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#ifdef CONFIG_SND_PCM_XRUN_DEBUG
36#define CREATE_TRACE_POINTS
37#include "pcm_trace.h"
38#else
39#define trace_hwptr(substream, pos, in_interrupt)
40#define trace_xrun(substream)
41#define trace_hw_ptr_error(substream, reason)
42#endif
43
44/*
45 * fill ring buffer with silence
46 * runtime->silence_start: starting pointer to silence area
47 * runtime->silence_filled: size filled with silence
48 * runtime->silence_threshold: threshold from application
49 * runtime->silence_size: maximal size from application
50 *
51 * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
52 */
53void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
54{
55	struct snd_pcm_runtime *runtime = substream->runtime;
56	snd_pcm_uframes_t frames, ofs, transfer;
57
58	if (runtime->silence_size < runtime->boundary) {
59		snd_pcm_sframes_t noise_dist, n;
60		if (runtime->silence_start != runtime->control->appl_ptr) {
61			n = runtime->control->appl_ptr - runtime->silence_start;
62			if (n < 0)
63				n += runtime->boundary;
64			if ((snd_pcm_uframes_t)n < runtime->silence_filled)
65				runtime->silence_filled -= n;
66			else
67				runtime->silence_filled = 0;
68			runtime->silence_start = runtime->control->appl_ptr;
69		}
70		if (runtime->silence_filled >= runtime->buffer_size)
71			return;
72		noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
73		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
74			return;
75		frames = runtime->silence_threshold - noise_dist;
76		if (frames > runtime->silence_size)
77			frames = runtime->silence_size;
78	} else {
79		if (new_hw_ptr == ULONG_MAX) {	/* initialization */
80			snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
81			if (avail > runtime->buffer_size)
82				avail = runtime->buffer_size;
83			runtime->silence_filled = avail > 0 ? avail : 0;
84			runtime->silence_start = (runtime->status->hw_ptr +
85						  runtime->silence_filled) %
86						 runtime->boundary;
87		} else {
88			ofs = runtime->status->hw_ptr;
89			frames = new_hw_ptr - ofs;
90			if ((snd_pcm_sframes_t)frames < 0)
91				frames += runtime->boundary;
92			runtime->silence_filled -= frames;
93			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
94				runtime->silence_filled = 0;
95				runtime->silence_start = new_hw_ptr;
96			} else {
97				runtime->silence_start = ofs;
98			}
99		}
100		frames = runtime->buffer_size - runtime->silence_filled;
101	}
102	if (snd_BUG_ON(frames > runtime->buffer_size))
103		return;
104	if (frames == 0)
105		return;
106	ofs = runtime->silence_start % runtime->buffer_size;
107	while (frames > 0) {
108		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
109		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
110		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
111			if (substream->ops->silence) {
112				int err;
113				err = substream->ops->silence(substream, -1, ofs, transfer);
114				snd_BUG_ON(err < 0);
115			} else {
116				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
117				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
118			}
119		} else {
120			unsigned int c;
121			unsigned int channels = runtime->channels;
122			if (substream->ops->silence) {
123				for (c = 0; c < channels; ++c) {
124					int err;
125					err = substream->ops->silence(substream, c, ofs, transfer);
126					snd_BUG_ON(err < 0);
127				}
128			} else {
129				size_t dma_csize = runtime->dma_bytes / channels;
130				for (c = 0; c < channels; ++c) {
131					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
132					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
133				}
134			}
135		}
136		runtime->silence_filled += transfer;
137		frames -= transfer;
138		ofs = 0;
139	}
140}
141
142#ifdef CONFIG_SND_DEBUG
143void snd_pcm_debug_name(struct snd_pcm_substream *substream,
144			   char *name, size_t len)
145{
146	snprintf(name, len, "pcmC%dD%d%c:%d",
147		 substream->pcm->card->number,
148		 substream->pcm->device,
149		 substream->stream ? 'c' : 'p',
150		 substream->number);
151}
152EXPORT_SYMBOL(snd_pcm_debug_name);
153#endif
154
155#define XRUN_DEBUG_BASIC	(1<<0)
156#define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
157#define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
158
159#ifdef CONFIG_SND_PCM_XRUN_DEBUG
160
161#define xrun_debug(substream, mask) \
162			((substream)->pstr->xrun_debug & (mask))
163#else
164#define xrun_debug(substream, mask)	0
165#endif
166
167#define dump_stack_on_xrun(substream) do {			\
168		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
169			dump_stack();				\
170	} while (0)
171
172static void xrun(struct snd_pcm_substream *substream)
173{
174	struct snd_pcm_runtime *runtime = substream->runtime;
175
176	trace_xrun(substream);
177	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
178		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
179	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
180	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
181		char name[16];
182		snd_pcm_debug_name(substream, name, sizeof(name));
183		pcm_warn(substream->pcm, "XRUN: %s\n", name);
184		dump_stack_on_xrun(substream);
185	}
186}
187
188#ifdef CONFIG_SND_PCM_XRUN_DEBUG
189#define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)	\
190	do {								\
191		trace_hw_ptr_error(substream, reason);	\
192		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
193			pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
194					   (in_interrupt) ? 'Q' : 'P', ##args);	\
195			dump_stack_on_xrun(substream);			\
196		}							\
197	} while (0)
198
199#else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
200
201#define hw_ptr_error(substream, fmt, args...) do { } while (0)
202
203#endif
204
205int snd_pcm_update_state(struct snd_pcm_substream *substream,
206			 struct snd_pcm_runtime *runtime)
207{
208	snd_pcm_uframes_t avail;
209
210	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
211		avail = snd_pcm_playback_avail(runtime);
212	else
213		avail = snd_pcm_capture_avail(runtime);
214	if (avail > runtime->avail_max)
215		runtime->avail_max = avail;
216	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
217		if (avail >= runtime->buffer_size) {
218			snd_pcm_drain_done(substream);
219			return -EPIPE;
220		}
221	} else {
222		if (avail >= runtime->stop_threshold) {
223			xrun(substream);
224			return -EPIPE;
225		}
226	}
227	if (runtime->twake) {
228		if (avail >= runtime->twake)
229			wake_up(&runtime->tsleep);
230	} else if (avail >= runtime->control->avail_min)
231		wake_up(&runtime->sleep);
232	return 0;
233}
234
235static void update_audio_tstamp(struct snd_pcm_substream *substream,
236				struct timespec *curr_tstamp,
237				struct timespec *audio_tstamp)
238{
239	struct snd_pcm_runtime *runtime = substream->runtime;
240	u64 audio_frames, audio_nsecs;
241	struct timespec driver_tstamp;
242
243	if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
244		return;
245
246	if (!(substream->ops->get_time_info) ||
247		(runtime->audio_tstamp_report.actual_type ==
248			SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
249
250		/*
251		 * provide audio timestamp derived from pointer position
252		 * add delay only if requested
253		 */
254
255		audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
256
257		if (runtime->audio_tstamp_config.report_delay) {
258			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
259				audio_frames -=  runtime->delay;
260			else
261				audio_frames +=  runtime->delay;
262		}
263		audio_nsecs = div_u64(audio_frames * 1000000000LL,
264				runtime->rate);
265		*audio_tstamp = ns_to_timespec(audio_nsecs);
266	}
267	runtime->status->audio_tstamp = *audio_tstamp;
268	runtime->status->tstamp = *curr_tstamp;
269
270	/*
271	 * re-take a driver timestamp to let apps detect if the reference tstamp
272	 * read by low-level hardware was provided with a delay
273	 */
274	snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
275	runtime->driver_tstamp = driver_tstamp;
276}
277
278static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
279				  unsigned int in_interrupt)
280{
281	struct snd_pcm_runtime *runtime = substream->runtime;
282	snd_pcm_uframes_t pos;
283	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
284	snd_pcm_sframes_t hdelta, delta;
285	unsigned long jdelta;
286	unsigned long curr_jiffies;
287	struct timespec curr_tstamp;
288	struct timespec audio_tstamp;
289	int crossed_boundary = 0;
290
291	old_hw_ptr = runtime->status->hw_ptr;
292
293	/*
294	 * group pointer, time and jiffies reads to allow for more
295	 * accurate correlations/corrections.
296	 * The values are stored at the end of this routine after
297	 * corrections for hw_ptr position
298	 */
299	pos = substream->ops->pointer(substream);
300	curr_jiffies = jiffies;
301	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
302		if ((substream->ops->get_time_info) &&
303			(runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
304			substream->ops->get_time_info(substream, &curr_tstamp,
305						&audio_tstamp,
306						&runtime->audio_tstamp_config,
307						&runtime->audio_tstamp_report);
308
309			/* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
310			if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
311				snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
312		} else
313			snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
314	}
315
316	if (pos == SNDRV_PCM_POS_XRUN) {
317		xrun(substream);
318		return -EPIPE;
319	}
320	if (pos >= runtime->buffer_size) {
321		if (printk_ratelimit()) {
322			char name[16];
323			snd_pcm_debug_name(substream, name, sizeof(name));
324			pcm_err(substream->pcm,
325				"invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
326				name, pos, runtime->buffer_size,
327				runtime->period_size);
328		}
329		pos = 0;
330	}
331	pos -= pos % runtime->min_align;
332	trace_hwptr(substream, pos, in_interrupt);
333	hw_base = runtime->hw_ptr_base;
334	new_hw_ptr = hw_base + pos;
335	if (in_interrupt) {
336		/* we know that one period was processed */
337		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
338		delta = runtime->hw_ptr_interrupt + runtime->period_size;
339		if (delta > new_hw_ptr) {
340			/* check for double acknowledged interrupts */
341			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
342			if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
343				hw_base += runtime->buffer_size;
344				if (hw_base >= runtime->boundary) {
345					hw_base = 0;
346					crossed_boundary++;
347				}
348				new_hw_ptr = hw_base + pos;
349				goto __delta;
350			}
351		}
352	}
353	/* new_hw_ptr might be lower than old_hw_ptr in case when */
354	/* pointer crosses the end of the ring buffer */
355	if (new_hw_ptr < old_hw_ptr) {
356		hw_base += runtime->buffer_size;
357		if (hw_base >= runtime->boundary) {
358			hw_base = 0;
359			crossed_boundary++;
360		}
361		new_hw_ptr = hw_base + pos;
362	}
363      __delta:
364	delta = new_hw_ptr - old_hw_ptr;
365	if (delta < 0)
366		delta += runtime->boundary;
367
368	if (runtime->no_period_wakeup) {
369		snd_pcm_sframes_t xrun_threshold;
370		/*
371		 * Without regular period interrupts, we have to check
372		 * the elapsed time to detect xruns.
373		 */
374		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
375		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
376			goto no_delta_check;
377		hdelta = jdelta - delta * HZ / runtime->rate;
378		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
379		while (hdelta > xrun_threshold) {
380			delta += runtime->buffer_size;
381			hw_base += runtime->buffer_size;
382			if (hw_base >= runtime->boundary) {
383				hw_base = 0;
384				crossed_boundary++;
385			}
386			new_hw_ptr = hw_base + pos;
387			hdelta -= runtime->hw_ptr_buffer_jiffies;
388		}
389		goto no_delta_check;
390	}
391
392	/* something must be really wrong */
393	if (delta >= runtime->buffer_size + runtime->period_size) {
394		hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
395			     "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
396			     substream->stream, (long)pos,
397			     (long)new_hw_ptr, (long)old_hw_ptr);
398		return 0;
399	}
400
401	/* Do jiffies check only in xrun_debug mode */
402	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
403		goto no_jiffies_check;
404
405	/* Skip the jiffies check for hardwares with BATCH flag.
406	 * Such hardware usually just increases the position at each IRQ,
407	 * thus it can't give any strange position.
408	 */
409	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
410		goto no_jiffies_check;
411	hdelta = delta;
412	if (hdelta < runtime->delay)
413		goto no_jiffies_check;
414	hdelta -= runtime->delay;
415	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
416	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
417		delta = jdelta /
418			(((runtime->period_size * HZ) / runtime->rate)
419								+ HZ/100);
420		/* move new_hw_ptr according jiffies not pos variable */
421		new_hw_ptr = old_hw_ptr;
422		hw_base = delta;
423		/* use loop to avoid checks for delta overflows */
424		/* the delta value is small or zero in most cases */
425		while (delta > 0) {
426			new_hw_ptr += runtime->period_size;
427			if (new_hw_ptr >= runtime->boundary) {
428				new_hw_ptr -= runtime->boundary;
429				crossed_boundary--;
430			}
431			delta--;
432		}
433		/* align hw_base to buffer_size */
434		hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
435			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
436			     (long)pos, (long)hdelta,
437			     (long)runtime->period_size, jdelta,
438			     ((hdelta * HZ) / runtime->rate), hw_base,
439			     (unsigned long)old_hw_ptr,
440			     (unsigned long)new_hw_ptr);
441		/* reset values to proper state */
442		delta = 0;
443		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
444	}
445 no_jiffies_check:
446	if (delta > runtime->period_size + runtime->period_size / 2) {
447		hw_ptr_error(substream, in_interrupt,
448			     "Lost interrupts?",
449			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
450			     substream->stream, (long)delta,
451			     (long)new_hw_ptr,
452			     (long)old_hw_ptr);
453	}
454
455 no_delta_check:
456	if (runtime->status->hw_ptr == new_hw_ptr) {
457		update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
458		return 0;
459	}
460
461	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
462	    runtime->silence_size > 0)
463		snd_pcm_playback_silence(substream, new_hw_ptr);
464
465	if (in_interrupt) {
466		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
467		if (delta < 0)
468			delta += runtime->boundary;
469		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
470		runtime->hw_ptr_interrupt += delta;
471		if (runtime->hw_ptr_interrupt >= runtime->boundary)
472			runtime->hw_ptr_interrupt -= runtime->boundary;
473	}
474	runtime->hw_ptr_base = hw_base;
475	runtime->status->hw_ptr = new_hw_ptr;
476	runtime->hw_ptr_jiffies = curr_jiffies;
477	if (crossed_boundary) {
478		snd_BUG_ON(crossed_boundary != 1);
479		runtime->hw_ptr_wrap += runtime->boundary;
480	}
481
482	update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
483
484	return snd_pcm_update_state(substream, runtime);
485}
486
487/* CAUTION: call it with irq disabled */
488int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
489{
490	return snd_pcm_update_hw_ptr0(substream, 0);
491}
492
493/**
494 * snd_pcm_set_ops - set the PCM operators
495 * @pcm: the pcm instance
496 * @direction: stream direction, SNDRV_PCM_STREAM_XXX
497 * @ops: the operator table
498 *
499 * Sets the given PCM operators to the pcm instance.
500 */
501void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
502		     const struct snd_pcm_ops *ops)
503{
504	struct snd_pcm_str *stream = &pcm->streams[direction];
505	struct snd_pcm_substream *substream;
506
507	for (substream = stream->substream; substream != NULL; substream = substream->next)
508		substream->ops = ops;
509}
510
511EXPORT_SYMBOL(snd_pcm_set_ops);
512
513/**
514 * snd_pcm_sync - set the PCM sync id
515 * @substream: the pcm substream
516 *
517 * Sets the PCM sync identifier for the card.
518 */
519void snd_pcm_set_sync(struct snd_pcm_substream *substream)
520{
521	struct snd_pcm_runtime *runtime = substream->runtime;
522
523	runtime->sync.id32[0] = substream->pcm->card->number;
524	runtime->sync.id32[1] = -1;
525	runtime->sync.id32[2] = -1;
526	runtime->sync.id32[3] = -1;
527}
528
529EXPORT_SYMBOL(snd_pcm_set_sync);
530
531/*
532 *  Standard ioctl routine
533 */
534
535static inline unsigned int div32(unsigned int a, unsigned int b,
536				 unsigned int *r)
537{
538	if (b == 0) {
539		*r = 0;
540		return UINT_MAX;
541	}
542	*r = a % b;
543	return a / b;
544}
545
546static inline unsigned int div_down(unsigned int a, unsigned int b)
547{
548	if (b == 0)
549		return UINT_MAX;
550	return a / b;
551}
552
553static inline unsigned int div_up(unsigned int a, unsigned int b)
554{
555	unsigned int r;
556	unsigned int q;
557	if (b == 0)
558		return UINT_MAX;
559	q = div32(a, b, &r);
560	if (r)
561		++q;
562	return q;
563}
564
565static inline unsigned int mul(unsigned int a, unsigned int b)
566{
567	if (a == 0)
568		return 0;
569	if (div_down(UINT_MAX, a) < b)
570		return UINT_MAX;
571	return a * b;
572}
573
574static inline unsigned int muldiv32(unsigned int a, unsigned int b,
575				    unsigned int c, unsigned int *r)
576{
577	u_int64_t n = (u_int64_t) a * b;
578	if (c == 0) {
579		snd_BUG_ON(!n);
580		*r = 0;
581		return UINT_MAX;
582	}
583	n = div_u64_rem(n, c, r);
584	if (n >= UINT_MAX) {
585		*r = 0;
586		return UINT_MAX;
587	}
588	return n;
589}
590
591/**
592 * snd_interval_refine - refine the interval value of configurator
593 * @i: the interval value to refine
594 * @v: the interval value to refer to
595 *
596 * Refines the interval value with the reference value.
597 * The interval is changed to the range satisfying both intervals.
598 * The interval status (min, max, integer, etc.) are evaluated.
599 *
600 * Return: Positive if the value is changed, zero if it's not changed, or a
601 * negative error code.
602 */
603int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
604{
605	int changed = 0;
606	if (snd_BUG_ON(snd_interval_empty(i)))
607		return -EINVAL;
608	if (i->min < v->min) {
609		i->min = v->min;
610		i->openmin = v->openmin;
611		changed = 1;
612	} else if (i->min == v->min && !i->openmin && v->openmin) {
613		i->openmin = 1;
614		changed = 1;
615	}
616	if (i->max > v->max) {
617		i->max = v->max;
618		i->openmax = v->openmax;
619		changed = 1;
620	} else if (i->max == v->max && !i->openmax && v->openmax) {
621		i->openmax = 1;
622		changed = 1;
623	}
624	if (!i->integer && v->integer) {
625		i->integer = 1;
626		changed = 1;
627	}
628	if (i->integer) {
629		if (i->openmin) {
630			i->min++;
631			i->openmin = 0;
632		}
633		if (i->openmax) {
634			i->max--;
635			i->openmax = 0;
636		}
637	} else if (!i->openmin && !i->openmax && i->min == i->max)
638		i->integer = 1;
639	if (snd_interval_checkempty(i)) {
640		snd_interval_none(i);
641		return -EINVAL;
642	}
643	return changed;
644}
645
646EXPORT_SYMBOL(snd_interval_refine);
647
648static int snd_interval_refine_first(struct snd_interval *i)
649{
650	if (snd_BUG_ON(snd_interval_empty(i)))
651		return -EINVAL;
652	if (snd_interval_single(i))
653		return 0;
654	i->max = i->min;
655	i->openmax = i->openmin;
656	if (i->openmax)
657		i->max++;
658	return 1;
659}
660
661static int snd_interval_refine_last(struct snd_interval *i)
662{
663	if (snd_BUG_ON(snd_interval_empty(i)))
664		return -EINVAL;
665	if (snd_interval_single(i))
666		return 0;
667	i->min = i->max;
668	i->openmin = i->openmax;
669	if (i->openmin)
670		i->min--;
671	return 1;
672}
673
674void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
675{
676	if (a->empty || b->empty) {
677		snd_interval_none(c);
678		return;
679	}
680	c->empty = 0;
681	c->min = mul(a->min, b->min);
682	c->openmin = (a->openmin || b->openmin);
683	c->max = mul(a->max,  b->max);
684	c->openmax = (a->openmax || b->openmax);
685	c->integer = (a->integer && b->integer);
686}
687
688/**
689 * snd_interval_div - refine the interval value with division
690 * @a: dividend
691 * @b: divisor
692 * @c: quotient
693 *
694 * c = a / b
695 *
696 * Returns non-zero if the value is changed, zero if not changed.
697 */
698void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
699{
700	unsigned int r;
701	if (a->empty || b->empty) {
702		snd_interval_none(c);
703		return;
704	}
705	c->empty = 0;
706	c->min = div32(a->min, b->max, &r);
707	c->openmin = (r || a->openmin || b->openmax);
708	if (b->min > 0) {
709		c->max = div32(a->max, b->min, &r);
710		if (r) {
711			c->max++;
712			c->openmax = 1;
713		} else
714			c->openmax = (a->openmax || b->openmin);
715	} else {
716		c->max = UINT_MAX;
717		c->openmax = 0;
718	}
719	c->integer = 0;
720}
721
722/**
723 * snd_interval_muldivk - refine the interval value
724 * @a: dividend 1
725 * @b: dividend 2
726 * @k: divisor (as integer)
727 * @c: result
728  *
729 * c = a * b / k
730 *
731 * Returns non-zero if the value is changed, zero if not changed.
732 */
733void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
734		      unsigned int k, struct snd_interval *c)
735{
736	unsigned int r;
737	if (a->empty || b->empty) {
738		snd_interval_none(c);
739		return;
740	}
741	c->empty = 0;
742	c->min = muldiv32(a->min, b->min, k, &r);
743	c->openmin = (r || a->openmin || b->openmin);
744	c->max = muldiv32(a->max, b->max, k, &r);
745	if (r) {
746		c->max++;
747		c->openmax = 1;
748	} else
749		c->openmax = (a->openmax || b->openmax);
750	c->integer = 0;
751}
752
753/**
754 * snd_interval_mulkdiv - refine the interval value
755 * @a: dividend 1
756 * @k: dividend 2 (as integer)
757 * @b: divisor
758 * @c: result
759 *
760 * c = a * k / b
761 *
762 * Returns non-zero if the value is changed, zero if not changed.
763 */
764void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
765		      const struct snd_interval *b, struct snd_interval *c)
766{
767	unsigned int r;
768	if (a->empty || b->empty) {
769		snd_interval_none(c);
770		return;
771	}
772	c->empty = 0;
773	c->min = muldiv32(a->min, k, b->max, &r);
774	c->openmin = (r || a->openmin || b->openmax);
775	if (b->min > 0) {
776		c->max = muldiv32(a->max, k, b->min, &r);
777		if (r) {
778			c->max++;
779			c->openmax = 1;
780		} else
781			c->openmax = (a->openmax || b->openmin);
782	} else {
783		c->max = UINT_MAX;
784		c->openmax = 0;
785	}
786	c->integer = 0;
787}
788
789/* ---- */
790
791
792/**
793 * snd_interval_ratnum - refine the interval value
794 * @i: interval to refine
795 * @rats_count: number of ratnum_t
796 * @rats: ratnum_t array
797 * @nump: pointer to store the resultant numerator
798 * @denp: pointer to store the resultant denominator
799 *
800 * Return: Positive if the value is changed, zero if it's not changed, or a
801 * negative error code.
802 */
803int snd_interval_ratnum(struct snd_interval *i,
804			unsigned int rats_count, const struct snd_ratnum *rats,
805			unsigned int *nump, unsigned int *denp)
806{
807	unsigned int best_num, best_den;
808	int best_diff;
809	unsigned int k;
810	struct snd_interval t;
811	int err;
812	unsigned int result_num, result_den;
813	int result_diff;
814
815	best_num = best_den = best_diff = 0;
816	for (k = 0; k < rats_count; ++k) {
817		unsigned int num = rats[k].num;
818		unsigned int den;
819		unsigned int q = i->min;
820		int diff;
821		if (q == 0)
822			q = 1;
823		den = div_up(num, q);
824		if (den < rats[k].den_min)
825			continue;
826		if (den > rats[k].den_max)
827			den = rats[k].den_max;
828		else {
829			unsigned int r;
830			r = (den - rats[k].den_min) % rats[k].den_step;
831			if (r != 0)
832				den -= r;
833		}
834		diff = num - q * den;
835		if (diff < 0)
836			diff = -diff;
837		if (best_num == 0 ||
838		    diff * best_den < best_diff * den) {
839			best_diff = diff;
840			best_den = den;
841			best_num = num;
842		}
843	}
844	if (best_den == 0) {
845		i->empty = 1;
846		return -EINVAL;
847	}
848	t.min = div_down(best_num, best_den);
849	t.openmin = !!(best_num % best_den);
850
851	result_num = best_num;
852	result_diff = best_diff;
853	result_den = best_den;
854	best_num = best_den = best_diff = 0;
855	for (k = 0; k < rats_count; ++k) {
856		unsigned int num = rats[k].num;
857		unsigned int den;
858		unsigned int q = i->max;
859		int diff;
860		if (q == 0) {
861			i->empty = 1;
862			return -EINVAL;
863		}
864		den = div_down(num, q);
865		if (den > rats[k].den_max)
866			continue;
867		if (den < rats[k].den_min)
868			den = rats[k].den_min;
869		else {
870			unsigned int r;
871			r = (den - rats[k].den_min) % rats[k].den_step;
872			if (r != 0)
873				den += rats[k].den_step - r;
874		}
875		diff = q * den - num;
876		if (diff < 0)
877			diff = -diff;
878		if (best_num == 0 ||
879		    diff * best_den < best_diff * den) {
880			best_diff = diff;
881			best_den = den;
882			best_num = num;
883		}
884	}
885	if (best_den == 0) {
886		i->empty = 1;
887		return -EINVAL;
888	}
889	t.max = div_up(best_num, best_den);
890	t.openmax = !!(best_num % best_den);
891	t.integer = 0;
892	err = snd_interval_refine(i, &t);
893	if (err < 0)
894		return err;
895
896	if (snd_interval_single(i)) {
897		if (best_diff * result_den < result_diff * best_den) {
898			result_num = best_num;
899			result_den = best_den;
900		}
901		if (nump)
902			*nump = result_num;
903		if (denp)
904			*denp = result_den;
905	}
906	return err;
907}
908
909EXPORT_SYMBOL(snd_interval_ratnum);
910
911/**
912 * snd_interval_ratden - refine the interval value
913 * @i: interval to refine
914 * @rats_count: number of struct ratden
915 * @rats: struct ratden array
916 * @nump: pointer to store the resultant numerator
917 * @denp: pointer to store the resultant denominator
918 *
919 * Return: Positive if the value is changed, zero if it's not changed, or a
920 * negative error code.
921 */
922static int snd_interval_ratden(struct snd_interval *i,
923			       unsigned int rats_count,
924			       const struct snd_ratden *rats,
925			       unsigned int *nump, unsigned int *denp)
926{
927	unsigned int best_num, best_diff, best_den;
928	unsigned int k;
929	struct snd_interval t;
930	int err;
931
932	best_num = best_den = best_diff = 0;
933	for (k = 0; k < rats_count; ++k) {
934		unsigned int num;
935		unsigned int den = rats[k].den;
936		unsigned int q = i->min;
937		int diff;
938		num = mul(q, den);
939		if (num > rats[k].num_max)
940			continue;
941		if (num < rats[k].num_min)
942			num = rats[k].num_max;
943		else {
944			unsigned int r;
945			r = (num - rats[k].num_min) % rats[k].num_step;
946			if (r != 0)
947				num += rats[k].num_step - r;
948		}
949		diff = num - q * den;
950		if (best_num == 0 ||
951		    diff * best_den < best_diff * den) {
952			best_diff = diff;
953			best_den = den;
954			best_num = num;
955		}
956	}
957	if (best_den == 0) {
958		i->empty = 1;
959		return -EINVAL;
960	}
961	t.min = div_down(best_num, best_den);
962	t.openmin = !!(best_num % best_den);
963
964	best_num = best_den = best_diff = 0;
965	for (k = 0; k < rats_count; ++k) {
966		unsigned int num;
967		unsigned int den = rats[k].den;
968		unsigned int q = i->max;
969		int diff;
970		num = mul(q, den);
971		if (num < rats[k].num_min)
972			continue;
973		if (num > rats[k].num_max)
974			num = rats[k].num_max;
975		else {
976			unsigned int r;
977			r = (num - rats[k].num_min) % rats[k].num_step;
978			if (r != 0)
979				num -= r;
980		}
981		diff = q * den - num;
982		if (best_num == 0 ||
983		    diff * best_den < best_diff * den) {
984			best_diff = diff;
985			best_den = den;
986			best_num = num;
987		}
988	}
989	if (best_den == 0) {
990		i->empty = 1;
991		return -EINVAL;
992	}
993	t.max = div_up(best_num, best_den);
994	t.openmax = !!(best_num % best_den);
995	t.integer = 0;
996	err = snd_interval_refine(i, &t);
997	if (err < 0)
998		return err;
999
1000	if (snd_interval_single(i)) {
1001		if (nump)
1002			*nump = best_num;
1003		if (denp)
1004			*denp = best_den;
1005	}
1006	return err;
1007}
1008
1009/**
1010 * snd_interval_list - refine the interval value from the list
1011 * @i: the interval value to refine
1012 * @count: the number of elements in the list
1013 * @list: the value list
1014 * @mask: the bit-mask to evaluate
1015 *
1016 * Refines the interval value from the list.
1017 * When mask is non-zero, only the elements corresponding to bit 1 are
1018 * evaluated.
1019 *
1020 * Return: Positive if the value is changed, zero if it's not changed, or a
1021 * negative error code.
1022 */
1023int snd_interval_list(struct snd_interval *i, unsigned int count,
1024		      const unsigned int *list, unsigned int mask)
1025{
1026        unsigned int k;
1027	struct snd_interval list_range;
1028
1029	if (!count) {
1030		i->empty = 1;
1031		return -EINVAL;
1032	}
1033	snd_interval_any(&list_range);
1034	list_range.min = UINT_MAX;
1035	list_range.max = 0;
1036        for (k = 0; k < count; k++) {
1037		if (mask && !(mask & (1 << k)))
1038			continue;
1039		if (!snd_interval_test(i, list[k]))
1040			continue;
1041		list_range.min = min(list_range.min, list[k]);
1042		list_range.max = max(list_range.max, list[k]);
1043        }
1044	return snd_interval_refine(i, &list_range);
1045}
1046
1047EXPORT_SYMBOL(snd_interval_list);
1048
1049/**
1050 * snd_interval_ranges - refine the interval value from the list of ranges
1051 * @i: the interval value to refine
1052 * @count: the number of elements in the list of ranges
1053 * @ranges: the ranges list
1054 * @mask: the bit-mask to evaluate
1055 *
1056 * Refines the interval value from the list of ranges.
1057 * When mask is non-zero, only the elements corresponding to bit 1 are
1058 * evaluated.
1059 *
1060 * Return: Positive if the value is changed, zero if it's not changed, or a
1061 * negative error code.
1062 */
1063int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1064			const struct snd_interval *ranges, unsigned int mask)
1065{
1066	unsigned int k;
1067	struct snd_interval range_union;
1068	struct snd_interval range;
1069
1070	if (!count) {
1071		snd_interval_none(i);
1072		return -EINVAL;
1073	}
1074	snd_interval_any(&range_union);
1075	range_union.min = UINT_MAX;
1076	range_union.max = 0;
1077	for (k = 0; k < count; k++) {
1078		if (mask && !(mask & (1 << k)))
1079			continue;
1080		snd_interval_copy(&range, &ranges[k]);
1081		if (snd_interval_refine(&range, i) < 0)
1082			continue;
1083		if (snd_interval_empty(&range))
1084			continue;
1085
1086		if (range.min < range_union.min) {
1087			range_union.min = range.min;
1088			range_union.openmin = 1;
1089		}
1090		if (range.min == range_union.min && !range.openmin)
1091			range_union.openmin = 0;
1092		if (range.max > range_union.max) {
1093			range_union.max = range.max;
1094			range_union.openmax = 1;
1095		}
1096		if (range.max == range_union.max && !range.openmax)
1097			range_union.openmax = 0;
1098	}
1099	return snd_interval_refine(i, &range_union);
1100}
1101EXPORT_SYMBOL(snd_interval_ranges);
1102
1103static int snd_interval_step(struct snd_interval *i, unsigned int step)
1104{
1105	unsigned int n;
1106	int changed = 0;
1107	n = i->min % step;
1108	if (n != 0 || i->openmin) {
1109		i->min += step - n;
1110		i->openmin = 0;
1111		changed = 1;
1112	}
1113	n = i->max % step;
1114	if (n != 0 || i->openmax) {
1115		i->max -= n;
1116		i->openmax = 0;
1117		changed = 1;
1118	}
1119	if (snd_interval_checkempty(i)) {
1120		i->empty = 1;
1121		return -EINVAL;
1122	}
1123	return changed;
1124}
1125
1126/* Info constraints helpers */
1127
1128/**
1129 * snd_pcm_hw_rule_add - add the hw-constraint rule
1130 * @runtime: the pcm runtime instance
1131 * @cond: condition bits
1132 * @var: the variable to evaluate
1133 * @func: the evaluation function
1134 * @private: the private data pointer passed to function
1135 * @dep: the dependent variables
1136 *
1137 * Return: Zero if successful, or a negative error code on failure.
1138 */
1139int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1140			int var,
1141			snd_pcm_hw_rule_func_t func, void *private,
1142			int dep, ...)
1143{
1144	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1145	struct snd_pcm_hw_rule *c;
1146	unsigned int k;
1147	va_list args;
1148	va_start(args, dep);
1149	if (constrs->rules_num >= constrs->rules_all) {
1150		struct snd_pcm_hw_rule *new;
1151		unsigned int new_rules = constrs->rules_all + 16;
1152		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1153		if (!new) {
1154			va_end(args);
1155			return -ENOMEM;
1156		}
1157		if (constrs->rules) {
1158			memcpy(new, constrs->rules,
1159			       constrs->rules_num * sizeof(*c));
1160			kfree(constrs->rules);
1161		}
1162		constrs->rules = new;
1163		constrs->rules_all = new_rules;
1164	}
1165	c = &constrs->rules[constrs->rules_num];
1166	c->cond = cond;
1167	c->func = func;
1168	c->var = var;
1169	c->private = private;
1170	k = 0;
1171	while (1) {
1172		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1173			va_end(args);
1174			return -EINVAL;
1175		}
1176		c->deps[k++] = dep;
1177		if (dep < 0)
1178			break;
1179		dep = va_arg(args, int);
1180	}
1181	constrs->rules_num++;
1182	va_end(args);
1183	return 0;
1184}
1185
1186EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1187
1188/**
1189 * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1190 * @runtime: PCM runtime instance
1191 * @var: hw_params variable to apply the mask
1192 * @mask: the bitmap mask
1193 *
1194 * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1195 *
1196 * Return: Zero if successful, or a negative error code on failure.
1197 */
1198int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1199			       u_int32_t mask)
1200{
1201	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1202	struct snd_mask *maskp = constrs_mask(constrs, var);
1203	*maskp->bits &= mask;
1204	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1205	if (*maskp->bits == 0)
1206		return -EINVAL;
1207	return 0;
1208}
1209
1210/**
1211 * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1212 * @runtime: PCM runtime instance
1213 * @var: hw_params variable to apply the mask
1214 * @mask: the 64bit bitmap mask
1215 *
1216 * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1217 *
1218 * Return: Zero if successful, or a negative error code on failure.
1219 */
1220int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1221				 u_int64_t mask)
1222{
1223	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1224	struct snd_mask *maskp = constrs_mask(constrs, var);
1225	maskp->bits[0] &= (u_int32_t)mask;
1226	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1227	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1228	if (! maskp->bits[0] && ! maskp->bits[1])
1229		return -EINVAL;
1230	return 0;
1231}
1232EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1233
1234/**
1235 * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1236 * @runtime: PCM runtime instance
1237 * @var: hw_params variable to apply the integer constraint
1238 *
1239 * Apply the constraint of integer to an interval parameter.
1240 *
1241 * Return: Positive if the value is changed, zero if it's not changed, or a
1242 * negative error code.
1243 */
1244int 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
1250EXPORT_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 * Return: Positive if the value is changed, zero if it's not changed, or a
1262 * negative error code.
1263 */
1264int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1265				 unsigned int min, unsigned int max)
1266{
1267	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1268	struct snd_interval t;
1269	t.min = min;
1270	t.max = max;
1271	t.openmin = t.openmax = 0;
1272	t.integer = 0;
1273	return snd_interval_refine(constrs_interval(constrs, var), &t);
1274}
1275
1276EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1277
1278static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1279				struct snd_pcm_hw_rule *rule)
1280{
1281	struct snd_pcm_hw_constraint_list *list = rule->private;
1282	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1283}
1284
1285
1286/**
1287 * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1288 * @runtime: PCM runtime instance
1289 * @cond: condition bits
1290 * @var: hw_params variable to apply the list constraint
1291 * @l: list
1292 *
1293 * Apply the list of constraints to an interval parameter.
1294 *
1295 * Return: Zero if successful, or a negative error code on failure.
1296 */
1297int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1298			       unsigned int cond,
1299			       snd_pcm_hw_param_t var,
1300			       const struct snd_pcm_hw_constraint_list *l)
1301{
1302	return snd_pcm_hw_rule_add(runtime, cond, var,
1303				   snd_pcm_hw_rule_list, (void *)l,
1304				   var, -1);
1305}
1306
1307EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1308
1309static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1310				  struct snd_pcm_hw_rule *rule)
1311{
1312	struct snd_pcm_hw_constraint_ranges *r = rule->private;
1313	return snd_interval_ranges(hw_param_interval(params, rule->var),
1314				   r->count, r->ranges, r->mask);
1315}
1316
1317
1318/**
1319 * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1320 * @runtime: PCM runtime instance
1321 * @cond: condition bits
1322 * @var: hw_params variable to apply the list of range constraints
1323 * @r: ranges
1324 *
1325 * Apply the list of range constraints to an interval parameter.
1326 *
1327 * Return: Zero if successful, or a negative error code on failure.
1328 */
1329int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1330				 unsigned int cond,
1331				 snd_pcm_hw_param_t var,
1332				 const struct snd_pcm_hw_constraint_ranges *r)
1333{
1334	return snd_pcm_hw_rule_add(runtime, cond, var,
1335				   snd_pcm_hw_rule_ranges, (void *)r,
1336				   var, -1);
1337}
1338EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1339
1340static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1341				   struct snd_pcm_hw_rule *rule)
1342{
1343	const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1344	unsigned int num = 0, den = 0;
1345	int err;
1346	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1347				  r->nrats, r->rats, &num, &den);
1348	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1349		params->rate_num = num;
1350		params->rate_den = den;
1351	}
1352	return err;
1353}
1354
1355/**
1356 * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1357 * @runtime: PCM runtime instance
1358 * @cond: condition bits
1359 * @var: hw_params variable to apply the ratnums constraint
1360 * @r: struct snd_ratnums constriants
1361 *
1362 * Return: Zero if successful, or a negative error code on failure.
1363 */
1364int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1365				  unsigned int cond,
1366				  snd_pcm_hw_param_t var,
1367				  const struct snd_pcm_hw_constraint_ratnums *r)
1368{
1369	return snd_pcm_hw_rule_add(runtime, cond, var,
1370				   snd_pcm_hw_rule_ratnums, (void *)r,
1371				   var, -1);
1372}
1373
1374EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1375
1376static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1377				   struct snd_pcm_hw_rule *rule)
1378{
1379	const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1380	unsigned int num = 0, den = 0;
1381	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1382				  r->nrats, r->rats, &num, &den);
1383	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1384		params->rate_num = num;
1385		params->rate_den = den;
1386	}
1387	return err;
1388}
1389
1390/**
1391 * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1392 * @runtime: PCM runtime instance
1393 * @cond: condition bits
1394 * @var: hw_params variable to apply the ratdens constraint
1395 * @r: struct snd_ratdens constriants
1396 *
1397 * Return: Zero if successful, or a negative error code on failure.
1398 */
1399int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1400				  unsigned int cond,
1401				  snd_pcm_hw_param_t var,
1402				  const struct snd_pcm_hw_constraint_ratdens *r)
1403{
1404	return snd_pcm_hw_rule_add(runtime, cond, var,
1405				   snd_pcm_hw_rule_ratdens, (void *)r,
1406				   var, -1);
1407}
1408
1409EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1410
1411static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1412				  struct snd_pcm_hw_rule *rule)
1413{
1414	unsigned int l = (unsigned long) rule->private;
1415	int width = l & 0xffff;
1416	unsigned int msbits = l >> 16;
1417	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1418
1419	if (!snd_interval_single(i))
1420		return 0;
1421
1422	if ((snd_interval_value(i) == width) ||
1423	    (width == 0 && snd_interval_value(i) > msbits))
1424		params->msbits = min_not_zero(params->msbits, msbits);
1425
1426	return 0;
1427}
1428
1429/**
1430 * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1431 * @runtime: PCM runtime instance
1432 * @cond: condition bits
1433 * @width: sample bits width
1434 * @msbits: msbits width
1435 *
1436 * This constraint will set the number of most significant bits (msbits) if a
1437 * sample format with the specified width has been select. If width is set to 0
1438 * the msbits will be set for any sample format with a width larger than the
1439 * specified msbits.
1440 *
1441 * Return: Zero if successful, or a negative error code on failure.
1442 */
1443int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1444				 unsigned int cond,
1445				 unsigned int width,
1446				 unsigned int msbits)
1447{
1448	unsigned long l = (msbits << 16) | width;
1449	return snd_pcm_hw_rule_add(runtime, cond, -1,
1450				    snd_pcm_hw_rule_msbits,
1451				    (void*) l,
1452				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1453}
1454
1455EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1456
1457static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1458				struct snd_pcm_hw_rule *rule)
1459{
1460	unsigned long step = (unsigned long) rule->private;
1461	return snd_interval_step(hw_param_interval(params, rule->var), step);
1462}
1463
1464/**
1465 * snd_pcm_hw_constraint_step - add a hw constraint step rule
1466 * @runtime: PCM runtime instance
1467 * @cond: condition bits
1468 * @var: hw_params variable to apply the step constraint
1469 * @step: step size
1470 *
1471 * Return: Zero if successful, or a negative error code on failure.
1472 */
1473int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1474			       unsigned int cond,
1475			       snd_pcm_hw_param_t var,
1476			       unsigned long step)
1477{
1478	return snd_pcm_hw_rule_add(runtime, cond, var,
1479				   snd_pcm_hw_rule_step, (void *) step,
1480				   var, -1);
1481}
1482
1483EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1484
1485static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1486{
1487	static unsigned int pow2_sizes[] = {
1488		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1489		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1490		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1491		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1492	};
1493	return snd_interval_list(hw_param_interval(params, rule->var),
1494				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1495}
1496
1497/**
1498 * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1499 * @runtime: PCM runtime instance
1500 * @cond: condition bits
1501 * @var: hw_params variable to apply the power-of-2 constraint
1502 *
1503 * Return: Zero if successful, or a negative error code on failure.
1504 */
1505int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1506			       unsigned int cond,
1507			       snd_pcm_hw_param_t var)
1508{
1509	return snd_pcm_hw_rule_add(runtime, cond, var,
1510				   snd_pcm_hw_rule_pow2, NULL,
1511				   var, -1);
1512}
1513
1514EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1515
1516static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1517					   struct snd_pcm_hw_rule *rule)
1518{
1519	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1520	struct snd_interval *rate;
1521
1522	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1523	return snd_interval_list(rate, 1, &base_rate, 0);
1524}
1525
1526/**
1527 * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1528 * @runtime: PCM runtime instance
1529 * @base_rate: the rate at which the hardware does not resample
1530 *
1531 * Return: Zero if successful, or a negative error code on failure.
1532 */
1533int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1534			       unsigned int base_rate)
1535{
1536	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1537				   SNDRV_PCM_HW_PARAM_RATE,
1538				   snd_pcm_hw_rule_noresample_func,
1539				   (void *)(uintptr_t)base_rate,
1540				   SNDRV_PCM_HW_PARAM_RATE, -1);
1541}
1542EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1543
1544static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1545				  snd_pcm_hw_param_t var)
1546{
1547	if (hw_is_mask(var)) {
1548		snd_mask_any(hw_param_mask(params, var));
1549		params->cmask |= 1 << var;
1550		params->rmask |= 1 << var;
1551		return;
1552	}
1553	if (hw_is_interval(var)) {
1554		snd_interval_any(hw_param_interval(params, var));
1555		params->cmask |= 1 << var;
1556		params->rmask |= 1 << var;
1557		return;
1558	}
1559	snd_BUG();
1560}
1561
1562void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1563{
1564	unsigned int k;
1565	memset(params, 0, sizeof(*params));
1566	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1567		_snd_pcm_hw_param_any(params, k);
1568	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1569		_snd_pcm_hw_param_any(params, k);
1570	params->info = ~0U;
1571}
1572
1573EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1574
1575/**
1576 * snd_pcm_hw_param_value - return @params field @var value
1577 * @params: the hw_params instance
1578 * @var: parameter to retrieve
1579 * @dir: pointer to the direction (-1,0,1) or %NULL
1580 *
1581 * Return: The value for field @var if it's fixed in configuration space
1582 * defined by @params. -%EINVAL otherwise.
1583 */
1584int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1585			   snd_pcm_hw_param_t var, int *dir)
1586{
1587	if (hw_is_mask(var)) {
1588		const struct snd_mask *mask = hw_param_mask_c(params, var);
1589		if (!snd_mask_single(mask))
1590			return -EINVAL;
1591		if (dir)
1592			*dir = 0;
1593		return snd_mask_value(mask);
1594	}
1595	if (hw_is_interval(var)) {
1596		const struct snd_interval *i = hw_param_interval_c(params, var);
1597		if (!snd_interval_single(i))
1598			return -EINVAL;
1599		if (dir)
1600			*dir = i->openmin;
1601		return snd_interval_value(i);
1602	}
1603	return -EINVAL;
1604}
1605
1606EXPORT_SYMBOL(snd_pcm_hw_param_value);
1607
1608void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1609				snd_pcm_hw_param_t var)
1610{
1611	if (hw_is_mask(var)) {
1612		snd_mask_none(hw_param_mask(params, var));
1613		params->cmask |= 1 << var;
1614		params->rmask |= 1 << var;
1615	} else if (hw_is_interval(var)) {
1616		snd_interval_none(hw_param_interval(params, var));
1617		params->cmask |= 1 << var;
1618		params->rmask |= 1 << var;
1619	} else {
1620		snd_BUG();
1621	}
1622}
1623
1624EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1625
1626static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1627				   snd_pcm_hw_param_t var)
1628{
1629	int changed;
1630	if (hw_is_mask(var))
1631		changed = snd_mask_refine_first(hw_param_mask(params, var));
1632	else if (hw_is_interval(var))
1633		changed = snd_interval_refine_first(hw_param_interval(params, var));
1634	else
1635		return -EINVAL;
1636	if (changed) {
1637		params->cmask |= 1 << var;
1638		params->rmask |= 1 << var;
1639	}
1640	return changed;
1641}
1642
1643
1644/**
1645 * snd_pcm_hw_param_first - refine config space and return minimum value
1646 * @pcm: PCM instance
1647 * @params: the hw_params instance
1648 * @var: parameter to retrieve
1649 * @dir: pointer to the direction (-1,0,1) or %NULL
1650 *
1651 * Inside configuration space defined by @params remove from @var all
1652 * values > minimum. Reduce configuration space accordingly.
1653 *
1654 * Return: The minimum, or a negative error code on failure.
1655 */
1656int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1657			   struct snd_pcm_hw_params *params,
1658			   snd_pcm_hw_param_t var, int *dir)
1659{
1660	int changed = _snd_pcm_hw_param_first(params, var);
1661	if (changed < 0)
1662		return changed;
1663	if (params->rmask) {
1664		int err = snd_pcm_hw_refine(pcm, params);
1665		if (snd_BUG_ON(err < 0))
1666			return err;
1667	}
1668	return snd_pcm_hw_param_value(params, var, dir);
1669}
1670
1671EXPORT_SYMBOL(snd_pcm_hw_param_first);
1672
1673static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1674				  snd_pcm_hw_param_t var)
1675{
1676	int changed;
1677	if (hw_is_mask(var))
1678		changed = snd_mask_refine_last(hw_param_mask(params, var));
1679	else if (hw_is_interval(var))
1680		changed = snd_interval_refine_last(hw_param_interval(params, var));
1681	else
1682		return -EINVAL;
1683	if (changed) {
1684		params->cmask |= 1 << var;
1685		params->rmask |= 1 << var;
1686	}
1687	return changed;
1688}
1689
1690
1691/**
1692 * snd_pcm_hw_param_last - refine config space and return maximum value
1693 * @pcm: PCM instance
1694 * @params: the hw_params instance
1695 * @var: parameter to retrieve
1696 * @dir: pointer to the direction (-1,0,1) or %NULL
1697 *
1698 * Inside configuration space defined by @params remove from @var all
1699 * values < maximum. Reduce configuration space accordingly.
1700 *
1701 * Return: The maximum, or a negative error code on failure.
1702 */
1703int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1704			  struct snd_pcm_hw_params *params,
1705			  snd_pcm_hw_param_t var, int *dir)
1706{
1707	int changed = _snd_pcm_hw_param_last(params, var);
1708	if (changed < 0)
1709		return changed;
1710	if (params->rmask) {
1711		int err = snd_pcm_hw_refine(pcm, params);
1712		if (snd_BUG_ON(err < 0))
1713			return err;
1714	}
1715	return snd_pcm_hw_param_value(params, var, dir);
1716}
1717
1718EXPORT_SYMBOL(snd_pcm_hw_param_last);
1719
1720/**
1721 * snd_pcm_hw_param_choose - choose a configuration defined by @params
1722 * @pcm: PCM instance
1723 * @params: the hw_params instance
1724 *
1725 * Choose one configuration from configuration space defined by @params.
1726 * The configuration chosen is that obtained fixing in this order:
1727 * first access, first format, first subformat, min channels,
1728 * min rate, min period time, max buffer size, min tick time
1729 *
1730 * Return: Zero if successful, or a negative error code on failure.
1731 */
1732int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1733			     struct snd_pcm_hw_params *params)
1734{
1735	static int vars[] = {
1736		SNDRV_PCM_HW_PARAM_ACCESS,
1737		SNDRV_PCM_HW_PARAM_FORMAT,
1738		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1739		SNDRV_PCM_HW_PARAM_CHANNELS,
1740		SNDRV_PCM_HW_PARAM_RATE,
1741		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1742		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1743		SNDRV_PCM_HW_PARAM_TICK_TIME,
1744		-1
1745	};
1746	int err, *v;
1747
1748	for (v = vars; *v != -1; v++) {
1749		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1750			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1751		else
1752			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1753		if (snd_BUG_ON(err < 0))
1754			return err;
1755	}
1756	return 0;
1757}
1758
1759static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1760				   void *arg)
1761{
1762	struct snd_pcm_runtime *runtime = substream->runtime;
1763	unsigned long flags;
1764	snd_pcm_stream_lock_irqsave(substream, flags);
1765	if (snd_pcm_running(substream) &&
1766	    snd_pcm_update_hw_ptr(substream) >= 0)
1767		runtime->status->hw_ptr %= runtime->buffer_size;
1768	else {
1769		runtime->status->hw_ptr = 0;
1770		runtime->hw_ptr_wrap = 0;
1771	}
1772	snd_pcm_stream_unlock_irqrestore(substream, flags);
1773	return 0;
1774}
1775
1776static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1777					  void *arg)
1778{
1779	struct snd_pcm_channel_info *info = arg;
1780	struct snd_pcm_runtime *runtime = substream->runtime;
1781	int width;
1782	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1783		info->offset = -1;
1784		return 0;
1785	}
1786	width = snd_pcm_format_physical_width(runtime->format);
1787	if (width < 0)
1788		return width;
1789	info->offset = 0;
1790	switch (runtime->access) {
1791	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1792	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1793		info->first = info->channel * width;
1794		info->step = runtime->channels * width;
1795		break;
1796	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1797	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1798	{
1799		size_t size = runtime->dma_bytes / runtime->channels;
1800		info->first = info->channel * size * 8;
1801		info->step = width;
1802		break;
1803	}
1804	default:
1805		snd_BUG();
1806		break;
1807	}
1808	return 0;
1809}
1810
1811static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1812				       void *arg)
1813{
1814	struct snd_pcm_hw_params *params = arg;
1815	snd_pcm_format_t format;
1816	int channels;
1817	ssize_t frame_size;
1818
1819	params->fifo_size = substream->runtime->hw.fifo_size;
1820	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1821		format = params_format(params);
1822		channels = params_channels(params);
1823		frame_size = snd_pcm_format_size(format, channels);
1824		if (frame_size > 0)
1825			params->fifo_size /= (unsigned)frame_size;
1826	}
1827	return 0;
1828}
1829
1830/**
1831 * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1832 * @substream: the pcm substream instance
1833 * @cmd: ioctl command
1834 * @arg: ioctl argument
1835 *
1836 * Processes the generic ioctl commands for PCM.
1837 * Can be passed as the ioctl callback for PCM ops.
1838 *
1839 * Return: Zero if successful, or a negative error code on failure.
1840 */
1841int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1842		      unsigned int cmd, void *arg)
1843{
1844	switch (cmd) {
1845	case SNDRV_PCM_IOCTL1_INFO:
1846		return 0;
1847	case SNDRV_PCM_IOCTL1_RESET:
1848		return snd_pcm_lib_ioctl_reset(substream, arg);
1849	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1850		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1851	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1852		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1853	}
1854	return -ENXIO;
1855}
1856
1857EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1858
1859/**
1860 * snd_pcm_period_elapsed - update the pcm status for the next period
1861 * @substream: the pcm substream instance
1862 *
1863 * This function is called from the interrupt handler when the
1864 * PCM has processed the period size.  It will update the current
1865 * pointer, wake up sleepers, etc.
1866 *
1867 * Even if more than one periods have elapsed since the last call, you
1868 * have to call this only once.
1869 */
1870void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1871{
1872	struct snd_pcm_runtime *runtime;
1873	unsigned long flags;
1874
1875	if (PCM_RUNTIME_CHECK(substream))
1876		return;
1877	runtime = substream->runtime;
1878
1879	snd_pcm_stream_lock_irqsave(substream, flags);
1880	if (!snd_pcm_running(substream) ||
1881	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1882		goto _end;
1883
1884#ifdef CONFIG_SND_PCM_TIMER
1885	if (substream->timer_running)
1886		snd_timer_interrupt(substream->timer, 1);
1887#endif
1888 _end:
1889	snd_pcm_stream_unlock_irqrestore(substream, flags);
1890	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1891}
1892
1893EXPORT_SYMBOL(snd_pcm_period_elapsed);
1894
1895/*
1896 * Wait until avail_min data becomes available
1897 * Returns a negative error code if any error occurs during operation.
1898 * The available space is stored on availp.  When err = 0 and avail = 0
1899 * on the capture stream, it indicates the stream is in DRAINING state.
1900 */
1901static int wait_for_avail(struct snd_pcm_substream *substream,
1902			      snd_pcm_uframes_t *availp)
1903{
1904	struct snd_pcm_runtime *runtime = substream->runtime;
1905	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1906	wait_queue_t wait;
1907	int err = 0;
1908	snd_pcm_uframes_t avail = 0;
1909	long wait_time, tout;
1910
1911	init_waitqueue_entry(&wait, current);
1912	set_current_state(TASK_INTERRUPTIBLE);
1913	add_wait_queue(&runtime->tsleep, &wait);
1914
1915	if (runtime->no_period_wakeup)
1916		wait_time = MAX_SCHEDULE_TIMEOUT;
1917	else {
1918		wait_time = 10;
1919		if (runtime->rate) {
1920			long t = runtime->period_size * 2 / runtime->rate;
1921			wait_time = max(t, wait_time);
1922		}
1923		wait_time = msecs_to_jiffies(wait_time * 1000);
1924	}
1925
1926	for (;;) {
1927		if (signal_pending(current)) {
1928			err = -ERESTARTSYS;
1929			break;
1930		}
1931
1932		/*
1933		 * We need to check if space became available already
1934		 * (and thus the wakeup happened already) first to close
1935		 * the race of space already having become available.
1936		 * This check must happen after been added to the waitqueue
1937		 * and having current state be INTERRUPTIBLE.
1938		 */
1939		if (is_playback)
1940			avail = snd_pcm_playback_avail(runtime);
1941		else
1942			avail = snd_pcm_capture_avail(runtime);
1943		if (avail >= runtime->twake)
1944			break;
1945		snd_pcm_stream_unlock_irq(substream);
1946
1947		tout = schedule_timeout(wait_time);
1948
1949		snd_pcm_stream_lock_irq(substream);
1950		set_current_state(TASK_INTERRUPTIBLE);
1951		switch (runtime->status->state) {
1952		case SNDRV_PCM_STATE_SUSPENDED:
1953			err = -ESTRPIPE;
1954			goto _endloop;
1955		case SNDRV_PCM_STATE_XRUN:
1956			err = -EPIPE;
1957			goto _endloop;
1958		case SNDRV_PCM_STATE_DRAINING:
1959			if (is_playback)
1960				err = -EPIPE;
1961			else
1962				avail = 0; /* indicate draining */
1963			goto _endloop;
1964		case SNDRV_PCM_STATE_OPEN:
1965		case SNDRV_PCM_STATE_SETUP:
1966		case SNDRV_PCM_STATE_DISCONNECTED:
1967			err = -EBADFD;
1968			goto _endloop;
1969		case SNDRV_PCM_STATE_PAUSED:
1970			continue;
1971		}
1972		if (!tout) {
1973			pcm_dbg(substream->pcm,
1974				"%s write error (DMA or IRQ trouble?)\n",
1975				is_playback ? "playback" : "capture");
1976			err = -EIO;
1977			break;
1978		}
1979	}
1980 _endloop:
1981	set_current_state(TASK_RUNNING);
1982	remove_wait_queue(&runtime->tsleep, &wait);
1983	*availp = avail;
1984	return err;
1985}
1986
1987static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1988				      unsigned int hwoff,
1989				      unsigned long data, unsigned int off,
1990				      snd_pcm_uframes_t frames)
1991{
1992	struct snd_pcm_runtime *runtime = substream->runtime;
1993	int err;
1994	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1995	if (substream->ops->copy) {
1996		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1997			return err;
1998	} else {
1999		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2000		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
2001			return -EFAULT;
2002	}
2003	return 0;
2004}
2005
2006typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
2007			  unsigned long data, unsigned int off,
2008			  snd_pcm_uframes_t size);
2009
2010static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
2011					    unsigned long data,
2012					    snd_pcm_uframes_t size,
2013					    int nonblock,
2014					    transfer_f transfer)
2015{
2016	struct snd_pcm_runtime *runtime = substream->runtime;
2017	snd_pcm_uframes_t xfer = 0;
2018	snd_pcm_uframes_t offset = 0;
2019	snd_pcm_uframes_t avail;
2020	int err = 0;
2021
2022	if (size == 0)
2023		return 0;
2024
2025	snd_pcm_stream_lock_irq(substream);
2026	switch (runtime->status->state) {
2027	case SNDRV_PCM_STATE_PREPARED:
2028	case SNDRV_PCM_STATE_RUNNING:
2029	case SNDRV_PCM_STATE_PAUSED:
2030		break;
2031	case SNDRV_PCM_STATE_XRUN:
2032		err = -EPIPE;
2033		goto _end_unlock;
2034	case SNDRV_PCM_STATE_SUSPENDED:
2035		err = -ESTRPIPE;
2036		goto _end_unlock;
2037	default:
2038		err = -EBADFD;
2039		goto _end_unlock;
2040	}
2041
2042	runtime->twake = runtime->control->avail_min ? : 1;
2043	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2044		snd_pcm_update_hw_ptr(substream);
2045	avail = snd_pcm_playback_avail(runtime);
2046	while (size > 0) {
2047		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2048		snd_pcm_uframes_t cont;
2049		if (!avail) {
2050			if (nonblock) {
2051				err = -EAGAIN;
2052				goto _end_unlock;
2053			}
2054			runtime->twake = min_t(snd_pcm_uframes_t, size,
2055					runtime->control->avail_min ? : 1);
2056			err = wait_for_avail(substream, &avail);
2057			if (err < 0)
2058				goto _end_unlock;
2059		}
2060		frames = size > avail ? avail : size;
2061		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2062		if (frames > cont)
2063			frames = cont;
2064		if (snd_BUG_ON(!frames)) {
2065			runtime->twake = 0;
2066			snd_pcm_stream_unlock_irq(substream);
2067			return -EINVAL;
2068		}
2069		appl_ptr = runtime->control->appl_ptr;
2070		appl_ofs = appl_ptr % runtime->buffer_size;
2071		snd_pcm_stream_unlock_irq(substream);
2072		err = transfer(substream, appl_ofs, data, offset, frames);
2073		snd_pcm_stream_lock_irq(substream);
2074		if (err < 0)
2075			goto _end_unlock;
2076		switch (runtime->status->state) {
2077		case SNDRV_PCM_STATE_XRUN:
2078			err = -EPIPE;
2079			goto _end_unlock;
2080		case SNDRV_PCM_STATE_SUSPENDED:
2081			err = -ESTRPIPE;
2082			goto _end_unlock;
2083		default:
2084			break;
2085		}
2086		appl_ptr += frames;
2087		if (appl_ptr >= runtime->boundary)
2088			appl_ptr -= runtime->boundary;
2089		runtime->control->appl_ptr = appl_ptr;
2090		if (substream->ops->ack)
2091			substream->ops->ack(substream);
2092
2093		offset += frames;
2094		size -= frames;
2095		xfer += frames;
2096		avail -= frames;
2097		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2098		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2099			err = snd_pcm_start(substream);
2100			if (err < 0)
2101				goto _end_unlock;
2102		}
2103	}
2104 _end_unlock:
2105	runtime->twake = 0;
2106	if (xfer > 0 && err >= 0)
2107		snd_pcm_update_state(substream, runtime);
2108	snd_pcm_stream_unlock_irq(substream);
2109	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2110}
2111
2112/* sanity-check for read/write methods */
2113static int pcm_sanity_check(struct snd_pcm_substream *substream)
2114{
2115	struct snd_pcm_runtime *runtime;
2116	if (PCM_RUNTIME_CHECK(substream))
2117		return -ENXIO;
2118	runtime = substream->runtime;
2119	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2120		return -EINVAL;
2121	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2122		return -EBADFD;
2123	return 0;
2124}
2125
2126snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2127{
2128	struct snd_pcm_runtime *runtime;
2129	int nonblock;
2130	int err;
2131
2132	err = pcm_sanity_check(substream);
2133	if (err < 0)
2134		return err;
2135	runtime = substream->runtime;
2136	nonblock = !!(substream->f_flags & O_NONBLOCK);
2137
2138	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2139	    runtime->channels > 1)
2140		return -EINVAL;
2141	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2142				  snd_pcm_lib_write_transfer);
2143}
2144
2145EXPORT_SYMBOL(snd_pcm_lib_write);
2146
2147static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2148				       unsigned int hwoff,
2149				       unsigned long data, unsigned int off,
2150				       snd_pcm_uframes_t frames)
2151{
2152	struct snd_pcm_runtime *runtime = substream->runtime;
2153	int err;
2154	void __user **bufs = (void __user **)data;
2155	int channels = runtime->channels;
2156	int c;
2157	if (substream->ops->copy) {
2158		if (snd_BUG_ON(!substream->ops->silence))
2159			return -EINVAL;
2160		for (c = 0; c < channels; ++c, ++bufs) {
2161			if (*bufs == NULL) {
2162				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2163					return err;
2164			} else {
2165				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2166				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2167					return err;
2168			}
2169		}
2170	} else {
2171		/* default transfer behaviour */
2172		size_t dma_csize = runtime->dma_bytes / channels;
2173		for (c = 0; c < channels; ++c, ++bufs) {
2174			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2175			if (*bufs == NULL) {
2176				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2177			} else {
2178				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2179				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2180					return -EFAULT;
2181			}
2182		}
2183	}
2184	return 0;
2185}
2186
2187snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2188				     void __user **bufs,
2189				     snd_pcm_uframes_t frames)
2190{
2191	struct snd_pcm_runtime *runtime;
2192	int nonblock;
2193	int err;
2194
2195	err = pcm_sanity_check(substream);
2196	if (err < 0)
2197		return err;
2198	runtime = substream->runtime;
2199	nonblock = !!(substream->f_flags & O_NONBLOCK);
2200
2201	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2202		return -EINVAL;
2203	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2204				  nonblock, snd_pcm_lib_writev_transfer);
2205}
2206
2207EXPORT_SYMBOL(snd_pcm_lib_writev);
2208
2209static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2210				     unsigned int hwoff,
2211				     unsigned long data, unsigned int off,
2212				     snd_pcm_uframes_t frames)
2213{
2214	struct snd_pcm_runtime *runtime = substream->runtime;
2215	int err;
2216	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2217	if (substream->ops->copy) {
2218		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2219			return err;
2220	} else {
2221		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2222		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2223			return -EFAULT;
2224	}
2225	return 0;
2226}
2227
2228static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2229					   unsigned long data,
2230					   snd_pcm_uframes_t size,
2231					   int nonblock,
2232					   transfer_f transfer)
2233{
2234	struct snd_pcm_runtime *runtime = substream->runtime;
2235	snd_pcm_uframes_t xfer = 0;
2236	snd_pcm_uframes_t offset = 0;
2237	snd_pcm_uframes_t avail;
2238	int err = 0;
2239
2240	if (size == 0)
2241		return 0;
2242
2243	snd_pcm_stream_lock_irq(substream);
2244	switch (runtime->status->state) {
2245	case SNDRV_PCM_STATE_PREPARED:
2246		if (size >= runtime->start_threshold) {
2247			err = snd_pcm_start(substream);
2248			if (err < 0)
2249				goto _end_unlock;
2250		}
2251		break;
2252	case SNDRV_PCM_STATE_DRAINING:
2253	case SNDRV_PCM_STATE_RUNNING:
2254	case SNDRV_PCM_STATE_PAUSED:
2255		break;
2256	case SNDRV_PCM_STATE_XRUN:
2257		err = -EPIPE;
2258		goto _end_unlock;
2259	case SNDRV_PCM_STATE_SUSPENDED:
2260		err = -ESTRPIPE;
2261		goto _end_unlock;
2262	default:
2263		err = -EBADFD;
2264		goto _end_unlock;
2265	}
2266
2267	runtime->twake = runtime->control->avail_min ? : 1;
2268	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2269		snd_pcm_update_hw_ptr(substream);
2270	avail = snd_pcm_capture_avail(runtime);
2271	while (size > 0) {
2272		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2273		snd_pcm_uframes_t cont;
2274		if (!avail) {
2275			if (runtime->status->state ==
2276			    SNDRV_PCM_STATE_DRAINING) {
2277				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2278				goto _end_unlock;
2279			}
2280			if (nonblock) {
2281				err = -EAGAIN;
2282				goto _end_unlock;
2283			}
2284			runtime->twake = min_t(snd_pcm_uframes_t, size,
2285					runtime->control->avail_min ? : 1);
2286			err = wait_for_avail(substream, &avail);
2287			if (err < 0)
2288				goto _end_unlock;
2289			if (!avail)
2290				continue; /* draining */
2291		}
2292		frames = size > avail ? avail : size;
2293		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2294		if (frames > cont)
2295			frames = cont;
2296		if (snd_BUG_ON(!frames)) {
2297			runtime->twake = 0;
2298			snd_pcm_stream_unlock_irq(substream);
2299			return -EINVAL;
2300		}
2301		appl_ptr = runtime->control->appl_ptr;
2302		appl_ofs = appl_ptr % runtime->buffer_size;
2303		snd_pcm_stream_unlock_irq(substream);
2304		err = transfer(substream, appl_ofs, data, offset, frames);
2305		snd_pcm_stream_lock_irq(substream);
2306		if (err < 0)
2307			goto _end_unlock;
2308		switch (runtime->status->state) {
2309		case SNDRV_PCM_STATE_XRUN:
2310			err = -EPIPE;
2311			goto _end_unlock;
2312		case SNDRV_PCM_STATE_SUSPENDED:
2313			err = -ESTRPIPE;
2314			goto _end_unlock;
2315		default:
2316			break;
2317		}
2318		appl_ptr += frames;
2319		if (appl_ptr >= runtime->boundary)
2320			appl_ptr -= runtime->boundary;
2321		runtime->control->appl_ptr = appl_ptr;
2322		if (substream->ops->ack)
2323			substream->ops->ack(substream);
2324
2325		offset += frames;
2326		size -= frames;
2327		xfer += frames;
2328		avail -= frames;
2329	}
2330 _end_unlock:
2331	runtime->twake = 0;
2332	if (xfer > 0 && err >= 0)
2333		snd_pcm_update_state(substream, runtime);
2334	snd_pcm_stream_unlock_irq(substream);
2335	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2336}
2337
2338snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2339{
2340	struct snd_pcm_runtime *runtime;
2341	int nonblock;
2342	int err;
2343
2344	err = pcm_sanity_check(substream);
2345	if (err < 0)
2346		return err;
2347	runtime = substream->runtime;
2348	nonblock = !!(substream->f_flags & O_NONBLOCK);
2349	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2350		return -EINVAL;
2351	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2352}
2353
2354EXPORT_SYMBOL(snd_pcm_lib_read);
2355
2356static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2357				      unsigned int hwoff,
2358				      unsigned long data, unsigned int off,
2359				      snd_pcm_uframes_t frames)
2360{
2361	struct snd_pcm_runtime *runtime = substream->runtime;
2362	int err;
2363	void __user **bufs = (void __user **)data;
2364	int channels = runtime->channels;
2365	int c;
2366	if (substream->ops->copy) {
2367		for (c = 0; c < channels; ++c, ++bufs) {
2368			char __user *buf;
2369			if (*bufs == NULL)
2370				continue;
2371			buf = *bufs + samples_to_bytes(runtime, off);
2372			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2373				return err;
2374		}
2375	} else {
2376		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2377		for (c = 0; c < channels; ++c, ++bufs) {
2378			char *hwbuf;
2379			char __user *buf;
2380			if (*bufs == NULL)
2381				continue;
2382
2383			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2384			buf = *bufs + samples_to_bytes(runtime, off);
2385			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2386				return -EFAULT;
2387		}
2388	}
2389	return 0;
2390}
2391
2392snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2393				    void __user **bufs,
2394				    snd_pcm_uframes_t frames)
2395{
2396	struct snd_pcm_runtime *runtime;
2397	int nonblock;
2398	int err;
2399
2400	err = pcm_sanity_check(substream);
2401	if (err < 0)
2402		return err;
2403	runtime = substream->runtime;
2404	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2405		return -EBADFD;
2406
2407	nonblock = !!(substream->f_flags & O_NONBLOCK);
2408	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2409		return -EINVAL;
2410	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2411}
2412
2413EXPORT_SYMBOL(snd_pcm_lib_readv);
2414
2415/*
2416 * standard channel mapping helpers
2417 */
2418
2419/* default channel maps for multi-channel playbacks, up to 8 channels */
2420const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2421	{ .channels = 1,
2422	  .map = { SNDRV_CHMAP_MONO } },
2423	{ .channels = 2,
2424	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2425	{ .channels = 4,
2426	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2427		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2428	{ .channels = 6,
2429	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2430		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2431		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2432	{ .channels = 8,
2433	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2434		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2435		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2436		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2437	{ }
2438};
2439EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2440
2441/* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2442const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2443	{ .channels = 1,
2444	  .map = { SNDRV_CHMAP_MONO } },
2445	{ .channels = 2,
2446	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2447	{ .channels = 4,
2448	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2449		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2450	{ .channels = 6,
2451	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2452		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2453		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2454	{ .channels = 8,
2455	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2456		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2457		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2458		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2459	{ }
2460};
2461EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2462
2463static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2464{
2465	if (ch > info->max_channels)
2466		return false;
2467	return !info->channel_mask || (info->channel_mask & (1U << ch));
2468}
2469
2470static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2471			      struct snd_ctl_elem_info *uinfo)
2472{
2473	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2474
2475	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2476	uinfo->count = 0;
2477	uinfo->count = info->max_channels;
2478	uinfo->value.integer.min = 0;
2479	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2480	return 0;
2481}
2482
2483/* get callback for channel map ctl element
2484 * stores the channel position firstly matching with the current channels
2485 */
2486static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2487			     struct snd_ctl_elem_value *ucontrol)
2488{
2489	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2490	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2491	struct snd_pcm_substream *substream;
2492	const struct snd_pcm_chmap_elem *map;
2493
2494	if (snd_BUG_ON(!info->chmap))
2495		return -EINVAL;
2496	substream = snd_pcm_chmap_substream(info, idx);
2497	if (!substream)
2498		return -ENODEV;
2499	memset(ucontrol->value.integer.value, 0,
2500	       sizeof(ucontrol->value.integer.value));
2501	if (!substream->runtime)
2502		return 0; /* no channels set */
2503	for (map = info->chmap; map->channels; map++) {
2504		int i;
2505		if (map->channels == substream->runtime->channels &&
2506		    valid_chmap_channels(info, map->channels)) {
2507			for (i = 0; i < map->channels; i++)
2508				ucontrol->value.integer.value[i] = map->map[i];
2509			return 0;
2510		}
2511	}
2512	return -EINVAL;
2513}
2514
2515/* tlv callback for channel map ctl element
2516 * expands the pre-defined channel maps in a form of TLV
2517 */
2518static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2519			     unsigned int size, unsigned int __user *tlv)
2520{
2521	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2522	const struct snd_pcm_chmap_elem *map;
2523	unsigned int __user *dst;
2524	int c, count = 0;
2525
2526	if (snd_BUG_ON(!info->chmap))
2527		return -EINVAL;
2528	if (size < 8)
2529		return -ENOMEM;
2530	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2531		return -EFAULT;
2532	size -= 8;
2533	dst = tlv + 2;
2534	for (map = info->chmap; map->channels; map++) {
2535		int chs_bytes = map->channels * 4;
2536		if (!valid_chmap_channels(info, map->channels))
2537			continue;
2538		if (size < 8)
2539			return -ENOMEM;
2540		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2541		    put_user(chs_bytes, dst + 1))
2542			return -EFAULT;
2543		dst += 2;
2544		size -= 8;
2545		count += 8;
2546		if (size < chs_bytes)
2547			return -ENOMEM;
2548		size -= chs_bytes;
2549		count += chs_bytes;
2550		for (c = 0; c < map->channels; c++) {
2551			if (put_user(map->map[c], dst))
2552				return -EFAULT;
2553			dst++;
2554		}
2555	}
2556	if (put_user(count, tlv + 1))
2557		return -EFAULT;
2558	return 0;
2559}
2560
2561static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2562{
2563	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2564	info->pcm->streams[info->stream].chmap_kctl = NULL;
2565	kfree(info);
2566}
2567
2568/**
2569 * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2570 * @pcm: the assigned PCM instance
2571 * @stream: stream direction
2572 * @chmap: channel map elements (for query)
2573 * @max_channels: the max number of channels for the stream
2574 * @private_value: the value passed to each kcontrol's private_value field
2575 * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2576 *
2577 * Create channel-mapping control elements assigned to the given PCM stream(s).
2578 * Return: Zero if successful, or a negative error value.
2579 */
2580int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2581			   const struct snd_pcm_chmap_elem *chmap,
2582			   int max_channels,
2583			   unsigned long private_value,
2584			   struct snd_pcm_chmap **info_ret)
2585{
2586	struct snd_pcm_chmap *info;
2587	struct snd_kcontrol_new knew = {
2588		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
2589		.access = SNDRV_CTL_ELEM_ACCESS_READ |
2590			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2591			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2592		.info = pcm_chmap_ctl_info,
2593		.get = pcm_chmap_ctl_get,
2594		.tlv.c = pcm_chmap_ctl_tlv,
2595	};
2596	int err;
2597
2598	info = kzalloc(sizeof(*info), GFP_KERNEL);
2599	if (!info)
2600		return -ENOMEM;
2601	info->pcm = pcm;
2602	info->stream = stream;
2603	info->chmap = chmap;
2604	info->max_channels = max_channels;
2605	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2606		knew.name = "Playback Channel Map";
2607	else
2608		knew.name = "Capture Channel Map";
2609	knew.device = pcm->device;
2610	knew.count = pcm->streams[stream].substream_count;
2611	knew.private_value = private_value;
2612	info->kctl = snd_ctl_new1(&knew, info);
2613	if (!info->kctl) {
2614		kfree(info);
2615		return -ENOMEM;
2616	}
2617	info->kctl->private_free = pcm_chmap_ctl_private_free;
2618	err = snd_ctl_add(pcm->card, info->kctl);
2619	if (err < 0)
2620		return err;
2621	pcm->streams[stream].chmap_kctl = info->kctl;
2622	if (info_ret)
2623		*info_ret = info;
2624	return 0;
2625}
2626EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2627