xref: /openbmc/linux/sound/core/pcm_lib.c (revision 565d76cb)
1 /*
2  *  Digital Audio (PCM) abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *                   Abramo Bagnara <abramo@alsa-project.org>
5  *
6  *
7  *   This program is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with this program; if not, write to the Free Software
19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  *
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/time.h>
25 #include <linux/math64.h>
26 #include <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 			if (avail > runtime->buffer_size)
71 				avail = runtime->buffer_size;
72 			runtime->silence_filled = avail > 0 ? avail : 0;
73 			runtime->silence_start = (runtime->status->hw_ptr +
74 						  runtime->silence_filled) %
75 						 runtime->boundary;
76 		} else {
77 			ofs = runtime->status->hw_ptr;
78 			frames = new_hw_ptr - ofs;
79 			if ((snd_pcm_sframes_t)frames < 0)
80 				frames += runtime->boundary;
81 			runtime->silence_filled -= frames;
82 			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
83 				runtime->silence_filled = 0;
84 				runtime->silence_start = new_hw_ptr;
85 			} else {
86 				runtime->silence_start = ofs;
87 			}
88 		}
89 		frames = runtime->buffer_size - runtime->silence_filled;
90 	}
91 	if (snd_BUG_ON(frames > runtime->buffer_size))
92 		return;
93 	if (frames == 0)
94 		return;
95 	ofs = runtime->silence_start % runtime->buffer_size;
96 	while (frames > 0) {
97 		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
98 		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
99 		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
100 			if (substream->ops->silence) {
101 				int err;
102 				err = substream->ops->silence(substream, -1, ofs, transfer);
103 				snd_BUG_ON(err < 0);
104 			} else {
105 				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
106 				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
107 			}
108 		} else {
109 			unsigned int c;
110 			unsigned int channels = runtime->channels;
111 			if (substream->ops->silence) {
112 				for (c = 0; c < channels; ++c) {
113 					int err;
114 					err = substream->ops->silence(substream, c, ofs, transfer);
115 					snd_BUG_ON(err < 0);
116 				}
117 			} else {
118 				size_t dma_csize = runtime->dma_bytes / channels;
119 				for (c = 0; c < channels; ++c) {
120 					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
121 					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
122 				}
123 			}
124 		}
125 		runtime->silence_filled += transfer;
126 		frames -= transfer;
127 		ofs = 0;
128 	}
129 }
130 
131 static void pcm_debug_name(struct snd_pcm_substream *substream,
132 			   char *name, size_t len)
133 {
134 	snprintf(name, len, "pcmC%dD%d%c:%d",
135 		 substream->pcm->card->number,
136 		 substream->pcm->device,
137 		 substream->stream ? 'c' : 'p',
138 		 substream->number);
139 }
140 
141 #define XRUN_DEBUG_BASIC	(1<<0)
142 #define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
143 #define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
144 #define XRUN_DEBUG_PERIODUPDATE	(1<<3)	/* full period update info */
145 #define XRUN_DEBUG_HWPTRUPDATE	(1<<4)	/* full hwptr update info */
146 #define XRUN_DEBUG_LOG		(1<<5)	/* show last 10 positions on err */
147 #define XRUN_DEBUG_LOGONCE	(1<<6)	/* do above only once */
148 
149 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
150 
151 #define xrun_debug(substream, mask) \
152 			((substream)->pstr->xrun_debug & (mask))
153 #else
154 #define xrun_debug(substream, mask)	0
155 #endif
156 
157 #define dump_stack_on_xrun(substream) do {			\
158 		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
159 			dump_stack();				\
160 	} while (0)
161 
162 static void xrun(struct snd_pcm_substream *substream)
163 {
164 	struct snd_pcm_runtime *runtime = substream->runtime;
165 
166 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
167 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
168 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
169 	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
170 		char name[16];
171 		pcm_debug_name(substream, name, sizeof(name));
172 		snd_printd(KERN_DEBUG "XRUN: %s\n", name);
173 		dump_stack_on_xrun(substream);
174 	}
175 }
176 
177 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
178 #define hw_ptr_error(substream, fmt, args...)				\
179 	do {								\
180 		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
181 			xrun_log_show(substream);			\
182 			if (printk_ratelimit()) {			\
183 				snd_printd("PCM: " fmt, ##args);	\
184 			}						\
185 			dump_stack_on_xrun(substream);			\
186 		}							\
187 	} while (0)
188 
189 #define XRUN_LOG_CNT	10
190 
191 struct hwptr_log_entry {
192 	unsigned long jiffies;
193 	snd_pcm_uframes_t pos;
194 	snd_pcm_uframes_t period_size;
195 	snd_pcm_uframes_t buffer_size;
196 	snd_pcm_uframes_t old_hw_ptr;
197 	snd_pcm_uframes_t hw_ptr_base;
198 };
199 
200 struct snd_pcm_hwptr_log {
201 	unsigned int idx;
202 	unsigned int hit: 1;
203 	struct hwptr_log_entry entries[XRUN_LOG_CNT];
204 };
205 
206 static void xrun_log(struct snd_pcm_substream *substream,
207 		     snd_pcm_uframes_t pos)
208 {
209 	struct snd_pcm_runtime *runtime = substream->runtime;
210 	struct snd_pcm_hwptr_log *log = runtime->hwptr_log;
211 	struct hwptr_log_entry *entry;
212 
213 	if (log == NULL) {
214 		log = kzalloc(sizeof(*log), GFP_ATOMIC);
215 		if (log == NULL)
216 			return;
217 		runtime->hwptr_log = log;
218 	} else {
219 		if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
220 			return;
221 	}
222 	entry = &log->entries[log->idx];
223 	entry->jiffies = jiffies;
224 	entry->pos = pos;
225 	entry->period_size = runtime->period_size;
226 	entry->buffer_size = runtime->buffer_size;
227 	entry->old_hw_ptr = runtime->status->hw_ptr;
228 	entry->hw_ptr_base = runtime->hw_ptr_base;
229 	log->idx = (log->idx + 1) % XRUN_LOG_CNT;
230 }
231 
232 static void xrun_log_show(struct snd_pcm_substream *substream)
233 {
234 	struct snd_pcm_hwptr_log *log = substream->runtime->hwptr_log;
235 	struct hwptr_log_entry *entry;
236 	char name[16];
237 	unsigned int idx;
238 	int cnt;
239 
240 	if (log == NULL)
241 		return;
242 	if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
243 		return;
244 	pcm_debug_name(substream, name, sizeof(name));
245 	for (cnt = 0, idx = log->idx; cnt < XRUN_LOG_CNT; cnt++) {
246 		entry = &log->entries[idx];
247 		if (entry->period_size == 0)
248 			break;
249 		snd_printd("hwptr log: %s: j=%lu, pos=%ld/%ld/%ld, "
250 			   "hwptr=%ld/%ld\n",
251 			   name, entry->jiffies, (unsigned long)entry->pos,
252 			   (unsigned long)entry->period_size,
253 			   (unsigned long)entry->buffer_size,
254 			   (unsigned long)entry->old_hw_ptr,
255 			   (unsigned long)entry->hw_ptr_base);
256 		idx++;
257 		idx %= XRUN_LOG_CNT;
258 	}
259 	log->hit = 1;
260 }
261 
262 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
263 
264 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
265 #define xrun_log(substream, pos)	do { } while (0)
266 #define xrun_log_show(substream)	do { } while (0)
267 
268 #endif
269 
270 int snd_pcm_update_state(struct snd_pcm_substream *substream,
271 			 struct snd_pcm_runtime *runtime)
272 {
273 	snd_pcm_uframes_t avail;
274 
275 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
276 		avail = snd_pcm_playback_avail(runtime);
277 	else
278 		avail = snd_pcm_capture_avail(runtime);
279 	if (avail > runtime->avail_max)
280 		runtime->avail_max = avail;
281 	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
282 		if (avail >= runtime->buffer_size) {
283 			snd_pcm_drain_done(substream);
284 			return -EPIPE;
285 		}
286 	} else {
287 		if (avail >= runtime->stop_threshold) {
288 			xrun(substream);
289 			return -EPIPE;
290 		}
291 	}
292 	if (runtime->twake) {
293 		if (avail >= runtime->twake)
294 			wake_up(&runtime->tsleep);
295 	} else if (avail >= runtime->control->avail_min)
296 		wake_up(&runtime->sleep);
297 	return 0;
298 }
299 
300 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
301 				  unsigned int in_interrupt)
302 {
303 	struct snd_pcm_runtime *runtime = substream->runtime;
304 	snd_pcm_uframes_t pos;
305 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
306 	snd_pcm_sframes_t hdelta, delta;
307 	unsigned long jdelta;
308 
309 	old_hw_ptr = runtime->status->hw_ptr;
310 	pos = substream->ops->pointer(substream);
311 	if (pos == SNDRV_PCM_POS_XRUN) {
312 		xrun(substream);
313 		return -EPIPE;
314 	}
315 	if (pos >= runtime->buffer_size) {
316 		if (printk_ratelimit()) {
317 			char name[16];
318 			pcm_debug_name(substream, name, sizeof(name));
319 			xrun_log_show(substream);
320 			snd_printd(KERN_ERR  "BUG: %s, pos = %ld, "
321 				   "buffer size = %ld, period size = %ld\n",
322 				   name, pos, runtime->buffer_size,
323 				   runtime->period_size);
324 		}
325 		pos = 0;
326 	}
327 	pos -= pos % runtime->min_align;
328 	if (xrun_debug(substream, XRUN_DEBUG_LOG))
329 		xrun_log(substream, pos);
330 	hw_base = runtime->hw_ptr_base;
331 	new_hw_ptr = hw_base + pos;
332 	if (in_interrupt) {
333 		/* we know that one period was processed */
334 		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
335 		delta = runtime->hw_ptr_interrupt + runtime->period_size;
336 		if (delta > new_hw_ptr) {
337 			/* check for double acknowledged interrupts */
338 			hdelta = jiffies - runtime->hw_ptr_jiffies;
339 			if (hdelta > runtime->hw_ptr_buffer_jiffies/2) {
340 				hw_base += runtime->buffer_size;
341 				if (hw_base >= runtime->boundary)
342 					hw_base = 0;
343 				new_hw_ptr = hw_base + pos;
344 				goto __delta;
345 			}
346 		}
347 	}
348 	/* new_hw_ptr might be lower than old_hw_ptr in case when */
349 	/* pointer crosses the end of the ring buffer */
350 	if (new_hw_ptr < old_hw_ptr) {
351 		hw_base += runtime->buffer_size;
352 		if (hw_base >= runtime->boundary)
353 			hw_base = 0;
354 		new_hw_ptr = hw_base + pos;
355 	}
356       __delta:
357 	delta = new_hw_ptr - old_hw_ptr;
358 	if (delta < 0)
359 		delta += runtime->boundary;
360 	if (xrun_debug(substream, in_interrupt ?
361 			XRUN_DEBUG_PERIODUPDATE : XRUN_DEBUG_HWPTRUPDATE)) {
362 		char name[16];
363 		pcm_debug_name(substream, name, sizeof(name));
364 		snd_printd("%s_update: %s: pos=%u/%u/%u, "
365 			   "hwptr=%ld/%ld/%ld/%ld\n",
366 			   in_interrupt ? "period" : "hwptr",
367 			   name,
368 			   (unsigned int)pos,
369 			   (unsigned int)runtime->period_size,
370 			   (unsigned int)runtime->buffer_size,
371 			   (unsigned long)delta,
372 			   (unsigned long)old_hw_ptr,
373 			   (unsigned long)new_hw_ptr,
374 			   (unsigned long)runtime->hw_ptr_base);
375 	}
376 
377 	if (runtime->no_period_wakeup) {
378 		/*
379 		 * Without regular period interrupts, we have to check
380 		 * the elapsed time to detect xruns.
381 		 */
382 		jdelta = jiffies - runtime->hw_ptr_jiffies;
383 		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
384 			goto no_delta_check;
385 		hdelta = jdelta - delta * HZ / runtime->rate;
386 		while (hdelta > runtime->hw_ptr_buffer_jiffies / 2 + 1) {
387 			delta += runtime->buffer_size;
388 			hw_base += runtime->buffer_size;
389 			if (hw_base >= runtime->boundary)
390 				hw_base = 0;
391 			new_hw_ptr = hw_base + pos;
392 			hdelta -= runtime->hw_ptr_buffer_jiffies;
393 		}
394 		goto no_delta_check;
395 	}
396 
397 	/* something must be really wrong */
398 	if (delta >= runtime->buffer_size + runtime->period_size) {
399 		hw_ptr_error(substream,
400 			       "Unexpected hw_pointer value %s"
401 			       "(stream=%i, pos=%ld, new_hw_ptr=%ld, "
402 			       "old_hw_ptr=%ld)\n",
403 				     in_interrupt ? "[Q] " : "[P]",
404 				     substream->stream, (long)pos,
405 				     (long)new_hw_ptr, (long)old_hw_ptr);
406 		return 0;
407 	}
408 
409 	/* Do jiffies check only in xrun_debug mode */
410 	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
411 		goto no_jiffies_check;
412 
413 	/* Skip the jiffies check for hardwares with BATCH flag.
414 	 * Such hardware usually just increases the position at each IRQ,
415 	 * thus it can't give any strange position.
416 	 */
417 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
418 		goto no_jiffies_check;
419 	hdelta = delta;
420 	if (hdelta < runtime->delay)
421 		goto no_jiffies_check;
422 	hdelta -= runtime->delay;
423 	jdelta = jiffies - runtime->hw_ptr_jiffies;
424 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
425 		delta = jdelta /
426 			(((runtime->period_size * HZ) / runtime->rate)
427 								+ HZ/100);
428 		/* move new_hw_ptr according jiffies not pos variable */
429 		new_hw_ptr = old_hw_ptr;
430 		hw_base = delta;
431 		/* use loop to avoid checks for delta overflows */
432 		/* the delta value is small or zero in most cases */
433 		while (delta > 0) {
434 			new_hw_ptr += runtime->period_size;
435 			if (new_hw_ptr >= runtime->boundary)
436 				new_hw_ptr -= runtime->boundary;
437 			delta--;
438 		}
439 		/* align hw_base to buffer_size */
440 		hw_ptr_error(substream,
441 			     "hw_ptr skipping! %s"
442 			     "(pos=%ld, delta=%ld, period=%ld, "
443 			     "jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
444 			     in_interrupt ? "[Q] " : "",
445 			     (long)pos, (long)hdelta,
446 			     (long)runtime->period_size, jdelta,
447 			     ((hdelta * HZ) / runtime->rate), hw_base,
448 			     (unsigned long)old_hw_ptr,
449 			     (unsigned long)new_hw_ptr);
450 		/* reset values to proper state */
451 		delta = 0;
452 		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
453 	}
454  no_jiffies_check:
455 	if (delta > runtime->period_size + runtime->period_size / 2) {
456 		hw_ptr_error(substream,
457 			     "Lost interrupts? %s"
458 			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, "
459 			     "old_hw_ptr=%ld)\n",
460 			     in_interrupt ? "[Q] " : "",
461 			     substream->stream, (long)delta,
462 			     (long)new_hw_ptr,
463 			     (long)old_hw_ptr);
464 	}
465 
466  no_delta_check:
467 	if (runtime->status->hw_ptr == new_hw_ptr)
468 		return 0;
469 
470 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
471 	    runtime->silence_size > 0)
472 		snd_pcm_playback_silence(substream, new_hw_ptr);
473 
474 	if (in_interrupt) {
475 		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
476 		if (delta < 0)
477 			delta += runtime->boundary;
478 		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
479 		runtime->hw_ptr_interrupt += delta;
480 		if (runtime->hw_ptr_interrupt >= runtime->boundary)
481 			runtime->hw_ptr_interrupt -= runtime->boundary;
482 	}
483 	runtime->hw_ptr_base = hw_base;
484 	runtime->status->hw_ptr = new_hw_ptr;
485 	runtime->hw_ptr_jiffies = jiffies;
486 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
487 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
488 
489 	return snd_pcm_update_state(substream, runtime);
490 }
491 
492 /* CAUTION: call it with irq disabled */
493 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
494 {
495 	return snd_pcm_update_hw_ptr0(substream, 0);
496 }
497 
498 /**
499  * snd_pcm_set_ops - set the PCM operators
500  * @pcm: the pcm instance
501  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
502  * @ops: the operator table
503  *
504  * Sets the given PCM operators to the pcm instance.
505  */
506 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, struct snd_pcm_ops *ops)
507 {
508 	struct snd_pcm_str *stream = &pcm->streams[direction];
509 	struct snd_pcm_substream *substream;
510 
511 	for (substream = stream->substream; substream != NULL; substream = substream->next)
512 		substream->ops = ops;
513 }
514 
515 EXPORT_SYMBOL(snd_pcm_set_ops);
516 
517 /**
518  * snd_pcm_sync - set the PCM sync id
519  * @substream: the pcm substream
520  *
521  * Sets the PCM sync identifier for the card.
522  */
523 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
524 {
525 	struct snd_pcm_runtime *runtime = substream->runtime;
526 
527 	runtime->sync.id32[0] = substream->pcm->card->number;
528 	runtime->sync.id32[1] = -1;
529 	runtime->sync.id32[2] = -1;
530 	runtime->sync.id32[3] = -1;
531 }
532 
533 EXPORT_SYMBOL(snd_pcm_set_sync);
534 
535 /*
536  *  Standard ioctl routine
537  */
538 
539 static inline unsigned int div32(unsigned int a, unsigned int b,
540 				 unsigned int *r)
541 {
542 	if (b == 0) {
543 		*r = 0;
544 		return UINT_MAX;
545 	}
546 	*r = a % b;
547 	return a / b;
548 }
549 
550 static inline unsigned int div_down(unsigned int a, unsigned int b)
551 {
552 	if (b == 0)
553 		return UINT_MAX;
554 	return a / b;
555 }
556 
557 static inline unsigned int div_up(unsigned int a, unsigned int b)
558 {
559 	unsigned int r;
560 	unsigned int q;
561 	if (b == 0)
562 		return UINT_MAX;
563 	q = div32(a, b, &r);
564 	if (r)
565 		++q;
566 	return q;
567 }
568 
569 static inline unsigned int mul(unsigned int a, unsigned int b)
570 {
571 	if (a == 0)
572 		return 0;
573 	if (div_down(UINT_MAX, a) < b)
574 		return UINT_MAX;
575 	return a * b;
576 }
577 
578 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
579 				    unsigned int c, unsigned int *r)
580 {
581 	u_int64_t n = (u_int64_t) a * b;
582 	if (c == 0) {
583 		snd_BUG_ON(!n);
584 		*r = 0;
585 		return UINT_MAX;
586 	}
587 	n = div_u64_rem(n, c, r);
588 	if (n >= UINT_MAX) {
589 		*r = 0;
590 		return UINT_MAX;
591 	}
592 	return n;
593 }
594 
595 /**
596  * snd_interval_refine - refine the interval value of configurator
597  * @i: the interval value to refine
598  * @v: the interval value to refer to
599  *
600  * Refines the interval value with the reference value.
601  * The interval is changed to the range satisfying both intervals.
602  * The interval status (min, max, integer, etc.) are evaluated.
603  *
604  * Returns non-zero if the value is changed, zero if not changed.
605  */
606 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
607 {
608 	int changed = 0;
609 	if (snd_BUG_ON(snd_interval_empty(i)))
610 		return -EINVAL;
611 	if (i->min < v->min) {
612 		i->min = v->min;
613 		i->openmin = v->openmin;
614 		changed = 1;
615 	} else if (i->min == v->min && !i->openmin && v->openmin) {
616 		i->openmin = 1;
617 		changed = 1;
618 	}
619 	if (i->max > v->max) {
620 		i->max = v->max;
621 		i->openmax = v->openmax;
622 		changed = 1;
623 	} else if (i->max == v->max && !i->openmax && v->openmax) {
624 		i->openmax = 1;
625 		changed = 1;
626 	}
627 	if (!i->integer && v->integer) {
628 		i->integer = 1;
629 		changed = 1;
630 	}
631 	if (i->integer) {
632 		if (i->openmin) {
633 			i->min++;
634 			i->openmin = 0;
635 		}
636 		if (i->openmax) {
637 			i->max--;
638 			i->openmax = 0;
639 		}
640 	} else if (!i->openmin && !i->openmax && i->min == i->max)
641 		i->integer = 1;
642 	if (snd_interval_checkempty(i)) {
643 		snd_interval_none(i);
644 		return -EINVAL;
645 	}
646 	return changed;
647 }
648 
649 EXPORT_SYMBOL(snd_interval_refine);
650 
651 static int snd_interval_refine_first(struct snd_interval *i)
652 {
653 	if (snd_BUG_ON(snd_interval_empty(i)))
654 		return -EINVAL;
655 	if (snd_interval_single(i))
656 		return 0;
657 	i->max = i->min;
658 	i->openmax = i->openmin;
659 	if (i->openmax)
660 		i->max++;
661 	return 1;
662 }
663 
664 static int snd_interval_refine_last(struct snd_interval *i)
665 {
666 	if (snd_BUG_ON(snd_interval_empty(i)))
667 		return -EINVAL;
668 	if (snd_interval_single(i))
669 		return 0;
670 	i->min = i->max;
671 	i->openmin = i->openmax;
672 	if (i->openmin)
673 		i->min--;
674 	return 1;
675 }
676 
677 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
678 {
679 	if (a->empty || b->empty) {
680 		snd_interval_none(c);
681 		return;
682 	}
683 	c->empty = 0;
684 	c->min = mul(a->min, b->min);
685 	c->openmin = (a->openmin || b->openmin);
686 	c->max = mul(a->max,  b->max);
687 	c->openmax = (a->openmax || b->openmax);
688 	c->integer = (a->integer && b->integer);
689 }
690 
691 /**
692  * snd_interval_div - refine the interval value with division
693  * @a: dividend
694  * @b: divisor
695  * @c: quotient
696  *
697  * c = a / b
698  *
699  * Returns non-zero if the value is changed, zero if not changed.
700  */
701 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
702 {
703 	unsigned int r;
704 	if (a->empty || b->empty) {
705 		snd_interval_none(c);
706 		return;
707 	}
708 	c->empty = 0;
709 	c->min = div32(a->min, b->max, &r);
710 	c->openmin = (r || a->openmin || b->openmax);
711 	if (b->min > 0) {
712 		c->max = div32(a->max, b->min, &r);
713 		if (r) {
714 			c->max++;
715 			c->openmax = 1;
716 		} else
717 			c->openmax = (a->openmax || b->openmin);
718 	} else {
719 		c->max = UINT_MAX;
720 		c->openmax = 0;
721 	}
722 	c->integer = 0;
723 }
724 
725 /**
726  * snd_interval_muldivk - refine the interval value
727  * @a: dividend 1
728  * @b: dividend 2
729  * @k: divisor (as integer)
730  * @c: result
731   *
732  * c = a * b / k
733  *
734  * Returns non-zero if the value is changed, zero if not changed.
735  */
736 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
737 		      unsigned int k, struct snd_interval *c)
738 {
739 	unsigned int r;
740 	if (a->empty || b->empty) {
741 		snd_interval_none(c);
742 		return;
743 	}
744 	c->empty = 0;
745 	c->min = muldiv32(a->min, b->min, k, &r);
746 	c->openmin = (r || a->openmin || b->openmin);
747 	c->max = muldiv32(a->max, b->max, k, &r);
748 	if (r) {
749 		c->max++;
750 		c->openmax = 1;
751 	} else
752 		c->openmax = (a->openmax || b->openmax);
753 	c->integer = 0;
754 }
755 
756 /**
757  * snd_interval_mulkdiv - refine the interval value
758  * @a: dividend 1
759  * @k: dividend 2 (as integer)
760  * @b: divisor
761  * @c: result
762  *
763  * c = a * k / b
764  *
765  * Returns non-zero if the value is changed, zero if not changed.
766  */
767 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
768 		      const struct snd_interval *b, struct snd_interval *c)
769 {
770 	unsigned int r;
771 	if (a->empty || b->empty) {
772 		snd_interval_none(c);
773 		return;
774 	}
775 	c->empty = 0;
776 	c->min = muldiv32(a->min, k, b->max, &r);
777 	c->openmin = (r || a->openmin || b->openmax);
778 	if (b->min > 0) {
779 		c->max = muldiv32(a->max, k, b->min, &r);
780 		if (r) {
781 			c->max++;
782 			c->openmax = 1;
783 		} else
784 			c->openmax = (a->openmax || b->openmin);
785 	} else {
786 		c->max = UINT_MAX;
787 		c->openmax = 0;
788 	}
789 	c->integer = 0;
790 }
791 
792 /* ---- */
793 
794 
795 /**
796  * snd_interval_ratnum - refine the interval value
797  * @i: interval to refine
798  * @rats_count: number of ratnum_t
799  * @rats: ratnum_t array
800  * @nump: pointer to store the resultant numerator
801  * @denp: pointer to store the resultant denominator
802  *
803  * Returns non-zero if the value is changed, zero if not changed.
804  */
805 int snd_interval_ratnum(struct snd_interval *i,
806 			unsigned int rats_count, struct snd_ratnum *rats,
807 			unsigned int *nump, unsigned int *denp)
808 {
809 	unsigned int best_num, best_den;
810 	int best_diff;
811 	unsigned int k;
812 	struct snd_interval t;
813 	int err;
814 	unsigned int result_num, result_den;
815 	int result_diff;
816 
817 	best_num = best_den = best_diff = 0;
818 	for (k = 0; k < rats_count; ++k) {
819 		unsigned int num = rats[k].num;
820 		unsigned int den;
821 		unsigned int q = i->min;
822 		int diff;
823 		if (q == 0)
824 			q = 1;
825 		den = div_up(num, q);
826 		if (den < rats[k].den_min)
827 			continue;
828 		if (den > rats[k].den_max)
829 			den = rats[k].den_max;
830 		else {
831 			unsigned int r;
832 			r = (den - rats[k].den_min) % rats[k].den_step;
833 			if (r != 0)
834 				den -= r;
835 		}
836 		diff = num - q * den;
837 		if (diff < 0)
838 			diff = -diff;
839 		if (best_num == 0 ||
840 		    diff * best_den < best_diff * den) {
841 			best_diff = diff;
842 			best_den = den;
843 			best_num = num;
844 		}
845 	}
846 	if (best_den == 0) {
847 		i->empty = 1;
848 		return -EINVAL;
849 	}
850 	t.min = div_down(best_num, best_den);
851 	t.openmin = !!(best_num % best_den);
852 
853 	result_num = best_num;
854 	result_diff = best_diff;
855 	result_den = best_den;
856 	best_num = best_den = best_diff = 0;
857 	for (k = 0; k < rats_count; ++k) {
858 		unsigned int num = rats[k].num;
859 		unsigned int den;
860 		unsigned int q = i->max;
861 		int diff;
862 		if (q == 0) {
863 			i->empty = 1;
864 			return -EINVAL;
865 		}
866 		den = div_down(num, q);
867 		if (den > rats[k].den_max)
868 			continue;
869 		if (den < rats[k].den_min)
870 			den = rats[k].den_min;
871 		else {
872 			unsigned int r;
873 			r = (den - rats[k].den_min) % rats[k].den_step;
874 			if (r != 0)
875 				den += rats[k].den_step - r;
876 		}
877 		diff = q * den - num;
878 		if (diff < 0)
879 			diff = -diff;
880 		if (best_num == 0 ||
881 		    diff * best_den < best_diff * den) {
882 			best_diff = diff;
883 			best_den = den;
884 			best_num = num;
885 		}
886 	}
887 	if (best_den == 0) {
888 		i->empty = 1;
889 		return -EINVAL;
890 	}
891 	t.max = div_up(best_num, best_den);
892 	t.openmax = !!(best_num % best_den);
893 	t.integer = 0;
894 	err = snd_interval_refine(i, &t);
895 	if (err < 0)
896 		return err;
897 
898 	if (snd_interval_single(i)) {
899 		if (best_diff * result_den < result_diff * best_den) {
900 			result_num = best_num;
901 			result_den = best_den;
902 		}
903 		if (nump)
904 			*nump = result_num;
905 		if (denp)
906 			*denp = result_den;
907 	}
908 	return err;
909 }
910 
911 EXPORT_SYMBOL(snd_interval_ratnum);
912 
913 /**
914  * snd_interval_ratden - refine the interval value
915  * @i: interval to refine
916  * @rats_count: number of struct ratden
917  * @rats: struct ratden array
918  * @nump: pointer to store the resultant numerator
919  * @denp: pointer to store the resultant denominator
920  *
921  * Returns non-zero if the value is changed, zero if not changed.
922  */
923 static int snd_interval_ratden(struct snd_interval *i,
924 			       unsigned int rats_count, struct snd_ratden *rats,
925 			       unsigned int *nump, unsigned int *denp)
926 {
927 	unsigned int best_num, best_diff, best_den;
928 	unsigned int k;
929 	struct snd_interval t;
930 	int err;
931 
932 	best_num = best_den = best_diff = 0;
933 	for (k = 0; k < rats_count; ++k) {
934 		unsigned int num;
935 		unsigned int den = rats[k].den;
936 		unsigned int q = i->min;
937 		int diff;
938 		num = mul(q, den);
939 		if (num > rats[k].num_max)
940 			continue;
941 		if (num < rats[k].num_min)
942 			num = rats[k].num_max;
943 		else {
944 			unsigned int r;
945 			r = (num - rats[k].num_min) % rats[k].num_step;
946 			if (r != 0)
947 				num += rats[k].num_step - r;
948 		}
949 		diff = num - q * den;
950 		if (best_num == 0 ||
951 		    diff * best_den < best_diff * den) {
952 			best_diff = diff;
953 			best_den = den;
954 			best_num = num;
955 		}
956 	}
957 	if (best_den == 0) {
958 		i->empty = 1;
959 		return -EINVAL;
960 	}
961 	t.min = div_down(best_num, best_den);
962 	t.openmin = !!(best_num % best_den);
963 
964 	best_num = best_den = best_diff = 0;
965 	for (k = 0; k < rats_count; ++k) {
966 		unsigned int num;
967 		unsigned int den = rats[k].den;
968 		unsigned int q = i->max;
969 		int diff;
970 		num = mul(q, den);
971 		if (num < rats[k].num_min)
972 			continue;
973 		if (num > rats[k].num_max)
974 			num = rats[k].num_max;
975 		else {
976 			unsigned int r;
977 			r = (num - rats[k].num_min) % rats[k].num_step;
978 			if (r != 0)
979 				num -= r;
980 		}
981 		diff = q * den - num;
982 		if (best_num == 0 ||
983 		    diff * best_den < best_diff * den) {
984 			best_diff = diff;
985 			best_den = den;
986 			best_num = num;
987 		}
988 	}
989 	if (best_den == 0) {
990 		i->empty = 1;
991 		return -EINVAL;
992 	}
993 	t.max = div_up(best_num, best_den);
994 	t.openmax = !!(best_num % best_den);
995 	t.integer = 0;
996 	err = snd_interval_refine(i, &t);
997 	if (err < 0)
998 		return err;
999 
1000 	if (snd_interval_single(i)) {
1001 		if (nump)
1002 			*nump = best_num;
1003 		if (denp)
1004 			*denp = best_den;
1005 	}
1006 	return err;
1007 }
1008 
1009 /**
1010  * snd_interval_list - refine the interval value from the list
1011  * @i: the interval value to refine
1012  * @count: the number of elements in the list
1013  * @list: the value list
1014  * @mask: the bit-mask to evaluate
1015  *
1016  * Refines the interval value from the list.
1017  * When mask is non-zero, only the elements corresponding to bit 1 are
1018  * evaluated.
1019  *
1020  * Returns non-zero if the value is changed, zero if not changed.
1021  */
1022 int snd_interval_list(struct snd_interval *i, unsigned int count, unsigned int *list, unsigned int mask)
1023 {
1024         unsigned int k;
1025 	struct snd_interval list_range;
1026 
1027 	if (!count) {
1028 		i->empty = 1;
1029 		return -EINVAL;
1030 	}
1031 	snd_interval_any(&list_range);
1032 	list_range.min = UINT_MAX;
1033 	list_range.max = 0;
1034         for (k = 0; k < count; k++) {
1035 		if (mask && !(mask & (1 << k)))
1036 			continue;
1037 		if (!snd_interval_test(i, list[k]))
1038 			continue;
1039 		list_range.min = min(list_range.min, list[k]);
1040 		list_range.max = max(list_range.max, list[k]);
1041         }
1042 	return snd_interval_refine(i, &list_range);
1043 }
1044 
1045 EXPORT_SYMBOL(snd_interval_list);
1046 
1047 static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned int step)
1048 {
1049 	unsigned int n;
1050 	int changed = 0;
1051 	n = (i->min - min) % step;
1052 	if (n != 0 || i->openmin) {
1053 		i->min += step - n;
1054 		changed = 1;
1055 	}
1056 	n = (i->max - min) % step;
1057 	if (n != 0 || i->openmax) {
1058 		i->max -= n;
1059 		changed = 1;
1060 	}
1061 	if (snd_interval_checkempty(i)) {
1062 		i->empty = 1;
1063 		return -EINVAL;
1064 	}
1065 	return changed;
1066 }
1067 
1068 /* Info constraints helpers */
1069 
1070 /**
1071  * snd_pcm_hw_rule_add - add the hw-constraint rule
1072  * @runtime: the pcm runtime instance
1073  * @cond: condition bits
1074  * @var: the variable to evaluate
1075  * @func: the evaluation function
1076  * @private: the private data pointer passed to function
1077  * @dep: the dependent variables
1078  *
1079  * Returns zero if successful, or a negative error code on failure.
1080  */
1081 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1082 			int var,
1083 			snd_pcm_hw_rule_func_t func, void *private,
1084 			int dep, ...)
1085 {
1086 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1087 	struct snd_pcm_hw_rule *c;
1088 	unsigned int k;
1089 	va_list args;
1090 	va_start(args, dep);
1091 	if (constrs->rules_num >= constrs->rules_all) {
1092 		struct snd_pcm_hw_rule *new;
1093 		unsigned int new_rules = constrs->rules_all + 16;
1094 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1095 		if (!new) {
1096 			va_end(args);
1097 			return -ENOMEM;
1098 		}
1099 		if (constrs->rules) {
1100 			memcpy(new, constrs->rules,
1101 			       constrs->rules_num * sizeof(*c));
1102 			kfree(constrs->rules);
1103 		}
1104 		constrs->rules = new;
1105 		constrs->rules_all = new_rules;
1106 	}
1107 	c = &constrs->rules[constrs->rules_num];
1108 	c->cond = cond;
1109 	c->func = func;
1110 	c->var = var;
1111 	c->private = private;
1112 	k = 0;
1113 	while (1) {
1114 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1115 			va_end(args);
1116 			return -EINVAL;
1117 		}
1118 		c->deps[k++] = dep;
1119 		if (dep < 0)
1120 			break;
1121 		dep = va_arg(args, int);
1122 	}
1123 	constrs->rules_num++;
1124 	va_end(args);
1125 	return 0;
1126 }
1127 
1128 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1129 
1130 /**
1131  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1132  * @runtime: PCM runtime instance
1133  * @var: hw_params variable to apply the mask
1134  * @mask: the bitmap mask
1135  *
1136  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1137  */
1138 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1139 			       u_int32_t mask)
1140 {
1141 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1142 	struct snd_mask *maskp = constrs_mask(constrs, var);
1143 	*maskp->bits &= mask;
1144 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1145 	if (*maskp->bits == 0)
1146 		return -EINVAL;
1147 	return 0;
1148 }
1149 
1150 /**
1151  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1152  * @runtime: PCM runtime instance
1153  * @var: hw_params variable to apply the mask
1154  * @mask: the 64bit bitmap mask
1155  *
1156  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1157  */
1158 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1159 				 u_int64_t mask)
1160 {
1161 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1162 	struct snd_mask *maskp = constrs_mask(constrs, var);
1163 	maskp->bits[0] &= (u_int32_t)mask;
1164 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1165 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1166 	if (! maskp->bits[0] && ! maskp->bits[1])
1167 		return -EINVAL;
1168 	return 0;
1169 }
1170 
1171 /**
1172  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1173  * @runtime: PCM runtime instance
1174  * @var: hw_params variable to apply the integer constraint
1175  *
1176  * Apply the constraint of integer to an interval parameter.
1177  */
1178 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1179 {
1180 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1181 	return snd_interval_setinteger(constrs_interval(constrs, var));
1182 }
1183 
1184 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1185 
1186 /**
1187  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1188  * @runtime: PCM runtime instance
1189  * @var: hw_params variable to apply the range
1190  * @min: the minimal value
1191  * @max: the maximal value
1192  *
1193  * Apply the min/max range constraint to an interval parameter.
1194  */
1195 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1196 				 unsigned int min, unsigned int max)
1197 {
1198 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1199 	struct snd_interval t;
1200 	t.min = min;
1201 	t.max = max;
1202 	t.openmin = t.openmax = 0;
1203 	t.integer = 0;
1204 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1205 }
1206 
1207 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1208 
1209 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1210 				struct snd_pcm_hw_rule *rule)
1211 {
1212 	struct snd_pcm_hw_constraint_list *list = rule->private;
1213 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1214 }
1215 
1216 
1217 /**
1218  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1219  * @runtime: PCM runtime instance
1220  * @cond: condition bits
1221  * @var: hw_params variable to apply the list constraint
1222  * @l: list
1223  *
1224  * Apply the list of constraints to an interval parameter.
1225  */
1226 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1227 			       unsigned int cond,
1228 			       snd_pcm_hw_param_t var,
1229 			       struct snd_pcm_hw_constraint_list *l)
1230 {
1231 	return snd_pcm_hw_rule_add(runtime, cond, var,
1232 				   snd_pcm_hw_rule_list, l,
1233 				   var, -1);
1234 }
1235 
1236 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1237 
1238 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1239 				   struct snd_pcm_hw_rule *rule)
1240 {
1241 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1242 	unsigned int num = 0, den = 0;
1243 	int err;
1244 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1245 				  r->nrats, r->rats, &num, &den);
1246 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1247 		params->rate_num = num;
1248 		params->rate_den = den;
1249 	}
1250 	return err;
1251 }
1252 
1253 /**
1254  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1255  * @runtime: PCM runtime instance
1256  * @cond: condition bits
1257  * @var: hw_params variable to apply the ratnums constraint
1258  * @r: struct snd_ratnums constriants
1259  */
1260 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1261 				  unsigned int cond,
1262 				  snd_pcm_hw_param_t var,
1263 				  struct snd_pcm_hw_constraint_ratnums *r)
1264 {
1265 	return snd_pcm_hw_rule_add(runtime, cond, var,
1266 				   snd_pcm_hw_rule_ratnums, r,
1267 				   var, -1);
1268 }
1269 
1270 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1271 
1272 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1273 				   struct snd_pcm_hw_rule *rule)
1274 {
1275 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1276 	unsigned int num = 0, den = 0;
1277 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1278 				  r->nrats, r->rats, &num, &den);
1279 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1280 		params->rate_num = num;
1281 		params->rate_den = den;
1282 	}
1283 	return err;
1284 }
1285 
1286 /**
1287  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1288  * @runtime: PCM runtime instance
1289  * @cond: condition bits
1290  * @var: hw_params variable to apply the ratdens constraint
1291  * @r: struct snd_ratdens constriants
1292  */
1293 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1294 				  unsigned int cond,
1295 				  snd_pcm_hw_param_t var,
1296 				  struct snd_pcm_hw_constraint_ratdens *r)
1297 {
1298 	return snd_pcm_hw_rule_add(runtime, cond, var,
1299 				   snd_pcm_hw_rule_ratdens, r,
1300 				   var, -1);
1301 }
1302 
1303 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1304 
1305 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1306 				  struct snd_pcm_hw_rule *rule)
1307 {
1308 	unsigned int l = (unsigned long) rule->private;
1309 	int width = l & 0xffff;
1310 	unsigned int msbits = l >> 16;
1311 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1312 	if (snd_interval_single(i) && snd_interval_value(i) == width)
1313 		params->msbits = msbits;
1314 	return 0;
1315 }
1316 
1317 /**
1318  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1319  * @runtime: PCM runtime instance
1320  * @cond: condition bits
1321  * @width: sample bits width
1322  * @msbits: msbits width
1323  */
1324 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1325 				 unsigned int cond,
1326 				 unsigned int width,
1327 				 unsigned int msbits)
1328 {
1329 	unsigned long l = (msbits << 16) | width;
1330 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1331 				    snd_pcm_hw_rule_msbits,
1332 				    (void*) l,
1333 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1334 }
1335 
1336 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1337 
1338 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1339 				struct snd_pcm_hw_rule *rule)
1340 {
1341 	unsigned long step = (unsigned long) rule->private;
1342 	return snd_interval_step(hw_param_interval(params, rule->var), 0, step);
1343 }
1344 
1345 /**
1346  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1347  * @runtime: PCM runtime instance
1348  * @cond: condition bits
1349  * @var: hw_params variable to apply the step constraint
1350  * @step: step size
1351  */
1352 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1353 			       unsigned int cond,
1354 			       snd_pcm_hw_param_t var,
1355 			       unsigned long step)
1356 {
1357 	return snd_pcm_hw_rule_add(runtime, cond, var,
1358 				   snd_pcm_hw_rule_step, (void *) step,
1359 				   var, -1);
1360 }
1361 
1362 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1363 
1364 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1365 {
1366 	static unsigned int pow2_sizes[] = {
1367 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1368 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1369 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1370 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1371 	};
1372 	return snd_interval_list(hw_param_interval(params, rule->var),
1373 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1374 }
1375 
1376 /**
1377  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1378  * @runtime: PCM runtime instance
1379  * @cond: condition bits
1380  * @var: hw_params variable to apply the power-of-2 constraint
1381  */
1382 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1383 			       unsigned int cond,
1384 			       snd_pcm_hw_param_t var)
1385 {
1386 	return snd_pcm_hw_rule_add(runtime, cond, var,
1387 				   snd_pcm_hw_rule_pow2, NULL,
1388 				   var, -1);
1389 }
1390 
1391 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1392 
1393 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1394 				  snd_pcm_hw_param_t var)
1395 {
1396 	if (hw_is_mask(var)) {
1397 		snd_mask_any(hw_param_mask(params, var));
1398 		params->cmask |= 1 << var;
1399 		params->rmask |= 1 << var;
1400 		return;
1401 	}
1402 	if (hw_is_interval(var)) {
1403 		snd_interval_any(hw_param_interval(params, var));
1404 		params->cmask |= 1 << var;
1405 		params->rmask |= 1 << var;
1406 		return;
1407 	}
1408 	snd_BUG();
1409 }
1410 
1411 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1412 {
1413 	unsigned int k;
1414 	memset(params, 0, sizeof(*params));
1415 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1416 		_snd_pcm_hw_param_any(params, k);
1417 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1418 		_snd_pcm_hw_param_any(params, k);
1419 	params->info = ~0U;
1420 }
1421 
1422 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1423 
1424 /**
1425  * snd_pcm_hw_param_value - return @params field @var value
1426  * @params: the hw_params instance
1427  * @var: parameter to retrieve
1428  * @dir: pointer to the direction (-1,0,1) or %NULL
1429  *
1430  * Return the value for field @var if it's fixed in configuration space
1431  * defined by @params. Return -%EINVAL otherwise.
1432  */
1433 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1434 			   snd_pcm_hw_param_t var, int *dir)
1435 {
1436 	if (hw_is_mask(var)) {
1437 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1438 		if (!snd_mask_single(mask))
1439 			return -EINVAL;
1440 		if (dir)
1441 			*dir = 0;
1442 		return snd_mask_value(mask);
1443 	}
1444 	if (hw_is_interval(var)) {
1445 		const struct snd_interval *i = hw_param_interval_c(params, var);
1446 		if (!snd_interval_single(i))
1447 			return -EINVAL;
1448 		if (dir)
1449 			*dir = i->openmin;
1450 		return snd_interval_value(i);
1451 	}
1452 	return -EINVAL;
1453 }
1454 
1455 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1456 
1457 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1458 				snd_pcm_hw_param_t var)
1459 {
1460 	if (hw_is_mask(var)) {
1461 		snd_mask_none(hw_param_mask(params, var));
1462 		params->cmask |= 1 << var;
1463 		params->rmask |= 1 << var;
1464 	} else if (hw_is_interval(var)) {
1465 		snd_interval_none(hw_param_interval(params, var));
1466 		params->cmask |= 1 << var;
1467 		params->rmask |= 1 << var;
1468 	} else {
1469 		snd_BUG();
1470 	}
1471 }
1472 
1473 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1474 
1475 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1476 				   snd_pcm_hw_param_t var)
1477 {
1478 	int changed;
1479 	if (hw_is_mask(var))
1480 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1481 	else if (hw_is_interval(var))
1482 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1483 	else
1484 		return -EINVAL;
1485 	if (changed) {
1486 		params->cmask |= 1 << var;
1487 		params->rmask |= 1 << var;
1488 	}
1489 	return changed;
1490 }
1491 
1492 
1493 /**
1494  * snd_pcm_hw_param_first - refine config space and return minimum value
1495  * @pcm: PCM instance
1496  * @params: the hw_params instance
1497  * @var: parameter to retrieve
1498  * @dir: pointer to the direction (-1,0,1) or %NULL
1499  *
1500  * Inside configuration space defined by @params remove from @var all
1501  * values > minimum. Reduce configuration space accordingly.
1502  * Return the minimum.
1503  */
1504 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1505 			   struct snd_pcm_hw_params *params,
1506 			   snd_pcm_hw_param_t var, int *dir)
1507 {
1508 	int changed = _snd_pcm_hw_param_first(params, var);
1509 	if (changed < 0)
1510 		return changed;
1511 	if (params->rmask) {
1512 		int err = snd_pcm_hw_refine(pcm, params);
1513 		if (snd_BUG_ON(err < 0))
1514 			return err;
1515 	}
1516 	return snd_pcm_hw_param_value(params, var, dir);
1517 }
1518 
1519 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1520 
1521 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1522 				  snd_pcm_hw_param_t var)
1523 {
1524 	int changed;
1525 	if (hw_is_mask(var))
1526 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1527 	else if (hw_is_interval(var))
1528 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1529 	else
1530 		return -EINVAL;
1531 	if (changed) {
1532 		params->cmask |= 1 << var;
1533 		params->rmask |= 1 << var;
1534 	}
1535 	return changed;
1536 }
1537 
1538 
1539 /**
1540  * snd_pcm_hw_param_last - refine config space and return maximum value
1541  * @pcm: PCM instance
1542  * @params: the hw_params instance
1543  * @var: parameter to retrieve
1544  * @dir: pointer to the direction (-1,0,1) or %NULL
1545  *
1546  * Inside configuration space defined by @params remove from @var all
1547  * values < maximum. Reduce configuration space accordingly.
1548  * Return the maximum.
1549  */
1550 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1551 			  struct snd_pcm_hw_params *params,
1552 			  snd_pcm_hw_param_t var, int *dir)
1553 {
1554 	int changed = _snd_pcm_hw_param_last(params, var);
1555 	if (changed < 0)
1556 		return changed;
1557 	if (params->rmask) {
1558 		int err = snd_pcm_hw_refine(pcm, params);
1559 		if (snd_BUG_ON(err < 0))
1560 			return err;
1561 	}
1562 	return snd_pcm_hw_param_value(params, var, dir);
1563 }
1564 
1565 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1566 
1567 /**
1568  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1569  * @pcm: PCM instance
1570  * @params: the hw_params instance
1571  *
1572  * Choose one configuration from configuration space defined by @params.
1573  * The configuration chosen is that obtained fixing in this order:
1574  * first access, first format, first subformat, min channels,
1575  * min rate, min period time, max buffer size, min tick time
1576  */
1577 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1578 			     struct snd_pcm_hw_params *params)
1579 {
1580 	static int vars[] = {
1581 		SNDRV_PCM_HW_PARAM_ACCESS,
1582 		SNDRV_PCM_HW_PARAM_FORMAT,
1583 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1584 		SNDRV_PCM_HW_PARAM_CHANNELS,
1585 		SNDRV_PCM_HW_PARAM_RATE,
1586 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1587 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1588 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1589 		-1
1590 	};
1591 	int err, *v;
1592 
1593 	for (v = vars; *v != -1; v++) {
1594 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1595 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1596 		else
1597 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1598 		if (snd_BUG_ON(err < 0))
1599 			return err;
1600 	}
1601 	return 0;
1602 }
1603 
1604 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1605 				   void *arg)
1606 {
1607 	struct snd_pcm_runtime *runtime = substream->runtime;
1608 	unsigned long flags;
1609 	snd_pcm_stream_lock_irqsave(substream, flags);
1610 	if (snd_pcm_running(substream) &&
1611 	    snd_pcm_update_hw_ptr(substream) >= 0)
1612 		runtime->status->hw_ptr %= runtime->buffer_size;
1613 	else
1614 		runtime->status->hw_ptr = 0;
1615 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1616 	return 0;
1617 }
1618 
1619 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1620 					  void *arg)
1621 {
1622 	struct snd_pcm_channel_info *info = arg;
1623 	struct snd_pcm_runtime *runtime = substream->runtime;
1624 	int width;
1625 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1626 		info->offset = -1;
1627 		return 0;
1628 	}
1629 	width = snd_pcm_format_physical_width(runtime->format);
1630 	if (width < 0)
1631 		return width;
1632 	info->offset = 0;
1633 	switch (runtime->access) {
1634 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1635 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1636 		info->first = info->channel * width;
1637 		info->step = runtime->channels * width;
1638 		break;
1639 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1640 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1641 	{
1642 		size_t size = runtime->dma_bytes / runtime->channels;
1643 		info->first = info->channel * size * 8;
1644 		info->step = width;
1645 		break;
1646 	}
1647 	default:
1648 		snd_BUG();
1649 		break;
1650 	}
1651 	return 0;
1652 }
1653 
1654 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1655 				       void *arg)
1656 {
1657 	struct snd_pcm_hw_params *params = arg;
1658 	snd_pcm_format_t format;
1659 	int channels, width;
1660 
1661 	params->fifo_size = substream->runtime->hw.fifo_size;
1662 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1663 		format = params_format(params);
1664 		channels = params_channels(params);
1665 		width = snd_pcm_format_physical_width(format);
1666 		params->fifo_size /= width * channels;
1667 	}
1668 	return 0;
1669 }
1670 
1671 /**
1672  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1673  * @substream: the pcm substream instance
1674  * @cmd: ioctl command
1675  * @arg: ioctl argument
1676  *
1677  * Processes the generic ioctl commands for PCM.
1678  * Can be passed as the ioctl callback for PCM ops.
1679  *
1680  * Returns zero if successful, or a negative error code on failure.
1681  */
1682 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1683 		      unsigned int cmd, void *arg)
1684 {
1685 	switch (cmd) {
1686 	case SNDRV_PCM_IOCTL1_INFO:
1687 		return 0;
1688 	case SNDRV_PCM_IOCTL1_RESET:
1689 		return snd_pcm_lib_ioctl_reset(substream, arg);
1690 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1691 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1692 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1693 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1694 	}
1695 	return -ENXIO;
1696 }
1697 
1698 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1699 
1700 /**
1701  * snd_pcm_period_elapsed - update the pcm status for the next period
1702  * @substream: the pcm substream instance
1703  *
1704  * This function is called from the interrupt handler when the
1705  * PCM has processed the period size.  It will update the current
1706  * pointer, wake up sleepers, etc.
1707  *
1708  * Even if more than one periods have elapsed since the last call, you
1709  * have to call this only once.
1710  */
1711 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1712 {
1713 	struct snd_pcm_runtime *runtime;
1714 	unsigned long flags;
1715 
1716 	if (PCM_RUNTIME_CHECK(substream))
1717 		return;
1718 	runtime = substream->runtime;
1719 
1720 	if (runtime->transfer_ack_begin)
1721 		runtime->transfer_ack_begin(substream);
1722 
1723 	snd_pcm_stream_lock_irqsave(substream, flags);
1724 	if (!snd_pcm_running(substream) ||
1725 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1726 		goto _end;
1727 
1728 	if (substream->timer_running)
1729 		snd_timer_interrupt(substream->timer, 1);
1730  _end:
1731 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1732 	if (runtime->transfer_ack_end)
1733 		runtime->transfer_ack_end(substream);
1734 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1735 }
1736 
1737 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1738 
1739 /*
1740  * Wait until avail_min data becomes available
1741  * Returns a negative error code if any error occurs during operation.
1742  * The available space is stored on availp.  When err = 0 and avail = 0
1743  * on the capture stream, it indicates the stream is in DRAINING state.
1744  */
1745 static int wait_for_avail(struct snd_pcm_substream *substream,
1746 			      snd_pcm_uframes_t *availp)
1747 {
1748 	struct snd_pcm_runtime *runtime = substream->runtime;
1749 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1750 	wait_queue_t wait;
1751 	int err = 0;
1752 	snd_pcm_uframes_t avail = 0;
1753 	long tout;
1754 
1755 	init_waitqueue_entry(&wait, current);
1756 	add_wait_queue(&runtime->tsleep, &wait);
1757 	for (;;) {
1758 		if (signal_pending(current)) {
1759 			err = -ERESTARTSYS;
1760 			break;
1761 		}
1762 		set_current_state(TASK_INTERRUPTIBLE);
1763 		snd_pcm_stream_unlock_irq(substream);
1764 		tout = schedule_timeout(msecs_to_jiffies(10000));
1765 		snd_pcm_stream_lock_irq(substream);
1766 		switch (runtime->status->state) {
1767 		case SNDRV_PCM_STATE_SUSPENDED:
1768 			err = -ESTRPIPE;
1769 			goto _endloop;
1770 		case SNDRV_PCM_STATE_XRUN:
1771 			err = -EPIPE;
1772 			goto _endloop;
1773 		case SNDRV_PCM_STATE_DRAINING:
1774 			if (is_playback)
1775 				err = -EPIPE;
1776 			else
1777 				avail = 0; /* indicate draining */
1778 			goto _endloop;
1779 		case SNDRV_PCM_STATE_OPEN:
1780 		case SNDRV_PCM_STATE_SETUP:
1781 		case SNDRV_PCM_STATE_DISCONNECTED:
1782 			err = -EBADFD;
1783 			goto _endloop;
1784 		}
1785 		if (!tout) {
1786 			snd_printd("%s write error (DMA or IRQ trouble?)\n",
1787 				   is_playback ? "playback" : "capture");
1788 			err = -EIO;
1789 			break;
1790 		}
1791 		if (is_playback)
1792 			avail = snd_pcm_playback_avail(runtime);
1793 		else
1794 			avail = snd_pcm_capture_avail(runtime);
1795 		if (avail >= runtime->twake)
1796 			break;
1797 	}
1798  _endloop:
1799 	remove_wait_queue(&runtime->tsleep, &wait);
1800 	*availp = avail;
1801 	return err;
1802 }
1803 
1804 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1805 				      unsigned int hwoff,
1806 				      unsigned long data, unsigned int off,
1807 				      snd_pcm_uframes_t frames)
1808 {
1809 	struct snd_pcm_runtime *runtime = substream->runtime;
1810 	int err;
1811 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1812 	if (substream->ops->copy) {
1813 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1814 			return err;
1815 	} else {
1816 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1817 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1818 			return -EFAULT;
1819 	}
1820 	return 0;
1821 }
1822 
1823 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1824 			  unsigned long data, unsigned int off,
1825 			  snd_pcm_uframes_t size);
1826 
1827 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1828 					    unsigned long data,
1829 					    snd_pcm_uframes_t size,
1830 					    int nonblock,
1831 					    transfer_f transfer)
1832 {
1833 	struct snd_pcm_runtime *runtime = substream->runtime;
1834 	snd_pcm_uframes_t xfer = 0;
1835 	snd_pcm_uframes_t offset = 0;
1836 	int err = 0;
1837 
1838 	if (size == 0)
1839 		return 0;
1840 
1841 	snd_pcm_stream_lock_irq(substream);
1842 	switch (runtime->status->state) {
1843 	case SNDRV_PCM_STATE_PREPARED:
1844 	case SNDRV_PCM_STATE_RUNNING:
1845 	case SNDRV_PCM_STATE_PAUSED:
1846 		break;
1847 	case SNDRV_PCM_STATE_XRUN:
1848 		err = -EPIPE;
1849 		goto _end_unlock;
1850 	case SNDRV_PCM_STATE_SUSPENDED:
1851 		err = -ESTRPIPE;
1852 		goto _end_unlock;
1853 	default:
1854 		err = -EBADFD;
1855 		goto _end_unlock;
1856 	}
1857 
1858 	runtime->twake = runtime->control->avail_min ? : 1;
1859 	while (size > 0) {
1860 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1861 		snd_pcm_uframes_t avail;
1862 		snd_pcm_uframes_t cont;
1863 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1864 			snd_pcm_update_hw_ptr(substream);
1865 		avail = snd_pcm_playback_avail(runtime);
1866 		if (!avail) {
1867 			if (nonblock) {
1868 				err = -EAGAIN;
1869 				goto _end_unlock;
1870 			}
1871 			runtime->twake = min_t(snd_pcm_uframes_t, size,
1872 					runtime->control->avail_min ? : 1);
1873 			err = wait_for_avail(substream, &avail);
1874 			if (err < 0)
1875 				goto _end_unlock;
1876 		}
1877 		frames = size > avail ? avail : size;
1878 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
1879 		if (frames > cont)
1880 			frames = cont;
1881 		if (snd_BUG_ON(!frames)) {
1882 			runtime->twake = 0;
1883 			snd_pcm_stream_unlock_irq(substream);
1884 			return -EINVAL;
1885 		}
1886 		appl_ptr = runtime->control->appl_ptr;
1887 		appl_ofs = appl_ptr % runtime->buffer_size;
1888 		snd_pcm_stream_unlock_irq(substream);
1889 		err = transfer(substream, appl_ofs, data, offset, frames);
1890 		snd_pcm_stream_lock_irq(substream);
1891 		if (err < 0)
1892 			goto _end_unlock;
1893 		switch (runtime->status->state) {
1894 		case SNDRV_PCM_STATE_XRUN:
1895 			err = -EPIPE;
1896 			goto _end_unlock;
1897 		case SNDRV_PCM_STATE_SUSPENDED:
1898 			err = -ESTRPIPE;
1899 			goto _end_unlock;
1900 		default:
1901 			break;
1902 		}
1903 		appl_ptr += frames;
1904 		if (appl_ptr >= runtime->boundary)
1905 			appl_ptr -= runtime->boundary;
1906 		runtime->control->appl_ptr = appl_ptr;
1907 		if (substream->ops->ack)
1908 			substream->ops->ack(substream);
1909 
1910 		offset += frames;
1911 		size -= frames;
1912 		xfer += frames;
1913 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
1914 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
1915 			err = snd_pcm_start(substream);
1916 			if (err < 0)
1917 				goto _end_unlock;
1918 		}
1919 	}
1920  _end_unlock:
1921 	runtime->twake = 0;
1922 	if (xfer > 0 && err >= 0)
1923 		snd_pcm_update_state(substream, runtime);
1924 	snd_pcm_stream_unlock_irq(substream);
1925 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
1926 }
1927 
1928 /* sanity-check for read/write methods */
1929 static int pcm_sanity_check(struct snd_pcm_substream *substream)
1930 {
1931 	struct snd_pcm_runtime *runtime;
1932 	if (PCM_RUNTIME_CHECK(substream))
1933 		return -ENXIO;
1934 	runtime = substream->runtime;
1935 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
1936 		return -EINVAL;
1937 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
1938 		return -EBADFD;
1939 	return 0;
1940 }
1941 
1942 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
1943 {
1944 	struct snd_pcm_runtime *runtime;
1945 	int nonblock;
1946 	int err;
1947 
1948 	err = pcm_sanity_check(substream);
1949 	if (err < 0)
1950 		return err;
1951 	runtime = substream->runtime;
1952 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1953 
1954 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
1955 	    runtime->channels > 1)
1956 		return -EINVAL;
1957 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
1958 				  snd_pcm_lib_write_transfer);
1959 }
1960 
1961 EXPORT_SYMBOL(snd_pcm_lib_write);
1962 
1963 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
1964 				       unsigned int hwoff,
1965 				       unsigned long data, unsigned int off,
1966 				       snd_pcm_uframes_t frames)
1967 {
1968 	struct snd_pcm_runtime *runtime = substream->runtime;
1969 	int err;
1970 	void __user **bufs = (void __user **)data;
1971 	int channels = runtime->channels;
1972 	int c;
1973 	if (substream->ops->copy) {
1974 		if (snd_BUG_ON(!substream->ops->silence))
1975 			return -EINVAL;
1976 		for (c = 0; c < channels; ++c, ++bufs) {
1977 			if (*bufs == NULL) {
1978 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
1979 					return err;
1980 			} else {
1981 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1982 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
1983 					return err;
1984 			}
1985 		}
1986 	} else {
1987 		/* default transfer behaviour */
1988 		size_t dma_csize = runtime->dma_bytes / channels;
1989 		for (c = 0; c < channels; ++c, ++bufs) {
1990 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
1991 			if (*bufs == NULL) {
1992 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
1993 			} else {
1994 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1995 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
1996 					return -EFAULT;
1997 			}
1998 		}
1999 	}
2000 	return 0;
2001 }
2002 
2003 snd_pcm_sframes_t snd_pcm_lib_writev(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 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2016 
2017 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2018 		return -EINVAL;
2019 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2020 				  nonblock, snd_pcm_lib_writev_transfer);
2021 }
2022 
2023 EXPORT_SYMBOL(snd_pcm_lib_writev);
2024 
2025 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2026 				     unsigned int hwoff,
2027 				     unsigned long data, unsigned int off,
2028 				     snd_pcm_uframes_t frames)
2029 {
2030 	struct snd_pcm_runtime *runtime = substream->runtime;
2031 	int err;
2032 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2033 	if (substream->ops->copy) {
2034 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2035 			return err;
2036 	} else {
2037 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2038 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2039 			return -EFAULT;
2040 	}
2041 	return 0;
2042 }
2043 
2044 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2045 					   unsigned long data,
2046 					   snd_pcm_uframes_t size,
2047 					   int nonblock,
2048 					   transfer_f transfer)
2049 {
2050 	struct snd_pcm_runtime *runtime = substream->runtime;
2051 	snd_pcm_uframes_t xfer = 0;
2052 	snd_pcm_uframes_t offset = 0;
2053 	int err = 0;
2054 
2055 	if (size == 0)
2056 		return 0;
2057 
2058 	snd_pcm_stream_lock_irq(substream);
2059 	switch (runtime->status->state) {
2060 	case SNDRV_PCM_STATE_PREPARED:
2061 		if (size >= runtime->start_threshold) {
2062 			err = snd_pcm_start(substream);
2063 			if (err < 0)
2064 				goto _end_unlock;
2065 		}
2066 		break;
2067 	case SNDRV_PCM_STATE_DRAINING:
2068 	case SNDRV_PCM_STATE_RUNNING:
2069 	case SNDRV_PCM_STATE_PAUSED:
2070 		break;
2071 	case SNDRV_PCM_STATE_XRUN:
2072 		err = -EPIPE;
2073 		goto _end_unlock;
2074 	case SNDRV_PCM_STATE_SUSPENDED:
2075 		err = -ESTRPIPE;
2076 		goto _end_unlock;
2077 	default:
2078 		err = -EBADFD;
2079 		goto _end_unlock;
2080 	}
2081 
2082 	runtime->twake = runtime->control->avail_min ? : 1;
2083 	while (size > 0) {
2084 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2085 		snd_pcm_uframes_t avail;
2086 		snd_pcm_uframes_t cont;
2087 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2088 			snd_pcm_update_hw_ptr(substream);
2089 		avail = snd_pcm_capture_avail(runtime);
2090 		if (!avail) {
2091 			if (runtime->status->state ==
2092 			    SNDRV_PCM_STATE_DRAINING) {
2093 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2094 				goto _end_unlock;
2095 			}
2096 			if (nonblock) {
2097 				err = -EAGAIN;
2098 				goto _end_unlock;
2099 			}
2100 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2101 					runtime->control->avail_min ? : 1);
2102 			err = wait_for_avail(substream, &avail);
2103 			if (err < 0)
2104 				goto _end_unlock;
2105 			if (!avail)
2106 				continue; /* draining */
2107 		}
2108 		frames = size > avail ? avail : size;
2109 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2110 		if (frames > cont)
2111 			frames = cont;
2112 		if (snd_BUG_ON(!frames)) {
2113 			runtime->twake = 0;
2114 			snd_pcm_stream_unlock_irq(substream);
2115 			return -EINVAL;
2116 		}
2117 		appl_ptr = runtime->control->appl_ptr;
2118 		appl_ofs = appl_ptr % runtime->buffer_size;
2119 		snd_pcm_stream_unlock_irq(substream);
2120 		err = transfer(substream, appl_ofs, data, offset, frames);
2121 		snd_pcm_stream_lock_irq(substream);
2122 		if (err < 0)
2123 			goto _end_unlock;
2124 		switch (runtime->status->state) {
2125 		case SNDRV_PCM_STATE_XRUN:
2126 			err = -EPIPE;
2127 			goto _end_unlock;
2128 		case SNDRV_PCM_STATE_SUSPENDED:
2129 			err = -ESTRPIPE;
2130 			goto _end_unlock;
2131 		default:
2132 			break;
2133 		}
2134 		appl_ptr += frames;
2135 		if (appl_ptr >= runtime->boundary)
2136 			appl_ptr -= runtime->boundary;
2137 		runtime->control->appl_ptr = appl_ptr;
2138 		if (substream->ops->ack)
2139 			substream->ops->ack(substream);
2140 
2141 		offset += frames;
2142 		size -= frames;
2143 		xfer += frames;
2144 	}
2145  _end_unlock:
2146 	runtime->twake = 0;
2147 	if (xfer > 0 && err >= 0)
2148 		snd_pcm_update_state(substream, runtime);
2149 	snd_pcm_stream_unlock_irq(substream);
2150 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2151 }
2152 
2153 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2154 {
2155 	struct snd_pcm_runtime *runtime;
2156 	int nonblock;
2157 	int err;
2158 
2159 	err = pcm_sanity_check(substream);
2160 	if (err < 0)
2161 		return err;
2162 	runtime = substream->runtime;
2163 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2164 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2165 		return -EINVAL;
2166 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2167 }
2168 
2169 EXPORT_SYMBOL(snd_pcm_lib_read);
2170 
2171 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2172 				      unsigned int hwoff,
2173 				      unsigned long data, unsigned int off,
2174 				      snd_pcm_uframes_t frames)
2175 {
2176 	struct snd_pcm_runtime *runtime = substream->runtime;
2177 	int err;
2178 	void __user **bufs = (void __user **)data;
2179 	int channels = runtime->channels;
2180 	int c;
2181 	if (substream->ops->copy) {
2182 		for (c = 0; c < channels; ++c, ++bufs) {
2183 			char __user *buf;
2184 			if (*bufs == NULL)
2185 				continue;
2186 			buf = *bufs + samples_to_bytes(runtime, off);
2187 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2188 				return err;
2189 		}
2190 	} else {
2191 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2192 		for (c = 0; c < channels; ++c, ++bufs) {
2193 			char *hwbuf;
2194 			char __user *buf;
2195 			if (*bufs == NULL)
2196 				continue;
2197 
2198 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2199 			buf = *bufs + samples_to_bytes(runtime, off);
2200 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2201 				return -EFAULT;
2202 		}
2203 	}
2204 	return 0;
2205 }
2206 
2207 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2208 				    void __user **bufs,
2209 				    snd_pcm_uframes_t frames)
2210 {
2211 	struct snd_pcm_runtime *runtime;
2212 	int nonblock;
2213 	int err;
2214 
2215 	err = pcm_sanity_check(substream);
2216 	if (err < 0)
2217 		return err;
2218 	runtime = substream->runtime;
2219 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2220 		return -EBADFD;
2221 
2222 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2223 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2224 		return -EINVAL;
2225 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2226 }
2227 
2228 EXPORT_SYMBOL(snd_pcm_lib_readv);
2229