xref: /linux/sound/core/pcm_lib.c (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
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 				"BUG: %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, 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, struct snd_ratden *rats,
924 			       unsigned int *nump, unsigned int *denp)
925 {
926 	unsigned int best_num, best_diff, best_den;
927 	unsigned int k;
928 	struct snd_interval t;
929 	int err;
930 
931 	best_num = best_den = best_diff = 0;
932 	for (k = 0; k < rats_count; ++k) {
933 		unsigned int num;
934 		unsigned int den = rats[k].den;
935 		unsigned int q = i->min;
936 		int diff;
937 		num = mul(q, den);
938 		if (num > rats[k].num_max)
939 			continue;
940 		if (num < rats[k].num_min)
941 			num = rats[k].num_max;
942 		else {
943 			unsigned int r;
944 			r = (num - rats[k].num_min) % rats[k].num_step;
945 			if (r != 0)
946 				num += rats[k].num_step - r;
947 		}
948 		diff = num - q * den;
949 		if (best_num == 0 ||
950 		    diff * best_den < best_diff * den) {
951 			best_diff = diff;
952 			best_den = den;
953 			best_num = num;
954 		}
955 	}
956 	if (best_den == 0) {
957 		i->empty = 1;
958 		return -EINVAL;
959 	}
960 	t.min = div_down(best_num, best_den);
961 	t.openmin = !!(best_num % best_den);
962 
963 	best_num = best_den = best_diff = 0;
964 	for (k = 0; k < rats_count; ++k) {
965 		unsigned int num;
966 		unsigned int den = rats[k].den;
967 		unsigned int q = i->max;
968 		int diff;
969 		num = mul(q, den);
970 		if (num < rats[k].num_min)
971 			continue;
972 		if (num > rats[k].num_max)
973 			num = rats[k].num_max;
974 		else {
975 			unsigned int r;
976 			r = (num - rats[k].num_min) % rats[k].num_step;
977 			if (r != 0)
978 				num -= r;
979 		}
980 		diff = q * den - num;
981 		if (best_num == 0 ||
982 		    diff * best_den < best_diff * den) {
983 			best_diff = diff;
984 			best_den = den;
985 			best_num = num;
986 		}
987 	}
988 	if (best_den == 0) {
989 		i->empty = 1;
990 		return -EINVAL;
991 	}
992 	t.max = div_up(best_num, best_den);
993 	t.openmax = !!(best_num % best_den);
994 	t.integer = 0;
995 	err = snd_interval_refine(i, &t);
996 	if (err < 0)
997 		return err;
998 
999 	if (snd_interval_single(i)) {
1000 		if (nump)
1001 			*nump = best_num;
1002 		if (denp)
1003 			*denp = best_den;
1004 	}
1005 	return err;
1006 }
1007 
1008 /**
1009  * snd_interval_list - refine the interval value from the list
1010  * @i: the interval value to refine
1011  * @count: the number of elements in the list
1012  * @list: the value list
1013  * @mask: the bit-mask to evaluate
1014  *
1015  * Refines the interval value from the list.
1016  * When mask is non-zero, only the elements corresponding to bit 1 are
1017  * evaluated.
1018  *
1019  * Return: Positive if the value is changed, zero if it's not changed, or a
1020  * negative error code.
1021  */
1022 int snd_interval_list(struct snd_interval *i, unsigned int count,
1023 		      const unsigned int *list, unsigned int mask)
1024 {
1025         unsigned int k;
1026 	struct snd_interval list_range;
1027 
1028 	if (!count) {
1029 		i->empty = 1;
1030 		return -EINVAL;
1031 	}
1032 	snd_interval_any(&list_range);
1033 	list_range.min = UINT_MAX;
1034 	list_range.max = 0;
1035         for (k = 0; k < count; k++) {
1036 		if (mask && !(mask & (1 << k)))
1037 			continue;
1038 		if (!snd_interval_test(i, list[k]))
1039 			continue;
1040 		list_range.min = min(list_range.min, list[k]);
1041 		list_range.max = max(list_range.max, list[k]);
1042         }
1043 	return snd_interval_refine(i, &list_range);
1044 }
1045 
1046 EXPORT_SYMBOL(snd_interval_list);
1047 
1048 /**
1049  * snd_interval_ranges - refine the interval value from the list of ranges
1050  * @i: the interval value to refine
1051  * @count: the number of elements in the list of ranges
1052  * @ranges: the ranges list
1053  * @mask: the bit-mask to evaluate
1054  *
1055  * Refines the interval value from the list of ranges.
1056  * When mask is non-zero, only the elements corresponding to bit 1 are
1057  * evaluated.
1058  *
1059  * Return: Positive if the value is changed, zero if it's not changed, or a
1060  * negative error code.
1061  */
1062 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1063 			const struct snd_interval *ranges, unsigned int mask)
1064 {
1065 	unsigned int k;
1066 	struct snd_interval range_union;
1067 	struct snd_interval range;
1068 
1069 	if (!count) {
1070 		snd_interval_none(i);
1071 		return -EINVAL;
1072 	}
1073 	snd_interval_any(&range_union);
1074 	range_union.min = UINT_MAX;
1075 	range_union.max = 0;
1076 	for (k = 0; k < count; k++) {
1077 		if (mask && !(mask & (1 << k)))
1078 			continue;
1079 		snd_interval_copy(&range, &ranges[k]);
1080 		if (snd_interval_refine(&range, i) < 0)
1081 			continue;
1082 		if (snd_interval_empty(&range))
1083 			continue;
1084 
1085 		if (range.min < range_union.min) {
1086 			range_union.min = range.min;
1087 			range_union.openmin = 1;
1088 		}
1089 		if (range.min == range_union.min && !range.openmin)
1090 			range_union.openmin = 0;
1091 		if (range.max > range_union.max) {
1092 			range_union.max = range.max;
1093 			range_union.openmax = 1;
1094 		}
1095 		if (range.max == range_union.max && !range.openmax)
1096 			range_union.openmax = 0;
1097 	}
1098 	return snd_interval_refine(i, &range_union);
1099 }
1100 EXPORT_SYMBOL(snd_interval_ranges);
1101 
1102 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1103 {
1104 	unsigned int n;
1105 	int changed = 0;
1106 	n = i->min % step;
1107 	if (n != 0 || i->openmin) {
1108 		i->min += step - n;
1109 		i->openmin = 0;
1110 		changed = 1;
1111 	}
1112 	n = i->max % step;
1113 	if (n != 0 || i->openmax) {
1114 		i->max -= n;
1115 		i->openmax = 0;
1116 		changed = 1;
1117 	}
1118 	if (snd_interval_checkempty(i)) {
1119 		i->empty = 1;
1120 		return -EINVAL;
1121 	}
1122 	return changed;
1123 }
1124 
1125 /* Info constraints helpers */
1126 
1127 /**
1128  * snd_pcm_hw_rule_add - add the hw-constraint rule
1129  * @runtime: the pcm runtime instance
1130  * @cond: condition bits
1131  * @var: the variable to evaluate
1132  * @func: the evaluation function
1133  * @private: the private data pointer passed to function
1134  * @dep: the dependent variables
1135  *
1136  * Return: Zero if successful, or a negative error code on failure.
1137  */
1138 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1139 			int var,
1140 			snd_pcm_hw_rule_func_t func, void *private,
1141 			int dep, ...)
1142 {
1143 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1144 	struct snd_pcm_hw_rule *c;
1145 	unsigned int k;
1146 	va_list args;
1147 	va_start(args, dep);
1148 	if (constrs->rules_num >= constrs->rules_all) {
1149 		struct snd_pcm_hw_rule *new;
1150 		unsigned int new_rules = constrs->rules_all + 16;
1151 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1152 		if (!new) {
1153 			va_end(args);
1154 			return -ENOMEM;
1155 		}
1156 		if (constrs->rules) {
1157 			memcpy(new, constrs->rules,
1158 			       constrs->rules_num * sizeof(*c));
1159 			kfree(constrs->rules);
1160 		}
1161 		constrs->rules = new;
1162 		constrs->rules_all = new_rules;
1163 	}
1164 	c = &constrs->rules[constrs->rules_num];
1165 	c->cond = cond;
1166 	c->func = func;
1167 	c->var = var;
1168 	c->private = private;
1169 	k = 0;
1170 	while (1) {
1171 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1172 			va_end(args);
1173 			return -EINVAL;
1174 		}
1175 		c->deps[k++] = dep;
1176 		if (dep < 0)
1177 			break;
1178 		dep = va_arg(args, int);
1179 	}
1180 	constrs->rules_num++;
1181 	va_end(args);
1182 	return 0;
1183 }
1184 
1185 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1186 
1187 /**
1188  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1189  * @runtime: PCM runtime instance
1190  * @var: hw_params variable to apply the mask
1191  * @mask: the bitmap mask
1192  *
1193  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1194  *
1195  * Return: Zero if successful, or a negative error code on failure.
1196  */
1197 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1198 			       u_int32_t mask)
1199 {
1200 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1201 	struct snd_mask *maskp = constrs_mask(constrs, var);
1202 	*maskp->bits &= mask;
1203 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1204 	if (*maskp->bits == 0)
1205 		return -EINVAL;
1206 	return 0;
1207 }
1208 
1209 /**
1210  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1211  * @runtime: PCM runtime instance
1212  * @var: hw_params variable to apply the mask
1213  * @mask: the 64bit bitmap mask
1214  *
1215  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1216  *
1217  * Return: Zero if successful, or a negative error code on failure.
1218  */
1219 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1220 				 u_int64_t mask)
1221 {
1222 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1223 	struct snd_mask *maskp = constrs_mask(constrs, var);
1224 	maskp->bits[0] &= (u_int32_t)mask;
1225 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1226 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1227 	if (! maskp->bits[0] && ! maskp->bits[1])
1228 		return -EINVAL;
1229 	return 0;
1230 }
1231 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1232 
1233 /**
1234  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1235  * @runtime: PCM runtime instance
1236  * @var: hw_params variable to apply the integer constraint
1237  *
1238  * Apply the constraint of integer to an interval parameter.
1239  *
1240  * Return: Positive if the value is changed, zero if it's not changed, or a
1241  * negative error code.
1242  */
1243 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1244 {
1245 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1246 	return snd_interval_setinteger(constrs_interval(constrs, var));
1247 }
1248 
1249 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1250 
1251 /**
1252  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1253  * @runtime: PCM runtime instance
1254  * @var: hw_params variable to apply the range
1255  * @min: the minimal value
1256  * @max: the maximal value
1257  *
1258  * Apply the min/max range constraint to an interval parameter.
1259  *
1260  * Return: Positive if the value is changed, zero if it's not changed, or a
1261  * negative error code.
1262  */
1263 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1264 				 unsigned int min, unsigned int max)
1265 {
1266 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1267 	struct snd_interval t;
1268 	t.min = min;
1269 	t.max = max;
1270 	t.openmin = t.openmax = 0;
1271 	t.integer = 0;
1272 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1273 }
1274 
1275 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1276 
1277 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1278 				struct snd_pcm_hw_rule *rule)
1279 {
1280 	struct snd_pcm_hw_constraint_list *list = rule->private;
1281 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1282 }
1283 
1284 
1285 /**
1286  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1287  * @runtime: PCM runtime instance
1288  * @cond: condition bits
1289  * @var: hw_params variable to apply the list constraint
1290  * @l: list
1291  *
1292  * Apply the list of constraints to an interval parameter.
1293  *
1294  * Return: Zero if successful, or a negative error code on failure.
1295  */
1296 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1297 			       unsigned int cond,
1298 			       snd_pcm_hw_param_t var,
1299 			       const struct snd_pcm_hw_constraint_list *l)
1300 {
1301 	return snd_pcm_hw_rule_add(runtime, cond, var,
1302 				   snd_pcm_hw_rule_list, (void *)l,
1303 				   var, -1);
1304 }
1305 
1306 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1307 
1308 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1309 				  struct snd_pcm_hw_rule *rule)
1310 {
1311 	struct snd_pcm_hw_constraint_ranges *r = rule->private;
1312 	return snd_interval_ranges(hw_param_interval(params, rule->var),
1313 				   r->count, r->ranges, r->mask);
1314 }
1315 
1316 
1317 /**
1318  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1319  * @runtime: PCM runtime instance
1320  * @cond: condition bits
1321  * @var: hw_params variable to apply the list of range constraints
1322  * @r: ranges
1323  *
1324  * Apply the list of range constraints to an interval parameter.
1325  *
1326  * Return: Zero if successful, or a negative error code on failure.
1327  */
1328 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1329 				 unsigned int cond,
1330 				 snd_pcm_hw_param_t var,
1331 				 const struct snd_pcm_hw_constraint_ranges *r)
1332 {
1333 	return snd_pcm_hw_rule_add(runtime, cond, var,
1334 				   snd_pcm_hw_rule_ranges, (void *)r,
1335 				   var, -1);
1336 }
1337 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1338 
1339 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1340 				   struct snd_pcm_hw_rule *rule)
1341 {
1342 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1343 	unsigned int num = 0, den = 0;
1344 	int err;
1345 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1346 				  r->nrats, r->rats, &num, &den);
1347 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1348 		params->rate_num = num;
1349 		params->rate_den = den;
1350 	}
1351 	return err;
1352 }
1353 
1354 /**
1355  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1356  * @runtime: PCM runtime instance
1357  * @cond: condition bits
1358  * @var: hw_params variable to apply the ratnums constraint
1359  * @r: struct snd_ratnums constriants
1360  *
1361  * Return: Zero if successful, or a negative error code on failure.
1362  */
1363 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1364 				  unsigned int cond,
1365 				  snd_pcm_hw_param_t var,
1366 				  struct snd_pcm_hw_constraint_ratnums *r)
1367 {
1368 	return snd_pcm_hw_rule_add(runtime, cond, var,
1369 				   snd_pcm_hw_rule_ratnums, r,
1370 				   var, -1);
1371 }
1372 
1373 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1374 
1375 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1376 				   struct snd_pcm_hw_rule *rule)
1377 {
1378 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1379 	unsigned int num = 0, den = 0;
1380 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1381 				  r->nrats, r->rats, &num, &den);
1382 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1383 		params->rate_num = num;
1384 		params->rate_den = den;
1385 	}
1386 	return err;
1387 }
1388 
1389 /**
1390  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1391  * @runtime: PCM runtime instance
1392  * @cond: condition bits
1393  * @var: hw_params variable to apply the ratdens constraint
1394  * @r: struct snd_ratdens constriants
1395  *
1396  * Return: Zero if successful, or a negative error code on failure.
1397  */
1398 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1399 				  unsigned int cond,
1400 				  snd_pcm_hw_param_t var,
1401 				  struct snd_pcm_hw_constraint_ratdens *r)
1402 {
1403 	return snd_pcm_hw_rule_add(runtime, cond, var,
1404 				   snd_pcm_hw_rule_ratdens, r,
1405 				   var, -1);
1406 }
1407 
1408 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1409 
1410 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1411 				  struct snd_pcm_hw_rule *rule)
1412 {
1413 	unsigned int l = (unsigned long) rule->private;
1414 	int width = l & 0xffff;
1415 	unsigned int msbits = l >> 16;
1416 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1417 
1418 	if (!snd_interval_single(i))
1419 		return 0;
1420 
1421 	if ((snd_interval_value(i) == width) ||
1422 	    (width == 0 && snd_interval_value(i) > msbits))
1423 		params->msbits = min_not_zero(params->msbits, msbits);
1424 
1425 	return 0;
1426 }
1427 
1428 /**
1429  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1430  * @runtime: PCM runtime instance
1431  * @cond: condition bits
1432  * @width: sample bits width
1433  * @msbits: msbits width
1434  *
1435  * This constraint will set the number of most significant bits (msbits) if a
1436  * sample format with the specified width has been select. If width is set to 0
1437  * the msbits will be set for any sample format with a width larger than the
1438  * specified msbits.
1439  *
1440  * Return: Zero if successful, or a negative error code on failure.
1441  */
1442 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1443 				 unsigned int cond,
1444 				 unsigned int width,
1445 				 unsigned int msbits)
1446 {
1447 	unsigned long l = (msbits << 16) | width;
1448 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1449 				    snd_pcm_hw_rule_msbits,
1450 				    (void*) l,
1451 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1452 }
1453 
1454 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1455 
1456 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1457 				struct snd_pcm_hw_rule *rule)
1458 {
1459 	unsigned long step = (unsigned long) rule->private;
1460 	return snd_interval_step(hw_param_interval(params, rule->var), step);
1461 }
1462 
1463 /**
1464  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1465  * @runtime: PCM runtime instance
1466  * @cond: condition bits
1467  * @var: hw_params variable to apply the step constraint
1468  * @step: step size
1469  *
1470  * Return: Zero if successful, or a negative error code on failure.
1471  */
1472 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1473 			       unsigned int cond,
1474 			       snd_pcm_hw_param_t var,
1475 			       unsigned long step)
1476 {
1477 	return snd_pcm_hw_rule_add(runtime, cond, var,
1478 				   snd_pcm_hw_rule_step, (void *) step,
1479 				   var, -1);
1480 }
1481 
1482 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1483 
1484 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1485 {
1486 	static unsigned int pow2_sizes[] = {
1487 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1488 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1489 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1490 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1491 	};
1492 	return snd_interval_list(hw_param_interval(params, rule->var),
1493 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1494 }
1495 
1496 /**
1497  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1498  * @runtime: PCM runtime instance
1499  * @cond: condition bits
1500  * @var: hw_params variable to apply the power-of-2 constraint
1501  *
1502  * Return: Zero if successful, or a negative error code on failure.
1503  */
1504 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1505 			       unsigned int cond,
1506 			       snd_pcm_hw_param_t var)
1507 {
1508 	return snd_pcm_hw_rule_add(runtime, cond, var,
1509 				   snd_pcm_hw_rule_pow2, NULL,
1510 				   var, -1);
1511 }
1512 
1513 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1514 
1515 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1516 					   struct snd_pcm_hw_rule *rule)
1517 {
1518 	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1519 	struct snd_interval *rate;
1520 
1521 	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1522 	return snd_interval_list(rate, 1, &base_rate, 0);
1523 }
1524 
1525 /**
1526  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1527  * @runtime: PCM runtime instance
1528  * @base_rate: the rate at which the hardware does not resample
1529  *
1530  * Return: Zero if successful, or a negative error code on failure.
1531  */
1532 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1533 			       unsigned int base_rate)
1534 {
1535 	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1536 				   SNDRV_PCM_HW_PARAM_RATE,
1537 				   snd_pcm_hw_rule_noresample_func,
1538 				   (void *)(uintptr_t)base_rate,
1539 				   SNDRV_PCM_HW_PARAM_RATE, -1);
1540 }
1541 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1542 
1543 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1544 				  snd_pcm_hw_param_t var)
1545 {
1546 	if (hw_is_mask(var)) {
1547 		snd_mask_any(hw_param_mask(params, var));
1548 		params->cmask |= 1 << var;
1549 		params->rmask |= 1 << var;
1550 		return;
1551 	}
1552 	if (hw_is_interval(var)) {
1553 		snd_interval_any(hw_param_interval(params, var));
1554 		params->cmask |= 1 << var;
1555 		params->rmask |= 1 << var;
1556 		return;
1557 	}
1558 	snd_BUG();
1559 }
1560 
1561 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1562 {
1563 	unsigned int k;
1564 	memset(params, 0, sizeof(*params));
1565 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1566 		_snd_pcm_hw_param_any(params, k);
1567 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1568 		_snd_pcm_hw_param_any(params, k);
1569 	params->info = ~0U;
1570 }
1571 
1572 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1573 
1574 /**
1575  * snd_pcm_hw_param_value - return @params field @var value
1576  * @params: the hw_params instance
1577  * @var: parameter to retrieve
1578  * @dir: pointer to the direction (-1,0,1) or %NULL
1579  *
1580  * Return: The value for field @var if it's fixed in configuration space
1581  * defined by @params. -%EINVAL otherwise.
1582  */
1583 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1584 			   snd_pcm_hw_param_t var, int *dir)
1585 {
1586 	if (hw_is_mask(var)) {
1587 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1588 		if (!snd_mask_single(mask))
1589 			return -EINVAL;
1590 		if (dir)
1591 			*dir = 0;
1592 		return snd_mask_value(mask);
1593 	}
1594 	if (hw_is_interval(var)) {
1595 		const struct snd_interval *i = hw_param_interval_c(params, var);
1596 		if (!snd_interval_single(i))
1597 			return -EINVAL;
1598 		if (dir)
1599 			*dir = i->openmin;
1600 		return snd_interval_value(i);
1601 	}
1602 	return -EINVAL;
1603 }
1604 
1605 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1606 
1607 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1608 				snd_pcm_hw_param_t var)
1609 {
1610 	if (hw_is_mask(var)) {
1611 		snd_mask_none(hw_param_mask(params, var));
1612 		params->cmask |= 1 << var;
1613 		params->rmask |= 1 << var;
1614 	} else if (hw_is_interval(var)) {
1615 		snd_interval_none(hw_param_interval(params, var));
1616 		params->cmask |= 1 << var;
1617 		params->rmask |= 1 << var;
1618 	} else {
1619 		snd_BUG();
1620 	}
1621 }
1622 
1623 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1624 
1625 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1626 				   snd_pcm_hw_param_t var)
1627 {
1628 	int changed;
1629 	if (hw_is_mask(var))
1630 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1631 	else if (hw_is_interval(var))
1632 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1633 	else
1634 		return -EINVAL;
1635 	if (changed) {
1636 		params->cmask |= 1 << var;
1637 		params->rmask |= 1 << var;
1638 	}
1639 	return changed;
1640 }
1641 
1642 
1643 /**
1644  * snd_pcm_hw_param_first - refine config space and return minimum value
1645  * @pcm: PCM instance
1646  * @params: the hw_params instance
1647  * @var: parameter to retrieve
1648  * @dir: pointer to the direction (-1,0,1) or %NULL
1649  *
1650  * Inside configuration space defined by @params remove from @var all
1651  * values > minimum. Reduce configuration space accordingly.
1652  *
1653  * Return: The minimum, or a negative error code on failure.
1654  */
1655 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1656 			   struct snd_pcm_hw_params *params,
1657 			   snd_pcm_hw_param_t var, int *dir)
1658 {
1659 	int changed = _snd_pcm_hw_param_first(params, var);
1660 	if (changed < 0)
1661 		return changed;
1662 	if (params->rmask) {
1663 		int err = snd_pcm_hw_refine(pcm, params);
1664 		if (snd_BUG_ON(err < 0))
1665 			return err;
1666 	}
1667 	return snd_pcm_hw_param_value(params, var, dir);
1668 }
1669 
1670 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1671 
1672 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1673 				  snd_pcm_hw_param_t var)
1674 {
1675 	int changed;
1676 	if (hw_is_mask(var))
1677 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1678 	else if (hw_is_interval(var))
1679 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1680 	else
1681 		return -EINVAL;
1682 	if (changed) {
1683 		params->cmask |= 1 << var;
1684 		params->rmask |= 1 << var;
1685 	}
1686 	return changed;
1687 }
1688 
1689 
1690 /**
1691  * snd_pcm_hw_param_last - refine config space and return maximum value
1692  * @pcm: PCM instance
1693  * @params: the hw_params instance
1694  * @var: parameter to retrieve
1695  * @dir: pointer to the direction (-1,0,1) or %NULL
1696  *
1697  * Inside configuration space defined by @params remove from @var all
1698  * values < maximum. Reduce configuration space accordingly.
1699  *
1700  * Return: The maximum, or a negative error code on failure.
1701  */
1702 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1703 			  struct snd_pcm_hw_params *params,
1704 			  snd_pcm_hw_param_t var, int *dir)
1705 {
1706 	int changed = _snd_pcm_hw_param_last(params, var);
1707 	if (changed < 0)
1708 		return changed;
1709 	if (params->rmask) {
1710 		int err = snd_pcm_hw_refine(pcm, params);
1711 		if (snd_BUG_ON(err < 0))
1712 			return err;
1713 	}
1714 	return snd_pcm_hw_param_value(params, var, dir);
1715 }
1716 
1717 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1718 
1719 /**
1720  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1721  * @pcm: PCM instance
1722  * @params: the hw_params instance
1723  *
1724  * Choose one configuration from configuration space defined by @params.
1725  * The configuration chosen is that obtained fixing in this order:
1726  * first access, first format, first subformat, min channels,
1727  * min rate, min period time, max buffer size, min tick time
1728  *
1729  * Return: Zero if successful, or a negative error code on failure.
1730  */
1731 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1732 			     struct snd_pcm_hw_params *params)
1733 {
1734 	static int vars[] = {
1735 		SNDRV_PCM_HW_PARAM_ACCESS,
1736 		SNDRV_PCM_HW_PARAM_FORMAT,
1737 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1738 		SNDRV_PCM_HW_PARAM_CHANNELS,
1739 		SNDRV_PCM_HW_PARAM_RATE,
1740 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1741 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1742 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1743 		-1
1744 	};
1745 	int err, *v;
1746 
1747 	for (v = vars; *v != -1; v++) {
1748 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1749 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1750 		else
1751 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1752 		if (snd_BUG_ON(err < 0))
1753 			return err;
1754 	}
1755 	return 0;
1756 }
1757 
1758 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1759 				   void *arg)
1760 {
1761 	struct snd_pcm_runtime *runtime = substream->runtime;
1762 	unsigned long flags;
1763 	snd_pcm_stream_lock_irqsave(substream, flags);
1764 	if (snd_pcm_running(substream) &&
1765 	    snd_pcm_update_hw_ptr(substream) >= 0)
1766 		runtime->status->hw_ptr %= runtime->buffer_size;
1767 	else {
1768 		runtime->status->hw_ptr = 0;
1769 		runtime->hw_ptr_wrap = 0;
1770 	}
1771 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1772 	return 0;
1773 }
1774 
1775 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1776 					  void *arg)
1777 {
1778 	struct snd_pcm_channel_info *info = arg;
1779 	struct snd_pcm_runtime *runtime = substream->runtime;
1780 	int width;
1781 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1782 		info->offset = -1;
1783 		return 0;
1784 	}
1785 	width = snd_pcm_format_physical_width(runtime->format);
1786 	if (width < 0)
1787 		return width;
1788 	info->offset = 0;
1789 	switch (runtime->access) {
1790 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1791 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1792 		info->first = info->channel * width;
1793 		info->step = runtime->channels * width;
1794 		break;
1795 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1796 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1797 	{
1798 		size_t size = runtime->dma_bytes / runtime->channels;
1799 		info->first = info->channel * size * 8;
1800 		info->step = width;
1801 		break;
1802 	}
1803 	default:
1804 		snd_BUG();
1805 		break;
1806 	}
1807 	return 0;
1808 }
1809 
1810 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1811 				       void *arg)
1812 {
1813 	struct snd_pcm_hw_params *params = arg;
1814 	snd_pcm_format_t format;
1815 	int channels;
1816 	ssize_t frame_size;
1817 
1818 	params->fifo_size = substream->runtime->hw.fifo_size;
1819 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1820 		format = params_format(params);
1821 		channels = params_channels(params);
1822 		frame_size = snd_pcm_format_size(format, channels);
1823 		if (frame_size > 0)
1824 			params->fifo_size /= (unsigned)frame_size;
1825 	}
1826 	return 0;
1827 }
1828 
1829 /**
1830  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1831  * @substream: the pcm substream instance
1832  * @cmd: ioctl command
1833  * @arg: ioctl argument
1834  *
1835  * Processes the generic ioctl commands for PCM.
1836  * Can be passed as the ioctl callback for PCM ops.
1837  *
1838  * Return: Zero if successful, or a negative error code on failure.
1839  */
1840 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1841 		      unsigned int cmd, void *arg)
1842 {
1843 	switch (cmd) {
1844 	case SNDRV_PCM_IOCTL1_INFO:
1845 		return 0;
1846 	case SNDRV_PCM_IOCTL1_RESET:
1847 		return snd_pcm_lib_ioctl_reset(substream, arg);
1848 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1849 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1850 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1851 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1852 	}
1853 	return -ENXIO;
1854 }
1855 
1856 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1857 
1858 /**
1859  * snd_pcm_period_elapsed - update the pcm status for the next period
1860  * @substream: the pcm substream instance
1861  *
1862  * This function is called from the interrupt handler when the
1863  * PCM has processed the period size.  It will update the current
1864  * pointer, wake up sleepers, etc.
1865  *
1866  * Even if more than one periods have elapsed since the last call, you
1867  * have to call this only once.
1868  */
1869 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1870 {
1871 	struct snd_pcm_runtime *runtime;
1872 	unsigned long flags;
1873 
1874 	if (PCM_RUNTIME_CHECK(substream))
1875 		return;
1876 	runtime = substream->runtime;
1877 
1878 	if (runtime->transfer_ack_begin)
1879 		runtime->transfer_ack_begin(substream);
1880 
1881 	snd_pcm_stream_lock_irqsave(substream, flags);
1882 	if (!snd_pcm_running(substream) ||
1883 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1884 		goto _end;
1885 
1886 	if (substream->timer_running)
1887 		snd_timer_interrupt(substream->timer, 1);
1888  _end:
1889 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1890 	if (runtime->transfer_ack_end)
1891 		runtime->transfer_ack_end(substream);
1892 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1893 }
1894 
1895 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1896 
1897 /*
1898  * Wait until avail_min data becomes available
1899  * Returns a negative error code if any error occurs during operation.
1900  * The available space is stored on availp.  When err = 0 and avail = 0
1901  * on the capture stream, it indicates the stream is in DRAINING state.
1902  */
1903 static int wait_for_avail(struct snd_pcm_substream *substream,
1904 			      snd_pcm_uframes_t *availp)
1905 {
1906 	struct snd_pcm_runtime *runtime = substream->runtime;
1907 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1908 	wait_queue_t wait;
1909 	int err = 0;
1910 	snd_pcm_uframes_t avail = 0;
1911 	long wait_time, tout;
1912 
1913 	init_waitqueue_entry(&wait, current);
1914 	set_current_state(TASK_INTERRUPTIBLE);
1915 	add_wait_queue(&runtime->tsleep, &wait);
1916 
1917 	if (runtime->no_period_wakeup)
1918 		wait_time = MAX_SCHEDULE_TIMEOUT;
1919 	else {
1920 		wait_time = 10;
1921 		if (runtime->rate) {
1922 			long t = runtime->period_size * 2 / runtime->rate;
1923 			wait_time = max(t, wait_time);
1924 		}
1925 		wait_time = msecs_to_jiffies(wait_time * 1000);
1926 	}
1927 
1928 	for (;;) {
1929 		if (signal_pending(current)) {
1930 			err = -ERESTARTSYS;
1931 			break;
1932 		}
1933 
1934 		/*
1935 		 * We need to check if space became available already
1936 		 * (and thus the wakeup happened already) first to close
1937 		 * the race of space already having become available.
1938 		 * This check must happen after been added to the waitqueue
1939 		 * and having current state be INTERRUPTIBLE.
1940 		 */
1941 		if (is_playback)
1942 			avail = snd_pcm_playback_avail(runtime);
1943 		else
1944 			avail = snd_pcm_capture_avail(runtime);
1945 		if (avail >= runtime->twake)
1946 			break;
1947 		snd_pcm_stream_unlock_irq(substream);
1948 
1949 		tout = schedule_timeout(wait_time);
1950 
1951 		snd_pcm_stream_lock_irq(substream);
1952 		set_current_state(TASK_INTERRUPTIBLE);
1953 		switch (runtime->status->state) {
1954 		case SNDRV_PCM_STATE_SUSPENDED:
1955 			err = -ESTRPIPE;
1956 			goto _endloop;
1957 		case SNDRV_PCM_STATE_XRUN:
1958 			err = -EPIPE;
1959 			goto _endloop;
1960 		case SNDRV_PCM_STATE_DRAINING:
1961 			if (is_playback)
1962 				err = -EPIPE;
1963 			else
1964 				avail = 0; /* indicate draining */
1965 			goto _endloop;
1966 		case SNDRV_PCM_STATE_OPEN:
1967 		case SNDRV_PCM_STATE_SETUP:
1968 		case SNDRV_PCM_STATE_DISCONNECTED:
1969 			err = -EBADFD;
1970 			goto _endloop;
1971 		case SNDRV_PCM_STATE_PAUSED:
1972 			continue;
1973 		}
1974 		if (!tout) {
1975 			pcm_dbg(substream->pcm,
1976 				"%s write error (DMA or IRQ trouble?)\n",
1977 				is_playback ? "playback" : "capture");
1978 			err = -EIO;
1979 			break;
1980 		}
1981 	}
1982  _endloop:
1983 	set_current_state(TASK_RUNNING);
1984 	remove_wait_queue(&runtime->tsleep, &wait);
1985 	*availp = avail;
1986 	return err;
1987 }
1988 
1989 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1990 				      unsigned int hwoff,
1991 				      unsigned long data, unsigned int off,
1992 				      snd_pcm_uframes_t frames)
1993 {
1994 	struct snd_pcm_runtime *runtime = substream->runtime;
1995 	int err;
1996 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1997 	if (substream->ops->copy) {
1998 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1999 			return err;
2000 	} else {
2001 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2002 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
2003 			return -EFAULT;
2004 	}
2005 	return 0;
2006 }
2007 
2008 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
2009 			  unsigned long data, unsigned int off,
2010 			  snd_pcm_uframes_t size);
2011 
2012 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
2013 					    unsigned long data,
2014 					    snd_pcm_uframes_t size,
2015 					    int nonblock,
2016 					    transfer_f transfer)
2017 {
2018 	struct snd_pcm_runtime *runtime = substream->runtime;
2019 	snd_pcm_uframes_t xfer = 0;
2020 	snd_pcm_uframes_t offset = 0;
2021 	snd_pcm_uframes_t avail;
2022 	int err = 0;
2023 
2024 	if (size == 0)
2025 		return 0;
2026 
2027 	snd_pcm_stream_lock_irq(substream);
2028 	switch (runtime->status->state) {
2029 	case SNDRV_PCM_STATE_PREPARED:
2030 	case SNDRV_PCM_STATE_RUNNING:
2031 	case SNDRV_PCM_STATE_PAUSED:
2032 		break;
2033 	case SNDRV_PCM_STATE_XRUN:
2034 		err = -EPIPE;
2035 		goto _end_unlock;
2036 	case SNDRV_PCM_STATE_SUSPENDED:
2037 		err = -ESTRPIPE;
2038 		goto _end_unlock;
2039 	default:
2040 		err = -EBADFD;
2041 		goto _end_unlock;
2042 	}
2043 
2044 	runtime->twake = runtime->control->avail_min ? : 1;
2045 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2046 		snd_pcm_update_hw_ptr(substream);
2047 	avail = snd_pcm_playback_avail(runtime);
2048 	while (size > 0) {
2049 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2050 		snd_pcm_uframes_t cont;
2051 		if (!avail) {
2052 			if (nonblock) {
2053 				err = -EAGAIN;
2054 				goto _end_unlock;
2055 			}
2056 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2057 					runtime->control->avail_min ? : 1);
2058 			err = wait_for_avail(substream, &avail);
2059 			if (err < 0)
2060 				goto _end_unlock;
2061 		}
2062 		frames = size > avail ? avail : size;
2063 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2064 		if (frames > cont)
2065 			frames = cont;
2066 		if (snd_BUG_ON(!frames)) {
2067 			runtime->twake = 0;
2068 			snd_pcm_stream_unlock_irq(substream);
2069 			return -EINVAL;
2070 		}
2071 		appl_ptr = runtime->control->appl_ptr;
2072 		appl_ofs = appl_ptr % runtime->buffer_size;
2073 		snd_pcm_stream_unlock_irq(substream);
2074 		err = transfer(substream, appl_ofs, data, offset, frames);
2075 		snd_pcm_stream_lock_irq(substream);
2076 		if (err < 0)
2077 			goto _end_unlock;
2078 		switch (runtime->status->state) {
2079 		case SNDRV_PCM_STATE_XRUN:
2080 			err = -EPIPE;
2081 			goto _end_unlock;
2082 		case SNDRV_PCM_STATE_SUSPENDED:
2083 			err = -ESTRPIPE;
2084 			goto _end_unlock;
2085 		default:
2086 			break;
2087 		}
2088 		appl_ptr += frames;
2089 		if (appl_ptr >= runtime->boundary)
2090 			appl_ptr -= runtime->boundary;
2091 		runtime->control->appl_ptr = appl_ptr;
2092 		if (substream->ops->ack)
2093 			substream->ops->ack(substream);
2094 
2095 		offset += frames;
2096 		size -= frames;
2097 		xfer += frames;
2098 		avail -= frames;
2099 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2100 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2101 			err = snd_pcm_start(substream);
2102 			if (err < 0)
2103 				goto _end_unlock;
2104 		}
2105 	}
2106  _end_unlock:
2107 	runtime->twake = 0;
2108 	if (xfer > 0 && err >= 0)
2109 		snd_pcm_update_state(substream, runtime);
2110 	snd_pcm_stream_unlock_irq(substream);
2111 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2112 }
2113 
2114 /* sanity-check for read/write methods */
2115 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2116 {
2117 	struct snd_pcm_runtime *runtime;
2118 	if (PCM_RUNTIME_CHECK(substream))
2119 		return -ENXIO;
2120 	runtime = substream->runtime;
2121 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2122 		return -EINVAL;
2123 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2124 		return -EBADFD;
2125 	return 0;
2126 }
2127 
2128 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2129 {
2130 	struct snd_pcm_runtime *runtime;
2131 	int nonblock;
2132 	int err;
2133 
2134 	err = pcm_sanity_check(substream);
2135 	if (err < 0)
2136 		return err;
2137 	runtime = substream->runtime;
2138 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2139 
2140 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2141 	    runtime->channels > 1)
2142 		return -EINVAL;
2143 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2144 				  snd_pcm_lib_write_transfer);
2145 }
2146 
2147 EXPORT_SYMBOL(snd_pcm_lib_write);
2148 
2149 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2150 				       unsigned int hwoff,
2151 				       unsigned long data, unsigned int off,
2152 				       snd_pcm_uframes_t frames)
2153 {
2154 	struct snd_pcm_runtime *runtime = substream->runtime;
2155 	int err;
2156 	void __user **bufs = (void __user **)data;
2157 	int channels = runtime->channels;
2158 	int c;
2159 	if (substream->ops->copy) {
2160 		if (snd_BUG_ON(!substream->ops->silence))
2161 			return -EINVAL;
2162 		for (c = 0; c < channels; ++c, ++bufs) {
2163 			if (*bufs == NULL) {
2164 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2165 					return err;
2166 			} else {
2167 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2168 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2169 					return err;
2170 			}
2171 		}
2172 	} else {
2173 		/* default transfer behaviour */
2174 		size_t dma_csize = runtime->dma_bytes / channels;
2175 		for (c = 0; c < channels; ++c, ++bufs) {
2176 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2177 			if (*bufs == NULL) {
2178 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2179 			} else {
2180 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2181 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2182 					return -EFAULT;
2183 			}
2184 		}
2185 	}
2186 	return 0;
2187 }
2188 
2189 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2190 				     void __user **bufs,
2191 				     snd_pcm_uframes_t frames)
2192 {
2193 	struct snd_pcm_runtime *runtime;
2194 	int nonblock;
2195 	int err;
2196 
2197 	err = pcm_sanity_check(substream);
2198 	if (err < 0)
2199 		return err;
2200 	runtime = substream->runtime;
2201 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2202 
2203 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2204 		return -EINVAL;
2205 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2206 				  nonblock, snd_pcm_lib_writev_transfer);
2207 }
2208 
2209 EXPORT_SYMBOL(snd_pcm_lib_writev);
2210 
2211 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2212 				     unsigned int hwoff,
2213 				     unsigned long data, unsigned int off,
2214 				     snd_pcm_uframes_t frames)
2215 {
2216 	struct snd_pcm_runtime *runtime = substream->runtime;
2217 	int err;
2218 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2219 	if (substream->ops->copy) {
2220 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2221 			return err;
2222 	} else {
2223 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2224 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2225 			return -EFAULT;
2226 	}
2227 	return 0;
2228 }
2229 
2230 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2231 					   unsigned long data,
2232 					   snd_pcm_uframes_t size,
2233 					   int nonblock,
2234 					   transfer_f transfer)
2235 {
2236 	struct snd_pcm_runtime *runtime = substream->runtime;
2237 	snd_pcm_uframes_t xfer = 0;
2238 	snd_pcm_uframes_t offset = 0;
2239 	snd_pcm_uframes_t avail;
2240 	int err = 0;
2241 
2242 	if (size == 0)
2243 		return 0;
2244 
2245 	snd_pcm_stream_lock_irq(substream);
2246 	switch (runtime->status->state) {
2247 	case SNDRV_PCM_STATE_PREPARED:
2248 		if (size >= runtime->start_threshold) {
2249 			err = snd_pcm_start(substream);
2250 			if (err < 0)
2251 				goto _end_unlock;
2252 		}
2253 		break;
2254 	case SNDRV_PCM_STATE_DRAINING:
2255 	case SNDRV_PCM_STATE_RUNNING:
2256 	case SNDRV_PCM_STATE_PAUSED:
2257 		break;
2258 	case SNDRV_PCM_STATE_XRUN:
2259 		err = -EPIPE;
2260 		goto _end_unlock;
2261 	case SNDRV_PCM_STATE_SUSPENDED:
2262 		err = -ESTRPIPE;
2263 		goto _end_unlock;
2264 	default:
2265 		err = -EBADFD;
2266 		goto _end_unlock;
2267 	}
2268 
2269 	runtime->twake = runtime->control->avail_min ? : 1;
2270 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2271 		snd_pcm_update_hw_ptr(substream);
2272 	avail = snd_pcm_capture_avail(runtime);
2273 	while (size > 0) {
2274 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2275 		snd_pcm_uframes_t cont;
2276 		if (!avail) {
2277 			if (runtime->status->state ==
2278 			    SNDRV_PCM_STATE_DRAINING) {
2279 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2280 				goto _end_unlock;
2281 			}
2282 			if (nonblock) {
2283 				err = -EAGAIN;
2284 				goto _end_unlock;
2285 			}
2286 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2287 					runtime->control->avail_min ? : 1);
2288 			err = wait_for_avail(substream, &avail);
2289 			if (err < 0)
2290 				goto _end_unlock;
2291 			if (!avail)
2292 				continue; /* draining */
2293 		}
2294 		frames = size > avail ? avail : size;
2295 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2296 		if (frames > cont)
2297 			frames = cont;
2298 		if (snd_BUG_ON(!frames)) {
2299 			runtime->twake = 0;
2300 			snd_pcm_stream_unlock_irq(substream);
2301 			return -EINVAL;
2302 		}
2303 		appl_ptr = runtime->control->appl_ptr;
2304 		appl_ofs = appl_ptr % runtime->buffer_size;
2305 		snd_pcm_stream_unlock_irq(substream);
2306 		err = transfer(substream, appl_ofs, data, offset, frames);
2307 		snd_pcm_stream_lock_irq(substream);
2308 		if (err < 0)
2309 			goto _end_unlock;
2310 		switch (runtime->status->state) {
2311 		case SNDRV_PCM_STATE_XRUN:
2312 			err = -EPIPE;
2313 			goto _end_unlock;
2314 		case SNDRV_PCM_STATE_SUSPENDED:
2315 			err = -ESTRPIPE;
2316 			goto _end_unlock;
2317 		default:
2318 			break;
2319 		}
2320 		appl_ptr += frames;
2321 		if (appl_ptr >= runtime->boundary)
2322 			appl_ptr -= runtime->boundary;
2323 		runtime->control->appl_ptr = appl_ptr;
2324 		if (substream->ops->ack)
2325 			substream->ops->ack(substream);
2326 
2327 		offset += frames;
2328 		size -= frames;
2329 		xfer += frames;
2330 		avail -= frames;
2331 	}
2332  _end_unlock:
2333 	runtime->twake = 0;
2334 	if (xfer > 0 && err >= 0)
2335 		snd_pcm_update_state(substream, runtime);
2336 	snd_pcm_stream_unlock_irq(substream);
2337 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2338 }
2339 
2340 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2341 {
2342 	struct snd_pcm_runtime *runtime;
2343 	int nonblock;
2344 	int err;
2345 
2346 	err = pcm_sanity_check(substream);
2347 	if (err < 0)
2348 		return err;
2349 	runtime = substream->runtime;
2350 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2351 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2352 		return -EINVAL;
2353 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2354 }
2355 
2356 EXPORT_SYMBOL(snd_pcm_lib_read);
2357 
2358 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2359 				      unsigned int hwoff,
2360 				      unsigned long data, unsigned int off,
2361 				      snd_pcm_uframes_t frames)
2362 {
2363 	struct snd_pcm_runtime *runtime = substream->runtime;
2364 	int err;
2365 	void __user **bufs = (void __user **)data;
2366 	int channels = runtime->channels;
2367 	int c;
2368 	if (substream->ops->copy) {
2369 		for (c = 0; c < channels; ++c, ++bufs) {
2370 			char __user *buf;
2371 			if (*bufs == NULL)
2372 				continue;
2373 			buf = *bufs + samples_to_bytes(runtime, off);
2374 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2375 				return err;
2376 		}
2377 	} else {
2378 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2379 		for (c = 0; c < channels; ++c, ++bufs) {
2380 			char *hwbuf;
2381 			char __user *buf;
2382 			if (*bufs == NULL)
2383 				continue;
2384 
2385 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2386 			buf = *bufs + samples_to_bytes(runtime, off);
2387 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2388 				return -EFAULT;
2389 		}
2390 	}
2391 	return 0;
2392 }
2393 
2394 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2395 				    void __user **bufs,
2396 				    snd_pcm_uframes_t frames)
2397 {
2398 	struct snd_pcm_runtime *runtime;
2399 	int nonblock;
2400 	int err;
2401 
2402 	err = pcm_sanity_check(substream);
2403 	if (err < 0)
2404 		return err;
2405 	runtime = substream->runtime;
2406 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2407 		return -EBADFD;
2408 
2409 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2410 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2411 		return -EINVAL;
2412 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2413 }
2414 
2415 EXPORT_SYMBOL(snd_pcm_lib_readv);
2416 
2417 /*
2418  * standard channel mapping helpers
2419  */
2420 
2421 /* default channel maps for multi-channel playbacks, up to 8 channels */
2422 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2423 	{ .channels = 1,
2424 	  .map = { SNDRV_CHMAP_MONO } },
2425 	{ .channels = 2,
2426 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2427 	{ .channels = 4,
2428 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2429 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2430 	{ .channels = 6,
2431 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2432 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2433 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2434 	{ .channels = 8,
2435 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2436 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2437 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2438 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2439 	{ }
2440 };
2441 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2442 
2443 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2444 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2445 	{ .channels = 1,
2446 	  .map = { SNDRV_CHMAP_MONO } },
2447 	{ .channels = 2,
2448 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2449 	{ .channels = 4,
2450 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2451 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2452 	{ .channels = 6,
2453 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2454 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2455 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2456 	{ .channels = 8,
2457 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2458 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2459 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2460 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2461 	{ }
2462 };
2463 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2464 
2465 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2466 {
2467 	if (ch > info->max_channels)
2468 		return false;
2469 	return !info->channel_mask || (info->channel_mask & (1U << ch));
2470 }
2471 
2472 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2473 			      struct snd_ctl_elem_info *uinfo)
2474 {
2475 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2476 
2477 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2478 	uinfo->count = 0;
2479 	uinfo->count = info->max_channels;
2480 	uinfo->value.integer.min = 0;
2481 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2482 	return 0;
2483 }
2484 
2485 /* get callback for channel map ctl element
2486  * stores the channel position firstly matching with the current channels
2487  */
2488 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2489 			     struct snd_ctl_elem_value *ucontrol)
2490 {
2491 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2492 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2493 	struct snd_pcm_substream *substream;
2494 	const struct snd_pcm_chmap_elem *map;
2495 
2496 	if (snd_BUG_ON(!info->chmap))
2497 		return -EINVAL;
2498 	substream = snd_pcm_chmap_substream(info, idx);
2499 	if (!substream)
2500 		return -ENODEV;
2501 	memset(ucontrol->value.integer.value, 0,
2502 	       sizeof(ucontrol->value.integer.value));
2503 	if (!substream->runtime)
2504 		return 0; /* no channels set */
2505 	for (map = info->chmap; map->channels; map++) {
2506 		int i;
2507 		if (map->channels == substream->runtime->channels &&
2508 		    valid_chmap_channels(info, map->channels)) {
2509 			for (i = 0; i < map->channels; i++)
2510 				ucontrol->value.integer.value[i] = map->map[i];
2511 			return 0;
2512 		}
2513 	}
2514 	return -EINVAL;
2515 }
2516 
2517 /* tlv callback for channel map ctl element
2518  * expands the pre-defined channel maps in a form of TLV
2519  */
2520 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2521 			     unsigned int size, unsigned int __user *tlv)
2522 {
2523 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2524 	const struct snd_pcm_chmap_elem *map;
2525 	unsigned int __user *dst;
2526 	int c, count = 0;
2527 
2528 	if (snd_BUG_ON(!info->chmap))
2529 		return -EINVAL;
2530 	if (size < 8)
2531 		return -ENOMEM;
2532 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2533 		return -EFAULT;
2534 	size -= 8;
2535 	dst = tlv + 2;
2536 	for (map = info->chmap; map->channels; map++) {
2537 		int chs_bytes = map->channels * 4;
2538 		if (!valid_chmap_channels(info, map->channels))
2539 			continue;
2540 		if (size < 8)
2541 			return -ENOMEM;
2542 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2543 		    put_user(chs_bytes, dst + 1))
2544 			return -EFAULT;
2545 		dst += 2;
2546 		size -= 8;
2547 		count += 8;
2548 		if (size < chs_bytes)
2549 			return -ENOMEM;
2550 		size -= chs_bytes;
2551 		count += chs_bytes;
2552 		for (c = 0; c < map->channels; c++) {
2553 			if (put_user(map->map[c], dst))
2554 				return -EFAULT;
2555 			dst++;
2556 		}
2557 	}
2558 	if (put_user(count, tlv + 1))
2559 		return -EFAULT;
2560 	return 0;
2561 }
2562 
2563 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2564 {
2565 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2566 	info->pcm->streams[info->stream].chmap_kctl = NULL;
2567 	kfree(info);
2568 }
2569 
2570 /**
2571  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2572  * @pcm: the assigned PCM instance
2573  * @stream: stream direction
2574  * @chmap: channel map elements (for query)
2575  * @max_channels: the max number of channels for the stream
2576  * @private_value: the value passed to each kcontrol's private_value field
2577  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2578  *
2579  * Create channel-mapping control elements assigned to the given PCM stream(s).
2580  * Return: Zero if successful, or a negative error value.
2581  */
2582 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2583 			   const struct snd_pcm_chmap_elem *chmap,
2584 			   int max_channels,
2585 			   unsigned long private_value,
2586 			   struct snd_pcm_chmap **info_ret)
2587 {
2588 	struct snd_pcm_chmap *info;
2589 	struct snd_kcontrol_new knew = {
2590 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
2591 		.access = SNDRV_CTL_ELEM_ACCESS_READ |
2592 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2593 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2594 		.info = pcm_chmap_ctl_info,
2595 		.get = pcm_chmap_ctl_get,
2596 		.tlv.c = pcm_chmap_ctl_tlv,
2597 	};
2598 	int err;
2599 
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