xref: /linux/sound/core/pcm.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
1 /*
2  *  Digital Audio (PCM) abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/time.h>
26 #include <linux/mutex.h>
27 #include <linux/device.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/pcm.h>
31 #include <sound/control.h>
32 #include <sound/info.h>
33 
34 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
35 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
36 MODULE_LICENSE("GPL");
37 
38 static LIST_HEAD(snd_pcm_devices);
39 static LIST_HEAD(snd_pcm_notify_list);
40 static DEFINE_MUTEX(register_mutex);
41 
42 static int snd_pcm_free(struct snd_pcm *pcm);
43 static int snd_pcm_dev_free(struct snd_device *device);
44 static int snd_pcm_dev_register(struct snd_device *device);
45 static int snd_pcm_dev_disconnect(struct snd_device *device);
46 
47 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
48 {
49 	struct snd_pcm *pcm;
50 
51 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
52 		if (pcm->card == card && pcm->device == device)
53 			return pcm;
54 	}
55 	return NULL;
56 }
57 
58 static int snd_pcm_next(struct snd_card *card, int device)
59 {
60 	struct snd_pcm *pcm;
61 
62 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
63 		if (pcm->card == card && pcm->device > device)
64 			return pcm->device;
65 		else if (pcm->card->number > card->number)
66 			return -1;
67 	}
68 	return -1;
69 }
70 
71 static int snd_pcm_add(struct snd_pcm *newpcm)
72 {
73 	struct snd_pcm *pcm;
74 
75 	if (newpcm->internal)
76 		return 0;
77 
78 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
79 		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
80 			return -EBUSY;
81 		if (pcm->card->number > newpcm->card->number ||
82 				(pcm->card == newpcm->card &&
83 				pcm->device > newpcm->device)) {
84 			list_add(&newpcm->list, pcm->list.prev);
85 			return 0;
86 		}
87 	}
88 	list_add_tail(&newpcm->list, &snd_pcm_devices);
89 	return 0;
90 }
91 
92 static int snd_pcm_control_ioctl(struct snd_card *card,
93 				 struct snd_ctl_file *control,
94 				 unsigned int cmd, unsigned long arg)
95 {
96 	switch (cmd) {
97 	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
98 		{
99 			int device;
100 
101 			if (get_user(device, (int __user *)arg))
102 				return -EFAULT;
103 			mutex_lock(&register_mutex);
104 			device = snd_pcm_next(card, device);
105 			mutex_unlock(&register_mutex);
106 			if (put_user(device, (int __user *)arg))
107 				return -EFAULT;
108 			return 0;
109 		}
110 	case SNDRV_CTL_IOCTL_PCM_INFO:
111 		{
112 			struct snd_pcm_info __user *info;
113 			unsigned int device, subdevice;
114 			int stream;
115 			struct snd_pcm *pcm;
116 			struct snd_pcm_str *pstr;
117 			struct snd_pcm_substream *substream;
118 			int err;
119 
120 			info = (struct snd_pcm_info __user *)arg;
121 			if (get_user(device, &info->device))
122 				return -EFAULT;
123 			if (get_user(stream, &info->stream))
124 				return -EFAULT;
125 			if (stream < 0 || stream > 1)
126 				return -EINVAL;
127 			if (get_user(subdevice, &info->subdevice))
128 				return -EFAULT;
129 			mutex_lock(&register_mutex);
130 			pcm = snd_pcm_get(card, device);
131 			if (pcm == NULL) {
132 				err = -ENXIO;
133 				goto _error;
134 			}
135 			pstr = &pcm->streams[stream];
136 			if (pstr->substream_count == 0) {
137 				err = -ENOENT;
138 				goto _error;
139 			}
140 			if (subdevice >= pstr->substream_count) {
141 				err = -ENXIO;
142 				goto _error;
143 			}
144 			for (substream = pstr->substream; substream;
145 			     substream = substream->next)
146 				if (substream->number == (int)subdevice)
147 					break;
148 			if (substream == NULL) {
149 				err = -ENXIO;
150 				goto _error;
151 			}
152 			err = snd_pcm_info_user(substream, info);
153 		_error:
154 			mutex_unlock(&register_mutex);
155 			return err;
156 		}
157 	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
158 		{
159 			int val;
160 
161 			if (get_user(val, (int __user *)arg))
162 				return -EFAULT;
163 			control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
164 			return 0;
165 		}
166 	}
167 	return -ENOIOCTLCMD;
168 }
169 
170 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
171 
172 static char *snd_pcm_format_names[] = {
173 	FORMAT(S8),
174 	FORMAT(U8),
175 	FORMAT(S16_LE),
176 	FORMAT(S16_BE),
177 	FORMAT(U16_LE),
178 	FORMAT(U16_BE),
179 	FORMAT(S24_LE),
180 	FORMAT(S24_BE),
181 	FORMAT(U24_LE),
182 	FORMAT(U24_BE),
183 	FORMAT(S32_LE),
184 	FORMAT(S32_BE),
185 	FORMAT(U32_LE),
186 	FORMAT(U32_BE),
187 	FORMAT(FLOAT_LE),
188 	FORMAT(FLOAT_BE),
189 	FORMAT(FLOAT64_LE),
190 	FORMAT(FLOAT64_BE),
191 	FORMAT(IEC958_SUBFRAME_LE),
192 	FORMAT(IEC958_SUBFRAME_BE),
193 	FORMAT(MU_LAW),
194 	FORMAT(A_LAW),
195 	FORMAT(IMA_ADPCM),
196 	FORMAT(MPEG),
197 	FORMAT(GSM),
198 	FORMAT(SPECIAL),
199 	FORMAT(S24_3LE),
200 	FORMAT(S24_3BE),
201 	FORMAT(U24_3LE),
202 	FORMAT(U24_3BE),
203 	FORMAT(S20_3LE),
204 	FORMAT(S20_3BE),
205 	FORMAT(U20_3LE),
206 	FORMAT(U20_3BE),
207 	FORMAT(S18_3LE),
208 	FORMAT(S18_3BE),
209 	FORMAT(U18_3LE),
210 	FORMAT(U18_3BE),
211 	FORMAT(G723_24),
212 	FORMAT(G723_24_1B),
213 	FORMAT(G723_40),
214 	FORMAT(G723_40_1B),
215 	FORMAT(DSD_U8),
216 	FORMAT(DSD_U16_LE),
217 	FORMAT(DSD_U32_LE),
218 	FORMAT(DSD_U16_BE),
219 	FORMAT(DSD_U32_BE),
220 };
221 
222 /**
223  * snd_pcm_format_name - Return a name string for the given PCM format
224  * @format: PCM format
225  */
226 const char *snd_pcm_format_name(snd_pcm_format_t format)
227 {
228 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
229 		return "Unknown";
230 	return snd_pcm_format_names[(__force unsigned int)format];
231 }
232 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
233 
234 #ifdef CONFIG_SND_VERBOSE_PROCFS
235 
236 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
237 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
238 #define READY(v) [SNDRV_PCM_READY_##v] = #v
239 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
240 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
241 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
242 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
243 #define START(v) [SNDRV_PCM_START_##v] = #v
244 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
245 
246 static char *snd_pcm_stream_names[] = {
247 	STREAM(PLAYBACK),
248 	STREAM(CAPTURE),
249 };
250 
251 static char *snd_pcm_state_names[] = {
252 	STATE(OPEN),
253 	STATE(SETUP),
254 	STATE(PREPARED),
255 	STATE(RUNNING),
256 	STATE(XRUN),
257 	STATE(DRAINING),
258 	STATE(PAUSED),
259 	STATE(SUSPENDED),
260 };
261 
262 static char *snd_pcm_access_names[] = {
263 	ACCESS(MMAP_INTERLEAVED),
264 	ACCESS(MMAP_NONINTERLEAVED),
265 	ACCESS(MMAP_COMPLEX),
266 	ACCESS(RW_INTERLEAVED),
267 	ACCESS(RW_NONINTERLEAVED),
268 };
269 
270 static char *snd_pcm_subformat_names[] = {
271 	SUBFORMAT(STD),
272 };
273 
274 static char *snd_pcm_tstamp_mode_names[] = {
275 	TSTAMP(NONE),
276 	TSTAMP(ENABLE),
277 };
278 
279 static const char *snd_pcm_stream_name(int stream)
280 {
281 	return snd_pcm_stream_names[stream];
282 }
283 
284 static const char *snd_pcm_access_name(snd_pcm_access_t access)
285 {
286 	return snd_pcm_access_names[(__force int)access];
287 }
288 
289 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
290 {
291 	return snd_pcm_subformat_names[(__force int)subformat];
292 }
293 
294 static const char *snd_pcm_tstamp_mode_name(int mode)
295 {
296 	return snd_pcm_tstamp_mode_names[mode];
297 }
298 
299 static const char *snd_pcm_state_name(snd_pcm_state_t state)
300 {
301 	return snd_pcm_state_names[(__force int)state];
302 }
303 
304 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
305 #include <linux/soundcard.h>
306 
307 static const char *snd_pcm_oss_format_name(int format)
308 {
309 	switch (format) {
310 	case AFMT_MU_LAW:
311 		return "MU_LAW";
312 	case AFMT_A_LAW:
313 		return "A_LAW";
314 	case AFMT_IMA_ADPCM:
315 		return "IMA_ADPCM";
316 	case AFMT_U8:
317 		return "U8";
318 	case AFMT_S16_LE:
319 		return "S16_LE";
320 	case AFMT_S16_BE:
321 		return "S16_BE";
322 	case AFMT_S8:
323 		return "S8";
324 	case AFMT_U16_LE:
325 		return "U16_LE";
326 	case AFMT_U16_BE:
327 		return "U16_BE";
328 	case AFMT_MPEG:
329 		return "MPEG";
330 	default:
331 		return "unknown";
332 	}
333 }
334 #endif
335 
336 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
337 				   struct snd_info_buffer *buffer)
338 {
339 	struct snd_pcm_info *info;
340 	int err;
341 
342 	if (! substream)
343 		return;
344 
345 	info = kmalloc(sizeof(*info), GFP_KERNEL);
346 	if (!info)
347 		return;
348 
349 	err = snd_pcm_info(substream, info);
350 	if (err < 0) {
351 		snd_iprintf(buffer, "error %d\n", err);
352 		kfree(info);
353 		return;
354 	}
355 	snd_iprintf(buffer, "card: %d\n", info->card);
356 	snd_iprintf(buffer, "device: %d\n", info->device);
357 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
358 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
359 	snd_iprintf(buffer, "id: %s\n", info->id);
360 	snd_iprintf(buffer, "name: %s\n", info->name);
361 	snd_iprintf(buffer, "subname: %s\n", info->subname);
362 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
363 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
364 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
365 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
366 	kfree(info);
367 }
368 
369 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
370 					  struct snd_info_buffer *buffer)
371 {
372 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
373 			       buffer);
374 }
375 
376 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
377 					     struct snd_info_buffer *buffer)
378 {
379 	snd_pcm_proc_info_read(entry->private_data, buffer);
380 }
381 
382 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
383 						  struct snd_info_buffer *buffer)
384 {
385 	struct snd_pcm_substream *substream = entry->private_data;
386 	struct snd_pcm_runtime *runtime;
387 
388 	mutex_lock(&substream->pcm->open_mutex);
389 	runtime = substream->runtime;
390 	if (!runtime) {
391 		snd_iprintf(buffer, "closed\n");
392 		goto unlock;
393 	}
394 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
395 		snd_iprintf(buffer, "no setup\n");
396 		goto unlock;
397 	}
398 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
399 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
400 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
401 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
402 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
403 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
404 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
405 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
406 	if (substream->oss.oss) {
407 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
408 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
409 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
410 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
411 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
412 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
413 	}
414 #endif
415  unlock:
416 	mutex_unlock(&substream->pcm->open_mutex);
417 }
418 
419 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
420 						  struct snd_info_buffer *buffer)
421 {
422 	struct snd_pcm_substream *substream = entry->private_data;
423 	struct snd_pcm_runtime *runtime;
424 
425 	mutex_lock(&substream->pcm->open_mutex);
426 	runtime = substream->runtime;
427 	if (!runtime) {
428 		snd_iprintf(buffer, "closed\n");
429 		goto unlock;
430 	}
431 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
432 		snd_iprintf(buffer, "no setup\n");
433 		goto unlock;
434 	}
435 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
436 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
437 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
438 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
439 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
440 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
441 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
442 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
443  unlock:
444 	mutex_unlock(&substream->pcm->open_mutex);
445 }
446 
447 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
448 					       struct snd_info_buffer *buffer)
449 {
450 	struct snd_pcm_substream *substream = entry->private_data;
451 	struct snd_pcm_runtime *runtime;
452 	struct snd_pcm_status status;
453 	int err;
454 
455 	mutex_lock(&substream->pcm->open_mutex);
456 	runtime = substream->runtime;
457 	if (!runtime) {
458 		snd_iprintf(buffer, "closed\n");
459 		goto unlock;
460 	}
461 	memset(&status, 0, sizeof(status));
462 	err = snd_pcm_status(substream, &status);
463 	if (err < 0) {
464 		snd_iprintf(buffer, "error %d\n", err);
465 		goto unlock;
466 	}
467 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
468 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
469 	snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
470 		status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
471 	snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
472 		status.tstamp.tv_sec, status.tstamp.tv_nsec);
473 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
474 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
475 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
476 	snd_iprintf(buffer, "-----\n");
477 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
478 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
479  unlock:
480 	mutex_unlock(&substream->pcm->open_mutex);
481 }
482 
483 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
484 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
485 					 struct snd_info_buffer *buffer)
486 {
487 	struct snd_pcm_substream *substream = entry->private_data;
488 	struct snd_pcm_runtime *runtime;
489 
490 	snd_pcm_stream_lock_irq(substream);
491 	runtime = substream->runtime;
492 	if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
493 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
494 	snd_pcm_stream_unlock_irq(substream);
495 }
496 
497 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
498 				    struct snd_info_buffer *buffer)
499 {
500 	struct snd_pcm_str *pstr = entry->private_data;
501 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
502 }
503 
504 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
505 				     struct snd_info_buffer *buffer)
506 {
507 	struct snd_pcm_str *pstr = entry->private_data;
508 	char line[64];
509 	if (!snd_info_get_line(buffer, line, sizeof(line)))
510 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
511 }
512 #endif
513 
514 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
515 {
516 	struct snd_pcm *pcm = pstr->pcm;
517 	struct snd_info_entry *entry;
518 	char name[16];
519 
520 	sprintf(name, "pcm%i%c", pcm->device,
521 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
522 	if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
523 		return -ENOMEM;
524 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
525 	if (snd_info_register(entry) < 0) {
526 		snd_info_free_entry(entry);
527 		return -ENOMEM;
528 	}
529 	pstr->proc_root = entry;
530 
531 	if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
532 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
533 		if (snd_info_register(entry) < 0) {
534 			snd_info_free_entry(entry);
535 			entry = NULL;
536 		}
537 	}
538 	pstr->proc_info_entry = entry;
539 
540 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
541 	if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
542 						pstr->proc_root)) != NULL) {
543 		entry->c.text.read = snd_pcm_xrun_debug_read;
544 		entry->c.text.write = snd_pcm_xrun_debug_write;
545 		entry->mode |= S_IWUSR;
546 		entry->private_data = pstr;
547 		if (snd_info_register(entry) < 0) {
548 			snd_info_free_entry(entry);
549 			entry = NULL;
550 		}
551 	}
552 	pstr->proc_xrun_debug_entry = entry;
553 #endif
554 	return 0;
555 }
556 
557 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
558 {
559 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
560 	snd_info_free_entry(pstr->proc_xrun_debug_entry);
561 	pstr->proc_xrun_debug_entry = NULL;
562 #endif
563 	snd_info_free_entry(pstr->proc_info_entry);
564 	pstr->proc_info_entry = NULL;
565 	snd_info_free_entry(pstr->proc_root);
566 	pstr->proc_root = NULL;
567 	return 0;
568 }
569 
570 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
571 {
572 	struct snd_info_entry *entry;
573 	struct snd_card *card;
574 	char name[16];
575 
576 	card = substream->pcm->card;
577 
578 	sprintf(name, "sub%i", substream->number);
579 	if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
580 		return -ENOMEM;
581 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
582 	if (snd_info_register(entry) < 0) {
583 		snd_info_free_entry(entry);
584 		return -ENOMEM;
585 	}
586 	substream->proc_root = entry;
587 
588 	if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
589 		snd_info_set_text_ops(entry, substream,
590 				      snd_pcm_substream_proc_info_read);
591 		if (snd_info_register(entry) < 0) {
592 			snd_info_free_entry(entry);
593 			entry = NULL;
594 		}
595 	}
596 	substream->proc_info_entry = entry;
597 
598 	if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
599 		snd_info_set_text_ops(entry, substream,
600 				      snd_pcm_substream_proc_hw_params_read);
601 		if (snd_info_register(entry) < 0) {
602 			snd_info_free_entry(entry);
603 			entry = NULL;
604 		}
605 	}
606 	substream->proc_hw_params_entry = entry;
607 
608 	if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
609 		snd_info_set_text_ops(entry, substream,
610 				      snd_pcm_substream_proc_sw_params_read);
611 		if (snd_info_register(entry) < 0) {
612 			snd_info_free_entry(entry);
613 			entry = NULL;
614 		}
615 	}
616 	substream->proc_sw_params_entry = entry;
617 
618 	if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
619 		snd_info_set_text_ops(entry, substream,
620 				      snd_pcm_substream_proc_status_read);
621 		if (snd_info_register(entry) < 0) {
622 			snd_info_free_entry(entry);
623 			entry = NULL;
624 		}
625 	}
626 	substream->proc_status_entry = entry;
627 
628 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
629 	entry = snd_info_create_card_entry(card, "xrun_injection",
630 					   substream->proc_root);
631 	if (entry) {
632 		entry->private_data = substream;
633 		entry->c.text.read = NULL;
634 		entry->c.text.write = snd_pcm_xrun_injection_write;
635 		entry->mode = S_IFREG | S_IWUSR;
636 		if (snd_info_register(entry) < 0) {
637 			snd_info_free_entry(entry);
638 			entry = NULL;
639 		}
640 	}
641 	substream->proc_xrun_injection_entry = entry;
642 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
643 
644 	return 0;
645 }
646 
647 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
648 {
649 	snd_info_free_entry(substream->proc_info_entry);
650 	substream->proc_info_entry = NULL;
651 	snd_info_free_entry(substream->proc_hw_params_entry);
652 	substream->proc_hw_params_entry = NULL;
653 	snd_info_free_entry(substream->proc_sw_params_entry);
654 	substream->proc_sw_params_entry = NULL;
655 	snd_info_free_entry(substream->proc_status_entry);
656 	substream->proc_status_entry = NULL;
657 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
658 	snd_info_free_entry(substream->proc_xrun_injection_entry);
659 	substream->proc_xrun_injection_entry = NULL;
660 #endif
661 	snd_info_free_entry(substream->proc_root);
662 	substream->proc_root = NULL;
663 	return 0;
664 }
665 #else /* !CONFIG_SND_VERBOSE_PROCFS */
666 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
667 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
668 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
669 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
670 #endif /* CONFIG_SND_VERBOSE_PROCFS */
671 
672 static const struct attribute_group *pcm_dev_attr_groups[];
673 
674 /**
675  * snd_pcm_new_stream - create a new PCM stream
676  * @pcm: the pcm instance
677  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
678  * @substream_count: the number of substreams
679  *
680  * Creates a new stream for the pcm.
681  * The corresponding stream on the pcm must have been empty before
682  * calling this, i.e. zero must be given to the argument of
683  * snd_pcm_new().
684  *
685  * Return: Zero if successful, or a negative error code on failure.
686  */
687 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
688 {
689 	int idx, err;
690 	struct snd_pcm_str *pstr = &pcm->streams[stream];
691 	struct snd_pcm_substream *substream, *prev;
692 
693 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
694 	mutex_init(&pstr->oss.setup_mutex);
695 #endif
696 	pstr->stream = stream;
697 	pstr->pcm = pcm;
698 	pstr->substream_count = substream_count;
699 	if (!substream_count)
700 		return 0;
701 
702 	snd_device_initialize(&pstr->dev, pcm->card);
703 	pstr->dev.groups = pcm_dev_attr_groups;
704 	dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
705 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
706 
707 	if (!pcm->internal) {
708 		err = snd_pcm_stream_proc_init(pstr);
709 		if (err < 0) {
710 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
711 			return err;
712 		}
713 	}
714 	prev = NULL;
715 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
716 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
717 		if (!substream)
718 			return -ENOMEM;
719 		substream->pcm = pcm;
720 		substream->pstr = pstr;
721 		substream->number = idx;
722 		substream->stream = stream;
723 		sprintf(substream->name, "subdevice #%i", idx);
724 		substream->buffer_bytes_max = UINT_MAX;
725 		if (prev == NULL)
726 			pstr->substream = substream;
727 		else
728 			prev->next = substream;
729 
730 		if (!pcm->internal) {
731 			err = snd_pcm_substream_proc_init(substream);
732 			if (err < 0) {
733 				pcm_err(pcm,
734 					"Error in snd_pcm_stream_proc_init\n");
735 				if (prev == NULL)
736 					pstr->substream = NULL;
737 				else
738 					prev->next = NULL;
739 				kfree(substream);
740 				return err;
741 			}
742 		}
743 		substream->group = &substream->self_group;
744 		spin_lock_init(&substream->self_group.lock);
745 		mutex_init(&substream->self_group.mutex);
746 		INIT_LIST_HEAD(&substream->self_group.substreams);
747 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
748 		atomic_set(&substream->mmap_count, 0);
749 		prev = substream;
750 	}
751 	return 0;
752 }
753 EXPORT_SYMBOL(snd_pcm_new_stream);
754 
755 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
756 		int playback_count, int capture_count, bool internal,
757 		struct snd_pcm **rpcm)
758 {
759 	struct snd_pcm *pcm;
760 	int err;
761 	static struct snd_device_ops ops = {
762 		.dev_free = snd_pcm_dev_free,
763 		.dev_register =	snd_pcm_dev_register,
764 		.dev_disconnect = snd_pcm_dev_disconnect,
765 	};
766 
767 	if (snd_BUG_ON(!card))
768 		return -ENXIO;
769 	if (rpcm)
770 		*rpcm = NULL;
771 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
772 	if (!pcm)
773 		return -ENOMEM;
774 	pcm->card = card;
775 	pcm->device = device;
776 	pcm->internal = internal;
777 	mutex_init(&pcm->open_mutex);
778 	init_waitqueue_head(&pcm->open_wait);
779 	INIT_LIST_HEAD(&pcm->list);
780 	if (id)
781 		strlcpy(pcm->id, id, sizeof(pcm->id));
782 	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
783 		snd_pcm_free(pcm);
784 		return err;
785 	}
786 	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
787 		snd_pcm_free(pcm);
788 		return err;
789 	}
790 	if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
791 		snd_pcm_free(pcm);
792 		return err;
793 	}
794 	if (rpcm)
795 		*rpcm = pcm;
796 	return 0;
797 }
798 
799 /**
800  * snd_pcm_new - create a new PCM instance
801  * @card: the card instance
802  * @id: the id string
803  * @device: the device index (zero based)
804  * @playback_count: the number of substreams for playback
805  * @capture_count: the number of substreams for capture
806  * @rpcm: the pointer to store the new pcm instance
807  *
808  * Creates a new PCM instance.
809  *
810  * The pcm operators have to be set afterwards to the new instance
811  * via snd_pcm_set_ops().
812  *
813  * Return: Zero if successful, or a negative error code on failure.
814  */
815 int snd_pcm_new(struct snd_card *card, const char *id, int device,
816 		int playback_count, int capture_count, struct snd_pcm **rpcm)
817 {
818 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
819 			false, rpcm);
820 }
821 EXPORT_SYMBOL(snd_pcm_new);
822 
823 /**
824  * snd_pcm_new_internal - create a new internal PCM instance
825  * @card: the card instance
826  * @id: the id string
827  * @device: the device index (zero based - shared with normal PCMs)
828  * @playback_count: the number of substreams for playback
829  * @capture_count: the number of substreams for capture
830  * @rpcm: the pointer to store the new pcm instance
831  *
832  * Creates a new internal PCM instance with no userspace device or procfs
833  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
834  * will only be used internally by kernel drivers. i.e. it cannot be opened
835  * by userspace. It provides existing ASoC components drivers with a substream
836  * and access to any private data.
837  *
838  * The pcm operators have to be set afterwards to the new instance
839  * via snd_pcm_set_ops().
840  *
841  * Return: Zero if successful, or a negative error code on failure.
842  */
843 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
844 	int playback_count, int capture_count,
845 	struct snd_pcm **rpcm)
846 {
847 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
848 			true, rpcm);
849 }
850 EXPORT_SYMBOL(snd_pcm_new_internal);
851 
852 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
853 {
854 	struct snd_pcm_substream *substream, *substream_next;
855 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
856 	struct snd_pcm_oss_setup *setup, *setupn;
857 #endif
858 	substream = pstr->substream;
859 	while (substream) {
860 		substream_next = substream->next;
861 		snd_pcm_timer_done(substream);
862 		snd_pcm_substream_proc_done(substream);
863 		kfree(substream);
864 		substream = substream_next;
865 	}
866 	snd_pcm_stream_proc_done(pstr);
867 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
868 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
869 		setupn = setup->next;
870 		kfree(setup->task_name);
871 		kfree(setup);
872 	}
873 #endif
874 	if (pstr->substream_count)
875 		put_device(&pstr->dev);
876 }
877 
878 static int snd_pcm_free(struct snd_pcm *pcm)
879 {
880 	struct snd_pcm_notify *notify;
881 
882 	if (!pcm)
883 		return 0;
884 	if (!pcm->internal) {
885 		list_for_each_entry(notify, &snd_pcm_notify_list, list)
886 			notify->n_unregister(pcm);
887 	}
888 	if (pcm->private_free)
889 		pcm->private_free(pcm);
890 	snd_pcm_lib_preallocate_free_for_all(pcm);
891 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
892 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
893 	kfree(pcm);
894 	return 0;
895 }
896 
897 static int snd_pcm_dev_free(struct snd_device *device)
898 {
899 	struct snd_pcm *pcm = device->device_data;
900 	return snd_pcm_free(pcm);
901 }
902 
903 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
904 			     struct file *file,
905 			     struct snd_pcm_substream **rsubstream)
906 {
907 	struct snd_pcm_str * pstr;
908 	struct snd_pcm_substream *substream;
909 	struct snd_pcm_runtime *runtime;
910 	struct snd_card *card;
911 	int prefer_subdevice;
912 	size_t size;
913 
914 	if (snd_BUG_ON(!pcm || !rsubstream))
915 		return -ENXIO;
916 	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
917 		       stream != SNDRV_PCM_STREAM_CAPTURE))
918 		return -EINVAL;
919 	*rsubstream = NULL;
920 	pstr = &pcm->streams[stream];
921 	if (pstr->substream == NULL || pstr->substream_count == 0)
922 		return -ENODEV;
923 
924 	card = pcm->card;
925 	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
926 
927 	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
928 		int opposite = !stream;
929 
930 		for (substream = pcm->streams[opposite].substream; substream;
931 		     substream = substream->next) {
932 			if (SUBSTREAM_BUSY(substream))
933 				return -EAGAIN;
934 		}
935 	}
936 
937 	if (file->f_flags & O_APPEND) {
938 		if (prefer_subdevice < 0) {
939 			if (pstr->substream_count > 1)
940 				return -EINVAL; /* must be unique */
941 			substream = pstr->substream;
942 		} else {
943 			for (substream = pstr->substream; substream;
944 			     substream = substream->next)
945 				if (substream->number == prefer_subdevice)
946 					break;
947 		}
948 		if (! substream)
949 			return -ENODEV;
950 		if (! SUBSTREAM_BUSY(substream))
951 			return -EBADFD;
952 		substream->ref_count++;
953 		*rsubstream = substream;
954 		return 0;
955 	}
956 
957 	for (substream = pstr->substream; substream; substream = substream->next) {
958 		if (!SUBSTREAM_BUSY(substream) &&
959 		    (prefer_subdevice == -1 ||
960 		     substream->number == prefer_subdevice))
961 			break;
962 	}
963 	if (substream == NULL)
964 		return -EAGAIN;
965 
966 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
967 	if (runtime == NULL)
968 		return -ENOMEM;
969 
970 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
971 	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
972 	if (runtime->status == NULL) {
973 		kfree(runtime);
974 		return -ENOMEM;
975 	}
976 	memset((void*)runtime->status, 0, size);
977 
978 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
979 	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
980 	if (runtime->control == NULL) {
981 		snd_free_pages((void*)runtime->status,
982 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
983 		kfree(runtime);
984 		return -ENOMEM;
985 	}
986 	memset((void*)runtime->control, 0, size);
987 
988 	init_waitqueue_head(&runtime->sleep);
989 	init_waitqueue_head(&runtime->tsleep);
990 
991 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
992 
993 	substream->runtime = runtime;
994 	substream->private_data = pcm->private_data;
995 	substream->ref_count = 1;
996 	substream->f_flags = file->f_flags;
997 	substream->pid = get_pid(task_pid(current));
998 	pstr->substream_opened++;
999 	*rsubstream = substream;
1000 	return 0;
1001 }
1002 
1003 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1004 {
1005 	struct snd_pcm_runtime *runtime;
1006 
1007 	if (PCM_RUNTIME_CHECK(substream))
1008 		return;
1009 	runtime = substream->runtime;
1010 	if (runtime->private_free != NULL)
1011 		runtime->private_free(runtime);
1012 	snd_free_pages((void*)runtime->status,
1013 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1014 	snd_free_pages((void*)runtime->control,
1015 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1016 	kfree(runtime->hw_constraints.rules);
1017 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
1018 	kfree(runtime->hwptr_log);
1019 #endif
1020 	kfree(runtime);
1021 	substream->runtime = NULL;
1022 	put_pid(substream->pid);
1023 	substream->pid = NULL;
1024 	substream->pstr->substream_opened--;
1025 }
1026 
1027 static ssize_t show_pcm_class(struct device *dev,
1028 			      struct device_attribute *attr, char *buf)
1029 {
1030 	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1031 	struct snd_pcm *pcm = pstr->pcm;
1032 	const char *str;
1033 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1034 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1035 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1036 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1037 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1038 	};
1039 
1040 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1041 		str = "none";
1042 	else
1043 		str = strs[pcm->dev_class];
1044         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1045 }
1046 
1047 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1048 static struct attribute *pcm_dev_attrs[] = {
1049 	&dev_attr_pcm_class.attr,
1050 	NULL
1051 };
1052 
1053 static struct attribute_group pcm_dev_attr_group = {
1054 	.attrs	= pcm_dev_attrs,
1055 };
1056 
1057 static const struct attribute_group *pcm_dev_attr_groups[] = {
1058 	&pcm_dev_attr_group,
1059 	NULL
1060 };
1061 
1062 static int snd_pcm_dev_register(struct snd_device *device)
1063 {
1064 	int cidx, err;
1065 	struct snd_pcm_substream *substream;
1066 	struct snd_pcm_notify *notify;
1067 	struct snd_pcm *pcm;
1068 
1069 	if (snd_BUG_ON(!device || !device->device_data))
1070 		return -ENXIO;
1071 	pcm = device->device_data;
1072 	if (pcm->internal)
1073 		return 0;
1074 
1075 	mutex_lock(&register_mutex);
1076 	err = snd_pcm_add(pcm);
1077 	if (err)
1078 		goto unlock;
1079 	for (cidx = 0; cidx < 2; cidx++) {
1080 		int devtype = -1;
1081 		if (pcm->streams[cidx].substream == NULL)
1082 			continue;
1083 		switch (cidx) {
1084 		case SNDRV_PCM_STREAM_PLAYBACK:
1085 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1086 			break;
1087 		case SNDRV_PCM_STREAM_CAPTURE:
1088 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1089 			break;
1090 		}
1091 		/* register pcm */
1092 		err = snd_register_device(devtype, pcm->card, pcm->device,
1093 					  &snd_pcm_f_ops[cidx], pcm,
1094 					  &pcm->streams[cidx].dev);
1095 		if (err < 0) {
1096 			list_del_init(&pcm->list);
1097 			goto unlock;
1098 		}
1099 
1100 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1101 			snd_pcm_timer_init(substream);
1102 	}
1103 
1104 	list_for_each_entry(notify, &snd_pcm_notify_list, list)
1105 		notify->n_register(pcm);
1106 
1107  unlock:
1108 	mutex_unlock(&register_mutex);
1109 	return err;
1110 }
1111 
1112 static int snd_pcm_dev_disconnect(struct snd_device *device)
1113 {
1114 	struct snd_pcm *pcm = device->device_data;
1115 	struct snd_pcm_notify *notify;
1116 	struct snd_pcm_substream *substream;
1117 	int cidx;
1118 
1119 	mutex_lock(&register_mutex);
1120 	mutex_lock(&pcm->open_mutex);
1121 	wake_up(&pcm->open_wait);
1122 	list_del_init(&pcm->list);
1123 	for (cidx = 0; cidx < 2; cidx++) {
1124 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1125 			snd_pcm_stream_lock_irq(substream);
1126 			if (substream->runtime) {
1127 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1128 				wake_up(&substream->runtime->sleep);
1129 				wake_up(&substream->runtime->tsleep);
1130 			}
1131 			snd_pcm_stream_unlock_irq(substream);
1132 		}
1133 	}
1134 	if (!pcm->internal) {
1135 		list_for_each_entry(notify, &snd_pcm_notify_list, list)
1136 			notify->n_disconnect(pcm);
1137 	}
1138 	for (cidx = 0; cidx < 2; cidx++) {
1139 		if (!pcm->internal)
1140 			snd_unregister_device(&pcm->streams[cidx].dev);
1141 		if (pcm->streams[cidx].chmap_kctl) {
1142 			snd_ctl_remove(pcm->card, pcm->streams[cidx].chmap_kctl);
1143 			pcm->streams[cidx].chmap_kctl = NULL;
1144 		}
1145 	}
1146 	mutex_unlock(&pcm->open_mutex);
1147 	mutex_unlock(&register_mutex);
1148 	return 0;
1149 }
1150 
1151 /**
1152  * snd_pcm_notify - Add/remove the notify list
1153  * @notify: PCM notify list
1154  * @nfree: 0 = register, 1 = unregister
1155  *
1156  * This adds the given notifier to the global list so that the callback is
1157  * called for each registered PCM devices.  This exists only for PCM OSS
1158  * emulation, so far.
1159  */
1160 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1161 {
1162 	struct snd_pcm *pcm;
1163 
1164 	if (snd_BUG_ON(!notify ||
1165 		       !notify->n_register ||
1166 		       !notify->n_unregister ||
1167 		       !notify->n_disconnect))
1168 		return -EINVAL;
1169 	mutex_lock(&register_mutex);
1170 	if (nfree) {
1171 		list_del(&notify->list);
1172 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1173 			notify->n_unregister(pcm);
1174 	} else {
1175 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1176 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1177 			notify->n_register(pcm);
1178 	}
1179 	mutex_unlock(&register_mutex);
1180 	return 0;
1181 }
1182 EXPORT_SYMBOL(snd_pcm_notify);
1183 
1184 #ifdef CONFIG_SND_PROC_FS
1185 /*
1186  *  Info interface
1187  */
1188 
1189 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1190 			      struct snd_info_buffer *buffer)
1191 {
1192 	struct snd_pcm *pcm;
1193 
1194 	mutex_lock(&register_mutex);
1195 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1196 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1197 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1198 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1199 			snd_iprintf(buffer, " : playback %i",
1200 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1201 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1202 			snd_iprintf(buffer, " : capture %i",
1203 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1204 		snd_iprintf(buffer, "\n");
1205 	}
1206 	mutex_unlock(&register_mutex);
1207 }
1208 
1209 static struct snd_info_entry *snd_pcm_proc_entry;
1210 
1211 static void snd_pcm_proc_init(void)
1212 {
1213 	struct snd_info_entry *entry;
1214 
1215 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
1216 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1217 		if (snd_info_register(entry) < 0) {
1218 			snd_info_free_entry(entry);
1219 			entry = NULL;
1220 		}
1221 	}
1222 	snd_pcm_proc_entry = entry;
1223 }
1224 
1225 static void snd_pcm_proc_done(void)
1226 {
1227 	snd_info_free_entry(snd_pcm_proc_entry);
1228 }
1229 
1230 #else /* !CONFIG_SND_PROC_FS */
1231 #define snd_pcm_proc_init()
1232 #define snd_pcm_proc_done()
1233 #endif /* CONFIG_SND_PROC_FS */
1234 
1235 
1236 /*
1237  *  ENTRY functions
1238  */
1239 
1240 static int __init alsa_pcm_init(void)
1241 {
1242 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1243 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1244 	snd_pcm_proc_init();
1245 	return 0;
1246 }
1247 
1248 static void __exit alsa_pcm_exit(void)
1249 {
1250 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1251 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1252 	snd_pcm_proc_done();
1253 }
1254 
1255 module_init(alsa_pcm_init)
1256 module_exit(alsa_pcm_exit)
1257