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 };
257 
258 static const char * const snd_pcm_access_names[] = {
259 	ACCESS(MMAP_INTERLEAVED),
260 	ACCESS(MMAP_NONINTERLEAVED),
261 	ACCESS(MMAP_COMPLEX),
262 	ACCESS(RW_INTERLEAVED),
263 	ACCESS(RW_NONINTERLEAVED),
264 };
265 
266 static const char * const snd_pcm_subformat_names[] = {
267 	SUBFORMAT(STD),
268 };
269 
270 static const char * const snd_pcm_tstamp_mode_names[] = {
271 	TSTAMP(NONE),
272 	TSTAMP(ENABLE),
273 };
274 
snd_pcm_stream_name(int stream)275 static const char *snd_pcm_stream_name(int stream)
276 {
277 	return snd_pcm_stream_names[stream];
278 }
279 
snd_pcm_access_name(snd_pcm_access_t access)280 static const char *snd_pcm_access_name(snd_pcm_access_t access)
281 {
282 	return snd_pcm_access_names[(__force int)access];
283 }
284 
snd_pcm_subformat_name(snd_pcm_subformat_t subformat)285 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
286 {
287 	return snd_pcm_subformat_names[(__force int)subformat];
288 }
289 
snd_pcm_tstamp_mode_name(int mode)290 static const char *snd_pcm_tstamp_mode_name(int mode)
291 {
292 	return snd_pcm_tstamp_mode_names[mode];
293 }
294 
snd_pcm_state_name(snd_pcm_state_t state)295 static const char *snd_pcm_state_name(snd_pcm_state_t state)
296 {
297 	return snd_pcm_state_names[(__force int)state];
298 }
299 
300 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
301 #include <linux/soundcard.h>
302 
snd_pcm_oss_format_name(int format)303 static const char *snd_pcm_oss_format_name(int format)
304 {
305 	switch (format) {
306 	case AFMT_MU_LAW:
307 		return "MU_LAW";
308 	case AFMT_A_LAW:
309 		return "A_LAW";
310 	case AFMT_IMA_ADPCM:
311 		return "IMA_ADPCM";
312 	case AFMT_U8:
313 		return "U8";
314 	case AFMT_S16_LE:
315 		return "S16_LE";
316 	case AFMT_S16_BE:
317 		return "S16_BE";
318 	case AFMT_S8:
319 		return "S8";
320 	case AFMT_U16_LE:
321 		return "U16_LE";
322 	case AFMT_U16_BE:
323 		return "U16_BE";
324 	case AFMT_MPEG:
325 		return "MPEG";
326 	default:
327 		return "unknown";
328 	}
329 }
330 #endif
331 
snd_pcm_proc_info_read(struct snd_pcm_substream * substream,struct snd_info_buffer * buffer)332 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
333 				   struct snd_info_buffer *buffer)
334 {
335 	struct snd_pcm_info *info;
336 	int err;
337 
338 	if (! substream)
339 		return;
340 
341 	info = kmalloc(sizeof(*info), GFP_KERNEL);
342 	if (!info)
343 		return;
344 
345 	err = snd_pcm_info(substream, info);
346 	if (err < 0) {
347 		snd_iprintf(buffer, "error %d\n", err);
348 		kfree(info);
349 		return;
350 	}
351 	snd_iprintf(buffer, "card: %d\n", info->card);
352 	snd_iprintf(buffer, "device: %d\n", info->device);
353 	snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
354 	snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
355 	snd_iprintf(buffer, "id: %s\n", info->id);
356 	snd_iprintf(buffer, "name: %s\n", info->name);
357 	snd_iprintf(buffer, "subname: %s\n", info->subname);
358 	snd_iprintf(buffer, "class: %d\n", info->dev_class);
359 	snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
360 	snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
361 	snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
362 	kfree(info);
363 }
364 
snd_pcm_stream_proc_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)365 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
366 					  struct snd_info_buffer *buffer)
367 {
368 	snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
369 			       buffer);
370 }
371 
snd_pcm_substream_proc_info_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)372 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
373 					     struct snd_info_buffer *buffer)
374 {
375 	snd_pcm_proc_info_read(entry->private_data, buffer);
376 }
377 
snd_pcm_substream_proc_hw_params_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)378 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
379 						  struct snd_info_buffer *buffer)
380 {
381 	struct snd_pcm_substream *substream = entry->private_data;
382 	struct snd_pcm_runtime *runtime;
383 
384 	mutex_lock(&substream->pcm->open_mutex);
385 	runtime = substream->runtime;
386 	if (!runtime) {
387 		snd_iprintf(buffer, "closed\n");
388 		goto unlock;
389 	}
390 	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
391 		snd_iprintf(buffer, "no setup\n");
392 		goto unlock;
393 	}
394 	snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
395 	snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
396 	snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
397 	snd_iprintf(buffer, "channels: %u\n", runtime->channels);
398 	snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
399 	snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
400 	snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
401 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
402 	if (substream->oss.oss) {
403 		snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
404 		snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
405 		snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
406 		snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
407 		snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
408 		snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
409 	}
410 #endif
411  unlock:
412 	mutex_unlock(&substream->pcm->open_mutex);
413 }
414 
snd_pcm_substream_proc_sw_params_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)415 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
416 						  struct snd_info_buffer *buffer)
417 {
418 	struct snd_pcm_substream *substream = entry->private_data;
419 	struct snd_pcm_runtime *runtime;
420 
421 	mutex_lock(&substream->pcm->open_mutex);
422 	runtime = substream->runtime;
423 	if (!runtime) {
424 		snd_iprintf(buffer, "closed\n");
425 		goto unlock;
426 	}
427 	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
428 		snd_iprintf(buffer, "no setup\n");
429 		goto unlock;
430 	}
431 	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
432 	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
433 	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
434 	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
435 	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
436 	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
437 	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
438 	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
439  unlock:
440 	mutex_unlock(&substream->pcm->open_mutex);
441 }
442 
snd_pcm_substream_proc_status_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)443 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
444 					       struct snd_info_buffer *buffer)
445 {
446 	struct snd_pcm_substream *substream = entry->private_data;
447 	struct snd_pcm_runtime *runtime;
448 	struct snd_pcm_status64 status;
449 	int err;
450 
451 	mutex_lock(&substream->pcm->open_mutex);
452 	runtime = substream->runtime;
453 	if (!runtime) {
454 		snd_iprintf(buffer, "closed\n");
455 		goto unlock;
456 	}
457 	memset(&status, 0, sizeof(status));
458 	err = snd_pcm_status64(substream, &status);
459 	if (err < 0) {
460 		snd_iprintf(buffer, "error %d\n", err);
461 		goto unlock;
462 	}
463 	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
464 	snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
465 	snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
466 		status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
467 	snd_iprintf(buffer, "tstamp      : %lld.%09lld\n",
468 		status.tstamp_sec, status.tstamp_nsec);
469 	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
470 	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
471 	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
472 	snd_iprintf(buffer, "-----\n");
473 	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
474 	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
475  unlock:
476 	mutex_unlock(&substream->pcm->open_mutex);
477 }
478 
479 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
snd_pcm_xrun_injection_write(struct snd_info_entry * entry,struct snd_info_buffer * buffer)480 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
481 					 struct snd_info_buffer *buffer)
482 {
483 	struct snd_pcm_substream *substream = entry->private_data;
484 
485 	snd_pcm_stop_xrun(substream);
486 }
487 
snd_pcm_xrun_debug_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)488 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
489 				    struct snd_info_buffer *buffer)
490 {
491 	struct snd_pcm_str *pstr = entry->private_data;
492 	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
493 }
494 
snd_pcm_xrun_debug_write(struct snd_info_entry * entry,struct snd_info_buffer * buffer)495 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
496 				     struct snd_info_buffer *buffer)
497 {
498 	struct snd_pcm_str *pstr = entry->private_data;
499 	char line[64];
500 	if (!snd_info_get_line(buffer, line, sizeof(line)))
501 		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
502 }
503 #endif
504 
snd_pcm_stream_proc_init(struct snd_pcm_str * pstr)505 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
506 {
507 	struct snd_pcm *pcm = pstr->pcm;
508 	struct snd_info_entry *entry;
509 	char name[16];
510 
511 	sprintf(name, "pcm%i%c", pcm->device,
512 		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
513 	entry = snd_info_create_card_entry(pcm->card, name,
514 					   pcm->card->proc_root);
515 	if (!entry)
516 		return -ENOMEM;
517 	entry->mode = S_IFDIR | 0555;
518 	pstr->proc_root = entry;
519 	entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
520 	if (entry)
521 		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
522 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
523 	entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
524 					   pstr->proc_root);
525 	if (entry) {
526 		snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
527 		entry->c.text.write = snd_pcm_xrun_debug_write;
528 		entry->mode |= 0200;
529 	}
530 #endif
531 	return 0;
532 }
533 
snd_pcm_stream_proc_done(struct snd_pcm_str * pstr)534 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
535 {
536 	snd_info_free_entry(pstr->proc_root);
537 	pstr->proc_root = NULL;
538 	return 0;
539 }
540 
541 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 *))542 create_substream_info_entry(struct snd_pcm_substream *substream,
543 			    const char *name,
544 			    void (*read)(struct snd_info_entry *,
545 					 struct snd_info_buffer *))
546 {
547 	struct snd_info_entry *entry;
548 
549 	entry = snd_info_create_card_entry(substream->pcm->card, name,
550 					   substream->proc_root);
551 	if (entry)
552 		snd_info_set_text_ops(entry, substream, read);
553 	return entry;
554 }
555 
snd_pcm_substream_proc_init(struct snd_pcm_substream * substream)556 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
557 {
558 	struct snd_info_entry *entry;
559 	struct snd_card *card;
560 	char name[16];
561 
562 	card = substream->pcm->card;
563 
564 	sprintf(name, "sub%i", substream->number);
565 	entry = snd_info_create_card_entry(card, name,
566 					   substream->pstr->proc_root);
567 	if (!entry)
568 		return -ENOMEM;
569 	entry->mode = S_IFDIR | 0555;
570 	substream->proc_root = entry;
571 
572 	create_substream_info_entry(substream, "info",
573 				    snd_pcm_substream_proc_info_read);
574 	create_substream_info_entry(substream, "hw_params",
575 				    snd_pcm_substream_proc_hw_params_read);
576 	create_substream_info_entry(substream, "sw_params",
577 				    snd_pcm_substream_proc_sw_params_read);
578 	create_substream_info_entry(substream, "status",
579 				    snd_pcm_substream_proc_status_read);
580 
581 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
582 	entry = create_substream_info_entry(substream, "xrun_injection", NULL);
583 	if (entry) {
584 		entry->c.text.write = snd_pcm_xrun_injection_write;
585 		entry->mode = S_IFREG | 0200;
586 	}
587 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
588 
589 	return 0;
590 }
591 
592 #else /* !CONFIG_SND_VERBOSE_PROCFS */
snd_pcm_stream_proc_init(struct snd_pcm_str * pstr)593 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)594 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)595 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
596 #endif /* CONFIG_SND_VERBOSE_PROCFS */
597 
598 static const struct attribute_group *pcm_dev_attr_groups[];
599 
600 /*
601  * PM callbacks: we need to deal only with suspend here, as the resume is
602  * triggered either from user-space or the driver's resume callback
603  */
604 #ifdef CONFIG_PM_SLEEP
do_pcm_suspend(struct device * dev)605 static int do_pcm_suspend(struct device *dev)
606 {
607 	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
608 
609 	if (!pstr->pcm->no_device_suspend)
610 		snd_pcm_suspend_all(pstr->pcm);
611 	return 0;
612 }
613 #endif
614 
615 static const struct dev_pm_ops pcm_dev_pm_ops = {
616 	SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
617 };
618 
619 /* device type for PCM -- basically only for passing PM callbacks */
620 static const struct device_type pcm_dev_type = {
621 	.name = "pcm",
622 	.pm = &pcm_dev_pm_ops,
623 };
624 
625 /**
626  * snd_pcm_new_stream - create a new PCM stream
627  * @pcm: the pcm instance
628  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
629  * @substream_count: the number of substreams
630  *
631  * Creates a new stream for the pcm.
632  * The corresponding stream on the pcm must have been empty before
633  * calling this, i.e. zero must be given to the argument of
634  * snd_pcm_new().
635  *
636  * Return: Zero if successful, or a negative error code on failure.
637  */
snd_pcm_new_stream(struct snd_pcm * pcm,int stream,int substream_count)638 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
639 {
640 	int idx, err;
641 	struct snd_pcm_str *pstr = &pcm->streams[stream];
642 	struct snd_pcm_substream *substream, *prev;
643 
644 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
645 	mutex_init(&pstr->oss.setup_mutex);
646 #endif
647 	pstr->stream = stream;
648 	pstr->pcm = pcm;
649 	pstr->substream_count = substream_count;
650 	if (!substream_count)
651 		return 0;
652 
653 	snd_device_initialize(&pstr->dev, pcm->card);
654 	pstr->dev.groups = pcm_dev_attr_groups;
655 	pstr->dev.type = &pcm_dev_type;
656 	dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
657 		     stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
658 
659 	if (!pcm->internal) {
660 		err = snd_pcm_stream_proc_init(pstr);
661 		if (err < 0) {
662 			pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
663 			return err;
664 		}
665 	}
666 	prev = NULL;
667 	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
668 		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
669 		if (!substream)
670 			return -ENOMEM;
671 		substream->pcm = pcm;
672 		substream->pstr = pstr;
673 		substream->number = idx;
674 		substream->stream = stream;
675 		sprintf(substream->name, "subdevice #%i", idx);
676 		substream->buffer_bytes_max = UINT_MAX;
677 		if (prev == NULL)
678 			pstr->substream = substream;
679 		else
680 			prev->next = substream;
681 
682 		if (!pcm->internal) {
683 			err = snd_pcm_substream_proc_init(substream);
684 			if (err < 0) {
685 				pcm_err(pcm,
686 					"Error in snd_pcm_stream_proc_init\n");
687 				if (prev == NULL)
688 					pstr->substream = NULL;
689 				else
690 					prev->next = NULL;
691 				kfree(substream);
692 				return err;
693 			}
694 		}
695 		substream->group = &substream->self_group;
696 		snd_pcm_group_init(&substream->self_group);
697 		list_add_tail(&substream->link_list, &substream->self_group.substreams);
698 		atomic_set(&substream->mmap_count, 0);
699 		prev = substream;
700 	}
701 	return 0;
702 }
703 EXPORT_SYMBOL(snd_pcm_new_stream);
704 
_snd_pcm_new(struct snd_card * card,const char * id,int device,int playback_count,int capture_count,bool internal,struct snd_pcm ** rpcm)705 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
706 		int playback_count, int capture_count, bool internal,
707 		struct snd_pcm **rpcm)
708 {
709 	struct snd_pcm *pcm;
710 	int err;
711 	static const struct snd_device_ops ops = {
712 		.dev_free = snd_pcm_dev_free,
713 		.dev_register =	snd_pcm_dev_register,
714 		.dev_disconnect = snd_pcm_dev_disconnect,
715 	};
716 	static const struct snd_device_ops internal_ops = {
717 		.dev_free = snd_pcm_dev_free,
718 	};
719 
720 	if (snd_BUG_ON(!card))
721 		return -ENXIO;
722 	if (rpcm)
723 		*rpcm = NULL;
724 	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
725 	if (!pcm)
726 		return -ENOMEM;
727 	pcm->card = card;
728 	pcm->device = device;
729 	pcm->internal = internal;
730 	mutex_init(&pcm->open_mutex);
731 	init_waitqueue_head(&pcm->open_wait);
732 	INIT_LIST_HEAD(&pcm->list);
733 	if (id)
734 		strscpy(pcm->id, id, sizeof(pcm->id));
735 
736 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
737 				 playback_count);
738 	if (err < 0)
739 		goto free_pcm;
740 
741 	err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
742 	if (err < 0)
743 		goto free_pcm;
744 
745 	err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
746 			     internal ? &internal_ops : &ops);
747 	if (err < 0)
748 		goto free_pcm;
749 
750 	if (rpcm)
751 		*rpcm = pcm;
752 	return 0;
753 
754 free_pcm:
755 	snd_pcm_free(pcm);
756 	return err;
757 }
758 
759 /**
760  * snd_pcm_new - create a new PCM instance
761  * @card: the card instance
762  * @id: the id string
763  * @device: the device index (zero based)
764  * @playback_count: the number of substreams for playback
765  * @capture_count: the number of substreams for capture
766  * @rpcm: the pointer to store the new pcm instance
767  *
768  * Creates a new PCM instance.
769  *
770  * The pcm operators have to be set afterwards to the new instance
771  * via snd_pcm_set_ops().
772  *
773  * Return: Zero if successful, or a negative error code on failure.
774  */
snd_pcm_new(struct snd_card * card,const char * id,int device,int playback_count,int capture_count,struct snd_pcm ** rpcm)775 int snd_pcm_new(struct snd_card *card, const char *id, int device,
776 		int playback_count, int capture_count, struct snd_pcm **rpcm)
777 {
778 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
779 			false, rpcm);
780 }
781 EXPORT_SYMBOL(snd_pcm_new);
782 
783 /**
784  * snd_pcm_new_internal - create a new internal PCM instance
785  * @card: the card instance
786  * @id: the id string
787  * @device: the device index (zero based - shared with normal PCMs)
788  * @playback_count: the number of substreams for playback
789  * @capture_count: the number of substreams for capture
790  * @rpcm: the pointer to store the new pcm instance
791  *
792  * Creates a new internal PCM instance with no userspace device or procfs
793  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
794  * will only be used internally by kernel drivers. i.e. it cannot be opened
795  * by userspace. It provides existing ASoC components drivers with a substream
796  * and access to any private data.
797  *
798  * The pcm operators have to be set afterwards to the new instance
799  * via snd_pcm_set_ops().
800  *
801  * Return: Zero if successful, or a negative error code on failure.
802  */
snd_pcm_new_internal(struct snd_card * card,const char * id,int device,int playback_count,int capture_count,struct snd_pcm ** rpcm)803 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
804 	int playback_count, int capture_count,
805 	struct snd_pcm **rpcm)
806 {
807 	return _snd_pcm_new(card, id, device, playback_count, capture_count,
808 			true, rpcm);
809 }
810 EXPORT_SYMBOL(snd_pcm_new_internal);
811 
free_chmap(struct snd_pcm_str * pstr)812 static void free_chmap(struct snd_pcm_str *pstr)
813 {
814 	if (pstr->chmap_kctl) {
815 		struct snd_card *card = pstr->pcm->card;
816 
817 		down_write(&card->controls_rwsem);
818 		snd_ctl_remove(card, pstr->chmap_kctl);
819 		up_write(&card->controls_rwsem);
820 		pstr->chmap_kctl = NULL;
821 	}
822 }
823 
snd_pcm_free_stream(struct snd_pcm_str * pstr)824 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
825 {
826 	struct snd_pcm_substream *substream, *substream_next;
827 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
828 	struct snd_pcm_oss_setup *setup, *setupn;
829 #endif
830 
831 	/* free all proc files under the stream */
832 	snd_pcm_stream_proc_done(pstr);
833 
834 	substream = pstr->substream;
835 	while (substream) {
836 		substream_next = substream->next;
837 		snd_pcm_timer_done(substream);
838 		kfree(substream);
839 		substream = substream_next;
840 	}
841 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
842 	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
843 		setupn = setup->next;
844 		kfree(setup->task_name);
845 		kfree(setup);
846 	}
847 #endif
848 	free_chmap(pstr);
849 	if (pstr->substream_count)
850 		put_device(&pstr->dev);
851 }
852 
853 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
854 #define pcm_call_notify(pcm, call)					\
855 	do {								\
856 		struct snd_pcm_notify *_notify;				\
857 		list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
858 			_notify->call(pcm);				\
859 	} while (0)
860 #else
861 #define pcm_call_notify(pcm, call) do {} while (0)
862 #endif
863 
snd_pcm_free(struct snd_pcm * pcm)864 static int snd_pcm_free(struct snd_pcm *pcm)
865 {
866 	if (!pcm)
867 		return 0;
868 	if (!pcm->internal)
869 		pcm_call_notify(pcm, n_unregister);
870 	if (pcm->private_free)
871 		pcm->private_free(pcm);
872 	snd_pcm_lib_preallocate_free_for_all(pcm);
873 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
874 	snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
875 	kfree(pcm);
876 	return 0;
877 }
878 
snd_pcm_dev_free(struct snd_device * device)879 static int snd_pcm_dev_free(struct snd_device *device)
880 {
881 	struct snd_pcm *pcm = device->device_data;
882 	return snd_pcm_free(pcm);
883 }
884 
snd_pcm_attach_substream(struct snd_pcm * pcm,int stream,struct file * file,struct snd_pcm_substream ** rsubstream)885 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
886 			     struct file *file,
887 			     struct snd_pcm_substream **rsubstream)
888 {
889 	struct snd_pcm_str * pstr;
890 	struct snd_pcm_substream *substream;
891 	struct snd_pcm_runtime *runtime;
892 	struct snd_card *card;
893 	int prefer_subdevice;
894 	size_t size;
895 
896 	if (snd_BUG_ON(!pcm || !rsubstream))
897 		return -ENXIO;
898 	if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
899 		       stream != SNDRV_PCM_STREAM_CAPTURE))
900 		return -EINVAL;
901 	*rsubstream = NULL;
902 	pstr = &pcm->streams[stream];
903 	if (pstr->substream == NULL || pstr->substream_count == 0)
904 		return -ENODEV;
905 
906 	card = pcm->card;
907 	prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
908 
909 	if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
910 		int opposite = !stream;
911 
912 		for (substream = pcm->streams[opposite].substream; substream;
913 		     substream = substream->next) {
914 			if (SUBSTREAM_BUSY(substream))
915 				return -EAGAIN;
916 		}
917 	}
918 
919 	if (file->f_flags & O_APPEND) {
920 		if (prefer_subdevice < 0) {
921 			if (pstr->substream_count > 1)
922 				return -EINVAL; /* must be unique */
923 			substream = pstr->substream;
924 		} else {
925 			for (substream = pstr->substream; substream;
926 			     substream = substream->next)
927 				if (substream->number == prefer_subdevice)
928 					break;
929 		}
930 		if (! substream)
931 			return -ENODEV;
932 		if (! SUBSTREAM_BUSY(substream))
933 			return -EBADFD;
934 		substream->ref_count++;
935 		*rsubstream = substream;
936 		return 0;
937 	}
938 
939 	for (substream = pstr->substream; substream; substream = substream->next) {
940 		if (!SUBSTREAM_BUSY(substream) &&
941 		    (prefer_subdevice == -1 ||
942 		     substream->number == prefer_subdevice))
943 			break;
944 	}
945 	if (substream == NULL)
946 		return -EAGAIN;
947 
948 	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
949 	if (runtime == NULL)
950 		return -ENOMEM;
951 
952 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
953 	runtime->status = alloc_pages_exact(size, GFP_KERNEL);
954 	if (runtime->status == NULL) {
955 		kfree(runtime);
956 		return -ENOMEM;
957 	}
958 	memset(runtime->status, 0, size);
959 
960 	size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
961 	runtime->control = alloc_pages_exact(size, GFP_KERNEL);
962 	if (runtime->control == NULL) {
963 		free_pages_exact(runtime->status,
964 			       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
965 		kfree(runtime);
966 		return -ENOMEM;
967 	}
968 	memset(runtime->control, 0, size);
969 
970 	init_waitqueue_head(&runtime->sleep);
971 	init_waitqueue_head(&runtime->tsleep);
972 
973 	__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
974 	mutex_init(&runtime->buffer_mutex);
975 	atomic_set(&runtime->buffer_accessing, 0);
976 
977 	substream->runtime = runtime;
978 	substream->private_data = pcm->private_data;
979 	substream->ref_count = 1;
980 	substream->f_flags = file->f_flags;
981 	substream->pid = get_pid(task_pid(current));
982 	pstr->substream_opened++;
983 	*rsubstream = substream;
984 	return 0;
985 }
986 
snd_pcm_detach_substream(struct snd_pcm_substream * substream)987 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
988 {
989 	struct snd_pcm_runtime *runtime;
990 
991 	if (PCM_RUNTIME_CHECK(substream))
992 		return;
993 	runtime = substream->runtime;
994 	if (runtime->private_free != NULL)
995 		runtime->private_free(runtime);
996 	free_pages_exact(runtime->status,
997 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
998 	free_pages_exact(runtime->control,
999 		       PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1000 	kfree(runtime->hw_constraints.rules);
1001 	/* Avoid concurrent access to runtime via PCM timer interface */
1002 	if (substream->timer) {
1003 		spin_lock_irq(&substream->timer->lock);
1004 		substream->runtime = NULL;
1005 		spin_unlock_irq(&substream->timer->lock);
1006 	} else {
1007 		substream->runtime = NULL;
1008 	}
1009 	mutex_destroy(&runtime->buffer_mutex);
1010 	snd_fasync_free(runtime->fasync);
1011 	kfree(runtime);
1012 	put_pid(substream->pid);
1013 	substream->pid = NULL;
1014 	substream->pstr->substream_opened--;
1015 }
1016 
pcm_class_show(struct device * dev,struct device_attribute * attr,char * buf)1017 static ssize_t pcm_class_show(struct device *dev,
1018 			      struct device_attribute *attr, char *buf)
1019 {
1020 	struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1021 	struct snd_pcm *pcm = pstr->pcm;
1022 	const char *str;
1023 	static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1024 		[SNDRV_PCM_CLASS_GENERIC] = "generic",
1025 		[SNDRV_PCM_CLASS_MULTI] = "multi",
1026 		[SNDRV_PCM_CLASS_MODEM] = "modem",
1027 		[SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1028 	};
1029 
1030 	if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1031 		str = "none";
1032 	else
1033 		str = strs[pcm->dev_class];
1034 	return sysfs_emit(buf, "%s\n", str);
1035 }
1036 
1037 static DEVICE_ATTR_RO(pcm_class);
1038 static struct attribute *pcm_dev_attrs[] = {
1039 	&dev_attr_pcm_class.attr,
1040 	NULL
1041 };
1042 
1043 static const struct attribute_group pcm_dev_attr_group = {
1044 	.attrs	= pcm_dev_attrs,
1045 };
1046 
1047 static const struct attribute_group *pcm_dev_attr_groups[] = {
1048 	&pcm_dev_attr_group,
1049 	NULL
1050 };
1051 
snd_pcm_dev_register(struct snd_device * device)1052 static int snd_pcm_dev_register(struct snd_device *device)
1053 {
1054 	int cidx, err;
1055 	struct snd_pcm_substream *substream;
1056 	struct snd_pcm *pcm;
1057 
1058 	if (snd_BUG_ON(!device || !device->device_data))
1059 		return -ENXIO;
1060 	pcm = device->device_data;
1061 
1062 	mutex_lock(&register_mutex);
1063 	err = snd_pcm_add(pcm);
1064 	if (err)
1065 		goto unlock;
1066 	for (cidx = 0; cidx < 2; cidx++) {
1067 		int devtype = -1;
1068 		if (pcm->streams[cidx].substream == NULL)
1069 			continue;
1070 		switch (cidx) {
1071 		case SNDRV_PCM_STREAM_PLAYBACK:
1072 			devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1073 			break;
1074 		case SNDRV_PCM_STREAM_CAPTURE:
1075 			devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1076 			break;
1077 		}
1078 		/* register pcm */
1079 		err = snd_register_device(devtype, pcm->card, pcm->device,
1080 					  &snd_pcm_f_ops[cidx], pcm,
1081 					  &pcm->streams[cidx].dev);
1082 		if (err < 0) {
1083 			list_del_init(&pcm->list);
1084 			goto unlock;
1085 		}
1086 
1087 		for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1088 			snd_pcm_timer_init(substream);
1089 	}
1090 
1091 	pcm_call_notify(pcm, n_register);
1092 
1093  unlock:
1094 	mutex_unlock(&register_mutex);
1095 	return err;
1096 }
1097 
snd_pcm_dev_disconnect(struct snd_device * device)1098 static int snd_pcm_dev_disconnect(struct snd_device *device)
1099 {
1100 	struct snd_pcm *pcm = device->device_data;
1101 	struct snd_pcm_substream *substream;
1102 	int cidx;
1103 
1104 	mutex_lock(&register_mutex);
1105 	mutex_lock(&pcm->open_mutex);
1106 	wake_up(&pcm->open_wait);
1107 	list_del_init(&pcm->list);
1108 
1109 	for_each_pcm_substream(pcm, cidx, substream) {
1110 		snd_pcm_stream_lock_irq(substream);
1111 		if (substream->runtime) {
1112 			if (snd_pcm_running(substream))
1113 				snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1114 			/* to be sure, set the state unconditionally */
1115 			__snd_pcm_set_state(substream->runtime,
1116 					    SNDRV_PCM_STATE_DISCONNECTED);
1117 			wake_up(&substream->runtime->sleep);
1118 			wake_up(&substream->runtime->tsleep);
1119 		}
1120 		snd_pcm_stream_unlock_irq(substream);
1121 	}
1122 
1123 	for_each_pcm_substream(pcm, cidx, substream)
1124 		snd_pcm_sync_stop(substream, false);
1125 
1126 	pcm_call_notify(pcm, n_disconnect);
1127 	for (cidx = 0; cidx < 2; cidx++) {
1128 		snd_unregister_device(&pcm->streams[cidx].dev);
1129 		free_chmap(&pcm->streams[cidx]);
1130 	}
1131 	mutex_unlock(&pcm->open_mutex);
1132 	mutex_unlock(&register_mutex);
1133 	return 0;
1134 }
1135 
1136 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1137 /**
1138  * snd_pcm_notify - Add/remove the notify list
1139  * @notify: PCM notify list
1140  * @nfree: 0 = register, 1 = unregister
1141  *
1142  * This adds the given notifier to the global list so that the callback is
1143  * called for each registered PCM devices.  This exists only for PCM OSS
1144  * emulation, so far.
1145  *
1146  * Return: zero if successful, or a negative error code
1147  */
snd_pcm_notify(struct snd_pcm_notify * notify,int nfree)1148 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1149 {
1150 	struct snd_pcm *pcm;
1151 
1152 	if (snd_BUG_ON(!notify ||
1153 		       !notify->n_register ||
1154 		       !notify->n_unregister ||
1155 		       !notify->n_disconnect))
1156 		return -EINVAL;
1157 	mutex_lock(&register_mutex);
1158 	if (nfree) {
1159 		list_del(&notify->list);
1160 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1161 			notify->n_unregister(pcm);
1162 	} else {
1163 		list_add_tail(&notify->list, &snd_pcm_notify_list);
1164 		list_for_each_entry(pcm, &snd_pcm_devices, list)
1165 			notify->n_register(pcm);
1166 	}
1167 	mutex_unlock(&register_mutex);
1168 	return 0;
1169 }
1170 EXPORT_SYMBOL(snd_pcm_notify);
1171 #endif /* CONFIG_SND_PCM_OSS */
1172 
1173 #ifdef CONFIG_SND_PROC_FS
1174 /*
1175  *  Info interface
1176  */
1177 
snd_pcm_proc_read(struct snd_info_entry * entry,struct snd_info_buffer * buffer)1178 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1179 			      struct snd_info_buffer *buffer)
1180 {
1181 	struct snd_pcm *pcm;
1182 
1183 	mutex_lock(&register_mutex);
1184 	list_for_each_entry(pcm, &snd_pcm_devices, list) {
1185 		snd_iprintf(buffer, "%02i-%02i: %s : %s",
1186 			    pcm->card->number, pcm->device, pcm->id, pcm->name);
1187 		if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1188 			snd_iprintf(buffer, " : playback %i",
1189 				    pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1190 		if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1191 			snd_iprintf(buffer, " : capture %i",
1192 				    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1193 		snd_iprintf(buffer, "\n");
1194 	}
1195 	mutex_unlock(&register_mutex);
1196 }
1197 
1198 static struct snd_info_entry *snd_pcm_proc_entry;
1199 
snd_pcm_proc_init(void)1200 static void snd_pcm_proc_init(void)
1201 {
1202 	struct snd_info_entry *entry;
1203 
1204 	entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1205 	if (entry) {
1206 		snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1207 		if (snd_info_register(entry) < 0) {
1208 			snd_info_free_entry(entry);
1209 			entry = NULL;
1210 		}
1211 	}
1212 	snd_pcm_proc_entry = entry;
1213 }
1214 
snd_pcm_proc_done(void)1215 static void snd_pcm_proc_done(void)
1216 {
1217 	snd_info_free_entry(snd_pcm_proc_entry);
1218 }
1219 
1220 #else /* !CONFIG_SND_PROC_FS */
1221 #define snd_pcm_proc_init()
1222 #define snd_pcm_proc_done()
1223 #endif /* CONFIG_SND_PROC_FS */
1224 
1225 
1226 /*
1227  *  ENTRY functions
1228  */
1229 
alsa_pcm_init(void)1230 static int __init alsa_pcm_init(void)
1231 {
1232 	snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1233 	snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1234 	snd_pcm_proc_init();
1235 	return 0;
1236 }
1237 
alsa_pcm_exit(void)1238 static void __exit alsa_pcm_exit(void)
1239 {
1240 	snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1241 	snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1242 	snd_pcm_proc_done();
1243 }
1244 
1245 module_init(alsa_pcm_init)
1246 module_exit(alsa_pcm_exit)
1247