xref: /linux/sound/core/pcm_lib.c (revision a7edd0e676d51145ae634a2acf7a447e319200fa)
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 = new_hw_ptr;
83 			} else {
84 				runtime->silence_start = ofs;
85 			}
86 		}
87 		frames = runtime->buffer_size - runtime->silence_filled;
88 	}
89 	snd_assert(frames <= runtime->buffer_size, return);
90 	if (frames == 0)
91 		return;
92 	ofs = runtime->silence_start % runtime->buffer_size;
93 	while (frames > 0) {
94 		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
95 		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
96 		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
97 			if (substream->ops->silence) {
98 				int err;
99 				err = substream->ops->silence(substream, -1, ofs, transfer);
100 				snd_assert(err >= 0, );
101 			} else {
102 				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
103 				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
104 			}
105 		} else {
106 			unsigned int c;
107 			unsigned int channels = runtime->channels;
108 			if (substream->ops->silence) {
109 				for (c = 0; c < channels; ++c) {
110 					int err;
111 					err = substream->ops->silence(substream, c, ofs, transfer);
112 					snd_assert(err >= 0, );
113 				}
114 			} else {
115 				size_t dma_csize = runtime->dma_bytes / channels;
116 				for (c = 0; c < channels; ++c) {
117 					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
118 					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
119 				}
120 			}
121 		}
122 		runtime->silence_filled += transfer;
123 		frames -= transfer;
124 		ofs = 0;
125 	}
126 }
127 
128 static void xrun(struct snd_pcm_substream *substream)
129 {
130 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
131 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
132 	if (substream->pstr->xrun_debug) {
133 		snd_printd(KERN_DEBUG "XRUN: pcmC%dD%d%c\n",
134 			   substream->pcm->card->number,
135 			   substream->pcm->device,
136 			   substream->stream ? 'c' : 'p');
137 		if (substream->pstr->xrun_debug > 1)
138 			dump_stack();
139 	}
140 #endif
141 }
142 
143 static inline snd_pcm_uframes_t snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
144 							  struct snd_pcm_runtime *runtime)
145 {
146 	snd_pcm_uframes_t pos;
147 
148 	pos = substream->ops->pointer(substream);
149 	if (pos == SNDRV_PCM_POS_XRUN)
150 		return pos; /* XRUN */
151 	if (runtime->tstamp_mode & SNDRV_PCM_TSTAMP_MMAP)
152 		getnstimeofday((struct timespec *)&runtime->status->tstamp);
153 #ifdef CONFIG_SND_DEBUG
154 	if (pos >= runtime->buffer_size) {
155 		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);
156 	}
157 #endif
158 	pos -= pos % runtime->min_align;
159 	return pos;
160 }
161 
162 static inline int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
163 					     struct snd_pcm_runtime *runtime)
164 {
165 	snd_pcm_uframes_t avail;
166 
167 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
168 		avail = snd_pcm_playback_avail(runtime);
169 	else
170 		avail = snd_pcm_capture_avail(runtime);
171 	if (avail > runtime->avail_max)
172 		runtime->avail_max = avail;
173 	if (avail >= runtime->stop_threshold) {
174 		if (substream->runtime->status->state == SNDRV_PCM_STATE_DRAINING)
175 			snd_pcm_drain_done(substream);
176 		else
177 			xrun(substream);
178 		return -EPIPE;
179 	}
180 	if (avail >= runtime->control->avail_min)
181 		wake_up(&runtime->sleep);
182 	return 0;
183 }
184 
185 static inline int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
186 {
187 	struct snd_pcm_runtime *runtime = substream->runtime;
188 	snd_pcm_uframes_t pos;
189 	snd_pcm_uframes_t new_hw_ptr, hw_ptr_interrupt;
190 	snd_pcm_sframes_t delta;
191 
192 	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
193 	if (pos == SNDRV_PCM_POS_XRUN) {
194 		xrun(substream);
195 		return -EPIPE;
196 	}
197 	if (runtime->period_size == runtime->buffer_size)
198 		goto __next_buf;
199 	new_hw_ptr = runtime->hw_ptr_base + pos;
200 	hw_ptr_interrupt = runtime->hw_ptr_interrupt + runtime->period_size;
201 
202 	delta = hw_ptr_interrupt - new_hw_ptr;
203 	if (delta > 0) {
204 		if ((snd_pcm_uframes_t)delta < runtime->buffer_size / 2) {
205 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
206 			if (runtime->periods > 1 && substream->pstr->xrun_debug) {
207 				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);
208 				if (substream->pstr->xrun_debug > 1)
209 					dump_stack();
210 			}
211 #endif
212 			return 0;
213 		}
214 	      __next_buf:
215 		runtime->hw_ptr_base += runtime->buffer_size;
216 		if (runtime->hw_ptr_base == runtime->boundary)
217 			runtime->hw_ptr_base = 0;
218 		new_hw_ptr = runtime->hw_ptr_base + pos;
219 	}
220 
221 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
222 	    runtime->silence_size > 0)
223 		snd_pcm_playback_silence(substream, new_hw_ptr);
224 
225 	runtime->status->hw_ptr = new_hw_ptr;
226 	runtime->hw_ptr_interrupt = new_hw_ptr - new_hw_ptr % runtime->period_size;
227 
228 	return snd_pcm_update_hw_ptr_post(substream, runtime);
229 }
230 
231 /* CAUTION: call it with irq disabled */
232 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
233 {
234 	struct snd_pcm_runtime *runtime = substream->runtime;
235 	snd_pcm_uframes_t pos;
236 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr;
237 	snd_pcm_sframes_t delta;
238 
239 	old_hw_ptr = runtime->status->hw_ptr;
240 	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
241 	if (pos == SNDRV_PCM_POS_XRUN) {
242 		xrun(substream);
243 		return -EPIPE;
244 	}
245 	new_hw_ptr = runtime->hw_ptr_base + pos;
246 
247 	delta = old_hw_ptr - new_hw_ptr;
248 	if (delta > 0) {
249 		if ((snd_pcm_uframes_t)delta < runtime->buffer_size / 2) {
250 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
251 			if (runtime->periods > 2 && substream->pstr->xrun_debug) {
252 				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);
253 				if (substream->pstr->xrun_debug > 1)
254 					dump_stack();
255 			}
256 #endif
257 			return 0;
258 		}
259 		runtime->hw_ptr_base += runtime->buffer_size;
260 		if (runtime->hw_ptr_base == runtime->boundary)
261 			runtime->hw_ptr_base = 0;
262 		new_hw_ptr = runtime->hw_ptr_base + pos;
263 	}
264 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
265 	    runtime->silence_size > 0)
266 		snd_pcm_playback_silence(substream, new_hw_ptr);
267 
268 	runtime->status->hw_ptr = new_hw_ptr;
269 
270 	return snd_pcm_update_hw_ptr_post(substream, runtime);
271 }
272 
273 /**
274  * snd_pcm_set_ops - set the PCM operators
275  * @pcm: the pcm instance
276  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
277  * @ops: the operator table
278  *
279  * Sets the given PCM operators to the pcm instance.
280  */
281 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, struct snd_pcm_ops *ops)
282 {
283 	struct snd_pcm_str *stream = &pcm->streams[direction];
284 	struct snd_pcm_substream *substream;
285 
286 	for (substream = stream->substream; substream != NULL; substream = substream->next)
287 		substream->ops = ops;
288 }
289 
290 EXPORT_SYMBOL(snd_pcm_set_ops);
291 
292 /**
293  * snd_pcm_sync - set the PCM sync id
294  * @substream: the pcm substream
295  *
296  * Sets the PCM sync identifier for the card.
297  */
298 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
299 {
300 	struct snd_pcm_runtime *runtime = substream->runtime;
301 
302 	runtime->sync.id32[0] = substream->pcm->card->number;
303 	runtime->sync.id32[1] = -1;
304 	runtime->sync.id32[2] = -1;
305 	runtime->sync.id32[3] = -1;
306 }
307 
308 EXPORT_SYMBOL(snd_pcm_set_sync);
309 
310 /*
311  *  Standard ioctl routine
312  */
313 
314 static inline unsigned int div32(unsigned int a, unsigned int b,
315 				 unsigned int *r)
316 {
317 	if (b == 0) {
318 		*r = 0;
319 		return UINT_MAX;
320 	}
321 	*r = a % b;
322 	return a / b;
323 }
324 
325 static inline unsigned int div_down(unsigned int a, unsigned int b)
326 {
327 	if (b == 0)
328 		return UINT_MAX;
329 	return a / b;
330 }
331 
332 static inline unsigned int div_up(unsigned int a, unsigned int b)
333 {
334 	unsigned int r;
335 	unsigned int q;
336 	if (b == 0)
337 		return UINT_MAX;
338 	q = div32(a, b, &r);
339 	if (r)
340 		++q;
341 	return q;
342 }
343 
344 static inline unsigned int mul(unsigned int a, unsigned int b)
345 {
346 	if (a == 0)
347 		return 0;
348 	if (div_down(UINT_MAX, a) < b)
349 		return UINT_MAX;
350 	return a * b;
351 }
352 
353 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
354 				    unsigned int c, unsigned int *r)
355 {
356 	u_int64_t n = (u_int64_t) a * b;
357 	if (c == 0) {
358 		snd_assert(n > 0, );
359 		*r = 0;
360 		return UINT_MAX;
361 	}
362 	div64_32(&n, c, r);
363 	if (n >= UINT_MAX) {
364 		*r = 0;
365 		return UINT_MAX;
366 	}
367 	return n;
368 }
369 
370 /**
371  * snd_interval_refine - refine the interval value of configurator
372  * @i: the interval value to refine
373  * @v: the interval value to refer to
374  *
375  * Refines the interval value with the reference value.
376  * The interval is changed to the range satisfying both intervals.
377  * The interval status (min, max, integer, etc.) are evaluated.
378  *
379  * Returns non-zero if the value is changed, zero if not changed.
380  */
381 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
382 {
383 	int changed = 0;
384 	snd_assert(!snd_interval_empty(i), return -EINVAL);
385 	if (i->min < v->min) {
386 		i->min = v->min;
387 		i->openmin = v->openmin;
388 		changed = 1;
389 	} else if (i->min == v->min && !i->openmin && v->openmin) {
390 		i->openmin = 1;
391 		changed = 1;
392 	}
393 	if (i->max > v->max) {
394 		i->max = v->max;
395 		i->openmax = v->openmax;
396 		changed = 1;
397 	} else if (i->max == v->max && !i->openmax && v->openmax) {
398 		i->openmax = 1;
399 		changed = 1;
400 	}
401 	if (!i->integer && v->integer) {
402 		i->integer = 1;
403 		changed = 1;
404 	}
405 	if (i->integer) {
406 		if (i->openmin) {
407 			i->min++;
408 			i->openmin = 0;
409 		}
410 		if (i->openmax) {
411 			i->max--;
412 			i->openmax = 0;
413 		}
414 	} else if (!i->openmin && !i->openmax && i->min == i->max)
415 		i->integer = 1;
416 	if (snd_interval_checkempty(i)) {
417 		snd_interval_none(i);
418 		return -EINVAL;
419 	}
420 	return changed;
421 }
422 
423 EXPORT_SYMBOL(snd_interval_refine);
424 
425 static int snd_interval_refine_first(struct snd_interval *i)
426 {
427 	snd_assert(!snd_interval_empty(i), return -EINVAL);
428 	if (snd_interval_single(i))
429 		return 0;
430 	i->max = i->min;
431 	i->openmax = i->openmin;
432 	if (i->openmax)
433 		i->max++;
434 	return 1;
435 }
436 
437 static int snd_interval_refine_last(struct snd_interval *i)
438 {
439 	snd_assert(!snd_interval_empty(i), return -EINVAL);
440 	if (snd_interval_single(i))
441 		return 0;
442 	i->min = i->max;
443 	i->openmin = i->openmax;
444 	if (i->openmin)
445 		i->min--;
446 	return 1;
447 }
448 
449 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
450 {
451 	if (a->empty || b->empty) {
452 		snd_interval_none(c);
453 		return;
454 	}
455 	c->empty = 0;
456 	c->min = mul(a->min, b->min);
457 	c->openmin = (a->openmin || b->openmin);
458 	c->max = mul(a->max,  b->max);
459 	c->openmax = (a->openmax || b->openmax);
460 	c->integer = (a->integer && b->integer);
461 }
462 
463 /**
464  * snd_interval_div - refine the interval value with division
465  * @a: dividend
466  * @b: divisor
467  * @c: quotient
468  *
469  * c = a / b
470  *
471  * Returns non-zero if the value is changed, zero if not changed.
472  */
473 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
474 {
475 	unsigned int r;
476 	if (a->empty || b->empty) {
477 		snd_interval_none(c);
478 		return;
479 	}
480 	c->empty = 0;
481 	c->min = div32(a->min, b->max, &r);
482 	c->openmin = (r || a->openmin || b->openmax);
483 	if (b->min > 0) {
484 		c->max = div32(a->max, b->min, &r);
485 		if (r) {
486 			c->max++;
487 			c->openmax = 1;
488 		} else
489 			c->openmax = (a->openmax || b->openmin);
490 	} else {
491 		c->max = UINT_MAX;
492 		c->openmax = 0;
493 	}
494 	c->integer = 0;
495 }
496 
497 /**
498  * snd_interval_muldivk - refine the interval value
499  * @a: dividend 1
500  * @b: dividend 2
501  * @k: divisor (as integer)
502  * @c: result
503   *
504  * c = a * b / k
505  *
506  * Returns non-zero if the value is changed, zero if not changed.
507  */
508 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
509 		      unsigned int k, struct snd_interval *c)
510 {
511 	unsigned int r;
512 	if (a->empty || b->empty) {
513 		snd_interval_none(c);
514 		return;
515 	}
516 	c->empty = 0;
517 	c->min = muldiv32(a->min, b->min, k, &r);
518 	c->openmin = (r || a->openmin || b->openmin);
519 	c->max = muldiv32(a->max, b->max, k, &r);
520 	if (r) {
521 		c->max++;
522 		c->openmax = 1;
523 	} else
524 		c->openmax = (a->openmax || b->openmax);
525 	c->integer = 0;
526 }
527 
528 /**
529  * snd_interval_mulkdiv - refine the interval value
530  * @a: dividend 1
531  * @k: dividend 2 (as integer)
532  * @b: divisor
533  * @c: result
534  *
535  * c = a * k / b
536  *
537  * Returns non-zero if the value is changed, zero if not changed.
538  */
539 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
540 		      const struct snd_interval *b, struct snd_interval *c)
541 {
542 	unsigned int r;
543 	if (a->empty || b->empty) {
544 		snd_interval_none(c);
545 		return;
546 	}
547 	c->empty = 0;
548 	c->min = muldiv32(a->min, k, b->max, &r);
549 	c->openmin = (r || a->openmin || b->openmax);
550 	if (b->min > 0) {
551 		c->max = muldiv32(a->max, k, b->min, &r);
552 		if (r) {
553 			c->max++;
554 			c->openmax = 1;
555 		} else
556 			c->openmax = (a->openmax || b->openmin);
557 	} else {
558 		c->max = UINT_MAX;
559 		c->openmax = 0;
560 	}
561 	c->integer = 0;
562 }
563 
564 /* ---- */
565 
566 
567 /**
568  * snd_interval_ratnum - refine the interval value
569  * @i: interval to refine
570  * @rats_count: number of ratnum_t
571  * @rats: ratnum_t array
572  * @nump: pointer to store the resultant numerator
573  * @denp: pointer to store the resultant denominator
574  *
575  * Returns non-zero if the value is changed, zero if not changed.
576  */
577 int snd_interval_ratnum(struct snd_interval *i,
578 			unsigned int rats_count, struct snd_ratnum *rats,
579 			unsigned int *nump, unsigned int *denp)
580 {
581 	unsigned int best_num, best_diff, best_den;
582 	unsigned int k;
583 	struct snd_interval t;
584 	int err;
585 
586 	best_num = best_den = best_diff = 0;
587 	for (k = 0; k < rats_count; ++k) {
588 		unsigned int num = rats[k].num;
589 		unsigned int den;
590 		unsigned int q = i->min;
591 		int diff;
592 		if (q == 0)
593 			q = 1;
594 		den = div_down(num, q);
595 		if (den < rats[k].den_min)
596 			continue;
597 		if (den > rats[k].den_max)
598 			den = rats[k].den_max;
599 		else {
600 			unsigned int r;
601 			r = (den - rats[k].den_min) % rats[k].den_step;
602 			if (r != 0)
603 				den -= r;
604 		}
605 		diff = num - q * den;
606 		if (best_num == 0 ||
607 		    diff * best_den < best_diff * den) {
608 			best_diff = diff;
609 			best_den = den;
610 			best_num = num;
611 		}
612 	}
613 	if (best_den == 0) {
614 		i->empty = 1;
615 		return -EINVAL;
616 	}
617 	t.min = div_down(best_num, best_den);
618 	t.openmin = !!(best_num % best_den);
619 
620 	best_num = best_den = best_diff = 0;
621 	for (k = 0; k < rats_count; ++k) {
622 		unsigned int num = rats[k].num;
623 		unsigned int den;
624 		unsigned int q = i->max;
625 		int diff;
626 		if (q == 0) {
627 			i->empty = 1;
628 			return -EINVAL;
629 		}
630 		den = div_up(num, q);
631 		if (den > rats[k].den_max)
632 			continue;
633 		if (den < rats[k].den_min)
634 			den = rats[k].den_min;
635 		else {
636 			unsigned int r;
637 			r = (den - rats[k].den_min) % rats[k].den_step;
638 			if (r != 0)
639 				den += rats[k].den_step - r;
640 		}
641 		diff = q * den - num;
642 		if (best_num == 0 ||
643 		    diff * best_den < best_diff * den) {
644 			best_diff = diff;
645 			best_den = den;
646 			best_num = num;
647 		}
648 	}
649 	if (best_den == 0) {
650 		i->empty = 1;
651 		return -EINVAL;
652 	}
653 	t.max = div_up(best_num, best_den);
654 	t.openmax = !!(best_num % best_den);
655 	t.integer = 0;
656 	err = snd_interval_refine(i, &t);
657 	if (err < 0)
658 		return err;
659 
660 	if (snd_interval_single(i)) {
661 		if (nump)
662 			*nump = best_num;
663 		if (denp)
664 			*denp = best_den;
665 	}
666 	return err;
667 }
668 
669 EXPORT_SYMBOL(snd_interval_ratnum);
670 
671 /**
672  * snd_interval_ratden - refine the interval value
673  * @i: interval to refine
674  * @rats_count: number of struct ratden
675  * @rats: struct ratden array
676  * @nump: pointer to store the resultant numerator
677  * @denp: pointer to store the resultant denominator
678  *
679  * Returns non-zero if the value is changed, zero if not changed.
680  */
681 static int snd_interval_ratden(struct snd_interval *i,
682 			       unsigned int rats_count, struct snd_ratden *rats,
683 			       unsigned int *nump, unsigned int *denp)
684 {
685 	unsigned int best_num, best_diff, best_den;
686 	unsigned int k;
687 	struct snd_interval t;
688 	int err;
689 
690 	best_num = best_den = best_diff = 0;
691 	for (k = 0; k < rats_count; ++k) {
692 		unsigned int num;
693 		unsigned int den = rats[k].den;
694 		unsigned int q = i->min;
695 		int diff;
696 		num = mul(q, den);
697 		if (num > rats[k].num_max)
698 			continue;
699 		if (num < rats[k].num_min)
700 			num = rats[k].num_max;
701 		else {
702 			unsigned int r;
703 			r = (num - rats[k].num_min) % rats[k].num_step;
704 			if (r != 0)
705 				num += rats[k].num_step - r;
706 		}
707 		diff = num - q * den;
708 		if (best_num == 0 ||
709 		    diff * best_den < best_diff * den) {
710 			best_diff = diff;
711 			best_den = den;
712 			best_num = num;
713 		}
714 	}
715 	if (best_den == 0) {
716 		i->empty = 1;
717 		return -EINVAL;
718 	}
719 	t.min = div_down(best_num, best_den);
720 	t.openmin = !!(best_num % best_den);
721 
722 	best_num = best_den = best_diff = 0;
723 	for (k = 0; k < rats_count; ++k) {
724 		unsigned int num;
725 		unsigned int den = rats[k].den;
726 		unsigned int q = i->max;
727 		int diff;
728 		num = mul(q, den);
729 		if (num < rats[k].num_min)
730 			continue;
731 		if (num > rats[k].num_max)
732 			num = rats[k].num_max;
733 		else {
734 			unsigned int r;
735 			r = (num - rats[k].num_min) % rats[k].num_step;
736 			if (r != 0)
737 				num -= r;
738 		}
739 		diff = q * den - num;
740 		if (best_num == 0 ||
741 		    diff * best_den < best_diff * den) {
742 			best_diff = diff;
743 			best_den = den;
744 			best_num = num;
745 		}
746 	}
747 	if (best_den == 0) {
748 		i->empty = 1;
749 		return -EINVAL;
750 	}
751 	t.max = div_up(best_num, best_den);
752 	t.openmax = !!(best_num % best_den);
753 	t.integer = 0;
754 	err = snd_interval_refine(i, &t);
755 	if (err < 0)
756 		return err;
757 
758 	if (snd_interval_single(i)) {
759 		if (nump)
760 			*nump = best_num;
761 		if (denp)
762 			*denp = best_den;
763 	}
764 	return err;
765 }
766 
767 /**
768  * snd_interval_list - refine the interval value from the list
769  * @i: the interval value to refine
770  * @count: the number of elements in the list
771  * @list: the value list
772  * @mask: the bit-mask to evaluate
773  *
774  * Refines the interval value from the list.
775  * When mask is non-zero, only the elements corresponding to bit 1 are
776  * evaluated.
777  *
778  * Returns non-zero if the value is changed, zero if not changed.
779  */
780 int snd_interval_list(struct snd_interval *i, unsigned int count, unsigned int *list, unsigned int mask)
781 {
782         unsigned int k;
783 	int changed = 0;
784 
785 	if (!count) {
786 		i->empty = 1;
787 		return -EINVAL;
788 	}
789         for (k = 0; k < count; k++) {
790 		if (mask && !(mask & (1 << k)))
791 			continue;
792                 if (i->min == list[k] && !i->openmin)
793                         goto _l1;
794                 if (i->min < list[k]) {
795                         i->min = list[k];
796 			i->openmin = 0;
797 			changed = 1;
798                         goto _l1;
799                 }
800         }
801         i->empty = 1;
802         return -EINVAL;
803  _l1:
804         for (k = count; k-- > 0;) {
805 		if (mask && !(mask & (1 << k)))
806 			continue;
807                 if (i->max == list[k] && !i->openmax)
808                         goto _l2;
809                 if (i->max > list[k]) {
810                         i->max = list[k];
811 			i->openmax = 0;
812 			changed = 1;
813                         goto _l2;
814                 }
815         }
816         i->empty = 1;
817         return -EINVAL;
818  _l2:
819 	if (snd_interval_checkempty(i)) {
820 		i->empty = 1;
821 		return -EINVAL;
822 	}
823         return changed;
824 }
825 
826 EXPORT_SYMBOL(snd_interval_list);
827 
828 static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned int step)
829 {
830 	unsigned int n;
831 	int changed = 0;
832 	n = (i->min - min) % step;
833 	if (n != 0 || i->openmin) {
834 		i->min += step - n;
835 		changed = 1;
836 	}
837 	n = (i->max - min) % step;
838 	if (n != 0 || i->openmax) {
839 		i->max -= n;
840 		changed = 1;
841 	}
842 	if (snd_interval_checkempty(i)) {
843 		i->empty = 1;
844 		return -EINVAL;
845 	}
846 	return changed;
847 }
848 
849 /* Info constraints helpers */
850 
851 /**
852  * snd_pcm_hw_rule_add - add the hw-constraint rule
853  * @runtime: the pcm runtime instance
854  * @cond: condition bits
855  * @var: the variable to evaluate
856  * @func: the evaluation function
857  * @private: the private data pointer passed to function
858  * @dep: the dependent variables
859  *
860  * Returns zero if successful, or a negative error code on failure.
861  */
862 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
863 			int var,
864 			snd_pcm_hw_rule_func_t func, void *private,
865 			int dep, ...)
866 {
867 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
868 	struct snd_pcm_hw_rule *c;
869 	unsigned int k;
870 	va_list args;
871 	va_start(args, dep);
872 	if (constrs->rules_num >= constrs->rules_all) {
873 		struct snd_pcm_hw_rule *new;
874 		unsigned int new_rules = constrs->rules_all + 16;
875 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
876 		if (!new)
877 			return -ENOMEM;
878 		if (constrs->rules) {
879 			memcpy(new, constrs->rules,
880 			       constrs->rules_num * sizeof(*c));
881 			kfree(constrs->rules);
882 		}
883 		constrs->rules = new;
884 		constrs->rules_all = new_rules;
885 	}
886 	c = &constrs->rules[constrs->rules_num];
887 	c->cond = cond;
888 	c->func = func;
889 	c->var = var;
890 	c->private = private;
891 	k = 0;
892 	while (1) {
893 		snd_assert(k < ARRAY_SIZE(c->deps), return -EINVAL);
894 		c->deps[k++] = dep;
895 		if (dep < 0)
896 			break;
897 		dep = va_arg(args, int);
898 	}
899 	constrs->rules_num++;
900 	va_end(args);
901 	return 0;
902 }
903 
904 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
905 
906 /**
907  * snd_pcm_hw_constraint_mask
908  * @runtime: PCM runtime instance
909  * @var: hw_params variable to apply the mask
910  * @mask: the bitmap mask
911  *
912  * Apply the constraint of the given bitmap mask to a mask parameter.
913  */
914 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
915 			       u_int32_t mask)
916 {
917 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
918 	struct snd_mask *maskp = constrs_mask(constrs, var);
919 	*maskp->bits &= mask;
920 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
921 	if (*maskp->bits == 0)
922 		return -EINVAL;
923 	return 0;
924 }
925 
926 /**
927  * snd_pcm_hw_constraint_mask64
928  * @runtime: PCM runtime instance
929  * @var: hw_params variable to apply the mask
930  * @mask: the 64bit bitmap mask
931  *
932  * Apply the constraint of the given bitmap mask to a mask parameter.
933  */
934 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
935 				 u_int64_t mask)
936 {
937 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
938 	struct snd_mask *maskp = constrs_mask(constrs, var);
939 	maskp->bits[0] &= (u_int32_t)mask;
940 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
941 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
942 	if (! maskp->bits[0] && ! maskp->bits[1])
943 		return -EINVAL;
944 	return 0;
945 }
946 
947 /**
948  * snd_pcm_hw_constraint_integer
949  * @runtime: PCM runtime instance
950  * @var: hw_params variable to apply the integer constraint
951  *
952  * Apply the constraint of integer to an interval parameter.
953  */
954 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
955 {
956 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
957 	return snd_interval_setinteger(constrs_interval(constrs, var));
958 }
959 
960 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
961 
962 /**
963  * snd_pcm_hw_constraint_minmax
964  * @runtime: PCM runtime instance
965  * @var: hw_params variable to apply the range
966  * @min: the minimal value
967  * @max: the maximal value
968  *
969  * Apply the min/max range constraint to an interval parameter.
970  */
971 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
972 				 unsigned int min, unsigned int max)
973 {
974 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
975 	struct snd_interval t;
976 	t.min = min;
977 	t.max = max;
978 	t.openmin = t.openmax = 0;
979 	t.integer = 0;
980 	return snd_interval_refine(constrs_interval(constrs, var), &t);
981 }
982 
983 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
984 
985 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
986 				struct snd_pcm_hw_rule *rule)
987 {
988 	struct snd_pcm_hw_constraint_list *list = rule->private;
989 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
990 }
991 
992 
993 /**
994  * snd_pcm_hw_constraint_list
995  * @runtime: PCM runtime instance
996  * @cond: condition bits
997  * @var: hw_params variable to apply the list constraint
998  * @l: list
999  *
1000  * Apply the list of constraints to an interval parameter.
1001  */
1002 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1003 			       unsigned int cond,
1004 			       snd_pcm_hw_param_t var,
1005 			       struct snd_pcm_hw_constraint_list *l)
1006 {
1007 	return snd_pcm_hw_rule_add(runtime, cond, var,
1008 				   snd_pcm_hw_rule_list, l,
1009 				   var, -1);
1010 }
1011 
1012 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1013 
1014 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1015 				   struct snd_pcm_hw_rule *rule)
1016 {
1017 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1018 	unsigned int num = 0, den = 0;
1019 	int err;
1020 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1021 				  r->nrats, r->rats, &num, &den);
1022 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1023 		params->rate_num = num;
1024 		params->rate_den = den;
1025 	}
1026 	return err;
1027 }
1028 
1029 /**
1030  * snd_pcm_hw_constraint_ratnums
1031  * @runtime: PCM runtime instance
1032  * @cond: condition bits
1033  * @var: hw_params variable to apply the ratnums constraint
1034  * @r: struct snd_ratnums constriants
1035  */
1036 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1037 				  unsigned int cond,
1038 				  snd_pcm_hw_param_t var,
1039 				  struct snd_pcm_hw_constraint_ratnums *r)
1040 {
1041 	return snd_pcm_hw_rule_add(runtime, cond, var,
1042 				   snd_pcm_hw_rule_ratnums, r,
1043 				   var, -1);
1044 }
1045 
1046 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1047 
1048 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1049 				   struct snd_pcm_hw_rule *rule)
1050 {
1051 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1052 	unsigned int num = 0, den = 0;
1053 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1054 				  r->nrats, r->rats, &num, &den);
1055 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1056 		params->rate_num = num;
1057 		params->rate_den = den;
1058 	}
1059 	return err;
1060 }
1061 
1062 /**
1063  * snd_pcm_hw_constraint_ratdens
1064  * @runtime: PCM runtime instance
1065  * @cond: condition bits
1066  * @var: hw_params variable to apply the ratdens constraint
1067  * @r: struct snd_ratdens constriants
1068  */
1069 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1070 				  unsigned int cond,
1071 				  snd_pcm_hw_param_t var,
1072 				  struct snd_pcm_hw_constraint_ratdens *r)
1073 {
1074 	return snd_pcm_hw_rule_add(runtime, cond, var,
1075 				   snd_pcm_hw_rule_ratdens, r,
1076 				   var, -1);
1077 }
1078 
1079 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1080 
1081 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1082 				  struct snd_pcm_hw_rule *rule)
1083 {
1084 	unsigned int l = (unsigned long) rule->private;
1085 	int width = l & 0xffff;
1086 	unsigned int msbits = l >> 16;
1087 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1088 	if (snd_interval_single(i) && snd_interval_value(i) == width)
1089 		params->msbits = msbits;
1090 	return 0;
1091 }
1092 
1093 /**
1094  * snd_pcm_hw_constraint_msbits
1095  * @runtime: PCM runtime instance
1096  * @cond: condition bits
1097  * @width: sample bits width
1098  * @msbits: msbits width
1099  */
1100 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1101 				 unsigned int cond,
1102 				 unsigned int width,
1103 				 unsigned int msbits)
1104 {
1105 	unsigned long l = (msbits << 16) | width;
1106 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1107 				    snd_pcm_hw_rule_msbits,
1108 				    (void*) l,
1109 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1110 }
1111 
1112 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1113 
1114 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1115 				struct snd_pcm_hw_rule *rule)
1116 {
1117 	unsigned long step = (unsigned long) rule->private;
1118 	return snd_interval_step(hw_param_interval(params, rule->var), 0, step);
1119 }
1120 
1121 /**
1122  * snd_pcm_hw_constraint_step
1123  * @runtime: PCM runtime instance
1124  * @cond: condition bits
1125  * @var: hw_params variable to apply the step constraint
1126  * @step: step size
1127  */
1128 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1129 			       unsigned int cond,
1130 			       snd_pcm_hw_param_t var,
1131 			       unsigned long step)
1132 {
1133 	return snd_pcm_hw_rule_add(runtime, cond, var,
1134 				   snd_pcm_hw_rule_step, (void *) step,
1135 				   var, -1);
1136 }
1137 
1138 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1139 
1140 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1141 {
1142 	static int pow2_sizes[] = {
1143 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1144 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1145 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1146 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1147 	};
1148 	return snd_interval_list(hw_param_interval(params, rule->var),
1149 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1150 }
1151 
1152 /**
1153  * snd_pcm_hw_constraint_pow2
1154  * @runtime: PCM runtime instance
1155  * @cond: condition bits
1156  * @var: hw_params variable to apply the power-of-2 constraint
1157  */
1158 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1159 			       unsigned int cond,
1160 			       snd_pcm_hw_param_t var)
1161 {
1162 	return snd_pcm_hw_rule_add(runtime, cond, var,
1163 				   snd_pcm_hw_rule_pow2, NULL,
1164 				   var, -1);
1165 }
1166 
1167 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1168 
1169 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1170 				  snd_pcm_hw_param_t var)
1171 {
1172 	if (hw_is_mask(var)) {
1173 		snd_mask_any(hw_param_mask(params, var));
1174 		params->cmask |= 1 << var;
1175 		params->rmask |= 1 << var;
1176 		return;
1177 	}
1178 	if (hw_is_interval(var)) {
1179 		snd_interval_any(hw_param_interval(params, var));
1180 		params->cmask |= 1 << var;
1181 		params->rmask |= 1 << var;
1182 		return;
1183 	}
1184 	snd_BUG();
1185 }
1186 
1187 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1188 {
1189 	unsigned int k;
1190 	memset(params, 0, sizeof(*params));
1191 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1192 		_snd_pcm_hw_param_any(params, k);
1193 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1194 		_snd_pcm_hw_param_any(params, k);
1195 	params->info = ~0U;
1196 }
1197 
1198 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1199 
1200 /**
1201  * snd_pcm_hw_param_value
1202  * @params: the hw_params instance
1203  * @var: parameter to retrieve
1204  * @dir: pointer to the direction (-1,0,1) or NULL
1205  *
1206  * Return the value for field PAR if it's fixed in configuration space
1207  *  defined by PARAMS. Return -EINVAL otherwise
1208  */
1209 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1210 			   snd_pcm_hw_param_t var, int *dir)
1211 {
1212 	if (hw_is_mask(var)) {
1213 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1214 		if (!snd_mask_single(mask))
1215 			return -EINVAL;
1216 		if (dir)
1217 			*dir = 0;
1218 		return snd_mask_value(mask);
1219 	}
1220 	if (hw_is_interval(var)) {
1221 		const struct snd_interval *i = hw_param_interval_c(params, var);
1222 		if (!snd_interval_single(i))
1223 			return -EINVAL;
1224 		if (dir)
1225 			*dir = i->openmin;
1226 		return snd_interval_value(i);
1227 	}
1228 	return -EINVAL;
1229 }
1230 
1231 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1232 
1233 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1234 				snd_pcm_hw_param_t var)
1235 {
1236 	if (hw_is_mask(var)) {
1237 		snd_mask_none(hw_param_mask(params, var));
1238 		params->cmask |= 1 << var;
1239 		params->rmask |= 1 << var;
1240 	} else if (hw_is_interval(var)) {
1241 		snd_interval_none(hw_param_interval(params, var));
1242 		params->cmask |= 1 << var;
1243 		params->rmask |= 1 << var;
1244 	} else {
1245 		snd_BUG();
1246 	}
1247 }
1248 
1249 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1250 
1251 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1252 				   snd_pcm_hw_param_t var)
1253 {
1254 	int changed;
1255 	if (hw_is_mask(var))
1256 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1257 	else if (hw_is_interval(var))
1258 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1259 	else
1260 		return -EINVAL;
1261 	if (changed) {
1262 		params->cmask |= 1 << var;
1263 		params->rmask |= 1 << var;
1264 	}
1265 	return changed;
1266 }
1267 
1268 
1269 /**
1270  * snd_pcm_hw_param_first
1271  * @pcm: PCM instance
1272  * @params: the hw_params instance
1273  * @var: parameter to retrieve
1274  * @dir: pointer to the direction (-1,0,1) or NULL
1275  *
1276  * Inside configuration space defined by PARAMS remove from PAR all
1277  * values > minimum. Reduce configuration space accordingly.
1278  * Return the minimum.
1279  */
1280 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1281 			   struct snd_pcm_hw_params *params,
1282 			   snd_pcm_hw_param_t var, int *dir)
1283 {
1284 	int changed = _snd_pcm_hw_param_first(params, var);
1285 	if (changed < 0)
1286 		return changed;
1287 	if (params->rmask) {
1288 		int err = snd_pcm_hw_refine(pcm, params);
1289 		snd_assert(err >= 0, return err);
1290 	}
1291 	return snd_pcm_hw_param_value(params, var, dir);
1292 }
1293 
1294 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1295 
1296 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1297 				  snd_pcm_hw_param_t var)
1298 {
1299 	int changed;
1300 	if (hw_is_mask(var))
1301 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1302 	else if (hw_is_interval(var))
1303 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1304 	else
1305 		return -EINVAL;
1306 	if (changed) {
1307 		params->cmask |= 1 << var;
1308 		params->rmask |= 1 << var;
1309 	}
1310 	return changed;
1311 }
1312 
1313 
1314 /**
1315  * snd_pcm_hw_param_last
1316  * @pcm: PCM instance
1317  * @params: the hw_params instance
1318  * @var: parameter to retrieve
1319  * @dir: pointer to the direction (-1,0,1) or NULL
1320  *
1321  * Inside configuration space defined by PARAMS remove from PAR all
1322  * values < maximum. Reduce configuration space accordingly.
1323  * Return the maximum.
1324  */
1325 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1326 			  struct snd_pcm_hw_params *params,
1327 			  snd_pcm_hw_param_t var, int *dir)
1328 {
1329 	int changed = _snd_pcm_hw_param_last(params, var);
1330 	if (changed < 0)
1331 		return changed;
1332 	if (params->rmask) {
1333 		int err = snd_pcm_hw_refine(pcm, params);
1334 		snd_assert(err >= 0, return err);
1335 	}
1336 	return snd_pcm_hw_param_value(params, var, dir);
1337 }
1338 
1339 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1340 
1341 /**
1342  * snd_pcm_hw_param_choose
1343  * @pcm: PCM instance
1344  * @params: the hw_params instance
1345  *
1346  * Choose one configuration from configuration space defined by PARAMS
1347  * The configuration chosen is that obtained fixing in this order:
1348  * first access, first format, first subformat, min channels,
1349  * min rate, min period time, max buffer size, min tick time
1350  */
1351 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1352 			     struct snd_pcm_hw_params *params)
1353 {
1354 	static int vars[] = {
1355 		SNDRV_PCM_HW_PARAM_ACCESS,
1356 		SNDRV_PCM_HW_PARAM_FORMAT,
1357 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1358 		SNDRV_PCM_HW_PARAM_CHANNELS,
1359 		SNDRV_PCM_HW_PARAM_RATE,
1360 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1361 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1362 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1363 		-1
1364 	};
1365 	int err, *v;
1366 
1367 	for (v = vars; *v != -1; v++) {
1368 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1369 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1370 		else
1371 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1372 		snd_assert(err >= 0, return err);
1373 	}
1374 	return 0;
1375 }
1376 
1377 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1378 				   void *arg)
1379 {
1380 	struct snd_pcm_runtime *runtime = substream->runtime;
1381 	unsigned long flags;
1382 	snd_pcm_stream_lock_irqsave(substream, flags);
1383 	if (snd_pcm_running(substream) &&
1384 	    snd_pcm_update_hw_ptr(substream) >= 0)
1385 		runtime->status->hw_ptr %= runtime->buffer_size;
1386 	else
1387 		runtime->status->hw_ptr = 0;
1388 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1389 	return 0;
1390 }
1391 
1392 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1393 					  void *arg)
1394 {
1395 	struct snd_pcm_channel_info *info = arg;
1396 	struct snd_pcm_runtime *runtime = substream->runtime;
1397 	int width;
1398 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1399 		info->offset = -1;
1400 		return 0;
1401 	}
1402 	width = snd_pcm_format_physical_width(runtime->format);
1403 	if (width < 0)
1404 		return width;
1405 	info->offset = 0;
1406 	switch (runtime->access) {
1407 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1408 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1409 		info->first = info->channel * width;
1410 		info->step = runtime->channels * width;
1411 		break;
1412 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1413 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1414 	{
1415 		size_t size = runtime->dma_bytes / runtime->channels;
1416 		info->first = info->channel * size * 8;
1417 		info->step = width;
1418 		break;
1419 	}
1420 	default:
1421 		snd_BUG();
1422 		break;
1423 	}
1424 	return 0;
1425 }
1426 
1427 /**
1428  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1429  * @substream: the pcm substream instance
1430  * @cmd: ioctl command
1431  * @arg: ioctl argument
1432  *
1433  * Processes the generic ioctl commands for PCM.
1434  * Can be passed as the ioctl callback for PCM ops.
1435  *
1436  * Returns zero if successful, or a negative error code on failure.
1437  */
1438 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1439 		      unsigned int cmd, void *arg)
1440 {
1441 	switch (cmd) {
1442 	case SNDRV_PCM_IOCTL1_INFO:
1443 		return 0;
1444 	case SNDRV_PCM_IOCTL1_RESET:
1445 		return snd_pcm_lib_ioctl_reset(substream, arg);
1446 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1447 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1448 	}
1449 	return -ENXIO;
1450 }
1451 
1452 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1453 
1454 /*
1455  *  Conditions
1456  */
1457 
1458 static void snd_pcm_system_tick_set(struct snd_pcm_substream *substream,
1459 				    unsigned long ticks)
1460 {
1461 	struct snd_pcm_runtime *runtime = substream->runtime;
1462 	if (ticks == 0)
1463 		del_timer(&runtime->tick_timer);
1464 	else {
1465 		ticks += (1000000 / HZ) - 1;
1466 		ticks /= (1000000 / HZ);
1467 		mod_timer(&runtime->tick_timer, jiffies + ticks);
1468 	}
1469 }
1470 
1471 /* Temporary alias */
1472 void snd_pcm_tick_set(struct snd_pcm_substream *substream, unsigned long ticks)
1473 {
1474 	snd_pcm_system_tick_set(substream, ticks);
1475 }
1476 
1477 void snd_pcm_tick_prepare(struct snd_pcm_substream *substream)
1478 {
1479 	struct snd_pcm_runtime *runtime = substream->runtime;
1480 	snd_pcm_uframes_t frames = ULONG_MAX;
1481 	snd_pcm_uframes_t avail, dist;
1482 	unsigned int ticks;
1483 	u_int64_t n;
1484 	u_int32_t r;
1485 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
1486 		if (runtime->silence_size >= runtime->boundary) {
1487 			frames = 1;
1488 		} else if (runtime->silence_size > 0 &&
1489 			   runtime->silence_filled < runtime->buffer_size) {
1490 			snd_pcm_sframes_t noise_dist;
1491 			noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
1492 			if (noise_dist > (snd_pcm_sframes_t)runtime->silence_threshold)
1493 				frames = noise_dist - runtime->silence_threshold;
1494 		}
1495 		avail = snd_pcm_playback_avail(runtime);
1496 	} else {
1497 		avail = snd_pcm_capture_avail(runtime);
1498 	}
1499 	if (avail < runtime->control->avail_min) {
1500 		snd_pcm_sframes_t n = runtime->control->avail_min - avail;
1501 		if (n > 0 && frames > (snd_pcm_uframes_t)n)
1502 			frames = n;
1503 	}
1504 	if (avail < runtime->buffer_size) {
1505 		snd_pcm_sframes_t n = runtime->buffer_size - avail;
1506 		if (n > 0 && frames > (snd_pcm_uframes_t)n)
1507 			frames = n;
1508 	}
1509 	if (frames == ULONG_MAX) {
1510 		snd_pcm_tick_set(substream, 0);
1511 		return;
1512 	}
1513 	dist = runtime->status->hw_ptr - runtime->hw_ptr_base;
1514 	/* Distance to next interrupt */
1515 	dist = runtime->period_size - dist % runtime->period_size;
1516 	if (dist <= frames) {
1517 		snd_pcm_tick_set(substream, 0);
1518 		return;
1519 	}
1520 	/* the base time is us */
1521 	n = frames;
1522 	n *= 1000000;
1523 	div64_32(&n, runtime->tick_time * runtime->rate, &r);
1524 	ticks = n + (r > 0 ? 1 : 0);
1525 	if (ticks < runtime->sleep_min)
1526 		ticks = runtime->sleep_min;
1527 	snd_pcm_tick_set(substream, (unsigned long) ticks);
1528 }
1529 
1530 void snd_pcm_tick_elapsed(struct snd_pcm_substream *substream)
1531 {
1532 	struct snd_pcm_runtime *runtime;
1533 	unsigned long flags;
1534 
1535 	snd_assert(substream != NULL, return);
1536 	runtime = substream->runtime;
1537 	snd_assert(runtime != NULL, return);
1538 
1539 	snd_pcm_stream_lock_irqsave(substream, flags);
1540 	if (!snd_pcm_running(substream) ||
1541 	    snd_pcm_update_hw_ptr(substream) < 0)
1542 		goto _end;
1543 	if (runtime->sleep_min)
1544 		snd_pcm_tick_prepare(substream);
1545  _end:
1546 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1547 }
1548 
1549 /**
1550  * snd_pcm_period_elapsed - update the pcm status for the next period
1551  * @substream: the pcm substream instance
1552  *
1553  * This function is called from the interrupt handler when the
1554  * PCM has processed the period size.  It will update the current
1555  * pointer, set up the tick, wake up sleepers, etc.
1556  *
1557  * Even if more than one periods have elapsed since the last call, you
1558  * have to call this only once.
1559  */
1560 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1561 {
1562 	struct snd_pcm_runtime *runtime;
1563 	unsigned long flags;
1564 
1565 	snd_assert(substream != NULL, return);
1566 	runtime = substream->runtime;
1567 	snd_assert(runtime != NULL, return);
1568 
1569 	if (runtime->transfer_ack_begin)
1570 		runtime->transfer_ack_begin(substream);
1571 
1572 	snd_pcm_stream_lock_irqsave(substream, flags);
1573 	if (!snd_pcm_running(substream) ||
1574 	    snd_pcm_update_hw_ptr_interrupt(substream) < 0)
1575 		goto _end;
1576 
1577 	if (substream->timer_running)
1578 		snd_timer_interrupt(substream->timer, 1);
1579 	if (runtime->sleep_min)
1580 		snd_pcm_tick_prepare(substream);
1581  _end:
1582 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1583 	if (runtime->transfer_ack_end)
1584 		runtime->transfer_ack_end(substream);
1585 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1586 }
1587 
1588 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1589 
1590 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1591 				      unsigned int hwoff,
1592 				      unsigned long data, unsigned int off,
1593 				      snd_pcm_uframes_t frames)
1594 {
1595 	struct snd_pcm_runtime *runtime = substream->runtime;
1596 	int err;
1597 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1598 	if (substream->ops->copy) {
1599 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1600 			return err;
1601 	} else {
1602 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1603 		snd_assert(runtime->dma_area, return -EFAULT);
1604 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1605 			return -EFAULT;
1606 	}
1607 	return 0;
1608 }
1609 
1610 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1611 			  unsigned long data, unsigned int off,
1612 			  snd_pcm_uframes_t size);
1613 
1614 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1615 					    unsigned long data,
1616 					    snd_pcm_uframes_t size,
1617 					    int nonblock,
1618 					    transfer_f transfer)
1619 {
1620 	struct snd_pcm_runtime *runtime = substream->runtime;
1621 	snd_pcm_uframes_t xfer = 0;
1622 	snd_pcm_uframes_t offset = 0;
1623 	int err = 0;
1624 
1625 	if (size == 0)
1626 		return 0;
1627 	if (size > runtime->xfer_align)
1628 		size -= size % runtime->xfer_align;
1629 
1630 	snd_pcm_stream_lock_irq(substream);
1631 	switch (runtime->status->state) {
1632 	case SNDRV_PCM_STATE_PREPARED:
1633 	case SNDRV_PCM_STATE_RUNNING:
1634 	case SNDRV_PCM_STATE_PAUSED:
1635 		break;
1636 	case SNDRV_PCM_STATE_XRUN:
1637 		err = -EPIPE;
1638 		goto _end_unlock;
1639 	case SNDRV_PCM_STATE_SUSPENDED:
1640 		err = -ESTRPIPE;
1641 		goto _end_unlock;
1642 	default:
1643 		err = -EBADFD;
1644 		goto _end_unlock;
1645 	}
1646 
1647 	while (size > 0) {
1648 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1649 		snd_pcm_uframes_t avail;
1650 		snd_pcm_uframes_t cont;
1651 		if (runtime->sleep_min == 0 && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1652 			snd_pcm_update_hw_ptr(substream);
1653 		avail = snd_pcm_playback_avail(runtime);
1654 		if (((avail < runtime->control->avail_min && size > avail) ||
1655 		   (size >= runtime->xfer_align && avail < runtime->xfer_align))) {
1656 			wait_queue_t wait;
1657 			enum { READY, SIGNALED, ERROR, SUSPENDED, EXPIRED, DROPPED } state;
1658 			long tout;
1659 
1660 			if (nonblock) {
1661 				err = -EAGAIN;
1662 				goto _end_unlock;
1663 			}
1664 
1665 			init_waitqueue_entry(&wait, current);
1666 			add_wait_queue(&runtime->sleep, &wait);
1667 			while (1) {
1668 				if (signal_pending(current)) {
1669 					state = SIGNALED;
1670 					break;
1671 				}
1672 				set_current_state(TASK_INTERRUPTIBLE);
1673 				snd_pcm_stream_unlock_irq(substream);
1674 				tout = schedule_timeout(10 * HZ);
1675 				snd_pcm_stream_lock_irq(substream);
1676 				if (tout == 0) {
1677 					if (runtime->status->state != SNDRV_PCM_STATE_PREPARED &&
1678 					    runtime->status->state != SNDRV_PCM_STATE_PAUSED) {
1679 						state = runtime->status->state == SNDRV_PCM_STATE_SUSPENDED ? SUSPENDED : EXPIRED;
1680 						break;
1681 					}
1682 				}
1683 				switch (runtime->status->state) {
1684 				case SNDRV_PCM_STATE_XRUN:
1685 				case SNDRV_PCM_STATE_DRAINING:
1686 					state = ERROR;
1687 					goto _end_loop;
1688 				case SNDRV_PCM_STATE_SUSPENDED:
1689 					state = SUSPENDED;
1690 					goto _end_loop;
1691 				case SNDRV_PCM_STATE_SETUP:
1692 					state = DROPPED;
1693 					goto _end_loop;
1694 				default:
1695 					break;
1696 				}
1697 				avail = snd_pcm_playback_avail(runtime);
1698 				if (avail >= runtime->control->avail_min) {
1699 					state = READY;
1700 					break;
1701 				}
1702 			}
1703 		       _end_loop:
1704 			remove_wait_queue(&runtime->sleep, &wait);
1705 
1706 			switch (state) {
1707 			case ERROR:
1708 				err = -EPIPE;
1709 				goto _end_unlock;
1710 			case SUSPENDED:
1711 				err = -ESTRPIPE;
1712 				goto _end_unlock;
1713 			case SIGNALED:
1714 				err = -ERESTARTSYS;
1715 				goto _end_unlock;
1716 			case EXPIRED:
1717 				snd_printd("playback write error (DMA or IRQ trouble?)\n");
1718 				err = -EIO;
1719 				goto _end_unlock;
1720 			case DROPPED:
1721 				err = -EBADFD;
1722 				goto _end_unlock;
1723 			default:
1724 				break;
1725 			}
1726 		}
1727 		if (avail > runtime->xfer_align)
1728 			avail -= avail % runtime->xfer_align;
1729 		frames = size > avail ? avail : size;
1730 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
1731 		if (frames > cont)
1732 			frames = cont;
1733 		snd_assert(frames != 0, snd_pcm_stream_unlock_irq(substream); return -EINVAL);
1734 		appl_ptr = runtime->control->appl_ptr;
1735 		appl_ofs = appl_ptr % runtime->buffer_size;
1736 		snd_pcm_stream_unlock_irq(substream);
1737 		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
1738 			goto _end;
1739 		snd_pcm_stream_lock_irq(substream);
1740 		switch (runtime->status->state) {
1741 		case SNDRV_PCM_STATE_XRUN:
1742 			err = -EPIPE;
1743 			goto _end_unlock;
1744 		case SNDRV_PCM_STATE_SUSPENDED:
1745 			err = -ESTRPIPE;
1746 			goto _end_unlock;
1747 		default:
1748 			break;
1749 		}
1750 		appl_ptr += frames;
1751 		if (appl_ptr >= runtime->boundary)
1752 			appl_ptr -= runtime->boundary;
1753 		runtime->control->appl_ptr = appl_ptr;
1754 		if (substream->ops->ack)
1755 			substream->ops->ack(substream);
1756 
1757 		offset += frames;
1758 		size -= frames;
1759 		xfer += frames;
1760 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
1761 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
1762 			err = snd_pcm_start(substream);
1763 			if (err < 0)
1764 				goto _end_unlock;
1765 		}
1766 		if (runtime->sleep_min &&
1767 		    runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1768 			snd_pcm_tick_prepare(substream);
1769 	}
1770  _end_unlock:
1771 	snd_pcm_stream_unlock_irq(substream);
1772  _end:
1773 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
1774 }
1775 
1776 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
1777 {
1778 	struct snd_pcm_runtime *runtime;
1779 	int nonblock;
1780 
1781 	snd_assert(substream != NULL, return -ENXIO);
1782 	runtime = substream->runtime;
1783 	snd_assert(runtime != NULL, return -ENXIO);
1784 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
1785 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
1786 		return -EBADFD;
1787 
1788 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1789 
1790 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
1791 	    runtime->channels > 1)
1792 		return -EINVAL;
1793 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
1794 				  snd_pcm_lib_write_transfer);
1795 }
1796 
1797 EXPORT_SYMBOL(snd_pcm_lib_write);
1798 
1799 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
1800 				       unsigned int hwoff,
1801 				       unsigned long data, unsigned int off,
1802 				       snd_pcm_uframes_t frames)
1803 {
1804 	struct snd_pcm_runtime *runtime = substream->runtime;
1805 	int err;
1806 	void __user **bufs = (void __user **)data;
1807 	int channels = runtime->channels;
1808 	int c;
1809 	if (substream->ops->copy) {
1810 		snd_assert(substream->ops->silence != NULL, return -EINVAL);
1811 		for (c = 0; c < channels; ++c, ++bufs) {
1812 			if (*bufs == NULL) {
1813 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
1814 					return err;
1815 			} else {
1816 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1817 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
1818 					return err;
1819 			}
1820 		}
1821 	} else {
1822 		/* default transfer behaviour */
1823 		size_t dma_csize = runtime->dma_bytes / channels;
1824 		snd_assert(runtime->dma_area, return -EFAULT);
1825 		for (c = 0; c < channels; ++c, ++bufs) {
1826 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
1827 			if (*bufs == NULL) {
1828 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
1829 			} else {
1830 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1831 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
1832 					return -EFAULT;
1833 			}
1834 		}
1835 	}
1836 	return 0;
1837 }
1838 
1839 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
1840 				     void __user **bufs,
1841 				     snd_pcm_uframes_t frames)
1842 {
1843 	struct snd_pcm_runtime *runtime;
1844 	int nonblock;
1845 
1846 	snd_assert(substream != NULL, return -ENXIO);
1847 	runtime = substream->runtime;
1848 	snd_assert(runtime != NULL, return -ENXIO);
1849 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
1850 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
1851 		return -EBADFD;
1852 
1853 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1854 
1855 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
1856 		return -EINVAL;
1857 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
1858 				  nonblock, snd_pcm_lib_writev_transfer);
1859 }
1860 
1861 EXPORT_SYMBOL(snd_pcm_lib_writev);
1862 
1863 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
1864 				     unsigned int hwoff,
1865 				     unsigned long data, unsigned int off,
1866 				     snd_pcm_uframes_t frames)
1867 {
1868 	struct snd_pcm_runtime *runtime = substream->runtime;
1869 	int err;
1870 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1871 	if (substream->ops->copy) {
1872 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1873 			return err;
1874 	} else {
1875 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1876 		snd_assert(runtime->dma_area, return -EFAULT);
1877 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
1878 			return -EFAULT;
1879 	}
1880 	return 0;
1881 }
1882 
1883 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
1884 					   unsigned long data,
1885 					   snd_pcm_uframes_t size,
1886 					   int nonblock,
1887 					   transfer_f transfer)
1888 {
1889 	struct snd_pcm_runtime *runtime = substream->runtime;
1890 	snd_pcm_uframes_t xfer = 0;
1891 	snd_pcm_uframes_t offset = 0;
1892 	int err = 0;
1893 
1894 	if (size == 0)
1895 		return 0;
1896 	if (size > runtime->xfer_align)
1897 		size -= size % runtime->xfer_align;
1898 
1899 	snd_pcm_stream_lock_irq(substream);
1900 	switch (runtime->status->state) {
1901 	case SNDRV_PCM_STATE_PREPARED:
1902 		if (size >= runtime->start_threshold) {
1903 			err = snd_pcm_start(substream);
1904 			if (err < 0)
1905 				goto _end_unlock;
1906 		}
1907 		break;
1908 	case SNDRV_PCM_STATE_DRAINING:
1909 	case SNDRV_PCM_STATE_RUNNING:
1910 	case SNDRV_PCM_STATE_PAUSED:
1911 		break;
1912 	case SNDRV_PCM_STATE_XRUN:
1913 		err = -EPIPE;
1914 		goto _end_unlock;
1915 	case SNDRV_PCM_STATE_SUSPENDED:
1916 		err = -ESTRPIPE;
1917 		goto _end_unlock;
1918 	default:
1919 		err = -EBADFD;
1920 		goto _end_unlock;
1921 	}
1922 
1923 	while (size > 0) {
1924 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1925 		snd_pcm_uframes_t avail;
1926 		snd_pcm_uframes_t cont;
1927 		if (runtime->sleep_min == 0 && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1928 			snd_pcm_update_hw_ptr(substream);
1929 	      __draining:
1930 		avail = snd_pcm_capture_avail(runtime);
1931 		if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
1932 			if (avail < runtime->xfer_align) {
1933 				err = -EPIPE;
1934 				goto _end_unlock;
1935 			}
1936 		} else if ((avail < runtime->control->avail_min && size > avail) ||
1937 			   (size >= runtime->xfer_align && avail < runtime->xfer_align)) {
1938 			wait_queue_t wait;
1939 			enum { READY, SIGNALED, ERROR, SUSPENDED, EXPIRED, DROPPED } state;
1940 			long tout;
1941 
1942 			if (nonblock) {
1943 				err = -EAGAIN;
1944 				goto _end_unlock;
1945 			}
1946 
1947 			init_waitqueue_entry(&wait, current);
1948 			add_wait_queue(&runtime->sleep, &wait);
1949 			while (1) {
1950 				if (signal_pending(current)) {
1951 					state = SIGNALED;
1952 					break;
1953 				}
1954 				set_current_state(TASK_INTERRUPTIBLE);
1955 				snd_pcm_stream_unlock_irq(substream);
1956 				tout = schedule_timeout(10 * HZ);
1957 				snd_pcm_stream_lock_irq(substream);
1958 				if (tout == 0) {
1959 					if (runtime->status->state != SNDRV_PCM_STATE_PREPARED &&
1960 					    runtime->status->state != SNDRV_PCM_STATE_PAUSED) {
1961 						state = runtime->status->state == SNDRV_PCM_STATE_SUSPENDED ? SUSPENDED : EXPIRED;
1962 						break;
1963 					}
1964 				}
1965 				switch (runtime->status->state) {
1966 				case SNDRV_PCM_STATE_XRUN:
1967 					state = ERROR;
1968 					goto _end_loop;
1969 				case SNDRV_PCM_STATE_SUSPENDED:
1970 					state = SUSPENDED;
1971 					goto _end_loop;
1972 				case SNDRV_PCM_STATE_DRAINING:
1973 					goto __draining;
1974 				case SNDRV_PCM_STATE_SETUP:
1975 					state = DROPPED;
1976 					goto _end_loop;
1977 				default:
1978 					break;
1979 				}
1980 				avail = snd_pcm_capture_avail(runtime);
1981 				if (avail >= runtime->control->avail_min) {
1982 					state = READY;
1983 					break;
1984 				}
1985 			}
1986 		       _end_loop:
1987 			remove_wait_queue(&runtime->sleep, &wait);
1988 
1989 			switch (state) {
1990 			case ERROR:
1991 				err = -EPIPE;
1992 				goto _end_unlock;
1993 			case SUSPENDED:
1994 				err = -ESTRPIPE;
1995 				goto _end_unlock;
1996 			case SIGNALED:
1997 				err = -ERESTARTSYS;
1998 				goto _end_unlock;
1999 			case EXPIRED:
2000 				snd_printd("capture read error (DMA or IRQ trouble?)\n");
2001 				err = -EIO;
2002 				goto _end_unlock;
2003 			case DROPPED:
2004 				err = -EBADFD;
2005 				goto _end_unlock;
2006 			default:
2007 				break;
2008 			}
2009 		}
2010 		if (avail > runtime->xfer_align)
2011 			avail -= avail % runtime->xfer_align;
2012 		frames = size > avail ? avail : size;
2013 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2014 		if (frames > cont)
2015 			frames = cont;
2016 		snd_assert(frames != 0, snd_pcm_stream_unlock_irq(substream); return -EINVAL);
2017 		appl_ptr = runtime->control->appl_ptr;
2018 		appl_ofs = appl_ptr % runtime->buffer_size;
2019 		snd_pcm_stream_unlock_irq(substream);
2020 		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
2021 			goto _end;
2022 		snd_pcm_stream_lock_irq(substream);
2023 		switch (runtime->status->state) {
2024 		case SNDRV_PCM_STATE_XRUN:
2025 			err = -EPIPE;
2026 			goto _end_unlock;
2027 		case SNDRV_PCM_STATE_SUSPENDED:
2028 			err = -ESTRPIPE;
2029 			goto _end_unlock;
2030 		default:
2031 			break;
2032 		}
2033 		appl_ptr += frames;
2034 		if (appl_ptr >= runtime->boundary)
2035 			appl_ptr -= runtime->boundary;
2036 		runtime->control->appl_ptr = appl_ptr;
2037 		if (substream->ops->ack)
2038 			substream->ops->ack(substream);
2039 
2040 		offset += frames;
2041 		size -= frames;
2042 		xfer += frames;
2043 		if (runtime->sleep_min &&
2044 		    runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2045 			snd_pcm_tick_prepare(substream);
2046 	}
2047  _end_unlock:
2048 	snd_pcm_stream_unlock_irq(substream);
2049  _end:
2050 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2051 }
2052 
2053 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2054 {
2055 	struct snd_pcm_runtime *runtime;
2056 	int nonblock;
2057 
2058 	snd_assert(substream != NULL, return -ENXIO);
2059 	runtime = substream->runtime;
2060 	snd_assert(runtime != NULL, return -ENXIO);
2061 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
2062 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2063 		return -EBADFD;
2064 
2065 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2066 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2067 		return -EINVAL;
2068 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2069 }
2070 
2071 EXPORT_SYMBOL(snd_pcm_lib_read);
2072 
2073 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2074 				      unsigned int hwoff,
2075 				      unsigned long data, unsigned int off,
2076 				      snd_pcm_uframes_t frames)
2077 {
2078 	struct snd_pcm_runtime *runtime = substream->runtime;
2079 	int err;
2080 	void __user **bufs = (void __user **)data;
2081 	int channels = runtime->channels;
2082 	int c;
2083 	if (substream->ops->copy) {
2084 		for (c = 0; c < channels; ++c, ++bufs) {
2085 			char __user *buf;
2086 			if (*bufs == NULL)
2087 				continue;
2088 			buf = *bufs + samples_to_bytes(runtime, off);
2089 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2090 				return err;
2091 		}
2092 	} else {
2093 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2094 		snd_assert(runtime->dma_area, return -EFAULT);
2095 		for (c = 0; c < channels; ++c, ++bufs) {
2096 			char *hwbuf;
2097 			char __user *buf;
2098 			if (*bufs == NULL)
2099 				continue;
2100 
2101 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2102 			buf = *bufs + samples_to_bytes(runtime, off);
2103 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2104 				return -EFAULT;
2105 		}
2106 	}
2107 	return 0;
2108 }
2109 
2110 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2111 				    void __user **bufs,
2112 				    snd_pcm_uframes_t frames)
2113 {
2114 	struct snd_pcm_runtime *runtime;
2115 	int nonblock;
2116 
2117 	snd_assert(substream != NULL, return -ENXIO);
2118 	runtime = substream->runtime;
2119 	snd_assert(runtime != NULL, return -ENXIO);
2120 	snd_assert(substream->ops->copy != NULL || runtime->dma_area != NULL, return -EINVAL);
2121 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2122 		return -EBADFD;
2123 
2124 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2125 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2126 		return -EINVAL;
2127 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2128 }
2129 
2130 EXPORT_SYMBOL(snd_pcm_lib_readv);
2131