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 <linux/nospec.h>
  29 #include <sound/core.h>
  30 #include <sound/minors.h>
  31 #include <sound/pcm.h>
  32 #include <sound/timer.h>
  33 #include <sound/control.h>
  34 #include <sound/info.h>
  35
  36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  37 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  38 MODULE_LICENSE("GPL");
  39
  40 static LIST_HEAD(snd_pcm_devices);
  41 static LIST_HEAD(snd_pcm_notify_list);
  42 static DEFINE_MUTEX(register_mutex);
  43
  44 static int snd_pcm_free(struct snd_pcm *pcm);
  45 static int snd_pcm_dev_free(struct snd_device *device);
  46 static int snd_pcm_dev_register(struct snd_device *device);
  47 static int snd_pcm_dev_disconnect(struct snd_device *device);
  48
  49 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  50 {
  51         struct snd_pcm *pcm;
  52
  53         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  54                 if (pcm->card == card && pcm->device == device)
  55                         return pcm;
  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->card == card && pcm->device > device)
  66                         return pcm->device;
  67                 else if (pcm->card->number > card->number)
  68                         return -1;
  69         }
  70         return -1;
  71 }
  72
  73 static int snd_pcm_add(struct snd_pcm *newpcm)
  74 {
  75         struct snd_pcm *pcm;
  76
  77         if (newpcm->internal)
  78                 return 0;
  79
  80         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  81                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  82                         return -EBUSY;
  83                 if (pcm->card->number > newpcm->card->number ||
  84                                 (pcm->card == newpcm->card &&
  85                                 pcm->device > newpcm->device)) {
  86                         list_add(&newpcm->list, pcm->list.prev);
  87                         return 0;
  88                 }
  89         }
  90         list_add_tail(&newpcm->list, &snd_pcm_devices);
  91         return 0;
  92 }
  93
  94 static int snd_pcm_control_ioctl(struct snd_card *card,
  95                                  struct snd_ctl_file *control,
  96                                  unsigned int cmd, unsigned long arg)
  97 {
  98         switch (cmd) {
  99         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
 100                 {
 101                         int device;
 102
 103                         if (get_user(device, (int __user *)arg))
 104                                 return -EFAULT;
 105                         mutex_lock(&register_mutex);
 106                         device = snd_pcm_next(card, device);
 107                         mutex_unlock(&register_mutex);
 108                         if (put_user(device, (int __user *)arg))
 109                                 return -EFAULT;
 110                         return 0;
 111                 }
 112         case SNDRV_CTL_IOCTL_PCM_INFO:
 113                 {
 114                         struct snd_pcm_info __user *info;
 115                         unsigned int device, subdevice;
 116                         int stream;
 117                         struct snd_pcm *pcm;
 118                         struct snd_pcm_str *pstr;
 119                         struct snd_pcm_substream *substream;
 120                         int err;
 121
 122                         info = (struct snd_pcm_info __user *)arg;
 123                         if (get_user(device, &info->device))
 124                                 return -EFAULT;
 125                         if (get_user(stream, &info->stream))
 126                                 return -EFAULT;
 127                         if (stream < 0 || stream > 1)
 128                                 return -EINVAL;
 129                         stream = array_index_nospec(stream, 2);
 130                         if (get_user(subdevice, &info->subdevice))
 131                                 return -EFAULT;
 132                         mutex_lock(&register_mutex);
 133                         pcm = snd_pcm_get(card, device);
 134                         if (pcm == NULL) {
 135                                 err = -ENXIO;
 136                                 goto _error;
 137                         }
 138                         pstr = &pcm->streams[stream];
 139                         if (pstr->substream_count == 0) {
 140                                 err = -ENOENT;
 141                                 goto _error;
 142                         }
 143                         if (subdevice >= pstr->substream_count) {
 144                                 err = -ENXIO;
 145                                 goto _error;
 146                         }
 147                         for (substream = pstr->substream; substream;
 148                              substream = substream->next)
 149                                 if (substream->number == (int)subdevice)
 150                                         break;
 151                         if (substream == NULL) {
 152                                 err = -ENXIO;
 153                                 goto _error;
 154                         }
 155                         mutex_lock(&pcm->open_mutex);
 156                         err = snd_pcm_info_user(substream, info);
 157                         mutex_unlock(&pcm->open_mutex);
 158                 _error:
 159                         mutex_unlock(&register_mutex);
 160                         return err;
 161                 }
 162         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 163                 {
 164                         int val;
 165
 166                         if (get_user(val, (int __user *)arg))
 167                                 return -EFAULT;
 168                         control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
 169                         return 0;
 170                 }
 171         }
 172         return -ENOIOCTLCMD;
 173 }
 174
 175 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 176
 177 static char *snd_pcm_format_names[] = {
 178         FORMAT(S8),
 179         FORMAT(U8),
 180         FORMAT(S16_LE),
 181         FORMAT(S16_BE),
 182         FORMAT(U16_LE),
 183         FORMAT(U16_BE),
 184         FORMAT(S24_LE),
 185         FORMAT(S24_BE),
 186         FORMAT(U24_LE),
 187         FORMAT(U24_BE),
 188         FORMAT(S32_LE),
 189         FORMAT(S32_BE),
 190         FORMAT(U32_LE),
 191         FORMAT(U32_BE),
 192         FORMAT(FLOAT_LE),
 193         FORMAT(FLOAT_BE),
 194         FORMAT(FLOAT64_LE),
 195         FORMAT(FLOAT64_BE),
 196         FORMAT(IEC958_SUBFRAME_LE),
 197         FORMAT(IEC958_SUBFRAME_BE),
 198         FORMAT(MU_LAW),
 199         FORMAT(A_LAW),
 200         FORMAT(IMA_ADPCM),
 201         FORMAT(MPEG),
 202         FORMAT(GSM),
 203         FORMAT(SPECIAL),
 204         FORMAT(S24_3LE),
 205         FORMAT(S24_3BE),
 206         FORMAT(U24_3LE),
 207         FORMAT(U24_3BE),
 208         FORMAT(S20_3LE),
 209         FORMAT(S20_3BE),
 210         FORMAT(U20_3LE),
 211         FORMAT(U20_3BE),
 212         FORMAT(S18_3LE),
 213         FORMAT(S18_3BE),
 214         FORMAT(U18_3LE),
 215         FORMAT(U18_3BE),
 216         FORMAT(G723_24),
 217         FORMAT(G723_24_1B),
 218         FORMAT(G723_40),
 219         FORMAT(G723_40_1B),
 220         FORMAT(DSD_U8),
 221         FORMAT(DSD_U16_LE),
 222         FORMAT(DSD_U32_LE),
 223         FORMAT(DSD_U16_BE),
 224         FORMAT(DSD_U32_BE),
 225 };
 226
 227 /**
 228  * snd_pcm_format_name - Return a name string for the given PCM format
 229  * @format: PCM format
 230  */
 231 const char *snd_pcm_format_name(snd_pcm_format_t format)
 232 {
 233         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 234                 return "Unknown";
 235         return snd_pcm_format_names[(__force unsigned int)format];
 236 }
 237 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 238
 239 #ifdef CONFIG_SND_VERBOSE_PROCFS
 240
 241 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 242 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 243 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 244 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 245 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 246 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 247 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 248 #define START(v) [SNDRV_PCM_START_##v] = #v
 249 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 250
 251 static char *snd_pcm_stream_names[] = {
 252         STREAM(PLAYBACK),
 253         STREAM(CAPTURE),
 254 };
 255
 256 static char *snd_pcm_state_names[] = {
 257         STATE(OPEN),
 258         STATE(SETUP),
 259         STATE(PREPARED),
 260         STATE(RUNNING),
 261         STATE(XRUN),
 262         STATE(DRAINING),
 263         STATE(PAUSED),
 264         STATE(SUSPENDED),
 265 };
 266
 267 static char *snd_pcm_access_names[] = {
 268         ACCESS(MMAP_INTERLEAVED),
 269         ACCESS(MMAP_NONINTERLEAVED),
 270         ACCESS(MMAP_COMPLEX),
 271         ACCESS(RW_INTERLEAVED),
 272         ACCESS(RW_NONINTERLEAVED),
 273 };
 274
 275 static char *snd_pcm_subformat_names[] = {
 276         SUBFORMAT(STD),
 277 };
 278
 279 static char *snd_pcm_tstamp_mode_names[] = {
 280         TSTAMP(NONE),
 281         TSTAMP(ENABLE),
 282 };
 283
 284 static const char *snd_pcm_stream_name(int stream)
 285 {
 286         return snd_pcm_stream_names[stream];
 287 }
 288
 289 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 290 {
 291         return snd_pcm_access_names[(__force int)access];
 292 }
 293
 294 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 295 {
 296         return snd_pcm_subformat_names[(__force int)subformat];
 297 }
 298
 299 static const char *snd_pcm_tstamp_mode_name(int mode)
 300 {
 301         return snd_pcm_tstamp_mode_names[mode];
 302 }
 303
 304 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 305 {
 306         return snd_pcm_state_names[(__force int)state];
 307 }
 308
 309 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 310 #include <linux/soundcard.h>
 311
 312 static const char *snd_pcm_oss_format_name(int format)
 313 {
 314         switch (format) {
 315         case AFMT_MU_LAW:
 316                 return "MU_LAW";
 317         case AFMT_A_LAW:
 318                 return "A_LAW";
 319         case AFMT_IMA_ADPCM:
 320                 return "IMA_ADPCM";
 321         case AFMT_U8:
 322                 return "U8";
 323         case AFMT_S16_LE:
 324                 return "S16_LE";
 325         case AFMT_S16_BE:
 326                 return "S16_BE";
 327         case AFMT_S8:
 328                 return "S8";
 329         case AFMT_U16_LE:
 330                 return "U16_LE";
 331         case AFMT_U16_BE:
 332                 return "U16_BE";
 333         case AFMT_MPEG:
 334                 return "MPEG";
 335         default:
 336                 return "unknown";
 337         }
 338 }
 339 #endif
 340
 341 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 342                                    struct snd_info_buffer *buffer)
 343 {
 344         struct snd_pcm_info *info;
 345         int err;
 346
 347         if (! substream)
 348                 return;
 349
 350         info = kmalloc(sizeof(*info), GFP_KERNEL);
 351         if (!info)
 352                 return;
 353
 354         err = snd_pcm_info(substream, info);
 355         if (err < 0) {
 356                 snd_iprintf(buffer, "error %d\n", err);
 357                 kfree(info);
 358                 return;
 359         }
 360         snd_iprintf(buffer, "card: %d\n", info->card);
 361         snd_iprintf(buffer, "device: %d\n", info->device);
 362         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 363         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 364         snd_iprintf(buffer, "id: %s\n", info->id);
 365         snd_iprintf(buffer, "name: %s\n", info->name);
 366         snd_iprintf(buffer, "subname: %s\n", info->subname);
 367         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 368         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 369         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 370         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 371         kfree(info);
 372 }
 373
 374 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 375                                           struct snd_info_buffer *buffer)
 376 {
 377         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 378                                buffer);
 379 }
 380
 381 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 382                                              struct snd_info_buffer *buffer)
 383 {
 384         snd_pcm_proc_info_read(entry->private_data, buffer);
 385 }
 386
 387 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 388                                                   struct snd_info_buffer *buffer)
 389 {
 390         struct snd_pcm_substream *substream = entry->private_data;
 391         struct snd_pcm_runtime *runtime;
 392
 393         mutex_lock(&substream->pcm->open_mutex);
 394         runtime = substream->runtime;
 395         if (!runtime) {
 396                 snd_iprintf(buffer, "closed\n");
 397                 goto unlock;
 398         }
 399         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 400                 snd_iprintf(buffer, "no setup\n");
 401                 goto unlock;
 402         }
 403         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 404         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 405         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 406         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 407         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 408         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 409         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 410 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 411         if (substream->oss.oss) {
 412                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 413                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 414                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 415                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 416                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 417                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 418         }
 419 #endif
 420  unlock:
 421         mutex_unlock(&substream->pcm->open_mutex);
 422 }
 423
 424 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 425                                                   struct snd_info_buffer *buffer)
 426 {
 427         struct snd_pcm_substream *substream = entry->private_data;
 428         struct snd_pcm_runtime *runtime;
 429
 430         mutex_lock(&substream->pcm->open_mutex);
 431         runtime = substream->runtime;
 432         if (!runtime) {
 433                 snd_iprintf(buffer, "closed\n");
 434                 goto unlock;
 435         }
 436         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 437                 snd_iprintf(buffer, "no setup\n");
 438                 goto unlock;
 439         }
 440         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 441         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 442         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 443         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 444         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 445         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 446         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 447         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 448  unlock:
 449         mutex_unlock(&substream->pcm->open_mutex);
 450 }
 451
 452 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 453                                                struct snd_info_buffer *buffer)
 454 {
 455         struct snd_pcm_substream *substream = entry->private_data;
 456         struct snd_pcm_runtime *runtime;
 457         struct snd_pcm_status status;
 458         int err;
 459
 460         mutex_lock(&substream->pcm->open_mutex);
 461         runtime = substream->runtime;
 462         if (!runtime) {
 463                 snd_iprintf(buffer, "closed\n");
 464                 goto unlock;
 465         }
 466         memset(&status, 0, sizeof(status));
 467         err = snd_pcm_status(substream, &status);
 468         if (err < 0) {
 469                 snd_iprintf(buffer, "error %d\n", err);
 470                 goto unlock;
 471         }
 472         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 473         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 474         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 475                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 476         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 477                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 478         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 479         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 480         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 481         snd_iprintf(buffer, "-----\n");
 482         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 483         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 484  unlock:
 485         mutex_unlock(&substream->pcm->open_mutex);
 486 }
 487
 488 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 489 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 490                                          struct snd_info_buffer *buffer)
 491 {
 492         struct snd_pcm_substream *substream = entry->private_data;
 493         struct snd_pcm_runtime *runtime;
 494
 495         snd_pcm_stream_lock_irq(substream);
 496         runtime = substream->runtime;
 497         if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
 498                 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 499         snd_pcm_stream_unlock_irq(substream);
 500 }
 501
 502 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 503                                     struct snd_info_buffer *buffer)
 504 {
 505         struct snd_pcm_str *pstr = entry->private_data;
 506         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 507 }
 508
 509 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 510                                      struct snd_info_buffer *buffer)
 511 {
 512         struct snd_pcm_str *pstr = entry->private_data;
 513         char line[64];
 514         if (!snd_info_get_line(buffer, line, sizeof(line)))
 515                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 516 }
 517 #endif
 518
 519 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 520 {
 521         struct snd_pcm *pcm = pstr->pcm;
 522         struct snd_info_entry *entry;
 523         char name[16];
 524
 525         sprintf(name, "pcm%i%c", pcm->device,
 526                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 527         if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
 528                 return -ENOMEM;
 529         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 530         if (snd_info_register(entry) < 0) {
 531                 snd_info_free_entry(entry);
 532                 return -ENOMEM;
 533         }
 534         pstr->proc_root = entry;
 535
 536         if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
 537                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 538                 if (snd_info_register(entry) < 0) {
 539                         snd_info_free_entry(entry);
 540                         entry = NULL;
 541                 }
 542         }
 543         pstr->proc_info_entry = entry;
 544
 545 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 546         if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 547                                                 pstr->proc_root)) != NULL) {
 548                 entry->c.text.read = snd_pcm_xrun_debug_read;
 549                 entry->c.text.write = snd_pcm_xrun_debug_write;
 550                 entry->mode |= S_IWUSR;
 551                 entry->private_data = pstr;
 552                 if (snd_info_register(entry) < 0) {
 553                         snd_info_free_entry(entry);
 554                         entry = NULL;
 555                 }
 556         }
 557         pstr->proc_xrun_debug_entry = entry;
 558 #endif
 559         return 0;
 560 }
 561
 562 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 563 {
 564 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 565         snd_info_free_entry(pstr->proc_xrun_debug_entry);
 566         pstr->proc_xrun_debug_entry = NULL;
 567 #endif
 568         snd_info_free_entry(pstr->proc_info_entry);
 569         pstr->proc_info_entry = NULL;
 570         snd_info_free_entry(pstr->proc_root);
 571         pstr->proc_root = NULL;
 572         return 0;
 573 }
 574
 575 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 576 {
 577         struct snd_info_entry *entry;
 578         struct snd_card *card;
 579         char name[16];
 580
 581         card = substream->pcm->card;
 582
 583         sprintf(name, "sub%i", substream->number);
 584         if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
 585                 return -ENOMEM;
 586         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 587         if (snd_info_register(entry) < 0) {
 588                 snd_info_free_entry(entry);
 589                 return -ENOMEM;
 590         }
 591         substream->proc_root = entry;
 592
 593         if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
 594                 snd_info_set_text_ops(entry, substream,
 595                                       snd_pcm_substream_proc_info_read);
 596                 if (snd_info_register(entry) < 0) {
 597                         snd_info_free_entry(entry);
 598                         entry = NULL;
 599                 }
 600         }
 601         substream->proc_info_entry = entry;
 602
 603         if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
 604                 snd_info_set_text_ops(entry, substream,
 605                                       snd_pcm_substream_proc_hw_params_read);
 606                 if (snd_info_register(entry) < 0) {
 607                         snd_info_free_entry(entry);
 608                         entry = NULL;
 609                 }
 610         }
 611         substream->proc_hw_params_entry = entry;
 612
 613         if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
 614                 snd_info_set_text_ops(entry, substream,
 615                                       snd_pcm_substream_proc_sw_params_read);
 616                 if (snd_info_register(entry) < 0) {
 617                         snd_info_free_entry(entry);
 618                         entry = NULL;
 619                 }
 620         }
 621         substream->proc_sw_params_entry = entry;
 622
 623         if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
 624                 snd_info_set_text_ops(entry, substream,
 625                                       snd_pcm_substream_proc_status_read);
 626                 if (snd_info_register(entry) < 0) {
 627                         snd_info_free_entry(entry);
 628                         entry = NULL;
 629                 }
 630         }
 631         substream->proc_status_entry = entry;
 632
 633 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 634         entry = snd_info_create_card_entry(card, "xrun_injection",
 635                                            substream->proc_root);
 636         if (entry) {
 637                 entry->private_data = substream;
 638                 entry->c.text.read = NULL;
 639                 entry->c.text.write = snd_pcm_xrun_injection_write;
 640                 entry->mode = S_IFREG | S_IWUSR;
 641                 if (snd_info_register(entry) < 0) {
 642                         snd_info_free_entry(entry);
 643                         entry = NULL;
 644                 }
 645         }
 646         substream->proc_xrun_injection_entry = entry;
 647 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 648
 649         return 0;
 650 }
 651
 652 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
 653 {
 654         snd_info_free_entry(substream->proc_info_entry);
 655         substream->proc_info_entry = NULL;
 656         snd_info_free_entry(substream->proc_hw_params_entry);
 657         substream->proc_hw_params_entry = NULL;
 658         snd_info_free_entry(substream->proc_sw_params_entry);
 659         substream->proc_sw_params_entry = NULL;
 660         snd_info_free_entry(substream->proc_status_entry);
 661         substream->proc_status_entry = NULL;
 662 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 663         snd_info_free_entry(substream->proc_xrun_injection_entry);
 664         substream->proc_xrun_injection_entry = NULL;
 665 #endif
 666         snd_info_free_entry(substream->proc_root);
 667         substream->proc_root = NULL;
 668         return 0;
 669 }
 670 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 671 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 672 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 673 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 674 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 675 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 676
 677 static const struct attribute_group *pcm_dev_attr_groups[];
 678
 679 /**
 680  * snd_pcm_new_stream - create a new PCM stream
 681  * @pcm: the pcm instance
 682  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 683  * @substream_count: the number of substreams
 684  *
 685  * Creates a new stream for the pcm.
 686  * The corresponding stream on the pcm must have been empty before
 687  * calling this, i.e. zero must be given to the argument of
 688  * snd_pcm_new().
 689  *
 690  * Return: Zero if successful, or a negative error code on failure.
 691  */
 692 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 693 {
 694         int idx, err;
 695         struct snd_pcm_str *pstr = &pcm->streams[stream];
 696         struct snd_pcm_substream *substream, *prev;
 697
 698 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 699         mutex_init(&pstr->oss.setup_mutex);
 700 #endif
 701         pstr->stream = stream;
 702         pstr->pcm = pcm;
 703         pstr->substream_count = substream_count;
 704         if (!substream_count)
 705                 return 0;
 706
 707         snd_device_initialize(&pstr->dev, pcm->card);
 708         pstr->dev.groups = pcm_dev_attr_groups;
 709         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 710                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 711
 712         if (!pcm->internal) {
 713                 err = snd_pcm_stream_proc_init(pstr);
 714                 if (err < 0) {
 715                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 716                         return err;
 717                 }
 718         }
 719         prev = NULL;
 720         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 721                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 722                 if (!substream)
 723                         return -ENOMEM;
 724                 substream->pcm = pcm;
 725                 substream->pstr = pstr;
 726                 substream->number = idx;
 727                 substream->stream = stream;
 728                 sprintf(substream->name, "subdevice #%i", idx);
 729                 substream->buffer_bytes_max = UINT_MAX;
 730                 if (prev == NULL)
 731                         pstr->substream = substream;
 732                 else
 733                         prev->next = substream;
 734
 735                 if (!pcm->internal) {
 736                         err = snd_pcm_substream_proc_init(substream);
 737                         if (err < 0) {
 738                                 pcm_err(pcm,
 739                                         "Error in snd_pcm_stream_proc_init\n");
 740                                 if (prev == NULL)
 741                                         pstr->substream = NULL;
 742                                 else
 743                                         prev->next = NULL;
 744                                 kfree(substream);
 745                                 return err;
 746                         }
 747                 }
 748                 substream->group = &substream->self_group;
 749                 spin_lock_init(&substream->self_group.lock);
 750                 mutex_init(&substream->self_group.mutex);
 751                 INIT_LIST_HEAD(&substream->self_group.substreams);
 752                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 753                 atomic_set(&substream->mmap_count, 0);
 754                 prev = substream;
 755         }
 756         return 0;
 757 }
 758 EXPORT_SYMBOL(snd_pcm_new_stream);
 759
 760 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 761                 int playback_count, int capture_count, bool internal,
 762                 struct snd_pcm **rpcm)
 763 {
 764         struct snd_pcm *pcm;
 765         int err;
 766         static struct snd_device_ops ops = {
 767                 .dev_free = snd_pcm_dev_free,
 768                 .dev_register = snd_pcm_dev_register,
 769                 .dev_disconnect = snd_pcm_dev_disconnect,
 770         };
 771
 772         if (snd_BUG_ON(!card))
 773                 return -ENXIO;
 774         if (rpcm)
 775                 *rpcm = NULL;
 776         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 777         if (!pcm)
 778                 return -ENOMEM;
 779         pcm->card = card;
 780         pcm->device = device;
 781         pcm->internal = internal;
 782         mutex_init(&pcm->open_mutex);
 783         init_waitqueue_head(&pcm->open_wait);
 784         INIT_LIST_HEAD(&pcm->list);
 785         if (id)
 786                 strlcpy(pcm->id, id, sizeof(pcm->id));
 787         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
 788                 snd_pcm_free(pcm);
 789                 return err;
 790         }
 791         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
 792                 snd_pcm_free(pcm);
 793                 return err;
 794         }
 795         if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
 796                 snd_pcm_free(pcm);
 797                 return err;
 798         }
 799         if (rpcm)
 800                 *rpcm = pcm;
 801         return 0;
 802 }
 803
 804 /**
 805  * snd_pcm_new - create a new PCM instance
 806  * @card: the card instance
 807  * @id: the id string
 808  * @device: the device index (zero based)
 809  * @playback_count: the number of substreams for playback
 810  * @capture_count: the number of substreams for capture
 811  * @rpcm: the pointer to store the new pcm instance
 812  *
 813  * Creates a new PCM instance.
 814  *
 815  * The pcm operators have to be set afterwards to the new instance
 816  * via snd_pcm_set_ops().
 817  *
 818  * Return: Zero if successful, or a negative error code on failure.
 819  */
 820 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 821                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 822 {
 823         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 824                         false, rpcm);
 825 }
 826 EXPORT_SYMBOL(snd_pcm_new);
 827
 828 /**
 829  * snd_pcm_new_internal - create a new internal PCM instance
 830  * @card: the card instance
 831  * @id: the id string
 832  * @device: the device index (zero based - shared with normal PCMs)
 833  * @playback_count: the number of substreams for playback
 834  * @capture_count: the number of substreams for capture
 835  * @rpcm: the pointer to store the new pcm instance
 836  *
 837  * Creates a new internal PCM instance with no userspace device or procfs
 838  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 839  * will only be used internally by kernel drivers. i.e. it cannot be opened
 840  * by userspace. It provides existing ASoC components drivers with a substream
 841  * and access to any private data.
 842  *
 843  * The pcm operators have to be set afterwards to the new instance
 844  * via snd_pcm_set_ops().
 845  *
 846  * Return: Zero if successful, or a negative error code on failure.
 847  */
 848 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 849         int playback_count, int capture_count,
 850         struct snd_pcm **rpcm)
 851 {
 852         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 853                         true, rpcm);
 854 }
 855 EXPORT_SYMBOL(snd_pcm_new_internal);
 856
 857 static void free_chmap(struct snd_pcm_str *pstr)
 858 {
 859         if (pstr->chmap_kctl) {
 860                 snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
 861                 pstr->chmap_kctl = NULL;
 862         }
 863 }
 864
 865 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 866 {
 867         struct snd_pcm_substream *substream, *substream_next;
 868 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 869         struct snd_pcm_oss_setup *setup, *setupn;
 870 #endif
 871         substream = pstr->substream;
 872         while (substream) {
 873                 substream_next = substream->next;
 874                 snd_pcm_timer_done(substream);
 875                 snd_pcm_substream_proc_done(substream);
 876                 kfree(substream);
 877                 substream = substream_next;
 878         }
 879         snd_pcm_stream_proc_done(pstr);
 880 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 881         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 882                 setupn = setup->next;
 883                 kfree(setup->task_name);
 884                 kfree(setup);
 885         }
 886 #endif
 887         free_chmap(pstr);
 888         if (pstr->substream_count)
 889                 put_device(&pstr->dev);
 890 }
 891
 892 static int snd_pcm_free(struct snd_pcm *pcm)
 893 {
 894         struct snd_pcm_notify *notify;
 895
 896         if (!pcm)
 897                 return 0;
 898         if (!pcm->internal) {
 899                 list_for_each_entry(notify, &snd_pcm_notify_list, list)
 900                         notify->n_unregister(pcm);
 901         }
 902         if (pcm->private_free)
 903                 pcm->private_free(pcm);
 904         snd_pcm_lib_preallocate_free_for_all(pcm);
 905         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 906         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 907         kfree(pcm);
 908         return 0;
 909 }
 910
 911 static int snd_pcm_dev_free(struct snd_device *device)
 912 {
 913         struct snd_pcm *pcm = device->device_data;
 914         return snd_pcm_free(pcm);
 915 }
 916
 917 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 918                              struct file *file,
 919                              struct snd_pcm_substream **rsubstream)
 920 {
 921         struct snd_pcm_str * pstr;
 922         struct snd_pcm_substream *substream;
 923         struct snd_pcm_runtime *runtime;
 924         struct snd_card *card;
 925         int prefer_subdevice;
 926         size_t size;
 927
 928         if (snd_BUG_ON(!pcm || !rsubstream))
 929                 return -ENXIO;
 930         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 931                        stream != SNDRV_PCM_STREAM_CAPTURE))
 932                 return -EINVAL;
 933         *rsubstream = NULL;
 934         pstr = &pcm->streams[stream];
 935         if (pstr->substream == NULL || pstr->substream_count == 0)
 936                 return -ENODEV;
 937
 938         card = pcm->card;
 939         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 940
 941         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 942                 int opposite = !stream;
 943
 944                 for (substream = pcm->streams[opposite].substream; substream;
 945                      substream = substream->next) {
 946                         if (SUBSTREAM_BUSY(substream))
 947                                 return -EAGAIN;
 948                 }
 949         }
 950
 951         if (file->f_flags & O_APPEND) {
 952                 if (prefer_subdevice < 0) {
 953                         if (pstr->substream_count > 1)
 954                                 return -EINVAL; /* must be unique */
 955                         substream = pstr->substream;
 956                 } else {
 957                         for (substream = pstr->substream; substream;
 958                              substream = substream->next)
 959                                 if (substream->number == prefer_subdevice)
 960                                         break;
 961                 }
 962                 if (! substream)
 963                         return -ENODEV;
 964                 if (! SUBSTREAM_BUSY(substream))
 965                         return -EBADFD;
 966                 substream->ref_count++;
 967                 *rsubstream = substream;
 968                 return 0;
 969         }
 970
 971         for (substream = pstr->substream; substream; substream = substream->next) {
 972                 if (!SUBSTREAM_BUSY(substream) &&
 973                     (prefer_subdevice == -1 ||
 974                      substream->number == prefer_subdevice))
 975                         break;
 976         }
 977         if (substream == NULL)
 978                 return -EAGAIN;
 979
 980         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 981         if (runtime == NULL)
 982                 return -ENOMEM;
 983
 984         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 985         runtime->status = snd_malloc_pages(size, GFP_KERNEL);
 986         if (runtime->status == NULL) {
 987                 kfree(runtime);
 988                 return -ENOMEM;
 989         }
 990         memset((void*)runtime->status, 0, size);
 991
 992         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 993         runtime->control = snd_malloc_pages(size, GFP_KERNEL);
 994         if (runtime->control == NULL) {
 995                 snd_free_pages((void*)runtime->status,
 996                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 997                 kfree(runtime);
 998                 return -ENOMEM;
 999         }
1000         memset((void*)runtime->control, 0, size);
1001
1002         init_waitqueue_head(&runtime->sleep);
1003         init_waitqueue_head(&runtime->tsleep);
1004
1005         runtime->status->state = SNDRV_PCM_STATE_OPEN;
1006
1007         substream->runtime = runtime;
1008         substream->private_data = pcm->private_data;
1009         substream->ref_count = 1;
1010         substream->f_flags = file->f_flags;
1011         substream->pid = get_pid(task_pid(current));
1012         pstr->substream_opened++;
1013         *rsubstream = substream;
1014         return 0;
1015 }
1016
1017 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1018 {
1019         struct snd_pcm_runtime *runtime;
1020
1021         if (PCM_RUNTIME_CHECK(substream))
1022                 return;
1023         runtime = substream->runtime;
1024         if (runtime->private_free != NULL)
1025                 runtime->private_free(runtime);
1026         snd_free_pages((void*)runtime->status,
1027                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1028         snd_free_pages((void*)runtime->control,
1029                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1030         kfree(runtime->hw_constraints.rules);
1031         /* Avoid concurrent access to runtime via PCM timer interface */
1032         if (substream->timer)
1033                 spin_lock_irq(&substream->timer->lock);
1034         substream->runtime = NULL;
1035         if (substream->timer)
1036                 spin_unlock_irq(&substream->timer->lock);
1037         kfree(runtime);
1038         put_pid(substream->pid);
1039         substream->pid = NULL;
1040         substream->pstr->substream_opened--;
1041 }
1042
1043 static ssize_t show_pcm_class(struct device *dev,
1044                               struct device_attribute *attr, char *buf)
1045 {
1046         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1047         struct snd_pcm *pcm = pstr->pcm;
1048         const char *str;
1049         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1050                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1051                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1052                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1053                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1054         };
1055
1056         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1057                 str = "none";
1058         else
1059                 str = strs[pcm->dev_class];
1060         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1061 }
1062
1063 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1064 static struct attribute *pcm_dev_attrs[] = {
1065         &dev_attr_pcm_class.attr,
1066         NULL
1067 };
1068
1069 static struct attribute_group pcm_dev_attr_group = {
1070         .attrs  = pcm_dev_attrs,
1071 };
1072
1073 static const struct attribute_group *pcm_dev_attr_groups[] = {
1074         &pcm_dev_attr_group,
1075         NULL
1076 };
1077
1078 static int snd_pcm_dev_register(struct snd_device *device)
1079 {
1080         int cidx, err;
1081         struct snd_pcm_substream *substream;
1082         struct snd_pcm_notify *notify;
1083         struct snd_pcm *pcm;
1084
1085         if (snd_BUG_ON(!device || !device->device_data))
1086                 return -ENXIO;
1087         pcm = device->device_data;
1088         if (pcm->internal)
1089                 return 0;
1090
1091         mutex_lock(&register_mutex);
1092         err = snd_pcm_add(pcm);
1093         if (err)
1094                 goto unlock;
1095         for (cidx = 0; cidx < 2; cidx++) {
1096                 int devtype = -1;
1097                 if (pcm->streams[cidx].substream == NULL)
1098                         continue;
1099                 switch (cidx) {
1100                 case SNDRV_PCM_STREAM_PLAYBACK:
1101                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1102                         break;
1103                 case SNDRV_PCM_STREAM_CAPTURE:
1104                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1105                         break;
1106                 }
1107                 /* register pcm */
1108                 err = snd_register_device(devtype, pcm->card, pcm->device,
1109                                           &snd_pcm_f_ops[cidx], pcm,
1110                                           &pcm->streams[cidx].dev);
1111                 if (err < 0) {
1112                         list_del_init(&pcm->list);
1113                         goto unlock;
1114                 }
1115
1116                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1117                         snd_pcm_timer_init(substream);
1118         }
1119
1120         list_for_each_entry(notify, &snd_pcm_notify_list, list)
1121                 notify->n_register(pcm);
1122
1123  unlock:
1124         mutex_unlock(&register_mutex);
1125         return err;
1126 }
1127
1128 static int snd_pcm_dev_disconnect(struct snd_device *device)
1129 {
1130         struct snd_pcm *pcm = device->device_data;
1131         struct snd_pcm_notify *notify;
1132         struct snd_pcm_substream *substream;
1133         int cidx;
1134
1135         mutex_lock(&register_mutex);
1136         mutex_lock(&pcm->open_mutex);
1137         wake_up(&pcm->open_wait);
1138         list_del_init(&pcm->list);
1139         for (cidx = 0; cidx < 2; cidx++) {
1140                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1141                         snd_pcm_stream_lock_irq(substream);
1142                         if (substream->runtime) {
1143                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1144                                 wake_up(&substream->runtime->sleep);
1145                                 wake_up(&substream->runtime->tsleep);
1146                         }
1147                         snd_pcm_stream_unlock_irq(substream);
1148                 }
1149         }
1150         if (!pcm->internal) {
1151                 list_for_each_entry(notify, &snd_pcm_notify_list, list)
1152                         notify->n_disconnect(pcm);
1153         }
1154         for (cidx = 0; cidx < 2; cidx++) {
1155                 if (!pcm->internal)
1156                         snd_unregister_device(&pcm->streams[cidx].dev);
1157                 free_chmap(&pcm->streams[cidx]);
1158         }
1159         mutex_unlock(&pcm->open_mutex);
1160         mutex_unlock(&register_mutex);
1161         return 0;
1162 }
1163
1164 /**
1165  * snd_pcm_notify - Add/remove the notify list
1166  * @notify: PCM notify list
1167  * @nfree: 0 = register, 1 = unregister
1168  *
1169  * This adds the given notifier to the global list so that the callback is
1170  * called for each registered PCM devices.  This exists only for PCM OSS
1171  * emulation, so far.
1172  */
1173 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1174 {
1175         struct snd_pcm *pcm;
1176
1177         if (snd_BUG_ON(!notify ||
1178                        !notify->n_register ||
1179                        !notify->n_unregister ||
1180                        !notify->n_disconnect))
1181                 return -EINVAL;
1182         mutex_lock(&register_mutex);
1183         if (nfree) {
1184                 list_del(&notify->list);
1185                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1186                         notify->n_unregister(pcm);
1187         } else {
1188                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1189                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1190                         notify->n_register(pcm);
1191         }
1192         mutex_unlock(&register_mutex);
1193         return 0;
1194 }
1195 EXPORT_SYMBOL(snd_pcm_notify);
1196
1197 #ifdef CONFIG_SND_PROC_FS
1198 /*
1199  *  Info interface
1200  */
1201
1202 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1203                               struct snd_info_buffer *buffer)
1204 {
1205         struct snd_pcm *pcm;
1206
1207         mutex_lock(&register_mutex);
1208         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1209                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1210                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1211                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1212                         snd_iprintf(buffer, " : playback %i",
1213                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1214                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1215                         snd_iprintf(buffer, " : capture %i",
1216                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1217                 snd_iprintf(buffer, "\n");
1218         }
1219         mutex_unlock(&register_mutex);
1220 }
1221
1222 static struct snd_info_entry *snd_pcm_proc_entry;
1223
1224 static void snd_pcm_proc_init(void)
1225 {
1226         struct snd_info_entry *entry;
1227
1228         if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
1229                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1230                 if (snd_info_register(entry) < 0) {
1231                         snd_info_free_entry(entry);
1232                         entry = NULL;
1233                 }
1234         }
1235         snd_pcm_proc_entry = entry;
1236 }
1237
1238 static void snd_pcm_proc_done(void)
1239 {
1240         snd_info_free_entry(snd_pcm_proc_entry);
1241 }
1242
1243 #else /* !CONFIG_SND_PROC_FS */
1244 #define snd_pcm_proc_init()
1245 #define snd_pcm_proc_done()
1246 #endif /* CONFIG_SND_PROC_FS */
1247
1248
1249 /*
1250  *  ENTRY functions
1251  */
1252
1253 static int __init alsa_pcm_init(void)
1254 {
1255         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1256         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1257         snd_pcm_proc_init();
1258         return 0;
1259 }
1260
1261 static void __exit alsa_pcm_exit(void)
1262 {
1263         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1264         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1265         snd_pcm_proc_done();
1266 }
1267
1268 module_init(alsa_pcm_init)
1269 module_exit(alsa_pcm_exit)