xref: /linux/sound/core/pcm_lib.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
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  */
53 void 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
143 void 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 }
152 EXPORT_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 
172 static 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 
205 int 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 
235 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
236 				  unsigned int in_interrupt)
237 {
238 	struct snd_pcm_runtime *runtime = substream->runtime;
239 	snd_pcm_uframes_t pos;
240 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
241 	snd_pcm_sframes_t hdelta, delta;
242 	unsigned long jdelta;
243 	unsigned long curr_jiffies;
244 	struct timespec curr_tstamp;
245 	struct timespec audio_tstamp;
246 	int crossed_boundary = 0;
247 
248 	old_hw_ptr = runtime->status->hw_ptr;
249 
250 	/*
251 	 * group pointer, time and jiffies reads to allow for more
252 	 * accurate correlations/corrections.
253 	 * The values are stored at the end of this routine after
254 	 * corrections for hw_ptr position
255 	 */
256 	pos = substream->ops->pointer(substream);
257 	curr_jiffies = jiffies;
258 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
259 		snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
260 
261 		if ((runtime->hw.info & SNDRV_PCM_INFO_HAS_WALL_CLOCK) &&
262 			(substream->ops->wall_clock))
263 			substream->ops->wall_clock(substream, &audio_tstamp);
264 	}
265 
266 	if (pos == SNDRV_PCM_POS_XRUN) {
267 		xrun(substream);
268 		return -EPIPE;
269 	}
270 	if (pos >= runtime->buffer_size) {
271 		if (printk_ratelimit()) {
272 			char name[16];
273 			snd_pcm_debug_name(substream, name, sizeof(name));
274 			pcm_err(substream->pcm,
275 				"BUG: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
276 				name, pos, runtime->buffer_size,
277 				runtime->period_size);
278 		}
279 		pos = 0;
280 	}
281 	pos -= pos % runtime->min_align;
282 	trace_hwptr(substream, pos, in_interrupt);
283 	hw_base = runtime->hw_ptr_base;
284 	new_hw_ptr = hw_base + pos;
285 	if (in_interrupt) {
286 		/* we know that one period was processed */
287 		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
288 		delta = runtime->hw_ptr_interrupt + runtime->period_size;
289 		if (delta > new_hw_ptr) {
290 			/* check for double acknowledged interrupts */
291 			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
292 			if (hdelta > runtime->hw_ptr_buffer_jiffies/2) {
293 				hw_base += runtime->buffer_size;
294 				if (hw_base >= runtime->boundary) {
295 					hw_base = 0;
296 					crossed_boundary++;
297 				}
298 				new_hw_ptr = hw_base + pos;
299 				goto __delta;
300 			}
301 		}
302 	}
303 	/* new_hw_ptr might be lower than old_hw_ptr in case when */
304 	/* pointer crosses the end of the ring buffer */
305 	if (new_hw_ptr < old_hw_ptr) {
306 		hw_base += runtime->buffer_size;
307 		if (hw_base >= runtime->boundary) {
308 			hw_base = 0;
309 			crossed_boundary++;
310 		}
311 		new_hw_ptr = hw_base + pos;
312 	}
313       __delta:
314 	delta = new_hw_ptr - old_hw_ptr;
315 	if (delta < 0)
316 		delta += runtime->boundary;
317 
318 	if (runtime->no_period_wakeup) {
319 		snd_pcm_sframes_t xrun_threshold;
320 		/*
321 		 * Without regular period interrupts, we have to check
322 		 * the elapsed time to detect xruns.
323 		 */
324 		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
325 		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
326 			goto no_delta_check;
327 		hdelta = jdelta - delta * HZ / runtime->rate;
328 		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
329 		while (hdelta > xrun_threshold) {
330 			delta += runtime->buffer_size;
331 			hw_base += runtime->buffer_size;
332 			if (hw_base >= runtime->boundary) {
333 				hw_base = 0;
334 				crossed_boundary++;
335 			}
336 			new_hw_ptr = hw_base + pos;
337 			hdelta -= runtime->hw_ptr_buffer_jiffies;
338 		}
339 		goto no_delta_check;
340 	}
341 
342 	/* something must be really wrong */
343 	if (delta >= runtime->buffer_size + runtime->period_size) {
344 		hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
345 			     "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
346 			     substream->stream, (long)pos,
347 			     (long)new_hw_ptr, (long)old_hw_ptr);
348 		return 0;
349 	}
350 
351 	/* Do jiffies check only in xrun_debug mode */
352 	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
353 		goto no_jiffies_check;
354 
355 	/* Skip the jiffies check for hardwares with BATCH flag.
356 	 * Such hardware usually just increases the position at each IRQ,
357 	 * thus it can't give any strange position.
358 	 */
359 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
360 		goto no_jiffies_check;
361 	hdelta = delta;
362 	if (hdelta < runtime->delay)
363 		goto no_jiffies_check;
364 	hdelta -= runtime->delay;
365 	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
366 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
367 		delta = jdelta /
368 			(((runtime->period_size * HZ) / runtime->rate)
369 								+ HZ/100);
370 		/* move new_hw_ptr according jiffies not pos variable */
371 		new_hw_ptr = old_hw_ptr;
372 		hw_base = delta;
373 		/* use loop to avoid checks for delta overflows */
374 		/* the delta value is small or zero in most cases */
375 		while (delta > 0) {
376 			new_hw_ptr += runtime->period_size;
377 			if (new_hw_ptr >= runtime->boundary) {
378 				new_hw_ptr -= runtime->boundary;
379 				crossed_boundary--;
380 			}
381 			delta--;
382 		}
383 		/* align hw_base to buffer_size */
384 		hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
385 			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
386 			     (long)pos, (long)hdelta,
387 			     (long)runtime->period_size, jdelta,
388 			     ((hdelta * HZ) / runtime->rate), hw_base,
389 			     (unsigned long)old_hw_ptr,
390 			     (unsigned long)new_hw_ptr);
391 		/* reset values to proper state */
392 		delta = 0;
393 		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
394 	}
395  no_jiffies_check:
396 	if (delta > runtime->period_size + runtime->period_size / 2) {
397 		hw_ptr_error(substream, in_interrupt,
398 			     "Lost interrupts?",
399 			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
400 			     substream->stream, (long)delta,
401 			     (long)new_hw_ptr,
402 			     (long)old_hw_ptr);
403 	}
404 
405  no_delta_check:
406 	if (runtime->status->hw_ptr == new_hw_ptr)
407 		return 0;
408 
409 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
410 	    runtime->silence_size > 0)
411 		snd_pcm_playback_silence(substream, new_hw_ptr);
412 
413 	if (in_interrupt) {
414 		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
415 		if (delta < 0)
416 			delta += runtime->boundary;
417 		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
418 		runtime->hw_ptr_interrupt += delta;
419 		if (runtime->hw_ptr_interrupt >= runtime->boundary)
420 			runtime->hw_ptr_interrupt -= runtime->boundary;
421 	}
422 	runtime->hw_ptr_base = hw_base;
423 	runtime->status->hw_ptr = new_hw_ptr;
424 	runtime->hw_ptr_jiffies = curr_jiffies;
425 	if (crossed_boundary) {
426 		snd_BUG_ON(crossed_boundary != 1);
427 		runtime->hw_ptr_wrap += runtime->boundary;
428 	}
429 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
430 		runtime->status->tstamp = curr_tstamp;
431 
432 		if (!(runtime->hw.info & SNDRV_PCM_INFO_HAS_WALL_CLOCK)) {
433 			/*
434 			 * no wall clock available, provide audio timestamp
435 			 * derived from pointer position+delay
436 			 */
437 			u64 audio_frames, audio_nsecs;
438 
439 			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
440 				audio_frames = runtime->hw_ptr_wrap
441 					+ runtime->status->hw_ptr
442 					- runtime->delay;
443 			else
444 				audio_frames = runtime->hw_ptr_wrap
445 					+ runtime->status->hw_ptr
446 					+ runtime->delay;
447 			audio_nsecs = div_u64(audio_frames * 1000000000LL,
448 					runtime->rate);
449 			audio_tstamp = ns_to_timespec(audio_nsecs);
450 		}
451 		runtime->status->audio_tstamp = audio_tstamp;
452 	}
453 
454 	return snd_pcm_update_state(substream, runtime);
455 }
456 
457 /* CAUTION: call it with irq disabled */
458 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
459 {
460 	return snd_pcm_update_hw_ptr0(substream, 0);
461 }
462 
463 /**
464  * snd_pcm_set_ops - set the PCM operators
465  * @pcm: the pcm instance
466  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
467  * @ops: the operator table
468  *
469  * Sets the given PCM operators to the pcm instance.
470  */
471 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
472 		     const struct snd_pcm_ops *ops)
473 {
474 	struct snd_pcm_str *stream = &pcm->streams[direction];
475 	struct snd_pcm_substream *substream;
476 
477 	for (substream = stream->substream; substream != NULL; substream = substream->next)
478 		substream->ops = ops;
479 }
480 
481 EXPORT_SYMBOL(snd_pcm_set_ops);
482 
483 /**
484  * snd_pcm_sync - set the PCM sync id
485  * @substream: the pcm substream
486  *
487  * Sets the PCM sync identifier for the card.
488  */
489 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
490 {
491 	struct snd_pcm_runtime *runtime = substream->runtime;
492 
493 	runtime->sync.id32[0] = substream->pcm->card->number;
494 	runtime->sync.id32[1] = -1;
495 	runtime->sync.id32[2] = -1;
496 	runtime->sync.id32[3] = -1;
497 }
498 
499 EXPORT_SYMBOL(snd_pcm_set_sync);
500 
501 /*
502  *  Standard ioctl routine
503  */
504 
505 static inline unsigned int div32(unsigned int a, unsigned int b,
506 				 unsigned int *r)
507 {
508 	if (b == 0) {
509 		*r = 0;
510 		return UINT_MAX;
511 	}
512 	*r = a % b;
513 	return a / b;
514 }
515 
516 static inline unsigned int div_down(unsigned int a, unsigned int b)
517 {
518 	if (b == 0)
519 		return UINT_MAX;
520 	return a / b;
521 }
522 
523 static inline unsigned int div_up(unsigned int a, unsigned int b)
524 {
525 	unsigned int r;
526 	unsigned int q;
527 	if (b == 0)
528 		return UINT_MAX;
529 	q = div32(a, b, &r);
530 	if (r)
531 		++q;
532 	return q;
533 }
534 
535 static inline unsigned int mul(unsigned int a, unsigned int b)
536 {
537 	if (a == 0)
538 		return 0;
539 	if (div_down(UINT_MAX, a) < b)
540 		return UINT_MAX;
541 	return a * b;
542 }
543 
544 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
545 				    unsigned int c, unsigned int *r)
546 {
547 	u_int64_t n = (u_int64_t) a * b;
548 	if (c == 0) {
549 		snd_BUG_ON(!n);
550 		*r = 0;
551 		return UINT_MAX;
552 	}
553 	n = div_u64_rem(n, c, r);
554 	if (n >= UINT_MAX) {
555 		*r = 0;
556 		return UINT_MAX;
557 	}
558 	return n;
559 }
560 
561 /**
562  * snd_interval_refine - refine the interval value of configurator
563  * @i: the interval value to refine
564  * @v: the interval value to refer to
565  *
566  * Refines the interval value with the reference value.
567  * The interval is changed to the range satisfying both intervals.
568  * The interval status (min, max, integer, etc.) are evaluated.
569  *
570  * Return: Positive if the value is changed, zero if it's not changed, or a
571  * negative error code.
572  */
573 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
574 {
575 	int changed = 0;
576 	if (snd_BUG_ON(snd_interval_empty(i)))
577 		return -EINVAL;
578 	if (i->min < v->min) {
579 		i->min = v->min;
580 		i->openmin = v->openmin;
581 		changed = 1;
582 	} else if (i->min == v->min && !i->openmin && v->openmin) {
583 		i->openmin = 1;
584 		changed = 1;
585 	}
586 	if (i->max > v->max) {
587 		i->max = v->max;
588 		i->openmax = v->openmax;
589 		changed = 1;
590 	} else if (i->max == v->max && !i->openmax && v->openmax) {
591 		i->openmax = 1;
592 		changed = 1;
593 	}
594 	if (!i->integer && v->integer) {
595 		i->integer = 1;
596 		changed = 1;
597 	}
598 	if (i->integer) {
599 		if (i->openmin) {
600 			i->min++;
601 			i->openmin = 0;
602 		}
603 		if (i->openmax) {
604 			i->max--;
605 			i->openmax = 0;
606 		}
607 	} else if (!i->openmin && !i->openmax && i->min == i->max)
608 		i->integer = 1;
609 	if (snd_interval_checkempty(i)) {
610 		snd_interval_none(i);
611 		return -EINVAL;
612 	}
613 	return changed;
614 }
615 
616 EXPORT_SYMBOL(snd_interval_refine);
617 
618 static int snd_interval_refine_first(struct snd_interval *i)
619 {
620 	if (snd_BUG_ON(snd_interval_empty(i)))
621 		return -EINVAL;
622 	if (snd_interval_single(i))
623 		return 0;
624 	i->max = i->min;
625 	i->openmax = i->openmin;
626 	if (i->openmax)
627 		i->max++;
628 	return 1;
629 }
630 
631 static int snd_interval_refine_last(struct snd_interval *i)
632 {
633 	if (snd_BUG_ON(snd_interval_empty(i)))
634 		return -EINVAL;
635 	if (snd_interval_single(i))
636 		return 0;
637 	i->min = i->max;
638 	i->openmin = i->openmax;
639 	if (i->openmin)
640 		i->min--;
641 	return 1;
642 }
643 
644 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
645 {
646 	if (a->empty || b->empty) {
647 		snd_interval_none(c);
648 		return;
649 	}
650 	c->empty = 0;
651 	c->min = mul(a->min, b->min);
652 	c->openmin = (a->openmin || b->openmin);
653 	c->max = mul(a->max,  b->max);
654 	c->openmax = (a->openmax || b->openmax);
655 	c->integer = (a->integer && b->integer);
656 }
657 
658 /**
659  * snd_interval_div - refine the interval value with division
660  * @a: dividend
661  * @b: divisor
662  * @c: quotient
663  *
664  * c = a / b
665  *
666  * Returns non-zero if the value is changed, zero if not changed.
667  */
668 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
669 {
670 	unsigned int r;
671 	if (a->empty || b->empty) {
672 		snd_interval_none(c);
673 		return;
674 	}
675 	c->empty = 0;
676 	c->min = div32(a->min, b->max, &r);
677 	c->openmin = (r || a->openmin || b->openmax);
678 	if (b->min > 0) {
679 		c->max = div32(a->max, b->min, &r);
680 		if (r) {
681 			c->max++;
682 			c->openmax = 1;
683 		} else
684 			c->openmax = (a->openmax || b->openmin);
685 	} else {
686 		c->max = UINT_MAX;
687 		c->openmax = 0;
688 	}
689 	c->integer = 0;
690 }
691 
692 /**
693  * snd_interval_muldivk - refine the interval value
694  * @a: dividend 1
695  * @b: dividend 2
696  * @k: divisor (as integer)
697  * @c: result
698   *
699  * c = a * b / k
700  *
701  * Returns non-zero if the value is changed, zero if not changed.
702  */
703 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
704 		      unsigned int k, struct snd_interval *c)
705 {
706 	unsigned int r;
707 	if (a->empty || b->empty) {
708 		snd_interval_none(c);
709 		return;
710 	}
711 	c->empty = 0;
712 	c->min = muldiv32(a->min, b->min, k, &r);
713 	c->openmin = (r || a->openmin || b->openmin);
714 	c->max = muldiv32(a->max, b->max, k, &r);
715 	if (r) {
716 		c->max++;
717 		c->openmax = 1;
718 	} else
719 		c->openmax = (a->openmax || b->openmax);
720 	c->integer = 0;
721 }
722 
723 /**
724  * snd_interval_mulkdiv - refine the interval value
725  * @a: dividend 1
726  * @k: dividend 2 (as integer)
727  * @b: divisor
728  * @c: result
729  *
730  * c = a * k / b
731  *
732  * Returns non-zero if the value is changed, zero if not changed.
733  */
734 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
735 		      const struct snd_interval *b, struct snd_interval *c)
736 {
737 	unsigned int r;
738 	if (a->empty || b->empty) {
739 		snd_interval_none(c);
740 		return;
741 	}
742 	c->empty = 0;
743 	c->min = muldiv32(a->min, k, b->max, &r);
744 	c->openmin = (r || a->openmin || b->openmax);
745 	if (b->min > 0) {
746 		c->max = muldiv32(a->max, k, b->min, &r);
747 		if (r) {
748 			c->max++;
749 			c->openmax = 1;
750 		} else
751 			c->openmax = (a->openmax || b->openmin);
752 	} else {
753 		c->max = UINT_MAX;
754 		c->openmax = 0;
755 	}
756 	c->integer = 0;
757 }
758 
759 /* ---- */
760 
761 
762 /**
763  * snd_interval_ratnum - refine the interval value
764  * @i: interval to refine
765  * @rats_count: number of ratnum_t
766  * @rats: ratnum_t array
767  * @nump: pointer to store the resultant numerator
768  * @denp: pointer to store the resultant denominator
769  *
770  * Return: Positive if the value is changed, zero if it's not changed, or a
771  * negative error code.
772  */
773 int snd_interval_ratnum(struct snd_interval *i,
774 			unsigned int rats_count, struct snd_ratnum *rats,
775 			unsigned int *nump, unsigned int *denp)
776 {
777 	unsigned int best_num, best_den;
778 	int best_diff;
779 	unsigned int k;
780 	struct snd_interval t;
781 	int err;
782 	unsigned int result_num, result_den;
783 	int result_diff;
784 
785 	best_num = best_den = best_diff = 0;
786 	for (k = 0; k < rats_count; ++k) {
787 		unsigned int num = rats[k].num;
788 		unsigned int den;
789 		unsigned int q = i->min;
790 		int diff;
791 		if (q == 0)
792 			q = 1;
793 		den = div_up(num, q);
794 		if (den < rats[k].den_min)
795 			continue;
796 		if (den > rats[k].den_max)
797 			den = rats[k].den_max;
798 		else {
799 			unsigned int r;
800 			r = (den - rats[k].den_min) % rats[k].den_step;
801 			if (r != 0)
802 				den -= r;
803 		}
804 		diff = num - q * den;
805 		if (diff < 0)
806 			diff = -diff;
807 		if (best_num == 0 ||
808 		    diff * best_den < best_diff * den) {
809 			best_diff = diff;
810 			best_den = den;
811 			best_num = num;
812 		}
813 	}
814 	if (best_den == 0) {
815 		i->empty = 1;
816 		return -EINVAL;
817 	}
818 	t.min = div_down(best_num, best_den);
819 	t.openmin = !!(best_num % best_den);
820 
821 	result_num = best_num;
822 	result_diff = best_diff;
823 	result_den = best_den;
824 	best_num = best_den = best_diff = 0;
825 	for (k = 0; k < rats_count; ++k) {
826 		unsigned int num = rats[k].num;
827 		unsigned int den;
828 		unsigned int q = i->max;
829 		int diff;
830 		if (q == 0) {
831 			i->empty = 1;
832 			return -EINVAL;
833 		}
834 		den = div_down(num, q);
835 		if (den > rats[k].den_max)
836 			continue;
837 		if (den < rats[k].den_min)
838 			den = rats[k].den_min;
839 		else {
840 			unsigned int r;
841 			r = (den - rats[k].den_min) % rats[k].den_step;
842 			if (r != 0)
843 				den += rats[k].den_step - r;
844 		}
845 		diff = q * den - num;
846 		if (diff < 0)
847 			diff = -diff;
848 		if (best_num == 0 ||
849 		    diff * best_den < best_diff * den) {
850 			best_diff = diff;
851 			best_den = den;
852 			best_num = num;
853 		}
854 	}
855 	if (best_den == 0) {
856 		i->empty = 1;
857 		return -EINVAL;
858 	}
859 	t.max = div_up(best_num, best_den);
860 	t.openmax = !!(best_num % best_den);
861 	t.integer = 0;
862 	err = snd_interval_refine(i, &t);
863 	if (err < 0)
864 		return err;
865 
866 	if (snd_interval_single(i)) {
867 		if (best_diff * result_den < result_diff * best_den) {
868 			result_num = best_num;
869 			result_den = best_den;
870 		}
871 		if (nump)
872 			*nump = result_num;
873 		if (denp)
874 			*denp = result_den;
875 	}
876 	return err;
877 }
878 
879 EXPORT_SYMBOL(snd_interval_ratnum);
880 
881 /**
882  * snd_interval_ratden - refine the interval value
883  * @i: interval to refine
884  * @rats_count: number of struct ratden
885  * @rats: struct ratden array
886  * @nump: pointer to store the resultant numerator
887  * @denp: pointer to store the resultant denominator
888  *
889  * Return: Positive if the value is changed, zero if it's not changed, or a
890  * negative error code.
891  */
892 static int snd_interval_ratden(struct snd_interval *i,
893 			       unsigned int rats_count, struct snd_ratden *rats,
894 			       unsigned int *nump, unsigned int *denp)
895 {
896 	unsigned int best_num, best_diff, best_den;
897 	unsigned int k;
898 	struct snd_interval t;
899 	int err;
900 
901 	best_num = best_den = best_diff = 0;
902 	for (k = 0; k < rats_count; ++k) {
903 		unsigned int num;
904 		unsigned int den = rats[k].den;
905 		unsigned int q = i->min;
906 		int diff;
907 		num = mul(q, den);
908 		if (num > rats[k].num_max)
909 			continue;
910 		if (num < rats[k].num_min)
911 			num = rats[k].num_max;
912 		else {
913 			unsigned int r;
914 			r = (num - rats[k].num_min) % rats[k].num_step;
915 			if (r != 0)
916 				num += rats[k].num_step - r;
917 		}
918 		diff = num - q * den;
919 		if (best_num == 0 ||
920 		    diff * best_den < best_diff * den) {
921 			best_diff = diff;
922 			best_den = den;
923 			best_num = num;
924 		}
925 	}
926 	if (best_den == 0) {
927 		i->empty = 1;
928 		return -EINVAL;
929 	}
930 	t.min = div_down(best_num, best_den);
931 	t.openmin = !!(best_num % best_den);
932 
933 	best_num = best_den = best_diff = 0;
934 	for (k = 0; k < rats_count; ++k) {
935 		unsigned int num;
936 		unsigned int den = rats[k].den;
937 		unsigned int q = i->max;
938 		int diff;
939 		num = mul(q, den);
940 		if (num < rats[k].num_min)
941 			continue;
942 		if (num > rats[k].num_max)
943 			num = rats[k].num_max;
944 		else {
945 			unsigned int r;
946 			r = (num - rats[k].num_min) % rats[k].num_step;
947 			if (r != 0)
948 				num -= r;
949 		}
950 		diff = q * den - num;
951 		if (best_num == 0 ||
952 		    diff * best_den < best_diff * den) {
953 			best_diff = diff;
954 			best_den = den;
955 			best_num = num;
956 		}
957 	}
958 	if (best_den == 0) {
959 		i->empty = 1;
960 		return -EINVAL;
961 	}
962 	t.max = div_up(best_num, best_den);
963 	t.openmax = !!(best_num % best_den);
964 	t.integer = 0;
965 	err = snd_interval_refine(i, &t);
966 	if (err < 0)
967 		return err;
968 
969 	if (snd_interval_single(i)) {
970 		if (nump)
971 			*nump = best_num;
972 		if (denp)
973 			*denp = best_den;
974 	}
975 	return err;
976 }
977 
978 /**
979  * snd_interval_list - refine the interval value from the list
980  * @i: the interval value to refine
981  * @count: the number of elements in the list
982  * @list: the value list
983  * @mask: the bit-mask to evaluate
984  *
985  * Refines the interval value from the list.
986  * When mask is non-zero, only the elements corresponding to bit 1 are
987  * evaluated.
988  *
989  * Return: Positive if the value is changed, zero if it's not changed, or a
990  * negative error code.
991  */
992 int snd_interval_list(struct snd_interval *i, unsigned int count,
993 		      const unsigned int *list, unsigned int mask)
994 {
995         unsigned int k;
996 	struct snd_interval list_range;
997 
998 	if (!count) {
999 		i->empty = 1;
1000 		return -EINVAL;
1001 	}
1002 	snd_interval_any(&list_range);
1003 	list_range.min = UINT_MAX;
1004 	list_range.max = 0;
1005         for (k = 0; k < count; k++) {
1006 		if (mask && !(mask & (1 << k)))
1007 			continue;
1008 		if (!snd_interval_test(i, list[k]))
1009 			continue;
1010 		list_range.min = min(list_range.min, list[k]);
1011 		list_range.max = max(list_range.max, list[k]);
1012         }
1013 	return snd_interval_refine(i, &list_range);
1014 }
1015 
1016 EXPORT_SYMBOL(snd_interval_list);
1017 
1018 /**
1019  * snd_interval_ranges - refine the interval value from the list of ranges
1020  * @i: the interval value to refine
1021  * @count: the number of elements in the list of ranges
1022  * @ranges: the ranges list
1023  * @mask: the bit-mask to evaluate
1024  *
1025  * Refines the interval value from the list of ranges.
1026  * When mask is non-zero, only the elements corresponding to bit 1 are
1027  * evaluated.
1028  *
1029  * Return: Positive if the value is changed, zero if it's not changed, or a
1030  * negative error code.
1031  */
1032 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1033 			const struct snd_interval *ranges, unsigned int mask)
1034 {
1035 	unsigned int k;
1036 	struct snd_interval range_union;
1037 	struct snd_interval range;
1038 
1039 	if (!count) {
1040 		snd_interval_none(i);
1041 		return -EINVAL;
1042 	}
1043 	snd_interval_any(&range_union);
1044 	range_union.min = UINT_MAX;
1045 	range_union.max = 0;
1046 	for (k = 0; k < count; k++) {
1047 		if (mask && !(mask & (1 << k)))
1048 			continue;
1049 		snd_interval_copy(&range, &ranges[k]);
1050 		if (snd_interval_refine(&range, i) < 0)
1051 			continue;
1052 		if (snd_interval_empty(&range))
1053 			continue;
1054 
1055 		if (range.min < range_union.min) {
1056 			range_union.min = range.min;
1057 			range_union.openmin = 1;
1058 		}
1059 		if (range.min == range_union.min && !range.openmin)
1060 			range_union.openmin = 0;
1061 		if (range.max > range_union.max) {
1062 			range_union.max = range.max;
1063 			range_union.openmax = 1;
1064 		}
1065 		if (range.max == range_union.max && !range.openmax)
1066 			range_union.openmax = 0;
1067 	}
1068 	return snd_interval_refine(i, &range_union);
1069 }
1070 EXPORT_SYMBOL(snd_interval_ranges);
1071 
1072 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1073 {
1074 	unsigned int n;
1075 	int changed = 0;
1076 	n = i->min % step;
1077 	if (n != 0 || i->openmin) {
1078 		i->min += step - n;
1079 		i->openmin = 0;
1080 		changed = 1;
1081 	}
1082 	n = i->max % step;
1083 	if (n != 0 || i->openmax) {
1084 		i->max -= n;
1085 		i->openmax = 0;
1086 		changed = 1;
1087 	}
1088 	if (snd_interval_checkempty(i)) {
1089 		i->empty = 1;
1090 		return -EINVAL;
1091 	}
1092 	return changed;
1093 }
1094 
1095 /* Info constraints helpers */
1096 
1097 /**
1098  * snd_pcm_hw_rule_add - add the hw-constraint rule
1099  * @runtime: the pcm runtime instance
1100  * @cond: condition bits
1101  * @var: the variable to evaluate
1102  * @func: the evaluation function
1103  * @private: the private data pointer passed to function
1104  * @dep: the dependent variables
1105  *
1106  * Return: Zero if successful, or a negative error code on failure.
1107  */
1108 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1109 			int var,
1110 			snd_pcm_hw_rule_func_t func, void *private,
1111 			int dep, ...)
1112 {
1113 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1114 	struct snd_pcm_hw_rule *c;
1115 	unsigned int k;
1116 	va_list args;
1117 	va_start(args, dep);
1118 	if (constrs->rules_num >= constrs->rules_all) {
1119 		struct snd_pcm_hw_rule *new;
1120 		unsigned int new_rules = constrs->rules_all + 16;
1121 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1122 		if (!new) {
1123 			va_end(args);
1124 			return -ENOMEM;
1125 		}
1126 		if (constrs->rules) {
1127 			memcpy(new, constrs->rules,
1128 			       constrs->rules_num * sizeof(*c));
1129 			kfree(constrs->rules);
1130 		}
1131 		constrs->rules = new;
1132 		constrs->rules_all = new_rules;
1133 	}
1134 	c = &constrs->rules[constrs->rules_num];
1135 	c->cond = cond;
1136 	c->func = func;
1137 	c->var = var;
1138 	c->private = private;
1139 	k = 0;
1140 	while (1) {
1141 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1142 			va_end(args);
1143 			return -EINVAL;
1144 		}
1145 		c->deps[k++] = dep;
1146 		if (dep < 0)
1147 			break;
1148 		dep = va_arg(args, int);
1149 	}
1150 	constrs->rules_num++;
1151 	va_end(args);
1152 	return 0;
1153 }
1154 
1155 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1156 
1157 /**
1158  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1159  * @runtime: PCM runtime instance
1160  * @var: hw_params variable to apply the mask
1161  * @mask: the bitmap mask
1162  *
1163  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1164  *
1165  * Return: Zero if successful, or a negative error code on failure.
1166  */
1167 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1168 			       u_int32_t mask)
1169 {
1170 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1171 	struct snd_mask *maskp = constrs_mask(constrs, var);
1172 	*maskp->bits &= mask;
1173 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1174 	if (*maskp->bits == 0)
1175 		return -EINVAL;
1176 	return 0;
1177 }
1178 
1179 /**
1180  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1181  * @runtime: PCM runtime instance
1182  * @var: hw_params variable to apply the mask
1183  * @mask: the 64bit bitmap mask
1184  *
1185  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1186  *
1187  * Return: Zero if successful, or a negative error code on failure.
1188  */
1189 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1190 				 u_int64_t mask)
1191 {
1192 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1193 	struct snd_mask *maskp = constrs_mask(constrs, var);
1194 	maskp->bits[0] &= (u_int32_t)mask;
1195 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1196 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1197 	if (! maskp->bits[0] && ! maskp->bits[1])
1198 		return -EINVAL;
1199 	return 0;
1200 }
1201 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1202 
1203 /**
1204  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1205  * @runtime: PCM runtime instance
1206  * @var: hw_params variable to apply the integer constraint
1207  *
1208  * Apply the constraint of integer to an interval parameter.
1209  *
1210  * Return: Positive if the value is changed, zero if it's not changed, or a
1211  * negative error code.
1212  */
1213 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1214 {
1215 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1216 	return snd_interval_setinteger(constrs_interval(constrs, var));
1217 }
1218 
1219 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1220 
1221 /**
1222  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1223  * @runtime: PCM runtime instance
1224  * @var: hw_params variable to apply the range
1225  * @min: the minimal value
1226  * @max: the maximal value
1227  *
1228  * Apply the min/max range constraint to an interval parameter.
1229  *
1230  * Return: Positive if the value is changed, zero if it's not changed, or a
1231  * negative error code.
1232  */
1233 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1234 				 unsigned int min, unsigned int max)
1235 {
1236 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1237 	struct snd_interval t;
1238 	t.min = min;
1239 	t.max = max;
1240 	t.openmin = t.openmax = 0;
1241 	t.integer = 0;
1242 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1243 }
1244 
1245 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1246 
1247 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1248 				struct snd_pcm_hw_rule *rule)
1249 {
1250 	struct snd_pcm_hw_constraint_list *list = rule->private;
1251 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1252 }
1253 
1254 
1255 /**
1256  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1257  * @runtime: PCM runtime instance
1258  * @cond: condition bits
1259  * @var: hw_params variable to apply the list constraint
1260  * @l: list
1261  *
1262  * Apply the list of constraints to an interval parameter.
1263  *
1264  * Return: Zero if successful, or a negative error code on failure.
1265  */
1266 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1267 			       unsigned int cond,
1268 			       snd_pcm_hw_param_t var,
1269 			       const struct snd_pcm_hw_constraint_list *l)
1270 {
1271 	return snd_pcm_hw_rule_add(runtime, cond, var,
1272 				   snd_pcm_hw_rule_list, (void *)l,
1273 				   var, -1);
1274 }
1275 
1276 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1277 
1278 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1279 				  struct snd_pcm_hw_rule *rule)
1280 {
1281 	struct snd_pcm_hw_constraint_ranges *r = rule->private;
1282 	return snd_interval_ranges(hw_param_interval(params, rule->var),
1283 				   r->count, r->ranges, r->mask);
1284 }
1285 
1286 
1287 /**
1288  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1289  * @runtime: PCM runtime instance
1290  * @cond: condition bits
1291  * @var: hw_params variable to apply the list of range constraints
1292  * @r: ranges
1293  *
1294  * Apply the list of range constraints to an interval parameter.
1295  *
1296  * Return: Zero if successful, or a negative error code on failure.
1297  */
1298 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1299 				 unsigned int cond,
1300 				 snd_pcm_hw_param_t var,
1301 				 const struct snd_pcm_hw_constraint_ranges *r)
1302 {
1303 	return snd_pcm_hw_rule_add(runtime, cond, var,
1304 				   snd_pcm_hw_rule_ranges, (void *)r,
1305 				   var, -1);
1306 }
1307 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1308 
1309 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1310 				   struct snd_pcm_hw_rule *rule)
1311 {
1312 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1313 	unsigned int num = 0, den = 0;
1314 	int err;
1315 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1316 				  r->nrats, r->rats, &num, &den);
1317 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1318 		params->rate_num = num;
1319 		params->rate_den = den;
1320 	}
1321 	return err;
1322 }
1323 
1324 /**
1325  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1326  * @runtime: PCM runtime instance
1327  * @cond: condition bits
1328  * @var: hw_params variable to apply the ratnums constraint
1329  * @r: struct snd_ratnums constriants
1330  *
1331  * Return: Zero if successful, or a negative error code on failure.
1332  */
1333 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1334 				  unsigned int cond,
1335 				  snd_pcm_hw_param_t var,
1336 				  struct snd_pcm_hw_constraint_ratnums *r)
1337 {
1338 	return snd_pcm_hw_rule_add(runtime, cond, var,
1339 				   snd_pcm_hw_rule_ratnums, r,
1340 				   var, -1);
1341 }
1342 
1343 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1344 
1345 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1346 				   struct snd_pcm_hw_rule *rule)
1347 {
1348 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1349 	unsigned int num = 0, den = 0;
1350 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1351 				  r->nrats, r->rats, &num, &den);
1352 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1353 		params->rate_num = num;
1354 		params->rate_den = den;
1355 	}
1356 	return err;
1357 }
1358 
1359 /**
1360  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1361  * @runtime: PCM runtime instance
1362  * @cond: condition bits
1363  * @var: hw_params variable to apply the ratdens constraint
1364  * @r: struct snd_ratdens constriants
1365  *
1366  * Return: Zero if successful, or a negative error code on failure.
1367  */
1368 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1369 				  unsigned int cond,
1370 				  snd_pcm_hw_param_t var,
1371 				  struct snd_pcm_hw_constraint_ratdens *r)
1372 {
1373 	return snd_pcm_hw_rule_add(runtime, cond, var,
1374 				   snd_pcm_hw_rule_ratdens, r,
1375 				   var, -1);
1376 }
1377 
1378 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1379 
1380 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1381 				  struct snd_pcm_hw_rule *rule)
1382 {
1383 	unsigned int l = (unsigned long) rule->private;
1384 	int width = l & 0xffff;
1385 	unsigned int msbits = l >> 16;
1386 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1387 
1388 	if (!snd_interval_single(i))
1389 		return 0;
1390 
1391 	if ((snd_interval_value(i) == width) ||
1392 	    (width == 0 && snd_interval_value(i) > msbits))
1393 		params->msbits = min_not_zero(params->msbits, msbits);
1394 
1395 	return 0;
1396 }
1397 
1398 /**
1399  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1400  * @runtime: PCM runtime instance
1401  * @cond: condition bits
1402  * @width: sample bits width
1403  * @msbits: msbits width
1404  *
1405  * This constraint will set the number of most significant bits (msbits) if a
1406  * sample format with the specified width has been select. If width is set to 0
1407  * the msbits will be set for any sample format with a width larger than the
1408  * specified msbits.
1409  *
1410  * Return: Zero if successful, or a negative error code on failure.
1411  */
1412 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1413 				 unsigned int cond,
1414 				 unsigned int width,
1415 				 unsigned int msbits)
1416 {
1417 	unsigned long l = (msbits << 16) | width;
1418 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1419 				    snd_pcm_hw_rule_msbits,
1420 				    (void*) l,
1421 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1422 }
1423 
1424 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1425 
1426 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1427 				struct snd_pcm_hw_rule *rule)
1428 {
1429 	unsigned long step = (unsigned long) rule->private;
1430 	return snd_interval_step(hw_param_interval(params, rule->var), step);
1431 }
1432 
1433 /**
1434  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1435  * @runtime: PCM runtime instance
1436  * @cond: condition bits
1437  * @var: hw_params variable to apply the step constraint
1438  * @step: step size
1439  *
1440  * Return: Zero if successful, or a negative error code on failure.
1441  */
1442 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1443 			       unsigned int cond,
1444 			       snd_pcm_hw_param_t var,
1445 			       unsigned long step)
1446 {
1447 	return snd_pcm_hw_rule_add(runtime, cond, var,
1448 				   snd_pcm_hw_rule_step, (void *) step,
1449 				   var, -1);
1450 }
1451 
1452 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1453 
1454 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1455 {
1456 	static unsigned int pow2_sizes[] = {
1457 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1458 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1459 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1460 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1461 	};
1462 	return snd_interval_list(hw_param_interval(params, rule->var),
1463 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1464 }
1465 
1466 /**
1467  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1468  * @runtime: PCM runtime instance
1469  * @cond: condition bits
1470  * @var: hw_params variable to apply the power-of-2 constraint
1471  *
1472  * Return: Zero if successful, or a negative error code on failure.
1473  */
1474 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1475 			       unsigned int cond,
1476 			       snd_pcm_hw_param_t var)
1477 {
1478 	return snd_pcm_hw_rule_add(runtime, cond, var,
1479 				   snd_pcm_hw_rule_pow2, NULL,
1480 				   var, -1);
1481 }
1482 
1483 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1484 
1485 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1486 					   struct snd_pcm_hw_rule *rule)
1487 {
1488 	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1489 	struct snd_interval *rate;
1490 
1491 	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1492 	return snd_interval_list(rate, 1, &base_rate, 0);
1493 }
1494 
1495 /**
1496  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1497  * @runtime: PCM runtime instance
1498  * @base_rate: the rate at which the hardware does not resample
1499  *
1500  * Return: Zero if successful, or a negative error code on failure.
1501  */
1502 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1503 			       unsigned int base_rate)
1504 {
1505 	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1506 				   SNDRV_PCM_HW_PARAM_RATE,
1507 				   snd_pcm_hw_rule_noresample_func,
1508 				   (void *)(uintptr_t)base_rate,
1509 				   SNDRV_PCM_HW_PARAM_RATE, -1);
1510 }
1511 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1512 
1513 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1514 				  snd_pcm_hw_param_t var)
1515 {
1516 	if (hw_is_mask(var)) {
1517 		snd_mask_any(hw_param_mask(params, var));
1518 		params->cmask |= 1 << var;
1519 		params->rmask |= 1 << var;
1520 		return;
1521 	}
1522 	if (hw_is_interval(var)) {
1523 		snd_interval_any(hw_param_interval(params, var));
1524 		params->cmask |= 1 << var;
1525 		params->rmask |= 1 << var;
1526 		return;
1527 	}
1528 	snd_BUG();
1529 }
1530 
1531 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1532 {
1533 	unsigned int k;
1534 	memset(params, 0, sizeof(*params));
1535 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1536 		_snd_pcm_hw_param_any(params, k);
1537 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1538 		_snd_pcm_hw_param_any(params, k);
1539 	params->info = ~0U;
1540 }
1541 
1542 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1543 
1544 /**
1545  * snd_pcm_hw_param_value - return @params field @var value
1546  * @params: the hw_params instance
1547  * @var: parameter to retrieve
1548  * @dir: pointer to the direction (-1,0,1) or %NULL
1549  *
1550  * Return: The value for field @var if it's fixed in configuration space
1551  * defined by @params. -%EINVAL otherwise.
1552  */
1553 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1554 			   snd_pcm_hw_param_t var, int *dir)
1555 {
1556 	if (hw_is_mask(var)) {
1557 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1558 		if (!snd_mask_single(mask))
1559 			return -EINVAL;
1560 		if (dir)
1561 			*dir = 0;
1562 		return snd_mask_value(mask);
1563 	}
1564 	if (hw_is_interval(var)) {
1565 		const struct snd_interval *i = hw_param_interval_c(params, var);
1566 		if (!snd_interval_single(i))
1567 			return -EINVAL;
1568 		if (dir)
1569 			*dir = i->openmin;
1570 		return snd_interval_value(i);
1571 	}
1572 	return -EINVAL;
1573 }
1574 
1575 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1576 
1577 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1578 				snd_pcm_hw_param_t var)
1579 {
1580 	if (hw_is_mask(var)) {
1581 		snd_mask_none(hw_param_mask(params, var));
1582 		params->cmask |= 1 << var;
1583 		params->rmask |= 1 << var;
1584 	} else if (hw_is_interval(var)) {
1585 		snd_interval_none(hw_param_interval(params, var));
1586 		params->cmask |= 1 << var;
1587 		params->rmask |= 1 << var;
1588 	} else {
1589 		snd_BUG();
1590 	}
1591 }
1592 
1593 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1594 
1595 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1596 				   snd_pcm_hw_param_t var)
1597 {
1598 	int changed;
1599 	if (hw_is_mask(var))
1600 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1601 	else if (hw_is_interval(var))
1602 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1603 	else
1604 		return -EINVAL;
1605 	if (changed) {
1606 		params->cmask |= 1 << var;
1607 		params->rmask |= 1 << var;
1608 	}
1609 	return changed;
1610 }
1611 
1612 
1613 /**
1614  * snd_pcm_hw_param_first - refine config space and return minimum value
1615  * @pcm: PCM instance
1616  * @params: the hw_params instance
1617  * @var: parameter to retrieve
1618  * @dir: pointer to the direction (-1,0,1) or %NULL
1619  *
1620  * Inside configuration space defined by @params remove from @var all
1621  * values > minimum. Reduce configuration space accordingly.
1622  *
1623  * Return: The minimum, or a negative error code on failure.
1624  */
1625 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1626 			   struct snd_pcm_hw_params *params,
1627 			   snd_pcm_hw_param_t var, int *dir)
1628 {
1629 	int changed = _snd_pcm_hw_param_first(params, var);
1630 	if (changed < 0)
1631 		return changed;
1632 	if (params->rmask) {
1633 		int err = snd_pcm_hw_refine(pcm, params);
1634 		if (snd_BUG_ON(err < 0))
1635 			return err;
1636 	}
1637 	return snd_pcm_hw_param_value(params, var, dir);
1638 }
1639 
1640 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1641 
1642 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1643 				  snd_pcm_hw_param_t var)
1644 {
1645 	int changed;
1646 	if (hw_is_mask(var))
1647 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1648 	else if (hw_is_interval(var))
1649 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1650 	else
1651 		return -EINVAL;
1652 	if (changed) {
1653 		params->cmask |= 1 << var;
1654 		params->rmask |= 1 << var;
1655 	}
1656 	return changed;
1657 }
1658 
1659 
1660 /**
1661  * snd_pcm_hw_param_last - refine config space and return maximum value
1662  * @pcm: PCM instance
1663  * @params: the hw_params instance
1664  * @var: parameter to retrieve
1665  * @dir: pointer to the direction (-1,0,1) or %NULL
1666  *
1667  * Inside configuration space defined by @params remove from @var all
1668  * values < maximum. Reduce configuration space accordingly.
1669  *
1670  * Return: The maximum, or a negative error code on failure.
1671  */
1672 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1673 			  struct snd_pcm_hw_params *params,
1674 			  snd_pcm_hw_param_t var, int *dir)
1675 {
1676 	int changed = _snd_pcm_hw_param_last(params, var);
1677 	if (changed < 0)
1678 		return changed;
1679 	if (params->rmask) {
1680 		int err = snd_pcm_hw_refine(pcm, params);
1681 		if (snd_BUG_ON(err < 0))
1682 			return err;
1683 	}
1684 	return snd_pcm_hw_param_value(params, var, dir);
1685 }
1686 
1687 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1688 
1689 /**
1690  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1691  * @pcm: PCM instance
1692  * @params: the hw_params instance
1693  *
1694  * Choose one configuration from configuration space defined by @params.
1695  * The configuration chosen is that obtained fixing in this order:
1696  * first access, first format, first subformat, min channels,
1697  * min rate, min period time, max buffer size, min tick time
1698  *
1699  * Return: Zero if successful, or a negative error code on failure.
1700  */
1701 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1702 			     struct snd_pcm_hw_params *params)
1703 {
1704 	static int vars[] = {
1705 		SNDRV_PCM_HW_PARAM_ACCESS,
1706 		SNDRV_PCM_HW_PARAM_FORMAT,
1707 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1708 		SNDRV_PCM_HW_PARAM_CHANNELS,
1709 		SNDRV_PCM_HW_PARAM_RATE,
1710 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1711 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1712 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1713 		-1
1714 	};
1715 	int err, *v;
1716 
1717 	for (v = vars; *v != -1; v++) {
1718 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1719 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1720 		else
1721 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1722 		if (snd_BUG_ON(err < 0))
1723 			return err;
1724 	}
1725 	return 0;
1726 }
1727 
1728 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1729 				   void *arg)
1730 {
1731 	struct snd_pcm_runtime *runtime = substream->runtime;
1732 	unsigned long flags;
1733 	snd_pcm_stream_lock_irqsave(substream, flags);
1734 	if (snd_pcm_running(substream) &&
1735 	    snd_pcm_update_hw_ptr(substream) >= 0)
1736 		runtime->status->hw_ptr %= runtime->buffer_size;
1737 	else {
1738 		runtime->status->hw_ptr = 0;
1739 		runtime->hw_ptr_wrap = 0;
1740 	}
1741 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1742 	return 0;
1743 }
1744 
1745 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1746 					  void *arg)
1747 {
1748 	struct snd_pcm_channel_info *info = arg;
1749 	struct snd_pcm_runtime *runtime = substream->runtime;
1750 	int width;
1751 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1752 		info->offset = -1;
1753 		return 0;
1754 	}
1755 	width = snd_pcm_format_physical_width(runtime->format);
1756 	if (width < 0)
1757 		return width;
1758 	info->offset = 0;
1759 	switch (runtime->access) {
1760 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1761 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1762 		info->first = info->channel * width;
1763 		info->step = runtime->channels * width;
1764 		break;
1765 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1766 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1767 	{
1768 		size_t size = runtime->dma_bytes / runtime->channels;
1769 		info->first = info->channel * size * 8;
1770 		info->step = width;
1771 		break;
1772 	}
1773 	default:
1774 		snd_BUG();
1775 		break;
1776 	}
1777 	return 0;
1778 }
1779 
1780 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1781 				       void *arg)
1782 {
1783 	struct snd_pcm_hw_params *params = arg;
1784 	snd_pcm_format_t format;
1785 	int channels;
1786 	ssize_t frame_size;
1787 
1788 	params->fifo_size = substream->runtime->hw.fifo_size;
1789 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1790 		format = params_format(params);
1791 		channels = params_channels(params);
1792 		frame_size = snd_pcm_format_size(format, channels);
1793 		if (frame_size > 0)
1794 			params->fifo_size /= (unsigned)frame_size;
1795 	}
1796 	return 0;
1797 }
1798 
1799 /**
1800  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1801  * @substream: the pcm substream instance
1802  * @cmd: ioctl command
1803  * @arg: ioctl argument
1804  *
1805  * Processes the generic ioctl commands for PCM.
1806  * Can be passed as the ioctl callback for PCM ops.
1807  *
1808  * Return: Zero if successful, or a negative error code on failure.
1809  */
1810 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1811 		      unsigned int cmd, void *arg)
1812 {
1813 	switch (cmd) {
1814 	case SNDRV_PCM_IOCTL1_INFO:
1815 		return 0;
1816 	case SNDRV_PCM_IOCTL1_RESET:
1817 		return snd_pcm_lib_ioctl_reset(substream, arg);
1818 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1819 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1820 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1821 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1822 	}
1823 	return -ENXIO;
1824 }
1825 
1826 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1827 
1828 /**
1829  * snd_pcm_period_elapsed - update the pcm status for the next period
1830  * @substream: the pcm substream instance
1831  *
1832  * This function is called from the interrupt handler when the
1833  * PCM has processed the period size.  It will update the current
1834  * pointer, wake up sleepers, etc.
1835  *
1836  * Even if more than one periods have elapsed since the last call, you
1837  * have to call this only once.
1838  */
1839 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1840 {
1841 	struct snd_pcm_runtime *runtime;
1842 	unsigned long flags;
1843 
1844 	if (PCM_RUNTIME_CHECK(substream))
1845 		return;
1846 	runtime = substream->runtime;
1847 
1848 	if (runtime->transfer_ack_begin)
1849 		runtime->transfer_ack_begin(substream);
1850 
1851 	snd_pcm_stream_lock_irqsave(substream, flags);
1852 	if (!snd_pcm_running(substream) ||
1853 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1854 		goto _end;
1855 
1856 	if (substream->timer_running)
1857 		snd_timer_interrupt(substream->timer, 1);
1858  _end:
1859 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1860 	if (runtime->transfer_ack_end)
1861 		runtime->transfer_ack_end(substream);
1862 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1863 }
1864 
1865 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1866 
1867 /*
1868  * Wait until avail_min data becomes available
1869  * Returns a negative error code if any error occurs during operation.
1870  * The available space is stored on availp.  When err = 0 and avail = 0
1871  * on the capture stream, it indicates the stream is in DRAINING state.
1872  */
1873 static int wait_for_avail(struct snd_pcm_substream *substream,
1874 			      snd_pcm_uframes_t *availp)
1875 {
1876 	struct snd_pcm_runtime *runtime = substream->runtime;
1877 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1878 	wait_queue_t wait;
1879 	int err = 0;
1880 	snd_pcm_uframes_t avail = 0;
1881 	long wait_time, tout;
1882 
1883 	init_waitqueue_entry(&wait, current);
1884 	set_current_state(TASK_INTERRUPTIBLE);
1885 	add_wait_queue(&runtime->tsleep, &wait);
1886 
1887 	if (runtime->no_period_wakeup)
1888 		wait_time = MAX_SCHEDULE_TIMEOUT;
1889 	else {
1890 		wait_time = 10;
1891 		if (runtime->rate) {
1892 			long t = runtime->period_size * 2 / runtime->rate;
1893 			wait_time = max(t, wait_time);
1894 		}
1895 		wait_time = msecs_to_jiffies(wait_time * 1000);
1896 	}
1897 
1898 	for (;;) {
1899 		if (signal_pending(current)) {
1900 			err = -ERESTARTSYS;
1901 			break;
1902 		}
1903 
1904 		/*
1905 		 * We need to check if space became available already
1906 		 * (and thus the wakeup happened already) first to close
1907 		 * the race of space already having become available.
1908 		 * This check must happen after been added to the waitqueue
1909 		 * and having current state be INTERRUPTIBLE.
1910 		 */
1911 		if (is_playback)
1912 			avail = snd_pcm_playback_avail(runtime);
1913 		else
1914 			avail = snd_pcm_capture_avail(runtime);
1915 		if (avail >= runtime->twake)
1916 			break;
1917 		snd_pcm_stream_unlock_irq(substream);
1918 
1919 		tout = schedule_timeout(wait_time);
1920 
1921 		snd_pcm_stream_lock_irq(substream);
1922 		set_current_state(TASK_INTERRUPTIBLE);
1923 		switch (runtime->status->state) {
1924 		case SNDRV_PCM_STATE_SUSPENDED:
1925 			err = -ESTRPIPE;
1926 			goto _endloop;
1927 		case SNDRV_PCM_STATE_XRUN:
1928 			err = -EPIPE;
1929 			goto _endloop;
1930 		case SNDRV_PCM_STATE_DRAINING:
1931 			if (is_playback)
1932 				err = -EPIPE;
1933 			else
1934 				avail = 0; /* indicate draining */
1935 			goto _endloop;
1936 		case SNDRV_PCM_STATE_OPEN:
1937 		case SNDRV_PCM_STATE_SETUP:
1938 		case SNDRV_PCM_STATE_DISCONNECTED:
1939 			err = -EBADFD;
1940 			goto _endloop;
1941 		case SNDRV_PCM_STATE_PAUSED:
1942 			continue;
1943 		}
1944 		if (!tout) {
1945 			pcm_dbg(substream->pcm,
1946 				"%s write error (DMA or IRQ trouble?)\n",
1947 				is_playback ? "playback" : "capture");
1948 			err = -EIO;
1949 			break;
1950 		}
1951 	}
1952  _endloop:
1953 	set_current_state(TASK_RUNNING);
1954 	remove_wait_queue(&runtime->tsleep, &wait);
1955 	*availp = avail;
1956 	return err;
1957 }
1958 
1959 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1960 				      unsigned int hwoff,
1961 				      unsigned long data, unsigned int off,
1962 				      snd_pcm_uframes_t frames)
1963 {
1964 	struct snd_pcm_runtime *runtime = substream->runtime;
1965 	int err;
1966 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1967 	if (substream->ops->copy) {
1968 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1969 			return err;
1970 	} else {
1971 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1972 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1973 			return -EFAULT;
1974 	}
1975 	return 0;
1976 }
1977 
1978 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1979 			  unsigned long data, unsigned int off,
1980 			  snd_pcm_uframes_t size);
1981 
1982 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1983 					    unsigned long data,
1984 					    snd_pcm_uframes_t size,
1985 					    int nonblock,
1986 					    transfer_f transfer)
1987 {
1988 	struct snd_pcm_runtime *runtime = substream->runtime;
1989 	snd_pcm_uframes_t xfer = 0;
1990 	snd_pcm_uframes_t offset = 0;
1991 	snd_pcm_uframes_t avail;
1992 	int err = 0;
1993 
1994 	if (size == 0)
1995 		return 0;
1996 
1997 	snd_pcm_stream_lock_irq(substream);
1998 	switch (runtime->status->state) {
1999 	case SNDRV_PCM_STATE_PREPARED:
2000 	case SNDRV_PCM_STATE_RUNNING:
2001 	case SNDRV_PCM_STATE_PAUSED:
2002 		break;
2003 	case SNDRV_PCM_STATE_XRUN:
2004 		err = -EPIPE;
2005 		goto _end_unlock;
2006 	case SNDRV_PCM_STATE_SUSPENDED:
2007 		err = -ESTRPIPE;
2008 		goto _end_unlock;
2009 	default:
2010 		err = -EBADFD;
2011 		goto _end_unlock;
2012 	}
2013 
2014 	runtime->twake = runtime->control->avail_min ? : 1;
2015 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2016 		snd_pcm_update_hw_ptr(substream);
2017 	avail = snd_pcm_playback_avail(runtime);
2018 	while (size > 0) {
2019 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2020 		snd_pcm_uframes_t cont;
2021 		if (!avail) {
2022 			if (nonblock) {
2023 				err = -EAGAIN;
2024 				goto _end_unlock;
2025 			}
2026 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2027 					runtime->control->avail_min ? : 1);
2028 			err = wait_for_avail(substream, &avail);
2029 			if (err < 0)
2030 				goto _end_unlock;
2031 		}
2032 		frames = size > avail ? avail : size;
2033 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2034 		if (frames > cont)
2035 			frames = cont;
2036 		if (snd_BUG_ON(!frames)) {
2037 			runtime->twake = 0;
2038 			snd_pcm_stream_unlock_irq(substream);
2039 			return -EINVAL;
2040 		}
2041 		appl_ptr = runtime->control->appl_ptr;
2042 		appl_ofs = appl_ptr % runtime->buffer_size;
2043 		snd_pcm_stream_unlock_irq(substream);
2044 		err = transfer(substream, appl_ofs, data, offset, frames);
2045 		snd_pcm_stream_lock_irq(substream);
2046 		if (err < 0)
2047 			goto _end_unlock;
2048 		switch (runtime->status->state) {
2049 		case SNDRV_PCM_STATE_XRUN:
2050 			err = -EPIPE;
2051 			goto _end_unlock;
2052 		case SNDRV_PCM_STATE_SUSPENDED:
2053 			err = -ESTRPIPE;
2054 			goto _end_unlock;
2055 		default:
2056 			break;
2057 		}
2058 		appl_ptr += frames;
2059 		if (appl_ptr >= runtime->boundary)
2060 			appl_ptr -= runtime->boundary;
2061 		runtime->control->appl_ptr = appl_ptr;
2062 		if (substream->ops->ack)
2063 			substream->ops->ack(substream);
2064 
2065 		offset += frames;
2066 		size -= frames;
2067 		xfer += frames;
2068 		avail -= frames;
2069 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2070 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2071 			err = snd_pcm_start(substream);
2072 			if (err < 0)
2073 				goto _end_unlock;
2074 		}
2075 	}
2076  _end_unlock:
2077 	runtime->twake = 0;
2078 	if (xfer > 0 && err >= 0)
2079 		snd_pcm_update_state(substream, runtime);
2080 	snd_pcm_stream_unlock_irq(substream);
2081 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2082 }
2083 
2084 /* sanity-check for read/write methods */
2085 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2086 {
2087 	struct snd_pcm_runtime *runtime;
2088 	if (PCM_RUNTIME_CHECK(substream))
2089 		return -ENXIO;
2090 	runtime = substream->runtime;
2091 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2092 		return -EINVAL;
2093 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2094 		return -EBADFD;
2095 	return 0;
2096 }
2097 
2098 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2099 {
2100 	struct snd_pcm_runtime *runtime;
2101 	int nonblock;
2102 	int err;
2103 
2104 	err = pcm_sanity_check(substream);
2105 	if (err < 0)
2106 		return err;
2107 	runtime = substream->runtime;
2108 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2109 
2110 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2111 	    runtime->channels > 1)
2112 		return -EINVAL;
2113 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2114 				  snd_pcm_lib_write_transfer);
2115 }
2116 
2117 EXPORT_SYMBOL(snd_pcm_lib_write);
2118 
2119 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2120 				       unsigned int hwoff,
2121 				       unsigned long data, unsigned int off,
2122 				       snd_pcm_uframes_t frames)
2123 {
2124 	struct snd_pcm_runtime *runtime = substream->runtime;
2125 	int err;
2126 	void __user **bufs = (void __user **)data;
2127 	int channels = runtime->channels;
2128 	int c;
2129 	if (substream->ops->copy) {
2130 		if (snd_BUG_ON(!substream->ops->silence))
2131 			return -EINVAL;
2132 		for (c = 0; c < channels; ++c, ++bufs) {
2133 			if (*bufs == NULL) {
2134 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2135 					return err;
2136 			} else {
2137 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2138 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2139 					return err;
2140 			}
2141 		}
2142 	} else {
2143 		/* default transfer behaviour */
2144 		size_t dma_csize = runtime->dma_bytes / channels;
2145 		for (c = 0; c < channels; ++c, ++bufs) {
2146 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2147 			if (*bufs == NULL) {
2148 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2149 			} else {
2150 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2151 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2152 					return -EFAULT;
2153 			}
2154 		}
2155 	}
2156 	return 0;
2157 }
2158 
2159 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2160 				     void __user **bufs,
2161 				     snd_pcm_uframes_t frames)
2162 {
2163 	struct snd_pcm_runtime *runtime;
2164 	int nonblock;
2165 	int err;
2166 
2167 	err = pcm_sanity_check(substream);
2168 	if (err < 0)
2169 		return err;
2170 	runtime = substream->runtime;
2171 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2172 
2173 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2174 		return -EINVAL;
2175 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2176 				  nonblock, snd_pcm_lib_writev_transfer);
2177 }
2178 
2179 EXPORT_SYMBOL(snd_pcm_lib_writev);
2180 
2181 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2182 				     unsigned int hwoff,
2183 				     unsigned long data, unsigned int off,
2184 				     snd_pcm_uframes_t frames)
2185 {
2186 	struct snd_pcm_runtime *runtime = substream->runtime;
2187 	int err;
2188 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2189 	if (substream->ops->copy) {
2190 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2191 			return err;
2192 	} else {
2193 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2194 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2195 			return -EFAULT;
2196 	}
2197 	return 0;
2198 }
2199 
2200 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2201 					   unsigned long data,
2202 					   snd_pcm_uframes_t size,
2203 					   int nonblock,
2204 					   transfer_f transfer)
2205 {
2206 	struct snd_pcm_runtime *runtime = substream->runtime;
2207 	snd_pcm_uframes_t xfer = 0;
2208 	snd_pcm_uframes_t offset = 0;
2209 	snd_pcm_uframes_t avail;
2210 	int err = 0;
2211 
2212 	if (size == 0)
2213 		return 0;
2214 
2215 	snd_pcm_stream_lock_irq(substream);
2216 	switch (runtime->status->state) {
2217 	case SNDRV_PCM_STATE_PREPARED:
2218 		if (size >= runtime->start_threshold) {
2219 			err = snd_pcm_start(substream);
2220 			if (err < 0)
2221 				goto _end_unlock;
2222 		}
2223 		break;
2224 	case SNDRV_PCM_STATE_DRAINING:
2225 	case SNDRV_PCM_STATE_RUNNING:
2226 	case SNDRV_PCM_STATE_PAUSED:
2227 		break;
2228 	case SNDRV_PCM_STATE_XRUN:
2229 		err = -EPIPE;
2230 		goto _end_unlock;
2231 	case SNDRV_PCM_STATE_SUSPENDED:
2232 		err = -ESTRPIPE;
2233 		goto _end_unlock;
2234 	default:
2235 		err = -EBADFD;
2236 		goto _end_unlock;
2237 	}
2238 
2239 	runtime->twake = runtime->control->avail_min ? : 1;
2240 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2241 		snd_pcm_update_hw_ptr(substream);
2242 	avail = snd_pcm_capture_avail(runtime);
2243 	while (size > 0) {
2244 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2245 		snd_pcm_uframes_t cont;
2246 		if (!avail) {
2247 			if (runtime->status->state ==
2248 			    SNDRV_PCM_STATE_DRAINING) {
2249 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2250 				goto _end_unlock;
2251 			}
2252 			if (nonblock) {
2253 				err = -EAGAIN;
2254 				goto _end_unlock;
2255 			}
2256 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2257 					runtime->control->avail_min ? : 1);
2258 			err = wait_for_avail(substream, &avail);
2259 			if (err < 0)
2260 				goto _end_unlock;
2261 			if (!avail)
2262 				continue; /* draining */
2263 		}
2264 		frames = size > avail ? avail : size;
2265 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2266 		if (frames > cont)
2267 			frames = cont;
2268 		if (snd_BUG_ON(!frames)) {
2269 			runtime->twake = 0;
2270 			snd_pcm_stream_unlock_irq(substream);
2271 			return -EINVAL;
2272 		}
2273 		appl_ptr = runtime->control->appl_ptr;
2274 		appl_ofs = appl_ptr % runtime->buffer_size;
2275 		snd_pcm_stream_unlock_irq(substream);
2276 		err = transfer(substream, appl_ofs, data, offset, frames);
2277 		snd_pcm_stream_lock_irq(substream);
2278 		if (err < 0)
2279 			goto _end_unlock;
2280 		switch (runtime->status->state) {
2281 		case SNDRV_PCM_STATE_XRUN:
2282 			err = -EPIPE;
2283 			goto _end_unlock;
2284 		case SNDRV_PCM_STATE_SUSPENDED:
2285 			err = -ESTRPIPE;
2286 			goto _end_unlock;
2287 		default:
2288 			break;
2289 		}
2290 		appl_ptr += frames;
2291 		if (appl_ptr >= runtime->boundary)
2292 			appl_ptr -= runtime->boundary;
2293 		runtime->control->appl_ptr = appl_ptr;
2294 		if (substream->ops->ack)
2295 			substream->ops->ack(substream);
2296 
2297 		offset += frames;
2298 		size -= frames;
2299 		xfer += frames;
2300 		avail -= frames;
2301 	}
2302  _end_unlock:
2303 	runtime->twake = 0;
2304 	if (xfer > 0 && err >= 0)
2305 		snd_pcm_update_state(substream, runtime);
2306 	snd_pcm_stream_unlock_irq(substream);
2307 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2308 }
2309 
2310 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2311 {
2312 	struct snd_pcm_runtime *runtime;
2313 	int nonblock;
2314 	int err;
2315 
2316 	err = pcm_sanity_check(substream);
2317 	if (err < 0)
2318 		return err;
2319 	runtime = substream->runtime;
2320 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2321 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2322 		return -EINVAL;
2323 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2324 }
2325 
2326 EXPORT_SYMBOL(snd_pcm_lib_read);
2327 
2328 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2329 				      unsigned int hwoff,
2330 				      unsigned long data, unsigned int off,
2331 				      snd_pcm_uframes_t frames)
2332 {
2333 	struct snd_pcm_runtime *runtime = substream->runtime;
2334 	int err;
2335 	void __user **bufs = (void __user **)data;
2336 	int channels = runtime->channels;
2337 	int c;
2338 	if (substream->ops->copy) {
2339 		for (c = 0; c < channels; ++c, ++bufs) {
2340 			char __user *buf;
2341 			if (*bufs == NULL)
2342 				continue;
2343 			buf = *bufs + samples_to_bytes(runtime, off);
2344 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2345 				return err;
2346 		}
2347 	} else {
2348 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2349 		for (c = 0; c < channels; ++c, ++bufs) {
2350 			char *hwbuf;
2351 			char __user *buf;
2352 			if (*bufs == NULL)
2353 				continue;
2354 
2355 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2356 			buf = *bufs + samples_to_bytes(runtime, off);
2357 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2358 				return -EFAULT;
2359 		}
2360 	}
2361 	return 0;
2362 }
2363 
2364 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2365 				    void __user **bufs,
2366 				    snd_pcm_uframes_t frames)
2367 {
2368 	struct snd_pcm_runtime *runtime;
2369 	int nonblock;
2370 	int err;
2371 
2372 	err = pcm_sanity_check(substream);
2373 	if (err < 0)
2374 		return err;
2375 	runtime = substream->runtime;
2376 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2377 		return -EBADFD;
2378 
2379 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2380 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2381 		return -EINVAL;
2382 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2383 }
2384 
2385 EXPORT_SYMBOL(snd_pcm_lib_readv);
2386 
2387 /*
2388  * standard channel mapping helpers
2389  */
2390 
2391 /* default channel maps for multi-channel playbacks, up to 8 channels */
2392 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2393 	{ .channels = 1,
2394 	  .map = { SNDRV_CHMAP_MONO } },
2395 	{ .channels = 2,
2396 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2397 	{ .channels = 4,
2398 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2399 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2400 	{ .channels = 6,
2401 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2402 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2403 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2404 	{ .channels = 8,
2405 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2406 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2407 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2408 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2409 	{ }
2410 };
2411 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2412 
2413 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2414 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2415 	{ .channels = 1,
2416 	  .map = { SNDRV_CHMAP_MONO } },
2417 	{ .channels = 2,
2418 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2419 	{ .channels = 4,
2420 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2421 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2422 	{ .channels = 6,
2423 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2424 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2425 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2426 	{ .channels = 8,
2427 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2428 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2429 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2430 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2431 	{ }
2432 };
2433 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2434 
2435 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2436 {
2437 	if (ch > info->max_channels)
2438 		return false;
2439 	return !info->channel_mask || (info->channel_mask & (1U << ch));
2440 }
2441 
2442 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2443 			      struct snd_ctl_elem_info *uinfo)
2444 {
2445 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2446 
2447 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2448 	uinfo->count = 0;
2449 	uinfo->count = info->max_channels;
2450 	uinfo->value.integer.min = 0;
2451 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2452 	return 0;
2453 }
2454 
2455 /* get callback for channel map ctl element
2456  * stores the channel position firstly matching with the current channels
2457  */
2458 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2459 			     struct snd_ctl_elem_value *ucontrol)
2460 {
2461 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2462 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2463 	struct snd_pcm_substream *substream;
2464 	const struct snd_pcm_chmap_elem *map;
2465 
2466 	if (snd_BUG_ON(!info->chmap))
2467 		return -EINVAL;
2468 	substream = snd_pcm_chmap_substream(info, idx);
2469 	if (!substream)
2470 		return -ENODEV;
2471 	memset(ucontrol->value.integer.value, 0,
2472 	       sizeof(ucontrol->value.integer.value));
2473 	if (!substream->runtime)
2474 		return 0; /* no channels set */
2475 	for (map = info->chmap; map->channels; map++) {
2476 		int i;
2477 		if (map->channels == substream->runtime->channels &&
2478 		    valid_chmap_channels(info, map->channels)) {
2479 			for (i = 0; i < map->channels; i++)
2480 				ucontrol->value.integer.value[i] = map->map[i];
2481 			return 0;
2482 		}
2483 	}
2484 	return -EINVAL;
2485 }
2486 
2487 /* tlv callback for channel map ctl element
2488  * expands the pre-defined channel maps in a form of TLV
2489  */
2490 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2491 			     unsigned int size, unsigned int __user *tlv)
2492 {
2493 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2494 	const struct snd_pcm_chmap_elem *map;
2495 	unsigned int __user *dst;
2496 	int c, count = 0;
2497 
2498 	if (snd_BUG_ON(!info->chmap))
2499 		return -EINVAL;
2500 	if (size < 8)
2501 		return -ENOMEM;
2502 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2503 		return -EFAULT;
2504 	size -= 8;
2505 	dst = tlv + 2;
2506 	for (map = info->chmap; map->channels; map++) {
2507 		int chs_bytes = map->channels * 4;
2508 		if (!valid_chmap_channels(info, map->channels))
2509 			continue;
2510 		if (size < 8)
2511 			return -ENOMEM;
2512 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2513 		    put_user(chs_bytes, dst + 1))
2514 			return -EFAULT;
2515 		dst += 2;
2516 		size -= 8;
2517 		count += 8;
2518 		if (size < chs_bytes)
2519 			return -ENOMEM;
2520 		size -= chs_bytes;
2521 		count += chs_bytes;
2522 		for (c = 0; c < map->channels; c++) {
2523 			if (put_user(map->map[c], dst))
2524 				return -EFAULT;
2525 			dst++;
2526 		}
2527 	}
2528 	if (put_user(count, tlv + 1))
2529 		return -EFAULT;
2530 	return 0;
2531 }
2532 
2533 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2534 {
2535 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2536 	info->pcm->streams[info->stream].chmap_kctl = NULL;
2537 	kfree(info);
2538 }
2539 
2540 /**
2541  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2542  * @pcm: the assigned PCM instance
2543  * @stream: stream direction
2544  * @chmap: channel map elements (for query)
2545  * @max_channels: the max number of channels for the stream
2546  * @private_value: the value passed to each kcontrol's private_value field
2547  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2548  *
2549  * Create channel-mapping control elements assigned to the given PCM stream(s).
2550  * Return: Zero if successful, or a negative error value.
2551  */
2552 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2553 			   const struct snd_pcm_chmap_elem *chmap,
2554 			   int max_channels,
2555 			   unsigned long private_value,
2556 			   struct snd_pcm_chmap **info_ret)
2557 {
2558 	struct snd_pcm_chmap *info;
2559 	struct snd_kcontrol_new knew = {
2560 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
2561 		.access = SNDRV_CTL_ELEM_ACCESS_READ |
2562 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2563 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2564 		.info = pcm_chmap_ctl_info,
2565 		.get = pcm_chmap_ctl_get,
2566 		.tlv.c = pcm_chmap_ctl_tlv,
2567 	};
2568 	int err;
2569 
2570 	info = kzalloc(sizeof(*info), GFP_KERNEL);
2571 	if (!info)
2572 		return -ENOMEM;
2573 	info->pcm = pcm;
2574 	info->stream = stream;
2575 	info->chmap = chmap;
2576 	info->max_channels = max_channels;
2577 	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2578 		knew.name = "Playback Channel Map";
2579 	else
2580 		knew.name = "Capture Channel Map";
2581 	knew.device = pcm->device;
2582 	knew.count = pcm->streams[stream].substream_count;
2583 	knew.private_value = private_value;
2584 	info->kctl = snd_ctl_new1(&knew, info);
2585 	if (!info->kctl) {
2586 		kfree(info);
2587 		return -ENOMEM;
2588 	}
2589 	info->kctl->private_free = pcm_chmap_ctl_private_free;
2590 	err = snd_ctl_add(pcm->card, info->kctl);
2591 	if (err < 0)
2592 		return err;
2593 	pcm->streams[stream].chmap_kctl = info->kctl;
2594 	if (info_ret)
2595 		*info_ret = info;
2596 	return 0;
2597 }
2598 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2599