xref: /openbmc/linux/sound/core/pcm.c (revision 8e6ac8c6)
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 
snd_pcm_get(struct snd_card * card,int device)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 
snd_pcm_next(struct snd_card * card,int device)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 
snd_pcm_add(struct snd_pcm * newpcm)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 
snd_pcm_control_ioctl(struct snd_card * card,struct snd_ctl_file * control,unsigned int cmd,unsigned long arg)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  */
snd_pcm_format_name(snd_pcm_format_t format)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 };
270 
271 static const char * const snd_pcm_tstamp_mode_names[] = {
272 	TSTAMP(NONE),
273 	TSTAMP(ENABLE),
274 };
275 
snd_pcm_stream_name(int stream)276 static const char *snd_pcm_stream_name(int stream)
277 {
278 	return snd_pcm_stream_names[stream];
279 }
280 
snd_pcm_access_name(snd_pcm_access_t access)281 static const char *snd_pcm_access_name(snd_pcm_access_t access)
282 {
283 	return snd_pcm_access_names[(__force int)access];
284 }
285 
snd_pcm_subformat_name(snd_pcm_subformat_t subformat)286 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
287 {
288 	return snd_pcm_subformat_names[(__force int)subformat];
289 }
290 
snd_pcm_tstamp_mode_name(int mode)291 static const char *snd_pcm_tstamp_mode_name(int mode)
292 {
293 	return snd_pcm_tstamp_mode_names[mode];
294 }
295 
snd_pcm_state_name(snd_pcm_state_t state)296 static const char *snd_pcm_state_name(snd_pcm_state_t state)
297 {
298 	return snd_pcm_state_names[(__force int)state];
299 }
300 
301 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
302 #include <linux/soundcard.h>
303 
snd_pcm_oss_format_name(int format)304 static const char *snd_pcm_oss_format_name(int format)
305 {
306 	switch (format) {
307 	case AFMT_MU_LAW:
308 		return "MU_LAW";
309 	case AFMT_A_LAW:
310 		return "A_LAW";
311 	case AFMT_IMA_ADPCM:
312 		return "IMA_ADPCM";
313 	case AFMT_U8:
314 		return "U8";
315 	case AFMT_S16_LE:
316 		return "S16_LE";
317 	case AFMT_S16_BE:
318 		return "S16_BE";
319 	case AFMT_S8:
320 		return "S8";
321 	case AFMT_U16_LE:
322 		return "U16_LE";
323 	case AFMT_U16_BE:
324 		return "U16_BE";
325 	case AFMT_MPEG:
326 		return "MPEG";
327 	default:
328 		return "unknown";
329 	}
330 }
331 #endif
332 
snd_pcm_proc_info_read(struct snd_pcm_substream * substream,struct snd_info_buffer * buffer)333 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
334 				   struct snd_info_buffer *buffer)
335 {
336 	struct snd_pcm_info *info;
337 	int err;
338 
339 	if (! substream)
340 		return;
341 
342 	info = kmalloc(sizeof(*info), GFP_KERNEL);
343 	if (!info)
344 		return;
345 
346 	err = snd_pcm_info(substream, info);
347 	if (err < 0) {
348 		snd_iprintf(buffer, "error %d\n", err);
349 		kfree(info);
350 		return;
351 	}
352 	snd_iprintf(buffer, "card: %d\n", info->card);
353 	snd_iprintf(buffer, "device: %d\n", info->device);
354 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
355 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
356 	snd_iprintf(buffer, "id: %s\n", info->id);
357 	snd_iprintf(buffer, "name: %s\n", info->name);
358 	snd_iprintf(buffer, "subname: %s\n", info->subname);
359 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
360 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
361 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
362 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
363 	kfree(info);
364 }
365 
snd_pcm_stream_proc_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)366 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
367 					  struct snd_info_buffer *buffer)
368 {
369 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
370 			       buffer);
371 }
372 
snd_pcm_substream_proc_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)373 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
374 					     struct snd_info_buffer *buffer)
375 {
376 	snd_pcm_proc_info_read(entry->private_data, buffer);
377 }
378 
snd_pcm_substream_proc_hw_params_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)379 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
380 						  struct snd_info_buffer *buffer)
381 {
382 	struct snd_pcm_substream *substream = entry->private_data;
383 	struct snd_pcm_runtime *runtime;
384 
385 	mutex_lock(&substream->pcm->open_mutex);
386 	runtime = substream->runtime;
387 	if (!runtime) {
388 		snd_iprintf(buffer, "closed\n");
389 		goto unlock;
390 	}
391 	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
392 		snd_iprintf(buffer, "no setup\n");
393 		goto unlock;
394 	}
395 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
396 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
397 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
398 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
399 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
400 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
401 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
402 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
403 	if (substream->oss.oss) {
404 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
405 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
406 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
407 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
408 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
409 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
410 	}
411 #endif
412  unlock:
413 	mutex_unlock(&substream->pcm->open_mutex);
414 }
415 
snd_pcm_substream_proc_sw_params_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)416 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
417 						  struct snd_info_buffer *buffer)
418 {
419 	struct snd_pcm_substream *substream = entry->private_data;
420 	struct snd_pcm_runtime *runtime;
421 
422 	mutex_lock(&substream->pcm->open_mutex);
423 	runtime = substream->runtime;
424 	if (!runtime) {
425 		snd_iprintf(buffer, "closed\n");
426 		goto unlock;
427 	}
428 	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
429 		snd_iprintf(buffer, "no setup\n");
430 		goto unlock;
431 	}
432 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
433 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
434 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
435 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
436 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
437 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
438 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
439 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
440  unlock:
441 	mutex_unlock(&substream->pcm->open_mutex);
442 }
443 
snd_pcm_substream_proc_status_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)444 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
445 					       struct snd_info_buffer *buffer)
446 {
447 	struct snd_pcm_substream *substream = entry->private_data;
448 	struct snd_pcm_runtime *runtime;
449 	struct snd_pcm_status64 status;
450 	int err;
451 
452 	mutex_lock(&substream->pcm->open_mutex);
453 	runtime = substream->runtime;
454 	if (!runtime) {
455 		snd_iprintf(buffer, "closed\n");
456 		goto unlock;
457 	}
458 	memset(&status, 0, sizeof(status));
459 	err = snd_pcm_status64(substream, &status);
460 	if (err < 0) {
461 		snd_iprintf(buffer, "error %d\n", err);
462 		goto unlock;
463 	}
464 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
465 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
466 	snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
467 		status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
468 	snd_iprintf(buffer, "tstamp      : %lld.%09lld\n",
469 		status.tstamp_sec, status.tstamp_nsec);
470 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
471 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
472 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
473 	snd_iprintf(buffer, "-----\n");
474 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
475 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
476  unlock:
477 	mutex_unlock(&substream->pcm->open_mutex);
478 }
479 
480 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
snd_pcm_xrun_injection_write(struct snd_info_entry * entry,struct snd_info_buffer * buffer)481 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
482 					 struct snd_info_buffer *buffer)
483 {
484 	struct snd_pcm_substream *substream = entry->private_data;
485 
486 	snd_pcm_stop_xrun(substream);
487 }
488 
snd_pcm_xrun_debug_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)489 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
490 				    struct snd_info_buffer *buffer)
491 {
492 	struct snd_pcm_str *pstr = entry->private_data;
493 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
494 }
495 
snd_pcm_xrun_debug_write(struct snd_info_entry * entry,struct snd_info_buffer * buffer)496 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
497 				     struct snd_info_buffer *buffer)
498 {
499 	struct snd_pcm_str *pstr = entry->private_data;
500 	char line[64];
501 	if (!snd_info_get_line(buffer, line, sizeof(line)))
502 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
503 }
504 #endif
505 
snd_pcm_stream_proc_init(struct snd_pcm_str * pstr)506 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
507 {
508 	struct snd_pcm *pcm = pstr->pcm;
509 	struct snd_info_entry *entry;
510 	char name[16];
511 
512 	sprintf(name, "pcm%i%c", pcm->device,
513 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
514 	entry = snd_info_create_card_entry(pcm->card, name,
515 					   pcm->card->proc_root);
516 	if (!entry)
517 		return -ENOMEM;
518 	entry->mode = S_IFDIR | 0555;
519 	pstr->proc_root = entry;
520 	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
521 	if (entry)
522 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
523 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
524 	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
525 					   pstr->proc_root);
526 	if (entry) {
527 		snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
528 		entry->c.text.write = snd_pcm_xrun_debug_write;
529 		entry->mode |= 0200;
530 	}
531 #endif
532 	return 0;
533 }
534 
snd_pcm_stream_proc_done(struct snd_pcm_str * pstr)535 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
536 {
537 	snd_info_free_entry(pstr->proc_root);
538 	pstr->proc_root = NULL;
539 	return 0;
540 }
541 
542 static struct snd_info_entry *
create_substream_info_entry(struct snd_pcm_substream * substream,const char * name,void (* read)(struct snd_info_entry *,struct snd_info_buffer *))543 create_substream_info_entry(struct snd_pcm_substream *substream,
544 			    const char *name,
545 			    void (*read)(struct snd_info_entry *,
546 					 struct snd_info_buffer *))
547 {
548 	struct snd_info_entry *entry;
549 
550 	entry = snd_info_create_card_entry(substream->pcm->card, name,
551 					   substream->proc_root);
552 	if (entry)
553 		snd_info_set_text_ops(entry, substream, read);
554 	return entry;
555 }
556 
snd_pcm_substream_proc_init(struct snd_pcm_substream * substream)557 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
558 {
559 	struct snd_info_entry *entry;
560 	struct snd_card *card;
561 	char name[16];
562 
563 	card = substream->pcm->card;
564 
565 	sprintf(name, "sub%i", substream->number);
566 	entry = snd_info_create_card_entry(card, name,
567 					   substream->pstr->proc_root);
568 	if (!entry)
569 		return -ENOMEM;
570 	entry->mode = S_IFDIR | 0555;
571 	substream->proc_root = entry;
572 
573 	create_substream_info_entry(substream, "info",
574 				    snd_pcm_substream_proc_info_read);
575 	create_substream_info_entry(substream, "hw_params",
576 				    snd_pcm_substream_proc_hw_params_read);
577 	create_substream_info_entry(substream, "sw_params",
578 				    snd_pcm_substream_proc_sw_params_read);
579 	create_substream_info_entry(substream, "status",
580 				    snd_pcm_substream_proc_status_read);
581 
582 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
583 	entry = create_substream_info_entry(substream, "xrun_injection", NULL);
584 	if (entry) {
585 		entry->c.text.write = snd_pcm_xrun_injection_write;
586 		entry->mode = S_IFREG | 0200;
587 	}
588 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
589 
590 	return 0;
591 }
592 
593 #else /* !CONFIG_SND_VERBOSE_PROCFS */
snd_pcm_stream_proc_init(struct snd_pcm_str * pstr)594 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
snd_pcm_stream_proc_done(struct snd_pcm_str * pstr)595 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
snd_pcm_substream_proc_init(struct snd_pcm_substream * substream)596 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
597 #endif /* CONFIG_SND_VERBOSE_PROCFS */
598 
599 static const struct attribute_group *pcm_dev_attr_groups[];
600 
601 /*
602  * PM callbacks: we need to deal only with suspend here, as the resume is
603  * triggered either from user-space or the driver's resume callback
604  */
605 #ifdef CONFIG_PM_SLEEP
do_pcm_suspend(struct device * dev)606 static int do_pcm_suspend(struct device *dev)
607 {
608 	struct snd_pcm_str *pstr = dev_get_drvdata(dev);
609 
610 	if (!pstr->pcm->no_device_suspend)
611 		snd_pcm_suspend_all(pstr->pcm);
612 	return 0;
613 }
614 #endif
615 
616 static const struct dev_pm_ops pcm_dev_pm_ops = {
617 	SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
618 };
619 
620 /* device type for PCM -- basically only for passing PM callbacks */
621 static const struct device_type pcm_dev_type = {
622 	.name = "pcm",
623 	.pm = &pcm_dev_pm_ops,
624 };
625 
626 /**
627  * snd_pcm_new_stream - create a new PCM stream
628  * @pcm: the pcm instance
629  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
630  * @substream_count: the number of substreams
631  *
632  * Creates a new stream for the pcm.
633  * The corresponding stream on the pcm must have been empty before
634  * calling this, i.e. zero must be given to the argument of
635  * snd_pcm_new().
636  *
637  * Return: Zero if successful, or a negative error code on failure.
638  */
snd_pcm_new_stream(struct snd_pcm * pcm,int stream,int substream_count)639 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
640 {
641 	int idx, err;
642 	struct snd_pcm_str *pstr = &pcm->streams[stream];
643 	struct snd_pcm_substream *substream, *prev;
644 
645 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
646 	mutex_init(&pstr->oss.setup_mutex);
647 #endif
648 	pstr->stream = stream;
649 	pstr->pcm = pcm;
650 	pstr->substream_count = substream_count;
651 	if (!substream_count)
652 		return 0;
653 
654 	err = snd_device_alloc(&pstr->dev, pcm->card);
655 	if (err < 0)
656 		return err;
657 	dev_set_name(pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
658 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
659 	pstr->dev->groups = pcm_dev_attr_groups;
660 	pstr->dev->type = &pcm_dev_type;
661 	dev_set_drvdata(pstr->dev, pstr);
662 
663 	if (!pcm->internal) {
664 		err = snd_pcm_stream_proc_init(pstr);
665 		if (err < 0) {
666 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
667 			return err;
668 		}
669 	}
670 	prev = NULL;
671 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
672 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
673 		if (!substream)
674 			return -ENOMEM;
675 		substream->pcm = pcm;
676 		substream->pstr = pstr;
677 		substream->number = idx;
678 		substream->stream = stream;
679 		sprintf(substream->name, "subdevice #%i", idx);
680 		substream->buffer_bytes_max = UINT_MAX;
681 		if (prev == NULL)
682 			pstr->substream = substream;
683 		else
684 			prev->next = substream;
685 
686 		if (!pcm->internal) {
687 			err = snd_pcm_substream_proc_init(substream);
688 			if (err < 0) {
689 				pcm_err(pcm,
690 					"Error in snd_pcm_stream_proc_init\n");
691 				if (prev == NULL)
692 					pstr->substream = NULL;
693 				else
694 					prev->next = NULL;
695 				kfree(substream);
696 				return err;
697 			}
698 		}
699 		substream->group = &substream->self_group;
700 		snd_pcm_group_init(&substream->self_group);
701 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
702 		atomic_set(&substream->mmap_count, 0);
703 		prev = substream;
704 	}
705 	return 0;
706 }
707 EXPORT_SYMBOL(snd_pcm_new_stream);
708 
_snd_pcm_new(struct snd_card * card,const char * id,int device,int playback_count,int capture_count,bool internal,struct snd_pcm ** rpcm)709 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
710 		int playback_count, int capture_count, bool internal,
711 		struct snd_pcm **rpcm)
712 {
713 	struct snd_pcm *pcm;
714 	int err;
715 	static const struct snd_device_ops ops = {
716 		.dev_free = snd_pcm_dev_free,
717 		.dev_register =	snd_pcm_dev_register,
718 		.dev_disconnect = snd_pcm_dev_disconnect,
719 	};
720 	static const struct snd_device_ops internal_ops = {
721 		.dev_free = snd_pcm_dev_free,
722 	};
723 
724 	if (snd_BUG_ON(!card))
725 		return -ENXIO;
726 	if (rpcm)
727 		*rpcm = NULL;
728 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
729 	if (!pcm)
730 		return -ENOMEM;
731 	pcm->card = card;
732 	pcm->device = device;
733 	pcm->internal = internal;
734 	mutex_init(&pcm->open_mutex);
735 	init_waitqueue_head(&pcm->open_wait);
736 	INIT_LIST_HEAD(&pcm->list);
737 	if (id)
738 		strscpy(pcm->id, id, sizeof(pcm->id));
739 
740 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
741 				 playback_count);
742 	if (err < 0)
743 		goto free_pcm;
744 
745 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
746 	if (err < 0)
747 		goto free_pcm;
748 
749 	err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
750 			     internal ? &internal_ops : &ops);
751 	if (err < 0)
752 		goto free_pcm;
753 
754 	if (rpcm)
755 		*rpcm = pcm;
756 	return 0;
757 
758 free_pcm:
759 	snd_pcm_free(pcm);
760 	return err;
761 }
762 
763 /**
764  * snd_pcm_new - create a new PCM instance
765  * @card: the card instance
766  * @id: the id string
767  * @device: the device index (zero based)
768  * @playback_count: the number of substreams for playback
769  * @capture_count: the number of substreams for capture
770  * @rpcm: the pointer to store the new pcm instance
771  *
772  * Creates a new PCM instance.
773  *
774  * The pcm operators have to be set afterwards to the new instance
775  * via snd_pcm_set_ops().
776  *
777  * Return: Zero if successful, or a negative error code on failure.
778  */
snd_pcm_new(struct snd_card * card,const char * id,int device,int playback_count,int capture_count,struct snd_pcm ** rpcm)779 int snd_pcm_new(struct snd_card *card, const char *id, int device,
780 		int playback_count, int capture_count, struct snd_pcm **rpcm)
781 {
782 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
783 			false, rpcm);
784 }
785 EXPORT_SYMBOL(snd_pcm_new);
786 
787 /**
788  * snd_pcm_new_internal - create a new internal PCM instance
789  * @card: the card instance
790  * @id: the id string
791  * @device: the device index (zero based - shared with normal PCMs)
792  * @playback_count: the number of substreams for playback
793  * @capture_count: the number of substreams for capture
794  * @rpcm: the pointer to store the new pcm instance
795  *
796  * Creates a new internal PCM instance with no userspace device or procfs
797  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
798  * will only be used internally by kernel drivers. i.e. it cannot be opened
799  * by userspace. It provides existing ASoC components drivers with a substream
800  * and access to any private data.
801  *
802  * The pcm operators have to be set afterwards to the new instance
803  * via snd_pcm_set_ops().
804  *
805  * Return: Zero if successful, or a negative error code on failure.
806  */
snd_pcm_new_internal(struct snd_card * card,const char * id,int device,int playback_count,int capture_count,struct snd_pcm ** rpcm)807 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
808 	int playback_count, int capture_count,
809 	struct snd_pcm **rpcm)
810 {
811 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
812 			true, rpcm);
813 }
814 EXPORT_SYMBOL(snd_pcm_new_internal);
815 
free_chmap(struct snd_pcm_str * pstr)816 static void free_chmap(struct snd_pcm_str *pstr)
817 {
818 	if (pstr->chmap_kctl) {
819 		struct snd_card *card = pstr->pcm->card;
820 
821 		snd_ctl_remove(card, pstr->chmap_kctl);
822 		pstr->chmap_kctl = NULL;
823 	}
824 }
825 
snd_pcm_free_stream(struct snd_pcm_str * pstr)826 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
827 {
828 	struct snd_pcm_substream *substream, *substream_next;
829 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
830 	struct snd_pcm_oss_setup *setup, *setupn;
831 #endif
832 
833 	/* free all proc files under the stream */
834 	snd_pcm_stream_proc_done(pstr);
835 
836 	substream = pstr->substream;
837 	while (substream) {
838 		substream_next = substream->next;
839 		snd_pcm_timer_done(substream);
840 		kfree(substream);
841 		substream = substream_next;
842 	}
843 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
844 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
845 		setupn = setup->next;
846 		kfree(setup->task_name);
847 		kfree(setup);
848 	}
849 #endif
850 	free_chmap(pstr);
851 	if (pstr->substream_count)
852 		put_device(pstr->dev);
853 }
854 
855 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
856 #define pcm_call_notify(pcm, call)					\
857 	do {								\
858 		struct snd_pcm_notify *_notify;				\
859 		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
860 			_notify->call(pcm);				\
861 	} while (0)
862 #else
863 #define pcm_call_notify(pcm, call) do {} while (0)
864 #endif
865 
snd_pcm_free(struct snd_pcm * pcm)866 static int snd_pcm_free(struct snd_pcm *pcm)
867 {
868 	if (!pcm)
869 		return 0;
870 	if (!pcm->internal)
871 		pcm_call_notify(pcm, n_unregister);
872 	if (pcm->private_free)
873 		pcm->private_free(pcm);
874 	snd_pcm_lib_preallocate_free_for_all(pcm);
875 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
876 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
877 	kfree(pcm);
878 	return 0;
879 }
880 
snd_pcm_dev_free(struct snd_device * device)881 static int snd_pcm_dev_free(struct snd_device *device)
882 {
883 	struct snd_pcm *pcm = device->device_data;
884 	return snd_pcm_free(pcm);
885 }
886 
snd_pcm_attach_substream(struct snd_pcm * pcm,int stream,struct file * file,struct snd_pcm_substream ** rsubstream)887 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
888 			     struct file *file,
889 			     struct snd_pcm_substream **rsubstream)
890 {
891 	struct snd_pcm_str * pstr;
892 	struct snd_pcm_substream *substream;
893 	struct snd_pcm_runtime *runtime;
894 	struct snd_card *card;
895 	int prefer_subdevice;
896 	size_t size;
897 
898 	if (snd_BUG_ON(!pcm || !rsubstream))
899 		return -ENXIO;
900 	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
901 		       stream != SNDRV_PCM_STREAM_CAPTURE))
902 		return -EINVAL;
903 	*rsubstream = NULL;
904 	pstr = &pcm->streams[stream];
905 	if (pstr->substream == NULL || pstr->substream_count == 0)
906 		return -ENODEV;
907 
908 	card = pcm->card;
909 	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
910 
911 	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
912 		int opposite = !stream;
913 
914 		for (substream = pcm->streams[opposite].substream; substream;
915 		     substream = substream->next) {
916 			if (SUBSTREAM_BUSY(substream))
917 				return -EAGAIN;
918 		}
919 	}
920 
921 	if (file->f_flags & O_APPEND) {
922 		if (prefer_subdevice < 0) {
923 			if (pstr->substream_count > 1)
924 				return -EINVAL; /* must be unique */
925 			substream = pstr->substream;
926 		} else {
927 			for (substream = pstr->substream; substream;
928 			     substream = substream->next)
929 				if (substream->number == prefer_subdevice)
930 					break;
931 		}
932 		if (! substream)
933 			return -ENODEV;
934 		if (! SUBSTREAM_BUSY(substream))
935 			return -EBADFD;
936 		substream->ref_count++;
937 		*rsubstream = substream;
938 		return 0;
939 	}
940 
941 	for (substream = pstr->substream; substream; substream = substream->next) {
942 		if (!SUBSTREAM_BUSY(substream) &&
943 		    (prefer_subdevice == -1 ||
944 		     substream->number == prefer_subdevice))
945 			break;
946 	}
947 	if (substream == NULL)
948 		return -EAGAIN;
949 
950 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
951 	if (runtime == NULL)
952 		return -ENOMEM;
953 
954 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
955 	runtime->status = alloc_pages_exact(size, GFP_KERNEL);
956 	if (runtime->status == NULL) {
957 		kfree(runtime);
958 		return -ENOMEM;
959 	}
960 	memset(runtime->status, 0, size);
961 
962 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
963 	runtime->control = alloc_pages_exact(size, GFP_KERNEL);
964 	if (runtime->control == NULL) {
965 		free_pages_exact(runtime->status,
966 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
967 		kfree(runtime);
968 		return -ENOMEM;
969 	}
970 	memset(runtime->control, 0, size);
971 
972 	init_waitqueue_head(&runtime->sleep);
973 	init_waitqueue_head(&runtime->tsleep);
974 
975 	__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
976 	mutex_init(&runtime->buffer_mutex);
977 	atomic_set(&runtime->buffer_accessing, 0);
978 
979 	substream->runtime = runtime;
980 	substream->private_data = pcm->private_data;
981 	substream->ref_count = 1;
982 	substream->f_flags = file->f_flags;
983 	substream->pid = get_pid(task_pid(current));
984 	pstr->substream_opened++;
985 	*rsubstream = substream;
986 	return 0;
987 }
988 
snd_pcm_detach_substream(struct snd_pcm_substream * substream)989 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
990 {
991 	struct snd_pcm_runtime *runtime;
992 
993 	if (PCM_RUNTIME_CHECK(substream))
994 		return;
995 	runtime = substream->runtime;
996 	if (runtime->private_free != NULL)
997 		runtime->private_free(runtime);
998 	free_pages_exact(runtime->status,
999 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1000 	free_pages_exact(runtime->control,
1001 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1002 	kfree(runtime->hw_constraints.rules);
1003 	/* Avoid concurrent access to runtime via PCM timer interface */
1004 	if (substream->timer) {
1005 		spin_lock_irq(&substream->timer->lock);
1006 		substream->runtime = NULL;
1007 		spin_unlock_irq(&substream->timer->lock);
1008 	} else {
1009 		substream->runtime = NULL;
1010 	}
1011 	mutex_destroy(&runtime->buffer_mutex);
1012 	snd_fasync_free(runtime->fasync);
1013 	kfree(runtime);
1014 	put_pid(substream->pid);
1015 	substream->pid = NULL;
1016 	substream->pstr->substream_opened--;
1017 }
1018 
pcm_class_show(struct device * dev,struct device_attribute * attr,char * buf)1019 static ssize_t pcm_class_show(struct device *dev,
1020 			      struct device_attribute *attr, char *buf)
1021 {
1022 	struct snd_pcm_str *pstr = dev_get_drvdata(dev);
1023 	struct snd_pcm *pcm = pstr->pcm;
1024 	const char *str;
1025 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1026 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1027 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1028 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1029 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1030 	};
1031 
1032 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1033 		str = "none";
1034 	else
1035 		str = strs[pcm->dev_class];
1036 	return sysfs_emit(buf, "%s\n", str);
1037 }
1038 
1039 static DEVICE_ATTR_RO(pcm_class);
1040 static struct attribute *pcm_dev_attrs[] = {
1041 	&dev_attr_pcm_class.attr,
1042 	NULL
1043 };
1044 
1045 static const struct attribute_group pcm_dev_attr_group = {
1046 	.attrs	= pcm_dev_attrs,
1047 };
1048 
1049 static const struct attribute_group *pcm_dev_attr_groups[] = {
1050 	&pcm_dev_attr_group,
1051 	NULL
1052 };
1053 
snd_pcm_dev_register(struct snd_device * device)1054 static int snd_pcm_dev_register(struct snd_device *device)
1055 {
1056 	int cidx, err;
1057 	struct snd_pcm_substream *substream;
1058 	struct snd_pcm *pcm;
1059 
1060 	if (snd_BUG_ON(!device || !device->device_data))
1061 		return -ENXIO;
1062 	pcm = device->device_data;
1063 
1064 	mutex_lock(&register_mutex);
1065 	err = snd_pcm_add(pcm);
1066 	if (err)
1067 		goto unlock;
1068 	for (cidx = 0; cidx < 2; cidx++) {
1069 		int devtype = -1;
1070 		if (pcm->streams[cidx].substream == NULL)
1071 			continue;
1072 		switch (cidx) {
1073 		case SNDRV_PCM_STREAM_PLAYBACK:
1074 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1075 			break;
1076 		case SNDRV_PCM_STREAM_CAPTURE:
1077 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1078 			break;
1079 		}
1080 		/* register pcm */
1081 		err = snd_register_device(devtype, pcm->card, pcm->device,
1082 					  &snd_pcm_f_ops[cidx], pcm,
1083 					  pcm->streams[cidx].dev);
1084 		if (err < 0) {
1085 			list_del_init(&pcm->list);
1086 			goto unlock;
1087 		}
1088 
1089 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1090 			snd_pcm_timer_init(substream);
1091 	}
1092 
1093 	pcm_call_notify(pcm, n_register);
1094 
1095  unlock:
1096 	mutex_unlock(&register_mutex);
1097 	return err;
1098 }
1099 
snd_pcm_dev_disconnect(struct snd_device * device)1100 static int snd_pcm_dev_disconnect(struct snd_device *device)
1101 {
1102 	struct snd_pcm *pcm = device->device_data;
1103 	struct snd_pcm_substream *substream;
1104 	int cidx;
1105 
1106 	mutex_lock(&register_mutex);
1107 	mutex_lock(&pcm->open_mutex);
1108 	wake_up(&pcm->open_wait);
1109 	list_del_init(&pcm->list);
1110 
1111 	for_each_pcm_substream(pcm, cidx, substream) {
1112 		snd_pcm_stream_lock_irq(substream);
1113 		if (substream->runtime) {
1114 			if (snd_pcm_running(substream))
1115 				snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1116 			/* to be sure, set the state unconditionally */
1117 			__snd_pcm_set_state(substream->runtime,
1118 					    SNDRV_PCM_STATE_DISCONNECTED);
1119 			wake_up(&substream->runtime->sleep);
1120 			wake_up(&substream->runtime->tsleep);
1121 		}
1122 		snd_pcm_stream_unlock_irq(substream);
1123 	}
1124 
1125 	for_each_pcm_substream(pcm, cidx, substream)
1126 		snd_pcm_sync_stop(substream, false);
1127 
1128 	pcm_call_notify(pcm, n_disconnect);
1129 	for (cidx = 0; cidx < 2; cidx++) {
1130 		if (pcm->streams[cidx].dev)
1131 			snd_unregister_device(pcm->streams[cidx].dev);
1132 		free_chmap(&pcm->streams[cidx]);
1133 	}
1134 	mutex_unlock(&pcm->open_mutex);
1135 	mutex_unlock(&register_mutex);
1136 	return 0;
1137 }
1138 
1139 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1140 /**
1141  * snd_pcm_notify - Add/remove the notify list
1142  * @notify: PCM notify list
1143  * @nfree: 0 = register, 1 = unregister
1144  *
1145  * This adds the given notifier to the global list so that the callback is
1146  * called for each registered PCM devices.  This exists only for PCM OSS
1147  * emulation, so far.
1148  *
1149  * Return: zero if successful, or a negative error code
1150  */
snd_pcm_notify(struct snd_pcm_notify * notify,int nfree)1151 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1152 {
1153 	struct snd_pcm *pcm;
1154 
1155 	if (snd_BUG_ON(!notify ||
1156 		       !notify->n_register ||
1157 		       !notify->n_unregister ||
1158 		       !notify->n_disconnect))
1159 		return -EINVAL;
1160 	mutex_lock(&register_mutex);
1161 	if (nfree) {
1162 		list_del(&notify->list);
1163 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1164 			notify->n_unregister(pcm);
1165 	} else {
1166 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1167 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1168 			notify->n_register(pcm);
1169 	}
1170 	mutex_unlock(&register_mutex);
1171 	return 0;
1172 }
1173 EXPORT_SYMBOL(snd_pcm_notify);
1174 #endif /* CONFIG_SND_PCM_OSS */
1175 
1176 #ifdef CONFIG_SND_PROC_FS
1177 /*
1178  *  Info interface
1179  */
1180 
snd_pcm_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)1181 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1182 			      struct snd_info_buffer *buffer)
1183 {
1184 	struct snd_pcm *pcm;
1185 
1186 	mutex_lock(&register_mutex);
1187 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1188 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1189 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1190 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1191 			snd_iprintf(buffer, " : playback %i",
1192 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1193 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1194 			snd_iprintf(buffer, " : capture %i",
1195 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1196 		snd_iprintf(buffer, "\n");
1197 	}
1198 	mutex_unlock(&register_mutex);
1199 }
1200 
1201 static struct snd_info_entry *snd_pcm_proc_entry;
1202 
snd_pcm_proc_init(void)1203 static void snd_pcm_proc_init(void)
1204 {
1205 	struct snd_info_entry *entry;
1206 
1207 	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1208 	if (entry) {
1209 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1210 		if (snd_info_register(entry) < 0) {
1211 			snd_info_free_entry(entry);
1212 			entry = NULL;
1213 		}
1214 	}
1215 	snd_pcm_proc_entry = entry;
1216 }
1217 
snd_pcm_proc_done(void)1218 static void snd_pcm_proc_done(void)
1219 {
1220 	snd_info_free_entry(snd_pcm_proc_entry);
1221 }
1222 
1223 #else /* !CONFIG_SND_PROC_FS */
1224 #define snd_pcm_proc_init()
1225 #define snd_pcm_proc_done()
1226 #endif /* CONFIG_SND_PROC_FS */
1227 
1228 
1229 /*
1230  *  ENTRY functions
1231  */
1232 
alsa_pcm_init(void)1233 static int __init alsa_pcm_init(void)
1234 {
1235 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1236 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1237 	snd_pcm_proc_init();
1238 	return 0;
1239 }
1240 
alsa_pcm_exit(void)1241 static void __exit alsa_pcm_exit(void)
1242 {
1243 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1244 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1245 	snd_pcm_proc_done();
1246 }
1247 
1248 module_init(alsa_pcm_init)
1249 module_exit(alsa_pcm_exit)
1250