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 #include "pcm_local.h"
  35
  36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  37 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  38 MODULE_LICENSE("GPL");
  39
  40 static LIST_HEAD(snd_pcm_devices);
  41 static DEFINE_MUTEX(register_mutex);
  42 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  43 static LIST_HEAD(snd_pcm_notify_list);
  44 #endif
  45
  46 static int snd_pcm_free(struct snd_pcm *pcm);
  47 static int snd_pcm_dev_free(struct snd_device *device);
  48 static int snd_pcm_dev_register(struct snd_device *device);
  49 static int snd_pcm_dev_disconnect(struct snd_device *device);
  50
  51 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  52 {
  53         struct snd_pcm *pcm;
  54
  55         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  56                 if (pcm->card == card && pcm->device == device)
  57                         return pcm;
  58         }
  59         return NULL;
  60 }
  61
  62 static int snd_pcm_next(struct snd_card *card, int device)
  63 {
  64         struct snd_pcm *pcm;
  65
  66         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  67                 if (pcm->card == card && pcm->device > device)
  68                         return pcm->device;
  69                 else if (pcm->card->number > card->number)
  70                         return -1;
  71         }
  72         return -1;
  73 }
  74
  75 static int snd_pcm_add(struct snd_pcm *newpcm)
  76 {
  77         struct snd_pcm *pcm;
  78
  79         if (newpcm->internal)
  80                 return 0;
  81
  82         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  83                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  84                         return -EBUSY;
  85                 if (pcm->card->number > newpcm->card->number ||
  86                                 (pcm->card == newpcm->card &&
  87                                 pcm->device > newpcm->device)) {
  88                         list_add(&newpcm->list, pcm->list.prev);
  89                         return 0;
  90                 }
  91         }
  92         list_add_tail(&newpcm->list, &snd_pcm_devices);
  93         return 0;
  94 }
  95
  96 static int snd_pcm_control_ioctl(struct snd_card *card,
  97                                  struct snd_ctl_file *control,
  98                                  unsigned int cmd, unsigned long arg)
  99 {
 100         switch (cmd) {
 101         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
 102                 {
 103                         int device;
 104
 105                         if (get_user(device, (int __user *)arg))
 106                                 return -EFAULT;
 107                         mutex_lock(&register_mutex);
 108                         device = snd_pcm_next(card, device);
 109                         mutex_unlock(&register_mutex);
 110                         if (put_user(device, (int __user *)arg))
 111                                 return -EFAULT;
 112                         return 0;
 113                 }
 114         case SNDRV_CTL_IOCTL_PCM_INFO:
 115                 {
 116                         struct snd_pcm_info __user *info;
 117                         unsigned int device, subdevice;
 118                         int stream;
 119                         struct snd_pcm *pcm;
 120                         struct snd_pcm_str *pstr;
 121                         struct snd_pcm_substream *substream;
 122                         int err;
 123
 124                         info = (struct snd_pcm_info __user *)arg;
 125                         if (get_user(device, &info->device))
 126                                 return -EFAULT;
 127                         if (get_user(stream, &info->stream))
 128                                 return -EFAULT;
 129                         if (stream < 0 || stream > 1)
 130                                 return -EINVAL;
 131                         if (get_user(subdevice, &info->subdevice))
 132                                 return -EFAULT;
 133                         mutex_lock(&register_mutex);
 134                         pcm = snd_pcm_get(card, device);
 135                         if (pcm == NULL) {
 136                                 err = -ENXIO;
 137                                 goto _error;
 138                         }
 139                         pstr = &pcm->streams[stream];
 140                         if (pstr->substream_count == 0) {
 141                                 err = -ENOENT;
 142                                 goto _error;
 143                         }
 144                         if (subdevice >= pstr->substream_count) {
 145                                 err = -ENXIO;
 146                                 goto _error;
 147                         }
 148                         for (substream = pstr->substream; substream;
 149                              substream = substream->next)
 150                                 if (substream->number == (int)subdevice)
 151                                         break;
 152                         if (substream == NULL) {
 153                                 err = -ENXIO;
 154                                 goto _error;
 155                         }
 156                         err = snd_pcm_info_user(substream, info);
 157                 _error:
 158                         mutex_unlock(&register_mutex);
 159                         return err;
 160                 }
 161         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 162                 {
 163                         int val;
 164
 165                         if (get_user(val, (int __user *)arg))
 166                                 return -EFAULT;
 167                         control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
 168                         return 0;
 169                 }
 170         }
 171         return -ENOIOCTLCMD;
 172 }
 173
 174 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 175
 176 static char *snd_pcm_format_names[] = {
 177         FORMAT(S8),
 178         FORMAT(U8),
 179         FORMAT(S16_LE),
 180         FORMAT(S16_BE),
 181         FORMAT(U16_LE),
 182         FORMAT(U16_BE),
 183         FORMAT(S24_LE),
 184         FORMAT(S24_BE),
 185         FORMAT(U24_LE),
 186         FORMAT(U24_BE),
 187         FORMAT(S32_LE),
 188         FORMAT(S32_BE),
 189         FORMAT(U32_LE),
 190         FORMAT(U32_BE),
 191         FORMAT(FLOAT_LE),
 192         FORMAT(FLOAT_BE),
 193         FORMAT(FLOAT64_LE),
 194         FORMAT(FLOAT64_BE),
 195         FORMAT(IEC958_SUBFRAME_LE),
 196         FORMAT(IEC958_SUBFRAME_BE),
 197         FORMAT(MU_LAW),
 198         FORMAT(A_LAW),
 199         FORMAT(IMA_ADPCM),
 200         FORMAT(MPEG),
 201         FORMAT(GSM),
 202         FORMAT(SPECIAL),
 203         FORMAT(S24_3LE),
 204         FORMAT(S24_3BE),
 205         FORMAT(U24_3LE),
 206         FORMAT(U24_3BE),
 207         FORMAT(S20_3LE),
 208         FORMAT(S20_3BE),
 209         FORMAT(U20_3LE),
 210         FORMAT(U20_3BE),
 211         FORMAT(S18_3LE),
 212         FORMAT(S18_3BE),
 213         FORMAT(U18_3LE),
 214         FORMAT(U18_3BE),
 215         FORMAT(G723_24),
 216         FORMAT(G723_24_1B),
 217         FORMAT(G723_40),
 218         FORMAT(G723_40_1B),
 219         FORMAT(DSD_U8),
 220         FORMAT(DSD_U16_LE),
 221         FORMAT(DSD_U32_LE),
 222         FORMAT(DSD_U16_BE),
 223         FORMAT(DSD_U32_BE),
 224 };
 225
 226 /**
 227  * snd_pcm_format_name - Return a name string for the given PCM format
 228  * @format: PCM format
 229  */
 230 const char *snd_pcm_format_name(snd_pcm_format_t format)
 231 {
 232         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 233                 return "Unknown";
 234         return snd_pcm_format_names[(__force unsigned int)format];
 235 }
 236 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 237
 238 #ifdef CONFIG_SND_VERBOSE_PROCFS
 239
 240 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 241 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 242 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 243 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 244 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 245 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 246 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 247 #define START(v) [SNDRV_PCM_START_##v] = #v
 248 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 249
 250 static char *snd_pcm_stream_names[] = {
 251         STREAM(PLAYBACK),
 252         STREAM(CAPTURE),
 253 };
 254
 255 static char *snd_pcm_state_names[] = {
 256         STATE(OPEN),
 257         STATE(SETUP),
 258         STATE(PREPARED),
 259         STATE(RUNNING),
 260         STATE(XRUN),
 261         STATE(DRAINING),
 262         STATE(PAUSED),
 263         STATE(SUSPENDED),
 264 };
 265
 266 static char *snd_pcm_access_names[] = {
 267         ACCESS(MMAP_INTERLEAVED),
 268         ACCESS(MMAP_NONINTERLEAVED),
 269         ACCESS(MMAP_COMPLEX),
 270         ACCESS(RW_INTERLEAVED),
 271         ACCESS(RW_NONINTERLEAVED),
 272 };
 273
 274 static char *snd_pcm_subformat_names[] = {
 275         SUBFORMAT(STD),
 276 };
 277
 278 static char *snd_pcm_tstamp_mode_names[] = {
 279         TSTAMP(NONE),
 280         TSTAMP(ENABLE),
 281 };
 282
 283 static const char *snd_pcm_stream_name(int stream)
 284 {
 285         return snd_pcm_stream_names[stream];
 286 }
 287
 288 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 289 {
 290         return snd_pcm_access_names[(__force int)access];
 291 }
 292
 293 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 294 {
 295         return snd_pcm_subformat_names[(__force int)subformat];
 296 }
 297
 298 static const char *snd_pcm_tstamp_mode_name(int mode)
 299 {
 300         return snd_pcm_tstamp_mode_names[mode];
 301 }
 302
 303 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 304 {
 305         return snd_pcm_state_names[(__force int)state];
 306 }
 307
 308 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 309 #include <linux/soundcard.h>
 310
 311 static const char *snd_pcm_oss_format_name(int format)
 312 {
 313         switch (format) {
 314         case AFMT_MU_LAW:
 315                 return "MU_LAW";
 316         case AFMT_A_LAW:
 317                 return "A_LAW";
 318         case AFMT_IMA_ADPCM:
 319                 return "IMA_ADPCM";
 320         case AFMT_U8:
 321                 return "U8";
 322         case AFMT_S16_LE:
 323                 return "S16_LE";
 324         case AFMT_S16_BE:
 325                 return "S16_BE";
 326         case AFMT_S8:
 327                 return "S8";
 328         case AFMT_U16_LE:
 329                 return "U16_LE";
 330         case AFMT_U16_BE:
 331                 return "U16_BE";
 332         case AFMT_MPEG:
 333                 return "MPEG";
 334         default:
 335                 return "unknown";
 336         }
 337 }
 338 #endif
 339
 340 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 341                                    struct snd_info_buffer *buffer)
 342 {
 343         struct snd_pcm_info *info;
 344         int err;
 345
 346         if (! substream)
 347                 return;
 348
 349         info = kmalloc(sizeof(*info), GFP_KERNEL);
 350         if (!info)
 351                 return;
 352
 353         err = snd_pcm_info(substream, info);
 354         if (err < 0) {
 355                 snd_iprintf(buffer, "error %d\n", err);
 356                 kfree(info);
 357                 return;
 358         }
 359         snd_iprintf(buffer, "card: %d\n", info->card);
 360         snd_iprintf(buffer, "device: %d\n", info->device);
 361         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 362         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 363         snd_iprintf(buffer, "id: %s\n", info->id);
 364         snd_iprintf(buffer, "name: %s\n", info->name);
 365         snd_iprintf(buffer, "subname: %s\n", info->subname);
 366         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 367         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 368         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 369         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 370         kfree(info);
 371 }
 372
 373 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 374                                           struct snd_info_buffer *buffer)
 375 {
 376         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 377                                buffer);
 378 }
 379
 380 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 381                                              struct snd_info_buffer *buffer)
 382 {
 383         snd_pcm_proc_info_read(entry->private_data, buffer);
 384 }
 385
 386 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 387                                                   struct snd_info_buffer *buffer)
 388 {
 389         struct snd_pcm_substream *substream = entry->private_data;
 390         struct snd_pcm_runtime *runtime;
 391
 392         mutex_lock(&substream->pcm->open_mutex);
 393         runtime = substream->runtime;
 394         if (!runtime) {
 395                 snd_iprintf(buffer, "closed\n");
 396                 goto unlock;
 397         }
 398         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 399                 snd_iprintf(buffer, "no setup\n");
 400                 goto unlock;
 401         }
 402         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 403         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 404         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 405         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 406         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 407         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 408         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 409 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 410         if (substream->oss.oss) {
 411                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 412                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 413                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 414                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 415                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 416                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 417         }
 418 #endif
 419  unlock:
 420         mutex_unlock(&substream->pcm->open_mutex);
 421 }
 422
 423 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 424                                                   struct snd_info_buffer *buffer)
 425 {
 426         struct snd_pcm_substream *substream = entry->private_data;
 427         struct snd_pcm_runtime *runtime;
 428
 429         mutex_lock(&substream->pcm->open_mutex);
 430         runtime = substream->runtime;
 431         if (!runtime) {
 432                 snd_iprintf(buffer, "closed\n");
 433                 goto unlock;
 434         }
 435         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 436                 snd_iprintf(buffer, "no setup\n");
 437                 goto unlock;
 438         }
 439         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 440         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 441         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 442         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 443         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 444         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 445         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 446         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 447  unlock:
 448         mutex_unlock(&substream->pcm->open_mutex);
 449 }
 450
 451 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 452                                                struct snd_info_buffer *buffer)
 453 {
 454         struct snd_pcm_substream *substream = entry->private_data;
 455         struct snd_pcm_runtime *runtime;
 456         struct snd_pcm_status status;
 457         int err;
 458
 459         mutex_lock(&substream->pcm->open_mutex);
 460         runtime = substream->runtime;
 461         if (!runtime) {
 462                 snd_iprintf(buffer, "closed\n");
 463                 goto unlock;
 464         }
 465         memset(&status, 0, sizeof(status));
 466         err = snd_pcm_status(substream, &status);
 467         if (err < 0) {
 468                 snd_iprintf(buffer, "error %d\n", err);
 469                 goto unlock;
 470         }
 471         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 472         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 473         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 474                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 475         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 476                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 477         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 478         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 479         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 480         snd_iprintf(buffer, "-----\n");
 481         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 482         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 483  unlock:
 484         mutex_unlock(&substream->pcm->open_mutex);
 485 }
 486
 487 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 488 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 489                                          struct snd_info_buffer *buffer)
 490 {
 491         struct snd_pcm_substream *substream = entry->private_data;
 492         struct snd_pcm_runtime *runtime;
 493
 494         snd_pcm_stream_lock_irq(substream);
 495         runtime = substream->runtime;
 496         if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
 497                 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 498         snd_pcm_stream_unlock_irq(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         if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
 527                 return -ENOMEM;
 528         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 529         if (snd_info_register(entry) < 0) {
 530                 snd_info_free_entry(entry);
 531                 return -ENOMEM;
 532         }
 533         pstr->proc_root = entry;
 534
 535         if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
 536                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 537                 if (snd_info_register(entry) < 0) {
 538                         snd_info_free_entry(entry);
 539                         entry = NULL;
 540                 }
 541         }
 542         pstr->proc_info_entry = entry;
 543
 544 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 545         if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 546                                                 pstr->proc_root)) != NULL) {
 547                 entry->c.text.read = snd_pcm_xrun_debug_read;
 548                 entry->c.text.write = snd_pcm_xrun_debug_write;
 549                 entry->mode |= S_IWUSR;
 550                 entry->private_data = pstr;
 551                 if (snd_info_register(entry) < 0) {
 552                         snd_info_free_entry(entry);
 553                         entry = NULL;
 554                 }
 555         }
 556         pstr->proc_xrun_debug_entry = entry;
 557 #endif
 558         return 0;
 559 }
 560
 561 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 562 {
 563 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 564         snd_info_free_entry(pstr->proc_xrun_debug_entry);
 565         pstr->proc_xrun_debug_entry = NULL;
 566 #endif
 567         snd_info_free_entry(pstr->proc_info_entry);
 568         pstr->proc_info_entry = NULL;
 569         snd_info_free_entry(pstr->proc_root);
 570         pstr->proc_root = NULL;
 571         return 0;
 572 }
 573
 574 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 575 {
 576         struct snd_info_entry *entry;
 577         struct snd_card *card;
 578         char name[16];
 579
 580         card = substream->pcm->card;
 581
 582         sprintf(name, "sub%i", substream->number);
 583         if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
 584                 return -ENOMEM;
 585         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 586         if (snd_info_register(entry) < 0) {
 587                 snd_info_free_entry(entry);
 588                 return -ENOMEM;
 589         }
 590         substream->proc_root = entry;
 591
 592         if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
 593                 snd_info_set_text_ops(entry, substream,
 594                                       snd_pcm_substream_proc_info_read);
 595                 if (snd_info_register(entry) < 0) {
 596                         snd_info_free_entry(entry);
 597                         entry = NULL;
 598                 }
 599         }
 600         substream->proc_info_entry = entry;
 601
 602         if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
 603                 snd_info_set_text_ops(entry, substream,
 604                                       snd_pcm_substream_proc_hw_params_read);
 605                 if (snd_info_register(entry) < 0) {
 606                         snd_info_free_entry(entry);
 607                         entry = NULL;
 608                 }
 609         }
 610         substream->proc_hw_params_entry = entry;
 611
 612         if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
 613                 snd_info_set_text_ops(entry, substream,
 614                                       snd_pcm_substream_proc_sw_params_read);
 615                 if (snd_info_register(entry) < 0) {
 616                         snd_info_free_entry(entry);
 617                         entry = NULL;
 618                 }
 619         }
 620         substream->proc_sw_params_entry = entry;
 621
 622         if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
 623                 snd_info_set_text_ops(entry, substream,
 624                                       snd_pcm_substream_proc_status_read);
 625                 if (snd_info_register(entry) < 0) {
 626                         snd_info_free_entry(entry);
 627                         entry = NULL;
 628                 }
 629         }
 630         substream->proc_status_entry = entry;
 631
 632 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 633         entry = snd_info_create_card_entry(card, "xrun_injection",
 634                                            substream->proc_root);
 635         if (entry) {
 636                 entry->private_data = substream;
 637                 entry->c.text.read = NULL;
 638                 entry->c.text.write = snd_pcm_xrun_injection_write;
 639                 entry->mode = S_IFREG | S_IWUSR;
 640                 if (snd_info_register(entry) < 0) {
 641                         snd_info_free_entry(entry);
 642                         entry = NULL;
 643                 }
 644         }
 645         substream->proc_xrun_injection_entry = entry;
 646 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 647
 648         return 0;
 649 }
 650
 651 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
 652 {
 653         snd_info_free_entry(substream->proc_info_entry);
 654         substream->proc_info_entry = NULL;
 655         snd_info_free_entry(substream->proc_hw_params_entry);
 656         substream->proc_hw_params_entry = NULL;
 657         snd_info_free_entry(substream->proc_sw_params_entry);
 658         substream->proc_sw_params_entry = NULL;
 659         snd_info_free_entry(substream->proc_status_entry);
 660         substream->proc_status_entry = NULL;
 661 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 662         snd_info_free_entry(substream->proc_xrun_injection_entry);
 663         substream->proc_xrun_injection_entry = NULL;
 664 #endif
 665         snd_info_free_entry(substream->proc_root);
 666         substream->proc_root = NULL;
 667         return 0;
 668 }
 669 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 670 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 671 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 672 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 673 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 674 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 675
 676 static const struct attribute_group *pcm_dev_attr_groups[];
 677
 678 /**
 679  * snd_pcm_new_stream - create a new PCM stream
 680  * @pcm: the pcm instance
 681  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 682  * @substream_count: the number of substreams
 683  *
 684  * Creates a new stream for the pcm.
 685  * The corresponding stream on the pcm must have been empty before
 686  * calling this, i.e. zero must be given to the argument of
 687  * snd_pcm_new().
 688  *
 689  * Return: Zero if successful, or a negative error code on failure.
 690  */
 691 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 692 {
 693         int idx, err;
 694         struct snd_pcm_str *pstr = &pcm->streams[stream];
 695         struct snd_pcm_substream *substream, *prev;
 696
 697 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 698         mutex_init(&pstr->oss.setup_mutex);
 699 #endif
 700         pstr->stream = stream;
 701         pstr->pcm = pcm;
 702         pstr->substream_count = substream_count;
 703         if (!substream_count)
 704                 return 0;
 705
 706         snd_device_initialize(&pstr->dev, pcm->card);
 707         pstr->dev.groups = pcm_dev_attr_groups;
 708         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 709                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 710
 711         if (!pcm->internal) {
 712                 err = snd_pcm_stream_proc_init(pstr);
 713                 if (err < 0) {
 714                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 715                         return err;
 716                 }
 717         }
 718         prev = NULL;
 719         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 720                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 721                 if (!substream)
 722                         return -ENOMEM;
 723                 substream->pcm = pcm;
 724                 substream->pstr = pstr;
 725                 substream->number = idx;
 726                 substream->stream = stream;
 727                 sprintf(substream->name, "subdevice #%i", idx);
 728                 substream->buffer_bytes_max = UINT_MAX;
 729                 if (prev == NULL)
 730                         pstr->substream = substream;
 731                 else
 732                         prev->next = substream;
 733
 734                 if (!pcm->internal) {
 735                         err = snd_pcm_substream_proc_init(substream);
 736                         if (err < 0) {
 737                                 pcm_err(pcm,
 738                                         "Error in snd_pcm_stream_proc_init\n");
 739                                 if (prev == NULL)
 740                                         pstr->substream = NULL;
 741                                 else
 742                                         prev->next = NULL;
 743                                 kfree(substream);
 744                                 return err;
 745                         }
 746                 }
 747                 substream->group = &substream->self_group;
 748                 spin_lock_init(&substream->self_group.lock);
 749                 mutex_init(&substream->self_group.mutex);
 750                 INIT_LIST_HEAD(&substream->self_group.substreams);
 751                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 752                 atomic_set(&substream->mmap_count, 0);
 753                 prev = substream;
 754         }
 755         return 0;
 756 }
 757 EXPORT_SYMBOL(snd_pcm_new_stream);
 758
 759 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 760                 int playback_count, int capture_count, bool internal,
 761                 struct snd_pcm **rpcm)
 762 {
 763         struct snd_pcm *pcm;
 764         int err;
 765         static struct snd_device_ops ops = {
 766                 .dev_free = snd_pcm_dev_free,
 767                 .dev_register = snd_pcm_dev_register,
 768                 .dev_disconnect = snd_pcm_dev_disconnect,
 769         };
 770
 771         if (snd_BUG_ON(!card))
 772                 return -ENXIO;
 773         if (rpcm)
 774                 *rpcm = NULL;
 775         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 776         if (!pcm)
 777                 return -ENOMEM;
 778         pcm->card = card;
 779         pcm->device = device;
 780         pcm->internal = internal;
 781         mutex_init(&pcm->open_mutex);
 782         init_waitqueue_head(&pcm->open_wait);
 783         INIT_LIST_HEAD(&pcm->list);
 784         if (id)
 785                 strlcpy(pcm->id, id, sizeof(pcm->id));
 786         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
 787                 snd_pcm_free(pcm);
 788                 return err;
 789         }
 790         if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
 791                 snd_pcm_free(pcm);
 792                 return err;
 793         }
 794         if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
 795                 snd_pcm_free(pcm);
 796                 return err;
 797         }
 798         if (rpcm)
 799                 *rpcm = pcm;
 800         return 0;
 801 }
 802
 803 /**
 804  * snd_pcm_new - create a new PCM instance
 805  * @card: the card instance
 806  * @id: the id string
 807  * @device: the device index (zero based)
 808  * @playback_count: the number of substreams for playback
 809  * @capture_count: the number of substreams for capture
 810  * @rpcm: the pointer to store the new pcm instance
 811  *
 812  * Creates a new PCM instance.
 813  *
 814  * The pcm operators have to be set afterwards to the new instance
 815  * via snd_pcm_set_ops().
 816  *
 817  * Return: Zero if successful, or a negative error code on failure.
 818  */
 819 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 820                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 821 {
 822         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 823                         false, rpcm);
 824 }
 825 EXPORT_SYMBOL(snd_pcm_new);
 826
 827 /**
 828  * snd_pcm_new_internal - create a new internal PCM instance
 829  * @card: the card instance
 830  * @id: the id string
 831  * @device: the device index (zero based - shared with normal PCMs)
 832  * @playback_count: the number of substreams for playback
 833  * @capture_count: the number of substreams for capture
 834  * @rpcm: the pointer to store the new pcm instance
 835  *
 836  * Creates a new internal PCM instance with no userspace device or procfs
 837  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 838  * will only be used internally by kernel drivers. i.e. it cannot be opened
 839  * by userspace. It provides existing ASoC components drivers with a substream
 840  * and access to any private data.
 841  *
 842  * The pcm operators have to be set afterwards to the new instance
 843  * via snd_pcm_set_ops().
 844  *
 845  * Return: Zero if successful, or a negative error code on failure.
 846  */
 847 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 848         int playback_count, int capture_count,
 849         struct snd_pcm **rpcm)
 850 {
 851         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 852                         true, rpcm);
 853 }
 854 EXPORT_SYMBOL(snd_pcm_new_internal);
 855
 856 static void free_chmap(struct snd_pcm_str *pstr)
 857 {
 858         if (pstr->chmap_kctl) {
 859                 snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
 860                 pstr->chmap_kctl = NULL;
 861         }
 862 }
 863
 864 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 865 {
 866         struct snd_pcm_substream *substream, *substream_next;
 867 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 868         struct snd_pcm_oss_setup *setup, *setupn;
 869 #endif
 870         substream = pstr->substream;
 871         while (substream) {
 872                 substream_next = substream->next;
 873                 snd_pcm_timer_done(substream);
 874                 snd_pcm_substream_proc_done(substream);
 875                 kfree(substream);
 876                 substream = substream_next;
 877         }
 878         snd_pcm_stream_proc_done(pstr);
 879 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 880         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 881                 setupn = setup->next;
 882                 kfree(setup->task_name);
 883                 kfree(setup);
 884         }
 885 #endif
 886         free_chmap(pstr);
 887         if (pstr->substream_count)
 888                 put_device(&pstr->dev);
 889 }
 890
 891 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 892 #define pcm_call_notify(pcm, call)                                      \
 893         do {                                                            \
 894                 struct snd_pcm_notify *_notify;                         \
 895                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 896                         _notify->call(pcm);                             \
 897         } while (0)
 898 #else
 899 #define pcm_call_notify(pcm, call) do {} while (0)
 900 #endif
 901
 902 static int snd_pcm_free(struct snd_pcm *pcm)
 903 {
 904         if (!pcm)
 905                 return 0;
 906         if (!pcm->internal)
 907                 pcm_call_notify(pcm, n_unregister);
 908         if (pcm->private_free)
 909                 pcm->private_free(pcm);
 910         snd_pcm_lib_preallocate_free_for_all(pcm);
 911         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 912         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 913         kfree(pcm);
 914         return 0;
 915 }
 916
 917 static int snd_pcm_dev_free(struct snd_device *device)
 918 {
 919         struct snd_pcm *pcm = device->device_data;
 920         return snd_pcm_free(pcm);
 921 }
 922
 923 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 924                              struct file *file,
 925                              struct snd_pcm_substream **rsubstream)
 926 {
 927         struct snd_pcm_str * pstr;
 928         struct snd_pcm_substream *substream;
 929         struct snd_pcm_runtime *runtime;
 930         struct snd_card *card;
 931         int prefer_subdevice;
 932         size_t size;
 933
 934         if (snd_BUG_ON(!pcm || !rsubstream))
 935                 return -ENXIO;
 936         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 937                        stream != SNDRV_PCM_STREAM_CAPTURE))
 938                 return -EINVAL;
 939         *rsubstream = NULL;
 940         pstr = &pcm->streams[stream];
 941         if (pstr->substream == NULL || pstr->substream_count == 0)
 942                 return -ENODEV;
 943
 944         card = pcm->card;
 945         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 946
 947         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 948                 int opposite = !stream;
 949
 950                 for (substream = pcm->streams[opposite].substream; substream;
 951                      substream = substream->next) {
 952                         if (SUBSTREAM_BUSY(substream))
 953                                 return -EAGAIN;
 954                 }
 955         }
 956
 957         if (file->f_flags & O_APPEND) {
 958                 if (prefer_subdevice < 0) {
 959                         if (pstr->substream_count > 1)
 960                                 return -EINVAL; /* must be unique */
 961                         substream = pstr->substream;
 962                 } else {
 963                         for (substream = pstr->substream; substream;
 964                              substream = substream->next)
 965                                 if (substream->number == prefer_subdevice)
 966                                         break;
 967                 }
 968                 if (! substream)
 969                         return -ENODEV;
 970                 if (! SUBSTREAM_BUSY(substream))
 971                         return -EBADFD;
 972                 substream->ref_count++;
 973                 *rsubstream = substream;
 974                 return 0;
 975         }
 976
 977         for (substream = pstr->substream; substream; substream = substream->next) {
 978                 if (!SUBSTREAM_BUSY(substream) &&
 979                     (prefer_subdevice == -1 ||
 980                      substream->number == prefer_subdevice))
 981                         break;
 982         }
 983         if (substream == NULL)
 984                 return -EAGAIN;
 985
 986         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
 987         if (runtime == NULL)
 988                 return -ENOMEM;
 989
 990         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
 991         runtime->status = snd_malloc_pages(size, GFP_KERNEL);
 992         if (runtime->status == NULL) {
 993                 kfree(runtime);
 994                 return -ENOMEM;
 995         }
 996         memset((void*)runtime->status, 0, size);
 997
 998         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
 999         runtime->control = snd_malloc_pages(size, GFP_KERNEL);
1000         if (runtime->control == NULL) {
1001                 snd_free_pages((void*)runtime->status,
1002                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1003                 kfree(runtime);
1004                 return -ENOMEM;
1005         }
1006         memset((void*)runtime->control, 0, size);
1007
1008         init_waitqueue_head(&runtime->sleep);
1009         init_waitqueue_head(&runtime->tsleep);
1010
1011         runtime->status->state = SNDRV_PCM_STATE_OPEN;
1012
1013         substream->runtime = runtime;
1014         substream->private_data = pcm->private_data;
1015         substream->ref_count = 1;
1016         substream->f_flags = file->f_flags;
1017         substream->pid = get_pid(task_pid(current));
1018         pstr->substream_opened++;
1019         *rsubstream = substream;
1020         return 0;
1021 }
1022
1023 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1024 {
1025         struct snd_pcm_runtime *runtime;
1026
1027         if (PCM_RUNTIME_CHECK(substream))
1028                 return;
1029         runtime = substream->runtime;
1030         if (runtime->private_free != NULL)
1031                 runtime->private_free(runtime);
1032         snd_free_pages((void*)runtime->status,
1033                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1034         snd_free_pages((void*)runtime->control,
1035                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1036         kfree(runtime->hw_constraints.rules);
1037         kfree(runtime);
1038         substream->runtime = NULL;
1039         put_pid(substream->pid);
1040         substream->pid = NULL;
1041         substream->pstr->substream_opened--;
1042 }
1043
1044 static ssize_t show_pcm_class(struct device *dev,
1045                               struct device_attribute *attr, char *buf)
1046 {
1047         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1048         struct snd_pcm *pcm = pstr->pcm;
1049         const char *str;
1050         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1051                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1052                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1053                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1054                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1055         };
1056
1057         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1058                 str = "none";
1059         else
1060                 str = strs[pcm->dev_class];
1061         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1062 }
1063
1064 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1065 static struct attribute *pcm_dev_attrs[] = {
1066         &dev_attr_pcm_class.attr,
1067         NULL
1068 };
1069
1070 static const struct attribute_group pcm_dev_attr_group = {
1071         .attrs  = pcm_dev_attrs,
1072 };
1073
1074 static const struct attribute_group *pcm_dev_attr_groups[] = {
1075         &pcm_dev_attr_group,
1076         NULL
1077 };
1078
1079 static int snd_pcm_dev_register(struct snd_device *device)
1080 {
1081         int cidx, err;
1082         struct snd_pcm_substream *substream;
1083         struct snd_pcm *pcm;
1084
1085         if (snd_BUG_ON(!device || !device->device_data))
1086                 return -ENXIO;
1087         pcm = device->device_data;
1088         if (pcm->internal)
1089                 return 0;
1090
1091         mutex_lock(&register_mutex);
1092         err = snd_pcm_add(pcm);
1093         if (err)
1094                 goto unlock;
1095         for (cidx = 0; cidx < 2; cidx++) {
1096                 int devtype = -1;
1097                 if (pcm->streams[cidx].substream == NULL)
1098                         continue;
1099                 switch (cidx) {
1100                 case SNDRV_PCM_STREAM_PLAYBACK:
1101                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1102                         break;
1103                 case SNDRV_PCM_STREAM_CAPTURE:
1104                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1105                         break;
1106                 }
1107                 /* register pcm */
1108                 err = snd_register_device(devtype, pcm->card, pcm->device,
1109                                           &snd_pcm_f_ops[cidx], pcm,
1110                                           &pcm->streams[cidx].dev);
1111                 if (err < 0) {
1112                         list_del_init(&pcm->list);
1113                         goto unlock;
1114                 }
1115
1116                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1117                         snd_pcm_timer_init(substream);
1118         }
1119
1120         pcm_call_notify(pcm, n_register);
1121
1122  unlock:
1123         mutex_unlock(&register_mutex);
1124         return err;
1125 }
1126
1127 static int snd_pcm_dev_disconnect(struct snd_device *device)
1128 {
1129         struct snd_pcm *pcm = device->device_data;
1130         struct snd_pcm_substream *substream;
1131         int cidx;
1132
1133         mutex_lock(&register_mutex);
1134         mutex_lock(&pcm->open_mutex);
1135         wake_up(&pcm->open_wait);
1136         list_del_init(&pcm->list);
1137         for (cidx = 0; cidx < 2; cidx++) {
1138                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1139                         snd_pcm_stream_lock_irq(substream);
1140                         if (substream->runtime) {
1141                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1142                                 wake_up(&substream->runtime->sleep);
1143                                 wake_up(&substream->runtime->tsleep);
1144                         }
1145                         snd_pcm_stream_unlock_irq(substream);
1146                 }
1147         }
1148         if (!pcm->internal) {
1149                 pcm_call_notify(pcm, n_disconnect);
1150         }
1151         for (cidx = 0; cidx < 2; cidx++) {
1152                 if (!pcm->internal)
1153                         snd_unregister_device(&pcm->streams[cidx].dev);
1154                 free_chmap(&pcm->streams[cidx]);
1155         }
1156         mutex_unlock(&pcm->open_mutex);
1157         mutex_unlock(&register_mutex);
1158         return 0;
1159 }
1160
1161 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1162 /**
1163  * snd_pcm_notify - Add/remove the notify list
1164  * @notify: PCM notify list
1165  * @nfree: 0 = register, 1 = unregister
1166  *
1167  * This adds the given notifier to the global list so that the callback is
1168  * called for each registered PCM devices.  This exists only for PCM OSS
1169  * emulation, so far.
1170  */
1171 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1172 {
1173         struct snd_pcm *pcm;
1174
1175         if (snd_BUG_ON(!notify ||
1176                        !notify->n_register ||
1177                        !notify->n_unregister ||
1178                        !notify->n_disconnect))
1179                 return -EINVAL;
1180         mutex_lock(&register_mutex);
1181         if (nfree) {
1182                 list_del(&notify->list);
1183                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1184                         notify->n_unregister(pcm);
1185         } else {
1186                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1187                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1188                         notify->n_register(pcm);
1189         }
1190         mutex_unlock(&register_mutex);
1191         return 0;
1192 }
1193 EXPORT_SYMBOL(snd_pcm_notify);
1194 #endif /* CONFIG_SND_PCM_OSS */
1195
1196 #ifdef CONFIG_SND_PROC_FS
1197 /*
1198  *  Info interface
1199  */
1200
1201 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1202                               struct snd_info_buffer *buffer)
1203 {
1204         struct snd_pcm *pcm;
1205
1206         mutex_lock(&register_mutex);
1207         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1208                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1209                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1210                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1211                         snd_iprintf(buffer, " : playback %i",
1212                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1213                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1214                         snd_iprintf(buffer, " : capture %i",
1215                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1216                 snd_iprintf(buffer, "\n");
1217         }
1218         mutex_unlock(&register_mutex);
1219 }
1220
1221 static struct snd_info_entry *snd_pcm_proc_entry;
1222
1223 static void snd_pcm_proc_init(void)
1224 {
1225         struct snd_info_entry *entry;
1226
1227         if ((entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL)) != NULL) {
1228                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1229                 if (snd_info_register(entry) < 0) {
1230                         snd_info_free_entry(entry);
1231                         entry = NULL;
1232                 }
1233         }
1234         snd_pcm_proc_entry = entry;
1235 }
1236
1237 static void snd_pcm_proc_done(void)
1238 {
1239         snd_info_free_entry(snd_pcm_proc_entry);
1240 }
1241
1242 #else /* !CONFIG_SND_PROC_FS */
1243 #define snd_pcm_proc_init()
1244 #define snd_pcm_proc_done()
1245 #endif /* CONFIG_SND_PROC_FS */
1246
1247
1248 /*
1249  *  ENTRY functions
1250  */
1251
1252 static int __init alsa_pcm_init(void)
1253 {
1254         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1255         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1256         snd_pcm_proc_init();
1257         return 0;
1258 }
1259
1260 static void __exit alsa_pcm_exit(void)
1261 {
1262         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1263         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1264         snd_pcm_proc_done();
1265 }
1266
1267 module_init(alsa_pcm_init)
1268 module_exit(alsa_pcm_exit)