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

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

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