xref: /linux/sound/core/pcm.c (revision 6179d4a213006491ff0d50073256f21fad22149b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Digital Audio (PCM) abstract layer
4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5  */
6 
7 #include <linux/init.h>
8 #include <linux/slab.h>
9 #include <linux/module.h>
10 #include <linux/time.h>
11 #include <linux/mutex.h>
12 #include <linux/device.h>
13 #include <linux/nospec.h>
14 #include <sound/core.h>
15 #include <sound/minors.h>
16 #include <sound/pcm.h>
17 #include <sound/timer.h>
18 #include <sound/control.h>
19 #include <sound/info.h>
20 
21 #include "pcm_local.h"
22 
23 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
24 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
25 MODULE_LICENSE("GPL");
26 
27 static LIST_HEAD(snd_pcm_devices);
28 static DEFINE_MUTEX(register_mutex);
29 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
30 static LIST_HEAD(snd_pcm_notify_list);
31 #endif
32 
33 static int snd_pcm_free(struct snd_pcm *pcm);
34 static int snd_pcm_dev_free(struct snd_device *device);
35 static int snd_pcm_dev_register(struct snd_device *device);
36 static int snd_pcm_dev_disconnect(struct snd_device *device);
37 
38 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
39 {
40 	struct snd_pcm *pcm;
41 
42 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
43 		if (pcm->card == card && pcm->device == device)
44 			return pcm;
45 	}
46 	return NULL;
47 }
48 
49 static int snd_pcm_next(struct snd_card *card, int device)
50 {
51 	struct snd_pcm *pcm;
52 
53 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
54 		if (pcm->card == card && pcm->device > device)
55 			return pcm->device;
56 		else if (pcm->card->number > card->number)
57 			return -1;
58 	}
59 	return -1;
60 }
61 
62 static int snd_pcm_add(struct snd_pcm *newpcm)
63 {
64 	struct snd_pcm *pcm;
65 
66 	if (newpcm->internal)
67 		return 0;
68 
69 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
70 		if (pcm->card == newpcm->card && pcm->device == newpcm->device)
71 			return -EBUSY;
72 		if (pcm->card->number > newpcm->card->number ||
73 				(pcm->card == newpcm->card &&
74 				pcm->device > newpcm->device)) {
75 			list_add(&newpcm->list, pcm->list.prev);
76 			return 0;
77 		}
78 	}
79 	list_add_tail(&newpcm->list, &snd_pcm_devices);
80 	return 0;
81 }
82 
83 static int snd_pcm_control_ioctl(struct snd_card *card,
84 				 struct snd_ctl_file *control,
85 				 unsigned int cmd, unsigned long arg)
86 {
87 	switch (cmd) {
88 	case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
89 		{
90 			int device;
91 
92 			if (get_user(device, (int __user *)arg))
93 				return -EFAULT;
94 			mutex_lock(&register_mutex);
95 			device = snd_pcm_next(card, device);
96 			mutex_unlock(&register_mutex);
97 			if (put_user(device, (int __user *)arg))
98 				return -EFAULT;
99 			return 0;
100 		}
101 	case SNDRV_CTL_IOCTL_PCM_INFO:
102 		{
103 			struct snd_pcm_info __user *info;
104 			unsigned int device, subdevice;
105 			int stream;
106 			struct snd_pcm *pcm;
107 			struct snd_pcm_str *pstr;
108 			struct snd_pcm_substream *substream;
109 			int err;
110 
111 			info = (struct snd_pcm_info __user *)arg;
112 			if (get_user(device, &info->device))
113 				return -EFAULT;
114 			if (get_user(stream, &info->stream))
115 				return -EFAULT;
116 			if (stream < 0 || stream > 1)
117 				return -EINVAL;
118 			stream = array_index_nospec(stream, 2);
119 			if (get_user(subdevice, &info->subdevice))
120 				return -EFAULT;
121 			mutex_lock(&register_mutex);
122 			pcm = snd_pcm_get(card, device);
123 			if (pcm == NULL) {
124 				err = -ENXIO;
125 				goto _error;
126 			}
127 			pstr = &pcm->streams[stream];
128 			if (pstr->substream_count == 0) {
129 				err = -ENOENT;
130 				goto _error;
131 			}
132 			if (subdevice >= pstr->substream_count) {
133 				err = -ENXIO;
134 				goto _error;
135 			}
136 			for (substream = pstr->substream; substream;
137 			     substream = substream->next)
138 				if (substream->number == (int)subdevice)
139 					break;
140 			if (substream == NULL) {
141 				err = -ENXIO;
142 				goto _error;
143 			}
144 			mutex_lock(&pcm->open_mutex);
145 			err = snd_pcm_info_user(substream, info);
146 			mutex_unlock(&pcm->open_mutex);
147 		_error:
148 			mutex_unlock(&register_mutex);
149 			return err;
150 		}
151 	case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
152 		{
153 			int val;
154 
155 			if (get_user(val, (int __user *)arg))
156 				return -EFAULT;
157 			control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
158 			return 0;
159 		}
160 	}
161 	return -ENOIOCTLCMD;
162 }
163 
164 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
165 
166 static const char * const snd_pcm_format_names[] = {
167 	FORMAT(S8),
168 	FORMAT(U8),
169 	FORMAT(S16_LE),
170 	FORMAT(S16_BE),
171 	FORMAT(U16_LE),
172 	FORMAT(U16_BE),
173 	FORMAT(S24_LE),
174 	FORMAT(S24_BE),
175 	FORMAT(U24_LE),
176 	FORMAT(U24_BE),
177 	FORMAT(S32_LE),
178 	FORMAT(S32_BE),
179 	FORMAT(U32_LE),
180 	FORMAT(U32_BE),
181 	FORMAT(FLOAT_LE),
182 	FORMAT(FLOAT_BE),
183 	FORMAT(FLOAT64_LE),
184 	FORMAT(FLOAT64_BE),
185 	FORMAT(IEC958_SUBFRAME_LE),
186 	FORMAT(IEC958_SUBFRAME_BE),
187 	FORMAT(MU_LAW),
188 	FORMAT(A_LAW),
189 	FORMAT(IMA_ADPCM),
190 	FORMAT(MPEG),
191 	FORMAT(GSM),
192 	FORMAT(SPECIAL),
193 	FORMAT(S24_3LE),
194 	FORMAT(S24_3BE),
195 	FORMAT(U24_3LE),
196 	FORMAT(U24_3BE),
197 	FORMAT(S20_3LE),
198 	FORMAT(S20_3BE),
199 	FORMAT(U20_3LE),
200 	FORMAT(U20_3BE),
201 	FORMAT(S18_3LE),
202 	FORMAT(S18_3BE),
203 	FORMAT(U18_3LE),
204 	FORMAT(U18_3BE),
205 	FORMAT(G723_24),
206 	FORMAT(G723_24_1B),
207 	FORMAT(G723_40),
208 	FORMAT(G723_40_1B),
209 	FORMAT(DSD_U8),
210 	FORMAT(DSD_U16_LE),
211 	FORMAT(DSD_U32_LE),
212 	FORMAT(DSD_U16_BE),
213 	FORMAT(DSD_U32_BE),
214 };
215 
216 /**
217  * snd_pcm_format_name - Return a name string for the given PCM format
218  * @format: PCM format
219  *
220  * Return: the format name string
221  */
222 const char *snd_pcm_format_name(snd_pcm_format_t format)
223 {
224 	if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
225 		return "Unknown";
226 	return snd_pcm_format_names[(__force unsigned int)format];
227 }
228 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
229 
230 #ifdef CONFIG_SND_VERBOSE_PROCFS
231 
232 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
233 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
234 #define READY(v) [SNDRV_PCM_READY_##v] = #v
235 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
236 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
237 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
238 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
239 #define START(v) [SNDRV_PCM_START_##v] = #v
240 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
241 
242 static const char * const snd_pcm_stream_names[] = {
243 	STREAM(PLAYBACK),
244 	STREAM(CAPTURE),
245 };
246 
247 static const char * const snd_pcm_state_names[] = {
248 	STATE(OPEN),
249 	STATE(SETUP),
250 	STATE(PREPARED),
251 	STATE(RUNNING),
252 	STATE(XRUN),
253 	STATE(DRAINING),
254 	STATE(PAUSED),
255 	STATE(SUSPENDED),
256 	STATE(DISCONNECTED),
257 };
258 
259 static const char * const snd_pcm_access_names[] = {
260 	ACCESS(MMAP_INTERLEAVED),
261 	ACCESS(MMAP_NONINTERLEAVED),
262 	ACCESS(MMAP_COMPLEX),
263 	ACCESS(RW_INTERLEAVED),
264 	ACCESS(RW_NONINTERLEAVED),
265 };
266 
267 static const char * const snd_pcm_subformat_names[] = {
268 	SUBFORMAT(STD),
269 	SUBFORMAT(MSBITS_MAX),
270 	SUBFORMAT(MSBITS_20),
271 	SUBFORMAT(MSBITS_24),
272 };
273 
274 static const char * const snd_pcm_tstamp_mode_names[] = {
275 	TSTAMP(NONE),
276 	TSTAMP(ENABLE),
277 };
278 
279 static const char *snd_pcm_stream_name(int stream)
280 {
281 	return snd_pcm_stream_names[stream];
282 }
283 
284 static const char *snd_pcm_access_name(snd_pcm_access_t access)
285 {
286 	return snd_pcm_access_names[(__force int)access];
287 }
288 
289 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
290 {
291 	return snd_pcm_subformat_names[(__force int)subformat];
292 }
293 
294 static const char *snd_pcm_tstamp_mode_name(int mode)
295 {
296 	return snd_pcm_tstamp_mode_names[mode];
297 }
298 
299 static const char *snd_pcm_state_name(snd_pcm_state_t state)
300 {
301 	return snd_pcm_state_names[(__force int)state];
302 }
303 
304 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
305 #include <linux/soundcard.h>
306 
307 static const char *snd_pcm_oss_format_name(int format)
308 {
309 	switch (format) {
310 	case AFMT_MU_LAW:
311 		return "MU_LAW";
312 	case AFMT_A_LAW:
313 		return "A_LAW";
314 	case AFMT_IMA_ADPCM:
315 		return "IMA_ADPCM";
316 	case AFMT_U8:
317 		return "U8";
318 	case AFMT_S16_LE:
319 		return "S16_LE";
320 	case AFMT_S16_BE:
321 		return "S16_BE";
322 	case AFMT_S8:
323 		return "S8";
324 	case AFMT_U16_LE:
325 		return "U16_LE";
326 	case AFMT_U16_BE:
327 		return "U16_BE";
328 	case AFMT_MPEG:
329 		return "MPEG";
330 	default:
331 		return "unknown";
332 	}
333 }
334 #endif
335 
336 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
337 				   struct snd_info_buffer *buffer)
338 {
339 	struct snd_pcm_info *info;
340 	int err;
341 
342 	if (! substream)
343 		return;
344 
345 	info = kmalloc(sizeof(*info), GFP_KERNEL);
346 	if (!info)
347 		return;
348 
349 	err = snd_pcm_info(substream, info);
350 	if (err < 0) {
351 		snd_iprintf(buffer, "error %d\n", err);
352 		kfree(info);
353 		return;
354 	}
355 	snd_iprintf(buffer, "card: %d\n", info->card);
356 	snd_iprintf(buffer, "device: %d\n", info->device);
357 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
358 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
359 	snd_iprintf(buffer, "id: %s\n", info->id);
360 	snd_iprintf(buffer, "name: %s\n", info->name);
361 	snd_iprintf(buffer, "subname: %s\n", info->subname);
362 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
363 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
364 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
365 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
366 	kfree(info);
367 }
368 
369 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
370 					  struct snd_info_buffer *buffer)
371 {
372 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
373 			       buffer);
374 }
375 
376 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
377 					     struct snd_info_buffer *buffer)
378 {
379 	snd_pcm_proc_info_read(entry->private_data, buffer);
380 }
381 
382 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
383 						  struct snd_info_buffer *buffer)
384 {
385 	struct snd_pcm_substream *substream = entry->private_data;
386 	struct snd_pcm_runtime *runtime;
387 
388 	mutex_lock(&substream->pcm->open_mutex);
389 	runtime = substream->runtime;
390 	if (!runtime) {
391 		snd_iprintf(buffer, "closed\n");
392 		goto unlock;
393 	}
394 	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
395 		snd_iprintf(buffer, "no setup\n");
396 		goto unlock;
397 	}
398 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
399 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
400 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
401 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
402 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
403 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
404 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
405 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
406 	if (substream->oss.oss) {
407 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
408 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
409 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
410 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
411 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
412 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
413 	}
414 #endif
415  unlock:
416 	mutex_unlock(&substream->pcm->open_mutex);
417 }
418 
419 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
420 						  struct snd_info_buffer *buffer)
421 {
422 	struct snd_pcm_substream *substream = entry->private_data;
423 	struct snd_pcm_runtime *runtime;
424 
425 	mutex_lock(&substream->pcm->open_mutex);
426 	runtime = substream->runtime;
427 	if (!runtime) {
428 		snd_iprintf(buffer, "closed\n");
429 		goto unlock;
430 	}
431 	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
432 		snd_iprintf(buffer, "no setup\n");
433 		goto unlock;
434 	}
435 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
436 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
437 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
438 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
439 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
440 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
441 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
442 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
443  unlock:
444 	mutex_unlock(&substream->pcm->open_mutex);
445 }
446 
447 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
448 					       struct snd_info_buffer *buffer)
449 {
450 	struct snd_pcm_substream *substream = entry->private_data;
451 	struct snd_pcm_runtime *runtime;
452 	struct snd_pcm_status64 status;
453 	int err;
454 
455 	mutex_lock(&substream->pcm->open_mutex);
456 	runtime = substream->runtime;
457 	if (!runtime) {
458 		snd_iprintf(buffer, "closed\n");
459 		goto unlock;
460 	}
461 	memset(&status, 0, sizeof(status));
462 	err = snd_pcm_status64(substream, &status);
463 	if (err < 0) {
464 		snd_iprintf(buffer, "error %d\n", err);
465 		goto unlock;
466 	}
467 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
468 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
469 	snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
470 		status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
471 	snd_iprintf(buffer, "tstamp      : %lld.%09lld\n",
472 		status.tstamp_sec, status.tstamp_nsec);
473 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
474 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
475 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
476 	snd_iprintf(buffer, "-----\n");
477 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
478 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
479  unlock:
480 	mutex_unlock(&substream->pcm->open_mutex);
481 }
482 
483 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
484 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
485 					 struct snd_info_buffer *buffer)
486 {
487 	struct snd_pcm_substream *substream = entry->private_data;
488 
489 	snd_pcm_stop_xrun(substream);
490 }
491 
492 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
493 				    struct snd_info_buffer *buffer)
494 {
495 	struct snd_pcm_str *pstr = entry->private_data;
496 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
497 }
498 
499 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
500 				     struct snd_info_buffer *buffer)
501 {
502 	struct snd_pcm_str *pstr = entry->private_data;
503 	char line[64];
504 	if (!snd_info_get_line(buffer, line, sizeof(line)))
505 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
506 }
507 #endif
508 
509 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
510 {
511 	struct snd_pcm *pcm = pstr->pcm;
512 	struct snd_info_entry *entry;
513 	char name[16];
514 
515 	sprintf(name, "pcm%i%c", pcm->device,
516 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
517 	entry = snd_info_create_card_entry(pcm->card, name,
518 					   pcm->card->proc_root);
519 	if (!entry)
520 		return -ENOMEM;
521 	entry->mode = S_IFDIR | 0555;
522 	pstr->proc_root = entry;
523 	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
524 	if (entry)
525 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
526 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
527 	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
528 					   pstr->proc_root);
529 	if (entry) {
530 		snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
531 		entry->c.text.write = snd_pcm_xrun_debug_write;
532 		entry->mode |= 0200;
533 	}
534 #endif
535 	return 0;
536 }
537 
538 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
539 {
540 	snd_info_free_entry(pstr->proc_root);
541 	pstr->proc_root = NULL;
542 	return 0;
543 }
544 
545 static struct snd_info_entry *
546 create_substream_info_entry(struct snd_pcm_substream *substream,
547 			    const char *name,
548 			    void (*read)(struct snd_info_entry *,
549 					 struct snd_info_buffer *))
550 {
551 	struct snd_info_entry *entry;
552 
553 	entry = snd_info_create_card_entry(substream->pcm->card, name,
554 					   substream->proc_root);
555 	if (entry)
556 		snd_info_set_text_ops(entry, substream, read);
557 	return entry;
558 }
559 
560 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
561 {
562 	struct snd_info_entry *entry;
563 	struct snd_card *card;
564 	char name[16];
565 
566 	card = substream->pcm->card;
567 
568 	sprintf(name, "sub%i", substream->number);
569 	entry = snd_info_create_card_entry(card, name,
570 					   substream->pstr->proc_root);
571 	if (!entry)
572 		return -ENOMEM;
573 	entry->mode = S_IFDIR | 0555;
574 	substream->proc_root = entry;
575 
576 	create_substream_info_entry(substream, "info",
577 				    snd_pcm_substream_proc_info_read);
578 	create_substream_info_entry(substream, "hw_params",
579 				    snd_pcm_substream_proc_hw_params_read);
580 	create_substream_info_entry(substream, "sw_params",
581 				    snd_pcm_substream_proc_sw_params_read);
582 	create_substream_info_entry(substream, "status",
583 				    snd_pcm_substream_proc_status_read);
584 
585 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
586 	entry = create_substream_info_entry(substream, "xrun_injection", NULL);
587 	if (entry) {
588 		entry->c.text.write = snd_pcm_xrun_injection_write;
589 		entry->mode = S_IFREG | 0200;
590 	}
591 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
592 
593 	return 0;
594 }
595 
596 #else /* !CONFIG_SND_VERBOSE_PROCFS */
597 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
598 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
599 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
600 #endif /* CONFIG_SND_VERBOSE_PROCFS */
601 
602 static const struct attribute_group *pcm_dev_attr_groups[];
603 
604 /*
605  * PM callbacks: we need to deal only with suspend here, as the resume is
606  * triggered either from user-space or the driver's resume callback
607  */
608 #ifdef CONFIG_PM_SLEEP
609 static int do_pcm_suspend(struct device *dev)
610 {
611 	struct snd_pcm_str *pstr = dev_get_drvdata(dev);
612 
613 	if (!pstr->pcm->no_device_suspend)
614 		snd_pcm_suspend_all(pstr->pcm);
615 	return 0;
616 }
617 #endif
618 
619 static const struct dev_pm_ops pcm_dev_pm_ops = {
620 	SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
621 };
622 
623 /* device type for PCM -- basically only for passing PM callbacks */
624 static const struct device_type pcm_dev_type = {
625 	.name = "pcm",
626 	.pm = &pcm_dev_pm_ops,
627 };
628 
629 /**
630  * snd_pcm_new_stream - create a new PCM stream
631  * @pcm: the pcm instance
632  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
633  * @substream_count: the number of substreams
634  *
635  * Creates a new stream for the pcm.
636  * The corresponding stream on the pcm must have been empty before
637  * calling this, i.e. zero must be given to the argument of
638  * snd_pcm_new().
639  *
640  * Return: Zero if successful, or a negative error code on failure.
641  */
642 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
643 {
644 	int idx, err;
645 	struct snd_pcm_str *pstr = &pcm->streams[stream];
646 	struct snd_pcm_substream *substream, *prev;
647 
648 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
649 	mutex_init(&pstr->oss.setup_mutex);
650 #endif
651 	pstr->stream = stream;
652 	pstr->pcm = pcm;
653 	pstr->substream_count = substream_count;
654 	if (!substream_count)
655 		return 0;
656 
657 	err = snd_device_alloc(&pstr->dev, pcm->card);
658 	if (err < 0)
659 		return err;
660 	dev_set_name(pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
661 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
662 	pstr->dev->groups = pcm_dev_attr_groups;
663 	pstr->dev->type = &pcm_dev_type;
664 	dev_set_drvdata(pstr->dev, pstr);
665 
666 	if (!pcm->internal) {
667 		err = snd_pcm_stream_proc_init(pstr);
668 		if (err < 0) {
669 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
670 			return err;
671 		}
672 	}
673 	prev = NULL;
674 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
675 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
676 		if (!substream)
677 			return -ENOMEM;
678 		substream->pcm = pcm;
679 		substream->pstr = pstr;
680 		substream->number = idx;
681 		substream->stream = stream;
682 		sprintf(substream->name, "subdevice #%i", idx);
683 		substream->buffer_bytes_max = UINT_MAX;
684 		if (prev == NULL)
685 			pstr->substream = substream;
686 		else
687 			prev->next = substream;
688 
689 		if (!pcm->internal) {
690 			err = snd_pcm_substream_proc_init(substream);
691 			if (err < 0) {
692 				pcm_err(pcm,
693 					"Error in snd_pcm_stream_proc_init\n");
694 				if (prev == NULL)
695 					pstr->substream = NULL;
696 				else
697 					prev->next = NULL;
698 				kfree(substream);
699 				return err;
700 			}
701 		}
702 		substream->group = &substream->self_group;
703 		snd_pcm_group_init(&substream->self_group);
704 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
705 		atomic_set(&substream->mmap_count, 0);
706 		prev = substream;
707 	}
708 	return 0;
709 }
710 EXPORT_SYMBOL(snd_pcm_new_stream);
711 
712 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
713 		int playback_count, int capture_count, bool internal,
714 		struct snd_pcm **rpcm)
715 {
716 	struct snd_pcm *pcm;
717 	int err;
718 	static const struct snd_device_ops ops = {
719 		.dev_free = snd_pcm_dev_free,
720 		.dev_register =	snd_pcm_dev_register,
721 		.dev_disconnect = snd_pcm_dev_disconnect,
722 	};
723 	static const struct snd_device_ops internal_ops = {
724 		.dev_free = snd_pcm_dev_free,
725 	};
726 
727 	if (snd_BUG_ON(!card))
728 		return -ENXIO;
729 	if (rpcm)
730 		*rpcm = NULL;
731 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
732 	if (!pcm)
733 		return -ENOMEM;
734 	pcm->card = card;
735 	pcm->device = device;
736 	pcm->internal = internal;
737 	mutex_init(&pcm->open_mutex);
738 	init_waitqueue_head(&pcm->open_wait);
739 	INIT_LIST_HEAD(&pcm->list);
740 	if (id)
741 		strscpy(pcm->id, id, sizeof(pcm->id));
742 
743 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
744 				 playback_count);
745 	if (err < 0)
746 		goto free_pcm;
747 
748 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
749 	if (err < 0)
750 		goto free_pcm;
751 
752 	err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
753 			     internal ? &internal_ops : &ops);
754 	if (err < 0)
755 		goto free_pcm;
756 
757 	if (rpcm)
758 		*rpcm = pcm;
759 	return 0;
760 
761 free_pcm:
762 	snd_pcm_free(pcm);
763 	return err;
764 }
765 
766 /**
767  * snd_pcm_new - create a new PCM instance
768  * @card: the card instance
769  * @id: the id string
770  * @device: the device index (zero based)
771  * @playback_count: the number of substreams for playback
772  * @capture_count: the number of substreams for capture
773  * @rpcm: the pointer to store the new pcm instance
774  *
775  * Creates a new PCM instance.
776  *
777  * The pcm operators have to be set afterwards to the new instance
778  * via snd_pcm_set_ops().
779  *
780  * Return: Zero if successful, or a negative error code on failure.
781  */
782 int snd_pcm_new(struct snd_card *card, const char *id, int device,
783 		int playback_count, int capture_count, struct snd_pcm **rpcm)
784 {
785 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
786 			false, rpcm);
787 }
788 EXPORT_SYMBOL(snd_pcm_new);
789 
790 /**
791  * snd_pcm_new_internal - create a new internal PCM instance
792  * @card: the card instance
793  * @id: the id string
794  * @device: the device index (zero based - shared with normal PCMs)
795  * @playback_count: the number of substreams for playback
796  * @capture_count: the number of substreams for capture
797  * @rpcm: the pointer to store the new pcm instance
798  *
799  * Creates a new internal PCM instance with no userspace device or procfs
800  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
801  * will only be used internally by kernel drivers. i.e. it cannot be opened
802  * by userspace. It provides existing ASoC components drivers with a substream
803  * and access to any private data.
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_internal(struct snd_card *card, const char *id, int device,
811 	int playback_count, int capture_count,
812 	struct snd_pcm **rpcm)
813 {
814 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
815 			true, rpcm);
816 }
817 EXPORT_SYMBOL(snd_pcm_new_internal);
818 
819 static void free_chmap(struct snd_pcm_str *pstr)
820 {
821 	if (pstr->chmap_kctl) {
822 		struct snd_card *card = pstr->pcm->card;
823 
824 		snd_ctl_remove(card, pstr->chmap_kctl);
825 		pstr->chmap_kctl = NULL;
826 	}
827 }
828 
829 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
830 {
831 	struct snd_pcm_substream *substream, *substream_next;
832 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
833 	struct snd_pcm_oss_setup *setup, *setupn;
834 #endif
835 
836 	/* free all proc files under the stream */
837 	snd_pcm_stream_proc_done(pstr);
838 
839 	substream = pstr->substream;
840 	while (substream) {
841 		substream_next = substream->next;
842 		snd_pcm_timer_done(substream);
843 		kfree(substream);
844 		substream = substream_next;
845 	}
846 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
847 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
848 		setupn = setup->next;
849 		kfree(setup->task_name);
850 		kfree(setup);
851 	}
852 #endif
853 	free_chmap(pstr);
854 	if (pstr->substream_count)
855 		put_device(pstr->dev);
856 }
857 
858 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
859 #define pcm_call_notify(pcm, call)					\
860 	do {								\
861 		struct snd_pcm_notify *_notify;				\
862 		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
863 			_notify->call(pcm);				\
864 	} while (0)
865 #else
866 #define pcm_call_notify(pcm, call) do {} while (0)
867 #endif
868 
869 static int snd_pcm_free(struct snd_pcm *pcm)
870 {
871 	if (!pcm)
872 		return 0;
873 	if (!pcm->internal)
874 		pcm_call_notify(pcm, n_unregister);
875 	if (pcm->private_free)
876 		pcm->private_free(pcm);
877 	snd_pcm_lib_preallocate_free_for_all(pcm);
878 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
879 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
880 	kfree(pcm);
881 	return 0;
882 }
883 
884 static int snd_pcm_dev_free(struct snd_device *device)
885 {
886 	struct snd_pcm *pcm = device->device_data;
887 	return snd_pcm_free(pcm);
888 }
889 
890 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
891 			     struct file *file,
892 			     struct snd_pcm_substream **rsubstream)
893 {
894 	struct snd_pcm_str * pstr;
895 	struct snd_pcm_substream *substream;
896 	struct snd_pcm_runtime *runtime;
897 	struct snd_card *card;
898 	int prefer_subdevice;
899 	size_t size;
900 
901 	if (snd_BUG_ON(!pcm || !rsubstream))
902 		return -ENXIO;
903 	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
904 		       stream != SNDRV_PCM_STREAM_CAPTURE))
905 		return -EINVAL;
906 	*rsubstream = NULL;
907 	pstr = &pcm->streams[stream];
908 	if (pstr->substream == NULL || pstr->substream_count == 0)
909 		return -ENODEV;
910 
911 	card = pcm->card;
912 	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
913 
914 	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
915 		int opposite = !stream;
916 
917 		for (substream = pcm->streams[opposite].substream; substream;
918 		     substream = substream->next) {
919 			if (SUBSTREAM_BUSY(substream))
920 				return -EAGAIN;
921 		}
922 	}
923 
924 	if (file->f_flags & O_APPEND) {
925 		if (prefer_subdevice < 0) {
926 			if (pstr->substream_count > 1)
927 				return -EINVAL; /* must be unique */
928 			substream = pstr->substream;
929 		} else {
930 			for (substream = pstr->substream; substream;
931 			     substream = substream->next)
932 				if (substream->number == prefer_subdevice)
933 					break;
934 		}
935 		if (! substream)
936 			return -ENODEV;
937 		if (! SUBSTREAM_BUSY(substream))
938 			return -EBADFD;
939 		substream->ref_count++;
940 		*rsubstream = substream;
941 		return 0;
942 	}
943 
944 	for (substream = pstr->substream; substream; substream = substream->next) {
945 		if (!SUBSTREAM_BUSY(substream) &&
946 		    (prefer_subdevice == -1 ||
947 		     substream->number == prefer_subdevice))
948 			break;
949 	}
950 	if (substream == NULL)
951 		return -EAGAIN;
952 
953 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
954 	if (runtime == NULL)
955 		return -ENOMEM;
956 
957 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
958 	runtime->status = alloc_pages_exact(size, GFP_KERNEL);
959 	if (runtime->status == NULL) {
960 		kfree(runtime);
961 		return -ENOMEM;
962 	}
963 	memset(runtime->status, 0, size);
964 
965 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
966 	runtime->control = alloc_pages_exact(size, GFP_KERNEL);
967 	if (runtime->control == NULL) {
968 		free_pages_exact(runtime->status,
969 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
970 		kfree(runtime);
971 		return -ENOMEM;
972 	}
973 	memset(runtime->control, 0, size);
974 
975 	init_waitqueue_head(&runtime->sleep);
976 	init_waitqueue_head(&runtime->tsleep);
977 
978 	__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
979 	mutex_init(&runtime->buffer_mutex);
980 	atomic_set(&runtime->buffer_accessing, 0);
981 
982 	substream->runtime = runtime;
983 	substream->private_data = pcm->private_data;
984 	substream->ref_count = 1;
985 	substream->f_flags = file->f_flags;
986 	substream->pid = get_pid(task_pid(current));
987 	pstr->substream_opened++;
988 	*rsubstream = substream;
989 	return 0;
990 }
991 
992 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
993 {
994 	struct snd_pcm_runtime *runtime;
995 
996 	if (PCM_RUNTIME_CHECK(substream))
997 		return;
998 	runtime = substream->runtime;
999 	if (runtime->private_free != NULL)
1000 		runtime->private_free(runtime);
1001 	free_pages_exact(runtime->status,
1002 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1003 	free_pages_exact(runtime->control,
1004 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1005 	kfree(runtime->hw_constraints.rules);
1006 	/* Avoid concurrent access to runtime via PCM timer interface */
1007 	if (substream->timer) {
1008 		spin_lock_irq(&substream->timer->lock);
1009 		substream->runtime = NULL;
1010 		spin_unlock_irq(&substream->timer->lock);
1011 	} else {
1012 		substream->runtime = NULL;
1013 	}
1014 	mutex_destroy(&runtime->buffer_mutex);
1015 	snd_fasync_free(runtime->fasync);
1016 	kfree(runtime);
1017 	put_pid(substream->pid);
1018 	substream->pid = NULL;
1019 	substream->pstr->substream_opened--;
1020 }
1021 
1022 static ssize_t pcm_class_show(struct device *dev,
1023 			      struct device_attribute *attr, char *buf)
1024 {
1025 	struct snd_pcm_str *pstr = dev_get_drvdata(dev);
1026 	struct snd_pcm *pcm = pstr->pcm;
1027 	const char *str;
1028 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1029 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1030 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1031 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1032 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1033 	};
1034 
1035 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1036 		str = "none";
1037 	else
1038 		str = strs[pcm->dev_class];
1039 	return sysfs_emit(buf, "%s\n", str);
1040 }
1041 
1042 static DEVICE_ATTR_RO(pcm_class);
1043 static struct attribute *pcm_dev_attrs[] = {
1044 	&dev_attr_pcm_class.attr,
1045 	NULL
1046 };
1047 
1048 static const struct attribute_group pcm_dev_attr_group = {
1049 	.attrs	= pcm_dev_attrs,
1050 };
1051 
1052 static const struct attribute_group *pcm_dev_attr_groups[] = {
1053 	&pcm_dev_attr_group,
1054 	NULL
1055 };
1056 
1057 static int snd_pcm_dev_register(struct snd_device *device)
1058 {
1059 	int cidx, err;
1060 	struct snd_pcm_substream *substream;
1061 	struct snd_pcm *pcm;
1062 
1063 	if (snd_BUG_ON(!device || !device->device_data))
1064 		return -ENXIO;
1065 	pcm = device->device_data;
1066 
1067 	mutex_lock(&register_mutex);
1068 	err = snd_pcm_add(pcm);
1069 	if (err)
1070 		goto unlock;
1071 	for (cidx = 0; cidx < 2; cidx++) {
1072 		int devtype = -1;
1073 		if (pcm->streams[cidx].substream == NULL)
1074 			continue;
1075 		switch (cidx) {
1076 		case SNDRV_PCM_STREAM_PLAYBACK:
1077 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1078 			break;
1079 		case SNDRV_PCM_STREAM_CAPTURE:
1080 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1081 			break;
1082 		}
1083 		/* register pcm */
1084 		err = snd_register_device(devtype, pcm->card, pcm->device,
1085 					  &snd_pcm_f_ops[cidx], pcm,
1086 					  pcm->streams[cidx].dev);
1087 		if (err < 0) {
1088 			list_del_init(&pcm->list);
1089 			goto unlock;
1090 		}
1091 
1092 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1093 			snd_pcm_timer_init(substream);
1094 	}
1095 
1096 	pcm_call_notify(pcm, n_register);
1097 
1098  unlock:
1099 	mutex_unlock(&register_mutex);
1100 	return err;
1101 }
1102 
1103 static int snd_pcm_dev_disconnect(struct snd_device *device)
1104 {
1105 	struct snd_pcm *pcm = device->device_data;
1106 	struct snd_pcm_substream *substream;
1107 	int cidx;
1108 
1109 	mutex_lock(&register_mutex);
1110 	mutex_lock(&pcm->open_mutex);
1111 	wake_up(&pcm->open_wait);
1112 	list_del_init(&pcm->list);
1113 
1114 	for_each_pcm_substream(pcm, cidx, substream) {
1115 		snd_pcm_stream_lock_irq(substream);
1116 		if (substream->runtime) {
1117 			if (snd_pcm_running(substream))
1118 				snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1119 			/* to be sure, set the state unconditionally */
1120 			__snd_pcm_set_state(substream->runtime,
1121 					    SNDRV_PCM_STATE_DISCONNECTED);
1122 			wake_up(&substream->runtime->sleep);
1123 			wake_up(&substream->runtime->tsleep);
1124 		}
1125 		snd_pcm_stream_unlock_irq(substream);
1126 	}
1127 
1128 	for_each_pcm_substream(pcm, cidx, substream)
1129 		snd_pcm_sync_stop(substream, false);
1130 
1131 	pcm_call_notify(pcm, n_disconnect);
1132 	for (cidx = 0; cidx < 2; cidx++) {
1133 		if (pcm->streams[cidx].dev)
1134 			snd_unregister_device(pcm->streams[cidx].dev);
1135 		free_chmap(&pcm->streams[cidx]);
1136 	}
1137 	mutex_unlock(&pcm->open_mutex);
1138 	mutex_unlock(&register_mutex);
1139 	return 0;
1140 }
1141 
1142 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1143 /**
1144  * snd_pcm_notify - Add/remove the notify list
1145  * @notify: PCM notify list
1146  * @nfree: 0 = register, 1 = unregister
1147  *
1148  * This adds the given notifier to the global list so that the callback is
1149  * called for each registered PCM devices.  This exists only for PCM OSS
1150  * emulation, so far.
1151  *
1152  * Return: zero if successful, or a negative error code
1153  */
1154 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1155 {
1156 	struct snd_pcm *pcm;
1157 
1158 	if (snd_BUG_ON(!notify ||
1159 		       !notify->n_register ||
1160 		       !notify->n_unregister ||
1161 		       !notify->n_disconnect))
1162 		return -EINVAL;
1163 	mutex_lock(&register_mutex);
1164 	if (nfree) {
1165 		list_del(&notify->list);
1166 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1167 			notify->n_unregister(pcm);
1168 	} else {
1169 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1170 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1171 			notify->n_register(pcm);
1172 	}
1173 	mutex_unlock(&register_mutex);
1174 	return 0;
1175 }
1176 EXPORT_SYMBOL(snd_pcm_notify);
1177 #endif /* CONFIG_SND_PCM_OSS */
1178 
1179 #ifdef CONFIG_SND_PROC_FS
1180 /*
1181  *  Info interface
1182  */
1183 
1184 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1185 			      struct snd_info_buffer *buffer)
1186 {
1187 	struct snd_pcm *pcm;
1188 
1189 	mutex_lock(&register_mutex);
1190 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1191 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1192 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1193 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1194 			snd_iprintf(buffer, " : playback %i",
1195 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1196 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1197 			snd_iprintf(buffer, " : capture %i",
1198 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1199 		snd_iprintf(buffer, "\n");
1200 	}
1201 	mutex_unlock(&register_mutex);
1202 }
1203 
1204 static struct snd_info_entry *snd_pcm_proc_entry;
1205 
1206 static void snd_pcm_proc_init(void)
1207 {
1208 	struct snd_info_entry *entry;
1209 
1210 	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1211 	if (entry) {
1212 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1213 		if (snd_info_register(entry) < 0) {
1214 			snd_info_free_entry(entry);
1215 			entry = NULL;
1216 		}
1217 	}
1218 	snd_pcm_proc_entry = entry;
1219 }
1220 
1221 static void snd_pcm_proc_done(void)
1222 {
1223 	snd_info_free_entry(snd_pcm_proc_entry);
1224 }
1225 
1226 #else /* !CONFIG_SND_PROC_FS */
1227 #define snd_pcm_proc_init()
1228 #define snd_pcm_proc_done()
1229 #endif /* CONFIG_SND_PROC_FS */
1230 
1231 
1232 /*
1233  *  ENTRY functions
1234  */
1235 
1236 static int __init alsa_pcm_init(void)
1237 {
1238 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1239 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1240 	snd_pcm_proc_init();
1241 	return 0;
1242 }
1243 
1244 static void __exit alsa_pcm_exit(void)
1245 {
1246 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1247 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1248 	snd_pcm_proc_done();
1249 }
1250 
1251 module_init(alsa_pcm_init)
1252 module_exit(alsa_pcm_exit)
1253