrupts, we have to check
 373                  * the elapsed time to detect xruns.
 374                  */
 375                 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 376                 if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
 377                         goto no_delta_check;
 378                 hdelta = jdelta - delta * HZ / runtime->rate;
 379                 xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
 380                 while (hdelta > xrun_threshold) {
 381                         delta += runtime->buffer_size;
 382                         hw_base += runtime->buffer_size;
 383                         if (hw_base >= runtime->boundary) {
 384                                 hw_base = 0;
 385                                 crossed_boundary++;
 386                         }
 387                         new_hw_ptr = hw_base + pos;
 388                         hdelta -= runtime->hw_ptr_buffer_jiffies;
 389                 }
 390                 goto no_delta_check;
 391         }
 392
 393         /* something must be really wrong */
 394         if (delta >= runtime->buffer_size + runtime->period_size) {
 395                 hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
 396                              "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 397                              substream->stream, (long)pos,
 398                              (long)new_hw_ptr, (long)old_hw_ptr);
 399                 return 0;
 400         }
 401
 402         /* Do jiffies check only in xrun_debug mode */
 403         if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
 404                 goto no_jiffies_check;
 405
 406         /* Skip the jiffies check for hardwares with BATCH flag.
 407          * Such hardware usually just increases the position at each IRQ,
 408          * thus it can't give any strange position.
 409          */
 410         if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
 411                 goto no_jiffies_check;
 412         hdelta = delta;
 413         if (hdelta < runtime->delay)
 414                 goto no_jiffies_check;
 415         hdelta -= runtime->delay;
 416         jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 417         if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
 418                 delta = jdelta /
 419                         (((runtime->period_size * HZ) / runtime->rate)
 420                                                                 + HZ/100);
 421                 /* move new_hw_ptr according jiffies not pos variable */
 422                 new_hw_ptr = old_hw_ptr;
 423                 hw_base = delta;
 424                 /* use loop to avoid checks for delta overflows */
 425                 /* the delta value is small or zero in most cases */
 426                 while (delta > 0) {
 427                         new_hw_ptr += runtime->period_size;
 428                         if (new_hw_ptr >= runtime->boundary) {
 429                                 new_hw_ptr -= runtime->boundary;
 430                                 crossed_boundary--;
 431                         }
 432                         delta--;
 433                 }
 434                 /* align hw_base to buffer_size */
 435                 hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
 436                              "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
 437                              (long)pos, (long)hdelta,
 438                              (long)runtime->period_size, jdelta,
 439                              ((hdelta * HZ) / runtime->rate), hw_base,
 440                              (unsigned long)old_hw_ptr,
 441                              (unsigned long)new_hw_ptr);
 442                 /* reset values to proper state */
 443                 delta = 0;
 444                 hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
 445         }
 446  no_jiffies_check:
 447         if (delta > runtime->period_size + runtime->period_size / 2) {
 448                 hw_ptr_error(substream, in_interrupt,
 449                              "Lost interrupts?",
 450                              "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 451                              substream->stream, (long)delta,
 452                              (long)new_hw_ptr,
 453                              (long)old_hw_ptr);
 454         }
 455
 456  no_delta_check:
 457         if (runtime->status->hw_ptr == new_hw_ptr) {
 458                 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 459                 return 0;
 460         }
 461
 462         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 463             runtime->silence_size > 0)
 464                 snd_pcm_playback_silence(substream, new_hw_ptr);
 465
 466         if (in_interrupt) {
 467                 delta = new_hw_ptr - runtime->hw_ptr_interrupt;
 468                 if (delta < 0)
 469                         delta += runtime->boundary;
 470                 delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
 471                 runtime->hw_ptr_interrupt += delta;
 472                 if (runtime->hw_ptr_interrupt >= runtime->boundary)
 473                         runtime->hw_ptr_interrupt -= runtime->boundary;
 474         }
 475         runtime->hw_ptr_base = hw_base;
 476         runtime->status->hw_ptr = new_hw_ptr;
 477         runtime->hw_ptr_jiffies = curr_jiffies;
 478         if (crossed_boundary) {
 479                 snd_BUG_ON(crossed_boundary != 1);
 480                 runtime->hw_ptr_wrap += runtime->boundary;
 481         }
 482
 483         update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 484
 485         return snd_pcm_update_state(substream, runtime);
 486 }
 487
 488 /* CAUTION: call it with irq disabled */
 489 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 490 {
 491         return snd_pcm_update_hw_ptr0(substream, 0);
 492 }
 493
 494 /**
 495  * snd_pcm_set_ops - set the PCM operators
 496  * @pcm: the pcm instance
 497  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
 498  * @ops: the operator table
 499  *
 500  * Sets the given PCM operators to the pcm instance.
 501  */
 502 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
 503                      const struct snd_pcm_ops *ops)
 504 {
 505         struct snd_pcm_str *stream = &pcm->streams[direction];
 506         struct snd_pcm_substream *substream;
 507
 508         for (substream = stream->substream; substream != NULL; substream = substream->next)
 509                 substream->ops = ops;
 510 }
 511
 512 EXPORT_SYMBOL(snd_pcm_set_ops);
 513
 514 /**
 515  * snd_pcm_sync - set the PCM sync id
 516  * @substream: the pcm substream
 517  *
 518  * Sets the PCM sync identifier for the card.
 519  */
 520 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
 521 {
 522         struct snd_pcm_runtime *runtime = substream->runtime;
 523
 524         runtime->sync.id32[0] = substream->pcm->card->number;
 525         runtime->sync.id32[1] = -1;
 526         runtime->sync.id32[2] = -1;
 527         runtime->sync.id32[3] = -1;
 528 }
 529
 530 EXPORT_SYMBOL(snd_pcm_set_sync);
 531
 532 /*
 533  *  Standard ioctl routine
 534  */
 535
 536 static inline unsigned int div32(unsigned int a, unsigned int b,
 537                                  unsigned int *r)
 538 {
 539         if (b == 0) {
 540                 *r = 0;
 541                 return UINT_MAX;
 542         }
 543         *r = a % b;
 544         return a / b;
 545 }
 546
 547 static inline unsigned int div_down(unsigned int a, unsigned int b)
 548 {
 549         if (b == 0)
 550                 return UINT_MAX;
 551         return a / b;
 552 }
 553
 554 static inline unsigned int div_up(unsigned int a, unsigned int b)
 555 {
 556         unsigned int r;
 557         unsigned int q;
 558         if (b == 0)
 559                 return UINT_MAX;
 560         q = div32(a, b, &r);
 561         if (r)
 562                 ++q;
 563         return q;
 564 }
 565
 566 static inline unsigned int mul(unsigned int a, unsigned int b)
 567 {
 568         if (a == 0)
 569                 return 0;
 570         if (div_down(UINT_MAX, a) < b)
 571                 return UINT_MAX;
 572         return a * b;
 573 }
 574
 575 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
 576                                     unsigned int c, unsigned int *r)
 577 {
 578         u_int64_t n = (u_int64_t) a * b;
 579         if (c == 0) {
 580                 snd_BUG_ON(!n);
 581                 *r = 0;
 582                 return UINT_MAX;
 583         }
 584         n = div_u64_rem(n, c, r);
 585         if (n >= UINT_MAX) {
 586                 *r = 0;
 587                 return UINT_MAX;
 588         }
 589         return n;
 590 }
 591
 592 /**
 593  * snd_interval_refine - refine the interval value of configurator
 594  * @i: the interval value to refine
 595  * @v: the interval value to refer to
 596  *
 597  * Refines the interval value with the reference value.
 598  * The interval is changed to the range satisfying both intervals.
 599  * The interval status (min, max, integer, etc.) are evaluated.
 600  *
 601  * Return: Positive if the value is changed, zero if it's not changed, or a
 602  * negative error code.
 603  */
 604 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
 605 {
 606         int changed = 0;
 607         if (snd_BUG_ON(snd_interval_empty(i)))
 608                 return -EINVAL;
 609         if (i->min < v->min) {
 610                 i->min = v->min;
 611                 i->openmin = v->openmin;
 612                 changed = 1;
 613         } else if (i->min == v->min && !i->openmin && v->openmin) {
 614                 i->openmin = 1;
 615                 changed = 1;
 616         }
 617         if (i->max > v->max) {
 618                 i->max = v->max;
 619                 i->openmax = v->openmax;
 620                 changed = 1;
 621         } else if (i->max == v->max && !i->openmax && v->openmax) {
 622                 i->openmax = 1;
 623                 changed = 1;
 624         }
 625         if (!i->integer && v->integer) {
 626                 i->integer = 1;
 627                 changed = 1;
 628         }
 629         if (i->integer) {
 630                 if (i->openmin) {
 631                         i->min++;
 632                         i->openmin = 0;
 633                 }
 634                 if (i->openmax) {
 635                         i->max--;
 636                         i->openmax = 0;
 637                 }
 638         } else if (!i->openmin && !i->openmax && i->min == i->max)
 639                 i->integer = 1;
 640         if (snd_interval_checkempty(i)) {
 641                 snd_interval_none(i);
 642                 return -EINVAL;
 643         }
 644         return changed;
 645 }
 646
 647 EXPORT_SYMBOL(snd_interval_refine);
 648
 649 static int snd_interval_refine_first(struct snd_interval *i)
 650 {
 651         if (snd_BUG_ON(snd_interval_empty(i)))
 652                 return -EINVAL;
 653         if (snd_interval_single(i))
 654                 return 0;
 655         i->max = i->min;
 656         i->openmax = i->openmin;
 657         if (i->openmax)
 658                 i->max++;
 659         return 1;
 660 }
 661
 662 static int snd_interval_refine_last(struct snd_interval *i)
 663 {
 664         if (snd_BUG_ON(snd_interval_empty(i)))
 665                 return -EINVAL;
 666         if (snd_interval_single(i))
 667                 return 0;
 668         i->min = i->max;
 669         i->openmin = i->openmax;
 670         if (i->openmin)
 671                 i->min--;
 672         return 1;
 673 }
 674
 675 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 676 {
 677         if (a->empty || b->empty) {
 678                 snd_interval_none(c);
 679                 return;
 680         }
 681         c->empty = 0;
 682         c->min = mul(a->min, b->min);
 683         c->openmin = (a->openmin || b->openmin);
 684         c->max = mul(a->max,  b->max);
 685         c->openmax = (a->openmax || b->openmax);
 686         c->integer = (a->integer && b->integer);
 687 }
 688
 689 /**
 690  * snd_interval_div - refine the interval value with division
 691  * @a: dividend
 692  * @b: divisor
 693  * @c: quotient
 694  *
 695  * c = a / b
 696  *
 697  * Returns non-zero if the value is changed, zero if not changed.
 698  */
 699 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 700 {
 701         unsigned int r;
 702         if (a->empty || b->empty) {
 703                 snd_interval_none(c);
 704                 return;
 705         }
 706         c->empty = 0;
 707         c->min = div32(a->min, b->max, &r);
 708         c->openmin = (r || a->openmin || b->openmax);
 709         if (b->min > 0) {
 710                 c->max = div32(a->max, b->min, &r);
 711                 if (r) {
 712                         c->max++;
 713                         c->openmax = 1;
 714                 } else
 715                         c->openmax = (a->openmax || b->openmin);
 716         } else {
 717                 c->max = UINT_MAX;
 718                 c->openmax = 0;
 719         }
 720         c->integer = 0;
 721 }
 722
 723 /**
 724  * snd_interval_muldivk - refine the interval value
 725  * @a: dividend 1
 726  * @b: dividend 2
 727  * @k: divisor (as integer)
 728  * @c: result
 729   *
 730  * c = a * b / k
 731  *
 732  * Returns non-zero if the value is changed, zero if not changed.
 733  */
 734 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
 735                       unsigned int k, struct snd_interval *c)
 736 {
 737         unsigned int r;
 738         if (a->empty || b->empty) {
 739                 snd_interval_none(c);
 740                 return;
 741         }
 742         c->empty = 0;
 743         c->min = muldiv32(a->min, b->min, k, &r);
 744         c->openmin = (r || a->openmin || b->openmin);
 745         c->max = muldiv32(a->max, b->max, k, &r);
 746         if (r) {
 747                 c->max++;
 748                 c->openmax = 1;
 749         } else
 750                 c->openmax = (a->openmax || b->openmax);
 751         c->integer = 0;
 752 }
 753
 754 /**
 755  * snd_interval_mulkdiv - refine the interval value
 756  * @a: dividend 1
 757  * @k: dividend 2 (as integer)
 758  * @b: divisor
 759  * @c: result
 760  *
 761  * c = a * k / b
 762  *
 763  * Returns non-zero if the value is changed, zero if not changed.
 764  */
 765 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
 766                       const struct snd_interval *b, struct snd_interval *c)
 767 {
 768         unsigned int r;
 769         if (a->empty || b->empty) {
 770                 snd_interval_none(c);
 771                 return;
 772         }
 773         c->empty = 0;
 774         c->min = muldiv32(a->min, k, b->max, &r);
 775         c->openmin = (r || a->openmin || b->openmax);
 776         if (b->min > 0) {
 777                 c->max = muldiv32(a->max, k, b->min, &r);
 778                 if (r) {
 779                         c->max++;
 780                         c->openmax = 1;
 781                 } else
 782                         c->openmax = (a->openmax || b->openmin);
 783         } else {
 784                 c->max = UINT_MAX;
 785                 c->openmax = 0;
 786         }
 787         c->integer = 0;
 788 }
 789
 790 /* ---- */
 791
 792
 793 /**
 794  * snd_interval_ratnum - refine the interval value
 795  * @i: interval to refine
 796  * @rats_count: number of ratnum_t
 797  * @rats: ratnum_t array
 798  * @nump: pointer to store the resultant numerator
 799  * @denp: pointer to store the resultant denominator
 800  *
 801  * Return: Positive if the value is changed, zero if it's not changed, or a
 802  * negative error code.
 803  */
 804 int snd_interval_ratnum(struct snd_interval *i,
 805                         unsigned int rats_count, const struct snd_ratnum *rats,
 806                         unsigned int *nump, unsigned int *denp)
 807 {
 808         unsigned int best_num, best_den;
 809         int best_diff;
 810         unsigned int k;
 811         struct snd_interval t;
 812         int err;
 813         unsigned int result_num, result_den;
 814         int result_diff;
 815
 816         best_num = best_den = best_diff = 0;
 817         for (k = 0; k < rats_count; ++k) {
 818                 unsigned int num = rats[k].num;
 819                 unsigned int den;
 820                 unsigned int q = i->min;
 821                 int diff;
 822                 if (q == 0)
 823                         q = 1;
 824                 den = div_up(num, q);
 825                 if (den < rats[k].den_min)
 826                         continue;
 827                 if (den > rats[k].den_max)
 828                         den = rats[k].den_max;
 829                 else {
 830                         unsigned int r;
 831                         r = (den - rats[k].den_min) % rats[k].den_step;
 832                         if (r != 0)
 833                                 den -= r;
 834                 }
 835                 diff = num - q * den;
 836                 if (diff < 0)
 837                         diff = -diff;
 838                 if (best_num == 0 ||
 839                     diff * best_den < best_diff * den) {
 840                         best_diff = diff;
 841                         best_den = den;
 842                         best_num = num;
 843                 }
 844         }
 845         if (best_den == 0) {
 846                 i->empty = 1;
 847                 return -EINVAL;
 848         }
 849         t.min = div_down(best_num, best_den);
 850         t.openmin = !!(best_num % best_den);
 851
 852         result_num = best_num;
 853         result_diff = best_diff;
 854         result_den = best_den;
 855         best_num = best_den = best_diff = 0;
 856         for (k = 0; k < rats_count; ++k) {
 857                 unsigned int num = rats[k].num;
 858                 unsigned int den;
 859                 unsigned int q = i->max;
 860                 int diff;
 861                 if (q == 0) {
 862                         i->empty = 1;
 863                         return -EINVAL;
 864                 }
 865                 den = div_down(num, q);
 866                 if (den > rats[k].den_max)
 867                         continue;
 868                 if (den < rats[k].den_min)
 869                         den = rats[k].den_min;
 870                 else {
 871                         unsigned int r;
 872                         r = (den - rats[k].den_min) % rats[k].den_step;
 873                         if (r != 0)
 874                                 den += rats[k].den_step - r;
 875                 }
 876                 diff = q * den - num;
 877                 if (diff < 0)
 878                         diff = -diff;
 879                 if (best_num == 0 ||
 880                     diff * best_den < best_diff * den) {
 881                         best_diff = diff;
 882                         best_den = den;
 883                         best_num = num;
 884                 }
 885         }
 886         if (best_den == 0) {
 887                 i->empty = 1;
 888                 return -EINVAL;
 889         }
 890         t.max = div_up(best_num, best_den);
 891         t.openmax = !!(best_num % best_den);
 892         t.integer = 0;
 893         err = snd_interval_refine(i, &t);
 894         if (err < 0)
 895                 return err;
 896
 897         if (snd_interval_single(i)) {
 898                 if (best_diff * result_den < result_diff * best_den) {
 899                         result_num = best_num;
 900                         result_den = best_den;
 901                 }
 902                 if (nump)
 903                         *nump = result_num;
 904                 if (denp)
 905                         *denp = result_den;
 906         }
 907         return err;
 908 }
 909
 910 EXPORT_SYMBOL(snd_interval_ratnum);
 911
 912 /**
 913  * snd_interval_ratden - refine the interval value
 914  * @i: interval to refine
 915  * @rats_count: number of struct ratden
 916  * @rats: struct ratden array
 917  * @nump: pointer to store the resultant numerator
 918  * @denp: pointer to store the resultant denominator
 919  *
 920  * Return: Positive if the value is changed, zero if it's not changed, or a
 921  * negative error code.
 922  */
 923 static int snd_interval_ratden(struct snd_interval *i,
 924                                unsigned int rats_count,
 925                                const struct snd_ratden *rats,
 926                                unsigned int *nump, unsigned int *denp)
 927 {
 928         unsigned int best_num, best_diff, best_den;
 929         unsigned int k;
 930         struct snd_interval t;
 931         int err;
 932
 933         best_num = best_den = best_diff = 0;
 934         for (k = 0; k < rats_count; ++k) {
 935                 unsigned int num;
 936                 unsigned int den = rats[k].den;
 937                 unsigned int q = i->min;
 938                 int diff;
 939                 num = mul(q, den);
 940                 if (num > rats[k].num_max)
 941                         continue;
 942                 if (num < rats[k].num_min)
 943                         num = rats[k].num_max;
 944                 else {
 945                         unsigned int r;
 946                         r = (num - rats[k].num_min) % rats[k].num_step;
 947                         if (r != 0)
 948                                 num += rats[k].num_step - r;
 949                 }
 950                 diff = num - q * den;
 951                 if (best_num == 0 ||
 952                     diff * best_den < best_diff * den) {
 953                         best_diff = diff;
 954                         best_den = den;
 955                         best_num = num;
 956                 }
 957         }
 958         if (best_den == 0) {
 959                 i->empty = 1;
 960                 return -EINVAL;
 961         }
 962         t.min = div_down(best_num, best_den);
 963         t.openmin = !!(best_num % best_den);
 964
 965         best_num = best_den = best_diff = 0;
 966         for (k = 0; k < rats_count; ++k) {
 967                 unsigned int num;
 968                 unsigned int den = rats[k].den;
 969                 unsigned int q = i->max;
 970                 int diff;
 971                 num = mul(q, den);
 972                 if (num < rats[k].num_min)
 973                         continue;
 974                 if (num > rats[k].num_max)
 975                         num = rats[k].num_max;
 976                 else {
 977                         unsigned int r;
 978                         r = (num - rats[k].num_min) % rats[k].num_step;
 979                         if (r != 0)
 980                                 num -= r;
 981                 }
 982                 diff = q * den - num;
 983                 if (best_num == 0 ||
 984                     diff * best_den < best_diff * den) {
 985                         best_diff = diff;
 986                         best_den = den;
 987                         best_num = num;
 988                 }
 989         }
 990         if (best_den == 0) {
 991                 i->empty = 1;
 992                 return -EINVAL;
 993         }
 994         t.max = div_up(best_num, best_den);
 995         t.openmax = !!(best_num % best_den);
 996         t.integer = 0;
 997         err = snd_interval_refine(i, &t);
 998         if (err < 0)
 999                 return err;
1000
1001         if (snd_interval_single(i)) {
1002                 if (nump)
1003                         *nump = best_num;
1004                 if (denp)
1005                         *denp = best_den;
1006         }
1007         return err;
1008 }
1009
1010 /**
1011  * snd_interval_list - refine the interval value from the list
1012  * @i: the interval value to refine
1013  * @count: the number of elements in the list
1014  * @list: the value list
1015  * @mask: the bit-mask to evaluate
1016  *
1017  * Refines the interval value from the list.
1018  * When mask is non-zero, only the elements corresponding to bit 1 are
1019  * evaluated.
1020  *
1021  * Return: Positive if the value is changed, zero if it's not changed, or a
1022  * negative error code.
1023  */
1024 int snd_interval_list(struct snd_interval *i, unsigned int count,
1025                       const unsigned int *list, unsigned int mask)
1026 {
1027         unsigned int k;
1028         struct snd_interval list_range;
1029
1030         if (!count) {
1031                 i->empty = 1;
1032                 return -EINVAL;
1033         }
1034         snd_interval_any(&list_range);
1035         list_range.min = UINT_MAX;
1036         list_range.max = 0;
1037         for (k = 0; k < count; k++) {
1038                 if (mask && !(mask & (1 << k)))
1039                         continue;
1040                 if (!snd_interval_test(i, list[k]))
1041                         continue;
1042                 list_range.min = min(list_range.min, list[k]);
1043                 list_range.max = max(list_range.max, list[k]);
1044         }
1045         return snd_interval_refine(i, &list_range);
1046 }
1047
1048 EXPORT_SYMBOL(snd_interval_list);
1049
1050 /**
1051  * snd_interval_ranges - refine the interval value from the list of ranges
1052  * @i: the interval value to refine
1053  * @count: the number of elements in the list of ranges
1054  * @ranges: the ranges list
1055  * @mask: the bit-mask to evaluate
1056  *
1057  * Refines the interval value from the list of ranges.
1058  * When mask is non-zero, only the elements corresponding to bit 1 are
1059  * evaluated.
1060  *
1061  * Return: Positive if the value is changed, zero if it's not changed, or a
1062  * negative error code.
1063  */
1064 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1065                         const struct snd_interval *ranges, unsigned int mask)
1066 {
1067         unsigned int k;
1068         struct snd_interval range_union;
1069         struct snd_interval range;
1070
1071         if (!count) {
1072                 snd_interval_none(i);
1073                 return -EINVAL;
1074         }
1075         snd_interval_any(&range_union);
1076         range_union.min = UINT_MAX;
1077         range_union.max = 0;
1078         for (k = 0; k < count; k++) {
1079                 if (mask && !(mask & (1 << k)))
1080                         continue;
1081                 snd_interval_copy(&range, &ranges[k]);
1082                 if (snd_interval_refine(&range, i) < 0)
1083                         continue;
1084                 if (snd_interval_empty(&range))
1085                         continue;
1086
1087                 if (range.min < range_union.min) {
1088                         range_union.min = range.min;
1089                         range_union.openmin = 1;
1090                 }
1091                 if (range.min == range_union.min && !range.openmin)
1092                         range_union.openmin = 0;
1093                 if (range.max > range_union.max) {
1094                         range_union.max = range.max;
1095                         range_union.openmax = 1;
1096                 }
1097                 if (range.max == range_union.max && !range.openmax)
1098                         range_union.openmax = 0;
1099         }
1100         return snd_interval_refine(i, &range_union);
1101 }
1102 EXPORT_SYMBOL(snd_interval_ranges);
1103
1104 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1105 {
1106         unsigned int n;
1107         int changed = 0;
1108         n = i->min % step;
1109         if (n != 0 || i->openmin) {
1110                 i->min += step - n;
1111                 i->openmin = 0;
1112                 changed = 1;
1113         }
1114         n = i->max % step;
1115         if (n != 0 || i->openmax) {
1116                 i->max -= n;
1117                 i->openmax = 0;
1118                 changed = 1;
1119         }
1120         if (snd_interval_checkempty(i)) {
1121                 i->empty = 1;
1122                 return -EINVAL;
1123         }
1124         return changed;
1125 }
1126
1127 /* Info constraints helpers */
1128
1129 /**
1130  * snd_pcm_hw_rule_add - add the hw-constraint rule
1131  * @runtime: the pcm runtime instance
1132  * @cond: condition bits
1133  * @var: the variable to evaluate
1134  * @func: the evaluation function
1135  * @private: the private data pointer passed to function
1136  * @dep: the dependent variables
1137  *
1138  * Return: Zero if successful, or a negative error code on failure.
1139  */
1140 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1141                         int var,
1142                         snd_pcm_hw_rule_func_t func, void *private,
1143                         int dep, ...)
1144 {
1145         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1146         struct snd_pcm_hw_rule *c;
1147         unsigned int k;
1148         va_list args;
1149         va_start(args, dep);
1150         if (constrs->rules_num >= constrs->rules_all) {
1151                 struct snd_pcm_hw_rule *new;
1152                 unsigned int new_rules = constrs->rules_all + 16;
1153                 new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1154                 if (!new) {
1155                         va_end(args);
1156                         return -ENOMEM;
1157                 }
1158                 if (constrs->rules) {
1159                         memcpy(new, constrs->rules,
1160                                constrs->rules_num * sizeof(*c));
1161                         kfree(constrs->rules);
1162                 }
1163                 constrs->rules = new;
1164                 constrs->rules_all = new_rules;
1165         }
1166         c = &constrs->rules[constrs->rules_num];
1167         c->cond = cond;
1168         c->func = func;
1169         c->var = var;
1170         c->private = private;
1171         k = 0;
1172         while (1) {
1173                 if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1174                         va_end(args);
1175                         return -EINVAL;
1176                 }
1177                 c->deps[k++] = dep;
1178                 if (dep < 0)
1179                         break;
1180                 dep = va_arg(args, int);
1181         }
1182         constrs->rules_num++;
1183         va_end(args);
1184         return 0;
1185 }
1186
1187 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1188
1189 /**
1190  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1191  * @runtime: PCM runtime instance
1192  * @var: hw_params variable to apply the mask
1193  * @mask: the bitmap mask
1194  *
1195  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1196  *
1197  * Return: Zero if successful, or a negative error code on failure.
1198  */
1199 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1200                                u_int32_t mask)
1201 {
1202         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1203         struct snd_mask *maskp = constrs_mask(constrs, var);
1204         *maskp->bits &= mask;
1205         memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1206         if (*maskp->bits == 0)
1207                 return -EINVAL;
1208         return 0;
1209 }
1210
1211 /**
1212  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1213  * @runtime: PCM runtime instance
1214  * @var: hw_params variable to apply the mask
1215  * @mask: the 64bit bitmap mask
1216  *
1217  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1218  *
1219  * Return: Zero if successful, or a negative error code on failure.
1220  */
1221 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1222                                  u_int64_t mask)
1223 {
1224         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1225         struct snd_mask *maskp = constrs_mask(constrs, var);
1226         maskp->bits[0] &= (u_int32_t)mask;
1227         maskp->bits[1] &= (u_int32_t)(mask >> 32);
1228         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1229         if (! maskp->bits[0] && ! maskp->bits[1])
1230                 return -EINVAL;
1231         return 0;
1232 }
1233 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1234
1235 /**
1236  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1237  * @runtime: PCM runtime instance
1238  * @var: hw_params variable to apply the integer constraint
1239  *
1240  * Apply the constraint of integer to an interval parameter.
1241  *
1242  * Return: Positive if the value is changed, zero if it's not changed, or a
1243  * negative error code.
1244  */
1245 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1246 {
1247         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1248         return snd_interval_setinteger(constrs_interval(constrs, var));
1249 }
1250
1251 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1252
1253 /**
1254  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1255  * @runtime: PCM runtime instance
1256  * @var: hw_params variable to apply the range
1257  * @min: the minimal value
1258  * @max: the maximal value
1259  *
1260  * Apply the min/max range constraint to an interval parameter.
1261  *
1262  * Return: Positive if the value is changed, zero if it's not changed, or a
1263  * negative error code.
1264  */
1265 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1266                                  unsigned int min, unsigned int max)
1267 {
1268         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1269         struct snd_interval t;
1270         t.min = min;
1271         t.max = max;
1272         t.openmin = t.openmax = 0;
1273         t.integer = 0;
1274         return snd_interval_refine(constrs_interval(constrs, var), &t);
1275 }
1276
1277 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1278
1279 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1280                                 struct snd_pcm_hw_rule *rule)
1281 {
1282         struct snd_pcm_hw_constraint_list *list = rule->private;
1283         return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1284 }
1285
1286
1287 /**
1288  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1289  * @runtime: PCM runtime instance
1290  * @cond: condition bits
1291  * @var: hw_params variable to apply the list constraint
1292  * @l: list
1293  *
1294  * Apply the list of constraints to an interval parameter.
1295  *
1296  * Return: Zero if successful, or a negative error code on failure.
1297  */
1298 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1299                                unsigned int cond,
1300                                snd_pcm_hw_param_t var,
1301                                const struct snd_pcm_hw_constraint_list *l)
1302 {
1303         return snd_pcm_hw_rule_add(runtime, cond, var,
1304                                    snd_pcm_hw_rule_list, (void *)l,
1305                                    var, -1);
1306 }
1307
1308 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1309
1310 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1311                                   struct snd_pcm_hw_rule *rule)
1312 {
1313         struct snd_pcm_hw_constraint_ranges *r = rule->private;
1314         return snd_interval_ranges(hw_param_interval(params, rule->var),
1315                                    r->count, r->ranges, r->mask);
1316 }
1317
1318
1319 /**
1320  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1321  * @runtime: PCM runtime instance
1322  * @cond: condition bits
1323  * @var: hw_params variable to apply the list of range constraints
1324  * @r: ranges
1325  *
1326  * Apply the list of range constraints to an interval parameter.
1327  *
1328  * Return: Zero if successful, or a negative error code on failure.
1329  */
1330 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1331                                  unsigned int cond,
1332                                  snd_pcm_hw_param_t var,
1333                                  const struct snd_pcm_hw_constraint_ranges *r)
1334 {
1335         return snd_pcm_hw_rule_add(runtime, cond, var,
1336                                    snd_pcm_hw_rule_ranges, (void *)r,
1337                                    var, -1);
1338 }
1339 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1340
1341 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1342                                    struct snd_pcm_hw_rule *rule)
1343 {
1344         const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1345         unsigned int num = 0, den = 0;
1346         int err;
1347         err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1348                                   r->nrats, r->rats, &num, &den);
1349         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1350                 params->rate_num = num;
1351                 params->rate_den = den;
1352         }
1353         return err;
1354 }
1355
1356 /**
1357  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1358  * @runtime: PCM runtime instance
1359  * @cond: condition bits
1360  * @var: hw_params variable to apply the ratnums constraint
1361  * @r: struct snd_ratnums constriants
1362  *
1363  * Return: Zero if successful, or a negative error code on failure.
1364  */
1365 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1366                                   unsigned int cond,
1367                                   snd_pcm_hw_param_t var,
1368                                   const struct snd_pcm_hw_constraint_ratnums *r)
1369 {
1370         return snd_pcm_hw_rule_add(runtime, cond, var,
1371                                    snd_pcm_hw_rule_ratnums, (void *)r,
1372                                    var, -1);
1373 }
1374
1375 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1376
1377 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1378                                    struct snd_pcm_hw_rule *rule)
1379 {
1380         const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1381         unsigned int num = 0, den = 0;
1382         int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1383                                   r->nrats, r->rats, &num, &den);
1384         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1385                 params->rate_num = num;
1386                 params->rate_den = den;
1387         }
1388         return err;
1389 }
1390
1391 /**
1392  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1393  * @runtime: PCM runtime instance
1394  * @cond: condition bits
1395  * @var: hw_params variable to apply the ratdens constraint
1396  * @r: struct snd_ratdens constriants
1397  *
1398  * Return: Zero if successful, or a negative error code on failure.
1399  */
1400 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1401                                   unsigned int cond,
1402                                   snd_pcm_hw_param_t var,
1403                                   const struct snd_pcm_hw_constraint_ratdens *r)
1404 {
1405         return snd_pcm_hw_rule_add(runtime, cond, var,
1406                                    snd_pcm_hw_rule_ratdens, (void *)r,
1407                                    var, -1);
1408 }
1409
1410 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1411
1412 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1413                                   struct snd_pcm_hw_rule *rule)
1414 {
1415         unsigned int l = (unsigned long) rule->private;
1416         int width = l & 0xffff;
1417         unsigned int msbits = l >> 16;
1418         const struct snd_interval *i =
1419                 hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1420
1421         if (!snd_interval_single(i))
1422                 return 0;
1423
1424         if ((snd_interval_value(i) == width) ||
1425             (width == 0 && snd_interval_value(i) > msbits))
1426                 params->msbits = min_not_zero(params->msbits, msbits);
1427
1428         return 0;
1429 }
1430
1431 /**
1432  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1433  * @runtime: PCM runtime instance
1434  * @cond: condition bits
1435  * @width: sample bits width
1436  * @msbits: msbits width
1437  *
1438  * This constraint will set the number of most significant bits (msbits) if a
1439  * sample format with the specified width has been select. If width is set to 0
1440  * the msbits will be set for any sample format with a width larger than the
1441  * specified msbits.
1442  *
1443  * Return: Zero if successful, or a negative error code on failure.
1444  */
1445 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1446                                  unsigned int cond,
1447                                  unsigned int width,
1448                                  unsigned int msbits)
1449 {
1450         unsigned long l = (msbits << 16) | width;
1451         return snd_pcm_hw_rule_add(runtime, cond, -1,
1452                                     snd_pcm_hw_rule_msbits,
1453                                     (void*) l,
1454                                     SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1455 }
1456
1457 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1458
1459 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1460                                 struct snd_pcm_hw_rule *rule)
1461 {
1462         unsigned long step = (unsigned long) rule->private;
1463         return snd_interval_step(hw_param_interval(params, rule->var), step);
1464 }
1465
1466 /**
1467  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1468  * @runtime: PCM runtime instance
1469  * @cond: condition bits
1470  * @var: hw_params variable to apply the step constraint
1471  * @step: step size
1472  *
1473  * Return: Zero if successful, or a negative error code on failure.
1474  */
1475 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1476                                unsigned int cond,
1477                                snd_pcm_hw_param_t var,
1478                                unsigned long step)
1479 {
1480         return snd_pcm_hw_rule_add(runtime, cond, var,
1481                                    snd_pcm_hw_rule_step, (void *) step,
1482                                    var, -1);
1483 }
1484
1485 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1486
1487 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1488 {
1489         static unsigned int pow2_sizes[] = {
1490                 1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1491                 1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1492                 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1493                 1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1494         };
1495         return snd_interval_list(hw_param_interval(params, rule->var),
1496                                  ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1497 }
1498
1499 /**
1500  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1501  * @runtime: PCM runtime instance
1502  * @cond: condition bits
1503  * @var: hw_params variable to apply the power-of-2 constraint
1504  *
1505  * Return: Zero if successful, or a negative error code on failure.
1506  */
1507 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1508                                unsigned int cond,
1509                                snd_pcm_hw_param_t var)
1510 {
1511         return snd_pcm_hw_rule_add(runtime, cond, var,
1512                                    snd_pcm_hw_rule_pow2, NULL,
1513                                    var, -1);
1514 }
1515
1516 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1517
1518 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1519                                            struct snd_pcm_hw_rule *rule)
1520 {
1521         unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1522         struct snd_interval *rate;
1523
1524         rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1525         return snd_interval_list(rate, 1, &base_rate, 0);
1526 }
1527
1528 /**
1529  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1530  * @runtime: PCM runtime instance
1531  * @base_rate: the rate at which the hardware does not resample
1532  *
1533  * Return: Zero if successful, or a negative error code on failure.
1534  */
1535 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1536                                unsigned int base_rate)
1537 {
1538         return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1539                                    SNDRV_PCM_HW_PARAM_RATE,
1540                                    snd_pcm_hw_rule_noresample_func,
1541                                    (void *)(uintptr_t)base_rate,
1542                                    SNDRV_PCM_HW_PARAM_RATE, -1);
1543 }
1544 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1545
1546 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1547                                   snd_pcm_hw_param_t var)
1548 {
1549         if (hw_is_mask(var)) {
1550                 snd_mask_any(hw_param_mask(params, var));
1551                 params->cmask |= 1 << var;
1552                 params->rmask |= 1 << var;
1553                 return;
1554         }
1555         if (hw_is_interval(var)) {
1556                 snd_interval_any(hw_param_interval(params, var));
1557                 params->cmask |= 1 << var;
1558                 params->rmask |= 1 << var;
1559                 return;
1560         }
1561         snd_BUG();
1562 }
1563
1564 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1565 {
1566         unsigned int k;
1567         memset(params, 0, sizeof(*params));
1568         for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1569                 _snd_pcm_hw_param_any(params, k);
1570         for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1571                 _snd_pcm_hw_param_any(params, k);
1572         params->info = ~0U;
1573 }
1574
1575 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1576
1577 /**
1578  * snd_pcm_hw_param_value - return @params field @var value
1579  * @params: the hw_params instance
1580  * @var: parameter to retrieve
1581  * @dir: pointer to the direction (-1,0,1) or %NULL
1582  *
1583  * Return: The value for field @var if it's fixed in configuration space
1584  * defined by @params. -%EINVAL otherwise.
1585  */
1586 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1587                            snd_pcm_hw_param_t var, int *dir)
1588 {
1589         if (hw_is_mask(var)) {
1590                 const struct snd_mask *mask = hw_param_mask_c(params, var);
1591                 if (!snd_mask_single(mask))
1592                         return -EINVAL;
1593                 if (dir)
1594                         *dir = 0;
1595                 return snd_mask_value(mask);
1596         }
1597         if (hw_is_interval(var)) {
1598                 const struct snd_interval *i = hw_param_interval_c(params, var);
1599                 if (!snd_interval_single(i))
1600                         return -EINVAL;
1601                 if (dir)
1602                         *dir = i->openmin;
1603                 return snd_interval_value(i);
1604         }
1605         return -EINVAL;
1606 }
1607
1608 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1609
1610 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1611                                 snd_pcm_hw_param_t var)
1612 {
1613         if (hw_is_mask(var)) {
1614                 snd_mask_none(hw_param_mask(params, var));
1615                 params->cmask |= 1 << var;
1616                 params->rmask |= 1 << var;
1617         } else if (hw_is_interval(var)) {
1618                 snd_interval_none(hw_param_interval(params, var));
1619                 params->cmask |= 1 << var;
1620                 params->rmask |= 1 << var;
1621         } else {
1622                 snd_BUG();
1623         }
1624 }
1625
1626 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1627
1628 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1629                                    snd_pcm_hw_param_t var)
1630 {
1631         int changed;
1632         if (hw_is_mask(var))
1633                 changed = snd_mask_refine_first(hw_param_mask(params, var));
1634         else if (hw_is_interval(var))
1635                 changed = snd_interval_refine_first(hw_param_interval(params, var));
1636         else
1637                 return -EINVAL;
1638         if (changed) {
1639                 params->cmask |= 1 << var;
1640                 params->rmask |= 1 << var;
1641         }
1642         return changed;
1643 }
1644
1645
1646 /**
1647  * snd_pcm_hw_param_first - refine config space and return minimum value
1648  * @pcm: PCM instance
1649  * @params: the hw_params instance
1650  * @var: parameter to retrieve
1651  * @dir: pointer to the direction (-1,0,1) or %NULL
1652  *
1653  * Inside configuration space defined by @params remove from @var all
1654  * values > minimum. Reduce configuration space accordingly.
1655  *
1656  * Return: The minimum, or a negative error code on failure.
1657  */
1658 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1659                            struct snd_pcm_hw_params *params,
1660                            snd_pcm_hw_param_t var, int *dir)
1661 {
1662         int changed = _snd_pcm_hw_param_first(params, var);
1663         if (changed < 0)
1664                 return changed;
1665         if (params->rmask) {
1666                 int err = snd_pcm_hw_refine(pcm, params);
1667                 if (snd_BUG_ON(err < 0))
1668                         return err;
1669         }
1670         return snd_pcm_hw_param_value(params, var, dir);
1671 }
1672
1673 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1674
1675 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1676                                   snd_pcm_hw_param_t var)
1677 {
1678         int changed;
1679         if (hw_is_mask(var))
1680                 changed = snd_mask_refine_last(hw_param_mask(params, var));
1681         else if (hw_is_interval(var))
1682                 changed = snd_interval_refine_last(hw_param_interval(params, var));
1683         else
1684                 return -EINVAL;
1685         if (changed) {
1686                 params->cmask |= 1 << var;
1687                 params->rmask |= 1 << var;
1688         }
1689         return changed;
1690 }
1691
1692
1693 /**
1694  * snd_pcm_hw_param_last - refine config space and return maximum value
1695  * @pcm: PCM instance
1696  * @params: the hw_params instance
1697  * @var: parameter to retrieve
1698  * @dir: pointer to the direction (-1,0,1) or %NULL
1699  *
1700  * Inside configuration space defined by @params remove from @var all
1701  * values < maximum. Reduce configuration space accordingly.
1702  *
1703  * Return: The maximum, or a negative error code on failure.
1704  */
1705 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1706                           struct snd_pcm_hw_params *params,
1707                           snd_pcm_hw_param_t var, int *dir)
1708 {
1709         int changed = _snd_pcm_hw_param_last(params, var);
1710         if (changed < 0)
1711                 return changed;
1712         if (params->rmask) {
1713                 int err = snd_pcm_hw_refine(pcm, params);
1714                 if (snd_BUG_ON(err < 0))
1715                         return err;
1716         }
1717         return snd_pcm_hw_param_value(params, var, dir);
1718 }
1719
1720 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1721
1722 /**
1723  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1724  * @pcm: PCM instance
1725  * @params: the hw_params instance
1726  *
1727  * Choose one configuration from configuration space defined by @params.
1728  * The configuration chosen is that obtained fixing in this order:
1729  * first access, first format, first subformat, min channels,
1730  * min rate, min period time, max buffer size, min tick time
1731  *
1732  * Return: Zero if successful, or a negative error code on failure.
1733  */
1734 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1735                              struct snd_pcm_hw_params *params)
1736 {
1737         static int vars[] = {
1738                 SNDRV_PCM_HW_PARAM_ACCESS,
1739                 SNDRV_PCM_HW_PARAM_FORMAT,
1740                 SNDRV_PCM_HW_PARAM_SUBFORMAT,
1741                 SNDRV_PCM_HW_PARAM_CHANNELS,
1742                 SNDRV_PCM_HW_PARAM_RATE,
1743                 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1744                 SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1745                 SNDRV_PCM_HW_PARAM_TICK_TIME,
1746                 -1
1747         };
1748         int err, *v;
1749
1750         for (v = vars; *v != -1; v++) {
1751                 if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1752                         err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1753                 else
1754                         err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1755                 if (snd_BUG_ON(err < 0))
1756                         return err;
1757         }
1758         return 0;
1759 }
1760
1761 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1762                                    void *arg)
1763 {
1764         struct snd_pcm_runtime *runtime = substream->runtime;
1765         unsigned long flags;
1766         snd_pcm_stream_lock_irqsave(substream, flags);
1767         if (snd_pcm_running(substream) &&
1768             snd_pcm_update_hw_ptr(substream) >= 0)
1769                 runtime->status->hw_ptr %= runtime->buffer_size;
1770         else {
1771                 runtime->status->hw_ptr = 0;
1772                 runtime->hw_ptr_wrap = 0;
1773         }
1774         snd_pcm_stream_unlock_irqrestore(substream, flags);
1775         return 0;
1776 }
1777
1778 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1779                                           void *arg)
1780 {
1781         struct snd_pcm_channel_info *info = arg;
1782         struct snd_pcm_runtime *runtime = substream->runtime;
1783         int width;
1784         if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1785                 info->offset = -1;
1786                 return 0;
1787         }
1788         width = snd_pcm_format_physical_width(runtime->format);
1789         if (width < 0)
1790                 return width;
1791         info->offset = 0;
1792         switch (runtime->access) {
1793         case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1794         case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1795                 info->first = info->channel * width;
1796                 info->step = runtime->channels * width;
1797                 break;
1798         case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1799         case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1800         {
1801                 size_t size = runtime->dma_bytes / runtime->channels;
1802                 info->first = info->channel * size * 8;
1803                 info->step = width;
1804                 break;
1805         }
1806         default:
1807                 snd_BUG();
1808                 break;
1809         }
1810         return 0;
1811 }
1812
1813 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1814                                        void *arg)
1815 {
1816         struct snd_pcm_hw_params *params = arg;
1817         snd_pcm_format_t format;
1818         int channels;
1819         ssize_t frame_size;
1820
1821         params->fifo_size = substream->runtime->hw.fifo_size;
1822         if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1823                 format = params_format(params);
1824                 channels = params_channels(params);
1825                 frame_size = snd_pcm_format_size(format, channels);
1826                 if (frame_size > 0)
1827                         params->fifo_size /= (unsigned)frame_size;
1828         }
1829         return 0;
1830 }
1831
1832 /**
1833  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1834  * @substream: the pcm substream instance
1835  * @cmd: ioctl command
1836  * @arg: ioctl argument
1837  *
1838  * Processes the generic ioctl commands for PCM.
1839  * Can be passed as the ioctl callback for PCM ops.
1840  *
1841  * Return: Zero if successful, or a negative error code on failure.
1842  */
1843 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1844                       unsigned int cmd, void *arg)
1845 {
1846         switch (cmd) {
1847         case SNDRV_PCM_IOCTL1_INFO:
1848                 return 0;
1849         case SNDRV_PCM_IOCTL1_RESET:
1850                 return snd_pcm_lib_ioctl_reset(substream, arg);
1851         case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1852                 return snd_pcm_lib_ioctl_channel_info(substream, arg);
1853         case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1854                 return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1855         }
1856         return -ENXIO;
1857 }
1858
1859 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1860
1861 /**
1862  * snd_pcm_period_elapsed - update the pcm status for the next period
1863  * @substream: the pcm substream instance
1864  *
1865  * This function is called from the interrupt handler when the
1866  * PCM has processed the period size.  It will update the current
1867  * pointer, wake up sleepers, etc.
1868  *
1869  * Even if more than one periods have elapsed since the last call, you
1870  * have to call this only once.
1871  */
1872 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1873 {
1874         struct snd_pcm_runtime *runtime;
1875         unsigned long flags;
1876
1877         if (PCM_RUNTIME_CHECK(substream))
1878                 return;
1879         runtime = substream->runtime;
1880
1881         snd_pcm_stream_lock_irqsave(substream, flags);
1882         if (!snd_pcm_running(substream) ||
1883             snd_pcm_update_hw_ptr0(substream, 1) < 0)
1884                 goto _end;
1885
1886 #ifdef CONFIG_SND_PCM_TIMER
1887         if (substream->timer_running)
1888                 snd_timer_interrupt(substream->timer, 1);
1889 #endif
1890  _end:
1891         kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1892         snd_pcm_stream_unlock_irqrestore(substream, flags);
1893 }
1894
1895 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1896
1897 /*
1898  * Wait until avail_min data becomes available
1899  * Returns a negative error code if any error occurs during operation.
1900  * The available space is stored on availp.  When err = 0 and avail = 0
1901  * on the capture stream, it indicates the stream is in DRAINING state.
1902  */
1903 static int wait_for_avail(struct snd_pcm_substream *substream,
1904                               snd_pcm_uframes_t *availp)
1905 {
1906         struct snd_pcm_runtime *runtime = substream->runtime;
1907         int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1908         wait_queue_t wait;
1909         int err = 0;
1910         snd_pcm_uframes_t avail = 0;
1911         long wait_time, tout;
1912
1913         init_waitqueue_entry(&wait, current);
1914         set_current_state(TASK_INTERRUPTIBLE);
1915         add_wait_queue(&runtime->tsleep, &wait);
1916
1917         if (runtime->no_period_wakeup)
1918                 wait_time = MAX_SCHEDULE_TIMEOUT;
1919         else {
1920                 wait_time = 10;
1921                 if (runtime->rate) {
1922                         long t = runtime->period_size * 2 / runtime->rate;
1923                         wait_time = max(t, wait_time);
1924                 }
1925                 wait_time = msecs_to_jiffies(wait_time * 1000);
1926         }
1927
1928         for (;;) {
1929                 if (signal_pending(current)) {
1930                         err = -ERESTARTSYS;
1931                         break;
1932                 }
1933
1934                 /*
1935                  * We need to check if space became available already
1936                  * (and thus the wakeup happened already) first to close
1937                  * the race of space already having become available.
1938                  * This check must happen after been added to the waitqueue
1939                  * and having current state be INTERRUPTIBLE.
1940                  */
1941                 if (is_playback)
1942                         avail = snd_pcm_playback_avail(runtime);
1943                 else
1944                         avail = snd_pcm_capture_avail(runtime);
1945                 if (avail >= runtime->twake)
1946                         break;
1947                 snd_pcm_stream_unlock_irq(substream);
1948
1949                 tout = schedule_timeout(wait_time);
1950
1951                 snd_pcm_stream_lock_irq(substream);
1952                 set_current_state(TASK_INTERRUPTIBLE);
1953                 switch (runtime->status->state) {
1954                 case SNDRV_PCM_STATE_SUSPENDED:
1955                         err = -ESTRPIPE;
1956                         goto _endloop;
1957                 case SNDRV_PCM_STATE_XRUN:
1958                         err = -EPIPE;
1959                         goto _endloop;
1960                 case SNDRV_PCM_STATE_DRAINING:
1961                         if (is_playback)
1962                                 err = -EPIPE;
1963                         else
1964                                 avail = 0; /* indicate draining */
1965                         goto _endloop;
1966                 case SNDRV_PCM_STATE_OPEN:
1967                 case SNDRV_PCM_STATE_SETUP:
1968                 case SNDRV_PCM_STATE_DISCONNECTED:
1969                         err = -EBADFD;
1970                         goto _endloop;
1971                 case SNDRV_PCM_STATE_PAUSED:
1972                         continue;
1973                 }
1974                 if (!tout) {
1975                         pcm_dbg(substream->pcm,
1976                                 "%s write error (DMA or IRQ trouble?)\n",
1977                                 is_playback ? "playback" : "capture");
1978                         err = -EIO;
1979                         break;
1980                 }
1981         }
1982  _endloop:
1983         set_current_state(TASK_RUNNING);
1984         remove_wait_queue(&runtime->tsleep, &wait);
1985         *availp = avail;
1986         return err;
1987 }
1988
1989 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1990                                       unsigned int hwoff,
1991                                       unsigned long data, unsigned int off,
1992                                       snd_pcm_uframes_t frames)
1993 {
1994         struct snd_pcm_runtime *runtime = substream->runtime;
1995         int err;
1996         char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1997         if (substream->ops->copy) {
1998                 if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1999                         return err;
2000         } else {
2001                 char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2002                 if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
2003                         return -EFAULT;
2004         }
2005         return 0;
2006 }
2007
2008 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
2009                           unsigned long data, unsigned int off,
2010                           snd_pcm_uframes_t size);
2011
2012 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
2013                                             unsigned long data,
2014                                             snd_pcm_uframes_t size,
2015                                             int nonblock,
2016                                             transfer_f transfer)
2017 {
2018         struct snd_pcm_runtime *runtime = substream->runtime;
2019         snd_pcm_uframes_t xfer = 0;
2020         snd_pcm_uframes_t offset = 0;
2021         snd_pcm_uframes_t avail;
2022         int err = 0;
2023
2024         if (size == 0)
2025                 return 0;
2026
2027         snd_pcm_stream_lock_irq(substream);
2028         switch (runtime->status->state) {
2029         case SNDRV_PCM_STATE_PREPARED:
2030         case SNDRV_PCM_STATE_RUNNING:
2031         case SNDRV_PCM_STATE_PAUSED:
2032                 break;
2033         case SNDRV_PCM_STATE_XRUN:
2034                 err = -EPIPE;
2035                 goto _end_unlock;
2036         case SNDRV_PCM_STATE_SUSPENDED:
2037                 err = -ESTRPIPE;
2038                 goto _end_unlock;
2039         default:
2040                 err = -EBADFD;
2041                 goto _end_unlock;
2042         }
2043
2044         runtime->twake = runtime->control->avail_min ? : 1;
2045         if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2046                 snd_pcm_update_hw_ptr(substream);
2047         avail = snd_pcm_playback_avail(runtime);
2048         while (size > 0) {
2049                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2050                 snd_pcm_uframes_t cont;
2051                 if (!avail) {
2052                         if (nonblock) {
2053                                 err = -EAGAIN;
2054                                 goto _end_unlock;
2055                         }
2056                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2057                                         runtime->control->avail_min ? : 1);
2058                         err = wait_for_avail(substream, &avail);
2059                         if (err < 0)
2060                                 goto _end_unlock;
2061                 }
2062                 frames = size > avail ? avail : size;
2063                 cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2064                 if (frames > cont)
2065                         frames = cont;
2066                 if (snd_BUG_ON(!frames)) {
2067                         runtime->twake = 0;
2068                         snd_pcm_stream_unlock_irq(substream);
2069                         return -EINVAL;
2070                 }
2071                 appl_ptr = runtime->control->appl_ptr;
2072                 appl_ofs = appl_ptr % runtime->buffer_size;
2073                 snd_pcm_stream_unlock_irq(substream);
2074                 err = transfer(substream, appl_ofs, data, offset, frames);
2075                 snd_pcm_stream_lock_irq(substream);
2076                 if (err < 0)
2077                         goto _end_unlock;
2078                 switch (runtime->status->state) {
2079                 case SNDRV_PCM_STATE_XRUN:
2080                         err = -EPIPE;
2081                         goto _end_unlock;
2082                 case SNDRV_PCM_STATE_SUSPENDED:
2083                         err = -ESTRPIPE;
2084                         goto _end_unlock;
2085                 default:
2086                         break;
2087                 }
2088                 appl_ptr += frames;
2089                 if (appl_ptr >= runtime->boundary)
2090                         appl_ptr -= runtime->boundary;
2091                 runtime->control->appl_ptr = appl_ptr;
2092                 if (substream->ops->ack)
2093                         substream->ops->ack(substream);
2094
2095                 offset += frames;
2096                 size -= frames;
2097                 xfer += frames;
2098                 avail -= frames;
2099                 if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2100                     snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2101                         err = snd_pcm_start(substream);
2102                         if (err < 0)
2103                                 goto _end_unlock;
2104                 }
2105         }
2106  _end_unlock:
2107         runtime->twake = 0;
2108         if (xfer > 0 && err >= 0)
2109                 snd_pcm_update_state(substream, runtime);
2110         snd_pcm_stream_unlock_irq(substream);
2111         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2112 }
2113
2114 /* sanity-check for read/write methods */
2115 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2116 {
2117         struct snd_pcm_runtime *runtime;
2118         if (PCM_RUNTIME_CHECK(substream))
2119                 return -ENXIO;
2120         runtime = substream->runtime;
2121         if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2122                 return -EINVAL;
2123         if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2124                 return -EBADFD;
2125         return 0;
2126 }
2127
2128 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2129 {
2130         struct snd_pcm_runtime *runtime;
2131         int nonblock;
2132         int err;
2133
2134         err = pcm_sanity_check(substream);
2135         if (err < 0)
2136                 return err;
2137         runtime = substream->runtime;
2138         nonblock = !!(substream->f_flags & O_NONBLOCK);
2139
2140         if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2141             runtime->channels > 1)
2142                 return -EINVAL;
2143         return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2144                                   snd_pcm_lib_write_transfer);
2145 }
2146
2147 EXPORT_SYMBOL(snd_pcm_lib_write);
2148
2149 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2150                                        unsigned int hwoff,
2151                                        unsigned long data, unsigned int off,
2152                                        snd_pcm_uframes_t frames)
2153 {
2154         struct snd_pcm_runtime *runtime = substream->runtime;
2155         int err;
2156         void __user **bufs = (void __user **)data;
2157         int channels = runtime->channels;
2158         int c;
2159         if (substream->ops->copy) {
2160                 if (snd_BUG_ON(!substream->ops->silence))
2161                         return -EINVAL;
2162                 for (c = 0; c < channels; ++c, ++bufs) {
2163                         if (*bufs == NULL) {
2164                                 if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2165                                         return err;
2166                         } else {
2167                                 char __user *buf = *bufs + samples_to_bytes(runtime, off);
2168                                 if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2169                                         return err;
2170                         }
2171                 }
2172         } else {
2173                 /* default transfer behaviour */
2174                 size_t dma_csize = runtime->dma_bytes / channels;
2175                 for (c = 0; c < channels; ++c, ++bufs) {
2176                         char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2177                         if (*bufs == NULL) {
2178                                 snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2179                         } else {
2180                                 char __user *buf = *bufs + samples_to_bytes(runtime, off);
2181                                 if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2182                                         return -EFAULT;
2183                         }
2184                 }
2185         }
2186         return 0;
2187 }
2188
2189 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2190                                      void __user **bufs,
2191                                      snd_pcm_uframes_t frames)
2192 {
2193         struct snd_pcm_runtime *runtime;
2194         int nonblock;
2195         int err;
2196
2197         err = pcm_sanity_check(substream);
2198         if (err < 0)
2199                 return err;
2200         runtime = substream->runtime;
2201         nonblock = !!(substream->f_flags & O_NONBLOCK);
2202
2203         if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2204                 return -EINVAL;
2205         return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2206                                   nonblock, snd_pcm_lib_writev_transfer);
2207 }
2208
2209 EXPORT_SYMBOL(snd_pcm_lib_writev);
2210
2211 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2212                                      unsigned int hwoff,
2213                                      unsigned long data, unsigned int off,
2214                                      snd_pcm_uframes_t frames)
2215 {
2216         struct snd_pcm_runtime *runtime = substream->runtime;
2217         int err;
2218         char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2219         if (substream->ops->copy) {
2220                 if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2221                         return err;
2222         } else {
2223                 char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2224                 if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2225                         return -EFAULT;
2226         }
2227         return 0;
2228 }
2229
2230 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2231                                            unsigned long data,
2232                                            snd_pcm_uframes_t size,
2233                                            int nonblock,
2234                                            transfer_f transfer)
2235 {
2236         struct snd_pcm_runtime *runtime = substream->runtime;
2237         snd_pcm_uframes_t xfer = 0;
2238         snd_pcm_uframes_t offset = 0;
2239         snd_pcm_uframes_t avail;
2240         int err = 0;
2241
2242         if (size == 0)
2243                 return 0;
2244
2245         snd_pcm_stream_lock_irq(substream);
2246         switch (runtime->status->state) {
2247         case SNDRV_PCM_STATE_PREPARED:
2248                 if (size >= runtime->start_threshold) {
2249                         err = snd_pcm_start(substream);
2250                         if (err < 0)
2251                                 goto _end_unlock;
2252                 }
2253                 break;
2254         case SNDRV_PCM_STATE_DRAINING:
2255         case SNDRV_PCM_STATE_RUNNING:
2256         case SNDRV_PCM_STATE_PAUSED:
2257                 break;
2258         case SNDRV_PCM_STATE_XRUN:
2259                 err = -EPIPE;
2260                 goto _end_unlock;
2261         case SNDRV_PCM_STATE_SUSPENDED:
2262                 err = -ESTRPIPE;
2263                 goto _end_unlock;
2264         default:
2265                 err = -EBADFD;
2266                 goto _end_unlock;
2267         }
2268
2269         runtime->twake = runtime->control->avail_min ? : 1;
2270         if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2271                 snd_pcm_update_hw_ptr(substream);
2272         avail = snd_pcm_capture_avail(runtime);
2273         while (size > 0) {
2274                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2275                 snd_pcm_uframes_t cont;
2276                 if (!avail) {
2277                         if (runtime->status->state ==
2278                             SNDRV_PCM_STATE_DRAINING) {
2279                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2280                                 goto _end_unlock;
2281                         }
2282                         if (nonblock) {
2283                                 err = -EAGAIN;
2284                                 goto _end_unlock;
2285                         }
2286                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2287                                         runtime->control->avail_min ? : 1);
2288                         err = wait_for_avail(substream, &avail);
2289                         if (err < 0)
2290                                 goto _end_unlock;
2291                         if (!avail)
2292                                 continue; /* draining */
2293                 }
2294                 frames = size > avail ? avail : size;
2295                 cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2296                 if (frames > cont)
2297                         frames = cont;
2298                 if (snd_BUG_ON(!frames)) {
2299                         runtime->twake = 0;
2300                         snd_pcm_stream_unlock_irq(substream);
2301                         return -EINVAL;
2302                 }
2303                 appl_ptr = runtime->control->appl_ptr;
2304                 appl_ofs = appl_ptr % runtime->buffer_size;
2305                 snd_pcm_stream_unlock_irq(substream);
2306                 err = transfer(substream, appl_ofs, data, offset, frames);
2307                 snd_pcm_stream_lock_irq(substream);
2308                 if (err < 0)
2309                         goto _end_unlock;
2310                 switch (runtime->status->state) {
2311                 case SNDRV_PCM_STATE_XRUN:
2312                         err = -EPIPE;
2313                         goto _end_unlock;
2314                 case SNDRV_PCM_STATE_SUSPENDED:
2315                         err = -ESTRPIPE;
2316                         goto _end_unlock;
2317                 default:
2318                         break;
2319                 }
2320                 appl_ptr += frames;
2321                 if (appl_ptr >= runtime->boundary)
2322                         appl_ptr -= runtime->boundary;
2323                 runtime->control->appl_ptr = appl_ptr;
2324                 if (substream->ops->ack)
2325                         substream->ops->ack(substream);
2326
2327                 offset += frames;
2328                 size -= frames;
2329                 xfer += frames;
2330                 avail -= frames;
2331         }
2332  _end_unlock:
2333         runtime->twake = 0;
2334         if (xfer > 0 && err >= 0)
2335                 snd_pcm_update_state(substream, runtime);
2336         snd_pcm_stream_unlock_irq(substream);
2337         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2338 }
2339
2340 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2341 {
2342         struct snd_pcm_runtime *runtime;
2343         int nonblock;
2344         int err;
2345
2346         err = pcm_sanity_check(substream);
2347         if (err < 0)
2348                 return err;
2349         runtime = substream->runtime;
2350         nonblock = !!(substream->f_flags & O_NONBLOCK);
2351         if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2352                 return -EINVAL;
2353         return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2354 }
2355
2356 EXPORT_SYMBOL(snd_pcm_lib_read);
2357
2358 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2359                                       unsigned int hwoff,
2360                                       unsigned long data, unsigned int off,
2361                                       snd_pcm_uframes_t frames)
2362 {
2363         struct snd_pcm_runtime *runtime = substream->runtime;
2364         int err;
2365         void __user **bufs = (void __user **)data;
2366         int channels = runtime->channels;
2367         int c;
2368         if (substream->ops->copy) {
2369                 for (c = 0; c < channels; ++c, ++bufs) {
2370                         char __user *buf;
2371                         if (*bufs == NULL)
2372                                 continue;
2373                         buf = *bufs + samples_to_bytes(runtime, off);
2374                         if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2375                                 return err;
2376                 }
2377         } else {
2378                 snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2379                 for (c = 0; c < channels; ++c, ++bufs) {
2380                         char *hwbuf;
2381                         char __user *buf;
2382                         if (*bufs == NULL)
2383                                 continue;
2384
2385                         hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2386                         buf = *bufs + samples_to_bytes(runtime, off);
2387                         if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2388                                 return -EFAULT;
2389                 }
2390         }
2391         return 0;
2392 }
2393
2394 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2395                                     void __user **bufs,
2396                                     snd_pcm_uframes_t frames)
2397 {
2398         struct snd_pcm_runtime *runtime;
2399         int nonblock;
2400         int err;
2401
2402         err = pcm_sanity_check(substream);
2403         if (err < 0)
2404                 return err;
2405         runtime = substream->runtime;
2406         if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2407                 return -EBADFD;
2408
2409         nonblock = !!(substream->f_flags & O_NONBLOCK);
2410         if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2411                 return -EINVAL;
2412         return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2413 }
2414
2415 EXPORT_SYMBOL(snd_pcm_lib_readv);
2416
2417 /*
2418  * standard channel mapping helpers
2419  */
2420
2421 /* default channel maps for multi-channel playbacks, up to 8 channels */
2422 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2423         { .channels = 1,
2424           .map = { SNDRV_CHMAP_MONO } },
2425         { .channels = 2,
2426           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2427         { .channels = 4,
2428           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2429                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2430         { .channels = 6,
2431           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2432                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2433                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2434         { .channels = 8,
2435           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2436                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2437                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2438                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2439         { }
2440 };
2441 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2442
2443 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2444 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2445         { .channels = 1,
2446           .map = { SNDRV_CHMAP_MONO } },
2447         { .channels = 2,
2448           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2449         { .channels = 4,
2450           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2451                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2452         { .channels = 6,
2453           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2454                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2455                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2456         { .channels = 8,
2457           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2458                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2459                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2460                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2461         { }
2462 };
2463 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2464
2465 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2466 {
2467         if (ch > info->max_channels)
2468                 return false;
2469         return !info->channel_mask || (info->channel_mask & (1U << ch));
2470 }
2471
2472 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2473                               struct snd_ctl_elem_info *uinfo)
2474 {
2475         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2476
2477         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2478         uinfo->count = 0;
2479         uinfo->count = info->max_channels;
2480         uinfo->value.integer.min = 0;
2481         uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2482         return 0;
2483 }
2484
2485 /* get callback for channel map ctl element
2486  * stores the channel position firstly matching with the current channels
2487  */
2488 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2489                              struct snd_ctl_elem_value *ucontrol)
2490 {
2491         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2492         unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2493         struct snd_pcm_substream *substream;
2494         const struct snd_pcm_chmap_elem *map;
2495
2496         if (snd_BUG_ON(!info->chmap))
2497                 return -EINVAL;
2498         substream = snd_pcm_chmap_substream(info, idx);
2499         if (!substream)
2500                 return -ENODEV;
2501         memset(ucontrol->value.integer.value, 0,
2502                sizeof(ucontrol->value.integer.value));
2503         if (!substream->runtime)
2504                 return 0; /* no channels set */
2505         for (map = info->chmap; map->channels; map++) {
2506                 int i;
2507                 if (map->channels == substream->runtime->channels &&
2508                     valid_chmap_channels(info, map->channels)) {
2509                         for (i = 0; i < map->channels; i++)
2510                                 ucontrol->value.integer.value[i] = map->map[i];
2511                         return 0;
2512                 }
2513         }
2514         return -EINVAL;
2515 }
2516
2517 /* tlv callback for channel map ctl element
2518  * expands the pre-defined channel maps in a form of TLV
2519  */
2520 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2521                              unsigned int size, unsigned int __user *tlv)
2522 {
2523         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2524         const struct snd_pcm_chmap_elem *map;
2525         unsigned int __user *dst;
2526         int c, count = 0;
2527
2528         if (snd_BUG_ON(!info->chmap))
2529                 return -EINVAL;
2530         if (size < 8)
2531                 return -ENOMEM;
2532         if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2533                 return -EFAULT;
2534         size -= 8;
2535         dst = tlv + 2;
2536         for (map = info->chmap; map->channels; map++) {
2537                 int chs_bytes = map->channels * 4;
2538                 if (!valid_chmap_channels(info, map->channels))
2539                         continue;
2540                 if (size < 8)
2541                         return -ENOMEM;
2542                 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2543                     put_user(chs_bytes, dst + 1))
2544                         return -EFAULT;
2545                 dst += 2;
2546                 size -= 8;
2547                 count += 8;
2548                 if (size < chs_bytes)
2549                         return -ENOMEM;
2550                 size -= chs_bytes;
2551                 count += chs_bytes;
2552                 for (c = 0; c < map->channels; c++) {
2553                         if (put_user(map->map[c], dst))
2554                                 return -EFAULT;
2555                         dst++;
2556                 }
2557         }
2558         if (put_user(count, tlv + 1))
2559                 return -EFAULT;
2560         return 0;
2561 }
2562
2563 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2564 {
2565         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2566         info->pcm->streams[info->stream].chmap_kctl = NULL;
2567         kfree(info);
2568 }
2569
2570 /**
2571  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2572  * @pcm: the assigned PCM instance
2573  * @stream: stream direction
2574  * @chmap: channel map elements (for query)
2575  * @max_channels: the max number of channels for the stream
2576  * @private_value: the value passed to each kcontrol's private_value field
2577  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2578  *
2579  * Create channel-mapping control elements assigned to the given PCM stream(s).
2580  * Return: Zero if successful, or a negative error value.
2581  */
2582 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2583                            const struct snd_pcm_chmap_elem *chmap,
2584                            int max_channels,
2585                            unsigned long private_value,
2586                            struct snd_pcm_chmap **info_ret)
2587 {
2588         struct snd_pcm_chmap *info;
2589         struct snd_kcontrol_new knew = {
2590                 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
2591                 .access = SNDRV_CTL_ELEM_ACCESS_READ |
2592                         SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2593                         SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2594                 .info = pcm_chmap_ctl_info,
2595                 .get = pcm_chmap_ctl_get,
2596                 .tlv.c = pcm_chmap_ctl_tlv,
2597         };
2598         int err;
2599
2600         if (WARN_ON(pcm->streams[stream].chmap_kctl))
2601                 return -EBUSY;
2602         info = kzalloc(sizeof(*info), GFP_KERNEL);
2603         if (!info)
2604                 return -ENOMEM;
2605         info->pcm = pcm;
2606         info->stream = stream;
2607         info->chmap = chmap;
2608         info->max_channels = max_channels;
2609         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2610                 knew.name = "Playback Channel Map";
2611         else
2612                 knew.name = "Capture Channel Map";
2613         knew.device = pcm->device;
2614         knew.count = pcm->streams[stream].substream_count;
2615         knew.private_value = private_value;
2616         info->kctl = snd_ctl_new1(&knew, info);
2617         if (!info->kctl) {
2618                 kfree(info);
2619                 return -ENOMEM;
2620         }
2621         info->kctl->private_free = pcm_chmap_ctl_private_free;
2622         err = snd_ctl_add(pcm->card, info->kctl);
2623         if (err < 0)
2624                 return err;
2625         pcm->streams[stream].chmap_kctl = info->kctl;
2626         if (info_ret)
2627                 *info_ret = info;
2628         return 0;
2629 }
2630 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);