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
23MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
24MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
25MODULE_LICENSE("GPL");
26
27static LIST_HEAD(snd_pcm_devices);
28static DEFINE_MUTEX(register_mutex);
29#if IS_ENABLED(CONFIG_SND_PCM_OSS)
30static LIST_HEAD(snd_pcm_notify_list);
31#endif
32
33static int snd_pcm_free(struct snd_pcm *pcm);
34static int snd_pcm_dev_free(struct snd_device *device);
35static int snd_pcm_dev_register(struct snd_device *device);
36static int snd_pcm_dev_disconnect(struct snd_device *device);
37
38static 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
49static 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
62static 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(new: &newpcm->list, head: pcm->list.prev);
76 return 0;
77 }
78 }
79 list_add_tail(new: &newpcm->list, head: &snd_pcm_devices);
80 return 0;
81}
82
83static 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(lock: &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(lock: &pcm->open_mutex);
147 _error:
148 mutex_unlock(lock: &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
166static 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 */
222const 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}
228EXPORT_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
242static const char * const snd_pcm_stream_names[] = {
243 STREAM(PLAYBACK),
244 STREAM(CAPTURE),
245};
246
247static 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
258static 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
266static const char * const snd_pcm_subformat_names[] = {
267 SUBFORMAT(STD),
268};
269
270static const char * const snd_pcm_tstamp_mode_names[] = {
271 TSTAMP(NONE),
272 TSTAMP(ENABLE),
273};
274
275static const char *snd_pcm_stream_name(int stream)
276{
277 return snd_pcm_stream_names[stream];
278}
279
280static const char *snd_pcm_access_name(snd_pcm_access_t access)
281{
282 return snd_pcm_access_names[(__force int)access];
283}
284
285static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
286{
287 return snd_pcm_subformat_names[(__force int)subformat];
288}
289
290static const char *snd_pcm_tstamp_mode_name(int mode)
291{
292 return snd_pcm_tstamp_mode_names[mode];
293}
294
295static 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
303static 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
332static 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(size: 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(objp: 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(objp: info);
363}
364
365static 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(substream: ((struct snd_pcm_str *)entry->private_data)->substream,
369 buffer);
370}
371
372static 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(substream: entry->private_data, buffer);
376}
377
378static 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(lock: &substream->pcm->open_mutex);
413}
414
415static 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(lock: &substream->pcm->open_mutex);
441}
442
443static 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: &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(lock: &substream->pcm->open_mutex);
477}
478
479#ifdef CONFIG_SND_PCM_XRUN_DEBUG
480static 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
488static 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
495static 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, len: sizeof(line)))
501 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
502}
503#endif
504
505static 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(buf: name, fmt: "pcm%i%c", pcm->device,
512 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
513 entry = snd_info_create_card_entry(card: pcm->card, name,
514 parent: 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(card: pcm->card, name: "info", parent: pstr->proc_root);
520 if (entry)
521 snd_info_set_text_ops(entry, private_data: pstr, read: snd_pcm_stream_proc_info_read);
522#ifdef CONFIG_SND_PCM_XRUN_DEBUG
523 entry = snd_info_create_card_entry(card: pcm->card, name: "xrun_debug",
524 parent: pstr->proc_root);
525 if (entry) {
526 snd_info_set_text_ops(entry, private_data: pstr, read: 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
534static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
535{
536 snd_info_free_entry(entry: pstr->proc_root);
537 pstr->proc_root = NULL;
538 return 0;
539}
540
541static struct snd_info_entry *
542create_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(card: substream->pcm->card, name,
550 parent: substream->proc_root);
551 if (entry)
552 snd_info_set_text_ops(entry, private_data: substream, read);
553 return entry;
554}
555
556static 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(buf: name, fmt: "sub%i", substream->number);
565 entry = snd_info_create_card_entry(card, name,
566 parent: 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, name: "info",
573 read: snd_pcm_substream_proc_info_read);
574 create_substream_info_entry(substream, name: "hw_params",
575 read: snd_pcm_substream_proc_hw_params_read);
576 create_substream_info_entry(substream, name: "sw_params",
577 read: snd_pcm_substream_proc_sw_params_read);
578 create_substream_info_entry(substream, name: "status",
579 read: snd_pcm_substream_proc_status_read);
580
581#ifdef CONFIG_SND_PCM_XRUN_DEBUG
582 entry = create_substream_info_entry(substream, name: "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 */
593static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
594static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
595static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
596#endif /* CONFIG_SND_VERBOSE_PROCFS */
597
598static 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
605static int do_pcm_suspend(struct device *dev)
606{
607 struct snd_pcm_str *pstr = dev_get_drvdata(dev);
608
609 if (!pstr->pcm->no_device_suspend)
610 snd_pcm_suspend_all(pcm: pstr->pcm);
611 return 0;
612}
613#endif
614
615static 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 */
620static 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 */
638int 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 err = snd_device_alloc(dev_p: &pstr->dev, card: pcm->card);
654 if (err < 0)
655 return err;
656 dev_set_name(dev: pstr->dev, name: "pcmC%iD%i%c", pcm->card->number, pcm->device,
657 stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
658 pstr->dev->groups = pcm_dev_attr_groups;
659 pstr->dev->type = &pcm_dev_type;
660 dev_set_drvdata(dev: pstr->dev, data: pstr);
661
662 if (!pcm->internal) {
663 err = snd_pcm_stream_proc_init(pstr);
664 if (err < 0) {
665 pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
666 return err;
667 }
668 }
669 prev = NULL;
670 for (idx = 0, prev = NULL; idx < substream_count; idx++) {
671 substream = kzalloc(size: sizeof(*substream), GFP_KERNEL);
672 if (!substream)
673 return -ENOMEM;
674 substream->pcm = pcm;
675 substream->pstr = pstr;
676 substream->number = idx;
677 substream->stream = stream;
678 sprintf(buf: substream->name, fmt: "subdevice #%i", idx);
679 substream->buffer_bytes_max = UINT_MAX;
680 if (prev == NULL)
681 pstr->substream = substream;
682 else
683 prev->next = substream;
684
685 if (!pcm->internal) {
686 err = snd_pcm_substream_proc_init(substream);
687 if (err < 0) {
688 pcm_err(pcm,
689 "Error in snd_pcm_stream_proc_init\n");
690 if (prev == NULL)
691 pstr->substream = NULL;
692 else
693 prev->next = NULL;
694 kfree(objp: substream);
695 return err;
696 }
697 }
698 substream->group = &substream->self_group;
699 snd_pcm_group_init(group: &substream->self_group);
700 list_add_tail(new: &substream->link_list, head: &substream->self_group.substreams);
701 atomic_set(v: &substream->mmap_count, i: 0);
702 prev = substream;
703 }
704 return 0;
705}
706EXPORT_SYMBOL(snd_pcm_new_stream);
707
708static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
709 int playback_count, int capture_count, bool internal,
710 struct snd_pcm **rpcm)
711{
712 struct snd_pcm *pcm;
713 int err;
714 static const struct snd_device_ops ops = {
715 .dev_free = snd_pcm_dev_free,
716 .dev_register = snd_pcm_dev_register,
717 .dev_disconnect = snd_pcm_dev_disconnect,
718 };
719 static const struct snd_device_ops internal_ops = {
720 .dev_free = snd_pcm_dev_free,
721 };
722
723 if (snd_BUG_ON(!card))
724 return -ENXIO;
725 if (rpcm)
726 *rpcm = NULL;
727 pcm = kzalloc(size: sizeof(*pcm), GFP_KERNEL);
728 if (!pcm)
729 return -ENOMEM;
730 pcm->card = card;
731 pcm->device = device;
732 pcm->internal = internal;
733 mutex_init(&pcm->open_mutex);
734 init_waitqueue_head(&pcm->open_wait);
735 INIT_LIST_HEAD(list: &pcm->list);
736 if (id)
737 strscpy(p: pcm->id, q: id, size: sizeof(pcm->id));
738
739 err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
740 playback_count);
741 if (err < 0)
742 goto free_pcm;
743
744 err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
745 if (err < 0)
746 goto free_pcm;
747
748 err = snd_device_new(card, type: SNDRV_DEV_PCM, device_data: pcm,
749 ops: internal ? &internal_ops : &ops);
750 if (err < 0)
751 goto free_pcm;
752
753 if (rpcm)
754 *rpcm = pcm;
755 return 0;
756
757free_pcm:
758 snd_pcm_free(pcm);
759 return err;
760}
761
762/**
763 * snd_pcm_new - create a new PCM instance
764 * @card: the card instance
765 * @id: the id string
766 * @device: the device index (zero based)
767 * @playback_count: the number of substreams for playback
768 * @capture_count: the number of substreams for capture
769 * @rpcm: the pointer to store the new pcm instance
770 *
771 * Creates a new PCM instance.
772 *
773 * The pcm operators have to be set afterwards to the new instance
774 * via snd_pcm_set_ops().
775 *
776 * Return: Zero if successful, or a negative error code on failure.
777 */
778int snd_pcm_new(struct snd_card *card, const char *id, int device,
779 int playback_count, int capture_count, struct snd_pcm **rpcm)
780{
781 return _snd_pcm_new(card, id, device, playback_count, capture_count,
782 internal: false, rpcm);
783}
784EXPORT_SYMBOL(snd_pcm_new);
785
786/**
787 * snd_pcm_new_internal - create a new internal PCM instance
788 * @card: the card instance
789 * @id: the id string
790 * @device: the device index (zero based - shared with normal PCMs)
791 * @playback_count: the number of substreams for playback
792 * @capture_count: the number of substreams for capture
793 * @rpcm: the pointer to store the new pcm instance
794 *
795 * Creates a new internal PCM instance with no userspace device or procfs
796 * entries. This is used by ASoC Back End PCMs in order to create a PCM that
797 * will only be used internally by kernel drivers. i.e. it cannot be opened
798 * by userspace. It provides existing ASoC components drivers with a substream
799 * and access to any private data.
800 *
801 * The pcm operators have to be set afterwards to the new instance
802 * via snd_pcm_set_ops().
803 *
804 * Return: Zero if successful, or a negative error code on failure.
805 */
806int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
807 int playback_count, int capture_count,
808 struct snd_pcm **rpcm)
809{
810 return _snd_pcm_new(card, id, device, playback_count, capture_count,
811 internal: true, rpcm);
812}
813EXPORT_SYMBOL(snd_pcm_new_internal);
814
815static void free_chmap(struct snd_pcm_str *pstr)
816{
817 if (pstr->chmap_kctl) {
818 struct snd_card *card = pstr->pcm->card;
819
820 snd_ctl_remove(card, kcontrol: pstr->chmap_kctl);
821 pstr->chmap_kctl = NULL;
822 }
823}
824
825static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
826{
827 struct snd_pcm_substream *substream, *substream_next;
828#if IS_ENABLED(CONFIG_SND_PCM_OSS)
829 struct snd_pcm_oss_setup *setup, *setupn;
830#endif
831
832 /* free all proc files under the stream */
833 snd_pcm_stream_proc_done(pstr);
834
835 substream = pstr->substream;
836 while (substream) {
837 substream_next = substream->next;
838 snd_pcm_timer_done(substream);
839 kfree(objp: substream);
840 substream = substream_next;
841 }
842#if IS_ENABLED(CONFIG_SND_PCM_OSS)
843 for (setup = pstr->oss.setup_list; setup; setup = setupn) {
844 setupn = setup->next;
845 kfree(objp: setup->task_name);
846 kfree(objp: setup);
847 }
848#endif
849 free_chmap(pstr);
850 if (pstr->substream_count)
851 put_device(dev: pstr->dev);
852}
853
854#if IS_ENABLED(CONFIG_SND_PCM_OSS)
855#define pcm_call_notify(pcm, call) \
856 do { \
857 struct snd_pcm_notify *_notify; \
858 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
859 _notify->call(pcm); \
860 } while (0)
861#else
862#define pcm_call_notify(pcm, call) do {} while (0)
863#endif
864
865static int snd_pcm_free(struct snd_pcm *pcm)
866{
867 if (!pcm)
868 return 0;
869 if (!pcm->internal)
870 pcm_call_notify(pcm, n_unregister);
871 if (pcm->private_free)
872 pcm->private_free(pcm);
873 snd_pcm_lib_preallocate_free_for_all(pcm);
874 snd_pcm_free_stream(pstr: &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
875 snd_pcm_free_stream(pstr: &pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
876 kfree(objp: pcm);
877 return 0;
878}
879
880static int snd_pcm_dev_free(struct snd_device *device)
881{
882 struct snd_pcm *pcm = device->device_data;
883 return snd_pcm_free(pcm);
884}
885
886int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
887 struct file *file,
888 struct snd_pcm_substream **rsubstream)
889{
890 struct snd_pcm_str * pstr;
891 struct snd_pcm_substream *substream;
892 struct snd_pcm_runtime *runtime;
893 struct snd_card *card;
894 int prefer_subdevice;
895 size_t size;
896
897 if (snd_BUG_ON(!pcm || !rsubstream))
898 return -ENXIO;
899 if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
900 stream != SNDRV_PCM_STREAM_CAPTURE))
901 return -EINVAL;
902 *rsubstream = NULL;
903 pstr = &pcm->streams[stream];
904 if (pstr->substream == NULL || pstr->substream_count == 0)
905 return -ENODEV;
906
907 card = pcm->card;
908 prefer_subdevice = snd_ctl_get_preferred_subdevice(card, type: SND_CTL_SUBDEV_PCM);
909
910 if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
911 int opposite = !stream;
912
913 for (substream = pcm->streams[opposite].substream; substream;
914 substream = substream->next) {
915 if (SUBSTREAM_BUSY(substream))
916 return -EAGAIN;
917 }
918 }
919
920 if (file->f_flags & O_APPEND) {
921 if (prefer_subdevice < 0) {
922 if (pstr->substream_count > 1)
923 return -EINVAL; /* must be unique */
924 substream = pstr->substream;
925 } else {
926 for (substream = pstr->substream; substream;
927 substream = substream->next)
928 if (substream->number == prefer_subdevice)
929 break;
930 }
931 if (! substream)
932 return -ENODEV;
933 if (! SUBSTREAM_BUSY(substream))
934 return -EBADFD;
935 substream->ref_count++;
936 *rsubstream = substream;
937 return 0;
938 }
939
940 for (substream = pstr->substream; substream; substream = substream->next) {
941 if (!SUBSTREAM_BUSY(substream) &&
942 (prefer_subdevice == -1 ||
943 substream->number == prefer_subdevice))
944 break;
945 }
946 if (substream == NULL)
947 return -EAGAIN;
948
949 runtime = kzalloc(size: sizeof(*runtime), GFP_KERNEL);
950 if (runtime == NULL)
951 return -ENOMEM;
952
953 size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
954 runtime->status = alloc_pages_exact(size, GFP_KERNEL);
955 if (runtime->status == NULL) {
956 kfree(objp: runtime);
957 return -ENOMEM;
958 }
959 memset(runtime->status, 0, size);
960
961 size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
962 runtime->control = alloc_pages_exact(size, GFP_KERNEL);
963 if (runtime->control == NULL) {
964 free_pages_exact(virt: runtime->status,
965 PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
966 kfree(objp: runtime);
967 return -ENOMEM;
968 }
969 memset(runtime->control, 0, size);
970
971 init_waitqueue_head(&runtime->sleep);
972 init_waitqueue_head(&runtime->tsleep);
973
974 __snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
975 mutex_init(&runtime->buffer_mutex);
976 atomic_set(v: &runtime->buffer_accessing, i: 0);
977
978 substream->runtime = runtime;
979 substream->private_data = pcm->private_data;
980 substream->ref_count = 1;
981 substream->f_flags = file->f_flags;
982 substream->pid = get_pid(pid: task_pid(current));
983 pstr->substream_opened++;
984 *rsubstream = substream;
985 return 0;
986}
987
988void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
989{
990 struct snd_pcm_runtime *runtime;
991
992 if (PCM_RUNTIME_CHECK(substream))
993 return;
994 runtime = substream->runtime;
995 if (runtime->private_free != NULL)
996 runtime->private_free(runtime);
997 free_pages_exact(virt: runtime->status,
998 PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
999 free_pages_exact(virt: runtime->control,
1000 PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1001 kfree(objp: runtime->hw_constraints.rules);
1002 /* Avoid concurrent access to runtime via PCM timer interface */
1003 if (substream->timer) {
1004 spin_lock_irq(lock: &substream->timer->lock);
1005 substream->runtime = NULL;
1006 spin_unlock_irq(lock: &substream->timer->lock);
1007 } else {
1008 substream->runtime = NULL;
1009 }
1010 mutex_destroy(lock: &runtime->buffer_mutex);
1011 snd_fasync_free(fasync: runtime->fasync);
1012 kfree(objp: runtime);
1013 put_pid(pid: substream->pid);
1014 substream->pid = NULL;
1015 substream->pstr->substream_opened--;
1016}
1017
1018static ssize_t pcm_class_show(struct device *dev,
1019 struct device_attribute *attr, char *buf)
1020{
1021 struct snd_pcm_str *pstr = dev_get_drvdata(dev);
1022 struct snd_pcm *pcm = pstr->pcm;
1023 const char *str;
1024 static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1025 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1026 [SNDRV_PCM_CLASS_MULTI] = "multi",
1027 [SNDRV_PCM_CLASS_MODEM] = "modem",
1028 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1029 };
1030
1031 if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1032 str = "none";
1033 else
1034 str = strs[pcm->dev_class];
1035 return sysfs_emit(buf, fmt: "%s\n", str);
1036}
1037
1038static DEVICE_ATTR_RO(pcm_class);
1039static struct attribute *pcm_dev_attrs[] = {
1040 &dev_attr_pcm_class.attr,
1041 NULL
1042};
1043
1044static const struct attribute_group pcm_dev_attr_group = {
1045 .attrs = pcm_dev_attrs,
1046};
1047
1048static const struct attribute_group *pcm_dev_attr_groups[] = {
1049 &pcm_dev_attr_group,
1050 NULL
1051};
1052
1053static int snd_pcm_dev_register(struct snd_device *device)
1054{
1055 int cidx, err;
1056 struct snd_pcm_substream *substream;
1057 struct snd_pcm *pcm;
1058
1059 if (snd_BUG_ON(!device || !device->device_data))
1060 return -ENXIO;
1061 pcm = device->device_data;
1062
1063 mutex_lock(&register_mutex);
1064 err = snd_pcm_add(newpcm: pcm);
1065 if (err)
1066 goto unlock;
1067 for (cidx = 0; cidx < 2; cidx++) {
1068 int devtype = -1;
1069 if (pcm->streams[cidx].substream == NULL)
1070 continue;
1071 switch (cidx) {
1072 case SNDRV_PCM_STREAM_PLAYBACK:
1073 devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1074 break;
1075 case SNDRV_PCM_STREAM_CAPTURE:
1076 devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1077 break;
1078 }
1079 /* register pcm */
1080 err = snd_register_device(type: devtype, card: pcm->card, dev: pcm->device,
1081 f_ops: &snd_pcm_f_ops[cidx], private_data: pcm,
1082 device: pcm->streams[cidx].dev);
1083 if (err < 0) {
1084 list_del_init(entry: &pcm->list);
1085 goto unlock;
1086 }
1087
1088 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1089 snd_pcm_timer_init(substream);
1090 }
1091
1092 pcm_call_notify(pcm, n_register);
1093
1094 unlock:
1095 mutex_unlock(lock: &register_mutex);
1096 return err;
1097}
1098
1099static int snd_pcm_dev_disconnect(struct snd_device *device)
1100{
1101 struct snd_pcm *pcm = device->device_data;
1102 struct snd_pcm_substream *substream;
1103 int cidx;
1104
1105 mutex_lock(&register_mutex);
1106 mutex_lock(&pcm->open_mutex);
1107 wake_up(&pcm->open_wait);
1108 list_del_init(entry: &pcm->list);
1109
1110 for_each_pcm_substream(pcm, cidx, substream) {
1111 snd_pcm_stream_lock_irq(substream);
1112 if (substream->runtime) {
1113 if (snd_pcm_running(substream))
1114 snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1115 /* to be sure, set the state unconditionally */
1116 __snd_pcm_set_state(runtime: substream->runtime,
1117 SNDRV_PCM_STATE_DISCONNECTED);
1118 wake_up(&substream->runtime->sleep);
1119 wake_up(&substream->runtime->tsleep);
1120 }
1121 snd_pcm_stream_unlock_irq(substream);
1122 }
1123
1124 for_each_pcm_substream(pcm, cidx, substream)
1125 snd_pcm_sync_stop(substream, sync_irq: false);
1126
1127 pcm_call_notify(pcm, n_disconnect);
1128 for (cidx = 0; cidx < 2; cidx++) {
1129 if (pcm->streams[cidx].dev)
1130 snd_unregister_device(dev: pcm->streams[cidx].dev);
1131 free_chmap(pstr: &pcm->streams[cidx]);
1132 }
1133 mutex_unlock(lock: &pcm->open_mutex);
1134 mutex_unlock(lock: &register_mutex);
1135 return 0;
1136}
1137
1138#if IS_ENABLED(CONFIG_SND_PCM_OSS)
1139/**
1140 * snd_pcm_notify - Add/remove the notify list
1141 * @notify: PCM notify list
1142 * @nfree: 0 = register, 1 = unregister
1143 *
1144 * This adds the given notifier to the global list so that the callback is
1145 * called for each registered PCM devices. This exists only for PCM OSS
1146 * emulation, so far.
1147 *
1148 * Return: zero if successful, or a negative error code
1149 */
1150int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1151{
1152 struct snd_pcm *pcm;
1153
1154 if (snd_BUG_ON(!notify ||
1155 !notify->n_register ||
1156 !notify->n_unregister ||
1157 !notify->n_disconnect))
1158 return -EINVAL;
1159 mutex_lock(&register_mutex);
1160 if (nfree) {
1161 list_del(entry: &notify->list);
1162 list_for_each_entry(pcm, &snd_pcm_devices, list)
1163 notify->n_unregister(pcm);
1164 } else {
1165 list_add_tail(new: &notify->list, head: &snd_pcm_notify_list);
1166 list_for_each_entry(pcm, &snd_pcm_devices, list)
1167 notify->n_register(pcm);
1168 }
1169 mutex_unlock(lock: &register_mutex);
1170 return 0;
1171}
1172EXPORT_SYMBOL(snd_pcm_notify);
1173#endif /* CONFIG_SND_PCM_OSS */
1174
1175#ifdef CONFIG_SND_PROC_FS
1176/*
1177 * Info interface
1178 */
1179
1180static void snd_pcm_proc_read(struct snd_info_entry *entry,
1181 struct snd_info_buffer *buffer)
1182{
1183 struct snd_pcm *pcm;
1184
1185 mutex_lock(&register_mutex);
1186 list_for_each_entry(pcm, &snd_pcm_devices, list) {
1187 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1188 pcm->card->number, pcm->device, pcm->id, pcm->name);
1189 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1190 snd_iprintf(buffer, " : playback %i",
1191 pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1192 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1193 snd_iprintf(buffer, " : capture %i",
1194 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1195 snd_iprintf(buffer, "\n");
1196 }
1197 mutex_unlock(lock: &register_mutex);
1198}
1199
1200static struct snd_info_entry *snd_pcm_proc_entry;
1201
1202static void snd_pcm_proc_init(void)
1203{
1204 struct snd_info_entry *entry;
1205
1206 entry = snd_info_create_module_entry(THIS_MODULE, name: "pcm", NULL);
1207 if (entry) {
1208 snd_info_set_text_ops(entry, NULL, read: snd_pcm_proc_read);
1209 if (snd_info_register(entry) < 0) {
1210 snd_info_free_entry(entry);
1211 entry = NULL;
1212 }
1213 }
1214 snd_pcm_proc_entry = entry;
1215}
1216
1217static void snd_pcm_proc_done(void)
1218{
1219 snd_info_free_entry(entry: snd_pcm_proc_entry);
1220}
1221
1222#else /* !CONFIG_SND_PROC_FS */
1223#define snd_pcm_proc_init()
1224#define snd_pcm_proc_done()
1225#endif /* CONFIG_SND_PROC_FS */
1226
1227
1228/*
1229 * ENTRY functions
1230 */
1231
1232static int __init alsa_pcm_init(void)
1233{
1234 snd_ctl_register_ioctl(fcn: snd_pcm_control_ioctl);
1235 snd_ctl_register_ioctl_compat(fcn: snd_pcm_control_ioctl);
1236 snd_pcm_proc_init();
1237 return 0;
1238}
1239
1240static void __exit alsa_pcm_exit(void)
1241{
1242 snd_ctl_unregister_ioctl(fcn: snd_pcm_control_ioctl);
1243 snd_ctl_unregister_ioctl_compat(fcn: snd_pcm_control_ioctl);
1244 snd_pcm_proc_done();
1245}
1246
1247module_init(alsa_pcm_init)
1248module_exit(alsa_pcm_exit)
1249

source code of linux/sound/core/pcm.c