sound/core/pcm.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/time.h>
  26 #include <linux/mutex.h>
  27 #include <linux/device.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/pcm.h>
  31 #include <sound/control.h>
  32 #include <sound/info.h>
  33
  34 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  35 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  36 MODULE_LICENSE("GPL");
  37
  38 static LIST_HEAD(snd_pcm_devices);
  39 static LIST_HEAD(snd_pcm_notify_list);
  40 static DEFINE_MUTEX(register_mutex);
  41
  42 static int snd_pcm_free(struct snd_pcm *pcm);
  43 static int snd_pcm_dev_free(struct snd_device *device);
  44 static int snd_pcm_dev_register(struct snd_device *device);
  45 static int snd_pcm_dev_disconnect(struct snd_device *device);
  46
  47 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  48 {
  49         struct snd_pcm *pcm;
  50
  51         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  52                 if (pcm->internal)
  53                         continue;
  54                 if (pcm->card == card && pcm->device == device)
  55                         return pcm;
  56         }
  57         return NULL;
  58 }
  59
  60 static int snd_pcm_next(struct snd_card *card, int device)
  61 {
  62         struct snd_pcm *pcm;
  63
  64         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  65                 if (pcm->internal)
  66                         continue;
  67                 if (pcm->card == card && pcm->device > device)
  68                         return pcm->device;
  69                 else if (pcm->card->number > card->number)
  70                         return -1;
  71         }
  72         return -1;
  73 }
  74
  75 static int snd_pcm_add(struct snd_pcm *newpcm)
  76 {
  77         struct snd_pcm *pcm;
  78
  79         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  80                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  81                         return -EBUSY;
  82                 if (pcm->card->number > newpcm->card->number ||
  83                                 (pcm->card == newpcm->card &&
  84                                 pcm->device > newpcm->device)) {
  85                         list_add(&newpcm->list, pcm->list.prev);
  86                         return 0;
  87                 }
  88         }
  89         list_add_tail(&newpcm->list, &snd_pcm_devices);
  90         return 0;
  91 }
  92
  93 static int snd_pcm_control_ioctl(struct snd_card *card,
  94                                  struct snd_ctl_file *control,
  95                                  unsigned int cmd, unsigned long arg)
  96 {
  97         switch (cmd) {
  98         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
  99                 {
 100                         int device;
 101
 102                         if (get_user(device, (int __user *)arg))
 103                                 return -EFAULT;
 104                         mutex_lock(&register_mutex);
 105                         device = snd_pcm_next(card, device);
 106                         mutex_unlock(&register_mutex);
 107                         if (put_user(device, (int __user *)arg))
 108                                 return -EFAULT;
 109                         return 0;
 110                 }
 111         case SNDRV_CTL_IOCTL_PCM_INFO:
 112                 {
 113                         struct snd_pcm_info __user *info;
 114                         unsigned int device, subdevice;
 115                         int stream;
 116                         struct snd_pcm *pcm;
 117                         struct snd_pcm_str *pstr;
 118                         struct snd_pcm_substream *substream;
 119                         int err;
 120
 121                         info = (struct snd_pcm_info __user *)arg;
 122                         if (get_user(device, &info->device))
 123                                 return -EFAULT;
 124                         if (get_user(stream, &info->stream))
 125                                 return -EFAULT;
 126                         if (stream < 0 || stream > 1)
 127                                 return -EINVAL;
 128                         if (get_user(subdevice, &info->subdevice))
 129                                 return -EFAULT;
 130                         mutex_lock(&register_mutex);
 131                         pcm = snd_pcm_get(card, device);
 132                         if (pcm == NULL) {
 133                                 err = -ENXIO;
 134                                 goto _error;
 135                         }
 136                         pstr = &pcm->streams[stream];
 137                         if (pstr->substream_count == 0) {
 138                                 err = -ENOENT;
 139                                 goto _error;
 140                         }
 141                         if (subdevice >= pstr->substream_count) {
 142                                 err = -ENXIO;
 143                                 goto _error;
 144                         }
 145                         for (substream = pstr->substream; substream;
 146                              substream = substream->next)
 147                                 if (substream->number == (int)subdevice)
 148                                         break;
 149                         if (substream == NULL) {
 150                                 err = -ENXIO;
 151                                 goto _error;
 152                         }
 153                         err = snd_pcm_info_user(substream, info);
 154                 _error:
 155                         mutex_unlock(&register_mutex);
 156                         return err;
 157                 }
 158         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 159                 {
 160                         int val;
 161
 162                         if (get_user(val, (int __user *)arg))
 163                                 return -EFAULT;
 164                         control->prefer_pcm_subdevice = val;
 165                         return 0;
 166                 }
 167         }
 168         return -ENOIOCTLCMD;
 169 }
 170
 171 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 172
 173 static char *snd_pcm_format_names[] = {
 174         FORMAT(S8),
 175         FORMAT(U8),
 176         FORMAT(S16_LE),
 177         FORMAT(S16_BE),
 178         FORMAT(U16_LE),
 179         FORMAT(U16_BE),
 180         FORMAT(S24_LE),
 181         FORMAT(S24_BE),
 182         FORMAT(U24_LE),
 183         FORMAT(U24_BE),
 184         FORMAT(S32_LE),
 185         FORMAT(S32_BE),
 186         FORMAT(U32_LE),
 187         FORMAT(U32_BE),
 188         FORMAT(FLOAT_LE),
 189         FORMAT(FLOAT_BE),
 190         FORMAT(FLOAT64_LE),
 191         FORMAT(FLOAT64_BE),
 192         FORMAT(IEC958_SUBFRAME_LE),
 193         FORMAT(IEC958_SUBFRAME_BE),
 194         FORMAT(MU_LAW),
 195         FORMAT(A_LAW),
 196         FORMAT(IMA_ADPCM),
 197         FORMAT(MPEG),
 198         FORMAT(GSM),
 199         FORMAT(SPECIAL),
 200         FORMAT(S24_3LE),
 201         FORMAT(S24_3BE),
 202         FORMAT(U24_3LE),
 203         FORMAT(U24_3BE),
 204         FORMAT(S20_3LE),
 205         FORMAT(S20_3BE),
 206         FORMAT(U20_3LE),
 207         FORMAT(U20_3BE),
 208         FORMAT(S18_3LE),
 209         FORMAT(S18_3BE),
 210         FORMAT(U18_3LE),
 211         FORMAT(U18_3BE),
 212         FORMAT(G723_24),
 213         FORMAT(G723_24_1B),
 214         FORMAT(G723_40),
 215         FORMAT(G723_40_1B),
 216         FORMAT(DSD_U8),
 217         FORMAT(DSD_U16_LE),
 218         FORMAT(DSD_U32_LE),
 219         FORMAT(DSD_U16_BE),
 220         FORMAT(DSD_U32_BE),
 221 };
 222
 223 const char *snd_pcm_format_name(snd_pcm_format_t format)
 224 {
 225         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 226                 return "Unknown";
 227         return snd_pcm_format_names[(__force unsigned int)format];
 228 }
 229 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 230
 231 #ifdef CONFIG_SND_VERBOSE_PROCFS
 232
 233 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 234 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 235 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 236 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 237 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 238 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 239 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 240 #define START(v) [SNDRV_PCM_START_##v] = #v
 241 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 242
 243 static char *snd_pcm_stream_names[] = {
 244         STREAM(PLAYBACK),
 245         STREAM(CAPTURE),
 246 };
 247
 248 static char *snd_pcm_state_names[] = {
 249         STATE(OPEN),
 250         STATE(SETUP),
 251         STATE(PREPARED),
 252         STATE(RUNNING),
 253         STATE(XRUN),
 254         STATE(DRAINING),
 255         STATE(PAUSED),
 256         STATE(SUSPENDED),
 257 };
 258
 259 static char *snd_pcm_access_names[] = {
 260         ACCESS(MMAP_INTERLEAVED),
 261         ACCESS(MMAP_NONINTERLEAVED),
 262         ACCESS(MMAP_COMPLEX),
 263         ACCESS(RW_INTERLEAVED),
 264         ACCESS(RW_NONINTERLEAVED),
 265 };
 266
 267 static char *snd_pcm_subformat_names[] = {
 268         SUBFORMAT(STD),
 269 };
 270
 271 static char *snd_pcm_tstamp_mode_names[] = {
 272         TSTAMP(NONE),
 273         TSTAMP(ENABLE),
 274 };
 275
 276 static const char *snd_pcm_stream_name(int stream)
 277 {
 278         return snd_pcm_stream_names[stream];
 279 }
 280
 281 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 282 {
 283         return snd_pcm_access_names[(__force int)access];
 284 }
 285
 286 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 287 {
 288         return snd_pcm_subformat_names[(__force int)subformat];
 289 }
 290
 291 static const char *snd_pcm_tstamp_mode_name(int mode)
 292 {
 293         return snd_pcm_tstamp_mode_names[mode];
 294 }
 295
 296 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 297 {
 298         return snd_pcm_state_names[(__force int)state];
 299 }
 300
 301 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 302 #include <linux/soundcard.h>
 303
 304 static const char *snd_pcm_oss_format_name(int format)
 305 {
 306         switch (format) {
 307         case AFMT_MU_LAW:
 308                 return "MU_LAW";
 309         case AFMT_A_LAW:
 310                 return "A_LAW";
 311         case AFMT_IMA_ADPCM:
 312                 return "IMA_ADPCM";
 313         case AFMT_U8:
 314                 return "U8";
 315         case AFMT_S16_LE:
 316                 return "S16_LE";
 317         case AFMT_S16_BE:
 318                 return "S16_BE";
 319         case AFMT_S8:
 320                 return "S8";
 321         case AFMT_U16_LE:
 322                 return "U16_LE";
 323         case AFMT_U16_BE:
 324                 return "U16_BE";
 325         case AFMT_MPEG:
 326                 return "MPEG";
 327         default:
 328                 return "unknown";
 329         }
 330 }
 331 #endif
 332
 333 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 334                                    struct snd_info_buffer *buffer)
 335 {
 336         struct snd_pcm_info *info;
 337         int err;
 338
 339         if (! substream)
 340                 return;
 341
 342         info = kmalloc(sizeof(*info), GFP_KERNEL);
 343         if (! info) {
 344                 pcm_dbg(substream->pcm,
 345                         "snd_pcm_proc_info_read: cannot malloc\n");
 346                 return;
 347         }
 348
 349         err = snd_pcm_info(substream, info);
 350         if (err < 0) {
 351                 snd_iprintf(buffer, "error %d\n", err);
 352                 kfree(info);
 353                 return;
 354         }
 355         snd_iprintf(buffer, "card: %d\n", info->card);
 356         snd_iprintf(buffer, "device: %d\n", info->device);
 357         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 358         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 359         snd_iprintf(buffer, "id: %s\n", info->id);
 360         snd_iprintf(buffer, "name: %s\n", info->name);
 361         snd_iprintf(buffer, "subname: %s\n", info->subname);
 362         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 363         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 364         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 365         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 366         kfree(info);
 367 }
 368
 369 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 370                                           struct snd_info_buffer *buffer)
 371 {
 372         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 373                                buffer);
 374 }
 375
 376 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 377                                              struct snd_info_buffer *buffer)
 378 {
 379         snd_pcm_proc_info_read(entry->private_data, buffer);
 380 }
 381
 382 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 383                                                   struct snd_info_buffer *buffer)
 384 {
 385         struct snd_pcm_substream *substream = entry->private_data;
 386         struct snd_pcm_runtime *runtime;
 387
 388         mutex_lock(&substream->pcm->open_mutex);
 389         runtime = substream->runtime;
 390         if (!runtime) {
 391                 snd_iprintf(buffer, "closed\n");
 392                 goto unlock;
 393         }
 394         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 395                 snd_iprintf(buffer, "no setup\n");
 396                 goto unlock;
 397         }
 398         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 399         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 400         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 401         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 402         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 403         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 404         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 405 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 406         if (substream->oss.oss) {
 407                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 408                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 409                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 410                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 411                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 412                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 413         }
 414 #endif
 415  unlock:
 416         mutex_unlock(&substream->pcm->open_mutex);
 417 }
 418
 419 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 420                                                   struct snd_info_buffer *buffer)
 421 {
 422         struct snd_pcm_substream *substream = entry->private_data;
 423         struct snd_pcm_runtime *runtime;
 424
 425         mutex_lock(&substream->pcm->open_mutex);
 426         runtime = substream->runtime;
 427         if (!runtime) {
 428                 snd_iprintf(buffer, "closed\n");
 429                 goto unlock;
 430         }
 431         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 432                 snd_iprintf(buffer, "no setup\n");
 433                 goto unlock;
 434         }
 435         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 436         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 437         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 438         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 439         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 440         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 441         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 442         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 443  unlock:
 444         mutex_unlock(&substream->pcm->open_mutex);
 445 }
 446
 447 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 448                                                struct snd_info_buffer *buffer)
 449 {
 450         struct snd_pcm_substream *substream = entry->private_data;
 451         struct snd_pcm_runtime *runtime;
 452         struct snd_pcm_status status;
 453         int err;
 454
 455         mutex_lock(&substream->pcm->open_mutex);
 456         runtime = substream->runtime;
 457         if (!runtime) {
 458                 snd_iprintf(buffer, "closed\n");
 459                 goto unlock;
 460         }
 461         memset(&status, 0, sizeof(status));
 462         err = snd_pcm_status(substream, &status);
 463         if (err < 0) {
 464                 snd_iprintf(buffer, "error %d\n", err);
 465                 goto unlock;
 466         }
 467         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 468         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 469         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 470                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 471         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 472                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 473         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 474         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 475         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 476         snd_iprintf(buffer, "-----\n");
 477         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 478         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 479  unlock:
 480         mutex_unlock(&substream->pcm->open_mutex);
 481 }
 482
 483 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 484 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 485                                     struct snd_info_buffer *buffer)
 486 {
 487         struct snd_pcm_str *pstr = entry->private_data;
 488         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 489 }
 490
 491 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 492                                      struct snd_info_buffer *buffer)
 493 {
 494         struct snd_pcm_str *pstr = entry->private_data;
 495         char line[64];
 496         if (!snd_info_get_line(buffer, line, sizeof(line)))
 497                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 498 }
 499 #endif
 500
 501 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 502 {
 503         struct snd_pcm *pcm = pstr->pcm;
 504         struct snd_info_entry *entry;
 505         char name[16];
 506
 507         sprintf(name, "pcm%i%c", pcm->device,
 508                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 509         if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
 510                 return -ENOMEM;
 511         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 512         if (snd_info_register(entry) < 0) {
 513                 snd_info_free_entry(entry);
 514                 return -ENOMEM;
 515         }
 516         pstr->proc_root = entry;
 517
 518         if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
 519                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 520                 if (snd_info_register(entry) < 0) {
 521                         snd_info_free_entry(entry);
 522                         entry = NULL;
 523                 }
 524         }
 525         pstr->proc_info_entry = entry;
 526
 527 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 528         if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 529                                                 pstr->proc_root)) != NULL) {
 530                 entry->c.text.read = snd_pcm_xrun_debug_read;
 531                 entry->c.text.write = snd_pcm_xrun_debug_write;
 532                 entry->mode |= S_IWUSR;
 533                 entry->private_data = pstr;
 534                 if (snd_info_register(entry) < 0) {
 535                         snd_info_free_entry(entry);
 536                         entry = NULL;
 537                 }
 538         }
 539         pstr->proc_xrun_debug_entry = entry;
 540 #endif
 541         return 0;
 542 }
 543
 544 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 545 {
 546 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 547         snd_info_free_entry(pstr->proc_xrun_debug_entry);
 548         pstr->proc_xrun_debug_entry = NULL;
 549 #endif
 550         snd_info_free_entry(pstr->proc_info_entry);
 551         pstr->proc_info_entry = NULL;
 552         snd_info_free_entry(pstr->proc_root);
 553         pstr->proc_root = NULL;
 554         return 0;
 555 }
 556
 557 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 558 {
 559         struct snd_info_entry *entry;
 560         struct snd_card *card;
 561         char name[16];
 562
 563         card = substream->pcm->card;
 564
 565         sprintf(name, "sub%i", substream->number);
 566         if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
 567                 return -ENOMEM;
 568         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 569         if (snd_info_register(entry) < 0) {
 570                 snd_info_free_entry(entry);
 571                 return -ENOMEM;
 572         }
 573         substream->proc_root = entry;
 574
 575         if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
 576                 snd_info_set_text_ops(entry, substream,
 577                                       snd_pcm_substream_proc_info_read);
 578                 if (snd_info_register(entry) < 0) {
 579                         snd_info_free_entry(entry);
 580                         entry = NULL;
 581                 }
 582         }
 583         substream->proc_info_entry = entry;
 584
 585         if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
 586                 snd_info_set_text_ops(entry, substream,
 587                                       snd_pcm_substream_proc_hw_params_read);
 588                 if (snd_info_register(entry) < 0) {
 589                         snd_info_free_entry(entry);
 590                         entry = NULL;
 591                 }
 592         }
 593         substream->proc_hw_params_entry = entry;
 594
 595         if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
 596                 snd_info_set_text_ops(entry, substream,
 597                                       snd_pcm_substream_proc_sw_params_read);
 598                 if (snd_info_register(entry) < 0) {
 599                         snd_info_free_entry(entry);
 600                         entry = NULL;
 601                 }
 602         }
 603         substream->proc_sw_params_entry = entry;
 604
 605         if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
 606                 snd_info_set_text_ops(entry, substream,
 607                                       snd_pcm_substream_proc_status_read);
 608                 if (snd_info_register(entry) < 0) {
 609                         snd_info_free_entry(entry);
 610                         entry = NULL;
 611                 }
 612         }
 613         substream->proc_status_entry = entry;
 614
 615         return 0;
 616 }
 617
 618 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
 619 {
 620         snd_info_free_entry(substream->proc_info_entry);
 621         substream->proc_info_entry = NULL;
 622         snd_info_free_entry(substream->proc_hw_params_entry);
 623         substream->proc_hw_params_entry = NULL;
 624         snd_info_free_entry(substream->proc_sw_params_entry);
 625         substream->proc_sw_params_entry = NULL;
 626         snd_info_free_entry(substream->proc_status_entry);
 627         substream->proc_status_entry = NULL;
 628         snd_info_free_entry(substream->proc_root);
 629         substream->proc_root = NULL;
 630         return 0;
 631 }
 632 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 633 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 634 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 635 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 636 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 637 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 638
 639 /**
 640  * snd_pcm_new_stream - create a new PCM stream
 641  * @pcm: the pcm instance
 642  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 643  * @substream_count: the number of substreams
 644  *
 645  * Creates a new stream for the pcm.
 646  * The corresponding stream on the pcm must have been empty before
 647  * calling this, i.e. zero must be given to the argument of
 648  * snd_pcm_new().
 649  *
 650  * Return: Zero if successful, or a negative error code on failure.
 651  */
 652 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 653 {
 654         int idx, err;
 655         struct snd_pcm_str *pstr = &pcm->streams[stream];
 656         struct snd_pcm_substream *substream, *prev;
 657
 658 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 659         mutex_init(&pstr->oss.setup_mutex);
 660 #endif
 661         pstr->stream = stream;
 662         pstr->pcm = pcm;
 663         pstr->substream_count = substream_count;
 664         if (substream_count > 0 && !pcm->internal) {
 665                 err = snd_pcm_stream_proc_init(pstr);
 666                 if (err < 0) {
 667                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 668                         return err;
 669                 }
 670         }
 671         prev = NULL;
 672         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 673                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 674                 if (substream == NULL) {
 675                         pcm_err(pcm, "Cannot allocate PCM substream\n");
 676                         return -ENOMEM;
 677                 }
 678                 substream->pcm = pcm;
 679                 substream->pstr = pstr;
 680                 substream->number = idx;
 681                 substream->stream = stream;
 682                 sprintf(substream->name, "subdevice #%i", idx);
 683                 substream->buffer_bytes_max = UINT_MAX;
 684                 if (prev == NULL)
 685                         pstr->substream = substream;
 686                 else
 687                         prev->next = substream;
 688
 689                 if (!pcm->internal) {
 690                         err = snd_pcm_substream_proc_init(substream);
 691                         if (err < 0) {
 692                                 pcm_err(pcm,
 693                                         "Error in snd_pcm_stream_proc_init\n");
 694                                 if (prev == NULL)
 695                                         pstr->substream = NULL;
 696                                 else
 697                                         prev->next = NULL;
 698                                 kfree(substream);
 699                                 return err;
 700                         }
 701                 }
 702                 substream->group = &substream->self_group;
 703                 spin_lock_init(&substream->self_group.lock);
 704                 mutex_init(&substream->self_group.mutex);
 705                 INIT_LIST_HEAD(&substream->self_group.substreams);
 706                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 707                 atomic_set(&substream->mmap_count, 0);
 708                 prev = substream;
 709         }
 710         return 0;
 711 }
 712
 713 EXPORT_SYMBOL(snd_pcm_new_stream);
 714
 715 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 716                 int playback_count, int capture_count, bool internal,
 717                 struct snd_pcm **rpcm)
 718 {
 719         struct snd_pcm *pcm;
 720         int err;
 721         static struct snd_device_ops ops = {
 722                 .dev_free = snd_pcm_dev_free,
 723                 .dev_register = snd_pcm_dev_register,
 724                 .dev_disconnect = snd_pcm_dev_disconnect,
 725         };
 726
 727         if (snd_BUG_ON(!card))
 728                 return -ENXIO;
 729         if (rpcm)
 730                 *rpcm = NULL;
 731         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 732         if (pcm == NULL) {
 733                 dev_err(card->dev, "Cannot allocate PCM\n");
 734                 return -ENOMEM;
 735         }
 736         pcm->card = card;
 737         pcm->device = device;
 738         pcm->internal = internal;
 739         if (id)
 740                 strlcpy(pcm->id, id, sizeof(pcm->id));
 741         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
 742                 snd_pcm_free(pcm);
 743                 return err;
 744         }
 745         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
 746                 snd_pcm_free(pcm);
 747                 return err;
 748         }
 749         mutex_init(&pcm->open_mutex);
 750         init_waitqueue_head(&pcm->open_wait);
 751         if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
 752                 snd_pcm_free(pcm);
 753                 return err;
 754         }
 755         if (rpcm)
 756                 *rpcm = pcm;
 757         return 0;
 758 }
 759
 760 /**
 761  * snd_pcm_new - create a new PCM instance
 762  * @card: the card instance
 763  * @id: the id string
 764  * @device: the device index (zero based)
 765  * @playback_count: the number of substreams for playback
 766  * @capture_count: the number of substreams for capture
 767  * @rpcm: the pointer to store the new pcm instance
 768  *
 769  * Creates a new PCM instance.
 770  *
 771  * The pcm operators have to be set afterwards to the new instance
 772  * via snd_pcm_set_ops().
 773  *
 774  * Return: Zero if successful, or a negative error code on failure.
 775  */
 776 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 777                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 778 {
 779         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 780                         false, rpcm);
 781 }
 782 EXPORT_SYMBOL(snd_pcm_new);
 783
 784 /**
 785  * snd_pcm_new_internal - create a new internal PCM instance
 786  * @card: the card instance
 787  * @id: the id string
 788  * @device: the device index (zero based - shared with normal PCMs)
 789  * @playback_count: the number of substreams for playback
 790  * @capture_count: the number of substreams for capture
 791  * @rpcm: the pointer to store the new pcm instance
 792  *
 793  * Creates a new internal PCM instance with no userspace device or procfs
 794  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 795  * will only be used internally by kernel drivers. i.e. it cannot be opened
 796  * by userspace. It provides existing ASoC components drivers with a substream
 797  * and access to any private data.
 798  *
 799  * The pcm operators have to be set afterwards to the new instance
 800  * via snd_pcm_set_ops().
 801  *
 802  * Return: Zero if successful, or a negative error code on failure.
 803  */
 804 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 805         int playback_count, int capture_count,
 806         struct snd_pcm **rpcm)
 807 {
 808         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 809                         true, rpcm);
 810 }
 811 EXPORT_SYMBOL(snd_pcm_new_internal);
 812
 813 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 814 {
 815         struct snd_pcm_substream *substream, *substream_next;
 816 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 817         struct snd_pcm_oss_setup *setup, *setupn;
 818 #endif
 819         substream = pstr->substream;
 820         while (substream) {
 821                 substream_next = substream->next;
 822                 snd_pcm_timer_done(substream);
 823                 snd_pcm_substream_proc_done(substream);
 824                 kfree(substream);
 825                 substream = substream_next;
 826         }
 827         snd_pcm_stream_proc_done(pstr);
 828 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 829         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 830                 setupn = setup->next;
 831                 kfree(setup->task_name);
 832                 kfree(setup);
 833         }
 834 #endif
 835 }
 836
 837 static int snd_pcm_free(struct snd_pcm *pcm)
 838 {
 839         struct snd_pcm_notify *notify;
 840
 841         if (!pcm)
 842                 return 0;
 843         list_for_each_entry(notify, &snd_pcm_notify_list, list) {
 844                 notify->n_unregister(pcm);
 845         }
 846         if (pcm->private_free)
 847                 pcm->private_free(pcm);
 848         snd_pcm_lib_preallocate_free_for_all(pcm);
 849         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 850         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 851         kfree(pcm);
 852         return 0;
 853 }
 854
 855 static int snd_pcm_dev_free(struct snd_device *device)
 856 {
 857         struct snd_pcm *pcm = device->device_data;
 858         return snd_pcm_free(pcm);
 859 }
 860
 861 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 862                              struct file *file,
 863                              struct snd_pcm_substream **rsubstream)
 864 {
 865         struct snd_pcm_str * pstr;
 866         struct snd_pcm_substream *substream;
 867         struct snd_pcm_runtime *runtime;
 868         struct snd_ctl_file *kctl;
 869         struct snd_card *card;
 870         int prefer_subdevice = -1;
 871         size_t size;
 872
 873         if (snd_BUG_ON(!pcm || !rsubstream))
 874                 return -ENXIO;
 875         *rsubstream = NULL;
 876         pstr = &pcm->streams[stream];
 877         if (pstr->substream == NULL || pstr->substream_count == 0)
 878                 return -ENODEV;
 879
 880         card = pcm->card;
 881         read_lock(&card->ctl_files_rwlock);
 882         list_for_each_entry(kctl, &card->ctl_files, list) {
 883                 if (kctl->pid == task_pid(current)) {
 884                         prefer_subdevice = kctl->prefer_pcm_subdevice;
 885                         if (prefer_subdevice != -1)
 886                                 break;
 887                 }
 888         }
 889         read_unlock(&card->ctl_files_rwlock);
 890
 891         switch (stream) {
 892         case SNDRV_PCM_STREAM_PLAYBACK:
 893                 if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 894                         for (substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; substream; substream = substream->next) {
 895                                 if (SUBSTREAM_BUSY(substream))
 896                                         return -EAGAIN;
 897                         }
 898                 }
 899                 break;
 900         case SNDRV_PCM_STREAM_CAPTURE:
 901                 if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 902                         for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next) {
 903                                 if (SUBSTREAM_BUSY(substream))
 904                                         return -EAGAIN;
 905                         }
 906                 }
 907                 break;
 908         default:
 909                 return -EINVAL;
 910         }
 911
 912         if (file->f_flags & O_APPEND) {
 913                 if (prefer_subdevice < 0) {
 914                         if (pstr->substream_count > 1)
 915                                 return -EINVAL; /* must be unique */
 916                         substream = pstr->substream;
 917                 } else {
 918                         for (substream = pstr->substream; substream;
 919                              substream = substream->next)
 920                                 if (substream->number == prefer_subdevice)
 921                                         break;
 922                 }
 923                 if (! substream)
 924                         return -ENODEV;
 925                 if (! SUBSTREAM_BUSY(substream))
 926                         return -EBADFD;
 927                 substream->ref_count++;
 928                 *rsubstream = substream;
 929                 return 0;
 930         }
 931
 932         if (prefer_subdevice >= 0) {
 933                 for (substream = pstr->substream; substream; substream = substream->next)
 934                         if (!SUBSTREAM_BUSY(substream) && substream->number == prefer_subdevice)
 935                                 goto __ok;
 936         }
 937         for (substream = pstr->substream; substream; substream = substream->next)
 938                 if (!SUBSTREAM_BUSY(substream))
 939                         break;
 940       __ok:
 941         if (substream == NULL)
 942                 return -EAGAIN;
 943
 944         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 945         if (runtime == NULL)
 946                 return -ENOMEM;
 947
 948         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 949         runtime->status = snd_malloc_pages(size, GFP_KERNEL);
 950         if (runtime->status == NULL) {
 951                 kfree(runtime);
 952                 return -ENOMEM;
 953         }
 954         memset((void*)runtime->status, 0, size);
 955
 956         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 957         runtime->control = snd_malloc_pages(size, GFP_KERNEL);
 958         if (runtime->control == NULL) {
 959                 snd_free_pages((void*)runtime->status,
 960                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 961                 kfree(runtime);
 962                 return -ENOMEM;
 963         }
 964         memset((void*)runtime->control, 0, size);
 965
 966         init_waitqueue_head(&runtime->sleep);
 967         init_waitqueue_head(&runtime->tsleep);
 968
 969         runtime->status->state = SNDRV_PCM_STATE_OPEN;
 970
 971         substream->runtime = runtime;
 972         substream->private_data = pcm->private_data;
 973         substream->ref_count = 1;
 974         substream->f_flags = file->f_flags;
 975         substream->pid = get_pid(task_pid(current));
 976         pstr->substream_opened++;
 977         *rsubstream = substream;
 978         return 0;
 979 }
 980
 981 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 982 {
 983         struct snd_pcm_runtime *runtime;
 984
 985         if (PCM_RUNTIME_CHECK(substream))
 986                 return;
 987         runtime = substream->runtime;
 988         if (runtime->private_free != NULL)
 989                 runtime->private_free(runtime);
 990         snd_free_pages((void*)runtime->status,
 991                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 992         snd_free_pages((void*)runtime->control,
 993                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
 994         kfree(runtime->hw_constraints.rules);
 995 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 996         kfree(runtime->hwptr_log);
 997 #endif
 998         kfree(runtime);
 999         substream->runtime = NULL;
1000         put_pid(substream->pid);
1001         substream->pid = NULL;
1002         substream->pstr->substream_opened--;
1003 }
1004
1005 static ssize_t show_pcm_class(struct device *dev,
1006                               struct device_attribute *attr, char *buf)
1007 {
1008         struct snd_pcm *pcm;
1009         const char *str;
1010         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1011                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1012                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1013                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1014                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1015         };
1016
1017         if (! (pcm = dev_get_drvdata(dev)) ||
1018             pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1019                 str = "none";
1020         else
1021                 str = strs[pcm->dev_class];
1022         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1023 }
1024
1025 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1026 static struct attribute *pcm_dev_attrs[] = {
1027         &dev_attr_pcm_class.attr,
1028         NULL
1029 };
1030
1031 static struct attribute_group pcm_dev_attr_group = {
1032         .attrs  = pcm_dev_attrs,
1033 };
1034
1035 static const struct attribute_group *pcm_dev_attr_groups[] = {
1036         &pcm_dev_attr_group,
1037         NULL
1038 };
1039
1040 static int snd_pcm_dev_register(struct snd_device *device)
1041 {
1042         int cidx, err;
1043         struct snd_pcm_substream *substream;
1044         struct snd_pcm_notify *notify;
1045         char str[16];
1046         struct snd_pcm *pcm;
1047         struct device *dev;
1048
1049         if (snd_BUG_ON(!device || !device->device_data))
1050                 return -ENXIO;
1051         pcm = device->device_data;
1052         mutex_lock(&register_mutex);
1053         err = snd_pcm_add(pcm);
1054         if (err) {
1055                 mutex_unlock(&register_mutex);
1056                 return err;
1057         }
1058         for (cidx = 0; cidx < 2; cidx++) {
1059                 int devtype = -1;
1060                 if (pcm->streams[cidx].substream == NULL || pcm->internal)
1061                         continue;
1062                 switch (cidx) {
1063                 case SNDRV_PCM_STREAM_PLAYBACK:
1064                         sprintf(str, "pcmC%iD%ip", pcm->card->number, pcm->device);
1065                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1066                         break;
1067                 case SNDRV_PCM_STREAM_CAPTURE:
1068                         sprintf(str, "pcmC%iD%ic", pcm->card->number, pcm->device);
1069                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1070                         break;
1071                 }
1072                 /* device pointer to use, pcm->dev takes precedence if
1073                  * it is assigned, otherwise fall back to card's device
1074                  * if possible */
1075                 dev = pcm->dev;
1076                 if (!dev)
1077                         dev = snd_card_get_device_link(pcm->card);
1078                 /* register pcm */
1079                 err = snd_register_device_for_dev(devtype, pcm->card,
1080                                                   pcm->device,
1081                                                   &snd_pcm_f_ops[cidx],
1082                                                   pcm, str, dev);
1083                 if (err < 0) {
1084                         list_del(&pcm->list);
1085                         mutex_unlock(&register_mutex);
1086                         return err;
1087                 }
1088
1089                 dev = snd_get_device(devtype, pcm->card, pcm->device);
1090                 if (dev) {
1091                         err = sysfs_create_groups(&dev->kobj,
1092                                                   pcm_dev_attr_groups);
1093                         if (err < 0)
1094                                 dev_warn(dev,
1095                                          "pcm %d:%d: cannot create sysfs groups\n",
1096                                          pcm->card->number, pcm->device);
1097                         put_device(dev);
1098                 }
1099
1100                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1101                         snd_pcm_timer_init(substream);
1102         }
1103
1104         list_for_each_entry(notify, &snd_pcm_notify_list, list)
1105                 notify->n_register(pcm);
1106
1107         mutex_unlock(&register_mutex);
1108         return 0;
1109 }
1110
1111 static int snd_pcm_dev_disconnect(struct snd_device *device)
1112 {
1113         struct snd_pcm *pcm = device->device_data;
1114         struct snd_pcm_notify *notify;
1115         struct snd_pcm_substream *substream;
1116         int cidx, devtype;
1117
1118         mutex_lock(&register_mutex);
1119         if (list_empty(&pcm->list))
1120                 goto unlock;
1121
1122         mutex_lock(&pcm->open_mutex);
1123         wake_up(&pcm->open_wait);
1124         list_del_init(&pcm->list);
1125         for (cidx = 0; cidx < 2; cidx++)
1126                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1127                         snd_pcm_stream_lock_irq(substream);
1128                         if (substream->runtime) {
1129                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1130                                 wake_up(&substream->runtime->sleep);
1131                                 wake_up(&substream->runtime->tsleep);
1132                         }
1133                         snd_pcm_stream_unlock_irq(substream);
1134                 }
1135         list_for_each_entry(notify, &snd_pcm_notify_list, list) {
1136                 notify->n_disconnect(pcm);
1137         }
1138         for (cidx = 0; cidx < 2; cidx++) {
1139                 devtype = -1;
1140                 switch (cidx) {
1141                 case SNDRV_PCM_STREAM_PLAYBACK:
1142                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1143                         break;
1144                 case SNDRV_PCM_STREAM_CAPTURE:
1145                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1146                         break;
1147                 }
1148                 snd_unregister_device(devtype, pcm->card, pcm->device);
1149                 if (pcm->streams[cidx].chmap_kctl) {
1150                         snd_ctl_remove(pcm->card, pcm->streams[cidx].chmap_kctl);
1151                         pcm->streams[cidx].chmap_kctl = NULL;
1152                 }
1153         }
1154         mutex_unlock(&pcm->open_mutex);
1155  unlock:
1156         mutex_unlock(&register_mutex);
1157         return 0;
1158 }
1159
1160 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1161 {
1162         struct snd_pcm *pcm;
1163
1164         if (snd_BUG_ON(!notify ||
1165                        !notify->n_register ||
1166                        !notify->n_unregister ||
1167                        !notify->n_disconnect))
1168                 return -EINVAL;
1169         mutex_lock(&register_mutex);
1170         if (nfree) {
1171                 list_del(&notify->list);
1172                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1173                         notify->n_unregister(pcm);
1174         } else {
1175                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1176                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1177                         notify->n_register(pcm);
1178         }
1179         mutex_unlock(&register_mutex);
1180         return 0;
1181 }
1182
1183 EXPORT_SYMBOL(snd_pcm_notify);
1184
1185 #ifdef CONFIG_PROC_FS
1186 /*
1187  *  Info interface
1188  */
1189
1190 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1191                               struct snd_info_buffer *buffer)
1192 {
1193         struct snd_pcm *pcm;
1194
1195         mutex_lock(&register_mutex);
1196         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1197                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1198                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1199                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1200                         snd_iprintf(buffer, " : playback %i",
1201                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1202                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1203                         snd_iprintf(buffer, " : capture %i",
1204                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1205                 snd_iprintf(buffer, "\n");
1206         }
1207         mutex_unlock(&register_mutex);
1208 }
1209
1210 static struct snd_info_entry *snd_pcm_proc_entry;
1211
1212 static void snd_pcm_proc_init(void)
1213 {
1214         struct snd_info_entry *entry;
1215
1216         if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
1217                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1218                 if (snd_info_register(entry) < 0) {
1219                         snd_info_free_entry(entry);
1220                         entry = NULL;
1221                 }
1222         }
1223         snd_pcm_proc_entry = entry;
1224 }
1225
1226 static void snd_pcm_proc_done(void)
1227 {
1228         snd_info_free_entry(snd_pcm_proc_entry);
1229 }
1230
1231 #else /* !CONFIG_PROC_FS */
1232 #define snd_pcm_proc_init()
1233 #define snd_pcm_proc_done()
1234 #endif /* CONFIG_PROC_FS */
1235
1236
1237 /*
1238  *  ENTRY functions
1239  */
1240
1241 static int __init alsa_pcm_init(void)
1242 {
1243         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1244         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1245         snd_pcm_proc_init();
1246         return 0;
1247 }
1248
1249 static void __exit alsa_pcm_exit(void)
1250 {
1251         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1252         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1253         snd_pcm_proc_done();
1254 }
1255
1256 module_init(alsa_pcm_init)
1257 module_exit(alsa_pcm_exit)