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