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

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