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Linux/sound/core/pcm_lib.c

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  *  Digital Audio (PCM) abstract layer
  4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
  5  *                   Abramo Bagnara <abramo@alsa-project.org>
  6  */
  7 
  8 #include <linux/slab.h>
  9 #include <linux/sched/signal.h>
 10 #include <linux/time.h>
 11 #include <linux/math64.h>
 12 #include <linux/export.h>
 13 #include <sound/core.h>
 14 #include <sound/control.h>
 15 #include <sound/tlv.h>
 16 #include <sound/info.h>
 17 #include <sound/pcm.h>
 18 #include <sound/pcm_params.h>
 19 #include <sound/timer.h>
 20 
 21 #include "pcm_local.h"
 22 
 23 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 24 #define CREATE_TRACE_POINTS
 25 #include "pcm_trace.h"
 26 #else
 27 #define trace_hwptr(substream, pos, in_interrupt)
 28 #define trace_xrun(substream)
 29 #define trace_hw_ptr_error(substream, reason)
 30 #define trace_applptr(substream, prev, curr)
 31 #endif
 32 
 33 static int fill_silence_frames(struct snd_pcm_substream *substream,
 34                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
 35 
 36 /*
 37  * fill ring buffer with silence
 38  * runtime->silence_start: starting pointer to silence area
 39  * runtime->silence_filled: size filled with silence
 40  * runtime->silence_threshold: threshold from application
 41  * runtime->silence_size: maximal size from application
 42  *
 43  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
 44  */
 45 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
 46 {
 47         struct snd_pcm_runtime *runtime = substream->runtime;
 48         snd_pcm_uframes_t frames, ofs, transfer;
 49         int err;
 50 
 51         if (runtime->silence_size < runtime->boundary) {
 52                 snd_pcm_sframes_t noise_dist, n;
 53                 snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr);
 54                 if (runtime->silence_start != appl_ptr) {
 55                         n = appl_ptr - runtime->silence_start;
 56                         if (n < 0)
 57                                 n += runtime->boundary;
 58                         if ((snd_pcm_uframes_t)n < runtime->silence_filled)
 59                                 runtime->silence_filled -= n;
 60                         else
 61                                 runtime->silence_filled = 0;
 62                         runtime->silence_start = appl_ptr;
 63                 }
 64                 if (runtime->silence_filled >= runtime->buffer_size)
 65                         return;
 66                 noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
 67                 if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
 68                         return;
 69                 frames = runtime->silence_threshold - noise_dist;
 70                 if (frames > runtime->silence_size)
 71                         frames = runtime->silence_size;
 72         } else {
 73                 if (new_hw_ptr == ULONG_MAX) {  /* initialization */
 74                         snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
 75                         if (avail > runtime->buffer_size)
 76                                 avail = runtime->buffer_size;
 77                         runtime->silence_filled = avail > 0 ? avail : 0;
 78                         runtime->silence_start = (runtime->status->hw_ptr +
 79                                                   runtime->silence_filled) %
 80                                                  runtime->boundary;
 81                 } else {
 82                         ofs = runtime->status->hw_ptr;
 83                         frames = new_hw_ptr - ofs;
 84                         if ((snd_pcm_sframes_t)frames < 0)
 85                                 frames += runtime->boundary;
 86                         runtime->silence_filled -= frames;
 87                         if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
 88                                 runtime->silence_filled = 0;
 89                                 runtime->silence_start = new_hw_ptr;
 90                         } else {
 91                                 runtime->silence_start = ofs;
 92                         }
 93                 }
 94                 frames = runtime->buffer_size - runtime->silence_filled;
 95         }
 96         if (snd_BUG_ON(frames > runtime->buffer_size))
 97                 return;
 98         if (frames == 0)
 99                 return;
100         ofs = runtime->silence_start % runtime->buffer_size;
101         while (frames > 0) {
102                 transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
103                 err = fill_silence_frames(substream, ofs, transfer);
104                 snd_BUG_ON(err < 0);
105                 runtime->silence_filled += transfer;
106                 frames -= transfer;
107                 ofs = 0;
108         }
109 }
110 
111 #ifdef CONFIG_SND_DEBUG
112 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
113                            char *name, size_t len)
114 {
115         snprintf(name, len, "pcmC%dD%d%c:%d",
116                  substream->pcm->card->number,
117                  substream->pcm->device,
118                  substream->stream ? 'c' : 'p',
119                  substream->number);
120 }
121 EXPORT_SYMBOL(snd_pcm_debug_name);
122 #endif
123 
124 #define XRUN_DEBUG_BASIC        (1<<0)
125 #define XRUN_DEBUG_STACK        (1<<1)  /* dump also stack */
126 #define XRUN_DEBUG_JIFFIESCHECK (1<<2)  /* do jiffies check */
127 
128 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
129 
130 #define xrun_debug(substream, mask) \
131                         ((substream)->pstr->xrun_debug & (mask))
132 #else
133 #define xrun_debug(substream, mask)     0
134 #endif
135 
136 #define dump_stack_on_xrun(substream) do {                      \
137                 if (xrun_debug(substream, XRUN_DEBUG_STACK))    \
138                         dump_stack();                           \
139         } while (0)
140 
141 /* call with stream lock held */
142 void __snd_pcm_xrun(struct snd_pcm_substream *substream)
143 {
144         struct snd_pcm_runtime *runtime = substream->runtime;
145 
146         trace_xrun(substream);
147         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
148                 struct timespec64 tstamp;
149 
150                 snd_pcm_gettime(runtime, &tstamp);
151                 runtime->status->tstamp.tv_sec = tstamp.tv_sec;
152                 runtime->status->tstamp.tv_nsec = tstamp.tv_nsec;
153         }
154         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
155         if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
156                 char name[16];
157                 snd_pcm_debug_name(substream, name, sizeof(name));
158                 pcm_warn(substream->pcm, "XRUN: %s\n", name);
159                 dump_stack_on_xrun(substream);
160         }
161 }
162 
163 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
164 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)     \
165         do {                                                            \
166                 trace_hw_ptr_error(substream, reason);  \
167                 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {          \
168                         pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
169                                            (in_interrupt) ? 'Q' : 'P', ##args); \
170                         dump_stack_on_xrun(substream);                  \
171                 }                                                       \
172         } while (0)
173 
174 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
175 
176 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
177 
178 #endif
179 
180 int snd_pcm_update_state(struct snd_pcm_substream *substream,
181                          struct snd_pcm_runtime *runtime)
182 {
183         snd_pcm_uframes_t avail;
184 
185         avail = snd_pcm_avail(substream);
186         if (avail > runtime->avail_max)
187                 runtime->avail_max = avail;
188         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
189                 if (avail >= runtime->buffer_size) {
190                         snd_pcm_drain_done(substream);
191                         return -EPIPE;
192                 }
193         } else {
194                 if (avail >= runtime->stop_threshold) {
195                         __snd_pcm_xrun(substream);
196                         return -EPIPE;
197                 }
198         }
199         if (runtime->twake) {
200                 if (avail >= runtime->twake)
201                         wake_up(&runtime->tsleep);
202         } else if (avail >= runtime->control->avail_min)
203                 wake_up(&runtime->sleep);
204         return 0;
205 }
206 
207 static void update_audio_tstamp(struct snd_pcm_substream *substream,
208                                 struct timespec64 *curr_tstamp,
209                                 struct timespec64 *audio_tstamp)
210 {
211         struct snd_pcm_runtime *runtime = substream->runtime;
212         u64 audio_frames, audio_nsecs;
213         struct timespec64 driver_tstamp;
214 
215         if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
216                 return;
217 
218         if (!(substream->ops->get_time_info) ||
219                 (runtime->audio_tstamp_report.actual_type ==
220                         SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
221 
222                 /*
223                  * provide audio timestamp derived from pointer position
224                  * add delay only if requested
225                  */
226 
227                 audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
228 
229                 if (runtime->audio_tstamp_config.report_delay) {
230                         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
231                                 audio_frames -=  runtime->delay;
232                         else
233                                 audio_frames +=  runtime->delay;
234                 }
235                 audio_nsecs = div_u64(audio_frames * 1000000000LL,
236                                 runtime->rate);
237                 *audio_tstamp = ns_to_timespec64(audio_nsecs);
238         }
239 
240         if (runtime->status->audio_tstamp.tv_sec != audio_tstamp->tv_sec ||
241             runtime->status->audio_tstamp.tv_nsec != audio_tstamp->tv_nsec) {
242                 runtime->status->audio_tstamp.tv_sec = audio_tstamp->tv_sec;
243                 runtime->status->audio_tstamp.tv_nsec = audio_tstamp->tv_nsec;
244                 runtime->status->tstamp.tv_sec = curr_tstamp->tv_sec;
245                 runtime->status->tstamp.tv_nsec = curr_tstamp->tv_nsec;
246         }
247 
248 
249         /*
250          * re-take a driver timestamp to let apps detect if the reference tstamp
251          * read by low-level hardware was provided with a delay
252          */
253         snd_pcm_gettime(substream->runtime, &driver_tstamp);
254         runtime->driver_tstamp = driver_tstamp;
255 }
256 
257 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
258                                   unsigned int in_interrupt)
259 {
260         struct snd_pcm_runtime *runtime = substream->runtime;
261         snd_pcm_uframes_t pos;
262         snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
263         snd_pcm_sframes_t hdelta, delta;
264         unsigned long jdelta;
265         unsigned long curr_jiffies;
266         struct timespec64 curr_tstamp;
267         struct timespec64 audio_tstamp;
268         int crossed_boundary = 0;
269 
270         old_hw_ptr = runtime->status->hw_ptr;
271 
272         /*
273          * group pointer, time and jiffies reads to allow for more
274          * accurate correlations/corrections.
275          * The values are stored at the end of this routine after
276          * corrections for hw_ptr position
277          */
278         pos = substream->ops->pointer(substream);
279         curr_jiffies = jiffies;
280         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
281                 if ((substream->ops->get_time_info) &&
282                         (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
283                         substream->ops->get_time_info(substream, &curr_tstamp,
284                                                 &audio_tstamp,
285                                                 &runtime->audio_tstamp_config,
286                                                 &runtime->audio_tstamp_report);
287 
288                         /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
289                         if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
290                                 snd_pcm_gettime(runtime, &curr_tstamp);
291                 } else
292                         snd_pcm_gettime(runtime, &curr_tstamp);
293         }
294 
295         if (pos == SNDRV_PCM_POS_XRUN) {
296                 __snd_pcm_xrun(substream);
297                 return -EPIPE;
298         }
299         if (pos >= runtime->buffer_size) {
300                 if (printk_ratelimit()) {
301                         char name[16];
302                         snd_pcm_debug_name(substream, name, sizeof(name));
303                         pcm_err(substream->pcm,
304                                 "invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
305                                 name, pos, runtime->buffer_size,
306                                 runtime->period_size);
307                 }
308                 pos = 0;
309         }
310         pos -= pos % runtime->min_align;
311         trace_hwptr(substream, pos, in_interrupt);
312         hw_base = runtime->hw_ptr_base;
313         new_hw_ptr = hw_base + pos;
314         if (in_interrupt) {
315                 /* we know that one period was processed */
316                 /* delta = "expected next hw_ptr" for in_interrupt != 0 */
317                 delta = runtime->hw_ptr_interrupt + runtime->period_size;
318                 if (delta > new_hw_ptr) {
319                         /* check for double acknowledged interrupts */
320                         hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
321                         if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
322                                 hw_base += runtime->buffer_size;
323                                 if (hw_base >= runtime->boundary) {
324                                         hw_base = 0;
325                                         crossed_boundary++;
326                                 }
327                                 new_hw_ptr = hw_base + pos;
328                                 goto __delta;
329                         }
330                 }
331         }
332         /* new_hw_ptr might be lower than old_hw_ptr in case when */
333         /* pointer crosses the end of the ring buffer */
334         if (new_hw_ptr < old_hw_ptr) {
335                 hw_base += runtime->buffer_size;
336                 if (hw_base >= runtime->boundary) {
337                         hw_base = 0;
338                         crossed_boundary++;
339                 }
340                 new_hw_ptr = hw_base + pos;
341         }
342       __delta:
343         delta = new_hw_ptr - old_hw_ptr;
344         if (delta < 0)
345                 delta += runtime->boundary;
346 
347         if (runtime->no_period_wakeup) {
348                 snd_pcm_sframes_t xrun_threshold;
349                 /*
350                  * Without regular period interrupts, we have to check
351                  * the elapsed time to detect xruns.
352                  */
353                 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
354                 if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
355                         goto no_delta_check;
356                 hdelta = jdelta - delta * HZ / runtime->rate;
357                 xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
358                 while (hdelta > xrun_threshold) {
359                         delta += runtime->buffer_size;
360                         hw_base += runtime->buffer_size;
361                         if (hw_base >= runtime->boundary) {
362                                 hw_base = 0;
363                                 crossed_boundary++;
364                         }
365                         new_hw_ptr = hw_base + pos;
366                         hdelta -= runtime->hw_ptr_buffer_jiffies;
367                 }
368                 goto no_delta_check;
369         }
370 
371         /* something must be really wrong */
372         if (delta >= runtime->buffer_size + runtime->period_size) {
373                 hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
374                              "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
375                              substream->stream, (long)pos,
376                              (long)new_hw_ptr, (long)old_hw_ptr);
377                 return 0;
378         }
379 
380         /* Do jiffies check only in xrun_debug mode */
381         if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
382                 goto no_jiffies_check;
383 
384         /* Skip the jiffies check for hardwares with BATCH flag.
385          * Such hardware usually just increases the position at each IRQ,
386          * thus it can't give any strange position.
387          */
388         if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
389                 goto no_jiffies_check;
390         hdelta = delta;
391         if (hdelta < runtime->delay)
392                 goto no_jiffies_check;
393         hdelta -= runtime->delay;
394         jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
395         if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
396                 delta = jdelta /
397                         (((runtime->period_size * HZ) / runtime->rate)
398                                                                 + HZ/100);
399                 /* move new_hw_ptr according jiffies not pos variable */
400                 new_hw_ptr = old_hw_ptr;
401                 hw_base = delta;
402                 /* use loop to avoid checks for delta overflows */
403                 /* the delta value is small or zero in most cases */
404                 while (delta > 0) {
405                         new_hw_ptr += runtime->period_size;
406                         if (new_hw_ptr >= runtime->boundary) {
407                                 new_hw_ptr -= runtime->boundary;
408                                 crossed_boundary--;
409                         }
410                         delta--;
411                 }
412                 /* align hw_base to buffer_size */
413                 hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
414                              "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
415                              (long)pos, (long)hdelta,
416                              (long)runtime->period_size, jdelta,
417                              ((hdelta * HZ) / runtime->rate), hw_base,
418                              (unsigned long)old_hw_ptr,
419                              (unsigned long)new_hw_ptr);
420                 /* reset values to proper state */
421                 delta = 0;
422                 hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
423         }
424  no_jiffies_check:
425         if (delta > runtime->period_size + runtime->period_size / 2) {
426                 hw_ptr_error(substream, in_interrupt,
427                              "Lost interrupts?",
428                              "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
429                              substream->stream, (long)delta,
430                              (long)new_hw_ptr,
431                              (long)old_hw_ptr);
432         }
433 
434  no_delta_check:
435         if (runtime->status->hw_ptr == new_hw_ptr) {
436                 runtime->hw_ptr_jiffies = curr_jiffies;
437                 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
438                 return 0;
439         }
440 
441         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
442             runtime->silence_size > 0)
443                 snd_pcm_playback_silence(substream, new_hw_ptr);
444 
445         if (in_interrupt) {
446                 delta = new_hw_ptr - runtime->hw_ptr_interrupt;
447                 if (delta < 0)
448                         delta += runtime->boundary;
449                 delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
450                 runtime->hw_ptr_interrupt += delta;
451                 if (runtime->hw_ptr_interrupt >= runtime->boundary)
452                         runtime->hw_ptr_interrupt -= runtime->boundary;
453         }
454         runtime->hw_ptr_base = hw_base;
455         runtime->status->hw_ptr = new_hw_ptr;
456         runtime->hw_ptr_jiffies = curr_jiffies;
457         if (crossed_boundary) {
458                 snd_BUG_ON(crossed_boundary != 1);
459                 runtime->hw_ptr_wrap += runtime->boundary;
460         }
461 
462         update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
463 
464         return snd_pcm_update_state(substream, runtime);
465 }
466 
467 /* CAUTION: call it with irq disabled */
468 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
469 {
470         return snd_pcm_update_hw_ptr0(substream, 0);
471 }
472 
473 /**
474  * snd_pcm_set_ops - set the PCM operators
475  * @pcm: the pcm instance
476  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
477  * @ops: the operator table
478  *
479  * Sets the given PCM operators to the pcm instance.
480  */
481 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
482                      const struct snd_pcm_ops *ops)
483 {
484         struct snd_pcm_str *stream = &pcm->streams[direction];
485         struct snd_pcm_substream *substream;
486         
487         for (substream = stream->substream; substream != NULL; substream = substream->next)
488                 substream->ops = ops;
489 }
490 EXPORT_SYMBOL(snd_pcm_set_ops);
491 
492 /**
493  * snd_pcm_set_sync - set the PCM sync id
494  * @substream: the pcm substream
495  *
496  * Sets the PCM sync identifier for the card.
497  */
498 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
499 {
500         struct snd_pcm_runtime *runtime = substream->runtime;
501         
502         runtime->sync.id32[0] = substream->pcm->card->number;
503         runtime->sync.id32[1] = -1;
504         runtime->sync.id32[2] = -1;
505         runtime->sync.id32[3] = -1;
506 }
507 EXPORT_SYMBOL(snd_pcm_set_sync);
508 
509 /*
510  *  Standard ioctl routine
511  */
512 
513 static inline unsigned int div32(unsigned int a, unsigned int b, 
514                                  unsigned int *r)
515 {
516         if (b == 0) {
517                 *r = 0;
518                 return UINT_MAX;
519         }
520         *r = a % b;
521         return a / b;
522 }
523 
524 static inline unsigned int div_down(unsigned int a, unsigned int b)
525 {
526         if (b == 0)
527                 return UINT_MAX;
528         return a / b;
529 }
530 
531 static inline unsigned int div_up(unsigned int a, unsigned int b)
532 {
533         unsigned int r;
534         unsigned int q;
535         if (b == 0)
536                 return UINT_MAX;
537         q = div32(a, b, &r);
538         if (r)
539                 ++q;
540         return q;
541 }
542 
543 static inline unsigned int mul(unsigned int a, unsigned int b)
544 {
545         if (a == 0)
546                 return 0;
547         if (div_down(UINT_MAX, a) < b)
548                 return UINT_MAX;
549         return a * b;
550 }
551 
552 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
553                                     unsigned int c, unsigned int *r)
554 {
555         u_int64_t n = (u_int64_t) a * b;
556         if (c == 0) {
557                 *r = 0;
558                 return UINT_MAX;
559         }
560         n = div_u64_rem(n, c, r);
561         if (n >= UINT_MAX) {
562                 *r = 0;
563                 return UINT_MAX;
564         }
565         return n;
566 }
567 
568 /**
569  * snd_interval_refine - refine the interval value of configurator
570  * @i: the interval value to refine
571  * @v: the interval value to refer to
572  *
573  * Refines the interval value with the reference value.
574  * The interval is changed to the range satisfying both intervals.
575  * The interval status (min, max, integer, etc.) are evaluated.
576  *
577  * Return: Positive if the value is changed, zero if it's not changed, or a
578  * negative error code.
579  */
580 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
581 {
582         int changed = 0;
583         if (snd_BUG_ON(snd_interval_empty(i)))
584                 return -EINVAL;
585         if (i->min < v->min) {
586                 i->min = v->min;
587                 i->openmin = v->openmin;
588                 changed = 1;
589         } else if (i->min == v->min && !i->openmin && v->openmin) {
590                 i->openmin = 1;
591                 changed = 1;
592         }
593         if (i->max > v->max) {
594                 i->max = v->max;
595                 i->openmax = v->openmax;
596                 changed = 1;
597         } else if (i->max == v->max && !i->openmax && v->openmax) {
598                 i->openmax = 1;
599                 changed = 1;
600         }
601         if (!i->integer && v->integer) {
602                 i->integer = 1;
603                 changed = 1;
604         }
605         if (i->integer) {
606                 if (i->openmin) {
607                         i->min++;
608                         i->openmin = 0;
609                 }
610                 if (i->openmax) {
611                         i->max--;
612                         i->openmax = 0;
613                 }
614         } else if (!i->openmin && !i->openmax && i->min == i->max)
615                 i->integer = 1;
616         if (snd_interval_checkempty(i)) {
617                 snd_interval_none(i);
618                 return -EINVAL;
619         }
620         return changed;
621 }
622 EXPORT_SYMBOL(snd_interval_refine);
623 
624 static int snd_interval_refine_first(struct snd_interval *i)
625 {
626         const unsigned int last_max = i->max;
627 
628         if (snd_BUG_ON(snd_interval_empty(i)))
629                 return -EINVAL;
630         if (snd_interval_single(i))
631                 return 0;
632         i->max = i->min;
633         if (i->openmin)
634                 i->max++;
635         /* only exclude max value if also excluded before refine */
636         i->openmax = (i->openmax && i->max >= last_max);
637         return 1;
638 }
639 
640 static int snd_interval_refine_last(struct snd_interval *i)
641 {
642         const unsigned int last_min = i->min;
643 
644         if (snd_BUG_ON(snd_interval_empty(i)))
645                 return -EINVAL;
646         if (snd_interval_single(i))
647                 return 0;
648         i->min = i->max;
649         if (i->openmax)
650                 i->min--;
651         /* only exclude min value if also excluded before refine */
652         i->openmin = (i->openmin && i->min <= last_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_array(constrs->rules, new_rules,
1133                                      sizeof(*c), 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 const 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 (snd_BUG_ON(!substream))
1797                 return;
1798 
1799         snd_pcm_stream_lock_irqsave(substream, flags);
1800         if (PCM_RUNTIME_CHECK(substream))
1801                 goto _unlock;
1802         runtime = substream->runtime;
1803 
1804         if (!snd_pcm_running(substream) ||
1805             snd_pcm_update_hw_ptr0(substream, 1) < 0)
1806                 goto _end;
1807 
1808 #ifdef CONFIG_SND_PCM_TIMER
1809         if (substream->timer_running)
1810                 snd_timer_interrupt(substream->timer, 1);
1811 #endif
1812  _end:
1813         kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1814  _unlock:
1815         snd_pcm_stream_unlock_irqrestore(substream, flags);
1816 }
1817 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1818 
1819 /*
1820  * Wait until avail_min data becomes available
1821  * Returns a negative error code if any error occurs during operation.
1822  * The available space is stored on availp.  When err = 0 and avail = 0
1823  * on the capture stream, it indicates the stream is in DRAINING state.
1824  */
1825 static int wait_for_avail(struct snd_pcm_substream *substream,
1826                               snd_pcm_uframes_t *availp)
1827 {
1828         struct snd_pcm_runtime *runtime = substream->runtime;
1829         int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1830         wait_queue_entry_t wait;
1831         int err = 0;
1832         snd_pcm_uframes_t avail = 0;
1833         long wait_time, tout;
1834 
1835         init_waitqueue_entry(&wait, current);
1836         set_current_state(TASK_INTERRUPTIBLE);
1837         add_wait_queue(&runtime->tsleep, &wait);
1838 
1839         if (runtime->no_period_wakeup)
1840                 wait_time = MAX_SCHEDULE_TIMEOUT;
1841         else {
1842                 /* use wait time from substream if available */
1843                 if (substream->wait_time) {
1844                         wait_time = substream->wait_time;
1845                 } else {
1846                         wait_time = 10;
1847 
1848                         if (runtime->rate) {
1849                                 long t = runtime->period_size * 2 /
1850                                          runtime->rate;
1851                                 wait_time = max(t, wait_time);
1852                         }
1853                         wait_time = msecs_to_jiffies(wait_time * 1000);
1854                 }
1855         }
1856 
1857         for (;;) {
1858                 if (signal_pending(current)) {
1859                         err = -ERESTARTSYS;
1860                         break;
1861                 }
1862 
1863                 /*
1864                  * We need to check if space became available already
1865                  * (and thus the wakeup happened already) first to close
1866                  * the race of space already having become available.
1867                  * This check must happen after been added to the waitqueue
1868                  * and having current state be INTERRUPTIBLE.
1869                  */
1870                 avail = snd_pcm_avail(substream);
1871                 if (avail >= runtime->twake)
1872                         break;
1873                 snd_pcm_stream_unlock_irq(substream);
1874 
1875                 tout = schedule_timeout(wait_time);
1876 
1877                 snd_pcm_stream_lock_irq(substream);
1878                 set_current_state(TASK_INTERRUPTIBLE);
1879                 switch (runtime->status->state) {
1880                 case SNDRV_PCM_STATE_SUSPENDED:
1881                         err = -ESTRPIPE;
1882                         goto _endloop;
1883                 case SNDRV_PCM_STATE_XRUN:
1884                         err = -EPIPE;
1885                         goto _endloop;
1886                 case SNDRV_PCM_STATE_DRAINING:
1887                         if (is_playback)
1888                                 err = -EPIPE;
1889                         else 
1890                                 avail = 0; /* indicate draining */
1891                         goto _endloop;
1892                 case SNDRV_PCM_STATE_OPEN:
1893                 case SNDRV_PCM_STATE_SETUP:
1894                 case SNDRV_PCM_STATE_DISCONNECTED:
1895                         err = -EBADFD;
1896                         goto _endloop;
1897                 case SNDRV_PCM_STATE_PAUSED:
1898                         continue;
1899                 }
1900                 if (!tout) {
1901                         pcm_dbg(substream->pcm,
1902                                 "%s write error (DMA or IRQ trouble?)\n",
1903                                 is_playback ? "playback" : "capture");
1904                         err = -EIO;
1905                         break;
1906                 }
1907         }
1908  _endloop:
1909         set_current_state(TASK_RUNNING);
1910         remove_wait_queue(&runtime->tsleep, &wait);
1911         *availp = avail;
1912         return err;
1913 }
1914         
1915 typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
1916                               int channel, unsigned long hwoff,
1917                               void *buf, unsigned long bytes);
1918 
1919 typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
1920                           snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
1921 
1922 /* calculate the target DMA-buffer position to be written/read */
1923 static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
1924                            int channel, unsigned long hwoff)
1925 {
1926         return runtime->dma_area + hwoff +
1927                 channel * (runtime->dma_bytes / runtime->channels);
1928 }
1929 
1930 /* default copy_user ops for write; used for both interleaved and non- modes */
1931 static int default_write_copy(struct snd_pcm_substream *substream,
1932                               int channel, unsigned long hwoff,
1933                               void *buf, unsigned long bytes)
1934 {
1935         if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
1936                            (void __user *)buf, bytes))
1937                 return -EFAULT;
1938         return 0;
1939 }
1940 
1941 /* default copy_kernel ops for write */
1942 static int default_write_copy_kernel(struct snd_pcm_substream *substream,
1943                                      int channel, unsigned long hwoff,
1944                                      void *buf, unsigned long bytes)
1945 {
1946         memcpy(get_dma_ptr(substream->runtime, channel, hwoff), buf, bytes);
1947         return 0;
1948 }
1949 
1950 /* fill silence instead of copy data; called as a transfer helper
1951  * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
1952  * a NULL buffer is passed
1953  */
1954 static int fill_silence(struct snd_pcm_substream *substream, int channel,
1955                         unsigned long hwoff, void *buf, unsigned long bytes)
1956 {
1957         struct snd_pcm_runtime *runtime = substream->runtime;
1958 
1959         if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
1960                 return 0;
1961         if (substream->ops->fill_silence)
1962                 return substream->ops->fill_silence(substream, channel,
1963                                                     hwoff, bytes);
1964 
1965         snd_pcm_format_set_silence(runtime->format,
1966                                    get_dma_ptr(runtime, channel, hwoff),
1967                                    bytes_to_samples(runtime, bytes));
1968         return 0;
1969 }
1970 
1971 /* default copy_user ops for read; used for both interleaved and non- modes */
1972 static int default_read_copy(struct snd_pcm_substream *substream,
1973                              int channel, unsigned long hwoff,
1974                              void *buf, unsigned long bytes)
1975 {
1976         if (copy_to_user((void __user *)buf,
1977                          get_dma_ptr(substream->runtime, channel, hwoff),
1978                          bytes))
1979                 return -EFAULT;
1980         return 0;
1981 }
1982 
1983 /* default copy_kernel ops for read */
1984 static int default_read_copy_kernel(struct snd_pcm_substream *substream,
1985                                     int channel, unsigned long hwoff,
1986                                     void *buf, unsigned long bytes)
1987 {
1988         memcpy(buf, get_dma_ptr(substream->runtime, channel, hwoff), bytes);
1989         return 0;
1990 }
1991 
1992 /* call transfer function with the converted pointers and sizes;
1993  * for interleaved mode, it's one shot for all samples
1994  */
1995 static int interleaved_copy(struct snd_pcm_substream *substream,
1996                             snd_pcm_uframes_t hwoff, void *data,
1997                             snd_pcm_uframes_t off,
1998                             snd_pcm_uframes_t frames,
1999                             pcm_transfer_f transfer)
2000 {
2001         struct snd_pcm_runtime *runtime = substream->runtime;
2002 
2003         /* convert to bytes */
2004         hwoff = frames_to_bytes(runtime, hwoff);
2005         off = frames_to_bytes(runtime, off);
2006         frames = frames_to_bytes(runtime, frames);
2007         return transfer(substream, 0, hwoff, data + off, frames);
2008 }
2009 
2010 /* call transfer function with the converted pointers and sizes for each
2011  * non-interleaved channel; when buffer is NULL, silencing instead of copying
2012  */
2013 static int noninterleaved_copy(struct snd_pcm_substream *substream,
2014                                snd_pcm_uframes_t hwoff, void *data,
2015                                snd_pcm_uframes_t off,
2016                                snd_pcm_uframes_t frames,
2017                                pcm_transfer_f transfer)
2018 {
2019         struct snd_pcm_runtime *runtime = substream->runtime;
2020         int channels = runtime->channels;
2021         void **bufs = data;
2022         int c, err;
2023 
2024         /* convert to bytes; note that it's not frames_to_bytes() here.
2025          * in non-interleaved mode, we copy for each channel, thus
2026          * each copy is n_samples bytes x channels = whole frames.
2027          */
2028         off = samples_to_bytes(runtime, off);
2029         frames = samples_to_bytes(runtime, frames);
2030         hwoff = samples_to_bytes(runtime, hwoff);
2031         for (c = 0; c < channels; ++c, ++bufs) {
2032                 if (!data || !*bufs)
2033                         err = fill_silence(substream, c, hwoff, NULL, frames);
2034                 else
2035                         err = transfer(substream, c, hwoff, *bufs + off,
2036                                        frames);
2037                 if (err < 0)
2038                         return err;
2039         }
2040         return 0;
2041 }
2042 
2043 /* fill silence on the given buffer position;
2044  * called from snd_pcm_playback_silence()
2045  */
2046 static int fill_silence_frames(struct snd_pcm_substream *substream,
2047                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
2048 {
2049         if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
2050             substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
2051                 return interleaved_copy(substream, off, NULL, 0, frames,
2052                                         fill_silence);
2053         else
2054                 return noninterleaved_copy(substream, off, NULL, 0, frames,
2055                                            fill_silence);
2056 }
2057 
2058 /* sanity-check for read/write methods */
2059 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2060 {
2061         struct snd_pcm_runtime *runtime;
2062         if (PCM_RUNTIME_CHECK(substream))
2063                 return -ENXIO;
2064         runtime = substream->runtime;
2065         if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area))
2066                 return -EINVAL;
2067         if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2068                 return -EBADFD;
2069         return 0;
2070 }
2071 
2072 static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
2073 {
2074         switch (runtime->status->state) {
2075         case SNDRV_PCM_STATE_PREPARED:
2076         case SNDRV_PCM_STATE_RUNNING:
2077         case SNDRV_PCM_STATE_PAUSED:
2078                 return 0;
2079         case SNDRV_PCM_STATE_XRUN:
2080                 return -EPIPE;
2081         case SNDRV_PCM_STATE_SUSPENDED:
2082                 return -ESTRPIPE;
2083         default:
2084                 return -EBADFD;
2085         }
2086 }
2087 
2088 /* update to the given appl_ptr and call ack callback if needed;
2089  * when an error is returned, take back to the original value
2090  */
2091 int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
2092                            snd_pcm_uframes_t appl_ptr)
2093 {
2094         struct snd_pcm_runtime *runtime = substream->runtime;
2095         snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
2096         int ret;
2097 
2098         if (old_appl_ptr == appl_ptr)
2099                 return 0;
2100 
2101         runtime->control->appl_ptr = appl_ptr;
2102         if (substream->ops->ack) {
2103                 ret = substream->ops->ack(substream);
2104                 if (ret < 0) {
2105                         runtime->control->appl_ptr = old_appl_ptr;
2106                         return ret;
2107                 }
2108         }
2109 
2110         trace_applptr(substream, old_appl_ptr, appl_ptr);
2111 
2112         return 0;
2113 }
2114 
2115 /* the common loop for read/write data */
2116 snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
2117                                      void *data, bool interleaved,
2118                                      snd_pcm_uframes_t size, bool in_kernel)
2119 {
2120         struct snd_pcm_runtime *runtime = substream->runtime;
2121         snd_pcm_uframes_t xfer = 0;
2122         snd_pcm_uframes_t offset = 0;
2123         snd_pcm_uframes_t avail;
2124         pcm_copy_f writer;
2125         pcm_transfer_f transfer;
2126         bool nonblock;
2127         bool is_playback;
2128         int err;
2129 
2130         err = pcm_sanity_check(substream);
2131         if (err < 0)
2132                 return err;
2133 
2134         is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
2135         if (interleaved) {
2136                 if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2137                     runtime->channels > 1)
2138                         return -EINVAL;
2139                 writer = interleaved_copy;
2140         } else {
2141                 if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2142                         return -EINVAL;
2143                 writer = noninterleaved_copy;
2144         }
2145 
2146         if (!data) {
2147                 if (is_playback)
2148                         transfer = fill_silence;
2149                 else
2150                         return -EINVAL;
2151         } else if (in_kernel) {
2152                 if (substream->ops->copy_kernel)
2153                         transfer = substream->ops->copy_kernel;
2154                 else
2155                         transfer = is_playback ?
2156                                 default_write_copy_kernel : default_read_copy_kernel;
2157         } else {
2158                 if (substream->ops->copy_user)
2159                         transfer = (pcm_transfer_f)substream->ops->copy_user;
2160                 else
2161                         transfer = is_playback ?
2162                                 default_write_copy : default_read_copy;
2163         }
2164 
2165         if (size == 0)
2166                 return 0;
2167 
2168         nonblock = !!(substream->f_flags & O_NONBLOCK);
2169 
2170         snd_pcm_stream_lock_irq(substream);
2171         err = pcm_accessible_state(runtime);
2172         if (err < 0)
2173                 goto _end_unlock;
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 
2179         /*
2180          * If size < start_threshold, wait indefinitely. Another
2181          * thread may start capture
2182          */
2183         if (!is_playback &&
2184             runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2185             size >= runtime->start_threshold) {
2186                 err = snd_pcm_start(substream);
2187                 if (err < 0)
2188                         goto _end_unlock;
2189         }
2190 
2191         avail = snd_pcm_avail(substream);
2192 
2193         while (size > 0) {
2194                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2195                 snd_pcm_uframes_t cont;
2196                 if (!avail) {
2197                         if (!is_playback &&
2198                             runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
2199                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2200                                 goto _end_unlock;
2201                         }
2202                         if (nonblock) {
2203                                 err = -EAGAIN;
2204                                 goto _end_unlock;
2205                         }
2206                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2207                                         runtime->control->avail_min ? : 1);
2208                         err = wait_for_avail(substream, &avail);
2209                         if (err < 0)
2210                                 goto _end_unlock;
2211                         if (!avail)
2212                                 continue; /* draining */
2213                 }
2214                 frames = size > avail ? avail : size;
2215                 appl_ptr = READ_ONCE(runtime->control->appl_ptr);
2216                 appl_ofs = appl_ptr % runtime->buffer_size;
2217                 cont = runtime->buffer_size - appl_ofs;
2218                 if (frames > cont)
2219                         frames = cont;
2220                 if (snd_BUG_ON(!frames)) {
2221                         err = -EINVAL;
2222                         goto _end_unlock;
2223                 }
2224                 snd_pcm_stream_unlock_irq(substream);
2225                 err = writer(substream, appl_ofs, data, offset, frames,
2226                              transfer);
2227                 snd_pcm_stream_lock_irq(substream);
2228                 if (err < 0)
2229                         goto _end_unlock;
2230                 err = pcm_accessible_state(runtime);
2231                 if (err < 0)
2232                         goto _end_unlock;
2233                 appl_ptr += frames;
2234                 if (appl_ptr >= runtime->boundary)
2235                         appl_ptr -= runtime->boundary;
2236                 err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
2237                 if (err < 0)
2238                         goto _end_unlock;
2239 
2240                 offset += frames;
2241                 size -= frames;
2242                 xfer += frames;
2243                 avail -= frames;
2244                 if (is_playback &&
2245                     runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2246                     snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2247                         err = snd_pcm_start(substream);
2248                         if (err < 0)
2249                                 goto _end_unlock;
2250                 }
2251         }
2252  _end_unlock:
2253         runtime->twake = 0;
2254         if (xfer > 0 && err >= 0)
2255                 snd_pcm_update_state(substream, runtime);
2256         snd_pcm_stream_unlock_irq(substream);
2257         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2258 }
2259 EXPORT_SYMBOL(__snd_pcm_lib_xfer);
2260 
2261 /*
2262  * standard channel mapping helpers
2263  */
2264 
2265 /* default channel maps for multi-channel playbacks, up to 8 channels */
2266 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2267         { .channels = 1,
2268           .map = { SNDRV_CHMAP_MONO } },
2269         { .channels = 2,
2270           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2271         { .channels = 4,
2272           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2273                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2274         { .channels = 6,
2275           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2276                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2277                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2278         { .channels = 8,
2279           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2280                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2281                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2282                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2283         { }
2284 };
2285 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2286 
2287 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2288 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2289         { .channels = 1,
2290           .map = { SNDRV_CHMAP_MONO } },
2291         { .channels = 2,
2292           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2293         { .channels = 4,
2294           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2295                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2296         { .channels = 6,
2297           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2298                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2299                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2300         { .channels = 8,
2301           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2302                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2303                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2304                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2305         { }
2306 };
2307 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2308 
2309 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2310 {
2311         if (ch > info->max_channels)
2312                 return false;
2313         return !info->channel_mask || (info->channel_mask & (1U << ch));
2314 }
2315 
2316 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2317                               struct snd_ctl_elem_info *uinfo)
2318 {
2319         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2320 
2321         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2322         uinfo->count = info->max_channels;
2323         uinfo->value.integer.min = 0;
2324         uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2325         return 0;
2326 }
2327 
2328 /* get callback for channel map ctl element
2329  * stores the channel position firstly matching with the current channels
2330  */
2331 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2332                              struct snd_ctl_elem_value *ucontrol)
2333 {
2334         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2335         unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2336         struct snd_pcm_substream *substream;
2337         const struct snd_pcm_chmap_elem *map;
2338 
2339         if (!info->chmap)
2340                 return -EINVAL;
2341         substream = snd_pcm_chmap_substream(info, idx);
2342         if (!substream)
2343                 return -ENODEV;
2344         memset(ucontrol->value.integer.value, 0,
2345                sizeof(long) * info->max_channels);
2346         if (!substream->runtime)
2347                 return 0; /* no channels set */
2348         for (map = info->chmap; map->channels; map++) {
2349                 int i;
2350                 if (map->channels == substream->runtime->channels &&
2351                     valid_chmap_channels(info, map->channels)) {
2352                         for (i = 0; i < map->channels; i++)
2353                                 ucontrol->value.integer.value[i] = map->map[i];
2354                         return 0;
2355                 }
2356         }
2357         return -EINVAL;
2358 }
2359 
2360 /* tlv callback for channel map ctl element
2361  * expands the pre-defined channel maps in a form of TLV
2362  */
2363 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2364                              unsigned int size, unsigned int __user *tlv)
2365 {
2366         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2367         const struct snd_pcm_chmap_elem *map;
2368         unsigned int __user *dst;
2369         int c, count = 0;
2370 
2371         if (!info->chmap)
2372                 return -EINVAL;
2373         if (size < 8)
2374                 return -ENOMEM;
2375         if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2376                 return -EFAULT;
2377         size -= 8;
2378         dst = tlv + 2;
2379         for (map = info->chmap; map->channels; map++) {
2380                 int chs_bytes = map->channels * 4;
2381                 if (!valid_chmap_channels(info, map->channels))
2382                         continue;
2383                 if (size < 8)
2384                         return -ENOMEM;
2385                 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2386                     put_user(chs_bytes, dst + 1))
2387                         return -EFAULT;
2388                 dst += 2;
2389                 size -= 8;
2390                 count += 8;
2391                 if (size < chs_bytes)
2392                         return -ENOMEM;
2393                 size -= chs_bytes;
2394                 count += chs_bytes;
2395                 for (c = 0; c < map->channels; c++) {
2396                         if (put_user(map->map[c], dst))
2397                                 return -EFAULT;
2398                         dst++;
2399                 }
2400         }
2401         if (put_user(count, tlv + 1))
2402                 return -EFAULT;
2403         return 0;
2404 }
2405 
2406 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2407 {
2408         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2409         info->pcm->streams[info->stream].chmap_kctl = NULL;
2410         kfree(info);
2411 }
2412 
2413 /**
2414  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2415  * @pcm: the assigned PCM instance
2416  * @stream: stream direction
2417  * @chmap: channel map elements (for query)
2418  * @max_channels: the max number of channels for the stream
2419  * @private_value: the value passed to each kcontrol's private_value field
2420  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2421  *
2422  * Create channel-mapping control elements assigned to the given PCM stream(s).
2423  * Return: Zero if successful, or a negative error value.
2424  */
2425 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2426                            const struct snd_pcm_chmap_elem *chmap,
2427                            int max_channels,
2428                            unsigned long private_value,
2429                            struct snd_pcm_chmap **info_ret)
2430 {
2431         struct snd_pcm_chmap *info;
2432         struct snd_kcontrol_new knew = {
2433                 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
2434                 .access = SNDRV_CTL_ELEM_ACCESS_READ |
2435                         SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2436                         SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2437                 .info = pcm_chmap_ctl_info,
2438                 .get = pcm_chmap_ctl_get,
2439                 .tlv.c = pcm_chmap_ctl_tlv,
2440         };
2441         int err;
2442 
2443         if (WARN_ON(pcm->streams[stream].chmap_kctl))
2444                 return -EBUSY;
2445         info = kzalloc(sizeof(*info), GFP_KERNEL);
2446         if (!info)
2447                 return -ENOMEM;
2448         info->pcm = pcm;
2449         info->stream = stream;
2450         info->chmap = chmap;
2451         info->max_channels = max_channels;
2452         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2453                 knew.name = "Playback Channel Map";
2454         else
2455                 knew.name = "Capture Channel Map";
2456         knew.device = pcm->device;
2457         knew.count = pcm->streams[stream].substream_count;
2458         knew.private_value = private_value;
2459         info->kctl = snd_ctl_new1(&knew, info);
2460         if (!info->kctl) {
2461                 kfree(info);
2462                 return -ENOMEM;
2463         }
2464         info->kctl->private_free = pcm_chmap_ctl_private_free;
2465         err = snd_ctl_add(pcm->card, info->kctl);
2466         if (err < 0)
2467                 return err;
2468         pcm->streams[stream].chmap_kctl = info->kctl;
2469         if (info_ret)
2470                 *info_ret = info;
2471         return 0;
2472 }
2473 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2474 

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