xref: /linux/sound/core/pcm_lib.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 (snd_printd_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 	struct timespec audio_tstamp;
320 	int crossed_boundary = 0;
321 
322 	old_hw_ptr = runtime->status->hw_ptr;
323 
324 	/*
325 	 * group pointer, time and jiffies reads to allow for more
326 	 * accurate correlations/corrections.
327 	 * The values are stored at the end of this routine after
328 	 * corrections for hw_ptr position
329 	 */
330 	pos = substream->ops->pointer(substream);
331 	curr_jiffies = jiffies;
332 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
333 		snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
334 
335 		if ((runtime->hw.info & SNDRV_PCM_INFO_HAS_WALL_CLOCK) &&
336 			(substream->ops->wall_clock))
337 			substream->ops->wall_clock(substream, &audio_tstamp);
338 	}
339 
340 	if (pos == SNDRV_PCM_POS_XRUN) {
341 		xrun(substream);
342 		return -EPIPE;
343 	}
344 	if (pos >= runtime->buffer_size) {
345 		if (snd_printd_ratelimit()) {
346 			char name[16];
347 			snd_pcm_debug_name(substream, name, sizeof(name));
348 			xrun_log_show(substream);
349 			snd_printd(KERN_ERR  "BUG: %s, pos = %ld, "
350 				   "buffer size = %ld, period size = %ld\n",
351 				   name, pos, runtime->buffer_size,
352 				   runtime->period_size);
353 		}
354 		pos = 0;
355 	}
356 	pos -= pos % runtime->min_align;
357 	if (xrun_debug(substream, XRUN_DEBUG_LOG))
358 		xrun_log(substream, pos, in_interrupt);
359 	hw_base = runtime->hw_ptr_base;
360 	new_hw_ptr = hw_base + pos;
361 	if (in_interrupt) {
362 		/* we know that one period was processed */
363 		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
364 		delta = runtime->hw_ptr_interrupt + runtime->period_size;
365 		if (delta > new_hw_ptr) {
366 			/* check for double acknowledged interrupts */
367 			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
368 			if (hdelta > runtime->hw_ptr_buffer_jiffies/2) {
369 				hw_base += runtime->buffer_size;
370 				if (hw_base >= runtime->boundary) {
371 					hw_base = 0;
372 					crossed_boundary++;
373 				}
374 				new_hw_ptr = hw_base + pos;
375 				goto __delta;
376 			}
377 		}
378 	}
379 	/* new_hw_ptr might be lower than old_hw_ptr in case when */
380 	/* pointer crosses the end of the ring buffer */
381 	if (new_hw_ptr < old_hw_ptr) {
382 		hw_base += runtime->buffer_size;
383 		if (hw_base >= runtime->boundary) {
384 			hw_base = 0;
385 			crossed_boundary++;
386 		}
387 		new_hw_ptr = hw_base + pos;
388 	}
389       __delta:
390 	delta = new_hw_ptr - old_hw_ptr;
391 	if (delta < 0)
392 		delta += runtime->boundary;
393 	if (xrun_debug(substream, in_interrupt ?
394 			XRUN_DEBUG_PERIODUPDATE : XRUN_DEBUG_HWPTRUPDATE)) {
395 		char name[16];
396 		snd_pcm_debug_name(substream, name, sizeof(name));
397 		snd_printd("%s_update: %s: pos=%u/%u/%u, "
398 			   "hwptr=%ld/%ld/%ld/%ld\n",
399 			   in_interrupt ? "period" : "hwptr",
400 			   name,
401 			   (unsigned int)pos,
402 			   (unsigned int)runtime->period_size,
403 			   (unsigned int)runtime->buffer_size,
404 			   (unsigned long)delta,
405 			   (unsigned long)old_hw_ptr,
406 			   (unsigned long)new_hw_ptr,
407 			   (unsigned long)runtime->hw_ptr_base);
408 	}
409 
410 	if (runtime->no_period_wakeup) {
411 		snd_pcm_sframes_t xrun_threshold;
412 		/*
413 		 * Without regular period interrupts, we have to check
414 		 * the elapsed time to detect xruns.
415 		 */
416 		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
417 		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
418 			goto no_delta_check;
419 		hdelta = jdelta - delta * HZ / runtime->rate;
420 		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
421 		while (hdelta > xrun_threshold) {
422 			delta += runtime->buffer_size;
423 			hw_base += runtime->buffer_size;
424 			if (hw_base >= runtime->boundary) {
425 				hw_base = 0;
426 				crossed_boundary++;
427 			}
428 			new_hw_ptr = hw_base + pos;
429 			hdelta -= runtime->hw_ptr_buffer_jiffies;
430 		}
431 		goto no_delta_check;
432 	}
433 
434 	/* something must be really wrong */
435 	if (delta >= runtime->buffer_size + runtime->period_size) {
436 		hw_ptr_error(substream,
437 			       "Unexpected hw_pointer value %s"
438 			       "(stream=%i, pos=%ld, new_hw_ptr=%ld, "
439 			       "old_hw_ptr=%ld)\n",
440 				     in_interrupt ? "[Q] " : "[P]",
441 				     substream->stream, (long)pos,
442 				     (long)new_hw_ptr, (long)old_hw_ptr);
443 		return 0;
444 	}
445 
446 	/* Do jiffies check only in xrun_debug mode */
447 	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
448 		goto no_jiffies_check;
449 
450 	/* Skip the jiffies check for hardwares with BATCH flag.
451 	 * Such hardware usually just increases the position at each IRQ,
452 	 * thus it can't give any strange position.
453 	 */
454 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
455 		goto no_jiffies_check;
456 	hdelta = delta;
457 	if (hdelta < runtime->delay)
458 		goto no_jiffies_check;
459 	hdelta -= runtime->delay;
460 	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
461 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
462 		delta = jdelta /
463 			(((runtime->period_size * HZ) / runtime->rate)
464 								+ HZ/100);
465 		/* move new_hw_ptr according jiffies not pos variable */
466 		new_hw_ptr = old_hw_ptr;
467 		hw_base = delta;
468 		/* use loop to avoid checks for delta overflows */
469 		/* the delta value is small or zero in most cases */
470 		while (delta > 0) {
471 			new_hw_ptr += runtime->period_size;
472 			if (new_hw_ptr >= runtime->boundary) {
473 				new_hw_ptr -= runtime->boundary;
474 				crossed_boundary--;
475 			}
476 			delta--;
477 		}
478 		/* align hw_base to buffer_size */
479 		hw_ptr_error(substream,
480 			     "hw_ptr skipping! %s"
481 			     "(pos=%ld, delta=%ld, period=%ld, "
482 			     "jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
483 			     in_interrupt ? "[Q] " : "",
484 			     (long)pos, (long)hdelta,
485 			     (long)runtime->period_size, jdelta,
486 			     ((hdelta * HZ) / runtime->rate), hw_base,
487 			     (unsigned long)old_hw_ptr,
488 			     (unsigned long)new_hw_ptr);
489 		/* reset values to proper state */
490 		delta = 0;
491 		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
492 	}
493  no_jiffies_check:
494 	if (delta > runtime->period_size + runtime->period_size / 2) {
495 		hw_ptr_error(substream,
496 			     "Lost interrupts? %s"
497 			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, "
498 			     "old_hw_ptr=%ld)\n",
499 			     in_interrupt ? "[Q] " : "",
500 			     substream->stream, (long)delta,
501 			     (long)new_hw_ptr,
502 			     (long)old_hw_ptr);
503 	}
504 
505  no_delta_check:
506 	if (runtime->status->hw_ptr == new_hw_ptr)
507 		return 0;
508 
509 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
510 	    runtime->silence_size > 0)
511 		snd_pcm_playback_silence(substream, new_hw_ptr);
512 
513 	if (in_interrupt) {
514 		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
515 		if (delta < 0)
516 			delta += runtime->boundary;
517 		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
518 		runtime->hw_ptr_interrupt += delta;
519 		if (runtime->hw_ptr_interrupt >= runtime->boundary)
520 			runtime->hw_ptr_interrupt -= runtime->boundary;
521 	}
522 	runtime->hw_ptr_base = hw_base;
523 	runtime->status->hw_ptr = new_hw_ptr;
524 	runtime->hw_ptr_jiffies = curr_jiffies;
525 	if (crossed_boundary) {
526 		snd_BUG_ON(crossed_boundary != 1);
527 		runtime->hw_ptr_wrap += runtime->boundary;
528 	}
529 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
530 		runtime->status->tstamp = curr_tstamp;
531 
532 		if (!(runtime->hw.info & SNDRV_PCM_INFO_HAS_WALL_CLOCK)) {
533 			/*
534 			 * no wall clock available, provide audio timestamp
535 			 * derived from pointer position+delay
536 			 */
537 			u64 audio_frames, audio_nsecs;
538 
539 			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
540 				audio_frames = runtime->hw_ptr_wrap
541 					+ runtime->status->hw_ptr
542 					- runtime->delay;
543 			else
544 				audio_frames = runtime->hw_ptr_wrap
545 					+ runtime->status->hw_ptr
546 					+ runtime->delay;
547 			audio_nsecs = div_u64(audio_frames * 1000000000LL,
548 					runtime->rate);
549 			audio_tstamp = ns_to_timespec(audio_nsecs);
550 		}
551 		runtime->status->audio_tstamp = audio_tstamp;
552 	}
553 
554 	return snd_pcm_update_state(substream, runtime);
555 }
556 
557 /* CAUTION: call it with irq disabled */
558 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
559 {
560 	return snd_pcm_update_hw_ptr0(substream, 0);
561 }
562 
563 /**
564  * snd_pcm_set_ops - set the PCM operators
565  * @pcm: the pcm instance
566  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
567  * @ops: the operator table
568  *
569  * Sets the given PCM operators to the pcm instance.
570  */
571 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
572 		     const struct snd_pcm_ops *ops)
573 {
574 	struct snd_pcm_str *stream = &pcm->streams[direction];
575 	struct snd_pcm_substream *substream;
576 
577 	for (substream = stream->substream; substream != NULL; substream = substream->next)
578 		substream->ops = ops;
579 }
580 
581 EXPORT_SYMBOL(snd_pcm_set_ops);
582 
583 /**
584  * snd_pcm_sync - set the PCM sync id
585  * @substream: the pcm substream
586  *
587  * Sets the PCM sync identifier for the card.
588  */
589 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
590 {
591 	struct snd_pcm_runtime *runtime = substream->runtime;
592 
593 	runtime->sync.id32[0] = substream->pcm->card->number;
594 	runtime->sync.id32[1] = -1;
595 	runtime->sync.id32[2] = -1;
596 	runtime->sync.id32[3] = -1;
597 }
598 
599 EXPORT_SYMBOL(snd_pcm_set_sync);
600 
601 /*
602  *  Standard ioctl routine
603  */
604 
605 static inline unsigned int div32(unsigned int a, unsigned int b,
606 				 unsigned int *r)
607 {
608 	if (b == 0) {
609 		*r = 0;
610 		return UINT_MAX;
611 	}
612 	*r = a % b;
613 	return a / b;
614 }
615 
616 static inline unsigned int div_down(unsigned int a, unsigned int b)
617 {
618 	if (b == 0)
619 		return UINT_MAX;
620 	return a / b;
621 }
622 
623 static inline unsigned int div_up(unsigned int a, unsigned int b)
624 {
625 	unsigned int r;
626 	unsigned int q;
627 	if (b == 0)
628 		return UINT_MAX;
629 	q = div32(a, b, &r);
630 	if (r)
631 		++q;
632 	return q;
633 }
634 
635 static inline unsigned int mul(unsigned int a, unsigned int b)
636 {
637 	if (a == 0)
638 		return 0;
639 	if (div_down(UINT_MAX, a) < b)
640 		return UINT_MAX;
641 	return a * b;
642 }
643 
644 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
645 				    unsigned int c, unsigned int *r)
646 {
647 	u_int64_t n = (u_int64_t) a * b;
648 	if (c == 0) {
649 		snd_BUG_ON(!n);
650 		*r = 0;
651 		return UINT_MAX;
652 	}
653 	n = div_u64_rem(n, c, r);
654 	if (n >= UINT_MAX) {
655 		*r = 0;
656 		return UINT_MAX;
657 	}
658 	return n;
659 }
660 
661 /**
662  * snd_interval_refine - refine the interval value of configurator
663  * @i: the interval value to refine
664  * @v: the interval value to refer to
665  *
666  * Refines the interval value with the reference value.
667  * The interval is changed to the range satisfying both intervals.
668  * The interval status (min, max, integer, etc.) are evaluated.
669  *
670  * Return: Positive if the value is changed, zero if it's not changed, or a
671  * negative error code.
672  */
673 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
674 {
675 	int changed = 0;
676 	if (snd_BUG_ON(snd_interval_empty(i)))
677 		return -EINVAL;
678 	if (i->min < v->min) {
679 		i->min = v->min;
680 		i->openmin = v->openmin;
681 		changed = 1;
682 	} else if (i->min == v->min && !i->openmin && v->openmin) {
683 		i->openmin = 1;
684 		changed = 1;
685 	}
686 	if (i->max > v->max) {
687 		i->max = v->max;
688 		i->openmax = v->openmax;
689 		changed = 1;
690 	} else if (i->max == v->max && !i->openmax && v->openmax) {
691 		i->openmax = 1;
692 		changed = 1;
693 	}
694 	if (!i->integer && v->integer) {
695 		i->integer = 1;
696 		changed = 1;
697 	}
698 	if (i->integer) {
699 		if (i->openmin) {
700 			i->min++;
701 			i->openmin = 0;
702 		}
703 		if (i->openmax) {
704 			i->max--;
705 			i->openmax = 0;
706 		}
707 	} else if (!i->openmin && !i->openmax && i->min == i->max)
708 		i->integer = 1;
709 	if (snd_interval_checkempty(i)) {
710 		snd_interval_none(i);
711 		return -EINVAL;
712 	}
713 	return changed;
714 }
715 
716 EXPORT_SYMBOL(snd_interval_refine);
717 
718 static int snd_interval_refine_first(struct snd_interval *i)
719 {
720 	if (snd_BUG_ON(snd_interval_empty(i)))
721 		return -EINVAL;
722 	if (snd_interval_single(i))
723 		return 0;
724 	i->max = i->min;
725 	i->openmax = i->openmin;
726 	if (i->openmax)
727 		i->max++;
728 	return 1;
729 }
730 
731 static int snd_interval_refine_last(struct snd_interval *i)
732 {
733 	if (snd_BUG_ON(snd_interval_empty(i)))
734 		return -EINVAL;
735 	if (snd_interval_single(i))
736 		return 0;
737 	i->min = i->max;
738 	i->openmin = i->openmax;
739 	if (i->openmin)
740 		i->min--;
741 	return 1;
742 }
743 
744 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
745 {
746 	if (a->empty || b->empty) {
747 		snd_interval_none(c);
748 		return;
749 	}
750 	c->empty = 0;
751 	c->min = mul(a->min, b->min);
752 	c->openmin = (a->openmin || b->openmin);
753 	c->max = mul(a->max,  b->max);
754 	c->openmax = (a->openmax || b->openmax);
755 	c->integer = (a->integer && b->integer);
756 }
757 
758 /**
759  * snd_interval_div - refine the interval value with division
760  * @a: dividend
761  * @b: divisor
762  * @c: quotient
763  *
764  * c = a / b
765  *
766  * Returns non-zero if the value is changed, zero if not changed.
767  */
768 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
769 {
770 	unsigned int r;
771 	if (a->empty || b->empty) {
772 		snd_interval_none(c);
773 		return;
774 	}
775 	c->empty = 0;
776 	c->min = div32(a->min, b->max, &r);
777 	c->openmin = (r || a->openmin || b->openmax);
778 	if (b->min > 0) {
779 		c->max = div32(a->max, b->min, &r);
780 		if (r) {
781 			c->max++;
782 			c->openmax = 1;
783 		} else
784 			c->openmax = (a->openmax || b->openmin);
785 	} else {
786 		c->max = UINT_MAX;
787 		c->openmax = 0;
788 	}
789 	c->integer = 0;
790 }
791 
792 /**
793  * snd_interval_muldivk - refine the interval value
794  * @a: dividend 1
795  * @b: dividend 2
796  * @k: divisor (as integer)
797  * @c: result
798   *
799  * c = a * b / k
800  *
801  * Returns non-zero if the value is changed, zero if not changed.
802  */
803 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
804 		      unsigned int k, struct snd_interval *c)
805 {
806 	unsigned int r;
807 	if (a->empty || b->empty) {
808 		snd_interval_none(c);
809 		return;
810 	}
811 	c->empty = 0;
812 	c->min = muldiv32(a->min, b->min, k, &r);
813 	c->openmin = (r || a->openmin || b->openmin);
814 	c->max = muldiv32(a->max, b->max, k, &r);
815 	if (r) {
816 		c->max++;
817 		c->openmax = 1;
818 	} else
819 		c->openmax = (a->openmax || b->openmax);
820 	c->integer = 0;
821 }
822 
823 /**
824  * snd_interval_mulkdiv - refine the interval value
825  * @a: dividend 1
826  * @k: dividend 2 (as integer)
827  * @b: divisor
828  * @c: result
829  *
830  * c = a * k / b
831  *
832  * Returns non-zero if the value is changed, zero if not changed.
833  */
834 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
835 		      const struct snd_interval *b, struct snd_interval *c)
836 {
837 	unsigned int r;
838 	if (a->empty || b->empty) {
839 		snd_interval_none(c);
840 		return;
841 	}
842 	c->empty = 0;
843 	c->min = muldiv32(a->min, k, b->max, &r);
844 	c->openmin = (r || a->openmin || b->openmax);
845 	if (b->min > 0) {
846 		c->max = muldiv32(a->max, k, b->min, &r);
847 		if (r) {
848 			c->max++;
849 			c->openmax = 1;
850 		} else
851 			c->openmax = (a->openmax || b->openmin);
852 	} else {
853 		c->max = UINT_MAX;
854 		c->openmax = 0;
855 	}
856 	c->integer = 0;
857 }
858 
859 /* ---- */
860 
861 
862 /**
863  * snd_interval_ratnum - refine the interval value
864  * @i: interval to refine
865  * @rats_count: number of ratnum_t
866  * @rats: ratnum_t array
867  * @nump: pointer to store the resultant numerator
868  * @denp: pointer to store the resultant denominator
869  *
870  * Return: Positive if the value is changed, zero if it's not changed, or a
871  * negative error code.
872  */
873 int snd_interval_ratnum(struct snd_interval *i,
874 			unsigned int rats_count, struct snd_ratnum *rats,
875 			unsigned int *nump, unsigned int *denp)
876 {
877 	unsigned int best_num, best_den;
878 	int best_diff;
879 	unsigned int k;
880 	struct snd_interval t;
881 	int err;
882 	unsigned int result_num, result_den;
883 	int result_diff;
884 
885 	best_num = best_den = best_diff = 0;
886 	for (k = 0; k < rats_count; ++k) {
887 		unsigned int num = rats[k].num;
888 		unsigned int den;
889 		unsigned int q = i->min;
890 		int diff;
891 		if (q == 0)
892 			q = 1;
893 		den = div_up(num, q);
894 		if (den < rats[k].den_min)
895 			continue;
896 		if (den > rats[k].den_max)
897 			den = rats[k].den_max;
898 		else {
899 			unsigned int r;
900 			r = (den - rats[k].den_min) % rats[k].den_step;
901 			if (r != 0)
902 				den -= r;
903 		}
904 		diff = num - q * den;
905 		if (diff < 0)
906 			diff = -diff;
907 		if (best_num == 0 ||
908 		    diff * best_den < best_diff * den) {
909 			best_diff = diff;
910 			best_den = den;
911 			best_num = num;
912 		}
913 	}
914 	if (best_den == 0) {
915 		i->empty = 1;
916 		return -EINVAL;
917 	}
918 	t.min = div_down(best_num, best_den);
919 	t.openmin = !!(best_num % best_den);
920 
921 	result_num = best_num;
922 	result_diff = best_diff;
923 	result_den = best_den;
924 	best_num = best_den = best_diff = 0;
925 	for (k = 0; k < rats_count; ++k) {
926 		unsigned int num = rats[k].num;
927 		unsigned int den;
928 		unsigned int q = i->max;
929 		int diff;
930 		if (q == 0) {
931 			i->empty = 1;
932 			return -EINVAL;
933 		}
934 		den = div_down(num, q);
935 		if (den > rats[k].den_max)
936 			continue;
937 		if (den < rats[k].den_min)
938 			den = rats[k].den_min;
939 		else {
940 			unsigned int r;
941 			r = (den - rats[k].den_min) % rats[k].den_step;
942 			if (r != 0)
943 				den += rats[k].den_step - r;
944 		}
945 		diff = q * den - num;
946 		if (diff < 0)
947 			diff = -diff;
948 		if (best_num == 0 ||
949 		    diff * best_den < best_diff * den) {
950 			best_diff = diff;
951 			best_den = den;
952 			best_num = num;
953 		}
954 	}
955 	if (best_den == 0) {
956 		i->empty = 1;
957 		return -EINVAL;
958 	}
959 	t.max = div_up(best_num, best_den);
960 	t.openmax = !!(best_num % best_den);
961 	t.integer = 0;
962 	err = snd_interval_refine(i, &t);
963 	if (err < 0)
964 		return err;
965 
966 	if (snd_interval_single(i)) {
967 		if (best_diff * result_den < result_diff * best_den) {
968 			result_num = best_num;
969 			result_den = best_den;
970 		}
971 		if (nump)
972 			*nump = result_num;
973 		if (denp)
974 			*denp = result_den;
975 	}
976 	return err;
977 }
978 
979 EXPORT_SYMBOL(snd_interval_ratnum);
980 
981 /**
982  * snd_interval_ratden - refine the interval value
983  * @i: interval to refine
984  * @rats_count: number of struct ratden
985  * @rats: struct ratden array
986  * @nump: pointer to store the resultant numerator
987  * @denp: pointer to store the resultant denominator
988  *
989  * Return: Positive if the value is changed, zero if it's not changed, or a
990  * negative error code.
991  */
992 static int snd_interval_ratden(struct snd_interval *i,
993 			       unsigned int rats_count, struct snd_ratden *rats,
994 			       unsigned int *nump, unsigned int *denp)
995 {
996 	unsigned int best_num, best_diff, best_den;
997 	unsigned int k;
998 	struct snd_interval t;
999 	int err;
1000 
1001 	best_num = best_den = best_diff = 0;
1002 	for (k = 0; k < rats_count; ++k) {
1003 		unsigned int num;
1004 		unsigned int den = rats[k].den;
1005 		unsigned int q = i->min;
1006 		int diff;
1007 		num = mul(q, den);
1008 		if (num > rats[k].num_max)
1009 			continue;
1010 		if (num < rats[k].num_min)
1011 			num = rats[k].num_max;
1012 		else {
1013 			unsigned int r;
1014 			r = (num - rats[k].num_min) % rats[k].num_step;
1015 			if (r != 0)
1016 				num += rats[k].num_step - r;
1017 		}
1018 		diff = num - q * den;
1019 		if (best_num == 0 ||
1020 		    diff * best_den < best_diff * den) {
1021 			best_diff = diff;
1022 			best_den = den;
1023 			best_num = num;
1024 		}
1025 	}
1026 	if (best_den == 0) {
1027 		i->empty = 1;
1028 		return -EINVAL;
1029 	}
1030 	t.min = div_down(best_num, best_den);
1031 	t.openmin = !!(best_num % best_den);
1032 
1033 	best_num = best_den = best_diff = 0;
1034 	for (k = 0; k < rats_count; ++k) {
1035 		unsigned int num;
1036 		unsigned int den = rats[k].den;
1037 		unsigned int q = i->max;
1038 		int diff;
1039 		num = mul(q, den);
1040 		if (num < rats[k].num_min)
1041 			continue;
1042 		if (num > rats[k].num_max)
1043 			num = rats[k].num_max;
1044 		else {
1045 			unsigned int r;
1046 			r = (num - rats[k].num_min) % rats[k].num_step;
1047 			if (r != 0)
1048 				num -= r;
1049 		}
1050 		diff = q * den - num;
1051 		if (best_num == 0 ||
1052 		    diff * best_den < best_diff * den) {
1053 			best_diff = diff;
1054 			best_den = den;
1055 			best_num = num;
1056 		}
1057 	}
1058 	if (best_den == 0) {
1059 		i->empty = 1;
1060 		return -EINVAL;
1061 	}
1062 	t.max = div_up(best_num, best_den);
1063 	t.openmax = !!(best_num % best_den);
1064 	t.integer = 0;
1065 	err = snd_interval_refine(i, &t);
1066 	if (err < 0)
1067 		return err;
1068 
1069 	if (snd_interval_single(i)) {
1070 		if (nump)
1071 			*nump = best_num;
1072 		if (denp)
1073 			*denp = best_den;
1074 	}
1075 	return err;
1076 }
1077 
1078 /**
1079  * snd_interval_list - refine the interval value from the list
1080  * @i: the interval value to refine
1081  * @count: the number of elements in the list
1082  * @list: the value list
1083  * @mask: the bit-mask to evaluate
1084  *
1085  * Refines the interval value from the list.
1086  * When mask is non-zero, only the elements corresponding to bit 1 are
1087  * evaluated.
1088  *
1089  * Return: Positive if the value is changed, zero if it's not changed, or a
1090  * negative error code.
1091  */
1092 int snd_interval_list(struct snd_interval *i, unsigned int count,
1093 		      const unsigned int *list, unsigned int mask)
1094 {
1095         unsigned int k;
1096 	struct snd_interval list_range;
1097 
1098 	if (!count) {
1099 		i->empty = 1;
1100 		return -EINVAL;
1101 	}
1102 	snd_interval_any(&list_range);
1103 	list_range.min = UINT_MAX;
1104 	list_range.max = 0;
1105         for (k = 0; k < count; k++) {
1106 		if (mask && !(mask & (1 << k)))
1107 			continue;
1108 		if (!snd_interval_test(i, list[k]))
1109 			continue;
1110 		list_range.min = min(list_range.min, list[k]);
1111 		list_range.max = max(list_range.max, list[k]);
1112         }
1113 	return snd_interval_refine(i, &list_range);
1114 }
1115 
1116 EXPORT_SYMBOL(snd_interval_list);
1117 
1118 static int snd_interval_step(struct snd_interval *i, unsigned int min, unsigned int step)
1119 {
1120 	unsigned int n;
1121 	int changed = 0;
1122 	n = (i->min - min) % step;
1123 	if (n != 0 || i->openmin) {
1124 		i->min += step - n;
1125 		changed = 1;
1126 	}
1127 	n = (i->max - min) % step;
1128 	if (n != 0 || i->openmax) {
1129 		i->max -= n;
1130 		changed = 1;
1131 	}
1132 	if (snd_interval_checkempty(i)) {
1133 		i->empty = 1;
1134 		return -EINVAL;
1135 	}
1136 	return changed;
1137 }
1138 
1139 /* Info constraints helpers */
1140 
1141 /**
1142  * snd_pcm_hw_rule_add - add the hw-constraint rule
1143  * @runtime: the pcm runtime instance
1144  * @cond: condition bits
1145  * @var: the variable to evaluate
1146  * @func: the evaluation function
1147  * @private: the private data pointer passed to function
1148  * @dep: the dependent variables
1149  *
1150  * Return: Zero if successful, or a negative error code on failure.
1151  */
1152 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1153 			int var,
1154 			snd_pcm_hw_rule_func_t func, void *private,
1155 			int dep, ...)
1156 {
1157 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1158 	struct snd_pcm_hw_rule *c;
1159 	unsigned int k;
1160 	va_list args;
1161 	va_start(args, dep);
1162 	if (constrs->rules_num >= constrs->rules_all) {
1163 		struct snd_pcm_hw_rule *new;
1164 		unsigned int new_rules = constrs->rules_all + 16;
1165 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1166 		if (!new) {
1167 			va_end(args);
1168 			return -ENOMEM;
1169 		}
1170 		if (constrs->rules) {
1171 			memcpy(new, constrs->rules,
1172 			       constrs->rules_num * sizeof(*c));
1173 			kfree(constrs->rules);
1174 		}
1175 		constrs->rules = new;
1176 		constrs->rules_all = new_rules;
1177 	}
1178 	c = &constrs->rules[constrs->rules_num];
1179 	c->cond = cond;
1180 	c->func = func;
1181 	c->var = var;
1182 	c->private = private;
1183 	k = 0;
1184 	while (1) {
1185 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1186 			va_end(args);
1187 			return -EINVAL;
1188 		}
1189 		c->deps[k++] = dep;
1190 		if (dep < 0)
1191 			break;
1192 		dep = va_arg(args, int);
1193 	}
1194 	constrs->rules_num++;
1195 	va_end(args);
1196 	return 0;
1197 }
1198 
1199 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1200 
1201 /**
1202  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1203  * @runtime: PCM runtime instance
1204  * @var: hw_params variable to apply the mask
1205  * @mask: the bitmap mask
1206  *
1207  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1208  *
1209  * Return: Zero if successful, or a negative error code on failure.
1210  */
1211 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1212 			       u_int32_t mask)
1213 {
1214 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1215 	struct snd_mask *maskp = constrs_mask(constrs, var);
1216 	*maskp->bits &= mask;
1217 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1218 	if (*maskp->bits == 0)
1219 		return -EINVAL;
1220 	return 0;
1221 }
1222 
1223 /**
1224  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1225  * @runtime: PCM runtime instance
1226  * @var: hw_params variable to apply the mask
1227  * @mask: the 64bit bitmap mask
1228  *
1229  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1230  *
1231  * Return: Zero if successful, or a negative error code on failure.
1232  */
1233 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1234 				 u_int64_t mask)
1235 {
1236 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1237 	struct snd_mask *maskp = constrs_mask(constrs, var);
1238 	maskp->bits[0] &= (u_int32_t)mask;
1239 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1240 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1241 	if (! maskp->bits[0] && ! maskp->bits[1])
1242 		return -EINVAL;
1243 	return 0;
1244 }
1245 
1246 /**
1247  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1248  * @runtime: PCM runtime instance
1249  * @var: hw_params variable to apply the integer constraint
1250  *
1251  * Apply the constraint of integer to an interval parameter.
1252  *
1253  * Return: Positive if the value is changed, zero if it's not changed, or a
1254  * negative error code.
1255  */
1256 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1257 {
1258 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1259 	return snd_interval_setinteger(constrs_interval(constrs, var));
1260 }
1261 
1262 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1263 
1264 /**
1265  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1266  * @runtime: PCM runtime instance
1267  * @var: hw_params variable to apply the range
1268  * @min: the minimal value
1269  * @max: the maximal value
1270  *
1271  * Apply the min/max range constraint to an interval parameter.
1272  *
1273  * Return: Positive if the value is changed, zero if it's not changed, or a
1274  * negative error code.
1275  */
1276 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1277 				 unsigned int min, unsigned int max)
1278 {
1279 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1280 	struct snd_interval t;
1281 	t.min = min;
1282 	t.max = max;
1283 	t.openmin = t.openmax = 0;
1284 	t.integer = 0;
1285 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1286 }
1287 
1288 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1289 
1290 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1291 				struct snd_pcm_hw_rule *rule)
1292 {
1293 	struct snd_pcm_hw_constraint_list *list = rule->private;
1294 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1295 }
1296 
1297 
1298 /**
1299  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1300  * @runtime: PCM runtime instance
1301  * @cond: condition bits
1302  * @var: hw_params variable to apply the list constraint
1303  * @l: list
1304  *
1305  * Apply the list of constraints to an interval parameter.
1306  *
1307  * Return: Zero if successful, or a negative error code on failure.
1308  */
1309 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1310 			       unsigned int cond,
1311 			       snd_pcm_hw_param_t var,
1312 			       const struct snd_pcm_hw_constraint_list *l)
1313 {
1314 	return snd_pcm_hw_rule_add(runtime, cond, var,
1315 				   snd_pcm_hw_rule_list, (void *)l,
1316 				   var, -1);
1317 }
1318 
1319 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1320 
1321 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1322 				   struct snd_pcm_hw_rule *rule)
1323 {
1324 	struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1325 	unsigned int num = 0, den = 0;
1326 	int err;
1327 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1328 				  r->nrats, r->rats, &num, &den);
1329 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1330 		params->rate_num = num;
1331 		params->rate_den = den;
1332 	}
1333 	return err;
1334 }
1335 
1336 /**
1337  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1338  * @runtime: PCM runtime instance
1339  * @cond: condition bits
1340  * @var: hw_params variable to apply the ratnums constraint
1341  * @r: struct snd_ratnums constriants
1342  *
1343  * Return: Zero if successful, or a negative error code on failure.
1344  */
1345 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1346 				  unsigned int cond,
1347 				  snd_pcm_hw_param_t var,
1348 				  struct snd_pcm_hw_constraint_ratnums *r)
1349 {
1350 	return snd_pcm_hw_rule_add(runtime, cond, var,
1351 				   snd_pcm_hw_rule_ratnums, r,
1352 				   var, -1);
1353 }
1354 
1355 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1356 
1357 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1358 				   struct snd_pcm_hw_rule *rule)
1359 {
1360 	struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1361 	unsigned int num = 0, den = 0;
1362 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1363 				  r->nrats, r->rats, &num, &den);
1364 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1365 		params->rate_num = num;
1366 		params->rate_den = den;
1367 	}
1368 	return err;
1369 }
1370 
1371 /**
1372  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1373  * @runtime: PCM runtime instance
1374  * @cond: condition bits
1375  * @var: hw_params variable to apply the ratdens constraint
1376  * @r: struct snd_ratdens constriants
1377  *
1378  * Return: Zero if successful, or a negative error code on failure.
1379  */
1380 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1381 				  unsigned int cond,
1382 				  snd_pcm_hw_param_t var,
1383 				  struct snd_pcm_hw_constraint_ratdens *r)
1384 {
1385 	return snd_pcm_hw_rule_add(runtime, cond, var,
1386 				   snd_pcm_hw_rule_ratdens, r,
1387 				   var, -1);
1388 }
1389 
1390 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1391 
1392 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1393 				  struct snd_pcm_hw_rule *rule)
1394 {
1395 	unsigned int l = (unsigned long) rule->private;
1396 	int width = l & 0xffff;
1397 	unsigned int msbits = l >> 16;
1398 	struct snd_interval *i = hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1399 	if (snd_interval_single(i) && snd_interval_value(i) == width)
1400 		params->msbits = msbits;
1401 	return 0;
1402 }
1403 
1404 /**
1405  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1406  * @runtime: PCM runtime instance
1407  * @cond: condition bits
1408  * @width: sample bits width
1409  * @msbits: msbits width
1410  *
1411  * Return: Zero if successful, or a negative error code on failure.
1412  */
1413 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1414 				 unsigned int cond,
1415 				 unsigned int width,
1416 				 unsigned int msbits)
1417 {
1418 	unsigned long l = (msbits << 16) | width;
1419 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1420 				    snd_pcm_hw_rule_msbits,
1421 				    (void*) l,
1422 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1423 }
1424 
1425 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1426 
1427 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1428 				struct snd_pcm_hw_rule *rule)
1429 {
1430 	unsigned long step = (unsigned long) rule->private;
1431 	return snd_interval_step(hw_param_interval(params, rule->var), 0, step);
1432 }
1433 
1434 /**
1435  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1436  * @runtime: PCM runtime instance
1437  * @cond: condition bits
1438  * @var: hw_params variable to apply the step constraint
1439  * @step: step size
1440  *
1441  * Return: Zero if successful, or a negative error code on failure.
1442  */
1443 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1444 			       unsigned int cond,
1445 			       snd_pcm_hw_param_t var,
1446 			       unsigned long step)
1447 {
1448 	return snd_pcm_hw_rule_add(runtime, cond, var,
1449 				   snd_pcm_hw_rule_step, (void *) step,
1450 				   var, -1);
1451 }
1452 
1453 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1454 
1455 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1456 {
1457 	static unsigned int pow2_sizes[] = {
1458 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1459 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1460 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1461 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1462 	};
1463 	return snd_interval_list(hw_param_interval(params, rule->var),
1464 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1465 }
1466 
1467 /**
1468  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1469  * @runtime: PCM runtime instance
1470  * @cond: condition bits
1471  * @var: hw_params variable to apply the power-of-2 constraint
1472  *
1473  * Return: Zero if successful, or a negative error code on failure.
1474  */
1475 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1476 			       unsigned int cond,
1477 			       snd_pcm_hw_param_t var)
1478 {
1479 	return snd_pcm_hw_rule_add(runtime, cond, var,
1480 				   snd_pcm_hw_rule_pow2, NULL,
1481 				   var, -1);
1482 }
1483 
1484 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1485 
1486 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1487 					   struct snd_pcm_hw_rule *rule)
1488 {
1489 	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1490 	struct snd_interval *rate;
1491 
1492 	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1493 	return snd_interval_list(rate, 1, &base_rate, 0);
1494 }
1495 
1496 /**
1497  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1498  * @runtime: PCM runtime instance
1499  * @base_rate: the rate at which the hardware does not resample
1500  *
1501  * Return: Zero if successful, or a negative error code on failure.
1502  */
1503 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1504 			       unsigned int base_rate)
1505 {
1506 	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1507 				   SNDRV_PCM_HW_PARAM_RATE,
1508 				   snd_pcm_hw_rule_noresample_func,
1509 				   (void *)(uintptr_t)base_rate,
1510 				   SNDRV_PCM_HW_PARAM_RATE, -1);
1511 }
1512 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1513 
1514 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1515 				  snd_pcm_hw_param_t var)
1516 {
1517 	if (hw_is_mask(var)) {
1518 		snd_mask_any(hw_param_mask(params, var));
1519 		params->cmask |= 1 << var;
1520 		params->rmask |= 1 << var;
1521 		return;
1522 	}
1523 	if (hw_is_interval(var)) {
1524 		snd_interval_any(hw_param_interval(params, var));
1525 		params->cmask |= 1 << var;
1526 		params->rmask |= 1 << var;
1527 		return;
1528 	}
1529 	snd_BUG();
1530 }
1531 
1532 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1533 {
1534 	unsigned int k;
1535 	memset(params, 0, sizeof(*params));
1536 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1537 		_snd_pcm_hw_param_any(params, k);
1538 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1539 		_snd_pcm_hw_param_any(params, k);
1540 	params->info = ~0U;
1541 }
1542 
1543 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1544 
1545 /**
1546  * snd_pcm_hw_param_value - return @params field @var value
1547  * @params: the hw_params instance
1548  * @var: parameter to retrieve
1549  * @dir: pointer to the direction (-1,0,1) or %NULL
1550  *
1551  * Return: The value for field @var if it's fixed in configuration space
1552  * defined by @params. -%EINVAL otherwise.
1553  */
1554 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1555 			   snd_pcm_hw_param_t var, int *dir)
1556 {
1557 	if (hw_is_mask(var)) {
1558 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1559 		if (!snd_mask_single(mask))
1560 			return -EINVAL;
1561 		if (dir)
1562 			*dir = 0;
1563 		return snd_mask_value(mask);
1564 	}
1565 	if (hw_is_interval(var)) {
1566 		const struct snd_interval *i = hw_param_interval_c(params, var);
1567 		if (!snd_interval_single(i))
1568 			return -EINVAL;
1569 		if (dir)
1570 			*dir = i->openmin;
1571 		return snd_interval_value(i);
1572 	}
1573 	return -EINVAL;
1574 }
1575 
1576 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1577 
1578 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1579 				snd_pcm_hw_param_t var)
1580 {
1581 	if (hw_is_mask(var)) {
1582 		snd_mask_none(hw_param_mask(params, var));
1583 		params->cmask |= 1 << var;
1584 		params->rmask |= 1 << var;
1585 	} else if (hw_is_interval(var)) {
1586 		snd_interval_none(hw_param_interval(params, var));
1587 		params->cmask |= 1 << var;
1588 		params->rmask |= 1 << var;
1589 	} else {
1590 		snd_BUG();
1591 	}
1592 }
1593 
1594 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1595 
1596 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1597 				   snd_pcm_hw_param_t var)
1598 {
1599 	int changed;
1600 	if (hw_is_mask(var))
1601 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1602 	else if (hw_is_interval(var))
1603 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1604 	else
1605 		return -EINVAL;
1606 	if (changed) {
1607 		params->cmask |= 1 << var;
1608 		params->rmask |= 1 << var;
1609 	}
1610 	return changed;
1611 }
1612 
1613 
1614 /**
1615  * snd_pcm_hw_param_first - refine config space and return minimum value
1616  * @pcm: PCM instance
1617  * @params: the hw_params instance
1618  * @var: parameter to retrieve
1619  * @dir: pointer to the direction (-1,0,1) or %NULL
1620  *
1621  * Inside configuration space defined by @params remove from @var all
1622  * values > minimum. Reduce configuration space accordingly.
1623  *
1624  * Return: The minimum, or a negative error code on failure.
1625  */
1626 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1627 			   struct snd_pcm_hw_params *params,
1628 			   snd_pcm_hw_param_t var, int *dir)
1629 {
1630 	int changed = _snd_pcm_hw_param_first(params, var);
1631 	if (changed < 0)
1632 		return changed;
1633 	if (params->rmask) {
1634 		int err = snd_pcm_hw_refine(pcm, params);
1635 		if (snd_BUG_ON(err < 0))
1636 			return err;
1637 	}
1638 	return snd_pcm_hw_param_value(params, var, dir);
1639 }
1640 
1641 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1642 
1643 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1644 				  snd_pcm_hw_param_t var)
1645 {
1646 	int changed;
1647 	if (hw_is_mask(var))
1648 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1649 	else if (hw_is_interval(var))
1650 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1651 	else
1652 		return -EINVAL;
1653 	if (changed) {
1654 		params->cmask |= 1 << var;
1655 		params->rmask |= 1 << var;
1656 	}
1657 	return changed;
1658 }
1659 
1660 
1661 /**
1662  * snd_pcm_hw_param_last - refine config space and return maximum value
1663  * @pcm: PCM instance
1664  * @params: the hw_params instance
1665  * @var: parameter to retrieve
1666  * @dir: pointer to the direction (-1,0,1) or %NULL
1667  *
1668  * Inside configuration space defined by @params remove from @var all
1669  * values < maximum. Reduce configuration space accordingly.
1670  *
1671  * Return: The maximum, or a negative error code on failure.
1672  */
1673 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1674 			  struct snd_pcm_hw_params *params,
1675 			  snd_pcm_hw_param_t var, int *dir)
1676 {
1677 	int changed = _snd_pcm_hw_param_last(params, var);
1678 	if (changed < 0)
1679 		return changed;
1680 	if (params->rmask) {
1681 		int err = snd_pcm_hw_refine(pcm, params);
1682 		if (snd_BUG_ON(err < 0))
1683 			return err;
1684 	}
1685 	return snd_pcm_hw_param_value(params, var, dir);
1686 }
1687 
1688 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1689 
1690 /**
1691  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1692  * @pcm: PCM instance
1693  * @params: the hw_params instance
1694  *
1695  * Choose one configuration from configuration space defined by @params.
1696  * The configuration chosen is that obtained fixing in this order:
1697  * first access, first format, first subformat, min channels,
1698  * min rate, min period time, max buffer size, min tick time
1699  *
1700  * Return: Zero if successful, or a negative error code on failure.
1701  */
1702 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1703 			     struct snd_pcm_hw_params *params)
1704 {
1705 	static int vars[] = {
1706 		SNDRV_PCM_HW_PARAM_ACCESS,
1707 		SNDRV_PCM_HW_PARAM_FORMAT,
1708 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1709 		SNDRV_PCM_HW_PARAM_CHANNELS,
1710 		SNDRV_PCM_HW_PARAM_RATE,
1711 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1712 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1713 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1714 		-1
1715 	};
1716 	int err, *v;
1717 
1718 	for (v = vars; *v != -1; v++) {
1719 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1720 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1721 		else
1722 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1723 		if (snd_BUG_ON(err < 0))
1724 			return err;
1725 	}
1726 	return 0;
1727 }
1728 
1729 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1730 				   void *arg)
1731 {
1732 	struct snd_pcm_runtime *runtime = substream->runtime;
1733 	unsigned long flags;
1734 	snd_pcm_stream_lock_irqsave(substream, flags);
1735 	if (snd_pcm_running(substream) &&
1736 	    snd_pcm_update_hw_ptr(substream) >= 0)
1737 		runtime->status->hw_ptr %= runtime->buffer_size;
1738 	else {
1739 		runtime->status->hw_ptr = 0;
1740 		runtime->hw_ptr_wrap = 0;
1741 	}
1742 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1743 	return 0;
1744 }
1745 
1746 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1747 					  void *arg)
1748 {
1749 	struct snd_pcm_channel_info *info = arg;
1750 	struct snd_pcm_runtime *runtime = substream->runtime;
1751 	int width;
1752 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1753 		info->offset = -1;
1754 		return 0;
1755 	}
1756 	width = snd_pcm_format_physical_width(runtime->format);
1757 	if (width < 0)
1758 		return width;
1759 	info->offset = 0;
1760 	switch (runtime->access) {
1761 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1762 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1763 		info->first = info->channel * width;
1764 		info->step = runtime->channels * width;
1765 		break;
1766 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1767 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1768 	{
1769 		size_t size = runtime->dma_bytes / runtime->channels;
1770 		info->first = info->channel * size * 8;
1771 		info->step = width;
1772 		break;
1773 	}
1774 	default:
1775 		snd_BUG();
1776 		break;
1777 	}
1778 	return 0;
1779 }
1780 
1781 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1782 				       void *arg)
1783 {
1784 	struct snd_pcm_hw_params *params = arg;
1785 	snd_pcm_format_t format;
1786 	int channels, width;
1787 
1788 	params->fifo_size = substream->runtime->hw.fifo_size;
1789 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1790 		format = params_format(params);
1791 		channels = params_channels(params);
1792 		width = snd_pcm_format_physical_width(format);
1793 		params->fifo_size /= width * channels;
1794 	}
1795 	return 0;
1796 }
1797 
1798 /**
1799  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1800  * @substream: the pcm substream instance
1801  * @cmd: ioctl command
1802  * @arg: ioctl argument
1803  *
1804  * Processes the generic ioctl commands for PCM.
1805  * Can be passed as the ioctl callback for PCM ops.
1806  *
1807  * Return: Zero if successful, or a negative error code on failure.
1808  */
1809 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1810 		      unsigned int cmd, void *arg)
1811 {
1812 	switch (cmd) {
1813 	case SNDRV_PCM_IOCTL1_INFO:
1814 		return 0;
1815 	case SNDRV_PCM_IOCTL1_RESET:
1816 		return snd_pcm_lib_ioctl_reset(substream, arg);
1817 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1818 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1819 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1820 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1821 	}
1822 	return -ENXIO;
1823 }
1824 
1825 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1826 
1827 /**
1828  * snd_pcm_period_elapsed - update the pcm status for the next period
1829  * @substream: the pcm substream instance
1830  *
1831  * This function is called from the interrupt handler when the
1832  * PCM has processed the period size.  It will update the current
1833  * pointer, wake up sleepers, etc.
1834  *
1835  * Even if more than one periods have elapsed since the last call, you
1836  * have to call this only once.
1837  */
1838 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1839 {
1840 	struct snd_pcm_runtime *runtime;
1841 	unsigned long flags;
1842 
1843 	if (PCM_RUNTIME_CHECK(substream))
1844 		return;
1845 	runtime = substream->runtime;
1846 
1847 	if (runtime->transfer_ack_begin)
1848 		runtime->transfer_ack_begin(substream);
1849 
1850 	snd_pcm_stream_lock_irqsave(substream, flags);
1851 	if (!snd_pcm_running(substream) ||
1852 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1853 		goto _end;
1854 
1855 	if (substream->timer_running)
1856 		snd_timer_interrupt(substream->timer, 1);
1857  _end:
1858 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1859 	if (runtime->transfer_ack_end)
1860 		runtime->transfer_ack_end(substream);
1861 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1862 }
1863 
1864 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1865 
1866 /*
1867  * Wait until avail_min data becomes available
1868  * Returns a negative error code if any error occurs during operation.
1869  * The available space is stored on availp.  When err = 0 and avail = 0
1870  * on the capture stream, it indicates the stream is in DRAINING state.
1871  */
1872 static int wait_for_avail(struct snd_pcm_substream *substream,
1873 			      snd_pcm_uframes_t *availp)
1874 {
1875 	struct snd_pcm_runtime *runtime = substream->runtime;
1876 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1877 	wait_queue_t wait;
1878 	int err = 0;
1879 	snd_pcm_uframes_t avail = 0;
1880 	long wait_time, tout;
1881 
1882 	init_waitqueue_entry(&wait, current);
1883 	set_current_state(TASK_INTERRUPTIBLE);
1884 	add_wait_queue(&runtime->tsleep, &wait);
1885 
1886 	if (runtime->no_period_wakeup)
1887 		wait_time = MAX_SCHEDULE_TIMEOUT;
1888 	else {
1889 		wait_time = 10;
1890 		if (runtime->rate) {
1891 			long t = runtime->period_size * 2 / runtime->rate;
1892 			wait_time = max(t, wait_time);
1893 		}
1894 		wait_time = msecs_to_jiffies(wait_time * 1000);
1895 	}
1896 
1897 	for (;;) {
1898 		if (signal_pending(current)) {
1899 			err = -ERESTARTSYS;
1900 			break;
1901 		}
1902 
1903 		/*
1904 		 * We need to check if space became available already
1905 		 * (and thus the wakeup happened already) first to close
1906 		 * the race of space already having become available.
1907 		 * This check must happen after been added to the waitqueue
1908 		 * and having current state be INTERRUPTIBLE.
1909 		 */
1910 		if (is_playback)
1911 			avail = snd_pcm_playback_avail(runtime);
1912 		else
1913 			avail = snd_pcm_capture_avail(runtime);
1914 		if (avail >= runtime->twake)
1915 			break;
1916 		snd_pcm_stream_unlock_irq(substream);
1917 
1918 		tout = schedule_timeout(wait_time);
1919 
1920 		snd_pcm_stream_lock_irq(substream);
1921 		set_current_state(TASK_INTERRUPTIBLE);
1922 		switch (runtime->status->state) {
1923 		case SNDRV_PCM_STATE_SUSPENDED:
1924 			err = -ESTRPIPE;
1925 			goto _endloop;
1926 		case SNDRV_PCM_STATE_XRUN:
1927 			err = -EPIPE;
1928 			goto _endloop;
1929 		case SNDRV_PCM_STATE_DRAINING:
1930 			if (is_playback)
1931 				err = -EPIPE;
1932 			else
1933 				avail = 0; /* indicate draining */
1934 			goto _endloop;
1935 		case SNDRV_PCM_STATE_OPEN:
1936 		case SNDRV_PCM_STATE_SETUP:
1937 		case SNDRV_PCM_STATE_DISCONNECTED:
1938 			err = -EBADFD;
1939 			goto _endloop;
1940 		case SNDRV_PCM_STATE_PAUSED:
1941 			continue;
1942 		}
1943 		if (!tout) {
1944 			snd_printd("%s write error (DMA or IRQ trouble?)\n",
1945 				   is_playback ? "playback" : "capture");
1946 			err = -EIO;
1947 			break;
1948 		}
1949 	}
1950  _endloop:
1951 	set_current_state(TASK_RUNNING);
1952 	remove_wait_queue(&runtime->tsleep, &wait);
1953 	*availp = avail;
1954 	return err;
1955 }
1956 
1957 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1958 				      unsigned int hwoff,
1959 				      unsigned long data, unsigned int off,
1960 				      snd_pcm_uframes_t frames)
1961 {
1962 	struct snd_pcm_runtime *runtime = substream->runtime;
1963 	int err;
1964 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
1965 	if (substream->ops->copy) {
1966 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
1967 			return err;
1968 	} else {
1969 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
1970 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
1971 			return -EFAULT;
1972 	}
1973 	return 0;
1974 }
1975 
1976 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
1977 			  unsigned long data, unsigned int off,
1978 			  snd_pcm_uframes_t size);
1979 
1980 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
1981 					    unsigned long data,
1982 					    snd_pcm_uframes_t size,
1983 					    int nonblock,
1984 					    transfer_f transfer)
1985 {
1986 	struct snd_pcm_runtime *runtime = substream->runtime;
1987 	snd_pcm_uframes_t xfer = 0;
1988 	snd_pcm_uframes_t offset = 0;
1989 	snd_pcm_uframes_t avail;
1990 	int err = 0;
1991 
1992 	if (size == 0)
1993 		return 0;
1994 
1995 	snd_pcm_stream_lock_irq(substream);
1996 	switch (runtime->status->state) {
1997 	case SNDRV_PCM_STATE_PREPARED:
1998 	case SNDRV_PCM_STATE_RUNNING:
1999 	case SNDRV_PCM_STATE_PAUSED:
2000 		break;
2001 	case SNDRV_PCM_STATE_XRUN:
2002 		err = -EPIPE;
2003 		goto _end_unlock;
2004 	case SNDRV_PCM_STATE_SUSPENDED:
2005 		err = -ESTRPIPE;
2006 		goto _end_unlock;
2007 	default:
2008 		err = -EBADFD;
2009 		goto _end_unlock;
2010 	}
2011 
2012 	runtime->twake = runtime->control->avail_min ? : 1;
2013 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2014 		snd_pcm_update_hw_ptr(substream);
2015 	avail = snd_pcm_playback_avail(runtime);
2016 	while (size > 0) {
2017 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2018 		snd_pcm_uframes_t cont;
2019 		if (!avail) {
2020 			if (nonblock) {
2021 				err = -EAGAIN;
2022 				goto _end_unlock;
2023 			}
2024 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2025 					runtime->control->avail_min ? : 1);
2026 			err = wait_for_avail(substream, &avail);
2027 			if (err < 0)
2028 				goto _end_unlock;
2029 		}
2030 		frames = size > avail ? avail : size;
2031 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2032 		if (frames > cont)
2033 			frames = cont;
2034 		if (snd_BUG_ON(!frames)) {
2035 			runtime->twake = 0;
2036 			snd_pcm_stream_unlock_irq(substream);
2037 			return -EINVAL;
2038 		}
2039 		appl_ptr = runtime->control->appl_ptr;
2040 		appl_ofs = appl_ptr % runtime->buffer_size;
2041 		snd_pcm_stream_unlock_irq(substream);
2042 		err = transfer(substream, appl_ofs, data, offset, frames);
2043 		snd_pcm_stream_lock_irq(substream);
2044 		if (err < 0)
2045 			goto _end_unlock;
2046 		switch (runtime->status->state) {
2047 		case SNDRV_PCM_STATE_XRUN:
2048 			err = -EPIPE;
2049 			goto _end_unlock;
2050 		case SNDRV_PCM_STATE_SUSPENDED:
2051 			err = -ESTRPIPE;
2052 			goto _end_unlock;
2053 		default:
2054 			break;
2055 		}
2056 		appl_ptr += frames;
2057 		if (appl_ptr >= runtime->boundary)
2058 			appl_ptr -= runtime->boundary;
2059 		runtime->control->appl_ptr = appl_ptr;
2060 		if (substream->ops->ack)
2061 			substream->ops->ack(substream);
2062 
2063 		offset += frames;
2064 		size -= frames;
2065 		xfer += frames;
2066 		avail -= frames;
2067 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2068 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2069 			err = snd_pcm_start(substream);
2070 			if (err < 0)
2071 				goto _end_unlock;
2072 		}
2073 	}
2074  _end_unlock:
2075 	runtime->twake = 0;
2076 	if (xfer > 0 && err >= 0)
2077 		snd_pcm_update_state(substream, runtime);
2078 	snd_pcm_stream_unlock_irq(substream);
2079 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2080 }
2081 
2082 /* sanity-check for read/write methods */
2083 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2084 {
2085 	struct snd_pcm_runtime *runtime;
2086 	if (PCM_RUNTIME_CHECK(substream))
2087 		return -ENXIO;
2088 	runtime = substream->runtime;
2089 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2090 		return -EINVAL;
2091 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2092 		return -EBADFD;
2093 	return 0;
2094 }
2095 
2096 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2097 {
2098 	struct snd_pcm_runtime *runtime;
2099 	int nonblock;
2100 	int err;
2101 
2102 	err = pcm_sanity_check(substream);
2103 	if (err < 0)
2104 		return err;
2105 	runtime = substream->runtime;
2106 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2107 
2108 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2109 	    runtime->channels > 1)
2110 		return -EINVAL;
2111 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2112 				  snd_pcm_lib_write_transfer);
2113 }
2114 
2115 EXPORT_SYMBOL(snd_pcm_lib_write);
2116 
2117 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2118 				       unsigned int hwoff,
2119 				       unsigned long data, unsigned int off,
2120 				       snd_pcm_uframes_t frames)
2121 {
2122 	struct snd_pcm_runtime *runtime = substream->runtime;
2123 	int err;
2124 	void __user **bufs = (void __user **)data;
2125 	int channels = runtime->channels;
2126 	int c;
2127 	if (substream->ops->copy) {
2128 		if (snd_BUG_ON(!substream->ops->silence))
2129 			return -EINVAL;
2130 		for (c = 0; c < channels; ++c, ++bufs) {
2131 			if (*bufs == NULL) {
2132 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2133 					return err;
2134 			} else {
2135 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2136 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2137 					return err;
2138 			}
2139 		}
2140 	} else {
2141 		/* default transfer behaviour */
2142 		size_t dma_csize = runtime->dma_bytes / channels;
2143 		for (c = 0; c < channels; ++c, ++bufs) {
2144 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2145 			if (*bufs == NULL) {
2146 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2147 			} else {
2148 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2149 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2150 					return -EFAULT;
2151 			}
2152 		}
2153 	}
2154 	return 0;
2155 }
2156 
2157 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2158 				     void __user **bufs,
2159 				     snd_pcm_uframes_t frames)
2160 {
2161 	struct snd_pcm_runtime *runtime;
2162 	int nonblock;
2163 	int err;
2164 
2165 	err = pcm_sanity_check(substream);
2166 	if (err < 0)
2167 		return err;
2168 	runtime = substream->runtime;
2169 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2170 
2171 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2172 		return -EINVAL;
2173 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2174 				  nonblock, snd_pcm_lib_writev_transfer);
2175 }
2176 
2177 EXPORT_SYMBOL(snd_pcm_lib_writev);
2178 
2179 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2180 				     unsigned int hwoff,
2181 				     unsigned long data, unsigned int off,
2182 				     snd_pcm_uframes_t frames)
2183 {
2184 	struct snd_pcm_runtime *runtime = substream->runtime;
2185 	int err;
2186 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2187 	if (substream->ops->copy) {
2188 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2189 			return err;
2190 	} else {
2191 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2192 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2193 			return -EFAULT;
2194 	}
2195 	return 0;
2196 }
2197 
2198 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2199 					   unsigned long data,
2200 					   snd_pcm_uframes_t size,
2201 					   int nonblock,
2202 					   transfer_f transfer)
2203 {
2204 	struct snd_pcm_runtime *runtime = substream->runtime;
2205 	snd_pcm_uframes_t xfer = 0;
2206 	snd_pcm_uframes_t offset = 0;
2207 	snd_pcm_uframes_t avail;
2208 	int err = 0;
2209 
2210 	if (size == 0)
2211 		return 0;
2212 
2213 	snd_pcm_stream_lock_irq(substream);
2214 	switch (runtime->status->state) {
2215 	case SNDRV_PCM_STATE_PREPARED:
2216 		if (size >= runtime->start_threshold) {
2217 			err = snd_pcm_start(substream);
2218 			if (err < 0)
2219 				goto _end_unlock;
2220 		}
2221 		break;
2222 	case SNDRV_PCM_STATE_DRAINING:
2223 	case SNDRV_PCM_STATE_RUNNING:
2224 	case SNDRV_PCM_STATE_PAUSED:
2225 		break;
2226 	case SNDRV_PCM_STATE_XRUN:
2227 		err = -EPIPE;
2228 		goto _end_unlock;
2229 	case SNDRV_PCM_STATE_SUSPENDED:
2230 		err = -ESTRPIPE;
2231 		goto _end_unlock;
2232 	default:
2233 		err = -EBADFD;
2234 		goto _end_unlock;
2235 	}
2236 
2237 	runtime->twake = runtime->control->avail_min ? : 1;
2238 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2239 		snd_pcm_update_hw_ptr(substream);
2240 	avail = snd_pcm_capture_avail(runtime);
2241 	while (size > 0) {
2242 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2243 		snd_pcm_uframes_t cont;
2244 		if (!avail) {
2245 			if (runtime->status->state ==
2246 			    SNDRV_PCM_STATE_DRAINING) {
2247 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2248 				goto _end_unlock;
2249 			}
2250 			if (nonblock) {
2251 				err = -EAGAIN;
2252 				goto _end_unlock;
2253 			}
2254 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2255 					runtime->control->avail_min ? : 1);
2256 			err = wait_for_avail(substream, &avail);
2257 			if (err < 0)
2258 				goto _end_unlock;
2259 			if (!avail)
2260 				continue; /* draining */
2261 		}
2262 		frames = size > avail ? avail : size;
2263 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2264 		if (frames > cont)
2265 			frames = cont;
2266 		if (snd_BUG_ON(!frames)) {
2267 			runtime->twake = 0;
2268 			snd_pcm_stream_unlock_irq(substream);
2269 			return -EINVAL;
2270 		}
2271 		appl_ptr = runtime->control->appl_ptr;
2272 		appl_ofs = appl_ptr % runtime->buffer_size;
2273 		snd_pcm_stream_unlock_irq(substream);
2274 		err = transfer(substream, appl_ofs, data, offset, frames);
2275 		snd_pcm_stream_lock_irq(substream);
2276 		if (err < 0)
2277 			goto _end_unlock;
2278 		switch (runtime->status->state) {
2279 		case SNDRV_PCM_STATE_XRUN:
2280 			err = -EPIPE;
2281 			goto _end_unlock;
2282 		case SNDRV_PCM_STATE_SUSPENDED:
2283 			err = -ESTRPIPE;
2284 			goto _end_unlock;
2285 		default:
2286 			break;
2287 		}
2288 		appl_ptr += frames;
2289 		if (appl_ptr >= runtime->boundary)
2290 			appl_ptr -= runtime->boundary;
2291 		runtime->control->appl_ptr = appl_ptr;
2292 		if (substream->ops->ack)
2293 			substream->ops->ack(substream);
2294 
2295 		offset += frames;
2296 		size -= frames;
2297 		xfer += frames;
2298 		avail -= frames;
2299 	}
2300  _end_unlock:
2301 	runtime->twake = 0;
2302 	if (xfer > 0 && err >= 0)
2303 		snd_pcm_update_state(substream, runtime);
2304 	snd_pcm_stream_unlock_irq(substream);
2305 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2306 }
2307 
2308 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2309 {
2310 	struct snd_pcm_runtime *runtime;
2311 	int nonblock;
2312 	int err;
2313 
2314 	err = pcm_sanity_check(substream);
2315 	if (err < 0)
2316 		return err;
2317 	runtime = substream->runtime;
2318 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2319 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2320 		return -EINVAL;
2321 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2322 }
2323 
2324 EXPORT_SYMBOL(snd_pcm_lib_read);
2325 
2326 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2327 				      unsigned int hwoff,
2328 				      unsigned long data, unsigned int off,
2329 				      snd_pcm_uframes_t frames)
2330 {
2331 	struct snd_pcm_runtime *runtime = substream->runtime;
2332 	int err;
2333 	void __user **bufs = (void __user **)data;
2334 	int channels = runtime->channels;
2335 	int c;
2336 	if (substream->ops->copy) {
2337 		for (c = 0; c < channels; ++c, ++bufs) {
2338 			char __user *buf;
2339 			if (*bufs == NULL)
2340 				continue;
2341 			buf = *bufs + samples_to_bytes(runtime, off);
2342 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2343 				return err;
2344 		}
2345 	} else {
2346 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2347 		for (c = 0; c < channels; ++c, ++bufs) {
2348 			char *hwbuf;
2349 			char __user *buf;
2350 			if (*bufs == NULL)
2351 				continue;
2352 
2353 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2354 			buf = *bufs + samples_to_bytes(runtime, off);
2355 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2356 				return -EFAULT;
2357 		}
2358 	}
2359 	return 0;
2360 }
2361 
2362 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2363 				    void __user **bufs,
2364 				    snd_pcm_uframes_t frames)
2365 {
2366 	struct snd_pcm_runtime *runtime;
2367 	int nonblock;
2368 	int err;
2369 
2370 	err = pcm_sanity_check(substream);
2371 	if (err < 0)
2372 		return err;
2373 	runtime = substream->runtime;
2374 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2375 		return -EBADFD;
2376 
2377 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2378 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2379 		return -EINVAL;
2380 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2381 }
2382 
2383 EXPORT_SYMBOL(snd_pcm_lib_readv);
2384 
2385 /*
2386  * standard channel mapping helpers
2387  */
2388 
2389 /* default channel maps for multi-channel playbacks, up to 8 channels */
2390 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2391 	{ .channels = 1,
2392 	  .map = { SNDRV_CHMAP_MONO } },
2393 	{ .channels = 2,
2394 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2395 	{ .channels = 4,
2396 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2397 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2398 	{ .channels = 6,
2399 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2400 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2401 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2402 	{ .channels = 8,
2403 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2404 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2405 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2406 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2407 	{ }
2408 };
2409 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2410 
2411 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2412 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2413 	{ .channels = 1,
2414 	  .map = { SNDRV_CHMAP_MONO } },
2415 	{ .channels = 2,
2416 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2417 	{ .channels = 4,
2418 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2419 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2420 	{ .channels = 6,
2421 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2422 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2423 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2424 	{ .channels = 8,
2425 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2426 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2427 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2428 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2429 	{ }
2430 };
2431 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2432 
2433 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2434 {
2435 	if (ch > info->max_channels)
2436 		return false;
2437 	return !info->channel_mask || (info->channel_mask & (1U << ch));
2438 }
2439 
2440 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2441 			      struct snd_ctl_elem_info *uinfo)
2442 {
2443 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2444 
2445 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2446 	uinfo->count = 0;
2447 	uinfo->count = info->max_channels;
2448 	uinfo->value.integer.min = 0;
2449 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2450 	return 0;
2451 }
2452 
2453 /* get callback for channel map ctl element
2454  * stores the channel position firstly matching with the current channels
2455  */
2456 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2457 			     struct snd_ctl_elem_value *ucontrol)
2458 {
2459 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2460 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2461 	struct snd_pcm_substream *substream;
2462 	const struct snd_pcm_chmap_elem *map;
2463 
2464 	if (snd_BUG_ON(!info->chmap))
2465 		return -EINVAL;
2466 	substream = snd_pcm_chmap_substream(info, idx);
2467 	if (!substream)
2468 		return -ENODEV;
2469 	memset(ucontrol->value.integer.value, 0,
2470 	       sizeof(ucontrol->value.integer.value));
2471 	if (!substream->runtime)
2472 		return 0; /* no channels set */
2473 	for (map = info->chmap; map->channels; map++) {
2474 		int i;
2475 		if (map->channels == substream->runtime->channels &&
2476 		    valid_chmap_channels(info, map->channels)) {
2477 			for (i = 0; i < map->channels; i++)
2478 				ucontrol->value.integer.value[i] = map->map[i];
2479 			return 0;
2480 		}
2481 	}
2482 	return -EINVAL;
2483 }
2484 
2485 /* tlv callback for channel map ctl element
2486  * expands the pre-defined channel maps in a form of TLV
2487  */
2488 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2489 			     unsigned int size, unsigned int __user *tlv)
2490 {
2491 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2492 	const struct snd_pcm_chmap_elem *map;
2493 	unsigned int __user *dst;
2494 	int c, count = 0;
2495 
2496 	if (snd_BUG_ON(!info->chmap))
2497 		return -EINVAL;
2498 	if (size < 8)
2499 		return -ENOMEM;
2500 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2501 		return -EFAULT;
2502 	size -= 8;
2503 	dst = tlv + 2;
2504 	for (map = info->chmap; map->channels; map++) {
2505 		int chs_bytes = map->channels * 4;
2506 		if (!valid_chmap_channels(info, map->channels))
2507 			continue;
2508 		if (size < 8)
2509 			return -ENOMEM;
2510 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2511 		    put_user(chs_bytes, dst + 1))
2512 			return -EFAULT;
2513 		dst += 2;
2514 		size -= 8;
2515 		count += 8;
2516 		if (size < chs_bytes)
2517 			return -ENOMEM;
2518 		size -= chs_bytes;
2519 		count += chs_bytes;
2520 		for (c = 0; c < map->channels; c++) {
2521 			if (put_user(map->map[c], dst))
2522 				return -EFAULT;
2523 			dst++;
2524 		}
2525 	}
2526 	if (put_user(count, tlv + 1))
2527 		return -EFAULT;
2528 	return 0;
2529 }
2530 
2531 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2532 {
2533 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2534 	info->pcm->streams[info->stream].chmap_kctl = NULL;
2535 	kfree(info);
2536 }
2537 
2538 /**
2539  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2540  * @pcm: the assigned PCM instance
2541  * @stream: stream direction
2542  * @chmap: channel map elements (for query)
2543  * @max_channels: the max number of channels for the stream
2544  * @private_value: the value passed to each kcontrol's private_value field
2545  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2546  *
2547  * Create channel-mapping control elements assigned to the given PCM stream(s).
2548  * Return: Zero if successful, or a negative error value.
2549  */
2550 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2551 			   const struct snd_pcm_chmap_elem *chmap,
2552 			   int max_channels,
2553 			   unsigned long private_value,
2554 			   struct snd_pcm_chmap **info_ret)
2555 {
2556 	struct snd_pcm_chmap *info;
2557 	struct snd_kcontrol_new knew = {
2558 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
2559 		.access = SNDRV_CTL_ELEM_ACCESS_READ |
2560 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2561 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2562 		.info = pcm_chmap_ctl_info,
2563 		.get = pcm_chmap_ctl_get,
2564 		.tlv.c = pcm_chmap_ctl_tlv,
2565 	};
2566 	int err;
2567 
2568 	info = kzalloc(sizeof(*info), GFP_KERNEL);
2569 	if (!info)
2570 		return -ENOMEM;
2571 	info->pcm = pcm;
2572 	info->stream = stream;
2573 	info->chmap = chmap;
2574 	info->max_channels = max_channels;
2575 	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2576 		knew.name = "Playback Channel Map";
2577 	else
2578 		knew.name = "Capture Channel Map";
2579 	knew.device = pcm->device;
2580 	knew.count = pcm->streams[stream].substream_count;
2581 	knew.private_value = private_value;
2582 	info->kctl = snd_ctl_new1(&knew, info);
2583 	if (!info->kctl) {
2584 		kfree(info);
2585 		return -ENOMEM;
2586 	}
2587 	info->kctl->private_free = pcm_chmap_ctl_private_free;
2588 	err = snd_ctl_add(pcm->card, info->kctl);
2589 	if (err < 0)
2590 		return err;
2591 	pcm->streams[stream].chmap_kctl = info->kctl;
2592 	if (info_ret)
2593 		*info_ret = info;
2594 	return 0;
2595 }
2596 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2597