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  * Return: the format name string
 221  */
 222 const char *snd_pcm_format_name(snd_pcm_format_t format)
 223 {
 224         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 225                 return "Unknown";
 226         return snd_pcm_format_names[(__force unsigned int)format];
 227 }
 228 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 229
 230 #ifdef CONFIG_SND_VERBOSE_PROCFS
 231
 232 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 233 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 234 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 235 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 236 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 237 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 238 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 239 #define START(v) [SNDRV_PCM_START_##v] = #v
 240 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 241
 242 static const char * const snd_pcm_stream_names[] = {
 243         STREAM(PLAYBACK),
 244         STREAM(CAPTURE),
 245 };
 246
 247 static const char * const snd_pcm_state_names[] = {
 248         STATE(OPEN),
 249         STATE(SETUP),
 250         STATE(PREPARED),
 251         STATE(RUNNING),
 252         STATE(XRUN),
 253         STATE(DRAINING),
 254         STATE(PAUSED),
 255         STATE(SUSPENDED),
 256 };
 257
 258 static const char * const snd_pcm_access_names[] = {
 259         ACCESS(MMAP_INTERLEAVED),
 260         ACCESS(MMAP_NONINTERLEAVED),
 261         ACCESS(MMAP_COMPLEX),
 262         ACCESS(RW_INTERLEAVED),
 263         ACCESS(RW_NONINTERLEAVED),
 264 };
 265
 266 static const char * const snd_pcm_subformat_names[] = {
 267         SUBFORMAT(STD),
 268 };
 269
 270 static const char * const snd_pcm_tstamp_mode_names[] = {
 271         TSTAMP(NONE),
 272         TSTAMP(ENABLE),
 273 };
 274
 275 static const char *snd_pcm_stream_name(int stream)
 276 {
 277         return snd_pcm_stream_names[stream];
 278 }
 279
 280 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 281 {
 282         return snd_pcm_access_names[(__force int)access];
 283 }
 284
 285 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 286 {
 287         return snd_pcm_subformat_names[(__force int)subformat];
 288 }
 289
 290 static const char *snd_pcm_tstamp_mode_name(int mode)
 291 {
 292         return snd_pcm_tstamp_mode_names[mode];
 293 }
 294
 295 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 296 {
 297         return snd_pcm_state_names[(__force int)state];
 298 }
 299
 300 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 301 #include <linux/soundcard.h>
 302
 303 static const char *snd_pcm_oss_format_name(int format)
 304 {
 305         switch (format) {
 306         case AFMT_MU_LAW:
 307                 return "MU_LAW";
 308         case AFMT_A_LAW:
 309                 return "A_LAW";
 310         case AFMT_IMA_ADPCM:
 311                 return "IMA_ADPCM";
 312         case AFMT_U8:
 313                 return "U8";
 314         case AFMT_S16_LE:
 315                 return "S16_LE";
 316         case AFMT_S16_BE:
 317                 return "S16_BE";
 318         case AFMT_S8:
 319                 return "S8";
 320         case AFMT_U16_LE:
 321                 return "U16_LE";
 322         case AFMT_U16_BE:
 323                 return "U16_BE";
 324         case AFMT_MPEG:
 325                 return "MPEG";
 326         default:
 327                 return "unknown";
 328         }
 329 }
 330 #endif
 331
 332 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 333                                    struct snd_info_buffer *buffer)
 334 {
 335         struct snd_pcm_info *info;
 336         int err;
 337
 338         if (! substream)
 339                 return;
 340
 341         info = kmalloc(sizeof(*info), GFP_KERNEL);
 342         if (!info)
 343                 return;
 344
 345         err = snd_pcm_info(substream, info);
 346         if (err < 0) {
 347                 snd_iprintf(buffer, "error %d\n", err);
 348                 kfree(info);
 349                 return;
 350         }
 351         snd_iprintf(buffer, "card: %d\n", info->card);
 352         snd_iprintf(buffer, "device: %d\n", info->device);
 353         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 354         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 355         snd_iprintf(buffer, "id: %s\n", info->id);
 356         snd_iprintf(buffer, "name: %s\n", info->name);
 357         snd_iprintf(buffer, "subname: %s\n", info->subname);
 358         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 359         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 360         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 361         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 362         kfree(info);
 363 }
 364
 365 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 366                                           struct snd_info_buffer *buffer)
 367 {
 368         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 369                                buffer);
 370 }
 371
 372 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 373                                              struct snd_info_buffer *buffer)
 374 {
 375         snd_pcm_proc_info_read(entry->private_data, buffer);
 376 }
 377
 378 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 379                                                   struct snd_info_buffer *buffer)
 380 {
 381         struct snd_pcm_substream *substream = entry->private_data;
 382         struct snd_pcm_runtime *runtime;
 383
 384         mutex_lock(&substream->pcm->open_mutex);
 385         runtime = substream->runtime;
 386         if (!runtime) {
 387                 snd_iprintf(buffer, "closed\n");
 388                 goto unlock;
 389         }
 390         if (runtime->state == SNDRV_PCM_STATE_OPEN) {
 391                 snd_iprintf(buffer, "no setup\n");
 392                 goto unlock;
 393         }
 394         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 395         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 396         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 397         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 398         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 399         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 400         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 401 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 402         if (substream->oss.oss) {
 403                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 404                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 405                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 406                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 407                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 408                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 409         }
 410 #endif
 411  unlock:
 412         mutex_unlock(&substream->pcm->open_mutex);
 413 }
 414
 415 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 416                                                   struct snd_info_buffer *buffer)
 417 {
 418         struct snd_pcm_substream *substream = entry->private_data;
 419         struct snd_pcm_runtime *runtime;
 420
 421         mutex_lock(&substream->pcm->open_mutex);
 422         runtime = substream->runtime;
 423         if (!runtime) {
 424                 snd_iprintf(buffer, "closed\n");
 425                 goto unlock;
 426         }
 427         if (runtime->state == SNDRV_PCM_STATE_OPEN) {
 428                 snd_iprintf(buffer, "no setup\n");
 429                 goto unlock;
 430         }
 431         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 432         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 433         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 434         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 435         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 436         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 437         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 438         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 439  unlock:
 440         mutex_unlock(&substream->pcm->open_mutex);
 441 }
 442
 443 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 444                                                struct snd_info_buffer *buffer)
 445 {
 446         struct snd_pcm_substream *substream = entry->private_data;
 447         struct snd_pcm_runtime *runtime;
 448         struct snd_pcm_status64 status;
 449         int err;
 450
 451         mutex_lock(&substream->pcm->open_mutex);
 452         runtime = substream->runtime;
 453         if (!runtime) {
 454                 snd_iprintf(buffer, "closed\n");
 455                 goto unlock;
 456         }
 457         memset(&status, 0, sizeof(status));
 458         err = snd_pcm_status64(substream, &status);
 459         if (err < 0) {
 460                 snd_iprintf(buffer, "error %d\n", err);
 461                 goto unlock;
 462         }
 463         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 464         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 465         snd_iprintf(buffer, "trigger_time: %lld.%09lld\n",
 466                 status.trigger_tstamp_sec, status.trigger_tstamp_nsec);
 467         snd_iprintf(buffer, "tstamp      : %lld.%09lld\n",
 468                 status.tstamp_sec, status.tstamp_nsec);
 469         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 470         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 471         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 472         snd_iprintf(buffer, "-----\n");
 473         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 474         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 475  unlock:
 476         mutex_unlock(&substream->pcm->open_mutex);
 477 }
 478
 479 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 480 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 481                                          struct snd_info_buffer *buffer)
 482 {
 483         struct snd_pcm_substream *substream = entry->private_data;
 484
 485         snd_pcm_stop_xrun(substream);
 486 }
 487
 488 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 489                                     struct snd_info_buffer *buffer)
 490 {
 491         struct snd_pcm_str *pstr = entry->private_data;
 492         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 493 }
 494
 495 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 496                                      struct snd_info_buffer *buffer)
 497 {
 498         struct snd_pcm_str *pstr = entry->private_data;
 499         char line[64];
 500         if (!snd_info_get_line(buffer, line, sizeof(line)))
 501                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 502 }
 503 #endif
 504
 505 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 506 {
 507         struct snd_pcm *pcm = pstr->pcm;
 508         struct snd_info_entry *entry;
 509         char name[16];
 510
 511         sprintf(name, "pcm%i%c", pcm->device,
 512                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 513         entry = snd_info_create_card_entry(pcm->card, name,
 514                                            pcm->card->proc_root);
 515         if (!entry)
 516                 return -ENOMEM;
 517         entry->mode = S_IFDIR | 0555;
 518         pstr->proc_root = entry;
 519         entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
 520         if (entry)
 521                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 522 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 523         entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 524                                            pstr->proc_root);
 525         if (entry) {
 526                 snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
 527                 entry->c.text.write = snd_pcm_xrun_debug_write;
 528                 entry->mode |= 0200;
 529         }
 530 #endif
 531         return 0;
 532 }
 533
 534 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 535 {
 536         snd_info_free_entry(pstr->proc_root);
 537         pstr->proc_root = NULL;
 538         return 0;
 539 }
 540
 541 static struct snd_info_entry *
 542 create_substream_info_entry(struct snd_pcm_substream *substream,
 543                             const char *name,
 544                             void (*read)(struct snd_info_entry *,
 545                                          struct snd_info_buffer *))
 546 {
 547         struct snd_info_entry *entry;
 548
 549         entry = snd_info_create_card_entry(substream->pcm->card, name,
 550                                            substream->proc_root);
 551         if (entry)
 552                 snd_info_set_text_ops(entry, substream, read);
 553         return entry;
 554 }
 555
 556 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 557 {
 558         struct snd_info_entry *entry;
 559         struct snd_card *card;
 560         char name[16];
 561
 562         card = substream->pcm->card;
 563
 564         sprintf(name, "sub%i", substream->number);
 565         entry = snd_info_create_card_entry(card, name,
 566                                            substream->pstr->proc_root);
 567         if (!entry)
 568                 return -ENOMEM;
 569         entry->mode = S_IFDIR | 0555;
 570         substream->proc_root = entry;
 571
 572         create_substream_info_entry(substream, "info",
 573                                     snd_pcm_substream_proc_info_read);
 574         create_substream_info_entry(substream, "hw_params",
 575                                     snd_pcm_substream_proc_hw_params_read);
 576         create_substream_info_entry(substream, "sw_params",
 577                                     snd_pcm_substream_proc_sw_params_read);
 578         create_substream_info_entry(substream, "status",
 579                                     snd_pcm_substream_proc_status_read);
 580
 581 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 582         entry = create_substream_info_entry(substream, "xrun_injection", NULL);
 583         if (entry) {
 584                 entry->c.text.write = snd_pcm_xrun_injection_write;
 585                 entry->mode = S_IFREG | 0200;
 586         }
 587 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 588
 589         return 0;
 590 }
 591
 592 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 593 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 594 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 595 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 596 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 597
 598 static const struct attribute_group *pcm_dev_attr_groups[];
 599
 600 /*
 601  * PM callbacks: we need to deal only with suspend here, as the resume is
 602  * triggered either from user-space or the driver's resume callback
 603  */
 604 #ifdef CONFIG_PM_SLEEP
 605 static int do_pcm_suspend(struct device *dev)
 606 {
 607         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
 608
 609         if (!pstr->pcm->no_device_suspend)
 610                 snd_pcm_suspend_all(pstr->pcm);
 611         return 0;
 612 }
 613 #endif
 614
 615 static const struct dev_pm_ops pcm_dev_pm_ops = {
 616         SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
 617 };
 618
 619 /* device type for PCM -- basically only for passing PM callbacks */
 620 static const struct device_type pcm_dev_type = {
 621         .name = "pcm",
 622         .pm = &pcm_dev_pm_ops,
 623 };
 624
 625 /**
 626  * snd_pcm_new_stream - create a new PCM stream
 627  * @pcm: the pcm instance
 628  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 629  * @substream_count: the number of substreams
 630  *
 631  * Creates a new stream for the pcm.
 632  * The corresponding stream on the pcm must have been empty before
 633  * calling this, i.e. zero must be given to the argument of
 634  * snd_pcm_new().
 635  *
 636  * Return: Zero if successful, or a negative error code on failure.
 637  */
 638 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 639 {
 640         int idx, err;
 641         struct snd_pcm_str *pstr = &pcm->streams[stream];
 642         struct snd_pcm_substream *substream, *prev;
 643
 644 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 645         mutex_init(&pstr->oss.setup_mutex);
 646 #endif
 647         pstr->stream = stream;
 648         pstr->pcm = pcm;
 649         pstr->substream_count = substream_count;
 650         if (!substream_count)
 651                 return 0;
 652
 653         snd_device_initialize(&pstr->dev, pcm->card);
 654         pstr->dev.groups = pcm_dev_attr_groups;
 655         pstr->dev.type = &pcm_dev_type;
 656         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 657                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 658
 659         if (!pcm->internal) {
 660                 err = snd_pcm_stream_proc_init(pstr);
 661                 if (err < 0) {
 662                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 663                         return err;
 664                 }
 665         }
 666         prev = NULL;
 667         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 668                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 669                 if (!substream)
 670                         return -ENOMEM;
 671                 substream->pcm = pcm;
 672                 substream->pstr = pstr;
 673                 substream->number = idx;
 674                 substream->stream = stream;
 675                 sprintf(substream->name, "subdevice #%i", idx);
 676                 substream->buffer_bytes_max = UINT_MAX;
 677                 if (prev == NULL)
 678                         pstr->substream = substream;
 679                 else
 680                         prev->next = substream;
 681
 682                 if (!pcm->internal) {
 683                         err = snd_pcm_substream_proc_init(substream);
 684                         if (err < 0) {
 685                                 pcm_err(pcm,
 686                                         "Error in snd_pcm_stream_proc_init\n");
 687                                 if (prev == NULL)
 688                                         pstr->substream = NULL;
 689                                 else
 690                                         prev->next = NULL;
 691                                 kfree(substream);
 692                                 return err;
 693                         }
 694                 }
 695                 substream->group = &substream->self_group;
 696                 snd_pcm_group_init(&substream->self_group);
 697                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 698                 atomic_set(&substream->mmap_count, 0);
 699                 prev = substream;
 700         }
 701         return 0;
 702 }
 703 EXPORT_SYMBOL(snd_pcm_new_stream);
 704
 705 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 706                 int playback_count, int capture_count, bool internal,
 707                 struct snd_pcm **rpcm)
 708 {
 709         struct snd_pcm *pcm;
 710         int err;
 711         static const struct snd_device_ops ops = {
 712                 .dev_free = snd_pcm_dev_free,
 713                 .dev_register = snd_pcm_dev_register,
 714                 .dev_disconnect = snd_pcm_dev_disconnect,
 715         };
 716         static const struct snd_device_ops internal_ops = {
 717                 .dev_free = snd_pcm_dev_free,
 718         };
 719
 720         if (snd_BUG_ON(!card))
 721                 return -ENXIO;
 722         if (rpcm)
 723                 *rpcm = NULL;
 724         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 725         if (!pcm)
 726                 return -ENOMEM;
 727         pcm->card = card;
 728         pcm->device = device;
 729         pcm->internal = internal;
 730         mutex_init(&pcm->open_mutex);
 731         init_waitqueue_head(&pcm->open_wait);
 732         INIT_LIST_HEAD(&pcm->list);
 733         if (id)
 734                 strscpy(pcm->id, id, sizeof(pcm->id));
 735
 736         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 737                                  playback_count);
 738         if (err < 0)
 739                 goto free_pcm;
 740
 741         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
 742         if (err < 0)
 743                 goto free_pcm;
 744
 745         err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
 746                              internal ? &internal_ops : &ops);
 747         if (err < 0)
 748                 goto free_pcm;
 749
 750         if (rpcm)
 751                 *rpcm = pcm;
 752         return 0;
 753
 754 free_pcm:
 755         snd_pcm_free(pcm);
 756         return err;
 757 }
 758
 759 /**
 760  * snd_pcm_new - create a new PCM instance
 761  * @card: the card instance
 762  * @id: the id string
 763  * @device: the device index (zero based)
 764  * @playback_count: the number of substreams for playback
 765  * @capture_count: the number of substreams for capture
 766  * @rpcm: the pointer to store the new pcm instance
 767  *
 768  * Creates a new PCM instance.
 769  *
 770  * The pcm operators have to be set afterwards to the new instance
 771  * via snd_pcm_set_ops().
 772  *
 773  * Return: Zero if successful, or a negative error code on failure.
 774  */
 775 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 776                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 777 {
 778         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 779                         false, rpcm);
 780 }
 781 EXPORT_SYMBOL(snd_pcm_new);
 782
 783 /**
 784  * snd_pcm_new_internal - create a new internal PCM instance
 785  * @card: the card instance
 786  * @id: the id string
 787  * @device: the device index (zero based - shared with normal PCMs)
 788  * @playback_count: the number of substreams for playback
 789  * @capture_count: the number of substreams for capture
 790  * @rpcm: the pointer to store the new pcm instance
 791  *
 792  * Creates a new internal PCM instance with no userspace device or procfs
 793  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 794  * will only be used internally by kernel drivers. i.e. it cannot be opened
 795  * by userspace. It provides existing ASoC components drivers with a substream
 796  * and access to any private data.
 797  *
 798  * The pcm operators have to be set afterwards to the new instance
 799  * via snd_pcm_set_ops().
 800  *
 801  * Return: Zero if successful, or a negative error code on failure.
 802  */
 803 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 804         int playback_count, int capture_count,
 805         struct snd_pcm **rpcm)
 806 {
 807         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 808                         true, rpcm);
 809 }
 810 EXPORT_SYMBOL(snd_pcm_new_internal);
 811
 812 static void free_chmap(struct snd_pcm_str *pstr)
 813 {
 814         if (pstr->chmap_kctl) {
 815                 struct snd_card *card = pstr->pcm->card;
 816
 817                 down_write(&card->controls_rwsem);
 818                 snd_ctl_remove(card, pstr->chmap_kctl);
 819                 up_write(&card->controls_rwsem);
 820                 pstr->chmap_kctl = NULL;
 821         }
 822 }
 823
 824 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 825 {
 826         struct snd_pcm_substream *substream, *substream_next;
 827 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 828         struct snd_pcm_oss_setup *setup, *setupn;
 829 #endif
 830
 831         /* free all proc files under the stream */
 832         snd_pcm_stream_proc_done(pstr);
 833
 834         substream = pstr->substream;
 835         while (substream) {
 836                 substream_next = substream->next;
 837                 snd_pcm_timer_done(substream);
 838                 kfree(substream);
 839                 substream = substream_next;
 840         }
 841 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 842         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 843                 setupn = setup->next;
 844                 kfree(setup->task_name);
 845                 kfree(setup);
 846         }
 847 #endif
 848         free_chmap(pstr);
 849         if (pstr->substream_count)
 850                 put_device(&pstr->dev);
 851 }
 852
 853 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 854 #define pcm_call_notify(pcm, call)                                      \
 855         do {                                                            \
 856                 struct snd_pcm_notify *_notify;                         \
 857                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 858                         _notify->call(pcm);                             \
 859         } while (0)
 860 #else
 861 #define pcm_call_notify(pcm, call) do {} while (0)
 862 #endif
 863
 864 static int snd_pcm_free(struct snd_pcm *pcm)
 865 {
 866         if (!pcm)
 867                 return 0;
 868         if (!pcm->internal)
 869                 pcm_call_notify(pcm, n_unregister);
 870         if (pcm->private_free)
 871                 pcm->private_free(pcm);
 872         snd_pcm_lib_preallocate_free_for_all(pcm);
 873         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 874         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 875         kfree(pcm);
 876         return 0;
 877 }
 878
 879 static int snd_pcm_dev_free(struct snd_device *device)
 880 {
 881         struct snd_pcm *pcm = device->device_data;
 882         return snd_pcm_free(pcm);
 883 }
 884
 885 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 886                              struct file *file,
 887                              struct snd_pcm_substream **rsubstream)
 888 {
 889         struct snd_pcm_str * pstr;
 890         struct snd_pcm_substream *substream;
 891         struct snd_pcm_runtime *runtime;
 892         struct snd_card *card;
 893         int prefer_subdevice;
 894         size_t size;
 895
 896         if (snd_BUG_ON(!pcm || !rsubstream))
 897                 return -ENXIO;
 898         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 899                        stream != SNDRV_PCM_STREAM_CAPTURE))
 900                 return -EINVAL;
 901         *rsubstream = NULL;
 902         pstr = &pcm->streams[stream];
 903         if (pstr->substream == NULL || pstr->substream_count == 0)
 904                 return -ENODEV;
 905
 906         card = pcm->card;
 907         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 908
 909         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 910                 int opposite = !stream;
 911
 912                 for (substream = pcm->streams[opposite].substream; substream;
 913                      substream = substream->next) {
 914                         if (SUBSTREAM_BUSY(substream))
 915                                 return -EAGAIN;
 916                 }
 917         }
 918
 919         if (file->f_flags & O_APPEND) {
 920                 if (prefer_subdevice < 0) {
 921                         if (pstr->substream_count > 1)
 922                                 return -EINVAL; /* must be unique */
 923                         substream = pstr->substream;
 924                 } else {
 925                         for (substream = pstr->substream; substream;
 926                              substream = substream->next)
 927                                 if (substream->number == prefer_subdevice)
 928                                         break;
 929                 }
 930                 if (! substream)
 931                         return -ENODEV;
 932                 if (! SUBSTREAM_BUSY(substream))
 933                         return -EBADFD;
 934                 substream->ref_count++;
 935                 *rsubstream = substream;
 936                 return 0;
 937         }
 938
 939         for (substream = pstr->substream; substream; substream = substream->next) {
 940                 if (!SUBSTREAM_BUSY(substream) &&
 941                     (prefer_subdevice == -1 ||
 942                      substream->number == prefer_subdevice))
 943                         break;
 944         }
 945         if (substream == NULL)
 946                 return -EAGAIN;
 947
 948         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 949         if (runtime == NULL)
 950                 return -ENOMEM;
 951
 952         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 953         runtime->status = alloc_pages_exact(size, GFP_KERNEL);
 954         if (runtime->status == NULL) {
 955                 kfree(runtime);
 956                 return -ENOMEM;
 957         }
 958         memset(runtime->status, 0, size);
 959
 960         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 961         runtime->control = alloc_pages_exact(size, GFP_KERNEL);
 962         if (runtime->control == NULL) {
 963                 free_pages_exact(runtime->status,
 964                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 965                 kfree(runtime);
 966                 return -ENOMEM;
 967         }
 968         memset(runtime->control, 0, size);
 969
 970         init_waitqueue_head(&runtime->sleep);
 971         init_waitqueue_head(&runtime->tsleep);
 972
 973         __snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
 974         mutex_init(&runtime->buffer_mutex);
 975         atomic_set(&runtime->buffer_accessing, 0);
 976
 977         substream->runtime = runtime;
 978         substream->private_data = pcm->private_data;
 979         substream->ref_count = 1;
 980         substream->f_flags = file->f_flags;
 981         substream->pid = get_pid(task_pid(current));
 982         pstr->substream_opened++;
 983         *rsubstream = substream;
 984         return 0;
 985 }
 986
 987 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 988 {
 989         struct snd_pcm_runtime *runtime;
 990
 991         if (PCM_RUNTIME_CHECK(substream))
 992                 return;
 993         runtime = substream->runtime;
 994         if (runtime->private_free != NULL)
 995                 runtime->private_free(runtime);
 996         free_pages_exact(runtime->status,
 997                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 998         free_pages_exact(runtime->control,
 999                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1000         kfree(runtime->hw_constraints.rules);
1001         /* Avoid concurrent access to runtime via PCM timer interface */
1002         if (substream->timer) {
1003                 spin_lock_irq(&substream->timer->lock);
1004                 substream->runtime = NULL;
1005                 spin_unlock_irq(&substream->timer->lock);
1006         } else {
1007                 substream->runtime = NULL;
1008         }
1009         mutex_destroy(&runtime->buffer_mutex);
1010         snd_fasync_free(runtime->fasync);
1011         kfree(runtime);
1012         put_pid(substream->pid);
1013         substream->pid = NULL;
1014         substream->pstr->substream_opened--;
1015 }
1016
1017 static ssize_t pcm_class_show(struct device *dev,
1018                               struct device_attribute *attr, char *buf)
1019 {
1020         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1021         struct snd_pcm *pcm = pstr->pcm;
1022         const char *str;
1023         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1024                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1025                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1026                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1027                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1028         };
1029
1030         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1031                 str = "none";
1032         else
1033                 str = strs[pcm->dev_class];
1034         return sysfs_emit(buf, "%s\n", str);
1035 }
1036
1037 static DEVICE_ATTR_RO(pcm_class);
1038 static struct attribute *pcm_dev_attrs[] = {
1039         &dev_attr_pcm_class.attr,
1040         NULL
1041 };
1042
1043 static const struct attribute_group pcm_dev_attr_group = {
1044         .attrs  = pcm_dev_attrs,
1045 };
1046
1047 static const struct attribute_group *pcm_dev_attr_groups[] = {
1048         &pcm_dev_attr_group,
1049         NULL
1050 };
1051
1052 static int snd_pcm_dev_register(struct snd_device *device)
1053 {
1054         int cidx, err;
1055         struct snd_pcm_substream *substream;
1056         struct snd_pcm *pcm;
1057
1058         if (snd_BUG_ON(!device || !device->device_data))
1059                 return -ENXIO;
1060         pcm = device->device_data;
1061
1062         mutex_lock(&register_mutex);
1063         err = snd_pcm_add(pcm);
1064         if (err)
1065                 goto unlock;
1066         for (cidx = 0; cidx < 2; cidx++) {
1067                 int devtype = -1;
1068                 if (pcm->streams[cidx].substream == NULL)
1069                         continue;
1070                 switch (cidx) {
1071                 case SNDRV_PCM_STREAM_PLAYBACK:
1072                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1073                         break;
1074                 case SNDRV_PCM_STREAM_CAPTURE:
1075                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1076                         break;
1077                 }
1078                 /* register pcm */
1079                 err = snd_register_device(devtype, pcm->card, pcm->device,
1080                                           &snd_pcm_f_ops[cidx], pcm,
1081                                           &pcm->streams[cidx].dev);
1082                 if (err < 0) {
1083                         list_del_init(&pcm->list);
1084                         goto unlock;
1085                 }
1086
1087                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1088                         snd_pcm_timer_init(substream);
1089         }
1090
1091         pcm_call_notify(pcm, n_register);
1092
1093  unlock:
1094         mutex_unlock(&register_mutex);
1095         return err;
1096 }
1097
1098 static int snd_pcm_dev_disconnect(struct snd_device *device)
1099 {
1100         struct snd_pcm *pcm = device->device_data;
1101         struct snd_pcm_substream *substream;
1102         int cidx;
1103
1104         mutex_lock(&register_mutex);
1105         mutex_lock(&pcm->open_mutex);
1106         wake_up(&pcm->open_wait);
1107         list_del_init(&pcm->list);
1108
1109         for_each_pcm_substream(pcm, cidx, substream) {
1110                 snd_pcm_stream_lock_irq(substream);
1111                 if (substream->runtime) {
1112                         if (snd_pcm_running(substream))
1113                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
1114                         /* to be sure, set the state unconditionally */
1115                         __snd_pcm_set_state(substream->runtime,
1116                                             SNDRV_PCM_STATE_DISCONNECTED);
1117                         wake_up(&substream->runtime->sleep);
1118                         wake_up(&substream->runtime->tsleep);
1119                 }
1120                 snd_pcm_stream_unlock_irq(substream);
1121         }
1122
1123         for_each_pcm_substream(pcm, cidx, substream)
1124                 snd_pcm_sync_stop(substream, false);
1125
1126         pcm_call_notify(pcm, n_disconnect);
1127         for (cidx = 0; cidx < 2; cidx++) {
1128                 snd_unregister_device(&pcm->streams[cidx].dev);
1129                 free_chmap(&pcm->streams[cidx]);
1130         }
1131         mutex_unlock(&pcm->open_mutex);
1132         mutex_unlock(&register_mutex);
1133         return 0;
1134 }
1135
1136 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1137 /**
1138  * snd_pcm_notify - Add/remove the notify list
1139  * @notify: PCM notify list
1140  * @nfree: 0 = register, 1 = unregister
1141  *
1142  * This adds the given notifier to the global list so that the callback is
1143  * called for each registered PCM devices.  This exists only for PCM OSS
1144  * emulation, so far.
1145  *
1146  * Return: zero if successful, or a negative error code
1147  */
1148 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1149 {
1150         struct snd_pcm *pcm;
1151
1152         if (snd_BUG_ON(!notify ||
1153                        !notify->n_register ||
1154                        !notify->n_unregister ||
1155                        !notify->n_disconnect))
1156                 return -EINVAL;
1157         mutex_lock(&register_mutex);
1158         if (nfree) {
1159                 list_del(&notify->list);
1160                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1161                         notify->n_unregister(pcm);
1162         } else {
1163                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1164                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1165                         notify->n_register(pcm);
1166         }
1167         mutex_unlock(&register_mutex);
1168         return 0;
1169 }
1170 EXPORT_SYMBOL(snd_pcm_notify);
1171 #endif /* CONFIG_SND_PCM_OSS */
1172
1173 #ifdef CONFIG_SND_PROC_FS
1174 /*
1175  *  Info interface
1176  */
1177
1178 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1179                               struct snd_info_buffer *buffer)
1180 {
1181         struct snd_pcm *pcm;
1182
1183         mutex_lock(&register_mutex);
1184         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1185                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1186                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1187                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1188                         snd_iprintf(buffer, " : playback %i",
1189                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1190                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1191                         snd_iprintf(buffer, " : capture %i",
1192                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1193                 snd_iprintf(buffer, "\n");
1194         }
1195         mutex_unlock(&register_mutex);
1196 }
1197
1198 static struct snd_info_entry *snd_pcm_proc_entry;
1199
1200 static void snd_pcm_proc_init(void)
1201 {
1202         struct snd_info_entry *entry;
1203
1204         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1205         if (entry) {
1206                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1207                 if (snd_info_register(entry) < 0) {
1208                         snd_info_free_entry(entry);
1209                         entry = NULL;
1210                 }
1211         }
1212         snd_pcm_proc_entry = entry;
1213 }
1214
1215 static void snd_pcm_proc_done(void)
1216 {
1217         snd_info_free_entry(snd_pcm_proc_entry);
1218 }
1219
1220 #else /* !CONFIG_SND_PROC_FS */
1221 #define snd_pcm_proc_init()
1222 #define snd_pcm_proc_done()
1223 #endif /* CONFIG_SND_PROC_FS */
1224
1225
1226 /*
1227  *  ENTRY functions
1228  */
1229
1230 static int __init alsa_pcm_init(void)
1231 {
1232         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1233         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1234         snd_pcm_proc_init();
1235         return 0;
1236 }
1237
1238 static void __exit alsa_pcm_exit(void)
1239 {
1240         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1241         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1242         snd_pcm_proc_done();
1243 }
1244
1245 module_init(alsa_pcm_init)
1246 module_exit(alsa_pcm_exit)