xref: /linux/sound/core/pcm_lib.c (revision 905e46acd3272d04566fec49afbd7ad9e2ed9ae3)
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/sched/signal.h>
25 #include <linux/time.h>
26 #include <linux/math64.h>
27 #include <linux/export.h>
28 #include <sound/core.h>
29 #include <sound/control.h>
30 #include <sound/tlv.h>
31 #include <sound/info.h>
32 #include <sound/pcm.h>
33 #include <sound/pcm_params.h>
34 #include <sound/timer.h>
35 
36 #include "pcm_local.h"
37 
38 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
39 #define CREATE_TRACE_POINTS
40 #include "pcm_trace.h"
41 #else
42 #define trace_hwptr(substream, pos, in_interrupt)
43 #define trace_xrun(substream)
44 #define trace_hw_ptr_error(substream, reason)
45 #endif
46 
47 /*
48  * fill ring buffer with silence
49  * runtime->silence_start: starting pointer to silence area
50  * runtime->silence_filled: size filled with silence
51  * runtime->silence_threshold: threshold from application
52  * runtime->silence_size: maximal size from application
53  *
54  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
55  */
56 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
57 {
58 	struct snd_pcm_runtime *runtime = substream->runtime;
59 	snd_pcm_uframes_t frames, ofs, transfer;
60 
61 	if (runtime->silence_size < runtime->boundary) {
62 		snd_pcm_sframes_t noise_dist, n;
63 		if (runtime->silence_start != runtime->control->appl_ptr) {
64 			n = runtime->control->appl_ptr - runtime->silence_start;
65 			if (n < 0)
66 				n += runtime->boundary;
67 			if ((snd_pcm_uframes_t)n < runtime->silence_filled)
68 				runtime->silence_filled -= n;
69 			else
70 				runtime->silence_filled = 0;
71 			runtime->silence_start = runtime->control->appl_ptr;
72 		}
73 		if (runtime->silence_filled >= runtime->buffer_size)
74 			return;
75 		noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
76 		if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
77 			return;
78 		frames = runtime->silence_threshold - noise_dist;
79 		if (frames > runtime->silence_size)
80 			frames = runtime->silence_size;
81 	} else {
82 		if (new_hw_ptr == ULONG_MAX) {	/* initialization */
83 			snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
84 			if (avail > runtime->buffer_size)
85 				avail = runtime->buffer_size;
86 			runtime->silence_filled = avail > 0 ? avail : 0;
87 			runtime->silence_start = (runtime->status->hw_ptr +
88 						  runtime->silence_filled) %
89 						 runtime->boundary;
90 		} else {
91 			ofs = runtime->status->hw_ptr;
92 			frames = new_hw_ptr - ofs;
93 			if ((snd_pcm_sframes_t)frames < 0)
94 				frames += runtime->boundary;
95 			runtime->silence_filled -= frames;
96 			if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
97 				runtime->silence_filled = 0;
98 				runtime->silence_start = new_hw_ptr;
99 			} else {
100 				runtime->silence_start = ofs;
101 			}
102 		}
103 		frames = runtime->buffer_size - runtime->silence_filled;
104 	}
105 	if (snd_BUG_ON(frames > runtime->buffer_size))
106 		return;
107 	if (frames == 0)
108 		return;
109 	ofs = runtime->silence_start % runtime->buffer_size;
110 	while (frames > 0) {
111 		transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
112 		if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
113 		    runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED) {
114 			if (substream->ops->silence) {
115 				int err;
116 				err = substream->ops->silence(substream, -1, ofs, transfer);
117 				snd_BUG_ON(err < 0);
118 			} else {
119 				char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, ofs);
120 				snd_pcm_format_set_silence(runtime->format, hwbuf, transfer * runtime->channels);
121 			}
122 		} else {
123 			unsigned int c;
124 			unsigned int channels = runtime->channels;
125 			if (substream->ops->silence) {
126 				for (c = 0; c < channels; ++c) {
127 					int err;
128 					err = substream->ops->silence(substream, c, ofs, transfer);
129 					snd_BUG_ON(err < 0);
130 				}
131 			} else {
132 				size_t dma_csize = runtime->dma_bytes / channels;
133 				for (c = 0; c < channels; ++c) {
134 					char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, ofs);
135 					snd_pcm_format_set_silence(runtime->format, hwbuf, transfer);
136 				}
137 			}
138 		}
139 		runtime->silence_filled += transfer;
140 		frames -= transfer;
141 		ofs = 0;
142 	}
143 }
144 
145 #ifdef CONFIG_SND_DEBUG
146 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
147 			   char *name, size_t len)
148 {
149 	snprintf(name, len, "pcmC%dD%d%c:%d",
150 		 substream->pcm->card->number,
151 		 substream->pcm->device,
152 		 substream->stream ? 'c' : 'p',
153 		 substream->number);
154 }
155 EXPORT_SYMBOL(snd_pcm_debug_name);
156 #endif
157 
158 #define XRUN_DEBUG_BASIC	(1<<0)
159 #define XRUN_DEBUG_STACK	(1<<1)	/* dump also stack */
160 #define XRUN_DEBUG_JIFFIESCHECK	(1<<2)	/* do jiffies check */
161 
162 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
163 
164 #define xrun_debug(substream, mask) \
165 			((substream)->pstr->xrun_debug & (mask))
166 #else
167 #define xrun_debug(substream, mask)	0
168 #endif
169 
170 #define dump_stack_on_xrun(substream) do {			\
171 		if (xrun_debug(substream, XRUN_DEBUG_STACK))	\
172 			dump_stack();				\
173 	} while (0)
174 
175 static void xrun(struct snd_pcm_substream *substream)
176 {
177 	struct snd_pcm_runtime *runtime = substream->runtime;
178 
179 	trace_xrun(substream);
180 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
181 		snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
182 	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
183 	if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
184 		char name[16];
185 		snd_pcm_debug_name(substream, name, sizeof(name));
186 		pcm_warn(substream->pcm, "XRUN: %s\n", name);
187 		dump_stack_on_xrun(substream);
188 	}
189 }
190 
191 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
192 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)	\
193 	do {								\
194 		trace_hw_ptr_error(substream, reason);	\
195 		if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {		\
196 			pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
197 					   (in_interrupt) ? 'Q' : 'P', ##args);	\
198 			dump_stack_on_xrun(substream);			\
199 		}							\
200 	} while (0)
201 
202 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
203 
204 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
205 
206 #endif
207 
208 int snd_pcm_update_state(struct snd_pcm_substream *substream,
209 			 struct snd_pcm_runtime *runtime)
210 {
211 	snd_pcm_uframes_t avail;
212 
213 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
214 		avail = snd_pcm_playback_avail(runtime);
215 	else
216 		avail = snd_pcm_capture_avail(runtime);
217 	if (avail > runtime->avail_max)
218 		runtime->avail_max = avail;
219 	if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
220 		if (avail >= runtime->buffer_size) {
221 			snd_pcm_drain_done(substream);
222 			return -EPIPE;
223 		}
224 	} else {
225 		if (avail >= runtime->stop_threshold) {
226 			xrun(substream);
227 			return -EPIPE;
228 		}
229 	}
230 	if (runtime->twake) {
231 		if (avail >= runtime->twake)
232 			wake_up(&runtime->tsleep);
233 	} else if (avail >= runtime->control->avail_min)
234 		wake_up(&runtime->sleep);
235 	return 0;
236 }
237 
238 static void update_audio_tstamp(struct snd_pcm_substream *substream,
239 				struct timespec *curr_tstamp,
240 				struct timespec *audio_tstamp)
241 {
242 	struct snd_pcm_runtime *runtime = substream->runtime;
243 	u64 audio_frames, audio_nsecs;
244 	struct timespec driver_tstamp;
245 
246 	if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
247 		return;
248 
249 	if (!(substream->ops->get_time_info) ||
250 		(runtime->audio_tstamp_report.actual_type ==
251 			SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
252 
253 		/*
254 		 * provide audio timestamp derived from pointer position
255 		 * add delay only if requested
256 		 */
257 
258 		audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
259 
260 		if (runtime->audio_tstamp_config.report_delay) {
261 			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
262 				audio_frames -=  runtime->delay;
263 			else
264 				audio_frames +=  runtime->delay;
265 		}
266 		audio_nsecs = div_u64(audio_frames * 1000000000LL,
267 				runtime->rate);
268 		*audio_tstamp = ns_to_timespec(audio_nsecs);
269 	}
270 	runtime->status->audio_tstamp = *audio_tstamp;
271 	runtime->status->tstamp = *curr_tstamp;
272 
273 	/*
274 	 * re-take a driver timestamp to let apps detect if the reference tstamp
275 	 * read by low-level hardware was provided with a delay
276 	 */
277 	snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
278 	runtime->driver_tstamp = driver_tstamp;
279 }
280 
281 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
282 				  unsigned int in_interrupt)
283 {
284 	struct snd_pcm_runtime *runtime = substream->runtime;
285 	snd_pcm_uframes_t pos;
286 	snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
287 	snd_pcm_sframes_t hdelta, delta;
288 	unsigned long jdelta;
289 	unsigned long curr_jiffies;
290 	struct timespec curr_tstamp;
291 	struct timespec audio_tstamp;
292 	int crossed_boundary = 0;
293 
294 	old_hw_ptr = runtime->status->hw_ptr;
295 
296 	/*
297 	 * group pointer, time and jiffies reads to allow for more
298 	 * accurate correlations/corrections.
299 	 * The values are stored at the end of this routine after
300 	 * corrections for hw_ptr position
301 	 */
302 	pos = substream->ops->pointer(substream);
303 	curr_jiffies = jiffies;
304 	if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
305 		if ((substream->ops->get_time_info) &&
306 			(runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
307 			substream->ops->get_time_info(substream, &curr_tstamp,
308 						&audio_tstamp,
309 						&runtime->audio_tstamp_config,
310 						&runtime->audio_tstamp_report);
311 
312 			/* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
313 			if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
314 				snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
315 		} else
316 			snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
317 	}
318 
319 	if (pos == SNDRV_PCM_POS_XRUN) {
320 		xrun(substream);
321 		return -EPIPE;
322 	}
323 	if (pos >= runtime->buffer_size) {
324 		if (printk_ratelimit()) {
325 			char name[16];
326 			snd_pcm_debug_name(substream, name, sizeof(name));
327 			pcm_err(substream->pcm,
328 				"invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
329 				name, pos, runtime->buffer_size,
330 				runtime->period_size);
331 		}
332 		pos = 0;
333 	}
334 	pos -= pos % runtime->min_align;
335 	trace_hwptr(substream, pos, in_interrupt);
336 	hw_base = runtime->hw_ptr_base;
337 	new_hw_ptr = hw_base + pos;
338 	if (in_interrupt) {
339 		/* we know that one period was processed */
340 		/* delta = "expected next hw_ptr" for in_interrupt != 0 */
341 		delta = runtime->hw_ptr_interrupt + runtime->period_size;
342 		if (delta > new_hw_ptr) {
343 			/* check for double acknowledged interrupts */
344 			hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
345 			if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
346 				hw_base += runtime->buffer_size;
347 				if (hw_base >= runtime->boundary) {
348 					hw_base = 0;
349 					crossed_boundary++;
350 				}
351 				new_hw_ptr = hw_base + pos;
352 				goto __delta;
353 			}
354 		}
355 	}
356 	/* new_hw_ptr might be lower than old_hw_ptr in case when */
357 	/* pointer crosses the end of the ring buffer */
358 	if (new_hw_ptr < old_hw_ptr) {
359 		hw_base += runtime->buffer_size;
360 		if (hw_base >= runtime->boundary) {
361 			hw_base = 0;
362 			crossed_boundary++;
363 		}
364 		new_hw_ptr = hw_base + pos;
365 	}
366       __delta:
367 	delta = new_hw_ptr - old_hw_ptr;
368 	if (delta < 0)
369 		delta += runtime->boundary;
370 
371 	if (runtime->no_period_wakeup) {
372 		snd_pcm_sframes_t xrun_threshold;
373 		/*
374 		 * Without regular period interrupts, we have to check
375 		 * the elapsed time to detect xruns.
376 		 */
377 		jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
378 		if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
379 			goto no_delta_check;
380 		hdelta = jdelta - delta * HZ / runtime->rate;
381 		xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
382 		while (hdelta > xrun_threshold) {
383 			delta += runtime->buffer_size;
384 			hw_base += runtime->buffer_size;
385 			if (hw_base >= runtime->boundary) {
386 				hw_base = 0;
387 				crossed_boundary++;
388 			}
389 			new_hw_ptr = hw_base + pos;
390 			hdelta -= runtime->hw_ptr_buffer_jiffies;
391 		}
392 		goto no_delta_check;
393 	}
394 
395 	/* something must be really wrong */
396 	if (delta >= runtime->buffer_size + runtime->period_size) {
397 		hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
398 			     "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
399 			     substream->stream, (long)pos,
400 			     (long)new_hw_ptr, (long)old_hw_ptr);
401 		return 0;
402 	}
403 
404 	/* Do jiffies check only in xrun_debug mode */
405 	if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
406 		goto no_jiffies_check;
407 
408 	/* Skip the jiffies check for hardwares with BATCH flag.
409 	 * Such hardware usually just increases the position at each IRQ,
410 	 * thus it can't give any strange position.
411 	 */
412 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
413 		goto no_jiffies_check;
414 	hdelta = delta;
415 	if (hdelta < runtime->delay)
416 		goto no_jiffies_check;
417 	hdelta -= runtime->delay;
418 	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
419 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
420 		delta = jdelta /
421 			(((runtime->period_size * HZ) / runtime->rate)
422 								+ HZ/100);
423 		/* move new_hw_ptr according jiffies not pos variable */
424 		new_hw_ptr = old_hw_ptr;
425 		hw_base = delta;
426 		/* use loop to avoid checks for delta overflows */
427 		/* the delta value is small or zero in most cases */
428 		while (delta > 0) {
429 			new_hw_ptr += runtime->period_size;
430 			if (new_hw_ptr >= runtime->boundary) {
431 				new_hw_ptr -= runtime->boundary;
432 				crossed_boundary--;
433 			}
434 			delta--;
435 		}
436 		/* align hw_base to buffer_size */
437 		hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
438 			     "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
439 			     (long)pos, (long)hdelta,
440 			     (long)runtime->period_size, jdelta,
441 			     ((hdelta * HZ) / runtime->rate), hw_base,
442 			     (unsigned long)old_hw_ptr,
443 			     (unsigned long)new_hw_ptr);
444 		/* reset values to proper state */
445 		delta = 0;
446 		hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
447 	}
448  no_jiffies_check:
449 	if (delta > runtime->period_size + runtime->period_size / 2) {
450 		hw_ptr_error(substream, in_interrupt,
451 			     "Lost interrupts?",
452 			     "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
453 			     substream->stream, (long)delta,
454 			     (long)new_hw_ptr,
455 			     (long)old_hw_ptr);
456 	}
457 
458  no_delta_check:
459 	if (runtime->status->hw_ptr == new_hw_ptr) {
460 		update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
461 		return 0;
462 	}
463 
464 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
465 	    runtime->silence_size > 0)
466 		snd_pcm_playback_silence(substream, new_hw_ptr);
467 
468 	if (in_interrupt) {
469 		delta = new_hw_ptr - runtime->hw_ptr_interrupt;
470 		if (delta < 0)
471 			delta += runtime->boundary;
472 		delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
473 		runtime->hw_ptr_interrupt += delta;
474 		if (runtime->hw_ptr_interrupt >= runtime->boundary)
475 			runtime->hw_ptr_interrupt -= runtime->boundary;
476 	}
477 	runtime->hw_ptr_base = hw_base;
478 	runtime->status->hw_ptr = new_hw_ptr;
479 	runtime->hw_ptr_jiffies = curr_jiffies;
480 	if (crossed_boundary) {
481 		snd_BUG_ON(crossed_boundary != 1);
482 		runtime->hw_ptr_wrap += runtime->boundary;
483 	}
484 
485 	update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
486 
487 	return snd_pcm_update_state(substream, runtime);
488 }
489 
490 /* CAUTION: call it with irq disabled */
491 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
492 {
493 	return snd_pcm_update_hw_ptr0(substream, 0);
494 }
495 
496 /**
497  * snd_pcm_set_ops - set the PCM operators
498  * @pcm: the pcm instance
499  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
500  * @ops: the operator table
501  *
502  * Sets the given PCM operators to the pcm instance.
503  */
504 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
505 		     const struct snd_pcm_ops *ops)
506 {
507 	struct snd_pcm_str *stream = &pcm->streams[direction];
508 	struct snd_pcm_substream *substream;
509 
510 	for (substream = stream->substream; substream != NULL; substream = substream->next)
511 		substream->ops = ops;
512 }
513 
514 EXPORT_SYMBOL(snd_pcm_set_ops);
515 
516 /**
517  * snd_pcm_sync - set the PCM sync id
518  * @substream: the pcm substream
519  *
520  * Sets the PCM sync identifier for the card.
521  */
522 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
523 {
524 	struct snd_pcm_runtime *runtime = substream->runtime;
525 
526 	runtime->sync.id32[0] = substream->pcm->card->number;
527 	runtime->sync.id32[1] = -1;
528 	runtime->sync.id32[2] = -1;
529 	runtime->sync.id32[3] = -1;
530 }
531 
532 EXPORT_SYMBOL(snd_pcm_set_sync);
533 
534 /*
535  *  Standard ioctl routine
536  */
537 
538 static inline unsigned int div32(unsigned int a, unsigned int b,
539 				 unsigned int *r)
540 {
541 	if (b == 0) {
542 		*r = 0;
543 		return UINT_MAX;
544 	}
545 	*r = a % b;
546 	return a / b;
547 }
548 
549 static inline unsigned int div_down(unsigned int a, unsigned int b)
550 {
551 	if (b == 0)
552 		return UINT_MAX;
553 	return a / b;
554 }
555 
556 static inline unsigned int div_up(unsigned int a, unsigned int b)
557 {
558 	unsigned int r;
559 	unsigned int q;
560 	if (b == 0)
561 		return UINT_MAX;
562 	q = div32(a, b, &r);
563 	if (r)
564 		++q;
565 	return q;
566 }
567 
568 static inline unsigned int mul(unsigned int a, unsigned int b)
569 {
570 	if (a == 0)
571 		return 0;
572 	if (div_down(UINT_MAX, a) < b)
573 		return UINT_MAX;
574 	return a * b;
575 }
576 
577 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
578 				    unsigned int c, unsigned int *r)
579 {
580 	u_int64_t n = (u_int64_t) a * b;
581 	if (c == 0) {
582 		snd_BUG_ON(!n);
583 		*r = 0;
584 		return UINT_MAX;
585 	}
586 	n = div_u64_rem(n, c, r);
587 	if (n >= UINT_MAX) {
588 		*r = 0;
589 		return UINT_MAX;
590 	}
591 	return n;
592 }
593 
594 /**
595  * snd_interval_refine - refine the interval value of configurator
596  * @i: the interval value to refine
597  * @v: the interval value to refer to
598  *
599  * Refines the interval value with the reference value.
600  * The interval is changed to the range satisfying both intervals.
601  * The interval status (min, max, integer, etc.) are evaluated.
602  *
603  * Return: Positive if the value is changed, zero if it's not changed, or a
604  * negative error code.
605  */
606 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
607 {
608 	int changed = 0;
609 	if (snd_BUG_ON(snd_interval_empty(i)))
610 		return -EINVAL;
611 	if (i->min < v->min) {
612 		i->min = v->min;
613 		i->openmin = v->openmin;
614 		changed = 1;
615 	} else if (i->min == v->min && !i->openmin && v->openmin) {
616 		i->openmin = 1;
617 		changed = 1;
618 	}
619 	if (i->max > v->max) {
620 		i->max = v->max;
621 		i->openmax = v->openmax;
622 		changed = 1;
623 	} else if (i->max == v->max && !i->openmax && v->openmax) {
624 		i->openmax = 1;
625 		changed = 1;
626 	}
627 	if (!i->integer && v->integer) {
628 		i->integer = 1;
629 		changed = 1;
630 	}
631 	if (i->integer) {
632 		if (i->openmin) {
633 			i->min++;
634 			i->openmin = 0;
635 		}
636 		if (i->openmax) {
637 			i->max--;
638 			i->openmax = 0;
639 		}
640 	} else if (!i->openmin && !i->openmax && i->min == i->max)
641 		i->integer = 1;
642 	if (snd_interval_checkempty(i)) {
643 		snd_interval_none(i);
644 		return -EINVAL;
645 	}
646 	return changed;
647 }
648 
649 EXPORT_SYMBOL(snd_interval_refine);
650 
651 static int snd_interval_refine_first(struct snd_interval *i)
652 {
653 	if (snd_BUG_ON(snd_interval_empty(i)))
654 		return -EINVAL;
655 	if (snd_interval_single(i))
656 		return 0;
657 	i->max = i->min;
658 	i->openmax = i->openmin;
659 	if (i->openmax)
660 		i->max++;
661 	return 1;
662 }
663 
664 static int snd_interval_refine_last(struct snd_interval *i)
665 {
666 	if (snd_BUG_ON(snd_interval_empty(i)))
667 		return -EINVAL;
668 	if (snd_interval_single(i))
669 		return 0;
670 	i->min = i->max;
671 	i->openmin = i->openmax;
672 	if (i->openmin)
673 		i->min--;
674 	return 1;
675 }
676 
677 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
678 {
679 	if (a->empty || b->empty) {
680 		snd_interval_none(c);
681 		return;
682 	}
683 	c->empty = 0;
684 	c->min = mul(a->min, b->min);
685 	c->openmin = (a->openmin || b->openmin);
686 	c->max = mul(a->max,  b->max);
687 	c->openmax = (a->openmax || b->openmax);
688 	c->integer = (a->integer && b->integer);
689 }
690 
691 /**
692  * snd_interval_div - refine the interval value with division
693  * @a: dividend
694  * @b: divisor
695  * @c: quotient
696  *
697  * c = a / b
698  *
699  * Returns non-zero if the value is changed, zero if not changed.
700  */
701 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
702 {
703 	unsigned int r;
704 	if (a->empty || b->empty) {
705 		snd_interval_none(c);
706 		return;
707 	}
708 	c->empty = 0;
709 	c->min = div32(a->min, b->max, &r);
710 	c->openmin = (r || a->openmin || b->openmax);
711 	if (b->min > 0) {
712 		c->max = div32(a->max, b->min, &r);
713 		if (r) {
714 			c->max++;
715 			c->openmax = 1;
716 		} else
717 			c->openmax = (a->openmax || b->openmin);
718 	} else {
719 		c->max = UINT_MAX;
720 		c->openmax = 0;
721 	}
722 	c->integer = 0;
723 }
724 
725 /**
726  * snd_interval_muldivk - refine the interval value
727  * @a: dividend 1
728  * @b: dividend 2
729  * @k: divisor (as integer)
730  * @c: result
731   *
732  * c = a * b / k
733  *
734  * Returns non-zero if the value is changed, zero if not changed.
735  */
736 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
737 		      unsigned int k, struct snd_interval *c)
738 {
739 	unsigned int r;
740 	if (a->empty || b->empty) {
741 		snd_interval_none(c);
742 		return;
743 	}
744 	c->empty = 0;
745 	c->min = muldiv32(a->min, b->min, k, &r);
746 	c->openmin = (r || a->openmin || b->openmin);
747 	c->max = muldiv32(a->max, b->max, k, &r);
748 	if (r) {
749 		c->max++;
750 		c->openmax = 1;
751 	} else
752 		c->openmax = (a->openmax || b->openmax);
753 	c->integer = 0;
754 }
755 
756 /**
757  * snd_interval_mulkdiv - refine the interval value
758  * @a: dividend 1
759  * @k: dividend 2 (as integer)
760  * @b: divisor
761  * @c: result
762  *
763  * c = a * k / b
764  *
765  * Returns non-zero if the value is changed, zero if not changed.
766  */
767 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
768 		      const struct snd_interval *b, struct snd_interval *c)
769 {
770 	unsigned int r;
771 	if (a->empty || b->empty) {
772 		snd_interval_none(c);
773 		return;
774 	}
775 	c->empty = 0;
776 	c->min = muldiv32(a->min, k, b->max, &r);
777 	c->openmin = (r || a->openmin || b->openmax);
778 	if (b->min > 0) {
779 		c->max = muldiv32(a->max, k, b->min, &r);
780 		if (r) {
781 			c->max++;
782 			c->openmax = 1;
783 		} else
784 			c->openmax = (a->openmax || b->openmin);
785 	} else {
786 		c->max = UINT_MAX;
787 		c->openmax = 0;
788 	}
789 	c->integer = 0;
790 }
791 
792 /* ---- */
793 
794 
795 /**
796  * snd_interval_ratnum - refine the interval value
797  * @i: interval to refine
798  * @rats_count: number of ratnum_t
799  * @rats: ratnum_t array
800  * @nump: pointer to store the resultant numerator
801  * @denp: pointer to store the resultant denominator
802  *
803  * Return: Positive if the value is changed, zero if it's not changed, or a
804  * negative error code.
805  */
806 int snd_interval_ratnum(struct snd_interval *i,
807 			unsigned int rats_count, const struct snd_ratnum *rats,
808 			unsigned int *nump, unsigned int *denp)
809 {
810 	unsigned int best_num, best_den;
811 	int best_diff;
812 	unsigned int k;
813 	struct snd_interval t;
814 	int err;
815 	unsigned int result_num, result_den;
816 	int result_diff;
817 
818 	best_num = best_den = best_diff = 0;
819 	for (k = 0; k < rats_count; ++k) {
820 		unsigned int num = rats[k].num;
821 		unsigned int den;
822 		unsigned int q = i->min;
823 		int diff;
824 		if (q == 0)
825 			q = 1;
826 		den = div_up(num, q);
827 		if (den < rats[k].den_min)
828 			continue;
829 		if (den > rats[k].den_max)
830 			den = rats[k].den_max;
831 		else {
832 			unsigned int r;
833 			r = (den - rats[k].den_min) % rats[k].den_step;
834 			if (r != 0)
835 				den -= r;
836 		}
837 		diff = num - q * den;
838 		if (diff < 0)
839 			diff = -diff;
840 		if (best_num == 0 ||
841 		    diff * best_den < best_diff * den) {
842 			best_diff = diff;
843 			best_den = den;
844 			best_num = num;
845 		}
846 	}
847 	if (best_den == 0) {
848 		i->empty = 1;
849 		return -EINVAL;
850 	}
851 	t.min = div_down(best_num, best_den);
852 	t.openmin = !!(best_num % best_den);
853 
854 	result_num = best_num;
855 	result_diff = best_diff;
856 	result_den = best_den;
857 	best_num = best_den = best_diff = 0;
858 	for (k = 0; k < rats_count; ++k) {
859 		unsigned int num = rats[k].num;
860 		unsigned int den;
861 		unsigned int q = i->max;
862 		int diff;
863 		if (q == 0) {
864 			i->empty = 1;
865 			return -EINVAL;
866 		}
867 		den = div_down(num, q);
868 		if (den > rats[k].den_max)
869 			continue;
870 		if (den < rats[k].den_min)
871 			den = rats[k].den_min;
872 		else {
873 			unsigned int r;
874 			r = (den - rats[k].den_min) % rats[k].den_step;
875 			if (r != 0)
876 				den += rats[k].den_step - r;
877 		}
878 		diff = q * den - num;
879 		if (diff < 0)
880 			diff = -diff;
881 		if (best_num == 0 ||
882 		    diff * best_den < best_diff * den) {
883 			best_diff = diff;
884 			best_den = den;
885 			best_num = num;
886 		}
887 	}
888 	if (best_den == 0) {
889 		i->empty = 1;
890 		return -EINVAL;
891 	}
892 	t.max = div_up(best_num, best_den);
893 	t.openmax = !!(best_num % best_den);
894 	t.integer = 0;
895 	err = snd_interval_refine(i, &t);
896 	if (err < 0)
897 		return err;
898 
899 	if (snd_interval_single(i)) {
900 		if (best_diff * result_den < result_diff * best_den) {
901 			result_num = best_num;
902 			result_den = best_den;
903 		}
904 		if (nump)
905 			*nump = result_num;
906 		if (denp)
907 			*denp = result_den;
908 	}
909 	return err;
910 }
911 
912 EXPORT_SYMBOL(snd_interval_ratnum);
913 
914 /**
915  * snd_interval_ratden - refine the interval value
916  * @i: interval to refine
917  * @rats_count: number of struct ratden
918  * @rats: struct ratden array
919  * @nump: pointer to store the resultant numerator
920  * @denp: pointer to store the resultant denominator
921  *
922  * Return: Positive if the value is changed, zero if it's not changed, or a
923  * negative error code.
924  */
925 static int snd_interval_ratden(struct snd_interval *i,
926 			       unsigned int rats_count,
927 			       const struct snd_ratden *rats,
928 			       unsigned int *nump, unsigned int *denp)
929 {
930 	unsigned int best_num, best_diff, best_den;
931 	unsigned int k;
932 	struct snd_interval t;
933 	int err;
934 
935 	best_num = best_den = best_diff = 0;
936 	for (k = 0; k < rats_count; ++k) {
937 		unsigned int num;
938 		unsigned int den = rats[k].den;
939 		unsigned int q = i->min;
940 		int diff;
941 		num = mul(q, den);
942 		if (num > rats[k].num_max)
943 			continue;
944 		if (num < rats[k].num_min)
945 			num = rats[k].num_max;
946 		else {
947 			unsigned int r;
948 			r = (num - rats[k].num_min) % rats[k].num_step;
949 			if (r != 0)
950 				num += rats[k].num_step - r;
951 		}
952 		diff = num - q * den;
953 		if (best_num == 0 ||
954 		    diff * best_den < best_diff * den) {
955 			best_diff = diff;
956 			best_den = den;
957 			best_num = num;
958 		}
959 	}
960 	if (best_den == 0) {
961 		i->empty = 1;
962 		return -EINVAL;
963 	}
964 	t.min = div_down(best_num, best_den);
965 	t.openmin = !!(best_num % best_den);
966 
967 	best_num = best_den = best_diff = 0;
968 	for (k = 0; k < rats_count; ++k) {
969 		unsigned int num;
970 		unsigned int den = rats[k].den;
971 		unsigned int q = i->max;
972 		int diff;
973 		num = mul(q, den);
974 		if (num < rats[k].num_min)
975 			continue;
976 		if (num > rats[k].num_max)
977 			num = rats[k].num_max;
978 		else {
979 			unsigned int r;
980 			r = (num - rats[k].num_min) % rats[k].num_step;
981 			if (r != 0)
982 				num -= r;
983 		}
984 		diff = q * den - num;
985 		if (best_num == 0 ||
986 		    diff * best_den < best_diff * den) {
987 			best_diff = diff;
988 			best_den = den;
989 			best_num = num;
990 		}
991 	}
992 	if (best_den == 0) {
993 		i->empty = 1;
994 		return -EINVAL;
995 	}
996 	t.max = div_up(best_num, best_den);
997 	t.openmax = !!(best_num % best_den);
998 	t.integer = 0;
999 	err = snd_interval_refine(i, &t);
1000 	if (err < 0)
1001 		return err;
1002 
1003 	if (snd_interval_single(i)) {
1004 		if (nump)
1005 			*nump = best_num;
1006 		if (denp)
1007 			*denp = best_den;
1008 	}
1009 	return err;
1010 }
1011 
1012 /**
1013  * snd_interval_list - refine the interval value from the list
1014  * @i: the interval value to refine
1015  * @count: the number of elements in the list
1016  * @list: the value list
1017  * @mask: the bit-mask to evaluate
1018  *
1019  * Refines the interval value from the list.
1020  * When mask is non-zero, only the elements corresponding to bit 1 are
1021  * evaluated.
1022  *
1023  * Return: Positive if the value is changed, zero if it's not changed, or a
1024  * negative error code.
1025  */
1026 int snd_interval_list(struct snd_interval *i, unsigned int count,
1027 		      const unsigned int *list, unsigned int mask)
1028 {
1029         unsigned int k;
1030 	struct snd_interval list_range;
1031 
1032 	if (!count) {
1033 		i->empty = 1;
1034 		return -EINVAL;
1035 	}
1036 	snd_interval_any(&list_range);
1037 	list_range.min = UINT_MAX;
1038 	list_range.max = 0;
1039         for (k = 0; k < count; k++) {
1040 		if (mask && !(mask & (1 << k)))
1041 			continue;
1042 		if (!snd_interval_test(i, list[k]))
1043 			continue;
1044 		list_range.min = min(list_range.min, list[k]);
1045 		list_range.max = max(list_range.max, list[k]);
1046         }
1047 	return snd_interval_refine(i, &list_range);
1048 }
1049 
1050 EXPORT_SYMBOL(snd_interval_list);
1051 
1052 /**
1053  * snd_interval_ranges - refine the interval value from the list of ranges
1054  * @i: the interval value to refine
1055  * @count: the number of elements in the list of ranges
1056  * @ranges: the ranges list
1057  * @mask: the bit-mask to evaluate
1058  *
1059  * Refines the interval value from the list of ranges.
1060  * When mask is non-zero, only the elements corresponding to bit 1 are
1061  * evaluated.
1062  *
1063  * Return: Positive if the value is changed, zero if it's not changed, or a
1064  * negative error code.
1065  */
1066 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1067 			const struct snd_interval *ranges, unsigned int mask)
1068 {
1069 	unsigned int k;
1070 	struct snd_interval range_union;
1071 	struct snd_interval range;
1072 
1073 	if (!count) {
1074 		snd_interval_none(i);
1075 		return -EINVAL;
1076 	}
1077 	snd_interval_any(&range_union);
1078 	range_union.min = UINT_MAX;
1079 	range_union.max = 0;
1080 	for (k = 0; k < count; k++) {
1081 		if (mask && !(mask & (1 << k)))
1082 			continue;
1083 		snd_interval_copy(&range, &ranges[k]);
1084 		if (snd_interval_refine(&range, i) < 0)
1085 			continue;
1086 		if (snd_interval_empty(&range))
1087 			continue;
1088 
1089 		if (range.min < range_union.min) {
1090 			range_union.min = range.min;
1091 			range_union.openmin = 1;
1092 		}
1093 		if (range.min == range_union.min && !range.openmin)
1094 			range_union.openmin = 0;
1095 		if (range.max > range_union.max) {
1096 			range_union.max = range.max;
1097 			range_union.openmax = 1;
1098 		}
1099 		if (range.max == range_union.max && !range.openmax)
1100 			range_union.openmax = 0;
1101 	}
1102 	return snd_interval_refine(i, &range_union);
1103 }
1104 EXPORT_SYMBOL(snd_interval_ranges);
1105 
1106 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1107 {
1108 	unsigned int n;
1109 	int changed = 0;
1110 	n = i->min % step;
1111 	if (n != 0 || i->openmin) {
1112 		i->min += step - n;
1113 		i->openmin = 0;
1114 		changed = 1;
1115 	}
1116 	n = i->max % step;
1117 	if (n != 0 || i->openmax) {
1118 		i->max -= n;
1119 		i->openmax = 0;
1120 		changed = 1;
1121 	}
1122 	if (snd_interval_checkempty(i)) {
1123 		i->empty = 1;
1124 		return -EINVAL;
1125 	}
1126 	return changed;
1127 }
1128 
1129 /* Info constraints helpers */
1130 
1131 /**
1132  * snd_pcm_hw_rule_add - add the hw-constraint rule
1133  * @runtime: the pcm runtime instance
1134  * @cond: condition bits
1135  * @var: the variable to evaluate
1136  * @func: the evaluation function
1137  * @private: the private data pointer passed to function
1138  * @dep: the dependent variables
1139  *
1140  * Return: Zero if successful, or a negative error code on failure.
1141  */
1142 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1143 			int var,
1144 			snd_pcm_hw_rule_func_t func, void *private,
1145 			int dep, ...)
1146 {
1147 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1148 	struct snd_pcm_hw_rule *c;
1149 	unsigned int k;
1150 	va_list args;
1151 	va_start(args, dep);
1152 	if (constrs->rules_num >= constrs->rules_all) {
1153 		struct snd_pcm_hw_rule *new;
1154 		unsigned int new_rules = constrs->rules_all + 16;
1155 		new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1156 		if (!new) {
1157 			va_end(args);
1158 			return -ENOMEM;
1159 		}
1160 		if (constrs->rules) {
1161 			memcpy(new, constrs->rules,
1162 			       constrs->rules_num * sizeof(*c));
1163 			kfree(constrs->rules);
1164 		}
1165 		constrs->rules = new;
1166 		constrs->rules_all = new_rules;
1167 	}
1168 	c = &constrs->rules[constrs->rules_num];
1169 	c->cond = cond;
1170 	c->func = func;
1171 	c->var = var;
1172 	c->private = private;
1173 	k = 0;
1174 	while (1) {
1175 		if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1176 			va_end(args);
1177 			return -EINVAL;
1178 		}
1179 		c->deps[k++] = dep;
1180 		if (dep < 0)
1181 			break;
1182 		dep = va_arg(args, int);
1183 	}
1184 	constrs->rules_num++;
1185 	va_end(args);
1186 	return 0;
1187 }
1188 
1189 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1190 
1191 /**
1192  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1193  * @runtime: PCM runtime instance
1194  * @var: hw_params variable to apply the mask
1195  * @mask: the bitmap mask
1196  *
1197  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1198  *
1199  * Return: Zero if successful, or a negative error code on failure.
1200  */
1201 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1202 			       u_int32_t mask)
1203 {
1204 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1205 	struct snd_mask *maskp = constrs_mask(constrs, var);
1206 	*maskp->bits &= mask;
1207 	memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1208 	if (*maskp->bits == 0)
1209 		return -EINVAL;
1210 	return 0;
1211 }
1212 
1213 /**
1214  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1215  * @runtime: PCM runtime instance
1216  * @var: hw_params variable to apply the mask
1217  * @mask: the 64bit bitmap mask
1218  *
1219  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1220  *
1221  * Return: Zero if successful, or a negative error code on failure.
1222  */
1223 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1224 				 u_int64_t mask)
1225 {
1226 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1227 	struct snd_mask *maskp = constrs_mask(constrs, var);
1228 	maskp->bits[0] &= (u_int32_t)mask;
1229 	maskp->bits[1] &= (u_int32_t)(mask >> 32);
1230 	memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1231 	if (! maskp->bits[0] && ! maskp->bits[1])
1232 		return -EINVAL;
1233 	return 0;
1234 }
1235 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1236 
1237 /**
1238  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1239  * @runtime: PCM runtime instance
1240  * @var: hw_params variable to apply the integer constraint
1241  *
1242  * Apply the constraint of integer to an interval parameter.
1243  *
1244  * Return: Positive if the value is changed, zero if it's not changed, or a
1245  * negative error code.
1246  */
1247 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1248 {
1249 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1250 	return snd_interval_setinteger(constrs_interval(constrs, var));
1251 }
1252 
1253 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1254 
1255 /**
1256  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1257  * @runtime: PCM runtime instance
1258  * @var: hw_params variable to apply the range
1259  * @min: the minimal value
1260  * @max: the maximal value
1261  *
1262  * Apply the min/max range constraint to an interval parameter.
1263  *
1264  * Return: Positive if the value is changed, zero if it's not changed, or a
1265  * negative error code.
1266  */
1267 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1268 				 unsigned int min, unsigned int max)
1269 {
1270 	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1271 	struct snd_interval t;
1272 	t.min = min;
1273 	t.max = max;
1274 	t.openmin = t.openmax = 0;
1275 	t.integer = 0;
1276 	return snd_interval_refine(constrs_interval(constrs, var), &t);
1277 }
1278 
1279 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1280 
1281 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1282 				struct snd_pcm_hw_rule *rule)
1283 {
1284 	struct snd_pcm_hw_constraint_list *list = rule->private;
1285 	return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1286 }
1287 
1288 
1289 /**
1290  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1291  * @runtime: PCM runtime instance
1292  * @cond: condition bits
1293  * @var: hw_params variable to apply the list constraint
1294  * @l: list
1295  *
1296  * Apply the list of constraints to an interval parameter.
1297  *
1298  * Return: Zero if successful, or a negative error code on failure.
1299  */
1300 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1301 			       unsigned int cond,
1302 			       snd_pcm_hw_param_t var,
1303 			       const struct snd_pcm_hw_constraint_list *l)
1304 {
1305 	return snd_pcm_hw_rule_add(runtime, cond, var,
1306 				   snd_pcm_hw_rule_list, (void *)l,
1307 				   var, -1);
1308 }
1309 
1310 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1311 
1312 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1313 				  struct snd_pcm_hw_rule *rule)
1314 {
1315 	struct snd_pcm_hw_constraint_ranges *r = rule->private;
1316 	return snd_interval_ranges(hw_param_interval(params, rule->var),
1317 				   r->count, r->ranges, r->mask);
1318 }
1319 
1320 
1321 /**
1322  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1323  * @runtime: PCM runtime instance
1324  * @cond: condition bits
1325  * @var: hw_params variable to apply the list of range constraints
1326  * @r: ranges
1327  *
1328  * Apply the list of range constraints to an interval parameter.
1329  *
1330  * Return: Zero if successful, or a negative error code on failure.
1331  */
1332 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1333 				 unsigned int cond,
1334 				 snd_pcm_hw_param_t var,
1335 				 const struct snd_pcm_hw_constraint_ranges *r)
1336 {
1337 	return snd_pcm_hw_rule_add(runtime, cond, var,
1338 				   snd_pcm_hw_rule_ranges, (void *)r,
1339 				   var, -1);
1340 }
1341 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1342 
1343 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1344 				   struct snd_pcm_hw_rule *rule)
1345 {
1346 	const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1347 	unsigned int num = 0, den = 0;
1348 	int err;
1349 	err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1350 				  r->nrats, r->rats, &num, &den);
1351 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1352 		params->rate_num = num;
1353 		params->rate_den = den;
1354 	}
1355 	return err;
1356 }
1357 
1358 /**
1359  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1360  * @runtime: PCM runtime instance
1361  * @cond: condition bits
1362  * @var: hw_params variable to apply the ratnums constraint
1363  * @r: struct snd_ratnums constriants
1364  *
1365  * Return: Zero if successful, or a negative error code on failure.
1366  */
1367 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1368 				  unsigned int cond,
1369 				  snd_pcm_hw_param_t var,
1370 				  const struct snd_pcm_hw_constraint_ratnums *r)
1371 {
1372 	return snd_pcm_hw_rule_add(runtime, cond, var,
1373 				   snd_pcm_hw_rule_ratnums, (void *)r,
1374 				   var, -1);
1375 }
1376 
1377 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1378 
1379 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1380 				   struct snd_pcm_hw_rule *rule)
1381 {
1382 	const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1383 	unsigned int num = 0, den = 0;
1384 	int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1385 				  r->nrats, r->rats, &num, &den);
1386 	if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1387 		params->rate_num = num;
1388 		params->rate_den = den;
1389 	}
1390 	return err;
1391 }
1392 
1393 /**
1394  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1395  * @runtime: PCM runtime instance
1396  * @cond: condition bits
1397  * @var: hw_params variable to apply the ratdens constraint
1398  * @r: struct snd_ratdens constriants
1399  *
1400  * Return: Zero if successful, or a negative error code on failure.
1401  */
1402 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1403 				  unsigned int cond,
1404 				  snd_pcm_hw_param_t var,
1405 				  const struct snd_pcm_hw_constraint_ratdens *r)
1406 {
1407 	return snd_pcm_hw_rule_add(runtime, cond, var,
1408 				   snd_pcm_hw_rule_ratdens, (void *)r,
1409 				   var, -1);
1410 }
1411 
1412 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1413 
1414 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1415 				  struct snd_pcm_hw_rule *rule)
1416 {
1417 	unsigned int l = (unsigned long) rule->private;
1418 	int width = l & 0xffff;
1419 	unsigned int msbits = l >> 16;
1420 	const struct snd_interval *i =
1421 		hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1422 
1423 	if (!snd_interval_single(i))
1424 		return 0;
1425 
1426 	if ((snd_interval_value(i) == width) ||
1427 	    (width == 0 && snd_interval_value(i) > msbits))
1428 		params->msbits = min_not_zero(params->msbits, msbits);
1429 
1430 	return 0;
1431 }
1432 
1433 /**
1434  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1435  * @runtime: PCM runtime instance
1436  * @cond: condition bits
1437  * @width: sample bits width
1438  * @msbits: msbits width
1439  *
1440  * This constraint will set the number of most significant bits (msbits) if a
1441  * sample format with the specified width has been select. If width is set to 0
1442  * the msbits will be set for any sample format with a width larger than the
1443  * specified msbits.
1444  *
1445  * Return: Zero if successful, or a negative error code on failure.
1446  */
1447 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1448 				 unsigned int cond,
1449 				 unsigned int width,
1450 				 unsigned int msbits)
1451 {
1452 	unsigned long l = (msbits << 16) | width;
1453 	return snd_pcm_hw_rule_add(runtime, cond, -1,
1454 				    snd_pcm_hw_rule_msbits,
1455 				    (void*) l,
1456 				    SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1457 }
1458 
1459 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1460 
1461 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1462 				struct snd_pcm_hw_rule *rule)
1463 {
1464 	unsigned long step = (unsigned long) rule->private;
1465 	return snd_interval_step(hw_param_interval(params, rule->var), step);
1466 }
1467 
1468 /**
1469  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1470  * @runtime: PCM runtime instance
1471  * @cond: condition bits
1472  * @var: hw_params variable to apply the step constraint
1473  * @step: step size
1474  *
1475  * Return: Zero if successful, or a negative error code on failure.
1476  */
1477 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1478 			       unsigned int cond,
1479 			       snd_pcm_hw_param_t var,
1480 			       unsigned long step)
1481 {
1482 	return snd_pcm_hw_rule_add(runtime, cond, var,
1483 				   snd_pcm_hw_rule_step, (void *) step,
1484 				   var, -1);
1485 }
1486 
1487 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1488 
1489 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1490 {
1491 	static unsigned int pow2_sizes[] = {
1492 		1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1493 		1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1494 		1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1495 		1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1496 	};
1497 	return snd_interval_list(hw_param_interval(params, rule->var),
1498 				 ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1499 }
1500 
1501 /**
1502  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1503  * @runtime: PCM runtime instance
1504  * @cond: condition bits
1505  * @var: hw_params variable to apply the power-of-2 constraint
1506  *
1507  * Return: Zero if successful, or a negative error code on failure.
1508  */
1509 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1510 			       unsigned int cond,
1511 			       snd_pcm_hw_param_t var)
1512 {
1513 	return snd_pcm_hw_rule_add(runtime, cond, var,
1514 				   snd_pcm_hw_rule_pow2, NULL,
1515 				   var, -1);
1516 }
1517 
1518 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1519 
1520 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1521 					   struct snd_pcm_hw_rule *rule)
1522 {
1523 	unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1524 	struct snd_interval *rate;
1525 
1526 	rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1527 	return snd_interval_list(rate, 1, &base_rate, 0);
1528 }
1529 
1530 /**
1531  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1532  * @runtime: PCM runtime instance
1533  * @base_rate: the rate at which the hardware does not resample
1534  *
1535  * Return: Zero if successful, or a negative error code on failure.
1536  */
1537 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1538 			       unsigned int base_rate)
1539 {
1540 	return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1541 				   SNDRV_PCM_HW_PARAM_RATE,
1542 				   snd_pcm_hw_rule_noresample_func,
1543 				   (void *)(uintptr_t)base_rate,
1544 				   SNDRV_PCM_HW_PARAM_RATE, -1);
1545 }
1546 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1547 
1548 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1549 				  snd_pcm_hw_param_t var)
1550 {
1551 	if (hw_is_mask(var)) {
1552 		snd_mask_any(hw_param_mask(params, var));
1553 		params->cmask |= 1 << var;
1554 		params->rmask |= 1 << var;
1555 		return;
1556 	}
1557 	if (hw_is_interval(var)) {
1558 		snd_interval_any(hw_param_interval(params, var));
1559 		params->cmask |= 1 << var;
1560 		params->rmask |= 1 << var;
1561 		return;
1562 	}
1563 	snd_BUG();
1564 }
1565 
1566 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1567 {
1568 	unsigned int k;
1569 	memset(params, 0, sizeof(*params));
1570 	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1571 		_snd_pcm_hw_param_any(params, k);
1572 	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1573 		_snd_pcm_hw_param_any(params, k);
1574 	params->info = ~0U;
1575 }
1576 
1577 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1578 
1579 /**
1580  * snd_pcm_hw_param_value - return @params field @var value
1581  * @params: the hw_params instance
1582  * @var: parameter to retrieve
1583  * @dir: pointer to the direction (-1,0,1) or %NULL
1584  *
1585  * Return: The value for field @var if it's fixed in configuration space
1586  * defined by @params. -%EINVAL otherwise.
1587  */
1588 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1589 			   snd_pcm_hw_param_t var, int *dir)
1590 {
1591 	if (hw_is_mask(var)) {
1592 		const struct snd_mask *mask = hw_param_mask_c(params, var);
1593 		if (!snd_mask_single(mask))
1594 			return -EINVAL;
1595 		if (dir)
1596 			*dir = 0;
1597 		return snd_mask_value(mask);
1598 	}
1599 	if (hw_is_interval(var)) {
1600 		const struct snd_interval *i = hw_param_interval_c(params, var);
1601 		if (!snd_interval_single(i))
1602 			return -EINVAL;
1603 		if (dir)
1604 			*dir = i->openmin;
1605 		return snd_interval_value(i);
1606 	}
1607 	return -EINVAL;
1608 }
1609 
1610 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1611 
1612 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1613 				snd_pcm_hw_param_t var)
1614 {
1615 	if (hw_is_mask(var)) {
1616 		snd_mask_none(hw_param_mask(params, var));
1617 		params->cmask |= 1 << var;
1618 		params->rmask |= 1 << var;
1619 	} else if (hw_is_interval(var)) {
1620 		snd_interval_none(hw_param_interval(params, var));
1621 		params->cmask |= 1 << var;
1622 		params->rmask |= 1 << var;
1623 	} else {
1624 		snd_BUG();
1625 	}
1626 }
1627 
1628 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1629 
1630 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1631 				   snd_pcm_hw_param_t var)
1632 {
1633 	int changed;
1634 	if (hw_is_mask(var))
1635 		changed = snd_mask_refine_first(hw_param_mask(params, var));
1636 	else if (hw_is_interval(var))
1637 		changed = snd_interval_refine_first(hw_param_interval(params, var));
1638 	else
1639 		return -EINVAL;
1640 	if (changed) {
1641 		params->cmask |= 1 << var;
1642 		params->rmask |= 1 << var;
1643 	}
1644 	return changed;
1645 }
1646 
1647 
1648 /**
1649  * snd_pcm_hw_param_first - refine config space and return minimum value
1650  * @pcm: PCM instance
1651  * @params: the hw_params instance
1652  * @var: parameter to retrieve
1653  * @dir: pointer to the direction (-1,0,1) or %NULL
1654  *
1655  * Inside configuration space defined by @params remove from @var all
1656  * values > minimum. Reduce configuration space accordingly.
1657  *
1658  * Return: The minimum, or a negative error code on failure.
1659  */
1660 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1661 			   struct snd_pcm_hw_params *params,
1662 			   snd_pcm_hw_param_t var, int *dir)
1663 {
1664 	int changed = _snd_pcm_hw_param_first(params, var);
1665 	if (changed < 0)
1666 		return changed;
1667 	if (params->rmask) {
1668 		int err = snd_pcm_hw_refine(pcm, params);
1669 		if (snd_BUG_ON(err < 0))
1670 			return err;
1671 	}
1672 	return snd_pcm_hw_param_value(params, var, dir);
1673 }
1674 
1675 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1676 
1677 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1678 				  snd_pcm_hw_param_t var)
1679 {
1680 	int changed;
1681 	if (hw_is_mask(var))
1682 		changed = snd_mask_refine_last(hw_param_mask(params, var));
1683 	else if (hw_is_interval(var))
1684 		changed = snd_interval_refine_last(hw_param_interval(params, var));
1685 	else
1686 		return -EINVAL;
1687 	if (changed) {
1688 		params->cmask |= 1 << var;
1689 		params->rmask |= 1 << var;
1690 	}
1691 	return changed;
1692 }
1693 
1694 
1695 /**
1696  * snd_pcm_hw_param_last - refine config space and return maximum value
1697  * @pcm: PCM instance
1698  * @params: the hw_params instance
1699  * @var: parameter to retrieve
1700  * @dir: pointer to the direction (-1,0,1) or %NULL
1701  *
1702  * Inside configuration space defined by @params remove from @var all
1703  * values < maximum. Reduce configuration space accordingly.
1704  *
1705  * Return: The maximum, or a negative error code on failure.
1706  */
1707 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1708 			  struct snd_pcm_hw_params *params,
1709 			  snd_pcm_hw_param_t var, int *dir)
1710 {
1711 	int changed = _snd_pcm_hw_param_last(params, var);
1712 	if (changed < 0)
1713 		return changed;
1714 	if (params->rmask) {
1715 		int err = snd_pcm_hw_refine(pcm, params);
1716 		if (snd_BUG_ON(err < 0))
1717 			return err;
1718 	}
1719 	return snd_pcm_hw_param_value(params, var, dir);
1720 }
1721 
1722 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1723 
1724 /**
1725  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1726  * @pcm: PCM instance
1727  * @params: the hw_params instance
1728  *
1729  * Choose one configuration from configuration space defined by @params.
1730  * The configuration chosen is that obtained fixing in this order:
1731  * first access, first format, first subformat, min channels,
1732  * min rate, min period time, max buffer size, min tick time
1733  *
1734  * Return: Zero if successful, or a negative error code on failure.
1735  */
1736 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1737 			     struct snd_pcm_hw_params *params)
1738 {
1739 	static const int vars[] = {
1740 		SNDRV_PCM_HW_PARAM_ACCESS,
1741 		SNDRV_PCM_HW_PARAM_FORMAT,
1742 		SNDRV_PCM_HW_PARAM_SUBFORMAT,
1743 		SNDRV_PCM_HW_PARAM_CHANNELS,
1744 		SNDRV_PCM_HW_PARAM_RATE,
1745 		SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1746 		SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1747 		SNDRV_PCM_HW_PARAM_TICK_TIME,
1748 		-1
1749 	};
1750 	const int *v;
1751 	int err;
1752 
1753 	for (v = vars; *v != -1; v++) {
1754 		if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1755 			err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1756 		else
1757 			err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1758 		if (snd_BUG_ON(err < 0))
1759 			return err;
1760 	}
1761 	return 0;
1762 }
1763 
1764 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1765 				   void *arg)
1766 {
1767 	struct snd_pcm_runtime *runtime = substream->runtime;
1768 	unsigned long flags;
1769 	snd_pcm_stream_lock_irqsave(substream, flags);
1770 	if (snd_pcm_running(substream) &&
1771 	    snd_pcm_update_hw_ptr(substream) >= 0)
1772 		runtime->status->hw_ptr %= runtime->buffer_size;
1773 	else {
1774 		runtime->status->hw_ptr = 0;
1775 		runtime->hw_ptr_wrap = 0;
1776 	}
1777 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1778 	return 0;
1779 }
1780 
1781 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1782 					  void *arg)
1783 {
1784 	struct snd_pcm_channel_info *info = arg;
1785 	struct snd_pcm_runtime *runtime = substream->runtime;
1786 	int width;
1787 	if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1788 		info->offset = -1;
1789 		return 0;
1790 	}
1791 	width = snd_pcm_format_physical_width(runtime->format);
1792 	if (width < 0)
1793 		return width;
1794 	info->offset = 0;
1795 	switch (runtime->access) {
1796 	case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1797 	case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1798 		info->first = info->channel * width;
1799 		info->step = runtime->channels * width;
1800 		break;
1801 	case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1802 	case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1803 	{
1804 		size_t size = runtime->dma_bytes / runtime->channels;
1805 		info->first = info->channel * size * 8;
1806 		info->step = width;
1807 		break;
1808 	}
1809 	default:
1810 		snd_BUG();
1811 		break;
1812 	}
1813 	return 0;
1814 }
1815 
1816 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1817 				       void *arg)
1818 {
1819 	struct snd_pcm_hw_params *params = arg;
1820 	snd_pcm_format_t format;
1821 	int channels;
1822 	ssize_t frame_size;
1823 
1824 	params->fifo_size = substream->runtime->hw.fifo_size;
1825 	if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1826 		format = params_format(params);
1827 		channels = params_channels(params);
1828 		frame_size = snd_pcm_format_size(format, channels);
1829 		if (frame_size > 0)
1830 			params->fifo_size /= (unsigned)frame_size;
1831 	}
1832 	return 0;
1833 }
1834 
1835 /**
1836  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1837  * @substream: the pcm substream instance
1838  * @cmd: ioctl command
1839  * @arg: ioctl argument
1840  *
1841  * Processes the generic ioctl commands for PCM.
1842  * Can be passed as the ioctl callback for PCM ops.
1843  *
1844  * Return: Zero if successful, or a negative error code on failure.
1845  */
1846 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1847 		      unsigned int cmd, void *arg)
1848 {
1849 	switch (cmd) {
1850 	case SNDRV_PCM_IOCTL1_INFO:
1851 		return 0;
1852 	case SNDRV_PCM_IOCTL1_RESET:
1853 		return snd_pcm_lib_ioctl_reset(substream, arg);
1854 	case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1855 		return snd_pcm_lib_ioctl_channel_info(substream, arg);
1856 	case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1857 		return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1858 	}
1859 	return -ENXIO;
1860 }
1861 
1862 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1863 
1864 /**
1865  * snd_pcm_period_elapsed - update the pcm status for the next period
1866  * @substream: the pcm substream instance
1867  *
1868  * This function is called from the interrupt handler when the
1869  * PCM has processed the period size.  It will update the current
1870  * pointer, wake up sleepers, etc.
1871  *
1872  * Even if more than one periods have elapsed since the last call, you
1873  * have to call this only once.
1874  */
1875 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1876 {
1877 	struct snd_pcm_runtime *runtime;
1878 	unsigned long flags;
1879 
1880 	if (PCM_RUNTIME_CHECK(substream))
1881 		return;
1882 	runtime = substream->runtime;
1883 
1884 	snd_pcm_stream_lock_irqsave(substream, flags);
1885 	if (!snd_pcm_running(substream) ||
1886 	    snd_pcm_update_hw_ptr0(substream, 1) < 0)
1887 		goto _end;
1888 
1889 #ifdef CONFIG_SND_PCM_TIMER
1890 	if (substream->timer_running)
1891 		snd_timer_interrupt(substream->timer, 1);
1892 #endif
1893  _end:
1894 	kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1895 	snd_pcm_stream_unlock_irqrestore(substream, flags);
1896 }
1897 
1898 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1899 
1900 /*
1901  * Wait until avail_min data becomes available
1902  * Returns a negative error code if any error occurs during operation.
1903  * The available space is stored on availp.  When err = 0 and avail = 0
1904  * on the capture stream, it indicates the stream is in DRAINING state.
1905  */
1906 static int wait_for_avail(struct snd_pcm_substream *substream,
1907 			      snd_pcm_uframes_t *availp)
1908 {
1909 	struct snd_pcm_runtime *runtime = substream->runtime;
1910 	int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1911 	wait_queue_t wait;
1912 	int err = 0;
1913 	snd_pcm_uframes_t avail = 0;
1914 	long wait_time, tout;
1915 
1916 	init_waitqueue_entry(&wait, current);
1917 	set_current_state(TASK_INTERRUPTIBLE);
1918 	add_wait_queue(&runtime->tsleep, &wait);
1919 
1920 	if (runtime->no_period_wakeup)
1921 		wait_time = MAX_SCHEDULE_TIMEOUT;
1922 	else {
1923 		wait_time = 10;
1924 		if (runtime->rate) {
1925 			long t = runtime->period_size * 2 / runtime->rate;
1926 			wait_time = max(t, wait_time);
1927 		}
1928 		wait_time = msecs_to_jiffies(wait_time * 1000);
1929 	}
1930 
1931 	for (;;) {
1932 		if (signal_pending(current)) {
1933 			err = -ERESTARTSYS;
1934 			break;
1935 		}
1936 
1937 		/*
1938 		 * We need to check if space became available already
1939 		 * (and thus the wakeup happened already) first to close
1940 		 * the race of space already having become available.
1941 		 * This check must happen after been added to the waitqueue
1942 		 * and having current state be INTERRUPTIBLE.
1943 		 */
1944 		if (is_playback)
1945 			avail = snd_pcm_playback_avail(runtime);
1946 		else
1947 			avail = snd_pcm_capture_avail(runtime);
1948 		if (avail >= runtime->twake)
1949 			break;
1950 		snd_pcm_stream_unlock_irq(substream);
1951 
1952 		tout = schedule_timeout(wait_time);
1953 
1954 		snd_pcm_stream_lock_irq(substream);
1955 		set_current_state(TASK_INTERRUPTIBLE);
1956 		switch (runtime->status->state) {
1957 		case SNDRV_PCM_STATE_SUSPENDED:
1958 			err = -ESTRPIPE;
1959 			goto _endloop;
1960 		case SNDRV_PCM_STATE_XRUN:
1961 			err = -EPIPE;
1962 			goto _endloop;
1963 		case SNDRV_PCM_STATE_DRAINING:
1964 			if (is_playback)
1965 				err = -EPIPE;
1966 			else
1967 				avail = 0; /* indicate draining */
1968 			goto _endloop;
1969 		case SNDRV_PCM_STATE_OPEN:
1970 		case SNDRV_PCM_STATE_SETUP:
1971 		case SNDRV_PCM_STATE_DISCONNECTED:
1972 			err = -EBADFD;
1973 			goto _endloop;
1974 		case SNDRV_PCM_STATE_PAUSED:
1975 			continue;
1976 		}
1977 		if (!tout) {
1978 			pcm_dbg(substream->pcm,
1979 				"%s write error (DMA or IRQ trouble?)\n",
1980 				is_playback ? "playback" : "capture");
1981 			err = -EIO;
1982 			break;
1983 		}
1984 	}
1985  _endloop:
1986 	set_current_state(TASK_RUNNING);
1987 	remove_wait_queue(&runtime->tsleep, &wait);
1988 	*availp = avail;
1989 	return err;
1990 }
1991 
1992 static int snd_pcm_lib_write_transfer(struct snd_pcm_substream *substream,
1993 				      unsigned int hwoff,
1994 				      unsigned long data, unsigned int off,
1995 				      snd_pcm_uframes_t frames)
1996 {
1997 	struct snd_pcm_runtime *runtime = substream->runtime;
1998 	int err;
1999 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2000 	if (substream->ops->copy) {
2001 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2002 			return err;
2003 	} else {
2004 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2005 		if (copy_from_user(hwbuf, buf, frames_to_bytes(runtime, frames)))
2006 			return -EFAULT;
2007 	}
2008 	return 0;
2009 }
2010 
2011 typedef int (*transfer_f)(struct snd_pcm_substream *substream, unsigned int hwoff,
2012 			  unsigned long data, unsigned int off,
2013 			  snd_pcm_uframes_t size);
2014 
2015 static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream,
2016 					    unsigned long data,
2017 					    snd_pcm_uframes_t size,
2018 					    int nonblock,
2019 					    transfer_f transfer)
2020 {
2021 	struct snd_pcm_runtime *runtime = substream->runtime;
2022 	snd_pcm_uframes_t xfer = 0;
2023 	snd_pcm_uframes_t offset = 0;
2024 	snd_pcm_uframes_t avail;
2025 	int err = 0;
2026 
2027 	if (size == 0)
2028 		return 0;
2029 
2030 	snd_pcm_stream_lock_irq(substream);
2031 	switch (runtime->status->state) {
2032 	case SNDRV_PCM_STATE_PREPARED:
2033 	case SNDRV_PCM_STATE_RUNNING:
2034 	case SNDRV_PCM_STATE_PAUSED:
2035 		break;
2036 	case SNDRV_PCM_STATE_XRUN:
2037 		err = -EPIPE;
2038 		goto _end_unlock;
2039 	case SNDRV_PCM_STATE_SUSPENDED:
2040 		err = -ESTRPIPE;
2041 		goto _end_unlock;
2042 	default:
2043 		err = -EBADFD;
2044 		goto _end_unlock;
2045 	}
2046 
2047 	runtime->twake = runtime->control->avail_min ? : 1;
2048 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2049 		snd_pcm_update_hw_ptr(substream);
2050 	avail = snd_pcm_playback_avail(runtime);
2051 	while (size > 0) {
2052 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2053 		snd_pcm_uframes_t cont;
2054 		if (!avail) {
2055 			if (nonblock) {
2056 				err = -EAGAIN;
2057 				goto _end_unlock;
2058 			}
2059 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2060 					runtime->control->avail_min ? : 1);
2061 			err = wait_for_avail(substream, &avail);
2062 			if (err < 0)
2063 				goto _end_unlock;
2064 		}
2065 		frames = size > avail ? avail : size;
2066 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2067 		if (frames > cont)
2068 			frames = cont;
2069 		if (snd_BUG_ON(!frames)) {
2070 			runtime->twake = 0;
2071 			snd_pcm_stream_unlock_irq(substream);
2072 			return -EINVAL;
2073 		}
2074 		appl_ptr = runtime->control->appl_ptr;
2075 		appl_ofs = appl_ptr % runtime->buffer_size;
2076 		snd_pcm_stream_unlock_irq(substream);
2077 		err = transfer(substream, appl_ofs, data, offset, frames);
2078 		snd_pcm_stream_lock_irq(substream);
2079 		if (err < 0)
2080 			goto _end_unlock;
2081 		switch (runtime->status->state) {
2082 		case SNDRV_PCM_STATE_XRUN:
2083 			err = -EPIPE;
2084 			goto _end_unlock;
2085 		case SNDRV_PCM_STATE_SUSPENDED:
2086 			err = -ESTRPIPE;
2087 			goto _end_unlock;
2088 		default:
2089 			break;
2090 		}
2091 		appl_ptr += frames;
2092 		if (appl_ptr >= runtime->boundary)
2093 			appl_ptr -= runtime->boundary;
2094 		runtime->control->appl_ptr = appl_ptr;
2095 		if (substream->ops->ack)
2096 			substream->ops->ack(substream);
2097 
2098 		offset += frames;
2099 		size -= frames;
2100 		xfer += frames;
2101 		avail -= frames;
2102 		if (runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2103 		    snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2104 			err = snd_pcm_start(substream);
2105 			if (err < 0)
2106 				goto _end_unlock;
2107 		}
2108 	}
2109  _end_unlock:
2110 	runtime->twake = 0;
2111 	if (xfer > 0 && err >= 0)
2112 		snd_pcm_update_state(substream, runtime);
2113 	snd_pcm_stream_unlock_irq(substream);
2114 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2115 }
2116 
2117 /* sanity-check for read/write methods */
2118 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2119 {
2120 	struct snd_pcm_runtime *runtime;
2121 	if (PCM_RUNTIME_CHECK(substream))
2122 		return -ENXIO;
2123 	runtime = substream->runtime;
2124 	if (snd_BUG_ON(!substream->ops->copy && !runtime->dma_area))
2125 		return -EINVAL;
2126 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2127 		return -EBADFD;
2128 	return 0;
2129 }
2130 
2131 snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream, const void __user *buf, snd_pcm_uframes_t size)
2132 {
2133 	struct snd_pcm_runtime *runtime;
2134 	int nonblock;
2135 	int err;
2136 
2137 	err = pcm_sanity_check(substream);
2138 	if (err < 0)
2139 		return err;
2140 	runtime = substream->runtime;
2141 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2142 
2143 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2144 	    runtime->channels > 1)
2145 		return -EINVAL;
2146 	return snd_pcm_lib_write1(substream, (unsigned long)buf, size, nonblock,
2147 				  snd_pcm_lib_write_transfer);
2148 }
2149 
2150 EXPORT_SYMBOL(snd_pcm_lib_write);
2151 
2152 static int snd_pcm_lib_writev_transfer(struct snd_pcm_substream *substream,
2153 				       unsigned int hwoff,
2154 				       unsigned long data, unsigned int off,
2155 				       snd_pcm_uframes_t frames)
2156 {
2157 	struct snd_pcm_runtime *runtime = substream->runtime;
2158 	int err;
2159 	void __user **bufs = (void __user **)data;
2160 	int channels = runtime->channels;
2161 	int c;
2162 	if (substream->ops->copy) {
2163 		if (snd_BUG_ON(!substream->ops->silence))
2164 			return -EINVAL;
2165 		for (c = 0; c < channels; ++c, ++bufs) {
2166 			if (*bufs == NULL) {
2167 				if ((err = substream->ops->silence(substream, c, hwoff, frames)) < 0)
2168 					return err;
2169 			} else {
2170 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2171 				if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2172 					return err;
2173 			}
2174 		}
2175 	} else {
2176 		/* default transfer behaviour */
2177 		size_t dma_csize = runtime->dma_bytes / channels;
2178 		for (c = 0; c < channels; ++c, ++bufs) {
2179 			char *hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2180 			if (*bufs == NULL) {
2181 				snd_pcm_format_set_silence(runtime->format, hwbuf, frames);
2182 			} else {
2183 				char __user *buf = *bufs + samples_to_bytes(runtime, off);
2184 				if (copy_from_user(hwbuf, buf, samples_to_bytes(runtime, frames)))
2185 					return -EFAULT;
2186 			}
2187 		}
2188 	}
2189 	return 0;
2190 }
2191 
2192 snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
2193 				     void __user **bufs,
2194 				     snd_pcm_uframes_t frames)
2195 {
2196 	struct snd_pcm_runtime *runtime;
2197 	int nonblock;
2198 	int err;
2199 
2200 	err = pcm_sanity_check(substream);
2201 	if (err < 0)
2202 		return err;
2203 	runtime = substream->runtime;
2204 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2205 
2206 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2207 		return -EINVAL;
2208 	return snd_pcm_lib_write1(substream, (unsigned long)bufs, frames,
2209 				  nonblock, snd_pcm_lib_writev_transfer);
2210 }
2211 
2212 EXPORT_SYMBOL(snd_pcm_lib_writev);
2213 
2214 static int snd_pcm_lib_read_transfer(struct snd_pcm_substream *substream,
2215 				     unsigned int hwoff,
2216 				     unsigned long data, unsigned int off,
2217 				     snd_pcm_uframes_t frames)
2218 {
2219 	struct snd_pcm_runtime *runtime = substream->runtime;
2220 	int err;
2221 	char __user *buf = (char __user *) data + frames_to_bytes(runtime, off);
2222 	if (substream->ops->copy) {
2223 		if ((err = substream->ops->copy(substream, -1, hwoff, buf, frames)) < 0)
2224 			return err;
2225 	} else {
2226 		char *hwbuf = runtime->dma_area + frames_to_bytes(runtime, hwoff);
2227 		if (copy_to_user(buf, hwbuf, frames_to_bytes(runtime, frames)))
2228 			return -EFAULT;
2229 	}
2230 	return 0;
2231 }
2232 
2233 static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream,
2234 					   unsigned long data,
2235 					   snd_pcm_uframes_t size,
2236 					   int nonblock,
2237 					   transfer_f transfer)
2238 {
2239 	struct snd_pcm_runtime *runtime = substream->runtime;
2240 	snd_pcm_uframes_t xfer = 0;
2241 	snd_pcm_uframes_t offset = 0;
2242 	snd_pcm_uframes_t avail;
2243 	int err = 0;
2244 
2245 	if (size == 0)
2246 		return 0;
2247 
2248 	snd_pcm_stream_lock_irq(substream);
2249 	switch (runtime->status->state) {
2250 	case SNDRV_PCM_STATE_PREPARED:
2251 		if (size >= runtime->start_threshold) {
2252 			err = snd_pcm_start(substream);
2253 			if (err < 0)
2254 				goto _end_unlock;
2255 		}
2256 		break;
2257 	case SNDRV_PCM_STATE_DRAINING:
2258 	case SNDRV_PCM_STATE_RUNNING:
2259 	case SNDRV_PCM_STATE_PAUSED:
2260 		break;
2261 	case SNDRV_PCM_STATE_XRUN:
2262 		err = -EPIPE;
2263 		goto _end_unlock;
2264 	case SNDRV_PCM_STATE_SUSPENDED:
2265 		err = -ESTRPIPE;
2266 		goto _end_unlock;
2267 	default:
2268 		err = -EBADFD;
2269 		goto _end_unlock;
2270 	}
2271 
2272 	runtime->twake = runtime->control->avail_min ? : 1;
2273 	if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2274 		snd_pcm_update_hw_ptr(substream);
2275 	avail = snd_pcm_capture_avail(runtime);
2276 	while (size > 0) {
2277 		snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2278 		snd_pcm_uframes_t cont;
2279 		if (!avail) {
2280 			if (runtime->status->state ==
2281 			    SNDRV_PCM_STATE_DRAINING) {
2282 				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2283 				goto _end_unlock;
2284 			}
2285 			if (nonblock) {
2286 				err = -EAGAIN;
2287 				goto _end_unlock;
2288 			}
2289 			runtime->twake = min_t(snd_pcm_uframes_t, size,
2290 					runtime->control->avail_min ? : 1);
2291 			err = wait_for_avail(substream, &avail);
2292 			if (err < 0)
2293 				goto _end_unlock;
2294 			if (!avail)
2295 				continue; /* draining */
2296 		}
2297 		frames = size > avail ? avail : size;
2298 		cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2299 		if (frames > cont)
2300 			frames = cont;
2301 		if (snd_BUG_ON(!frames)) {
2302 			runtime->twake = 0;
2303 			snd_pcm_stream_unlock_irq(substream);
2304 			return -EINVAL;
2305 		}
2306 		appl_ptr = runtime->control->appl_ptr;
2307 		appl_ofs = appl_ptr % runtime->buffer_size;
2308 		snd_pcm_stream_unlock_irq(substream);
2309 		err = transfer(substream, appl_ofs, data, offset, frames);
2310 		snd_pcm_stream_lock_irq(substream);
2311 		if (err < 0)
2312 			goto _end_unlock;
2313 		switch (runtime->status->state) {
2314 		case SNDRV_PCM_STATE_XRUN:
2315 			err = -EPIPE;
2316 			goto _end_unlock;
2317 		case SNDRV_PCM_STATE_SUSPENDED:
2318 			err = -ESTRPIPE;
2319 			goto _end_unlock;
2320 		default:
2321 			break;
2322 		}
2323 		appl_ptr += frames;
2324 		if (appl_ptr >= runtime->boundary)
2325 			appl_ptr -= runtime->boundary;
2326 		runtime->control->appl_ptr = appl_ptr;
2327 		if (substream->ops->ack)
2328 			substream->ops->ack(substream);
2329 
2330 		offset += frames;
2331 		size -= frames;
2332 		xfer += frames;
2333 		avail -= frames;
2334 	}
2335  _end_unlock:
2336 	runtime->twake = 0;
2337 	if (xfer > 0 && err >= 0)
2338 		snd_pcm_update_state(substream, runtime);
2339 	snd_pcm_stream_unlock_irq(substream);
2340 	return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2341 }
2342 
2343 snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream, void __user *buf, snd_pcm_uframes_t size)
2344 {
2345 	struct snd_pcm_runtime *runtime;
2346 	int nonblock;
2347 	int err;
2348 
2349 	err = pcm_sanity_check(substream);
2350 	if (err < 0)
2351 		return err;
2352 	runtime = substream->runtime;
2353 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2354 	if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED)
2355 		return -EINVAL;
2356 	return snd_pcm_lib_read1(substream, (unsigned long)buf, size, nonblock, snd_pcm_lib_read_transfer);
2357 }
2358 
2359 EXPORT_SYMBOL(snd_pcm_lib_read);
2360 
2361 static int snd_pcm_lib_readv_transfer(struct snd_pcm_substream *substream,
2362 				      unsigned int hwoff,
2363 				      unsigned long data, unsigned int off,
2364 				      snd_pcm_uframes_t frames)
2365 {
2366 	struct snd_pcm_runtime *runtime = substream->runtime;
2367 	int err;
2368 	void __user **bufs = (void __user **)data;
2369 	int channels = runtime->channels;
2370 	int c;
2371 	if (substream->ops->copy) {
2372 		for (c = 0; c < channels; ++c, ++bufs) {
2373 			char __user *buf;
2374 			if (*bufs == NULL)
2375 				continue;
2376 			buf = *bufs + samples_to_bytes(runtime, off);
2377 			if ((err = substream->ops->copy(substream, c, hwoff, buf, frames)) < 0)
2378 				return err;
2379 		}
2380 	} else {
2381 		snd_pcm_uframes_t dma_csize = runtime->dma_bytes / channels;
2382 		for (c = 0; c < channels; ++c, ++bufs) {
2383 			char *hwbuf;
2384 			char __user *buf;
2385 			if (*bufs == NULL)
2386 				continue;
2387 
2388 			hwbuf = runtime->dma_area + (c * dma_csize) + samples_to_bytes(runtime, hwoff);
2389 			buf = *bufs + samples_to_bytes(runtime, off);
2390 			if (copy_to_user(buf, hwbuf, samples_to_bytes(runtime, frames)))
2391 				return -EFAULT;
2392 		}
2393 	}
2394 	return 0;
2395 }
2396 
2397 snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
2398 				    void __user **bufs,
2399 				    snd_pcm_uframes_t frames)
2400 {
2401 	struct snd_pcm_runtime *runtime;
2402 	int nonblock;
2403 	int err;
2404 
2405 	err = pcm_sanity_check(substream);
2406 	if (err < 0)
2407 		return err;
2408 	runtime = substream->runtime;
2409 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2410 		return -EBADFD;
2411 
2412 	nonblock = !!(substream->f_flags & O_NONBLOCK);
2413 	if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2414 		return -EINVAL;
2415 	return snd_pcm_lib_read1(substream, (unsigned long)bufs, frames, nonblock, snd_pcm_lib_readv_transfer);
2416 }
2417 
2418 EXPORT_SYMBOL(snd_pcm_lib_readv);
2419 
2420 /*
2421  * standard channel mapping helpers
2422  */
2423 
2424 /* default channel maps for multi-channel playbacks, up to 8 channels */
2425 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2426 	{ .channels = 1,
2427 	  .map = { SNDRV_CHMAP_MONO } },
2428 	{ .channels = 2,
2429 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2430 	{ .channels = 4,
2431 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2432 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2433 	{ .channels = 6,
2434 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2435 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2436 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2437 	{ .channels = 8,
2438 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2439 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2440 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2441 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2442 	{ }
2443 };
2444 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2445 
2446 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2447 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2448 	{ .channels = 1,
2449 	  .map = { SNDRV_CHMAP_MONO } },
2450 	{ .channels = 2,
2451 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2452 	{ .channels = 4,
2453 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2454 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2455 	{ .channels = 6,
2456 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2457 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2458 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2459 	{ .channels = 8,
2460 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2461 		   SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2462 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2463 		   SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2464 	{ }
2465 };
2466 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2467 
2468 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2469 {
2470 	if (ch > info->max_channels)
2471 		return false;
2472 	return !info->channel_mask || (info->channel_mask & (1U << ch));
2473 }
2474 
2475 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2476 			      struct snd_ctl_elem_info *uinfo)
2477 {
2478 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2479 
2480 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2481 	uinfo->count = 0;
2482 	uinfo->count = info->max_channels;
2483 	uinfo->value.integer.min = 0;
2484 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2485 	return 0;
2486 }
2487 
2488 /* get callback for channel map ctl element
2489  * stores the channel position firstly matching with the current channels
2490  */
2491 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2492 			     struct snd_ctl_elem_value *ucontrol)
2493 {
2494 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2495 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2496 	struct snd_pcm_substream *substream;
2497 	const struct snd_pcm_chmap_elem *map;
2498 
2499 	if (snd_BUG_ON(!info->chmap))
2500 		return -EINVAL;
2501 	substream = snd_pcm_chmap_substream(info, idx);
2502 	if (!substream)
2503 		return -ENODEV;
2504 	memset(ucontrol->value.integer.value, 0,
2505 	       sizeof(ucontrol->value.integer.value));
2506 	if (!substream->runtime)
2507 		return 0; /* no channels set */
2508 	for (map = info->chmap; map->channels; map++) {
2509 		int i;
2510 		if (map->channels == substream->runtime->channels &&
2511 		    valid_chmap_channels(info, map->channels)) {
2512 			for (i = 0; i < map->channels; i++)
2513 				ucontrol->value.integer.value[i] = map->map[i];
2514 			return 0;
2515 		}
2516 	}
2517 	return -EINVAL;
2518 }
2519 
2520 /* tlv callback for channel map ctl element
2521  * expands the pre-defined channel maps in a form of TLV
2522  */
2523 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2524 			     unsigned int size, unsigned int __user *tlv)
2525 {
2526 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2527 	const struct snd_pcm_chmap_elem *map;
2528 	unsigned int __user *dst;
2529 	int c, count = 0;
2530 
2531 	if (snd_BUG_ON(!info->chmap))
2532 		return -EINVAL;
2533 	if (size < 8)
2534 		return -ENOMEM;
2535 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2536 		return -EFAULT;
2537 	size -= 8;
2538 	dst = tlv + 2;
2539 	for (map = info->chmap; map->channels; map++) {
2540 		int chs_bytes = map->channels * 4;
2541 		if (!valid_chmap_channels(info, map->channels))
2542 			continue;
2543 		if (size < 8)
2544 			return -ENOMEM;
2545 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2546 		    put_user(chs_bytes, dst + 1))
2547 			return -EFAULT;
2548 		dst += 2;
2549 		size -= 8;
2550 		count += 8;
2551 		if (size < chs_bytes)
2552 			return -ENOMEM;
2553 		size -= chs_bytes;
2554 		count += chs_bytes;
2555 		for (c = 0; c < map->channels; c++) {
2556 			if (put_user(map->map[c], dst))
2557 				return -EFAULT;
2558 			dst++;
2559 		}
2560 	}
2561 	if (put_user(count, tlv + 1))
2562 		return -EFAULT;
2563 	return 0;
2564 }
2565 
2566 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2567 {
2568 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2569 	info->pcm->streams[info->stream].chmap_kctl = NULL;
2570 	kfree(info);
2571 }
2572 
2573 /**
2574  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2575  * @pcm: the assigned PCM instance
2576  * @stream: stream direction
2577  * @chmap: channel map elements (for query)
2578  * @max_channels: the max number of channels for the stream
2579  * @private_value: the value passed to each kcontrol's private_value field
2580  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2581  *
2582  * Create channel-mapping control elements assigned to the given PCM stream(s).
2583  * Return: Zero if successful, or a negative error value.
2584  */
2585 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2586 			   const struct snd_pcm_chmap_elem *chmap,
2587 			   int max_channels,
2588 			   unsigned long private_value,
2589 			   struct snd_pcm_chmap **info_ret)
2590 {
2591 	struct snd_pcm_chmap *info;
2592 	struct snd_kcontrol_new knew = {
2593 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
2594 		.access = SNDRV_CTL_ELEM_ACCESS_READ |
2595 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2596 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2597 		.info = pcm_chmap_ctl_info,
2598 		.get = pcm_chmap_ctl_get,
2599 		.tlv.c = pcm_chmap_ctl_tlv,
2600 	};
2601 	int err;
2602 
2603 	if (WARN_ON(pcm->streams[stream].chmap_kctl))
2604 		return -EBUSY;
2605 	info = kzalloc(sizeof(*info), GFP_KERNEL);
2606 	if (!info)
2607 		return -ENOMEM;
2608 	info->pcm = pcm;
2609 	info->stream = stream;
2610 	info->chmap = chmap;
2611 	info->max_channels = max_channels;
2612 	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2613 		knew.name = "Playback Channel Map";
2614 	else
2615 		knew.name = "Capture Channel Map";
2616 	knew.device = pcm->device;
2617 	knew.count = pcm->streams[stream].substream_count;
2618 	knew.private_value = private_value;
2619 	info->kctl = snd_ctl_new1(&knew, info);
2620 	if (!info->kctl) {
2621 		kfree(info);
2622 		return -ENOMEM;
2623 	}
2624 	info->kctl->private_free = pcm_chmap_ctl_private_free;
2625 	err = snd_ctl_add(pcm->card, info->kctl);
2626 	if (err < 0)
2627 		return err;
2628 	pcm->streams[stream].chmap_kctl = info->kctl;
2629 	if (info_ret)
2630 		*info_ret = info;
2631 	return 0;
2632 }
2633 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);
2634