xref: /openbmc/linux/sound/core/pcm.c (revision 5b4cb650)
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 <linux/nospec.h>
29 #include <sound/core.h>
30 #include <sound/minors.h>
31 #include <sound/pcm.h>
32 #include <sound/timer.h>
33 #include <sound/control.h>
34 #include <sound/info.h>
35 
36 #include "pcm_local.h"
37 
38 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
39 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
40 MODULE_LICENSE("GPL");
41 
42 static LIST_HEAD(snd_pcm_devices);
43 static DEFINE_MUTEX(register_mutex);
44 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
45 static LIST_HEAD(snd_pcm_notify_list);
46 #endif
47 
48 static int snd_pcm_free(struct snd_pcm *pcm);
49 static int snd_pcm_dev_free(struct snd_device *device);
50 static int snd_pcm_dev_register(struct snd_device *device);
51 static int snd_pcm_dev_disconnect(struct snd_device *device);
52 
53 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
54 {
55 	struct snd_pcm *pcm;
56 
57 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
58 		if (pcm->card == card && pcm->device == device)
59 			return pcm;
60 	}
61 	return NULL;
62 }
63 
64 static int snd_pcm_next(struct snd_card *card, int device)
65 {
66 	struct snd_pcm *pcm;
67 
68 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
69 		if (pcm->card == card && pcm->device > device)
70 			return pcm->device;
71 		else if (pcm->card->number > card->number)
72 			return -1;
73 	}
74 	return -1;
75 }
76 
77 static int snd_pcm_add(struct snd_pcm *newpcm)
78 {
79 	struct snd_pcm *pcm;
80 
81 	if (newpcm->internal)
82 		return 0;
83 
84 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
85 		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
86 			return -EBUSY;
87 		if (pcm->card->number > newpcm->card->number ||
88 				(pcm->card == newpcm->card &&
89 				pcm->device > newpcm->device)) {
90 			list_add(&newpcm->list, pcm->list.prev);
91 			return 0;
92 		}
93 	}
94 	list_add_tail(&newpcm->list, &snd_pcm_devices);
95 	return 0;
96 }
97 
98 static int snd_pcm_control_ioctl(struct snd_card *card,
99 				 struct snd_ctl_file *control,
100 				 unsigned int cmd, unsigned long arg)
101 {
102 	switch (cmd) {
103 	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
104 		{
105 			int device;
106 
107 			if (get_user(device, (int __user *)arg))
108 				return -EFAULT;
109 			mutex_lock(&register_mutex);
110 			device = snd_pcm_next(card, device);
111 			mutex_unlock(&register_mutex);
112 			if (put_user(device, (int __user *)arg))
113 				return -EFAULT;
114 			return 0;
115 		}
116 	case SNDRV_CTL_IOCTL_PCM_INFO:
117 		{
118 			struct snd_pcm_info __user *info;
119 			unsigned int device, subdevice;
120 			int stream;
121 			struct snd_pcm *pcm;
122 			struct snd_pcm_str *pstr;
123 			struct snd_pcm_substream *substream;
124 			int err;
125 
126 			info = (struct snd_pcm_info __user *)arg;
127 			if (get_user(device, &info->device))
128 				return -EFAULT;
129 			if (get_user(stream, &info->stream))
130 				return -EFAULT;
131 			if (stream < 0 || stream > 1)
132 				return -EINVAL;
133 			stream = array_index_nospec(stream, 2);
134 			if (get_user(subdevice, &info->subdevice))
135 				return -EFAULT;
136 			mutex_lock(&register_mutex);
137 			pcm = snd_pcm_get(card, device);
138 			if (pcm == NULL) {
139 				err = -ENXIO;
140 				goto _error;
141 			}
142 			pstr = &pcm->streams[stream];
143 			if (pstr->substream_count == 0) {
144 				err = -ENOENT;
145 				goto _error;
146 			}
147 			if (subdevice >= pstr->substream_count) {
148 				err = -ENXIO;
149 				goto _error;
150 			}
151 			for (substream = pstr->substream; substream;
152 			     substream = substream->next)
153 				if (substream->number == (int)subdevice)
154 					break;
155 			if (substream == NULL) {
156 				err = -ENXIO;
157 				goto _error;
158 			}
159 			mutex_lock(&pcm->open_mutex);
160 			err = snd_pcm_info_user(substream, info);
161 			mutex_unlock(&pcm->open_mutex);
162 		_error:
163 			mutex_unlock(&register_mutex);
164 			return err;
165 		}
166 	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
167 		{
168 			int val;
169 
170 			if (get_user(val, (int __user *)arg))
171 				return -EFAULT;
172 			control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
173 			return 0;
174 		}
175 	}
176 	return -ENOIOCTLCMD;
177 }
178 
179 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
180 
181 static char *snd_pcm_format_names[] = {
182 	FORMAT(S8),
183 	FORMAT(U8),
184 	FORMAT(S16_LE),
185 	FORMAT(S16_BE),
186 	FORMAT(U16_LE),
187 	FORMAT(U16_BE),
188 	FORMAT(S24_LE),
189 	FORMAT(S24_BE),
190 	FORMAT(U24_LE),
191 	FORMAT(U24_BE),
192 	FORMAT(S32_LE),
193 	FORMAT(S32_BE),
194 	FORMAT(U32_LE),
195 	FORMAT(U32_BE),
196 	FORMAT(FLOAT_LE),
197 	FORMAT(FLOAT_BE),
198 	FORMAT(FLOAT64_LE),
199 	FORMAT(FLOAT64_BE),
200 	FORMAT(IEC958_SUBFRAME_LE),
201 	FORMAT(IEC958_SUBFRAME_BE),
202 	FORMAT(MU_LAW),
203 	FORMAT(A_LAW),
204 	FORMAT(IMA_ADPCM),
205 	FORMAT(MPEG),
206 	FORMAT(GSM),
207 	FORMAT(SPECIAL),
208 	FORMAT(S24_3LE),
209 	FORMAT(S24_3BE),
210 	FORMAT(U24_3LE),
211 	FORMAT(U24_3BE),
212 	FORMAT(S20_3LE),
213 	FORMAT(S20_3BE),
214 	FORMAT(U20_3LE),
215 	FORMAT(U20_3BE),
216 	FORMAT(S18_3LE),
217 	FORMAT(S18_3BE),
218 	FORMAT(U18_3LE),
219 	FORMAT(U18_3BE),
220 	FORMAT(G723_24),
221 	FORMAT(G723_24_1B),
222 	FORMAT(G723_40),
223 	FORMAT(G723_40_1B),
224 	FORMAT(DSD_U8),
225 	FORMAT(DSD_U16_LE),
226 	FORMAT(DSD_U32_LE),
227 	FORMAT(DSD_U16_BE),
228 	FORMAT(DSD_U32_BE),
229 };
230 
231 /**
232  * snd_pcm_format_name - Return a name string for the given PCM format
233  * @format: PCM format
234  */
235 const char *snd_pcm_format_name(snd_pcm_format_t format)
236 {
237 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
238 		return "Unknown";
239 	return snd_pcm_format_names[(__force unsigned int)format];
240 }
241 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
242 
243 #ifdef CONFIG_SND_VERBOSE_PROCFS
244 
245 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
246 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
247 #define READY(v) [SNDRV_PCM_READY_##v] = #v
248 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
249 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
250 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
251 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
252 #define START(v) [SNDRV_PCM_START_##v] = #v
253 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
254 
255 static char *snd_pcm_stream_names[] = {
256 	STREAM(PLAYBACK),
257 	STREAM(CAPTURE),
258 };
259 
260 static char *snd_pcm_state_names[] = {
261 	STATE(OPEN),
262 	STATE(SETUP),
263 	STATE(PREPARED),
264 	STATE(RUNNING),
265 	STATE(XRUN),
266 	STATE(DRAINING),
267 	STATE(PAUSED),
268 	STATE(SUSPENDED),
269 };
270 
271 static char *snd_pcm_access_names[] = {
272 	ACCESS(MMAP_INTERLEAVED),
273 	ACCESS(MMAP_NONINTERLEAVED),
274 	ACCESS(MMAP_COMPLEX),
275 	ACCESS(RW_INTERLEAVED),
276 	ACCESS(RW_NONINTERLEAVED),
277 };
278 
279 static char *snd_pcm_subformat_names[] = {
280 	SUBFORMAT(STD),
281 };
282 
283 static char *snd_pcm_tstamp_mode_names[] = {
284 	TSTAMP(NONE),
285 	TSTAMP(ENABLE),
286 };
287 
288 static const char *snd_pcm_stream_name(int stream)
289 {
290 	return snd_pcm_stream_names[stream];
291 }
292 
293 static const char *snd_pcm_access_name(snd_pcm_access_t access)
294 {
295 	return snd_pcm_access_names[(__force int)access];
296 }
297 
298 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
299 {
300 	return snd_pcm_subformat_names[(__force int)subformat];
301 }
302 
303 static const char *snd_pcm_tstamp_mode_name(int mode)
304 {
305 	return snd_pcm_tstamp_mode_names[mode];
306 }
307 
308 static const char *snd_pcm_state_name(snd_pcm_state_t state)
309 {
310 	return snd_pcm_state_names[(__force int)state];
311 }
312 
313 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
314 #include <linux/soundcard.h>
315 
316 static const char *snd_pcm_oss_format_name(int format)
317 {
318 	switch (format) {
319 	case AFMT_MU_LAW:
320 		return "MU_LAW";
321 	case AFMT_A_LAW:
322 		return "A_LAW";
323 	case AFMT_IMA_ADPCM:
324 		return "IMA_ADPCM";
325 	case AFMT_U8:
326 		return "U8";
327 	case AFMT_S16_LE:
328 		return "S16_LE";
329 	case AFMT_S16_BE:
330 		return "S16_BE";
331 	case AFMT_S8:
332 		return "S8";
333 	case AFMT_U16_LE:
334 		return "U16_LE";
335 	case AFMT_U16_BE:
336 		return "U16_BE";
337 	case AFMT_MPEG:
338 		return "MPEG";
339 	default:
340 		return "unknown";
341 	}
342 }
343 #endif
344 
345 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
346 				   struct snd_info_buffer *buffer)
347 {
348 	struct snd_pcm_info *info;
349 	int err;
350 
351 	if (! substream)
352 		return;
353 
354 	info = kmalloc(sizeof(*info), GFP_KERNEL);
355 	if (!info)
356 		return;
357 
358 	err = snd_pcm_info(substream, info);
359 	if (err < 0) {
360 		snd_iprintf(buffer, "error %d\n", err);
361 		kfree(info);
362 		return;
363 	}
364 	snd_iprintf(buffer, "card: %d\n", info->card);
365 	snd_iprintf(buffer, "device: %d\n", info->device);
366 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
367 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
368 	snd_iprintf(buffer, "id: %s\n", info->id);
369 	snd_iprintf(buffer, "name: %s\n", info->name);
370 	snd_iprintf(buffer, "subname: %s\n", info->subname);
371 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
372 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
373 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
374 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
375 	kfree(info);
376 }
377 
378 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
379 					  struct snd_info_buffer *buffer)
380 {
381 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
382 			       buffer);
383 }
384 
385 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
386 					     struct snd_info_buffer *buffer)
387 {
388 	snd_pcm_proc_info_read(entry->private_data, buffer);
389 }
390 
391 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
392 						  struct snd_info_buffer *buffer)
393 {
394 	struct snd_pcm_substream *substream = entry->private_data;
395 	struct snd_pcm_runtime *runtime;
396 
397 	mutex_lock(&substream->pcm->open_mutex);
398 	runtime = substream->runtime;
399 	if (!runtime) {
400 		snd_iprintf(buffer, "closed\n");
401 		goto unlock;
402 	}
403 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
404 		snd_iprintf(buffer, "no setup\n");
405 		goto unlock;
406 	}
407 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
408 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
409 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
410 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
411 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
412 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
413 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
414 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
415 	if (substream->oss.oss) {
416 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
417 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
418 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
419 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
420 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
421 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
422 	}
423 #endif
424  unlock:
425 	mutex_unlock(&substream->pcm->open_mutex);
426 }
427 
428 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
429 						  struct snd_info_buffer *buffer)
430 {
431 	struct snd_pcm_substream *substream = entry->private_data;
432 	struct snd_pcm_runtime *runtime;
433 
434 	mutex_lock(&substream->pcm->open_mutex);
435 	runtime = substream->runtime;
436 	if (!runtime) {
437 		snd_iprintf(buffer, "closed\n");
438 		goto unlock;
439 	}
440 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
441 		snd_iprintf(buffer, "no setup\n");
442 		goto unlock;
443 	}
444 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
445 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
446 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
447 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
448 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
449 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
450 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
451 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
452  unlock:
453 	mutex_unlock(&substream->pcm->open_mutex);
454 }
455 
456 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
457 					       struct snd_info_buffer *buffer)
458 {
459 	struct snd_pcm_substream *substream = entry->private_data;
460 	struct snd_pcm_runtime *runtime;
461 	struct snd_pcm_status status;
462 	int err;
463 
464 	mutex_lock(&substream->pcm->open_mutex);
465 	runtime = substream->runtime;
466 	if (!runtime) {
467 		snd_iprintf(buffer, "closed\n");
468 		goto unlock;
469 	}
470 	memset(&status, 0, sizeof(status));
471 	err = snd_pcm_status(substream, &status);
472 	if (err < 0) {
473 		snd_iprintf(buffer, "error %d\n", err);
474 		goto unlock;
475 	}
476 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
477 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
478 	snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
479 		status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
480 	snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
481 		status.tstamp.tv_sec, status.tstamp.tv_nsec);
482 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
483 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
484 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
485 	snd_iprintf(buffer, "-----\n");
486 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
487 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
488  unlock:
489 	mutex_unlock(&substream->pcm->open_mutex);
490 }
491 
492 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
493 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
494 					 struct snd_info_buffer *buffer)
495 {
496 	struct snd_pcm_substream *substream = entry->private_data;
497 
498 	snd_pcm_stop_xrun(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 | 0555;
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 |= 0200;
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 | 0555;
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 | 0200;
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 	/* Avoid concurrent access to runtime via PCM timer interface */
1056 	if (substream->timer)
1057 		spin_lock_irq(&substream->timer->lock);
1058 	substream->runtime = NULL;
1059 	if (substream->timer)
1060 		spin_unlock_irq(&substream->timer->lock);
1061 	kfree(runtime);
1062 	put_pid(substream->pid);
1063 	substream->pid = NULL;
1064 	substream->pstr->substream_opened--;
1065 }
1066 
1067 static ssize_t show_pcm_class(struct device *dev,
1068 			      struct device_attribute *attr, char *buf)
1069 {
1070 	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1071 	struct snd_pcm *pcm = pstr->pcm;
1072 	const char *str;
1073 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1074 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1075 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1076 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1077 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1078 	};
1079 
1080 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1081 		str = "none";
1082 	else
1083 		str = strs[pcm->dev_class];
1084         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1085 }
1086 
1087 static DEVICE_ATTR(pcm_class, 0444, show_pcm_class, NULL);
1088 static struct attribute *pcm_dev_attrs[] = {
1089 	&dev_attr_pcm_class.attr,
1090 	NULL
1091 };
1092 
1093 static const struct attribute_group pcm_dev_attr_group = {
1094 	.attrs	= pcm_dev_attrs,
1095 };
1096 
1097 static const struct attribute_group *pcm_dev_attr_groups[] = {
1098 	&pcm_dev_attr_group,
1099 	NULL
1100 };
1101 
1102 static int snd_pcm_dev_register(struct snd_device *device)
1103 {
1104 	int cidx, err;
1105 	struct snd_pcm_substream *substream;
1106 	struct snd_pcm *pcm;
1107 
1108 	if (snd_BUG_ON(!device || !device->device_data))
1109 		return -ENXIO;
1110 	pcm = device->device_data;
1111 
1112 	mutex_lock(&register_mutex);
1113 	err = snd_pcm_add(pcm);
1114 	if (err)
1115 		goto unlock;
1116 	for (cidx = 0; cidx < 2; cidx++) {
1117 		int devtype = -1;
1118 		if (pcm->streams[cidx].substream == NULL)
1119 			continue;
1120 		switch (cidx) {
1121 		case SNDRV_PCM_STREAM_PLAYBACK:
1122 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1123 			break;
1124 		case SNDRV_PCM_STREAM_CAPTURE:
1125 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1126 			break;
1127 		}
1128 		/* register pcm */
1129 		err = snd_register_device(devtype, pcm->card, pcm->device,
1130 					  &snd_pcm_f_ops[cidx], pcm,
1131 					  &pcm->streams[cidx].dev);
1132 		if (err < 0) {
1133 			list_del_init(&pcm->list);
1134 			goto unlock;
1135 		}
1136 
1137 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1138 			snd_pcm_timer_init(substream);
1139 	}
1140 
1141 	pcm_call_notify(pcm, n_register);
1142 
1143  unlock:
1144 	mutex_unlock(&register_mutex);
1145 	return err;
1146 }
1147 
1148 static int snd_pcm_dev_disconnect(struct snd_device *device)
1149 {
1150 	struct snd_pcm *pcm = device->device_data;
1151 	struct snd_pcm_substream *substream;
1152 	int cidx;
1153 
1154 	mutex_lock(&register_mutex);
1155 	mutex_lock(&pcm->open_mutex);
1156 	wake_up(&pcm->open_wait);
1157 	list_del_init(&pcm->list);
1158 	for (cidx = 0; cidx < 2; cidx++) {
1159 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1160 			snd_pcm_stream_lock_irq(substream);
1161 			if (substream->runtime) {
1162 				if (snd_pcm_running(substream))
1163 					snd_pcm_stop(substream,
1164 						     SNDRV_PCM_STATE_DISCONNECTED);
1165 				/* to be sure, set the state unconditionally */
1166 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1167 				wake_up(&substream->runtime->sleep);
1168 				wake_up(&substream->runtime->tsleep);
1169 			}
1170 			snd_pcm_stream_unlock_irq(substream);
1171 		}
1172 	}
1173 
1174 	pcm_call_notify(pcm, n_disconnect);
1175 	for (cidx = 0; cidx < 2; cidx++) {
1176 		snd_unregister_device(&pcm->streams[cidx].dev);
1177 		free_chmap(&pcm->streams[cidx]);
1178 	}
1179 	mutex_unlock(&pcm->open_mutex);
1180 	mutex_unlock(&register_mutex);
1181 	return 0;
1182 }
1183 
1184 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1185 /**
1186  * snd_pcm_notify - Add/remove the notify list
1187  * @notify: PCM notify list
1188  * @nfree: 0 = register, 1 = unregister
1189  *
1190  * This adds the given notifier to the global list so that the callback is
1191  * called for each registered PCM devices.  This exists only for PCM OSS
1192  * emulation, so far.
1193  */
1194 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1195 {
1196 	struct snd_pcm *pcm;
1197 
1198 	if (snd_BUG_ON(!notify ||
1199 		       !notify->n_register ||
1200 		       !notify->n_unregister ||
1201 		       !notify->n_disconnect))
1202 		return -EINVAL;
1203 	mutex_lock(&register_mutex);
1204 	if (nfree) {
1205 		list_del(&notify->list);
1206 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1207 			notify->n_unregister(pcm);
1208 	} else {
1209 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1210 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1211 			notify->n_register(pcm);
1212 	}
1213 	mutex_unlock(&register_mutex);
1214 	return 0;
1215 }
1216 EXPORT_SYMBOL(snd_pcm_notify);
1217 #endif /* CONFIG_SND_PCM_OSS */
1218 
1219 #ifdef CONFIG_SND_PROC_FS
1220 /*
1221  *  Info interface
1222  */
1223 
1224 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1225 			      struct snd_info_buffer *buffer)
1226 {
1227 	struct snd_pcm *pcm;
1228 
1229 	mutex_lock(&register_mutex);
1230 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1231 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1232 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1233 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1234 			snd_iprintf(buffer, " : playback %i",
1235 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1236 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1237 			snd_iprintf(buffer, " : capture %i",
1238 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1239 		snd_iprintf(buffer, "\n");
1240 	}
1241 	mutex_unlock(&register_mutex);
1242 }
1243 
1244 static struct snd_info_entry *snd_pcm_proc_entry;
1245 
1246 static void snd_pcm_proc_init(void)
1247 {
1248 	struct snd_info_entry *entry;
1249 
1250 	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1251 	if (entry) {
1252 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1253 		if (snd_info_register(entry) < 0) {
1254 			snd_info_free_entry(entry);
1255 			entry = NULL;
1256 		}
1257 	}
1258 	snd_pcm_proc_entry = entry;
1259 }
1260 
1261 static void snd_pcm_proc_done(void)
1262 {
1263 	snd_info_free_entry(snd_pcm_proc_entry);
1264 }
1265 
1266 #else /* !CONFIG_SND_PROC_FS */
1267 #define snd_pcm_proc_init()
1268 #define snd_pcm_proc_done()
1269 #endif /* CONFIG_SND_PROC_FS */
1270 
1271 
1272 /*
1273  *  ENTRY functions
1274  */
1275 
1276 static int __init alsa_pcm_init(void)
1277 {
1278 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1279 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1280 	snd_pcm_proc_init();
1281 	return 0;
1282 }
1283 
1284 static void __exit alsa_pcm_exit(void)
1285 {
1286 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1287 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1288 	snd_pcm_proc_done();
1289 }
1290 
1291 module_init(alsa_pcm_init)
1292 module_exit(alsa_pcm_exit)
1293