xref: /linux/sound/core/pcm_lib.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  *  Digital Audio (PCM) abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 #include <sound/core.h>
27 #include <sound/control.h>
28 #include <sound/info.h>
29 #include <sound/pcm.h>
30 #include <sound/pcm_params.h>
31 #include <sound/timer.h>
32 
33 /*
34  * fill ring buffer with silence
35  * runtime->silence_start: starting pointer to silence area
36  * runtime->silence_filled: size filled with silence
37  * runtime->silence_threshold: threshold from application
38  * runtime->silence_size: maximal size from application
39  *
40  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
41  */
42 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
43 {
44 	struct snd_pcm_runtime *runtime = substream->runtime;
45 	snd_pcm_uframes_t frames, ofs, transfer;
46 
47 	if (runtime->silence_size < runtime->boundary) {
48 		snd_pcm_sframes_t noise_dist, n;
49 		if (runtime->silence_start != runtime->control->appl_ptr) {
50 			n = runtime->control->appl_ptr - runtime->silence_start;
51 			if (n < 0)
52 				n += runtime->boundary;
53 			if ((snd_pcm_uframes_t)n < runtime->silence_filled)
54 				runtime->silence_filled -= n;
55 			else
56 				runtime->silence_filled = 0;
57 			runtime->silence_start = runtime->control->appl_ptr;
58 		}
59 		if (runtime->silence_filled >= runtime->buffer_size)
60 			return;
61 		noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
62 		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
63 			return;
64 		frames = runtime->silence_threshold - noise_dist;
65 		if (frames > runtime->silence_size)
66 			frames = runtime->silence_size;
67 	} else {
68 		if (new_hw_ptr == ULONG_MAX) {	/* initialization */
69 			snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
70 			runtime->silence_filled = avail > 0 ? avail : 0;
71 			runtime->silence_start = (runtime->status->hw_ptr +
72 						  runtime->silence_filled) %
73 						 runtime->boundary;
74 		} else {
75 			ofs = runtime->status->hw_ptr;
76 			frames = new_hw_ptr - ofs;
77 			if ((snd_pcm_sframes_t)frames < 0)
78 				frames += runtime->boundary;
79 			runtime->silence_filled -= frames;
80 			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
81 				runtime->silence_filled = 0;
82 				runtime->silence_start = (ofs + frames) - runtime->buffer_size;
83 			} else {
84 				runtime->silence_start = ofs - runtime->silence_filled;
85 			}
86 			if ((snd_pcm_sframes_t)runtime->silence_start < 0)
87 				runtime->silence_start += runtime->boundary;
88 		}
89 		frames = runtime->buffer_size - runtime->silence_filled;
90 	}
91 	snd_assert(frames <= runtime->buffer_size, return);
92 	if (frames == 0)
93 		return;
94 	ofs = (runtime->silence_start + runtime->silence_filled) % runtime->buffer_size;
95 	while (frames > 0) {
96 		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
97 		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
98 		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
99 			if (substream->ops->silence) {
100 				int err;
101 				err = substream->ops->silence(substream, -1, ofs, transfer);
102 				snd_assert(err >= 0, );
103 			} else {
104 				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
105 				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
106 			}
107 		} else {
108 			unsigned int c;
109 			unsigned int channels = runtime->channels;
110 			if (substream->ops->silence) {
111 				for (c = 0; c < channels; ++c) {
112 					int err;
113 					err = substream->ops->silence(substream, c, ofs, transfer);
114 					snd_assert(err >= 0, );
115 				}
116 			} else {
117 				size_t dma_csize = runtime->dma_bytes / channels;
118 				for (c = 0; c < channels; ++c) {
119 					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
120 					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
121 				}
122 			}
123 		}
124 		runtime->silence_filled += transfer;
125 		frames -= transfer;
126 		ofs = 0;
127 	}
128 }
129 
130 static void xrun(struct snd_pcm_substream *substream)
131 {
132 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
133 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
134 	if (substream->pstr->xrun_debug) {
135 		snd_printd(KERN_DEBUG "XRUN: pcmC%dD%d%c\n",
136 			   substream->pcm->card->number,
137 			   substream->pcm->device,
138 			   substream->stream ? 'c' : 'p');
139 		if (substream->pstr->xrun_debug > 1)
140 			dump_stack();
141 	}
142 #endif
143 }
144 
145 static inline snd_pcm_uframes_t snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
146 							  struct snd_pcm_runtime *runtime)
147 {
148 	snd_pcm_uframes_t pos;
149 
150 	pos = substream->ops->pointer(substream);
151 	if (pos == SNDRV_PCM_POS_XRUN)
152 		return pos; /* XRUN */
153 	if (runtime->tstamp_mode & SNDRV_PCM_TSTAMP_MMAP)
154 		getnstimeofday((struct timespec *)&runtime->status->tstamp);
155 #ifdef CONFIG_SND_DEBUG
156 	if (pos >= runtime->buffer_size) {
157 		snd_printk(KERN_ERR  "BUG: stream = %i, pos = 0x%lx, buffer size = 0x%lx, period size = 0x%lx\n", substream->stream, pos, runtime->buffer_size, runtime->period_size);
158 	}
159 #endif
160 	pos -= pos % runtime->min_align;
161 	return pos;
162 }
163 
164 static inline int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
165 					     struct snd_pcm_runtime *runtime)
166 {
167 	snd_pcm_uframes_t avail;
168 
169 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
170 		avail = snd_pcm_playback_avail(runtime);
171 	else
172 		avail = snd_pcm_capture_avail(runtime);
173 	if (avail > runtime->avail_max)
174 		runtime->avail_max = avail;
175 	if (avail >= runtime->stop_threshold) {
176 		if (substream->runtime->status->state == SNDRV_PCM_STATE_DRAINING)
177 			snd_pcm_drain_done(substream);
178 		else
179 			xrun(substream);
180 		return -EPIPE;
181 	}
182 	if (avail >= runtime->control->avail_min)
183 		wake_up(&runtime->sleep);
184 	return 0;
185 }
186 
187 static inline int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
188 {
189 	struct snd_pcm_runtime *runtime = substream->runtime;
190 	snd_pcm_uframes_t pos;
191 	snd_pcm_uframes_t new_hw_ptr, hw_ptr_interrupt;
192 	snd_pcm_sframes_t delta;
193 
194 	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
195 	if (pos == SNDRV_PCM_POS_XRUN) {
196 		xrun(substream);
197 		return -EPIPE;
198 	}
199 	if (runtime->period_size == runtime->buffer_size)
200 		goto __next_buf;
201 	new_hw_ptr = runtime->hw_ptr_base + pos;
202 	hw_ptr_interrupt = runtime->hw_ptr_interrupt + runtime->period_size;
203 
204 	delta = hw_ptr_interrupt - new_hw_ptr;
205 	if (delta > 0) {
206 		if ((snd_pcm_uframes_t)delta < runtime->buffer_size / 2) {
207 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
208 			if (runtime->periods > 1 && substream->pstr->xrun_debug) {
209 				snd_printd(KERN_ERR "Unexpected hw_pointer value [1] (stream = %i, delta: -%ld, max jitter = %ld): wrong interrupt acknowledge?\n", substream->stream, (long) delta, runtime->buffer_size / 2);
210 				if (substream->pstr->xrun_debug > 1)
211 					dump_stack();
212 			}
213 #endif
214 			return 0;
215 		}
216 	      __next_buf:
217 		runtime->hw_ptr_base += runtime->buffer_size;
218 		if (runtime->hw_ptr_base == runtime->boundary)
219 			runtime->hw_ptr_base = 0;
220 		new_hw_ptr = runtime->hw_ptr_base + pos;
221 	}
222 
223 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
224 	    runtime->silence_size > 0)
225 		snd_pcm_playback_silence(substream, new_hw_ptr);
226 
227 	runtime->status->hw_ptr = new_hw_ptr;
228 	runtime->hw_ptr_interrupt = new_hw_ptr - new_hw_ptr % runtime->period_size;
229 
230 	return snd_pcm_update_hw_ptr_post(substream, runtime);
231 }
232 
233 /* CAUTION: call it with irq disabled */
234 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
235 {
236 	struct snd_pcm_runtime *runtime = substream->runtime;
237 	snd_pcm_uframes_t pos;
238 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr;
239 	snd_pcm_sframes_t delta;
240 
241 	old_hw_ptr = runtime->status->hw_ptr;
242 	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
243 	if (pos == SNDRV_PCM_POS_XRUN) {
244 		xrun(substream);
245 		return -EPIPE;
246 	}
247 	new_hw_ptr = runtime->hw_ptr_base + pos;
248 
249 	delta = old_hw_ptr - new_hw_ptr;
250 	if (delta > 0) {
251 		if ((snd_pcm_uframes_t)delta < runtime->buffer_size / 2) {
252 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
253 			if (runtime->periods > 2 && substream->pstr->xrun_debug) {
254 				snd_printd(KERN_ERR "Unexpected hw_pointer value [2] (stream = %i, delta: -%ld, max jitter = %ld): wrong interrupt acknowledge?\n", substream->stream, (long) delta, runtime->buffer_size / 2);
255 				if (substream->pstr->xrun_debug > 1)
256 					dump_stack();
257 			}
258 #endif
259 			return 0;
260 		}
261 		runtime->hw_ptr_base += runtime->buffer_size;
262 		if (runtime->hw_ptr_base == runtime->boundary)
263 			runtime->hw_ptr_base = 0;
264 		new_hw_ptr = runtime->hw_ptr_base + pos;
265 	}
266 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
267 	    runtime->silence_size > 0)
268 		snd_pcm_playback_silence(substream, new_hw_ptr);
269 
270 	runtime->status->hw_ptr = new_hw_ptr;
271 
272 	return snd_pcm_update_hw_ptr_post(substream, runtime);
273 }
274 
275 /**
276  * snd_pcm_set_ops - set the PCM operators
277  * @pcm: the pcm instance
278  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
279  * @ops: the operator table
280  *
281  * Sets the given PCM operators to the pcm instance.
282  */
283 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, struct snd_pcm_ops *ops)
284 {
285 	struct snd_pcm_str *stream = &pcm->streams[direction];
286 	struct snd_pcm_substream *substream;
287 
288 	for (substream = stream->substream; substream != NULL; substream = substream->next)
289 		substream->ops = ops;
290 }
291 
292 EXPORT_SYMBOL(snd_pcm_set_ops);
293 
294 /**
295  * snd_pcm_sync - set the PCM sync id
296  * @substream: the pcm substream
297  *
298  * Sets the PCM sync identifier for the card.
299  */
300 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
301 {
302 	struct snd_pcm_runtime *runtime = substream->runtime;
303 
304 	runtime->sync.id32[0] = substream->pcm->card->number;
305 	runtime->sync.id32[1] = -1;
306 	runtime->sync.id32[2] = -1;
307 	runtime->sync.id32[3] = -1;
308 }
309 
310 EXPORT_SYMBOL(snd_pcm_set_sync);
311 
312 /*
313  *  Standard ioctl routine
314  */
315 
316 static inline unsigned int div32(unsigned int a, unsigned int b,
317 				 unsigned int *r)
318 {
319 	if (b == 0) {
320 		*r = 0;
321 		return UINT_MAX;
322 	}
323 	*r = a % b;
324 	return a / b;
325 }
326 
327 static inline unsigned int div_down(unsigned int a, unsigned int b)
328 {
329 	if (b == 0)
330 		return UINT_MAX;
331 	return a / b;
332 }
333 
334 static inline unsigned int div_up(unsigned int a, unsigned int b)
335 {
336 	unsigned int r;
337 	unsigned int q;
338 	if (b == 0)
339 		return UINT_MAX;
340 	q = div32(a, b, &r);
341 	if (r)
342 		++q;
343 	return q;
344 }
345 
346 static inline unsigned int mul(unsigned int a, unsigned int b)
347 {
348 	if (a == 0)
349 		return 0;
350 	if (div_down(UINT_MAX, a) < b)
351 		return UINT_MAX;
352 	return a * b;
353 }
354 
355 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
356 				    unsigned int c, unsigned int *r)
357 {
358 	u_int64_t n = (u_int64_t) a * b;
359 	if (c == 0) {
360 		snd_assert(n > 0, );
361 		*r = 0;
362 		return UINT_MAX;
363 	}
364 	div64_32(&n, c, r);
365 	if (n >= UINT_MAX) {
366 		*r = 0;
367 		return UINT_MAX;
368 	}
369 	return n;
370 }
371 
372 /**
373  * snd_interval_refine - refine the interval value of configurator
374  * @i: the interval value to refine
375  * @v: the interval value to refer to
376  *
377  * Refines the interval value with the reference value.
378  * The interval is changed to the range satisfying both intervals.
379  * The interval status (min, max, integer, etc.) are evaluated.
380  *
381  * Returns non-zero if the value is changed, zero if not changed.
382  */
383 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
384 {
385 	int changed = 0;
386 	snd_assert(!snd_interval_empty(i), return -EINVAL);
387 	if (i->min < v->min) {
388 		i->min = v->min;
389 		i->openmin = v->openmin;
390 		changed = 1;
391 	} else if (i->min == v->min && !i->openmin && v->openmin) {
392 		i->openmin = 1;
393 		changed = 1;
394 	}
395 	if (i->max > v->max) {
396 		i->max = v->max;
397 		i->openmax = v->openmax;
398 		changed = 1;
399 	} else if (i->max == v->max && !i->openmax && v->openmax) {
400 		i->openmax = 1;
401 		changed = 1;
402 	}
403 	if (!i->integer && v->integer) {
404 		i->integer = 1;
405 		changed = 1;
406 	}
407 	if (i->integer) {
408 		if (i->openmin) {
409 			i->min++;
410 			i->openmin = 0;
411 		}
412 		if (i->openmax) {
413 			i->max--;
414 			i->openmax = 0;
415 		}
416 	} else if (!i->openmin && !i->openmax && i->min == i->max)
417 		i->integer = 1;
418 	if (snd_interval_checkempty(i)) {
419 		snd_interval_none(i);
420 		return -EINVAL;
421 	}
422 	return changed;
423 }
424 
425 EXPORT_SYMBOL(snd_interval_refine);
426 
427 static int snd_interval_refine_first(struct snd_interval *i)
428 {
429 	snd_assert(!snd_interval_empty(i), return -EINVAL);
430 	if (snd_interval_single(i))
431 		return 0;
432 	i->max = i->min;
433 	i->openmax = i->openmin;
434 	if (i->openmax)
435 		i->max++;
436 	return 1;
437 }
438 
439 static int snd_interval_refine_last(struct snd_interval *i)
440 {
441 	snd_assert(!snd_interval_empty(i), return -EINVAL);
442 	if (snd_interval_single(i))
443 		return 0;
444 	i->min = i->max;
445 	i->openmin = i->openmax;
446 	if (i->openmin)
447 		i->min--;
448 	return 1;
449 }
450 
451 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
452 {
453 	if (a->empty || b->empty) {
454 		snd_interval_none(c);
455 		return;
456 	}
457 	c->empty = 0;
458 	c->min = mul(a->min, b->min);
459 	c->openmin = (a->openmin || b->openmin);
460 	c->max = mul(a->max,  b->max);
461 	c->openmax = (a->openmax || b->openmax);
462 	c->integer = (a->integer && b->integer);
463 }
464 
465 /**
466  * snd_interval_div - refine the interval value with division
467  * @a: dividend
468  * @b: divisor
469  * @c: quotient
470  *
471  * c = a / b
472  *
473  * Returns non-zero if the value is changed, zero if not changed.
474  */
475 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
476 {
477 	unsigned int r;
478 	if (a->empty || b->empty) {
479 		snd_interval_none(c);
480 		return;
481 	}
482 	c->empty = 0;
483 	c->min = div32(a->min, b->max, &r);
484 	c->openmin = (r || a->openmin || b->openmax);
485 	if (b->min > 0) {
486 		c->max = div32(a->max, b->min, &r);
487 		if (r) {
488 			c->max++;
489 			c->openmax = 1;
490 		} else
491 			c->openmax = (a->openmax || b->openmin);
492 	} else {
493 		c->max = UINT_MAX;
494 		c->openmax = 0;
495 	}
496 	c->integer = 0;
497 }
498 
499 /**
500  * snd_interval_muldivk - refine the interval value
501  * @a: dividend 1
502  * @b: dividend 2
503  * @k: divisor (as integer)
504  * @c: result
505   *
506  * c = a * b / k
507  *
508  * Returns non-zero if the value is changed, zero if not changed.
509  */
510 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
511 		      unsigned int k, struct snd_interval *c)
512 {
513 	unsigned int r;
514 	if (a->empty || b->empty) {
515 		snd_interval_none(c);
516 		return;
517 	}
518 	c->empty = 0;
519 	c->min = muldiv32(a->min, b->min, k, &r);
520 	c->openmin = (r || a->openmin || b->openmin);
521 	c->max = muldiv32(a->max, b->max, k, &r);
522 	if (r) {
523 		c->max++;
524 		c->openmax = 1;
525 	} else
526 		c->openmax = (a->openmax || b->openmax);
527 	c->integer = 0;
528 }
529 
530 /**
531  * snd_interval_mulkdiv - refine the interval value
532  * @a: dividend 1
533  * @k: dividend 2 (as integer)
534  * @b: divisor
535  * @c: result
536  *
537  * c = a * k / b
538  *
539  * Returns non-zero if the value is changed, zero if not changed.
540  */
541 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
542 		      const struct snd_interval *b, struct snd_interval *c)
543 {
544 	unsigned int r;
545 	if (a->empty || b->empty) {
546 		snd_interval_none(c);
547 		return;
548 	}
549 	c->empty = 0;
550 	c->min = muldiv32(a->min, k, b->max, &r);
551 	c->openmin = (r || a->openmin || b->openmax);
552 	if (b->min > 0) {
553 		c->max = muldiv32(a->max, k, b->min, &r);
554 		if (r) {
555 			c->max++;
556 			c->openmax = 1;
557 		} else
558 			c->openmax = (a->openmax || b->openmin);
559 	} else {
560 		c->max = UINT_MAX;
561 		c->openmax = 0;
562 	}
563 	c->integer = 0;
564 }
565 
566 /* ---- */
567 
568 
569 /**
570  * snd_interval_ratnum - refine the interval value
571  * @i: interval to refine
572  * @rats_count: number of ratnum_t
573  * @rats: ratnum_t array
574  * @nump: pointer to store the resultant numerator
575  * @denp: pointer to store the resultant denominator
576  *
577  * Returns non-zero if the value is changed, zero if not changed.
578  */
579 int snd_interval_ratnum(struct snd_interval *i,
580 			unsigned int rats_count, struct snd_ratnum *rats,
581 			unsigned int *nump, unsigned int *denp)
582 {
583 	unsigned int best_num, best_diff, best_den;
584 	unsigned int k;
585 	struct snd_interval t;
586 	int err;
587 
588 	best_num = best_den = best_diff = 0;
589 	for (k = 0; k < rats_count; ++k) {
590 		unsigned int num = rats[k].num;
591 		unsigned int den;
592 		unsigned int q = i->min;
593 		int diff;
594 		if (q == 0)
595 			q = 1;
596 		den = div_down(num, q);
597 		if (den < rats[k].den_min)
598 			continue;
599 		if (den > rats[k].den_max)
600 			den = rats[k].den_max;
601 		else {
602 			unsigned int r;
603 			r = (den - rats[k].den_min) % rats[k].den_step;
604 			if (r != 0)
605 				den -= r;
606 		}
607 		diff = num - q * den;
608 		if (best_num == 0 ||
609 		    diff * best_den < best_diff * den) {
610 			best_diff = diff;
611 			best_den = den;
612 			best_num = num;
613 		}
614 	}
615 	if (best_den == 0) {
616 		i->empty = 1;
617 		return -EINVAL;
618 	}
619 	t.min = div_down(best_num, best_den);
620 	t.openmin = !!(best_num % best_den);
621 
622 	best_num = best_den = best_diff = 0;
623 	for (k = 0; k < rats_count; ++k) {
624 		unsigned int num = rats[k].num;
625 		unsigned int den;
626 		unsigned int q = i->max;
627 		int diff;
628 		if (q == 0) {
629 			i->empty = 1;
630 			return -EINVAL;
631 		}
632 		den = div_up(num, q);
633 		if (den > rats[k].den_max)
634 			continue;
635 		if (den < rats[k].den_min)
636 			den = rats[k].den_min;
637 		else {
638 			unsigned int r;
639 			r = (den - rats[k].den_min) % rats[k].den_step;
640 			if (r != 0)
641 				den += rats[k].den_step - r;
642 		}
643 		diff = q * den - num;
644 		if (best_num == 0 ||
645 		    diff * best_den < best_diff * den) {
646 			best_diff = diff;
647 			best_den = den;
648 			best_num = num;
649 		}
650 	}
651 	if (best_den == 0) {
652 		i->empty = 1;
653 		return -EINVAL;
654 	}
655 	t.max = div_up(best_num, best_den);
656 	t.openmax = !!(best_num % best_den);
657 	t.integer = 0;
658 	err = snd_interval_refine(i, &t);
659 	if (err < 0)
660 		return err;
661 
662 	if (snd_interval_single(i)) {
663 		if (nump)
664 			*nump = best_num;
665 		if (denp)
666 			*denp = best_den;
667 	}
668 	return err;
669 }
670 
671 EXPORT_SYMBOL(snd_interval_ratnum);
672 
673 /**
674  * snd_interval_ratden - refine the interval value
675  * @i: interval to refine
676  * @rats_count: number of struct ratden
677  * @rats: struct ratden array
678  * @nump: pointer to store the resultant numerator
679  * @denp: pointer to store the resultant denominator
680  *
681  * Returns non-zero if the value is changed, zero if not changed.
682  */
683 static int snd_interval_ratden(struct snd_interval *i,
684 			       unsigned int rats_count, struct snd_ratden *rats,
685 			       unsigned int *nump, unsigned int *denp)
686 {
687 	unsigned int best_num, best_diff, best_den;
688 	unsigned int k;
689 	struct snd_interval t;
690 	int err;
691 
692 	best_num = best_den = best_diff = 0;
693 	for (k = 0; k < rats_count; ++k) {
694 		unsigned int num;
695 		unsigned int den = rats[k].den;
696 		unsigned int q = i->min;
697 		int diff;
698 		num = mul(q, den);
699 		if (num > rats[k].num_max)
700 			continue;
701 		if (num < rats[k].num_min)
702 			num = rats[k].num_max;
703 		else {
704 			unsigned int r;
705 			r = (num - rats[k].num_min) % rats[k].num_step;
706 			if (r != 0)
707 				num += rats[k].num_step - r;
708 		}
709 		diff = num - q * den;
710 		if (best_num == 0 ||
711 		    diff * best_den < best_diff * den) {
712 			best_diff = diff;
713 			best_den = den;
714 			best_num = num;
715 		}
716 	}
717 	if (best_den == 0) {
718 		i->empty = 1;
719 		return -EINVAL;
720 	}
721 	t.min = div_down(best_num, best_den);
722 	t.openmin = !!(best_num % best_den);
723 
724 	best_num = best_den = best_diff = 0;
725 	for (k = 0; k < rats_count; ++k) {
726 		unsigned int num;
727 		unsigned int den = rats[k].den;
728 		unsigned int q = i->max;
729 		int diff;
730 		num = mul(q, den);
731 		if (num < rats[k].num_min)
732 			continue;
733 		if (num > rats[k].num_max)
734 			num = rats[k].num_max;
735 		else {
736 			unsigned int r;
737 			r = (num - rats[k].num_min) % rats[k].num_step;
738 			if (r != 0)
739 				num -= r;
740 		}
741 		diff = q * den - num;
742 		if (best_num == 0 ||
743 		    diff * best_den < best_diff * den) {
744 			best_diff = diff;
745 			best_den = den;
746 			best_num = num;
747 		}
748 	}
749 	if (best_den == 0) {
750 		i->empty = 1;
751 		return -EINVAL;
752 	}
753 	t.max = div_up(best_num, best_den);
754 	t.openmax = !!(best_num % best_den);
755 	t.integer = 0;
756 	err = snd_interval_refine(i, &t);
757 	if (err < 0)
758 		return err;
759 
760 	if (snd_interval_single(i)) {
761 		if (nump)
762 			*nump = best_num;
763 		if (denp)
764 			*denp = best_den;
765 	}
766 	return err;
767 }
768 
769 /**
770  * snd_interval_list - refine the interval value from the list
771  * @i: the interval value to refine
772  * @count: the number of elements in the list
773  * @list: the value list
774  * @mask: the bit-mask to evaluate
775  *
776  * Refines the interval value from the list.
777  * When mask is non-zero, only the elements corresponding to bit 1 are
778  * evaluated.
779  *
780  * Returns non-zero if the value is changed, zero if not changed.
781  */
782 int snd_interval_list(struct snd_interval *i, unsigned int count, unsigned int *list, unsigned int mask)
783 {
784         unsigned int k;
785 	int changed = 0;
786         for (k = 0; k < count; k++) {
787 		if (mask && !(mask & (1 << k)))
788 			continue;
789                 if (i->min == list[k] && !i->openmin)
790                         goto _l1;
791                 if (i->min < list[k]) {
792                         i->min = list[k];
793 			i->openmin = 0;
794 			changed = 1;
795                         goto _l1;
796                 }
797         }
798         i->empty = 1;
799         return -EINVAL;
800  _l1:
801         for (k = count; k-- > 0;) {
802 		if (mask && !(mask & (1 << k)))
803 			continue;
804                 if (i->max == list[k] && !i->openmax)
805                         goto _l2;
806                 if (i->max > list[k]) {
807                         i->max = list[k];
808 			i->openmax = 0;
809 			changed = 1;
810                         goto _l2;
811                 }
812         }
813         i->empty = 1;
814         return -EINVAL;
815  _l2:
816 	if (snd_interval_checkempty(i)) {
817 		i->empty = 1;
818 		return -EINVAL;
819 	}
820         return changed;
821 }
822 
823 EXPORT_SYMBOL(snd_interval_list);
824 
825 static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned int step)
826 {
827 	unsigned int n;
828 	int changed = 0;
829 	n = (i->min - min) % step;
830 	if (n != 0 || i->openmin) {
831 		i->min += step - n;
832 		changed = 1;
833 	}
834 	n = (i->max - min) % step;
835 	if (n != 0 || i->openmax) {
836 		i->max -= n;
837 		changed = 1;
838 	}
839 	if (snd_interval_checkempty(i)) {
840 		i->empty = 1;
841 		return -EINVAL;
842 	}
843 	return changed;
844 }
845 
846 /* Info constraints helpers */
847 
848 /**
849  * snd_pcm_hw_rule_add - add the hw-constraint rule
850  * @runtime: the pcm runtime instance
851  * @cond: condition bits
852  * @var: the variable to evaluate
853  * @func: the evaluation function
854  * @private: the private data pointer passed to function
855  * @dep: the dependent variables
856  *
857  * Returns zero if successful, or a negative error code on failure.
858  */
859 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
860 			int var,
861 			snd_pcm_hw_rule_func_t func, void *private,
862 			int dep, ...)
863 {
864 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
865 	struct snd_pcm_hw_rule *c;
866 	unsigned int k;
867 	va_list args;
868 	va_start(args, dep);
869 	if (constrs->rules_num >= constrs->rules_all) {
870 		struct snd_pcm_hw_rule *new;
871 		unsigned int new_rules = constrs->rules_all + 16;
872 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
873 		if (!new)
874 			return -ENOMEM;
875 		if (constrs->rules) {
876 			memcpy(new, constrs->rules,
877 			       constrs->rules_num * sizeof(*c));
878 			kfree(constrs->rules);
879 		}
880 		constrs->rules = new;
881 		constrs->rules_all = new_rules;
882 	}
883 	c = &constrs->rules[constrs->rules_num];
884 	c->cond = cond;
885 	c->func = func;
886 	c->var = var;
887 	c->private = private;
888 	k = 0;
889 	while (1) {
890 		snd_assert(k < ARRAY_SIZE(c->deps), return -EINVAL);
891 		c->deps[k++] = dep;
892 		if (dep < 0)
893 			break;
894 		dep = va_arg(args, int);
895 	}
896 	constrs->rules_num++;
897 	va_end(args);
898 	return 0;
899 }
900 
901 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
902 
903 /**
904  * snd_pcm_hw_constraint_mask
905  * @runtime: PCM runtime instance
906  * @var: hw_params variable to apply the mask
907  * @mask: the bitmap mask
908  *
909  * Apply the constraint of the given bitmap mask to a mask parameter.
910  */
911 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
912 			       u_int32_t mask)
913 {
914 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
915 	struct snd_mask *maskp = constrs_mask(constrs, var);
916 	*maskp->bits &= mask;
917 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
918 	if (*maskp->bits == 0)
919 		return -EINVAL;
920 	return 0;
921 }
922 
923 /**
924  * snd_pcm_hw_constraint_mask64
925  * @runtime: PCM runtime instance
926  * @var: hw_params variable to apply the mask
927  * @mask: the 64bit bitmap mask
928  *
929  * Apply the constraint of the given bitmap mask to a mask parameter.
930  */
931 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
932 				 u_int64_t mask)
933 {
934 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
935 	struct snd_mask *maskp = constrs_mask(constrs, var);
936 	maskp->bits[0] &= (u_int32_t)mask;
937 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
938 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
939 	if (! maskp->bits[0] && ! maskp->bits[1])
940 		return -EINVAL;
941 	return 0;
942 }
943 
944 /**
945  * snd_pcm_hw_constraint_integer
946  * @runtime: PCM runtime instance
947  * @var: hw_params variable to apply the integer constraint
948  *
949  * Apply the constraint of integer to an interval parameter.
950  */
951 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
952 {
953 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
954 	return snd_interval_setinteger(constrs_interval(constrs, var));
955 }
956 
957 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
958 
959 /**
960  * snd_pcm_hw_constraint_minmax
961  * @runtime: PCM runtime instance
962  * @var: hw_params variable to apply the range
963  * @min: the minimal value
964  * @max: the maximal value
965  *
966  * Apply the min/max range constraint to an interval parameter.
967  */
968 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
969 				 unsigned int min, unsigned int max)
970 {
971 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
972 	struct snd_interval t;
973 	t.min = min;
974 	t.max = max;
975 	t.openmin = t.openmax = 0;
976 	t.integer = 0;
977 	return snd_interval_refine(constrs_interval(constrs, var), &t);
978 }
979 
980 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
981 
982 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
983 				struct snd_pcm_hw_rule *rule)
984 {
985 	struct snd_pcm_hw_constraint_list *list = rule->private;
986 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
987 }
988 
989 
990 /**
991  * snd_pcm_hw_constraint_list
992  * @runtime: PCM runtime instance
993  * @cond: condition bits
994  * @var: hw_params variable to apply the list constraint
995  * @l: list
996  *
997  * Apply the list of constraints to an interval parameter.
998  */
999 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1000 			       unsigned int cond,
1001 			       snd_pcm_hw_param_t var,
1002 			       struct snd_pcm_hw_constraint_list *l)
1003 {
1004 	return snd_pcm_hw_rule_add(runtime, cond, var,
1005 				   snd_pcm_hw_rule_list, l,
1006 				   var, -1);
1007 }
1008 
1009 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1010 
1011 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1012 				   struct snd_pcm_hw_rule *rule)
1013 {
1014 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1015 	unsigned int num = 0, den = 0;
1016 	int err;
1017 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1018 				  r->nrats, r->rats, &num, &den);
1019 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1020 		params->rate_num = num;
1021 		params->rate_den = den;
1022 	}
1023 	return err;
1024 }
1025 
1026 /**
1027  * snd_pcm_hw_constraint_ratnums
1028  * @runtime: PCM runtime instance
1029  * @cond: condition bits
1030  * @var: hw_params variable to apply the ratnums constraint
1031  * @r: struct snd_ratnums constriants
1032  */
1033 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1034 				  unsigned int cond,
1035 				  snd_pcm_hw_param_t var,
1036 				  struct snd_pcm_hw_constraint_ratnums *r)
1037 {
1038 	return snd_pcm_hw_rule_add(runtime, cond, var,
1039 				   snd_pcm_hw_rule_ratnums, r,
1040 				   var, -1);
1041 }
1042 
1043 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1044 
1045 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1046 				   struct snd_pcm_hw_rule *rule)
1047 {
1048 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1049 	unsigned int num = 0, den = 0;
1050 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1051 				  r->nrats, r->rats, &num, &den);
1052 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1053 		params->rate_num = num;
1054 		params->rate_den = den;
1055 	}
1056 	return err;
1057 }
1058 
1059 /**
1060  * snd_pcm_hw_constraint_ratdens
1061  * @runtime: PCM runtime instance
1062  * @cond: condition bits
1063  * @var: hw_params variable to apply the ratdens constraint
1064  * @r: struct snd_ratdens constriants
1065  */
1066 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1067 				  unsigned int cond,
1068 				  snd_pcm_hw_param_t var,
1069 				  struct snd_pcm_hw_constraint_ratdens *r)
1070 {
1071 	return snd_pcm_hw_rule_add(runtime, cond, var,
1072 				   snd_pcm_hw_rule_ratdens, r,
1073 				   var, -1);
1074 }
1075 
1076 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1077 
1078 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1079 				  struct snd_pcm_hw_rule *rule)
1080 {
1081 	unsigned int l = (unsigned long) rule->private;
1082 	int width = l & 0xffff;
1083 	unsigned int msbits = l >> 16;
1084 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1085 	if (snd_interval_single(i) && snd_interval_value(i) == width)
1086 		params->msbits = msbits;
1087 	return 0;
1088 }
1089 
1090 /**
1091  * snd_pcm_hw_constraint_msbits
1092  * @runtime: PCM runtime instance
1093  * @cond: condition bits
1094  * @width: sample bits width
1095  * @msbits: msbits width
1096  */
1097 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1098 				 unsigned int cond,
1099 				 unsigned int width,
1100 				 unsigned int msbits)
1101 {
1102 	unsigned long l = (msbits << 16) | width;
1103 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1104 				    snd_pcm_hw_rule_msbits,
1105 				    (void*) l,
1106 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1107 }
1108 
1109 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1110 
1111 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1112 				struct snd_pcm_hw_rule *rule)
1113 {
1114 	unsigned long step = (unsigned long) rule->private;
1115 	return snd_interval_step(hw_param_interval(params, rule->var), 0, step);
1116 }
1117 
1118 /**
1119  * snd_pcm_hw_constraint_step
1120  * @runtime: PCM runtime instance
1121  * @cond: condition bits
1122  * @var: hw_params variable to apply the step constraint
1123  * @step: step size
1124  */
1125 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1126 			       unsigned int cond,
1127 			       snd_pcm_hw_param_t var,
1128 			       unsigned long step)
1129 {
1130 	return snd_pcm_hw_rule_add(runtime, cond, var,
1131 				   snd_pcm_hw_rule_step, (void *) step,
1132 				   var, -1);
1133 }
1134 
1135 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1136 
1137 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1138 {
1139 	static int pow2_sizes[] = {
1140 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1141 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1142 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1143 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1144 	};
1145 	return snd_interval_list(hw_param_interval(params, rule->var),
1146 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1147 }
1148 
1149 /**
1150  * snd_pcm_hw_constraint_pow2
1151  * @runtime: PCM runtime instance
1152  * @cond: condition bits
1153  * @var: hw_params variable to apply the power-of-2 constraint
1154  */
1155 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1156 			       unsigned int cond,
1157 			       snd_pcm_hw_param_t var)
1158 {
1159 	return snd_pcm_hw_rule_add(runtime, cond, var,
1160 				   snd_pcm_hw_rule_pow2, NULL,
1161 				   var, -1);
1162 }
1163 
1164 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1165 
1166 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1167 				  snd_pcm_hw_param_t var)
1168 {
1169 	if (hw_is_mask(var)) {
1170 		snd_mask_any(hw_param_mask(params, var));
1171 		params->cmask |= 1 << var;
1172 		params->rmask |= 1 << var;
1173 		return;
1174 	}
1175 	if (hw_is_interval(var)) {
1176 		snd_interval_any(hw_param_interval(params, var));
1177 		params->cmask |= 1 << var;
1178 		params->rmask |= 1 << var;
1179 		return;
1180 	}
1181 	snd_BUG();
1182 }
1183 
1184 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1185 {
1186 	unsigned int k;
1187 	memset(params, 0, sizeof(*params));
1188 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1189 		_snd_pcm_hw_param_any(params, k);
1190 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1191 		_snd_pcm_hw_param_any(params, k);
1192 	params->info = ~0U;
1193 }
1194 
1195 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1196 
1197 /**
1198  * snd_pcm_hw_param_value
1199  * @params: the hw_params instance
1200  * @var: parameter to retrieve
1201  * @dir: pointer to the direction (-1,0,1) or NULL
1202  *
1203  * Return the value for field PAR if it's fixed in configuration space
1204  *  defined by PARAMS. Return -EINVAL otherwise
1205  */
1206 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1207 			   snd_pcm_hw_param_t var, int *dir)
1208 {
1209 	if (hw_is_mask(var)) {
1210 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1211 		if (!snd_mask_single(mask))
1212 			return -EINVAL;
1213 		if (dir)
1214 			*dir = 0;
1215 		return snd_mask_value(mask);
1216 	}
1217 	if (hw_is_interval(var)) {
1218 		const struct snd_interval *i = hw_param_interval_c(params, var);
1219 		if (!snd_interval_single(i))
1220 			return -EINVAL;
1221 		if (dir)
1222 			*dir = i->openmin;
1223 		return snd_interval_value(i);
1224 	}
1225 	return -EINVAL;
1226 }
1227 
1228 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1229 
1230 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1231 				snd_pcm_hw_param_t var)
1232 {
1233 	if (hw_is_mask(var)) {
1234 		snd_mask_none(hw_param_mask(params, var));
1235 		params->cmask |= 1 << var;
1236 		params->rmask |= 1 << var;
1237 	} else if (hw_is_interval(var)) {
1238 		snd_interval_none(hw_param_interval(params, var));
1239 		params->cmask |= 1 << var;
1240 		params->rmask |= 1 << var;
1241 	} else {
1242 		snd_BUG();
1243 	}
1244 }
1245 
1246 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1247 
1248 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1249 				   snd_pcm_hw_param_t var)
1250 {
1251 	int changed;
1252 	if (hw_is_mask(var))
1253 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1254 	else if (hw_is_interval(var))
1255 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1256 	else
1257 		return -EINVAL;
1258 	if (changed) {
1259 		params->cmask |= 1 << var;
1260 		params->rmask |= 1 << var;
1261 	}
1262 	return changed;
1263 }
1264 
1265 
1266 /**
1267  * snd_pcm_hw_param_first
1268  * @pcm: PCM instance
1269  * @params: the hw_params instance
1270  * @var: parameter to retrieve
1271  * @dir: pointer to the direction (-1,0,1) or NULL
1272  *
1273  * Inside configuration space defined by PARAMS remove from PAR all
1274  * values > minimum. Reduce configuration space accordingly.
1275  * Return the minimum.
1276  */
1277 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1278 			   struct snd_pcm_hw_params *params,
1279 			   snd_pcm_hw_param_t var, int *dir)
1280 {
1281 	int changed = _snd_pcm_hw_param_first(params, var);
1282 	if (changed < 0)
1283 		return changed;
1284 	if (params->rmask) {
1285 		int err = snd_pcm_hw_refine(pcm, params);
1286 		snd_assert(err >= 0, return err);
1287 	}
1288 	return snd_pcm_hw_param_value(params, var, dir);
1289 }
1290 
1291 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1292 
1293 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1294 				  snd_pcm_hw_param_t var)
1295 {
1296 	int changed;
1297 	if (hw_is_mask(var))
1298 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1299 	else if (hw_is_interval(var))
1300 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1301 	else
1302 		return -EINVAL;
1303 	if (changed) {
1304 		params->cmask |= 1 << var;
1305 		params->rmask |= 1 << var;
1306 	}
1307 	return changed;
1308 }
1309 
1310 
1311 /**
1312  * snd_pcm_hw_param_last
1313  * @pcm: PCM instance
1314  * @params: the hw_params instance
1315  * @var: parameter to retrieve
1316  * @dir: pointer to the direction (-1,0,1) or NULL
1317  *
1318  * Inside configuration space defined by PARAMS remove from PAR all
1319  * values < maximum. Reduce configuration space accordingly.
1320  * Return the maximum.
1321  */
1322 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1323 			  struct snd_pcm_hw_params *params,
1324 			  snd_pcm_hw_param_t var, int *dir)
1325 {
1326 	int changed = _snd_pcm_hw_param_last(params, var);
1327 	if (changed < 0)
1328 		return changed;
1329 	if (params->rmask) {
1330 		int err = snd_pcm_hw_refine(pcm, params);
1331 		snd_assert(err >= 0, return err);
1332 	}
1333 	return snd_pcm_hw_param_value(params, var, dir);
1334 }
1335 
1336 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1337 
1338 /**
1339  * snd_pcm_hw_param_choose
1340  * @pcm: PCM instance
1341  * @params: the hw_params instance
1342  *
1343  * Choose one configuration from configuration space defined by PARAMS
1344  * The configuration chosen is that obtained fixing in this order:
1345  * first access, first format, first subformat, min channels,
1346  * min rate, min period time, max buffer size, min tick time
1347  */
1348 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1349 			     struct snd_pcm_hw_params *params)
1350 {
1351 	static int vars[] = {
1352 		SNDRV_PCM_HW_PARAM_ACCESS,
1353 		SNDRV_PCM_HW_PARAM_FORMAT,
1354 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1355 		SNDRV_PCM_HW_PARAM_CHANNELS,
1356 		SNDRV_PCM_HW_PARAM_RATE,
1357 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1358 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1359 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1360 		-1
1361 	};
1362 	int err, *v;
1363 
1364 	for (v = vars; *v != -1; v++) {
1365 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1366 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1367 		else
1368 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1369 		snd_assert(err >= 0, return err);
1370 	}
1371 	return 0;
1372 }
1373 
1374 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1375 				   void *arg)
1376 {
1377 	struct snd_pcm_runtime *runtime = substream->runtime;
1378 	unsigned long flags;
1379 	snd_pcm_stream_lock_irqsave(substream, flags);
1380 	if (snd_pcm_running(substream) &&
1381 	    snd_pcm_update_hw_ptr(substream) >= 0)
1382 		runtime->status->hw_ptr %= runtime->buffer_size;
1383 	else
1384 		runtime->status->hw_ptr = 0;
1385 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1386 	return 0;
1387 }
1388 
1389 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1390 					  void *arg)
1391 {
1392 	struct snd_pcm_channel_info *info = arg;
1393 	struct snd_pcm_runtime *runtime = substream->runtime;
1394 	int width;
1395 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1396 		info->offset = -1;
1397 		return 0;
1398 	}
1399 	width = snd_pcm_format_physical_width(runtime->format);
1400 	if (width < 0)
1401 		return width;
1402 	info->offset = 0;
1403 	switch (runtime->access) {
1404 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1405 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1406 		info->first = info->channel * width;
1407 		info->step = runtime->channels * width;
1408 		break;
1409 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1410 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1411 	{
1412 		size_t size = runtime->dma_bytes / runtime->channels;
1413 		info->first = info->channel * size * 8;
1414 		info->step = width;
1415 		break;
1416 	}
1417 	default:
1418 		snd_BUG();
1419 		break;
1420 	}
1421 	return 0;
1422 }
1423 
1424 /**
1425  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1426  * @substream: the pcm substream instance
1427  * @cmd: ioctl command
1428  * @arg: ioctl argument
1429  *
1430  * Processes the generic ioctl commands for PCM.
1431  * Can be passed as the ioctl callback for PCM ops.
1432  *
1433  * Returns zero if successful, or a negative error code on failure.
1434  */
1435 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1436 		      unsigned int cmd, void *arg)
1437 {
1438 	switch (cmd) {
1439 	case SNDRV_PCM_IOCTL1_INFO:
1440 		return 0;
1441 	case SNDRV_PCM_IOCTL1_RESET:
1442 		return snd_pcm_lib_ioctl_reset(substream, arg);
1443 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1444 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1445 	}
1446 	return -ENXIO;
1447 }
1448 
1449 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1450 
1451 /*
1452  *  Conditions
1453  */
1454 
1455 static void snd_pcm_system_tick_set(struct snd_pcm_substream *substream,
1456 				    unsigned long ticks)
1457 {
1458 	struct snd_pcm_runtime *runtime = substream->runtime;
1459 	if (ticks == 0)
1460 		del_timer(&runtime->tick_timer);
1461 	else {
1462 		ticks += (1000000 / HZ) - 1;
1463 		ticks /= (1000000 / HZ);
1464 		mod_timer(&runtime->tick_timer, jiffies + ticks);
1465 	}
1466 }
1467 
1468 /* Temporary alias */
1469 void snd_pcm_tick_set(struct snd_pcm_substream *substream, unsigned long ticks)
1470 {
1471 	snd_pcm_system_tick_set(substream, ticks);
1472 }
1473 
1474 void snd_pcm_tick_prepare(struct snd_pcm_substream *substream)
1475 {
1476 	struct snd_pcm_runtime *runtime = substream->runtime;
1477 	snd_pcm_uframes_t frames = ULONG_MAX;
1478 	snd_pcm_uframes_t avail, dist;
1479 	unsigned int ticks;
1480 	u_int64_t n;
1481 	u_int32_t r;
1482 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
1483 		if (runtime->silence_size >= runtime->boundary) {
1484 			frames = 1;
1485 		} else if (runtime->silence_size > 0 &&
1486 			   runtime->silence_filled < runtime->buffer_size) {
1487 			snd_pcm_sframes_t noise_dist;
1488 			noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
1489 			if (noise_dist > (snd_pcm_sframes_t)runtime->silence_threshold)
1490 				frames = noise_dist - runtime->silence_threshold;
1491 		}
1492 		avail = snd_pcm_playback_avail(runtime);
1493 	} else {
1494 		avail = snd_pcm_capture_avail(runtime);
1495 	}
1496 	if (avail < runtime->control->avail_min) {
1497 		snd_pcm_sframes_t n = runtime->control->avail_min - avail;
1498 		if (n > 0 && frames > (snd_pcm_uframes_t)n)
1499 			frames = n;
1500 	}
1501 	if (avail < runtime->buffer_size) {
1502 		snd_pcm_sframes_t n = runtime->buffer_size - avail;
1503 		if (n > 0 && frames > (snd_pcm_uframes_t)n)
1504 			frames = n;
1505 	}
1506 	if (frames == ULONG_MAX) {
1507 		snd_pcm_tick_set(substream, 0);
1508 		return;
1509 	}
1510 	dist = runtime->status->hw_ptr - runtime->hw_ptr_base;
1511 	/* Distance to next interrupt */
1512 	dist = runtime->period_size - dist % runtime->period_size;
1513 	if (dist <= frames) {
1514 		snd_pcm_tick_set(substream, 0);
1515 		return;
1516 	}
1517 	/* the base time is us */
1518 	n = frames;
1519 	n *= 1000000;
1520 	div64_32(&n, runtime->tick_time * runtime->rate, &r);
1521 	ticks = n + (r > 0 ? 1 : 0);
1522 	if (ticks < runtime->sleep_min)
1523 		ticks = runtime->sleep_min;
1524 	snd_pcm_tick_set(substream, (unsigned long) ticks);
1525 }
1526 
1527 void snd_pcm_tick_elapsed(struct snd_pcm_substream *substream)
1528 {
1529 	struct snd_pcm_runtime *runtime;
1530 	unsigned long flags;
1531 
1532 	snd_assert(substream != NULL, return);
1533 	runtime = substream->runtime;
1534 	snd_assert(runtime != NULL, return);
1535 
1536 	snd_pcm_stream_lock_irqsave(substream, flags);
1537 	if (!snd_pcm_running(substream) ||
1538 	    snd_pcm_update_hw_ptr(substream) < 0)
1539 		goto _end;
1540 	if (runtime->sleep_min)
1541 		snd_pcm_tick_prepare(substream);
1542  _end:
1543 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1544 }
1545 
1546 /**
1547  * snd_pcm_period_elapsed - update the pcm status for the next period
1548  * @substream: the pcm substream instance
1549  *
1550  * This function is called from the interrupt handler when the
1551  * PCM has processed the period size.  It will update the current
1552  * pointer, set up the tick, wake up sleepers, etc.
1553  *
1554  * Even if more than one periods have elapsed since the last call, you
1555  * have to call this only once.
1556  */
1557 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1558 {
1559 	struct snd_pcm_runtime *runtime;
1560 	unsigned long flags;
1561 
1562 	snd_assert(substream != NULL, return);
1563 	runtime = substream->runtime;
1564 	snd_assert(runtime != NULL, return);
1565 
1566 	if (runtime->transfer_ack_begin)
1567 		runtime->transfer_ack_begin(substream);
1568 
1569 	snd_pcm_stream_lock_irqsave(substream, flags);
1570 	if (!snd_pcm_running(substream) ||
1571 	    snd_pcm_update_hw_ptr_interrupt(substream) < 0)
1572 		goto _end;
1573 
1574 	if (substream->timer_running)
1575 		snd_timer_interrupt(substream->timer, 1);
1576 	if (runtime->sleep_min)
1577 		snd_pcm_tick_prepare(substream);
1578  _end:
1579 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1580 	if (runtime->transfer_ack_end)
1581 		runtime->transfer_ack_end(substream);
1582 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1583 }
1584 
1585 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1586 
1587 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1588 				      unsigned int hwoff,
1589 				      unsigned long data, unsigned int off,
1590 				      snd_pcm_uframes_t frames)
1591 {
1592 	struct snd_pcm_runtime *runtime = substream->runtime;
1593 	int err;
1594 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1595 	if (substream->ops->copy) {
1596 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1597 			return err;
1598 	} else {
1599 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1600 		snd_assert(runtime->dma_area, return -EFAULT);
1601 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1602 			return -EFAULT;
1603 	}
1604 	return 0;
1605 }
1606 
1607 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1608 			  unsigned long data, unsigned int off,
1609 			  snd_pcm_uframes_t size);
1610 
1611 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1612 					    unsigned long data,
1613 					    snd_pcm_uframes_t size,
1614 					    int nonblock,
1615 					    transfer_f transfer)
1616 {
1617 	struct snd_pcm_runtime *runtime = substream->runtime;
1618 	snd_pcm_uframes_t xfer = 0;
1619 	snd_pcm_uframes_t offset = 0;
1620 	int err = 0;
1621 
1622 	if (size == 0)
1623 		return 0;
1624 	if (size > runtime->xfer_align)
1625 		size -= size % runtime->xfer_align;
1626 
1627 	snd_pcm_stream_lock_irq(substream);
1628 	switch (runtime->status->state) {
1629 	case SNDRV_PCM_STATE_PREPARED:
1630 	case SNDRV_PCM_STATE_RUNNING:
1631 	case SNDRV_PCM_STATE_PAUSED:
1632 		break;
1633 	case SNDRV_PCM_STATE_XRUN:
1634 		err = -EPIPE;
1635 		goto _end_unlock;
1636 	case SNDRV_PCM_STATE_SUSPENDED:
1637 		err = -ESTRPIPE;
1638 		goto _end_unlock;
1639 	default:
1640 		err = -EBADFD;
1641 		goto _end_unlock;
1642 	}
1643 
1644 	while (size > 0) {
1645 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1646 		snd_pcm_uframes_t avail;
1647 		snd_pcm_uframes_t cont;
1648 		if (runtime->sleep_min == 0 && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1649 			snd_pcm_update_hw_ptr(substream);
1650 		avail = snd_pcm_playback_avail(runtime);
1651 		if (((avail < runtime->control->avail_min && size > avail) ||
1652 		   (size >= runtime->xfer_align && avail < runtime->xfer_align))) {
1653 			wait_queue_t wait;
1654 			enum { READY, SIGNALED, ERROR, SUSPENDED, EXPIRED, DROPPED } state;
1655 			long tout;
1656 
1657 			if (nonblock) {
1658 				err = -EAGAIN;
1659 				goto _end_unlock;
1660 			}
1661 
1662 			init_waitqueue_entry(&wait, current);
1663 			add_wait_queue(&runtime->sleep, &wait);
1664 			while (1) {
1665 				if (signal_pending(current)) {
1666 					state = SIGNALED;
1667 					break;
1668 				}
1669 				set_current_state(TASK_INTERRUPTIBLE);
1670 				snd_pcm_stream_unlock_irq(substream);
1671 				tout = schedule_timeout(10 * HZ);
1672 				snd_pcm_stream_lock_irq(substream);
1673 				if (tout == 0) {
1674 					if (runtime->status->state != SNDRV_PCM_STATE_PREPARED &&
1675 					    runtime->status->state != SNDRV_PCM_STATE_PAUSED) {
1676 						state = runtime->status->state == SNDRV_PCM_STATE_SUSPENDED ? SUSPENDED : EXPIRED;
1677 						break;
1678 					}
1679 				}
1680 				switch (runtime->status->state) {
1681 				case SNDRV_PCM_STATE_XRUN:
1682 				case SNDRV_PCM_STATE_DRAINING:
1683 					state = ERROR;
1684 					goto _end_loop;
1685 				case SNDRV_PCM_STATE_SUSPENDED:
1686 					state = SUSPENDED;
1687 					goto _end_loop;
1688 				case SNDRV_PCM_STATE_SETUP:
1689 					state = DROPPED;
1690 					goto _end_loop;
1691 				default:
1692 					break;
1693 				}
1694 				avail = snd_pcm_playback_avail(runtime);
1695 				if (avail >= runtime->control->avail_min) {
1696 					state = READY;
1697 					break;
1698 				}
1699 			}
1700 		       _end_loop:
1701 			remove_wait_queue(&runtime->sleep, &wait);
1702 
1703 			switch (state) {
1704 			case ERROR:
1705 				err = -EPIPE;
1706 				goto _end_unlock;
1707 			case SUSPENDED:
1708 				err = -ESTRPIPE;
1709 				goto _end_unlock;
1710 			case SIGNALED:
1711 				err = -ERESTARTSYS;
1712 				goto _end_unlock;
1713 			case EXPIRED:
1714 				snd_printd("playback write error (DMA or IRQ trouble?)\n");
1715 				err = -EIO;
1716 				goto _end_unlock;
1717 			case DROPPED:
1718 				err = -EBADFD;
1719 				goto _end_unlock;
1720 			default:
1721 				break;
1722 			}
1723 		}
1724 		if (avail > runtime->xfer_align)
1725 			avail -= avail % runtime->xfer_align;
1726 		frames = size > avail ? avail : size;
1727 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
1728 		if (frames > cont)
1729 			frames = cont;
1730 		snd_assert(frames != 0, snd_pcm_stream_unlock_irq(substream); return -EINVAL);
1731 		appl_ptr = runtime->control->appl_ptr;
1732 		appl_ofs = appl_ptr % runtime->buffer_size;
1733 		snd_pcm_stream_unlock_irq(substream);
1734 		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
1735 			goto _end;
1736 		snd_pcm_stream_lock_irq(substream);
1737 		switch (runtime->status->state) {
1738 		case SNDRV_PCM_STATE_XRUN:
1739 			err = -EPIPE;
1740 			goto _end_unlock;
1741 		case SNDRV_PCM_STATE_SUSPENDED:
1742 			err = -ESTRPIPE;
1743 			goto _end_unlock;
1744 		default:
1745 			break;
1746 		}
1747 		appl_ptr += frames;
1748 		if (appl_ptr >= runtime->boundary)
1749 			appl_ptr -= runtime->boundary;
1750 		runtime->control->appl_ptr = appl_ptr;
1751 		if (substream->ops->ack)
1752 			substream->ops->ack(substream);
1753 
1754 		offset += frames;
1755 		size -= frames;
1756 		xfer += frames;
1757 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
1758 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
1759 			err = snd_pcm_start(substream);
1760 			if (err < 0)
1761 				goto _end_unlock;
1762 		}
1763 		if (runtime->sleep_min &&
1764 		    runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1765 			snd_pcm_tick_prepare(substream);
1766 	}
1767  _end_unlock:
1768 	snd_pcm_stream_unlock_irq(substream);
1769  _end:
1770 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
1771 }
1772 
1773 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
1774 {
1775 	struct snd_pcm_runtime *runtime;
1776 	int nonblock;
1777 
1778 	snd_assert(substream != NULL, return -ENXIO);
1779 	runtime = substream->runtime;
1780 	snd_assert(runtime != NULL, return -ENXIO);
1781 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
1782 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
1783 		return -EBADFD;
1784 
1785 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1786 
1787 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
1788 	    runtime->channels > 1)
1789 		return -EINVAL;
1790 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
1791 				  snd_pcm_lib_write_transfer);
1792 }
1793 
1794 EXPORT_SYMBOL(snd_pcm_lib_write);
1795 
1796 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
1797 				       unsigned int hwoff,
1798 				       unsigned long data, unsigned int off,
1799 				       snd_pcm_uframes_t frames)
1800 {
1801 	struct snd_pcm_runtime *runtime = substream->runtime;
1802 	int err;
1803 	void __user **bufs = (void __user **)data;
1804 	int channels = runtime->channels;
1805 	int c;
1806 	if (substream->ops->copy) {
1807 		snd_assert(substream->ops->silence != NULL, return -EINVAL);
1808 		for (c = 0; c < channels; ++c, ++bufs) {
1809 			if (*bufs == NULL) {
1810 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
1811 					return err;
1812 			} else {
1813 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1814 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
1815 					return err;
1816 			}
1817 		}
1818 	} else {
1819 		/* default transfer behaviour */
1820 		size_t dma_csize = runtime->dma_bytes / channels;
1821 		snd_assert(runtime->dma_area, return -EFAULT);
1822 		for (c = 0; c < channels; ++c, ++bufs) {
1823 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
1824 			if (*bufs == NULL) {
1825 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
1826 			} else {
1827 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1828 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
1829 					return -EFAULT;
1830 			}
1831 		}
1832 	}
1833 	return 0;
1834 }
1835 
1836 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
1837 				     void __user **bufs,
1838 				     snd_pcm_uframes_t frames)
1839 {
1840 	struct snd_pcm_runtime *runtime;
1841 	int nonblock;
1842 
1843 	snd_assert(substream != NULL, return -ENXIO);
1844 	runtime = substream->runtime;
1845 	snd_assert(runtime != NULL, return -ENXIO);
1846 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
1847 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
1848 		return -EBADFD;
1849 
1850 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1851 
1852 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
1853 		return -EINVAL;
1854 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
1855 				  nonblock, snd_pcm_lib_writev_transfer);
1856 }
1857 
1858 EXPORT_SYMBOL(snd_pcm_lib_writev);
1859 
1860 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
1861 				     unsigned int hwoff,
1862 				     unsigned long data, unsigned int off,
1863 				     snd_pcm_uframes_t frames)
1864 {
1865 	struct snd_pcm_runtime *runtime = substream->runtime;
1866 	int err;
1867 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1868 	if (substream->ops->copy) {
1869 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1870 			return err;
1871 	} else {
1872 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1873 		snd_assert(runtime->dma_area, return -EFAULT);
1874 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
1875 			return -EFAULT;
1876 	}
1877 	return 0;
1878 }
1879 
1880 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
1881 					   unsigned long data,
1882 					   snd_pcm_uframes_t size,
1883 					   int nonblock,
1884 					   transfer_f transfer)
1885 {
1886 	struct snd_pcm_runtime *runtime = substream->runtime;
1887 	snd_pcm_uframes_t xfer = 0;
1888 	snd_pcm_uframes_t offset = 0;
1889 	int err = 0;
1890 
1891 	if (size == 0)
1892 		return 0;
1893 	if (size > runtime->xfer_align)
1894 		size -= size % runtime->xfer_align;
1895 
1896 	snd_pcm_stream_lock_irq(substream);
1897 	switch (runtime->status->state) {
1898 	case SNDRV_PCM_STATE_PREPARED:
1899 		if (size >= runtime->start_threshold) {
1900 			err = snd_pcm_start(substream);
1901 			if (err < 0)
1902 				goto _end_unlock;
1903 		}
1904 		break;
1905 	case SNDRV_PCM_STATE_DRAINING:
1906 	case SNDRV_PCM_STATE_RUNNING:
1907 	case SNDRV_PCM_STATE_PAUSED:
1908 		break;
1909 	case SNDRV_PCM_STATE_XRUN:
1910 		err = -EPIPE;
1911 		goto _end_unlock;
1912 	case SNDRV_PCM_STATE_SUSPENDED:
1913 		err = -ESTRPIPE;
1914 		goto _end_unlock;
1915 	default:
1916 		err = -EBADFD;
1917 		goto _end_unlock;
1918 	}
1919 
1920 	while (size > 0) {
1921 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1922 		snd_pcm_uframes_t avail;
1923 		snd_pcm_uframes_t cont;
1924 		if (runtime->sleep_min == 0 && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1925 			snd_pcm_update_hw_ptr(substream);
1926 	      __draining:
1927 		avail = snd_pcm_capture_avail(runtime);
1928 		if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
1929 			if (avail < runtime->xfer_align) {
1930 				err = -EPIPE;
1931 				goto _end_unlock;
1932 			}
1933 		} else if ((avail < runtime->control->avail_min && size > avail) ||
1934 			   (size >= runtime->xfer_align && avail < runtime->xfer_align)) {
1935 			wait_queue_t wait;
1936 			enum { READY, SIGNALED, ERROR, SUSPENDED, EXPIRED, DROPPED } state;
1937 			long tout;
1938 
1939 			if (nonblock) {
1940 				err = -EAGAIN;
1941 				goto _end_unlock;
1942 			}
1943 
1944 			init_waitqueue_entry(&wait, current);
1945 			add_wait_queue(&runtime->sleep, &wait);
1946 			while (1) {
1947 				if (signal_pending(current)) {
1948 					state = SIGNALED;
1949 					break;
1950 				}
1951 				set_current_state(TASK_INTERRUPTIBLE);
1952 				snd_pcm_stream_unlock_irq(substream);
1953 				tout = schedule_timeout(10 * HZ);
1954 				snd_pcm_stream_lock_irq(substream);
1955 				if (tout == 0) {
1956 					if (runtime->status->state != SNDRV_PCM_STATE_PREPARED &&
1957 					    runtime->status->state != SNDRV_PCM_STATE_PAUSED) {
1958 						state = runtime->status->state == SNDRV_PCM_STATE_SUSPENDED ? SUSPENDED : EXPIRED;
1959 						break;
1960 					}
1961 				}
1962 				switch (runtime->status->state) {
1963 				case SNDRV_PCM_STATE_XRUN:
1964 					state = ERROR;
1965 					goto _end_loop;
1966 				case SNDRV_PCM_STATE_SUSPENDED:
1967 					state = SUSPENDED;
1968 					goto _end_loop;
1969 				case SNDRV_PCM_STATE_DRAINING:
1970 					goto __draining;
1971 				case SNDRV_PCM_STATE_SETUP:
1972 					state = DROPPED;
1973 					goto _end_loop;
1974 				default:
1975 					break;
1976 				}
1977 				avail = snd_pcm_capture_avail(runtime);
1978 				if (avail >= runtime->control->avail_min) {
1979 					state = READY;
1980 					break;
1981 				}
1982 			}
1983 		       _end_loop:
1984 			remove_wait_queue(&runtime->sleep, &wait);
1985 
1986 			switch (state) {
1987 			case ERROR:
1988 				err = -EPIPE;
1989 				goto _end_unlock;
1990 			case SUSPENDED:
1991 				err = -ESTRPIPE;
1992 				goto _end_unlock;
1993 			case SIGNALED:
1994 				err = -ERESTARTSYS;
1995 				goto _end_unlock;
1996 			case EXPIRED:
1997 				snd_printd("capture read error (DMA or IRQ trouble?)\n");
1998 				err = -EIO;
1999 				goto _end_unlock;
2000 			case DROPPED:
2001 				err = -EBADFD;
2002 				goto _end_unlock;
2003 			default:
2004 				break;
2005 			}
2006 		}
2007 		if (avail > runtime->xfer_align)
2008 			avail -= avail % runtime->xfer_align;
2009 		frames = size > avail ? avail : size;
2010 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2011 		if (frames > cont)
2012 			frames = cont;
2013 		snd_assert(frames != 0, snd_pcm_stream_unlock_irq(substream); return -EINVAL);
2014 		appl_ptr = runtime->control->appl_ptr;
2015 		appl_ofs = appl_ptr % runtime->buffer_size;
2016 		snd_pcm_stream_unlock_irq(substream);
2017 		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
2018 			goto _end;
2019 		snd_pcm_stream_lock_irq(substream);
2020 		switch (runtime->status->state) {
2021 		case SNDRV_PCM_STATE_XRUN:
2022 			err = -EPIPE;
2023 			goto _end_unlock;
2024 		case SNDRV_PCM_STATE_SUSPENDED:
2025 			err = -ESTRPIPE;
2026 			goto _end_unlock;
2027 		default:
2028 			break;
2029 		}
2030 		appl_ptr += frames;
2031 		if (appl_ptr >= runtime->boundary)
2032 			appl_ptr -= runtime->boundary;
2033 		runtime->control->appl_ptr = appl_ptr;
2034 		if (substream->ops->ack)
2035 			substream->ops->ack(substream);
2036 
2037 		offset += frames;
2038 		size -= frames;
2039 		xfer += frames;
2040 		if (runtime->sleep_min &&
2041 		    runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2042 			snd_pcm_tick_prepare(substream);
2043 	}
2044  _end_unlock:
2045 	snd_pcm_stream_unlock_irq(substream);
2046  _end:
2047 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2048 }
2049 
2050 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2051 {
2052 	struct snd_pcm_runtime *runtime;
2053 	int nonblock;
2054 
2055 	snd_assert(substream != NULL, return -ENXIO);
2056 	runtime = substream->runtime;
2057 	snd_assert(runtime != NULL, return -ENXIO);
2058 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
2059 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2060 		return -EBADFD;
2061 
2062 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2063 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2064 		return -EINVAL;
2065 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2066 }
2067 
2068 EXPORT_SYMBOL(snd_pcm_lib_read);
2069 
2070 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2071 				      unsigned int hwoff,
2072 				      unsigned long data, unsigned int off,
2073 				      snd_pcm_uframes_t frames)
2074 {
2075 	struct snd_pcm_runtime *runtime = substream->runtime;
2076 	int err;
2077 	void __user **bufs = (void __user **)data;
2078 	int channels = runtime->channels;
2079 	int c;
2080 	if (substream->ops->copy) {
2081 		for (c = 0; c < channels; ++c, ++bufs) {
2082 			char __user *buf;
2083 			if (*bufs == NULL)
2084 				continue;
2085 			buf = *bufs + samples_to_bytes(runtime, off);
2086 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2087 				return err;
2088 		}
2089 	} else {
2090 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2091 		snd_assert(runtime->dma_area, return -EFAULT);
2092 		for (c = 0; c < channels; ++c, ++bufs) {
2093 			char *hwbuf;
2094 			char __user *buf;
2095 			if (*bufs == NULL)
2096 				continue;
2097 
2098 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2099 			buf = *bufs + samples_to_bytes(runtime, off);
2100 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2101 				return -EFAULT;
2102 		}
2103 	}
2104 	return 0;
2105 }
2106 
2107 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2108 				    void __user **bufs,
2109 				    snd_pcm_uframes_t frames)
2110 {
2111 	struct snd_pcm_runtime *runtime;
2112 	int nonblock;
2113 
2114 	snd_assert(substream != NULL, return -ENXIO);
2115 	runtime = substream->runtime;
2116 	snd_assert(runtime != NULL, return -ENXIO);
2117 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
2118 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2119 		return -EBADFD;
2120 
2121 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2122 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2123 		return -EINVAL;
2124 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2125 }
2126 
2127 EXPORT_SYMBOL(snd_pcm_lib_readv);
2128