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