xref: /linux/sound/core/pcm_lib.c (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
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 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 
278 static 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 */
488 int 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  */
501 void 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 
511 EXPORT_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  */
519 void 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 
529 EXPORT_SYMBOL(snd_pcm_set_sync);
530 
531 /*
532  *  Standard ioctl routine
533  */
534 
535 static 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 
546 static 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 
553 static 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 
565 static 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 
574 static 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  */
603 int 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 
646 EXPORT_SYMBOL(snd_interval_refine);
647 
648 static 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 
661 static 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 
674 void 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  */
698 void 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  */
733 void 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  */
764 void 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  */
803 int 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 
909 EXPORT_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  */
922 static 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  */
1023 int 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 
1047 EXPORT_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  */
1063 int 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 }
1101 EXPORT_SYMBOL(snd_interval_ranges);
1102 
1103 static 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  */
1139 int 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 
1186 EXPORT_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  */
1198 int 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  */
1220 int 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 }
1232 EXPORT_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  */
1244 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1245 {
1246 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1247 	return snd_interval_setinteger(constrs_interval(constrs, var));
1248 }
1249 
1250 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1251 
1252 /**
1253  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1254  * @runtime: PCM runtime instance
1255  * @var: hw_params variable to apply the range
1256  * @min: the minimal value
1257  * @max: the maximal value
1258  *
1259  * Apply the min/max range constraint to an interval parameter.
1260  *
1261  * Return: Positive if the value is changed, zero if it's not changed, or a
1262  * negative error code.
1263  */
1264 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1265 				 unsigned int min, unsigned int max)
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 
1276 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1277 
1278 static 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  */
1297 int 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 
1307 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1308 
1309 static 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  */
1329 int 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 }
1338 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1339 
1340 static 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  */
1364 int 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 
1374 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1375 
1376 static 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  */
1399 int 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 
1409 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1410 
1411 static 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  */
1443 int 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 
1455 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1456 
1457 static 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  */
1473 int 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 
1483 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1484 
1485 static 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  */
1505 int 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 
1514 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1515 
1516 static 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  */
1533 int 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 }
1542 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1543 
1544 static 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 
1562 void _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 
1573 EXPORT_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  */
1584 int 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 
1606 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1607 
1608 void _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 
1624 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1625 
1626 static 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  */
1656 int 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 
1671 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1672 
1673 static 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  */
1703 int 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 
1718 EXPORT_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  */
1732 int 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 
1759 static 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 
1776 static 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 
1811 static 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  */
1841 int 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 
1857 EXPORT_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  */
1870 void 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 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1890 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1891 }
1892 
1893 EXPORT_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  */
1901 static 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 
1987 static 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 
2006 typedef 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 
2010 static 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 */
2113 static 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 
2126 snd_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 
2145 EXPORT_SYMBOL(snd_pcm_lib_write);
2146 
2147 static 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 
2187 snd_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 
2207 EXPORT_SYMBOL(snd_pcm_lib_writev);
2208 
2209 static 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 
2228 static 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 
2338 snd_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 
2354 EXPORT_SYMBOL(snd_pcm_lib_read);
2355 
2356 static 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 
2392 snd_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 
2413 EXPORT_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 */
2420 const 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 };
2439 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2440 
2441 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2442 const 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 };
2461 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2462 
2463 static 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 
2470 static 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  */
2486 static 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  */
2518 static 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 
2561 static 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  */
2580 int 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 	if (WARN_ON(pcm->streams[stream].chmap_kctl))
2599 		return -EBUSY;
2600 	info = kzalloc(sizeof(*info), GFP_KERNEL);
2601 	if (!info)
2602 		return -ENOMEM;
2603 	info->pcm = pcm;
2604 	info->stream = stream;
2605 	info->chmap = chmap;
2606 	info->max_channels = max_channels;
2607 	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2608 		knew.name = "Playback Channel Map";
2609 	else
2610 		knew.name = "Capture Channel Map";
2611 	knew.device = pcm->device;
2612 	knew.count = pcm->streams[stream].substream_count;
2613 	knew.private_value = private_value;
2614 	info->kctl = snd_ctl_new1(&knew, info);
2615 	if (!info->kctl) {
2616 		kfree(info);
2617 		return -ENOMEM;
2618 	}
2619 	info->kctl->private_free = pcm_chmap_ctl_private_free;
2620 	err = snd_ctl_add(pcm->card, info->kctl);
2621 	if (err < 0)
2622 		return err;
2623 	pcm->streams[stream].chmap_kctl = info->kctl;
2624 	if (info_ret)
2625 		*info_ret = info;
2626 	return 0;
2627 }
2628 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2629