xref: /linux/sound/core/pcm.c (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
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/timer.h>
32 #include <sound/control.h>
33 #include <sound/info.h>
34 
35 #include "pcm_local.h"
36 
37 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
38 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
39 MODULE_LICENSE("GPL");
40 
41 static LIST_HEAD(snd_pcm_devices);
42 static DEFINE_MUTEX(register_mutex);
43 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
44 static LIST_HEAD(snd_pcm_notify_list);
45 #endif
46 
47 static int snd_pcm_free(struct snd_pcm *pcm);
48 static int snd_pcm_dev_free(struct snd_device *device);
49 static int snd_pcm_dev_register(struct snd_device *device);
50 static int snd_pcm_dev_disconnect(struct snd_device *device);
51 
52 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
53 {
54 	struct snd_pcm *pcm;
55 
56 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
57 		if (pcm->card == card && pcm->device == device)
58 			return pcm;
59 	}
60 	return NULL;
61 }
62 
63 static int snd_pcm_next(struct snd_card *card, int device)
64 {
65 	struct snd_pcm *pcm;
66 
67 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
68 		if (pcm->card == card && pcm->device > device)
69 			return pcm->device;
70 		else if (pcm->card->number > card->number)
71 			return -1;
72 	}
73 	return -1;
74 }
75 
76 static int snd_pcm_add(struct snd_pcm *newpcm)
77 {
78 	struct snd_pcm *pcm;
79 
80 	if (newpcm->internal)
81 		return 0;
82 
83 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
84 		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
85 			return -EBUSY;
86 		if (pcm->card->number > newpcm->card->number ||
87 				(pcm->card == newpcm->card &&
88 				pcm->device > newpcm->device)) {
89 			list_add(&newpcm->list, pcm->list.prev);
90 			return 0;
91 		}
92 	}
93 	list_add_tail(&newpcm->list, &snd_pcm_devices);
94 	return 0;
95 }
96 
97 static int snd_pcm_control_ioctl(struct snd_card *card,
98 				 struct snd_ctl_file *control,
99 				 unsigned int cmd, unsigned long arg)
100 {
101 	switch (cmd) {
102 	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
103 		{
104 			int device;
105 
106 			if (get_user(device, (int __user *)arg))
107 				return -EFAULT;
108 			mutex_lock(&register_mutex);
109 			device = snd_pcm_next(card, device);
110 			mutex_unlock(&register_mutex);
111 			if (put_user(device, (int __user *)arg))
112 				return -EFAULT;
113 			return 0;
114 		}
115 	case SNDRV_CTL_IOCTL_PCM_INFO:
116 		{
117 			struct snd_pcm_info __user *info;
118 			unsigned int device, subdevice;
119 			int stream;
120 			struct snd_pcm *pcm;
121 			struct snd_pcm_str *pstr;
122 			struct snd_pcm_substream *substream;
123 			int err;
124 
125 			info = (struct snd_pcm_info __user *)arg;
126 			if (get_user(device, &info->device))
127 				return -EFAULT;
128 			if (get_user(stream, &info->stream))
129 				return -EFAULT;
130 			if (stream < 0 || stream > 1)
131 				return -EINVAL;
132 			if (get_user(subdevice, &info->subdevice))
133 				return -EFAULT;
134 			mutex_lock(&register_mutex);
135 			pcm = snd_pcm_get(card, device);
136 			if (pcm == NULL) {
137 				err = -ENXIO;
138 				goto _error;
139 			}
140 			pstr = &pcm->streams[stream];
141 			if (pstr->substream_count == 0) {
142 				err = -ENOENT;
143 				goto _error;
144 			}
145 			if (subdevice >= pstr->substream_count) {
146 				err = -ENXIO;
147 				goto _error;
148 			}
149 			for (substream = pstr->substream; substream;
150 			     substream = substream->next)
151 				if (substream->number == (int)subdevice)
152 					break;
153 			if (substream == NULL) {
154 				err = -ENXIO;
155 				goto _error;
156 			}
157 			mutex_lock(&pcm->open_mutex);
158 			err = snd_pcm_info_user(substream, info);
159 			mutex_unlock(&pcm->open_mutex);
160 		_error:
161 			mutex_unlock(&register_mutex);
162 			return err;
163 		}
164 	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
165 		{
166 			int val;
167 
168 			if (get_user(val, (int __user *)arg))
169 				return -EFAULT;
170 			control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
171 			return 0;
172 		}
173 	}
174 	return -ENOIOCTLCMD;
175 }
176 
177 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
178 
179 static char *snd_pcm_format_names[] = {
180 	FORMAT(S8),
181 	FORMAT(U8),
182 	FORMAT(S16_LE),
183 	FORMAT(S16_BE),
184 	FORMAT(U16_LE),
185 	FORMAT(U16_BE),
186 	FORMAT(S24_LE),
187 	FORMAT(S24_BE),
188 	FORMAT(U24_LE),
189 	FORMAT(U24_BE),
190 	FORMAT(S32_LE),
191 	FORMAT(S32_BE),
192 	FORMAT(U32_LE),
193 	FORMAT(U32_BE),
194 	FORMAT(FLOAT_LE),
195 	FORMAT(FLOAT_BE),
196 	FORMAT(FLOAT64_LE),
197 	FORMAT(FLOAT64_BE),
198 	FORMAT(IEC958_SUBFRAME_LE),
199 	FORMAT(IEC958_SUBFRAME_BE),
200 	FORMAT(MU_LAW),
201 	FORMAT(A_LAW),
202 	FORMAT(IMA_ADPCM),
203 	FORMAT(MPEG),
204 	FORMAT(GSM),
205 	FORMAT(SPECIAL),
206 	FORMAT(S24_3LE),
207 	FORMAT(S24_3BE),
208 	FORMAT(U24_3LE),
209 	FORMAT(U24_3BE),
210 	FORMAT(S20_3LE),
211 	FORMAT(S20_3BE),
212 	FORMAT(U20_3LE),
213 	FORMAT(U20_3BE),
214 	FORMAT(S18_3LE),
215 	FORMAT(S18_3BE),
216 	FORMAT(U18_3LE),
217 	FORMAT(U18_3BE),
218 	FORMAT(G723_24),
219 	FORMAT(G723_24_1B),
220 	FORMAT(G723_40),
221 	FORMAT(G723_40_1B),
222 	FORMAT(DSD_U8),
223 	FORMAT(DSD_U16_LE),
224 	FORMAT(DSD_U32_LE),
225 	FORMAT(DSD_U16_BE),
226 	FORMAT(DSD_U32_BE),
227 };
228 
229 /**
230  * snd_pcm_format_name - Return a name string for the given PCM format
231  * @format: PCM format
232  */
233 const char *snd_pcm_format_name(snd_pcm_format_t format)
234 {
235 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
236 		return "Unknown";
237 	return snd_pcm_format_names[(__force unsigned int)format];
238 }
239 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
240 
241 #ifdef CONFIG_SND_VERBOSE_PROCFS
242 
243 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
244 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
245 #define READY(v) [SNDRV_PCM_READY_##v] = #v
246 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
247 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
248 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
249 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
250 #define START(v) [SNDRV_PCM_START_##v] = #v
251 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
252 
253 static char *snd_pcm_stream_names[] = {
254 	STREAM(PLAYBACK),
255 	STREAM(CAPTURE),
256 };
257 
258 static char *snd_pcm_state_names[] = {
259 	STATE(OPEN),
260 	STATE(SETUP),
261 	STATE(PREPARED),
262 	STATE(RUNNING),
263 	STATE(XRUN),
264 	STATE(DRAINING),
265 	STATE(PAUSED),
266 	STATE(SUSPENDED),
267 };
268 
269 static char *snd_pcm_access_names[] = {
270 	ACCESS(MMAP_INTERLEAVED),
271 	ACCESS(MMAP_NONINTERLEAVED),
272 	ACCESS(MMAP_COMPLEX),
273 	ACCESS(RW_INTERLEAVED),
274 	ACCESS(RW_NONINTERLEAVED),
275 };
276 
277 static char *snd_pcm_subformat_names[] = {
278 	SUBFORMAT(STD),
279 };
280 
281 static char *snd_pcm_tstamp_mode_names[] = {
282 	TSTAMP(NONE),
283 	TSTAMP(ENABLE),
284 };
285 
286 static const char *snd_pcm_stream_name(int stream)
287 {
288 	return snd_pcm_stream_names[stream];
289 }
290 
291 static const char *snd_pcm_access_name(snd_pcm_access_t access)
292 {
293 	return snd_pcm_access_names[(__force int)access];
294 }
295 
296 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
297 {
298 	return snd_pcm_subformat_names[(__force int)subformat];
299 }
300 
301 static const char *snd_pcm_tstamp_mode_name(int mode)
302 {
303 	return snd_pcm_tstamp_mode_names[mode];
304 }
305 
306 static const char *snd_pcm_state_name(snd_pcm_state_t state)
307 {
308 	return snd_pcm_state_names[(__force int)state];
309 }
310 
311 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
312 #include <linux/soundcard.h>
313 
314 static const char *snd_pcm_oss_format_name(int format)
315 {
316 	switch (format) {
317 	case AFMT_MU_LAW:
318 		return "MU_LAW";
319 	case AFMT_A_LAW:
320 		return "A_LAW";
321 	case AFMT_IMA_ADPCM:
322 		return "IMA_ADPCM";
323 	case AFMT_U8:
324 		return "U8";
325 	case AFMT_S16_LE:
326 		return "S16_LE";
327 	case AFMT_S16_BE:
328 		return "S16_BE";
329 	case AFMT_S8:
330 		return "S8";
331 	case AFMT_U16_LE:
332 		return "U16_LE";
333 	case AFMT_U16_BE:
334 		return "U16_BE";
335 	case AFMT_MPEG:
336 		return "MPEG";
337 	default:
338 		return "unknown";
339 	}
340 }
341 #endif
342 
343 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
344 				   struct snd_info_buffer *buffer)
345 {
346 	struct snd_pcm_info *info;
347 	int err;
348 
349 	if (! substream)
350 		return;
351 
352 	info = kmalloc(sizeof(*info), GFP_KERNEL);
353 	if (!info)
354 		return;
355 
356 	err = snd_pcm_info(substream, info);
357 	if (err < 0) {
358 		snd_iprintf(buffer, "error %d\n", err);
359 		kfree(info);
360 		return;
361 	}
362 	snd_iprintf(buffer, "card: %d\n", info->card);
363 	snd_iprintf(buffer, "device: %d\n", info->device);
364 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
365 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
366 	snd_iprintf(buffer, "id: %s\n", info->id);
367 	snd_iprintf(buffer, "name: %s\n", info->name);
368 	snd_iprintf(buffer, "subname: %s\n", info->subname);
369 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
370 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
371 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
372 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
373 	kfree(info);
374 }
375 
376 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
377 					  struct snd_info_buffer *buffer)
378 {
379 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
380 			       buffer);
381 }
382 
383 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
384 					     struct snd_info_buffer *buffer)
385 {
386 	snd_pcm_proc_info_read(entry->private_data, buffer);
387 }
388 
389 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
390 						  struct snd_info_buffer *buffer)
391 {
392 	struct snd_pcm_substream *substream = entry->private_data;
393 	struct snd_pcm_runtime *runtime;
394 
395 	mutex_lock(&substream->pcm->open_mutex);
396 	runtime = substream->runtime;
397 	if (!runtime) {
398 		snd_iprintf(buffer, "closed\n");
399 		goto unlock;
400 	}
401 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
402 		snd_iprintf(buffer, "no setup\n");
403 		goto unlock;
404 	}
405 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
406 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
407 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
408 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
409 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
410 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
411 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
412 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
413 	if (substream->oss.oss) {
414 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
415 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
416 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
417 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
418 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
419 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
420 	}
421 #endif
422  unlock:
423 	mutex_unlock(&substream->pcm->open_mutex);
424 }
425 
426 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
427 						  struct snd_info_buffer *buffer)
428 {
429 	struct snd_pcm_substream *substream = entry->private_data;
430 	struct snd_pcm_runtime *runtime;
431 
432 	mutex_lock(&substream->pcm->open_mutex);
433 	runtime = substream->runtime;
434 	if (!runtime) {
435 		snd_iprintf(buffer, "closed\n");
436 		goto unlock;
437 	}
438 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
439 		snd_iprintf(buffer, "no setup\n");
440 		goto unlock;
441 	}
442 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
443 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
444 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
445 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
446 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
447 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
448 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
449 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
450  unlock:
451 	mutex_unlock(&substream->pcm->open_mutex);
452 }
453 
454 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
455 					       struct snd_info_buffer *buffer)
456 {
457 	struct snd_pcm_substream *substream = entry->private_data;
458 	struct snd_pcm_runtime *runtime;
459 	struct snd_pcm_status status;
460 	int err;
461 
462 	mutex_lock(&substream->pcm->open_mutex);
463 	runtime = substream->runtime;
464 	if (!runtime) {
465 		snd_iprintf(buffer, "closed\n");
466 		goto unlock;
467 	}
468 	memset(&status, 0, sizeof(status));
469 	err = snd_pcm_status(substream, &status);
470 	if (err < 0) {
471 		snd_iprintf(buffer, "error %d\n", err);
472 		goto unlock;
473 	}
474 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
475 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
476 	snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
477 		status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
478 	snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
479 		status.tstamp.tv_sec, status.tstamp.tv_nsec);
480 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
481 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
482 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
483 	snd_iprintf(buffer, "-----\n");
484 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
485 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
486  unlock:
487 	mutex_unlock(&substream->pcm->open_mutex);
488 }
489 
490 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
491 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
492 					 struct snd_info_buffer *buffer)
493 {
494 	struct snd_pcm_substream *substream = entry->private_data;
495 	struct snd_pcm_runtime *runtime;
496 
497 	snd_pcm_stream_lock_irq(substream);
498 	runtime = substream->runtime;
499 	if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
500 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
501 	snd_pcm_stream_unlock_irq(substream);
502 }
503 
504 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
505 				    struct snd_info_buffer *buffer)
506 {
507 	struct snd_pcm_str *pstr = entry->private_data;
508 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
509 }
510 
511 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
512 				     struct snd_info_buffer *buffer)
513 {
514 	struct snd_pcm_str *pstr = entry->private_data;
515 	char line[64];
516 	if (!snd_info_get_line(buffer, line, sizeof(line)))
517 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
518 }
519 #endif
520 
521 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
522 {
523 	struct snd_pcm *pcm = pstr->pcm;
524 	struct snd_info_entry *entry;
525 	char name[16];
526 
527 	sprintf(name, "pcm%i%c", pcm->device,
528 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
529 	entry = snd_info_create_card_entry(pcm->card, name,
530 					   pcm->card->proc_root);
531 	if (!entry)
532 		return -ENOMEM;
533 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
534 	if (snd_info_register(entry) < 0) {
535 		snd_info_free_entry(entry);
536 		return -ENOMEM;
537 	}
538 	pstr->proc_root = entry;
539 	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
540 	if (entry) {
541 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
542 		if (snd_info_register(entry) < 0) {
543 			snd_info_free_entry(entry);
544 			entry = NULL;
545 		}
546 	}
547 	pstr->proc_info_entry = entry;
548 
549 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
550 	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
551 					   pstr->proc_root);
552 	if (entry) {
553 		entry->c.text.read = snd_pcm_xrun_debug_read;
554 		entry->c.text.write = snd_pcm_xrun_debug_write;
555 		entry->mode |= S_IWUSR;
556 		entry->private_data = pstr;
557 		if (snd_info_register(entry) < 0) {
558 			snd_info_free_entry(entry);
559 			entry = NULL;
560 		}
561 	}
562 	pstr->proc_xrun_debug_entry = entry;
563 #endif
564 	return 0;
565 }
566 
567 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
568 {
569 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
570 	snd_info_free_entry(pstr->proc_xrun_debug_entry);
571 	pstr->proc_xrun_debug_entry = NULL;
572 #endif
573 	snd_info_free_entry(pstr->proc_info_entry);
574 	pstr->proc_info_entry = NULL;
575 	snd_info_free_entry(pstr->proc_root);
576 	pstr->proc_root = NULL;
577 	return 0;
578 }
579 
580 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
581 {
582 	struct snd_info_entry *entry;
583 	struct snd_card *card;
584 	char name[16];
585 
586 	card = substream->pcm->card;
587 
588 	sprintf(name, "sub%i", substream->number);
589 	entry = snd_info_create_card_entry(card, name,
590 					   substream->pstr->proc_root);
591 	if (!entry)
592 		return -ENOMEM;
593 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
594 	if (snd_info_register(entry) < 0) {
595 		snd_info_free_entry(entry);
596 		return -ENOMEM;
597 	}
598 	substream->proc_root = entry;
599 	entry = snd_info_create_card_entry(card, "info", substream->proc_root);
600 	if (entry) {
601 		snd_info_set_text_ops(entry, substream,
602 				      snd_pcm_substream_proc_info_read);
603 		if (snd_info_register(entry) < 0) {
604 			snd_info_free_entry(entry);
605 			entry = NULL;
606 		}
607 	}
608 	substream->proc_info_entry = entry;
609 	entry = snd_info_create_card_entry(card, "hw_params",
610 					   substream->proc_root);
611 	if (entry) {
612 		snd_info_set_text_ops(entry, substream,
613 				      snd_pcm_substream_proc_hw_params_read);
614 		if (snd_info_register(entry) < 0) {
615 			snd_info_free_entry(entry);
616 			entry = NULL;
617 		}
618 	}
619 	substream->proc_hw_params_entry = entry;
620 	entry = snd_info_create_card_entry(card, "sw_params",
621 					   substream->proc_root);
622 	if (entry) {
623 		snd_info_set_text_ops(entry, substream,
624 				      snd_pcm_substream_proc_sw_params_read);
625 		if (snd_info_register(entry) < 0) {
626 			snd_info_free_entry(entry);
627 			entry = NULL;
628 		}
629 	}
630 	substream->proc_sw_params_entry = entry;
631 	entry = snd_info_create_card_entry(card, "status",
632 					   substream->proc_root);
633 	if (entry) {
634 		snd_info_set_text_ops(entry, substream,
635 				      snd_pcm_substream_proc_status_read);
636 		if (snd_info_register(entry) < 0) {
637 			snd_info_free_entry(entry);
638 			entry = NULL;
639 		}
640 	}
641 	substream->proc_status_entry = entry;
642 
643 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
644 	entry = snd_info_create_card_entry(card, "xrun_injection",
645 					   substream->proc_root);
646 	if (entry) {
647 		entry->private_data = substream;
648 		entry->c.text.read = NULL;
649 		entry->c.text.write = snd_pcm_xrun_injection_write;
650 		entry->mode = S_IFREG | S_IWUSR;
651 		if (snd_info_register(entry) < 0) {
652 			snd_info_free_entry(entry);
653 			entry = NULL;
654 		}
655 	}
656 	substream->proc_xrun_injection_entry = entry;
657 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
658 
659 	return 0;
660 }
661 
662 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
663 {
664 	snd_info_free_entry(substream->proc_info_entry);
665 	substream->proc_info_entry = NULL;
666 	snd_info_free_entry(substream->proc_hw_params_entry);
667 	substream->proc_hw_params_entry = NULL;
668 	snd_info_free_entry(substream->proc_sw_params_entry);
669 	substream->proc_sw_params_entry = NULL;
670 	snd_info_free_entry(substream->proc_status_entry);
671 	substream->proc_status_entry = NULL;
672 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
673 	snd_info_free_entry(substream->proc_xrun_injection_entry);
674 	substream->proc_xrun_injection_entry = NULL;
675 #endif
676 	snd_info_free_entry(substream->proc_root);
677 	substream->proc_root = NULL;
678 	return 0;
679 }
680 #else /* !CONFIG_SND_VERBOSE_PROCFS */
681 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
682 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
683 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
684 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
685 #endif /* CONFIG_SND_VERBOSE_PROCFS */
686 
687 static const struct attribute_group *pcm_dev_attr_groups[];
688 
689 /**
690  * snd_pcm_new_stream - create a new PCM stream
691  * @pcm: the pcm instance
692  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
693  * @substream_count: the number of substreams
694  *
695  * Creates a new stream for the pcm.
696  * The corresponding stream on the pcm must have been empty before
697  * calling this, i.e. zero must be given to the argument of
698  * snd_pcm_new().
699  *
700  * Return: Zero if successful, or a negative error code on failure.
701  */
702 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
703 {
704 	int idx, err;
705 	struct snd_pcm_str *pstr = &pcm->streams[stream];
706 	struct snd_pcm_substream *substream, *prev;
707 
708 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
709 	mutex_init(&pstr->oss.setup_mutex);
710 #endif
711 	pstr->stream = stream;
712 	pstr->pcm = pcm;
713 	pstr->substream_count = substream_count;
714 	if (!substream_count)
715 		return 0;
716 
717 	snd_device_initialize(&pstr->dev, pcm->card);
718 	pstr->dev.groups = pcm_dev_attr_groups;
719 	dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
720 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
721 
722 	if (!pcm->internal) {
723 		err = snd_pcm_stream_proc_init(pstr);
724 		if (err < 0) {
725 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
726 			return err;
727 		}
728 	}
729 	prev = NULL;
730 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
731 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
732 		if (!substream)
733 			return -ENOMEM;
734 		substream->pcm = pcm;
735 		substream->pstr = pstr;
736 		substream->number = idx;
737 		substream->stream = stream;
738 		sprintf(substream->name, "subdevice #%i", idx);
739 		substream->buffer_bytes_max = UINT_MAX;
740 		if (prev == NULL)
741 			pstr->substream = substream;
742 		else
743 			prev->next = substream;
744 
745 		if (!pcm->internal) {
746 			err = snd_pcm_substream_proc_init(substream);
747 			if (err < 0) {
748 				pcm_err(pcm,
749 					"Error in snd_pcm_stream_proc_init\n");
750 				if (prev == NULL)
751 					pstr->substream = NULL;
752 				else
753 					prev->next = NULL;
754 				kfree(substream);
755 				return err;
756 			}
757 		}
758 		substream->group = &substream->self_group;
759 		spin_lock_init(&substream->self_group.lock);
760 		mutex_init(&substream->self_group.mutex);
761 		INIT_LIST_HEAD(&substream->self_group.substreams);
762 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
763 		atomic_set(&substream->mmap_count, 0);
764 		prev = substream;
765 	}
766 	return 0;
767 }
768 EXPORT_SYMBOL(snd_pcm_new_stream);
769 
770 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
771 		int playback_count, int capture_count, bool internal,
772 		struct snd_pcm **rpcm)
773 {
774 	struct snd_pcm *pcm;
775 	int err;
776 	static struct snd_device_ops ops = {
777 		.dev_free = snd_pcm_dev_free,
778 		.dev_register =	snd_pcm_dev_register,
779 		.dev_disconnect = snd_pcm_dev_disconnect,
780 	};
781 	static struct snd_device_ops internal_ops = {
782 		.dev_free = snd_pcm_dev_free,
783 	};
784 
785 	if (snd_BUG_ON(!card))
786 		return -ENXIO;
787 	if (rpcm)
788 		*rpcm = NULL;
789 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
790 	if (!pcm)
791 		return -ENOMEM;
792 	pcm->card = card;
793 	pcm->device = device;
794 	pcm->internal = internal;
795 	mutex_init(&pcm->open_mutex);
796 	init_waitqueue_head(&pcm->open_wait);
797 	INIT_LIST_HEAD(&pcm->list);
798 	if (id)
799 		strlcpy(pcm->id, id, sizeof(pcm->id));
800 
801 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
802 				 playback_count);
803 	if (err < 0)
804 		goto free_pcm;
805 
806 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
807 	if (err < 0)
808 		goto free_pcm;
809 
810 	err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
811 			     internal ? &internal_ops : &ops);
812 	if (err < 0)
813 		goto free_pcm;
814 
815 	if (rpcm)
816 		*rpcm = pcm;
817 	return 0;
818 
819 free_pcm:
820 	snd_pcm_free(pcm);
821 	return err;
822 }
823 
824 /**
825  * snd_pcm_new - create a new PCM instance
826  * @card: the card instance
827  * @id: the id string
828  * @device: the device index (zero based)
829  * @playback_count: the number of substreams for playback
830  * @capture_count: the number of substreams for capture
831  * @rpcm: the pointer to store the new pcm instance
832  *
833  * Creates a new PCM instance.
834  *
835  * The pcm operators have to be set afterwards to the new instance
836  * via snd_pcm_set_ops().
837  *
838  * Return: Zero if successful, or a negative error code on failure.
839  */
840 int snd_pcm_new(struct snd_card *card, const char *id, int device,
841 		int playback_count, int capture_count, struct snd_pcm **rpcm)
842 {
843 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
844 			false, rpcm);
845 }
846 EXPORT_SYMBOL(snd_pcm_new);
847 
848 /**
849  * snd_pcm_new_internal - create a new internal PCM instance
850  * @card: the card instance
851  * @id: the id string
852  * @device: the device index (zero based - shared with normal PCMs)
853  * @playback_count: the number of substreams for playback
854  * @capture_count: the number of substreams for capture
855  * @rpcm: the pointer to store the new pcm instance
856  *
857  * Creates a new internal PCM instance with no userspace device or procfs
858  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
859  * will only be used internally by kernel drivers. i.e. it cannot be opened
860  * by userspace. It provides existing ASoC components drivers with a substream
861  * and access to any private data.
862  *
863  * The pcm operators have to be set afterwards to the new instance
864  * via snd_pcm_set_ops().
865  *
866  * Return: Zero if successful, or a negative error code on failure.
867  */
868 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
869 	int playback_count, int capture_count,
870 	struct snd_pcm **rpcm)
871 {
872 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
873 			true, rpcm);
874 }
875 EXPORT_SYMBOL(snd_pcm_new_internal);
876 
877 static void free_chmap(struct snd_pcm_str *pstr)
878 {
879 	if (pstr->chmap_kctl) {
880 		snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
881 		pstr->chmap_kctl = NULL;
882 	}
883 }
884 
885 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
886 {
887 	struct snd_pcm_substream *substream, *substream_next;
888 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
889 	struct snd_pcm_oss_setup *setup, *setupn;
890 #endif
891 	substream = pstr->substream;
892 	while (substream) {
893 		substream_next = substream->next;
894 		snd_pcm_timer_done(substream);
895 		snd_pcm_substream_proc_done(substream);
896 		kfree(substream);
897 		substream = substream_next;
898 	}
899 	snd_pcm_stream_proc_done(pstr);
900 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
901 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
902 		setupn = setup->next;
903 		kfree(setup->task_name);
904 		kfree(setup);
905 	}
906 #endif
907 	free_chmap(pstr);
908 	if (pstr->substream_count)
909 		put_device(&pstr->dev);
910 }
911 
912 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
913 #define pcm_call_notify(pcm, call)					\
914 	do {								\
915 		struct snd_pcm_notify *_notify;				\
916 		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
917 			_notify->call(pcm);				\
918 	} while (0)
919 #else
920 #define pcm_call_notify(pcm, call) do {} while (0)
921 #endif
922 
923 static int snd_pcm_free(struct snd_pcm *pcm)
924 {
925 	if (!pcm)
926 		return 0;
927 	if (!pcm->internal)
928 		pcm_call_notify(pcm, n_unregister);
929 	if (pcm->private_free)
930 		pcm->private_free(pcm);
931 	snd_pcm_lib_preallocate_free_for_all(pcm);
932 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
933 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
934 	kfree(pcm);
935 	return 0;
936 }
937 
938 static int snd_pcm_dev_free(struct snd_device *device)
939 {
940 	struct snd_pcm *pcm = device->device_data;
941 	return snd_pcm_free(pcm);
942 }
943 
944 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
945 			     struct file *file,
946 			     struct snd_pcm_substream **rsubstream)
947 {
948 	struct snd_pcm_str * pstr;
949 	struct snd_pcm_substream *substream;
950 	struct snd_pcm_runtime *runtime;
951 	struct snd_card *card;
952 	int prefer_subdevice;
953 	size_t size;
954 
955 	if (snd_BUG_ON(!pcm || !rsubstream))
956 		return -ENXIO;
957 	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
958 		       stream != SNDRV_PCM_STREAM_CAPTURE))
959 		return -EINVAL;
960 	*rsubstream = NULL;
961 	pstr = &pcm->streams[stream];
962 	if (pstr->substream == NULL || pstr->substream_count == 0)
963 		return -ENODEV;
964 
965 	card = pcm->card;
966 	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
967 
968 	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
969 		int opposite = !stream;
970 
971 		for (substream = pcm->streams[opposite].substream; substream;
972 		     substream = substream->next) {
973 			if (SUBSTREAM_BUSY(substream))
974 				return -EAGAIN;
975 		}
976 	}
977 
978 	if (file->f_flags & O_APPEND) {
979 		if (prefer_subdevice < 0) {
980 			if (pstr->substream_count > 1)
981 				return -EINVAL; /* must be unique */
982 			substream = pstr->substream;
983 		} else {
984 			for (substream = pstr->substream; substream;
985 			     substream = substream->next)
986 				if (substream->number == prefer_subdevice)
987 					break;
988 		}
989 		if (! substream)
990 			return -ENODEV;
991 		if (! SUBSTREAM_BUSY(substream))
992 			return -EBADFD;
993 		substream->ref_count++;
994 		*rsubstream = substream;
995 		return 0;
996 	}
997 
998 	for (substream = pstr->substream; substream; substream = substream->next) {
999 		if (!SUBSTREAM_BUSY(substream) &&
1000 		    (prefer_subdevice == -1 ||
1001 		     substream->number == prefer_subdevice))
1002 			break;
1003 	}
1004 	if (substream == NULL)
1005 		return -EAGAIN;
1006 
1007 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
1008 	if (runtime == NULL)
1009 		return -ENOMEM;
1010 
1011 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
1012 	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
1013 	if (runtime->status == NULL) {
1014 		kfree(runtime);
1015 		return -ENOMEM;
1016 	}
1017 	memset((void*)runtime->status, 0, size);
1018 
1019 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
1020 	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
1021 	if (runtime->control == NULL) {
1022 		snd_free_pages((void*)runtime->status,
1023 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1024 		kfree(runtime);
1025 		return -ENOMEM;
1026 	}
1027 	memset((void*)runtime->control, 0, size);
1028 
1029 	init_waitqueue_head(&runtime->sleep);
1030 	init_waitqueue_head(&runtime->tsleep);
1031 
1032 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
1033 
1034 	substream->runtime = runtime;
1035 	substream->private_data = pcm->private_data;
1036 	substream->ref_count = 1;
1037 	substream->f_flags = file->f_flags;
1038 	substream->pid = get_pid(task_pid(current));
1039 	pstr->substream_opened++;
1040 	*rsubstream = substream;
1041 	return 0;
1042 }
1043 
1044 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1045 {
1046 	struct snd_pcm_runtime *runtime;
1047 
1048 	if (PCM_RUNTIME_CHECK(substream))
1049 		return;
1050 	runtime = substream->runtime;
1051 	if (runtime->private_free != NULL)
1052 		runtime->private_free(runtime);
1053 	snd_free_pages((void*)runtime->status,
1054 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1055 	snd_free_pages((void*)runtime->control,
1056 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1057 	kfree(runtime->hw_constraints.rules);
1058 	/* Avoid concurrent access to runtime via PCM timer interface */
1059 	if (substream->timer)
1060 		spin_lock_irq(&substream->timer->lock);
1061 	substream->runtime = NULL;
1062 	if (substream->timer)
1063 		spin_unlock_irq(&substream->timer->lock);
1064 	kfree(runtime);
1065 	put_pid(substream->pid);
1066 	substream->pid = NULL;
1067 	substream->pstr->substream_opened--;
1068 }
1069 
1070 static ssize_t show_pcm_class(struct device *dev,
1071 			      struct device_attribute *attr, char *buf)
1072 {
1073 	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1074 	struct snd_pcm *pcm = pstr->pcm;
1075 	const char *str;
1076 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1077 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1078 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1079 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1080 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1081 	};
1082 
1083 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1084 		str = "none";
1085 	else
1086 		str = strs[pcm->dev_class];
1087         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1088 }
1089 
1090 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1091 static struct attribute *pcm_dev_attrs[] = {
1092 	&dev_attr_pcm_class.attr,
1093 	NULL
1094 };
1095 
1096 static const struct attribute_group pcm_dev_attr_group = {
1097 	.attrs	= pcm_dev_attrs,
1098 };
1099 
1100 static const struct attribute_group *pcm_dev_attr_groups[] = {
1101 	&pcm_dev_attr_group,
1102 	NULL
1103 };
1104 
1105 static int snd_pcm_dev_register(struct snd_device *device)
1106 {
1107 	int cidx, err;
1108 	struct snd_pcm_substream *substream;
1109 	struct snd_pcm *pcm;
1110 
1111 	if (snd_BUG_ON(!device || !device->device_data))
1112 		return -ENXIO;
1113 	pcm = device->device_data;
1114 
1115 	mutex_lock(&register_mutex);
1116 	err = snd_pcm_add(pcm);
1117 	if (err)
1118 		goto unlock;
1119 	for (cidx = 0; cidx < 2; cidx++) {
1120 		int devtype = -1;
1121 		if (pcm->streams[cidx].substream == NULL)
1122 			continue;
1123 		switch (cidx) {
1124 		case SNDRV_PCM_STREAM_PLAYBACK:
1125 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1126 			break;
1127 		case SNDRV_PCM_STREAM_CAPTURE:
1128 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1129 			break;
1130 		}
1131 		/* register pcm */
1132 		err = snd_register_device(devtype, pcm->card, pcm->device,
1133 					  &snd_pcm_f_ops[cidx], pcm,
1134 					  &pcm->streams[cidx].dev);
1135 		if (err < 0) {
1136 			list_del_init(&pcm->list);
1137 			goto unlock;
1138 		}
1139 
1140 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1141 			snd_pcm_timer_init(substream);
1142 	}
1143 
1144 	pcm_call_notify(pcm, n_register);
1145 
1146  unlock:
1147 	mutex_unlock(&register_mutex);
1148 	return err;
1149 }
1150 
1151 static int snd_pcm_dev_disconnect(struct snd_device *device)
1152 {
1153 	struct snd_pcm *pcm = device->device_data;
1154 	struct snd_pcm_substream *substream;
1155 	int cidx;
1156 
1157 	mutex_lock(&register_mutex);
1158 	mutex_lock(&pcm->open_mutex);
1159 	wake_up(&pcm->open_wait);
1160 	list_del_init(&pcm->list);
1161 	for (cidx = 0; cidx < 2; cidx++) {
1162 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1163 			snd_pcm_stream_lock_irq(substream);
1164 			if (substream->runtime) {
1165 				if (snd_pcm_running(substream))
1166 					snd_pcm_stop(substream,
1167 						     SNDRV_PCM_STATE_DISCONNECTED);
1168 				/* to be sure, set the state unconditionally */
1169 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1170 				wake_up(&substream->runtime->sleep);
1171 				wake_up(&substream->runtime->tsleep);
1172 			}
1173 			snd_pcm_stream_unlock_irq(substream);
1174 		}
1175 	}
1176 
1177 	pcm_call_notify(pcm, n_disconnect);
1178 	for (cidx = 0; cidx < 2; cidx++) {
1179 		snd_unregister_device(&pcm->streams[cidx].dev);
1180 		free_chmap(&pcm->streams[cidx]);
1181 	}
1182 	mutex_unlock(&pcm->open_mutex);
1183 	mutex_unlock(&register_mutex);
1184 	return 0;
1185 }
1186 
1187 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1188 /**
1189  * snd_pcm_notify - Add/remove the notify list
1190  * @notify: PCM notify list
1191  * @nfree: 0 = register, 1 = unregister
1192  *
1193  * This adds the given notifier to the global list so that the callback is
1194  * called for each registered PCM devices.  This exists only for PCM OSS
1195  * emulation, so far.
1196  */
1197 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1198 {
1199 	struct snd_pcm *pcm;
1200 
1201 	if (snd_BUG_ON(!notify ||
1202 		       !notify->n_register ||
1203 		       !notify->n_unregister ||
1204 		       !notify->n_disconnect))
1205 		return -EINVAL;
1206 	mutex_lock(&register_mutex);
1207 	if (nfree) {
1208 		list_del(&notify->list);
1209 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1210 			notify->n_unregister(pcm);
1211 	} else {
1212 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1213 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1214 			notify->n_register(pcm);
1215 	}
1216 	mutex_unlock(&register_mutex);
1217 	return 0;
1218 }
1219 EXPORT_SYMBOL(snd_pcm_notify);
1220 #endif /* CONFIG_SND_PCM_OSS */
1221 
1222 #ifdef CONFIG_SND_PROC_FS
1223 /*
1224  *  Info interface
1225  */
1226 
1227 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1228 			      struct snd_info_buffer *buffer)
1229 {
1230 	struct snd_pcm *pcm;
1231 
1232 	mutex_lock(&register_mutex);
1233 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1234 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1235 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1236 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1237 			snd_iprintf(buffer, " : playback %i",
1238 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1239 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1240 			snd_iprintf(buffer, " : capture %i",
1241 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1242 		snd_iprintf(buffer, "\n");
1243 	}
1244 	mutex_unlock(&register_mutex);
1245 }
1246 
1247 static struct snd_info_entry *snd_pcm_proc_entry;
1248 
1249 static void snd_pcm_proc_init(void)
1250 {
1251 	struct snd_info_entry *entry;
1252 
1253 	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1254 	if (entry) {
1255 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1256 		if (snd_info_register(entry) < 0) {
1257 			snd_info_free_entry(entry);
1258 			entry = NULL;
1259 		}
1260 	}
1261 	snd_pcm_proc_entry = entry;
1262 }
1263 
1264 static void snd_pcm_proc_done(void)
1265 {
1266 	snd_info_free_entry(snd_pcm_proc_entry);
1267 }
1268 
1269 #else /* !CONFIG_SND_PROC_FS */
1270 #define snd_pcm_proc_init()
1271 #define snd_pcm_proc_done()
1272 #endif /* CONFIG_SND_PROC_FS */
1273 
1274 
1275 /*
1276  *  ENTRY functions
1277  */
1278 
1279 static int __init alsa_pcm_init(void)
1280 {
1281 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1282 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1283 	snd_pcm_proc_init();
1284 	return 0;
1285 }
1286 
1287 static void __exit alsa_pcm_exit(void)
1288 {
1289 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1290 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1291 	snd_pcm_proc_done();
1292 }
1293 
1294 module_init(alsa_pcm_init)
1295 module_exit(alsa_pcm_exit)
1296