xref: /linux/sound/core/pcm_lib.c (revision f8324e20f8289dffc646d64366332e05eaacab25)
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 			runtime->silence_filled = avail > 0 ? avail : 0;
71 			runtime->silence_start = (runtime->status->hw_ptr +
72 						  runtime->silence_filled) %
73 						 runtime->boundary;
74 		} else {
75 			ofs = runtime->status->hw_ptr;
76 			frames = new_hw_ptr - ofs;
77 			if ((snd_pcm_sframes_t)frames < 0)
78 				frames += runtime->boundary;
79 			runtime->silence_filled -= frames;
80 			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
81 				runtime->silence_filled = 0;
82 				runtime->silence_start = new_hw_ptr;
83 			} else {
84 				runtime->silence_start = ofs;
85 			}
86 		}
87 		frames = runtime->buffer_size - runtime->silence_filled;
88 	}
89 	if (snd_BUG_ON(frames > runtime->buffer_size))
90 		return;
91 	if (frames == 0)
92 		return;
93 	ofs = runtime->silence_start % runtime->buffer_size;
94 	while (frames > 0) {
95 		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
96 		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
97 		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
98 			if (substream->ops->silence) {
99 				int err;
100 				err = substream->ops->silence(substream, -1, ofs, transfer);
101 				snd_BUG_ON(err < 0);
102 			} else {
103 				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
104 				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
105 			}
106 		} else {
107 			unsigned int c;
108 			unsigned int channels = runtime->channels;
109 			if (substream->ops->silence) {
110 				for (c = 0; c < channels; ++c) {
111 					int err;
112 					err = substream->ops->silence(substream, c, ofs, transfer);
113 					snd_BUG_ON(err < 0);
114 				}
115 			} else {
116 				size_t dma_csize = runtime->dma_bytes / channels;
117 				for (c = 0; c < channels; ++c) {
118 					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
119 					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
120 				}
121 			}
122 		}
123 		runtime->silence_filled += transfer;
124 		frames -= transfer;
125 		ofs = 0;
126 	}
127 }
128 
129 static void pcm_debug_name(struct snd_pcm_substream *substream,
130 			   char *name, size_t len)
131 {
132 	snprintf(name, len, "pcmC%dD%d%c:%d",
133 		 substream->pcm->card->number,
134 		 substream->pcm->device,
135 		 substream->stream ? 'c' : 'p',
136 		 substream->number);
137 }
138 
139 #define XRUN_DEBUG_BASIC	(1<<0)
140 #define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
141 #define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
142 #define XRUN_DEBUG_PERIODUPDATE	(1<<3)	/* full period update info */
143 #define XRUN_DEBUG_HWPTRUPDATE	(1<<4)	/* full hwptr update info */
144 #define XRUN_DEBUG_LOG		(1<<5)	/* show last 10 positions on err */
145 #define XRUN_DEBUG_LOGONCE	(1<<6)	/* do above only once */
146 
147 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
148 
149 #define xrun_debug(substream, mask) \
150 			((substream)->pstr->xrun_debug & (mask))
151 #else
152 #define xrun_debug(substream, mask)	0
153 #endif
154 
155 #define dump_stack_on_xrun(substream) do {			\
156 		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
157 			dump_stack();				\
158 	} while (0)
159 
160 static void xrun(struct snd_pcm_substream *substream)
161 {
162 	struct snd_pcm_runtime *runtime = substream->runtime;
163 
164 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
165 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
166 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
167 	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
168 		char name[16];
169 		pcm_debug_name(substream, name, sizeof(name));
170 		snd_printd(KERN_DEBUG "XRUN: %s\n", name);
171 		dump_stack_on_xrun(substream);
172 	}
173 }
174 
175 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
176 #define hw_ptr_error(substream, fmt, args...)				\
177 	do {								\
178 		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
179 			xrun_log_show(substream);			\
180 			if (printk_ratelimit()) {			\
181 				snd_printd("PCM: " fmt, ##args);	\
182 			}						\
183 			dump_stack_on_xrun(substream);			\
184 		}							\
185 	} while (0)
186 
187 #define XRUN_LOG_CNT	10
188 
189 struct hwptr_log_entry {
190 	unsigned long jiffies;
191 	snd_pcm_uframes_t pos;
192 	snd_pcm_uframes_t period_size;
193 	snd_pcm_uframes_t buffer_size;
194 	snd_pcm_uframes_t old_hw_ptr;
195 	snd_pcm_uframes_t hw_ptr_base;
196 };
197 
198 struct snd_pcm_hwptr_log {
199 	unsigned int idx;
200 	unsigned int hit: 1;
201 	struct hwptr_log_entry entries[XRUN_LOG_CNT];
202 };
203 
204 static void xrun_log(struct snd_pcm_substream *substream,
205 		     snd_pcm_uframes_t pos)
206 {
207 	struct snd_pcm_runtime *runtime = substream->runtime;
208 	struct snd_pcm_hwptr_log *log = runtime->hwptr_log;
209 	struct hwptr_log_entry *entry;
210 
211 	if (log == NULL) {
212 		log = kzalloc(sizeof(*log), GFP_ATOMIC);
213 		if (log == NULL)
214 			return;
215 		runtime->hwptr_log = log;
216 	} else {
217 		if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
218 			return;
219 	}
220 	entry = &log->entries[log->idx];
221 	entry->jiffies = jiffies;
222 	entry->pos = pos;
223 	entry->period_size = runtime->period_size;
224 	entry->buffer_size = runtime->buffer_size;;
225 	entry->old_hw_ptr = runtime->status->hw_ptr;
226 	entry->hw_ptr_base = runtime->hw_ptr_base;
227 	log->idx = (log->idx + 1) % XRUN_LOG_CNT;
228 }
229 
230 static void xrun_log_show(struct snd_pcm_substream *substream)
231 {
232 	struct snd_pcm_hwptr_log *log = substream->runtime->hwptr_log;
233 	struct hwptr_log_entry *entry;
234 	char name[16];
235 	unsigned int idx;
236 	int cnt;
237 
238 	if (log == NULL)
239 		return;
240 	if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
241 		return;
242 	pcm_debug_name(substream, name, sizeof(name));
243 	for (cnt = 0, idx = log->idx; cnt < XRUN_LOG_CNT; cnt++) {
244 		entry = &log->entries[idx];
245 		if (entry->period_size == 0)
246 			break;
247 		snd_printd("hwptr log: %s: j=%lu, pos=%ld/%ld/%ld, "
248 			   "hwptr=%ld/%ld\n",
249 			   name, entry->jiffies, (unsigned long)entry->pos,
250 			   (unsigned long)entry->period_size,
251 			   (unsigned long)entry->buffer_size,
252 			   (unsigned long)entry->old_hw_ptr,
253 			   (unsigned long)entry->hw_ptr_base);
254 		idx++;
255 		idx %= XRUN_LOG_CNT;
256 	}
257 	log->hit = 1;
258 }
259 
260 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
261 
262 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
263 #define xrun_log(substream, pos)	do { } while (0)
264 #define xrun_log_show(substream)	do { } while (0)
265 
266 #endif
267 
268 int snd_pcm_update_state(struct snd_pcm_substream *substream,
269 			 struct snd_pcm_runtime *runtime)
270 {
271 	snd_pcm_uframes_t avail;
272 
273 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
274 		avail = snd_pcm_playback_avail(runtime);
275 	else
276 		avail = snd_pcm_capture_avail(runtime);
277 	if (avail > runtime->avail_max)
278 		runtime->avail_max = avail;
279 	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
280 		if (avail >= runtime->buffer_size) {
281 			snd_pcm_drain_done(substream);
282 			return -EPIPE;
283 		}
284 	} else {
285 		if (avail >= runtime->stop_threshold) {
286 			xrun(substream);
287 			return -EPIPE;
288 		}
289 	}
290 	if (avail >= runtime->control->avail_min)
291 		wake_up(runtime->twake ? &runtime->tsleep : &runtime->sleep);
292 	return 0;
293 }
294 
295 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
296 				  unsigned int in_interrupt)
297 {
298 	struct snd_pcm_runtime *runtime = substream->runtime;
299 	snd_pcm_uframes_t pos;
300 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
301 	snd_pcm_sframes_t hdelta, delta;
302 	unsigned long jdelta;
303 
304 	old_hw_ptr = runtime->status->hw_ptr;
305 	pos = substream->ops->pointer(substream);
306 	if (pos == SNDRV_PCM_POS_XRUN) {
307 		xrun(substream);
308 		return -EPIPE;
309 	}
310 	if (pos >= runtime->buffer_size) {
311 		if (printk_ratelimit()) {
312 			char name[16];
313 			pcm_debug_name(substream, name, sizeof(name));
314 			xrun_log_show(substream);
315 			snd_printd(KERN_ERR  "BUG: %s, pos = %ld, "
316 				   "buffer size = %ld, period size = %ld\n",
317 				   name, pos, runtime->buffer_size,
318 				   runtime->period_size);
319 		}
320 		pos = 0;
321 	}
322 	pos -= pos % runtime->min_align;
323 	if (xrun_debug(substream, XRUN_DEBUG_LOG))
324 		xrun_log(substream, pos);
325 	hw_base = runtime->hw_ptr_base;
326 	new_hw_ptr = hw_base + pos;
327 	if (in_interrupt) {
328 		/* we know that one period was processed */
329 		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
330 		delta = runtime->hw_ptr_interrupt + runtime->period_size;
331 		if (delta > new_hw_ptr) {
332 			hw_base += runtime->buffer_size;
333 			if (hw_base >= runtime->boundary)
334 				hw_base = 0;
335 			new_hw_ptr = hw_base + pos;
336 			goto __delta;
337 		}
338 	}
339 	/* new_hw_ptr might be lower than old_hw_ptr in case when */
340 	/* pointer crosses the end of the ring buffer */
341 	if (new_hw_ptr < old_hw_ptr) {
342 		hw_base += runtime->buffer_size;
343 		if (hw_base >= runtime->boundary)
344 			hw_base = 0;
345 		new_hw_ptr = hw_base + pos;
346 	}
347       __delta:
348 	delta = new_hw_ptr - old_hw_ptr;
349 	if (delta < 0)
350 		delta += runtime->boundary;
351 	if (xrun_debug(substream, in_interrupt ?
352 			XRUN_DEBUG_PERIODUPDATE : XRUN_DEBUG_HWPTRUPDATE)) {
353 		char name[16];
354 		pcm_debug_name(substream, name, sizeof(name));
355 		snd_printd("%s_update: %s: pos=%u/%u/%u, "
356 			   "hwptr=%ld/%ld/%ld/%ld\n",
357 			   in_interrupt ? "period" : "hwptr",
358 			   name,
359 			   (unsigned int)pos,
360 			   (unsigned int)runtime->period_size,
361 			   (unsigned int)runtime->buffer_size,
362 			   (unsigned long)delta,
363 			   (unsigned long)old_hw_ptr,
364 			   (unsigned long)new_hw_ptr,
365 			   (unsigned long)runtime->hw_ptr_base);
366 	}
367 	/* something must be really wrong */
368 	if (delta >= runtime->buffer_size + runtime->period_size) {
369 		hw_ptr_error(substream,
370 			       "Unexpected hw_pointer value %s"
371 			       "(stream=%i, pos=%ld, new_hw_ptr=%ld, "
372 			       "old_hw_ptr=%ld)\n",
373 				     in_interrupt ? "[Q] " : "[P]",
374 				     substream->stream, (long)pos,
375 				     (long)new_hw_ptr, (long)old_hw_ptr);
376 		return 0;
377 	}
378 
379 	/* Do jiffies check only in xrun_debug mode */
380 	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
381 		goto no_jiffies_check;
382 
383 	/* Skip the jiffies check for hardwares with BATCH flag.
384 	 * Such hardware usually just increases the position at each IRQ,
385 	 * thus it can't give any strange position.
386 	 */
387 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
388 		goto no_jiffies_check;
389 	hdelta = delta;
390 	if (hdelta < runtime->delay)
391 		goto no_jiffies_check;
392 	hdelta -= runtime->delay;
393 	jdelta = jiffies - runtime->hw_ptr_jiffies;
394 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
395 		delta = jdelta /
396 			(((runtime->period_size * HZ) / runtime->rate)
397 								+ HZ/100);
398 		/* move new_hw_ptr according jiffies not pos variable */
399 		new_hw_ptr = old_hw_ptr;
400 		hw_base = delta;
401 		/* use loop to avoid checks for delta overflows */
402 		/* the delta value is small or zero in most cases */
403 		while (delta > 0) {
404 			new_hw_ptr += runtime->period_size;
405 			if (new_hw_ptr >= runtime->boundary)
406 				new_hw_ptr -= runtime->boundary;
407 			delta--;
408 		}
409 		/* align hw_base to buffer_size */
410 		hw_ptr_error(substream,
411 			     "hw_ptr skipping! %s"
412 			     "(pos=%ld, delta=%ld, period=%ld, "
413 			     "jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
414 			     in_interrupt ? "[Q] " : "",
415 			     (long)pos, (long)hdelta,
416 			     (long)runtime->period_size, jdelta,
417 			     ((hdelta * HZ) / runtime->rate), hw_base,
418 			     (unsigned long)old_hw_ptr,
419 			     (unsigned long)new_hw_ptr);
420 		/* reset values to proper state */
421 		delta = 0;
422 		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
423 	}
424  no_jiffies_check:
425 	if (delta > runtime->period_size + runtime->period_size / 2) {
426 		hw_ptr_error(substream,
427 			     "Lost interrupts? %s"
428 			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, "
429 			     "old_hw_ptr=%ld)\n",
430 			     in_interrupt ? "[Q] " : "",
431 			     substream->stream, (long)delta,
432 			     (long)new_hw_ptr,
433 			     (long)old_hw_ptr);
434 	}
435 
436 	if (runtime->status->hw_ptr == new_hw_ptr)
437 		return 0;
438 
439 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
440 	    runtime->silence_size > 0)
441 		snd_pcm_playback_silence(substream, new_hw_ptr);
442 
443 	if (in_interrupt) {
444 		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
445 		if (delta < 0)
446 			delta += runtime->boundary;
447 		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
448 		runtime->hw_ptr_interrupt += delta;
449 		if (runtime->hw_ptr_interrupt >= runtime->boundary)
450 			runtime->hw_ptr_interrupt -= runtime->boundary;
451 	}
452 	runtime->hw_ptr_base = hw_base;
453 	runtime->status->hw_ptr = new_hw_ptr;
454 	runtime->hw_ptr_jiffies = jiffies;
455 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
456 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
457 
458 	return snd_pcm_update_state(substream, runtime);
459 }
460 
461 /* CAUTION: call it with irq disabled */
462 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
463 {
464 	return snd_pcm_update_hw_ptr0(substream, 0);
465 }
466 
467 /**
468  * snd_pcm_set_ops - set the PCM operators
469  * @pcm: the pcm instance
470  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
471  * @ops: the operator table
472  *
473  * Sets the given PCM operators to the pcm instance.
474  */
475 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, struct snd_pcm_ops *ops)
476 {
477 	struct snd_pcm_str *stream = &pcm->streams[direction];
478 	struct snd_pcm_substream *substream;
479 
480 	for (substream = stream->substream; substream != NULL; substream = substream->next)
481 		substream->ops = ops;
482 }
483 
484 EXPORT_SYMBOL(snd_pcm_set_ops);
485 
486 /**
487  * snd_pcm_sync - set the PCM sync id
488  * @substream: the pcm substream
489  *
490  * Sets the PCM sync identifier for the card.
491  */
492 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
493 {
494 	struct snd_pcm_runtime *runtime = substream->runtime;
495 
496 	runtime->sync.id32[0] = substream->pcm->card->number;
497 	runtime->sync.id32[1] = -1;
498 	runtime->sync.id32[2] = -1;
499 	runtime->sync.id32[3] = -1;
500 }
501 
502 EXPORT_SYMBOL(snd_pcm_set_sync);
503 
504 /*
505  *  Standard ioctl routine
506  */
507 
508 static inline unsigned int div32(unsigned int a, unsigned int b,
509 				 unsigned int *r)
510 {
511 	if (b == 0) {
512 		*r = 0;
513 		return UINT_MAX;
514 	}
515 	*r = a % b;
516 	return a / b;
517 }
518 
519 static inline unsigned int div_down(unsigned int a, unsigned int b)
520 {
521 	if (b == 0)
522 		return UINT_MAX;
523 	return a / b;
524 }
525 
526 static inline unsigned int div_up(unsigned int a, unsigned int b)
527 {
528 	unsigned int r;
529 	unsigned int q;
530 	if (b == 0)
531 		return UINT_MAX;
532 	q = div32(a, b, &r);
533 	if (r)
534 		++q;
535 	return q;
536 }
537 
538 static inline unsigned int mul(unsigned int a, unsigned int b)
539 {
540 	if (a == 0)
541 		return 0;
542 	if (div_down(UINT_MAX, a) < b)
543 		return UINT_MAX;
544 	return a * b;
545 }
546 
547 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
548 				    unsigned int c, unsigned int *r)
549 {
550 	u_int64_t n = (u_int64_t) a * b;
551 	if (c == 0) {
552 		snd_BUG_ON(!n);
553 		*r = 0;
554 		return UINT_MAX;
555 	}
556 	n = div_u64_rem(n, c, r);
557 	if (n >= UINT_MAX) {
558 		*r = 0;
559 		return UINT_MAX;
560 	}
561 	return n;
562 }
563 
564 /**
565  * snd_interval_refine - refine the interval value of configurator
566  * @i: the interval value to refine
567  * @v: the interval value to refer to
568  *
569  * Refines the interval value with the reference value.
570  * The interval is changed to the range satisfying both intervals.
571  * The interval status (min, max, integer, etc.) are evaluated.
572  *
573  * Returns non-zero if the value is changed, zero if not changed.
574  */
575 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
576 {
577 	int changed = 0;
578 	if (snd_BUG_ON(snd_interval_empty(i)))
579 		return -EINVAL;
580 	if (i->min < v->min) {
581 		i->min = v->min;
582 		i->openmin = v->openmin;
583 		changed = 1;
584 	} else if (i->min == v->min && !i->openmin && v->openmin) {
585 		i->openmin = 1;
586 		changed = 1;
587 	}
588 	if (i->max > v->max) {
589 		i->max = v->max;
590 		i->openmax = v->openmax;
591 		changed = 1;
592 	} else if (i->max == v->max && !i->openmax && v->openmax) {
593 		i->openmax = 1;
594 		changed = 1;
595 	}
596 	if (!i->integer && v->integer) {
597 		i->integer = 1;
598 		changed = 1;
599 	}
600 	if (i->integer) {
601 		if (i->openmin) {
602 			i->min++;
603 			i->openmin = 0;
604 		}
605 		if (i->openmax) {
606 			i->max--;
607 			i->openmax = 0;
608 		}
609 	} else if (!i->openmin && !i->openmax && i->min == i->max)
610 		i->integer = 1;
611 	if (snd_interval_checkempty(i)) {
612 		snd_interval_none(i);
613 		return -EINVAL;
614 	}
615 	return changed;
616 }
617 
618 EXPORT_SYMBOL(snd_interval_refine);
619 
620 static int snd_interval_refine_first(struct snd_interval *i)
621 {
622 	if (snd_BUG_ON(snd_interval_empty(i)))
623 		return -EINVAL;
624 	if (snd_interval_single(i))
625 		return 0;
626 	i->max = i->min;
627 	i->openmax = i->openmin;
628 	if (i->openmax)
629 		i->max++;
630 	return 1;
631 }
632 
633 static int snd_interval_refine_last(struct snd_interval *i)
634 {
635 	if (snd_BUG_ON(snd_interval_empty(i)))
636 		return -EINVAL;
637 	if (snd_interval_single(i))
638 		return 0;
639 	i->min = i->max;
640 	i->openmin = i->openmax;
641 	if (i->openmin)
642 		i->min--;
643 	return 1;
644 }
645 
646 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
647 {
648 	if (a->empty || b->empty) {
649 		snd_interval_none(c);
650 		return;
651 	}
652 	c->empty = 0;
653 	c->min = mul(a->min, b->min);
654 	c->openmin = (a->openmin || b->openmin);
655 	c->max = mul(a->max,  b->max);
656 	c->openmax = (a->openmax || b->openmax);
657 	c->integer = (a->integer && b->integer);
658 }
659 
660 /**
661  * snd_interval_div - refine the interval value with division
662  * @a: dividend
663  * @b: divisor
664  * @c: quotient
665  *
666  * c = a / b
667  *
668  * Returns non-zero if the value is changed, zero if not changed.
669  */
670 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
671 {
672 	unsigned int r;
673 	if (a->empty || b->empty) {
674 		snd_interval_none(c);
675 		return;
676 	}
677 	c->empty = 0;
678 	c->min = div32(a->min, b->max, &r);
679 	c->openmin = (r || a->openmin || b->openmax);
680 	if (b->min > 0) {
681 		c->max = div32(a->max, b->min, &r);
682 		if (r) {
683 			c->max++;
684 			c->openmax = 1;
685 		} else
686 			c->openmax = (a->openmax || b->openmin);
687 	} else {
688 		c->max = UINT_MAX;
689 		c->openmax = 0;
690 	}
691 	c->integer = 0;
692 }
693 
694 /**
695  * snd_interval_muldivk - refine the interval value
696  * @a: dividend 1
697  * @b: dividend 2
698  * @k: divisor (as integer)
699  * @c: result
700   *
701  * c = a * b / k
702  *
703  * Returns non-zero if the value is changed, zero if not changed.
704  */
705 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
706 		      unsigned int k, struct snd_interval *c)
707 {
708 	unsigned int r;
709 	if (a->empty || b->empty) {
710 		snd_interval_none(c);
711 		return;
712 	}
713 	c->empty = 0;
714 	c->min = muldiv32(a->min, b->min, k, &r);
715 	c->openmin = (r || a->openmin || b->openmin);
716 	c->max = muldiv32(a->max, b->max, k, &r);
717 	if (r) {
718 		c->max++;
719 		c->openmax = 1;
720 	} else
721 		c->openmax = (a->openmax || b->openmax);
722 	c->integer = 0;
723 }
724 
725 /**
726  * snd_interval_mulkdiv - refine the interval value
727  * @a: dividend 1
728  * @k: dividend 2 (as integer)
729  * @b: divisor
730  * @c: result
731  *
732  * c = a * k / b
733  *
734  * Returns non-zero if the value is changed, zero if not changed.
735  */
736 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
737 		      const struct snd_interval *b, 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, k, b->max, &r);
746 	c->openmin = (r || a->openmin || b->openmax);
747 	if (b->min > 0) {
748 		c->max = muldiv32(a->max, k, b->min, &r);
749 		if (r) {
750 			c->max++;
751 			c->openmax = 1;
752 		} else
753 			c->openmax = (a->openmax || b->openmin);
754 	} else {
755 		c->max = UINT_MAX;
756 		c->openmax = 0;
757 	}
758 	c->integer = 0;
759 }
760 
761 /* ---- */
762 
763 
764 /**
765  * snd_interval_ratnum - refine the interval value
766  * @i: interval to refine
767  * @rats_count: number of ratnum_t
768  * @rats: ratnum_t array
769  * @nump: pointer to store the resultant numerator
770  * @denp: pointer to store the resultant denominator
771  *
772  * Returns non-zero if the value is changed, zero if not changed.
773  */
774 int snd_interval_ratnum(struct snd_interval *i,
775 			unsigned int rats_count, struct snd_ratnum *rats,
776 			unsigned int *nump, unsigned int *denp)
777 {
778 	unsigned int best_num, best_den;
779 	int best_diff;
780 	unsigned int k;
781 	struct snd_interval t;
782 	int err;
783 	unsigned int result_num, result_den;
784 	int result_diff;
785 
786 	best_num = best_den = best_diff = 0;
787 	for (k = 0; k < rats_count; ++k) {
788 		unsigned int num = rats[k].num;
789 		unsigned int den;
790 		unsigned int q = i->min;
791 		int diff;
792 		if (q == 0)
793 			q = 1;
794 		den = div_up(num, q);
795 		if (den < rats[k].den_min)
796 			continue;
797 		if (den > rats[k].den_max)
798 			den = rats[k].den_max;
799 		else {
800 			unsigned int r;
801 			r = (den - rats[k].den_min) % rats[k].den_step;
802 			if (r != 0)
803 				den -= r;
804 		}
805 		diff = num - q * den;
806 		if (diff < 0)
807 			diff = -diff;
808 		if (best_num == 0 ||
809 		    diff * best_den < best_diff * den) {
810 			best_diff = diff;
811 			best_den = den;
812 			best_num = num;
813 		}
814 	}
815 	if (best_den == 0) {
816 		i->empty = 1;
817 		return -EINVAL;
818 	}
819 	t.min = div_down(best_num, best_den);
820 	t.openmin = !!(best_num % best_den);
821 
822 	result_num = best_num;
823 	result_diff = best_diff;
824 	result_den = best_den;
825 	best_num = best_den = best_diff = 0;
826 	for (k = 0; k < rats_count; ++k) {
827 		unsigned int num = rats[k].num;
828 		unsigned int den;
829 		unsigned int q = i->max;
830 		int diff;
831 		if (q == 0) {
832 			i->empty = 1;
833 			return -EINVAL;
834 		}
835 		den = div_down(num, q);
836 		if (den > rats[k].den_max)
837 			continue;
838 		if (den < rats[k].den_min)
839 			den = rats[k].den_min;
840 		else {
841 			unsigned int r;
842 			r = (den - rats[k].den_min) % rats[k].den_step;
843 			if (r != 0)
844 				den += rats[k].den_step - r;
845 		}
846 		diff = q * den - num;
847 		if (diff < 0)
848 			diff = -diff;
849 		if (best_num == 0 ||
850 		    diff * best_den < best_diff * den) {
851 			best_diff = diff;
852 			best_den = den;
853 			best_num = num;
854 		}
855 	}
856 	if (best_den == 0) {
857 		i->empty = 1;
858 		return -EINVAL;
859 	}
860 	t.max = div_up(best_num, best_den);
861 	t.openmax = !!(best_num % best_den);
862 	t.integer = 0;
863 	err = snd_interval_refine(i, &t);
864 	if (err < 0)
865 		return err;
866 
867 	if (snd_interval_single(i)) {
868 		if (best_diff * result_den < result_diff * best_den) {
869 			result_num = best_num;
870 			result_den = best_den;
871 		}
872 		if (nump)
873 			*nump = result_num;
874 		if (denp)
875 			*denp = result_den;
876 	}
877 	return err;
878 }
879 
880 EXPORT_SYMBOL(snd_interval_ratnum);
881 
882 /**
883  * snd_interval_ratden - refine the interval value
884  * @i: interval to refine
885  * @rats_count: number of struct ratden
886  * @rats: struct ratden array
887  * @nump: pointer to store the resultant numerator
888  * @denp: pointer to store the resultant denominator
889  *
890  * Returns non-zero if the value is changed, zero if not changed.
891  */
892 static int snd_interval_ratden(struct snd_interval *i,
893 			       unsigned int rats_count, struct snd_ratden *rats,
894 			       unsigned int *nump, unsigned int *denp)
895 {
896 	unsigned int best_num, best_diff, best_den;
897 	unsigned int k;
898 	struct snd_interval t;
899 	int err;
900 
901 	best_num = best_den = best_diff = 0;
902 	for (k = 0; k < rats_count; ++k) {
903 		unsigned int num;
904 		unsigned int den = rats[k].den;
905 		unsigned int q = i->min;
906 		int diff;
907 		num = mul(q, den);
908 		if (num > rats[k].num_max)
909 			continue;
910 		if (num < rats[k].num_min)
911 			num = rats[k].num_max;
912 		else {
913 			unsigned int r;
914 			r = (num - rats[k].num_min) % rats[k].num_step;
915 			if (r != 0)
916 				num += rats[k].num_step - r;
917 		}
918 		diff = num - q * den;
919 		if (best_num == 0 ||
920 		    diff * best_den < best_diff * den) {
921 			best_diff = diff;
922 			best_den = den;
923 			best_num = num;
924 		}
925 	}
926 	if (best_den == 0) {
927 		i->empty = 1;
928 		return -EINVAL;
929 	}
930 	t.min = div_down(best_num, best_den);
931 	t.openmin = !!(best_num % best_den);
932 
933 	best_num = best_den = best_diff = 0;
934 	for (k = 0; k < rats_count; ++k) {
935 		unsigned int num;
936 		unsigned int den = rats[k].den;
937 		unsigned int q = i->max;
938 		int diff;
939 		num = mul(q, den);
940 		if (num < rats[k].num_min)
941 			continue;
942 		if (num > rats[k].num_max)
943 			num = rats[k].num_max;
944 		else {
945 			unsigned int r;
946 			r = (num - rats[k].num_min) % rats[k].num_step;
947 			if (r != 0)
948 				num -= r;
949 		}
950 		diff = q * den - num;
951 		if (best_num == 0 ||
952 		    diff * best_den < best_diff * den) {
953 			best_diff = diff;
954 			best_den = den;
955 			best_num = num;
956 		}
957 	}
958 	if (best_den == 0) {
959 		i->empty = 1;
960 		return -EINVAL;
961 	}
962 	t.max = div_up(best_num, best_den);
963 	t.openmax = !!(best_num % best_den);
964 	t.integer = 0;
965 	err = snd_interval_refine(i, &t);
966 	if (err < 0)
967 		return err;
968 
969 	if (snd_interval_single(i)) {
970 		if (nump)
971 			*nump = best_num;
972 		if (denp)
973 			*denp = best_den;
974 	}
975 	return err;
976 }
977 
978 /**
979  * snd_interval_list - refine the interval value from the list
980  * @i: the interval value to refine
981  * @count: the number of elements in the list
982  * @list: the value list
983  * @mask: the bit-mask to evaluate
984  *
985  * Refines the interval value from the list.
986  * When mask is non-zero, only the elements corresponding to bit 1 are
987  * evaluated.
988  *
989  * Returns non-zero if the value is changed, zero if not changed.
990  */
991 int snd_interval_list(struct snd_interval *i, unsigned int count, unsigned int *list, unsigned int mask)
992 {
993         unsigned int k;
994 	struct snd_interval list_range;
995 
996 	if (!count) {
997 		i->empty = 1;
998 		return -EINVAL;
999 	}
1000 	snd_interval_any(&list_range);
1001 	list_range.min = UINT_MAX;
1002 	list_range.max = 0;
1003         for (k = 0; k < count; k++) {
1004 		if (mask && !(mask & (1 << k)))
1005 			continue;
1006 		if (!snd_interval_test(i, list[k]))
1007 			continue;
1008 		list_range.min = min(list_range.min, list[k]);
1009 		list_range.max = max(list_range.max, list[k]);
1010         }
1011 	return snd_interval_refine(i, &list_range);
1012 }
1013 
1014 EXPORT_SYMBOL(snd_interval_list);
1015 
1016 static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned int step)
1017 {
1018 	unsigned int n;
1019 	int changed = 0;
1020 	n = (i->min - min) % step;
1021 	if (n != 0 || i->openmin) {
1022 		i->min += step - n;
1023 		changed = 1;
1024 	}
1025 	n = (i->max - min) % step;
1026 	if (n != 0 || i->openmax) {
1027 		i->max -= n;
1028 		changed = 1;
1029 	}
1030 	if (snd_interval_checkempty(i)) {
1031 		i->empty = 1;
1032 		return -EINVAL;
1033 	}
1034 	return changed;
1035 }
1036 
1037 /* Info constraints helpers */
1038 
1039 /**
1040  * snd_pcm_hw_rule_add - add the hw-constraint rule
1041  * @runtime: the pcm runtime instance
1042  * @cond: condition bits
1043  * @var: the variable to evaluate
1044  * @func: the evaluation function
1045  * @private: the private data pointer passed to function
1046  * @dep: the dependent variables
1047  *
1048  * Returns zero if successful, or a negative error code on failure.
1049  */
1050 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1051 			int var,
1052 			snd_pcm_hw_rule_func_t func, void *private,
1053 			int dep, ...)
1054 {
1055 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1056 	struct snd_pcm_hw_rule *c;
1057 	unsigned int k;
1058 	va_list args;
1059 	va_start(args, dep);
1060 	if (constrs->rules_num >= constrs->rules_all) {
1061 		struct snd_pcm_hw_rule *new;
1062 		unsigned int new_rules = constrs->rules_all + 16;
1063 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1064 		if (!new)
1065 			return -ENOMEM;
1066 		if (constrs->rules) {
1067 			memcpy(new, constrs->rules,
1068 			       constrs->rules_num * sizeof(*c));
1069 			kfree(constrs->rules);
1070 		}
1071 		constrs->rules = new;
1072 		constrs->rules_all = new_rules;
1073 	}
1074 	c = &constrs->rules[constrs->rules_num];
1075 	c->cond = cond;
1076 	c->func = func;
1077 	c->var = var;
1078 	c->private = private;
1079 	k = 0;
1080 	while (1) {
1081 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps)))
1082 			return -EINVAL;
1083 		c->deps[k++] = dep;
1084 		if (dep < 0)
1085 			break;
1086 		dep = va_arg(args, int);
1087 	}
1088 	constrs->rules_num++;
1089 	va_end(args);
1090 	return 0;
1091 }
1092 
1093 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1094 
1095 /**
1096  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1097  * @runtime: PCM runtime instance
1098  * @var: hw_params variable to apply the mask
1099  * @mask: the bitmap mask
1100  *
1101  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1102  */
1103 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1104 			       u_int32_t mask)
1105 {
1106 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1107 	struct snd_mask *maskp = constrs_mask(constrs, var);
1108 	*maskp->bits &= mask;
1109 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1110 	if (*maskp->bits == 0)
1111 		return -EINVAL;
1112 	return 0;
1113 }
1114 
1115 /**
1116  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1117  * @runtime: PCM runtime instance
1118  * @var: hw_params variable to apply the mask
1119  * @mask: the 64bit bitmap mask
1120  *
1121  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1122  */
1123 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1124 				 u_int64_t mask)
1125 {
1126 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1127 	struct snd_mask *maskp = constrs_mask(constrs, var);
1128 	maskp->bits[0] &= (u_int32_t)mask;
1129 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1130 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1131 	if (! maskp->bits[0] && ! maskp->bits[1])
1132 		return -EINVAL;
1133 	return 0;
1134 }
1135 
1136 /**
1137  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1138  * @runtime: PCM runtime instance
1139  * @var: hw_params variable to apply the integer constraint
1140  *
1141  * Apply the constraint of integer to an interval parameter.
1142  */
1143 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1144 {
1145 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1146 	return snd_interval_setinteger(constrs_interval(constrs, var));
1147 }
1148 
1149 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1150 
1151 /**
1152  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1153  * @runtime: PCM runtime instance
1154  * @var: hw_params variable to apply the range
1155  * @min: the minimal value
1156  * @max: the maximal value
1157  *
1158  * Apply the min/max range constraint to an interval parameter.
1159  */
1160 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1161 				 unsigned int min, unsigned int max)
1162 {
1163 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1164 	struct snd_interval t;
1165 	t.min = min;
1166 	t.max = max;
1167 	t.openmin = t.openmax = 0;
1168 	t.integer = 0;
1169 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1170 }
1171 
1172 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1173 
1174 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1175 				struct snd_pcm_hw_rule *rule)
1176 {
1177 	struct snd_pcm_hw_constraint_list *list = rule->private;
1178 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1179 }
1180 
1181 
1182 /**
1183  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1184  * @runtime: PCM runtime instance
1185  * @cond: condition bits
1186  * @var: hw_params variable to apply the list constraint
1187  * @l: list
1188  *
1189  * Apply the list of constraints to an interval parameter.
1190  */
1191 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1192 			       unsigned int cond,
1193 			       snd_pcm_hw_param_t var,
1194 			       struct snd_pcm_hw_constraint_list *l)
1195 {
1196 	return snd_pcm_hw_rule_add(runtime, cond, var,
1197 				   snd_pcm_hw_rule_list, l,
1198 				   var, -1);
1199 }
1200 
1201 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1202 
1203 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1204 				   struct snd_pcm_hw_rule *rule)
1205 {
1206 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1207 	unsigned int num = 0, den = 0;
1208 	int err;
1209 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1210 				  r->nrats, r->rats, &num, &den);
1211 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1212 		params->rate_num = num;
1213 		params->rate_den = den;
1214 	}
1215 	return err;
1216 }
1217 
1218 /**
1219  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1220  * @runtime: PCM runtime instance
1221  * @cond: condition bits
1222  * @var: hw_params variable to apply the ratnums constraint
1223  * @r: struct snd_ratnums constriants
1224  */
1225 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1226 				  unsigned int cond,
1227 				  snd_pcm_hw_param_t var,
1228 				  struct snd_pcm_hw_constraint_ratnums *r)
1229 {
1230 	return snd_pcm_hw_rule_add(runtime, cond, var,
1231 				   snd_pcm_hw_rule_ratnums, r,
1232 				   var, -1);
1233 }
1234 
1235 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1236 
1237 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1238 				   struct snd_pcm_hw_rule *rule)
1239 {
1240 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1241 	unsigned int num = 0, den = 0;
1242 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1243 				  r->nrats, r->rats, &num, &den);
1244 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1245 		params->rate_num = num;
1246 		params->rate_den = den;
1247 	}
1248 	return err;
1249 }
1250 
1251 /**
1252  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1253  * @runtime: PCM runtime instance
1254  * @cond: condition bits
1255  * @var: hw_params variable to apply the ratdens constraint
1256  * @r: struct snd_ratdens constriants
1257  */
1258 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1259 				  unsigned int cond,
1260 				  snd_pcm_hw_param_t var,
1261 				  struct snd_pcm_hw_constraint_ratdens *r)
1262 {
1263 	return snd_pcm_hw_rule_add(runtime, cond, var,
1264 				   snd_pcm_hw_rule_ratdens, r,
1265 				   var, -1);
1266 }
1267 
1268 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1269 
1270 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1271 				  struct snd_pcm_hw_rule *rule)
1272 {
1273 	unsigned int l = (unsigned long) rule->private;
1274 	int width = l & 0xffff;
1275 	unsigned int msbits = l >> 16;
1276 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1277 	if (snd_interval_single(i) && snd_interval_value(i) == width)
1278 		params->msbits = msbits;
1279 	return 0;
1280 }
1281 
1282 /**
1283  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1284  * @runtime: PCM runtime instance
1285  * @cond: condition bits
1286  * @width: sample bits width
1287  * @msbits: msbits width
1288  */
1289 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1290 				 unsigned int cond,
1291 				 unsigned int width,
1292 				 unsigned int msbits)
1293 {
1294 	unsigned long l = (msbits << 16) | width;
1295 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1296 				    snd_pcm_hw_rule_msbits,
1297 				    (void*) l,
1298 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1299 }
1300 
1301 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1302 
1303 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1304 				struct snd_pcm_hw_rule *rule)
1305 {
1306 	unsigned long step = (unsigned long) rule->private;
1307 	return snd_interval_step(hw_param_interval(params, rule->var), 0, step);
1308 }
1309 
1310 /**
1311  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1312  * @runtime: PCM runtime instance
1313  * @cond: condition bits
1314  * @var: hw_params variable to apply the step constraint
1315  * @step: step size
1316  */
1317 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1318 			       unsigned int cond,
1319 			       snd_pcm_hw_param_t var,
1320 			       unsigned long step)
1321 {
1322 	return snd_pcm_hw_rule_add(runtime, cond, var,
1323 				   snd_pcm_hw_rule_step, (void *) step,
1324 				   var, -1);
1325 }
1326 
1327 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1328 
1329 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1330 {
1331 	static unsigned int pow2_sizes[] = {
1332 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1333 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1334 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1335 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1336 	};
1337 	return snd_interval_list(hw_param_interval(params, rule->var),
1338 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1339 }
1340 
1341 /**
1342  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1343  * @runtime: PCM runtime instance
1344  * @cond: condition bits
1345  * @var: hw_params variable to apply the power-of-2 constraint
1346  */
1347 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1348 			       unsigned int cond,
1349 			       snd_pcm_hw_param_t var)
1350 {
1351 	return snd_pcm_hw_rule_add(runtime, cond, var,
1352 				   snd_pcm_hw_rule_pow2, NULL,
1353 				   var, -1);
1354 }
1355 
1356 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1357 
1358 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1359 				  snd_pcm_hw_param_t var)
1360 {
1361 	if (hw_is_mask(var)) {
1362 		snd_mask_any(hw_param_mask(params, var));
1363 		params->cmask |= 1 << var;
1364 		params->rmask |= 1 << var;
1365 		return;
1366 	}
1367 	if (hw_is_interval(var)) {
1368 		snd_interval_any(hw_param_interval(params, var));
1369 		params->cmask |= 1 << var;
1370 		params->rmask |= 1 << var;
1371 		return;
1372 	}
1373 	snd_BUG();
1374 }
1375 
1376 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1377 {
1378 	unsigned int k;
1379 	memset(params, 0, sizeof(*params));
1380 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1381 		_snd_pcm_hw_param_any(params, k);
1382 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1383 		_snd_pcm_hw_param_any(params, k);
1384 	params->info = ~0U;
1385 }
1386 
1387 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1388 
1389 /**
1390  * snd_pcm_hw_param_value - return @params field @var value
1391  * @params: the hw_params instance
1392  * @var: parameter to retrieve
1393  * @dir: pointer to the direction (-1,0,1) or %NULL
1394  *
1395  * Return the value for field @var if it's fixed in configuration space
1396  * defined by @params. Return -%EINVAL otherwise.
1397  */
1398 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1399 			   snd_pcm_hw_param_t var, int *dir)
1400 {
1401 	if (hw_is_mask(var)) {
1402 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1403 		if (!snd_mask_single(mask))
1404 			return -EINVAL;
1405 		if (dir)
1406 			*dir = 0;
1407 		return snd_mask_value(mask);
1408 	}
1409 	if (hw_is_interval(var)) {
1410 		const struct snd_interval *i = hw_param_interval_c(params, var);
1411 		if (!snd_interval_single(i))
1412 			return -EINVAL;
1413 		if (dir)
1414 			*dir = i->openmin;
1415 		return snd_interval_value(i);
1416 	}
1417 	return -EINVAL;
1418 }
1419 
1420 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1421 
1422 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1423 				snd_pcm_hw_param_t var)
1424 {
1425 	if (hw_is_mask(var)) {
1426 		snd_mask_none(hw_param_mask(params, var));
1427 		params->cmask |= 1 << var;
1428 		params->rmask |= 1 << var;
1429 	} else if (hw_is_interval(var)) {
1430 		snd_interval_none(hw_param_interval(params, var));
1431 		params->cmask |= 1 << var;
1432 		params->rmask |= 1 << var;
1433 	} else {
1434 		snd_BUG();
1435 	}
1436 }
1437 
1438 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1439 
1440 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1441 				   snd_pcm_hw_param_t var)
1442 {
1443 	int changed;
1444 	if (hw_is_mask(var))
1445 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1446 	else if (hw_is_interval(var))
1447 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1448 	else
1449 		return -EINVAL;
1450 	if (changed) {
1451 		params->cmask |= 1 << var;
1452 		params->rmask |= 1 << var;
1453 	}
1454 	return changed;
1455 }
1456 
1457 
1458 /**
1459  * snd_pcm_hw_param_first - refine config space and return minimum value
1460  * @pcm: PCM instance
1461  * @params: the hw_params instance
1462  * @var: parameter to retrieve
1463  * @dir: pointer to the direction (-1,0,1) or %NULL
1464  *
1465  * Inside configuration space defined by @params remove from @var all
1466  * values > minimum. Reduce configuration space accordingly.
1467  * Return the minimum.
1468  */
1469 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1470 			   struct snd_pcm_hw_params *params,
1471 			   snd_pcm_hw_param_t var, int *dir)
1472 {
1473 	int changed = _snd_pcm_hw_param_first(params, var);
1474 	if (changed < 0)
1475 		return changed;
1476 	if (params->rmask) {
1477 		int err = snd_pcm_hw_refine(pcm, params);
1478 		if (snd_BUG_ON(err < 0))
1479 			return err;
1480 	}
1481 	return snd_pcm_hw_param_value(params, var, dir);
1482 }
1483 
1484 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1485 
1486 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1487 				  snd_pcm_hw_param_t var)
1488 {
1489 	int changed;
1490 	if (hw_is_mask(var))
1491 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1492 	else if (hw_is_interval(var))
1493 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1494 	else
1495 		return -EINVAL;
1496 	if (changed) {
1497 		params->cmask |= 1 << var;
1498 		params->rmask |= 1 << var;
1499 	}
1500 	return changed;
1501 }
1502 
1503 
1504 /**
1505  * snd_pcm_hw_param_last - refine config space and return maximum value
1506  * @pcm: PCM instance
1507  * @params: the hw_params instance
1508  * @var: parameter to retrieve
1509  * @dir: pointer to the direction (-1,0,1) or %NULL
1510  *
1511  * Inside configuration space defined by @params remove from @var all
1512  * values < maximum. Reduce configuration space accordingly.
1513  * Return the maximum.
1514  */
1515 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1516 			  struct snd_pcm_hw_params *params,
1517 			  snd_pcm_hw_param_t var, int *dir)
1518 {
1519 	int changed = _snd_pcm_hw_param_last(params, var);
1520 	if (changed < 0)
1521 		return changed;
1522 	if (params->rmask) {
1523 		int err = snd_pcm_hw_refine(pcm, params);
1524 		if (snd_BUG_ON(err < 0))
1525 			return err;
1526 	}
1527 	return snd_pcm_hw_param_value(params, var, dir);
1528 }
1529 
1530 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1531 
1532 /**
1533  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1534  * @pcm: PCM instance
1535  * @params: the hw_params instance
1536  *
1537  * Choose one configuration from configuration space defined by @params.
1538  * The configuration chosen is that obtained fixing in this order:
1539  * first access, first format, first subformat, min channels,
1540  * min rate, min period time, max buffer size, min tick time
1541  */
1542 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1543 			     struct snd_pcm_hw_params *params)
1544 {
1545 	static int vars[] = {
1546 		SNDRV_PCM_HW_PARAM_ACCESS,
1547 		SNDRV_PCM_HW_PARAM_FORMAT,
1548 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1549 		SNDRV_PCM_HW_PARAM_CHANNELS,
1550 		SNDRV_PCM_HW_PARAM_RATE,
1551 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1552 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1553 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1554 		-1
1555 	};
1556 	int err, *v;
1557 
1558 	for (v = vars; *v != -1; v++) {
1559 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1560 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1561 		else
1562 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1563 		if (snd_BUG_ON(err < 0))
1564 			return err;
1565 	}
1566 	return 0;
1567 }
1568 
1569 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1570 				   void *arg)
1571 {
1572 	struct snd_pcm_runtime *runtime = substream->runtime;
1573 	unsigned long flags;
1574 	snd_pcm_stream_lock_irqsave(substream, flags);
1575 	if (snd_pcm_running(substream) &&
1576 	    snd_pcm_update_hw_ptr(substream) >= 0)
1577 		runtime->status->hw_ptr %= runtime->buffer_size;
1578 	else
1579 		runtime->status->hw_ptr = 0;
1580 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1581 	return 0;
1582 }
1583 
1584 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1585 					  void *arg)
1586 {
1587 	struct snd_pcm_channel_info *info = arg;
1588 	struct snd_pcm_runtime *runtime = substream->runtime;
1589 	int width;
1590 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1591 		info->offset = -1;
1592 		return 0;
1593 	}
1594 	width = snd_pcm_format_physical_width(runtime->format);
1595 	if (width < 0)
1596 		return width;
1597 	info->offset = 0;
1598 	switch (runtime->access) {
1599 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1600 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1601 		info->first = info->channel * width;
1602 		info->step = runtime->channels * width;
1603 		break;
1604 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1605 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1606 	{
1607 		size_t size = runtime->dma_bytes / runtime->channels;
1608 		info->first = info->channel * size * 8;
1609 		info->step = width;
1610 		break;
1611 	}
1612 	default:
1613 		snd_BUG();
1614 		break;
1615 	}
1616 	return 0;
1617 }
1618 
1619 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1620 				       void *arg)
1621 {
1622 	struct snd_pcm_hw_params *params = arg;
1623 	snd_pcm_format_t format;
1624 	int channels, width;
1625 
1626 	params->fifo_size = substream->runtime->hw.fifo_size;
1627 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1628 		format = params_format(params);
1629 		channels = params_channels(params);
1630 		width = snd_pcm_format_physical_width(format);
1631 		params->fifo_size /= width * channels;
1632 	}
1633 	return 0;
1634 }
1635 
1636 /**
1637  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1638  * @substream: the pcm substream instance
1639  * @cmd: ioctl command
1640  * @arg: ioctl argument
1641  *
1642  * Processes the generic ioctl commands for PCM.
1643  * Can be passed as the ioctl callback for PCM ops.
1644  *
1645  * Returns zero if successful, or a negative error code on failure.
1646  */
1647 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1648 		      unsigned int cmd, void *arg)
1649 {
1650 	switch (cmd) {
1651 	case SNDRV_PCM_IOCTL1_INFO:
1652 		return 0;
1653 	case SNDRV_PCM_IOCTL1_RESET:
1654 		return snd_pcm_lib_ioctl_reset(substream, arg);
1655 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1656 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1657 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1658 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1659 	}
1660 	return -ENXIO;
1661 }
1662 
1663 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1664 
1665 /**
1666  * snd_pcm_period_elapsed - update the pcm status for the next period
1667  * @substream: the pcm substream instance
1668  *
1669  * This function is called from the interrupt handler when the
1670  * PCM has processed the period size.  It will update the current
1671  * pointer, wake up sleepers, etc.
1672  *
1673  * Even if more than one periods have elapsed since the last call, you
1674  * have to call this only once.
1675  */
1676 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1677 {
1678 	struct snd_pcm_runtime *runtime;
1679 	unsigned long flags;
1680 
1681 	if (PCM_RUNTIME_CHECK(substream))
1682 		return;
1683 	runtime = substream->runtime;
1684 
1685 	if (runtime->transfer_ack_begin)
1686 		runtime->transfer_ack_begin(substream);
1687 
1688 	snd_pcm_stream_lock_irqsave(substream, flags);
1689 	if (!snd_pcm_running(substream) ||
1690 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1691 		goto _end;
1692 
1693 	if (substream->timer_running)
1694 		snd_timer_interrupt(substream->timer, 1);
1695  _end:
1696 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1697 	if (runtime->transfer_ack_end)
1698 		runtime->transfer_ack_end(substream);
1699 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1700 }
1701 
1702 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1703 
1704 /*
1705  * Wait until avail_min data becomes available
1706  * Returns a negative error code if any error occurs during operation.
1707  * The available space is stored on availp.  When err = 0 and avail = 0
1708  * on the capture stream, it indicates the stream is in DRAINING state.
1709  */
1710 static int wait_for_avail_min(struct snd_pcm_substream *substream,
1711 			      snd_pcm_uframes_t *availp)
1712 {
1713 	struct snd_pcm_runtime *runtime = substream->runtime;
1714 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1715 	wait_queue_t wait;
1716 	int err = 0;
1717 	snd_pcm_uframes_t avail = 0;
1718 	long tout;
1719 
1720 	init_waitqueue_entry(&wait, current);
1721 	add_wait_queue(&runtime->tsleep, &wait);
1722 	for (;;) {
1723 		if (signal_pending(current)) {
1724 			err = -ERESTARTSYS;
1725 			break;
1726 		}
1727 		set_current_state(TASK_INTERRUPTIBLE);
1728 		snd_pcm_stream_unlock_irq(substream);
1729 		tout = schedule_timeout(msecs_to_jiffies(10000));
1730 		snd_pcm_stream_lock_irq(substream);
1731 		switch (runtime->status->state) {
1732 		case SNDRV_PCM_STATE_SUSPENDED:
1733 			err = -ESTRPIPE;
1734 			goto _endloop;
1735 		case SNDRV_PCM_STATE_XRUN:
1736 			err = -EPIPE;
1737 			goto _endloop;
1738 		case SNDRV_PCM_STATE_DRAINING:
1739 			if (is_playback)
1740 				err = -EPIPE;
1741 			else
1742 				avail = 0; /* indicate draining */
1743 			goto _endloop;
1744 		case SNDRV_PCM_STATE_OPEN:
1745 		case SNDRV_PCM_STATE_SETUP:
1746 		case SNDRV_PCM_STATE_DISCONNECTED:
1747 			err = -EBADFD;
1748 			goto _endloop;
1749 		}
1750 		if (!tout) {
1751 			snd_printd("%s write error (DMA or IRQ trouble?)\n",
1752 				   is_playback ? "playback" : "capture");
1753 			err = -EIO;
1754 			break;
1755 		}
1756 		if (is_playback)
1757 			avail = snd_pcm_playback_avail(runtime);
1758 		else
1759 			avail = snd_pcm_capture_avail(runtime);
1760 		if (avail >= runtime->control->avail_min)
1761 			break;
1762 	}
1763  _endloop:
1764 	remove_wait_queue(&runtime->tsleep, &wait);
1765 	*availp = avail;
1766 	return err;
1767 }
1768 
1769 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1770 				      unsigned int hwoff,
1771 				      unsigned long data, unsigned int off,
1772 				      snd_pcm_uframes_t frames)
1773 {
1774 	struct snd_pcm_runtime *runtime = substream->runtime;
1775 	int err;
1776 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1777 	if (substream->ops->copy) {
1778 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1779 			return err;
1780 	} else {
1781 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1782 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1783 			return -EFAULT;
1784 	}
1785 	return 0;
1786 }
1787 
1788 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1789 			  unsigned long data, unsigned int off,
1790 			  snd_pcm_uframes_t size);
1791 
1792 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1793 					    unsigned long data,
1794 					    snd_pcm_uframes_t size,
1795 					    int nonblock,
1796 					    transfer_f transfer)
1797 {
1798 	struct snd_pcm_runtime *runtime = substream->runtime;
1799 	snd_pcm_uframes_t xfer = 0;
1800 	snd_pcm_uframes_t offset = 0;
1801 	int err = 0;
1802 
1803 	if (size == 0)
1804 		return 0;
1805 
1806 	snd_pcm_stream_lock_irq(substream);
1807 	switch (runtime->status->state) {
1808 	case SNDRV_PCM_STATE_PREPARED:
1809 	case SNDRV_PCM_STATE_RUNNING:
1810 	case SNDRV_PCM_STATE_PAUSED:
1811 		break;
1812 	case SNDRV_PCM_STATE_XRUN:
1813 		err = -EPIPE;
1814 		goto _end_unlock;
1815 	case SNDRV_PCM_STATE_SUSPENDED:
1816 		err = -ESTRPIPE;
1817 		goto _end_unlock;
1818 	default:
1819 		err = -EBADFD;
1820 		goto _end_unlock;
1821 	}
1822 
1823 	runtime->twake = 1;
1824 	while (size > 0) {
1825 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1826 		snd_pcm_uframes_t avail;
1827 		snd_pcm_uframes_t cont;
1828 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1829 			snd_pcm_update_hw_ptr(substream);
1830 		avail = snd_pcm_playback_avail(runtime);
1831 		if (!avail) {
1832 			if (nonblock) {
1833 				err = -EAGAIN;
1834 				goto _end_unlock;
1835 			}
1836 			err = wait_for_avail_min(substream, &avail);
1837 			if (err < 0)
1838 				goto _end_unlock;
1839 		}
1840 		frames = size > avail ? avail : size;
1841 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
1842 		if (frames > cont)
1843 			frames = cont;
1844 		if (snd_BUG_ON(!frames)) {
1845 			runtime->twake = 0;
1846 			snd_pcm_stream_unlock_irq(substream);
1847 			return -EINVAL;
1848 		}
1849 		appl_ptr = runtime->control->appl_ptr;
1850 		appl_ofs = appl_ptr % runtime->buffer_size;
1851 		snd_pcm_stream_unlock_irq(substream);
1852 		err = transfer(substream, appl_ofs, data, offset, frames);
1853 		snd_pcm_stream_lock_irq(substream);
1854 		if (err < 0)
1855 			goto _end_unlock;
1856 		switch (runtime->status->state) {
1857 		case SNDRV_PCM_STATE_XRUN:
1858 			err = -EPIPE;
1859 			goto _end_unlock;
1860 		case SNDRV_PCM_STATE_SUSPENDED:
1861 			err = -ESTRPIPE;
1862 			goto _end_unlock;
1863 		default:
1864 			break;
1865 		}
1866 		appl_ptr += frames;
1867 		if (appl_ptr >= runtime->boundary)
1868 			appl_ptr -= runtime->boundary;
1869 		runtime->control->appl_ptr = appl_ptr;
1870 		if (substream->ops->ack)
1871 			substream->ops->ack(substream);
1872 
1873 		offset += frames;
1874 		size -= frames;
1875 		xfer += frames;
1876 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
1877 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
1878 			err = snd_pcm_start(substream);
1879 			if (err < 0)
1880 				goto _end_unlock;
1881 		}
1882 	}
1883  _end_unlock:
1884 	runtime->twake = 0;
1885 	if (xfer > 0 && err >= 0)
1886 		snd_pcm_update_state(substream, runtime);
1887 	snd_pcm_stream_unlock_irq(substream);
1888 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
1889 }
1890 
1891 /* sanity-check for read/write methods */
1892 static int pcm_sanity_check(struct snd_pcm_substream *substream)
1893 {
1894 	struct snd_pcm_runtime *runtime;
1895 	if (PCM_RUNTIME_CHECK(substream))
1896 		return -ENXIO;
1897 	runtime = substream->runtime;
1898 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
1899 		return -EINVAL;
1900 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
1901 		return -EBADFD;
1902 	return 0;
1903 }
1904 
1905 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
1906 {
1907 	struct snd_pcm_runtime *runtime;
1908 	int nonblock;
1909 	int err;
1910 
1911 	err = pcm_sanity_check(substream);
1912 	if (err < 0)
1913 		return err;
1914 	runtime = substream->runtime;
1915 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1916 
1917 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
1918 	    runtime->channels > 1)
1919 		return -EINVAL;
1920 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
1921 				  snd_pcm_lib_write_transfer);
1922 }
1923 
1924 EXPORT_SYMBOL(snd_pcm_lib_write);
1925 
1926 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
1927 				       unsigned int hwoff,
1928 				       unsigned long data, unsigned int off,
1929 				       snd_pcm_uframes_t frames)
1930 {
1931 	struct snd_pcm_runtime *runtime = substream->runtime;
1932 	int err;
1933 	void __user **bufs = (void __user **)data;
1934 	int channels = runtime->channels;
1935 	int c;
1936 	if (substream->ops->copy) {
1937 		if (snd_BUG_ON(!substream->ops->silence))
1938 			return -EINVAL;
1939 		for (c = 0; c < channels; ++c, ++bufs) {
1940 			if (*bufs == NULL) {
1941 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
1942 					return err;
1943 			} else {
1944 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1945 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
1946 					return err;
1947 			}
1948 		}
1949 	} else {
1950 		/* default transfer behaviour */
1951 		size_t dma_csize = runtime->dma_bytes / channels;
1952 		for (c = 0; c < channels; ++c, ++bufs) {
1953 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
1954 			if (*bufs == NULL) {
1955 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
1956 			} else {
1957 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
1958 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
1959 					return -EFAULT;
1960 			}
1961 		}
1962 	}
1963 	return 0;
1964 }
1965 
1966 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
1967 				     void __user **bufs,
1968 				     snd_pcm_uframes_t frames)
1969 {
1970 	struct snd_pcm_runtime *runtime;
1971 	int nonblock;
1972 	int err;
1973 
1974 	err = pcm_sanity_check(substream);
1975 	if (err < 0)
1976 		return err;
1977 	runtime = substream->runtime;
1978 	nonblock = !!(substream->f_flags & O_NONBLOCK);
1979 
1980 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
1981 		return -EINVAL;
1982 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
1983 				  nonblock, snd_pcm_lib_writev_transfer);
1984 }
1985 
1986 EXPORT_SYMBOL(snd_pcm_lib_writev);
1987 
1988 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
1989 				     unsigned int hwoff,
1990 				     unsigned long data, unsigned int off,
1991 				     snd_pcm_uframes_t frames)
1992 {
1993 	struct snd_pcm_runtime *runtime = substream->runtime;
1994 	int err;
1995 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1996 	if (substream->ops->copy) {
1997 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1998 			return err;
1999 	} else {
2000 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2001 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2002 			return -EFAULT;
2003 	}
2004 	return 0;
2005 }
2006 
2007 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2008 					   unsigned long data,
2009 					   snd_pcm_uframes_t size,
2010 					   int nonblock,
2011 					   transfer_f transfer)
2012 {
2013 	struct snd_pcm_runtime *runtime = substream->runtime;
2014 	snd_pcm_uframes_t xfer = 0;
2015 	snd_pcm_uframes_t offset = 0;
2016 	int err = 0;
2017 
2018 	if (size == 0)
2019 		return 0;
2020 
2021 	snd_pcm_stream_lock_irq(substream);
2022 	switch (runtime->status->state) {
2023 	case SNDRV_PCM_STATE_PREPARED:
2024 		if (size >= runtime->start_threshold) {
2025 			err = snd_pcm_start(substream);
2026 			if (err < 0)
2027 				goto _end_unlock;
2028 		}
2029 		break;
2030 	case SNDRV_PCM_STATE_DRAINING:
2031 	case SNDRV_PCM_STATE_RUNNING:
2032 	case SNDRV_PCM_STATE_PAUSED:
2033 		break;
2034 	case SNDRV_PCM_STATE_XRUN:
2035 		err = -EPIPE;
2036 		goto _end_unlock;
2037 	case SNDRV_PCM_STATE_SUSPENDED:
2038 		err = -ESTRPIPE;
2039 		goto _end_unlock;
2040 	default:
2041 		err = -EBADFD;
2042 		goto _end_unlock;
2043 	}
2044 
2045 	runtime->twake = 1;
2046 	while (size > 0) {
2047 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2048 		snd_pcm_uframes_t avail;
2049 		snd_pcm_uframes_t cont;
2050 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2051 			snd_pcm_update_hw_ptr(substream);
2052 		avail = snd_pcm_capture_avail(runtime);
2053 		if (!avail) {
2054 			if (runtime->status->state ==
2055 			    SNDRV_PCM_STATE_DRAINING) {
2056 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2057 				goto _end_unlock;
2058 			}
2059 			if (nonblock) {
2060 				err = -EAGAIN;
2061 				goto _end_unlock;
2062 			}
2063 			err = wait_for_avail_min(substream, &avail);
2064 			if (err < 0)
2065 				goto _end_unlock;
2066 			if (!avail)
2067 				continue; /* draining */
2068 		}
2069 		frames = size > avail ? avail : size;
2070 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2071 		if (frames > cont)
2072 			frames = cont;
2073 		if (snd_BUG_ON(!frames)) {
2074 			runtime->twake = 0;
2075 			snd_pcm_stream_unlock_irq(substream);
2076 			return -EINVAL;
2077 		}
2078 		appl_ptr = runtime->control->appl_ptr;
2079 		appl_ofs = appl_ptr % runtime->buffer_size;
2080 		snd_pcm_stream_unlock_irq(substream);
2081 		err = transfer(substream, appl_ofs, data, offset, frames);
2082 		snd_pcm_stream_lock_irq(substream);
2083 		if (err < 0)
2084 			goto _end_unlock;
2085 		switch (runtime->status->state) {
2086 		case SNDRV_PCM_STATE_XRUN:
2087 			err = -EPIPE;
2088 			goto _end_unlock;
2089 		case SNDRV_PCM_STATE_SUSPENDED:
2090 			err = -ESTRPIPE;
2091 			goto _end_unlock;
2092 		default:
2093 			break;
2094 		}
2095 		appl_ptr += frames;
2096 		if (appl_ptr >= runtime->boundary)
2097 			appl_ptr -= runtime->boundary;
2098 		runtime->control->appl_ptr = appl_ptr;
2099 		if (substream->ops->ack)
2100 			substream->ops->ack(substream);
2101 
2102 		offset += frames;
2103 		size -= frames;
2104 		xfer += frames;
2105 	}
2106  _end_unlock:
2107 	runtime->twake = 0;
2108 	if (xfer > 0 && err >= 0)
2109 		snd_pcm_update_state(substream, runtime);
2110 	snd_pcm_stream_unlock_irq(substream);
2111 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2112 }
2113 
2114 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2115 {
2116 	struct snd_pcm_runtime *runtime;
2117 	int nonblock;
2118 	int err;
2119 
2120 	err = pcm_sanity_check(substream);
2121 	if (err < 0)
2122 		return err;
2123 	runtime = substream->runtime;
2124 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2125 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2126 		return -EINVAL;
2127 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2128 }
2129 
2130 EXPORT_SYMBOL(snd_pcm_lib_read);
2131 
2132 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2133 				      unsigned int hwoff,
2134 				      unsigned long data, unsigned int off,
2135 				      snd_pcm_uframes_t frames)
2136 {
2137 	struct snd_pcm_runtime *runtime = substream->runtime;
2138 	int err;
2139 	void __user **bufs = (void __user **)data;
2140 	int channels = runtime->channels;
2141 	int c;
2142 	if (substream->ops->copy) {
2143 		for (c = 0; c < channels; ++c, ++bufs) {
2144 			char __user *buf;
2145 			if (*bufs == NULL)
2146 				continue;
2147 			buf = *bufs + samples_to_bytes(runtime, off);
2148 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2149 				return err;
2150 		}
2151 	} else {
2152 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2153 		for (c = 0; c < channels; ++c, ++bufs) {
2154 			char *hwbuf;
2155 			char __user *buf;
2156 			if (*bufs == NULL)
2157 				continue;
2158 
2159 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2160 			buf = *bufs + samples_to_bytes(runtime, off);
2161 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2162 				return -EFAULT;
2163 		}
2164 	}
2165 	return 0;
2166 }
2167 
2168 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2169 				    void __user **bufs,
2170 				    snd_pcm_uframes_t frames)
2171 {
2172 	struct snd_pcm_runtime *runtime;
2173 	int nonblock;
2174 	int err;
2175 
2176 	err = pcm_sanity_check(substream);
2177 	if (err < 0)
2178 		return err;
2179 	runtime = substream->runtime;
2180 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2181 		return -EBADFD;
2182 
2183 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2184 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2185 		return -EINVAL;
2186 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2187 }
2188 
2189 EXPORT_SYMBOL(snd_pcm_lib_readv);
2190