xref: /linux/sound/core/pcm_lib.c (revision 0c93ea4064a209cdc36de8a9a3003d43d08f46f7)
1 /*
2  *  Digital Audio (PCM) abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *                   Abramo Bagnara <abramo@alsa-project.org>
5  *
6  *
7  *   This program is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with this program; if not, write to the Free Software
19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  *
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/time.h>
25 #include <sound/core.h>
26 #include <sound/control.h>
27 #include <sound/info.h>
28 #include <sound/pcm.h>
29 #include <sound/pcm_params.h>
30 #include <sound/timer.h>
31 
32 /*
33  * fill ring buffer with silence
34  * runtime->silence_start: starting pointer to silence area
35  * runtime->silence_filled: size filled with silence
36  * runtime->silence_threshold: threshold from application
37  * runtime->silence_size: maximal size from application
38  *
39  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
40  */
41 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
42 {
43 	struct snd_pcm_runtime *runtime = substream->runtime;
44 	snd_pcm_uframes_t frames, ofs, transfer;
45 
46 	if (runtime->silence_size < runtime->boundary) {
47 		snd_pcm_sframes_t noise_dist, n;
48 		if (runtime->silence_start != runtime->control->appl_ptr) {
49 			n = runtime->control->appl_ptr - runtime->silence_start;
50 			if (n < 0)
51 				n += runtime->boundary;
52 			if ((snd_pcm_uframes_t)n < runtime->silence_filled)
53 				runtime->silence_filled -= n;
54 			else
55 				runtime->silence_filled = 0;
56 			runtime->silence_start = runtime->control->appl_ptr;
57 		}
58 		if (runtime->silence_filled >= runtime->buffer_size)
59 			return;
60 		noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
61 		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
62 			return;
63 		frames = runtime->silence_threshold - noise_dist;
64 		if (frames > runtime->silence_size)
65 			frames = runtime->silence_size;
66 	} else {
67 		if (new_hw_ptr == ULONG_MAX) {	/* initialization */
68 			snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
69 			runtime->silence_filled = avail > 0 ? avail : 0;
70 			runtime->silence_start = (runtime->status->hw_ptr +
71 						  runtime->silence_filled) %
72 						 runtime->boundary;
73 		} else {
74 			ofs = runtime->status->hw_ptr;
75 			frames = new_hw_ptr - ofs;
76 			if ((snd_pcm_sframes_t)frames < 0)
77 				frames += runtime->boundary;
78 			runtime->silence_filled -= frames;
79 			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
80 				runtime->silence_filled = 0;
81 				runtime->silence_start = new_hw_ptr;
82 			} else {
83 				runtime->silence_start = ofs;
84 			}
85 		}
86 		frames = runtime->buffer_size - runtime->silence_filled;
87 	}
88 	if (snd_BUG_ON(frames > runtime->buffer_size))
89 		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_BUG_ON(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_BUG_ON(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 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
129 #define xrun_debug(substream)	((substream)->pstr->xrun_debug)
130 #else
131 #define xrun_debug(substream)	0
132 #endif
133 
134 #define dump_stack_on_xrun(substream) do {	\
135 		if (xrun_debug(substream) > 1)	\
136 			dump_stack();		\
137 	} while (0)
138 
139 static void xrun(struct snd_pcm_substream *substream)
140 {
141 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
142 	if (xrun_debug(substream)) {
143 		snd_printd(KERN_DEBUG "XRUN: pcmC%dD%d%c\n",
144 			   substream->pcm->card->number,
145 			   substream->pcm->device,
146 			   substream->stream ? 'c' : 'p');
147 		dump_stack_on_xrun(substream);
148 	}
149 }
150 
151 static snd_pcm_uframes_t
152 snd_pcm_update_hw_ptr_pos(struct snd_pcm_substream *substream,
153 			  struct snd_pcm_runtime *runtime)
154 {
155 	snd_pcm_uframes_t pos;
156 
157 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
158 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
159 	pos = substream->ops->pointer(substream);
160 	if (pos == SNDRV_PCM_POS_XRUN)
161 		return pos; /* XRUN */
162 	if (pos >= runtime->buffer_size) {
163 		if (printk_ratelimit()) {
164 			snd_printd(KERN_ERR  "BUG: stream = %i, pos = 0x%lx, "
165 				   "buffer size = 0x%lx, period size = 0x%lx\n",
166 				   substream->stream, pos, runtime->buffer_size,
167 				   runtime->period_size);
168 		}
169 		pos = 0;
170 	}
171 	pos -= pos % runtime->min_align;
172 	return pos;
173 }
174 
175 static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream,
176 				      struct snd_pcm_runtime *runtime)
177 {
178 	snd_pcm_uframes_t avail;
179 
180 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
181 		avail = snd_pcm_playback_avail(runtime);
182 	else
183 		avail = snd_pcm_capture_avail(runtime);
184 	if (avail > runtime->avail_max)
185 		runtime->avail_max = avail;
186 	if (avail >= runtime->stop_threshold) {
187 		if (substream->runtime->status->state == SNDRV_PCM_STATE_DRAINING)
188 			snd_pcm_drain_done(substream);
189 		else
190 			xrun(substream);
191 		return -EPIPE;
192 	}
193 	if (avail >= runtime->control->avail_min)
194 		wake_up(&runtime->sleep);
195 	return 0;
196 }
197 
198 #define hw_ptr_error(substream, fmt, args...)				\
199 	do {								\
200 		if (xrun_debug(substream)) {				\
201 			if (printk_ratelimit()) {			\
202 				snd_printd("PCM: " fmt, ##args);	\
203 			}						\
204 			dump_stack_on_xrun(substream);			\
205 		}							\
206 	} while (0)
207 
208 static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
209 {
210 	struct snd_pcm_runtime *runtime = substream->runtime;
211 	snd_pcm_uframes_t pos;
212 	snd_pcm_uframes_t new_hw_ptr, hw_ptr_interrupt, hw_base;
213 	snd_pcm_sframes_t delta;
214 
215 	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
216 	if (pos == SNDRV_PCM_POS_XRUN) {
217 		xrun(substream);
218 		return -EPIPE;
219 	}
220 	hw_base = runtime->hw_ptr_base;
221 	new_hw_ptr = hw_base + pos;
222 	hw_ptr_interrupt = runtime->hw_ptr_interrupt + runtime->period_size;
223 	delta = new_hw_ptr - hw_ptr_interrupt;
224 	if (hw_ptr_interrupt >= runtime->boundary) {
225 		hw_ptr_interrupt -= runtime->boundary;
226 		if (hw_base < runtime->boundary / 2)
227 			/* hw_base was already lapped; recalc delta */
228 			delta = new_hw_ptr - hw_ptr_interrupt;
229 	}
230 	if (delta < 0) {
231 		delta += runtime->buffer_size;
232 		if (delta < 0) {
233 			hw_ptr_error(substream,
234 				     "Unexpected hw_pointer value "
235 				     "(stream=%i, pos=%ld, intr_ptr=%ld)\n",
236 				     substream->stream, (long)pos,
237 				     (long)hw_ptr_interrupt);
238 			/* rebase to interrupt position */
239 			hw_base = new_hw_ptr = hw_ptr_interrupt;
240 			/* align hw_base to buffer_size */
241 			hw_base -= hw_base % runtime->buffer_size;
242 			delta = 0;
243 		} else {
244 			hw_base += runtime->buffer_size;
245 			if (hw_base >= runtime->boundary)
246 				hw_base = 0;
247 			new_hw_ptr = hw_base + pos;
248 		}
249 	}
250 	if (delta > runtime->period_size) {
251 		hw_ptr_error(substream,
252 			     "Lost interrupts? "
253 			     "(stream=%i, delta=%ld, intr_ptr=%ld)\n",
254 			     substream->stream, (long)delta,
255 			     (long)hw_ptr_interrupt);
256 		/* rebase hw_ptr_interrupt */
257 		hw_ptr_interrupt =
258 			new_hw_ptr - new_hw_ptr % runtime->period_size;
259 	}
260 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
261 	    runtime->silence_size > 0)
262 		snd_pcm_playback_silence(substream, new_hw_ptr);
263 
264 	runtime->hw_ptr_base = hw_base;
265 	runtime->status->hw_ptr = new_hw_ptr;
266 	runtime->hw_ptr_interrupt = hw_ptr_interrupt;
267 
268 	return snd_pcm_update_hw_ptr_post(substream, runtime);
269 }
270 
271 /* CAUTION: call it with irq disabled */
272 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
273 {
274 	struct snd_pcm_runtime *runtime = substream->runtime;
275 	snd_pcm_uframes_t pos;
276 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
277 	snd_pcm_sframes_t delta;
278 
279 	old_hw_ptr = runtime->status->hw_ptr;
280 	pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
281 	if (pos == SNDRV_PCM_POS_XRUN) {
282 		xrun(substream);
283 		return -EPIPE;
284 	}
285 	hw_base = runtime->hw_ptr_base;
286 	new_hw_ptr = hw_base + pos;
287 
288 	delta = new_hw_ptr - old_hw_ptr;
289 	if (delta < 0) {
290 		delta += runtime->buffer_size;
291 		if (delta < 0) {
292 			hw_ptr_error(substream,
293 				     "Unexpected hw_pointer value [2] "
294 				     "(stream=%i, pos=%ld, old_ptr=%ld)\n",
295 				     substream->stream, (long)pos,
296 				     (long)old_hw_ptr);
297 			return 0;
298 		}
299 		hw_base += runtime->buffer_size;
300 		if (hw_base >= runtime->boundary)
301 			hw_base = 0;
302 		new_hw_ptr = hw_base + pos;
303 	}
304 	if (delta > runtime->period_size && runtime->periods > 1) {
305 		hw_ptr_error(substream,
306 			     "hw_ptr skipping! "
307 			     "(pos=%ld, delta=%ld, period=%ld)\n",
308 			     (long)pos, (long)delta,
309 			     (long)runtime->period_size);
310 		return 0;
311 	}
312 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
313 	    runtime->silence_size > 0)
314 		snd_pcm_playback_silence(substream, new_hw_ptr);
315 
316 	runtime->hw_ptr_base = hw_base;
317 	runtime->status->hw_ptr = new_hw_ptr;
318 
319 	return snd_pcm_update_hw_ptr_post(substream, runtime);
320 }
321 
322 /**
323  * snd_pcm_set_ops - set the PCM operators
324  * @pcm: the pcm instance
325  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
326  * @ops: the operator table
327  *
328  * Sets the given PCM operators to the pcm instance.
329  */
330 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, struct snd_pcm_ops *ops)
331 {
332 	struct snd_pcm_str *stream = &pcm->streams[direction];
333 	struct snd_pcm_substream *substream;
334 
335 	for (substream = stream->substream; substream != NULL; substream = substream->next)
336 		substream->ops = ops;
337 }
338 
339 EXPORT_SYMBOL(snd_pcm_set_ops);
340 
341 /**
342  * snd_pcm_sync - set the PCM sync id
343  * @substream: the pcm substream
344  *
345  * Sets the PCM sync identifier for the card.
346  */
347 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
348 {
349 	struct snd_pcm_runtime *runtime = substream->runtime;
350 
351 	runtime->sync.id32[0] = substream->pcm->card->number;
352 	runtime->sync.id32[1] = -1;
353 	runtime->sync.id32[2] = -1;
354 	runtime->sync.id32[3] = -1;
355 }
356 
357 EXPORT_SYMBOL(snd_pcm_set_sync);
358 
359 /*
360  *  Standard ioctl routine
361  */
362 
363 static inline unsigned int div32(unsigned int a, unsigned int b,
364 				 unsigned int *r)
365 {
366 	if (b == 0) {
367 		*r = 0;
368 		return UINT_MAX;
369 	}
370 	*r = a % b;
371 	return a / b;
372 }
373 
374 static inline unsigned int div_down(unsigned int a, unsigned int b)
375 {
376 	if (b == 0)
377 		return UINT_MAX;
378 	return a / b;
379 }
380 
381 static inline unsigned int div_up(unsigned int a, unsigned int b)
382 {
383 	unsigned int r;
384 	unsigned int q;
385 	if (b == 0)
386 		return UINT_MAX;
387 	q = div32(a, b, &r);
388 	if (r)
389 		++q;
390 	return q;
391 }
392 
393 static inline unsigned int mul(unsigned int a, unsigned int b)
394 {
395 	if (a == 0)
396 		return 0;
397 	if (div_down(UINT_MAX, a) < b)
398 		return UINT_MAX;
399 	return a * b;
400 }
401 
402 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
403 				    unsigned int c, unsigned int *r)
404 {
405 	u_int64_t n = (u_int64_t) a * b;
406 	if (c == 0) {
407 		snd_BUG_ON(!n);
408 		*r = 0;
409 		return UINT_MAX;
410 	}
411 	div64_32(&n, c, r);
412 	if (n >= UINT_MAX) {
413 		*r = 0;
414 		return UINT_MAX;
415 	}
416 	return n;
417 }
418 
419 /**
420  * snd_interval_refine - refine the interval value of configurator
421  * @i: the interval value to refine
422  * @v: the interval value to refer to
423  *
424  * Refines the interval value with the reference value.
425  * The interval is changed to the range satisfying both intervals.
426  * The interval status (min, max, integer, etc.) are evaluated.
427  *
428  * Returns non-zero if the value is changed, zero if not changed.
429  */
430 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
431 {
432 	int changed = 0;
433 	if (snd_BUG_ON(snd_interval_empty(i)))
434 		return -EINVAL;
435 	if (i->min < v->min) {
436 		i->min = v->min;
437 		i->openmin = v->openmin;
438 		changed = 1;
439 	} else if (i->min == v->min && !i->openmin && v->openmin) {
440 		i->openmin = 1;
441 		changed = 1;
442 	}
443 	if (i->max > v->max) {
444 		i->max = v->max;
445 		i->openmax = v->openmax;
446 		changed = 1;
447 	} else if (i->max == v->max && !i->openmax && v->openmax) {
448 		i->openmax = 1;
449 		changed = 1;
450 	}
451 	if (!i->integer && v->integer) {
452 		i->integer = 1;
453 		changed = 1;
454 	}
455 	if (i->integer) {
456 		if (i->openmin) {
457 			i->min++;
458 			i->openmin = 0;
459 		}
460 		if (i->openmax) {
461 			i->max--;
462 			i->openmax = 0;
463 		}
464 	} else if (!i->openmin && !i->openmax && i->min == i->max)
465 		i->integer = 1;
466 	if (snd_interval_checkempty(i)) {
467 		snd_interval_none(i);
468 		return -EINVAL;
469 	}
470 	return changed;
471 }
472 
473 EXPORT_SYMBOL(snd_interval_refine);
474 
475 static int snd_interval_refine_first(struct snd_interval *i)
476 {
477 	if (snd_BUG_ON(snd_interval_empty(i)))
478 		return -EINVAL;
479 	if (snd_interval_single(i))
480 		return 0;
481 	i->max = i->min;
482 	i->openmax = i->openmin;
483 	if (i->openmax)
484 		i->max++;
485 	return 1;
486 }
487 
488 static int snd_interval_refine_last(struct snd_interval *i)
489 {
490 	if (snd_BUG_ON(snd_interval_empty(i)))
491 		return -EINVAL;
492 	if (snd_interval_single(i))
493 		return 0;
494 	i->min = i->max;
495 	i->openmin = i->openmax;
496 	if (i->openmin)
497 		i->min--;
498 	return 1;
499 }
500 
501 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
502 {
503 	if (a->empty || b->empty) {
504 		snd_interval_none(c);
505 		return;
506 	}
507 	c->empty = 0;
508 	c->min = mul(a->min, b->min);
509 	c->openmin = (a->openmin || b->openmin);
510 	c->max = mul(a->max,  b->max);
511 	c->openmax = (a->openmax || b->openmax);
512 	c->integer = (a->integer && b->integer);
513 }
514 
515 /**
516  * snd_interval_div - refine the interval value with division
517  * @a: dividend
518  * @b: divisor
519  * @c: quotient
520  *
521  * c = a / b
522  *
523  * Returns non-zero if the value is changed, zero if not changed.
524  */
525 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
526 {
527 	unsigned int r;
528 	if (a->empty || b->empty) {
529 		snd_interval_none(c);
530 		return;
531 	}
532 	c->empty = 0;
533 	c->min = div32(a->min, b->max, &r);
534 	c->openmin = (r || a->openmin || b->openmax);
535 	if (b->min > 0) {
536 		c->max = div32(a->max, b->min, &r);
537 		if (r) {
538 			c->max++;
539 			c->openmax = 1;
540 		} else
541 			c->openmax = (a->openmax || b->openmin);
542 	} else {
543 		c->max = UINT_MAX;
544 		c->openmax = 0;
545 	}
546 	c->integer = 0;
547 }
548 
549 /**
550  * snd_interval_muldivk - refine the interval value
551  * @a: dividend 1
552  * @b: dividend 2
553  * @k: divisor (as integer)
554  * @c: result
555   *
556  * c = a * b / k
557  *
558  * Returns non-zero if the value is changed, zero if not changed.
559  */
560 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
561 		      unsigned int k, struct snd_interval *c)
562 {
563 	unsigned int r;
564 	if (a->empty || b->empty) {
565 		snd_interval_none(c);
566 		return;
567 	}
568 	c->empty = 0;
569 	c->min = muldiv32(a->min, b->min, k, &r);
570 	c->openmin = (r || a->openmin || b->openmin);
571 	c->max = muldiv32(a->max, b->max, k, &r);
572 	if (r) {
573 		c->max++;
574 		c->openmax = 1;
575 	} else
576 		c->openmax = (a->openmax || b->openmax);
577 	c->integer = 0;
578 }
579 
580 /**
581  * snd_interval_mulkdiv - refine the interval value
582  * @a: dividend 1
583  * @k: dividend 2 (as integer)
584  * @b: divisor
585  * @c: result
586  *
587  * c = a * k / b
588  *
589  * Returns non-zero if the value is changed, zero if not changed.
590  */
591 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
592 		      const struct snd_interval *b, struct snd_interval *c)
593 {
594 	unsigned int r;
595 	if (a->empty || b->empty) {
596 		snd_interval_none(c);
597 		return;
598 	}
599 	c->empty = 0;
600 	c->min = muldiv32(a->min, k, b->max, &r);
601 	c->openmin = (r || a->openmin || b->openmax);
602 	if (b->min > 0) {
603 		c->max = muldiv32(a->max, k, b->min, &r);
604 		if (r) {
605 			c->max++;
606 			c->openmax = 1;
607 		} else
608 			c->openmax = (a->openmax || b->openmin);
609 	} else {
610 		c->max = UINT_MAX;
611 		c->openmax = 0;
612 	}
613 	c->integer = 0;
614 }
615 
616 /* ---- */
617 
618 
619 /**
620  * snd_interval_ratnum - refine the interval value
621  * @i: interval to refine
622  * @rats_count: number of ratnum_t
623  * @rats: ratnum_t array
624  * @nump: pointer to store the resultant numerator
625  * @denp: pointer to store the resultant denominator
626  *
627  * Returns non-zero if the value is changed, zero if not changed.
628  */
629 int snd_interval_ratnum(struct snd_interval *i,
630 			unsigned int rats_count, struct snd_ratnum *rats,
631 			unsigned int *nump, unsigned int *denp)
632 {
633 	unsigned int best_num, best_diff, best_den;
634 	unsigned int k;
635 	struct snd_interval t;
636 	int err;
637 
638 	best_num = best_den = best_diff = 0;
639 	for (k = 0; k < rats_count; ++k) {
640 		unsigned int num = rats[k].num;
641 		unsigned int den;
642 		unsigned int q = i->min;
643 		int diff;
644 		if (q == 0)
645 			q = 1;
646 		den = div_down(num, q);
647 		if (den < rats[k].den_min)
648 			continue;
649 		if (den > rats[k].den_max)
650 			den = rats[k].den_max;
651 		else {
652 			unsigned int r;
653 			r = (den - rats[k].den_min) % rats[k].den_step;
654 			if (r != 0)
655 				den -= r;
656 		}
657 		diff = num - q * den;
658 		if (best_num == 0 ||
659 		    diff * best_den < best_diff * den) {
660 			best_diff = diff;
661 			best_den = den;
662 			best_num = num;
663 		}
664 	}
665 	if (best_den == 0) {
666 		i->empty = 1;
667 		return -EINVAL;
668 	}
669 	t.min = div_down(best_num, best_den);
670 	t.openmin = !!(best_num % best_den);
671 
672 	best_num = best_den = best_diff = 0;
673 	for (k = 0; k < rats_count; ++k) {
674 		unsigned int num = rats[k].num;
675 		unsigned int den;
676 		unsigned int q = i->max;
677 		int diff;
678 		if (q == 0) {
679 			i->empty = 1;
680 			return -EINVAL;
681 		}
682 		den = div_up(num, q);
683 		if (den > rats[k].den_max)
684 			continue;
685 		if (den < rats[k].den_min)
686 			den = rats[k].den_min;
687 		else {
688 			unsigned int r;
689 			r = (den - rats[k].den_min) % rats[k].den_step;
690 			if (r != 0)
691 				den += rats[k].den_step - r;
692 		}
693 		diff = q * den - num;
694 		if (best_num == 0 ||
695 		    diff * best_den < best_diff * den) {
696 			best_diff = diff;
697 			best_den = den;
698 			best_num = num;
699 		}
700 	}
701 	if (best_den == 0) {
702 		i->empty = 1;
703 		return -EINVAL;
704 	}
705 	t.max = div_up(best_num, best_den);
706 	t.openmax = !!(best_num % best_den);
707 	t.integer = 0;
708 	err = snd_interval_refine(i, &t);
709 	if (err < 0)
710 		return err;
711 
712 	if (snd_interval_single(i)) {
713 		if (nump)
714 			*nump = best_num;
715 		if (denp)
716 			*denp = best_den;
717 	}
718 	return err;
719 }
720 
721 EXPORT_SYMBOL(snd_interval_ratnum);
722 
723 /**
724  * snd_interval_ratden - refine the interval value
725  * @i: interval to refine
726  * @rats_count: number of struct ratden
727  * @rats: struct ratden array
728  * @nump: pointer to store the resultant numerator
729  * @denp: pointer to store the resultant denominator
730  *
731  * Returns non-zero if the value is changed, zero if not changed.
732  */
733 static int snd_interval_ratden(struct snd_interval *i,
734 			       unsigned int rats_count, struct snd_ratden *rats,
735 			       unsigned int *nump, unsigned int *denp)
736 {
737 	unsigned int best_num, best_diff, best_den;
738 	unsigned int k;
739 	struct snd_interval t;
740 	int err;
741 
742 	best_num = best_den = best_diff = 0;
743 	for (k = 0; k < rats_count; ++k) {
744 		unsigned int num;
745 		unsigned int den = rats[k].den;
746 		unsigned int q = i->min;
747 		int diff;
748 		num = mul(q, den);
749 		if (num > rats[k].num_max)
750 			continue;
751 		if (num < rats[k].num_min)
752 			num = rats[k].num_max;
753 		else {
754 			unsigned int r;
755 			r = (num - rats[k].num_min) % rats[k].num_step;
756 			if (r != 0)
757 				num += rats[k].num_step - r;
758 		}
759 		diff = num - q * den;
760 		if (best_num == 0 ||
761 		    diff * best_den < best_diff * den) {
762 			best_diff = diff;
763 			best_den = den;
764 			best_num = num;
765 		}
766 	}
767 	if (best_den == 0) {
768 		i->empty = 1;
769 		return -EINVAL;
770 	}
771 	t.min = div_down(best_num, best_den);
772 	t.openmin = !!(best_num % best_den);
773 
774 	best_num = best_den = best_diff = 0;
775 	for (k = 0; k < rats_count; ++k) {
776 		unsigned int num;
777 		unsigned int den = rats[k].den;
778 		unsigned int q = i->max;
779 		int diff;
780 		num = mul(q, den);
781 		if (num < rats[k].num_min)
782 			continue;
783 		if (num > rats[k].num_max)
784 			num = rats[k].num_max;
785 		else {
786 			unsigned int r;
787 			r = (num - rats[k].num_min) % rats[k].num_step;
788 			if (r != 0)
789 				num -= r;
790 		}
791 		diff = q * den - num;
792 		if (best_num == 0 ||
793 		    diff * best_den < best_diff * den) {
794 			best_diff = diff;
795 			best_den = den;
796 			best_num = num;
797 		}
798 	}
799 	if (best_den == 0) {
800 		i->empty = 1;
801 		return -EINVAL;
802 	}
803 	t.max = div_up(best_num, best_den);
804 	t.openmax = !!(best_num % best_den);
805 	t.integer = 0;
806 	err = snd_interval_refine(i, &t);
807 	if (err < 0)
808 		return err;
809 
810 	if (snd_interval_single(i)) {
811 		if (nump)
812 			*nump = best_num;
813 		if (denp)
814 			*denp = best_den;
815 	}
816 	return err;
817 }
818 
819 /**
820  * snd_interval_list - refine the interval value from the list
821  * @i: the interval value to refine
822  * @count: the number of elements in the list
823  * @list: the value list
824  * @mask: the bit-mask to evaluate
825  *
826  * Refines the interval value from the list.
827  * When mask is non-zero, only the elements corresponding to bit 1 are
828  * evaluated.
829  *
830  * Returns non-zero if the value is changed, zero if not changed.
831  */
832 int snd_interval_list(struct snd_interval *i, unsigned int count, unsigned int *list, unsigned int mask)
833 {
834         unsigned int k;
835 	int changed = 0;
836 
837 	if (!count) {
838 		i->empty = 1;
839 		return -EINVAL;
840 	}
841         for (k = 0; k < count; k++) {
842 		if (mask && !(mask & (1 << k)))
843 			continue;
844                 if (i->min == list[k] && !i->openmin)
845                         goto _l1;
846                 if (i->min < list[k]) {
847                         i->min = list[k];
848 			i->openmin = 0;
849 			changed = 1;
850                         goto _l1;
851                 }
852         }
853         i->empty = 1;
854         return -EINVAL;
855  _l1:
856         for (k = count; k-- > 0;) {
857 		if (mask && !(mask & (1 << k)))
858 			continue;
859                 if (i->max == list[k] && !i->openmax)
860                         goto _l2;
861                 if (i->max > list[k]) {
862                         i->max = list[k];
863 			i->openmax = 0;
864 			changed = 1;
865                         goto _l2;
866                 }
867         }
868         i->empty = 1;
869         return -EINVAL;
870  _l2:
871 	if (snd_interval_checkempty(i)) {
872 		i->empty = 1;
873 		return -EINVAL;
874 	}
875         return changed;
876 }
877 
878 EXPORT_SYMBOL(snd_interval_list);
879 
880 static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned int step)
881 {
882 	unsigned int n;
883 	int changed = 0;
884 	n = (i->min - min) % step;
885 	if (n != 0 || i->openmin) {
886 		i->min += step - n;
887 		changed = 1;
888 	}
889 	n = (i->max - min) % step;
890 	if (n != 0 || i->openmax) {
891 		i->max -= n;
892 		changed = 1;
893 	}
894 	if (snd_interval_checkempty(i)) {
895 		i->empty = 1;
896 		return -EINVAL;
897 	}
898 	return changed;
899 }
900 
901 /* Info constraints helpers */
902 
903 /**
904  * snd_pcm_hw_rule_add - add the hw-constraint rule
905  * @runtime: the pcm runtime instance
906  * @cond: condition bits
907  * @var: the variable to evaluate
908  * @func: the evaluation function
909  * @private: the private data pointer passed to function
910  * @dep: the dependent variables
911  *
912  * Returns zero if successful, or a negative error code on failure.
913  */
914 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
915 			int var,
916 			snd_pcm_hw_rule_func_t func, void *private,
917 			int dep, ...)
918 {
919 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
920 	struct snd_pcm_hw_rule *c;
921 	unsigned int k;
922 	va_list args;
923 	va_start(args, dep);
924 	if (constrs->rules_num >= constrs->rules_all) {
925 		struct snd_pcm_hw_rule *new;
926 		unsigned int new_rules = constrs->rules_all + 16;
927 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
928 		if (!new)
929 			return -ENOMEM;
930 		if (constrs->rules) {
931 			memcpy(new, constrs->rules,
932 			       constrs->rules_num * sizeof(*c));
933 			kfree(constrs->rules);
934 		}
935 		constrs->rules = new;
936 		constrs->rules_all = new_rules;
937 	}
938 	c = &constrs->rules[constrs->rules_num];
939 	c->cond = cond;
940 	c->func = func;
941 	c->var = var;
942 	c->private = private;
943 	k = 0;
944 	while (1) {
945 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps)))
946 			return -EINVAL;
947 		c->deps[k++] = dep;
948 		if (dep < 0)
949 			break;
950 		dep = va_arg(args, int);
951 	}
952 	constrs->rules_num++;
953 	va_end(args);
954 	return 0;
955 }
956 
957 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
958 
959 /**
960  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
961  * @runtime: PCM runtime instance
962  * @var: hw_params variable to apply the mask
963  * @mask: the bitmap mask
964  *
965  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
966  */
967 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
968 			       u_int32_t mask)
969 {
970 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
971 	struct snd_mask *maskp = constrs_mask(constrs, var);
972 	*maskp->bits &= mask;
973 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
974 	if (*maskp->bits == 0)
975 		return -EINVAL;
976 	return 0;
977 }
978 
979 /**
980  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
981  * @runtime: PCM runtime instance
982  * @var: hw_params variable to apply the mask
983  * @mask: the 64bit bitmap mask
984  *
985  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
986  */
987 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
988 				 u_int64_t mask)
989 {
990 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
991 	struct snd_mask *maskp = constrs_mask(constrs, var);
992 	maskp->bits[0] &= (u_int32_t)mask;
993 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
994 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
995 	if (! maskp->bits[0] && ! maskp->bits[1])
996 		return -EINVAL;
997 	return 0;
998 }
999 
1000 /**
1001  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1002  * @runtime: PCM runtime instance
1003  * @var: hw_params variable to apply the integer constraint
1004  *
1005  * Apply the constraint of integer to an interval parameter.
1006  */
1007 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1008 {
1009 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1010 	return snd_interval_setinteger(constrs_interval(constrs, var));
1011 }
1012 
1013 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1014 
1015 /**
1016  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1017  * @runtime: PCM runtime instance
1018  * @var: hw_params variable to apply the range
1019  * @min: the minimal value
1020  * @max: the maximal value
1021  *
1022  * Apply the min/max range constraint to an interval parameter.
1023  */
1024 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1025 				 unsigned int min, unsigned int max)
1026 {
1027 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1028 	struct snd_interval t;
1029 	t.min = min;
1030 	t.max = max;
1031 	t.openmin = t.openmax = 0;
1032 	t.integer = 0;
1033 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1034 }
1035 
1036 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1037 
1038 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1039 				struct snd_pcm_hw_rule *rule)
1040 {
1041 	struct snd_pcm_hw_constraint_list *list = rule->private;
1042 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1043 }
1044 
1045 
1046 /**
1047  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1048  * @runtime: PCM runtime instance
1049  * @cond: condition bits
1050  * @var: hw_params variable to apply the list constraint
1051  * @l: list
1052  *
1053  * Apply the list of constraints to an interval parameter.
1054  */
1055 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1056 			       unsigned int cond,
1057 			       snd_pcm_hw_param_t var,
1058 			       struct snd_pcm_hw_constraint_list *l)
1059 {
1060 	return snd_pcm_hw_rule_add(runtime, cond, var,
1061 				   snd_pcm_hw_rule_list, l,
1062 				   var, -1);
1063 }
1064 
1065 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1066 
1067 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1068 				   struct snd_pcm_hw_rule *rule)
1069 {
1070 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1071 	unsigned int num = 0, den = 0;
1072 	int err;
1073 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1074 				  r->nrats, r->rats, &num, &den);
1075 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1076 		params->rate_num = num;
1077 		params->rate_den = den;
1078 	}
1079 	return err;
1080 }
1081 
1082 /**
1083  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1084  * @runtime: PCM runtime instance
1085  * @cond: condition bits
1086  * @var: hw_params variable to apply the ratnums constraint
1087  * @r: struct snd_ratnums constriants
1088  */
1089 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1090 				  unsigned int cond,
1091 				  snd_pcm_hw_param_t var,
1092 				  struct snd_pcm_hw_constraint_ratnums *r)
1093 {
1094 	return snd_pcm_hw_rule_add(runtime, cond, var,
1095 				   snd_pcm_hw_rule_ratnums, r,
1096 				   var, -1);
1097 }
1098 
1099 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1100 
1101 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1102 				   struct snd_pcm_hw_rule *rule)
1103 {
1104 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1105 	unsigned int num = 0, den = 0;
1106 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1107 				  r->nrats, r->rats, &num, &den);
1108 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1109 		params->rate_num = num;
1110 		params->rate_den = den;
1111 	}
1112 	return err;
1113 }
1114 
1115 /**
1116  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1117  * @runtime: PCM runtime instance
1118  * @cond: condition bits
1119  * @var: hw_params variable to apply the ratdens constraint
1120  * @r: struct snd_ratdens constriants
1121  */
1122 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1123 				  unsigned int cond,
1124 				  snd_pcm_hw_param_t var,
1125 				  struct snd_pcm_hw_constraint_ratdens *r)
1126 {
1127 	return snd_pcm_hw_rule_add(runtime, cond, var,
1128 				   snd_pcm_hw_rule_ratdens, r,
1129 				   var, -1);
1130 }
1131 
1132 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1133 
1134 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1135 				  struct snd_pcm_hw_rule *rule)
1136 {
1137 	unsigned int l = (unsigned long) rule->private;
1138 	int width = l & 0xffff;
1139 	unsigned int msbits = l >> 16;
1140 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1141 	if (snd_interval_single(i) && snd_interval_value(i) == width)
1142 		params->msbits = msbits;
1143 	return 0;
1144 }
1145 
1146 /**
1147  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1148  * @runtime: PCM runtime instance
1149  * @cond: condition bits
1150  * @width: sample bits width
1151  * @msbits: msbits width
1152  */
1153 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1154 				 unsigned int cond,
1155 				 unsigned int width,
1156 				 unsigned int msbits)
1157 {
1158 	unsigned long l = (msbits << 16) | width;
1159 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1160 				    snd_pcm_hw_rule_msbits,
1161 				    (void*) l,
1162 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1163 }
1164 
1165 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1166 
1167 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1168 				struct snd_pcm_hw_rule *rule)
1169 {
1170 	unsigned long step = (unsigned long) rule->private;
1171 	return snd_interval_step(hw_param_interval(params, rule->var), 0, step);
1172 }
1173 
1174 /**
1175  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1176  * @runtime: PCM runtime instance
1177  * @cond: condition bits
1178  * @var: hw_params variable to apply the step constraint
1179  * @step: step size
1180  */
1181 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1182 			       unsigned int cond,
1183 			       snd_pcm_hw_param_t var,
1184 			       unsigned long step)
1185 {
1186 	return snd_pcm_hw_rule_add(runtime, cond, var,
1187 				   snd_pcm_hw_rule_step, (void *) step,
1188 				   var, -1);
1189 }
1190 
1191 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1192 
1193 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1194 {
1195 	static unsigned int pow2_sizes[] = {
1196 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1197 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1198 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1199 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1200 	};
1201 	return snd_interval_list(hw_param_interval(params, rule->var),
1202 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1203 }
1204 
1205 /**
1206  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1207  * @runtime: PCM runtime instance
1208  * @cond: condition bits
1209  * @var: hw_params variable to apply the power-of-2 constraint
1210  */
1211 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1212 			       unsigned int cond,
1213 			       snd_pcm_hw_param_t var)
1214 {
1215 	return snd_pcm_hw_rule_add(runtime, cond, var,
1216 				   snd_pcm_hw_rule_pow2, NULL,
1217 				   var, -1);
1218 }
1219 
1220 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1221 
1222 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1223 				  snd_pcm_hw_param_t var)
1224 {
1225 	if (hw_is_mask(var)) {
1226 		snd_mask_any(hw_param_mask(params, var));
1227 		params->cmask |= 1 << var;
1228 		params->rmask |= 1 << var;
1229 		return;
1230 	}
1231 	if (hw_is_interval(var)) {
1232 		snd_interval_any(hw_param_interval(params, var));
1233 		params->cmask |= 1 << var;
1234 		params->rmask |= 1 << var;
1235 		return;
1236 	}
1237 	snd_BUG();
1238 }
1239 
1240 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1241 {
1242 	unsigned int k;
1243 	memset(params, 0, sizeof(*params));
1244 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1245 		_snd_pcm_hw_param_any(params, k);
1246 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1247 		_snd_pcm_hw_param_any(params, k);
1248 	params->info = ~0U;
1249 }
1250 
1251 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1252 
1253 /**
1254  * snd_pcm_hw_param_value - return @params field @var value
1255  * @params: the hw_params instance
1256  * @var: parameter to retrieve
1257  * @dir: pointer to the direction (-1,0,1) or %NULL
1258  *
1259  * Return the value for field @var if it's fixed in configuration space
1260  * defined by @params. Return -%EINVAL otherwise.
1261  */
1262 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1263 			   snd_pcm_hw_param_t var, int *dir)
1264 {
1265 	if (hw_is_mask(var)) {
1266 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1267 		if (!snd_mask_single(mask))
1268 			return -EINVAL;
1269 		if (dir)
1270 			*dir = 0;
1271 		return snd_mask_value(mask);
1272 	}
1273 	if (hw_is_interval(var)) {
1274 		const struct snd_interval *i = hw_param_interval_c(params, var);
1275 		if (!snd_interval_single(i))
1276 			return -EINVAL;
1277 		if (dir)
1278 			*dir = i->openmin;
1279 		return snd_interval_value(i);
1280 	}
1281 	return -EINVAL;
1282 }
1283 
1284 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1285 
1286 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1287 				snd_pcm_hw_param_t var)
1288 {
1289 	if (hw_is_mask(var)) {
1290 		snd_mask_none(hw_param_mask(params, var));
1291 		params->cmask |= 1 << var;
1292 		params->rmask |= 1 << var;
1293 	} else if (hw_is_interval(var)) {
1294 		snd_interval_none(hw_param_interval(params, var));
1295 		params->cmask |= 1 << var;
1296 		params->rmask |= 1 << var;
1297 	} else {
1298 		snd_BUG();
1299 	}
1300 }
1301 
1302 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1303 
1304 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1305 				   snd_pcm_hw_param_t var)
1306 {
1307 	int changed;
1308 	if (hw_is_mask(var))
1309 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1310 	else if (hw_is_interval(var))
1311 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1312 	else
1313 		return -EINVAL;
1314 	if (changed) {
1315 		params->cmask |= 1 << var;
1316 		params->rmask |= 1 << var;
1317 	}
1318 	return changed;
1319 }
1320 
1321 
1322 /**
1323  * snd_pcm_hw_param_first - refine config space and return minimum value
1324  * @pcm: PCM instance
1325  * @params: the hw_params instance
1326  * @var: parameter to retrieve
1327  * @dir: pointer to the direction (-1,0,1) or %NULL
1328  *
1329  * Inside configuration space defined by @params remove from @var all
1330  * values > minimum. Reduce configuration space accordingly.
1331  * Return the minimum.
1332  */
1333 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1334 			   struct snd_pcm_hw_params *params,
1335 			   snd_pcm_hw_param_t var, int *dir)
1336 {
1337 	int changed = _snd_pcm_hw_param_first(params, var);
1338 	if (changed < 0)
1339 		return changed;
1340 	if (params->rmask) {
1341 		int err = snd_pcm_hw_refine(pcm, params);
1342 		if (snd_BUG_ON(err < 0))
1343 			return err;
1344 	}
1345 	return snd_pcm_hw_param_value(params, var, dir);
1346 }
1347 
1348 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1349 
1350 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1351 				  snd_pcm_hw_param_t var)
1352 {
1353 	int changed;
1354 	if (hw_is_mask(var))
1355 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1356 	else if (hw_is_interval(var))
1357 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1358 	else
1359 		return -EINVAL;
1360 	if (changed) {
1361 		params->cmask |= 1 << var;
1362 		params->rmask |= 1 << var;
1363 	}
1364 	return changed;
1365 }
1366 
1367 
1368 /**
1369  * snd_pcm_hw_param_last - refine config space and return maximum value
1370  * @pcm: PCM instance
1371  * @params: the hw_params instance
1372  * @var: parameter to retrieve
1373  * @dir: pointer to the direction (-1,0,1) or %NULL
1374  *
1375  * Inside configuration space defined by @params remove from @var all
1376  * values < maximum. Reduce configuration space accordingly.
1377  * Return the maximum.
1378  */
1379 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1380 			  struct snd_pcm_hw_params *params,
1381 			  snd_pcm_hw_param_t var, int *dir)
1382 {
1383 	int changed = _snd_pcm_hw_param_last(params, var);
1384 	if (changed < 0)
1385 		return changed;
1386 	if (params->rmask) {
1387 		int err = snd_pcm_hw_refine(pcm, params);
1388 		if (snd_BUG_ON(err < 0))
1389 			return err;
1390 	}
1391 	return snd_pcm_hw_param_value(params, var, dir);
1392 }
1393 
1394 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1395 
1396 /**
1397  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1398  * @pcm: PCM instance
1399  * @params: the hw_params instance
1400  *
1401  * Choose one configuration from configuration space defined by @params.
1402  * The configuration chosen is that obtained fixing in this order:
1403  * first access, first format, first subformat, min channels,
1404  * min rate, min period time, max buffer size, min tick time
1405  */
1406 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1407 			     struct snd_pcm_hw_params *params)
1408 {
1409 	static int vars[] = {
1410 		SNDRV_PCM_HW_PARAM_ACCESS,
1411 		SNDRV_PCM_HW_PARAM_FORMAT,
1412 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1413 		SNDRV_PCM_HW_PARAM_CHANNELS,
1414 		SNDRV_PCM_HW_PARAM_RATE,
1415 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1416 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1417 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1418 		-1
1419 	};
1420 	int err, *v;
1421 
1422 	for (v = vars; *v != -1; v++) {
1423 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1424 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1425 		else
1426 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1427 		if (snd_BUG_ON(err < 0))
1428 			return err;
1429 	}
1430 	return 0;
1431 }
1432 
1433 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1434 				   void *arg)
1435 {
1436 	struct snd_pcm_runtime *runtime = substream->runtime;
1437 	unsigned long flags;
1438 	snd_pcm_stream_lock_irqsave(substream, flags);
1439 	if (snd_pcm_running(substream) &&
1440 	    snd_pcm_update_hw_ptr(substream) >= 0)
1441 		runtime->status->hw_ptr %= runtime->buffer_size;
1442 	else
1443 		runtime->status->hw_ptr = 0;
1444 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1445 	return 0;
1446 }
1447 
1448 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1449 					  void *arg)
1450 {
1451 	struct snd_pcm_channel_info *info = arg;
1452 	struct snd_pcm_runtime *runtime = substream->runtime;
1453 	int width;
1454 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1455 		info->offset = -1;
1456 		return 0;
1457 	}
1458 	width = snd_pcm_format_physical_width(runtime->format);
1459 	if (width < 0)
1460 		return width;
1461 	info->offset = 0;
1462 	switch (runtime->access) {
1463 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1464 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1465 		info->first = info->channel * width;
1466 		info->step = runtime->channels * width;
1467 		break;
1468 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1469 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1470 	{
1471 		size_t size = runtime->dma_bytes / runtime->channels;
1472 		info->first = info->channel * size * 8;
1473 		info->step = width;
1474 		break;
1475 	}
1476 	default:
1477 		snd_BUG();
1478 		break;
1479 	}
1480 	return 0;
1481 }
1482 
1483 /**
1484  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1485  * @substream: the pcm substream instance
1486  * @cmd: ioctl command
1487  * @arg: ioctl argument
1488  *
1489  * Processes the generic ioctl commands for PCM.
1490  * Can be passed as the ioctl callback for PCM ops.
1491  *
1492  * Returns zero if successful, or a negative error code on failure.
1493  */
1494 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1495 		      unsigned int cmd, void *arg)
1496 {
1497 	switch (cmd) {
1498 	case SNDRV_PCM_IOCTL1_INFO:
1499 		return 0;
1500 	case SNDRV_PCM_IOCTL1_RESET:
1501 		return snd_pcm_lib_ioctl_reset(substream, arg);
1502 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1503 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1504 	}
1505 	return -ENXIO;
1506 }
1507 
1508 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1509 
1510 /**
1511  * snd_pcm_period_elapsed - update the pcm status for the next period
1512  * @substream: the pcm substream instance
1513  *
1514  * This function is called from the interrupt handler when the
1515  * PCM has processed the period size.  It will update the current
1516  * pointer, wake up sleepers, etc.
1517  *
1518  * Even if more than one periods have elapsed since the last call, you
1519  * have to call this only once.
1520  */
1521 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1522 {
1523 	struct snd_pcm_runtime *runtime;
1524 	unsigned long flags;
1525 
1526 	if (PCM_RUNTIME_CHECK(substream))
1527 		return;
1528 	runtime = substream->runtime;
1529 
1530 	if (runtime->transfer_ack_begin)
1531 		runtime->transfer_ack_begin(substream);
1532 
1533 	snd_pcm_stream_lock_irqsave(substream, flags);
1534 	if (!snd_pcm_running(substream) ||
1535 	    snd_pcm_update_hw_ptr_interrupt(substream) < 0)
1536 		goto _end;
1537 
1538 	if (substream->timer_running)
1539 		snd_timer_interrupt(substream->timer, 1);
1540  _end:
1541 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1542 	if (runtime->transfer_ack_end)
1543 		runtime->transfer_ack_end(substream);
1544 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1545 }
1546 
1547 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1548 
1549 /*
1550  * Wait until avail_min data becomes available
1551  * Returns a negative error code if any error occurs during operation.
1552  * The available space is stored on availp.  When err = 0 and avail = 0
1553  * on the capture stream, it indicates the stream is in DRAINING state.
1554  */
1555 static int wait_for_avail_min(struct snd_pcm_substream *substream,
1556 			      snd_pcm_uframes_t *availp)
1557 {
1558 	struct snd_pcm_runtime *runtime = substream->runtime;
1559 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1560 	wait_queue_t wait;
1561 	int err = 0;
1562 	snd_pcm_uframes_t avail = 0;
1563 	long tout;
1564 
1565 	init_waitqueue_entry(&wait, current);
1566 	add_wait_queue(&runtime->sleep, &wait);
1567 	for (;;) {
1568 		if (signal_pending(current)) {
1569 			err = -ERESTARTSYS;
1570 			break;
1571 		}
1572 		set_current_state(TASK_INTERRUPTIBLE);
1573 		snd_pcm_stream_unlock_irq(substream);
1574 		tout = schedule_timeout(msecs_to_jiffies(10000));
1575 		snd_pcm_stream_lock_irq(substream);
1576 		switch (runtime->status->state) {
1577 		case SNDRV_PCM_STATE_SUSPENDED:
1578 			err = -ESTRPIPE;
1579 			goto _endloop;
1580 		case SNDRV_PCM_STATE_XRUN:
1581 			err = -EPIPE;
1582 			goto _endloop;
1583 		case SNDRV_PCM_STATE_DRAINING:
1584 			if (is_playback)
1585 				err = -EPIPE;
1586 			else
1587 				avail = 0; /* indicate draining */
1588 			goto _endloop;
1589 		case SNDRV_PCM_STATE_OPEN:
1590 		case SNDRV_PCM_STATE_SETUP:
1591 		case SNDRV_PCM_STATE_DISCONNECTED:
1592 			err = -EBADFD;
1593 			goto _endloop;
1594 		}
1595 		if (!tout) {
1596 			snd_printd("%s write error (DMA or IRQ trouble?)\n",
1597 				   is_playback ? "playback" : "capture");
1598 			err = -EIO;
1599 			break;
1600 		}
1601 		if (is_playback)
1602 			avail = snd_pcm_playback_avail(runtime);
1603 		else
1604 			avail = snd_pcm_capture_avail(runtime);
1605 		if (avail >= runtime->control->avail_min)
1606 			break;
1607 	}
1608  _endloop:
1609 	remove_wait_queue(&runtime->sleep, &wait);
1610 	*availp = avail;
1611 	return err;
1612 }
1613 
1614 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1615 				      unsigned int hwoff,
1616 				      unsigned long data, unsigned int off,
1617 				      snd_pcm_uframes_t frames)
1618 {
1619 	struct snd_pcm_runtime *runtime = substream->runtime;
1620 	int err;
1621 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1622 	if (substream->ops->copy) {
1623 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1624 			return err;
1625 	} else {
1626 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1627 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1628 			return -EFAULT;
1629 	}
1630 	return 0;
1631 }
1632 
1633 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1634 			  unsigned long data, unsigned int off,
1635 			  snd_pcm_uframes_t size);
1636 
1637 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1638 					    unsigned long data,
1639 					    snd_pcm_uframes_t size,
1640 					    int nonblock,
1641 					    transfer_f transfer)
1642 {
1643 	struct snd_pcm_runtime *runtime = substream->runtime;
1644 	snd_pcm_uframes_t xfer = 0;
1645 	snd_pcm_uframes_t offset = 0;
1646 	int err = 0;
1647 
1648 	if (size == 0)
1649 		return 0;
1650 
1651 	snd_pcm_stream_lock_irq(substream);
1652 	switch (runtime->status->state) {
1653 	case SNDRV_PCM_STATE_PREPARED:
1654 	case SNDRV_PCM_STATE_RUNNING:
1655 	case SNDRV_PCM_STATE_PAUSED:
1656 		break;
1657 	case SNDRV_PCM_STATE_XRUN:
1658 		err = -EPIPE;
1659 		goto _end_unlock;
1660 	case SNDRV_PCM_STATE_SUSPENDED:
1661 		err = -ESTRPIPE;
1662 		goto _end_unlock;
1663 	default:
1664 		err = -EBADFD;
1665 		goto _end_unlock;
1666 	}
1667 
1668 	while (size > 0) {
1669 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1670 		snd_pcm_uframes_t avail;
1671 		snd_pcm_uframes_t cont;
1672 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1673 			snd_pcm_update_hw_ptr(substream);
1674 		avail = snd_pcm_playback_avail(runtime);
1675 		if (!avail) {
1676 			if (nonblock) {
1677 				err = -EAGAIN;
1678 				goto _end_unlock;
1679 			}
1680 			err = wait_for_avail_min(substream, &avail);
1681 			if (err < 0)
1682 				goto _end_unlock;
1683 		}
1684 		frames = size > avail ? avail : size;
1685 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
1686 		if (frames > cont)
1687 			frames = cont;
1688 		if (snd_BUG_ON(!frames)) {
1689 			snd_pcm_stream_unlock_irq(substream);
1690 			return -EINVAL;
1691 		}
1692 		appl_ptr = runtime->control->appl_ptr;
1693 		appl_ofs = appl_ptr % runtime->buffer_size;
1694 		snd_pcm_stream_unlock_irq(substream);
1695 		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
1696 			goto _end;
1697 		snd_pcm_stream_lock_irq(substream);
1698 		switch (runtime->status->state) {
1699 		case SNDRV_PCM_STATE_XRUN:
1700 			err = -EPIPE;
1701 			goto _end_unlock;
1702 		case SNDRV_PCM_STATE_SUSPENDED:
1703 			err = -ESTRPIPE;
1704 			goto _end_unlock;
1705 		default:
1706 			break;
1707 		}
1708 		appl_ptr += frames;
1709 		if (appl_ptr >= runtime->boundary)
1710 			appl_ptr -= runtime->boundary;
1711 		runtime->control->appl_ptr = appl_ptr;
1712 		if (substream->ops->ack)
1713 			substream->ops->ack(substream);
1714 
1715 		offset += frames;
1716 		size -= frames;
1717 		xfer += frames;
1718 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
1719 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
1720 			err = snd_pcm_start(substream);
1721 			if (err < 0)
1722 				goto _end_unlock;
1723 		}
1724 	}
1725  _end_unlock:
1726 	snd_pcm_stream_unlock_irq(substream);
1727  _end:
1728 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
1729 }
1730 
1731 /* sanity-check for read/write methods */
1732 static int pcm_sanity_check(struct snd_pcm_substream *substream)
1733 {
1734 	struct snd_pcm_runtime *runtime;
1735 	if (PCM_RUNTIME_CHECK(substream))
1736 		return -ENXIO;
1737 	runtime = substream->runtime;
1738 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
1739 		return -EINVAL;
1740 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
1741 		return -EBADFD;
1742 	return 0;
1743 }
1744 
1745 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
1746 {
1747 	struct snd_pcm_runtime *runtime;
1748 	int nonblock;
1749 	int err;
1750 
1751 	err = pcm_sanity_check(substream);
1752 	if (err < 0)
1753 		return err;
1754 	runtime = substream->runtime;
1755 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1756 
1757 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
1758 	    runtime->channels > 1)
1759 		return -EINVAL;
1760 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
1761 				  snd_pcm_lib_write_transfer);
1762 }
1763 
1764 EXPORT_SYMBOL(snd_pcm_lib_write);
1765 
1766 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
1767 				       unsigned int hwoff,
1768 				       unsigned long data, unsigned int off,
1769 				       snd_pcm_uframes_t frames)
1770 {
1771 	struct snd_pcm_runtime *runtime = substream->runtime;
1772 	int err;
1773 	void __user **bufs = (void __user **)data;
1774 	int channels = runtime->channels;
1775 	int c;
1776 	if (substream->ops->copy) {
1777 		if (snd_BUG_ON(!substream->ops->silence))
1778 			return -EINVAL;
1779 		for (c = 0; c < channels; ++c, ++bufs) {
1780 			if (*bufs == NULL) {
1781 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
1782 					return err;
1783 			} else {
1784 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1785 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
1786 					return err;
1787 			}
1788 		}
1789 	} else {
1790 		/* default transfer behaviour */
1791 		size_t dma_csize = runtime->dma_bytes / channels;
1792 		for (c = 0; c < channels; ++c, ++bufs) {
1793 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
1794 			if (*bufs == NULL) {
1795 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
1796 			} else {
1797 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1798 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
1799 					return -EFAULT;
1800 			}
1801 		}
1802 	}
1803 	return 0;
1804 }
1805 
1806 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
1807 				     void __user **bufs,
1808 				     snd_pcm_uframes_t frames)
1809 {
1810 	struct snd_pcm_runtime *runtime;
1811 	int nonblock;
1812 	int err;
1813 
1814 	err = pcm_sanity_check(substream);
1815 	if (err < 0)
1816 		return err;
1817 	runtime = substream->runtime;
1818 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1819 
1820 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
1821 		return -EINVAL;
1822 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
1823 				  nonblock, snd_pcm_lib_writev_transfer);
1824 }
1825 
1826 EXPORT_SYMBOL(snd_pcm_lib_writev);
1827 
1828 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
1829 				     unsigned int hwoff,
1830 				     unsigned long data, unsigned int off,
1831 				     snd_pcm_uframes_t frames)
1832 {
1833 	struct snd_pcm_runtime *runtime = substream->runtime;
1834 	int err;
1835 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1836 	if (substream->ops->copy) {
1837 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1838 			return err;
1839 	} else {
1840 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1841 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
1842 			return -EFAULT;
1843 	}
1844 	return 0;
1845 }
1846 
1847 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
1848 					   unsigned long data,
1849 					   snd_pcm_uframes_t size,
1850 					   int nonblock,
1851 					   transfer_f transfer)
1852 {
1853 	struct snd_pcm_runtime *runtime = substream->runtime;
1854 	snd_pcm_uframes_t xfer = 0;
1855 	snd_pcm_uframes_t offset = 0;
1856 	int err = 0;
1857 
1858 	if (size == 0)
1859 		return 0;
1860 
1861 	snd_pcm_stream_lock_irq(substream);
1862 	switch (runtime->status->state) {
1863 	case SNDRV_PCM_STATE_PREPARED:
1864 		if (size >= runtime->start_threshold) {
1865 			err = snd_pcm_start(substream);
1866 			if (err < 0)
1867 				goto _end_unlock;
1868 		}
1869 		break;
1870 	case SNDRV_PCM_STATE_DRAINING:
1871 	case SNDRV_PCM_STATE_RUNNING:
1872 	case SNDRV_PCM_STATE_PAUSED:
1873 		break;
1874 	case SNDRV_PCM_STATE_XRUN:
1875 		err = -EPIPE;
1876 		goto _end_unlock;
1877 	case SNDRV_PCM_STATE_SUSPENDED:
1878 		err = -ESTRPIPE;
1879 		goto _end_unlock;
1880 	default:
1881 		err = -EBADFD;
1882 		goto _end_unlock;
1883 	}
1884 
1885 	while (size > 0) {
1886 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1887 		snd_pcm_uframes_t avail;
1888 		snd_pcm_uframes_t cont;
1889 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1890 			snd_pcm_update_hw_ptr(substream);
1891 		avail = snd_pcm_capture_avail(runtime);
1892 		if (!avail) {
1893 			if (runtime->status->state ==
1894 			    SNDRV_PCM_STATE_DRAINING) {
1895 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
1896 				goto _end_unlock;
1897 			}
1898 			if (nonblock) {
1899 				err = -EAGAIN;
1900 				goto _end_unlock;
1901 			}
1902 			err = wait_for_avail_min(substream, &avail);
1903 			if (err < 0)
1904 				goto _end_unlock;
1905 			if (!avail)
1906 				continue; /* draining */
1907 		}
1908 		frames = size > avail ? avail : size;
1909 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
1910 		if (frames > cont)
1911 			frames = cont;
1912 		if (snd_BUG_ON(!frames)) {
1913 			snd_pcm_stream_unlock_irq(substream);
1914 			return -EINVAL;
1915 		}
1916 		appl_ptr = runtime->control->appl_ptr;
1917 		appl_ofs = appl_ptr % runtime->buffer_size;
1918 		snd_pcm_stream_unlock_irq(substream);
1919 		if ((err = transfer(substream, appl_ofs, data, offset, frames)) < 0)
1920 			goto _end;
1921 		snd_pcm_stream_lock_irq(substream);
1922 		switch (runtime->status->state) {
1923 		case SNDRV_PCM_STATE_XRUN:
1924 			err = -EPIPE;
1925 			goto _end_unlock;
1926 		case SNDRV_PCM_STATE_SUSPENDED:
1927 			err = -ESTRPIPE;
1928 			goto _end_unlock;
1929 		default:
1930 			break;
1931 		}
1932 		appl_ptr += frames;
1933 		if (appl_ptr >= runtime->boundary)
1934 			appl_ptr -= runtime->boundary;
1935 		runtime->control->appl_ptr = appl_ptr;
1936 		if (substream->ops->ack)
1937 			substream->ops->ack(substream);
1938 
1939 		offset += frames;
1940 		size -= frames;
1941 		xfer += frames;
1942 	}
1943  _end_unlock:
1944 	snd_pcm_stream_unlock_irq(substream);
1945  _end:
1946 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
1947 }
1948 
1949 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
1950 {
1951 	struct snd_pcm_runtime *runtime;
1952 	int nonblock;
1953 	int err;
1954 
1955 	err = pcm_sanity_check(substream);
1956 	if (err < 0)
1957 		return err;
1958 	runtime = substream->runtime;
1959 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1960 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
1961 		return -EINVAL;
1962 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
1963 }
1964 
1965 EXPORT_SYMBOL(snd_pcm_lib_read);
1966 
1967 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
1968 				      unsigned int hwoff,
1969 				      unsigned long data, unsigned int off,
1970 				      snd_pcm_uframes_t frames)
1971 {
1972 	struct snd_pcm_runtime *runtime = substream->runtime;
1973 	int err;
1974 	void __user **bufs = (void __user **)data;
1975 	int channels = runtime->channels;
1976 	int c;
1977 	if (substream->ops->copy) {
1978 		for (c = 0; c < channels; ++c, ++bufs) {
1979 			char __user *buf;
1980 			if (*bufs == NULL)
1981 				continue;
1982 			buf = *bufs + samples_to_bytes(runtime, off);
1983 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
1984 				return err;
1985 		}
1986 	} else {
1987 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
1988 		for (c = 0; c < channels; ++c, ++bufs) {
1989 			char *hwbuf;
1990 			char __user *buf;
1991 			if (*bufs == NULL)
1992 				continue;
1993 
1994 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
1995 			buf = *bufs + samples_to_bytes(runtime, off);
1996 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
1997 				return -EFAULT;
1998 		}
1999 	}
2000 	return 0;
2001 }
2002 
2003 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2004 				    void __user **bufs,
2005 				    snd_pcm_uframes_t frames)
2006 {
2007 	struct snd_pcm_runtime *runtime;
2008 	int nonblock;
2009 	int err;
2010 
2011 	err = pcm_sanity_check(substream);
2012 	if (err < 0)
2013 		return err;
2014 	runtime = substream->runtime;
2015 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2016 		return -EBADFD;
2017 
2018 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2019 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2020 		return -EINVAL;
2021 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2022 }
2023 
2024 EXPORT_SYMBOL(snd_pcm_lib_readv);
2025