sound/core/pcm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Digital Audio (PCM) abstract layer
   4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   5  */
   6
   7 #include <linux/init.h>
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10 #include <linux/time.h>
  11 #include <linux/mutex.h>
  12 #include <linux/device.h>
  13 #include <linux/nospec.h>
  14 #include <sound/core.h>
  15 #include <sound/minors.h>
  16 #include <sound/pcm.h>
  17 #include <sound/timer.h>
  18 #include <sound/control.h>
  19 #include <sound/info.h>
  20
  21 #include "pcm_local.h"
  22
  23 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  24 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  25 MODULE_LICENSE("GPL");
  26
  27 static LIST_HEAD(snd_pcm_devices);
  28 static DEFINE_MUTEX(register_mutex);
  29 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  30 static LIST_HEAD(snd_pcm_notify_list);
  31 #endif
  32
  33 static int snd_pcm_free(struct snd_pcm *pcm);
  34 static int snd_pcm_dev_free(struct snd_device *device);
  35 static int snd_pcm_dev_register(struct snd_device *device);
  36 static int snd_pcm_dev_disconnect(struct snd_device *device);
  37
  38 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  39 {
  40         struct snd_pcm *pcm;
  41
  42         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  43                 if (pcm->card == card && pcm->device == device)
  44                         return pcm;
  45         }
  46         return NULL;
  47 }
  48
  49 static int snd_pcm_next(struct snd_card *card, int device)
  50 {
  51         struct snd_pcm *pcm;
  52
  53         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  54                 if (pcm->card == card && pcm->device > device)
  55                         return pcm->device;
  56                 else if (pcm->card->number > card->number)
  57                         return -1;
  58         }
  59         return -1;
  60 }
  61
  62 static int snd_pcm_add(struct snd_pcm *newpcm)
  63 {
  64         struct snd_pcm *pcm;
  65
  66         if (newpcm->internal)
  67                 return 0;
  68
  69         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  70                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  71                         return -EBUSY;
  72                 if (pcm->card->number > newpcm->card->number ||
  73                                 (pcm->card == newpcm->card &&
  74                                 pcm->device > newpcm->device)) {
  75                         list_add(&newpcm->list, pcm->list.prev);
  76                         return 0;
  77                 }
  78         }
  79         list_add_tail(&newpcm->list, &snd_pcm_devices);
  80         return 0;
  81 }
  82
  83 static int snd_pcm_control_ioctl(struct snd_card *card,
  84                                  struct snd_ctl_file *control,
  85                                  unsigned int cmd, unsigned long arg)
  86 {
  87         switch (cmd) {
  88         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
  89                 {
  90                         int device;
  91
  92                         if (get_user(device, (int __user *)arg))
  93                                 return -EFAULT;
  94                         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)(&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)(&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
 152 static 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  */
 212 const 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 }
 220 EXPORT_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
 234 static const char * const snd_pcm_stream_names[] = {
 235         STREAM(PLAYBACK),
 236         STREAM(CAPTURE),
 237 };
 238
 239 static 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
 251 static 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
 259 static const char * const snd_pcm_subformat_names[] = {
 260         SUBFORMAT(STD),
 261         SUBFORMAT(MSBITS_MAX),
 262         SUBFORMAT(MSBITS_20),
 263         SUBFORMAT(MSBITS_24),
 264 };
 265
 266 static const char * const snd_pcm_tstamp_mode_names[] = {
 267         TSTAMP(NONE),
 268         TSTAMP(ENABLE),
 269 };
 270
 271 static const char *snd_pcm_stream_name(int stream)
 272 {
 273         return snd_pcm_stream_names[stream];
 274 }
 275
 276 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 277 {
 278         return snd_pcm_access_names[(__force int)access];
 279 }
 280
 281 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 282 {
 283         return snd_pcm_subformat_names[(__force int)subformat];
 284 }
 285
 286 static const char *snd_pcm_tstamp_mode_name(int mode)
 287 {
 288         return snd_pcm_tstamp_mode_names[mode];
 289 }
 290
 291 static 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
 299 static 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
 328 static 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(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
 359 static 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(((struct snd_pcm_str *)entry->private_data)->substream,
 363                                buffer);
 364 }
 365
 366 static 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(entry->private_data, buffer);
 370 }
 371
 372 static 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)(&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
 407 static 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)(&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
 433 static 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)(&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);
 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 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 466         snd_iprintf(buffer, "xrun_counter: %d\n", substream->xrun_counter);
 467 #endif
 468 }
 469
 470 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 471 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 472                                          struct snd_info_buffer *buffer)
 473 {
 474         struct snd_pcm_substream *substream = entry->private_data;
 475
 476         snd_pcm_stop_xrun(substream);
 477 }
 478
 479 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 480                                     struct snd_info_buffer *buffer)
 481 {
 482         struct snd_pcm_str *pstr = entry->private_data;
 483         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 484 }
 485
 486 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 487                                      struct snd_info_buffer *buffer)
 488 {
 489         struct snd_pcm_str *pstr = entry->private_data;
 490         char line[64];
 491         if (!snd_info_get_line(buffer, line, sizeof(line)))
 492                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 493 }
 494 #endif
 495
 496 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 497 {
 498         struct snd_pcm *pcm = pstr->pcm;
 499         struct snd_info_entry *entry;
 500         char name[16];
 501
 502         sprintf(name, "pcm%i%c", pcm->device,
 503                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 504         entry = snd_info_create_card_entry(pcm->card, name,
 505                                            pcm->card->proc_root);
 506         if (!entry)
 507                 return -ENOMEM;
 508         entry->mode = S_IFDIR | 0555;
 509         pstr->proc_root = entry;
 510         entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
 511         if (entry)
 512                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 513 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 514         entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 515                                            pstr->proc_root);
 516         if (entry) {
 517                 snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
 518                 entry->c.text.write = snd_pcm_xrun_debug_write;
 519                 entry->mode |= 0200;
 520         }
 521 #endif
 522         return 0;
 523 }
 524
 525 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 526 {
 527         snd_info_free_entry(pstr->proc_root);
 528         pstr->proc_root = NULL;
 529         return 0;
 530 }
 531
 532 static struct snd_info_entry *
 533 create_substream_info_entry(struct snd_pcm_substream *substream,
 534                             const char *name,
 535                             void (*read)(struct snd_info_entry *,
 536                                          struct snd_info_buffer *))
 537 {
 538         struct snd_info_entry *entry;
 539
 540         entry = snd_info_create_card_entry(substream->pcm->card, name,
 541                                            substream->proc_root);
 542         if (entry)
 543                 snd_info_set_text_ops(entry, substream, read);
 544         return entry;
 545 }
 546
 547 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 548 {
 549         struct snd_info_entry *entry;
 550         struct snd_card *card;
 551         char name[16];
 552
 553         card = substream->pcm->card;
 554
 555         sprintf(name, "sub%i", substream->number);
 556         entry = snd_info_create_card_entry(card, name,
 557                                            substream->pstr->proc_root);
 558         if (!entry)
 559                 return -ENOMEM;
 560         entry->mode = S_IFDIR | 0555;
 561         substream->proc_root = entry;
 562
 563         create_substream_info_entry(substream, "info",
 564                                     snd_pcm_substream_proc_info_read);
 565         create_substream_info_entry(substream, "hw_params",
 566                                     snd_pcm_substream_proc_hw_params_read);
 567         create_substream_info_entry(substream, "sw_params",
 568                                     snd_pcm_substream_proc_sw_params_read);
 569         create_substream_info_entry(substream, "status",
 570                                     snd_pcm_substream_proc_status_read);
 571
 572 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 573         entry = create_substream_info_entry(substream, "xrun_injection", NULL);
 574         if (entry) {
 575                 entry->c.text.write = snd_pcm_xrun_injection_write;
 576                 entry->mode = S_IFREG | 0200;
 577         }
 578 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 579
 580         return 0;
 581 }
 582
 583 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 584 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 585 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 586 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 587 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 588
 589 static const struct attribute_group *pcm_dev_attr_groups[];
 590
 591 /*
 592  * PM callbacks: we need to deal only with suspend here, as the resume is
 593  * triggered either from user-space or the driver's resume callback
 594  */
 595 #ifdef CONFIG_PM_SLEEP
 596 static int do_pcm_suspend(struct device *dev)
 597 {
 598         struct snd_pcm_str *pstr = dev_get_drvdata(dev);
 599
 600         if (!pstr->pcm->no_device_suspend)
 601                 snd_pcm_suspend_all(pstr->pcm);
 602         return 0;
 603 }
 604 #endif
 605
 606 static const struct dev_pm_ops pcm_dev_pm_ops = {
 607         SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
 608 };
 609
 610 /* device type for PCM -- basically only for passing PM callbacks */
 611 static const struct device_type pcm_dev_type = {
 612         .name = "pcm",
 613         .pm = &pcm_dev_pm_ops,
 614 };
 615
 616 /**
 617  * snd_pcm_new_stream - create a new PCM stream
 618  * @pcm: the pcm instance
 619  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 620  * @substream_count: the number of substreams
 621  *
 622  * Creates a new stream for the pcm.
 623  * The corresponding stream on the pcm must have been empty before
 624  * calling this, i.e. zero must be given to the argument of
 625  * snd_pcm_new().
 626  *
 627  * Return: Zero if successful, or a negative error code on failure.
 628  */
 629 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 630 {
 631         int idx, err;
 632         struct snd_pcm_str *pstr = &pcm->streams[stream];
 633         struct snd_pcm_substream *substream, *prev;
 634
 635 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 636         mutex_init(&pstr->oss.setup_mutex);
 637 #endif
 638         pstr->stream = stream;
 639         pstr->pcm = pcm;
 640         pstr->substream_count = substream_count;
 641         if (!substream_count)
 642                 return 0;
 643
 644         err = snd_device_alloc(&pstr->dev, pcm->card);
 645         if (err < 0)
 646                 return err;
 647         dev_set_name(pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 648                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 649         pstr->dev->groups = pcm_dev_attr_groups;
 650         pstr->dev->type = &pcm_dev_type;
 651         dev_set_drvdata(pstr->dev, pstr);
 652
 653         if (!pcm->internal) {
 654                 err = snd_pcm_stream_proc_init(pstr);
 655                 if (err < 0) {
 656                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 657                         return err;
 658                 }
 659         }
 660         prev = NULL;
 661         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 662                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 663                 if (!substream)
 664                         return -ENOMEM;
 665                 substream->pcm = pcm;
 666                 substream->pstr = pstr;
 667                 substream->number = idx;
 668                 substream->stream = stream;
 669                 sprintf(substream->name, "subdevice #%i", idx);
 670                 substream->buffer_bytes_max = UINT_MAX;
 671                 if (prev == NULL)
 672                         pstr->substream = substream;
 673                 else
 674                         prev->next = substream;
 675
 676                 if (!pcm->internal) {
 677                         err = snd_pcm_substream_proc_init(substream);
 678                         if (err < 0) {
 679                                 pcm_err(pcm,
 680                                         "Error in snd_pcm_stream_proc_init\n");
 681                                 if (prev == NULL)
 682                                         pstr->substream = NULL;
 683                                 else
 684                                         prev->next = NULL;
 685                                 kfree(substream);
 686                                 return err;
 687                         }
 688                 }
 689                 substream->group = &substream->self_group;
 690                 snd_pcm_group_init(&substream->self_group);
 691                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 692                 atomic_set(&substream->mmap_count, 0);
 693                 prev = substream;
 694         }
 695         return 0;
 696 }
 697 EXPORT_SYMBOL(snd_pcm_new_stream);
 698
 699 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 700                 int playback_count, int capture_count, bool internal,
 701                 struct snd_pcm **rpcm)
 702 {
 703         struct snd_pcm *pcm;
 704         int err;
 705         static const struct snd_device_ops ops = {
 706                 .dev_free = snd_pcm_dev_free,
 707                 .dev_register = snd_pcm_dev_register,
 708                 .dev_disconnect = snd_pcm_dev_disconnect,
 709         };
 710         static const struct snd_device_ops internal_ops = {
 711                 .dev_free = snd_pcm_dev_free,
 712         };
 713
 714         if (snd_BUG_ON(!card))
 715                 return -ENXIO;
 716         if (rpcm)
 717                 *rpcm = NULL;
 718         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 719         if (!pcm)
 720                 return -ENOMEM;
 721         pcm->card = card;
 722         pcm->device = device;
 723         pcm->internal = internal;
 724         mutex_init(&pcm->open_mutex);
 725         init_waitqueue_head(&pcm->open_wait);
 726         INIT_LIST_HEAD(&pcm->list);
 727         if (id)
 728                 strscpy(pcm->id, id, sizeof(pcm->id));
 729
 730         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 731                                  playback_count);
 732         if (err < 0)
 733                 goto free_pcm;
 734
 735         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
 736         if (err < 0)
 737                 goto free_pcm;
 738
 739         err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
 740                              internal ? &internal_ops : &ops);
 741         if (err < 0)
 742                 goto free_pcm;
 743
 744         if (rpcm)
 745                 *rpcm = pcm;
 746         return 0;
 747
 748 free_pcm:
 749         snd_pcm_free(pcm);
 750         return err;
 751 }
 752
 753 /**
 754  * snd_pcm_new - create a new PCM instance
 755  * @card: the card instance
 756  * @id: the id string
 757  * @device: the device index (zero based)
 758  * @playback_count: the number of substreams for playback
 759  * @capture_count: the number of substreams for capture
 760  * @rpcm: the pointer to store the new pcm instance
 761  *
 762  * Creates a new PCM instance.
 763  *
 764  * The pcm operators have to be set afterwards to the new instance
 765  * via snd_pcm_set_ops().
 766  *
 767  * Return: Zero if successful, or a negative error code on failure.
 768  */
 769 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 770                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 771 {
 772         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 773                         false, rpcm);
 774 }
 775 EXPORT_SYMBOL(snd_pcm_new);
 776
 777 /**
 778  * snd_pcm_new_internal - create a new internal PCM instance
 779  * @card: the card instance
 780  * @id: the id string
 781  * @device: the device index (zero based - shared with normal PCMs)
 782  * @playback_count: the number of substreams for playback
 783  * @capture_count: the number of substreams for capture
 784  * @rpcm: the pointer to store the new pcm instance
 785  *
 786  * Creates a new internal PCM instance with no userspace device or procfs
 787  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 788  * will only be used internally by kernel drivers. i.e. it cannot be opened
 789  * by userspace. It provides existing ASoC components drivers with a substream
 790  * and access to any private data.
 791  *
 792  * The pcm operators have to be set afterwards to the new instance
 793  * via snd_pcm_set_ops().
 794  *
 795  * Return: Zero if successful, or a negative error code on failure.
 796  */
 797 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 798         int playback_count, int capture_count,
 799         struct snd_pcm **rpcm)
 800 {
 801         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 802                         true, rpcm);
 803 }
 804 EXPORT_SYMBOL(snd_pcm_new_internal);
 805
 806 static void free_chmap(struct snd_pcm_str *pstr)
 807 {
 808         if (pstr->chmap_kctl) {
 809                 struct snd_card *card = pstr->pcm->card;
 810
 811                 snd_ctl_remove(card, pstr->chmap_kctl);
 812                 pstr->chmap_kctl = NULL;
 813         }
 814 }
 815
 816 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 817 {
 818         struct snd_pcm_substream *substream, *substream_next;
 819 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 820         struct snd_pcm_oss_setup *setup, *setupn;
 821 #endif
 822
 823         /* free all proc files under the stream */
 824         snd_pcm_stream_proc_done(pstr);
 825
 826         substream = pstr->substream;
 827         while (substream) {
 828                 substream_next = substream->next;
 829                 snd_pcm_timer_done(substream);
 830                 kfree(substream);
 831                 substream = substream_next;
 832         }
 833 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 834         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 835                 setupn = setup->next;
 836                 kfree(setup->task_name);
 837                 kfree(setup);
 838         }
 839 #endif
 840         free_chmap(pstr);
 841         if (pstr->substream_count)
 842                 put_device(pstr->dev);
 843 }
 844
 845 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 846 #define pcm_call_notify(pcm, call)                                      \
 847         do {                                                            \
 848                 struct snd_pcm_notify *_notify;                         \
 849                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 850                         _notify->call(pcm);                             \
 851         } while (0)
 852 #else
 853 #define pcm_call_notify(pcm, call) do {} while (0)
 854 #endif
 855
 856 static int snd_pcm_free(struct snd_pcm *pcm)
 857 {
 858         if (!pcm)
 859                 return 0;
 860         if (!pcm->internal)
 861                 pcm_call_notify(pcm, n_unregister);
 862         if (pcm->private_free)
 863                 pcm->private_free(pcm);
 864         snd_pcm_lib_preallocate_free_for_all(pcm);
 865         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 866         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 867         kfree(pcm);
 868         return 0;
 869 }
 870
 871 static int snd_pcm_dev_free(struct snd_device *device)
 872 {
 873         struct snd_pcm *pcm = device->device_data;
 874         return snd_pcm_free(pcm);
 875 }
 876
 877 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 878                              struct file *file,
 879                              struct snd_pcm_substream **rsubstream)
 880 {
 881         struct snd_pcm_str * pstr;
 882         struct snd_pcm_substream *substream;
 883         struct snd_pcm_runtime *runtime;
 884         struct snd_card *card;
 885         int prefer_subdevice;
 886         size_t size;
 887
 888         if (snd_BUG_ON(!pcm || !rsubstream))
 889                 return -ENXIO;
 890         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 891                        stream != SNDRV_PCM_STREAM_CAPTURE))
 892                 return -EINVAL;
 893         *rsubstream = NULL;
 894         pstr = &pcm->streams[stream];
 895         if (pstr->substream == NULL || pstr->substream_count == 0)
 896                 return -ENODEV;
 897
 898         card = pcm->card;
 899         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 900
 901         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 902                 int opposite = !stream;
 903
 904                 for (substream = pcm->streams[opposite].substream; substream;
 905                      substream = substream->next) {
 906                         if (SUBSTREAM_BUSY(substream))
 907                                 return -EAGAIN;
 908                 }
 909         }
 910
 911         if (file->f_flags & O_APPEND) {
 912                 if (prefer_subdevice < 0) {
 913                         if (pstr->substream_count > 1)
 914                                 return -EINVAL; /* must be unique */
 915                         substream = pstr->substream;
 916                 } else {
 917                         for (substream = pstr->substream; substream;
 918                              substream = substream->next)
 919                                 if (substream->number == prefer_subdevice)
 920                                         break;
 921                 }
 922                 if (! substream)
 923                         return -ENODEV;
 924                 if (! SUBSTREAM_BUSY(substream))
 925                         return -EBADFD;
 926                 substream->ref_count++;
 927                 *rsubstream = substream;
 928                 return 0;
 929         }
 930
 931         for (substream = pstr->substream; substream; substream = substream->next) {
 932                 if (!SUBSTREAM_BUSY(substream) &&
 933                     (prefer_subdevice == -1 ||
 934                      substream->number == prefer_subdevice))
 935                         break;
 936         }
 937         if (substream == NULL)
 938                 return -EAGAIN;
 939
 940         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 941         if (runtime == NULL)
 942                 return -ENOMEM;
 943
 944         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 945         runtime->status = alloc_pages_exact(size, GFP_KERNEL);
 946         if (runtime->status == NULL) {
 947                 kfree(runtime);
 948                 return -ENOMEM;
 949         }
 950         memset(runtime->status, 0, size);
 951
 952         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 953         runtime->control = alloc_pages_exact(size, GFP_KERNEL);
 954         if (runtime->control == NULL) {
 955                 free_pages_exact(runtime->status,
 956                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 957                 kfree(runtime);
 958                 return -ENOMEM;
 959         }
 960         memset(runtime->control, 0, size);
 961
 962         init_waitqueue_head(&runtime->sleep);
 963         init_waitqueue_head(&runtime->tsleep);
 964
 965         __snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
 966         mutex_init(&runtime->buffer_mutex);
 967         atomic_set(&runtime->buffer_accessing, 0);
 968
 969         substream->runtime = runtime;
 970         substream->private_data = pcm->private_data;
 971         substream->ref_count = 1;
 972         substream->f_flags = file->f_flags;
 973         substream->pid = get_pid(task_pid(current));
 974         pstr->substream_opened++;
 975         *rsubstream = substream;
 976 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 977         substream->xrun_counter = 0;
 978 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 979         return 0;
 980 }
 981
 982 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 983 {
 984         struct snd_pcm_runtime *runtime;
 985
 986         if (PCM_RUNTIME_CHECK(substream))
 987                 return;
 988         runtime = substream->runtime;
 989         if (runtime->private_free != NULL)
 990                 runtime->private_free(runtime);
 991         free_pages_exact(runtime->status,
 992                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 993         free_pages_exact(runtime->control,
 994                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
 995         kfree(runtime->hw_constraints.rules);
 996         /* Avoid concurrent access to runtime via PCM timer interface */
 997         if (substream->timer) {
 998                 scoped_guard(spinlock_irq, &substream->timer->lock)
 999                         substream->runtime = NULL;
1000         } else {
1001                 substream->runtime = NULL;
1002         }
1003         mutex_destroy(&runtime->buffer_mutex);
1004         snd_fasync_free(runtime->fasync);
1005         kfree(runtime);
1006         put_pid(substream->pid);
1007         substream->pid = NULL;
1008         substream->pstr->substream_opened--;
1009 }
1010
1011 static ssize_t pcm_class_show(struct device *dev,
1012                               struct device_attribute *attr, char *buf)
1013 {
1014         struct snd_pcm_str *pstr = dev_get_drvdata(dev);
1015         struct snd_pcm *pcm = pstr->pcm;
1016         const char *str;
1017         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1018                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1019                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1020                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1021                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1022         };
1023
1024         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1025                 str = "none";
1026         else
1027                 str = strs[pcm->dev_class];
1028         return sysfs_emit(buf, "%s\n", str);
1029 }
1030
1031 static DEVICE_ATTR_RO(pcm_class);
1032 static struct attribute *pcm_dev_attrs[] = {
1033         &dev_attr_pcm_class.attr,
1034         NULL
1035 };
1036
1037 static const struct attribute_group pcm_dev_attr_group = {
1038         .attrs  = pcm_dev_attrs,
1039 };
1040
1041 static const struct attribute_group *pcm_dev_attr_groups[] = {
1042         &pcm_dev_attr_group,
1043         NULL
1044 };
1045
1046 static int snd_pcm_dev_register(struct snd_device *device)
1047 {
1048         int cidx, err;
1049         struct snd_pcm_substream *substream;
1050         struct snd_pcm *pcm;
1051
1052         if (snd_BUG_ON(!device || !device->device_data))
1053                 return -ENXIO;
1054         pcm = device->device_data;
1055
1056         guard(mutex)(&register_mutex);
1057         err = snd_pcm_add(pcm);
1058         if (err)
1059                 return err;
1060         for (cidx = 0; cidx < 2; cidx++) {
1061                 int devtype = -1;
1062                 if (pcm->streams[cidx].substream == NULL)
1063                         continue;
1064                 switch (cidx) {
1065                 case SNDRV_PCM_STREAM_PLAYBACK:
1066                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1067                         break;
1068                 case SNDRV_PCM_STREAM_CAPTURE:
1069                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1070                         break;
1071                 }
1072                 /* register pcm */
1073                 err = snd_register_device(devtype, pcm->card, pcm->device,
1074                                           &snd_pcm_f_ops[cidx], pcm,
1075                                           pcm->streams[cidx].dev);
1076                 if (err < 0) {
1077                         list_del_init(&pcm->list);
1078                         return err;
1079                 }
1080
1081                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1082                         snd_pcm_timer_init(substream);
1083         }
1084
1085         pcm_call_notify(pcm, n_register);
1086         return err;
1087 }
1088
1089 static int snd_pcm_dev_disconnect(struct snd_device *device)
1090 {
1091         struct snd_pcm *pcm = device->device_data;
1092         struct snd_pcm_substream *substream;
1093         int cidx;
1094
1095         guard(mutex)(&register_mutex);
1096         guard(mutex)(&pcm->open_mutex);
1097         wake_up(&pcm->open_wait);
1098         list_del_init(&pcm->list);
1099
1100         for_each_pcm_substream(pcm, cidx, substream) {
1101                 snd_pcm_stream_lock_irq(substream);
1102                 if (substream->runtime) {
1103                         if (snd_pcm_running(substream))
1104                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1105                         /* to be sure, set the state unconditionally */
1106                         __snd_pcm_set_state(substream->runtime,
1107                                             SNDRV_PCM_STATE_DISCONNECTED);
1108                         wake_up(&substream->runtime->sleep);
1109                         wake_up(&substream->runtime->tsleep);
1110                 }
1111                 snd_pcm_stream_unlock_irq(substream);
1112         }
1113
1114         for_each_pcm_substream(pcm, cidx, substream)
1115                 snd_pcm_sync_stop(substream, false);
1116
1117         pcm_call_notify(pcm, n_disconnect);
1118         for (cidx = 0; cidx < 2; cidx++) {
1119                 if (pcm->streams[cidx].dev)
1120                         snd_unregister_device(pcm->streams[cidx].dev);
1121                 free_chmap(&pcm->streams[cidx]);
1122         }
1123         return 0;
1124 }
1125
1126 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1127 /**
1128  * snd_pcm_notify - Add/remove the notify list
1129  * @notify: PCM notify list
1130  * @nfree: 0 = register, 1 = unregister
1131  *
1132  * This adds the given notifier to the global list so that the callback is
1133  * called for each registered PCM devices.  This exists only for PCM OSS
1134  * emulation, so far.
1135  *
1136  * Return: zero if successful, or a negative error code
1137  */
1138 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1139 {
1140         struct snd_pcm *pcm;
1141
1142         if (snd_BUG_ON(!notify ||
1143                        !notify->n_register ||
1144                        !notify->n_unregister ||
1145                        !notify->n_disconnect))
1146                 return -EINVAL;
1147         guard(mutex)(&register_mutex);
1148         if (nfree) {
1149                 list_del(&notify->list);
1150                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1151                         notify->n_unregister(pcm);
1152         } else {
1153                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1154                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1155                         notify->n_register(pcm);
1156         }
1157         return 0;
1158 }
1159 EXPORT_SYMBOL(snd_pcm_notify);
1160 #endif /* CONFIG_SND_PCM_OSS */
1161
1162 #ifdef CONFIG_SND_PROC_FS
1163 /*
1164  *  Info interface
1165  */
1166
1167 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1168                               struct snd_info_buffer *buffer)
1169 {
1170         struct snd_pcm *pcm;
1171
1172         guard(mutex)(&register_mutex);
1173         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1174                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1175                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1176                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1177                         snd_iprintf(buffer, " : playback %i",
1178                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1179                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1180                         snd_iprintf(buffer, " : capture %i",
1181                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1182                 snd_iprintf(buffer, "\n");
1183         }
1184 }
1185
1186 static struct snd_info_entry *snd_pcm_proc_entry;
1187
1188 static void snd_pcm_proc_init(void)
1189 {
1190         struct snd_info_entry *entry;
1191
1192         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1193         if (entry) {
1194                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1195                 if (snd_info_register(entry) < 0) {
1196                         snd_info_free_entry(entry);
1197                         entry = NULL;
1198                 }
1199         }
1200         snd_pcm_proc_entry = entry;
1201 }
1202
1203 static void snd_pcm_proc_done(void)
1204 {
1205         snd_info_free_entry(snd_pcm_proc_entry);
1206 }
1207
1208 #else /* !CONFIG_SND_PROC_FS */
1209 #define snd_pcm_proc_init()
1210 #define snd_pcm_proc_done()
1211 #endif /* CONFIG_SND_PROC_FS */
1212
1213
1214 /*
1215  *  ENTRY functions
1216  */
1217
1218 static int __init alsa_pcm_init(void)
1219 {
1220         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1221         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1222         snd_pcm_proc_init();
1223         return 0;
1224 }
1225
1226 static void __exit alsa_pcm_exit(void)
1227 {
1228         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1229         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1230         snd_pcm_proc_done();
1231 }
1232
1233 module_init(alsa_pcm_init)
1234 module_exit(alsa_pcm_exit)