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 scoped_guard(mutex, &register_mutex)
95 device = snd_pcm_next(card, device);
96 if (put_user(device, (int __user *)arg))
97 return -EFAULT;
98 return 0;
99 }
100 case SNDRV_CTL_IOCTL_PCM_INFO:
101 {
102 struct snd_pcm_info __user *info;
103 unsigned int device, subdevice;
104 int stream;
105 struct snd_pcm *pcm;
106 struct snd_pcm_str *pstr;
107 struct snd_pcm_substream *substream;
108
109 info = (struct snd_pcm_info __user *)arg;
110 if (get_user(device, &info->device))
111 return -EFAULT;
112 if (get_user(stream, &info->stream))
113 return -EFAULT;
114 if (stream < 0 || stream > 1)
115 return -EINVAL;
116 stream = array_index_nospec(stream, 2);
117 if (get_user(subdevice, &info->subdevice))
118 return -EFAULT;
119 guard(mutex)(T: &register_mutex);
120 pcm = snd_pcm_get(card, device);
121 if (pcm == NULL)
122 return -ENXIO;
123 pstr = &pcm->streams[stream];
124 if (pstr->substream_count == 0)
125 return -ENOENT;
126 if (subdevice >= pstr->substream_count)
127 return -ENXIO;
128 for (substream = pstr->substream; substream;
129 substream = substream->next)
130 if (substream->number == (int)subdevice)
131 break;
132 if (substream == NULL)
133 return -ENXIO;
134 guard(mutex)(T: &pcm->open_mutex);
135 return snd_pcm_info_user(substream, info);
136 }
137 case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
138 {
139 int val;
140
141 if (get_user(val, (int __user *)arg))
142 return -EFAULT;
143 control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
144 return 0;
145 }
146 }
147 return -ENOIOCTLCMD;
148}
149
150#define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
151
152static const char * const snd_pcm_format_names[] = {
153 FORMAT(S8),
154 FORMAT(U8),
155 FORMAT(S16_LE),
156 FORMAT(S16_BE),
157 FORMAT(U16_LE),
158 FORMAT(U16_BE),
159 FORMAT(S24_LE),
160 FORMAT(S24_BE),
161 FORMAT(U24_LE),
162 FORMAT(U24_BE),
163 FORMAT(S32_LE),
164 FORMAT(S32_BE),
165 FORMAT(U32_LE),
166 FORMAT(U32_BE),
167 FORMAT(FLOAT_LE),
168 FORMAT(FLOAT_BE),
169 FORMAT(FLOAT64_LE),
170 FORMAT(FLOAT64_BE),
171 FORMAT(IEC958_SUBFRAME_LE),
172 FORMAT(IEC958_SUBFRAME_BE),
173 FORMAT(MU_LAW),
174 FORMAT(A_LAW),
175 FORMAT(IMA_ADPCM),
176 FORMAT(MPEG),
177 FORMAT(GSM),
178 FORMAT(SPECIAL),
179 FORMAT(S24_3LE),
180 FORMAT(S24_3BE),
181 FORMAT(U24_3LE),
182 FORMAT(U24_3BE),
183 FORMAT(S20_3LE),
184 FORMAT(S20_3BE),
185 FORMAT(U20_3LE),
186 FORMAT(U20_3BE),
187 FORMAT(S18_3LE),
188 FORMAT(S18_3BE),
189 FORMAT(U18_3LE),
190 FORMAT(U18_3BE),
191 FORMAT(G723_24),
192 FORMAT(G723_24_1B),
193 FORMAT(G723_40),
194 FORMAT(G723_40_1B),
195 FORMAT(DSD_U8),
196 FORMAT(DSD_U16_LE),
197 FORMAT(DSD_U32_LE),
198 FORMAT(DSD_U16_BE),
199 FORMAT(DSD_U32_BE),
200 FORMAT(S20_LE),
201 FORMAT(S20_BE),
202 FORMAT(U20_LE),
203 FORMAT(U20_BE),
204};
205
206/**
207 * snd_pcm_format_name - Return a name string for the given PCM format
208 * @format: PCM format
209 *
210 * Return: the format name string
211 */
212const char *snd_pcm_format_name(snd_pcm_format_t format)
213{
214 unsigned int format_num = (__force unsigned int)format;
215
216 if (format_num >= ARRAY_SIZE(snd_pcm_format_names) || !snd_pcm_format_names[format_num])
217 return "Unknown";
218 return snd_pcm_format_names[format_num];
219}
220EXPORT_SYMBOL_GPL(snd_pcm_format_name);
221
222#ifdef CONFIG_SND_VERBOSE_PROCFS
223
224#define STATE(v) [SNDRV_PCM_STATE_##v] = #v
225#define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
226#define READY(v) [SNDRV_PCM_READY_##v] = #v
227#define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
228#define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
229#define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
230#define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
231#define START(v) [SNDRV_PCM_START_##v] = #v
232#define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
233
234static const char * const snd_pcm_stream_names[] = {
235 STREAM(PLAYBACK),
236 STREAM(CAPTURE),
237};
238
239static const char * const snd_pcm_state_names[] = {
240 STATE(OPEN),
241 STATE(SETUP),
242 STATE(PREPARED),
243 STATE(RUNNING),
244 STATE(XRUN),
245 STATE(DRAINING),
246 STATE(PAUSED),
247 STATE(SUSPENDED),
248 STATE(DISCONNECTED),
249};
250
251static const char * const snd_pcm_access_names[] = {
252 ACCESS(MMAP_INTERLEAVED),
253 ACCESS(MMAP_NONINTERLEAVED),
254 ACCESS(MMAP_COMPLEX),
255 ACCESS(RW_INTERLEAVED),
256 ACCESS(RW_NONINTERLEAVED),
257};
258
259static const char * const snd_pcm_subformat_names[] = {
260 SUBFORMAT(STD),
261 SUBFORMAT(MSBITS_MAX),
262 SUBFORMAT(MSBITS_20),
263 SUBFORMAT(MSBITS_24),
264};
265
266static const char * const snd_pcm_tstamp_mode_names[] = {
267 TSTAMP(NONE),
268 TSTAMP(ENABLE),
269};
270
271static const char *snd_pcm_stream_name(int stream)
272{
273 return snd_pcm_stream_names[stream];
274}
275
276static const char *snd_pcm_access_name(snd_pcm_access_t access)
277{
278 return snd_pcm_access_names[(__force int)access];
279}
280
281static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
282{
283 return snd_pcm_subformat_names[(__force int)subformat];
284}
285
286static const char *snd_pcm_tstamp_mode_name(int mode)
287{
288 return snd_pcm_tstamp_mode_names[mode];
289}
290
291static const char *snd_pcm_state_name(snd_pcm_state_t state)
292{
293 return snd_pcm_state_names[(__force int)state];
294}
295
296#if IS_ENABLED(CONFIG_SND_PCM_OSS)
297#include <linux/soundcard.h>
298
299static const char *snd_pcm_oss_format_name(int format)
300{
301 switch (format) {
302 case AFMT_MU_LAW:
303 return "MU_LAW";
304 case AFMT_A_LAW:
305 return "A_LAW";
306 case AFMT_IMA_ADPCM:
307 return "IMA_ADPCM";
308 case AFMT_U8:
309 return "U8";
310 case AFMT_S16_LE:
311 return "S16_LE";
312 case AFMT_S16_BE:
313 return "S16_BE";
314 case AFMT_S8:
315 return "S8";
316 case AFMT_U16_LE:
317 return "U16_LE";
318 case AFMT_U16_BE:
319 return "U16_BE";
320 case AFMT_MPEG:
321 return "MPEG";
322 default:
323 return "unknown";
324 }
325}
326#endif
327
328static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
329 struct snd_info_buffer *buffer)
330{
331 struct snd_pcm_info *info __free(kfree) = NULL;
332 int err;
333
334 if (! substream)
335 return;
336
337 info = kmalloc(size: sizeof(*info), GFP_KERNEL);
338 if (!info)
339 return;
340
341 err = snd_pcm_info(substream, info);
342 if (err < 0) {
343 snd_iprintf(buffer, "error %d\n", err);
344 return;
345 }
346 snd_iprintf(buffer, "card: %d\n", info->card);
347 snd_iprintf(buffer, "device: %d\n", info->device);
348 snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
349 snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
350 snd_iprintf(buffer, "id: %s\n", info->id);
351 snd_iprintf(buffer, "name: %s\n", info->name);
352 snd_iprintf(buffer, "subname: %s\n", info->subname);
353 snd_iprintf(buffer, "class: %d\n", info->dev_class);
354 snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
355 snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
356 snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
357}
358
359static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
360 struct snd_info_buffer *buffer)
361{
362 snd_pcm_proc_info_read(substream: ((struct snd_pcm_str *)entry->private_data)->substream,
363 buffer);
364}
365
366static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
367 struct snd_info_buffer *buffer)
368{
369 snd_pcm_proc_info_read(substream: entry->private_data, buffer);
370}
371
372static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
373 struct snd_info_buffer *buffer)
374{
375 struct snd_pcm_substream *substream = entry->private_data;
376 struct snd_pcm_runtime *runtime;
377
378 guard(mutex)(T: &substream->pcm->open_mutex);
379 runtime = substream->runtime;
380 if (!runtime) {
381 snd_iprintf(buffer, "closed\n");
382 return;
383 }
384 if (runtime->state == SNDRV_PCM_STATE_OPEN) {
385 snd_iprintf(buffer, "no setup\n");
386 return;
387 }
388 snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
389 snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
390 snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
391 snd_iprintf(buffer, "channels: %u\n", runtime->channels);
392 snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
393 snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
394 snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
395#if IS_ENABLED(CONFIG_SND_PCM_OSS)
396 if (substream->oss.oss) {
397 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
398 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
399 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
400 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
401 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
402 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
403 }
404#endif
405}
406
407static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
408 struct snd_info_buffer *buffer)
409{
410 struct snd_pcm_substream *substream = entry->private_data;
411 struct snd_pcm_runtime *runtime;
412
413 guard(mutex)(T: &substream->pcm->open_mutex);
414 runtime = substream->runtime;
415 if (!runtime) {
416 snd_iprintf(buffer, "closed\n");
417 return;
418 }
419 if (runtime->state == SNDRV_PCM_STATE_OPEN) {
420 snd_iprintf(buffer, "no setup\n");
421 return;
422 }
423 snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
424 snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
425 snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
426 snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
427 snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
428 snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
429 snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
430 snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
431}
432
433static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
434 struct snd_info_buffer *buffer)
435{
436 struct snd_pcm_substream *substream = entry->private_data;
437 struct snd_pcm_runtime *runtime;
438 struct snd_pcm_status64 status;
439 int err;
440
441 guard(mutex)(T: &substream->pcm->open_mutex);
442 runtime = substream->runtime;
443 if (!runtime) {
444 snd_iprintf(buffer, "closed\n");
445 return;
446 }
447 memset(&status, 0, sizeof(status));
448 err = snd_pcm_status64(substream, status: &status);
449 if (err < 0) {
450 snd_iprintf(buffer, "error %d\n", err);
451 return;
452 }
453 snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
454 snd_iprintf(buffer, "owner_pid : %d\n", pid_vnr(substream->pid));
455 snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
456 status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
457 snd_iprintf(buffer, "tstamp : %lld.%09lld\n",
458 status.tstamp_sec, status.tstamp_nsec);
459 snd_iprintf(buffer, "delay : %ld\n", status.delay);
460 snd_iprintf(buffer, "avail : %ld\n", status.avail);
461 snd_iprintf(buffer, "avail_max : %ld\n", status.avail_max);
462 snd_iprintf(buffer, "-----\n");
463 snd_iprintf(buffer, "hw_ptr : %ld\n", runtime->status->hw_ptr);
464 snd_iprintf(buffer, "appl_ptr : %ld\n", runtime->control->appl_ptr);
465}
466
467#ifdef CONFIG_SND_PCM_XRUN_DEBUG
468static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
469 struct snd_info_buffer *buffer)
470{
471 struct snd_pcm_substream *substream = entry->private_data;
472
473 snd_pcm_stop_xrun(substream);
474}
475
476static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
477 struct snd_info_buffer *buffer)
478{
479 struct snd_pcm_str *pstr = entry->private_data;
480 snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
481}
482
483static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
484 struct snd_info_buffer *buffer)
485{
486 struct snd_pcm_str *pstr = entry->private_data;
487 char line[64];
488 if (!snd_info_get_line(buffer, line, len: sizeof(line)))
489 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
490}
491#endif
492
493static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
494{
495 struct snd_pcm *pcm = pstr->pcm;
496 struct snd_info_entry *entry;
497 char name[16];
498
499 sprintf(buf: name, fmt: "pcm%i%c", pcm->device,
500 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
501 entry = snd_info_create_card_entry(card: pcm->card, name,
502 parent: pcm->card->proc_root);
503 if (!entry)
504 return -ENOMEM;
505 entry->mode = S_IFDIR | 0555;
506 pstr->proc_root = entry;
507 entry = snd_info_create_card_entry(card: pcm->card, name: "info", parent: pstr->proc_root);
508 if (entry)
509 snd_info_set_text_ops(entry, private_data: pstr, read: snd_pcm_stream_proc_info_read);
510#ifdef CONFIG_SND_PCM_XRUN_DEBUG
511 entry = snd_info_create_card_entry(card: pcm->card, name: "xrun_debug",
512 parent: pstr->proc_root);
513 if (entry) {
514 snd_info_set_text_ops(entry, private_data: pstr, read: snd_pcm_xrun_debug_read);
515 entry->c.text.write = snd_pcm_xrun_debug_write;
516 entry->mode |= 0200;
517 }
518#endif
519 return 0;
520}
521
522static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
523{
524 snd_info_free_entry(entry: pstr->proc_root);
525 pstr->proc_root = NULL;
526 return 0;
527}
528
529static struct snd_info_entry *
530create_substream_info_entry(struct snd_pcm_substream *substream,
531 const char *name,
532 void (*read)(struct snd_info_entry *,
533 struct snd_info_buffer *))
534{
535 struct snd_info_entry *entry;
536
537 entry = snd_info_create_card_entry(card: substream->pcm->card, name,
538 parent: substream->proc_root);
539 if (entry)
540 snd_info_set_text_ops(entry, private_data: substream, read);
541 return entry;
542}
543
544static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
545{
546 struct snd_info_entry *entry;
547 struct snd_card *card;
548 char name[16];
549
550 card = substream->pcm->card;
551
552 sprintf(buf: name, fmt: "sub%i", substream->number);
553 entry = snd_info_create_card_entry(card, name,
554 parent: substream->pstr->proc_root);
555 if (!entry)
556 return -ENOMEM;
557 entry->mode = S_IFDIR | 0555;
558 substream->proc_root = entry;
559
560 create_substream_info_entry(substream, name: "info",
561 read: snd_pcm_substream_proc_info_read);
562 create_substream_info_entry(substream, name: "hw_params",
563 read: snd_pcm_substream_proc_hw_params_read);
564 create_substream_info_entry(substream, name: "sw_params",
565 read: snd_pcm_substream_proc_sw_params_read);
566 create_substream_info_entry(substream, name: "status",
567 read: snd_pcm_substream_proc_status_read);
568
569#ifdef CONFIG_SND_PCM_XRUN_DEBUG
570 entry = create_substream_info_entry(substream, name: "xrun_injection", NULL);
571 if (entry) {
572 entry->c.text.write = snd_pcm_xrun_injection_write;
573 entry->mode = S_IFREG | 0200;
574 }
575#endif /* CONFIG_SND_PCM_XRUN_DEBUG */
576
577 return 0;
578}
579
580#else /* !CONFIG_SND_VERBOSE_PROCFS */
581static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
582static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
583static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
584#endif /* CONFIG_SND_VERBOSE_PROCFS */
585
586static const struct attribute_group *pcm_dev_attr_groups[];
587
588/*
589 * PM callbacks: we need to deal only with suspend here, as the resume is
590 * triggered either from user-space or the driver's resume callback
591 */
592#ifdef CONFIG_PM_SLEEP
593static int do_pcm_suspend(struct device *dev)
594{
595 struct snd_pcm_str *pstr = dev_get_drvdata(dev);
596
597 if (!pstr->pcm->no_device_suspend)
598 snd_pcm_suspend_all(pcm: pstr->pcm);
599 return 0;
600}
601#endif
602
603static const struct dev_pm_ops pcm_dev_pm_ops = {
604 SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
605};
606
607/* device type for PCM -- basically only for passing PM callbacks */
608static const struct device_type pcm_dev_type = {
609 .name = "pcm",
610 .pm = &pcm_dev_pm_ops,
611};
612
613/**
614 * snd_pcm_new_stream - create a new PCM stream
615 * @pcm: the pcm instance
616 * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
617 * @substream_count: the number of substreams
618 *
619 * Creates a new stream for the pcm.
620 * The corresponding stream on the pcm must have been empty before
621 * calling this, i.e. zero must be given to the argument of
622 * snd_pcm_new().
623 *
624 * Return: Zero if successful, or a negative error code on failure.
625 */
626int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
627{
628 int idx, err;
629 struct snd_pcm_str *pstr = &pcm->streams[stream];
630 struct snd_pcm_substream *substream, *prev;
631
632#if IS_ENABLED(CONFIG_SND_PCM_OSS)
633 mutex_init(&pstr->oss.setup_mutex);
634#endif
635 pstr->stream = stream;
636 pstr->pcm = pcm;
637 pstr->substream_count = substream_count;
638 if (!substream_count)
639 return 0;
640
641 err = snd_device_alloc(dev_p: &pstr->dev, card: pcm->card);
642 if (err < 0)
643 return err;
644 dev_set_name(dev: pstr->dev, name: "pcmC%iD%i%c", pcm->card->number, pcm->device,
645 stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
646 pstr->dev->groups = pcm_dev_attr_groups;
647 pstr->dev->type = &pcm_dev_type;
648 dev_set_drvdata(dev: pstr->dev, data: pstr);
649
650 if (!pcm->internal) {
651 err = snd_pcm_stream_proc_init(pstr);
652 if (err < 0) {
653 pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
654 return err;
655 }
656 }
657 prev = NULL;
658 for (idx = 0, prev = NULL; idx < substream_count; idx++) {
659 substream = kzalloc(size: sizeof(*substream), GFP_KERNEL);
660 if (!substream)
661 return -ENOMEM;
662 substream->pcm = pcm;
663 substream->pstr = pstr;
664 substream->number = idx;
665 substream->stream = stream;
666 sprintf(buf: substream->name, fmt: "subdevice #%i", idx);
667 substream->buffer_bytes_max = UINT_MAX;
668 if (prev == NULL)
669 pstr->substream = substream;
670 else
671 prev->next = substream;
672
673 if (!pcm->internal) {
674 err = snd_pcm_substream_proc_init(substream);
675 if (err < 0) {
676 pcm_err(pcm,
677 "Error in snd_pcm_stream_proc_init\n");
678 if (prev == NULL)
679 pstr->substream = NULL;
680 else
681 prev->next = NULL;
682 kfree(objp: substream);
683 return err;
684 }
685 }
686 substream->group = &substream->self_group;
687 snd_pcm_group_init(group: &substream->self_group);
688 list_add_tail(new: &substream->link_list, head: &substream->self_group.substreams);
689 atomic_set(v: &substream->mmap_count, i: 0);
690 prev = substream;
691 }
692 return 0;
693}
694EXPORT_SYMBOL(snd_pcm_new_stream);
695
696static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
697 int playback_count, int capture_count, bool internal,
698 struct snd_pcm **rpcm)
699{
700 struct snd_pcm *pcm;
701 int err;
702 static const struct snd_device_ops ops = {
703 .dev_free = snd_pcm_dev_free,
704 .dev_register = snd_pcm_dev_register,
705 .dev_disconnect = snd_pcm_dev_disconnect,
706 };
707 static const struct snd_device_ops internal_ops = {
708 .dev_free = snd_pcm_dev_free,
709 };
710
711 if (snd_BUG_ON(!card))
712 return -ENXIO;
713 if (rpcm)
714 *rpcm = NULL;
715 pcm = kzalloc(size: sizeof(*pcm), GFP_KERNEL);
716 if (!pcm)
717 return -ENOMEM;
718 pcm->card = card;
719 pcm->device = device;
720 pcm->internal = internal;
721 mutex_init(&pcm->open_mutex);
722 init_waitqueue_head(&pcm->open_wait);
723 INIT_LIST_HEAD(list: &pcm->list);
724 if (id)
725 strscpy(pcm->id, id, sizeof(pcm->id));
726
727 err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
728 playback_count);
729 if (err < 0)
730 goto free_pcm;
731
732 err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
733 if (err < 0)
734 goto free_pcm;
735
736 err = snd_device_new(card, type: SNDRV_DEV_PCM, device_data: pcm,
737 ops: internal ? &internal_ops : &ops);
738 if (err < 0)
739 goto free_pcm;
740
741 if (rpcm)
742 *rpcm = pcm;
743 return 0;
744
745free_pcm:
746 snd_pcm_free(pcm);
747 return err;
748}
749
750/**
751 * snd_pcm_new - create a new PCM instance
752 * @card: the card instance
753 * @id: the id string
754 * @device: the device index (zero based)
755 * @playback_count: the number of substreams for playback
756 * @capture_count: the number of substreams for capture
757 * @rpcm: the pointer to store the new pcm instance
758 *
759 * Creates a new PCM instance.
760 *
761 * The pcm operators have to be set afterwards to the new instance
762 * via snd_pcm_set_ops().
763 *
764 * Return: Zero if successful, or a negative error code on failure.
765 */
766int snd_pcm_new(struct snd_card *card, const char *id, int device,
767 int playback_count, int capture_count, struct snd_pcm **rpcm)
768{
769 return _snd_pcm_new(card, id, device, playback_count, capture_count,
770 internal: false, rpcm);
771}
772EXPORT_SYMBOL(snd_pcm_new);
773
774/**
775 * snd_pcm_new_internal - create a new internal PCM instance
776 * @card: the card instance
777 * @id: the id string
778 * @device: the device index (zero based - shared with normal PCMs)
779 * @playback_count: the number of substreams for playback
780 * @capture_count: the number of substreams for capture
781 * @rpcm: the pointer to store the new pcm instance
782 *
783 * Creates a new internal PCM instance with no userspace device or procfs
784 * entries. This is used by ASoC Back End PCMs in order to create a PCM that
785 * will only be used internally by kernel drivers. i.e. it cannot be opened
786 * by userspace. It provides existing ASoC components drivers with a substream
787 * and access to any private data.
788 *
789 * The pcm operators have to be set afterwards to the new instance
790 * via snd_pcm_set_ops().
791 *
792 * Return: Zero if successful, or a negative error code on failure.
793 */
794int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
795 int playback_count, int capture_count,
796 struct snd_pcm **rpcm)
797{
798 return _snd_pcm_new(card, id, device, playback_count, capture_count,
799 internal: true, rpcm);
800}
801EXPORT_SYMBOL(snd_pcm_new_internal);
802
803static void free_chmap(struct snd_pcm_str *pstr)
804{
805 if (pstr->chmap_kctl) {
806 struct snd_card *card = pstr->pcm->card;
807
808 snd_ctl_remove(card, kcontrol: pstr->chmap_kctl);
809 pstr->chmap_kctl = NULL;
810 }
811}
812
813static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
814{
815 struct snd_pcm_substream *substream, *substream_next;
816#if IS_ENABLED(CONFIG_SND_PCM_OSS)
817 struct snd_pcm_oss_setup *setup, *setupn;
818#endif
819
820 /* free all proc files under the stream */
821 snd_pcm_stream_proc_done(pstr);
822
823 substream = pstr->substream;
824 while (substream) {
825 substream_next = substream->next;
826 snd_pcm_timer_done(substream);
827 kfree(objp: substream);
828 substream = substream_next;
829 }
830#if IS_ENABLED(CONFIG_SND_PCM_OSS)
831 for (setup = pstr->oss.setup_list; setup; setup = setupn) {
832 setupn = setup->next;
833 kfree(objp: setup->task_name);
834 kfree(objp: setup);
835 }
836#endif
837 free_chmap(pstr);
838 if (pstr->substream_count)
839 put_device(dev: pstr->dev);
840}
841
842#if IS_ENABLED(CONFIG_SND_PCM_OSS)
843#define pcm_call_notify(pcm, call) \
844 do { \
845 struct snd_pcm_notify *_notify; \
846 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
847 _notify->call(pcm); \
848 } while (0)
849#else
850#define pcm_call_notify(pcm, call) do {} while (0)
851#endif
852
853static int snd_pcm_free(struct snd_pcm *pcm)
854{
855 if (!pcm)
856 return 0;
857 if (!pcm->internal)
858 pcm_call_notify(pcm, n_unregister);
859 if (pcm->private_free)
860 pcm->private_free(pcm);
861 snd_pcm_lib_preallocate_free_for_all(pcm);
862 snd_pcm_free_stream(pstr: &pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
863 snd_pcm_free_stream(pstr: &pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
864 kfree(objp: pcm);
865 return 0;
866}
867
868static int snd_pcm_dev_free(struct snd_device *device)
869{
870 struct snd_pcm *pcm = device->device_data;
871 return snd_pcm_free(pcm);
872}
873
874int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
875 struct file *file,
876 struct snd_pcm_substream **rsubstream)
877{
878 struct snd_pcm_str * pstr;
879 struct snd_pcm_substream *substream;
880 struct snd_pcm_runtime *runtime;
881 struct snd_card *card;
882 int prefer_subdevice;
883 size_t size;
884
885 if (snd_BUG_ON(!pcm || !rsubstream))
886 return -ENXIO;
887 if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
888 stream != SNDRV_PCM_STREAM_CAPTURE))
889 return -EINVAL;
890 *rsubstream = NULL;
891 pstr = &pcm->streams[stream];
892 if (pstr->substream == NULL || pstr->substream_count == 0)
893 return -ENODEV;
894
895 card = pcm->card;
896 prefer_subdevice = snd_ctl_get_preferred_subdevice(card, type: SND_CTL_SUBDEV_PCM);
897
898 if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
899 int opposite = !stream;
900
901 for (substream = pcm->streams[opposite].substream; substream;
902 substream = substream->next) {
903 if (SUBSTREAM_BUSY(substream))
904 return -EAGAIN;
905 }
906 }
907
908 if (file->f_flags & O_APPEND) {
909 if (prefer_subdevice < 0) {
910 if (pstr->substream_count > 1)
911 return -EINVAL; /* must be unique */
912 substream = pstr->substream;
913 } else {
914 for (substream = pstr->substream; substream;
915 substream = substream->next)
916 if (substream->number == prefer_subdevice)
917 break;
918 }
919 if (! substream)
920 return -ENODEV;
921 if (! SUBSTREAM_BUSY(substream))
922 return -EBADFD;
923 substream->ref_count++;
924 *rsubstream = substream;
925 return 0;
926 }
927
928 for (substream = pstr->substream; substream; substream = substream->next) {
929 if (!SUBSTREAM_BUSY(substream) &&
930 (prefer_subdevice == -1 ||
931 substream->number == prefer_subdevice))
932 break;
933 }
934 if (substream == NULL)
935 return -EAGAIN;
936
937 runtime = kzalloc(size: sizeof(*runtime), GFP_KERNEL);
938 if (runtime == NULL)
939 return -ENOMEM;
940
941 size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
942 runtime->status = alloc_pages_exact(size, GFP_KERNEL);
943 if (runtime->status == NULL) {
944 kfree(objp: runtime);
945 return -ENOMEM;
946 }
947 memset(runtime->status, 0, size);
948
949 size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
950 runtime->control = alloc_pages_exact(size, GFP_KERNEL);
951 if (runtime->control == NULL) {
952 free_pages_exact(virt: runtime->status,
953 PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
954 kfree(objp: runtime);
955 return -ENOMEM;
956 }
957 memset(runtime->control, 0, size);
958
959 init_waitqueue_head(&runtime->sleep);
960 init_waitqueue_head(&runtime->tsleep);
961
962 __snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
963 mutex_init(&runtime->buffer_mutex);
964 atomic_set(v: &runtime->buffer_accessing, i: 0);
965
966 substream->runtime = runtime;
967 substream->private_data = pcm->private_data;
968 substream->ref_count = 1;
969 substream->f_flags = file->f_flags;
970 substream->pid = get_pid(pid: task_pid(current));
971 pstr->substream_opened++;
972 *rsubstream = substream;
973 return 0;
974}
975
976void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
977{
978 struct snd_pcm_runtime *runtime;
979
980 if (PCM_RUNTIME_CHECK(substream))
981 return;
982 runtime = substream->runtime;
983 if (runtime->private_free != NULL)
984 runtime->private_free(runtime);
985 free_pages_exact(virt: runtime->status,
986 PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
987 free_pages_exact(virt: runtime->control,
988 PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
989 kfree(objp: runtime->hw_constraints.rules);
990 /* Avoid concurrent access to runtime via PCM timer interface */
991 if (substream->timer) {
992 scoped_guard(spinlock_irq, &substream->timer->lock)
993 substream->runtime = NULL;
994 } else {
995 substream->runtime = NULL;
996 }
997 mutex_destroy(lock: &runtime->buffer_mutex);
998 snd_fasync_free(fasync: runtime->fasync);
999 kfree(objp: runtime);
1000 put_pid(pid: substream->pid);
1001 substream->pid = NULL;
1002 substream->pstr->substream_opened--;
1003}
1004
1005static ssize_t pcm_class_show(struct device *dev,
1006 struct device_attribute *attr, char *buf)
1007{
1008 struct snd_pcm_str *pstr = dev_get_drvdata(dev);
1009 struct snd_pcm *pcm = pstr->pcm;
1010 const char *str;
1011 static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1012 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1013 [SNDRV_PCM_CLASS_MULTI] = "multi",
1014 [SNDRV_PCM_CLASS_MODEM] = "modem",
1015 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1016 };
1017
1018 if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1019 str = "none";
1020 else
1021 str = strs[pcm->dev_class];
1022 return sysfs_emit(buf, fmt: "%s\n", str);
1023}
1024
1025static DEVICE_ATTR_RO(pcm_class);
1026static struct attribute *pcm_dev_attrs[] = {
1027 &dev_attr_pcm_class.attr,
1028 NULL
1029};
1030
1031static const struct attribute_group pcm_dev_attr_group = {
1032 .attrs = pcm_dev_attrs,
1033};
1034
1035static const struct attribute_group *pcm_dev_attr_groups[] = {
1036 &pcm_dev_attr_group,
1037 NULL
1038};
1039
1040static int snd_pcm_dev_register(struct snd_device *device)
1041{
1042 int cidx, err;
1043 struct snd_pcm_substream *substream;
1044 struct snd_pcm *pcm;
1045
1046 if (snd_BUG_ON(!device || !device->device_data))
1047 return -ENXIO;
1048 pcm = device->device_data;
1049
1050 guard(mutex)(T: &register_mutex);
1051 err = snd_pcm_add(newpcm: pcm);
1052 if (err)
1053 return err;
1054 for (cidx = 0; cidx < 2; cidx++) {
1055 int devtype = -1;
1056 if (pcm->streams[cidx].substream == NULL)
1057 continue;
1058 switch (cidx) {
1059 case SNDRV_PCM_STREAM_PLAYBACK:
1060 devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1061 break;
1062 case SNDRV_PCM_STREAM_CAPTURE:
1063 devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1064 break;
1065 }
1066 /* register pcm */
1067 err = snd_register_device(type: devtype, card: pcm->card, dev: pcm->device,
1068 f_ops: &snd_pcm_f_ops[cidx], private_data: pcm,
1069 device: pcm->streams[cidx].dev);
1070 if (err < 0) {
1071 list_del_init(entry: &pcm->list);
1072 return err;
1073 }
1074
1075 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1076 snd_pcm_timer_init(substream);
1077 }
1078
1079 pcm_call_notify(pcm, n_register);
1080 return err;
1081}
1082
1083static int snd_pcm_dev_disconnect(struct snd_device *device)
1084{
1085 struct snd_pcm *pcm = device->device_data;
1086 struct snd_pcm_substream *substream;
1087 int cidx;
1088
1089 guard(mutex)(T: &register_mutex);
1090 guard(mutex)(T: &pcm->open_mutex);
1091 wake_up(&pcm->open_wait);
1092 list_del_init(entry: &pcm->list);
1093
1094 for_each_pcm_substream(pcm, cidx, substream) {
1095 snd_pcm_stream_lock_irq(substream);
1096 if (substream->runtime) {
1097 if (snd_pcm_running(substream))
1098 snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1099 /* to be sure, set the state unconditionally */
1100 __snd_pcm_set_state(runtime: substream->runtime,
1101 SNDRV_PCM_STATE_DISCONNECTED);
1102 wake_up(&substream->runtime->sleep);
1103 wake_up(&substream->runtime->tsleep);
1104 }
1105 snd_pcm_stream_unlock_irq(substream);
1106 }
1107
1108 for_each_pcm_substream(pcm, cidx, substream)
1109 snd_pcm_sync_stop(substream, sync_irq: false);
1110
1111 pcm_call_notify(pcm, n_disconnect);
1112 for (cidx = 0; cidx < 2; cidx++) {
1113 if (pcm->streams[cidx].dev)
1114 snd_unregister_device(dev: pcm->streams[cidx].dev);
1115 free_chmap(pstr: &pcm->streams[cidx]);
1116 }
1117 return 0;
1118}
1119
1120#if IS_ENABLED(CONFIG_SND_PCM_OSS)
1121/**
1122 * snd_pcm_notify - Add/remove the notify list
1123 * @notify: PCM notify list
1124 * @nfree: 0 = register, 1 = unregister
1125 *
1126 * This adds the given notifier to the global list so that the callback is
1127 * called for each registered PCM devices. This exists only for PCM OSS
1128 * emulation, so far.
1129 *
1130 * Return: zero if successful, or a negative error code
1131 */
1132int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1133{
1134 struct snd_pcm *pcm;
1135
1136 if (snd_BUG_ON(!notify ||
1137 !notify->n_register ||
1138 !notify->n_unregister ||
1139 !notify->n_disconnect))
1140 return -EINVAL;
1141 guard(mutex)(T: &register_mutex);
1142 if (nfree) {
1143 list_del(entry: &notify->list);
1144 list_for_each_entry(pcm, &snd_pcm_devices, list)
1145 notify->n_unregister(pcm);
1146 } else {
1147 list_add_tail(new: &notify->list, head: &snd_pcm_notify_list);
1148 list_for_each_entry(pcm, &snd_pcm_devices, list)
1149 notify->n_register(pcm);
1150 }
1151 return 0;
1152}
1153EXPORT_SYMBOL(snd_pcm_notify);
1154#endif /* CONFIG_SND_PCM_OSS */
1155
1156#ifdef CONFIG_SND_PROC_FS
1157/*
1158 * Info interface
1159 */
1160
1161static void snd_pcm_proc_read(struct snd_info_entry *entry,
1162 struct snd_info_buffer *buffer)
1163{
1164 struct snd_pcm *pcm;
1165
1166 guard(mutex)(T: &register_mutex);
1167 list_for_each_entry(pcm, &snd_pcm_devices, list) {
1168 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1169 pcm->card->number, pcm->device, pcm->id, pcm->name);
1170 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1171 snd_iprintf(buffer, " : playback %i",
1172 pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1173 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1174 snd_iprintf(buffer, " : capture %i",
1175 pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1176 snd_iprintf(buffer, "\n");
1177 }
1178}
1179
1180static struct snd_info_entry *snd_pcm_proc_entry;
1181
1182static void snd_pcm_proc_init(void)
1183{
1184 struct snd_info_entry *entry;
1185
1186 entry = snd_info_create_module_entry(THIS_MODULE, name: "pcm", NULL);
1187 if (entry) {
1188 snd_info_set_text_ops(entry, NULL, read: snd_pcm_proc_read);
1189 if (snd_info_register(entry) < 0) {
1190 snd_info_free_entry(entry);
1191 entry = NULL;
1192 }
1193 }
1194 snd_pcm_proc_entry = entry;
1195}
1196
1197static void snd_pcm_proc_done(void)
1198{
1199 snd_info_free_entry(entry: snd_pcm_proc_entry);
1200}
1201
1202#else /* !CONFIG_SND_PROC_FS */
1203#define snd_pcm_proc_init()
1204#define snd_pcm_proc_done()
1205#endif /* CONFIG_SND_PROC_FS */
1206
1207
1208/*
1209 * ENTRY functions
1210 */
1211
1212static int __init alsa_pcm_init(void)
1213{
1214 snd_ctl_register_ioctl(fcn: snd_pcm_control_ioctl);
1215 snd_ctl_register_ioctl_compat(fcn: snd_pcm_control_ioctl);
1216 snd_pcm_proc_init();
1217 return 0;
1218}
1219
1220static void __exit alsa_pcm_exit(void)
1221{
1222 snd_ctl_unregister_ioctl(fcn: snd_pcm_control_ioctl);
1223 snd_ctl_unregister_ioctl_compat(fcn: snd_pcm_control_ioctl);
1224 snd_pcm_proc_done();
1225}
1226
1227module_init(alsa_pcm_init)
1228module_exit(alsa_pcm_exit)
1229

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