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 #include "pcm_local.h"
  37
  38 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  39 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  40 MODULE_LICENSE("GPL");
  41
  42 static LIST_HEAD(snd_pcm_devices);
  43 static DEFINE_MUTEX(register_mutex);
  44 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  45 static LIST_HEAD(snd_pcm_notify_list);
  46 #endif
  47
  48 static int snd_pcm_free(struct snd_pcm *pcm);
  49 static int snd_pcm_dev_free(struct snd_device *device);
  50 static int snd_pcm_dev_register(struct snd_device *device);
  51 static int snd_pcm_dev_disconnect(struct snd_device *device);
  52
  53 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  54 {
  55         struct snd_pcm *pcm;
  56
  57         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  58                 if (pcm->card == card && pcm->device == device)
  59                         return pcm;
  60         }
  61         return NULL;
  62 }
  63
  64 static int snd_pcm_next(struct snd_card *card, int device)
  65 {
  66         struct snd_pcm *pcm;
  67
  68         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  69                 if (pcm->card == card && pcm->device > device)
  70                         return pcm->device;
  71                 else if (pcm->card->number > card->number)
  72                         return -1;
  73         }
  74         return -1;
  75 }
  76
  77 static int snd_pcm_add(struct snd_pcm *newpcm)
  78 {
  79         struct snd_pcm *pcm;
  80
  81         if (newpcm->internal)
  82                 return 0;
  83
  84         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  85                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  86                         return -EBUSY;
  87                 if (pcm->card->number > newpcm->card->number ||
  88                                 (pcm->card == newpcm->card &&
  89                                 pcm->device > newpcm->device)) {
  90                         list_add(&newpcm->list, pcm->list.prev);
  91                         return 0;
  92                 }
  93         }
  94         list_add_tail(&newpcm->list, &snd_pcm_devices);
  95         return 0;
  96 }
  97
  98 static int snd_pcm_control_ioctl(struct snd_card *card,
  99                                  struct snd_ctl_file *control,
 100                                  unsigned int cmd, unsigned long arg)
 101 {
 102         switch (cmd) {
 103         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
 104                 {
 105                         int device;
 106
 107                         if (get_user(device, (int __user *)arg))
 108                                 return -EFAULT;
 109                         mutex_lock(&register_mutex);
 110                         device = snd_pcm_next(card, device);
 111                         mutex_unlock(&register_mutex);
 112                         if (put_user(device, (int __user *)arg))
 113                                 return -EFAULT;
 114                         return 0;
 115                 }
 116         case SNDRV_CTL_IOCTL_PCM_INFO:
 117                 {
 118                         struct snd_pcm_info __user *info;
 119                         unsigned int device, subdevice;
 120                         int stream;
 121                         struct snd_pcm *pcm;
 122                         struct snd_pcm_str *pstr;
 123                         struct snd_pcm_substream *substream;
 124                         int err;
 125
 126                         info = (struct snd_pcm_info __user *)arg;
 127                         if (get_user(device, &info->device))
 128                                 return -EFAULT;
 129                         if (get_user(stream, &info->stream))
 130                                 return -EFAULT;
 131                         if (stream < 0 || stream > 1)
 132                                 return -EINVAL;
 133                         stream = array_index_nospec(stream, 2);
 134                         if (get_user(subdevice, &info->subdevice))
 135                                 return -EFAULT;
 136                         mutex_lock(&register_mutex);
 137                         pcm = snd_pcm_get(card, device);
 138                         if (pcm == NULL) {
 139                                 err = -ENXIO;
 140                                 goto _error;
 141                         }
 142                         pstr = &pcm->streams[stream];
 143                         if (pstr->substream_count == 0) {
 144                                 err = -ENOENT;
 145                                 goto _error;
 146                         }
 147                         if (subdevice >= pstr->substream_count) {
 148                                 err = -ENXIO;
 149                                 goto _error;
 150                         }
 151                         for (substream = pstr->substream; substream;
 152                              substream = substream->next)
 153                                 if (substream->number == (int)subdevice)
 154                                         break;
 155                         if (substream == NULL) {
 156                                 err = -ENXIO;
 157                                 goto _error;
 158                         }
 159                         mutex_lock(&pcm->open_mutex);
 160                         err = snd_pcm_info_user(substream, info);
 161                         mutex_unlock(&pcm->open_mutex);
 162                 _error:
 163                         mutex_unlock(&register_mutex);
 164                         return err;
 165                 }
 166         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 167                 {
 168                         int val;
 169
 170                         if (get_user(val, (int __user *)arg))
 171                                 return -EFAULT;
 172                         control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
 173                         return 0;
 174                 }
 175         }
 176         return -ENOIOCTLCMD;
 177 }
 178
 179 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 180
 181 static char *snd_pcm_format_names[] = {
 182         FORMAT(S8),
 183         FORMAT(U8),
 184         FORMAT(S16_LE),
 185         FORMAT(S16_BE),
 186         FORMAT(U16_LE),
 187         FORMAT(U16_BE),
 188         FORMAT(S24_LE),
 189         FORMAT(S24_BE),
 190         FORMAT(U24_LE),
 191         FORMAT(U24_BE),
 192         FORMAT(S32_LE),
 193         FORMAT(S32_BE),
 194         FORMAT(U32_LE),
 195         FORMAT(U32_BE),
 196         FORMAT(FLOAT_LE),
 197         FORMAT(FLOAT_BE),
 198         FORMAT(FLOAT64_LE),
 199         FORMAT(FLOAT64_BE),
 200         FORMAT(IEC958_SUBFRAME_LE),
 201         FORMAT(IEC958_SUBFRAME_BE),
 202         FORMAT(MU_LAW),
 203         FORMAT(A_LAW),
 204         FORMAT(IMA_ADPCM),
 205         FORMAT(MPEG),
 206         FORMAT(GSM),
 207         FORMAT(SPECIAL),
 208         FORMAT(S24_3LE),
 209         FORMAT(S24_3BE),
 210         FORMAT(U24_3LE),
 211         FORMAT(U24_3BE),
 212         FORMAT(S20_3LE),
 213         FORMAT(S20_3BE),
 214         FORMAT(U20_3LE),
 215         FORMAT(U20_3BE),
 216         FORMAT(S18_3LE),
 217         FORMAT(S18_3BE),
 218         FORMAT(U18_3LE),
 219         FORMAT(U18_3BE),
 220         FORMAT(G723_24),
 221         FORMAT(G723_24_1B),
 222         FORMAT(G723_40),
 223         FORMAT(G723_40_1B),
 224         FORMAT(DSD_U8),
 225         FORMAT(DSD_U16_LE),
 226         FORMAT(DSD_U32_LE),
 227         FORMAT(DSD_U16_BE),
 228         FORMAT(DSD_U32_BE),
 229 };
 230
 231 /**
 232  * snd_pcm_format_name - Return a name string for the given PCM format
 233  * @format: PCM format
 234  */
 235 const char *snd_pcm_format_name(snd_pcm_format_t format)
 236 {
 237         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 238                 return "Unknown";
 239         return snd_pcm_format_names[(__force unsigned int)format];
 240 }
 241 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 242
 243 #ifdef CONFIG_SND_VERBOSE_PROCFS
 244
 245 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 246 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 247 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 248 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 249 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 250 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 251 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 252 #define START(v) [SNDRV_PCM_START_##v] = #v
 253 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 254
 255 static char *snd_pcm_stream_names[] = {
 256         STREAM(PLAYBACK),
 257         STREAM(CAPTURE),
 258 };
 259
 260 static char *snd_pcm_state_names[] = {
 261         STATE(OPEN),
 262         STATE(SETUP),
 263         STATE(PREPARED),
 264         STATE(RUNNING),
 265         STATE(XRUN),
 266         STATE(DRAINING),
 267         STATE(PAUSED),
 268         STATE(SUSPENDED),
 269 };
 270
 271 static char *snd_pcm_access_names[] = {
 272         ACCESS(MMAP_INTERLEAVED),
 273         ACCESS(MMAP_NONINTERLEAVED),
 274         ACCESS(MMAP_COMPLEX),
 275         ACCESS(RW_INTERLEAVED),
 276         ACCESS(RW_NONINTERLEAVED),
 277 };
 278
 279 static char *snd_pcm_subformat_names[] = {
 280         SUBFORMAT(STD),
 281 };
 282
 283 static char *snd_pcm_tstamp_mode_names[] = {
 284         TSTAMP(NONE),
 285         TSTAMP(ENABLE),
 286 };
 287
 288 static const char *snd_pcm_stream_name(int stream)
 289 {
 290         return snd_pcm_stream_names[stream];
 291 }
 292
 293 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 294 {
 295         return snd_pcm_access_names[(__force int)access];
 296 }
 297
 298 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 299 {
 300         return snd_pcm_subformat_names[(__force int)subformat];
 301 }
 302
 303 static const char *snd_pcm_tstamp_mode_name(int mode)
 304 {
 305         return snd_pcm_tstamp_mode_names[mode];
 306 }
 307
 308 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 309 {
 310         return snd_pcm_state_names[(__force int)state];
 311 }
 312
 313 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 314 #include <linux/soundcard.h>
 315
 316 static const char *snd_pcm_oss_format_name(int format)
 317 {
 318         switch (format) {
 319         case AFMT_MU_LAW:
 320                 return "MU_LAW";
 321         case AFMT_A_LAW:
 322                 return "A_LAW";
 323         case AFMT_IMA_ADPCM:
 324                 return "IMA_ADPCM";
 325         case AFMT_U8:
 326                 return "U8";
 327         case AFMT_S16_LE:
 328                 return "S16_LE";
 329         case AFMT_S16_BE:
 330                 return "S16_BE";
 331         case AFMT_S8:
 332                 return "S8";
 333         case AFMT_U16_LE:
 334                 return "U16_LE";
 335         case AFMT_U16_BE:
 336                 return "U16_BE";
 337         case AFMT_MPEG:
 338                 return "MPEG";
 339         default:
 340                 return "unknown";
 341         }
 342 }
 343 #endif
 344
 345 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 346                                    struct snd_info_buffer *buffer)
 347 {
 348         struct snd_pcm_info *info;
 349         int err;
 350
 351         if (! substream)
 352                 return;
 353
 354         info = kmalloc(sizeof(*info), GFP_KERNEL);
 355         if (!info)
 356                 return;
 357
 358         err = snd_pcm_info(substream, info);
 359         if (err < 0) {
 360                 snd_iprintf(buffer, "error %d\n", err);
 361                 kfree(info);
 362                 return;
 363         }
 364         snd_iprintf(buffer, "card: %d\n", info->card);
 365         snd_iprintf(buffer, "device: %d\n", info->device);
 366         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 367         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 368         snd_iprintf(buffer, "id: %s\n", info->id);
 369         snd_iprintf(buffer, "name: %s\n", info->name);
 370         snd_iprintf(buffer, "subname: %s\n", info->subname);
 371         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 372         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 373         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 374         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 375         kfree(info);
 376 }
 377
 378 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 379                                           struct snd_info_buffer *buffer)
 380 {
 381         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 382                                buffer);
 383 }
 384
 385 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 386                                              struct snd_info_buffer *buffer)
 387 {
 388         snd_pcm_proc_info_read(entry->private_data, buffer);
 389 }
 390
 391 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 392                                                   struct snd_info_buffer *buffer)
 393 {
 394         struct snd_pcm_substream *substream = entry->private_data;
 395         struct snd_pcm_runtime *runtime;
 396
 397         mutex_lock(&substream->pcm->open_mutex);
 398         runtime = substream->runtime;
 399         if (!runtime) {
 400                 snd_iprintf(buffer, "closed\n");
 401                 goto unlock;
 402         }
 403         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 404                 snd_iprintf(buffer, "no setup\n");
 405                 goto unlock;
 406         }
 407         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 408         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 409         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 410         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 411         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 412         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 413         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 414 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 415         if (substream->oss.oss) {
 416                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 417                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 418                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 419                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 420                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 421                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 422         }
 423 #endif
 424  unlock:
 425         mutex_unlock(&substream->pcm->open_mutex);
 426 }
 427
 428 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 429                                                   struct snd_info_buffer *buffer)
 430 {
 431         struct snd_pcm_substream *substream = entry->private_data;
 432         struct snd_pcm_runtime *runtime;
 433
 434         mutex_lock(&substream->pcm->open_mutex);
 435         runtime = substream->runtime;
 436         if (!runtime) {
 437                 snd_iprintf(buffer, "closed\n");
 438                 goto unlock;
 439         }
 440         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 441                 snd_iprintf(buffer, "no setup\n");
 442                 goto unlock;
 443         }
 444         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 445         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 446         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 447         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 448         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 449         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 450         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 451         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 452  unlock:
 453         mutex_unlock(&substream->pcm->open_mutex);
 454 }
 455
 456 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 457                                                struct snd_info_buffer *buffer)
 458 {
 459         struct snd_pcm_substream *substream = entry->private_data;
 460         struct snd_pcm_runtime *runtime;
 461         struct snd_pcm_status status;
 462         int err;
 463
 464         mutex_lock(&substream->pcm->open_mutex);
 465         runtime = substream->runtime;
 466         if (!runtime) {
 467                 snd_iprintf(buffer, "closed\n");
 468                 goto unlock;
 469         }
 470         memset(&status, 0, sizeof(status));
 471         err = snd_pcm_status(substream, &status);
 472         if (err < 0) {
 473                 snd_iprintf(buffer, "error %d\n", err);
 474                 goto unlock;
 475         }
 476         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 477         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 478         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 479                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 480         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 481                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 482         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 483         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 484         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 485         snd_iprintf(buffer, "-----\n");
 486         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 487         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 488  unlock:
 489         mutex_unlock(&substream->pcm->open_mutex);
 490 }
 491
 492 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 493 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 494                                          struct snd_info_buffer *buffer)
 495 {
 496         struct snd_pcm_substream *substream = entry->private_data;
 497
 498         snd_pcm_stop_xrun(substream);
 499 }
 500
 501 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 502                                     struct snd_info_buffer *buffer)
 503 {
 504         struct snd_pcm_str *pstr = entry->private_data;
 505         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 506 }
 507
 508 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 509                                      struct snd_info_buffer *buffer)
 510 {
 511         struct snd_pcm_str *pstr = entry->private_data;
 512         char line[64];
 513         if (!snd_info_get_line(buffer, line, sizeof(line)))
 514                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 515 }
 516 #endif
 517
 518 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 519 {
 520         struct snd_pcm *pcm = pstr->pcm;
 521         struct snd_info_entry *entry;
 522         char name[16];
 523
 524         sprintf(name, "pcm%i%c", pcm->device,
 525                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 526         entry = snd_info_create_card_entry(pcm->card, name,
 527                                            pcm->card->proc_root);
 528         if (!entry)
 529                 return -ENOMEM;
 530         entry->mode = S_IFDIR | 0555;
 531         pstr->proc_root = entry;
 532         entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
 533         if (entry)
 534                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 535 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 536         entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 537                                            pstr->proc_root);
 538         if (entry) {
 539                 snd_info_set_text_ops(entry, pstr, snd_pcm_xrun_debug_read);
 540                 entry->c.text.write = snd_pcm_xrun_debug_write;
 541                 entry->mode |= 0200;
 542         }
 543 #endif
 544         return 0;
 545 }
 546
 547 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 548 {
 549         snd_info_free_entry(pstr->proc_root);
 550         pstr->proc_root = NULL;
 551         return 0;
 552 }
 553
 554 static struct snd_info_entry *
 555 create_substream_info_entry(struct snd_pcm_substream *substream,
 556                             const char *name,
 557                             void (*read)(struct snd_info_entry *,
 558                                          struct snd_info_buffer *))
 559 {
 560         struct snd_info_entry *entry;
 561
 562         entry = snd_info_create_card_entry(substream->pcm->card, name,
 563                                            substream->proc_root);
 564         if (entry)
 565                 snd_info_set_text_ops(entry, substream, read);
 566         return entry;
 567 }
 568
 569 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 570 {
 571         struct snd_info_entry *entry;
 572         struct snd_card *card;
 573         char name[16];
 574
 575         card = substream->pcm->card;
 576
 577         sprintf(name, "sub%i", substream->number);
 578         entry = snd_info_create_card_entry(card, name,
 579                                            substream->pstr->proc_root);
 580         if (!entry)
 581                 return -ENOMEM;
 582         entry->mode = S_IFDIR | 0555;
 583         substream->proc_root = entry;
 584
 585         create_substream_info_entry(substream, "info",
 586                                     snd_pcm_substream_proc_info_read);
 587         create_substream_info_entry(substream, "hw_params",
 588                                     snd_pcm_substream_proc_hw_params_read);
 589         create_substream_info_entry(substream, "sw_params",
 590                                     snd_pcm_substream_proc_sw_params_read);
 591         create_substream_info_entry(substream, "status",
 592                                     snd_pcm_substream_proc_status_read);
 593
 594 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 595         entry = create_substream_info_entry(substream, "xrun_injection", NULL);
 596         if (entry) {
 597                 entry->c.text.write = snd_pcm_xrun_injection_write;
 598                 entry->mode = S_IFREG | 0200;
 599         }
 600 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 601
 602         return 0;
 603 }
 604
 605 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 606 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 607 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 608 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 609 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 610
 611 static const struct attribute_group *pcm_dev_attr_groups[];
 612
 613 /*
 614  * PM callbacks: we need to deal only with suspend here, as the resume is
 615  * triggered either from user-space or the driver's resume callback
 616  */
 617 #ifdef CONFIG_PM_SLEEP
 618 static int do_pcm_suspend(struct device *dev)
 619 {
 620         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
 621
 622         if (!pstr->pcm->no_device_suspend)
 623                 snd_pcm_suspend_all(pstr->pcm);
 624         return 0;
 625 }
 626 #endif
 627
 628 static const struct dev_pm_ops pcm_dev_pm_ops = {
 629         SET_SYSTEM_SLEEP_PM_OPS(do_pcm_suspend, NULL)
 630 };
 631
 632 /* device type for PCM -- basically only for passing PM callbacks */
 633 static const struct device_type pcm_dev_type = {
 634         .name = "pcm",
 635         .pm = &pcm_dev_pm_ops,
 636 };
 637
 638 /**
 639  * snd_pcm_new_stream - create a new PCM stream
 640  * @pcm: the pcm instance
 641  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 642  * @substream_count: the number of substreams
 643  *
 644  * Creates a new stream for the pcm.
 645  * The corresponding stream on the pcm must have been empty before
 646  * calling this, i.e. zero must be given to the argument of
 647  * snd_pcm_new().
 648  *
 649  * Return: Zero if successful, or a negative error code on failure.
 650  */
 651 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 652 {
 653         int idx, err;
 654         struct snd_pcm_str *pstr = &pcm->streams[stream];
 655         struct snd_pcm_substream *substream, *prev;
 656
 657 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 658         mutex_init(&pstr->oss.setup_mutex);
 659 #endif
 660         pstr->stream = stream;
 661         pstr->pcm = pcm;
 662         pstr->substream_count = substream_count;
 663         if (!substream_count)
 664                 return 0;
 665
 666         snd_device_initialize(&pstr->dev, pcm->card);
 667         pstr->dev.groups = pcm_dev_attr_groups;
 668         pstr->dev.type = &pcm_dev_type;
 669         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 670                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 671
 672         if (!pcm->internal) {
 673                 err = snd_pcm_stream_proc_init(pstr);
 674                 if (err < 0) {
 675                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 676                         return err;
 677                 }
 678         }
 679         prev = NULL;
 680         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 681                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 682                 if (!substream)
 683                         return -ENOMEM;
 684                 substream->pcm = pcm;
 685                 substream->pstr = pstr;
 686                 substream->number = idx;
 687                 substream->stream = stream;
 688                 sprintf(substream->name, "subdevice #%i", idx);
 689                 substream->buffer_bytes_max = UINT_MAX;
 690                 if (prev == NULL)
 691                         pstr->substream = substream;
 692                 else
 693                         prev->next = substream;
 694
 695                 if (!pcm->internal) {
 696                         err = snd_pcm_substream_proc_init(substream);
 697                         if (err < 0) {
 698                                 pcm_err(pcm,
 699                                         "Error in snd_pcm_stream_proc_init\n");
 700                                 if (prev == NULL)
 701                                         pstr->substream = NULL;
 702                                 else
 703                                         prev->next = NULL;
 704                                 kfree(substream);
 705                                 return err;
 706                         }
 707                 }
 708                 substream->group = &substream->self_group;
 709                 snd_pcm_group_init(&substream->self_group);
 710                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 711                 atomic_set(&substream->mmap_count, 0);
 712                 prev = substream;
 713         }
 714         return 0;
 715 }
 716 EXPORT_SYMBOL(snd_pcm_new_stream);
 717
 718 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 719                 int playback_count, int capture_count, bool internal,
 720                 struct snd_pcm **rpcm)
 721 {
 722         struct snd_pcm *pcm;
 723         int err;
 724         static struct snd_device_ops ops = {
 725                 .dev_free = snd_pcm_dev_free,
 726                 .dev_register = snd_pcm_dev_register,
 727                 .dev_disconnect = snd_pcm_dev_disconnect,
 728         };
 729         static struct snd_device_ops internal_ops = {
 730                 .dev_free = snd_pcm_dev_free,
 731         };
 732
 733         if (snd_BUG_ON(!card))
 734                 return -ENXIO;
 735         if (rpcm)
 736                 *rpcm = NULL;
 737         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 738         if (!pcm)
 739                 return -ENOMEM;
 740         pcm->card = card;
 741         pcm->device = device;
 742         pcm->internal = internal;
 743         mutex_init(&pcm->open_mutex);
 744         init_waitqueue_head(&pcm->open_wait);
 745         INIT_LIST_HEAD(&pcm->list);
 746         if (id)
 747                 strlcpy(pcm->id, id, sizeof(pcm->id));
 748
 749         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 750                                  playback_count);
 751         if (err < 0)
 752                 goto free_pcm;
 753
 754         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
 755         if (err < 0)
 756                 goto free_pcm;
 757
 758         err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
 759                              internal ? &internal_ops : &ops);
 760         if (err < 0)
 761                 goto free_pcm;
 762
 763         if (rpcm)
 764                 *rpcm = pcm;
 765         return 0;
 766
 767 free_pcm:
 768         snd_pcm_free(pcm);
 769         return err;
 770 }
 771
 772 /**
 773  * snd_pcm_new - create a new PCM instance
 774  * @card: the card instance
 775  * @id: the id string
 776  * @device: the device index (zero based)
 777  * @playback_count: the number of substreams for playback
 778  * @capture_count: the number of substreams for capture
 779  * @rpcm: the pointer to store the new pcm instance
 780  *
 781  * Creates a new PCM instance.
 782  *
 783  * The pcm operators have to be set afterwards to the new instance
 784  * via snd_pcm_set_ops().
 785  *
 786  * Return: Zero if successful, or a negative error code on failure.
 787  */
 788 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 789                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 790 {
 791         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 792                         false, rpcm);
 793 }
 794 EXPORT_SYMBOL(snd_pcm_new);
 795
 796 /**
 797  * snd_pcm_new_internal - create a new internal PCM instance
 798  * @card: the card instance
 799  * @id: the id string
 800  * @device: the device index (zero based - shared with normal PCMs)
 801  * @playback_count: the number of substreams for playback
 802  * @capture_count: the number of substreams for capture
 803  * @rpcm: the pointer to store the new pcm instance
 804  *
 805  * Creates a new internal PCM instance with no userspace device or procfs
 806  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 807  * will only be used internally by kernel drivers. i.e. it cannot be opened
 808  * by userspace. It provides existing ASoC components drivers with a substream
 809  * and access to any private data.
 810  *
 811  * The pcm operators have to be set afterwards to the new instance
 812  * via snd_pcm_set_ops().
 813  *
 814  * Return: Zero if successful, or a negative error code on failure.
 815  */
 816 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 817         int playback_count, int capture_count,
 818         struct snd_pcm **rpcm)
 819 {
 820         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 821                         true, rpcm);
 822 }
 823 EXPORT_SYMBOL(snd_pcm_new_internal);
 824
 825 static void free_chmap(struct snd_pcm_str *pstr)
 826 {
 827         if (pstr->chmap_kctl) {
 828                 snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
 829                 pstr->chmap_kctl = NULL;
 830         }
 831 }
 832
 833 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 834 {
 835         struct snd_pcm_substream *substream, *substream_next;
 836 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 837         struct snd_pcm_oss_setup *setup, *setupn;
 838 #endif
 839
 840         /* free all proc files under the stream */
 841         snd_pcm_stream_proc_done(pstr);
 842
 843         substream = pstr->substream;
 844         while (substream) {
 845                 substream_next = substream->next;
 846                 snd_pcm_timer_done(substream);
 847                 kfree(substream);
 848                 substream = substream_next;
 849         }
 850 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 851         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 852                 setupn = setup->next;
 853                 kfree(setup->task_name);
 854                 kfree(setup);
 855         }
 856 #endif
 857         free_chmap(pstr);
 858         if (pstr->substream_count)
 859                 put_device(&pstr->dev);
 860 }
 861
 862 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 863 #define pcm_call_notify(pcm, call)                                      \
 864         do {                                                            \
 865                 struct snd_pcm_notify *_notify;                         \
 866                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 867                         _notify->call(pcm);                             \
 868         } while (0)
 869 #else
 870 #define pcm_call_notify(pcm, call) do {} while (0)
 871 #endif
 872
 873 static int snd_pcm_free(struct snd_pcm *pcm)
 874 {
 875         if (!pcm)
 876                 return 0;
 877         if (!pcm->internal)
 878                 pcm_call_notify(pcm, n_unregister);
 879         if (pcm->private_free)
 880                 pcm->private_free(pcm);
 881         snd_pcm_lib_preallocate_free_for_all(pcm);
 882         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 883         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 884         kfree(pcm);
 885         return 0;
 886 }
 887
 888 static int snd_pcm_dev_free(struct snd_device *device)
 889 {
 890         struct snd_pcm *pcm = device->device_data;
 891         return snd_pcm_free(pcm);
 892 }
 893
 894 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 895                              struct file *file,
 896                              struct snd_pcm_substream **rsubstream)
 897 {
 898         struct snd_pcm_str * pstr;
 899         struct snd_pcm_substream *substream;
 900         struct snd_pcm_runtime *runtime;
 901         struct snd_card *card;
 902         int prefer_subdevice;
 903         size_t size;
 904
 905         if (snd_BUG_ON(!pcm || !rsubstream))
 906                 return -ENXIO;
 907         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 908                        stream != SNDRV_PCM_STREAM_CAPTURE))
 909                 return -EINVAL;
 910         *rsubstream = NULL;
 911         pstr = &pcm->streams[stream];
 912         if (pstr->substream == NULL || pstr->substream_count == 0)
 913                 return -ENODEV;
 914
 915         card = pcm->card;
 916         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 917
 918         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 919                 int opposite = !stream;
 920
 921                 for (substream = pcm->streams[opposite].substream; substream;
 922                      substream = substream->next) {
 923                         if (SUBSTREAM_BUSY(substream))
 924                                 return -EAGAIN;
 925                 }
 926         }
 927
 928         if (file->f_flags & O_APPEND) {
 929                 if (prefer_subdevice < 0) {
 930                         if (pstr->substream_count > 1)
 931                                 return -EINVAL; /* must be unique */
 932                         substream = pstr->substream;
 933                 } else {
 934                         for (substream = pstr->substream; substream;
 935                              substream = substream->next)
 936                                 if (substream->number == prefer_subdevice)
 937                                         break;
 938                 }
 939                 if (! substream)
 940                         return -ENODEV;
 941                 if (! SUBSTREAM_BUSY(substream))
 942                         return -EBADFD;
 943                 substream->ref_count++;
 944                 *rsubstream = substream;
 945                 return 0;
 946         }
 947
 948         for (substream = pstr->substream; substream; substream = substream->next) {
 949                 if (!SUBSTREAM_BUSY(substream) &&
 950                     (prefer_subdevice == -1 ||
 951                      substream->number == prefer_subdevice))
 952                         break;
 953         }
 954         if (substream == NULL)
 955                 return -EAGAIN;
 956
 957         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 958         if (runtime == NULL)
 959                 return -ENOMEM;
 960
 961         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 962         runtime->status = alloc_pages_exact(size, GFP_KERNEL);
 963         if (runtime->status == NULL) {
 964                 kfree(runtime);
 965                 return -ENOMEM;
 966         }
 967         memset(runtime->status, 0, size);
 968
 969         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 970         runtime->control = alloc_pages_exact(size, GFP_KERNEL);
 971         if (runtime->control == NULL) {
 972                 free_pages_exact(runtime->status,
 973                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
 974                 kfree(runtime);
 975                 return -ENOMEM;
 976         }
 977         memset(runtime->control, 0, size);
 978
 979         init_waitqueue_head(&runtime->sleep);
 980         init_waitqueue_head(&runtime->tsleep);
 981
 982         runtime->status->state = SNDRV_PCM_STATE_OPEN;
 983
 984         substream->runtime = runtime;
 985         substream->private_data = pcm->private_data;
 986         substream->ref_count = 1;
 987         substream->f_flags = file->f_flags;
 988         substream->pid = get_pid(task_pid(current));
 989         pstr->substream_opened++;
 990         *rsubstream = substream;
 991         return 0;
 992 }
 993
 994 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
 995 {
 996         struct snd_pcm_runtime *runtime;
 997
 998         if (PCM_RUNTIME_CHECK(substream))
 999                 return;
1000         runtime = substream->runtime;
1001         if (runtime->private_free != NULL)
1002                 runtime->private_free(runtime);
1003         free_pages_exact(runtime->status,
1004                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1005         free_pages_exact(runtime->control,
1006                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1007         kfree(runtime->hw_constraints.rules);
1008         /* Avoid concurrent access to runtime via PCM timer interface */
1009         if (substream->timer)
1010                 spin_lock_irq(&substream->timer->lock);
1011         substream->runtime = NULL;
1012         if (substream->timer)
1013                 spin_unlock_irq(&substream->timer->lock);
1014         kfree(runtime);
1015         put_pid(substream->pid);
1016         substream->pid = NULL;
1017         substream->pstr->substream_opened--;
1018 }
1019
1020 static ssize_t show_pcm_class(struct device *dev,
1021                               struct device_attribute *attr, char *buf)
1022 {
1023         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1024         struct snd_pcm *pcm = pstr->pcm;
1025         const char *str;
1026         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1027                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1028                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1029                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1030                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1031         };
1032
1033         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1034                 str = "none";
1035         else
1036                 str = strs[pcm->dev_class];
1037         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1038 }
1039
1040 static DEVICE_ATTR(pcm_class, 0444, show_pcm_class, NULL);
1041 static struct attribute *pcm_dev_attrs[] = {
1042         &dev_attr_pcm_class.attr,
1043         NULL
1044 };
1045
1046 static const struct attribute_group pcm_dev_attr_group = {
1047         .attrs  = pcm_dev_attrs,
1048 };
1049
1050 static const struct attribute_group *pcm_dev_attr_groups[] = {
1051         &pcm_dev_attr_group,
1052         NULL
1053 };
1054
1055 static int snd_pcm_dev_register(struct snd_device *device)
1056 {
1057         int cidx, err;
1058         struct snd_pcm_substream *substream;
1059         struct snd_pcm *pcm;
1060
1061         if (snd_BUG_ON(!device || !device->device_data))
1062                 return -ENXIO;
1063         pcm = device->device_data;
1064
1065         mutex_lock(&register_mutex);
1066         err = snd_pcm_add(pcm);
1067         if (err)
1068                 goto unlock;
1069         for (cidx = 0; cidx < 2; cidx++) {
1070                 int devtype = -1;
1071                 if (pcm->streams[cidx].substream == NULL)
1072                         continue;
1073                 switch (cidx) {
1074                 case SNDRV_PCM_STREAM_PLAYBACK:
1075                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1076                         break;
1077                 case SNDRV_PCM_STREAM_CAPTURE:
1078                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1079                         break;
1080                 }
1081                 /* register pcm */
1082                 err = snd_register_device(devtype, pcm->card, pcm->device,
1083                                           &snd_pcm_f_ops[cidx], pcm,
1084                                           &pcm->streams[cidx].dev);
1085                 if (err < 0) {
1086                         list_del_init(&pcm->list);
1087                         goto unlock;
1088                 }
1089
1090                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1091                         snd_pcm_timer_init(substream);
1092         }
1093
1094         pcm_call_notify(pcm, n_register);
1095
1096  unlock:
1097         mutex_unlock(&register_mutex);
1098         return err;
1099 }
1100
1101 static int snd_pcm_dev_disconnect(struct snd_device *device)
1102 {
1103         struct snd_pcm *pcm = device->device_data;
1104         struct snd_pcm_substream *substream;
1105         int cidx;
1106
1107         mutex_lock(&register_mutex);
1108         mutex_lock(&pcm->open_mutex);
1109         wake_up(&pcm->open_wait);
1110         list_del_init(&pcm->list);
1111         for (cidx = 0; cidx < 2; cidx++) {
1112                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1113                         snd_pcm_stream_lock_irq(substream);
1114                         if (substream->runtime) {
1115                                 if (snd_pcm_running(substream))
1116                                         snd_pcm_stop(substream,
1117                                                      SNDRV_PCM_STATE_DISCONNECTED);
1118                                 /* to be sure, set the state unconditionally */
1119                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1120                                 wake_up(&substream->runtime->sleep);
1121                                 wake_up(&substream->runtime->tsleep);
1122                         }
1123                         snd_pcm_stream_unlock_irq(substream);
1124                 }
1125         }
1126
1127         pcm_call_notify(pcm, n_disconnect);
1128         for (cidx = 0; cidx < 2; cidx++) {
1129                 snd_unregister_device(&pcm->streams[cidx].dev);
1130                 free_chmap(&pcm->streams[cidx]);
1131         }
1132         mutex_unlock(&pcm->open_mutex);
1133         mutex_unlock(&register_mutex);
1134         return 0;
1135 }
1136
1137 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1138 /**
1139  * snd_pcm_notify - Add/remove the notify list
1140  * @notify: PCM notify list
1141  * @nfree: 0 = register, 1 = unregister
1142  *
1143  * This adds the given notifier to the global list so that the callback is
1144  * called for each registered PCM devices.  This exists only for PCM OSS
1145  * emulation, so far.
1146  */
1147 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1148 {
1149         struct snd_pcm *pcm;
1150
1151         if (snd_BUG_ON(!notify ||
1152                        !notify->n_register ||
1153                        !notify->n_unregister ||
1154                        !notify->n_disconnect))
1155                 return -EINVAL;
1156         mutex_lock(&register_mutex);
1157         if (nfree) {
1158                 list_del(&notify->list);
1159                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1160                         notify->n_unregister(pcm);
1161         } else {
1162                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1163                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1164                         notify->n_register(pcm);
1165         }
1166         mutex_unlock(&register_mutex);
1167         return 0;
1168 }
1169 EXPORT_SYMBOL(snd_pcm_notify);
1170 #endif /* CONFIG_SND_PCM_OSS */
1171
1172 #ifdef CONFIG_SND_PROC_FS
1173 /*
1174  *  Info interface
1175  */
1176
1177 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1178                               struct snd_info_buffer *buffer)
1179 {
1180         struct snd_pcm *pcm;
1181
1182         mutex_lock(&register_mutex);
1183         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1184                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1185                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1186                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1187                         snd_iprintf(buffer, " : playback %i",
1188                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1189                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1190                         snd_iprintf(buffer, " : capture %i",
1191                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1192                 snd_iprintf(buffer, "\n");
1193         }
1194         mutex_unlock(&register_mutex);
1195 }
1196
1197 static struct snd_info_entry *snd_pcm_proc_entry;
1198
1199 static void snd_pcm_proc_init(void)
1200 {
1201         struct snd_info_entry *entry;
1202
1203         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1204         if (entry) {
1205                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1206                 if (snd_info_register(entry) < 0) {
1207                         snd_info_free_entry(entry);
1208                         entry = NULL;
1209                 }
1210         }
1211         snd_pcm_proc_entry = entry;
1212 }
1213
1214 static void snd_pcm_proc_done(void)
1215 {
1216         snd_info_free_entry(snd_pcm_proc_entry);
1217 }
1218
1219 #else /* !CONFIG_SND_PROC_FS */
1220 #define snd_pcm_proc_init()
1221 #define snd_pcm_proc_done()
1222 #endif /* CONFIG_SND_PROC_FS */
1223
1224
1225 /*
1226  *  ENTRY functions
1227  */
1228
1229 static int __init alsa_pcm_init(void)
1230 {
1231         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1232         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1233         snd_pcm_proc_init();
1234         return 0;
1235 }
1236
1237 static void __exit alsa_pcm_exit(void)
1238 {
1239         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1240         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1241         snd_pcm_proc_done();
1242 }
1243
1244 module_init(alsa_pcm_init)
1245 module_exit(alsa_pcm_exit)