xref: /linux/sound/core/pcm.c (revision 2b30d411dbc6eddfb5b4f9afd5a2c57b6f4dd96c)
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 };
220 
221 /**
222  * snd_pcm_format_name - Return a name string for the given PCM format
223  * @format: PCM format
224  */
225 const char *snd_pcm_format_name(snd_pcm_format_t format)
226 {
227 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
228 		return "Unknown";
229 	return snd_pcm_format_names[(__force unsigned int)format];
230 }
231 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
232 
233 #ifdef CONFIG_SND_VERBOSE_PROCFS
234 
235 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
236 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
237 #define READY(v) [SNDRV_PCM_READY_##v] = #v
238 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
239 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
240 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
241 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
242 #define START(v) [SNDRV_PCM_START_##v] = #v
243 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
244 
245 static char *snd_pcm_stream_names[] = {
246 	STREAM(PLAYBACK),
247 	STREAM(CAPTURE),
248 };
249 
250 static char *snd_pcm_state_names[] = {
251 	STATE(OPEN),
252 	STATE(SETUP),
253 	STATE(PREPARED),
254 	STATE(RUNNING),
255 	STATE(XRUN),
256 	STATE(DRAINING),
257 	STATE(PAUSED),
258 	STATE(SUSPENDED),
259 };
260 
261 static char *snd_pcm_access_names[] = {
262 	ACCESS(MMAP_INTERLEAVED),
263 	ACCESS(MMAP_NONINTERLEAVED),
264 	ACCESS(MMAP_COMPLEX),
265 	ACCESS(RW_INTERLEAVED),
266 	ACCESS(RW_NONINTERLEAVED),
267 };
268 
269 static char *snd_pcm_subformat_names[] = {
270 	SUBFORMAT(STD),
271 };
272 
273 static char *snd_pcm_tstamp_mode_names[] = {
274 	TSTAMP(NONE),
275 	TSTAMP(ENABLE),
276 };
277 
278 static const char *snd_pcm_stream_name(int stream)
279 {
280 	return snd_pcm_stream_names[stream];
281 }
282 
283 static const char *snd_pcm_access_name(snd_pcm_access_t access)
284 {
285 	return snd_pcm_access_names[(__force int)access];
286 }
287 
288 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
289 {
290 	return snd_pcm_subformat_names[(__force int)subformat];
291 }
292 
293 static const char *snd_pcm_tstamp_mode_name(int mode)
294 {
295 	return snd_pcm_tstamp_mode_names[mode];
296 }
297 
298 static const char *snd_pcm_state_name(snd_pcm_state_t state)
299 {
300 	return snd_pcm_state_names[(__force int)state];
301 }
302 
303 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
304 #include <linux/soundcard.h>
305 
306 static const char *snd_pcm_oss_format_name(int format)
307 {
308 	switch (format) {
309 	case AFMT_MU_LAW:
310 		return "MU_LAW";
311 	case AFMT_A_LAW:
312 		return "A_LAW";
313 	case AFMT_IMA_ADPCM:
314 		return "IMA_ADPCM";
315 	case AFMT_U8:
316 		return "U8";
317 	case AFMT_S16_LE:
318 		return "S16_LE";
319 	case AFMT_S16_BE:
320 		return "S16_BE";
321 	case AFMT_S8:
322 		return "S8";
323 	case AFMT_U16_LE:
324 		return "U16_LE";
325 	case AFMT_U16_BE:
326 		return "U16_BE";
327 	case AFMT_MPEG:
328 		return "MPEG";
329 	default:
330 		return "unknown";
331 	}
332 }
333 #endif
334 
335 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
336 				   struct snd_info_buffer *buffer)
337 {
338 	struct snd_pcm_info *info;
339 	int err;
340 
341 	if (! substream)
342 		return;
343 
344 	info = kmalloc(sizeof(*info), GFP_KERNEL);
345 	if (! info) {
346 		pcm_dbg(substream->pcm,
347 			"snd_pcm_proc_info_read: cannot malloc\n");
348 		return;
349 	}
350 
351 	err = snd_pcm_info(substream, info);
352 	if (err < 0) {
353 		snd_iprintf(buffer, "error %d\n", err);
354 		kfree(info);
355 		return;
356 	}
357 	snd_iprintf(buffer, "card: %d\n", info->card);
358 	snd_iprintf(buffer, "device: %d\n", info->device);
359 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
360 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
361 	snd_iprintf(buffer, "id: %s\n", info->id);
362 	snd_iprintf(buffer, "name: %s\n", info->name);
363 	snd_iprintf(buffer, "subname: %s\n", info->subname);
364 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
365 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
366 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
367 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
368 	kfree(info);
369 }
370 
371 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
372 					  struct snd_info_buffer *buffer)
373 {
374 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
375 			       buffer);
376 }
377 
378 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
379 					     struct snd_info_buffer *buffer)
380 {
381 	snd_pcm_proc_info_read(entry->private_data, buffer);
382 }
383 
384 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
385 						  struct snd_info_buffer *buffer)
386 {
387 	struct snd_pcm_substream *substream = entry->private_data;
388 	struct snd_pcm_runtime *runtime;
389 
390 	mutex_lock(&substream->pcm->open_mutex);
391 	runtime = substream->runtime;
392 	if (!runtime) {
393 		snd_iprintf(buffer, "closed\n");
394 		goto unlock;
395 	}
396 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
397 		snd_iprintf(buffer, "no setup\n");
398 		goto unlock;
399 	}
400 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
401 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
402 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
403 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
404 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
405 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
406 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
407 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
408 	if (substream->oss.oss) {
409 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
410 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
411 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
412 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
413 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
414 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
415 	}
416 #endif
417  unlock:
418 	mutex_unlock(&substream->pcm->open_mutex);
419 }
420 
421 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
422 						  struct snd_info_buffer *buffer)
423 {
424 	struct snd_pcm_substream *substream = entry->private_data;
425 	struct snd_pcm_runtime *runtime;
426 
427 	mutex_lock(&substream->pcm->open_mutex);
428 	runtime = substream->runtime;
429 	if (!runtime) {
430 		snd_iprintf(buffer, "closed\n");
431 		goto unlock;
432 	}
433 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
434 		snd_iprintf(buffer, "no setup\n");
435 		goto unlock;
436 	}
437 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
438 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
439 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
440 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
441 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
442 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
443 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
444 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
445  unlock:
446 	mutex_unlock(&substream->pcm->open_mutex);
447 }
448 
449 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
450 					       struct snd_info_buffer *buffer)
451 {
452 	struct snd_pcm_substream *substream = entry->private_data;
453 	struct snd_pcm_runtime *runtime;
454 	struct snd_pcm_status status;
455 	int err;
456 
457 	mutex_lock(&substream->pcm->open_mutex);
458 	runtime = substream->runtime;
459 	if (!runtime) {
460 		snd_iprintf(buffer, "closed\n");
461 		goto unlock;
462 	}
463 	memset(&status, 0, sizeof(status));
464 	err = snd_pcm_status(substream, &status);
465 	if (err < 0) {
466 		snd_iprintf(buffer, "error %d\n", err);
467 		goto unlock;
468 	}
469 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
470 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
471 	snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
472 		status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
473 	snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
474 		status.tstamp.tv_sec, status.tstamp.tv_nsec);
475 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
476 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
477 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
478 	snd_iprintf(buffer, "-----\n");
479 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
480 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
481  unlock:
482 	mutex_unlock(&substream->pcm->open_mutex);
483 }
484 
485 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
486 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
487 					 struct snd_info_buffer *buffer)
488 {
489 	struct snd_pcm_substream *substream = entry->private_data;
490 	struct snd_pcm_runtime *runtime;
491 
492 	snd_pcm_stream_lock_irq(substream);
493 	runtime = substream->runtime;
494 	if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
495 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
496 	snd_pcm_stream_unlock_irq(substream);
497 }
498 
499 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
500 				    struct snd_info_buffer *buffer)
501 {
502 	struct snd_pcm_str *pstr = entry->private_data;
503 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
504 }
505 
506 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
507 				     struct snd_info_buffer *buffer)
508 {
509 	struct snd_pcm_str *pstr = entry->private_data;
510 	char line[64];
511 	if (!snd_info_get_line(buffer, line, sizeof(line)))
512 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
513 }
514 #endif
515 
516 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
517 {
518 	struct snd_pcm *pcm = pstr->pcm;
519 	struct snd_info_entry *entry;
520 	char name[16];
521 
522 	sprintf(name, "pcm%i%c", pcm->device,
523 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
524 	if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
525 		return -ENOMEM;
526 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
527 	if (snd_info_register(entry) < 0) {
528 		snd_info_free_entry(entry);
529 		return -ENOMEM;
530 	}
531 	pstr->proc_root = entry;
532 
533 	if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
534 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
535 		if (snd_info_register(entry) < 0) {
536 			snd_info_free_entry(entry);
537 			entry = NULL;
538 		}
539 	}
540 	pstr->proc_info_entry = entry;
541 
542 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
543 	if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
544 						pstr->proc_root)) != NULL) {
545 		entry->c.text.read = snd_pcm_xrun_debug_read;
546 		entry->c.text.write = snd_pcm_xrun_debug_write;
547 		entry->mode |= S_IWUSR;
548 		entry->private_data = pstr;
549 		if (snd_info_register(entry) < 0) {
550 			snd_info_free_entry(entry);
551 			entry = NULL;
552 		}
553 	}
554 	pstr->proc_xrun_debug_entry = entry;
555 #endif
556 	return 0;
557 }
558 
559 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
560 {
561 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
562 	snd_info_free_entry(pstr->proc_xrun_debug_entry);
563 	pstr->proc_xrun_debug_entry = NULL;
564 #endif
565 	snd_info_free_entry(pstr->proc_info_entry);
566 	pstr->proc_info_entry = NULL;
567 	snd_info_free_entry(pstr->proc_root);
568 	pstr->proc_root = NULL;
569 	return 0;
570 }
571 
572 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
573 {
574 	struct snd_info_entry *entry;
575 	struct snd_card *card;
576 	char name[16];
577 
578 	card = substream->pcm->card;
579 
580 	sprintf(name, "sub%i", substream->number);
581 	if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
582 		return -ENOMEM;
583 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
584 	if (snd_info_register(entry) < 0) {
585 		snd_info_free_entry(entry);
586 		return -ENOMEM;
587 	}
588 	substream->proc_root = entry;
589 
590 	if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
591 		snd_info_set_text_ops(entry, substream,
592 				      snd_pcm_substream_proc_info_read);
593 		if (snd_info_register(entry) < 0) {
594 			snd_info_free_entry(entry);
595 			entry = NULL;
596 		}
597 	}
598 	substream->proc_info_entry = entry;
599 
600 	if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
601 		snd_info_set_text_ops(entry, substream,
602 				      snd_pcm_substream_proc_hw_params_read);
603 		if (snd_info_register(entry) < 0) {
604 			snd_info_free_entry(entry);
605 			entry = NULL;
606 		}
607 	}
608 	substream->proc_hw_params_entry = entry;
609 
610 	if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
611 		snd_info_set_text_ops(entry, substream,
612 				      snd_pcm_substream_proc_sw_params_read);
613 		if (snd_info_register(entry) < 0) {
614 			snd_info_free_entry(entry);
615 			entry = NULL;
616 		}
617 	}
618 	substream->proc_sw_params_entry = entry;
619 
620 	if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
621 		snd_info_set_text_ops(entry, substream,
622 				      snd_pcm_substream_proc_status_read);
623 		if (snd_info_register(entry) < 0) {
624 			snd_info_free_entry(entry);
625 			entry = NULL;
626 		}
627 	}
628 	substream->proc_status_entry = entry;
629 
630 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
631 	entry = snd_info_create_card_entry(card, "xrun_injection",
632 					   substream->proc_root);
633 	if (entry) {
634 		entry->private_data = substream;
635 		entry->c.text.read = NULL;
636 		entry->c.text.write = snd_pcm_xrun_injection_write;
637 		entry->mode = S_IFREG | S_IWUSR;
638 		if (snd_info_register(entry) < 0) {
639 			snd_info_free_entry(entry);
640 			entry = NULL;
641 		}
642 	}
643 	substream->proc_xrun_injection_entry = entry;
644 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
645 
646 	return 0;
647 }
648 
649 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
650 {
651 	snd_info_free_entry(substream->proc_info_entry);
652 	substream->proc_info_entry = NULL;
653 	snd_info_free_entry(substream->proc_hw_params_entry);
654 	substream->proc_hw_params_entry = NULL;
655 	snd_info_free_entry(substream->proc_sw_params_entry);
656 	substream->proc_sw_params_entry = NULL;
657 	snd_info_free_entry(substream->proc_status_entry);
658 	substream->proc_status_entry = NULL;
659 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
660 	snd_info_free_entry(substream->proc_xrun_injection_entry);
661 	substream->proc_xrun_injection_entry = NULL;
662 #endif
663 	snd_info_free_entry(substream->proc_root);
664 	substream->proc_root = NULL;
665 	return 0;
666 }
667 #else /* !CONFIG_SND_VERBOSE_PROCFS */
668 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
669 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
670 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
671 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
672 #endif /* CONFIG_SND_VERBOSE_PROCFS */
673 
674 /**
675  * snd_pcm_new_stream - create a new PCM stream
676  * @pcm: the pcm instance
677  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
678  * @substream_count: the number of substreams
679  *
680  * Creates a new stream for the pcm.
681  * The corresponding stream on the pcm must have been empty before
682  * calling this, i.e. zero must be given to the argument of
683  * snd_pcm_new().
684  *
685  * Return: Zero if successful, or a negative error code on failure.
686  */
687 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
688 {
689 	int idx, err;
690 	struct snd_pcm_str *pstr = &pcm->streams[stream];
691 	struct snd_pcm_substream *substream, *prev;
692 
693 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
694 	mutex_init(&pstr->oss.setup_mutex);
695 #endif
696 	pstr->stream = stream;
697 	pstr->pcm = pcm;
698 	pstr->substream_count = substream_count;
699 	if (substream_count > 0 && !pcm->internal) {
700 		err = snd_pcm_stream_proc_init(pstr);
701 		if (err < 0) {
702 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
703 			return err;
704 		}
705 	}
706 	prev = NULL;
707 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
708 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
709 		if (substream == NULL) {
710 			pcm_err(pcm, "Cannot allocate PCM substream\n");
711 			return -ENOMEM;
712 		}
713 		substream->pcm = pcm;
714 		substream->pstr = pstr;
715 		substream->number = idx;
716 		substream->stream = stream;
717 		sprintf(substream->name, "subdevice #%i", idx);
718 		substream->buffer_bytes_max = UINT_MAX;
719 		if (prev == NULL)
720 			pstr->substream = substream;
721 		else
722 			prev->next = substream;
723 
724 		if (!pcm->internal) {
725 			err = snd_pcm_substream_proc_init(substream);
726 			if (err < 0) {
727 				pcm_err(pcm,
728 					"Error in snd_pcm_stream_proc_init\n");
729 				if (prev == NULL)
730 					pstr->substream = NULL;
731 				else
732 					prev->next = NULL;
733 				kfree(substream);
734 				return err;
735 			}
736 		}
737 		substream->group = &substream->self_group;
738 		spin_lock_init(&substream->self_group.lock);
739 		mutex_init(&substream->self_group.mutex);
740 		INIT_LIST_HEAD(&substream->self_group.substreams);
741 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
742 		atomic_set(&substream->mmap_count, 0);
743 		prev = substream;
744 	}
745 	return 0;
746 }
747 EXPORT_SYMBOL(snd_pcm_new_stream);
748 
749 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
750 		int playback_count, int capture_count, bool internal,
751 		struct snd_pcm **rpcm)
752 {
753 	struct snd_pcm *pcm;
754 	int err;
755 	static struct snd_device_ops ops = {
756 		.dev_free = snd_pcm_dev_free,
757 		.dev_register =	snd_pcm_dev_register,
758 		.dev_disconnect = snd_pcm_dev_disconnect,
759 	};
760 
761 	if (snd_BUG_ON(!card))
762 		return -ENXIO;
763 	if (rpcm)
764 		*rpcm = NULL;
765 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
766 	if (pcm == NULL) {
767 		dev_err(card->dev, "Cannot allocate PCM\n");
768 		return -ENOMEM;
769 	}
770 	pcm->card = card;
771 	pcm->device = device;
772 	pcm->internal = internal;
773 	if (id)
774 		strlcpy(pcm->id, id, sizeof(pcm->id));
775 	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
776 		snd_pcm_free(pcm);
777 		return err;
778 	}
779 	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
780 		snd_pcm_free(pcm);
781 		return err;
782 	}
783 	mutex_init(&pcm->open_mutex);
784 	init_waitqueue_head(&pcm->open_wait);
785 	if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
786 		snd_pcm_free(pcm);
787 		return err;
788 	}
789 	if (rpcm)
790 		*rpcm = pcm;
791 	return 0;
792 }
793 
794 /**
795  * snd_pcm_new - create a new PCM instance
796  * @card: the card instance
797  * @id: the id string
798  * @device: the device index (zero based)
799  * @playback_count: the number of substreams for playback
800  * @capture_count: the number of substreams for capture
801  * @rpcm: the pointer to store the new pcm instance
802  *
803  * Creates a new PCM instance.
804  *
805  * The pcm operators have to be set afterwards to the new instance
806  * via snd_pcm_set_ops().
807  *
808  * Return: Zero if successful, or a negative error code on failure.
809  */
810 int snd_pcm_new(struct snd_card *card, const char *id, int device,
811 		int playback_count, int capture_count, struct snd_pcm **rpcm)
812 {
813 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
814 			false, rpcm);
815 }
816 EXPORT_SYMBOL(snd_pcm_new);
817 
818 /**
819  * snd_pcm_new_internal - create a new internal PCM instance
820  * @card: the card instance
821  * @id: the id string
822  * @device: the device index (zero based - shared with normal PCMs)
823  * @playback_count: the number of substreams for playback
824  * @capture_count: the number of substreams for capture
825  * @rpcm: the pointer to store the new pcm instance
826  *
827  * Creates a new internal PCM instance with no userspace device or procfs
828  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
829  * will only be used internally by kernel drivers. i.e. it cannot be opened
830  * by userspace. It provides existing ASoC components drivers with a substream
831  * and access to any private data.
832  *
833  * The pcm operators have to be set afterwards to the new instance
834  * via snd_pcm_set_ops().
835  *
836  * Return: Zero if successful, or a negative error code on failure.
837  */
838 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
839 	int playback_count, int capture_count,
840 	struct snd_pcm **rpcm)
841 {
842 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
843 			true, rpcm);
844 }
845 EXPORT_SYMBOL(snd_pcm_new_internal);
846 
847 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
848 {
849 	struct snd_pcm_substream *substream, *substream_next;
850 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
851 	struct snd_pcm_oss_setup *setup, *setupn;
852 #endif
853 	substream = pstr->substream;
854 	while (substream) {
855 		substream_next = substream->next;
856 		snd_pcm_timer_done(substream);
857 		snd_pcm_substream_proc_done(substream);
858 		kfree(substream);
859 		substream = substream_next;
860 	}
861 	snd_pcm_stream_proc_done(pstr);
862 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
863 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
864 		setupn = setup->next;
865 		kfree(setup->task_name);
866 		kfree(setup);
867 	}
868 #endif
869 }
870 
871 static int snd_pcm_free(struct snd_pcm *pcm)
872 {
873 	struct snd_pcm_notify *notify;
874 
875 	if (!pcm)
876 		return 0;
877 	list_for_each_entry(notify, &snd_pcm_notify_list, list) {
878 		notify->n_unregister(pcm);
879 	}
880 	if (pcm->private_free)
881 		pcm->private_free(pcm);
882 	snd_pcm_lib_preallocate_free_for_all(pcm);
883 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
884 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
885 	kfree(pcm);
886 	return 0;
887 }
888 
889 static int snd_pcm_dev_free(struct snd_device *device)
890 {
891 	struct snd_pcm *pcm = device->device_data;
892 	return snd_pcm_free(pcm);
893 }
894 
895 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
896 			     struct file *file,
897 			     struct snd_pcm_substream **rsubstream)
898 {
899 	struct snd_pcm_str * pstr;
900 	struct snd_pcm_substream *substream;
901 	struct snd_pcm_runtime *runtime;
902 	struct snd_ctl_file *kctl;
903 	struct snd_card *card;
904 	int prefer_subdevice = -1;
905 	size_t size;
906 
907 	if (snd_BUG_ON(!pcm || !rsubstream))
908 		return -ENXIO;
909 	*rsubstream = NULL;
910 	pstr = &pcm->streams[stream];
911 	if (pstr->substream == NULL || pstr->substream_count == 0)
912 		return -ENODEV;
913 
914 	card = pcm->card;
915 	read_lock(&card->ctl_files_rwlock);
916 	list_for_each_entry(kctl, &card->ctl_files, list) {
917 		if (kctl->pid == task_pid(current)) {
918 			prefer_subdevice = kctl->prefer_pcm_subdevice;
919 			if (prefer_subdevice != -1)
920 				break;
921 		}
922 	}
923 	read_unlock(&card->ctl_files_rwlock);
924 
925 	switch (stream) {
926 	case SNDRV_PCM_STREAM_PLAYBACK:
927 		if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
928 			for (substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; substream; substream = substream->next) {
929 				if (SUBSTREAM_BUSY(substream))
930 					return -EAGAIN;
931 			}
932 		}
933 		break;
934 	case SNDRV_PCM_STREAM_CAPTURE:
935 		if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
936 			for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next) {
937 				if (SUBSTREAM_BUSY(substream))
938 					return -EAGAIN;
939 			}
940 		}
941 		break;
942 	default:
943 		return -EINVAL;
944 	}
945 
946 	if (file->f_flags & O_APPEND) {
947 		if (prefer_subdevice < 0) {
948 			if (pstr->substream_count > 1)
949 				return -EINVAL; /* must be unique */
950 			substream = pstr->substream;
951 		} else {
952 			for (substream = pstr->substream; substream;
953 			     substream = substream->next)
954 				if (substream->number == prefer_subdevice)
955 					break;
956 		}
957 		if (! substream)
958 			return -ENODEV;
959 		if (! SUBSTREAM_BUSY(substream))
960 			return -EBADFD;
961 		substream->ref_count++;
962 		*rsubstream = substream;
963 		return 0;
964 	}
965 
966 	if (prefer_subdevice >= 0) {
967 		for (substream = pstr->substream; substream; substream = substream->next)
968 			if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
969 				goto __ok;
970 	}
971 	for (substream = pstr->substream; substream; substream = substream->next)
972 		if (!SUBSTREAM_BUSY(substream))
973 			break;
974       __ok:
975 	if (substream == NULL)
976 		return -EAGAIN;
977 
978 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
979 	if (runtime == NULL)
980 		return -ENOMEM;
981 
982 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
983 	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
984 	if (runtime->status == NULL) {
985 		kfree(runtime);
986 		return -ENOMEM;
987 	}
988 	memset((void*)runtime->status, 0, size);
989 
990 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
991 	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
992 	if (runtime->control == NULL) {
993 		snd_free_pages((void*)runtime->status,
994 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
995 		kfree(runtime);
996 		return -ENOMEM;
997 	}
998 	memset((void*)runtime->control, 0, size);
999 
1000 	init_waitqueue_head(&runtime->sleep);
1001 	init_waitqueue_head(&runtime->tsleep);
1002 
1003 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
1004 
1005 	substream->runtime = runtime;
1006 	substream->private_data = pcm->private_data;
1007 	substream->ref_count = 1;
1008 	substream->f_flags = file->f_flags;
1009 	substream->pid = get_pid(task_pid(current));
1010 	pstr->substream_opened++;
1011 	*rsubstream = substream;
1012 	return 0;
1013 }
1014 
1015 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1016 {
1017 	struct snd_pcm_runtime *runtime;
1018 
1019 	if (PCM_RUNTIME_CHECK(substream))
1020 		return;
1021 	runtime = substream->runtime;
1022 	if (runtime->private_free != NULL)
1023 		runtime->private_free(runtime);
1024 	snd_free_pages((void*)runtime->status,
1025 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1026 	snd_free_pages((void*)runtime->control,
1027 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1028 	kfree(runtime->hw_constraints.rules);
1029 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
1030 	kfree(runtime->hwptr_log);
1031 #endif
1032 	kfree(runtime);
1033 	substream->runtime = NULL;
1034 	put_pid(substream->pid);
1035 	substream->pid = NULL;
1036 	substream->pstr->substream_opened--;
1037 }
1038 
1039 static ssize_t show_pcm_class(struct device *dev,
1040 			      struct device_attribute *attr, char *buf)
1041 {
1042 	struct snd_pcm *pcm;
1043 	const char *str;
1044 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1045 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1046 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1047 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1048 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1049 	};
1050 
1051 	if (! (pcm = dev_get_drvdata(dev)) ||
1052 	    pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1053 		str = "none";
1054 	else
1055 		str = strs[pcm->dev_class];
1056         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1057 }
1058 
1059 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1060 static struct attribute *pcm_dev_attrs[] = {
1061 	&dev_attr_pcm_class.attr,
1062 	NULL
1063 };
1064 
1065 static struct attribute_group pcm_dev_attr_group = {
1066 	.attrs	= pcm_dev_attrs,
1067 };
1068 
1069 static const struct attribute_group *pcm_dev_attr_groups[] = {
1070 	&pcm_dev_attr_group,
1071 	NULL
1072 };
1073 
1074 static int snd_pcm_dev_register(struct snd_device *device)
1075 {
1076 	int cidx, err;
1077 	struct snd_pcm_substream *substream;
1078 	struct snd_pcm_notify *notify;
1079 	char str[16];
1080 	struct snd_pcm *pcm;
1081 	struct device *dev;
1082 
1083 	if (snd_BUG_ON(!device || !device->device_data))
1084 		return -ENXIO;
1085 	pcm = device->device_data;
1086 	mutex_lock(&register_mutex);
1087 	err = snd_pcm_add(pcm);
1088 	if (err) {
1089 		mutex_unlock(&register_mutex);
1090 		return err;
1091 	}
1092 	for (cidx = 0; cidx < 2; cidx++) {
1093 		int devtype = -1;
1094 		if (pcm->streams[cidx].substream == NULL || pcm->internal)
1095 			continue;
1096 		switch (cidx) {
1097 		case SNDRV_PCM_STREAM_PLAYBACK:
1098 			sprintf(str, "pcmC%iD%ip", pcm->card->number, pcm->device);
1099 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1100 			break;
1101 		case SNDRV_PCM_STREAM_CAPTURE:
1102 			sprintf(str, "pcmC%iD%ic", pcm->card->number, pcm->device);
1103 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1104 			break;
1105 		}
1106 		/* device pointer to use, pcm->dev takes precedence if
1107 		 * it is assigned, otherwise fall back to card's device
1108 		 * if possible */
1109 		dev = pcm->dev;
1110 		if (!dev)
1111 			dev = snd_card_get_device_link(pcm->card);
1112 		/* register pcm */
1113 		err = snd_register_device_for_dev(devtype, pcm->card,
1114 						  pcm->device,
1115 						  &snd_pcm_f_ops[cidx],
1116 						  pcm, str, dev);
1117 		if (err < 0) {
1118 			list_del(&pcm->list);
1119 			mutex_unlock(&register_mutex);
1120 			return err;
1121 		}
1122 
1123 		dev = snd_get_device(devtype, pcm->card, pcm->device);
1124 		if (dev) {
1125 			err = sysfs_create_groups(&dev->kobj,
1126 						  pcm_dev_attr_groups);
1127 			if (err < 0)
1128 				dev_warn(dev,
1129 					 "pcm %d:%d: cannot create sysfs groups\n",
1130 					 pcm->card->number, pcm->device);
1131 			put_device(dev);
1132 		}
1133 
1134 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1135 			snd_pcm_timer_init(substream);
1136 	}
1137 
1138 	list_for_each_entry(notify, &snd_pcm_notify_list, list)
1139 		notify->n_register(pcm);
1140 
1141 	mutex_unlock(&register_mutex);
1142 	return 0;
1143 }
1144 
1145 static int snd_pcm_dev_disconnect(struct snd_device *device)
1146 {
1147 	struct snd_pcm *pcm = device->device_data;
1148 	struct snd_pcm_notify *notify;
1149 	struct snd_pcm_substream *substream;
1150 	int cidx, devtype;
1151 
1152 	mutex_lock(&register_mutex);
1153 	if (list_empty(&pcm->list))
1154 		goto unlock;
1155 
1156 	mutex_lock(&pcm->open_mutex);
1157 	wake_up(&pcm->open_wait);
1158 	list_del_init(&pcm->list);
1159 	for (cidx = 0; cidx < 2; cidx++)
1160 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1161 			snd_pcm_stream_lock_irq(substream);
1162 			if (substream->runtime) {
1163 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1164 				wake_up(&substream->runtime->sleep);
1165 				wake_up(&substream->runtime->tsleep);
1166 			}
1167 			snd_pcm_stream_unlock_irq(substream);
1168 		}
1169 	list_for_each_entry(notify, &snd_pcm_notify_list, list) {
1170 		notify->n_disconnect(pcm);
1171 	}
1172 	for (cidx = 0; cidx < 2; cidx++) {
1173 		devtype = -1;
1174 		switch (cidx) {
1175 		case SNDRV_PCM_STREAM_PLAYBACK:
1176 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1177 			break;
1178 		case SNDRV_PCM_STREAM_CAPTURE:
1179 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1180 			break;
1181 		}
1182 		snd_unregister_device(devtype, pcm->card, pcm->device);
1183 		if (pcm->streams[cidx].chmap_kctl) {
1184 			snd_ctl_remove(pcm->card, pcm->streams[cidx].chmap_kctl);
1185 			pcm->streams[cidx].chmap_kctl = NULL;
1186 		}
1187 	}
1188 	mutex_unlock(&pcm->open_mutex);
1189  unlock:
1190 	mutex_unlock(&register_mutex);
1191 	return 0;
1192 }
1193 
1194 /**
1195  * snd_pcm_notify - Add/remove the notify list
1196  * @notify: PCM notify list
1197  * @nfree: 0 = register, 1 = unregister
1198  *
1199  * This adds the given notifier to the global list so that the callback is
1200  * called for each registered PCM devices.  This exists only for PCM OSS
1201  * emulation, so far.
1202  */
1203 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1204 {
1205 	struct snd_pcm *pcm;
1206 
1207 	if (snd_BUG_ON(!notify ||
1208 		       !notify->n_register ||
1209 		       !notify->n_unregister ||
1210 		       !notify->n_disconnect))
1211 		return -EINVAL;
1212 	mutex_lock(&register_mutex);
1213 	if (nfree) {
1214 		list_del(&notify->list);
1215 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1216 			notify->n_unregister(pcm);
1217 	} else {
1218 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1219 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1220 			notify->n_register(pcm);
1221 	}
1222 	mutex_unlock(&register_mutex);
1223 	return 0;
1224 }
1225 EXPORT_SYMBOL(snd_pcm_notify);
1226 
1227 #ifdef CONFIG_PROC_FS
1228 /*
1229  *  Info interface
1230  */
1231 
1232 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1233 			      struct snd_info_buffer *buffer)
1234 {
1235 	struct snd_pcm *pcm;
1236 
1237 	mutex_lock(&register_mutex);
1238 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1239 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1240 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1241 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1242 			snd_iprintf(buffer, " : playback %i",
1243 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1244 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1245 			snd_iprintf(buffer, " : capture %i",
1246 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1247 		snd_iprintf(buffer, "\n");
1248 	}
1249 	mutex_unlock(&register_mutex);
1250 }
1251 
1252 static struct snd_info_entry *snd_pcm_proc_entry;
1253 
1254 static void snd_pcm_proc_init(void)
1255 {
1256 	struct snd_info_entry *entry;
1257 
1258 	if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
1259 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1260 		if (snd_info_register(entry) < 0) {
1261 			snd_info_free_entry(entry);
1262 			entry = NULL;
1263 		}
1264 	}
1265 	snd_pcm_proc_entry = entry;
1266 }
1267 
1268 static void snd_pcm_proc_done(void)
1269 {
1270 	snd_info_free_entry(snd_pcm_proc_entry);
1271 }
1272 
1273 #else /* !CONFIG_PROC_FS */
1274 #define snd_pcm_proc_init()
1275 #define snd_pcm_proc_done()
1276 #endif /* CONFIG_PROC_FS */
1277 
1278 
1279 /*
1280  *  ENTRY functions
1281  */
1282 
1283 static int __init alsa_pcm_init(void)
1284 {
1285 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1286 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1287 	snd_pcm_proc_init();
1288 	return 0;
1289 }
1290 
1291 static void __exit alsa_pcm_exit(void)
1292 {
1293 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1294 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1295 	snd_pcm_proc_done();
1296 }
1297 
1298 module_init(alsa_pcm_init)
1299 module_exit(alsa_pcm_exit)
1300