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                         mutex_lock(&register_mutex);
  95                         device = snd_pcm_next(card, device);
  96                         mutex_unlock(&register_mutex);
  97                         if (put_user(device, (int __user *)arg))
  98                                 return -EFAULT;
  99                         return 0;
 100                 }
 101         case SNDRV_CTL_IOCTL_PCM_INFO:
 102                 {
 103                         struct snd_pcm_info __user *info;
 104                         unsigned int device, subdevice;
 105                         int stream;
 106                         struct snd_pcm *pcm;
 107                         struct snd_pcm_str *pstr;
 108                         struct snd_pcm_substream *substream;
 109                         int err;
 110
 111                         info = (struct snd_pcm_info __user *)arg;
 112                         if (get_user(device, &info->device))
 113                                 return -EFAULT;
 114                         if (get_user(stream, &info->stream))
 115                                 return -EFAULT;
 116                         if (stream < 0 || stream > 1)
 117                                 return -EINVAL;
 118                         stream = array_index_nospec(stream, 2);
 119                         if (get_user(subdevice, &info->subdevice))
 120                                 return -EFAULT;
 121                         mutex_lock(&register_mutex);
 122                         pcm = snd_pcm_get(card, device);
 123                         if (pcm == NULL) {
 124                                 err = -ENXIO;
 125                                 goto _error;
 126                         }
 127                         pstr = &pcm->streams[stream];
 128                         if (pstr->substream_count == 0) {
 129                                 err = -ENOENT;
 130                                 goto _error;
 131                         }
 132                         if (subdevice >= pstr->substream_count) {
 133                                 err = -ENXIO;
 134                                 goto _error;
 135                         }
 136                         for (substream = pstr->substream; substream;
 137                              substream = substream->next)
 138                                 if (substream->number == (int)subdevice)
 139                                         break;
 140                         if (substream == NULL) {
 141                                 err = -ENXIO;
 142                                 goto _error;
 143                         }
 144                         mutex_lock(&pcm->open_mutex);
 145                         err = snd_pcm_info_user(substream, info);
 146                         mutex_unlock(&pcm->open_mutex);
 147                 _error:
 148                         mutex_unlock(&register_mutex);
 149                         return err;
 150                 }
 151         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 152                 {
 153                         int val;
 154
 155                         if (get_user(val, (int __user *)arg))
 156                                 return -EFAULT;
 157                         control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
 158                         return 0;
 159                 }
 160         }
 161         return -ENOIOCTLCMD;
 162 }
 163
 164 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 165
 166 static const char * const snd_pcm_format_names[] = {
 167         FORMAT(S8),
 168         FORMAT(U8),
 169         FORMAT(S16_LE),
 170         FORMAT(S16_BE),
 171         FORMAT(U16_LE),
 172         FORMAT(U16_BE),
 173         FORMAT(S24_LE),
 174         FORMAT(S24_BE),
 175         FORMAT(U24_LE),
 176         FORMAT(U24_BE),
 177         FORMAT(S32_LE),
 178         FORMAT(S32_BE),
 179         FORMAT(U32_LE),
 180         FORMAT(U32_BE),
 181         FORMAT(FLOAT_LE),
 182         FORMAT(FLOAT_BE),
 183         FORMAT(FLOAT64_LE),
 184         FORMAT(FLOAT64_BE),
 185         FORMAT(IEC958_SUBFRAME_LE),
 186         FORMAT(IEC958_SUBFRAME_BE),
 187         FORMAT(MU_LAW),
 188         FORMAT(A_LAW),
 189         FORMAT(IMA_ADPCM),
 190         FORMAT(MPEG),
 191         FORMAT(GSM),
 192         FORMAT(SPECIAL),
 193         FORMAT(S24_3LE),
 194         FORMAT(S24_3BE),
 195         FORMAT(U24_3LE),
 196         FORMAT(U24_3BE),
 197         FORMAT(S20_3LE),
 198         FORMAT(S20_3BE),
 199         FORMAT(U20_3LE),
 200         FORMAT(U20_3BE),
 201         FORMAT(S18_3LE),
 202         FORMAT(S18_3BE),
 203         FORMAT(U18_3LE),
 204         FORMAT(U18_3BE),
 205         FORMAT(G723_24),
 206         FORMAT(G723_24_1B),
 207         FORMAT(G723_40),
 208         FORMAT(G723_40_1B),
 209         FORMAT(DSD_U8),
 210         FORMAT(DSD_U16_LE),
 211         FORMAT(DSD_U32_LE),
 212         FORMAT(DSD_U16_BE),
 213         FORMAT(DSD_U32_BE),
 214 };
 215
 216 /**
 217  * snd_pcm_format_name - Return a name string for the given PCM format
 218  * @format: PCM format
 219  */
 220 const char *snd_pcm_format_name(snd_pcm_format_t format)
 221 {
 222         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 223                 return "Unknown";
 224         return snd_pcm_format_names[(__force unsigned int)format];
 225 }
 226 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 227
 228 #ifdef CONFIG_SND_VERBOSE_PROCFS
 229
 230 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 231 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 232 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 233 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 234 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 235 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 236 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 237 #define START(v) [SNDRV_PCM_START_##v] = #v
 238 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 239
 240 static const char * const snd_pcm_stream_names[] = {
 241         STREAM(PLAYBACK),
 242         STREAM(CAPTURE),
 243 };
 244
 245 static const char * const snd_pcm_state_names[] = {
 246         STATE(OPEN),
 247         STATE(SETUP),
 248         STATE(PREPARED),
 249         STATE(RUNNING),
 250         STATE(XRUN),
 251         STATE(DRAINING),
 252         STATE(PAUSED),
 253         STATE(SUSPENDED),
 254 };
 255
 256 static const char * const snd_pcm_access_names[] = {
 257         ACCESS(MMAP_INTERLEAVED),
 258         ACCESS(MMAP_NONINTERLEAVED),
 259         ACCESS(MMAP_COMPLEX),
 260         ACCESS(RW_INTERLEAVED),
 261         ACCESS(RW_NONINTERLEAVED),
 262 };
 263
 264 static const char * const snd_pcm_subformat_names[] = {
 265         SUBFORMAT(STD),
 266 };
 267
 268 static const char * const snd_pcm_tstamp_mode_names[] = {
 269         TSTAMP(NONE),
 270         TSTAMP(ENABLE),
 271 };
 272
 273 static const char *snd_pcm_stream_name(int stream)
 274 {
 275         return snd_pcm_stream_names[stream];
 276 }
 277
 278 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 279 {
 280         return snd_pcm_access_names[(__force int)access];
 281 }
 282
 283 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 284 {
 285         return snd_pcm_subformat_names[(__force int)subformat];
 286 }
 287
 288 static const char *snd_pcm_tstamp_mode_name(int mode)
 289 {
 290         return snd_pcm_tstamp_mode_names[mode];
 291 }
 292
 293 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 294 {
 295         return snd_pcm_state_names[(__force int)state];
 296 }
 297
 298 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 299 #include <linux/soundcard.h>
 300
 301 static const char *snd_pcm_oss_format_name(int format)
 302 {
 303         switch (format) {
 304         case AFMT_MU_LAW:
 305                 return "MU_LAW";
 306         case AFMT_A_LAW:
 307                 return "A_LAW";
 308         case AFMT_IMA_ADPCM:
 309                 return "IMA_ADPCM";
 310         case AFMT_U8:
 311                 return "U8";
 312         case AFMT_S16_LE:
 313                 return "S16_LE";
 314         case AFMT_S16_BE:
 315                 return "S16_BE";
 316         case AFMT_S8:
 317                 return "S8";
 318         case AFMT_U16_LE:
 319                 return "U16_LE";
 320         case AFMT_U16_BE:
 321                 return "U16_BE";
 322         case AFMT_MPEG:
 323                 return "MPEG";
 324         default:
 325                 return "unknown";
 326         }
 327 }
 328 #endif
 329
 330 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 331                                    struct snd_info_buffer *buffer)
 332 {
 333         struct snd_pcm_info *info;
 334         int err;
 335
 336         if (! substream)
 337                 return;
 338
 339         info = kmalloc(sizeof(*info), GFP_KERNEL);
 340         if (!info)
 341                 return;
 342
 343         err = snd_pcm_info(substream, info);
 344         if (err < 0) {
 345                 snd_iprintf(buffer, "error %d\n", err);
 346                 kfree(info);
 347                 return;
 348         }
 349         snd_iprintf(buffer, "card: %d\n", info->card);
 350         snd_iprintf(buffer, "device: %d\n", info->device);
 351         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 352         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 353         snd_iprintf(buffer, "id: %s\n", info->id);
 354         snd_iprintf(buffer, "name: %s\n", info->name);
 355         snd_iprintf(buffer, "subname: %s\n", info->subname);
 356         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 357         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 358         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 359         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 360         kfree(info);
 361 }
 362
 363 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 364                                           struct snd_info_buffer *buffer)
 365 {
 366         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 367                                buffer);
 368 }
 369
 370 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 371                                              struct snd_info_buffer *buffer)
 372 {
 373         snd_pcm_proc_info_read(entry->private_data, buffer);
 374 }
 375
 376 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 377                                                   struct snd_info_buffer *buffer)
 378 {
 379         struct snd_pcm_substream *substream = entry->private_data;
 380         struct snd_pcm_runtime *runtime;
 381
 382         mutex_lock(&substream->pcm->open_mutex);
 383         runtime = substream->runtime;
 384         if (!runtime) {
 385                 snd_iprintf(buffer, "closed\n");
 386                 goto unlock;
 387         }
 388         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 389                 snd_iprintf(buffer, "no setup\n");
 390                 goto unlock;
 391         }
 392         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 393         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 394         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 395         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 396         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 397         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 398         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 399 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 400         if (substream->oss.oss) {
 401                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 402                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 403                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 404                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 405                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 406                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 407         }
 408 #endif
 409  unlock:
 410         mutex_unlock(&substream->pcm->open_mutex);
 411 }
 412
 413 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 414                                                   struct snd_info_buffer *buffer)
 415 {
 416         struct snd_pcm_substream *substream = entry->private_data;
 417         struct snd_pcm_runtime *runtime;
 418
 419         mutex_lock(&substream->pcm->open_mutex);
 420         runtime = substream->runtime;
 421         if (!runtime) {
 422                 snd_iprintf(buffer, "closed\n");
 423                 goto unlock;
 424         }
 425         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 426                 snd_iprintf(buffer, "no setup\n");
 427                 goto unlock;
 428         }
 429         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 430         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 431         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 432         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 433         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 434         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 435         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 436         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 437  unlock:
 438         mutex_unlock(&substream->pcm->open_mutex);
 439 }
 440
 441 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 442                                                struct snd_info_buffer *buffer)
 443 {
 444         struct snd_pcm_substream *substream = entry->private_data;
 445         struct snd_pcm_runtime *runtime;
 446         struct snd_pcm_status64 status;
 447         int err;
 448
 449         mutex_lock(&substream->pcm->open_mutex);
 450         runtime = substream->runtime;
 451         if (!runtime) {
 452                 snd_iprintf(buffer, "closed\n");
 453                 goto unlock;
 454         }
 455         memset(&status, 0, sizeof(status));
 456         err = snd_pcm_status64(substream, &status);
 457         if (err < 0) {
 458                 snd_iprintf(buffer, "error %d\n", err);
 459                 goto unlock;
 460         }
 461         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 462         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 463         snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
 464                 status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
 465         snd_iprintf(buffer, "tstamp      : %lld.%09lld\n",
 466                 status.tstamp_sec, status.tstamp_nsec);
 467         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 468         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 469         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 470         snd_iprintf(buffer, "-----\n");
 471         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 472         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 473  unlock:
 474         mutex_unlock(&substream->pcm->open_mutex);
 475 }
 476
 477 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 478 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 479                                          struct snd_info_buffer *buffer)
 480 {
 481         struct snd_pcm_substream *substream = entry->private_data;
 482
 483         snd_pcm_stop_xrun(substream);
 484 }
 485
 486 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 487                                     struct snd_info_buffer *buffer)
 488 {
 489         struct snd_pcm_str *pstr = entry->private_data;
 490         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 491 }
 492
 493 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 494                                      struct snd_info_buffer *buffer)
 495 {
 496         struct snd_pcm_str *pstr = entry->private_data;
 497         char line[64];
 498         if (!snd_info_get_line(buffer, line, sizeof(line)))
 499                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 500 }
 501 #endif
 502
 503 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 504 {
 505         struct snd_pcm *pcm = pstr->pcm;
 506         struct snd_info_entry *entry;
 507         char name[16];
 508
 509         sprintf(name, "pcm%i%c", pcm->device,
 510                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 511         entry = snd_info_create_card_entry(pcm->card, name,
 512                                            pcm->card->proc_root);
 513         if (!entry)
 514                 return -ENOMEM;
 515         entry->mode = S_IFDIR | 0555;
 516         pstr->proc_root = entry;
 517         entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
 518         if (entry)
 519                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 520 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 521         entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 522                                            pstr->proc_root);
 523         if (entry) {
 524                 snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
 525                 entry->c.text.write = snd_pcm_xrun_debug_write;
 526                 entry->mode |= 0200;
 527         }
 528 #endif
 529         return 0;
 530 }
 531
 532 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 533 {
 534         snd_info_free_entry(pstr->proc_root);
 535         pstr->proc_root = NULL;
 536         return 0;
 537 }
 538
 539 static struct snd_info_entry *
 540 create_substream_info_entry(struct snd_pcm_substream *substream,
 541                             const char *name,
 542                             void (*read)(struct snd_info_entry *,
 543                                          struct snd_info_buffer *))
 544 {
 545         struct snd_info_entry *entry;
 546
 547         entry = snd_info_create_card_entry(substream->pcm->card, name,
 548                                            substream->proc_root);
 549         if (entry)
 550                 snd_info_set_text_ops(entry, substream, read);
 551         return entry;
 552 }
 553
 554 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 555 {
 556         struct snd_info_entry *entry;
 557         struct snd_card *card;
 558         char name[16];
 559
 560         card = substream->pcm->card;
 561
 562         sprintf(name, "sub%i", substream->number);
 563         entry = snd_info_create_card_entry(card, name,
 564                                            substream->pstr->proc_root);
 565         if (!entry)
 566                 return -ENOMEM;
 567         entry->mode = S_IFDIR | 0555;
 568         substream->proc_root = entry;
 569
 570         create_substream_info_entry(substream, "info",
 571                                     snd_pcm_substream_proc_info_read);
 572         create_substream_info_entry(substream, "hw_params",
 573                                     snd_pcm_substream_proc_hw_params_read);
 574         create_substream_info_entry(substream, "sw_params",
 575                                     snd_pcm_substream_proc_sw_params_read);
 576         create_substream_info_entry(substream, "status",
 577                                     snd_pcm_substream_proc_status_read);
 578
 579 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 580         entry = create_substream_info_entry(substream, "xrun_injection", NULL);
 581         if (entry) {
 582                 entry->c.text.write = snd_pcm_xrun_injection_write;
 583                 entry->mode = S_IFREG | 0200;
 584         }
 585 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 586
 587         return 0;
 588 }
 589
 590 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 591 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 592 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 593 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 594 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 595
 596 static const struct attribute_group *pcm_dev_attr_groups[];
 597
 598 /*
 599  * PM callbacks: we need to deal only with suspend here, as the resume is
 600  * triggered either from user-space or the driver's resume callback
 601  */
 602 #ifdef CONFIG_PM_SLEEP
 603 static int do_pcm_suspend(struct device *dev)
 604 {
 605         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
 606
 607         if (!pstr->pcm->no_device_suspend)
 608                 snd_pcm_suspend_all(pstr->pcm);
 609         return 0;
 610 }
 611 #endif
 612
 613 static const struct dev_pm_ops pcm_dev_pm_ops = {
 614         SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
 615 };
 616
 617 /* device type for PCM -- basically only for passing PM callbacks */
 618 static const struct device_type pcm_dev_type = {
 619         .name = "pcm",
 620         .pm = &pcm_dev_pm_ops,
 621 };
 622
 623 /**
 624  * snd_pcm_new_stream - create a new PCM stream
 625  * @pcm: the pcm instance
 626  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 627  * @substream_count: the number of substreams
 628  *
 629  * Creates a new stream for the pcm.
 630  * The corresponding stream on the pcm must have been empty before
 631  * calling this, i.e. zero must be given to the argument of
 632  * snd_pcm_new().
 633  *
 634  * Return: Zero if successful, or a negative error code on failure.
 635  */
 636 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 637 {
 638         int idx, err;
 639         struct snd_pcm_str *pstr = &pcm->streams[stream];
 640         struct snd_pcm_substream *substream, *prev;
 641
 642 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 643         mutex_init(&pstr->oss.setup_mutex);
 644 #endif
 645         pstr->stream = stream;
 646         pstr->pcm = pcm;
 647         pstr->substream_count = substream_count;
 648         if (!substream_count)
 649                 return 0;
 650
 651         snd_device_initialize(&pstr->dev, pcm->card);
 652         pstr->dev.groups = pcm_dev_attr_groups;
 653         pstr->dev.type = &pcm_dev_type;
 654         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 655                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 656
 657         if (!pcm->internal) {
 658                 err = snd_pcm_stream_proc_init(pstr);
 659                 if (err < 0) {
 660                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 661                         return err;
 662                 }
 663         }
 664         prev = NULL;
 665         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 666                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 667                 if (!substream)
 668                         return -ENOMEM;
 669                 substream->pcm = pcm;
 670                 substream->pstr = pstr;
 671                 substream->number = idx;
 672                 substream->stream = stream;
 673                 sprintf(substream->name, "subdevice #%i", idx);
 674                 substream->buffer_bytes_max = UINT_MAX;
 675                 if (prev == NULL)
 676                         pstr->substream = substream;
 677                 else
 678                         prev->next = substream;
 679
 680                 if (!pcm->internal) {
 681                         err = snd_pcm_substream_proc_init(substream);
 682                         if (err < 0) {
 683                                 pcm_err(pcm,
 684                                         "Error in snd_pcm_stream_proc_init\n");
 685                                 if (prev == NULL)
 686                                         pstr->substream = NULL;
 687                                 else
 688                                         prev->next = NULL;
 689                                 kfree(substream);
 690                                 return err;
 691                         }
 692                 }
 693                 substream->group = &substream->self_group;
 694                 snd_pcm_group_init(&substream->self_group);
 695                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 696                 atomic_set(&substream->mmap_count, 0);
 697                 prev = substream;
 698         }
 699         return 0;
 700 }
 701 EXPORT_SYMBOL(snd_pcm_new_stream);
 702
 703 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 704                 int playback_count, int capture_count, bool internal,
 705                 struct snd_pcm **rpcm)
 706 {
 707         struct snd_pcm *pcm;
 708         int err;
 709         static const struct snd_device_ops ops = {
 710                 .dev_free = snd_pcm_dev_free,
 711                 .dev_register = snd_pcm_dev_register,
 712                 .dev_disconnect = snd_pcm_dev_disconnect,
 713         };
 714         static const struct snd_device_ops internal_ops = {
 715                 .dev_free = snd_pcm_dev_free,
 716         };
 717
 718         if (snd_BUG_ON(!card))
 719                 return -ENXIO;
 720         if (rpcm)
 721                 *rpcm = NULL;
 722         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 723         if (!pcm)
 724                 return -ENOMEM;
 725         pcm->card = card;
 726         pcm->device = device;
 727         pcm->internal = internal;
 728         mutex_init(&pcm->open_mutex);
 729         init_waitqueue_head(&pcm->open_wait);
 730         INIT_LIST_HEAD(&pcm->list);
 731         if (id)
 732                 strscpy(pcm->id, id, sizeof(pcm->id));
 733
 734         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 735                                  playback_count);
 736         if (err < 0)
 737                 goto free_pcm;
 738
 739         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
 740         if (err < 0)
 741                 goto free_pcm;
 742
 743         err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
 744                              internal ? &internal_ops : &ops);
 745         if (err < 0)
 746                 goto free_pcm;
 747
 748         if (rpcm)
 749                 *rpcm = pcm;
 750         return 0;
 751
 752 free_pcm:
 753         snd_pcm_free(pcm);
 754         return err;
 755 }
 756
 757 /**
 758  * snd_pcm_new - create a new PCM instance
 759  * @card: the card instance
 760  * @id: the id string
 761  * @device: the device index (zero based)
 762  * @playback_count: the number of substreams for playback
 763  * @capture_count: the number of substreams for capture
 764  * @rpcm: the pointer to store the new pcm instance
 765  *
 766  * Creates a new PCM instance.
 767  *
 768  * The pcm operators have to be set afterwards to the new instance
 769  * via snd_pcm_set_ops().
 770  *
 771  * Return: Zero if successful, or a negative error code on failure.
 772  */
 773 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 774                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 775 {
 776         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 777                         false, rpcm);
 778 }
 779 EXPORT_SYMBOL(snd_pcm_new);
 780
 781 /**
 782  * snd_pcm_new_internal - create a new internal PCM instance
 783  * @card: the card instance
 784  * @id: the id string
 785  * @device: the device index (zero based - shared with normal PCMs)
 786  * @playback_count: the number of substreams for playback
 787  * @capture_count: the number of substreams for capture
 788  * @rpcm: the pointer to store the new pcm instance
 789  *
 790  * Creates a new internal PCM instance with no userspace device or procfs
 791  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 792  * will only be used internally by kernel drivers. i.e. it cannot be opened
 793  * by userspace. It provides existing ASoC components drivers with a substream
 794  * and access to any private data.
 795  *
 796  * The pcm operators have to be set afterwards to the new instance
 797  * via snd_pcm_set_ops().
 798  *
 799  * Return: Zero if successful, or a negative error code on failure.
 800  */
 801 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 802         int playback_count, int capture_count,
 803         struct snd_pcm **rpcm)
 804 {
 805         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 806                         true, rpcm);
 807 }
 808 EXPORT_SYMBOL(snd_pcm_new_internal);
 809
 810 static void free_chmap(struct snd_pcm_str *pstr)
 811 {
 812         if (pstr->chmap_kctl) {
 813                 struct snd_card *card = pstr->pcm->card;
 814
 815                 down_write(&card->controls_rwsem);
 816                 snd_ctl_remove(card, pstr->chmap_kctl);
 817                 up_write(&card->controls_rwsem);
 818                 pstr->chmap_kctl = NULL;
 819         }
 820 }
 821
 822 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 823 {
 824         struct snd_pcm_substream *substream, *substream_next;
 825 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 826         struct snd_pcm_oss_setup *setup, *setupn;
 827 #endif
 828
 829         /* free all proc files under the stream */
 830         snd_pcm_stream_proc_done(pstr);
 831
 832         substream = pstr->substream;
 833         while (substream) {
 834                 substream_next = substream->next;
 835                 snd_pcm_timer_done(substream);
 836                 kfree(substream);
 837                 substream = substream_next;
 838         }
 839 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 840         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 841                 setupn = setup->next;
 842                 kfree(setup->task_name);
 843                 kfree(setup);
 844         }
 845 #endif
 846         free_chmap(pstr);
 847         if (pstr->substream_count)
 848                 put_device(&pstr->dev);
 849 }
 850
 851 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 852 #define pcm_call_notify(pcm, call)                                      \
 853         do {                                                            \
 854                 struct snd_pcm_notify *_notify;                         \
 855                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 856                         _notify->call(pcm);                             \
 857         } while (0)
 858 #else
 859 #define pcm_call_notify(pcm, call) do {} while (0)
 860 #endif
 861
 862 static int snd_pcm_free(struct snd_pcm *pcm)
 863 {
 864         if (!pcm)
 865                 return 0;
 866         if (!pcm->internal)
 867                 pcm_call_notify(pcm, n_unregister);
 868         if (pcm->private_free)
 869                 pcm->private_free(pcm);
 870         snd_pcm_lib_preallocate_free_for_all(pcm);
 871         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 872         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 873         kfree(pcm);
 874         return 0;
 875 }
 876
 877 static int snd_pcm_dev_free(struct snd_device *device)
 878 {
 879         struct snd_pcm *pcm = device->device_data;
 880         return snd_pcm_free(pcm);
 881 }
 882
 883 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 884                              struct file *file,
 885                              struct snd_pcm_substream **rsubstream)
 886 {
 887         struct snd_pcm_str * pstr;
 888         struct snd_pcm_substream *substream;
 889         struct snd_pcm_runtime *runtime;
 890         struct snd_card *card;
 891         int prefer_subdevice;
 892         size_t size;
 893
 894         if (snd_BUG_ON(!pcm || !rsubstream))
 895                 return -ENXIO;
 896         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 897                        stream != SNDRV_PCM_STREAM_CAPTURE))
 898                 return -EINVAL;
 899         *rsubstream = NULL;
 900         pstr = &pcm->streams[stream];
 901         if (pstr->substream == NULL || pstr->substream_count == 0)
 902                 return -ENODEV;
 903
 904         card = pcm->card;
 905         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 906
 907         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 908                 int opposite = !stream;
 909
 910                 for (substream = pcm->streams[opposite].substream; substream;
 911                      substream = substream->next) {
 912                         if (SUBSTREAM_BUSY(substream))
 913                                 return -EAGAIN;
 914                 }
 915         }
 916
 917         if (file->f_flags & O_APPEND) {
 918                 if (prefer_subdevice < 0) {
 919                         if (pstr->substream_count > 1)
 920                                 return -EINVAL; /* must be unique */
 921                         substream = pstr->substream;
 922                 } else {
 923                         for (substream = pstr->substream; substream;
 924                              substream = substream->next)
 925                                 if (substream->number == prefer_subdevice)
 926                                         break;
 927                 }
 928                 if (! substream)
 929                         return -ENODEV;
 930                 if (! SUBSTREAM_BUSY(substream))
 931                         return -EBADFD;
 932                 substream->ref_count++;
 933                 *rsubstream = substream;
 934                 return 0;
 935         }
 936
 937         for (substream = pstr->substream; substream; substream = substream->next) {
 938                 if (!SUBSTREAM_BUSY(substream) &&
 939                     (prefer_subdevice == -1 ||
 940                      substream->number == prefer_subdevice))
 941                         break;
 942         }
 943         if (substream == NULL)
 944                 return -EAGAIN;
 945
 946         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 947         if (runtime == NULL)
 948                 return -ENOMEM;
 949
 950         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 951         runtime->status = alloc_pages_exact(size, GFP_KERNEL);
 952         if (runtime->status == NULL) {
 953                 kfree(runtime);
 954                 return -ENOMEM;
 955         }
 956         memset(runtime->status, 0, size);
 957
 958         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 959         runtime->control = alloc_pages_exact(size, GFP_KERNEL);
 960         if (runtime->control == NULL) {
 961                 free_pages_exact(runtime->status,
 962                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 963                 kfree(runtime);
 964                 return -ENOMEM;
 965         }
 966         memset(runtime->control, 0, size);
 967
 968         init_waitqueue_head(&runtime->sleep);
 969         init_waitqueue_head(&runtime->tsleep);
 970
 971         runtime->status->state = SNDRV_PCM_STATE_OPEN;
 972         mutex_init(&runtime->buffer_mutex);
 973         atomic_set(&runtime->buffer_accessing, 0);
 974
 975         substream->runtime = runtime;
 976         substream->private_data = pcm->private_data;
 977         substream->ref_count = 1;
 978         substream->f_flags = file->f_flags;
 979         substream->pid = get_pid(task_pid(current));
 980         pstr->substream_opened++;
 981         *rsubstream = substream;
 982         return 0;
 983 }
 984
 985 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 986 {
 987         struct snd_pcm_runtime *runtime;
 988
 989         if (PCM_RUNTIME_CHECK(substream))
 990                 return;
 991         runtime = substream->runtime;
 992         if (runtime->private_free != NULL)
 993                 runtime->private_free(runtime);
 994         free_pages_exact(runtime->status,
 995                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 996         free_pages_exact(runtime->control,
 997                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
 998         kfree(runtime->hw_constraints.rules);
 999         /* Avoid concurrent access to runtime via PCM timer interface */
1000         if (substream->timer) {
1001                 spin_lock_irq(&substream->timer->lock);
1002                 substream->runtime = NULL;
1003                 spin_unlock_irq(&substream->timer->lock);
1004         } else {
1005                 substream->runtime = NULL;
1006         }
1007         mutex_destroy(&runtime->buffer_mutex);
1008         kfree(runtime);
1009         put_pid(substream->pid);
1010         substream->pid = NULL;
1011         substream->pstr->substream_opened--;
1012 }
1013
1014 static ssize_t pcm_class_show(struct device *dev,
1015                               struct device_attribute *attr, char *buf)
1016 {
1017         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1018         struct snd_pcm *pcm = pstr->pcm;
1019         const char *str;
1020         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1021                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1022                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1023                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1024                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1025         };
1026
1027         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1028                 str = "none";
1029         else
1030                 str = strs[pcm->dev_class];
1031         return sprintf(buf, "%s\n", str);
1032 }
1033
1034 static DEVICE_ATTR_RO(pcm_class);
1035 static struct attribute *pcm_dev_attrs[] = {
1036         &dev_attr_pcm_class.attr,
1037         NULL
1038 };
1039
1040 static const struct attribute_group pcm_dev_attr_group = {
1041         .attrs  = pcm_dev_attrs,
1042 };
1043
1044 static const struct attribute_group *pcm_dev_attr_groups[] = {
1045         &pcm_dev_attr_group,
1046         NULL
1047 };
1048
1049 static int snd_pcm_dev_register(struct snd_device *device)
1050 {
1051         int cidx, err;
1052         struct snd_pcm_substream *substream;
1053         struct snd_pcm *pcm;
1054
1055         if (snd_BUG_ON(!device || !device->device_data))
1056                 return -ENXIO;
1057         pcm = device->device_data;
1058
1059         mutex_lock(&register_mutex);
1060         err = snd_pcm_add(pcm);
1061         if (err)
1062                 goto unlock;
1063         for (cidx = 0; cidx < 2; cidx++) {
1064                 int devtype = -1;
1065                 if (pcm->streams[cidx].substream == NULL)
1066                         continue;
1067                 switch (cidx) {
1068                 case SNDRV_PCM_STREAM_PLAYBACK:
1069                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1070                         break;
1071                 case SNDRV_PCM_STREAM_CAPTURE:
1072                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1073                         break;
1074                 }
1075                 /* register pcm */
1076                 err = snd_register_device(devtype, pcm->card, pcm->device,
1077                                           &snd_pcm_f_ops[cidx], pcm,
1078                                           &pcm->streams[cidx].dev);
1079                 if (err < 0) {
1080                         list_del_init(&pcm->list);
1081                         goto unlock;
1082                 }
1083
1084                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1085                         snd_pcm_timer_init(substream);
1086         }
1087
1088         pcm_call_notify(pcm, n_register);
1089
1090  unlock:
1091         mutex_unlock(&register_mutex);
1092         return err;
1093 }
1094
1095 static int snd_pcm_dev_disconnect(struct snd_device *device)
1096 {
1097         struct snd_pcm *pcm = device->device_data;
1098         struct snd_pcm_substream *substream;
1099         int cidx;
1100
1101         mutex_lock(&register_mutex);
1102         mutex_lock(&pcm->open_mutex);
1103         wake_up(&pcm->open_wait);
1104         list_del_init(&pcm->list);
1105
1106         for_each_pcm_substream(pcm, cidx, substream) {
1107                 snd_pcm_stream_lock_irq(substream);
1108                 if (substream->runtime) {
1109                         if (snd_pcm_running(substream))
1110                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1111                         /* to be sure, set the state unconditionally */
1112                         substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1113                         wake_up(&substream->runtime->sleep);
1114                         wake_up(&substream->runtime->tsleep);
1115                 }
1116                 snd_pcm_stream_unlock_irq(substream);
1117         }
1118
1119         for_each_pcm_substream(pcm, cidx, substream)
1120                 snd_pcm_sync_stop(substream, false);
1121
1122         pcm_call_notify(pcm, n_disconnect);
1123         for (cidx = 0; cidx < 2; cidx++) {
1124                 snd_unregister_device(&pcm->streams[cidx].dev);
1125                 free_chmap(&pcm->streams[cidx]);
1126         }
1127         mutex_unlock(&pcm->open_mutex);
1128         mutex_unlock(&register_mutex);
1129         return 0;
1130 }
1131
1132 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1133 /**
1134  * snd_pcm_notify - Add/remove the notify list
1135  * @notify: PCM notify list
1136  * @nfree: 0 = register, 1 = unregister
1137  *
1138  * This adds the given notifier to the global list so that the callback is
1139  * called for each registered PCM devices.  This exists only for PCM OSS
1140  * emulation, so far.
1141  */
1142 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1143 {
1144         struct snd_pcm *pcm;
1145
1146         if (snd_BUG_ON(!notify ||
1147                        !notify->n_register ||
1148                        !notify->n_unregister ||
1149                        !notify->n_disconnect))
1150                 return -EINVAL;
1151         mutex_lock(&register_mutex);
1152         if (nfree) {
1153                 list_del(&notify->list);
1154                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1155                         notify->n_unregister(pcm);
1156         } else {
1157                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1158                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1159                         notify->n_register(pcm);
1160         }
1161         mutex_unlock(&register_mutex);
1162         return 0;
1163 }
1164 EXPORT_SYMBOL(snd_pcm_notify);
1165 #endif /* CONFIG_SND_PCM_OSS */
1166
1167 #ifdef CONFIG_SND_PROC_FS
1168 /*
1169  *  Info interface
1170  */
1171
1172 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1173                               struct snd_info_buffer *buffer)
1174 {
1175         struct snd_pcm *pcm;
1176
1177         mutex_lock(&register_mutex);
1178         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1179                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1180                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1181                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1182                         snd_iprintf(buffer, " : playback %i",
1183                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1184                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1185                         snd_iprintf(buffer, " : capture %i",
1186                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1187                 snd_iprintf(buffer, "\n");
1188         }
1189         mutex_unlock(&register_mutex);
1190 }
1191
1192 static struct snd_info_entry *snd_pcm_proc_entry;
1193
1194 static void snd_pcm_proc_init(void)
1195 {
1196         struct snd_info_entry *entry;
1197
1198         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1199         if (entry) {
1200                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1201                 if (snd_info_register(entry) < 0) {
1202                         snd_info_free_entry(entry);
1203                         entry = NULL;
1204                 }
1205         }
1206         snd_pcm_proc_entry = entry;
1207 }
1208
1209 static void snd_pcm_proc_done(void)
1210 {
1211         snd_info_free_entry(snd_pcm_proc_entry);
1212 }
1213
1214 #else /* !CONFIG_SND_PROC_FS */
1215 #define snd_pcm_proc_init()
1216 #define snd_pcm_proc_done()
1217 #endif /* CONFIG_SND_PROC_FS */
1218
1219
1220 /*
1221  *  ENTRY functions
1222  */
1223
1224 static int __init alsa_pcm_init(void)
1225 {
1226         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1227         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1228         snd_pcm_proc_init();
1229         return 0;
1230 }
1231
1232 static void __exit alsa_pcm_exit(void)
1233 {
1234         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1235         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1236         snd_pcm_proc_done();
1237 }
1238
1239 module_init(alsa_pcm_init)
1240 module_exit(alsa_pcm_exit)