xref: /openbmc/linux/sound/core/pcm.c (revision 4161b450)
1 /*
2  *  Digital Audio (PCM) abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/time.h>
26 #include <linux/mutex.h>
27 #include <linux/device.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/pcm.h>
31 #include <sound/control.h>
32 #include <sound/info.h>
33 
34 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
35 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
36 MODULE_LICENSE("GPL");
37 
38 static LIST_HEAD(snd_pcm_devices);
39 static LIST_HEAD(snd_pcm_notify_list);
40 static DEFINE_MUTEX(register_mutex);
41 
42 static int snd_pcm_free(struct snd_pcm *pcm);
43 static int snd_pcm_dev_free(struct snd_device *device);
44 static int snd_pcm_dev_register(struct snd_device *device);
45 static int snd_pcm_dev_disconnect(struct snd_device *device);
46 
47 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
48 {
49 	struct snd_pcm *pcm;
50 
51 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
52 		if (pcm->internal)
53 			continue;
54 		if (pcm->card == card && pcm->device == device)
55 			return pcm;
56 	}
57 	return NULL;
58 }
59 
60 static int snd_pcm_next(struct snd_card *card, int device)
61 {
62 	struct snd_pcm *pcm;
63 
64 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
65 		if (pcm->internal)
66 			continue;
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 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
80 		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
81 			return -EBUSY;
82 		if (pcm->card->number > newpcm->card->number ||
83 				(pcm->card == newpcm->card &&
84 				pcm->device > newpcm->device)) {
85 			list_add(&newpcm->list, pcm->list.prev);
86 			return 0;
87 		}
88 	}
89 	list_add_tail(&newpcm->list, &snd_pcm_devices);
90 	return 0;
91 }
92 
93 static int snd_pcm_control_ioctl(struct snd_card *card,
94 				 struct snd_ctl_file *control,
95 				 unsigned int cmd, unsigned long arg)
96 {
97 	switch (cmd) {
98 	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
99 		{
100 			int device;
101 
102 			if (get_user(device, (int __user *)arg))
103 				return -EFAULT;
104 			mutex_lock(&register_mutex);
105 			device = snd_pcm_next(card, device);
106 			mutex_unlock(&register_mutex);
107 			if (put_user(device, (int __user *)arg))
108 				return -EFAULT;
109 			return 0;
110 		}
111 	case SNDRV_CTL_IOCTL_PCM_INFO:
112 		{
113 			struct snd_pcm_info __user *info;
114 			unsigned int device, subdevice;
115 			int stream;
116 			struct snd_pcm *pcm;
117 			struct snd_pcm_str *pstr;
118 			struct snd_pcm_substream *substream;
119 			int err;
120 
121 			info = (struct snd_pcm_info __user *)arg;
122 			if (get_user(device, &info->device))
123 				return -EFAULT;
124 			if (get_user(stream, &info->stream))
125 				return -EFAULT;
126 			if (stream < 0 || stream > 1)
127 				return -EINVAL;
128 			if (get_user(subdevice, &info->subdevice))
129 				return -EFAULT;
130 			mutex_lock(&register_mutex);
131 			pcm = snd_pcm_get(card, device);
132 			if (pcm == NULL) {
133 				err = -ENXIO;
134 				goto _error;
135 			}
136 			pstr = &pcm->streams[stream];
137 			if (pstr->substream_count == 0) {
138 				err = -ENOENT;
139 				goto _error;
140 			}
141 			if (subdevice >= pstr->substream_count) {
142 				err = -ENXIO;
143 				goto _error;
144 			}
145 			for (substream = pstr->substream; substream;
146 			     substream = substream->next)
147 				if (substream->number == (int)subdevice)
148 					break;
149 			if (substream == NULL) {
150 				err = -ENXIO;
151 				goto _error;
152 			}
153 			err = snd_pcm_info_user(substream, info);
154 		_error:
155 			mutex_unlock(&register_mutex);
156 			return err;
157 		}
158 	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
159 		{
160 			int val;
161 
162 			if (get_user(val, (int __user *)arg))
163 				return -EFAULT;
164 			control->prefer_pcm_subdevice = val;
165 			return 0;
166 		}
167 	}
168 	return -ENOIOCTLCMD;
169 }
170 
171 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
172 
173 static char *snd_pcm_format_names[] = {
174 	FORMAT(S8),
175 	FORMAT(U8),
176 	FORMAT(S16_LE),
177 	FORMAT(S16_BE),
178 	FORMAT(U16_LE),
179 	FORMAT(U16_BE),
180 	FORMAT(S24_LE),
181 	FORMAT(S24_BE),
182 	FORMAT(U24_LE),
183 	FORMAT(U24_BE),
184 	FORMAT(S32_LE),
185 	FORMAT(S32_BE),
186 	FORMAT(U32_LE),
187 	FORMAT(U32_BE),
188 	FORMAT(FLOAT_LE),
189 	FORMAT(FLOAT_BE),
190 	FORMAT(FLOAT64_LE),
191 	FORMAT(FLOAT64_BE),
192 	FORMAT(IEC958_SUBFRAME_LE),
193 	FORMAT(IEC958_SUBFRAME_BE),
194 	FORMAT(MU_LAW),
195 	FORMAT(A_LAW),
196 	FORMAT(IMA_ADPCM),
197 	FORMAT(MPEG),
198 	FORMAT(GSM),
199 	FORMAT(SPECIAL),
200 	FORMAT(S24_3LE),
201 	FORMAT(S24_3BE),
202 	FORMAT(U24_3LE),
203 	FORMAT(U24_3BE),
204 	FORMAT(S20_3LE),
205 	FORMAT(S20_3BE),
206 	FORMAT(U20_3LE),
207 	FORMAT(U20_3BE),
208 	FORMAT(S18_3LE),
209 	FORMAT(S18_3BE),
210 	FORMAT(U18_3LE),
211 	FORMAT(U18_3BE),
212 	FORMAT(G723_24),
213 	FORMAT(G723_24_1B),
214 	FORMAT(G723_40),
215 	FORMAT(G723_40_1B),
216 	FORMAT(DSD_U8),
217 	FORMAT(DSD_U16_LE),
218 	FORMAT(DSD_U32_LE),
219 	FORMAT(DSD_U16_BE),
220 	FORMAT(DSD_U32_BE),
221 };
222 
223 /**
224  * snd_pcm_format_name - Return a name string for the given PCM format
225  * @format: PCM format
226  */
227 const char *snd_pcm_format_name(snd_pcm_format_t format)
228 {
229 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
230 		return "Unknown";
231 	return snd_pcm_format_names[(__force unsigned int)format];
232 }
233 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
234 
235 #ifdef CONFIG_SND_VERBOSE_PROCFS
236 
237 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
238 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
239 #define READY(v) [SNDRV_PCM_READY_##v] = #v
240 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
241 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
242 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
243 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
244 #define START(v) [SNDRV_PCM_START_##v] = #v
245 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
246 
247 static char *snd_pcm_stream_names[] = {
248 	STREAM(PLAYBACK),
249 	STREAM(CAPTURE),
250 };
251 
252 static char *snd_pcm_state_names[] = {
253 	STATE(OPEN),
254 	STATE(SETUP),
255 	STATE(PREPARED),
256 	STATE(RUNNING),
257 	STATE(XRUN),
258 	STATE(DRAINING),
259 	STATE(PAUSED),
260 	STATE(SUSPENDED),
261 };
262 
263 static char *snd_pcm_access_names[] = {
264 	ACCESS(MMAP_INTERLEAVED),
265 	ACCESS(MMAP_NONINTERLEAVED),
266 	ACCESS(MMAP_COMPLEX),
267 	ACCESS(RW_INTERLEAVED),
268 	ACCESS(RW_NONINTERLEAVED),
269 };
270 
271 static char *snd_pcm_subformat_names[] = {
272 	SUBFORMAT(STD),
273 };
274 
275 static char *snd_pcm_tstamp_mode_names[] = {
276 	TSTAMP(NONE),
277 	TSTAMP(ENABLE),
278 };
279 
280 static const char *snd_pcm_stream_name(int stream)
281 {
282 	return snd_pcm_stream_names[stream];
283 }
284 
285 static const char *snd_pcm_access_name(snd_pcm_access_t access)
286 {
287 	return snd_pcm_access_names[(__force int)access];
288 }
289 
290 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
291 {
292 	return snd_pcm_subformat_names[(__force int)subformat];
293 }
294 
295 static const char *snd_pcm_tstamp_mode_name(int mode)
296 {
297 	return snd_pcm_tstamp_mode_names[mode];
298 }
299 
300 static const char *snd_pcm_state_name(snd_pcm_state_t state)
301 {
302 	return snd_pcm_state_names[(__force int)state];
303 }
304 
305 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
306 #include <linux/soundcard.h>
307 
308 static const char *snd_pcm_oss_format_name(int format)
309 {
310 	switch (format) {
311 	case AFMT_MU_LAW:
312 		return "MU_LAW";
313 	case AFMT_A_LAW:
314 		return "A_LAW";
315 	case AFMT_IMA_ADPCM:
316 		return "IMA_ADPCM";
317 	case AFMT_U8:
318 		return "U8";
319 	case AFMT_S16_LE:
320 		return "S16_LE";
321 	case AFMT_S16_BE:
322 		return "S16_BE";
323 	case AFMT_S8:
324 		return "S8";
325 	case AFMT_U16_LE:
326 		return "U16_LE";
327 	case AFMT_U16_BE:
328 		return "U16_BE";
329 	case AFMT_MPEG:
330 		return "MPEG";
331 	default:
332 		return "unknown";
333 	}
334 }
335 #endif
336 
337 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
338 				   struct snd_info_buffer *buffer)
339 {
340 	struct snd_pcm_info *info;
341 	int err;
342 
343 	if (! substream)
344 		return;
345 
346 	info = kmalloc(sizeof(*info), GFP_KERNEL);
347 	if (! info) {
348 		pcm_dbg(substream->pcm,
349 			"snd_pcm_proc_info_read: cannot malloc\n");
350 		return;
351 	}
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 	if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
527 		return -ENOMEM;
528 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
529 	if (snd_info_register(entry) < 0) {
530 		snd_info_free_entry(entry);
531 		return -ENOMEM;
532 	}
533 	pstr->proc_root = entry;
534 
535 	if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
536 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
537 		if (snd_info_register(entry) < 0) {
538 			snd_info_free_entry(entry);
539 			entry = NULL;
540 		}
541 	}
542 	pstr->proc_info_entry = entry;
543 
544 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
545 	if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
546 						pstr->proc_root)) != NULL) {
547 		entry->c.text.read = snd_pcm_xrun_debug_read;
548 		entry->c.text.write = snd_pcm_xrun_debug_write;
549 		entry->mode |= S_IWUSR;
550 		entry->private_data = pstr;
551 		if (snd_info_register(entry) < 0) {
552 			snd_info_free_entry(entry);
553 			entry = NULL;
554 		}
555 	}
556 	pstr->proc_xrun_debug_entry = entry;
557 #endif
558 	return 0;
559 }
560 
561 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
562 {
563 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
564 	snd_info_free_entry(pstr->proc_xrun_debug_entry);
565 	pstr->proc_xrun_debug_entry = NULL;
566 #endif
567 	snd_info_free_entry(pstr->proc_info_entry);
568 	pstr->proc_info_entry = NULL;
569 	snd_info_free_entry(pstr->proc_root);
570 	pstr->proc_root = NULL;
571 	return 0;
572 }
573 
574 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
575 {
576 	struct snd_info_entry *entry;
577 	struct snd_card *card;
578 	char name[16];
579 
580 	card = substream->pcm->card;
581 
582 	sprintf(name, "sub%i", substream->number);
583 	if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
584 		return -ENOMEM;
585 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
586 	if (snd_info_register(entry) < 0) {
587 		snd_info_free_entry(entry);
588 		return -ENOMEM;
589 	}
590 	substream->proc_root = entry;
591 
592 	if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
593 		snd_info_set_text_ops(entry, substream,
594 				      snd_pcm_substream_proc_info_read);
595 		if (snd_info_register(entry) < 0) {
596 			snd_info_free_entry(entry);
597 			entry = NULL;
598 		}
599 	}
600 	substream->proc_info_entry = entry;
601 
602 	if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
603 		snd_info_set_text_ops(entry, substream,
604 				      snd_pcm_substream_proc_hw_params_read);
605 		if (snd_info_register(entry) < 0) {
606 			snd_info_free_entry(entry);
607 			entry = NULL;
608 		}
609 	}
610 	substream->proc_hw_params_entry = entry;
611 
612 	if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
613 		snd_info_set_text_ops(entry, substream,
614 				      snd_pcm_substream_proc_sw_params_read);
615 		if (snd_info_register(entry) < 0) {
616 			snd_info_free_entry(entry);
617 			entry = NULL;
618 		}
619 	}
620 	substream->proc_sw_params_entry = entry;
621 
622 	if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
623 		snd_info_set_text_ops(entry, substream,
624 				      snd_pcm_substream_proc_status_read);
625 		if (snd_info_register(entry) < 0) {
626 			snd_info_free_entry(entry);
627 			entry = NULL;
628 		}
629 	}
630 	substream->proc_status_entry = entry;
631 
632 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
633 	entry = snd_info_create_card_entry(card, "xrun_injection",
634 					   substream->proc_root);
635 	if (entry) {
636 		entry->private_data = substream;
637 		entry->c.text.read = NULL;
638 		entry->c.text.write = snd_pcm_xrun_injection_write;
639 		entry->mode = S_IFREG | S_IWUSR;
640 		if (snd_info_register(entry) < 0) {
641 			snd_info_free_entry(entry);
642 			entry = NULL;
643 		}
644 	}
645 	substream->proc_xrun_injection_entry = entry;
646 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
647 
648 	return 0;
649 }
650 
651 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
652 {
653 	snd_info_free_entry(substream->proc_info_entry);
654 	substream->proc_info_entry = NULL;
655 	snd_info_free_entry(substream->proc_hw_params_entry);
656 	substream->proc_hw_params_entry = NULL;
657 	snd_info_free_entry(substream->proc_sw_params_entry);
658 	substream->proc_sw_params_entry = NULL;
659 	snd_info_free_entry(substream->proc_status_entry);
660 	substream->proc_status_entry = NULL;
661 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
662 	snd_info_free_entry(substream->proc_xrun_injection_entry);
663 	substream->proc_xrun_injection_entry = NULL;
664 #endif
665 	snd_info_free_entry(substream->proc_root);
666 	substream->proc_root = NULL;
667 	return 0;
668 }
669 #else /* !CONFIG_SND_VERBOSE_PROCFS */
670 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
671 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
672 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
673 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
674 #endif /* CONFIG_SND_VERBOSE_PROCFS */
675 
676 /**
677  * snd_pcm_new_stream - create a new PCM stream
678  * @pcm: the pcm instance
679  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
680  * @substream_count: the number of substreams
681  *
682  * Creates a new stream for the pcm.
683  * The corresponding stream on the pcm must have been empty before
684  * calling this, i.e. zero must be given to the argument of
685  * snd_pcm_new().
686  *
687  * Return: Zero if successful, or a negative error code on failure.
688  */
689 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
690 {
691 	int idx, err;
692 	struct snd_pcm_str *pstr = &pcm->streams[stream];
693 	struct snd_pcm_substream *substream, *prev;
694 
695 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
696 	mutex_init(&pstr->oss.setup_mutex);
697 #endif
698 	pstr->stream = stream;
699 	pstr->pcm = pcm;
700 	pstr->substream_count = substream_count;
701 	if (substream_count > 0 && !pcm->internal) {
702 		err = snd_pcm_stream_proc_init(pstr);
703 		if (err < 0) {
704 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
705 			return err;
706 		}
707 	}
708 	prev = NULL;
709 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
710 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
711 		if (substream == NULL) {
712 			pcm_err(pcm, "Cannot allocate PCM substream\n");
713 			return -ENOMEM;
714 		}
715 		substream->pcm = pcm;
716 		substream->pstr = pstr;
717 		substream->number = idx;
718 		substream->stream = stream;
719 		sprintf(substream->name, "subdevice #%i", idx);
720 		substream->buffer_bytes_max = UINT_MAX;
721 		if (prev == NULL)
722 			pstr->substream = substream;
723 		else
724 			prev->next = substream;
725 
726 		if (!pcm->internal) {
727 			err = snd_pcm_substream_proc_init(substream);
728 			if (err < 0) {
729 				pcm_err(pcm,
730 					"Error in snd_pcm_stream_proc_init\n");
731 				if (prev == NULL)
732 					pstr->substream = NULL;
733 				else
734 					prev->next = NULL;
735 				kfree(substream);
736 				return err;
737 			}
738 		}
739 		substream->group = &substream->self_group;
740 		spin_lock_init(&substream->self_group.lock);
741 		mutex_init(&substream->self_group.mutex);
742 		INIT_LIST_HEAD(&substream->self_group.substreams);
743 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
744 		atomic_set(&substream->mmap_count, 0);
745 		prev = substream;
746 	}
747 	return 0;
748 }
749 EXPORT_SYMBOL(snd_pcm_new_stream);
750 
751 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
752 		int playback_count, int capture_count, bool internal,
753 		struct snd_pcm **rpcm)
754 {
755 	struct snd_pcm *pcm;
756 	int err;
757 	static struct snd_device_ops ops = {
758 		.dev_free = snd_pcm_dev_free,
759 		.dev_register =	snd_pcm_dev_register,
760 		.dev_disconnect = snd_pcm_dev_disconnect,
761 	};
762 
763 	if (snd_BUG_ON(!card))
764 		return -ENXIO;
765 	if (rpcm)
766 		*rpcm = NULL;
767 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
768 	if (pcm == NULL) {
769 		dev_err(card->dev, "Cannot allocate PCM\n");
770 		return -ENOMEM;
771 	}
772 	pcm->card = card;
773 	pcm->device = device;
774 	pcm->internal = internal;
775 	if (id)
776 		strlcpy(pcm->id, id, sizeof(pcm->id));
777 	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
778 		snd_pcm_free(pcm);
779 		return err;
780 	}
781 	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
782 		snd_pcm_free(pcm);
783 		return err;
784 	}
785 	mutex_init(&pcm->open_mutex);
786 	init_waitqueue_head(&pcm->open_wait);
787 	if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
788 		snd_pcm_free(pcm);
789 		return err;
790 	}
791 	if (rpcm)
792 		*rpcm = pcm;
793 	return 0;
794 }
795 
796 /**
797  * snd_pcm_new - create a new PCM instance
798  * @card: the card instance
799  * @id: the id string
800  * @device: the device index (zero based)
801  * @playback_count: the number of substreams for playback
802  * @capture_count: the number of substreams for capture
803  * @rpcm: the pointer to store the new pcm instance
804  *
805  * Creates a new PCM instance.
806  *
807  * The pcm operators have to be set afterwards to the new instance
808  * via snd_pcm_set_ops().
809  *
810  * Return: Zero if successful, or a negative error code on failure.
811  */
812 int snd_pcm_new(struct snd_card *card, const char *id, int device,
813 		int playback_count, int capture_count, struct snd_pcm **rpcm)
814 {
815 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
816 			false, rpcm);
817 }
818 EXPORT_SYMBOL(snd_pcm_new);
819 
820 /**
821  * snd_pcm_new_internal - create a new internal PCM instance
822  * @card: the card instance
823  * @id: the id string
824  * @device: the device index (zero based - shared with normal PCMs)
825  * @playback_count: the number of substreams for playback
826  * @capture_count: the number of substreams for capture
827  * @rpcm: the pointer to store the new pcm instance
828  *
829  * Creates a new internal PCM instance with no userspace device or procfs
830  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
831  * will only be used internally by kernel drivers. i.e. it cannot be opened
832  * by userspace. It provides existing ASoC components drivers with a substream
833  * and access to any private data.
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_internal(struct snd_card *card, const char *id, int device,
841 	int playback_count, int capture_count,
842 	struct snd_pcm **rpcm)
843 {
844 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
845 			true, rpcm);
846 }
847 EXPORT_SYMBOL(snd_pcm_new_internal);
848 
849 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
850 {
851 	struct snd_pcm_substream *substream, *substream_next;
852 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
853 	struct snd_pcm_oss_setup *setup, *setupn;
854 #endif
855 	substream = pstr->substream;
856 	while (substream) {
857 		substream_next = substream->next;
858 		snd_pcm_timer_done(substream);
859 		snd_pcm_substream_proc_done(substream);
860 		kfree(substream);
861 		substream = substream_next;
862 	}
863 	snd_pcm_stream_proc_done(pstr);
864 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
865 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
866 		setupn = setup->next;
867 		kfree(setup->task_name);
868 		kfree(setup);
869 	}
870 #endif
871 }
872 
873 static int snd_pcm_free(struct snd_pcm *pcm)
874 {
875 	struct snd_pcm_notify *notify;
876 
877 	if (!pcm)
878 		return 0;
879 	list_for_each_entry(notify, &snd_pcm_notify_list, list) {
880 		notify->n_unregister(pcm);
881 	}
882 	if (pcm->private_free)
883 		pcm->private_free(pcm);
884 	snd_pcm_lib_preallocate_free_for_all(pcm);
885 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
886 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
887 	kfree(pcm);
888 	return 0;
889 }
890 
891 static int snd_pcm_dev_free(struct snd_device *device)
892 {
893 	struct snd_pcm *pcm = device->device_data;
894 	return snd_pcm_free(pcm);
895 }
896 
897 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
898 			     struct file *file,
899 			     struct snd_pcm_substream **rsubstream)
900 {
901 	struct snd_pcm_str * pstr;
902 	struct snd_pcm_substream *substream;
903 	struct snd_pcm_runtime *runtime;
904 	struct snd_ctl_file *kctl;
905 	struct snd_card *card;
906 	int prefer_subdevice = -1;
907 	size_t size;
908 
909 	if (snd_BUG_ON(!pcm || !rsubstream))
910 		return -ENXIO;
911 	*rsubstream = NULL;
912 	pstr = &pcm->streams[stream];
913 	if (pstr->substream == NULL || pstr->substream_count == 0)
914 		return -ENODEV;
915 
916 	card = pcm->card;
917 	read_lock(&card->ctl_files_rwlock);
918 	list_for_each_entry(kctl, &card->ctl_files, list) {
919 		if (kctl->pid == task_pid(current)) {
920 			prefer_subdevice = kctl->prefer_pcm_subdevice;
921 			if (prefer_subdevice != -1)
922 				break;
923 		}
924 	}
925 	read_unlock(&card->ctl_files_rwlock);
926 
927 	switch (stream) {
928 	case SNDRV_PCM_STREAM_PLAYBACK:
929 		if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
930 			for (substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; substream; substream = substream->next) {
931 				if (SUBSTREAM_BUSY(substream))
932 					return -EAGAIN;
933 			}
934 		}
935 		break;
936 	case SNDRV_PCM_STREAM_CAPTURE:
937 		if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
938 			for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next) {
939 				if (SUBSTREAM_BUSY(substream))
940 					return -EAGAIN;
941 			}
942 		}
943 		break;
944 	default:
945 		return -EINVAL;
946 	}
947 
948 	if (file->f_flags & O_APPEND) {
949 		if (prefer_subdevice < 0) {
950 			if (pstr->substream_count > 1)
951 				return -EINVAL; /* must be unique */
952 			substream = pstr->substream;
953 		} else {
954 			for (substream = pstr->substream; substream;
955 			     substream = substream->next)
956 				if (substream->number == prefer_subdevice)
957 					break;
958 		}
959 		if (! substream)
960 			return -ENODEV;
961 		if (! SUBSTREAM_BUSY(substream))
962 			return -EBADFD;
963 		substream->ref_count++;
964 		*rsubstream = substream;
965 		return 0;
966 	}
967 
968 	if (prefer_subdevice >= 0) {
969 		for (substream = pstr->substream; substream; substream = substream->next)
970 			if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
971 				goto __ok;
972 	}
973 	for (substream = pstr->substream; substream; substream = substream->next)
974 		if (!SUBSTREAM_BUSY(substream))
975 			break;
976       __ok:
977 	if (substream == NULL)
978 		return -EAGAIN;
979 
980 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
981 	if (runtime == NULL)
982 		return -ENOMEM;
983 
984 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
985 	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
986 	if (runtime->status == NULL) {
987 		kfree(runtime);
988 		return -ENOMEM;
989 	}
990 	memset((void*)runtime->status, 0, size);
991 
992 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
993 	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
994 	if (runtime->control == NULL) {
995 		snd_free_pages((void*)runtime->status,
996 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
997 		kfree(runtime);
998 		return -ENOMEM;
999 	}
1000 	memset((void*)runtime->control, 0, size);
1001 
1002 	init_waitqueue_head(&runtime->sleep);
1003 	init_waitqueue_head(&runtime->tsleep);
1004 
1005 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
1006 
1007 	substream->runtime = runtime;
1008 	substream->private_data = pcm->private_data;
1009 	substream->ref_count = 1;
1010 	substream->f_flags = file->f_flags;
1011 	substream->pid = get_pid(task_pid(current));
1012 	pstr->substream_opened++;
1013 	*rsubstream = substream;
1014 	return 0;
1015 }
1016 
1017 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1018 {
1019 	struct snd_pcm_runtime *runtime;
1020 
1021 	if (PCM_RUNTIME_CHECK(substream))
1022 		return;
1023 	runtime = substream->runtime;
1024 	if (runtime->private_free != NULL)
1025 		runtime->private_free(runtime);
1026 	snd_free_pages((void*)runtime->status,
1027 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1028 	snd_free_pages((void*)runtime->control,
1029 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1030 	kfree(runtime->hw_constraints.rules);
1031 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
1032 	kfree(runtime->hwptr_log);
1033 #endif
1034 	kfree(runtime);
1035 	substream->runtime = NULL;
1036 	put_pid(substream->pid);
1037 	substream->pid = NULL;
1038 	substream->pstr->substream_opened--;
1039 }
1040 
1041 static ssize_t show_pcm_class(struct device *dev,
1042 			      struct device_attribute *attr, char *buf)
1043 {
1044 	struct snd_pcm *pcm;
1045 	const char *str;
1046 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1047 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1048 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1049 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1050 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1051 	};
1052 
1053 	if (! (pcm = dev_get_drvdata(dev)) ||
1054 	    pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1055 		str = "none";
1056 	else
1057 		str = strs[pcm->dev_class];
1058         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1059 }
1060 
1061 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1062 static struct attribute *pcm_dev_attrs[] = {
1063 	&dev_attr_pcm_class.attr,
1064 	NULL
1065 };
1066 
1067 static struct attribute_group pcm_dev_attr_group = {
1068 	.attrs	= pcm_dev_attrs,
1069 };
1070 
1071 static const struct attribute_group *pcm_dev_attr_groups[] = {
1072 	&pcm_dev_attr_group,
1073 	NULL
1074 };
1075 
1076 static int snd_pcm_dev_register(struct snd_device *device)
1077 {
1078 	int cidx, err;
1079 	struct snd_pcm_substream *substream;
1080 	struct snd_pcm_notify *notify;
1081 	char str[16];
1082 	struct snd_pcm *pcm;
1083 	struct device *dev;
1084 
1085 	if (snd_BUG_ON(!device || !device->device_data))
1086 		return -ENXIO;
1087 	pcm = device->device_data;
1088 	mutex_lock(&register_mutex);
1089 	err = snd_pcm_add(pcm);
1090 	if (err) {
1091 		mutex_unlock(&register_mutex);
1092 		return err;
1093 	}
1094 	for (cidx = 0; cidx < 2; cidx++) {
1095 		int devtype = -1;
1096 		if (pcm->streams[cidx].substream == NULL || pcm->internal)
1097 			continue;
1098 		switch (cidx) {
1099 		case SNDRV_PCM_STREAM_PLAYBACK:
1100 			sprintf(str, "pcmC%iD%ip", pcm->card->number, pcm->device);
1101 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1102 			break;
1103 		case SNDRV_PCM_STREAM_CAPTURE:
1104 			sprintf(str, "pcmC%iD%ic", pcm->card->number, pcm->device);
1105 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1106 			break;
1107 		}
1108 		/* device pointer to use, pcm->dev takes precedence if
1109 		 * it is assigned, otherwise fall back to card's device
1110 		 * if possible */
1111 		dev = pcm->dev;
1112 		if (!dev)
1113 			dev = snd_card_get_device_link(pcm->card);
1114 		/* register pcm */
1115 		err = snd_register_device_for_dev(devtype, pcm->card,
1116 						  pcm->device,
1117 						  &snd_pcm_f_ops[cidx],
1118 						  pcm, str, dev);
1119 		if (err < 0) {
1120 			list_del(&pcm->list);
1121 			mutex_unlock(&register_mutex);
1122 			return err;
1123 		}
1124 
1125 		dev = snd_get_device(devtype, pcm->card, pcm->device);
1126 		if (dev) {
1127 			err = sysfs_create_groups(&dev->kobj,
1128 						  pcm_dev_attr_groups);
1129 			if (err < 0)
1130 				dev_warn(dev,
1131 					 "pcm %d:%d: cannot create sysfs groups\n",
1132 					 pcm->card->number, pcm->device);
1133 			put_device(dev);
1134 		}
1135 
1136 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1137 			snd_pcm_timer_init(substream);
1138 	}
1139 
1140 	list_for_each_entry(notify, &snd_pcm_notify_list, list)
1141 		notify->n_register(pcm);
1142 
1143 	mutex_unlock(&register_mutex);
1144 	return 0;
1145 }
1146 
1147 static int snd_pcm_dev_disconnect(struct snd_device *device)
1148 {
1149 	struct snd_pcm *pcm = device->device_data;
1150 	struct snd_pcm_notify *notify;
1151 	struct snd_pcm_substream *substream;
1152 	int cidx, devtype;
1153 
1154 	mutex_lock(&register_mutex);
1155 	if (list_empty(&pcm->list))
1156 		goto unlock;
1157 
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 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1166 				wake_up(&substream->runtime->sleep);
1167 				wake_up(&substream->runtime->tsleep);
1168 			}
1169 			snd_pcm_stream_unlock_irq(substream);
1170 		}
1171 	list_for_each_entry(notify, &snd_pcm_notify_list, list) {
1172 		notify->n_disconnect(pcm);
1173 	}
1174 	for (cidx = 0; cidx < 2; cidx++) {
1175 		devtype = -1;
1176 		switch (cidx) {
1177 		case SNDRV_PCM_STREAM_PLAYBACK:
1178 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1179 			break;
1180 		case SNDRV_PCM_STREAM_CAPTURE:
1181 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1182 			break;
1183 		}
1184 		snd_unregister_device(devtype, pcm->card, pcm->device);
1185 		if (pcm->streams[cidx].chmap_kctl) {
1186 			snd_ctl_remove(pcm->card, pcm->streams[cidx].chmap_kctl);
1187 			pcm->streams[cidx].chmap_kctl = NULL;
1188 		}
1189 	}
1190 	mutex_unlock(&pcm->open_mutex);
1191  unlock:
1192 	mutex_unlock(&register_mutex);
1193 	return 0;
1194 }
1195 
1196 /**
1197  * snd_pcm_notify - Add/remove the notify list
1198  * @notify: PCM notify list
1199  * @nfree: 0 = register, 1 = unregister
1200  *
1201  * This adds the given notifier to the global list so that the callback is
1202  * called for each registered PCM devices.  This exists only for PCM OSS
1203  * emulation, so far.
1204  */
1205 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1206 {
1207 	struct snd_pcm *pcm;
1208 
1209 	if (snd_BUG_ON(!notify ||
1210 		       !notify->n_register ||
1211 		       !notify->n_unregister ||
1212 		       !notify->n_disconnect))
1213 		return -EINVAL;
1214 	mutex_lock(&register_mutex);
1215 	if (nfree) {
1216 		list_del(&notify->list);
1217 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1218 			notify->n_unregister(pcm);
1219 	} else {
1220 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1221 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1222 			notify->n_register(pcm);
1223 	}
1224 	mutex_unlock(&register_mutex);
1225 	return 0;
1226 }
1227 EXPORT_SYMBOL(snd_pcm_notify);
1228 
1229 #ifdef CONFIG_PROC_FS
1230 /*
1231  *  Info interface
1232  */
1233 
1234 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1235 			      struct snd_info_buffer *buffer)
1236 {
1237 	struct snd_pcm *pcm;
1238 
1239 	mutex_lock(&register_mutex);
1240 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1241 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1242 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1243 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1244 			snd_iprintf(buffer, " : playback %i",
1245 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1246 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1247 			snd_iprintf(buffer, " : capture %i",
1248 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1249 		snd_iprintf(buffer, "\n");
1250 	}
1251 	mutex_unlock(&register_mutex);
1252 }
1253 
1254 static struct snd_info_entry *snd_pcm_proc_entry;
1255 
1256 static void snd_pcm_proc_init(void)
1257 {
1258 	struct snd_info_entry *entry;
1259 
1260 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
1261 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1262 		if (snd_info_register(entry) < 0) {
1263 			snd_info_free_entry(entry);
1264 			entry = NULL;
1265 		}
1266 	}
1267 	snd_pcm_proc_entry = entry;
1268 }
1269 
1270 static void snd_pcm_proc_done(void)
1271 {
1272 	snd_info_free_entry(snd_pcm_proc_entry);
1273 }
1274 
1275 #else /* !CONFIG_PROC_FS */
1276 #define snd_pcm_proc_init()
1277 #define snd_pcm_proc_done()
1278 #endif /* CONFIG_PROC_FS */
1279 
1280 
1281 /*
1282  *  ENTRY functions
1283  */
1284 
1285 static int __init alsa_pcm_init(void)
1286 {
1287 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1288 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1289 	snd_pcm_proc_init();
1290 	return 0;
1291 }
1292 
1293 static void __exit alsa_pcm_exit(void)
1294 {
1295 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1296 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1297 	snd_pcm_proc_done();
1298 }
1299 
1300 module_init(alsa_pcm_init)
1301 module_exit(alsa_pcm_exit)
1302