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TOMOYO Linux Cross Reference
Linux/sound/core/pcm_lib.c

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

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