xref: /linux/sound/core/pcm_lib.c (revision 08ec212c0f92cbf30e3ecc7349f18151714041d6)
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 <linux/export.h>
27 #include <sound/core.h>
28 #include <sound/control.h>
29 #include <sound/tlv.h>
30 #include <sound/info.h>
31 #include <sound/pcm.h>
32 #include <sound/pcm_params.h>
33 #include <sound/timer.h>
34 
35 /*
36  * fill ring buffer with silence
37  * runtime->silence_start: starting pointer to silence area
38  * runtime->silence_filled: size filled with silence
39  * runtime->silence_threshold: threshold from application
40  * runtime->silence_size: maximal size from application
41  *
42  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
43  */
44 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
45 {
46 	struct snd_pcm_runtime *runtime = substream->runtime;
47 	snd_pcm_uframes_t frames, ofs, transfer;
48 
49 	if (runtime->silence_size < runtime->boundary) {
50 		snd_pcm_sframes_t noise_dist, n;
51 		if (runtime->silence_start != runtime->control->appl_ptr) {
52 			n = runtime->control->appl_ptr - runtime->silence_start;
53 			if (n < 0)
54 				n += runtime->boundary;
55 			if ((snd_pcm_uframes_t)n < runtime->silence_filled)
56 				runtime->silence_filled -= n;
57 			else
58 				runtime->silence_filled = 0;
59 			runtime->silence_start = runtime->control->appl_ptr;
60 		}
61 		if (runtime->silence_filled >= runtime->buffer_size)
62 			return;
63 		noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
64 		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
65 			return;
66 		frames = runtime->silence_threshold - noise_dist;
67 		if (frames > runtime->silence_size)
68 			frames = runtime->silence_size;
69 	} else {
70 		if (new_hw_ptr == ULONG_MAX) {	/* initialization */
71 			snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
72 			if (avail > runtime->buffer_size)
73 				avail = runtime->buffer_size;
74 			runtime->silence_filled = avail > 0 ? avail : 0;
75 			runtime->silence_start = (runtime->status->hw_ptr +
76 						  runtime->silence_filled) %
77 						 runtime->boundary;
78 		} else {
79 			ofs = runtime->status->hw_ptr;
80 			frames = new_hw_ptr - ofs;
81 			if ((snd_pcm_sframes_t)frames < 0)
82 				frames += runtime->boundary;
83 			runtime->silence_filled -= frames;
84 			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
85 				runtime->silence_filled = 0;
86 				runtime->silence_start = new_hw_ptr;
87 			} else {
88 				runtime->silence_start = ofs;
89 			}
90 		}
91 		frames = runtime->buffer_size - runtime->silence_filled;
92 	}
93 	if (snd_BUG_ON(frames > runtime->buffer_size))
94 		return;
95 	if (frames == 0)
96 		return;
97 	ofs = runtime->silence_start % runtime->buffer_size;
98 	while (frames > 0) {
99 		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
100 		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
101 		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
102 			if (substream->ops->silence) {
103 				int err;
104 				err = substream->ops->silence(substream, -1, ofs, transfer);
105 				snd_BUG_ON(err < 0);
106 			} else {
107 				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
108 				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
109 			}
110 		} else {
111 			unsigned int c;
112 			unsigned int channels = runtime->channels;
113 			if (substream->ops->silence) {
114 				for (c = 0; c < channels; ++c) {
115 					int err;
116 					err = substream->ops->silence(substream, c, ofs, transfer);
117 					snd_BUG_ON(err < 0);
118 				}
119 			} else {
120 				size_t dma_csize = runtime->dma_bytes / channels;
121 				for (c = 0; c < channels; ++c) {
122 					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
123 					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
124 				}
125 			}
126 		}
127 		runtime->silence_filled += transfer;
128 		frames -= transfer;
129 		ofs = 0;
130 	}
131 }
132 
133 #ifdef CONFIG_SND_DEBUG
134 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
135 			   char *name, size_t len)
136 {
137 	snprintf(name, len, "pcmC%dD%d%c:%d",
138 		 substream->pcm->card->number,
139 		 substream->pcm->device,
140 		 substream->stream ? 'c' : 'p',
141 		 substream->number);
142 }
143 EXPORT_SYMBOL(snd_pcm_debug_name);
144 #endif
145 
146 #define XRUN_DEBUG_BASIC	(1<<0)
147 #define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
148 #define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
149 #define XRUN_DEBUG_PERIODUPDATE	(1<<3)	/* full period update info */
150 #define XRUN_DEBUG_HWPTRUPDATE	(1<<4)	/* full hwptr update info */
151 #define XRUN_DEBUG_LOG		(1<<5)	/* show last 10 positions on err */
152 #define XRUN_DEBUG_LOGONCE	(1<<6)	/* do above only once */
153 
154 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
155 
156 #define xrun_debug(substream, mask) \
157 			((substream)->pstr->xrun_debug & (mask))
158 #else
159 #define xrun_debug(substream, mask)	0
160 #endif
161 
162 #define dump_stack_on_xrun(substream) do {			\
163 		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
164 			dump_stack();				\
165 	} while (0)
166 
167 static void xrun(struct snd_pcm_substream *substream)
168 {
169 	struct snd_pcm_runtime *runtime = substream->runtime;
170 
171 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
172 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
173 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
174 	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
175 		char name[16];
176 		snd_pcm_debug_name(substream, name, sizeof(name));
177 		snd_printd(KERN_DEBUG "XRUN: %s\n", name);
178 		dump_stack_on_xrun(substream);
179 	}
180 }
181 
182 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
183 #define hw_ptr_error(substream, fmt, args...)				\
184 	do {								\
185 		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
186 			xrun_log_show(substream);			\
187 			if (printk_ratelimit()) {			\
188 				snd_printd("PCM: " fmt, ##args);	\
189 			}						\
190 			dump_stack_on_xrun(substream);			\
191 		}							\
192 	} while (0)
193 
194 #define XRUN_LOG_CNT	10
195 
196 struct hwptr_log_entry {
197 	unsigned int in_interrupt;
198 	unsigned long jiffies;
199 	snd_pcm_uframes_t pos;
200 	snd_pcm_uframes_t period_size;
201 	snd_pcm_uframes_t buffer_size;
202 	snd_pcm_uframes_t old_hw_ptr;
203 	snd_pcm_uframes_t hw_ptr_base;
204 };
205 
206 struct snd_pcm_hwptr_log {
207 	unsigned int idx;
208 	unsigned int hit: 1;
209 	struct hwptr_log_entry entries[XRUN_LOG_CNT];
210 };
211 
212 static void xrun_log(struct snd_pcm_substream *substream,
213 		     snd_pcm_uframes_t pos, int in_interrupt)
214 {
215 	struct snd_pcm_runtime *runtime = substream->runtime;
216 	struct snd_pcm_hwptr_log *log = runtime->hwptr_log;
217 	struct hwptr_log_entry *entry;
218 
219 	if (log == NULL) {
220 		log = kzalloc(sizeof(*log), GFP_ATOMIC);
221 		if (log == NULL)
222 			return;
223 		runtime->hwptr_log = log;
224 	} else {
225 		if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
226 			return;
227 	}
228 	entry = &log->entries[log->idx];
229 	entry->in_interrupt = in_interrupt;
230 	entry->jiffies = jiffies;
231 	entry->pos = pos;
232 	entry->period_size = runtime->period_size;
233 	entry->buffer_size = runtime->buffer_size;
234 	entry->old_hw_ptr = runtime->status->hw_ptr;
235 	entry->hw_ptr_base = runtime->hw_ptr_base;
236 	log->idx = (log->idx + 1) % XRUN_LOG_CNT;
237 }
238 
239 static void xrun_log_show(struct snd_pcm_substream *substream)
240 {
241 	struct snd_pcm_hwptr_log *log = substream->runtime->hwptr_log;
242 	struct hwptr_log_entry *entry;
243 	char name[16];
244 	unsigned int idx;
245 	int cnt;
246 
247 	if (log == NULL)
248 		return;
249 	if (xrun_debug(substream, XRUN_DEBUG_LOGONCE) && log->hit)
250 		return;
251 	snd_pcm_debug_name(substream, name, sizeof(name));
252 	for (cnt = 0, idx = log->idx; cnt < XRUN_LOG_CNT; cnt++) {
253 		entry = &log->entries[idx];
254 		if (entry->period_size == 0)
255 			break;
256 		snd_printd("hwptr log: %s: %sj=%lu, pos=%ld/%ld/%ld, "
257 			   "hwptr=%ld/%ld\n",
258 			   name, entry->in_interrupt ? "[Q] " : "",
259 			   entry->jiffies,
260 			   (unsigned long)entry->pos,
261 			   (unsigned long)entry->period_size,
262 			   (unsigned long)entry->buffer_size,
263 			   (unsigned long)entry->old_hw_ptr,
264 			   (unsigned long)entry->hw_ptr_base);
265 		idx++;
266 		idx %= XRUN_LOG_CNT;
267 	}
268 	log->hit = 1;
269 }
270 
271 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
272 
273 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
274 #define xrun_log(substream, pos, in_interrupt)	do { } while (0)
275 #define xrun_log_show(substream)	do { } while (0)
276 
277 #endif
278 
279 int snd_pcm_update_state(struct snd_pcm_substream *substream,
280 			 struct snd_pcm_runtime *runtime)
281 {
282 	snd_pcm_uframes_t avail;
283 
284 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
285 		avail = snd_pcm_playback_avail(runtime);
286 	else
287 		avail = snd_pcm_capture_avail(runtime);
288 	if (avail > runtime->avail_max)
289 		runtime->avail_max = avail;
290 	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
291 		if (avail >= runtime->buffer_size) {
292 			snd_pcm_drain_done(substream);
293 			return -EPIPE;
294 		}
295 	} else {
296 		if (avail >= runtime->stop_threshold) {
297 			xrun(substream);
298 			return -EPIPE;
299 		}
300 	}
301 	if (runtime->twake) {
302 		if (avail >= runtime->twake)
303 			wake_up(&runtime->tsleep);
304 	} else if (avail >= runtime->control->avail_min)
305 		wake_up(&runtime->sleep);
306 	return 0;
307 }
308 
309 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
310 				  unsigned int in_interrupt)
311 {
312 	struct snd_pcm_runtime *runtime = substream->runtime;
313 	snd_pcm_uframes_t pos;
314 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
315 	snd_pcm_sframes_t hdelta, delta;
316 	unsigned long jdelta;
317 	unsigned long curr_jiffies;
318 	struct timespec curr_tstamp;
319 
320 	old_hw_ptr = runtime->status->hw_ptr;
321 
322 	/*
323 	 * group pointer, time and jiffies reads to allow for more
324 	 * accurate correlations/corrections.
325 	 * The values are stored at the end of this routine after
326 	 * corrections for hw_ptr position
327 	 */
328 	pos = substream->ops->pointer(substream);
329 	curr_jiffies = jiffies;
330 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
331 		snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
332 
333 	if (pos == SNDRV_PCM_POS_XRUN) {
334 		xrun(substream);
335 		return -EPIPE;
336 	}
337 	if (pos >= runtime->buffer_size) {
338 		if (printk_ratelimit()) {
339 			char name[16];
340 			snd_pcm_debug_name(substream, name, sizeof(name));
341 			xrun_log_show(substream);
342 			snd_printd(KERN_ERR  "BUG: %s, pos = %ld, "
343 				   "buffer size = %ld, period size = %ld\n",
344 				   name, pos, runtime->buffer_size,
345 				   runtime->period_size);
346 		}
347 		pos = 0;
348 	}
349 	pos -= pos % runtime->min_align;
350 	if (xrun_debug(substream, XRUN_DEBUG_LOG))
351 		xrun_log(substream, pos, in_interrupt);
352 	hw_base = runtime->hw_ptr_base;
353 	new_hw_ptr = hw_base + pos;
354 	if (in_interrupt) {
355 		/* we know that one period was processed */
356 		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
357 		delta = runtime->hw_ptr_interrupt + runtime->period_size;
358 		if (delta > new_hw_ptr) {
359 			/* check for double acknowledged interrupts */
360 			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
361 			if (hdelta > runtime->hw_ptr_buffer_jiffies/2) {
362 				hw_base += runtime->buffer_size;
363 				if (hw_base >= runtime->boundary)
364 					hw_base = 0;
365 				new_hw_ptr = hw_base + pos;
366 				goto __delta;
367 			}
368 		}
369 	}
370 	/* new_hw_ptr might be lower than old_hw_ptr in case when */
371 	/* pointer crosses the end of the ring buffer */
372 	if (new_hw_ptr < old_hw_ptr) {
373 		hw_base += runtime->buffer_size;
374 		if (hw_base >= runtime->boundary)
375 			hw_base = 0;
376 		new_hw_ptr = hw_base + pos;
377 	}
378       __delta:
379 	delta = new_hw_ptr - old_hw_ptr;
380 	if (delta < 0)
381 		delta += runtime->boundary;
382 	if (xrun_debug(substream, in_interrupt ?
383 			XRUN_DEBUG_PERIODUPDATE : XRUN_DEBUG_HWPTRUPDATE)) {
384 		char name[16];
385 		snd_pcm_debug_name(substream, name, sizeof(name));
386 		snd_printd("%s_update: %s: pos=%u/%u/%u, "
387 			   "hwptr=%ld/%ld/%ld/%ld\n",
388 			   in_interrupt ? "period" : "hwptr",
389 			   name,
390 			   (unsigned int)pos,
391 			   (unsigned int)runtime->period_size,
392 			   (unsigned int)runtime->buffer_size,
393 			   (unsigned long)delta,
394 			   (unsigned long)old_hw_ptr,
395 			   (unsigned long)new_hw_ptr,
396 			   (unsigned long)runtime->hw_ptr_base);
397 	}
398 
399 	if (runtime->no_period_wakeup) {
400 		snd_pcm_sframes_t xrun_threshold;
401 		/*
402 		 * Without regular period interrupts, we have to check
403 		 * the elapsed time to detect xruns.
404 		 */
405 		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
406 		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
407 			goto no_delta_check;
408 		hdelta = jdelta - delta * HZ / runtime->rate;
409 		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
410 		while (hdelta > xrun_threshold) {
411 			delta += runtime->buffer_size;
412 			hw_base += runtime->buffer_size;
413 			if (hw_base >= runtime->boundary)
414 				hw_base = 0;
415 			new_hw_ptr = hw_base + pos;
416 			hdelta -= runtime->hw_ptr_buffer_jiffies;
417 		}
418 		goto no_delta_check;
419 	}
420 
421 	/* something must be really wrong */
422 	if (delta >= runtime->buffer_size + runtime->period_size) {
423 		hw_ptr_error(substream,
424 			       "Unexpected hw_pointer value %s"
425 			       "(stream=%i, pos=%ld, new_hw_ptr=%ld, "
426 			       "old_hw_ptr=%ld)\n",
427 				     in_interrupt ? "[Q] " : "[P]",
428 				     substream->stream, (long)pos,
429 				     (long)new_hw_ptr, (long)old_hw_ptr);
430 		return 0;
431 	}
432 
433 	/* Do jiffies check only in xrun_debug mode */
434 	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
435 		goto no_jiffies_check;
436 
437 	/* Skip the jiffies check for hardwares with BATCH flag.
438 	 * Such hardware usually just increases the position at each IRQ,
439 	 * thus it can't give any strange position.
440 	 */
441 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
442 		goto no_jiffies_check;
443 	hdelta = delta;
444 	if (hdelta < runtime->delay)
445 		goto no_jiffies_check;
446 	hdelta -= runtime->delay;
447 	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
448 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
449 		delta = jdelta /
450 			(((runtime->period_size * HZ) / runtime->rate)
451 								+ HZ/100);
452 		/* move new_hw_ptr according jiffies not pos variable */
453 		new_hw_ptr = old_hw_ptr;
454 		hw_base = delta;
455 		/* use loop to avoid checks for delta overflows */
456 		/* the delta value is small or zero in most cases */
457 		while (delta > 0) {
458 			new_hw_ptr += runtime->period_size;
459 			if (new_hw_ptr >= runtime->boundary)
460 				new_hw_ptr -= runtime->boundary;
461 			delta--;
462 		}
463 		/* align hw_base to buffer_size */
464 		hw_ptr_error(substream,
465 			     "hw_ptr skipping! %s"
466 			     "(pos=%ld, delta=%ld, period=%ld, "
467 			     "jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
468 			     in_interrupt ? "[Q] " : "",
469 			     (long)pos, (long)hdelta,
470 			     (long)runtime->period_size, jdelta,
471 			     ((hdelta * HZ) / runtime->rate), hw_base,
472 			     (unsigned long)old_hw_ptr,
473 			     (unsigned long)new_hw_ptr);
474 		/* reset values to proper state */
475 		delta = 0;
476 		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
477 	}
478  no_jiffies_check:
479 	if (delta > runtime->period_size + runtime->period_size / 2) {
480 		hw_ptr_error(substream,
481 			     "Lost interrupts? %s"
482 			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, "
483 			     "old_hw_ptr=%ld)\n",
484 			     in_interrupt ? "[Q] " : "",
485 			     substream->stream, (long)delta,
486 			     (long)new_hw_ptr,
487 			     (long)old_hw_ptr);
488 	}
489 
490  no_delta_check:
491 	if (runtime->status->hw_ptr == new_hw_ptr)
492 		return 0;
493 
494 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
495 	    runtime->silence_size > 0)
496 		snd_pcm_playback_silence(substream, new_hw_ptr);
497 
498 	if (in_interrupt) {
499 		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
500 		if (delta < 0)
501 			delta += runtime->boundary;
502 		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
503 		runtime->hw_ptr_interrupt += delta;
504 		if (runtime->hw_ptr_interrupt >= runtime->boundary)
505 			runtime->hw_ptr_interrupt -= runtime->boundary;
506 	}
507 	runtime->hw_ptr_base = hw_base;
508 	runtime->status->hw_ptr = new_hw_ptr;
509 	runtime->hw_ptr_jiffies = curr_jiffies;
510 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
511 		runtime->status->tstamp = curr_tstamp;
512 
513 	return snd_pcm_update_state(substream, runtime);
514 }
515 
516 /* CAUTION: call it with irq disabled */
517 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
518 {
519 	return snd_pcm_update_hw_ptr0(substream, 0);
520 }
521 
522 /**
523  * snd_pcm_set_ops - set the PCM operators
524  * @pcm: the pcm instance
525  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
526  * @ops: the operator table
527  *
528  * Sets the given PCM operators to the pcm instance.
529  */
530 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, struct snd_pcm_ops *ops)
531 {
532 	struct snd_pcm_str *stream = &pcm->streams[direction];
533 	struct snd_pcm_substream *substream;
534 
535 	for (substream = stream->substream; substream != NULL; substream = substream->next)
536 		substream->ops = ops;
537 }
538 
539 EXPORT_SYMBOL(snd_pcm_set_ops);
540 
541 /**
542  * snd_pcm_sync - set the PCM sync id
543  * @substream: the pcm substream
544  *
545  * Sets the PCM sync identifier for the card.
546  */
547 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
548 {
549 	struct snd_pcm_runtime *runtime = substream->runtime;
550 
551 	runtime->sync.id32[0] = substream->pcm->card->number;
552 	runtime->sync.id32[1] = -1;
553 	runtime->sync.id32[2] = -1;
554 	runtime->sync.id32[3] = -1;
555 }
556 
557 EXPORT_SYMBOL(snd_pcm_set_sync);
558 
559 /*
560  *  Standard ioctl routine
561  */
562 
563 static inline unsigned int div32(unsigned int a, unsigned int b,
564 				 unsigned int *r)
565 {
566 	if (b == 0) {
567 		*r = 0;
568 		return UINT_MAX;
569 	}
570 	*r = a % b;
571 	return a / b;
572 }
573 
574 static inline unsigned int div_down(unsigned int a, unsigned int b)
575 {
576 	if (b == 0)
577 		return UINT_MAX;
578 	return a / b;
579 }
580 
581 static inline unsigned int div_up(unsigned int a, unsigned int b)
582 {
583 	unsigned int r;
584 	unsigned int q;
585 	if (b == 0)
586 		return UINT_MAX;
587 	q = div32(a, b, &r);
588 	if (r)
589 		++q;
590 	return q;
591 }
592 
593 static inline unsigned int mul(unsigned int a, unsigned int b)
594 {
595 	if (a == 0)
596 		return 0;
597 	if (div_down(UINT_MAX, a) < b)
598 		return UINT_MAX;
599 	return a * b;
600 }
601 
602 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
603 				    unsigned int c, unsigned int *r)
604 {
605 	u_int64_t n = (u_int64_t) a * b;
606 	if (c == 0) {
607 		snd_BUG_ON(!n);
608 		*r = 0;
609 		return UINT_MAX;
610 	}
611 	n = div_u64_rem(n, c, r);
612 	if (n >= UINT_MAX) {
613 		*r = 0;
614 		return UINT_MAX;
615 	}
616 	return n;
617 }
618 
619 /**
620  * snd_interval_refine - refine the interval value of configurator
621  * @i: the interval value to refine
622  * @v: the interval value to refer to
623  *
624  * Refines the interval value with the reference value.
625  * The interval is changed to the range satisfying both intervals.
626  * The interval status (min, max, integer, etc.) are evaluated.
627  *
628  * Returns non-zero if the value is changed, zero if not changed.
629  */
630 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
631 {
632 	int changed = 0;
633 	if (snd_BUG_ON(snd_interval_empty(i)))
634 		return -EINVAL;
635 	if (i->min < v->min) {
636 		i->min = v->min;
637 		i->openmin = v->openmin;
638 		changed = 1;
639 	} else if (i->min == v->min && !i->openmin && v->openmin) {
640 		i->openmin = 1;
641 		changed = 1;
642 	}
643 	if (i->max > v->max) {
644 		i->max = v->max;
645 		i->openmax = v->openmax;
646 		changed = 1;
647 	} else if (i->max == v->max && !i->openmax && v->openmax) {
648 		i->openmax = 1;
649 		changed = 1;
650 	}
651 	if (!i->integer && v->integer) {
652 		i->integer = 1;
653 		changed = 1;
654 	}
655 	if (i->integer) {
656 		if (i->openmin) {
657 			i->min++;
658 			i->openmin = 0;
659 		}
660 		if (i->openmax) {
661 			i->max--;
662 			i->openmax = 0;
663 		}
664 	} else if (!i->openmin && !i->openmax && i->min == i->max)
665 		i->integer = 1;
666 	if (snd_interval_checkempty(i)) {
667 		snd_interval_none(i);
668 		return -EINVAL;
669 	}
670 	return changed;
671 }
672 
673 EXPORT_SYMBOL(snd_interval_refine);
674 
675 static int snd_interval_refine_first(struct snd_interval *i)
676 {
677 	if (snd_BUG_ON(snd_interval_empty(i)))
678 		return -EINVAL;
679 	if (snd_interval_single(i))
680 		return 0;
681 	i->max = i->min;
682 	i->openmax = i->openmin;
683 	if (i->openmax)
684 		i->max++;
685 	return 1;
686 }
687 
688 static int snd_interval_refine_last(struct snd_interval *i)
689 {
690 	if (snd_BUG_ON(snd_interval_empty(i)))
691 		return -EINVAL;
692 	if (snd_interval_single(i))
693 		return 0;
694 	i->min = i->max;
695 	i->openmin = i->openmax;
696 	if (i->openmin)
697 		i->min--;
698 	return 1;
699 }
700 
701 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
702 {
703 	if (a->empty || b->empty) {
704 		snd_interval_none(c);
705 		return;
706 	}
707 	c->empty = 0;
708 	c->min = mul(a->min, b->min);
709 	c->openmin = (a->openmin || b->openmin);
710 	c->max = mul(a->max,  b->max);
711 	c->openmax = (a->openmax || b->openmax);
712 	c->integer = (a->integer && b->integer);
713 }
714 
715 /**
716  * snd_interval_div - refine the interval value with division
717  * @a: dividend
718  * @b: divisor
719  * @c: quotient
720  *
721  * c = a / b
722  *
723  * Returns non-zero if the value is changed, zero if not changed.
724  */
725 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
726 {
727 	unsigned int r;
728 	if (a->empty || b->empty) {
729 		snd_interval_none(c);
730 		return;
731 	}
732 	c->empty = 0;
733 	c->min = div32(a->min, b->max, &r);
734 	c->openmin = (r || a->openmin || b->openmax);
735 	if (b->min > 0) {
736 		c->max = div32(a->max, b->min, &r);
737 		if (r) {
738 			c->max++;
739 			c->openmax = 1;
740 		} else
741 			c->openmax = (a->openmax || b->openmin);
742 	} else {
743 		c->max = UINT_MAX;
744 		c->openmax = 0;
745 	}
746 	c->integer = 0;
747 }
748 
749 /**
750  * snd_interval_muldivk - refine the interval value
751  * @a: dividend 1
752  * @b: dividend 2
753  * @k: divisor (as integer)
754  * @c: result
755   *
756  * c = a * b / k
757  *
758  * Returns non-zero if the value is changed, zero if not changed.
759  */
760 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
761 		      unsigned int k, struct snd_interval *c)
762 {
763 	unsigned int r;
764 	if (a->empty || b->empty) {
765 		snd_interval_none(c);
766 		return;
767 	}
768 	c->empty = 0;
769 	c->min = muldiv32(a->min, b->min, k, &r);
770 	c->openmin = (r || a->openmin || b->openmin);
771 	c->max = muldiv32(a->max, b->max, k, &r);
772 	if (r) {
773 		c->max++;
774 		c->openmax = 1;
775 	} else
776 		c->openmax = (a->openmax || b->openmax);
777 	c->integer = 0;
778 }
779 
780 /**
781  * snd_interval_mulkdiv - refine the interval value
782  * @a: dividend 1
783  * @k: dividend 2 (as integer)
784  * @b: divisor
785  * @c: result
786  *
787  * c = a * k / b
788  *
789  * Returns non-zero if the value is changed, zero if not changed.
790  */
791 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
792 		      const struct snd_interval *b, struct snd_interval *c)
793 {
794 	unsigned int r;
795 	if (a->empty || b->empty) {
796 		snd_interval_none(c);
797 		return;
798 	}
799 	c->empty = 0;
800 	c->min = muldiv32(a->min, k, b->max, &r);
801 	c->openmin = (r || a->openmin || b->openmax);
802 	if (b->min > 0) {
803 		c->max = muldiv32(a->max, k, b->min, &r);
804 		if (r) {
805 			c->max++;
806 			c->openmax = 1;
807 		} else
808 			c->openmax = (a->openmax || b->openmin);
809 	} else {
810 		c->max = UINT_MAX;
811 		c->openmax = 0;
812 	}
813 	c->integer = 0;
814 }
815 
816 /* ---- */
817 
818 
819 /**
820  * snd_interval_ratnum - refine the interval value
821  * @i: interval to refine
822  * @rats_count: number of ratnum_t
823  * @rats: ratnum_t array
824  * @nump: pointer to store the resultant numerator
825  * @denp: pointer to store the resultant denominator
826  *
827  * Returns non-zero if the value is changed, zero if not changed.
828  */
829 int snd_interval_ratnum(struct snd_interval *i,
830 			unsigned int rats_count, struct snd_ratnum *rats,
831 			unsigned int *nump, unsigned int *denp)
832 {
833 	unsigned int best_num, best_den;
834 	int best_diff;
835 	unsigned int k;
836 	struct snd_interval t;
837 	int err;
838 	unsigned int result_num, result_den;
839 	int result_diff;
840 
841 	best_num = best_den = best_diff = 0;
842 	for (k = 0; k < rats_count; ++k) {
843 		unsigned int num = rats[k].num;
844 		unsigned int den;
845 		unsigned int q = i->min;
846 		int diff;
847 		if (q == 0)
848 			q = 1;
849 		den = div_up(num, q);
850 		if (den < rats[k].den_min)
851 			continue;
852 		if (den > rats[k].den_max)
853 			den = rats[k].den_max;
854 		else {
855 			unsigned int r;
856 			r = (den - rats[k].den_min) % rats[k].den_step;
857 			if (r != 0)
858 				den -= r;
859 		}
860 		diff = num - q * den;
861 		if (diff < 0)
862 			diff = -diff;
863 		if (best_num == 0 ||
864 		    diff * best_den < best_diff * den) {
865 			best_diff = diff;
866 			best_den = den;
867 			best_num = num;
868 		}
869 	}
870 	if (best_den == 0) {
871 		i->empty = 1;
872 		return -EINVAL;
873 	}
874 	t.min = div_down(best_num, best_den);
875 	t.openmin = !!(best_num % best_den);
876 
877 	result_num = best_num;
878 	result_diff = best_diff;
879 	result_den = best_den;
880 	best_num = best_den = best_diff = 0;
881 	for (k = 0; k < rats_count; ++k) {
882 		unsigned int num = rats[k].num;
883 		unsigned int den;
884 		unsigned int q = i->max;
885 		int diff;
886 		if (q == 0) {
887 			i->empty = 1;
888 			return -EINVAL;
889 		}
890 		den = div_down(num, q);
891 		if (den > rats[k].den_max)
892 			continue;
893 		if (den < rats[k].den_min)
894 			den = rats[k].den_min;
895 		else {
896 			unsigned int r;
897 			r = (den - rats[k].den_min) % rats[k].den_step;
898 			if (r != 0)
899 				den += rats[k].den_step - r;
900 		}
901 		diff = q * den - num;
902 		if (diff < 0)
903 			diff = -diff;
904 		if (best_num == 0 ||
905 		    diff * best_den < best_diff * den) {
906 			best_diff = diff;
907 			best_den = den;
908 			best_num = num;
909 		}
910 	}
911 	if (best_den == 0) {
912 		i->empty = 1;
913 		return -EINVAL;
914 	}
915 	t.max = div_up(best_num, best_den);
916 	t.openmax = !!(best_num % best_den);
917 	t.integer = 0;
918 	err = snd_interval_refine(i, &t);
919 	if (err < 0)
920 		return err;
921 
922 	if (snd_interval_single(i)) {
923 		if (best_diff * result_den < result_diff * best_den) {
924 			result_num = best_num;
925 			result_den = best_den;
926 		}
927 		if (nump)
928 			*nump = result_num;
929 		if (denp)
930 			*denp = result_den;
931 	}
932 	return err;
933 }
934 
935 EXPORT_SYMBOL(snd_interval_ratnum);
936 
937 /**
938  * snd_interval_ratden - refine the interval value
939  * @i: interval to refine
940  * @rats_count: number of struct ratden
941  * @rats: struct ratden array
942  * @nump: pointer to store the resultant numerator
943  * @denp: pointer to store the resultant denominator
944  *
945  * Returns non-zero if the value is changed, zero if not changed.
946  */
947 static int snd_interval_ratden(struct snd_interval *i,
948 			       unsigned int rats_count, struct snd_ratden *rats,
949 			       unsigned int *nump, unsigned int *denp)
950 {
951 	unsigned int best_num, best_diff, best_den;
952 	unsigned int k;
953 	struct snd_interval t;
954 	int err;
955 
956 	best_num = best_den = best_diff = 0;
957 	for (k = 0; k < rats_count; ++k) {
958 		unsigned int num;
959 		unsigned int den = rats[k].den;
960 		unsigned int q = i->min;
961 		int diff;
962 		num = mul(q, den);
963 		if (num > rats[k].num_max)
964 			continue;
965 		if (num < rats[k].num_min)
966 			num = rats[k].num_max;
967 		else {
968 			unsigned int r;
969 			r = (num - rats[k].num_min) % rats[k].num_step;
970 			if (r != 0)
971 				num += rats[k].num_step - r;
972 		}
973 		diff = num - q * den;
974 		if (best_num == 0 ||
975 		    diff * best_den < best_diff * den) {
976 			best_diff = diff;
977 			best_den = den;
978 			best_num = num;
979 		}
980 	}
981 	if (best_den == 0) {
982 		i->empty = 1;
983 		return -EINVAL;
984 	}
985 	t.min = div_down(best_num, best_den);
986 	t.openmin = !!(best_num % best_den);
987 
988 	best_num = best_den = best_diff = 0;
989 	for (k = 0; k < rats_count; ++k) {
990 		unsigned int num;
991 		unsigned int den = rats[k].den;
992 		unsigned int q = i->max;
993 		int diff;
994 		num = mul(q, den);
995 		if (num < rats[k].num_min)
996 			continue;
997 		if (num > rats[k].num_max)
998 			num = rats[k].num_max;
999 		else {
1000 			unsigned int r;
1001 			r = (num - rats[k].num_min) % rats[k].num_step;
1002 			if (r != 0)
1003 				num -= r;
1004 		}
1005 		diff = q * den - num;
1006 		if (best_num == 0 ||
1007 		    diff * best_den < best_diff * den) {
1008 			best_diff = diff;
1009 			best_den = den;
1010 			best_num = num;
1011 		}
1012 	}
1013 	if (best_den == 0) {
1014 		i->empty = 1;
1015 		return -EINVAL;
1016 	}
1017 	t.max = div_up(best_num, best_den);
1018 	t.openmax = !!(best_num % best_den);
1019 	t.integer = 0;
1020 	err = snd_interval_refine(i, &t);
1021 	if (err < 0)
1022 		return err;
1023 
1024 	if (snd_interval_single(i)) {
1025 		if (nump)
1026 			*nump = best_num;
1027 		if (denp)
1028 			*denp = best_den;
1029 	}
1030 	return err;
1031 }
1032 
1033 /**
1034  * snd_interval_list - refine the interval value from the list
1035  * @i: the interval value to refine
1036  * @count: the number of elements in the list
1037  * @list: the value list
1038  * @mask: the bit-mask to evaluate
1039  *
1040  * Refines the interval value from the list.
1041  * When mask is non-zero, only the elements corresponding to bit 1 are
1042  * evaluated.
1043  *
1044  * Returns non-zero if the value is changed, zero if not changed.
1045  */
1046 int snd_interval_list(struct snd_interval *i, unsigned int count,
1047 		      const unsigned int *list, unsigned int mask)
1048 {
1049         unsigned int k;
1050 	struct snd_interval list_range;
1051 
1052 	if (!count) {
1053 		i->empty = 1;
1054 		return -EINVAL;
1055 	}
1056 	snd_interval_any(&list_range);
1057 	list_range.min = UINT_MAX;
1058 	list_range.max = 0;
1059         for (k = 0; k < count; k++) {
1060 		if (mask && !(mask & (1 << k)))
1061 			continue;
1062 		if (!snd_interval_test(i, list[k]))
1063 			continue;
1064 		list_range.min = min(list_range.min, list[k]);
1065 		list_range.max = max(list_range.max, list[k]);
1066         }
1067 	return snd_interval_refine(i, &list_range);
1068 }
1069 
1070 EXPORT_SYMBOL(snd_interval_list);
1071 
1072 static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned int step)
1073 {
1074 	unsigned int n;
1075 	int changed = 0;
1076 	n = (i->min - min) % step;
1077 	if (n != 0 || i->openmin) {
1078 		i->min += step - n;
1079 		changed = 1;
1080 	}
1081 	n = (i->max - min) % step;
1082 	if (n != 0 || i->openmax) {
1083 		i->max -= n;
1084 		changed = 1;
1085 	}
1086 	if (snd_interval_checkempty(i)) {
1087 		i->empty = 1;
1088 		return -EINVAL;
1089 	}
1090 	return changed;
1091 }
1092 
1093 /* Info constraints helpers */
1094 
1095 /**
1096  * snd_pcm_hw_rule_add - add the hw-constraint rule
1097  * @runtime: the pcm runtime instance
1098  * @cond: condition bits
1099  * @var: the variable to evaluate
1100  * @func: the evaluation function
1101  * @private: the private data pointer passed to function
1102  * @dep: the dependent variables
1103  *
1104  * Returns zero if successful, or a negative error code on failure.
1105  */
1106 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1107 			int var,
1108 			snd_pcm_hw_rule_func_t func, void *private,
1109 			int dep, ...)
1110 {
1111 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1112 	struct snd_pcm_hw_rule *c;
1113 	unsigned int k;
1114 	va_list args;
1115 	va_start(args, dep);
1116 	if (constrs->rules_num >= constrs->rules_all) {
1117 		struct snd_pcm_hw_rule *new;
1118 		unsigned int new_rules = constrs->rules_all + 16;
1119 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1120 		if (!new) {
1121 			va_end(args);
1122 			return -ENOMEM;
1123 		}
1124 		if (constrs->rules) {
1125 			memcpy(new, constrs->rules,
1126 			       constrs->rules_num * sizeof(*c));
1127 			kfree(constrs->rules);
1128 		}
1129 		constrs->rules = new;
1130 		constrs->rules_all = new_rules;
1131 	}
1132 	c = &constrs->rules[constrs->rules_num];
1133 	c->cond = cond;
1134 	c->func = func;
1135 	c->var = var;
1136 	c->private = private;
1137 	k = 0;
1138 	while (1) {
1139 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1140 			va_end(args);
1141 			return -EINVAL;
1142 		}
1143 		c->deps[k++] = dep;
1144 		if (dep < 0)
1145 			break;
1146 		dep = va_arg(args, int);
1147 	}
1148 	constrs->rules_num++;
1149 	va_end(args);
1150 	return 0;
1151 }
1152 
1153 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1154 
1155 /**
1156  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1157  * @runtime: PCM runtime instance
1158  * @var: hw_params variable to apply the mask
1159  * @mask: the bitmap mask
1160  *
1161  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1162  */
1163 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1164 			       u_int32_t mask)
1165 {
1166 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1167 	struct snd_mask *maskp = constrs_mask(constrs, var);
1168 	*maskp->bits &= mask;
1169 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1170 	if (*maskp->bits == 0)
1171 		return -EINVAL;
1172 	return 0;
1173 }
1174 
1175 /**
1176  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1177  * @runtime: PCM runtime instance
1178  * @var: hw_params variable to apply the mask
1179  * @mask: the 64bit bitmap mask
1180  *
1181  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1182  */
1183 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1184 				 u_int64_t mask)
1185 {
1186 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1187 	struct snd_mask *maskp = constrs_mask(constrs, var);
1188 	maskp->bits[0] &= (u_int32_t)mask;
1189 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1190 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1191 	if (! maskp->bits[0] && ! maskp->bits[1])
1192 		return -EINVAL;
1193 	return 0;
1194 }
1195 
1196 /**
1197  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1198  * @runtime: PCM runtime instance
1199  * @var: hw_params variable to apply the integer constraint
1200  *
1201  * Apply the constraint of integer to an interval parameter.
1202  */
1203 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1204 {
1205 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1206 	return snd_interval_setinteger(constrs_interval(constrs, var));
1207 }
1208 
1209 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1210 
1211 /**
1212  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1213  * @runtime: PCM runtime instance
1214  * @var: hw_params variable to apply the range
1215  * @min: the minimal value
1216  * @max: the maximal value
1217  *
1218  * Apply the min/max range constraint to an interval parameter.
1219  */
1220 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1221 				 unsigned int min, unsigned int max)
1222 {
1223 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1224 	struct snd_interval t;
1225 	t.min = min;
1226 	t.max = max;
1227 	t.openmin = t.openmax = 0;
1228 	t.integer = 0;
1229 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1230 }
1231 
1232 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1233 
1234 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1235 				struct snd_pcm_hw_rule *rule)
1236 {
1237 	struct snd_pcm_hw_constraint_list *list = rule->private;
1238 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1239 }
1240 
1241 
1242 /**
1243  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1244  * @runtime: PCM runtime instance
1245  * @cond: condition bits
1246  * @var: hw_params variable to apply the list constraint
1247  * @l: list
1248  *
1249  * Apply the list of constraints to an interval parameter.
1250  */
1251 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1252 			       unsigned int cond,
1253 			       snd_pcm_hw_param_t var,
1254 			       const struct snd_pcm_hw_constraint_list *l)
1255 {
1256 	return snd_pcm_hw_rule_add(runtime, cond, var,
1257 				   snd_pcm_hw_rule_list, (void *)l,
1258 				   var, -1);
1259 }
1260 
1261 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1262 
1263 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1264 				   struct snd_pcm_hw_rule *rule)
1265 {
1266 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1267 	unsigned int num = 0, den = 0;
1268 	int err;
1269 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1270 				  r->nrats, r->rats, &num, &den);
1271 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1272 		params->rate_num = num;
1273 		params->rate_den = den;
1274 	}
1275 	return err;
1276 }
1277 
1278 /**
1279  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1280  * @runtime: PCM runtime instance
1281  * @cond: condition bits
1282  * @var: hw_params variable to apply the ratnums constraint
1283  * @r: struct snd_ratnums constriants
1284  */
1285 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1286 				  unsigned int cond,
1287 				  snd_pcm_hw_param_t var,
1288 				  struct snd_pcm_hw_constraint_ratnums *r)
1289 {
1290 	return snd_pcm_hw_rule_add(runtime, cond, var,
1291 				   snd_pcm_hw_rule_ratnums, r,
1292 				   var, -1);
1293 }
1294 
1295 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1296 
1297 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1298 				   struct snd_pcm_hw_rule *rule)
1299 {
1300 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1301 	unsigned int num = 0, den = 0;
1302 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1303 				  r->nrats, r->rats, &num, &den);
1304 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1305 		params->rate_num = num;
1306 		params->rate_den = den;
1307 	}
1308 	return err;
1309 }
1310 
1311 /**
1312  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1313  * @runtime: PCM runtime instance
1314  * @cond: condition bits
1315  * @var: hw_params variable to apply the ratdens constraint
1316  * @r: struct snd_ratdens constriants
1317  */
1318 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1319 				  unsigned int cond,
1320 				  snd_pcm_hw_param_t var,
1321 				  struct snd_pcm_hw_constraint_ratdens *r)
1322 {
1323 	return snd_pcm_hw_rule_add(runtime, cond, var,
1324 				   snd_pcm_hw_rule_ratdens, r,
1325 				   var, -1);
1326 }
1327 
1328 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1329 
1330 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1331 				  struct snd_pcm_hw_rule *rule)
1332 {
1333 	unsigned int l = (unsigned long) rule->private;
1334 	int width = l & 0xffff;
1335 	unsigned int msbits = l >> 16;
1336 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1337 	if (snd_interval_single(i) && snd_interval_value(i) == width)
1338 		params->msbits = msbits;
1339 	return 0;
1340 }
1341 
1342 /**
1343  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1344  * @runtime: PCM runtime instance
1345  * @cond: condition bits
1346  * @width: sample bits width
1347  * @msbits: msbits width
1348  */
1349 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1350 				 unsigned int cond,
1351 				 unsigned int width,
1352 				 unsigned int msbits)
1353 {
1354 	unsigned long l = (msbits << 16) | width;
1355 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1356 				    snd_pcm_hw_rule_msbits,
1357 				    (void*) l,
1358 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1359 }
1360 
1361 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1362 
1363 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1364 				struct snd_pcm_hw_rule *rule)
1365 {
1366 	unsigned long step = (unsigned long) rule->private;
1367 	return snd_interval_step(hw_param_interval(params, rule->var), 0, step);
1368 }
1369 
1370 /**
1371  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1372  * @runtime: PCM runtime instance
1373  * @cond: condition bits
1374  * @var: hw_params variable to apply the step constraint
1375  * @step: step size
1376  */
1377 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1378 			       unsigned int cond,
1379 			       snd_pcm_hw_param_t var,
1380 			       unsigned long step)
1381 {
1382 	return snd_pcm_hw_rule_add(runtime, cond, var,
1383 				   snd_pcm_hw_rule_step, (void *) step,
1384 				   var, -1);
1385 }
1386 
1387 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1388 
1389 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1390 {
1391 	static unsigned int pow2_sizes[] = {
1392 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1393 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1394 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1395 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1396 	};
1397 	return snd_interval_list(hw_param_interval(params, rule->var),
1398 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1399 }
1400 
1401 /**
1402  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1403  * @runtime: PCM runtime instance
1404  * @cond: condition bits
1405  * @var: hw_params variable to apply the power-of-2 constraint
1406  */
1407 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1408 			       unsigned int cond,
1409 			       snd_pcm_hw_param_t var)
1410 {
1411 	return snd_pcm_hw_rule_add(runtime, cond, var,
1412 				   snd_pcm_hw_rule_pow2, NULL,
1413 				   var, -1);
1414 }
1415 
1416 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1417 
1418 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1419 					   struct snd_pcm_hw_rule *rule)
1420 {
1421 	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1422 	struct snd_interval *rate;
1423 
1424 	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1425 	return snd_interval_list(rate, 1, &base_rate, 0);
1426 }
1427 
1428 /**
1429  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1430  * @runtime: PCM runtime instance
1431  * @base_rate: the rate at which the hardware does not resample
1432  */
1433 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1434 			       unsigned int base_rate)
1435 {
1436 	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1437 				   SNDRV_PCM_HW_PARAM_RATE,
1438 				   snd_pcm_hw_rule_noresample_func,
1439 				   (void *)(uintptr_t)base_rate,
1440 				   SNDRV_PCM_HW_PARAM_RATE, -1);
1441 }
1442 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1443 
1444 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1445 				  snd_pcm_hw_param_t var)
1446 {
1447 	if (hw_is_mask(var)) {
1448 		snd_mask_any(hw_param_mask(params, var));
1449 		params->cmask |= 1 << var;
1450 		params->rmask |= 1 << var;
1451 		return;
1452 	}
1453 	if (hw_is_interval(var)) {
1454 		snd_interval_any(hw_param_interval(params, var));
1455 		params->cmask |= 1 << var;
1456 		params->rmask |= 1 << var;
1457 		return;
1458 	}
1459 	snd_BUG();
1460 }
1461 
1462 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1463 {
1464 	unsigned int k;
1465 	memset(params, 0, sizeof(*params));
1466 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1467 		_snd_pcm_hw_param_any(params, k);
1468 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1469 		_snd_pcm_hw_param_any(params, k);
1470 	params->info = ~0U;
1471 }
1472 
1473 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1474 
1475 /**
1476  * snd_pcm_hw_param_value - return @params field @var value
1477  * @params: the hw_params instance
1478  * @var: parameter to retrieve
1479  * @dir: pointer to the direction (-1,0,1) or %NULL
1480  *
1481  * Return the value for field @var if it's fixed in configuration space
1482  * defined by @params. Return -%EINVAL otherwise.
1483  */
1484 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1485 			   snd_pcm_hw_param_t var, int *dir)
1486 {
1487 	if (hw_is_mask(var)) {
1488 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1489 		if (!snd_mask_single(mask))
1490 			return -EINVAL;
1491 		if (dir)
1492 			*dir = 0;
1493 		return snd_mask_value(mask);
1494 	}
1495 	if (hw_is_interval(var)) {
1496 		const struct snd_interval *i = hw_param_interval_c(params, var);
1497 		if (!snd_interval_single(i))
1498 			return -EINVAL;
1499 		if (dir)
1500 			*dir = i->openmin;
1501 		return snd_interval_value(i);
1502 	}
1503 	return -EINVAL;
1504 }
1505 
1506 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1507 
1508 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1509 				snd_pcm_hw_param_t var)
1510 {
1511 	if (hw_is_mask(var)) {
1512 		snd_mask_none(hw_param_mask(params, var));
1513 		params->cmask |= 1 << var;
1514 		params->rmask |= 1 << var;
1515 	} else if (hw_is_interval(var)) {
1516 		snd_interval_none(hw_param_interval(params, var));
1517 		params->cmask |= 1 << var;
1518 		params->rmask |= 1 << var;
1519 	} else {
1520 		snd_BUG();
1521 	}
1522 }
1523 
1524 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1525 
1526 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1527 				   snd_pcm_hw_param_t var)
1528 {
1529 	int changed;
1530 	if (hw_is_mask(var))
1531 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1532 	else if (hw_is_interval(var))
1533 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1534 	else
1535 		return -EINVAL;
1536 	if (changed) {
1537 		params->cmask |= 1 << var;
1538 		params->rmask |= 1 << var;
1539 	}
1540 	return changed;
1541 }
1542 
1543 
1544 /**
1545  * snd_pcm_hw_param_first - refine config space and return minimum value
1546  * @pcm: PCM instance
1547  * @params: the hw_params instance
1548  * @var: parameter to retrieve
1549  * @dir: pointer to the direction (-1,0,1) or %NULL
1550  *
1551  * Inside configuration space defined by @params remove from @var all
1552  * values > minimum. Reduce configuration space accordingly.
1553  * Return the minimum.
1554  */
1555 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1556 			   struct snd_pcm_hw_params *params,
1557 			   snd_pcm_hw_param_t var, int *dir)
1558 {
1559 	int changed = _snd_pcm_hw_param_first(params, var);
1560 	if (changed < 0)
1561 		return changed;
1562 	if (params->rmask) {
1563 		int err = snd_pcm_hw_refine(pcm, params);
1564 		if (snd_BUG_ON(err < 0))
1565 			return err;
1566 	}
1567 	return snd_pcm_hw_param_value(params, var, dir);
1568 }
1569 
1570 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1571 
1572 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1573 				  snd_pcm_hw_param_t var)
1574 {
1575 	int changed;
1576 	if (hw_is_mask(var))
1577 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1578 	else if (hw_is_interval(var))
1579 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1580 	else
1581 		return -EINVAL;
1582 	if (changed) {
1583 		params->cmask |= 1 << var;
1584 		params->rmask |= 1 << var;
1585 	}
1586 	return changed;
1587 }
1588 
1589 
1590 /**
1591  * snd_pcm_hw_param_last - refine config space and return maximum value
1592  * @pcm: PCM instance
1593  * @params: the hw_params instance
1594  * @var: parameter to retrieve
1595  * @dir: pointer to the direction (-1,0,1) or %NULL
1596  *
1597  * Inside configuration space defined by @params remove from @var all
1598  * values < maximum. Reduce configuration space accordingly.
1599  * Return the maximum.
1600  */
1601 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1602 			  struct snd_pcm_hw_params *params,
1603 			  snd_pcm_hw_param_t var, int *dir)
1604 {
1605 	int changed = _snd_pcm_hw_param_last(params, var);
1606 	if (changed < 0)
1607 		return changed;
1608 	if (params->rmask) {
1609 		int err = snd_pcm_hw_refine(pcm, params);
1610 		if (snd_BUG_ON(err < 0))
1611 			return err;
1612 	}
1613 	return snd_pcm_hw_param_value(params, var, dir);
1614 }
1615 
1616 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1617 
1618 /**
1619  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1620  * @pcm: PCM instance
1621  * @params: the hw_params instance
1622  *
1623  * Choose one configuration from configuration space defined by @params.
1624  * The configuration chosen is that obtained fixing in this order:
1625  * first access, first format, first subformat, min channels,
1626  * min rate, min period time, max buffer size, min tick time
1627  */
1628 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1629 			     struct snd_pcm_hw_params *params)
1630 {
1631 	static int vars[] = {
1632 		SNDRV_PCM_HW_PARAM_ACCESS,
1633 		SNDRV_PCM_HW_PARAM_FORMAT,
1634 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1635 		SNDRV_PCM_HW_PARAM_CHANNELS,
1636 		SNDRV_PCM_HW_PARAM_RATE,
1637 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1638 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1639 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1640 		-1
1641 	};
1642 	int err, *v;
1643 
1644 	for (v = vars; *v != -1; v++) {
1645 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1646 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1647 		else
1648 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1649 		if (snd_BUG_ON(err < 0))
1650 			return err;
1651 	}
1652 	return 0;
1653 }
1654 
1655 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1656 				   void *arg)
1657 {
1658 	struct snd_pcm_runtime *runtime = substream->runtime;
1659 	unsigned long flags;
1660 	snd_pcm_stream_lock_irqsave(substream, flags);
1661 	if (snd_pcm_running(substream) &&
1662 	    snd_pcm_update_hw_ptr(substream) >= 0)
1663 		runtime->status->hw_ptr %= runtime->buffer_size;
1664 	else
1665 		runtime->status->hw_ptr = 0;
1666 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1667 	return 0;
1668 }
1669 
1670 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1671 					  void *arg)
1672 {
1673 	struct snd_pcm_channel_info *info = arg;
1674 	struct snd_pcm_runtime *runtime = substream->runtime;
1675 	int width;
1676 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1677 		info->offset = -1;
1678 		return 0;
1679 	}
1680 	width = snd_pcm_format_physical_width(runtime->format);
1681 	if (width < 0)
1682 		return width;
1683 	info->offset = 0;
1684 	switch (runtime->access) {
1685 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1686 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1687 		info->first = info->channel * width;
1688 		info->step = runtime->channels * width;
1689 		break;
1690 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1691 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1692 	{
1693 		size_t size = runtime->dma_bytes / runtime->channels;
1694 		info->first = info->channel * size * 8;
1695 		info->step = width;
1696 		break;
1697 	}
1698 	default:
1699 		snd_BUG();
1700 		break;
1701 	}
1702 	return 0;
1703 }
1704 
1705 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1706 				       void *arg)
1707 {
1708 	struct snd_pcm_hw_params *params = arg;
1709 	snd_pcm_format_t format;
1710 	int channels, width;
1711 
1712 	params->fifo_size = substream->runtime->hw.fifo_size;
1713 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1714 		format = params_format(params);
1715 		channels = params_channels(params);
1716 		width = snd_pcm_format_physical_width(format);
1717 		params->fifo_size /= width * channels;
1718 	}
1719 	return 0;
1720 }
1721 
1722 /**
1723  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1724  * @substream: the pcm substream instance
1725  * @cmd: ioctl command
1726  * @arg: ioctl argument
1727  *
1728  * Processes the generic ioctl commands for PCM.
1729  * Can be passed as the ioctl callback for PCM ops.
1730  *
1731  * Returns zero if successful, or a negative error code on failure.
1732  */
1733 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1734 		      unsigned int cmd, void *arg)
1735 {
1736 	switch (cmd) {
1737 	case SNDRV_PCM_IOCTL1_INFO:
1738 		return 0;
1739 	case SNDRV_PCM_IOCTL1_RESET:
1740 		return snd_pcm_lib_ioctl_reset(substream, arg);
1741 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1742 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1743 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1744 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1745 	}
1746 	return -ENXIO;
1747 }
1748 
1749 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1750 
1751 /**
1752  * snd_pcm_period_elapsed - update the pcm status for the next period
1753  * @substream: the pcm substream instance
1754  *
1755  * This function is called from the interrupt handler when the
1756  * PCM has processed the period size.  It will update the current
1757  * pointer, wake up sleepers, etc.
1758  *
1759  * Even if more than one periods have elapsed since the last call, you
1760  * have to call this only once.
1761  */
1762 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1763 {
1764 	struct snd_pcm_runtime *runtime;
1765 	unsigned long flags;
1766 
1767 	if (PCM_RUNTIME_CHECK(substream))
1768 		return;
1769 	runtime = substream->runtime;
1770 
1771 	if (runtime->transfer_ack_begin)
1772 		runtime->transfer_ack_begin(substream);
1773 
1774 	snd_pcm_stream_lock_irqsave(substream, flags);
1775 	if (!snd_pcm_running(substream) ||
1776 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1777 		goto _end;
1778 
1779 	if (substream->timer_running)
1780 		snd_timer_interrupt(substream->timer, 1);
1781  _end:
1782 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1783 	if (runtime->transfer_ack_end)
1784 		runtime->transfer_ack_end(substream);
1785 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1786 }
1787 
1788 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1789 
1790 /*
1791  * Wait until avail_min data becomes available
1792  * Returns a negative error code if any error occurs during operation.
1793  * The available space is stored on availp.  When err = 0 and avail = 0
1794  * on the capture stream, it indicates the stream is in DRAINING state.
1795  */
1796 static int wait_for_avail(struct snd_pcm_substream *substream,
1797 			      snd_pcm_uframes_t *availp)
1798 {
1799 	struct snd_pcm_runtime *runtime = substream->runtime;
1800 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1801 	wait_queue_t wait;
1802 	int err = 0;
1803 	snd_pcm_uframes_t avail = 0;
1804 	long wait_time, tout;
1805 
1806 	init_waitqueue_entry(&wait, current);
1807 	set_current_state(TASK_INTERRUPTIBLE);
1808 	add_wait_queue(&runtime->tsleep, &wait);
1809 
1810 	if (runtime->no_period_wakeup)
1811 		wait_time = MAX_SCHEDULE_TIMEOUT;
1812 	else {
1813 		wait_time = 10;
1814 		if (runtime->rate) {
1815 			long t = runtime->period_size * 2 / runtime->rate;
1816 			wait_time = max(t, wait_time);
1817 		}
1818 		wait_time = msecs_to_jiffies(wait_time * 1000);
1819 	}
1820 
1821 	for (;;) {
1822 		if (signal_pending(current)) {
1823 			err = -ERESTARTSYS;
1824 			break;
1825 		}
1826 
1827 		/*
1828 		 * We need to check if space became available already
1829 		 * (and thus the wakeup happened already) first to close
1830 		 * the race of space already having become available.
1831 		 * This check must happen after been added to the waitqueue
1832 		 * and having current state be INTERRUPTIBLE.
1833 		 */
1834 		if (is_playback)
1835 			avail = snd_pcm_playback_avail(runtime);
1836 		else
1837 			avail = snd_pcm_capture_avail(runtime);
1838 		if (avail >= runtime->twake)
1839 			break;
1840 		snd_pcm_stream_unlock_irq(substream);
1841 
1842 		tout = schedule_timeout(wait_time);
1843 
1844 		snd_pcm_stream_lock_irq(substream);
1845 		set_current_state(TASK_INTERRUPTIBLE);
1846 		switch (runtime->status->state) {
1847 		case SNDRV_PCM_STATE_SUSPENDED:
1848 			err = -ESTRPIPE;
1849 			goto _endloop;
1850 		case SNDRV_PCM_STATE_XRUN:
1851 			err = -EPIPE;
1852 			goto _endloop;
1853 		case SNDRV_PCM_STATE_DRAINING:
1854 			if (is_playback)
1855 				err = -EPIPE;
1856 			else
1857 				avail = 0; /* indicate draining */
1858 			goto _endloop;
1859 		case SNDRV_PCM_STATE_OPEN:
1860 		case SNDRV_PCM_STATE_SETUP:
1861 		case SNDRV_PCM_STATE_DISCONNECTED:
1862 			err = -EBADFD;
1863 			goto _endloop;
1864 		}
1865 		if (!tout) {
1866 			snd_printd("%s write error (DMA or IRQ trouble?)\n",
1867 				   is_playback ? "playback" : "capture");
1868 			err = -EIO;
1869 			break;
1870 		}
1871 	}
1872  _endloop:
1873 	set_current_state(TASK_RUNNING);
1874 	remove_wait_queue(&runtime->tsleep, &wait);
1875 	*availp = avail;
1876 	return err;
1877 }
1878 
1879 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1880 				      unsigned int hwoff,
1881 				      unsigned long data, unsigned int off,
1882 				      snd_pcm_uframes_t frames)
1883 {
1884 	struct snd_pcm_runtime *runtime = substream->runtime;
1885 	int err;
1886 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1887 	if (substream->ops->copy) {
1888 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1889 			return err;
1890 	} else {
1891 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1892 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1893 			return -EFAULT;
1894 	}
1895 	return 0;
1896 }
1897 
1898 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1899 			  unsigned long data, unsigned int off,
1900 			  snd_pcm_uframes_t size);
1901 
1902 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1903 					    unsigned long data,
1904 					    snd_pcm_uframes_t size,
1905 					    int nonblock,
1906 					    transfer_f transfer)
1907 {
1908 	struct snd_pcm_runtime *runtime = substream->runtime;
1909 	snd_pcm_uframes_t xfer = 0;
1910 	snd_pcm_uframes_t offset = 0;
1911 	snd_pcm_uframes_t avail;
1912 	int err = 0;
1913 
1914 	if (size == 0)
1915 		return 0;
1916 
1917 	snd_pcm_stream_lock_irq(substream);
1918 	switch (runtime->status->state) {
1919 	case SNDRV_PCM_STATE_PREPARED:
1920 	case SNDRV_PCM_STATE_RUNNING:
1921 	case SNDRV_PCM_STATE_PAUSED:
1922 		break;
1923 	case SNDRV_PCM_STATE_XRUN:
1924 		err = -EPIPE;
1925 		goto _end_unlock;
1926 	case SNDRV_PCM_STATE_SUSPENDED:
1927 		err = -ESTRPIPE;
1928 		goto _end_unlock;
1929 	default:
1930 		err = -EBADFD;
1931 		goto _end_unlock;
1932 	}
1933 
1934 	runtime->twake = runtime->control->avail_min ? : 1;
1935 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
1936 		snd_pcm_update_hw_ptr(substream);
1937 	avail = snd_pcm_playback_avail(runtime);
1938 	while (size > 0) {
1939 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
1940 		snd_pcm_uframes_t cont;
1941 		if (!avail) {
1942 			if (nonblock) {
1943 				err = -EAGAIN;
1944 				goto _end_unlock;
1945 			}
1946 			runtime->twake = min_t(snd_pcm_uframes_t, size,
1947 					runtime->control->avail_min ? : 1);
1948 			err = wait_for_avail(substream, &avail);
1949 			if (err < 0)
1950 				goto _end_unlock;
1951 		}
1952 		frames = size > avail ? avail : size;
1953 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
1954 		if (frames > cont)
1955 			frames = cont;
1956 		if (snd_BUG_ON(!frames)) {
1957 			runtime->twake = 0;
1958 			snd_pcm_stream_unlock_irq(substream);
1959 			return -EINVAL;
1960 		}
1961 		appl_ptr = runtime->control->appl_ptr;
1962 		appl_ofs = appl_ptr % runtime->buffer_size;
1963 		snd_pcm_stream_unlock_irq(substream);
1964 		err = transfer(substream, appl_ofs, data, offset, frames);
1965 		snd_pcm_stream_lock_irq(substream);
1966 		if (err < 0)
1967 			goto _end_unlock;
1968 		switch (runtime->status->state) {
1969 		case SNDRV_PCM_STATE_XRUN:
1970 			err = -EPIPE;
1971 			goto _end_unlock;
1972 		case SNDRV_PCM_STATE_SUSPENDED:
1973 			err = -ESTRPIPE;
1974 			goto _end_unlock;
1975 		default:
1976 			break;
1977 		}
1978 		appl_ptr += frames;
1979 		if (appl_ptr >= runtime->boundary)
1980 			appl_ptr -= runtime->boundary;
1981 		runtime->control->appl_ptr = appl_ptr;
1982 		if (substream->ops->ack)
1983 			substream->ops->ack(substream);
1984 
1985 		offset += frames;
1986 		size -= frames;
1987 		xfer += frames;
1988 		avail -= frames;
1989 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
1990 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
1991 			err = snd_pcm_start(substream);
1992 			if (err < 0)
1993 				goto _end_unlock;
1994 		}
1995 	}
1996  _end_unlock:
1997 	runtime->twake = 0;
1998 	if (xfer > 0 && err >= 0)
1999 		snd_pcm_update_state(substream, runtime);
2000 	snd_pcm_stream_unlock_irq(substream);
2001 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2002 }
2003 
2004 /* sanity-check for read/write methods */
2005 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2006 {
2007 	struct snd_pcm_runtime *runtime;
2008 	if (PCM_RUNTIME_CHECK(substream))
2009 		return -ENXIO;
2010 	runtime = substream->runtime;
2011 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2012 		return -EINVAL;
2013 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2014 		return -EBADFD;
2015 	return 0;
2016 }
2017 
2018 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2019 {
2020 	struct snd_pcm_runtime *runtime;
2021 	int nonblock;
2022 	int err;
2023 
2024 	err = pcm_sanity_check(substream);
2025 	if (err < 0)
2026 		return err;
2027 	runtime = substream->runtime;
2028 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2029 
2030 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2031 	    runtime->channels > 1)
2032 		return -EINVAL;
2033 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2034 				  snd_pcm_lib_write_transfer);
2035 }
2036 
2037 EXPORT_SYMBOL(snd_pcm_lib_write);
2038 
2039 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2040 				       unsigned int hwoff,
2041 				       unsigned long data, unsigned int off,
2042 				       snd_pcm_uframes_t frames)
2043 {
2044 	struct snd_pcm_runtime *runtime = substream->runtime;
2045 	int err;
2046 	void __user **bufs = (void __user **)data;
2047 	int channels = runtime->channels;
2048 	int c;
2049 	if (substream->ops->copy) {
2050 		if (snd_BUG_ON(!substream->ops->silence))
2051 			return -EINVAL;
2052 		for (c = 0; c < channels; ++c, ++bufs) {
2053 			if (*bufs == NULL) {
2054 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2055 					return err;
2056 			} else {
2057 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2058 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2059 					return err;
2060 			}
2061 		}
2062 	} else {
2063 		/* default transfer behaviour */
2064 		size_t dma_csize = runtime->dma_bytes / channels;
2065 		for (c = 0; c < channels; ++c, ++bufs) {
2066 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2067 			if (*bufs == NULL) {
2068 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2069 			} else {
2070 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2071 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2072 					return -EFAULT;
2073 			}
2074 		}
2075 	}
2076 	return 0;
2077 }
2078 
2079 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2080 				     void __user **bufs,
2081 				     snd_pcm_uframes_t frames)
2082 {
2083 	struct snd_pcm_runtime *runtime;
2084 	int nonblock;
2085 	int err;
2086 
2087 	err = pcm_sanity_check(substream);
2088 	if (err < 0)
2089 		return err;
2090 	runtime = substream->runtime;
2091 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2092 
2093 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2094 		return -EINVAL;
2095 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2096 				  nonblock, snd_pcm_lib_writev_transfer);
2097 }
2098 
2099 EXPORT_SYMBOL(snd_pcm_lib_writev);
2100 
2101 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2102 				     unsigned int hwoff,
2103 				     unsigned long data, unsigned int off,
2104 				     snd_pcm_uframes_t frames)
2105 {
2106 	struct snd_pcm_runtime *runtime = substream->runtime;
2107 	int err;
2108 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2109 	if (substream->ops->copy) {
2110 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2111 			return err;
2112 	} else {
2113 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2114 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2115 			return -EFAULT;
2116 	}
2117 	return 0;
2118 }
2119 
2120 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2121 					   unsigned long data,
2122 					   snd_pcm_uframes_t size,
2123 					   int nonblock,
2124 					   transfer_f transfer)
2125 {
2126 	struct snd_pcm_runtime *runtime = substream->runtime;
2127 	snd_pcm_uframes_t xfer = 0;
2128 	snd_pcm_uframes_t offset = 0;
2129 	snd_pcm_uframes_t avail;
2130 	int err = 0;
2131 
2132 	if (size == 0)
2133 		return 0;
2134 
2135 	snd_pcm_stream_lock_irq(substream);
2136 	switch (runtime->status->state) {
2137 	case SNDRV_PCM_STATE_PREPARED:
2138 		if (size >= runtime->start_threshold) {
2139 			err = snd_pcm_start(substream);
2140 			if (err < 0)
2141 				goto _end_unlock;
2142 		}
2143 		break;
2144 	case SNDRV_PCM_STATE_DRAINING:
2145 	case SNDRV_PCM_STATE_RUNNING:
2146 	case SNDRV_PCM_STATE_PAUSED:
2147 		break;
2148 	case SNDRV_PCM_STATE_XRUN:
2149 		err = -EPIPE;
2150 		goto _end_unlock;
2151 	case SNDRV_PCM_STATE_SUSPENDED:
2152 		err = -ESTRPIPE;
2153 		goto _end_unlock;
2154 	default:
2155 		err = -EBADFD;
2156 		goto _end_unlock;
2157 	}
2158 
2159 	runtime->twake = runtime->control->avail_min ? : 1;
2160 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2161 		snd_pcm_update_hw_ptr(substream);
2162 	avail = snd_pcm_capture_avail(runtime);
2163 	while (size > 0) {
2164 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2165 		snd_pcm_uframes_t cont;
2166 		if (!avail) {
2167 			if (runtime->status->state ==
2168 			    SNDRV_PCM_STATE_DRAINING) {
2169 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2170 				goto _end_unlock;
2171 			}
2172 			if (nonblock) {
2173 				err = -EAGAIN;
2174 				goto _end_unlock;
2175 			}
2176 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2177 					runtime->control->avail_min ? : 1);
2178 			err = wait_for_avail(substream, &avail);
2179 			if (err < 0)
2180 				goto _end_unlock;
2181 			if (!avail)
2182 				continue; /* draining */
2183 		}
2184 		frames = size > avail ? avail : size;
2185 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2186 		if (frames > cont)
2187 			frames = cont;
2188 		if (snd_BUG_ON(!frames)) {
2189 			runtime->twake = 0;
2190 			snd_pcm_stream_unlock_irq(substream);
2191 			return -EINVAL;
2192 		}
2193 		appl_ptr = runtime->control->appl_ptr;
2194 		appl_ofs = appl_ptr % runtime->buffer_size;
2195 		snd_pcm_stream_unlock_irq(substream);
2196 		err = transfer(substream, appl_ofs, data, offset, frames);
2197 		snd_pcm_stream_lock_irq(substream);
2198 		if (err < 0)
2199 			goto _end_unlock;
2200 		switch (runtime->status->state) {
2201 		case SNDRV_PCM_STATE_XRUN:
2202 			err = -EPIPE;
2203 			goto _end_unlock;
2204 		case SNDRV_PCM_STATE_SUSPENDED:
2205 			err = -ESTRPIPE;
2206 			goto _end_unlock;
2207 		default:
2208 			break;
2209 		}
2210 		appl_ptr += frames;
2211 		if (appl_ptr >= runtime->boundary)
2212 			appl_ptr -= runtime->boundary;
2213 		runtime->control->appl_ptr = appl_ptr;
2214 		if (substream->ops->ack)
2215 			substream->ops->ack(substream);
2216 
2217 		offset += frames;
2218 		size -= frames;
2219 		xfer += frames;
2220 		avail -= frames;
2221 	}
2222  _end_unlock:
2223 	runtime->twake = 0;
2224 	if (xfer > 0 && err >= 0)
2225 		snd_pcm_update_state(substream, runtime);
2226 	snd_pcm_stream_unlock_irq(substream);
2227 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2228 }
2229 
2230 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2231 {
2232 	struct snd_pcm_runtime *runtime;
2233 	int nonblock;
2234 	int err;
2235 
2236 	err = pcm_sanity_check(substream);
2237 	if (err < 0)
2238 		return err;
2239 	runtime = substream->runtime;
2240 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2241 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2242 		return -EINVAL;
2243 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2244 }
2245 
2246 EXPORT_SYMBOL(snd_pcm_lib_read);
2247 
2248 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2249 				      unsigned int hwoff,
2250 				      unsigned long data, unsigned int off,
2251 				      snd_pcm_uframes_t frames)
2252 {
2253 	struct snd_pcm_runtime *runtime = substream->runtime;
2254 	int err;
2255 	void __user **bufs = (void __user **)data;
2256 	int channels = runtime->channels;
2257 	int c;
2258 	if (substream->ops->copy) {
2259 		for (c = 0; c < channels; ++c, ++bufs) {
2260 			char __user *buf;
2261 			if (*bufs == NULL)
2262 				continue;
2263 			buf = *bufs + samples_to_bytes(runtime, off);
2264 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2265 				return err;
2266 		}
2267 	} else {
2268 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2269 		for (c = 0; c < channels; ++c, ++bufs) {
2270 			char *hwbuf;
2271 			char __user *buf;
2272 			if (*bufs == NULL)
2273 				continue;
2274 
2275 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2276 			buf = *bufs + samples_to_bytes(runtime, off);
2277 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2278 				return -EFAULT;
2279 		}
2280 	}
2281 	return 0;
2282 }
2283 
2284 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2285 				    void __user **bufs,
2286 				    snd_pcm_uframes_t frames)
2287 {
2288 	struct snd_pcm_runtime *runtime;
2289 	int nonblock;
2290 	int err;
2291 
2292 	err = pcm_sanity_check(substream);
2293 	if (err < 0)
2294 		return err;
2295 	runtime = substream->runtime;
2296 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2297 		return -EBADFD;
2298 
2299 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2300 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2301 		return -EINVAL;
2302 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2303 }
2304 
2305 EXPORT_SYMBOL(snd_pcm_lib_readv);
2306 
2307 /*
2308  * standard channel mapping helpers
2309  */
2310 
2311 /* default channel maps for multi-channel playbacks, up to 8 channels */
2312 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2313 	{ .channels = 1,
2314 	  .map = { SNDRV_CHMAP_MONO } },
2315 	{ .channels = 2,
2316 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2317 	{ .channels = 4,
2318 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2319 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2320 	{ .channels = 6,
2321 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2322 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2323 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2324 	{ .channels = 8,
2325 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2326 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2327 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2328 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2329 	{ }
2330 };
2331 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2332 
2333 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2334 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2335 	{ .channels = 1,
2336 	  .map = { SNDRV_CHMAP_MONO } },
2337 	{ .channels = 2,
2338 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2339 	{ .channels = 4,
2340 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2341 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2342 	{ .channels = 6,
2343 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2344 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2345 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2346 	{ .channels = 8,
2347 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2348 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2349 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2350 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2351 	{ }
2352 };
2353 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2354 
2355 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2356 {
2357 	if (ch > info->max_channels)
2358 		return false;
2359 	return !info->channel_mask || (info->channel_mask & (1U << ch));
2360 }
2361 
2362 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2363 			      struct snd_ctl_elem_info *uinfo)
2364 {
2365 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2366 
2367 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2368 	uinfo->count = 0;
2369 	uinfo->count = info->max_channels;
2370 	uinfo->value.integer.min = 0;
2371 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2372 	return 0;
2373 }
2374 
2375 /* get callback for channel map ctl element
2376  * stores the channel position firstly matching with the current channels
2377  */
2378 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2379 			     struct snd_ctl_elem_value *ucontrol)
2380 {
2381 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2382 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2383 	struct snd_pcm_substream *substream;
2384 	const struct snd_pcm_chmap_elem *map;
2385 
2386 	if (snd_BUG_ON(!info->chmap))
2387 		return -EINVAL;
2388 	substream = snd_pcm_chmap_substream(info, idx);
2389 	if (!substream)
2390 		return -ENODEV;
2391 	memset(ucontrol->value.integer.value, 0,
2392 	       sizeof(ucontrol->value.integer.value));
2393 	if (!substream->runtime)
2394 		return 0; /* no channels set */
2395 	for (map = info->chmap; map->channels; map++) {
2396 		int i;
2397 		if (map->channels == substream->runtime->channels &&
2398 		    valid_chmap_channels(info, map->channels)) {
2399 			for (i = 0; i < map->channels; i++)
2400 				ucontrol->value.integer.value[i] = map->map[i];
2401 			return 0;
2402 		}
2403 	}
2404 	return -EINVAL;
2405 }
2406 
2407 /* tlv callback for channel map ctl element
2408  * expands the pre-defined channel maps in a form of TLV
2409  */
2410 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2411 			     unsigned int size, unsigned int __user *tlv)
2412 {
2413 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2414 	const struct snd_pcm_chmap_elem *map;
2415 	unsigned int __user *dst;
2416 	int c, count = 0;
2417 
2418 	if (snd_BUG_ON(!info->chmap))
2419 		return -EINVAL;
2420 	if (size < 8)
2421 		return -ENOMEM;
2422 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2423 		return -EFAULT;
2424 	size -= 8;
2425 	dst = tlv + 2;
2426 	for (map = info->chmap; map->channels; map++) {
2427 		int chs_bytes = map->channels * 4;
2428 		if (!valid_chmap_channels(info, map->channels))
2429 			continue;
2430 		if (size < 8)
2431 			return -ENOMEM;
2432 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2433 		    put_user(chs_bytes, dst + 1))
2434 			return -EFAULT;
2435 		dst += 2;
2436 		size -= 8;
2437 		count += 8;
2438 		if (size < chs_bytes)
2439 			return -ENOMEM;
2440 		size -= chs_bytes;
2441 		count += chs_bytes;
2442 		for (c = 0; c < map->channels; c++) {
2443 			if (put_user(map->map[c], dst))
2444 				return -EFAULT;
2445 			dst++;
2446 		}
2447 	}
2448 	if (put_user(count, tlv + 1))
2449 		return -EFAULT;
2450 	return 0;
2451 }
2452 
2453 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2454 {
2455 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2456 	info->pcm->streams[info->stream].chmap_kctl = NULL;
2457 	kfree(info);
2458 }
2459 
2460 /**
2461  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2462  * @pcm: the assigned PCM instance
2463  * @stream: stream direction
2464  * @chmap: channel map elements (for query)
2465  * @max_channels: the max number of channels for the stream
2466  * @private_value: the value passed to each kcontrol's private_value field
2467  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2468  *
2469  * Create channel-mapping control elements assigned to the given PCM stream(s).
2470  * Returns zero if succeed, or a negative error value.
2471  */
2472 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2473 			   const struct snd_pcm_chmap_elem *chmap,
2474 			   int max_channels,
2475 			   unsigned long private_value,
2476 			   struct snd_pcm_chmap **info_ret)
2477 {
2478 	struct snd_pcm_chmap *info;
2479 	struct snd_kcontrol_new knew = {
2480 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
2481 		.access = SNDRV_CTL_ELEM_ACCESS_READ |
2482 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2483 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2484 		.info = pcm_chmap_ctl_info,
2485 		.get = pcm_chmap_ctl_get,
2486 		.tlv.c = pcm_chmap_ctl_tlv,
2487 	};
2488 	int err;
2489 
2490 	info = kzalloc(sizeof(*info), GFP_KERNEL);
2491 	if (!info)
2492 		return -ENOMEM;
2493 	info->pcm = pcm;
2494 	info->stream = stream;
2495 	info->chmap = chmap;
2496 	info->max_channels = max_channels;
2497 	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2498 		knew.name = "Playback Channel Map";
2499 	else
2500 		knew.name = "Capture Channel Map";
2501 	knew.device = pcm->device;
2502 	knew.count = pcm->streams[stream].substream_count;
2503 	knew.private_value = private_value;
2504 	info->kctl = snd_ctl_new1(&knew, info);
2505 	if (!info->kctl) {
2506 		kfree(info);
2507 		return -ENOMEM;
2508 	}
2509 	info->kctl->private_free = pcm_chmap_ctl_private_free;
2510 	err = snd_ctl_add(pcm->card, info->kctl);
2511 	if (err < 0)
2512 		return err;
2513 	pcm->streams[stream].chmap_kctl = info->kctl;
2514 	if (info_ret)
2515 		*info_ret = info;
2516 	return 0;
2517 }
2518 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2519