xref: /openbmc/linux/sound/core/pcm_lib.c (revision 4f6cce39)
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/sched/signal.h>
25 #include <linux/time.h>
26 #include <linux/math64.h>
27 #include <linux/export.h>
28 #include <sound/core.h>
29 #include <sound/control.h>
30 #include <sound/tlv.h>
31 #include <sound/info.h>
32 #include <sound/pcm.h>
33 #include <sound/pcm_params.h>
34 #include <sound/timer.h>
35 
36 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
37 #define CREATE_TRACE_POINTS
38 #include "pcm_trace.h"
39 #else
40 #define trace_hwptr(substream, pos, in_interrupt)
41 #define trace_xrun(substream)
42 #define trace_hw_ptr_error(substream, reason)
43 #endif
44 
45 /*
46  * fill ring buffer with silence
47  * runtime->silence_start: starting pointer to silence area
48  * runtime->silence_filled: size filled with silence
49  * runtime->silence_threshold: threshold from application
50  * runtime->silence_size: maximal size from application
51  *
52  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
53  */
54 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
55 {
56 	struct snd_pcm_runtime *runtime = substream->runtime;
57 	snd_pcm_uframes_t frames, ofs, transfer;
58 
59 	if (runtime->silence_size < runtime->boundary) {
60 		snd_pcm_sframes_t noise_dist, n;
61 		if (runtime->silence_start != runtime->control->appl_ptr) {
62 			n = runtime->control->appl_ptr - runtime->silence_start;
63 			if (n < 0)
64 				n += runtime->boundary;
65 			if ((snd_pcm_uframes_t)n < runtime->silence_filled)
66 				runtime->silence_filled -= n;
67 			else
68 				runtime->silence_filled = 0;
69 			runtime->silence_start = runtime->control->appl_ptr;
70 		}
71 		if (runtime->silence_filled >= runtime->buffer_size)
72 			return;
73 		noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
74 		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
75 			return;
76 		frames = runtime->silence_threshold - noise_dist;
77 		if (frames > runtime->silence_size)
78 			frames = runtime->silence_size;
79 	} else {
80 		if (new_hw_ptr == ULONG_MAX) {	/* initialization */
81 			snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
82 			if (avail > runtime->buffer_size)
83 				avail = runtime->buffer_size;
84 			runtime->silence_filled = avail > 0 ? avail : 0;
85 			runtime->silence_start = (runtime->status->hw_ptr +
86 						  runtime->silence_filled) %
87 						 runtime->boundary;
88 		} else {
89 			ofs = runtime->status->hw_ptr;
90 			frames = new_hw_ptr - ofs;
91 			if ((snd_pcm_sframes_t)frames < 0)
92 				frames += runtime->boundary;
93 			runtime->silence_filled -= frames;
94 			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
95 				runtime->silence_filled = 0;
96 				runtime->silence_start = new_hw_ptr;
97 			} else {
98 				runtime->silence_start = ofs;
99 			}
100 		}
101 		frames = runtime->buffer_size - runtime->silence_filled;
102 	}
103 	if (snd_BUG_ON(frames > runtime->buffer_size))
104 		return;
105 	if (frames == 0)
106 		return;
107 	ofs = runtime->silence_start % runtime->buffer_size;
108 	while (frames > 0) {
109 		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
110 		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
111 		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
112 			if (substream->ops->silence) {
113 				int err;
114 				err = substream->ops->silence(substream, -1, ofs, transfer);
115 				snd_BUG_ON(err < 0);
116 			} else {
117 				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
118 				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
119 			}
120 		} else {
121 			unsigned int c;
122 			unsigned int channels = runtime->channels;
123 			if (substream->ops->silence) {
124 				for (c = 0; c < channels; ++c) {
125 					int err;
126 					err = substream->ops->silence(substream, c, ofs, transfer);
127 					snd_BUG_ON(err < 0);
128 				}
129 			} else {
130 				size_t dma_csize = runtime->dma_bytes / channels;
131 				for (c = 0; c < channels; ++c) {
132 					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
133 					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
134 				}
135 			}
136 		}
137 		runtime->silence_filled += transfer;
138 		frames -= transfer;
139 		ofs = 0;
140 	}
141 }
142 
143 #ifdef CONFIG_SND_DEBUG
144 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
145 			   char *name, size_t len)
146 {
147 	snprintf(name, len, "pcmC%dD%d%c:%d",
148 		 substream->pcm->card->number,
149 		 substream->pcm->device,
150 		 substream->stream ? 'c' : 'p',
151 		 substream->number);
152 }
153 EXPORT_SYMBOL(snd_pcm_debug_name);
154 #endif
155 
156 #define XRUN_DEBUG_BASIC	(1<<0)
157 #define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
158 #define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
159 
160 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
161 
162 #define xrun_debug(substream, mask) \
163 			((substream)->pstr->xrun_debug & (mask))
164 #else
165 #define xrun_debug(substream, mask)	0
166 #endif
167 
168 #define dump_stack_on_xrun(substream) do {			\
169 		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
170 			dump_stack();				\
171 	} while (0)
172 
173 static void xrun(struct snd_pcm_substream *substream)
174 {
175 	struct snd_pcm_runtime *runtime = substream->runtime;
176 
177 	trace_xrun(substream);
178 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
179 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
180 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
181 	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
182 		char name[16];
183 		snd_pcm_debug_name(substream, name, sizeof(name));
184 		pcm_warn(substream->pcm, "XRUN: %s\n", name);
185 		dump_stack_on_xrun(substream);
186 	}
187 }
188 
189 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
190 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)	\
191 	do {								\
192 		trace_hw_ptr_error(substream, reason);	\
193 		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
194 			pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
195 					   (in_interrupt) ? 'Q' : 'P', ##args);	\
196 			dump_stack_on_xrun(substream);			\
197 		}							\
198 	} while (0)
199 
200 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
201 
202 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
203 
204 #endif
205 
206 int snd_pcm_update_state(struct snd_pcm_substream *substream,
207 			 struct snd_pcm_runtime *runtime)
208 {
209 	snd_pcm_uframes_t avail;
210 
211 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
212 		avail = snd_pcm_playback_avail(runtime);
213 	else
214 		avail = snd_pcm_capture_avail(runtime);
215 	if (avail > runtime->avail_max)
216 		runtime->avail_max = avail;
217 	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
218 		if (avail >= runtime->buffer_size) {
219 			snd_pcm_drain_done(substream);
220 			return -EPIPE;
221 		}
222 	} else {
223 		if (avail >= runtime->stop_threshold) {
224 			xrun(substream);
225 			return -EPIPE;
226 		}
227 	}
228 	if (runtime->twake) {
229 		if (avail >= runtime->twake)
230 			wake_up(&runtime->tsleep);
231 	} else if (avail >= runtime->control->avail_min)
232 		wake_up(&runtime->sleep);
233 	return 0;
234 }
235 
236 static void update_audio_tstamp(struct snd_pcm_substream *substream,
237 				struct timespec *curr_tstamp,
238 				struct timespec *audio_tstamp)
239 {
240 	struct snd_pcm_runtime *runtime = substream->runtime;
241 	u64 audio_frames, audio_nsecs;
242 	struct timespec driver_tstamp;
243 
244 	if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
245 		return;
246 
247 	if (!(substream->ops->get_time_info) ||
248 		(runtime->audio_tstamp_report.actual_type ==
249 			SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
250 
251 		/*
252 		 * provide audio timestamp derived from pointer position
253 		 * add delay only if requested
254 		 */
255 
256 		audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
257 
258 		if (runtime->audio_tstamp_config.report_delay) {
259 			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
260 				audio_frames -=  runtime->delay;
261 			else
262 				audio_frames +=  runtime->delay;
263 		}
264 		audio_nsecs = div_u64(audio_frames * 1000000000LL,
265 				runtime->rate);
266 		*audio_tstamp = ns_to_timespec(audio_nsecs);
267 	}
268 	runtime->status->audio_tstamp = *audio_tstamp;
269 	runtime->status->tstamp = *curr_tstamp;
270 
271 	/*
272 	 * re-take a driver timestamp to let apps detect if the reference tstamp
273 	 * read by low-level hardware was provided with a delay
274 	 */
275 	snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
276 	runtime->driver_tstamp = driver_tstamp;
277 }
278 
279 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
280 				  unsigned int in_interrupt)
281 {
282 	struct snd_pcm_runtime *runtime = substream->runtime;
283 	snd_pcm_uframes_t pos;
284 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
285 	snd_pcm_sframes_t hdelta, delta;
286 	unsigned long jdelta;
287 	unsigned long curr_jiffies;
288 	struct timespec curr_tstamp;
289 	struct timespec audio_tstamp;
290 	int crossed_boundary = 0;
291 
292 	old_hw_ptr = runtime->status->hw_ptr;
293 
294 	/*
295 	 * group pointer, time and jiffies reads to allow for more
296 	 * accurate correlations/corrections.
297 	 * The values are stored at the end of this routine after
298 	 * corrections for hw_ptr position
299 	 */
300 	pos = substream->ops->pointer(substream);
301 	curr_jiffies = jiffies;
302 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
303 		if ((substream->ops->get_time_info) &&
304 			(runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
305 			substream->ops->get_time_info(substream, &curr_tstamp,
306 						&audio_tstamp,
307 						&runtime->audio_tstamp_config,
308 						&runtime->audio_tstamp_report);
309 
310 			/* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
311 			if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
312 				snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
313 		} else
314 			snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
315 	}
316 
317 	if (pos == SNDRV_PCM_POS_XRUN) {
318 		xrun(substream);
319 		return -EPIPE;
320 	}
321 	if (pos >= runtime->buffer_size) {
322 		if (printk_ratelimit()) {
323 			char name[16];
324 			snd_pcm_debug_name(substream, name, sizeof(name));
325 			pcm_err(substream->pcm,
326 				"invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
327 				name, pos, runtime->buffer_size,
328 				runtime->period_size);
329 		}
330 		pos = 0;
331 	}
332 	pos -= pos % runtime->min_align;
333 	trace_hwptr(substream, pos, in_interrupt);
334 	hw_base = runtime->hw_ptr_base;
335 	new_hw_ptr = hw_base + pos;
336 	if (in_interrupt) {
337 		/* we know that one period was processed */
338 		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
339 		delta = runtime->hw_ptr_interrupt + runtime->period_size;
340 		if (delta > new_hw_ptr) {
341 			/* check for double acknowledged interrupts */
342 			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
343 			if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
344 				hw_base += runtime->buffer_size;
345 				if (hw_base >= runtime->boundary) {
346 					hw_base = 0;
347 					crossed_boundary++;
348 				}
349 				new_hw_ptr = hw_base + pos;
350 				goto __delta;
351 			}
352 		}
353 	}
354 	/* new_hw_ptr might be lower than old_hw_ptr in case when */
355 	/* pointer crosses the end of the ring buffer */
356 	if (new_hw_ptr < old_hw_ptr) {
357 		hw_base += runtime->buffer_size;
358 		if (hw_base >= runtime->boundary) {
359 			hw_base = 0;
360 			crossed_boundary++;
361 		}
362 		new_hw_ptr = hw_base + pos;
363 	}
364       __delta:
365 	delta = new_hw_ptr - old_hw_ptr;
366 	if (delta < 0)
367 		delta += runtime->boundary;
368 
369 	if (runtime->no_period_wakeup) {
370 		snd_pcm_sframes_t xrun_threshold;
371 		/*
372 		 * Without regular period interrupts, we have to check
373 		 * the elapsed time to detect xruns.
374 		 */
375 		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
376 		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
377 			goto no_delta_check;
378 		hdelta = jdelta - delta * HZ / runtime->rate;
379 		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
380 		while (hdelta > xrun_threshold) {
381 			delta += runtime->buffer_size;
382 			hw_base += runtime->buffer_size;
383 			if (hw_base >= runtime->boundary) {
384 				hw_base = 0;
385 				crossed_boundary++;
386 			}
387 			new_hw_ptr = hw_base + pos;
388 			hdelta -= runtime->hw_ptr_buffer_jiffies;
389 		}
390 		goto no_delta_check;
391 	}
392 
393 	/* something must be really wrong */
394 	if (delta >= runtime->buffer_size + runtime->period_size) {
395 		hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
396 			     "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
397 			     substream->stream, (long)pos,
398 			     (long)new_hw_ptr, (long)old_hw_ptr);
399 		return 0;
400 	}
401 
402 	/* Do jiffies check only in xrun_debug mode */
403 	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
404 		goto no_jiffies_check;
405 
406 	/* Skip the jiffies check for hardwares with BATCH flag.
407 	 * Such hardware usually just increases the position at each IRQ,
408 	 * thus it can't give any strange position.
409 	 */
410 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
411 		goto no_jiffies_check;
412 	hdelta = delta;
413 	if (hdelta < runtime->delay)
414 		goto no_jiffies_check;
415 	hdelta -= runtime->delay;
416 	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
417 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
418 		delta = jdelta /
419 			(((runtime->period_size * HZ) / runtime->rate)
420 								+ HZ/100);
421 		/* move new_hw_ptr according jiffies not pos variable */
422 		new_hw_ptr = old_hw_ptr;
423 		hw_base = delta;
424 		/* use loop to avoid checks for delta overflows */
425 		/* the delta value is small or zero in most cases */
426 		while (delta > 0) {
427 			new_hw_ptr += runtime->period_size;
428 			if (new_hw_ptr >= runtime->boundary) {
429 				new_hw_ptr -= runtime->boundary;
430 				crossed_boundary--;
431 			}
432 			delta--;
433 		}
434 		/* align hw_base to buffer_size */
435 		hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
436 			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
437 			     (long)pos, (long)hdelta,
438 			     (long)runtime->period_size, jdelta,
439 			     ((hdelta * HZ) / runtime->rate), hw_base,
440 			     (unsigned long)old_hw_ptr,
441 			     (unsigned long)new_hw_ptr);
442 		/* reset values to proper state */
443 		delta = 0;
444 		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
445 	}
446  no_jiffies_check:
447 	if (delta > runtime->period_size + runtime->period_size / 2) {
448 		hw_ptr_error(substream, in_interrupt,
449 			     "Lost interrupts?",
450 			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
451 			     substream->stream, (long)delta,
452 			     (long)new_hw_ptr,
453 			     (long)old_hw_ptr);
454 	}
455 
456  no_delta_check:
457 	if (runtime->status->hw_ptr == new_hw_ptr) {
458 		update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
459 		return 0;
460 	}
461 
462 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
463 	    runtime->silence_size > 0)
464 		snd_pcm_playback_silence(substream, new_hw_ptr);
465 
466 	if (in_interrupt) {
467 		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
468 		if (delta < 0)
469 			delta += runtime->boundary;
470 		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
471 		runtime->hw_ptr_interrupt += delta;
472 		if (runtime->hw_ptr_interrupt >= runtime->boundary)
473 			runtime->hw_ptr_interrupt -= runtime->boundary;
474 	}
475 	runtime->hw_ptr_base = hw_base;
476 	runtime->status->hw_ptr = new_hw_ptr;
477 	runtime->hw_ptr_jiffies = curr_jiffies;
478 	if (crossed_boundary) {
479 		snd_BUG_ON(crossed_boundary != 1);
480 		runtime->hw_ptr_wrap += runtime->boundary;
481 	}
482 
483 	update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
484 
485 	return snd_pcm_update_state(substream, runtime);
486 }
487 
488 /* CAUTION: call it with irq disabled */
489 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
490 {
491 	return snd_pcm_update_hw_ptr0(substream, 0);
492 }
493 
494 /**
495  * snd_pcm_set_ops - set the PCM operators
496  * @pcm: the pcm instance
497  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
498  * @ops: the operator table
499  *
500  * Sets the given PCM operators to the pcm instance.
501  */
502 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
503 		     const struct snd_pcm_ops *ops)
504 {
505 	struct snd_pcm_str *stream = &pcm->streams[direction];
506 	struct snd_pcm_substream *substream;
507 
508 	for (substream = stream->substream; substream != NULL; substream = substream->next)
509 		substream->ops = ops;
510 }
511 
512 EXPORT_SYMBOL(snd_pcm_set_ops);
513 
514 /**
515  * snd_pcm_sync - set the PCM sync id
516  * @substream: the pcm substream
517  *
518  * Sets the PCM sync identifier for the card.
519  */
520 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
521 {
522 	struct snd_pcm_runtime *runtime = substream->runtime;
523 
524 	runtime->sync.id32[0] = substream->pcm->card->number;
525 	runtime->sync.id32[1] = -1;
526 	runtime->sync.id32[2] = -1;
527 	runtime->sync.id32[3] = -1;
528 }
529 
530 EXPORT_SYMBOL(snd_pcm_set_sync);
531 
532 /*
533  *  Standard ioctl routine
534  */
535 
536 static inline unsigned int div32(unsigned int a, unsigned int b,
537 				 unsigned int *r)
538 {
539 	if (b == 0) {
540 		*r = 0;
541 		return UINT_MAX;
542 	}
543 	*r = a % b;
544 	return a / b;
545 }
546 
547 static inline unsigned int div_down(unsigned int a, unsigned int b)
548 {
549 	if (b == 0)
550 		return UINT_MAX;
551 	return a / b;
552 }
553 
554 static inline unsigned int div_up(unsigned int a, unsigned int b)
555 {
556 	unsigned int r;
557 	unsigned int q;
558 	if (b == 0)
559 		return UINT_MAX;
560 	q = div32(a, b, &r);
561 	if (r)
562 		++q;
563 	return q;
564 }
565 
566 static inline unsigned int mul(unsigned int a, unsigned int b)
567 {
568 	if (a == 0)
569 		return 0;
570 	if (div_down(UINT_MAX, a) < b)
571 		return UINT_MAX;
572 	return a * b;
573 }
574 
575 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
576 				    unsigned int c, unsigned int *r)
577 {
578 	u_int64_t n = (u_int64_t) a * b;
579 	if (c == 0) {
580 		snd_BUG_ON(!n);
581 		*r = 0;
582 		return UINT_MAX;
583 	}
584 	n = div_u64_rem(n, c, r);
585 	if (n >= UINT_MAX) {
586 		*r = 0;
587 		return UINT_MAX;
588 	}
589 	return n;
590 }
591 
592 /**
593  * snd_interval_refine - refine the interval value of configurator
594  * @i: the interval value to refine
595  * @v: the interval value to refer to
596  *
597  * Refines the interval value with the reference value.
598  * The interval is changed to the range satisfying both intervals.
599  * The interval status (min, max, integer, etc.) are evaluated.
600  *
601  * Return: Positive if the value is changed, zero if it's not changed, or a
602  * negative error code.
603  */
604 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
605 {
606 	int changed = 0;
607 	if (snd_BUG_ON(snd_interval_empty(i)))
608 		return -EINVAL;
609 	if (i->min < v->min) {
610 		i->min = v->min;
611 		i->openmin = v->openmin;
612 		changed = 1;
613 	} else if (i->min == v->min && !i->openmin && v->openmin) {
614 		i->openmin = 1;
615 		changed = 1;
616 	}
617 	if (i->max > v->max) {
618 		i->max = v->max;
619 		i->openmax = v->openmax;
620 		changed = 1;
621 	} else if (i->max == v->max && !i->openmax && v->openmax) {
622 		i->openmax = 1;
623 		changed = 1;
624 	}
625 	if (!i->integer && v->integer) {
626 		i->integer = 1;
627 		changed = 1;
628 	}
629 	if (i->integer) {
630 		if (i->openmin) {
631 			i->min++;
632 			i->openmin = 0;
633 		}
634 		if (i->openmax) {
635 			i->max--;
636 			i->openmax = 0;
637 		}
638 	} else if (!i->openmin && !i->openmax && i->min == i->max)
639 		i->integer = 1;
640 	if (snd_interval_checkempty(i)) {
641 		snd_interval_none(i);
642 		return -EINVAL;
643 	}
644 	return changed;
645 }
646 
647 EXPORT_SYMBOL(snd_interval_refine);
648 
649 static int snd_interval_refine_first(struct snd_interval *i)
650 {
651 	if (snd_BUG_ON(snd_interval_empty(i)))
652 		return -EINVAL;
653 	if (snd_interval_single(i))
654 		return 0;
655 	i->max = i->min;
656 	i->openmax = i->openmin;
657 	if (i->openmax)
658 		i->max++;
659 	return 1;
660 }
661 
662 static int snd_interval_refine_last(struct snd_interval *i)
663 {
664 	if (snd_BUG_ON(snd_interval_empty(i)))
665 		return -EINVAL;
666 	if (snd_interval_single(i))
667 		return 0;
668 	i->min = i->max;
669 	i->openmin = i->openmax;
670 	if (i->openmin)
671 		i->min--;
672 	return 1;
673 }
674 
675 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
676 {
677 	if (a->empty || b->empty) {
678 		snd_interval_none(c);
679 		return;
680 	}
681 	c->empty = 0;
682 	c->min = mul(a->min, b->min);
683 	c->openmin = (a->openmin || b->openmin);
684 	c->max = mul(a->max,  b->max);
685 	c->openmax = (a->openmax || b->openmax);
686 	c->integer = (a->integer && b->integer);
687 }
688 
689 /**
690  * snd_interval_div - refine the interval value with division
691  * @a: dividend
692  * @b: divisor
693  * @c: quotient
694  *
695  * c = a / b
696  *
697  * Returns non-zero if the value is changed, zero if not changed.
698  */
699 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
700 {
701 	unsigned int r;
702 	if (a->empty || b->empty) {
703 		snd_interval_none(c);
704 		return;
705 	}
706 	c->empty = 0;
707 	c->min = div32(a->min, b->max, &r);
708 	c->openmin = (r || a->openmin || b->openmax);
709 	if (b->min > 0) {
710 		c->max = div32(a->max, b->min, &r);
711 		if (r) {
712 			c->max++;
713 			c->openmax = 1;
714 		} else
715 			c->openmax = (a->openmax || b->openmin);
716 	} else {
717 		c->max = UINT_MAX;
718 		c->openmax = 0;
719 	}
720 	c->integer = 0;
721 }
722 
723 /**
724  * snd_interval_muldivk - refine the interval value
725  * @a: dividend 1
726  * @b: dividend 2
727  * @k: divisor (as integer)
728  * @c: result
729   *
730  * c = a * b / k
731  *
732  * Returns non-zero if the value is changed, zero if not changed.
733  */
734 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
735 		      unsigned int k, 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, b->min, k, &r);
744 	c->openmin = (r || a->openmin || b->openmin);
745 	c->max = muldiv32(a->max, b->max, k, &r);
746 	if (r) {
747 		c->max++;
748 		c->openmax = 1;
749 	} else
750 		c->openmax = (a->openmax || b->openmax);
751 	c->integer = 0;
752 }
753 
754 /**
755  * snd_interval_mulkdiv - refine the interval value
756  * @a: dividend 1
757  * @k: dividend 2 (as integer)
758  * @b: divisor
759  * @c: result
760  *
761  * c = a * k / b
762  *
763  * Returns non-zero if the value is changed, zero if not changed.
764  */
765 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
766 		      const struct snd_interval *b, struct snd_interval *c)
767 {
768 	unsigned int r;
769 	if (a->empty || b->empty) {
770 		snd_interval_none(c);
771 		return;
772 	}
773 	c->empty = 0;
774 	c->min = muldiv32(a->min, k, b->max, &r);
775 	c->openmin = (r || a->openmin || b->openmax);
776 	if (b->min > 0) {
777 		c->max = muldiv32(a->max, k, b->min, &r);
778 		if (r) {
779 			c->max++;
780 			c->openmax = 1;
781 		} else
782 			c->openmax = (a->openmax || b->openmin);
783 	} else {
784 		c->max = UINT_MAX;
785 		c->openmax = 0;
786 	}
787 	c->integer = 0;
788 }
789 
790 /* ---- */
791 
792 
793 /**
794  * snd_interval_ratnum - refine the interval value
795  * @i: interval to refine
796  * @rats_count: number of ratnum_t
797  * @rats: ratnum_t array
798  * @nump: pointer to store the resultant numerator
799  * @denp: pointer to store the resultant denominator
800  *
801  * Return: Positive if the value is changed, zero if it's not changed, or a
802  * negative error code.
803  */
804 int snd_interval_ratnum(struct snd_interval *i,
805 			unsigned int rats_count, const struct snd_ratnum *rats,
806 			unsigned int *nump, unsigned int *denp)
807 {
808 	unsigned int best_num, best_den;
809 	int best_diff;
810 	unsigned int k;
811 	struct snd_interval t;
812 	int err;
813 	unsigned int result_num, result_den;
814 	int result_diff;
815 
816 	best_num = best_den = best_diff = 0;
817 	for (k = 0; k < rats_count; ++k) {
818 		unsigned int num = rats[k].num;
819 		unsigned int den;
820 		unsigned int q = i->min;
821 		int diff;
822 		if (q == 0)
823 			q = 1;
824 		den = div_up(num, q);
825 		if (den < rats[k].den_min)
826 			continue;
827 		if (den > rats[k].den_max)
828 			den = rats[k].den_max;
829 		else {
830 			unsigned int r;
831 			r = (den - rats[k].den_min) % rats[k].den_step;
832 			if (r != 0)
833 				den -= r;
834 		}
835 		diff = num - q * den;
836 		if (diff < 0)
837 			diff = -diff;
838 		if (best_num == 0 ||
839 		    diff * best_den < best_diff * den) {
840 			best_diff = diff;
841 			best_den = den;
842 			best_num = num;
843 		}
844 	}
845 	if (best_den == 0) {
846 		i->empty = 1;
847 		return -EINVAL;
848 	}
849 	t.min = div_down(best_num, best_den);
850 	t.openmin = !!(best_num % best_den);
851 
852 	result_num = best_num;
853 	result_diff = best_diff;
854 	result_den = best_den;
855 	best_num = best_den = best_diff = 0;
856 	for (k = 0; k < rats_count; ++k) {
857 		unsigned int num = rats[k].num;
858 		unsigned int den;
859 		unsigned int q = i->max;
860 		int diff;
861 		if (q == 0) {
862 			i->empty = 1;
863 			return -EINVAL;
864 		}
865 		den = div_down(num, q);
866 		if (den > rats[k].den_max)
867 			continue;
868 		if (den < rats[k].den_min)
869 			den = rats[k].den_min;
870 		else {
871 			unsigned int r;
872 			r = (den - rats[k].den_min) % rats[k].den_step;
873 			if (r != 0)
874 				den += rats[k].den_step - r;
875 		}
876 		diff = q * den - num;
877 		if (diff < 0)
878 			diff = -diff;
879 		if (best_num == 0 ||
880 		    diff * best_den < best_diff * den) {
881 			best_diff = diff;
882 			best_den = den;
883 			best_num = num;
884 		}
885 	}
886 	if (best_den == 0) {
887 		i->empty = 1;
888 		return -EINVAL;
889 	}
890 	t.max = div_up(best_num, best_den);
891 	t.openmax = !!(best_num % best_den);
892 	t.integer = 0;
893 	err = snd_interval_refine(i, &t);
894 	if (err < 0)
895 		return err;
896 
897 	if (snd_interval_single(i)) {
898 		if (best_diff * result_den < result_diff * best_den) {
899 			result_num = best_num;
900 			result_den = best_den;
901 		}
902 		if (nump)
903 			*nump = result_num;
904 		if (denp)
905 			*denp = result_den;
906 	}
907 	return err;
908 }
909 
910 EXPORT_SYMBOL(snd_interval_ratnum);
911 
912 /**
913  * snd_interval_ratden - refine the interval value
914  * @i: interval to refine
915  * @rats_count: number of struct ratden
916  * @rats: struct ratden array
917  * @nump: pointer to store the resultant numerator
918  * @denp: pointer to store the resultant denominator
919  *
920  * Return: Positive if the value is changed, zero if it's not changed, or a
921  * negative error code.
922  */
923 static int snd_interval_ratden(struct snd_interval *i,
924 			       unsigned int rats_count,
925 			       const struct snd_ratden *rats,
926 			       unsigned int *nump, unsigned int *denp)
927 {
928 	unsigned int best_num, best_diff, best_den;
929 	unsigned int k;
930 	struct snd_interval t;
931 	int err;
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->min;
938 		int diff;
939 		num = mul(q, den);
940 		if (num > rats[k].num_max)
941 			continue;
942 		if (num < rats[k].num_min)
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 += rats[k].num_step - r;
949 		}
950 		diff = num - q * den;
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.min = div_down(best_num, best_den);
963 	t.openmin = !!(best_num % best_den);
964 
965 	best_num = best_den = best_diff = 0;
966 	for (k = 0; k < rats_count; ++k) {
967 		unsigned int num;
968 		unsigned int den = rats[k].den;
969 		unsigned int q = i->max;
970 		int diff;
971 		num = mul(q, den);
972 		if (num < rats[k].num_min)
973 			continue;
974 		if (num > rats[k].num_max)
975 			num = rats[k].num_max;
976 		else {
977 			unsigned int r;
978 			r = (num - rats[k].num_min) % rats[k].num_step;
979 			if (r != 0)
980 				num -= r;
981 		}
982 		diff = q * den - num;
983 		if (best_num == 0 ||
984 		    diff * best_den < best_diff * den) {
985 			best_diff = diff;
986 			best_den = den;
987 			best_num = num;
988 		}
989 	}
990 	if (best_den == 0) {
991 		i->empty = 1;
992 		return -EINVAL;
993 	}
994 	t.max = div_up(best_num, best_den);
995 	t.openmax = !!(best_num % best_den);
996 	t.integer = 0;
997 	err = snd_interval_refine(i, &t);
998 	if (err < 0)
999 		return err;
1000 
1001 	if (snd_interval_single(i)) {
1002 		if (nump)
1003 			*nump = best_num;
1004 		if (denp)
1005 			*denp = best_den;
1006 	}
1007 	return err;
1008 }
1009 
1010 /**
1011  * snd_interval_list - refine the interval value from the list
1012  * @i: the interval value to refine
1013  * @count: the number of elements in the list
1014  * @list: the value list
1015  * @mask: the bit-mask to evaluate
1016  *
1017  * Refines the interval value from the list.
1018  * When mask is non-zero, only the elements corresponding to bit 1 are
1019  * evaluated.
1020  *
1021  * Return: Positive if the value is changed, zero if it's not changed, or a
1022  * negative error code.
1023  */
1024 int snd_interval_list(struct snd_interval *i, unsigned int count,
1025 		      const unsigned int *list, unsigned int mask)
1026 {
1027         unsigned int k;
1028 	struct snd_interval list_range;
1029 
1030 	if (!count) {
1031 		i->empty = 1;
1032 		return -EINVAL;
1033 	}
1034 	snd_interval_any(&list_range);
1035 	list_range.min = UINT_MAX;
1036 	list_range.max = 0;
1037         for (k = 0; k < count; k++) {
1038 		if (mask && !(mask & (1 << k)))
1039 			continue;
1040 		if (!snd_interval_test(i, list[k]))
1041 			continue;
1042 		list_range.min = min(list_range.min, list[k]);
1043 		list_range.max = max(list_range.max, list[k]);
1044         }
1045 	return snd_interval_refine(i, &list_range);
1046 }
1047 
1048 EXPORT_SYMBOL(snd_interval_list);
1049 
1050 /**
1051  * snd_interval_ranges - refine the interval value from the list of ranges
1052  * @i: the interval value to refine
1053  * @count: the number of elements in the list of ranges
1054  * @ranges: the ranges list
1055  * @mask: the bit-mask to evaluate
1056  *
1057  * Refines the interval value from the list of ranges.
1058  * When mask is non-zero, only the elements corresponding to bit 1 are
1059  * evaluated.
1060  *
1061  * Return: Positive if the value is changed, zero if it's not changed, or a
1062  * negative error code.
1063  */
1064 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1065 			const struct snd_interval *ranges, unsigned int mask)
1066 {
1067 	unsigned int k;
1068 	struct snd_interval range_union;
1069 	struct snd_interval range;
1070 
1071 	if (!count) {
1072 		snd_interval_none(i);
1073 		return -EINVAL;
1074 	}
1075 	snd_interval_any(&range_union);
1076 	range_union.min = UINT_MAX;
1077 	range_union.max = 0;
1078 	for (k = 0; k < count; k++) {
1079 		if (mask && !(mask & (1 << k)))
1080 			continue;
1081 		snd_interval_copy(&range, &ranges[k]);
1082 		if (snd_interval_refine(&range, i) < 0)
1083 			continue;
1084 		if (snd_interval_empty(&range))
1085 			continue;
1086 
1087 		if (range.min < range_union.min) {
1088 			range_union.min = range.min;
1089 			range_union.openmin = 1;
1090 		}
1091 		if (range.min == range_union.min && !range.openmin)
1092 			range_union.openmin = 0;
1093 		if (range.max > range_union.max) {
1094 			range_union.max = range.max;
1095 			range_union.openmax = 1;
1096 		}
1097 		if (range.max == range_union.max && !range.openmax)
1098 			range_union.openmax = 0;
1099 	}
1100 	return snd_interval_refine(i, &range_union);
1101 }
1102 EXPORT_SYMBOL(snd_interval_ranges);
1103 
1104 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1105 {
1106 	unsigned int n;
1107 	int changed = 0;
1108 	n = i->min % step;
1109 	if (n != 0 || i->openmin) {
1110 		i->min += step - n;
1111 		i->openmin = 0;
1112 		changed = 1;
1113 	}
1114 	n = i->max % step;
1115 	if (n != 0 || i->openmax) {
1116 		i->max -= n;
1117 		i->openmax = 0;
1118 		changed = 1;
1119 	}
1120 	if (snd_interval_checkempty(i)) {
1121 		i->empty = 1;
1122 		return -EINVAL;
1123 	}
1124 	return changed;
1125 }
1126 
1127 /* Info constraints helpers */
1128 
1129 /**
1130  * snd_pcm_hw_rule_add - add the hw-constraint rule
1131  * @runtime: the pcm runtime instance
1132  * @cond: condition bits
1133  * @var: the variable to evaluate
1134  * @func: the evaluation function
1135  * @private: the private data pointer passed to function
1136  * @dep: the dependent variables
1137  *
1138  * Return: Zero if successful, or a negative error code on failure.
1139  */
1140 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1141 			int var,
1142 			snd_pcm_hw_rule_func_t func, void *private,
1143 			int dep, ...)
1144 {
1145 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1146 	struct snd_pcm_hw_rule *c;
1147 	unsigned int k;
1148 	va_list args;
1149 	va_start(args, dep);
1150 	if (constrs->rules_num >= constrs->rules_all) {
1151 		struct snd_pcm_hw_rule *new;
1152 		unsigned int new_rules = constrs->rules_all + 16;
1153 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1154 		if (!new) {
1155 			va_end(args);
1156 			return -ENOMEM;
1157 		}
1158 		if (constrs->rules) {
1159 			memcpy(new, constrs->rules,
1160 			       constrs->rules_num * sizeof(*c));
1161 			kfree(constrs->rules);
1162 		}
1163 		constrs->rules = new;
1164 		constrs->rules_all = new_rules;
1165 	}
1166 	c = &constrs->rules[constrs->rules_num];
1167 	c->cond = cond;
1168 	c->func = func;
1169 	c->var = var;
1170 	c->private = private;
1171 	k = 0;
1172 	while (1) {
1173 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1174 			va_end(args);
1175 			return -EINVAL;
1176 		}
1177 		c->deps[k++] = dep;
1178 		if (dep < 0)
1179 			break;
1180 		dep = va_arg(args, int);
1181 	}
1182 	constrs->rules_num++;
1183 	va_end(args);
1184 	return 0;
1185 }
1186 
1187 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1188 
1189 /**
1190  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1191  * @runtime: PCM runtime instance
1192  * @var: hw_params variable to apply the mask
1193  * @mask: the bitmap mask
1194  *
1195  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1196  *
1197  * Return: Zero if successful, or a negative error code on failure.
1198  */
1199 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1200 			       u_int32_t mask)
1201 {
1202 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1203 	struct snd_mask *maskp = constrs_mask(constrs, var);
1204 	*maskp->bits &= mask;
1205 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1206 	if (*maskp->bits == 0)
1207 		return -EINVAL;
1208 	return 0;
1209 }
1210 
1211 /**
1212  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1213  * @runtime: PCM runtime instance
1214  * @var: hw_params variable to apply the mask
1215  * @mask: the 64bit bitmap mask
1216  *
1217  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1218  *
1219  * Return: Zero if successful, or a negative error code on failure.
1220  */
1221 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1222 				 u_int64_t mask)
1223 {
1224 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1225 	struct snd_mask *maskp = constrs_mask(constrs, var);
1226 	maskp->bits[0] &= (u_int32_t)mask;
1227 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1228 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1229 	if (! maskp->bits[0] && ! maskp->bits[1])
1230 		return -EINVAL;
1231 	return 0;
1232 }
1233 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1234 
1235 /**
1236  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1237  * @runtime: PCM runtime instance
1238  * @var: hw_params variable to apply the integer constraint
1239  *
1240  * Apply the constraint of integer to an interval parameter.
1241  *
1242  * Return: Positive if the value is changed, zero if it's not changed, or a
1243  * negative error code.
1244  */
1245 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1246 {
1247 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1248 	return snd_interval_setinteger(constrs_interval(constrs, var));
1249 }
1250 
1251 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1252 
1253 /**
1254  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1255  * @runtime: PCM runtime instance
1256  * @var: hw_params variable to apply the range
1257  * @min: the minimal value
1258  * @max: the maximal value
1259  *
1260  * Apply the min/max range constraint to an interval parameter.
1261  *
1262  * Return: Positive if the value is changed, zero if it's not changed, or a
1263  * negative error code.
1264  */
1265 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1266 				 unsigned int min, unsigned int max)
1267 {
1268 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1269 	struct snd_interval t;
1270 	t.min = min;
1271 	t.max = max;
1272 	t.openmin = t.openmax = 0;
1273 	t.integer = 0;
1274 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1275 }
1276 
1277 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1278 
1279 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1280 				struct snd_pcm_hw_rule *rule)
1281 {
1282 	struct snd_pcm_hw_constraint_list *list = rule->private;
1283 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1284 }
1285 
1286 
1287 /**
1288  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1289  * @runtime: PCM runtime instance
1290  * @cond: condition bits
1291  * @var: hw_params variable to apply the list constraint
1292  * @l: list
1293  *
1294  * Apply the list of 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_list(struct snd_pcm_runtime *runtime,
1299 			       unsigned int cond,
1300 			       snd_pcm_hw_param_t var,
1301 			       const struct snd_pcm_hw_constraint_list *l)
1302 {
1303 	return snd_pcm_hw_rule_add(runtime, cond, var,
1304 				   snd_pcm_hw_rule_list, (void *)l,
1305 				   var, -1);
1306 }
1307 
1308 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1309 
1310 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1311 				  struct snd_pcm_hw_rule *rule)
1312 {
1313 	struct snd_pcm_hw_constraint_ranges *r = rule->private;
1314 	return snd_interval_ranges(hw_param_interval(params, rule->var),
1315 				   r->count, r->ranges, r->mask);
1316 }
1317 
1318 
1319 /**
1320  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1321  * @runtime: PCM runtime instance
1322  * @cond: condition bits
1323  * @var: hw_params variable to apply the list of range constraints
1324  * @r: ranges
1325  *
1326  * Apply the list of range constraints to an interval parameter.
1327  *
1328  * Return: Zero if successful, or a negative error code on failure.
1329  */
1330 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1331 				 unsigned int cond,
1332 				 snd_pcm_hw_param_t var,
1333 				 const struct snd_pcm_hw_constraint_ranges *r)
1334 {
1335 	return snd_pcm_hw_rule_add(runtime, cond, var,
1336 				   snd_pcm_hw_rule_ranges, (void *)r,
1337 				   var, -1);
1338 }
1339 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1340 
1341 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1342 				   struct snd_pcm_hw_rule *rule)
1343 {
1344 	const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1345 	unsigned int num = 0, den = 0;
1346 	int err;
1347 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1348 				  r->nrats, r->rats, &num, &den);
1349 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1350 		params->rate_num = num;
1351 		params->rate_den = den;
1352 	}
1353 	return err;
1354 }
1355 
1356 /**
1357  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1358  * @runtime: PCM runtime instance
1359  * @cond: condition bits
1360  * @var: hw_params variable to apply the ratnums constraint
1361  * @r: struct snd_ratnums constriants
1362  *
1363  * Return: Zero if successful, or a negative error code on failure.
1364  */
1365 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1366 				  unsigned int cond,
1367 				  snd_pcm_hw_param_t var,
1368 				  const struct snd_pcm_hw_constraint_ratnums *r)
1369 {
1370 	return snd_pcm_hw_rule_add(runtime, cond, var,
1371 				   snd_pcm_hw_rule_ratnums, (void *)r,
1372 				   var, -1);
1373 }
1374 
1375 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1376 
1377 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1378 				   struct snd_pcm_hw_rule *rule)
1379 {
1380 	const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1381 	unsigned int num = 0, den = 0;
1382 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1383 				  r->nrats, r->rats, &num, &den);
1384 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1385 		params->rate_num = num;
1386 		params->rate_den = den;
1387 	}
1388 	return err;
1389 }
1390 
1391 /**
1392  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1393  * @runtime: PCM runtime instance
1394  * @cond: condition bits
1395  * @var: hw_params variable to apply the ratdens constraint
1396  * @r: struct snd_ratdens constriants
1397  *
1398  * Return: Zero if successful, or a negative error code on failure.
1399  */
1400 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1401 				  unsigned int cond,
1402 				  snd_pcm_hw_param_t var,
1403 				  const struct snd_pcm_hw_constraint_ratdens *r)
1404 {
1405 	return snd_pcm_hw_rule_add(runtime, cond, var,
1406 				   snd_pcm_hw_rule_ratdens, (void *)r,
1407 				   var, -1);
1408 }
1409 
1410 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1411 
1412 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1413 				  struct snd_pcm_hw_rule *rule)
1414 {
1415 	unsigned int l = (unsigned long) rule->private;
1416 	int width = l & 0xffff;
1417 	unsigned int msbits = l >> 16;
1418 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1419 
1420 	if (!snd_interval_single(i))
1421 		return 0;
1422 
1423 	if ((snd_interval_value(i) == width) ||
1424 	    (width == 0 && snd_interval_value(i) > msbits))
1425 		params->msbits = min_not_zero(params->msbits, msbits);
1426 
1427 	return 0;
1428 }
1429 
1430 /**
1431  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1432  * @runtime: PCM runtime instance
1433  * @cond: condition bits
1434  * @width: sample bits width
1435  * @msbits: msbits width
1436  *
1437  * This constraint will set the number of most significant bits (msbits) if a
1438  * sample format with the specified width has been select. If width is set to 0
1439  * the msbits will be set for any sample format with a width larger than the
1440  * specified msbits.
1441  *
1442  * Return: Zero if successful, or a negative error code on failure.
1443  */
1444 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1445 				 unsigned int cond,
1446 				 unsigned int width,
1447 				 unsigned int msbits)
1448 {
1449 	unsigned long l = (msbits << 16) | width;
1450 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1451 				    snd_pcm_hw_rule_msbits,
1452 				    (void*) l,
1453 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1454 }
1455 
1456 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1457 
1458 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1459 				struct snd_pcm_hw_rule *rule)
1460 {
1461 	unsigned long step = (unsigned long) rule->private;
1462 	return snd_interval_step(hw_param_interval(params, rule->var), step);
1463 }
1464 
1465 /**
1466  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1467  * @runtime: PCM runtime instance
1468  * @cond: condition bits
1469  * @var: hw_params variable to apply the step constraint
1470  * @step: step size
1471  *
1472  * Return: Zero if successful, or a negative error code on failure.
1473  */
1474 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1475 			       unsigned int cond,
1476 			       snd_pcm_hw_param_t var,
1477 			       unsigned long step)
1478 {
1479 	return snd_pcm_hw_rule_add(runtime, cond, var,
1480 				   snd_pcm_hw_rule_step, (void *) step,
1481 				   var, -1);
1482 }
1483 
1484 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1485 
1486 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1487 {
1488 	static unsigned int pow2_sizes[] = {
1489 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1490 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1491 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1492 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1493 	};
1494 	return snd_interval_list(hw_param_interval(params, rule->var),
1495 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1496 }
1497 
1498 /**
1499  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1500  * @runtime: PCM runtime instance
1501  * @cond: condition bits
1502  * @var: hw_params variable to apply the power-of-2 constraint
1503  *
1504  * Return: Zero if successful, or a negative error code on failure.
1505  */
1506 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1507 			       unsigned int cond,
1508 			       snd_pcm_hw_param_t var)
1509 {
1510 	return snd_pcm_hw_rule_add(runtime, cond, var,
1511 				   snd_pcm_hw_rule_pow2, NULL,
1512 				   var, -1);
1513 }
1514 
1515 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1516 
1517 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1518 					   struct snd_pcm_hw_rule *rule)
1519 {
1520 	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1521 	struct snd_interval *rate;
1522 
1523 	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1524 	return snd_interval_list(rate, 1, &base_rate, 0);
1525 }
1526 
1527 /**
1528  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1529  * @runtime: PCM runtime instance
1530  * @base_rate: the rate at which the hardware does not resample
1531  *
1532  * Return: Zero if successful, or a negative error code on failure.
1533  */
1534 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1535 			       unsigned int base_rate)
1536 {
1537 	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1538 				   SNDRV_PCM_HW_PARAM_RATE,
1539 				   snd_pcm_hw_rule_noresample_func,
1540 				   (void *)(uintptr_t)base_rate,
1541 				   SNDRV_PCM_HW_PARAM_RATE, -1);
1542 }
1543 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1544 
1545 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1546 				  snd_pcm_hw_param_t var)
1547 {
1548 	if (hw_is_mask(var)) {
1549 		snd_mask_any(hw_param_mask(params, var));
1550 		params->cmask |= 1 << var;
1551 		params->rmask |= 1 << var;
1552 		return;
1553 	}
1554 	if (hw_is_interval(var)) {
1555 		snd_interval_any(hw_param_interval(params, var));
1556 		params->cmask |= 1 << var;
1557 		params->rmask |= 1 << var;
1558 		return;
1559 	}
1560 	snd_BUG();
1561 }
1562 
1563 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1564 {
1565 	unsigned int k;
1566 	memset(params, 0, sizeof(*params));
1567 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1568 		_snd_pcm_hw_param_any(params, k);
1569 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1570 		_snd_pcm_hw_param_any(params, k);
1571 	params->info = ~0U;
1572 }
1573 
1574 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1575 
1576 /**
1577  * snd_pcm_hw_param_value - return @params field @var value
1578  * @params: the hw_params instance
1579  * @var: parameter to retrieve
1580  * @dir: pointer to the direction (-1,0,1) or %NULL
1581  *
1582  * Return: The value for field @var if it's fixed in configuration space
1583  * defined by @params. -%EINVAL otherwise.
1584  */
1585 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1586 			   snd_pcm_hw_param_t var, int *dir)
1587 {
1588 	if (hw_is_mask(var)) {
1589 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1590 		if (!snd_mask_single(mask))
1591 			return -EINVAL;
1592 		if (dir)
1593 			*dir = 0;
1594 		return snd_mask_value(mask);
1595 	}
1596 	if (hw_is_interval(var)) {
1597 		const struct snd_interval *i = hw_param_interval_c(params, var);
1598 		if (!snd_interval_single(i))
1599 			return -EINVAL;
1600 		if (dir)
1601 			*dir = i->openmin;
1602 		return snd_interval_value(i);
1603 	}
1604 	return -EINVAL;
1605 }
1606 
1607 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1608 
1609 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1610 				snd_pcm_hw_param_t var)
1611 {
1612 	if (hw_is_mask(var)) {
1613 		snd_mask_none(hw_param_mask(params, var));
1614 		params->cmask |= 1 << var;
1615 		params->rmask |= 1 << var;
1616 	} else if (hw_is_interval(var)) {
1617 		snd_interval_none(hw_param_interval(params, var));
1618 		params->cmask |= 1 << var;
1619 		params->rmask |= 1 << var;
1620 	} else {
1621 		snd_BUG();
1622 	}
1623 }
1624 
1625 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1626 
1627 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1628 				   snd_pcm_hw_param_t var)
1629 {
1630 	int changed;
1631 	if (hw_is_mask(var))
1632 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1633 	else if (hw_is_interval(var))
1634 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1635 	else
1636 		return -EINVAL;
1637 	if (changed) {
1638 		params->cmask |= 1 << var;
1639 		params->rmask |= 1 << var;
1640 	}
1641 	return changed;
1642 }
1643 
1644 
1645 /**
1646  * snd_pcm_hw_param_first - refine config space and return minimum value
1647  * @pcm: PCM instance
1648  * @params: the hw_params instance
1649  * @var: parameter to retrieve
1650  * @dir: pointer to the direction (-1,0,1) or %NULL
1651  *
1652  * Inside configuration space defined by @params remove from @var all
1653  * values > minimum. Reduce configuration space accordingly.
1654  *
1655  * Return: The minimum, or a negative error code on failure.
1656  */
1657 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1658 			   struct snd_pcm_hw_params *params,
1659 			   snd_pcm_hw_param_t var, int *dir)
1660 {
1661 	int changed = _snd_pcm_hw_param_first(params, var);
1662 	if (changed < 0)
1663 		return changed;
1664 	if (params->rmask) {
1665 		int err = snd_pcm_hw_refine(pcm, params);
1666 		if (snd_BUG_ON(err < 0))
1667 			return err;
1668 	}
1669 	return snd_pcm_hw_param_value(params, var, dir);
1670 }
1671 
1672 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1673 
1674 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1675 				  snd_pcm_hw_param_t var)
1676 {
1677 	int changed;
1678 	if (hw_is_mask(var))
1679 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1680 	else if (hw_is_interval(var))
1681 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1682 	else
1683 		return -EINVAL;
1684 	if (changed) {
1685 		params->cmask |= 1 << var;
1686 		params->rmask |= 1 << var;
1687 	}
1688 	return changed;
1689 }
1690 
1691 
1692 /**
1693  * snd_pcm_hw_param_last - refine config space and return maximum value
1694  * @pcm: PCM instance
1695  * @params: the hw_params instance
1696  * @var: parameter to retrieve
1697  * @dir: pointer to the direction (-1,0,1) or %NULL
1698  *
1699  * Inside configuration space defined by @params remove from @var all
1700  * values < maximum. Reduce configuration space accordingly.
1701  *
1702  * Return: The maximum, or a negative error code on failure.
1703  */
1704 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1705 			  struct snd_pcm_hw_params *params,
1706 			  snd_pcm_hw_param_t var, int *dir)
1707 {
1708 	int changed = _snd_pcm_hw_param_last(params, var);
1709 	if (changed < 0)
1710 		return changed;
1711 	if (params->rmask) {
1712 		int err = snd_pcm_hw_refine(pcm, params);
1713 		if (snd_BUG_ON(err < 0))
1714 			return err;
1715 	}
1716 	return snd_pcm_hw_param_value(params, var, dir);
1717 }
1718 
1719 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1720 
1721 /**
1722  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1723  * @pcm: PCM instance
1724  * @params: the hw_params instance
1725  *
1726  * Choose one configuration from configuration space defined by @params.
1727  * The configuration chosen is that obtained fixing in this order:
1728  * first access, first format, first subformat, min channels,
1729  * min rate, min period time, max buffer size, min tick time
1730  *
1731  * Return: Zero if successful, or a negative error code on failure.
1732  */
1733 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1734 			     struct snd_pcm_hw_params *params)
1735 {
1736 	static int vars[] = {
1737 		SNDRV_PCM_HW_PARAM_ACCESS,
1738 		SNDRV_PCM_HW_PARAM_FORMAT,
1739 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1740 		SNDRV_PCM_HW_PARAM_CHANNELS,
1741 		SNDRV_PCM_HW_PARAM_RATE,
1742 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1743 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1744 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1745 		-1
1746 	};
1747 	int err, *v;
1748 
1749 	for (v = vars; *v != -1; v++) {
1750 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1751 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1752 		else
1753 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1754 		if (snd_BUG_ON(err < 0))
1755 			return err;
1756 	}
1757 	return 0;
1758 }
1759 
1760 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1761 				   void *arg)
1762 {
1763 	struct snd_pcm_runtime *runtime = substream->runtime;
1764 	unsigned long flags;
1765 	snd_pcm_stream_lock_irqsave(substream, flags);
1766 	if (snd_pcm_running(substream) &&
1767 	    snd_pcm_update_hw_ptr(substream) >= 0)
1768 		runtime->status->hw_ptr %= runtime->buffer_size;
1769 	else {
1770 		runtime->status->hw_ptr = 0;
1771 		runtime->hw_ptr_wrap = 0;
1772 	}
1773 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1774 	return 0;
1775 }
1776 
1777 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1778 					  void *arg)
1779 {
1780 	struct snd_pcm_channel_info *info = arg;
1781 	struct snd_pcm_runtime *runtime = substream->runtime;
1782 	int width;
1783 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1784 		info->offset = -1;
1785 		return 0;
1786 	}
1787 	width = snd_pcm_format_physical_width(runtime->format);
1788 	if (width < 0)
1789 		return width;
1790 	info->offset = 0;
1791 	switch (runtime->access) {
1792 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1793 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1794 		info->first = info->channel * width;
1795 		info->step = runtime->channels * width;
1796 		break;
1797 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1798 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1799 	{
1800 		size_t size = runtime->dma_bytes / runtime->channels;
1801 		info->first = info->channel * size * 8;
1802 		info->step = width;
1803 		break;
1804 	}
1805 	default:
1806 		snd_BUG();
1807 		break;
1808 	}
1809 	return 0;
1810 }
1811 
1812 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1813 				       void *arg)
1814 {
1815 	struct snd_pcm_hw_params *params = arg;
1816 	snd_pcm_format_t format;
1817 	int channels;
1818 	ssize_t frame_size;
1819 
1820 	params->fifo_size = substream->runtime->hw.fifo_size;
1821 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1822 		format = params_format(params);
1823 		channels = params_channels(params);
1824 		frame_size = snd_pcm_format_size(format, channels);
1825 		if (frame_size > 0)
1826 			params->fifo_size /= (unsigned)frame_size;
1827 	}
1828 	return 0;
1829 }
1830 
1831 /**
1832  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1833  * @substream: the pcm substream instance
1834  * @cmd: ioctl command
1835  * @arg: ioctl argument
1836  *
1837  * Processes the generic ioctl commands for PCM.
1838  * Can be passed as the ioctl callback for PCM ops.
1839  *
1840  * Return: Zero if successful, or a negative error code on failure.
1841  */
1842 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1843 		      unsigned int cmd, void *arg)
1844 {
1845 	switch (cmd) {
1846 	case SNDRV_PCM_IOCTL1_INFO:
1847 		return 0;
1848 	case SNDRV_PCM_IOCTL1_RESET:
1849 		return snd_pcm_lib_ioctl_reset(substream, arg);
1850 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1851 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1852 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1853 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1854 	}
1855 	return -ENXIO;
1856 }
1857 
1858 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1859 
1860 /**
1861  * snd_pcm_period_elapsed - update the pcm status for the next period
1862  * @substream: the pcm substream instance
1863  *
1864  * This function is called from the interrupt handler when the
1865  * PCM has processed the period size.  It will update the current
1866  * pointer, wake up sleepers, etc.
1867  *
1868  * Even if more than one periods have elapsed since the last call, you
1869  * have to call this only once.
1870  */
1871 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1872 {
1873 	struct snd_pcm_runtime *runtime;
1874 	unsigned long flags;
1875 
1876 	if (PCM_RUNTIME_CHECK(substream))
1877 		return;
1878 	runtime = substream->runtime;
1879 
1880 	snd_pcm_stream_lock_irqsave(substream, flags);
1881 	if (!snd_pcm_running(substream) ||
1882 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1883 		goto _end;
1884 
1885 #ifdef CONFIG_SND_PCM_TIMER
1886 	if (substream->timer_running)
1887 		snd_timer_interrupt(substream->timer, 1);
1888 #endif
1889  _end:
1890 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1891 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1892 }
1893 
1894 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1895 
1896 /*
1897  * Wait until avail_min data becomes available
1898  * Returns a negative error code if any error occurs during operation.
1899  * The available space is stored on availp.  When err = 0 and avail = 0
1900  * on the capture stream, it indicates the stream is in DRAINING state.
1901  */
1902 static int wait_for_avail(struct snd_pcm_substream *substream,
1903 			      snd_pcm_uframes_t *availp)
1904 {
1905 	struct snd_pcm_runtime *runtime = substream->runtime;
1906 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1907 	wait_queue_t wait;
1908 	int err = 0;
1909 	snd_pcm_uframes_t avail = 0;
1910 	long wait_time, tout;
1911 
1912 	init_waitqueue_entry(&wait, current);
1913 	set_current_state(TASK_INTERRUPTIBLE);
1914 	add_wait_queue(&runtime->tsleep, &wait);
1915 
1916 	if (runtime->no_period_wakeup)
1917 		wait_time = MAX_SCHEDULE_TIMEOUT;
1918 	else {
1919 		wait_time = 10;
1920 		if (runtime->rate) {
1921 			long t = runtime->period_size * 2 / runtime->rate;
1922 			wait_time = max(t, wait_time);
1923 		}
1924 		wait_time = msecs_to_jiffies(wait_time * 1000);
1925 	}
1926 
1927 	for (;;) {
1928 		if (signal_pending(current)) {
1929 			err = -ERESTARTSYS;
1930 			break;
1931 		}
1932 
1933 		/*
1934 		 * We need to check if space became available already
1935 		 * (and thus the wakeup happened already) first to close
1936 		 * the race of space already having become available.
1937 		 * This check must happen after been added to the waitqueue
1938 		 * and having current state be INTERRUPTIBLE.
1939 		 */
1940 		if (is_playback)
1941 			avail = snd_pcm_playback_avail(runtime);
1942 		else
1943 			avail = snd_pcm_capture_avail(runtime);
1944 		if (avail >= runtime->twake)
1945 			break;
1946 		snd_pcm_stream_unlock_irq(substream);
1947 
1948 		tout = schedule_timeout(wait_time);
1949 
1950 		snd_pcm_stream_lock_irq(substream);
1951 		set_current_state(TASK_INTERRUPTIBLE);
1952 		switch (runtime->status->state) {
1953 		case SNDRV_PCM_STATE_SUSPENDED:
1954 			err = -ESTRPIPE;
1955 			goto _endloop;
1956 		case SNDRV_PCM_STATE_XRUN:
1957 			err = -EPIPE;
1958 			goto _endloop;
1959 		case SNDRV_PCM_STATE_DRAINING:
1960 			if (is_playback)
1961 				err = -EPIPE;
1962 			else
1963 				avail = 0; /* indicate draining */
1964 			goto _endloop;
1965 		case SNDRV_PCM_STATE_OPEN:
1966 		case SNDRV_PCM_STATE_SETUP:
1967 		case SNDRV_PCM_STATE_DISCONNECTED:
1968 			err = -EBADFD;
1969 			goto _endloop;
1970 		case SNDRV_PCM_STATE_PAUSED:
1971 			continue;
1972 		}
1973 		if (!tout) {
1974 			pcm_dbg(substream->pcm,
1975 				"%s write error (DMA or IRQ trouble?)\n",
1976 				is_playback ? "playback" : "capture");
1977 			err = -EIO;
1978 			break;
1979 		}
1980 	}
1981  _endloop:
1982 	set_current_state(TASK_RUNNING);
1983 	remove_wait_queue(&runtime->tsleep, &wait);
1984 	*availp = avail;
1985 	return err;
1986 }
1987 
1988 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1989 				      unsigned int hwoff,
1990 				      unsigned long data, unsigned int off,
1991 				      snd_pcm_uframes_t frames)
1992 {
1993 	struct snd_pcm_runtime *runtime = substream->runtime;
1994 	int err;
1995 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1996 	if (substream->ops->copy) {
1997 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1998 			return err;
1999 	} else {
2000 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2001 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
2002 			return -EFAULT;
2003 	}
2004 	return 0;
2005 }
2006 
2007 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
2008 			  unsigned long data, unsigned int off,
2009 			  snd_pcm_uframes_t size);
2010 
2011 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
2012 					    unsigned long data,
2013 					    snd_pcm_uframes_t size,
2014 					    int nonblock,
2015 					    transfer_f transfer)
2016 {
2017 	struct snd_pcm_runtime *runtime = substream->runtime;
2018 	snd_pcm_uframes_t xfer = 0;
2019 	snd_pcm_uframes_t offset = 0;
2020 	snd_pcm_uframes_t avail;
2021 	int err = 0;
2022 
2023 	if (size == 0)
2024 		return 0;
2025 
2026 	snd_pcm_stream_lock_irq(substream);
2027 	switch (runtime->status->state) {
2028 	case SNDRV_PCM_STATE_PREPARED:
2029 	case SNDRV_PCM_STATE_RUNNING:
2030 	case SNDRV_PCM_STATE_PAUSED:
2031 		break;
2032 	case SNDRV_PCM_STATE_XRUN:
2033 		err = -EPIPE;
2034 		goto _end_unlock;
2035 	case SNDRV_PCM_STATE_SUSPENDED:
2036 		err = -ESTRPIPE;
2037 		goto _end_unlock;
2038 	default:
2039 		err = -EBADFD;
2040 		goto _end_unlock;
2041 	}
2042 
2043 	runtime->twake = runtime->control->avail_min ? : 1;
2044 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2045 		snd_pcm_update_hw_ptr(substream);
2046 	avail = snd_pcm_playback_avail(runtime);
2047 	while (size > 0) {
2048 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2049 		snd_pcm_uframes_t cont;
2050 		if (!avail) {
2051 			if (nonblock) {
2052 				err = -EAGAIN;
2053 				goto _end_unlock;
2054 			}
2055 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2056 					runtime->control->avail_min ? : 1);
2057 			err = wait_for_avail(substream, &avail);
2058 			if (err < 0)
2059 				goto _end_unlock;
2060 		}
2061 		frames = size > avail ? avail : size;
2062 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2063 		if (frames > cont)
2064 			frames = cont;
2065 		if (snd_BUG_ON(!frames)) {
2066 			runtime->twake = 0;
2067 			snd_pcm_stream_unlock_irq(substream);
2068 			return -EINVAL;
2069 		}
2070 		appl_ptr = runtime->control->appl_ptr;
2071 		appl_ofs = appl_ptr % runtime->buffer_size;
2072 		snd_pcm_stream_unlock_irq(substream);
2073 		err = transfer(substream, appl_ofs, data, offset, frames);
2074 		snd_pcm_stream_lock_irq(substream);
2075 		if (err < 0)
2076 			goto _end_unlock;
2077 		switch (runtime->status->state) {
2078 		case SNDRV_PCM_STATE_XRUN:
2079 			err = -EPIPE;
2080 			goto _end_unlock;
2081 		case SNDRV_PCM_STATE_SUSPENDED:
2082 			err = -ESTRPIPE;
2083 			goto _end_unlock;
2084 		default:
2085 			break;
2086 		}
2087 		appl_ptr += frames;
2088 		if (appl_ptr >= runtime->boundary)
2089 			appl_ptr -= runtime->boundary;
2090 		runtime->control->appl_ptr = appl_ptr;
2091 		if (substream->ops->ack)
2092 			substream->ops->ack(substream);
2093 
2094 		offset += frames;
2095 		size -= frames;
2096 		xfer += frames;
2097 		avail -= frames;
2098 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2099 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2100 			err = snd_pcm_start(substream);
2101 			if (err < 0)
2102 				goto _end_unlock;
2103 		}
2104 	}
2105  _end_unlock:
2106 	runtime->twake = 0;
2107 	if (xfer > 0 && err >= 0)
2108 		snd_pcm_update_state(substream, runtime);
2109 	snd_pcm_stream_unlock_irq(substream);
2110 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2111 }
2112 
2113 /* sanity-check for read/write methods */
2114 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2115 {
2116 	struct snd_pcm_runtime *runtime;
2117 	if (PCM_RUNTIME_CHECK(substream))
2118 		return -ENXIO;
2119 	runtime = substream->runtime;
2120 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2121 		return -EINVAL;
2122 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2123 		return -EBADFD;
2124 	return 0;
2125 }
2126 
2127 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2128 {
2129 	struct snd_pcm_runtime *runtime;
2130 	int nonblock;
2131 	int err;
2132 
2133 	err = pcm_sanity_check(substream);
2134 	if (err < 0)
2135 		return err;
2136 	runtime = substream->runtime;
2137 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2138 
2139 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2140 	    runtime->channels > 1)
2141 		return -EINVAL;
2142 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2143 				  snd_pcm_lib_write_transfer);
2144 }
2145 
2146 EXPORT_SYMBOL(snd_pcm_lib_write);
2147 
2148 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2149 				       unsigned int hwoff,
2150 				       unsigned long data, unsigned int off,
2151 				       snd_pcm_uframes_t frames)
2152 {
2153 	struct snd_pcm_runtime *runtime = substream->runtime;
2154 	int err;
2155 	void __user **bufs = (void __user **)data;
2156 	int channels = runtime->channels;
2157 	int c;
2158 	if (substream->ops->copy) {
2159 		if (snd_BUG_ON(!substream->ops->silence))
2160 			return -EINVAL;
2161 		for (c = 0; c < channels; ++c, ++bufs) {
2162 			if (*bufs == NULL) {
2163 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2164 					return err;
2165 			} else {
2166 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2167 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2168 					return err;
2169 			}
2170 		}
2171 	} else {
2172 		/* default transfer behaviour */
2173 		size_t dma_csize = runtime->dma_bytes / channels;
2174 		for (c = 0; c < channels; ++c, ++bufs) {
2175 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2176 			if (*bufs == NULL) {
2177 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2178 			} else {
2179 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2180 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2181 					return -EFAULT;
2182 			}
2183 		}
2184 	}
2185 	return 0;
2186 }
2187 
2188 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2189 				     void __user **bufs,
2190 				     snd_pcm_uframes_t frames)
2191 {
2192 	struct snd_pcm_runtime *runtime;
2193 	int nonblock;
2194 	int err;
2195 
2196 	err = pcm_sanity_check(substream);
2197 	if (err < 0)
2198 		return err;
2199 	runtime = substream->runtime;
2200 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2201 
2202 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2203 		return -EINVAL;
2204 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2205 				  nonblock, snd_pcm_lib_writev_transfer);
2206 }
2207 
2208 EXPORT_SYMBOL(snd_pcm_lib_writev);
2209 
2210 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2211 				     unsigned int hwoff,
2212 				     unsigned long data, unsigned int off,
2213 				     snd_pcm_uframes_t frames)
2214 {
2215 	struct snd_pcm_runtime *runtime = substream->runtime;
2216 	int err;
2217 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2218 	if (substream->ops->copy) {
2219 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2220 			return err;
2221 	} else {
2222 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2223 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2224 			return -EFAULT;
2225 	}
2226 	return 0;
2227 }
2228 
2229 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2230 					   unsigned long data,
2231 					   snd_pcm_uframes_t size,
2232 					   int nonblock,
2233 					   transfer_f transfer)
2234 {
2235 	struct snd_pcm_runtime *runtime = substream->runtime;
2236 	snd_pcm_uframes_t xfer = 0;
2237 	snd_pcm_uframes_t offset = 0;
2238 	snd_pcm_uframes_t avail;
2239 	int err = 0;
2240 
2241 	if (size == 0)
2242 		return 0;
2243 
2244 	snd_pcm_stream_lock_irq(substream);
2245 	switch (runtime->status->state) {
2246 	case SNDRV_PCM_STATE_PREPARED:
2247 		if (size >= runtime->start_threshold) {
2248 			err = snd_pcm_start(substream);
2249 			if (err < 0)
2250 				goto _end_unlock;
2251 		}
2252 		break;
2253 	case SNDRV_PCM_STATE_DRAINING:
2254 	case SNDRV_PCM_STATE_RUNNING:
2255 	case SNDRV_PCM_STATE_PAUSED:
2256 		break;
2257 	case SNDRV_PCM_STATE_XRUN:
2258 		err = -EPIPE;
2259 		goto _end_unlock;
2260 	case SNDRV_PCM_STATE_SUSPENDED:
2261 		err = -ESTRPIPE;
2262 		goto _end_unlock;
2263 	default:
2264 		err = -EBADFD;
2265 		goto _end_unlock;
2266 	}
2267 
2268 	runtime->twake = runtime->control->avail_min ? : 1;
2269 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2270 		snd_pcm_update_hw_ptr(substream);
2271 	avail = snd_pcm_capture_avail(runtime);
2272 	while (size > 0) {
2273 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2274 		snd_pcm_uframes_t cont;
2275 		if (!avail) {
2276 			if (runtime->status->state ==
2277 			    SNDRV_PCM_STATE_DRAINING) {
2278 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2279 				goto _end_unlock;
2280 			}
2281 			if (nonblock) {
2282 				err = -EAGAIN;
2283 				goto _end_unlock;
2284 			}
2285 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2286 					runtime->control->avail_min ? : 1);
2287 			err = wait_for_avail(substream, &avail);
2288 			if (err < 0)
2289 				goto _end_unlock;
2290 			if (!avail)
2291 				continue; /* draining */
2292 		}
2293 		frames = size > avail ? avail : size;
2294 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2295 		if (frames > cont)
2296 			frames = cont;
2297 		if (snd_BUG_ON(!frames)) {
2298 			runtime->twake = 0;
2299 			snd_pcm_stream_unlock_irq(substream);
2300 			return -EINVAL;
2301 		}
2302 		appl_ptr = runtime->control->appl_ptr;
2303 		appl_ofs = appl_ptr % runtime->buffer_size;
2304 		snd_pcm_stream_unlock_irq(substream);
2305 		err = transfer(substream, appl_ofs, data, offset, frames);
2306 		snd_pcm_stream_lock_irq(substream);
2307 		if (err < 0)
2308 			goto _end_unlock;
2309 		switch (runtime->status->state) {
2310 		case SNDRV_PCM_STATE_XRUN:
2311 			err = -EPIPE;
2312 			goto _end_unlock;
2313 		case SNDRV_PCM_STATE_SUSPENDED:
2314 			err = -ESTRPIPE;
2315 			goto _end_unlock;
2316 		default:
2317 			break;
2318 		}
2319 		appl_ptr += frames;
2320 		if (appl_ptr >= runtime->boundary)
2321 			appl_ptr -= runtime->boundary;
2322 		runtime->control->appl_ptr = appl_ptr;
2323 		if (substream->ops->ack)
2324 			substream->ops->ack(substream);
2325 
2326 		offset += frames;
2327 		size -= frames;
2328 		xfer += frames;
2329 		avail -= frames;
2330 	}
2331  _end_unlock:
2332 	runtime->twake = 0;
2333 	if (xfer > 0 && err >= 0)
2334 		snd_pcm_update_state(substream, runtime);
2335 	snd_pcm_stream_unlock_irq(substream);
2336 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2337 }
2338 
2339 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2340 {
2341 	struct snd_pcm_runtime *runtime;
2342 	int nonblock;
2343 	int err;
2344 
2345 	err = pcm_sanity_check(substream);
2346 	if (err < 0)
2347 		return err;
2348 	runtime = substream->runtime;
2349 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2350 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2351 		return -EINVAL;
2352 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2353 }
2354 
2355 EXPORT_SYMBOL(snd_pcm_lib_read);
2356 
2357 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2358 				      unsigned int hwoff,
2359 				      unsigned long data, unsigned int off,
2360 				      snd_pcm_uframes_t frames)
2361 {
2362 	struct snd_pcm_runtime *runtime = substream->runtime;
2363 	int err;
2364 	void __user **bufs = (void __user **)data;
2365 	int channels = runtime->channels;
2366 	int c;
2367 	if (substream->ops->copy) {
2368 		for (c = 0; c < channels; ++c, ++bufs) {
2369 			char __user *buf;
2370 			if (*bufs == NULL)
2371 				continue;
2372 			buf = *bufs + samples_to_bytes(runtime, off);
2373 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2374 				return err;
2375 		}
2376 	} else {
2377 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2378 		for (c = 0; c < channels; ++c, ++bufs) {
2379 			char *hwbuf;
2380 			char __user *buf;
2381 			if (*bufs == NULL)
2382 				continue;
2383 
2384 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2385 			buf = *bufs + samples_to_bytes(runtime, off);
2386 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2387 				return -EFAULT;
2388 		}
2389 	}
2390 	return 0;
2391 }
2392 
2393 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2394 				    void __user **bufs,
2395 				    snd_pcm_uframes_t frames)
2396 {
2397 	struct snd_pcm_runtime *runtime;
2398 	int nonblock;
2399 	int err;
2400 
2401 	err = pcm_sanity_check(substream);
2402 	if (err < 0)
2403 		return err;
2404 	runtime = substream->runtime;
2405 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2406 		return -EBADFD;
2407 
2408 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2409 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2410 		return -EINVAL;
2411 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2412 }
2413 
2414 EXPORT_SYMBOL(snd_pcm_lib_readv);
2415 
2416 /*
2417  * standard channel mapping helpers
2418  */
2419 
2420 /* default channel maps for multi-channel playbacks, up to 8 channels */
2421 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2422 	{ .channels = 1,
2423 	  .map = { SNDRV_CHMAP_MONO } },
2424 	{ .channels = 2,
2425 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2426 	{ .channels = 4,
2427 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2428 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2429 	{ .channels = 6,
2430 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2431 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2432 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2433 	{ .channels = 8,
2434 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2435 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2436 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2437 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2438 	{ }
2439 };
2440 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2441 
2442 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2443 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2444 	{ .channels = 1,
2445 	  .map = { SNDRV_CHMAP_MONO } },
2446 	{ .channels = 2,
2447 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2448 	{ .channels = 4,
2449 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2450 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2451 	{ .channels = 6,
2452 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2453 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2454 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2455 	{ .channels = 8,
2456 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2457 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2458 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2459 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2460 	{ }
2461 };
2462 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2463 
2464 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2465 {
2466 	if (ch > info->max_channels)
2467 		return false;
2468 	return !info->channel_mask || (info->channel_mask & (1U << ch));
2469 }
2470 
2471 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2472 			      struct snd_ctl_elem_info *uinfo)
2473 {
2474 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2475 
2476 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2477 	uinfo->count = 0;
2478 	uinfo->count = info->max_channels;
2479 	uinfo->value.integer.min = 0;
2480 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2481 	return 0;
2482 }
2483 
2484 /* get callback for channel map ctl element
2485  * stores the channel position firstly matching with the current channels
2486  */
2487 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2488 			     struct snd_ctl_elem_value *ucontrol)
2489 {
2490 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2491 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2492 	struct snd_pcm_substream *substream;
2493 	const struct snd_pcm_chmap_elem *map;
2494 
2495 	if (snd_BUG_ON(!info->chmap))
2496 		return -EINVAL;
2497 	substream = snd_pcm_chmap_substream(info, idx);
2498 	if (!substream)
2499 		return -ENODEV;
2500 	memset(ucontrol->value.integer.value, 0,
2501 	       sizeof(ucontrol->value.integer.value));
2502 	if (!substream->runtime)
2503 		return 0; /* no channels set */
2504 	for (map = info->chmap; map->channels; map++) {
2505 		int i;
2506 		if (map->channels == substream->runtime->channels &&
2507 		    valid_chmap_channels(info, map->channels)) {
2508 			for (i = 0; i < map->channels; i++)
2509 				ucontrol->value.integer.value[i] = map->map[i];
2510 			return 0;
2511 		}
2512 	}
2513 	return -EINVAL;
2514 }
2515 
2516 /* tlv callback for channel map ctl element
2517  * expands the pre-defined channel maps in a form of TLV
2518  */
2519 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2520 			     unsigned int size, unsigned int __user *tlv)
2521 {
2522 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2523 	const struct snd_pcm_chmap_elem *map;
2524 	unsigned int __user *dst;
2525 	int c, count = 0;
2526 
2527 	if (snd_BUG_ON(!info->chmap))
2528 		return -EINVAL;
2529 	if (size < 8)
2530 		return -ENOMEM;
2531 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2532 		return -EFAULT;
2533 	size -= 8;
2534 	dst = tlv + 2;
2535 	for (map = info->chmap; map->channels; map++) {
2536 		int chs_bytes = map->channels * 4;
2537 		if (!valid_chmap_channels(info, map->channels))
2538 			continue;
2539 		if (size < 8)
2540 			return -ENOMEM;
2541 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2542 		    put_user(chs_bytes, dst + 1))
2543 			return -EFAULT;
2544 		dst += 2;
2545 		size -= 8;
2546 		count += 8;
2547 		if (size < chs_bytes)
2548 			return -ENOMEM;
2549 		size -= chs_bytes;
2550 		count += chs_bytes;
2551 		for (c = 0; c < map->channels; c++) {
2552 			if (put_user(map->map[c], dst))
2553 				return -EFAULT;
2554 			dst++;
2555 		}
2556 	}
2557 	if (put_user(count, tlv + 1))
2558 		return -EFAULT;
2559 	return 0;
2560 }
2561 
2562 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2563 {
2564 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2565 	info->pcm->streams[info->stream].chmap_kctl = NULL;
2566 	kfree(info);
2567 }
2568 
2569 /**
2570  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2571  * @pcm: the assigned PCM instance
2572  * @stream: stream direction
2573  * @chmap: channel map elements (for query)
2574  * @max_channels: the max number of channels for the stream
2575  * @private_value: the value passed to each kcontrol's private_value field
2576  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2577  *
2578  * Create channel-mapping control elements assigned to the given PCM stream(s).
2579  * Return: Zero if successful, or a negative error value.
2580  */
2581 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2582 			   const struct snd_pcm_chmap_elem *chmap,
2583 			   int max_channels,
2584 			   unsigned long private_value,
2585 			   struct snd_pcm_chmap **info_ret)
2586 {
2587 	struct snd_pcm_chmap *info;
2588 	struct snd_kcontrol_new knew = {
2589 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
2590 		.access = SNDRV_CTL_ELEM_ACCESS_READ |
2591 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2592 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2593 		.info = pcm_chmap_ctl_info,
2594 		.get = pcm_chmap_ctl_get,
2595 		.tlv.c = pcm_chmap_ctl_tlv,
2596 	};
2597 	int err;
2598 
2599 	if (WARN_ON(pcm->streams[stream].chmap_kctl))
2600 		return -EBUSY;
2601 	info = kzalloc(sizeof(*info), GFP_KERNEL);
2602 	if (!info)
2603 		return -ENOMEM;
2604 	info->pcm = pcm;
2605 	info->stream = stream;
2606 	info->chmap = chmap;
2607 	info->max_channels = max_channels;
2608 	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2609 		knew.name = "Playback Channel Map";
2610 	else
2611 		knew.name = "Capture Channel Map";
2612 	knew.device = pcm->device;
2613 	knew.count = pcm->streams[stream].substream_count;
2614 	knew.private_value = private_value;
2615 	info->kctl = snd_ctl_new1(&knew, info);
2616 	if (!info->kctl) {
2617 		kfree(info);
2618 		return -ENOMEM;
2619 	}
2620 	info->kctl->private_free = pcm_chmap_ctl_private_free;
2621 	err = snd_ctl_add(pcm->card, info->kctl);
2622 	if (err < 0)
2623 		return err;
2624 	pcm->streams[stream].chmap_kctl = info->kctl;
2625 	if (info_ret)
2626 		*info_ret = info;
2627 	return 0;
2628 }
2629 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2630