xref: /linux/sound/core/pcm.c (revision 37cb8e1f8e10c6e9bd2a1b95cdda0620a21b0551)
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 #include "pcm_local.h"
35 
36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
37 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
38 MODULE_LICENSE("GPL");
39 
40 static LIST_HEAD(snd_pcm_devices);
41 static DEFINE_MUTEX(register_mutex);
42 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
43 static LIST_HEAD(snd_pcm_notify_list);
44 #endif
45 
46 static int snd_pcm_free(struct snd_pcm *pcm);
47 static int snd_pcm_dev_free(struct snd_device *device);
48 static int snd_pcm_dev_register(struct snd_device *device);
49 static int snd_pcm_dev_disconnect(struct snd_device *device);
50 
51 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
52 {
53 	struct snd_pcm *pcm;
54 
55 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
56 		if (pcm->card == card && pcm->device == device)
57 			return pcm;
58 	}
59 	return NULL;
60 }
61 
62 static int snd_pcm_next(struct snd_card *card, int device)
63 {
64 	struct snd_pcm *pcm;
65 
66 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
67 		if (pcm->card == card && pcm->device > device)
68 			return pcm->device;
69 		else if (pcm->card->number > card->number)
70 			return -1;
71 	}
72 	return -1;
73 }
74 
75 static int snd_pcm_add(struct snd_pcm *newpcm)
76 {
77 	struct snd_pcm *pcm;
78 
79 	if (newpcm->internal)
80 		return 0;
81 
82 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
83 		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
84 			return -EBUSY;
85 		if (pcm->card->number > newpcm->card->number ||
86 				(pcm->card == newpcm->card &&
87 				pcm->device > newpcm->device)) {
88 			list_add(&newpcm->list, pcm->list.prev);
89 			return 0;
90 		}
91 	}
92 	list_add_tail(&newpcm->list, &snd_pcm_devices);
93 	return 0;
94 }
95 
96 static int snd_pcm_control_ioctl(struct snd_card *card,
97 				 struct snd_ctl_file *control,
98 				 unsigned int cmd, unsigned long arg)
99 {
100 	switch (cmd) {
101 	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
102 		{
103 			int device;
104 
105 			if (get_user(device, (int __user *)arg))
106 				return -EFAULT;
107 			mutex_lock(&register_mutex);
108 			device = snd_pcm_next(card, device);
109 			mutex_unlock(&register_mutex);
110 			if (put_user(device, (int __user *)arg))
111 				return -EFAULT;
112 			return 0;
113 		}
114 	case SNDRV_CTL_IOCTL_PCM_INFO:
115 		{
116 			struct snd_pcm_info __user *info;
117 			unsigned int device, subdevice;
118 			int stream;
119 			struct snd_pcm *pcm;
120 			struct snd_pcm_str *pstr;
121 			struct snd_pcm_substream *substream;
122 			int err;
123 
124 			info = (struct snd_pcm_info __user *)arg;
125 			if (get_user(device, &info->device))
126 				return -EFAULT;
127 			if (get_user(stream, &info->stream))
128 				return -EFAULT;
129 			if (stream < 0 || stream > 1)
130 				return -EINVAL;
131 			if (get_user(subdevice, &info->subdevice))
132 				return -EFAULT;
133 			mutex_lock(&register_mutex);
134 			pcm = snd_pcm_get(card, device);
135 			if (pcm == NULL) {
136 				err = -ENXIO;
137 				goto _error;
138 			}
139 			pstr = &pcm->streams[stream];
140 			if (pstr->substream_count == 0) {
141 				err = -ENOENT;
142 				goto _error;
143 			}
144 			if (subdevice >= pstr->substream_count) {
145 				err = -ENXIO;
146 				goto _error;
147 			}
148 			for (substream = pstr->substream; substream;
149 			     substream = substream->next)
150 				if (substream->number == (int)subdevice)
151 					break;
152 			if (substream == NULL) {
153 				err = -ENXIO;
154 				goto _error;
155 			}
156 			err = snd_pcm_info_user(substream, info);
157 		_error:
158 			mutex_unlock(&register_mutex);
159 			return err;
160 		}
161 	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
162 		{
163 			int val;
164 
165 			if (get_user(val, (int __user *)arg))
166 				return -EFAULT;
167 			control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
168 			return 0;
169 		}
170 	}
171 	return -ENOIOCTLCMD;
172 }
173 
174 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
175 
176 static char *snd_pcm_format_names[] = {
177 	FORMAT(S8),
178 	FORMAT(U8),
179 	FORMAT(S16_LE),
180 	FORMAT(S16_BE),
181 	FORMAT(U16_LE),
182 	FORMAT(U16_BE),
183 	FORMAT(S24_LE),
184 	FORMAT(S24_BE),
185 	FORMAT(U24_LE),
186 	FORMAT(U24_BE),
187 	FORMAT(S32_LE),
188 	FORMAT(S32_BE),
189 	FORMAT(U32_LE),
190 	FORMAT(U32_BE),
191 	FORMAT(FLOAT_LE),
192 	FORMAT(FLOAT_BE),
193 	FORMAT(FLOAT64_LE),
194 	FORMAT(FLOAT64_BE),
195 	FORMAT(IEC958_SUBFRAME_LE),
196 	FORMAT(IEC958_SUBFRAME_BE),
197 	FORMAT(MU_LAW),
198 	FORMAT(A_LAW),
199 	FORMAT(IMA_ADPCM),
200 	FORMAT(MPEG),
201 	FORMAT(GSM),
202 	FORMAT(SPECIAL),
203 	FORMAT(S24_3LE),
204 	FORMAT(S24_3BE),
205 	FORMAT(U24_3LE),
206 	FORMAT(U24_3BE),
207 	FORMAT(S20_3LE),
208 	FORMAT(S20_3BE),
209 	FORMAT(U20_3LE),
210 	FORMAT(U20_3BE),
211 	FORMAT(S18_3LE),
212 	FORMAT(S18_3BE),
213 	FORMAT(U18_3LE),
214 	FORMAT(U18_3BE),
215 	FORMAT(G723_24),
216 	FORMAT(G723_24_1B),
217 	FORMAT(G723_40),
218 	FORMAT(G723_40_1B),
219 	FORMAT(DSD_U8),
220 	FORMAT(DSD_U16_LE),
221 	FORMAT(DSD_U32_LE),
222 	FORMAT(DSD_U16_BE),
223 	FORMAT(DSD_U32_BE),
224 };
225 
226 /**
227  * snd_pcm_format_name - Return a name string for the given PCM format
228  * @format: PCM format
229  */
230 const char *snd_pcm_format_name(snd_pcm_format_t format)
231 {
232 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
233 		return "Unknown";
234 	return snd_pcm_format_names[(__force unsigned int)format];
235 }
236 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
237 
238 #ifdef CONFIG_SND_VERBOSE_PROCFS
239 
240 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
241 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
242 #define READY(v) [SNDRV_PCM_READY_##v] = #v
243 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
244 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
245 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
246 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
247 #define START(v) [SNDRV_PCM_START_##v] = #v
248 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
249 
250 static char *snd_pcm_stream_names[] = {
251 	STREAM(PLAYBACK),
252 	STREAM(CAPTURE),
253 };
254 
255 static char *snd_pcm_state_names[] = {
256 	STATE(OPEN),
257 	STATE(SETUP),
258 	STATE(PREPARED),
259 	STATE(RUNNING),
260 	STATE(XRUN),
261 	STATE(DRAINING),
262 	STATE(PAUSED),
263 	STATE(SUSPENDED),
264 };
265 
266 static char *snd_pcm_access_names[] = {
267 	ACCESS(MMAP_INTERLEAVED),
268 	ACCESS(MMAP_NONINTERLEAVED),
269 	ACCESS(MMAP_COMPLEX),
270 	ACCESS(RW_INTERLEAVED),
271 	ACCESS(RW_NONINTERLEAVED),
272 };
273 
274 static char *snd_pcm_subformat_names[] = {
275 	SUBFORMAT(STD),
276 };
277 
278 static char *snd_pcm_tstamp_mode_names[] = {
279 	TSTAMP(NONE),
280 	TSTAMP(ENABLE),
281 };
282 
283 static const char *snd_pcm_stream_name(int stream)
284 {
285 	return snd_pcm_stream_names[stream];
286 }
287 
288 static const char *snd_pcm_access_name(snd_pcm_access_t access)
289 {
290 	return snd_pcm_access_names[(__force int)access];
291 }
292 
293 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
294 {
295 	return snd_pcm_subformat_names[(__force int)subformat];
296 }
297 
298 static const char *snd_pcm_tstamp_mode_name(int mode)
299 {
300 	return snd_pcm_tstamp_mode_names[mode];
301 }
302 
303 static const char *snd_pcm_state_name(snd_pcm_state_t state)
304 {
305 	return snd_pcm_state_names[(__force int)state];
306 }
307 
308 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
309 #include <linux/soundcard.h>
310 
311 static const char *snd_pcm_oss_format_name(int format)
312 {
313 	switch (format) {
314 	case AFMT_MU_LAW:
315 		return "MU_LAW";
316 	case AFMT_A_LAW:
317 		return "A_LAW";
318 	case AFMT_IMA_ADPCM:
319 		return "IMA_ADPCM";
320 	case AFMT_U8:
321 		return "U8";
322 	case AFMT_S16_LE:
323 		return "S16_LE";
324 	case AFMT_S16_BE:
325 		return "S16_BE";
326 	case AFMT_S8:
327 		return "S8";
328 	case AFMT_U16_LE:
329 		return "U16_LE";
330 	case AFMT_U16_BE:
331 		return "U16_BE";
332 	case AFMT_MPEG:
333 		return "MPEG";
334 	default:
335 		return "unknown";
336 	}
337 }
338 #endif
339 
340 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
341 				   struct snd_info_buffer *buffer)
342 {
343 	struct snd_pcm_info *info;
344 	int err;
345 
346 	if (! substream)
347 		return;
348 
349 	info = kmalloc(sizeof(*info), GFP_KERNEL);
350 	if (!info)
351 		return;
352 
353 	err = snd_pcm_info(substream, info);
354 	if (err < 0) {
355 		snd_iprintf(buffer, "error %d\n", err);
356 		kfree(info);
357 		return;
358 	}
359 	snd_iprintf(buffer, "card: %d\n", info->card);
360 	snd_iprintf(buffer, "device: %d\n", info->device);
361 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
362 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
363 	snd_iprintf(buffer, "id: %s\n", info->id);
364 	snd_iprintf(buffer, "name: %s\n", info->name);
365 	snd_iprintf(buffer, "subname: %s\n", info->subname);
366 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
367 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
368 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
369 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
370 	kfree(info);
371 }
372 
373 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
374 					  struct snd_info_buffer *buffer)
375 {
376 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
377 			       buffer);
378 }
379 
380 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
381 					     struct snd_info_buffer *buffer)
382 {
383 	snd_pcm_proc_info_read(entry->private_data, buffer);
384 }
385 
386 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
387 						  struct snd_info_buffer *buffer)
388 {
389 	struct snd_pcm_substream *substream = entry->private_data;
390 	struct snd_pcm_runtime *runtime;
391 
392 	mutex_lock(&substream->pcm->open_mutex);
393 	runtime = substream->runtime;
394 	if (!runtime) {
395 		snd_iprintf(buffer, "closed\n");
396 		goto unlock;
397 	}
398 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
399 		snd_iprintf(buffer, "no setup\n");
400 		goto unlock;
401 	}
402 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
403 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
404 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
405 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
406 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
407 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
408 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
409 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
410 	if (substream->oss.oss) {
411 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
412 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
413 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
414 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
415 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
416 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
417 	}
418 #endif
419  unlock:
420 	mutex_unlock(&substream->pcm->open_mutex);
421 }
422 
423 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
424 						  struct snd_info_buffer *buffer)
425 {
426 	struct snd_pcm_substream *substream = entry->private_data;
427 	struct snd_pcm_runtime *runtime;
428 
429 	mutex_lock(&substream->pcm->open_mutex);
430 	runtime = substream->runtime;
431 	if (!runtime) {
432 		snd_iprintf(buffer, "closed\n");
433 		goto unlock;
434 	}
435 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
436 		snd_iprintf(buffer, "no setup\n");
437 		goto unlock;
438 	}
439 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
440 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
441 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
442 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
443 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
444 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
445 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
446 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
447  unlock:
448 	mutex_unlock(&substream->pcm->open_mutex);
449 }
450 
451 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
452 					       struct snd_info_buffer *buffer)
453 {
454 	struct snd_pcm_substream *substream = entry->private_data;
455 	struct snd_pcm_runtime *runtime;
456 	struct snd_pcm_status status;
457 	int err;
458 
459 	mutex_lock(&substream->pcm->open_mutex);
460 	runtime = substream->runtime;
461 	if (!runtime) {
462 		snd_iprintf(buffer, "closed\n");
463 		goto unlock;
464 	}
465 	memset(&status, 0, sizeof(status));
466 	err = snd_pcm_status(substream, &status);
467 	if (err < 0) {
468 		snd_iprintf(buffer, "error %d\n", err);
469 		goto unlock;
470 	}
471 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
472 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
473 	snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
474 		status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
475 	snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
476 		status.tstamp.tv_sec, status.tstamp.tv_nsec);
477 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
478 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
479 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
480 	snd_iprintf(buffer, "-----\n");
481 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
482 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
483  unlock:
484 	mutex_unlock(&substream->pcm->open_mutex);
485 }
486 
487 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
488 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
489 					 struct snd_info_buffer *buffer)
490 {
491 	struct snd_pcm_substream *substream = entry->private_data;
492 	struct snd_pcm_runtime *runtime;
493 
494 	snd_pcm_stream_lock_irq(substream);
495 	runtime = substream->runtime;
496 	if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
497 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
498 	snd_pcm_stream_unlock_irq(substream);
499 }
500 
501 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
502 				    struct snd_info_buffer *buffer)
503 {
504 	struct snd_pcm_str *pstr = entry->private_data;
505 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
506 }
507 
508 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
509 				     struct snd_info_buffer *buffer)
510 {
511 	struct snd_pcm_str *pstr = entry->private_data;
512 	char line[64];
513 	if (!snd_info_get_line(buffer, line, sizeof(line)))
514 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
515 }
516 #endif
517 
518 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
519 {
520 	struct snd_pcm *pcm = pstr->pcm;
521 	struct snd_info_entry *entry;
522 	char name[16];
523 
524 	sprintf(name, "pcm%i%c", pcm->device,
525 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
526 	entry = snd_info_create_card_entry(pcm->card, name,
527 					   pcm->card->proc_root);
528 	if (!entry)
529 		return -ENOMEM;
530 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
531 	if (snd_info_register(entry) < 0) {
532 		snd_info_free_entry(entry);
533 		return -ENOMEM;
534 	}
535 	pstr->proc_root = entry;
536 	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
537 	if (entry) {
538 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
539 		if (snd_info_register(entry) < 0) {
540 			snd_info_free_entry(entry);
541 			entry = NULL;
542 		}
543 	}
544 	pstr->proc_info_entry = entry;
545 
546 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
547 	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
548 					   pstr->proc_root);
549 	if (entry) {
550 		entry->c.text.read = snd_pcm_xrun_debug_read;
551 		entry->c.text.write = snd_pcm_xrun_debug_write;
552 		entry->mode |= S_IWUSR;
553 		entry->private_data = pstr;
554 		if (snd_info_register(entry) < 0) {
555 			snd_info_free_entry(entry);
556 			entry = NULL;
557 		}
558 	}
559 	pstr->proc_xrun_debug_entry = entry;
560 #endif
561 	return 0;
562 }
563 
564 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
565 {
566 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
567 	snd_info_free_entry(pstr->proc_xrun_debug_entry);
568 	pstr->proc_xrun_debug_entry = NULL;
569 #endif
570 	snd_info_free_entry(pstr->proc_info_entry);
571 	pstr->proc_info_entry = NULL;
572 	snd_info_free_entry(pstr->proc_root);
573 	pstr->proc_root = NULL;
574 	return 0;
575 }
576 
577 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
578 {
579 	struct snd_info_entry *entry;
580 	struct snd_card *card;
581 	char name[16];
582 
583 	card = substream->pcm->card;
584 
585 	sprintf(name, "sub%i", substream->number);
586 	entry = snd_info_create_card_entry(card, name,
587 					   substream->pstr->proc_root);
588 	if (!entry)
589 		return -ENOMEM;
590 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
591 	if (snd_info_register(entry) < 0) {
592 		snd_info_free_entry(entry);
593 		return -ENOMEM;
594 	}
595 	substream->proc_root = entry;
596 	entry = snd_info_create_card_entry(card, "info", substream->proc_root);
597 	if (entry) {
598 		snd_info_set_text_ops(entry, substream,
599 				      snd_pcm_substream_proc_info_read);
600 		if (snd_info_register(entry) < 0) {
601 			snd_info_free_entry(entry);
602 			entry = NULL;
603 		}
604 	}
605 	substream->proc_info_entry = entry;
606 	entry = snd_info_create_card_entry(card, "hw_params",
607 					   substream->proc_root);
608 	if (entry) {
609 		snd_info_set_text_ops(entry, substream,
610 				      snd_pcm_substream_proc_hw_params_read);
611 		if (snd_info_register(entry) < 0) {
612 			snd_info_free_entry(entry);
613 			entry = NULL;
614 		}
615 	}
616 	substream->proc_hw_params_entry = entry;
617 	entry = snd_info_create_card_entry(card, "sw_params",
618 					   substream->proc_root);
619 	if (entry) {
620 		snd_info_set_text_ops(entry, substream,
621 				      snd_pcm_substream_proc_sw_params_read);
622 		if (snd_info_register(entry) < 0) {
623 			snd_info_free_entry(entry);
624 			entry = NULL;
625 		}
626 	}
627 	substream->proc_sw_params_entry = entry;
628 	entry = snd_info_create_card_entry(card, "status",
629 					   substream->proc_root);
630 	if (entry) {
631 		snd_info_set_text_ops(entry, substream,
632 				      snd_pcm_substream_proc_status_read);
633 		if (snd_info_register(entry) < 0) {
634 			snd_info_free_entry(entry);
635 			entry = NULL;
636 		}
637 	}
638 	substream->proc_status_entry = entry;
639 
640 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
641 	entry = snd_info_create_card_entry(card, "xrun_injection",
642 					   substream->proc_root);
643 	if (entry) {
644 		entry->private_data = substream;
645 		entry->c.text.read = NULL;
646 		entry->c.text.write = snd_pcm_xrun_injection_write;
647 		entry->mode = S_IFREG | S_IWUSR;
648 		if (snd_info_register(entry) < 0) {
649 			snd_info_free_entry(entry);
650 			entry = NULL;
651 		}
652 	}
653 	substream->proc_xrun_injection_entry = entry;
654 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
655 
656 	return 0;
657 }
658 
659 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
660 {
661 	snd_info_free_entry(substream->proc_info_entry);
662 	substream->proc_info_entry = NULL;
663 	snd_info_free_entry(substream->proc_hw_params_entry);
664 	substream->proc_hw_params_entry = NULL;
665 	snd_info_free_entry(substream->proc_sw_params_entry);
666 	substream->proc_sw_params_entry = NULL;
667 	snd_info_free_entry(substream->proc_status_entry);
668 	substream->proc_status_entry = NULL;
669 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
670 	snd_info_free_entry(substream->proc_xrun_injection_entry);
671 	substream->proc_xrun_injection_entry = NULL;
672 #endif
673 	snd_info_free_entry(substream->proc_root);
674 	substream->proc_root = NULL;
675 	return 0;
676 }
677 #else /* !CONFIG_SND_VERBOSE_PROCFS */
678 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
679 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
680 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
681 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
682 #endif /* CONFIG_SND_VERBOSE_PROCFS */
683 
684 static const struct attribute_group *pcm_dev_attr_groups[];
685 
686 /**
687  * snd_pcm_new_stream - create a new PCM stream
688  * @pcm: the pcm instance
689  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
690  * @substream_count: the number of substreams
691  *
692  * Creates a new stream for the pcm.
693  * The corresponding stream on the pcm must have been empty before
694  * calling this, i.e. zero must be given to the argument of
695  * snd_pcm_new().
696  *
697  * Return: Zero if successful, or a negative error code on failure.
698  */
699 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
700 {
701 	int idx, err;
702 	struct snd_pcm_str *pstr = &pcm->streams[stream];
703 	struct snd_pcm_substream *substream, *prev;
704 
705 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
706 	mutex_init(&pstr->oss.setup_mutex);
707 #endif
708 	pstr->stream = stream;
709 	pstr->pcm = pcm;
710 	pstr->substream_count = substream_count;
711 	if (!substream_count)
712 		return 0;
713 
714 	snd_device_initialize(&pstr->dev, pcm->card);
715 	pstr->dev.groups = pcm_dev_attr_groups;
716 	dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
717 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
718 
719 	if (!pcm->internal) {
720 		err = snd_pcm_stream_proc_init(pstr);
721 		if (err < 0) {
722 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
723 			return err;
724 		}
725 	}
726 	prev = NULL;
727 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
728 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
729 		if (!substream)
730 			return -ENOMEM;
731 		substream->pcm = pcm;
732 		substream->pstr = pstr;
733 		substream->number = idx;
734 		substream->stream = stream;
735 		sprintf(substream->name, "subdevice #%i", idx);
736 		substream->buffer_bytes_max = UINT_MAX;
737 		if (prev == NULL)
738 			pstr->substream = substream;
739 		else
740 			prev->next = substream;
741 
742 		if (!pcm->internal) {
743 			err = snd_pcm_substream_proc_init(substream);
744 			if (err < 0) {
745 				pcm_err(pcm,
746 					"Error in snd_pcm_stream_proc_init\n");
747 				if (prev == NULL)
748 					pstr->substream = NULL;
749 				else
750 					prev->next = NULL;
751 				kfree(substream);
752 				return err;
753 			}
754 		}
755 		substream->group = &substream->self_group;
756 		spin_lock_init(&substream->self_group.lock);
757 		mutex_init(&substream->self_group.mutex);
758 		INIT_LIST_HEAD(&substream->self_group.substreams);
759 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
760 		atomic_set(&substream->mmap_count, 0);
761 		prev = substream;
762 	}
763 	return 0;
764 }
765 EXPORT_SYMBOL(snd_pcm_new_stream);
766 
767 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
768 		int playback_count, int capture_count, bool internal,
769 		struct snd_pcm **rpcm)
770 {
771 	struct snd_pcm *pcm;
772 	int err;
773 	static struct snd_device_ops ops = {
774 		.dev_free = snd_pcm_dev_free,
775 		.dev_register =	snd_pcm_dev_register,
776 		.dev_disconnect = snd_pcm_dev_disconnect,
777 	};
778 	static struct snd_device_ops internal_ops = {
779 		.dev_free = snd_pcm_dev_free,
780 	};
781 
782 	if (snd_BUG_ON(!card))
783 		return -ENXIO;
784 	if (rpcm)
785 		*rpcm = NULL;
786 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
787 	if (!pcm)
788 		return -ENOMEM;
789 	pcm->card = card;
790 	pcm->device = device;
791 	pcm->internal = internal;
792 	mutex_init(&pcm->open_mutex);
793 	init_waitqueue_head(&pcm->open_wait);
794 	INIT_LIST_HEAD(&pcm->list);
795 	if (id)
796 		strlcpy(pcm->id, id, sizeof(pcm->id));
797 
798 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
799 				 playback_count);
800 	if (err < 0)
801 		goto free_pcm;
802 
803 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
804 	if (err < 0)
805 		goto free_pcm;
806 
807 	err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
808 			     internal ? &internal_ops : &ops);
809 	if (err < 0)
810 		goto free_pcm;
811 
812 	if (rpcm)
813 		*rpcm = pcm;
814 	return 0;
815 
816 free_pcm:
817 	snd_pcm_free(pcm);
818 	return err;
819 }
820 
821 /**
822  * snd_pcm_new - create a new PCM instance
823  * @card: the card instance
824  * @id: the id string
825  * @device: the device index (zero based)
826  * @playback_count: the number of substreams for playback
827  * @capture_count: the number of substreams for capture
828  * @rpcm: the pointer to store the new pcm instance
829  *
830  * Creates a new PCM instance.
831  *
832  * The pcm operators have to be set afterwards to the new instance
833  * via snd_pcm_set_ops().
834  *
835  * Return: Zero if successful, or a negative error code on failure.
836  */
837 int snd_pcm_new(struct snd_card *card, const char *id, int device,
838 		int playback_count, int capture_count, struct snd_pcm **rpcm)
839 {
840 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
841 			false, rpcm);
842 }
843 EXPORT_SYMBOL(snd_pcm_new);
844 
845 /**
846  * snd_pcm_new_internal - create a new internal PCM instance
847  * @card: the card instance
848  * @id: the id string
849  * @device: the device index (zero based - shared with normal PCMs)
850  * @playback_count: the number of substreams for playback
851  * @capture_count: the number of substreams for capture
852  * @rpcm: the pointer to store the new pcm instance
853  *
854  * Creates a new internal PCM instance with no userspace device or procfs
855  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
856  * will only be used internally by kernel drivers. i.e. it cannot be opened
857  * by userspace. It provides existing ASoC components drivers with a substream
858  * and access to any private data.
859  *
860  * The pcm operators have to be set afterwards to the new instance
861  * via snd_pcm_set_ops().
862  *
863  * Return: Zero if successful, or a negative error code on failure.
864  */
865 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
866 	int playback_count, int capture_count,
867 	struct snd_pcm **rpcm)
868 {
869 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
870 			true, rpcm);
871 }
872 EXPORT_SYMBOL(snd_pcm_new_internal);
873 
874 static void free_chmap(struct snd_pcm_str *pstr)
875 {
876 	if (pstr->chmap_kctl) {
877 		snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
878 		pstr->chmap_kctl = NULL;
879 	}
880 }
881 
882 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
883 {
884 	struct snd_pcm_substream *substream, *substream_next;
885 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
886 	struct snd_pcm_oss_setup *setup, *setupn;
887 #endif
888 	substream = pstr->substream;
889 	while (substream) {
890 		substream_next = substream->next;
891 		snd_pcm_timer_done(substream);
892 		snd_pcm_substream_proc_done(substream);
893 		kfree(substream);
894 		substream = substream_next;
895 	}
896 	snd_pcm_stream_proc_done(pstr);
897 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
898 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
899 		setupn = setup->next;
900 		kfree(setup->task_name);
901 		kfree(setup);
902 	}
903 #endif
904 	free_chmap(pstr);
905 	if (pstr->substream_count)
906 		put_device(&pstr->dev);
907 }
908 
909 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
910 #define pcm_call_notify(pcm, call)					\
911 	do {								\
912 		struct snd_pcm_notify *_notify;				\
913 		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
914 			_notify->call(pcm);				\
915 	} while (0)
916 #else
917 #define pcm_call_notify(pcm, call) do {} while (0)
918 #endif
919 
920 static int snd_pcm_free(struct snd_pcm *pcm)
921 {
922 	if (!pcm)
923 		return 0;
924 	if (!pcm->internal)
925 		pcm_call_notify(pcm, n_unregister);
926 	if (pcm->private_free)
927 		pcm->private_free(pcm);
928 	snd_pcm_lib_preallocate_free_for_all(pcm);
929 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
930 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
931 	kfree(pcm);
932 	return 0;
933 }
934 
935 static int snd_pcm_dev_free(struct snd_device *device)
936 {
937 	struct snd_pcm *pcm = device->device_data;
938 	return snd_pcm_free(pcm);
939 }
940 
941 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
942 			     struct file *file,
943 			     struct snd_pcm_substream **rsubstream)
944 {
945 	struct snd_pcm_str * pstr;
946 	struct snd_pcm_substream *substream;
947 	struct snd_pcm_runtime *runtime;
948 	struct snd_card *card;
949 	int prefer_subdevice;
950 	size_t size;
951 
952 	if (snd_BUG_ON(!pcm || !rsubstream))
953 		return -ENXIO;
954 	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
955 		       stream != SNDRV_PCM_STREAM_CAPTURE))
956 		return -EINVAL;
957 	*rsubstream = NULL;
958 	pstr = &pcm->streams[stream];
959 	if (pstr->substream == NULL || pstr->substream_count == 0)
960 		return -ENODEV;
961 
962 	card = pcm->card;
963 	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
964 
965 	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
966 		int opposite = !stream;
967 
968 		for (substream = pcm->streams[opposite].substream; substream;
969 		     substream = substream->next) {
970 			if (SUBSTREAM_BUSY(substream))
971 				return -EAGAIN;
972 		}
973 	}
974 
975 	if (file->f_flags & O_APPEND) {
976 		if (prefer_subdevice < 0) {
977 			if (pstr->substream_count > 1)
978 				return -EINVAL; /* must be unique */
979 			substream = pstr->substream;
980 		} else {
981 			for (substream = pstr->substream; substream;
982 			     substream = substream->next)
983 				if (substream->number == prefer_subdevice)
984 					break;
985 		}
986 		if (! substream)
987 			return -ENODEV;
988 		if (! SUBSTREAM_BUSY(substream))
989 			return -EBADFD;
990 		substream->ref_count++;
991 		*rsubstream = substream;
992 		return 0;
993 	}
994 
995 	for (substream = pstr->substream; substream; substream = substream->next) {
996 		if (!SUBSTREAM_BUSY(substream) &&
997 		    (prefer_subdevice == -1 ||
998 		     substream->number == prefer_subdevice))
999 			break;
1000 	}
1001 	if (substream == NULL)
1002 		return -EAGAIN;
1003 
1004 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
1005 	if (runtime == NULL)
1006 		return -ENOMEM;
1007 
1008 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
1009 	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
1010 	if (runtime->status == NULL) {
1011 		kfree(runtime);
1012 		return -ENOMEM;
1013 	}
1014 	memset((void*)runtime->status, 0, size);
1015 
1016 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
1017 	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
1018 	if (runtime->control == NULL) {
1019 		snd_free_pages((void*)runtime->status,
1020 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1021 		kfree(runtime);
1022 		return -ENOMEM;
1023 	}
1024 	memset((void*)runtime->control, 0, size);
1025 
1026 	init_waitqueue_head(&runtime->sleep);
1027 	init_waitqueue_head(&runtime->tsleep);
1028 
1029 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
1030 
1031 	substream->runtime = runtime;
1032 	substream->private_data = pcm->private_data;
1033 	substream->ref_count = 1;
1034 	substream->f_flags = file->f_flags;
1035 	substream->pid = get_pid(task_pid(current));
1036 	pstr->substream_opened++;
1037 	*rsubstream = substream;
1038 	return 0;
1039 }
1040 
1041 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1042 {
1043 	struct snd_pcm_runtime *runtime;
1044 
1045 	if (PCM_RUNTIME_CHECK(substream))
1046 		return;
1047 	runtime = substream->runtime;
1048 	if (runtime->private_free != NULL)
1049 		runtime->private_free(runtime);
1050 	snd_free_pages((void*)runtime->status,
1051 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1052 	snd_free_pages((void*)runtime->control,
1053 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1054 	kfree(runtime->hw_constraints.rules);
1055 	kfree(runtime);
1056 	substream->runtime = NULL;
1057 	put_pid(substream->pid);
1058 	substream->pid = NULL;
1059 	substream->pstr->substream_opened--;
1060 }
1061 
1062 static ssize_t show_pcm_class(struct device *dev,
1063 			      struct device_attribute *attr, char *buf)
1064 {
1065 	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1066 	struct snd_pcm *pcm = pstr->pcm;
1067 	const char *str;
1068 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1069 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1070 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1071 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1072 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1073 	};
1074 
1075 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1076 		str = "none";
1077 	else
1078 		str = strs[pcm->dev_class];
1079         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1080 }
1081 
1082 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1083 static struct attribute *pcm_dev_attrs[] = {
1084 	&dev_attr_pcm_class.attr,
1085 	NULL
1086 };
1087 
1088 static const struct attribute_group pcm_dev_attr_group = {
1089 	.attrs	= pcm_dev_attrs,
1090 };
1091 
1092 static const struct attribute_group *pcm_dev_attr_groups[] = {
1093 	&pcm_dev_attr_group,
1094 	NULL
1095 };
1096 
1097 static int snd_pcm_dev_register(struct snd_device *device)
1098 {
1099 	int cidx, err;
1100 	struct snd_pcm_substream *substream;
1101 	struct snd_pcm *pcm;
1102 
1103 	if (snd_BUG_ON(!device || !device->device_data))
1104 		return -ENXIO;
1105 	pcm = device->device_data;
1106 
1107 	mutex_lock(&register_mutex);
1108 	err = snd_pcm_add(pcm);
1109 	if (err)
1110 		goto unlock;
1111 	for (cidx = 0; cidx < 2; cidx++) {
1112 		int devtype = -1;
1113 		if (pcm->streams[cidx].substream == NULL)
1114 			continue;
1115 		switch (cidx) {
1116 		case SNDRV_PCM_STREAM_PLAYBACK:
1117 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1118 			break;
1119 		case SNDRV_PCM_STREAM_CAPTURE:
1120 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1121 			break;
1122 		}
1123 		/* register pcm */
1124 		err = snd_register_device(devtype, pcm->card, pcm->device,
1125 					  &snd_pcm_f_ops[cidx], pcm,
1126 					  &pcm->streams[cidx].dev);
1127 		if (err < 0) {
1128 			list_del_init(&pcm->list);
1129 			goto unlock;
1130 		}
1131 
1132 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1133 			snd_pcm_timer_init(substream);
1134 	}
1135 
1136 	pcm_call_notify(pcm, n_register);
1137 
1138  unlock:
1139 	mutex_unlock(&register_mutex);
1140 	return err;
1141 }
1142 
1143 static int snd_pcm_dev_disconnect(struct snd_device *device)
1144 {
1145 	struct snd_pcm *pcm = device->device_data;
1146 	struct snd_pcm_substream *substream;
1147 	int cidx;
1148 
1149 	mutex_lock(&register_mutex);
1150 	mutex_lock(&pcm->open_mutex);
1151 	wake_up(&pcm->open_wait);
1152 	list_del_init(&pcm->list);
1153 	for (cidx = 0; cidx < 2; cidx++) {
1154 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1155 			snd_pcm_stream_lock_irq(substream);
1156 			if (substream->runtime) {
1157 				if (snd_pcm_running(substream))
1158 					snd_pcm_stop(substream,
1159 						     SNDRV_PCM_STATE_DISCONNECTED);
1160 				/* to be sure, set the state unconditionally */
1161 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1162 				wake_up(&substream->runtime->sleep);
1163 				wake_up(&substream->runtime->tsleep);
1164 			}
1165 			snd_pcm_stream_unlock_irq(substream);
1166 		}
1167 	}
1168 
1169 	pcm_call_notify(pcm, n_disconnect);
1170 	for (cidx = 0; cidx < 2; cidx++) {
1171 		snd_unregister_device(&pcm->streams[cidx].dev);
1172 		free_chmap(&pcm->streams[cidx]);
1173 	}
1174 	mutex_unlock(&pcm->open_mutex);
1175 	mutex_unlock(&register_mutex);
1176 	return 0;
1177 }
1178 
1179 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1180 /**
1181  * snd_pcm_notify - Add/remove the notify list
1182  * @notify: PCM notify list
1183  * @nfree: 0 = register, 1 = unregister
1184  *
1185  * This adds the given notifier to the global list so that the callback is
1186  * called for each registered PCM devices.  This exists only for PCM OSS
1187  * emulation, so far.
1188  */
1189 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1190 {
1191 	struct snd_pcm *pcm;
1192 
1193 	if (snd_BUG_ON(!notify ||
1194 		       !notify->n_register ||
1195 		       !notify->n_unregister ||
1196 		       !notify->n_disconnect))
1197 		return -EINVAL;
1198 	mutex_lock(&register_mutex);
1199 	if (nfree) {
1200 		list_del(&notify->list);
1201 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1202 			notify->n_unregister(pcm);
1203 	} else {
1204 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1205 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1206 			notify->n_register(pcm);
1207 	}
1208 	mutex_unlock(&register_mutex);
1209 	return 0;
1210 }
1211 EXPORT_SYMBOL(snd_pcm_notify);
1212 #endif /* CONFIG_SND_PCM_OSS */
1213 
1214 #ifdef CONFIG_SND_PROC_FS
1215 /*
1216  *  Info interface
1217  */
1218 
1219 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1220 			      struct snd_info_buffer *buffer)
1221 {
1222 	struct snd_pcm *pcm;
1223 
1224 	mutex_lock(&register_mutex);
1225 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1226 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1227 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1228 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1229 			snd_iprintf(buffer, " : playback %i",
1230 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1231 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1232 			snd_iprintf(buffer, " : capture %i",
1233 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1234 		snd_iprintf(buffer, "\n");
1235 	}
1236 	mutex_unlock(&register_mutex);
1237 }
1238 
1239 static struct snd_info_entry *snd_pcm_proc_entry;
1240 
1241 static void snd_pcm_proc_init(void)
1242 {
1243 	struct snd_info_entry *entry;
1244 
1245 	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1246 	if (entry) {
1247 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1248 		if (snd_info_register(entry) < 0) {
1249 			snd_info_free_entry(entry);
1250 			entry = NULL;
1251 		}
1252 	}
1253 	snd_pcm_proc_entry = entry;
1254 }
1255 
1256 static void snd_pcm_proc_done(void)
1257 {
1258 	snd_info_free_entry(snd_pcm_proc_entry);
1259 }
1260 
1261 #else /* !CONFIG_SND_PROC_FS */
1262 #define snd_pcm_proc_init()
1263 #define snd_pcm_proc_done()
1264 #endif /* CONFIG_SND_PROC_FS */
1265 
1266 
1267 /*
1268  *  ENTRY functions
1269  */
1270 
1271 static int __init alsa_pcm_init(void)
1272 {
1273 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1274 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1275 	snd_pcm_proc_init();
1276 	return 0;
1277 }
1278 
1279 static void __exit alsa_pcm_exit(void)
1280 {
1281 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1282 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1283 	snd_pcm_proc_done();
1284 }
1285 
1286 module_init(alsa_pcm_init)
1287 module_exit(alsa_pcm_exit)
1288