summaryrefslogtreecommitdiffstats
path: root/sound/soc/soc-pcm.c
blob: b5759397afa342a89fe494b51d2d97e2a0d3e346 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
/*
 * soc-pcm.c  --  ALSA SoC PCM
 *
 * Copyright 2005 Wolfson Microelectronics PLC.
 * Copyright 2005 Openedhand Ltd.
 * Copyright (C) 2010 Slimlogic Ltd.
 * Copyright (C) 2010 Texas Instruments Inc.
 *
 * Authors: Liam Girdwood <lrg@ti.com>
 *          Mark Brown <broonie@opensource.wolfsonmicro.com>       
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/initval.h>

static DEFINE_MUTEX(pcm_mutex);

static int soc_pcm_apply_symmetry(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	int ret;

	if (!codec_dai->driver->symmetric_rates &&
	    !cpu_dai->driver->symmetric_rates &&
	    !rtd->dai_link->symmetric_rates)
		return 0;

	/* This can happen if multiple streams are starting simultaneously -
	 * the second can need to get its constraints before the first has
	 * picked a rate.  Complain and allow the application to carry on.
	 */
	if (!rtd->rate) {
		dev_warn(&rtd->dev,
			 "Not enforcing symmetric_rates due to race\n");
		return 0;
	}

	dev_dbg(&rtd->dev, "Symmetry forces %dHz rate\n", rtd->rate);

	ret = snd_pcm_hw_constraint_minmax(substream->runtime,
					   SNDRV_PCM_HW_PARAM_RATE,
					   rtd->rate, rtd->rate);
	if (ret < 0) {
		dev_err(&rtd->dev,
			"Unable to apply rate symmetry constraint: %d\n", ret);
		return ret;
	}

	return 0;
}

/*
 * Called by ALSA when a PCM substream is opened, the runtime->hw record is
 * then initialized and any private data can be allocated. This also calls
 * startup for the cpu DAI, platform, machine and codec DAI.
 */
static int soc_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
	struct snd_soc_dai_driver *codec_dai_drv = codec_dai->driver;
	int ret = 0;

	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);

	/* startup the audio subsystem */
	if (cpu_dai->driver->ops->startup) {
		ret = cpu_dai->driver->ops->startup(substream, cpu_dai);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't open interface %s\n",
				cpu_dai->name);
			goto out;
		}
	}

	if (platform->driver->ops && platform->driver->ops->open) {
		ret = platform->driver->ops->open(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't open platform %s\n", platform->name);
			goto platform_err;
		}
	}

	if (codec_dai->driver->ops->startup) {
		ret = codec_dai->driver->ops->startup(substream, codec_dai);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't open codec %s\n",
				codec_dai->name);
			goto codec_dai_err;
		}
	}

	if (rtd->dai_link->ops && rtd->dai_link->ops->startup) {
		ret = rtd->dai_link->ops->startup(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: %s startup failed\n", rtd->dai_link->name);
			goto machine_err;
		}
	}

	/* Check that the codec and cpu DAIs are compatible */
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		runtime->hw.rate_min =
			max(codec_dai_drv->playback.rate_min,
			    cpu_dai_drv->playback.rate_min);
		runtime->hw.rate_max =
			min(codec_dai_drv->playback.rate_max,
			    cpu_dai_drv->playback.rate_max);
		runtime->hw.channels_min =
			max(codec_dai_drv->playback.channels_min,
				cpu_dai_drv->playback.channels_min);
		runtime->hw.channels_max =
			min(codec_dai_drv->playback.channels_max,
				cpu_dai_drv->playback.channels_max);
		runtime->hw.formats =
			codec_dai_drv->playback.formats & cpu_dai_drv->playback.formats;
		runtime->hw.rates =
			codec_dai_drv->playback.rates & cpu_dai_drv->playback.rates;
		if (codec_dai_drv->playback.rates
			   & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
			runtime->hw.rates |= cpu_dai_drv->playback.rates;
		if (cpu_dai_drv->playback.rates
			   & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
			runtime->hw.rates |= codec_dai_drv->playback.rates;
	} else {
		runtime->hw.rate_min =
			max(codec_dai_drv->capture.rate_min,
			    cpu_dai_drv->capture.rate_min);
		runtime->hw.rate_max =
			min(codec_dai_drv->capture.rate_max,
			    cpu_dai_drv->capture.rate_max);
		runtime->hw.channels_min =
			max(codec_dai_drv->capture.channels_min,
				cpu_dai_drv->capture.channels_min);
		runtime->hw.channels_max =
			min(codec_dai_drv->capture.channels_max,
				cpu_dai_drv->capture.channels_max);
		runtime->hw.formats =
			codec_dai_drv->capture.formats & cpu_dai_drv->capture.formats;
		runtime->hw.rates =
			codec_dai_drv->capture.rates & cpu_dai_drv->capture.rates;
		if (codec_dai_drv->capture.rates
			   & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
			runtime->hw.rates |= cpu_dai_drv->capture.rates;
		if (cpu_dai_drv->capture.rates
			   & (SNDRV_PCM_RATE_KNOT | SNDRV_PCM_RATE_CONTINUOUS))
			runtime->hw.rates |= codec_dai_drv->capture.rates;
	}

	ret = -EINVAL;
	snd_pcm_limit_hw_rates(runtime);
	if (!runtime->hw.rates) {
		printk(KERN_ERR "asoc: %s <-> %s No matching rates\n",
			codec_dai->name, cpu_dai->name);
		goto config_err;
	}
	if (!runtime->hw.formats) {
		printk(KERN_ERR "asoc: %s <-> %s No matching formats\n",
			codec_dai->name, cpu_dai->name);
		goto config_err;
	}
	if (!runtime->hw.channels_min || !runtime->hw.channels_max ||
	    runtime->hw.channels_min > runtime->hw.channels_max) {
		printk(KERN_ERR "asoc: %s <-> %s No matching channels\n",
				codec_dai->name, cpu_dai->name);
		goto config_err;
	}

	/* Symmetry only applies if we've already got an active stream. */
	if (cpu_dai->active || codec_dai->active) {
		ret = soc_pcm_apply_symmetry(substream);
		if (ret != 0)
			goto config_err;
	}

	pr_debug("asoc: %s <-> %s info:\n",
			codec_dai->name, cpu_dai->name);
	pr_debug("asoc: rate mask 0x%x\n", runtime->hw.rates);
	pr_debug("asoc: min ch %d max ch %d\n", runtime->hw.channels_min,
		 runtime->hw.channels_max);
	pr_debug("asoc: min rate %d max rate %d\n", runtime->hw.rate_min,
		 runtime->hw.rate_max);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		cpu_dai->playback_active++;
		codec_dai->playback_active++;
	} else {
		cpu_dai->capture_active++;
		codec_dai->capture_active++;
	}
	cpu_dai->active++;
	codec_dai->active++;
	rtd->codec->active++;
	mutex_unlock(&rtd->pcm_mutex);
	return 0;

config_err:
	if (rtd->dai_link->ops && rtd->dai_link->ops->shutdown)
		rtd->dai_link->ops->shutdown(substream);

machine_err:
	if (codec_dai->driver->ops->shutdown)
		codec_dai->driver->ops->shutdown(substream, codec_dai);

codec_dai_err:
	if (platform->driver->ops && platform->driver->ops->close)
		platform->driver->ops->close(substream);

platform_err:
	if (cpu_dai->driver->ops->shutdown)
		cpu_dai->driver->ops->shutdown(substream, cpu_dai);
out:
	mutex_unlock(&rtd->pcm_mutex);
	return ret;
}

/*
 * Power down the audio subsystem pmdown_time msecs after close is called.
 * This is to ensure there are no pops or clicks in between any music tracks
 * due to DAPM power cycling.
 */
static void close_delayed_work(struct work_struct *work)
{
	struct snd_soc_pcm_runtime *rtd =
			container_of(work, struct snd_soc_pcm_runtime, delayed_work.work);
	struct snd_soc_dai *codec_dai = rtd->codec_dai;

	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);

	pr_debug("pop wq checking: %s status: %s waiting: %s\n",
		 codec_dai->driver->playback.stream_name,
		 codec_dai->playback_active ? "active" : "inactive",
		 codec_dai->pop_wait ? "yes" : "no");

	/* are we waiting on this codec DAI stream */
	if (codec_dai->pop_wait == 1) {
		codec_dai->pop_wait = 0;
		snd_soc_dapm_stream_event(rtd,
			codec_dai->driver->playback.stream_name,
			SND_SOC_DAPM_STREAM_STOP);
	}

	mutex_unlock(&rtd->pcm_mutex);
}

/*
 * Called by ALSA when a PCM substream is closed. Private data can be
 * freed here. The cpu DAI, codec DAI, machine and platform are also
 * shutdown.
 */
static int soc_pcm_close(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	struct snd_soc_codec *codec = rtd->codec;

	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		cpu_dai->playback_active--;
		codec_dai->playback_active--;
	} else {
		cpu_dai->capture_active--;
		codec_dai->capture_active--;
	}

	cpu_dai->active--;
	codec_dai->active--;
	codec->active--;

	/* Muting the DAC suppresses artifacts caused during digital
	 * shutdown, for example from stopping clocks.
	 */
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		snd_soc_dai_digital_mute(codec_dai, 1);

	if (cpu_dai->driver->ops->shutdown)
		cpu_dai->driver->ops->shutdown(substream, cpu_dai);

	if (codec_dai->driver->ops->shutdown)
		codec_dai->driver->ops->shutdown(substream, codec_dai);

	if (rtd->dai_link->ops && rtd->dai_link->ops->shutdown)
		rtd->dai_link->ops->shutdown(substream);

	if (platform->driver->ops && platform->driver->ops->close)
		platform->driver->ops->close(substream);
	cpu_dai->runtime = NULL;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		/* start delayed pop wq here for playback streams */
		codec_dai->pop_wait = 1;
		schedule_delayed_work(&rtd->delayed_work,
			msecs_to_jiffies(rtd->pmdown_time));
	} else {
		/* capture streams can be powered down now */
		snd_soc_dapm_stream_event(rtd,
			codec_dai->driver->capture.stream_name,
			SND_SOC_DAPM_STREAM_STOP);
	}

	mutex_unlock(&rtd->pcm_mutex);
	return 0;
}

/*
 * Called by ALSA when the PCM substream is prepared, can set format, sample
 * rate, etc.  This function is non atomic and can be called multiple times,
 * it can refer to the runtime info.
 */
static int soc_pcm_prepare(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	int ret = 0;

	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);

	if (rtd->dai_link->ops && rtd->dai_link->ops->prepare) {
		ret = rtd->dai_link->ops->prepare(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: machine prepare error\n");
			goto out;
		}
	}

	if (platform->driver->ops && platform->driver->ops->prepare) {
		ret = platform->driver->ops->prepare(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: platform prepare error\n");
			goto out;
		}
	}

	if (codec_dai->driver->ops->prepare) {
		ret = codec_dai->driver->ops->prepare(substream, codec_dai);
		if (ret < 0) {
			printk(KERN_ERR "asoc: codec DAI prepare error\n");
			goto out;
		}
	}

	if (cpu_dai->driver->ops->prepare) {
		ret = cpu_dai->driver->ops->prepare(substream, cpu_dai);
		if (ret < 0) {
			printk(KERN_ERR "asoc: cpu DAI prepare error\n");
			goto out;
		}
	}

	/* cancel any delayed stream shutdown that is pending */
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
	    codec_dai->pop_wait) {
		codec_dai->pop_wait = 0;
		cancel_delayed_work(&rtd->delayed_work);
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		snd_soc_dapm_stream_event(rtd,
					  codec_dai->driver->playback.stream_name,
					  SND_SOC_DAPM_STREAM_START);
	else
		snd_soc_dapm_stream_event(rtd,
					  codec_dai->driver->capture.stream_name,
					  SND_SOC_DAPM_STREAM_START);

	snd_soc_dai_digital_mute(codec_dai, 0);

out:
	mutex_unlock(&rtd->pcm_mutex);
	return ret;
}

/*
 * Called by ALSA when the hardware params are set by application. This
 * function can also be called multiple times and can allocate buffers
 * (using snd_pcm_lib_* ). It's non-atomic.
 */
static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	int ret = 0;

	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);

	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_params) {
		ret = rtd->dai_link->ops->hw_params(substream, params);
		if (ret < 0) {
			printk(KERN_ERR "asoc: machine hw_params failed\n");
			goto out;
		}
	}

	if (codec_dai->driver->ops->hw_params) {
		ret = codec_dai->driver->ops->hw_params(substream, params, codec_dai);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't set codec %s hw params\n",
				codec_dai->name);
			goto codec_err;
		}
	}

	if (cpu_dai->driver->ops->hw_params) {
		ret = cpu_dai->driver->ops->hw_params(substream, params, cpu_dai);
		if (ret < 0) {
			printk(KERN_ERR "asoc: interface %s hw params failed\n",
				cpu_dai->name);
			goto interface_err;
		}
	}

	if (platform->driver->ops && platform->driver->ops->hw_params) {
		ret = platform->driver->ops->hw_params(substream, params);
		if (ret < 0) {
			printk(KERN_ERR "asoc: platform %s hw params failed\n",
				platform->name);
			goto platform_err;
		}
	}

	rtd->rate = params_rate(params);

out:
	mutex_unlock(&rtd->pcm_mutex);
	return ret;

platform_err:
	if (cpu_dai->driver->ops->hw_free)
		cpu_dai->driver->ops->hw_free(substream, cpu_dai);

interface_err:
	if (codec_dai->driver->ops->hw_free)
		codec_dai->driver->ops->hw_free(substream, codec_dai);

codec_err:
	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_free)
		rtd->dai_link->ops->hw_free(substream);

	mutex_unlock(&rtd->pcm_mutex);
	return ret;
}

/*
 * Frees resources allocated by hw_params, can be called multiple times
 */
static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	struct snd_soc_codec *codec = rtd->codec;

	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);

	/* apply codec digital mute */
	if (!codec->active)
		snd_soc_dai_digital_mute(codec_dai, 1);

	/* free any machine hw params */
	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_free)
		rtd->dai_link->ops->hw_free(substream);

	/* free any DMA resources */
	if (platform->driver->ops && platform->driver->ops->hw_free)
		platform->driver->ops->hw_free(substream);

	/* now free hw params for the DAIs  */
	if (codec_dai->driver->ops->hw_free)
		codec_dai->driver->ops->hw_free(substream, codec_dai);

	if (cpu_dai->driver->ops->hw_free)
		cpu_dai->driver->ops->hw_free(substream, cpu_dai);

	mutex_unlock(&rtd->pcm_mutex);
	return 0;
}

static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	int ret;

	if (codec_dai->driver->ops->trigger) {
		ret = codec_dai->driver->ops->trigger(substream, cmd, codec_dai);
		if (ret < 0)
			return ret;
	}

	if (platform->driver->ops && platform->driver->ops->trigger) {
		ret = platform->driver->ops->trigger(substream, cmd);
		if (ret < 0)
			return ret;
	}

	if (cpu_dai->driver->ops->trigger) {
		ret = cpu_dai->driver->ops->trigger(substream, cmd, cpu_dai);
		if (ret < 0)
			return ret;
	}
	return 0;
}

/*
 * soc level wrapper for pointer callback
 * If cpu_dai, codec_dai, platform driver has the delay callback, than
 * the runtime->delay will be updated accordingly.
 */
static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t offset = 0;
	snd_pcm_sframes_t delay = 0;

	if (platform->driver->ops && platform->driver->ops->pointer)
		offset = platform->driver->ops->pointer(substream);

	if (cpu_dai->driver->ops->delay)
		delay += cpu_dai->driver->ops->delay(substream, cpu_dai);

	if (codec_dai->driver->ops->delay)
		delay += codec_dai->driver->ops->delay(substream, codec_dai);

	if (platform->driver->delay)
		delay += platform->driver->delay(substream, codec_dai);

	runtime->delay = delay;

	return offset;
}

/* ASoC PCM operations */
static struct snd_pcm_ops soc_pcm_ops = {
	.open		= soc_pcm_open,
	.close		= soc_pcm_close,
	.hw_params	= soc_pcm_hw_params,
	.hw_free	= soc_pcm_hw_free,
	.prepare	= soc_pcm_prepare,
	.trigger	= soc_pcm_trigger,
	.pointer	= soc_pcm_pointer,
};

/* create a new pcm */
int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
{
	struct snd_soc_codec *codec = rtd->codec;
	struct snd_soc_platform *platform = rtd->platform;
	struct snd_soc_dai *codec_dai = rtd->codec_dai;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct snd_pcm *pcm;
	char new_name[64];
	int ret = 0, playback = 0, capture = 0;

	/* check client and interface hw capabilities */
	snprintf(new_name, sizeof(new_name), "%s %s-%d",
			rtd->dai_link->stream_name, codec_dai->name, num);

	if (codec_dai->driver->playback.channels_min)
		playback = 1;
	if (codec_dai->driver->capture.channels_min)
		capture = 1;

	dev_dbg(rtd->card->dev, "registered pcm #%d %s\n",num,new_name);
	ret = snd_pcm_new(rtd->card->snd_card, new_name,
			num, playback, capture, &pcm);
	if (ret < 0) {
		printk(KERN_ERR "asoc: can't create pcm for codec %s\n", codec->name);
		return ret;
	}

	/* DAPM dai link stream work */
	INIT_DELAYED_WORK(&rtd->delayed_work, close_delayed_work);

	rtd->pcm = pcm;
	pcm->private_data = rtd;
	if (platform->driver->ops) {
		soc_pcm_ops.mmap = platform->driver->ops->mmap;
		soc_pcm_ops.pointer = platform->driver->ops->pointer;
		soc_pcm_ops.ioctl = platform->driver->ops->ioctl;
		soc_pcm_ops.copy = platform->driver->ops->copy;
		soc_pcm_ops.silence = platform->driver->ops->silence;
		soc_pcm_ops.ack = platform->driver->ops->ack;
		soc_pcm_ops.page = platform->driver->ops->page;
	}

	if (playback)
		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &soc_pcm_ops);

	if (capture)
		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &soc_pcm_ops);

	if (platform->driver->pcm_new) {
		ret = platform->driver->pcm_new(rtd);
		if (ret < 0) {
			pr_err("asoc: platform pcm constructor failed\n");
			return ret;
		}
	}

	pcm->private_free = platform->driver->pcm_free;
	printk(KERN_INFO "asoc: %s <-> %s mapping ok\n", codec_dai->name,
		cpu_dai->name);
	return ret;
}