1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Digital Audio (PCM) abstract layer
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 * Abramo Bagnara <abramo@alsa-project.org>
8 #include <linux/slab.h>
9 #include <linux/sched/signal.h>
10 #include <linux/time.h>
11 #include <linux/math64.h>
12 #include <linux/export.h>
13 #include <sound/core.h>
14 #include <sound/control.h>
15 #include <sound/tlv.h>
16 #include <sound/info.h>
17 #include <sound/pcm.h>
18 #include <sound/pcm_params.h>
19 #include <sound/timer.h>
21 #include "pcm_local.h"
23 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
24 #define CREATE_TRACE_POINTS
25 #include "pcm_trace.h"
27 #define trace_hwptr(substream, pos, in_interrupt)
28 #define trace_xrun(substream)
29 #define trace_hw_ptr_error(substream, reason)
30 #define trace_applptr(substream, prev, curr)
33 static int fill_silence_frames(struct snd_pcm_substream *substream,
34 snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
37 static inline void update_silence_vars(struct snd_pcm_runtime *runtime,
38 snd_pcm_uframes_t ptr,
39 snd_pcm_uframes_t new_ptr)
41 snd_pcm_sframes_t delta;
43 delta = new_ptr - ptr;
47 delta += runtime->boundary;
48 if ((snd_pcm_uframes_t)delta < runtime->silence_filled)
49 runtime->silence_filled -= delta;
51 runtime->silence_filled = 0;
52 runtime->silence_start = new_ptr;
56 * fill ring buffer with silence
57 * runtime->silence_start: starting pointer to silence area
58 * runtime->silence_filled: size filled with silence
59 * runtime->silence_threshold: threshold from application
60 * runtime->silence_size: maximal size from application
62 * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
64 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
66 struct snd_pcm_runtime *runtime = substream->runtime;
67 snd_pcm_uframes_t frames, ofs, transfer;
70 if (runtime->silence_size < runtime->boundary) {
71 snd_pcm_sframes_t noise_dist;
72 snd_pcm_uframes_t appl_ptr = READ_ONCE(runtime->control->appl_ptr);
73 update_silence_vars(runtime, runtime->silence_start, appl_ptr);
74 /* initialization outside pointer updates */
75 if (new_hw_ptr == ULONG_MAX)
76 new_hw_ptr = runtime->status->hw_ptr;
77 /* get hw_avail with the boundary crossing */
78 noise_dist = appl_ptr - new_hw_ptr;
80 noise_dist += runtime->boundary;
81 /* total noise distance */
82 noise_dist += runtime->silence_filled;
83 if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
85 frames = runtime->silence_threshold - noise_dist;
86 if (frames > runtime->silence_size)
87 frames = runtime->silence_size;
90 * This filling mode aims at free-running mode (used for example by dmix),
91 * which doesn't update the application pointer.
93 snd_pcm_uframes_t hw_ptr = runtime->status->hw_ptr;
94 if (new_hw_ptr == ULONG_MAX) {
96 * Initialization, fill the whole unused buffer with silence.
98 * Usually, this is entered while stopped, before data is queued,
99 * so both pointers are expected to be zero.
101 snd_pcm_sframes_t avail = runtime->control->appl_ptr - hw_ptr;
103 avail += runtime->boundary;
105 * In free-running mode, appl_ptr will be zero even while running,
106 * so we end up with a huge number. There is no useful way to
107 * handle this, so we just clear the whole buffer.
109 runtime->silence_filled = avail > runtime->buffer_size ? 0 : avail;
110 runtime->silence_start = hw_ptr;
112 /* Silence the just played area immediately */
113 update_silence_vars(runtime, hw_ptr, new_hw_ptr);
116 * In this mode, silence_filled actually includes the valid
117 * sample data from the user.
119 frames = runtime->buffer_size - runtime->silence_filled;
121 if (snd_BUG_ON(frames > runtime->buffer_size))
125 ofs = (runtime->silence_start + runtime->silence_filled) % runtime->buffer_size;
127 transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
128 err = fill_silence_frames(substream, ofs, transfer);
130 runtime->silence_filled += transfer;
133 } while (frames > 0);
134 snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
137 #ifdef CONFIG_SND_DEBUG
138 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
139 char *name, size_t len)
141 snprintf(name, len, "pcmC%dD%d%c:%d",
142 substream->pcm->card->number,
143 substream->pcm->device,
144 substream->stream ? 'c' : 'p',
147 EXPORT_SYMBOL(snd_pcm_debug_name);
150 #define XRUN_DEBUG_BASIC (1<<0)
151 #define XRUN_DEBUG_STACK (1<<1) /* dump also stack */
152 #define XRUN_DEBUG_JIFFIESCHECK (1<<2) /* do jiffies check */
154 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
156 #define xrun_debug(substream, mask) \
157 ((substream)->pstr->xrun_debug & (mask))
159 #define xrun_debug(substream, mask) 0
162 #define dump_stack_on_xrun(substream) do { \
163 if (xrun_debug(substream, XRUN_DEBUG_STACK)) \
167 /* call with stream lock held */
168 void __snd_pcm_xrun(struct snd_pcm_substream *substream)
170 struct snd_pcm_runtime *runtime = substream->runtime;
172 trace_xrun(substream);
173 if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
174 struct timespec64 tstamp;
176 snd_pcm_gettime(runtime, &tstamp);
177 runtime->status->tstamp.tv_sec = tstamp.tv_sec;
178 runtime->status->tstamp.tv_nsec = tstamp.tv_nsec;
180 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
181 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
183 snd_pcm_debug_name(substream, name, sizeof(name));
184 pcm_warn(substream->pcm, "XRUN: %s\n", name);
185 dump_stack_on_xrun(substream);
189 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
190 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...) \
192 trace_hw_ptr_error(substream, reason); \
193 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) { \
194 pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
195 (in_interrupt) ? 'Q' : 'P', ##args); \
196 dump_stack_on_xrun(substream); \
200 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
202 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
206 int snd_pcm_update_state(struct snd_pcm_substream *substream,
207 struct snd_pcm_runtime *runtime)
209 snd_pcm_uframes_t avail;
211 avail = snd_pcm_avail(substream);
212 if (avail > runtime->avail_max)
213 runtime->avail_max = avail;
214 if (runtime->state == SNDRV_PCM_STATE_DRAINING) {
215 if (avail >= runtime->buffer_size) {
216 snd_pcm_drain_done(substream);
220 if (avail >= runtime->stop_threshold) {
221 __snd_pcm_xrun(substream);
225 if (runtime->twake) {
226 if (avail >= runtime->twake)
227 wake_up(&runtime->tsleep);
228 } else if (avail >= runtime->control->avail_min)
229 wake_up(&runtime->sleep);
233 static void update_audio_tstamp(struct snd_pcm_substream *substream,
234 struct timespec64 *curr_tstamp,
235 struct timespec64 *audio_tstamp)
237 struct snd_pcm_runtime *runtime = substream->runtime;
238 u64 audio_frames, audio_nsecs;
239 struct timespec64 driver_tstamp;
241 if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
244 if (!(substream->ops->get_time_info) ||
245 (runtime->audio_tstamp_report.actual_type ==
246 SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
249 * provide audio timestamp derived from pointer position
250 * add delay only if requested
253 audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
255 if (runtime->audio_tstamp_config.report_delay) {
256 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
257 audio_frames -= runtime->delay;
259 audio_frames += runtime->delay;
261 audio_nsecs = div_u64(audio_frames * 1000000000LL,
263 *audio_tstamp = ns_to_timespec64(audio_nsecs);
266 if (runtime->status->audio_tstamp.tv_sec != audio_tstamp->tv_sec ||
267 runtime->status->audio_tstamp.tv_nsec != audio_tstamp->tv_nsec) {
268 runtime->status->audio_tstamp.tv_sec = audio_tstamp->tv_sec;
269 runtime->status->audio_tstamp.tv_nsec = audio_tstamp->tv_nsec;
270 runtime->status->tstamp.tv_sec = curr_tstamp->tv_sec;
271 runtime->status->tstamp.tv_nsec = curr_tstamp->tv_nsec;
276 * re-take a driver timestamp to let apps detect if the reference tstamp
277 * read by low-level hardware was provided with a delay
279 snd_pcm_gettime(substream->runtime, &driver_tstamp);
280 runtime->driver_tstamp = driver_tstamp;
283 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
284 unsigned int in_interrupt)
286 struct snd_pcm_runtime *runtime = substream->runtime;
287 snd_pcm_uframes_t pos;
288 snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
289 snd_pcm_sframes_t hdelta, delta;
290 unsigned long jdelta;
291 unsigned long curr_jiffies;
292 struct timespec64 curr_tstamp;
293 struct timespec64 audio_tstamp;
294 int crossed_boundary = 0;
296 old_hw_ptr = runtime->status->hw_ptr;
299 * group pointer, time and jiffies reads to allow for more
300 * accurate correlations/corrections.
301 * The values are stored at the end of this routine after
302 * corrections for hw_ptr position
304 pos = substream->ops->pointer(substream);
305 curr_jiffies = jiffies;
306 if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
307 if ((substream->ops->get_time_info) &&
308 (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
309 substream->ops->get_time_info(substream, &curr_tstamp,
311 &runtime->audio_tstamp_config,
312 &runtime->audio_tstamp_report);
314 /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
315 if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
316 snd_pcm_gettime(runtime, &curr_tstamp);
318 snd_pcm_gettime(runtime, &curr_tstamp);
321 if (pos == SNDRV_PCM_POS_XRUN) {
322 __snd_pcm_xrun(substream);
325 if (pos >= runtime->buffer_size) {
326 if (printk_ratelimit()) {
328 snd_pcm_debug_name(substream, name, sizeof(name));
329 pcm_err(substream->pcm,
330 "invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
331 name, pos, runtime->buffer_size,
332 runtime->period_size);
336 pos -= pos % runtime->min_align;
337 trace_hwptr(substream, pos, in_interrupt);
338 hw_base = runtime->hw_ptr_base;
339 new_hw_ptr = hw_base + pos;
341 /* we know that one period was processed */
342 /* delta = "expected next hw_ptr" for in_interrupt != 0 */
343 delta = runtime->hw_ptr_interrupt + runtime->period_size;
344 if (delta > new_hw_ptr) {
345 /* check for double acknowledged interrupts */
346 hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
347 if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
348 hw_base += runtime->buffer_size;
349 if (hw_base >= runtime->boundary) {
353 new_hw_ptr = hw_base + pos;
358 /* new_hw_ptr might be lower than old_hw_ptr in case when */
359 /* pointer crosses the end of the ring buffer */
360 if (new_hw_ptr < old_hw_ptr) {
361 hw_base += runtime->buffer_size;
362 if (hw_base >= runtime->boundary) {
366 new_hw_ptr = hw_base + pos;
369 delta = new_hw_ptr - old_hw_ptr;
371 delta += runtime->boundary;
373 if (runtime->no_period_wakeup) {
374 snd_pcm_sframes_t xrun_threshold;
376 * Without regular period interrupts, we have to check
377 * the elapsed time to detect xruns.
379 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
380 if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
382 hdelta = jdelta - delta * HZ / runtime->rate;
383 xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
384 while (hdelta > xrun_threshold) {
385 delta += runtime->buffer_size;
386 hw_base += runtime->buffer_size;
387 if (hw_base >= runtime->boundary) {
391 new_hw_ptr = hw_base + pos;
392 hdelta -= runtime->hw_ptr_buffer_jiffies;
397 /* something must be really wrong */
398 if (delta >= runtime->buffer_size + runtime->period_size) {
399 hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
400 "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
401 substream->stream, (long)pos,
402 (long)new_hw_ptr, (long)old_hw_ptr);
406 /* Do jiffies check only in xrun_debug mode */
407 if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
408 goto no_jiffies_check;
410 /* Skip the jiffies check for hardwares with BATCH flag.
411 * Such hardware usually just increases the position at each IRQ,
412 * thus it can't give any strange position.
414 if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
415 goto no_jiffies_check;
417 if (hdelta < runtime->delay)
418 goto no_jiffies_check;
419 hdelta -= runtime->delay;
420 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
421 if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
423 (((runtime->period_size * HZ) / runtime->rate)
425 /* move new_hw_ptr according jiffies not pos variable */
426 new_hw_ptr = old_hw_ptr;
428 /* use loop to avoid checks for delta overflows */
429 /* the delta value is small or zero in most cases */
431 new_hw_ptr += runtime->period_size;
432 if (new_hw_ptr >= runtime->boundary) {
433 new_hw_ptr -= runtime->boundary;
438 /* align hw_base to buffer_size */
439 hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
440 "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
441 (long)pos, (long)hdelta,
442 (long)runtime->period_size, jdelta,
443 ((hdelta * HZ) / runtime->rate), hw_base,
444 (unsigned long)old_hw_ptr,
445 (unsigned long)new_hw_ptr);
446 /* reset values to proper state */
448 hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
451 if (delta > runtime->period_size + runtime->period_size / 2) {
452 hw_ptr_error(substream, in_interrupt,
454 "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
455 substream->stream, (long)delta,
461 if (runtime->status->hw_ptr == new_hw_ptr) {
462 runtime->hw_ptr_jiffies = curr_jiffies;
463 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
467 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
468 runtime->silence_size > 0)
469 snd_pcm_playback_silence(substream, new_hw_ptr);
472 delta = new_hw_ptr - runtime->hw_ptr_interrupt;
474 delta += runtime->boundary;
475 delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
476 runtime->hw_ptr_interrupt += delta;
477 if (runtime->hw_ptr_interrupt >= runtime->boundary)
478 runtime->hw_ptr_interrupt -= runtime->boundary;
480 runtime->hw_ptr_base = hw_base;
481 runtime->status->hw_ptr = new_hw_ptr;
482 runtime->hw_ptr_jiffies = curr_jiffies;
483 if (crossed_boundary) {
484 snd_BUG_ON(crossed_boundary != 1);
485 runtime->hw_ptr_wrap += runtime->boundary;
488 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
490 return snd_pcm_update_state(substream, runtime);
493 /* CAUTION: call it with irq disabled */
494 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
496 return snd_pcm_update_hw_ptr0(substream, 0);
500 * snd_pcm_set_ops - set the PCM operators
501 * @pcm: the pcm instance
502 * @direction: stream direction, SNDRV_PCM_STREAM_XXX
503 * @ops: the operator table
505 * Sets the given PCM operators to the pcm instance.
507 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
508 const struct snd_pcm_ops *ops)
510 struct snd_pcm_str *stream = &pcm->streams[direction];
511 struct snd_pcm_substream *substream;
513 for (substream = stream->substream; substream != NULL; substream = substream->next)
514 substream->ops = ops;
516 EXPORT_SYMBOL(snd_pcm_set_ops);
519 * snd_pcm_set_sync - set the PCM sync id
520 * @substream: the pcm substream
522 * Sets the PCM sync identifier for the card.
524 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
526 struct snd_pcm_runtime *runtime = substream->runtime;
528 runtime->sync.id32[0] = substream->pcm->card->number;
529 runtime->sync.id32[1] = -1;
530 runtime->sync.id32[2] = -1;
531 runtime->sync.id32[3] = -1;
533 EXPORT_SYMBOL(snd_pcm_set_sync);
536 * Standard ioctl routine
539 static inline unsigned int div32(unsigned int a, unsigned int b,
550 static inline unsigned int div_down(unsigned int a, unsigned int b)
557 static inline unsigned int div_up(unsigned int a, unsigned int b)
569 static inline unsigned int mul(unsigned int a, unsigned int b)
573 if (div_down(UINT_MAX, a) < b)
578 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
579 unsigned int c, unsigned int *r)
581 u_int64_t n = (u_int64_t) a * b;
586 n = div_u64_rem(n, c, r);
595 * snd_interval_refine - refine the interval value of configurator
596 * @i: the interval value to refine
597 * @v: the interval value to refer to
599 * Refines the interval value with the reference value.
600 * The interval is changed to the range satisfying both intervals.
601 * The interval status (min, max, integer, etc.) are evaluated.
603 * Return: Positive if the value is changed, zero if it's not changed, or a
604 * negative error code.
606 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
609 if (snd_BUG_ON(snd_interval_empty(i)))
611 if (i->min < v->min) {
613 i->openmin = v->openmin;
615 } else if (i->min == v->min && !i->openmin && v->openmin) {
619 if (i->max > v->max) {
621 i->openmax = v->openmax;
623 } else if (i->max == v->max && !i->openmax && v->openmax) {
627 if (!i->integer && v->integer) {
640 } else if (!i->openmin && !i->openmax && i->min == i->max)
642 if (snd_interval_checkempty(i)) {
643 snd_interval_none(i);
648 EXPORT_SYMBOL(snd_interval_refine);
650 static int snd_interval_refine_first(struct snd_interval *i)
652 const unsigned int last_max = i->max;
654 if (snd_BUG_ON(snd_interval_empty(i)))
656 if (snd_interval_single(i))
661 /* only exclude max value if also excluded before refine */
662 i->openmax = (i->openmax && i->max >= last_max);
666 static int snd_interval_refine_last(struct snd_interval *i)
668 const unsigned int last_min = i->min;
670 if (snd_BUG_ON(snd_interval_empty(i)))
672 if (snd_interval_single(i))
677 /* only exclude min value if also excluded before refine */
678 i->openmin = (i->openmin && i->min <= last_min);
682 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
684 if (a->empty || b->empty) {
685 snd_interval_none(c);
689 c->min = mul(a->min, b->min);
690 c->openmin = (a->openmin || b->openmin);
691 c->max = mul(a->max, b->max);
692 c->openmax = (a->openmax || b->openmax);
693 c->integer = (a->integer && b->integer);
697 * snd_interval_div - refine the interval value with division
704 * Returns non-zero if the value is changed, zero if not changed.
706 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
709 if (a->empty || b->empty) {
710 snd_interval_none(c);
714 c->min = div32(a->min, b->max, &r);
715 c->openmin = (r || a->openmin || b->openmax);
717 c->max = div32(a->max, b->min, &r);
722 c->openmax = (a->openmax || b->openmin);
731 * snd_interval_muldivk - refine the interval value
734 * @k: divisor (as integer)
739 * Returns non-zero if the value is changed, zero if not changed.
741 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
742 unsigned int k, struct snd_interval *c)
745 if (a->empty || b->empty) {
746 snd_interval_none(c);
750 c->min = muldiv32(a->min, b->min, k, &r);
751 c->openmin = (r || a->openmin || b->openmin);
752 c->max = muldiv32(a->max, b->max, k, &r);
757 c->openmax = (a->openmax || b->openmax);
762 * snd_interval_mulkdiv - refine the interval value
764 * @k: dividend 2 (as integer)
770 * Returns non-zero if the value is changed, zero if not changed.
772 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
773 const struct snd_interval *b, struct snd_interval *c)
776 if (a->empty || b->empty) {
777 snd_interval_none(c);
781 c->min = muldiv32(a->min, k, b->max, &r);
782 c->openmin = (r || a->openmin || b->openmax);
784 c->max = muldiv32(a->max, k, b->min, &r);
789 c->openmax = (a->openmax || b->openmin);
801 * snd_interval_ratnum - refine the interval value
802 * @i: interval to refine
803 * @rats_count: number of ratnum_t
804 * @rats: ratnum_t array
805 * @nump: pointer to store the resultant numerator
806 * @denp: pointer to store the resultant denominator
808 * Return: Positive if the value is changed, zero if it's not changed, or a
809 * negative error code.
811 int snd_interval_ratnum(struct snd_interval *i,
812 unsigned int rats_count, const struct snd_ratnum *rats,
813 unsigned int *nump, unsigned int *denp)
815 unsigned int best_num, best_den;
818 struct snd_interval t;
820 unsigned int result_num, result_den;
823 best_num = best_den = best_diff = 0;
824 for (k = 0; k < rats_count; ++k) {
825 unsigned int num = rats[k].num;
827 unsigned int q = i->min;
831 den = div_up(num, q);
832 if (den < rats[k].den_min)
834 if (den > rats[k].den_max)
835 den = rats[k].den_max;
838 r = (den - rats[k].den_min) % rats[k].den_step;
842 diff = num - q * den;
846 diff * best_den < best_diff * den) {
856 t.min = div_down(best_num, best_den);
857 t.openmin = !!(best_num % best_den);
859 result_num = best_num;
860 result_diff = best_diff;
861 result_den = best_den;
862 best_num = best_den = best_diff = 0;
863 for (k = 0; k < rats_count; ++k) {
864 unsigned int num = rats[k].num;
866 unsigned int q = i->max;
872 den = div_down(num, q);
873 if (den > rats[k].den_max)
875 if (den < rats[k].den_min)
876 den = rats[k].den_min;
879 r = (den - rats[k].den_min) % rats[k].den_step;
881 den += rats[k].den_step - r;
883 diff = q * den - num;
887 diff * best_den < best_diff * den) {
897 t.max = div_up(best_num, best_den);
898 t.openmax = !!(best_num % best_den);
900 err = snd_interval_refine(i, &t);
904 if (snd_interval_single(i)) {
905 if (best_diff * result_den < result_diff * best_den) {
906 result_num = best_num;
907 result_den = best_den;
916 EXPORT_SYMBOL(snd_interval_ratnum);
919 * snd_interval_ratden - refine the interval value
920 * @i: interval to refine
921 * @rats_count: number of struct ratden
922 * @rats: struct ratden array
923 * @nump: pointer to store the resultant numerator
924 * @denp: pointer to store the resultant denominator
926 * Return: Positive if the value is changed, zero if it's not changed, or a
927 * negative error code.
929 static int snd_interval_ratden(struct snd_interval *i,
930 unsigned int rats_count,
931 const struct snd_ratden *rats,
932 unsigned int *nump, unsigned int *denp)
934 unsigned int best_num, best_diff, best_den;
936 struct snd_interval t;
939 best_num = best_den = best_diff = 0;
940 for (k = 0; k < rats_count; ++k) {
942 unsigned int den = rats[k].den;
943 unsigned int q = i->min;
946 if (num > rats[k].num_max)
948 if (num < rats[k].num_min)
949 num = rats[k].num_max;
952 r = (num - rats[k].num_min) % rats[k].num_step;
954 num += rats[k].num_step - r;
956 diff = num - q * den;
958 diff * best_den < best_diff * den) {
968 t.min = div_down(best_num, best_den);
969 t.openmin = !!(best_num % best_den);
971 best_num = best_den = best_diff = 0;
972 for (k = 0; k < rats_count; ++k) {
974 unsigned int den = rats[k].den;
975 unsigned int q = i->max;
978 if (num < rats[k].num_min)
980 if (num > rats[k].num_max)
981 num = rats[k].num_max;
984 r = (num - rats[k].num_min) % rats[k].num_step;
988 diff = q * den - num;
990 diff * best_den < best_diff * den) {
1000 t.max = div_up(best_num, best_den);
1001 t.openmax = !!(best_num % best_den);
1003 err = snd_interval_refine(i, &t);
1007 if (snd_interval_single(i)) {
1017 * snd_interval_list - refine the interval value from the list
1018 * @i: the interval value to refine
1019 * @count: the number of elements in the list
1020 * @list: the value list
1021 * @mask: the bit-mask to evaluate
1023 * Refines the interval value from the list.
1024 * When mask is non-zero, only the elements corresponding to bit 1 are
1027 * Return: Positive if the value is changed, zero if it's not changed, or a
1028 * negative error code.
1030 int snd_interval_list(struct snd_interval *i, unsigned int count,
1031 const unsigned int *list, unsigned int mask)
1034 struct snd_interval list_range;
1040 snd_interval_any(&list_range);
1041 list_range.min = UINT_MAX;
1043 for (k = 0; k < count; k++) {
1044 if (mask && !(mask & (1 << k)))
1046 if (!snd_interval_test(i, list[k]))
1048 list_range.min = min(list_range.min, list[k]);
1049 list_range.max = max(list_range.max, list[k]);
1051 return snd_interval_refine(i, &list_range);
1053 EXPORT_SYMBOL(snd_interval_list);
1056 * snd_interval_ranges - refine the interval value from the list of ranges
1057 * @i: the interval value to refine
1058 * @count: the number of elements in the list of ranges
1059 * @ranges: the ranges list
1060 * @mask: the bit-mask to evaluate
1062 * Refines the interval value from the list of ranges.
1063 * When mask is non-zero, only the elements corresponding to bit 1 are
1066 * Return: Positive if the value is changed, zero if it's not changed, or a
1067 * negative error code.
1069 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1070 const struct snd_interval *ranges, unsigned int mask)
1073 struct snd_interval range_union;
1074 struct snd_interval range;
1077 snd_interval_none(i);
1080 snd_interval_any(&range_union);
1081 range_union.min = UINT_MAX;
1082 range_union.max = 0;
1083 for (k = 0; k < count; k++) {
1084 if (mask && !(mask & (1 << k)))
1086 snd_interval_copy(&range, &ranges[k]);
1087 if (snd_interval_refine(&range, i) < 0)
1089 if (snd_interval_empty(&range))
1092 if (range.min < range_union.min) {
1093 range_union.min = range.min;
1094 range_union.openmin = 1;
1096 if (range.min == range_union.min && !range.openmin)
1097 range_union.openmin = 0;
1098 if (range.max > range_union.max) {
1099 range_union.max = range.max;
1100 range_union.openmax = 1;
1102 if (range.max == range_union.max && !range.openmax)
1103 range_union.openmax = 0;
1105 return snd_interval_refine(i, &range_union);
1107 EXPORT_SYMBOL(snd_interval_ranges);
1109 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1114 if (n != 0 || i->openmin) {
1120 if (n != 0 || i->openmax) {
1125 if (snd_interval_checkempty(i)) {
1132 /* Info constraints helpers */
1135 * snd_pcm_hw_rule_add - add the hw-constraint rule
1136 * @runtime: the pcm runtime instance
1137 * @cond: condition bits
1138 * @var: the variable to evaluate
1139 * @func: the evaluation function
1140 * @private: the private data pointer passed to function
1141 * @dep: the dependent variables
1143 * Return: Zero if successful, or a negative error code on failure.
1145 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1147 snd_pcm_hw_rule_func_t func, void *private,
1150 struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1151 struct snd_pcm_hw_rule *c;
1154 va_start(args, dep);
1155 if (constrs->rules_num >= constrs->rules_all) {
1156 struct snd_pcm_hw_rule *new;
1157 unsigned int new_rules = constrs->rules_all + 16;
1158 new = krealloc_array(constrs->rules, new_rules,
1159 sizeof(*c), GFP_KERNEL);
1164 constrs->rules = new;
1165 constrs->rules_all = new_rules;
1167 c = &constrs->rules[constrs->rules_num];
1171 c->private = private;
1174 if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1181 dep = va_arg(args, int);
1183 constrs->rules_num++;
1187 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1190 * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1191 * @runtime: PCM runtime instance
1192 * @var: hw_params variable to apply the mask
1193 * @mask: the bitmap mask
1195 * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1197 * Return: Zero if successful, or a negative error code on failure.
1199 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1202 struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1203 struct snd_mask *maskp = constrs_mask(constrs, var);
1204 *maskp->bits &= mask;
1205 memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1206 if (*maskp->bits == 0)
1212 * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1213 * @runtime: PCM runtime instance
1214 * @var: hw_params variable to apply the mask
1215 * @mask: the 64bit bitmap mask
1217 * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1219 * Return: Zero if successful, or a negative error code on failure.
1221 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1224 struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1225 struct snd_mask *maskp = constrs_mask(constrs, var);
1226 maskp->bits[0] &= (u_int32_t)mask;
1227 maskp->bits[1] &= (u_int32_t)(mask >> 32);
1228 memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1229 if (! maskp->bits[0] && ! maskp->bits[1])
1233 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1236 * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1237 * @runtime: PCM runtime instance
1238 * @var: hw_params variable to apply the integer constraint
1240 * Apply the constraint of integer to an interval parameter.
1242 * Return: Positive if the value is changed, zero if it's not changed, or a
1243 * negative error code.
1245 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1247 struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1248 return snd_interval_setinteger(constrs_interval(constrs, var));
1250 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
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
1259 * Apply the min/max range constraint to an interval parameter.
1261 * Return: Positive if the value is changed, zero if it's not changed, or a
1262 * negative error code.
1264 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1265 unsigned int min, unsigned int max)
1267 struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1268 struct snd_interval t;
1271 t.openmin = t.openmax = 0;
1273 return snd_interval_refine(constrs_interval(constrs, var), &t);
1275 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1277 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1278 struct snd_pcm_hw_rule *rule)
1280 struct snd_pcm_hw_constraint_list *list = rule->private;
1281 return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1286 * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1287 * @runtime: PCM runtime instance
1288 * @cond: condition bits
1289 * @var: hw_params variable to apply the list constraint
1292 * Apply the list of constraints to an interval parameter.
1294 * Return: Zero if successful, or a negative error code on failure.
1296 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1298 snd_pcm_hw_param_t var,
1299 const struct snd_pcm_hw_constraint_list *l)
1301 return snd_pcm_hw_rule_add(runtime, cond, var,
1302 snd_pcm_hw_rule_list, (void *)l,
1305 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1307 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1308 struct snd_pcm_hw_rule *rule)
1310 struct snd_pcm_hw_constraint_ranges *r = rule->private;
1311 return snd_interval_ranges(hw_param_interval(params, rule->var),
1312 r->count, r->ranges, r->mask);
1317 * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1318 * @runtime: PCM runtime instance
1319 * @cond: condition bits
1320 * @var: hw_params variable to apply the list of range constraints
1323 * Apply the list of range constraints to an interval parameter.
1325 * Return: Zero if successful, or a negative error code on failure.
1327 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1329 snd_pcm_hw_param_t var,
1330 const struct snd_pcm_hw_constraint_ranges *r)
1332 return snd_pcm_hw_rule_add(runtime, cond, var,
1333 snd_pcm_hw_rule_ranges, (void *)r,
1336 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1338 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1339 struct snd_pcm_hw_rule *rule)
1341 const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1342 unsigned int num = 0, den = 0;
1344 err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1345 r->nrats, r->rats, &num, &den);
1346 if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1347 params->rate_num = num;
1348 params->rate_den = den;
1354 * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1355 * @runtime: PCM runtime instance
1356 * @cond: condition bits
1357 * @var: hw_params variable to apply the ratnums constraint
1358 * @r: struct snd_ratnums constriants
1360 * Return: Zero if successful, or a negative error code on failure.
1362 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1364 snd_pcm_hw_param_t var,
1365 const struct snd_pcm_hw_constraint_ratnums *r)
1367 return snd_pcm_hw_rule_add(runtime, cond, var,
1368 snd_pcm_hw_rule_ratnums, (void *)r,
1371 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1373 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1374 struct snd_pcm_hw_rule *rule)
1376 const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1377 unsigned int num = 0, den = 0;
1378 int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1379 r->nrats, r->rats, &num, &den);
1380 if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1381 params->rate_num = num;
1382 params->rate_den = den;
1388 * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1389 * @runtime: PCM runtime instance
1390 * @cond: condition bits
1391 * @var: hw_params variable to apply the ratdens constraint
1392 * @r: struct snd_ratdens constriants
1394 * Return: Zero if successful, or a negative error code on failure.
1396 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1398 snd_pcm_hw_param_t var,
1399 const struct snd_pcm_hw_constraint_ratdens *r)
1401 return snd_pcm_hw_rule_add(runtime, cond, var,
1402 snd_pcm_hw_rule_ratdens, (void *)r,
1405 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1407 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1408 struct snd_pcm_hw_rule *rule)
1410 unsigned int l = (unsigned long) rule->private;
1411 int width = l & 0xffff;
1412 unsigned int msbits = l >> 16;
1413 const struct snd_interval *i =
1414 hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1416 if (!snd_interval_single(i))
1419 if ((snd_interval_value(i) == width) ||
1420 (width == 0 && snd_interval_value(i) > msbits))
1421 params->msbits = min_not_zero(params->msbits, msbits);
1427 * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1428 * @runtime: PCM runtime instance
1429 * @cond: condition bits
1430 * @width: sample bits width
1431 * @msbits: msbits width
1433 * This constraint will set the number of most significant bits (msbits) if a
1434 * sample format with the specified width has been select. If width is set to 0
1435 * the msbits will be set for any sample format with a width larger than the
1438 * Return: Zero if successful, or a negative error code on failure.
1440 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1443 unsigned int msbits)
1445 unsigned long l = (msbits << 16) | width;
1446 return snd_pcm_hw_rule_add(runtime, cond, -1,
1447 snd_pcm_hw_rule_msbits,
1449 SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1451 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1453 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1454 struct snd_pcm_hw_rule *rule)
1456 unsigned long step = (unsigned long) rule->private;
1457 return snd_interval_step(hw_param_interval(params, rule->var), step);
1461 * snd_pcm_hw_constraint_step - add a hw constraint step rule
1462 * @runtime: PCM runtime instance
1463 * @cond: condition bits
1464 * @var: hw_params variable to apply the step constraint
1467 * Return: Zero if successful, or a negative error code on failure.
1469 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1471 snd_pcm_hw_param_t var,
1474 return snd_pcm_hw_rule_add(runtime, cond, var,
1475 snd_pcm_hw_rule_step, (void *) step,
1478 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1480 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1482 static const unsigned int pow2_sizes[] = {
1483 1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1484 1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1485 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1486 1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1488 return snd_interval_list(hw_param_interval(params, rule->var),
1489 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1493 * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1494 * @runtime: PCM runtime instance
1495 * @cond: condition bits
1496 * @var: hw_params variable to apply the power-of-2 constraint
1498 * Return: Zero if successful, or a negative error code on failure.
1500 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1502 snd_pcm_hw_param_t var)
1504 return snd_pcm_hw_rule_add(runtime, cond, var,
1505 snd_pcm_hw_rule_pow2, NULL,
1508 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1510 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1511 struct snd_pcm_hw_rule *rule)
1513 unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1514 struct snd_interval *rate;
1516 rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1517 return snd_interval_list(rate, 1, &base_rate, 0);
1521 * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1522 * @runtime: PCM runtime instance
1523 * @base_rate: the rate at which the hardware does not resample
1525 * Return: Zero if successful, or a negative error code on failure.
1527 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1528 unsigned int base_rate)
1530 return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1531 SNDRV_PCM_HW_PARAM_RATE,
1532 snd_pcm_hw_rule_noresample_func,
1533 (void *)(uintptr_t)base_rate,
1534 SNDRV_PCM_HW_PARAM_RATE, -1);
1536 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1538 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1539 snd_pcm_hw_param_t var)
1541 if (hw_is_mask(var)) {
1542 snd_mask_any(hw_param_mask(params, var));
1543 params->cmask |= 1 << var;
1544 params->rmask |= 1 << var;
1547 if (hw_is_interval(var)) {
1548 snd_interval_any(hw_param_interval(params, var));
1549 params->cmask |= 1 << var;
1550 params->rmask |= 1 << var;
1556 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1559 memset(params, 0, sizeof(*params));
1560 for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1561 _snd_pcm_hw_param_any(params, k);
1562 for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1563 _snd_pcm_hw_param_any(params, k);
1566 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1569 * snd_pcm_hw_param_value - return @params field @var value
1570 * @params: the hw_params instance
1571 * @var: parameter to retrieve
1572 * @dir: pointer to the direction (-1,0,1) or %NULL
1574 * Return: The value for field @var if it's fixed in configuration space
1575 * defined by @params. -%EINVAL otherwise.
1577 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1578 snd_pcm_hw_param_t var, int *dir)
1580 if (hw_is_mask(var)) {
1581 const struct snd_mask *mask = hw_param_mask_c(params, var);
1582 if (!snd_mask_single(mask))
1586 return snd_mask_value(mask);
1588 if (hw_is_interval(var)) {
1589 const struct snd_interval *i = hw_param_interval_c(params, var);
1590 if (!snd_interval_single(i))
1594 return snd_interval_value(i);
1598 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1600 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1601 snd_pcm_hw_param_t var)
1603 if (hw_is_mask(var)) {
1604 snd_mask_none(hw_param_mask(params, var));
1605 params->cmask |= 1 << var;
1606 params->rmask |= 1 << var;
1607 } else if (hw_is_interval(var)) {
1608 snd_interval_none(hw_param_interval(params, var));
1609 params->cmask |= 1 << var;
1610 params->rmask |= 1 << var;
1615 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1617 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1618 snd_pcm_hw_param_t var)
1621 if (hw_is_mask(var))
1622 changed = snd_mask_refine_first(hw_param_mask(params, var));
1623 else if (hw_is_interval(var))
1624 changed = snd_interval_refine_first(hw_param_interval(params, var));
1628 params->cmask |= 1 << var;
1629 params->rmask |= 1 << var;
1636 * snd_pcm_hw_param_first - refine config space and return minimum value
1637 * @pcm: PCM instance
1638 * @params: the hw_params instance
1639 * @var: parameter to retrieve
1640 * @dir: pointer to the direction (-1,0,1) or %NULL
1642 * Inside configuration space defined by @params remove from @var all
1643 * values > minimum. Reduce configuration space accordingly.
1645 * Return: The minimum, or a negative error code on failure.
1647 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1648 struct snd_pcm_hw_params *params,
1649 snd_pcm_hw_param_t var, int *dir)
1651 int changed = _snd_pcm_hw_param_first(params, var);
1654 if (params->rmask) {
1655 int err = snd_pcm_hw_refine(pcm, params);
1659 return snd_pcm_hw_param_value(params, var, dir);
1661 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1663 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1664 snd_pcm_hw_param_t var)
1667 if (hw_is_mask(var))
1668 changed = snd_mask_refine_last(hw_param_mask(params, var));
1669 else if (hw_is_interval(var))
1670 changed = snd_interval_refine_last(hw_param_interval(params, var));
1674 params->cmask |= 1 << var;
1675 params->rmask |= 1 << var;
1682 * snd_pcm_hw_param_last - refine config space and return maximum value
1683 * @pcm: PCM instance
1684 * @params: the hw_params instance
1685 * @var: parameter to retrieve
1686 * @dir: pointer to the direction (-1,0,1) or %NULL
1688 * Inside configuration space defined by @params remove from @var all
1689 * values < maximum. Reduce configuration space accordingly.
1691 * Return: The maximum, or a negative error code on failure.
1693 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1694 struct snd_pcm_hw_params *params,
1695 snd_pcm_hw_param_t var, int *dir)
1697 int changed = _snd_pcm_hw_param_last(params, var);
1700 if (params->rmask) {
1701 int err = snd_pcm_hw_refine(pcm, params);
1705 return snd_pcm_hw_param_value(params, var, dir);
1707 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1710 * snd_pcm_hw_params_bits - Get the number of bits per the sample.
1711 * @p: hardware parameters
1713 * Return: The number of bits per sample based on the format,
1714 * subformat and msbits the specified hw params has.
1716 int snd_pcm_hw_params_bits(const struct snd_pcm_hw_params *p)
1718 snd_pcm_subformat_t subformat = params_subformat(p);
1719 snd_pcm_format_t format = params_format(p);
1722 case SNDRV_PCM_FORMAT_S32_LE:
1723 case SNDRV_PCM_FORMAT_U32_LE:
1724 case SNDRV_PCM_FORMAT_S32_BE:
1725 case SNDRV_PCM_FORMAT_U32_BE:
1726 switch (subformat) {
1727 case SNDRV_PCM_SUBFORMAT_MSBITS_20:
1729 case SNDRV_PCM_SUBFORMAT_MSBITS_24:
1731 case SNDRV_PCM_SUBFORMAT_MSBITS_MAX:
1732 case SNDRV_PCM_SUBFORMAT_STD:
1738 return snd_pcm_format_width(format);
1741 EXPORT_SYMBOL(snd_pcm_hw_params_bits);
1743 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1746 struct snd_pcm_runtime *runtime = substream->runtime;
1747 unsigned long flags;
1748 snd_pcm_stream_lock_irqsave(substream, flags);
1749 if (snd_pcm_running(substream) &&
1750 snd_pcm_update_hw_ptr(substream) >= 0)
1751 runtime->status->hw_ptr %= runtime->buffer_size;
1753 runtime->status->hw_ptr = 0;
1754 runtime->hw_ptr_wrap = 0;
1756 snd_pcm_stream_unlock_irqrestore(substream, flags);
1760 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1763 struct snd_pcm_channel_info *info = arg;
1764 struct snd_pcm_runtime *runtime = substream->runtime;
1766 if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1770 width = snd_pcm_format_physical_width(runtime->format);
1774 switch (runtime->access) {
1775 case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1776 case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1777 info->first = info->channel * width;
1778 info->step = runtime->channels * width;
1780 case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1781 case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1783 size_t size = runtime->dma_bytes / runtime->channels;
1784 info->first = info->channel * size * 8;
1795 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1798 struct snd_pcm_hw_params *params = arg;
1799 snd_pcm_format_t format;
1803 params->fifo_size = substream->runtime->hw.fifo_size;
1804 if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1805 format = params_format(params);
1806 channels = params_channels(params);
1807 frame_size = snd_pcm_format_size(format, channels);
1809 params->fifo_size /= frame_size;
1815 * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1816 * @substream: the pcm substream instance
1817 * @cmd: ioctl command
1818 * @arg: ioctl argument
1820 * Processes the generic ioctl commands for PCM.
1821 * Can be passed as the ioctl callback for PCM ops.
1823 * Return: Zero if successful, or a negative error code on failure.
1825 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1826 unsigned int cmd, void *arg)
1829 case SNDRV_PCM_IOCTL1_RESET:
1830 return snd_pcm_lib_ioctl_reset(substream, arg);
1831 case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1832 return snd_pcm_lib_ioctl_channel_info(substream, arg);
1833 case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1834 return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1838 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1841 * snd_pcm_period_elapsed_under_stream_lock() - update the status of runtime for the next period
1842 * under acquired lock of PCM substream.
1843 * @substream: the instance of pcm substream.
1845 * This function is called when the batch of audio data frames as the same size as the period of
1846 * buffer is already processed in audio data transmission.
1848 * The call of function updates the status of runtime with the latest position of audio data
1849 * transmission, checks overrun and underrun over buffer, awaken user processes from waiting for
1850 * available audio data frames, sampling audio timestamp, and performs stop or drain the PCM
1851 * substream according to configured threshold.
1853 * The function is intended to use for the case that PCM driver operates audio data frames under
1854 * acquired lock of PCM substream; e.g. in callback of any operation of &snd_pcm_ops in process
1855 * context. In any interrupt context, it's preferrable to use ``snd_pcm_period_elapsed()`` instead
1856 * since lock of PCM substream should be acquired in advance.
1858 * Developer should pay enough attention that some callbacks in &snd_pcm_ops are done by the call of
1861 * - .pointer - to retrieve current position of audio data transmission by frame count or XRUN state.
1862 * - .trigger - with SNDRV_PCM_TRIGGER_STOP at XRUN or DRAINING state.
1863 * - .get_time_info - to retrieve audio time stamp if needed.
1865 * Even if more than one periods have elapsed since the last call, you have to call this only once.
1867 void snd_pcm_period_elapsed_under_stream_lock(struct snd_pcm_substream *substream)
1869 struct snd_pcm_runtime *runtime;
1871 if (PCM_RUNTIME_CHECK(substream))
1873 runtime = substream->runtime;
1875 if (!snd_pcm_running(substream) ||
1876 snd_pcm_update_hw_ptr0(substream, 1) < 0)
1879 #ifdef CONFIG_SND_PCM_TIMER
1880 if (substream->timer_running)
1881 snd_timer_interrupt(substream->timer, 1);
1884 snd_kill_fasync(runtime->fasync, SIGIO, POLL_IN);
1886 EXPORT_SYMBOL(snd_pcm_period_elapsed_under_stream_lock);
1889 * snd_pcm_period_elapsed() - update the status of runtime for the next period by acquiring lock of
1891 * @substream: the instance of PCM substream.
1893 * This function is mostly similar to ``snd_pcm_period_elapsed_under_stream_lock()`` except for
1894 * acquiring lock of PCM substream voluntarily.
1896 * It's typically called by any type of IRQ handler when hardware IRQ occurs to notify event that
1897 * the batch of audio data frames as the same size as the period of buffer is already processed in
1898 * audio data transmission.
1900 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1902 unsigned long flags;
1904 if (snd_BUG_ON(!substream))
1907 snd_pcm_stream_lock_irqsave(substream, flags);
1908 snd_pcm_period_elapsed_under_stream_lock(substream);
1909 snd_pcm_stream_unlock_irqrestore(substream, flags);
1911 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1914 * Wait until avail_min data becomes available
1915 * Returns a negative error code if any error occurs during operation.
1916 * The available space is stored on availp. When err = 0 and avail = 0
1917 * on the capture stream, it indicates the stream is in DRAINING state.
1919 static int wait_for_avail(struct snd_pcm_substream *substream,
1920 snd_pcm_uframes_t *availp)
1922 struct snd_pcm_runtime *runtime = substream->runtime;
1923 int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1924 wait_queue_entry_t wait;
1926 snd_pcm_uframes_t avail = 0;
1927 long wait_time, tout;
1929 init_waitqueue_entry(&wait, current);
1930 set_current_state(TASK_INTERRUPTIBLE);
1931 add_wait_queue(&runtime->tsleep, &wait);
1933 if (runtime->no_period_wakeup)
1934 wait_time = MAX_SCHEDULE_TIMEOUT;
1936 /* use wait time from substream if available */
1937 if (substream->wait_time) {
1938 wait_time = substream->wait_time;
1942 if (runtime->rate) {
1943 long t = runtime->buffer_size * 1100 / runtime->rate;
1944 wait_time = max(t, wait_time);
1947 wait_time = msecs_to_jiffies(wait_time);
1951 if (signal_pending(current)) {
1957 * We need to check if space became available already
1958 * (and thus the wakeup happened already) first to close
1959 * the race of space already having become available.
1960 * This check must happen after been added to the waitqueue
1961 * and having current state be INTERRUPTIBLE.
1963 avail = snd_pcm_avail(substream);
1964 if (avail >= runtime->twake)
1966 snd_pcm_stream_unlock_irq(substream);
1968 tout = schedule_timeout(wait_time);
1970 snd_pcm_stream_lock_irq(substream);
1971 set_current_state(TASK_INTERRUPTIBLE);
1972 switch (runtime->state) {
1973 case SNDRV_PCM_STATE_SUSPENDED:
1976 case SNDRV_PCM_STATE_XRUN:
1979 case SNDRV_PCM_STATE_DRAINING:
1983 avail = 0; /* indicate draining */
1985 case SNDRV_PCM_STATE_OPEN:
1986 case SNDRV_PCM_STATE_SETUP:
1987 case SNDRV_PCM_STATE_DISCONNECTED:
1990 case SNDRV_PCM_STATE_PAUSED:
1994 pcm_dbg(substream->pcm,
1995 "%s timeout (DMA or IRQ trouble?)\n",
1996 is_playback ? "playback write" : "capture read");
2002 set_current_state(TASK_RUNNING);
2003 remove_wait_queue(&runtime->tsleep, &wait);
2008 typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
2009 int channel, unsigned long hwoff,
2010 struct iov_iter *iter, unsigned long bytes);
2012 typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
2013 snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f,
2016 /* calculate the target DMA-buffer position to be written/read */
2017 static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
2018 int channel, unsigned long hwoff)
2020 return runtime->dma_area + hwoff +
2021 channel * (runtime->dma_bytes / runtime->channels);
2024 /* default copy ops for write; used for both interleaved and non- modes */
2025 static int default_write_copy(struct snd_pcm_substream *substream,
2026 int channel, unsigned long hwoff,
2027 struct iov_iter *iter, unsigned long bytes)
2029 if (copy_from_iter(get_dma_ptr(substream->runtime, channel, hwoff),
2030 bytes, iter) != bytes)
2035 /* fill silence instead of copy data; called as a transfer helper
2036 * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
2037 * a NULL buffer is passed
2039 static int fill_silence(struct snd_pcm_substream *substream, int channel,
2040 unsigned long hwoff, struct iov_iter *iter,
2041 unsigned long bytes)
2043 struct snd_pcm_runtime *runtime = substream->runtime;
2045 if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
2047 if (substream->ops->fill_silence)
2048 return substream->ops->fill_silence(substream, channel,
2051 snd_pcm_format_set_silence(runtime->format,
2052 get_dma_ptr(runtime, channel, hwoff),
2053 bytes_to_samples(runtime, bytes));
2057 /* default copy ops for read; used for both interleaved and non- modes */
2058 static int default_read_copy(struct snd_pcm_substream *substream,
2059 int channel, unsigned long hwoff,
2060 struct iov_iter *iter, unsigned long bytes)
2062 if (copy_to_iter(get_dma_ptr(substream->runtime, channel, hwoff),
2063 bytes, iter) != bytes)
2068 /* call transfer with the filled iov_iter */
2069 static int do_transfer(struct snd_pcm_substream *substream, int c,
2070 unsigned long hwoff, void *data, unsigned long bytes,
2071 pcm_transfer_f transfer, bool in_kernel)
2073 struct iov_iter iter;
2076 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
2082 struct kvec kvec = { data, bytes };
2084 iov_iter_kvec(&iter, type, &kvec, 1, bytes);
2085 return transfer(substream, c, hwoff, &iter, bytes);
2088 err = import_ubuf(type, (__force void __user *)data, bytes, &iter);
2091 return transfer(substream, c, hwoff, &iter, bytes);
2094 /* call transfer function with the converted pointers and sizes;
2095 * for interleaved mode, it's one shot for all samples
2097 static int interleaved_copy(struct snd_pcm_substream *substream,
2098 snd_pcm_uframes_t hwoff, void *data,
2099 snd_pcm_uframes_t off,
2100 snd_pcm_uframes_t frames,
2101 pcm_transfer_f transfer,
2104 struct snd_pcm_runtime *runtime = substream->runtime;
2106 /* convert to bytes */
2107 hwoff = frames_to_bytes(runtime, hwoff);
2108 off = frames_to_bytes(runtime, off);
2109 frames = frames_to_bytes(runtime, frames);
2111 return do_transfer(substream, 0, hwoff, data + off, frames, transfer,
2115 /* call transfer function with the converted pointers and sizes for each
2116 * non-interleaved channel; when buffer is NULL, silencing instead of copying
2118 static int noninterleaved_copy(struct snd_pcm_substream *substream,
2119 snd_pcm_uframes_t hwoff, void *data,
2120 snd_pcm_uframes_t off,
2121 snd_pcm_uframes_t frames,
2122 pcm_transfer_f transfer,
2125 struct snd_pcm_runtime *runtime = substream->runtime;
2126 int channels = runtime->channels;
2130 /* convert to bytes; note that it's not frames_to_bytes() here.
2131 * in non-interleaved mode, we copy for each channel, thus
2132 * each copy is n_samples bytes x channels = whole frames.
2134 off = samples_to_bytes(runtime, off);
2135 frames = samples_to_bytes(runtime, frames);
2136 hwoff = samples_to_bytes(runtime, hwoff);
2137 for (c = 0; c < channels; ++c, ++bufs) {
2138 if (!data || !*bufs)
2139 err = fill_silence(substream, c, hwoff, NULL, frames);
2141 err = do_transfer(substream, c, hwoff, *bufs + off,
2142 frames, transfer, in_kernel);
2149 /* fill silence on the given buffer position;
2150 * called from snd_pcm_playback_silence()
2152 static int fill_silence_frames(struct snd_pcm_substream *substream,
2153 snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
2155 if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
2156 substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
2157 return interleaved_copy(substream, off, NULL, 0, frames,
2158 fill_silence, true);
2160 return noninterleaved_copy(substream, off, NULL, 0, frames,
2161 fill_silence, true);
2164 /* sanity-check for read/write methods */
2165 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2167 struct snd_pcm_runtime *runtime;
2168 if (PCM_RUNTIME_CHECK(substream))
2170 runtime = substream->runtime;
2171 if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2173 if (runtime->state == SNDRV_PCM_STATE_OPEN)
2178 static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
2180 switch (runtime->state) {
2181 case SNDRV_PCM_STATE_PREPARED:
2182 case SNDRV_PCM_STATE_RUNNING:
2183 case SNDRV_PCM_STATE_PAUSED:
2185 case SNDRV_PCM_STATE_XRUN:
2187 case SNDRV_PCM_STATE_SUSPENDED:
2194 /* update to the given appl_ptr and call ack callback if needed;
2195 * when an error is returned, take back to the original value
2197 int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
2198 snd_pcm_uframes_t appl_ptr)
2200 struct snd_pcm_runtime *runtime = substream->runtime;
2201 snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
2202 snd_pcm_sframes_t diff;
2205 if (old_appl_ptr == appl_ptr)
2208 if (appl_ptr >= runtime->boundary)
2211 * check if a rewind is requested by the application
2213 if (substream->runtime->info & SNDRV_PCM_INFO_NO_REWINDS) {
2214 diff = appl_ptr - old_appl_ptr;
2216 if (diff > runtime->buffer_size)
2219 if (runtime->boundary + diff > runtime->buffer_size)
2224 runtime->control->appl_ptr = appl_ptr;
2225 if (substream->ops->ack) {
2226 ret = substream->ops->ack(substream);
2228 runtime->control->appl_ptr = old_appl_ptr;
2230 __snd_pcm_xrun(substream);
2235 trace_applptr(substream, old_appl_ptr, appl_ptr);
2240 /* the common loop for read/write data */
2241 snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
2242 void *data, bool interleaved,
2243 snd_pcm_uframes_t size, bool in_kernel)
2245 struct snd_pcm_runtime *runtime = substream->runtime;
2246 snd_pcm_uframes_t xfer = 0;
2247 snd_pcm_uframes_t offset = 0;
2248 snd_pcm_uframes_t avail;
2250 pcm_transfer_f transfer;
2255 err = pcm_sanity_check(substream);
2259 is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
2261 if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2262 runtime->channels > 1)
2264 writer = interleaved_copy;
2266 if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2268 writer = noninterleaved_copy;
2273 transfer = fill_silence;
2277 if (substream->ops->copy)
2278 transfer = substream->ops->copy;
2280 transfer = is_playback ?
2281 default_write_copy : default_read_copy;
2287 nonblock = !!(substream->f_flags & O_NONBLOCK);
2289 snd_pcm_stream_lock_irq(substream);
2290 err = pcm_accessible_state(runtime);
2294 runtime->twake = runtime->control->avail_min ? : 1;
2295 if (runtime->state == SNDRV_PCM_STATE_RUNNING)
2296 snd_pcm_update_hw_ptr(substream);
2299 * If size < start_threshold, wait indefinitely. Another
2300 * thread may start capture
2303 runtime->state == SNDRV_PCM_STATE_PREPARED &&
2304 size >= runtime->start_threshold) {
2305 err = snd_pcm_start(substream);
2310 avail = snd_pcm_avail(substream);
2313 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2314 snd_pcm_uframes_t cont;
2317 runtime->state == SNDRV_PCM_STATE_DRAINING) {
2318 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2325 runtime->twake = min_t(snd_pcm_uframes_t, size,
2326 runtime->control->avail_min ? : 1);
2327 err = wait_for_avail(substream, &avail);
2331 continue; /* draining */
2333 frames = size > avail ? avail : size;
2334 appl_ptr = READ_ONCE(runtime->control->appl_ptr);
2335 appl_ofs = appl_ptr % runtime->buffer_size;
2336 cont = runtime->buffer_size - appl_ofs;
2339 if (snd_BUG_ON(!frames)) {
2343 if (!atomic_inc_unless_negative(&runtime->buffer_accessing)) {
2347 snd_pcm_stream_unlock_irq(substream);
2349 snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_CPU);
2350 err = writer(substream, appl_ofs, data, offset, frames,
2351 transfer, in_kernel);
2353 snd_pcm_dma_buffer_sync(substream, SNDRV_DMA_SYNC_DEVICE);
2354 snd_pcm_stream_lock_irq(substream);
2355 atomic_dec(&runtime->buffer_accessing);
2358 err = pcm_accessible_state(runtime);
2362 if (appl_ptr >= runtime->boundary)
2363 appl_ptr -= runtime->boundary;
2364 err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
2373 runtime->state == SNDRV_PCM_STATE_PREPARED &&
2374 snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2375 err = snd_pcm_start(substream);
2382 if (xfer > 0 && err >= 0)
2383 snd_pcm_update_state(substream, runtime);
2384 snd_pcm_stream_unlock_irq(substream);
2385 return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2387 EXPORT_SYMBOL(__snd_pcm_lib_xfer);
2390 * standard channel mapping helpers
2393 /* default channel maps for multi-channel playbacks, up to 8 channels */
2394 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2396 .map = { SNDRV_CHMAP_MONO } },
2398 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2400 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2401 SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2403 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2404 SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2405 SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2407 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2408 SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2409 SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2410 SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2413 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2415 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2416 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2418 .map = { SNDRV_CHMAP_MONO } },
2420 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2422 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2423 SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2425 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2426 SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2427 SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2429 .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2430 SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2431 SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2432 SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2435 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2437 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2439 if (ch > info->max_channels)
2441 return !info->channel_mask || (info->channel_mask & (1U << ch));
2444 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2445 struct snd_ctl_elem_info *uinfo)
2447 struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2449 uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2450 uinfo->count = info->max_channels;
2451 uinfo->value.integer.min = 0;
2452 uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2456 /* get callback for channel map ctl element
2457 * stores the channel position firstly matching with the current channels
2459 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2460 struct snd_ctl_elem_value *ucontrol)
2462 struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2463 unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2464 struct snd_pcm_substream *substream;
2465 const struct snd_pcm_chmap_elem *map;
2469 substream = snd_pcm_chmap_substream(info, idx);
2472 memset(ucontrol->value.integer.value, 0,
2473 sizeof(long) * info->max_channels);
2474 if (!substream->runtime)
2475 return 0; /* no channels set */
2476 for (map = info->chmap; map->channels; map++) {
2478 if (map->channels == substream->runtime->channels &&
2479 valid_chmap_channels(info, map->channels)) {
2480 for (i = 0; i < map->channels; i++)
2481 ucontrol->value.integer.value[i] = map->map[i];
2488 /* tlv callback for channel map ctl element
2489 * expands the pre-defined channel maps in a form of TLV
2491 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2492 unsigned int size, unsigned int __user *tlv)
2494 struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2495 const struct snd_pcm_chmap_elem *map;
2496 unsigned int __user *dst;
2503 if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2507 for (map = info->chmap; map->channels; map++) {
2508 int chs_bytes = map->channels * 4;
2509 if (!valid_chmap_channels(info, map->channels))
2513 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2514 put_user(chs_bytes, dst + 1))
2519 if (size < chs_bytes)
2523 for (c = 0; c < map->channels; c++) {
2524 if (put_user(map->map[c], dst))
2529 if (put_user(count, tlv + 1))
2534 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2536 struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2537 info->pcm->streams[info->stream].chmap_kctl = NULL;
2542 * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2543 * @pcm: the assigned PCM instance
2544 * @stream: stream direction
2545 * @chmap: channel map elements (for query)
2546 * @max_channels: the max number of channels for the stream
2547 * @private_value: the value passed to each kcontrol's private_value field
2548 * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2550 * Create channel-mapping control elements assigned to the given PCM stream(s).
2551 * Return: Zero if successful, or a negative error value.
2553 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2554 const struct snd_pcm_chmap_elem *chmap,
2556 unsigned long private_value,
2557 struct snd_pcm_chmap **info_ret)
2559 struct snd_pcm_chmap *info;
2560 struct snd_kcontrol_new knew = {
2561 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
2562 .access = SNDRV_CTL_ELEM_ACCESS_READ |
2563 SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2564 SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2565 .info = pcm_chmap_ctl_info,
2566 .get = pcm_chmap_ctl_get,
2567 .tlv.c = pcm_chmap_ctl_tlv,
2571 if (WARN_ON(pcm->streams[stream].chmap_kctl))
2573 info = kzalloc(sizeof(*info), GFP_KERNEL);
2577 info->stream = stream;
2578 info->chmap = chmap;
2579 info->max_channels = max_channels;
2580 if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2581 knew.name = "Playback Channel Map";
2583 knew.name = "Capture Channel Map";
2584 knew.device = pcm->device;
2585 knew.count = pcm->streams[stream].substream_count;
2586 knew.private_value = private_value;
2587 info->kctl = snd_ctl_new1(&knew, info);
2592 info->kctl->private_free = pcm_chmap_ctl_private_free;
2593 err = snd_ctl_add(pcm->card, info->kctl);
2596 pcm->streams[stream].chmap_kctl = info->kctl;
2601 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);