xref: /linux/sound/core/pcm.c (revision 5cc619db5c34146ee821acd08382b9d78579b52e)
1 /*
2  *  Digital Audio (PCM) abstract layer
3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21 
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/time.h>
26 #include <linux/mutex.h>
27 #include <linux/device.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/pcm.h>
31 #include <sound/control.h>
32 #include <sound/info.h>
33 
34 #include "pcm_local.h"
35 
36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
37 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
38 MODULE_LICENSE("GPL");
39 
40 static LIST_HEAD(snd_pcm_devices);
41 static DEFINE_MUTEX(register_mutex);
42 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
43 static LIST_HEAD(snd_pcm_notify_list);
44 #endif
45 
46 static int snd_pcm_free(struct snd_pcm *pcm);
47 static int snd_pcm_dev_free(struct snd_device *device);
48 static int snd_pcm_dev_register(struct snd_device *device);
49 static int snd_pcm_dev_disconnect(struct snd_device *device);
50 
51 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
52 {
53 	struct snd_pcm *pcm;
54 
55 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
56 		if (pcm->card == card && pcm->device == device)
57 			return pcm;
58 	}
59 	return NULL;
60 }
61 
62 static int snd_pcm_next(struct snd_card *card, int device)
63 {
64 	struct snd_pcm *pcm;
65 
66 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
67 		if (pcm->card == card && pcm->device > device)
68 			return pcm->device;
69 		else if (pcm->card->number > card->number)
70 			return -1;
71 	}
72 	return -1;
73 }
74 
75 static int snd_pcm_add(struct snd_pcm *newpcm)
76 {
77 	struct snd_pcm *pcm;
78 
79 	if (newpcm->internal)
80 		return 0;
81 
82 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
83 		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
84 			return -EBUSY;
85 		if (pcm->card->number > newpcm->card->number ||
86 				(pcm->card == newpcm->card &&
87 				pcm->device > newpcm->device)) {
88 			list_add(&newpcm->list, pcm->list.prev);
89 			return 0;
90 		}
91 	}
92 	list_add_tail(&newpcm->list, &snd_pcm_devices);
93 	return 0;
94 }
95 
96 static int snd_pcm_control_ioctl(struct snd_card *card,
97 				 struct snd_ctl_file *control,
98 				 unsigned int cmd, unsigned long arg)
99 {
100 	switch (cmd) {
101 	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
102 		{
103 			int device;
104 
105 			if (get_user(device, (int __user *)arg))
106 				return -EFAULT;
107 			mutex_lock(&register_mutex);
108 			device = snd_pcm_next(card, device);
109 			mutex_unlock(&register_mutex);
110 			if (put_user(device, (int __user *)arg))
111 				return -EFAULT;
112 			return 0;
113 		}
114 	case SNDRV_CTL_IOCTL_PCM_INFO:
115 		{
116 			struct snd_pcm_info __user *info;
117 			unsigned int device, subdevice;
118 			int stream;
119 			struct snd_pcm *pcm;
120 			struct snd_pcm_str *pstr;
121 			struct snd_pcm_substream *substream;
122 			int err;
123 
124 			info = (struct snd_pcm_info __user *)arg;
125 			if (get_user(device, &info->device))
126 				return -EFAULT;
127 			if (get_user(stream, &info->stream))
128 				return -EFAULT;
129 			if (stream < 0 || stream > 1)
130 				return -EINVAL;
131 			if (get_user(subdevice, &info->subdevice))
132 				return -EFAULT;
133 			mutex_lock(&register_mutex);
134 			pcm = snd_pcm_get(card, device);
135 			if (pcm == NULL) {
136 				err = -ENXIO;
137 				goto _error;
138 			}
139 			pstr = &pcm->streams[stream];
140 			if (pstr->substream_count == 0) {
141 				err = -ENOENT;
142 				goto _error;
143 			}
144 			if (subdevice >= pstr->substream_count) {
145 				err = -ENXIO;
146 				goto _error;
147 			}
148 			for (substream = pstr->substream; substream;
149 			     substream = substream->next)
150 				if (substream->number == (int)subdevice)
151 					break;
152 			if (substream == NULL) {
153 				err = -ENXIO;
154 				goto _error;
155 			}
156 			err = snd_pcm_info_user(substream, info);
157 		_error:
158 			mutex_unlock(&register_mutex);
159 			return err;
160 		}
161 	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
162 		{
163 			int val;
164 
165 			if (get_user(val, (int __user *)arg))
166 				return -EFAULT;
167 			control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
168 			return 0;
169 		}
170 	}
171 	return -ENOIOCTLCMD;
172 }
173 
174 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
175 
176 static char *snd_pcm_format_names[] = {
177 	FORMAT(S8),
178 	FORMAT(U8),
179 	FORMAT(S16_LE),
180 	FORMAT(S16_BE),
181 	FORMAT(U16_LE),
182 	FORMAT(U16_BE),
183 	FORMAT(S24_LE),
184 	FORMAT(S24_BE),
185 	FORMAT(U24_LE),
186 	FORMAT(U24_BE),
187 	FORMAT(S32_LE),
188 	FORMAT(S32_BE),
189 	FORMAT(U32_LE),
190 	FORMAT(U32_BE),
191 	FORMAT(FLOAT_LE),
192 	FORMAT(FLOAT_BE),
193 	FORMAT(FLOAT64_LE),
194 	FORMAT(FLOAT64_BE),
195 	FORMAT(IEC958_SUBFRAME_LE),
196 	FORMAT(IEC958_SUBFRAME_BE),
197 	FORMAT(MU_LAW),
198 	FORMAT(A_LAW),
199 	FORMAT(IMA_ADPCM),
200 	FORMAT(MPEG),
201 	FORMAT(GSM),
202 	FORMAT(SPECIAL),
203 	FORMAT(S24_3LE),
204 	FORMAT(S24_3BE),
205 	FORMAT(U24_3LE),
206 	FORMAT(U24_3BE),
207 	FORMAT(S20_3LE),
208 	FORMAT(S20_3BE),
209 	FORMAT(U20_3LE),
210 	FORMAT(U20_3BE),
211 	FORMAT(S18_3LE),
212 	FORMAT(S18_3BE),
213 	FORMAT(U18_3LE),
214 	FORMAT(U18_3BE),
215 	FORMAT(G723_24),
216 	FORMAT(G723_24_1B),
217 	FORMAT(G723_40),
218 	FORMAT(G723_40_1B),
219 	FORMAT(DSD_U8),
220 	FORMAT(DSD_U16_LE),
221 	FORMAT(DSD_U32_LE),
222 	FORMAT(DSD_U16_BE),
223 	FORMAT(DSD_U32_BE),
224 };
225 
226 /**
227  * snd_pcm_format_name - Return a name string for the given PCM format
228  * @format: PCM format
229  */
230 const char *snd_pcm_format_name(snd_pcm_format_t format)
231 {
232 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
233 		return "Unknown";
234 	return snd_pcm_format_names[(__force unsigned int)format];
235 }
236 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
237 
238 #ifdef CONFIG_SND_VERBOSE_PROCFS
239 
240 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
241 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
242 #define READY(v) [SNDRV_PCM_READY_##v] = #v
243 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
244 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
245 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
246 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
247 #define START(v) [SNDRV_PCM_START_##v] = #v
248 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
249 
250 static char *snd_pcm_stream_names[] = {
251 	STREAM(PLAYBACK),
252 	STREAM(CAPTURE),
253 };
254 
255 static char *snd_pcm_state_names[] = {
256 	STATE(OPEN),
257 	STATE(SETUP),
258 	STATE(PREPARED),
259 	STATE(RUNNING),
260 	STATE(XRUN),
261 	STATE(DRAINING),
262 	STATE(PAUSED),
263 	STATE(SUSPENDED),
264 };
265 
266 static char *snd_pcm_access_names[] = {
267 	ACCESS(MMAP_INTERLEAVED),
268 	ACCESS(MMAP_NONINTERLEAVED),
269 	ACCESS(MMAP_COMPLEX),
270 	ACCESS(RW_INTERLEAVED),
271 	ACCESS(RW_NONINTERLEAVED),
272 };
273 
274 static char *snd_pcm_subformat_names[] = {
275 	SUBFORMAT(STD),
276 };
277 
278 static char *snd_pcm_tstamp_mode_names[] = {
279 	TSTAMP(NONE),
280 	TSTAMP(ENABLE),
281 };
282 
283 static const char *snd_pcm_stream_name(int stream)
284 {
285 	return snd_pcm_stream_names[stream];
286 }
287 
288 static const char *snd_pcm_access_name(snd_pcm_access_t access)
289 {
290 	return snd_pcm_access_names[(__force int)access];
291 }
292 
293 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
294 {
295 	return snd_pcm_subformat_names[(__force int)subformat];
296 }
297 
298 static const char *snd_pcm_tstamp_mode_name(int mode)
299 {
300 	return snd_pcm_tstamp_mode_names[mode];
301 }
302 
303 static const char *snd_pcm_state_name(snd_pcm_state_t state)
304 {
305 	return snd_pcm_state_names[(__force int)state];
306 }
307 
308 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
309 #include <linux/soundcard.h>
310 
311 static const char *snd_pcm_oss_format_name(int format)
312 {
313 	switch (format) {
314 	case AFMT_MU_LAW:
315 		return "MU_LAW";
316 	case AFMT_A_LAW:
317 		return "A_LAW";
318 	case AFMT_IMA_ADPCM:
319 		return "IMA_ADPCM";
320 	case AFMT_U8:
321 		return "U8";
322 	case AFMT_S16_LE:
323 		return "S16_LE";
324 	case AFMT_S16_BE:
325 		return "S16_BE";
326 	case AFMT_S8:
327 		return "S8";
328 	case AFMT_U16_LE:
329 		return "U16_LE";
330 	case AFMT_U16_BE:
331 		return "U16_BE";
332 	case AFMT_MPEG:
333 		return "MPEG";
334 	default:
335 		return "unknown";
336 	}
337 }
338 #endif
339 
340 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
341 				   struct snd_info_buffer *buffer)
342 {
343 	struct snd_pcm_info *info;
344 	int err;
345 
346 	if (! substream)
347 		return;
348 
349 	info = kmalloc(sizeof(*info), GFP_KERNEL);
350 	if (!info)
351 		return;
352 
353 	err = snd_pcm_info(substream, info);
354 	if (err < 0) {
355 		snd_iprintf(buffer, "error %d\n", err);
356 		kfree(info);
357 		return;
358 	}
359 	snd_iprintf(buffer, "card: %d\n", info->card);
360 	snd_iprintf(buffer, "device: %d\n", info->device);
361 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
362 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
363 	snd_iprintf(buffer, "id: %s\n", info->id);
364 	snd_iprintf(buffer, "name: %s\n", info->name);
365 	snd_iprintf(buffer, "subname: %s\n", info->subname);
366 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
367 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
368 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
369 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
370 	kfree(info);
371 }
372 
373 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
374 					  struct snd_info_buffer *buffer)
375 {
376 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
377 			       buffer);
378 }
379 
380 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
381 					     struct snd_info_buffer *buffer)
382 {
383 	snd_pcm_proc_info_read(entry->private_data, buffer);
384 }
385 
386 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
387 						  struct snd_info_buffer *buffer)
388 {
389 	struct snd_pcm_substream *substream = entry->private_data;
390 	struct snd_pcm_runtime *runtime;
391 
392 	mutex_lock(&substream->pcm->open_mutex);
393 	runtime = substream->runtime;
394 	if (!runtime) {
395 		snd_iprintf(buffer, "closed\n");
396 		goto unlock;
397 	}
398 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
399 		snd_iprintf(buffer, "no setup\n");
400 		goto unlock;
401 	}
402 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
403 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
404 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
405 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
406 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
407 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
408 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
409 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
410 	if (substream->oss.oss) {
411 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
412 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
413 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
414 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
415 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
416 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
417 	}
418 #endif
419  unlock:
420 	mutex_unlock(&substream->pcm->open_mutex);
421 }
422 
423 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
424 						  struct snd_info_buffer *buffer)
425 {
426 	struct snd_pcm_substream *substream = entry->private_data;
427 	struct snd_pcm_runtime *runtime;
428 
429 	mutex_lock(&substream->pcm->open_mutex);
430 	runtime = substream->runtime;
431 	if (!runtime) {
432 		snd_iprintf(buffer, "closed\n");
433 		goto unlock;
434 	}
435 	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
436 		snd_iprintf(buffer, "no setup\n");
437 		goto unlock;
438 	}
439 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
440 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
441 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
442 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
443 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
444 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
445 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
446 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
447  unlock:
448 	mutex_unlock(&substream->pcm->open_mutex);
449 }
450 
451 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
452 					       struct snd_info_buffer *buffer)
453 {
454 	struct snd_pcm_substream *substream = entry->private_data;
455 	struct snd_pcm_runtime *runtime;
456 	struct snd_pcm_status status;
457 	int err;
458 
459 	mutex_lock(&substream->pcm->open_mutex);
460 	runtime = substream->runtime;
461 	if (!runtime) {
462 		snd_iprintf(buffer, "closed\n");
463 		goto unlock;
464 	}
465 	memset(&status, 0, sizeof(status));
466 	err = snd_pcm_status(substream, &status);
467 	if (err < 0) {
468 		snd_iprintf(buffer, "error %d\n", err);
469 		goto unlock;
470 	}
471 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
472 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
473 	snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
474 		status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
475 	snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
476 		status.tstamp.tv_sec, status.tstamp.tv_nsec);
477 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
478 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
479 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
480 	snd_iprintf(buffer, "-----\n");
481 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
482 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
483  unlock:
484 	mutex_unlock(&substream->pcm->open_mutex);
485 }
486 
487 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
488 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
489 					 struct snd_info_buffer *buffer)
490 {
491 	struct snd_pcm_substream *substream = entry->private_data;
492 	struct snd_pcm_runtime *runtime;
493 
494 	snd_pcm_stream_lock_irq(substream);
495 	runtime = substream->runtime;
496 	if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
497 		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
498 	snd_pcm_stream_unlock_irq(substream);
499 }
500 
501 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
502 				    struct snd_info_buffer *buffer)
503 {
504 	struct snd_pcm_str *pstr = entry->private_data;
505 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
506 }
507 
508 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
509 				     struct snd_info_buffer *buffer)
510 {
511 	struct snd_pcm_str *pstr = entry->private_data;
512 	char line[64];
513 	if (!snd_info_get_line(buffer, line, sizeof(line)))
514 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
515 }
516 #endif
517 
518 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
519 {
520 	struct snd_pcm *pcm = pstr->pcm;
521 	struct snd_info_entry *entry;
522 	char name[16];
523 
524 	sprintf(name, "pcm%i%c", pcm->device,
525 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
526 	entry = snd_info_create_card_entry(pcm->card, name,
527 					   pcm->card->proc_root);
528 	if (!entry)
529 		return -ENOMEM;
530 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
531 	if (snd_info_register(entry) < 0) {
532 		snd_info_free_entry(entry);
533 		return -ENOMEM;
534 	}
535 	pstr->proc_root = entry;
536 	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
537 	if (entry) {
538 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
539 		if (snd_info_register(entry) < 0) {
540 			snd_info_free_entry(entry);
541 			entry = NULL;
542 		}
543 	}
544 	pstr->proc_info_entry = entry;
545 
546 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
547 	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
548 					   pstr->proc_root);
549 	if (entry) {
550 		entry->c.text.read = snd_pcm_xrun_debug_read;
551 		entry->c.text.write = snd_pcm_xrun_debug_write;
552 		entry->mode |= S_IWUSR;
553 		entry->private_data = pstr;
554 		if (snd_info_register(entry) < 0) {
555 			snd_info_free_entry(entry);
556 			entry = NULL;
557 		}
558 	}
559 	pstr->proc_xrun_debug_entry = entry;
560 #endif
561 	return 0;
562 }
563 
564 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
565 {
566 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
567 	snd_info_free_entry(pstr->proc_xrun_debug_entry);
568 	pstr->proc_xrun_debug_entry = NULL;
569 #endif
570 	snd_info_free_entry(pstr->proc_info_entry);
571 	pstr->proc_info_entry = NULL;
572 	snd_info_free_entry(pstr->proc_root);
573 	pstr->proc_root = NULL;
574 	return 0;
575 }
576 
577 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
578 {
579 	struct snd_info_entry *entry;
580 	struct snd_card *card;
581 	char name[16];
582 
583 	card = substream->pcm->card;
584 
585 	sprintf(name, "sub%i", substream->number);
586 	entry = snd_info_create_card_entry(card, name,
587 					   substream->pstr->proc_root);
588 	if (!entry)
589 		return -ENOMEM;
590 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
591 	if (snd_info_register(entry) < 0) {
592 		snd_info_free_entry(entry);
593 		return -ENOMEM;
594 	}
595 	substream->proc_root = entry;
596 	entry = snd_info_create_card_entry(card, "info", substream->proc_root);
597 	if (entry) {
598 		snd_info_set_text_ops(entry, substream,
599 				      snd_pcm_substream_proc_info_read);
600 		if (snd_info_register(entry) < 0) {
601 			snd_info_free_entry(entry);
602 			entry = NULL;
603 		}
604 	}
605 	substream->proc_info_entry = entry;
606 	entry = snd_info_create_card_entry(card, "hw_params",
607 					   substream->proc_root);
608 	if (entry) {
609 		snd_info_set_text_ops(entry, substream,
610 				      snd_pcm_substream_proc_hw_params_read);
611 		if (snd_info_register(entry) < 0) {
612 			snd_info_free_entry(entry);
613 			entry = NULL;
614 		}
615 	}
616 	substream->proc_hw_params_entry = entry;
617 	entry = snd_info_create_card_entry(card, "sw_params",
618 					   substream->proc_root);
619 	if (entry) {
620 		snd_info_set_text_ops(entry, substream,
621 				      snd_pcm_substream_proc_sw_params_read);
622 		if (snd_info_register(entry) < 0) {
623 			snd_info_free_entry(entry);
624 			entry = NULL;
625 		}
626 	}
627 	substream->proc_sw_params_entry = entry;
628 	entry = snd_info_create_card_entry(card, "status",
629 					   substream->proc_root);
630 	if (entry) {
631 		snd_info_set_text_ops(entry, substream,
632 				      snd_pcm_substream_proc_status_read);
633 		if (snd_info_register(entry) < 0) {
634 			snd_info_free_entry(entry);
635 			entry = NULL;
636 		}
637 	}
638 	substream->proc_status_entry = entry;
639 
640 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
641 	entry = snd_info_create_card_entry(card, "xrun_injection",
642 					   substream->proc_root);
643 	if (entry) {
644 		entry->private_data = substream;
645 		entry->c.text.read = NULL;
646 		entry->c.text.write = snd_pcm_xrun_injection_write;
647 		entry->mode = S_IFREG | S_IWUSR;
648 		if (snd_info_register(entry) < 0) {
649 			snd_info_free_entry(entry);
650 			entry = NULL;
651 		}
652 	}
653 	substream->proc_xrun_injection_entry = entry;
654 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
655 
656 	return 0;
657 }
658 
659 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
660 {
661 	snd_info_free_entry(substream->proc_info_entry);
662 	substream->proc_info_entry = NULL;
663 	snd_info_free_entry(substream->proc_hw_params_entry);
664 	substream->proc_hw_params_entry = NULL;
665 	snd_info_free_entry(substream->proc_sw_params_entry);
666 	substream->proc_sw_params_entry = NULL;
667 	snd_info_free_entry(substream->proc_status_entry);
668 	substream->proc_status_entry = NULL;
669 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
670 	snd_info_free_entry(substream->proc_xrun_injection_entry);
671 	substream->proc_xrun_injection_entry = NULL;
672 #endif
673 	snd_info_free_entry(substream->proc_root);
674 	substream->proc_root = NULL;
675 	return 0;
676 }
677 #else /* !CONFIG_SND_VERBOSE_PROCFS */
678 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
679 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
680 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
681 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
682 #endif /* CONFIG_SND_VERBOSE_PROCFS */
683 
684 static const struct attribute_group *pcm_dev_attr_groups[];
685 
686 /**
687  * snd_pcm_new_stream - create a new PCM stream
688  * @pcm: the pcm instance
689  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
690  * @substream_count: the number of substreams
691  *
692  * Creates a new stream for the pcm.
693  * The corresponding stream on the pcm must have been empty before
694  * calling this, i.e. zero must be given to the argument of
695  * snd_pcm_new().
696  *
697  * Return: Zero if successful, or a negative error code on failure.
698  */
699 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
700 {
701 	int idx, err;
702 	struct snd_pcm_str *pstr = &pcm->streams[stream];
703 	struct snd_pcm_substream *substream, *prev;
704 
705 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
706 	mutex_init(&pstr->oss.setup_mutex);
707 #endif
708 	pstr->stream = stream;
709 	pstr->pcm = pcm;
710 	pstr->substream_count = substream_count;
711 	if (!substream_count)
712 		return 0;
713 
714 	snd_device_initialize(&pstr->dev, pcm->card);
715 	pstr->dev.groups = pcm_dev_attr_groups;
716 	dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
717 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
718 
719 	if (!pcm->internal) {
720 		err = snd_pcm_stream_proc_init(pstr);
721 		if (err < 0) {
722 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
723 			return err;
724 		}
725 	}
726 	prev = NULL;
727 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
728 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
729 		if (!substream)
730 			return -ENOMEM;
731 		substream->pcm = pcm;
732 		substream->pstr = pstr;
733 		substream->number = idx;
734 		substream->stream = stream;
735 		sprintf(substream->name, "subdevice #%i", idx);
736 		substream->buffer_bytes_max = UINT_MAX;
737 		if (prev == NULL)
738 			pstr->substream = substream;
739 		else
740 			prev->next = substream;
741 
742 		if (!pcm->internal) {
743 			err = snd_pcm_substream_proc_init(substream);
744 			if (err < 0) {
745 				pcm_err(pcm,
746 					"Error in snd_pcm_stream_proc_init\n");
747 				if (prev == NULL)
748 					pstr->substream = NULL;
749 				else
750 					prev->next = NULL;
751 				kfree(substream);
752 				return err;
753 			}
754 		}
755 		substream->group = &substream->self_group;
756 		spin_lock_init(&substream->self_group.lock);
757 		mutex_init(&substream->self_group.mutex);
758 		INIT_LIST_HEAD(&substream->self_group.substreams);
759 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
760 		atomic_set(&substream->mmap_count, 0);
761 		prev = substream;
762 	}
763 	return 0;
764 }
765 EXPORT_SYMBOL(snd_pcm_new_stream);
766 
767 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
768 		int playback_count, int capture_count, bool internal,
769 		struct snd_pcm **rpcm)
770 {
771 	struct snd_pcm *pcm;
772 	int err;
773 	static struct snd_device_ops ops = {
774 		.dev_free = snd_pcm_dev_free,
775 		.dev_register =	snd_pcm_dev_register,
776 		.dev_disconnect = snd_pcm_dev_disconnect,
777 	};
778 
779 	if (snd_BUG_ON(!card))
780 		return -ENXIO;
781 	if (rpcm)
782 		*rpcm = NULL;
783 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
784 	if (!pcm)
785 		return -ENOMEM;
786 	pcm->card = card;
787 	pcm->device = device;
788 	pcm->internal = internal;
789 	mutex_init(&pcm->open_mutex);
790 	init_waitqueue_head(&pcm->open_wait);
791 	INIT_LIST_HEAD(&pcm->list);
792 	if (id)
793 		strlcpy(pcm->id, id, sizeof(pcm->id));
794 
795 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
796 				 playback_count);
797 	if (err < 0)
798 		goto free_pcm;
799 
800 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
801 	if (err < 0)
802 		goto free_pcm;
803 
804 	err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops);
805 	if (err < 0)
806 		goto free_pcm;
807 
808 	if (rpcm)
809 		*rpcm = pcm;
810 	return 0;
811 
812 free_pcm:
813 	snd_pcm_free(pcm);
814 	return err;
815 }
816 
817 /**
818  * snd_pcm_new - create a new PCM instance
819  * @card: the card instance
820  * @id: the id string
821  * @device: the device index (zero based)
822  * @playback_count: the number of substreams for playback
823  * @capture_count: the number of substreams for capture
824  * @rpcm: the pointer to store the new pcm instance
825  *
826  * Creates a new PCM instance.
827  *
828  * The pcm operators have to be set afterwards to the new instance
829  * via snd_pcm_set_ops().
830  *
831  * Return: Zero if successful, or a negative error code on failure.
832  */
833 int snd_pcm_new(struct snd_card *card, const char *id, int device,
834 		int playback_count, int capture_count, struct snd_pcm **rpcm)
835 {
836 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
837 			false, rpcm);
838 }
839 EXPORT_SYMBOL(snd_pcm_new);
840 
841 /**
842  * snd_pcm_new_internal - create a new internal PCM instance
843  * @card: the card instance
844  * @id: the id string
845  * @device: the device index (zero based - shared with normal PCMs)
846  * @playback_count: the number of substreams for playback
847  * @capture_count: the number of substreams for capture
848  * @rpcm: the pointer to store the new pcm instance
849  *
850  * Creates a new internal PCM instance with no userspace device or procfs
851  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
852  * will only be used internally by kernel drivers. i.e. it cannot be opened
853  * by userspace. It provides existing ASoC components drivers with a substream
854  * and access to any private data.
855  *
856  * The pcm operators have to be set afterwards to the new instance
857  * via snd_pcm_set_ops().
858  *
859  * Return: Zero if successful, or a negative error code on failure.
860  */
861 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
862 	int playback_count, int capture_count,
863 	struct snd_pcm **rpcm)
864 {
865 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
866 			true, rpcm);
867 }
868 EXPORT_SYMBOL(snd_pcm_new_internal);
869 
870 static void free_chmap(struct snd_pcm_str *pstr)
871 {
872 	if (pstr->chmap_kctl) {
873 		snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
874 		pstr->chmap_kctl = NULL;
875 	}
876 }
877 
878 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
879 {
880 	struct snd_pcm_substream *substream, *substream_next;
881 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
882 	struct snd_pcm_oss_setup *setup, *setupn;
883 #endif
884 	substream = pstr->substream;
885 	while (substream) {
886 		substream_next = substream->next;
887 		snd_pcm_timer_done(substream);
888 		snd_pcm_substream_proc_done(substream);
889 		kfree(substream);
890 		substream = substream_next;
891 	}
892 	snd_pcm_stream_proc_done(pstr);
893 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
894 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
895 		setupn = setup->next;
896 		kfree(setup->task_name);
897 		kfree(setup);
898 	}
899 #endif
900 	free_chmap(pstr);
901 	if (pstr->substream_count)
902 		put_device(&pstr->dev);
903 }
904 
905 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
906 #define pcm_call_notify(pcm, call)					\
907 	do {								\
908 		struct snd_pcm_notify *_notify;				\
909 		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
910 			_notify->call(pcm);				\
911 	} while (0)
912 #else
913 #define pcm_call_notify(pcm, call) do {} while (0)
914 #endif
915 
916 static int snd_pcm_free(struct snd_pcm *pcm)
917 {
918 	if (!pcm)
919 		return 0;
920 	if (!pcm->internal)
921 		pcm_call_notify(pcm, n_unregister);
922 	if (pcm->private_free)
923 		pcm->private_free(pcm);
924 	snd_pcm_lib_preallocate_free_for_all(pcm);
925 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
926 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
927 	kfree(pcm);
928 	return 0;
929 }
930 
931 static int snd_pcm_dev_free(struct snd_device *device)
932 {
933 	struct snd_pcm *pcm = device->device_data;
934 	return snd_pcm_free(pcm);
935 }
936 
937 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
938 			     struct file *file,
939 			     struct snd_pcm_substream **rsubstream)
940 {
941 	struct snd_pcm_str * pstr;
942 	struct snd_pcm_substream *substream;
943 	struct snd_pcm_runtime *runtime;
944 	struct snd_card *card;
945 	int prefer_subdevice;
946 	size_t size;
947 
948 	if (snd_BUG_ON(!pcm || !rsubstream))
949 		return -ENXIO;
950 	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
951 		       stream != SNDRV_PCM_STREAM_CAPTURE))
952 		return -EINVAL;
953 	*rsubstream = NULL;
954 	pstr = &pcm->streams[stream];
955 	if (pstr->substream == NULL || pstr->substream_count == 0)
956 		return -ENODEV;
957 
958 	card = pcm->card;
959 	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
960 
961 	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
962 		int opposite = !stream;
963 
964 		for (substream = pcm->streams[opposite].substream; substream;
965 		     substream = substream->next) {
966 			if (SUBSTREAM_BUSY(substream))
967 				return -EAGAIN;
968 		}
969 	}
970 
971 	if (file->f_flags & O_APPEND) {
972 		if (prefer_subdevice < 0) {
973 			if (pstr->substream_count > 1)
974 				return -EINVAL; /* must be unique */
975 			substream = pstr->substream;
976 		} else {
977 			for (substream = pstr->substream; substream;
978 			     substream = substream->next)
979 				if (substream->number == prefer_subdevice)
980 					break;
981 		}
982 		if (! substream)
983 			return -ENODEV;
984 		if (! SUBSTREAM_BUSY(substream))
985 			return -EBADFD;
986 		substream->ref_count++;
987 		*rsubstream = substream;
988 		return 0;
989 	}
990 
991 	for (substream = pstr->substream; substream; substream = substream->next) {
992 		if (!SUBSTREAM_BUSY(substream) &&
993 		    (prefer_subdevice == -1 ||
994 		     substream->number == prefer_subdevice))
995 			break;
996 	}
997 	if (substream == NULL)
998 		return -EAGAIN;
999 
1000 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
1001 	if (runtime == NULL)
1002 		return -ENOMEM;
1003 
1004 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
1005 	runtime->status = snd_malloc_pages(size, GFP_KERNEL);
1006 	if (runtime->status == NULL) {
1007 		kfree(runtime);
1008 		return -ENOMEM;
1009 	}
1010 	memset((void*)runtime->status, 0, size);
1011 
1012 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
1013 	runtime->control = snd_malloc_pages(size, GFP_KERNEL);
1014 	if (runtime->control == NULL) {
1015 		snd_free_pages((void*)runtime->status,
1016 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1017 		kfree(runtime);
1018 		return -ENOMEM;
1019 	}
1020 	memset((void*)runtime->control, 0, size);
1021 
1022 	init_waitqueue_head(&runtime->sleep);
1023 	init_waitqueue_head(&runtime->tsleep);
1024 
1025 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
1026 
1027 	substream->runtime = runtime;
1028 	substream->private_data = pcm->private_data;
1029 	substream->ref_count = 1;
1030 	substream->f_flags = file->f_flags;
1031 	substream->pid = get_pid(task_pid(current));
1032 	pstr->substream_opened++;
1033 	*rsubstream = substream;
1034 	return 0;
1035 }
1036 
1037 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1038 {
1039 	struct snd_pcm_runtime *runtime;
1040 
1041 	if (PCM_RUNTIME_CHECK(substream))
1042 		return;
1043 	runtime = substream->runtime;
1044 	if (runtime->private_free != NULL)
1045 		runtime->private_free(runtime);
1046 	snd_free_pages((void*)runtime->status,
1047 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1048 	snd_free_pages((void*)runtime->control,
1049 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1050 	kfree(runtime->hw_constraints.rules);
1051 	kfree(runtime);
1052 	substream->runtime = NULL;
1053 	put_pid(substream->pid);
1054 	substream->pid = NULL;
1055 	substream->pstr->substream_opened--;
1056 }
1057 
1058 static ssize_t show_pcm_class(struct device *dev,
1059 			      struct device_attribute *attr, char *buf)
1060 {
1061 	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1062 	struct snd_pcm *pcm = pstr->pcm;
1063 	const char *str;
1064 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1065 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1066 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1067 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1068 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1069 	};
1070 
1071 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1072 		str = "none";
1073 	else
1074 		str = strs[pcm->dev_class];
1075         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1076 }
1077 
1078 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1079 static struct attribute *pcm_dev_attrs[] = {
1080 	&dev_attr_pcm_class.attr,
1081 	NULL
1082 };
1083 
1084 static const struct attribute_group pcm_dev_attr_group = {
1085 	.attrs	= pcm_dev_attrs,
1086 };
1087 
1088 static const struct attribute_group *pcm_dev_attr_groups[] = {
1089 	&pcm_dev_attr_group,
1090 	NULL
1091 };
1092 
1093 static int snd_pcm_dev_register(struct snd_device *device)
1094 {
1095 	int cidx, err;
1096 	struct snd_pcm_substream *substream;
1097 	struct snd_pcm *pcm;
1098 
1099 	if (snd_BUG_ON(!device || !device->device_data))
1100 		return -ENXIO;
1101 	pcm = device->device_data;
1102 	if (pcm->internal)
1103 		return 0;
1104 
1105 	mutex_lock(&register_mutex);
1106 	err = snd_pcm_add(pcm);
1107 	if (err)
1108 		goto unlock;
1109 	for (cidx = 0; cidx < 2; cidx++) {
1110 		int devtype = -1;
1111 		if (pcm->streams[cidx].substream == NULL)
1112 			continue;
1113 		switch (cidx) {
1114 		case SNDRV_PCM_STREAM_PLAYBACK:
1115 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1116 			break;
1117 		case SNDRV_PCM_STREAM_CAPTURE:
1118 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1119 			break;
1120 		}
1121 		/* register pcm */
1122 		err = snd_register_device(devtype, pcm->card, pcm->device,
1123 					  &snd_pcm_f_ops[cidx], pcm,
1124 					  &pcm->streams[cidx].dev);
1125 		if (err < 0) {
1126 			list_del_init(&pcm->list);
1127 			goto unlock;
1128 		}
1129 
1130 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1131 			snd_pcm_timer_init(substream);
1132 	}
1133 
1134 	pcm_call_notify(pcm, n_register);
1135 
1136  unlock:
1137 	mutex_unlock(&register_mutex);
1138 	return err;
1139 }
1140 
1141 static int snd_pcm_dev_disconnect(struct snd_device *device)
1142 {
1143 	struct snd_pcm *pcm = device->device_data;
1144 	struct snd_pcm_substream *substream;
1145 	int cidx;
1146 
1147 	mutex_lock(&register_mutex);
1148 	mutex_lock(&pcm->open_mutex);
1149 	wake_up(&pcm->open_wait);
1150 	list_del_init(&pcm->list);
1151 	for (cidx = 0; cidx < 2; cidx++) {
1152 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1153 			snd_pcm_stream_lock_irq(substream);
1154 			if (substream->runtime) {
1155 				substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1156 				wake_up(&substream->runtime->sleep);
1157 				wake_up(&substream->runtime->tsleep);
1158 			}
1159 			snd_pcm_stream_unlock_irq(substream);
1160 		}
1161 	}
1162 	if (!pcm->internal) {
1163 		pcm_call_notify(pcm, n_disconnect);
1164 	}
1165 	for (cidx = 0; cidx < 2; cidx++) {
1166 		if (!pcm->internal)
1167 			snd_unregister_device(&pcm->streams[cidx].dev);
1168 		free_chmap(&pcm->streams[cidx]);
1169 	}
1170 	mutex_unlock(&pcm->open_mutex);
1171 	mutex_unlock(&register_mutex);
1172 	return 0;
1173 }
1174 
1175 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1176 /**
1177  * snd_pcm_notify - Add/remove the notify list
1178  * @notify: PCM notify list
1179  * @nfree: 0 = register, 1 = unregister
1180  *
1181  * This adds the given notifier to the global list so that the callback is
1182  * called for each registered PCM devices.  This exists only for PCM OSS
1183  * emulation, so far.
1184  */
1185 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1186 {
1187 	struct snd_pcm *pcm;
1188 
1189 	if (snd_BUG_ON(!notify ||
1190 		       !notify->n_register ||
1191 		       !notify->n_unregister ||
1192 		       !notify->n_disconnect))
1193 		return -EINVAL;
1194 	mutex_lock(&register_mutex);
1195 	if (nfree) {
1196 		list_del(&notify->list);
1197 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1198 			notify->n_unregister(pcm);
1199 	} else {
1200 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1201 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1202 			notify->n_register(pcm);
1203 	}
1204 	mutex_unlock(&register_mutex);
1205 	return 0;
1206 }
1207 EXPORT_SYMBOL(snd_pcm_notify);
1208 #endif /* CONFIG_SND_PCM_OSS */
1209 
1210 #ifdef CONFIG_SND_PROC_FS
1211 /*
1212  *  Info interface
1213  */
1214 
1215 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1216 			      struct snd_info_buffer *buffer)
1217 {
1218 	struct snd_pcm *pcm;
1219 
1220 	mutex_lock(&register_mutex);
1221 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1222 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1223 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1224 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1225 			snd_iprintf(buffer, " : playback %i",
1226 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1227 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1228 			snd_iprintf(buffer, " : capture %i",
1229 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1230 		snd_iprintf(buffer, "\n");
1231 	}
1232 	mutex_unlock(&register_mutex);
1233 }
1234 
1235 static struct snd_info_entry *snd_pcm_proc_entry;
1236 
1237 static void snd_pcm_proc_init(void)
1238 {
1239 	struct snd_info_entry *entry;
1240 
1241 	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1242 	if (entry) {
1243 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1244 		if (snd_info_register(entry) < 0) {
1245 			snd_info_free_entry(entry);
1246 			entry = NULL;
1247 		}
1248 	}
1249 	snd_pcm_proc_entry = entry;
1250 }
1251 
1252 static void snd_pcm_proc_done(void)
1253 {
1254 	snd_info_free_entry(snd_pcm_proc_entry);
1255 }
1256 
1257 #else /* !CONFIG_SND_PROC_FS */
1258 #define snd_pcm_proc_init()
1259 #define snd_pcm_proc_done()
1260 #endif /* CONFIG_SND_PROC_FS */
1261 
1262 
1263 /*
1264  *  ENTRY functions
1265  */
1266 
1267 static int __init alsa_pcm_init(void)
1268 {
1269 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1270 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1271 	snd_pcm_proc_init();
1272 	return 0;
1273 }
1274 
1275 static void __exit alsa_pcm_exit(void)
1276 {
1277 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1278 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1279 	snd_pcm_proc_done();
1280 }
1281 
1282 module_init(alsa_pcm_init)
1283 module_exit(alsa_pcm_exit)
1284