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/timer.h>
  32 #include <sound/control.h>
  33 #include <sound/info.h>
  34
  35 #include "pcm_local.h"
  36
  37 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  38 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  39 MODULE_LICENSE("GPL");
  40
  41 static LIST_HEAD(snd_pcm_devices);
  42 static DEFINE_MUTEX(register_mutex);
  43 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  44 static LIST_HEAD(snd_pcm_notify_list);
  45 #endif
  46
  47 static int snd_pcm_free(struct snd_pcm *pcm);
  48 static int snd_pcm_dev_free(struct snd_device *device);
  49 static int snd_pcm_dev_register(struct snd_device *device);
  50 static int snd_pcm_dev_disconnect(struct snd_device *device);
  51
  52 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  53 {
  54         struct snd_pcm *pcm;
  55
  56         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  57                 if (pcm->card == card && pcm->device == device)
  58                         return pcm;
  59         }
  60         return NULL;
  61 }
  62
  63 static int snd_pcm_next(struct snd_card *card, int device)
  64 {
  65         struct snd_pcm *pcm;
  66
  67         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  68                 if (pcm->card == card && pcm->device > device)
  69                         return pcm->device;
  70                 else if (pcm->card->number > card->number)
  71                         return -1;
  72         }
  73         return -1;
  74 }
  75
  76 static int snd_pcm_add(struct snd_pcm *newpcm)
  77 {
  78         struct snd_pcm *pcm;
  79
  80         if (newpcm->internal)
  81                 return 0;
  82
  83         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  84                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  85                         return -EBUSY;
  86                 if (pcm->card->number > newpcm->card->number ||
  87                                 (pcm->card == newpcm->card &&
  88                                 pcm->device > newpcm->device)) {
  89                         list_add(&newpcm->list, pcm->list.prev);
  90                         return 0;
  91                 }
  92         }
  93         list_add_tail(&newpcm->list, &snd_pcm_devices);
  94         return 0;
  95 }
  96
  97 static int snd_pcm_control_ioctl(struct snd_card *card,
  98                                  struct snd_ctl_file *control,
  99                                  unsigned int cmd, unsigned long arg)
 100 {
 101         switch (cmd) {
 102         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
 103                 {
 104                         int device;
 105
 106                         if (get_user(device, (int __user *)arg))
 107                                 return -EFAULT;
 108                         mutex_lock(&register_mutex);
 109                         device = snd_pcm_next(card, device);
 110                         mutex_unlock(&register_mutex);
 111                         if (put_user(device, (int __user *)arg))
 112                                 return -EFAULT;
 113                         return 0;
 114                 }
 115         case SNDRV_CTL_IOCTL_PCM_INFO:
 116                 {
 117                         struct snd_pcm_info __user *info;
 118                         unsigned int device, subdevice;
 119                         int stream;
 120                         struct snd_pcm *pcm;
 121                         struct snd_pcm_str *pstr;
 122                         struct snd_pcm_substream *substream;
 123                         int err;
 124
 125                         info = (struct snd_pcm_info __user *)arg;
 126                         if (get_user(device, &info->device))
 127                                 return -EFAULT;
 128                         if (get_user(stream, &info->stream))
 129                                 return -EFAULT;
 130                         if (stream < 0 || stream > 1)
 131                                 return -EINVAL;
 132                         if (get_user(subdevice, &info->subdevice))
 133                                 return -EFAULT;
 134                         mutex_lock(&register_mutex);
 135                         pcm = snd_pcm_get(card, device);
 136                         if (pcm == NULL) {
 137                                 err = -ENXIO;
 138                                 goto _error;
 139                         }
 140                         pstr = &pcm->streams[stream];
 141                         if (pstr->substream_count == 0) {
 142                                 err = -ENOENT;
 143                                 goto _error;
 144                         }
 145                         if (subdevice >= pstr->substream_count) {
 146                                 err = -ENXIO;
 147                                 goto _error;
 148                         }
 149                         for (substream = pstr->substream; substream;
 150                              substream = substream->next)
 151                                 if (substream->number == (int)subdevice)
 152                                         break;
 153                         if (substream == NULL) {
 154                                 err = -ENXIO;
 155                                 goto _error;
 156                         }
 157                         mutex_lock(&pcm->open_mutex);
 158                         err = snd_pcm_info_user(substream, info);
 159                         mutex_unlock(&pcm->open_mutex);
 160                 _error:
 161                         mutex_unlock(&register_mutex);
 162                         return err;
 163                 }
 164         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 165                 {
 166                         int val;
 167
 168                         if (get_user(val, (int __user *)arg))
 169                                 return -EFAULT;
 170                         control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
 171                         return 0;
 172                 }
 173         }
 174         return -ENOIOCTLCMD;
 175 }
 176
 177 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 178
 179 static char *snd_pcm_format_names[] = {
 180         FORMAT(S8),
 181         FORMAT(U8),
 182         FORMAT(S16_LE),
 183         FORMAT(S16_BE),
 184         FORMAT(U16_LE),
 185         FORMAT(U16_BE),
 186         FORMAT(S24_LE),
 187         FORMAT(S24_BE),
 188         FORMAT(U24_LE),
 189         FORMAT(U24_BE),
 190         FORMAT(S32_LE),
 191         FORMAT(S32_BE),
 192         FORMAT(U32_LE),
 193         FORMAT(U32_BE),
 194         FORMAT(FLOAT_LE),
 195         FORMAT(FLOAT_BE),
 196         FORMAT(FLOAT64_LE),
 197         FORMAT(FLOAT64_BE),
 198         FORMAT(IEC958_SUBFRAME_LE),
 199         FORMAT(IEC958_SUBFRAME_BE),
 200         FORMAT(MU_LAW),
 201         FORMAT(A_LAW),
 202         FORMAT(IMA_ADPCM),
 203         FORMAT(MPEG),
 204         FORMAT(GSM),
 205         FORMAT(SPECIAL),
 206         FORMAT(S24_3LE),
 207         FORMAT(S24_3BE),
 208         FORMAT(U24_3LE),
 209         FORMAT(U24_3BE),
 210         FORMAT(S20_3LE),
 211         FORMAT(S20_3BE),
 212         FORMAT(U20_3LE),
 213         FORMAT(U20_3BE),
 214         FORMAT(S18_3LE),
 215         FORMAT(S18_3BE),
 216         FORMAT(U18_3LE),
 217         FORMAT(U18_3BE),
 218         FORMAT(G723_24),
 219         FORMAT(G723_24_1B),
 220         FORMAT(G723_40),
 221         FORMAT(G723_40_1B),
 222         FORMAT(DSD_U8),
 223         FORMAT(DSD_U16_LE),
 224         FORMAT(DSD_U32_LE),
 225         FORMAT(DSD_U16_BE),
 226         FORMAT(DSD_U32_BE),
 227 };
 228
 229 /**
 230  * snd_pcm_format_name - Return a name string for the given PCM format
 231  * @format: PCM format
 232  */
 233 const char *snd_pcm_format_name(snd_pcm_format_t format)
 234 {
 235         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 236                 return "Unknown";
 237         return snd_pcm_format_names[(__force unsigned int)format];
 238 }
 239 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 240
 241 #ifdef CONFIG_SND_VERBOSE_PROCFS
 242
 243 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 244 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 245 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 246 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 247 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 248 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 249 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 250 #define START(v) [SNDRV_PCM_START_##v] = #v
 251 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 252
 253 static char *snd_pcm_stream_names[] = {
 254         STREAM(PLAYBACK),
 255         STREAM(CAPTURE),
 256 };
 257
 258 static char *snd_pcm_state_names[] = {
 259         STATE(OPEN),
 260         STATE(SETUP),
 261         STATE(PREPARED),
 262         STATE(RUNNING),
 263         STATE(XRUN),
 264         STATE(DRAINING),
 265         STATE(PAUSED),
 266         STATE(SUSPENDED),
 267 };
 268
 269 static char *snd_pcm_access_names[] = {
 270         ACCESS(MMAP_INTERLEAVED),
 271         ACCESS(MMAP_NONINTERLEAVED),
 272         ACCESS(MMAP_COMPLEX),
 273         ACCESS(RW_INTERLEAVED),
 274         ACCESS(RW_NONINTERLEAVED),
 275 };
 276
 277 static char *snd_pcm_subformat_names[] = {
 278         SUBFORMAT(STD),
 279 };
 280
 281 static char *snd_pcm_tstamp_mode_names[] = {
 282         TSTAMP(NONE),
 283         TSTAMP(ENABLE),
 284 };
 285
 286 static const char *snd_pcm_stream_name(int stream)
 287 {
 288         return snd_pcm_stream_names[stream];
 289 }
 290
 291 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 292 {
 293         return snd_pcm_access_names[(__force int)access];
 294 }
 295
 296 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 297 {
 298         return snd_pcm_subformat_names[(__force int)subformat];
 299 }
 300
 301 static const char *snd_pcm_tstamp_mode_name(int mode)
 302 {
 303         return snd_pcm_tstamp_mode_names[mode];
 304 }
 305
 306 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 307 {
 308         return snd_pcm_state_names[(__force int)state];
 309 }
 310
 311 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 312 #include <linux/soundcard.h>
 313
 314 static const char *snd_pcm_oss_format_name(int format)
 315 {
 316         switch (format) {
 317         case AFMT_MU_LAW:
 318                 return "MU_LAW";
 319         case AFMT_A_LAW:
 320                 return "A_LAW";
 321         case AFMT_IMA_ADPCM:
 322                 return "IMA_ADPCM";
 323         case AFMT_U8:
 324                 return "U8";
 325         case AFMT_S16_LE:
 326                 return "S16_LE";
 327         case AFMT_S16_BE:
 328                 return "S16_BE";
 329         case AFMT_S8:
 330                 return "S8";
 331         case AFMT_U16_LE:
 332                 return "U16_LE";
 333         case AFMT_U16_BE:
 334                 return "U16_BE";
 335         case AFMT_MPEG:
 336                 return "MPEG";
 337         default:
 338                 return "unknown";
 339         }
 340 }
 341 #endif
 342
 343 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 344                                    struct snd_info_buffer *buffer)
 345 {
 346         struct snd_pcm_info *info;
 347         int err;
 348
 349         if (! substream)
 350                 return;
 351
 352         info = kmalloc(sizeof(*info), GFP_KERNEL);
 353         if (!info)
 354                 return;
 355
 356         err = snd_pcm_info(substream, info);
 357         if (err < 0) {
 358                 snd_iprintf(buffer, "error %d\n", err);
 359                 kfree(info);
 360                 return;
 361         }
 362         snd_iprintf(buffer, "card: %d\n", info->card);
 363         snd_iprintf(buffer, "device: %d\n", info->device);
 364         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 365         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 366         snd_iprintf(buffer, "id: %s\n", info->id);
 367         snd_iprintf(buffer, "name: %s\n", info->name);
 368         snd_iprintf(buffer, "subname: %s\n", info->subname);
 369         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 370         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 371         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 372         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 373         kfree(info);
 374 }
 375
 376 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 377                                           struct snd_info_buffer *buffer)
 378 {
 379         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 380                                buffer);
 381 }
 382
 383 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 384                                              struct snd_info_buffer *buffer)
 385 {
 386         snd_pcm_proc_info_read(entry->private_data, buffer);
 387 }
 388
 389 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 390                                                   struct snd_info_buffer *buffer)
 391 {
 392         struct snd_pcm_substream *substream = entry->private_data;
 393         struct snd_pcm_runtime *runtime;
 394
 395         mutex_lock(&substream->pcm->open_mutex);
 396         runtime = substream->runtime;
 397         if (!runtime) {
 398                 snd_iprintf(buffer, "closed\n");
 399                 goto unlock;
 400         }
 401         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 402                 snd_iprintf(buffer, "no setup\n");
 403                 goto unlock;
 404         }
 405         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 406         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 407         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 408         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 409         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 410         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 411         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 412 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 413         if (substream->oss.oss) {
 414                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 415                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 416                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 417                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 418                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 419                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 420         }
 421 #endif
 422  unlock:
 423         mutex_unlock(&substream->pcm->open_mutex);
 424 }
 425
 426 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 427                                                   struct snd_info_buffer *buffer)
 428 {
 429         struct snd_pcm_substream *substream = entry->private_data;
 430         struct snd_pcm_runtime *runtime;
 431
 432         mutex_lock(&substream->pcm->open_mutex);
 433         runtime = substream->runtime;
 434         if (!runtime) {
 435                 snd_iprintf(buffer, "closed\n");
 436                 goto unlock;
 437         }
 438         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 439                 snd_iprintf(buffer, "no setup\n");
 440                 goto unlock;
 441         }
 442         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 443         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 444         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 445         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 446         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 447         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 448         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 449         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 450  unlock:
 451         mutex_unlock(&substream->pcm->open_mutex);
 452 }
 453
 454 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 455                                                struct snd_info_buffer *buffer)
 456 {
 457         struct snd_pcm_substream *substream = entry->private_data;
 458         struct snd_pcm_runtime *runtime;
 459         struct snd_pcm_status status;
 460         int err;
 461
 462         mutex_lock(&substream->pcm->open_mutex);
 463         runtime = substream->runtime;
 464         if (!runtime) {
 465                 snd_iprintf(buffer, "closed\n");
 466                 goto unlock;
 467         }
 468         memset(&status, 0, sizeof(status));
 469         err = snd_pcm_status(substream, &status);
 470         if (err < 0) {
 471                 snd_iprintf(buffer, "error %d\n", err);
 472                 goto unlock;
 473         }
 474         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 475         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 476         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 477                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 478         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 479                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 480         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 481         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 482         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 483         snd_iprintf(buffer, "-----\n");
 484         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 485         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 486  unlock:
 487         mutex_unlock(&substream->pcm->open_mutex);
 488 }
 489
 490 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 491 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 492                                          struct snd_info_buffer *buffer)
 493 {
 494         struct snd_pcm_substream *substream = entry->private_data;
 495         struct snd_pcm_runtime *runtime;
 496
 497         snd_pcm_stream_lock_irq(substream);
 498         runtime = substream->runtime;
 499         if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
 500                 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 501         snd_pcm_stream_unlock_irq(substream);
 502 }
 503
 504 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 505                                     struct snd_info_buffer *buffer)
 506 {
 507         struct snd_pcm_str *pstr = entry->private_data;
 508         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 509 }
 510
 511 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 512                                      struct snd_info_buffer *buffer)
 513 {
 514         struct snd_pcm_str *pstr = entry->private_data;
 515         char line[64];
 516         if (!snd_info_get_line(buffer, line, sizeof(line)))
 517                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 518 }
 519 #endif
 520
 521 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 522 {
 523         struct snd_pcm *pcm = pstr->pcm;
 524         struct snd_info_entry *entry;
 525         char name[16];
 526
 527         sprintf(name, "pcm%i%c", pcm->device,
 528                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 529         entry = snd_info_create_card_entry(pcm->card, name,
 530                                            pcm->card->proc_root);
 531         if (!entry)
 532                 return -ENOMEM;
 533         entry->mode = S_IFDIR | 0555;
 534         if (snd_info_register(entry) < 0) {
 535                 snd_info_free_entry(entry);
 536                 return -ENOMEM;
 537         }
 538         pstr->proc_root = entry;
 539         entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
 540         if (entry) {
 541                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 542                 if (snd_info_register(entry) < 0) {
 543                         snd_info_free_entry(entry);
 544                         entry = NULL;
 545                 }
 546         }
 547         pstr->proc_info_entry = entry;
 548
 549 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 550         entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 551                                            pstr->proc_root);
 552         if (entry) {
 553                 entry->c.text.read = snd_pcm_xrun_debug_read;
 554                 entry->c.text.write = snd_pcm_xrun_debug_write;
 555                 entry->mode |= 0200;
 556                 entry->private_data = pstr;
 557                 if (snd_info_register(entry) < 0) {
 558                         snd_info_free_entry(entry);
 559                         entry = NULL;
 560                 }
 561         }
 562         pstr->proc_xrun_debug_entry = entry;
 563 #endif
 564         return 0;
 565 }
 566
 567 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 568 {
 569 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 570         snd_info_free_entry(pstr->proc_xrun_debug_entry);
 571         pstr->proc_xrun_debug_entry = NULL;
 572 #endif
 573         snd_info_free_entry(pstr->proc_info_entry);
 574         pstr->proc_info_entry = NULL;
 575         snd_info_free_entry(pstr->proc_root);
 576         pstr->proc_root = NULL;
 577         return 0;
 578 }
 579
 580 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 581 {
 582         struct snd_info_entry *entry;
 583         struct snd_card *card;
 584         char name[16];
 585
 586         card = substream->pcm->card;
 587
 588         sprintf(name, "sub%i", substream->number);
 589         entry = snd_info_create_card_entry(card, name,
 590                                            substream->pstr->proc_root);
 591         if (!entry)
 592                 return -ENOMEM;
 593         entry->mode = S_IFDIR | 0555;
 594         if (snd_info_register(entry) < 0) {
 595                 snd_info_free_entry(entry);
 596                 return -ENOMEM;
 597         }
 598         substream->proc_root = entry;
 599         entry = snd_info_create_card_entry(card, "info", substream->proc_root);
 600         if (entry) {
 601                 snd_info_set_text_ops(entry, substream,
 602                                       snd_pcm_substream_proc_info_read);
 603                 if (snd_info_register(entry) < 0) {
 604                         snd_info_free_entry(entry);
 605                         entry = NULL;
 606                 }
 607         }
 608         substream->proc_info_entry = entry;
 609         entry = snd_info_create_card_entry(card, "hw_params",
 610                                            substream->proc_root);
 611         if (entry) {
 612                 snd_info_set_text_ops(entry, substream,
 613                                       snd_pcm_substream_proc_hw_params_read);
 614                 if (snd_info_register(entry) < 0) {
 615                         snd_info_free_entry(entry);
 616                         entry = NULL;
 617                 }
 618         }
 619         substream->proc_hw_params_entry = entry;
 620         entry = snd_info_create_card_entry(card, "sw_params",
 621                                            substream->proc_root);
 622         if (entry) {
 623                 snd_info_set_text_ops(entry, substream,
 624                                       snd_pcm_substream_proc_sw_params_read);
 625                 if (snd_info_register(entry) < 0) {
 626                         snd_info_free_entry(entry);
 627                         entry = NULL;
 628                 }
 629         }
 630         substream->proc_sw_params_entry = entry;
 631         entry = snd_info_create_card_entry(card, "status",
 632                                            substream->proc_root);
 633         if (entry) {
 634                 snd_info_set_text_ops(entry, substream,
 635                                       snd_pcm_substream_proc_status_read);
 636                 if (snd_info_register(entry) < 0) {
 637                         snd_info_free_entry(entry);
 638                         entry = NULL;
 639                 }
 640         }
 641         substream->proc_status_entry = entry;
 642
 643 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 644         entry = snd_info_create_card_entry(card, "xrun_injection",
 645                                            substream->proc_root);
 646         if (entry) {
 647                 entry->private_data = substream;
 648                 entry->c.text.read = NULL;
 649                 entry->c.text.write = snd_pcm_xrun_injection_write;
 650                 entry->mode = S_IFREG | 0200;
 651                 if (snd_info_register(entry) < 0) {
 652                         snd_info_free_entry(entry);
 653                         entry = NULL;
 654                 }
 655         }
 656         substream->proc_xrun_injection_entry = entry;
 657 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 658
 659         return 0;
 660 }
 661
 662 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
 663 {
 664         snd_info_free_entry(substream->proc_info_entry);
 665         substream->proc_info_entry = NULL;
 666         snd_info_free_entry(substream->proc_hw_params_entry);
 667         substream->proc_hw_params_entry = NULL;
 668         snd_info_free_entry(substream->proc_sw_params_entry);
 669         substream->proc_sw_params_entry = NULL;
 670         snd_info_free_entry(substream->proc_status_entry);
 671         substream->proc_status_entry = NULL;
 672 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 673         snd_info_free_entry(substream->proc_xrun_injection_entry);
 674         substream->proc_xrun_injection_entry = NULL;
 675 #endif
 676         snd_info_free_entry(substream->proc_root);
 677         substream->proc_root = NULL;
 678         return 0;
 679 }
 680 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 681 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 682 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 683 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 684 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 685 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 686
 687 static const struct attribute_group *pcm_dev_attr_groups[];
 688
 689 /**
 690  * snd_pcm_new_stream - create a new PCM stream
 691  * @pcm: the pcm instance
 692  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 693  * @substream_count: the number of substreams
 694  *
 695  * Creates a new stream for the pcm.
 696  * The corresponding stream on the pcm must have been empty before
 697  * calling this, i.e. zero must be given to the argument of
 698  * snd_pcm_new().
 699  *
 700  * Return: Zero if successful, or a negative error code on failure.
 701  */
 702 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 703 {
 704         int idx, err;
 705         struct snd_pcm_str *pstr = &pcm->streams[stream];
 706         struct snd_pcm_substream *substream, *prev;
 707
 708 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 709         mutex_init(&pstr->oss.setup_mutex);
 710 #endif
 711         pstr->stream = stream;
 712         pstr->pcm = pcm;
 713         pstr->substream_count = substream_count;
 714         if (!substream_count)
 715                 return 0;
 716
 717         snd_device_initialize(&pstr->dev, pcm->card);
 718         pstr->dev.groups = pcm_dev_attr_groups;
 719         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 720                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 721
 722         if (!pcm->internal) {
 723                 err = snd_pcm_stream_proc_init(pstr);
 724                 if (err < 0) {
 725                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 726                         return err;
 727                 }
 728         }
 729         prev = NULL;
 730         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 731                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 732                 if (!substream)
 733                         return -ENOMEM;
 734                 substream->pcm = pcm;
 735                 substream->pstr = pstr;
 736                 substream->number = idx;
 737                 substream->stream = stream;
 738                 sprintf(substream->name, "subdevice #%i", idx);
 739                 substream->buffer_bytes_max = UINT_MAX;
 740                 if (prev == NULL)
 741                         pstr->substream = substream;
 742                 else
 743                         prev->next = substream;
 744
 745                 if (!pcm->internal) {
 746                         err = snd_pcm_substream_proc_init(substream);
 747                         if (err < 0) {
 748                                 pcm_err(pcm,
 749                                         "Error in snd_pcm_stream_proc_init\n");
 750                                 if (prev == NULL)
 751                                         pstr->substream = NULL;
 752                                 else
 753                                         prev->next = NULL;
 754                                 kfree(substream);
 755                                 return err;
 756                         }
 757                 }
 758                 substream->group = &substream->self_group;
 759                 spin_lock_init(&substream->self_group.lock);
 760                 mutex_init(&substream->self_group.mutex);
 761                 INIT_LIST_HEAD(&substream->self_group.substreams);
 762                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 763                 atomic_set(&substream->mmap_count, 0);
 764                 prev = substream;
 765         }
 766         return 0;
 767 }
 768 EXPORT_SYMBOL(snd_pcm_new_stream);
 769
 770 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 771                 int playback_count, int capture_count, bool internal,
 772                 struct snd_pcm **rpcm)
 773 {
 774         struct snd_pcm *pcm;
 775         int err;
 776         static struct snd_device_ops ops = {
 777                 .dev_free = snd_pcm_dev_free,
 778                 .dev_register = snd_pcm_dev_register,
 779                 .dev_disconnect = snd_pcm_dev_disconnect,
 780         };
 781         static struct snd_device_ops internal_ops = {
 782                 .dev_free = snd_pcm_dev_free,
 783         };
 784
 785         if (snd_BUG_ON(!card))
 786                 return -ENXIO;
 787         if (rpcm)
 788                 *rpcm = NULL;
 789         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 790         if (!pcm)
 791                 return -ENOMEM;
 792         pcm->card = card;
 793         pcm->device = device;
 794         pcm->internal = internal;
 795         mutex_init(&pcm->open_mutex);
 796         init_waitqueue_head(&pcm->open_wait);
 797         INIT_LIST_HEAD(&pcm->list);
 798         if (id)
 799                 strlcpy(pcm->id, id, sizeof(pcm->id));
 800
 801         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 802                                  playback_count);
 803         if (err < 0)
 804                 goto free_pcm;
 805
 806         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
 807         if (err < 0)
 808                 goto free_pcm;
 809
 810         err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
 811                              internal ? &internal_ops : &ops);
 812         if (err < 0)
 813                 goto free_pcm;
 814
 815         if (rpcm)
 816                 *rpcm = pcm;
 817         return 0;
 818
 819 free_pcm:
 820         snd_pcm_free(pcm);
 821         return err;
 822 }
 823
 824 /**
 825  * snd_pcm_new - create a new PCM instance
 826  * @card: the card instance
 827  * @id: the id string
 828  * @device: the device index (zero based)
 829  * @playback_count: the number of substreams for playback
 830  * @capture_count: the number of substreams for capture
 831  * @rpcm: the pointer to store the new pcm instance
 832  *
 833  * Creates a new PCM instance.
 834  *
 835  * The pcm operators have to be set afterwards to the new instance
 836  * via snd_pcm_set_ops().
 837  *
 838  * Return: Zero if successful, or a negative error code on failure.
 839  */
 840 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 841                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 842 {
 843         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 844                         false, rpcm);
 845 }
 846 EXPORT_SYMBOL(snd_pcm_new);
 847
 848 /**
 849  * snd_pcm_new_internal - create a new internal PCM instance
 850  * @card: the card instance
 851  * @id: the id string
 852  * @device: the device index (zero based - shared with normal PCMs)
 853  * @playback_count: the number of substreams for playback
 854  * @capture_count: the number of substreams for capture
 855  * @rpcm: the pointer to store the new pcm instance
 856  *
 857  * Creates a new internal PCM instance with no userspace device or procfs
 858  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 859  * will only be used internally by kernel drivers. i.e. it cannot be opened
 860  * by userspace. It provides existing ASoC components drivers with a substream
 861  * and access to any private data.
 862  *
 863  * The pcm operators have to be set afterwards to the new instance
 864  * via snd_pcm_set_ops().
 865  *
 866  * Return: Zero if successful, or a negative error code on failure.
 867  */
 868 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 869         int playback_count, int capture_count,
 870         struct snd_pcm **rpcm)
 871 {
 872         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 873                         true, rpcm);
 874 }
 875 EXPORT_SYMBOL(snd_pcm_new_internal);
 876
 877 static void free_chmap(struct snd_pcm_str *pstr)
 878 {
 879         if (pstr->chmap_kctl) {
 880                 snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
 881                 pstr->chmap_kctl = NULL;
 882         }
 883 }
 884
 885 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 886 {
 887         struct snd_pcm_substream *substream, *substream_next;
 888 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 889         struct snd_pcm_oss_setup *setup, *setupn;
 890 #endif
 891         substream = pstr->substream;
 892         while (substream) {
 893                 substream_next = substream->next;
 894                 snd_pcm_timer_done(substream);
 895                 snd_pcm_substream_proc_done(substream);
 896                 kfree(substream);
 897                 substream = substream_next;
 898         }
 899         snd_pcm_stream_proc_done(pstr);
 900 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 901         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 902                 setupn = setup->next;
 903                 kfree(setup->task_name);
 904                 kfree(setup);
 905         }
 906 #endif
 907         free_chmap(pstr);
 908         if (pstr->substream_count)
 909                 put_device(&pstr->dev);
 910 }
 911
 912 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 913 #define pcm_call_notify(pcm, call)                                      \
 914         do {                                                            \
 915                 struct snd_pcm_notify *_notify;                         \
 916                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 917                         _notify->call(pcm);                             \
 918         } while (0)
 919 #else
 920 #define pcm_call_notify(pcm, call) do {} while (0)
 921 #endif
 922
 923 static int snd_pcm_free(struct snd_pcm *pcm)
 924 {
 925         if (!pcm)
 926                 return 0;
 927         if (!pcm->internal)
 928                 pcm_call_notify(pcm, n_unregister);
 929         if (pcm->private_free)
 930                 pcm->private_free(pcm);
 931         snd_pcm_lib_preallocate_free_for_all(pcm);
 932         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 933         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 934         kfree(pcm);
 935         return 0;
 936 }
 937
 938 static int snd_pcm_dev_free(struct snd_device *device)
 939 {
 940         struct snd_pcm *pcm = device->device_data;
 941         return snd_pcm_free(pcm);
 942 }
 943
 944 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 945                              struct file *file,
 946                              struct snd_pcm_substream **rsubstream)
 947 {
 948         struct snd_pcm_str * pstr;
 949         struct snd_pcm_substream *substream;
 950         struct snd_pcm_runtime *runtime;
 951         struct snd_card *card;
 952         int prefer_subdevice;
 953         size_t size;
 954
 955         if (snd_BUG_ON(!pcm || !rsubstream))
 956                 return -ENXIO;
 957         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 958                        stream != SNDRV_PCM_STREAM_CAPTURE))
 959                 return -EINVAL;
 960         *rsubstream = NULL;
 961         pstr = &pcm->streams[stream];
 962         if (pstr->substream == NULL || pstr->substream_count == 0)
 963                 return -ENODEV;
 964
 965         card = pcm->card;
 966         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 967
 968         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 969                 int opposite = !stream;
 970
 971                 for (substream = pcm->streams[opposite].substream; substream;
 972                      substream = substream->next) {
 973                         if (SUBSTREAM_BUSY(substream))
 974                                 return -EAGAIN;
 975                 }
 976         }
 977
 978         if (file->f_flags & O_APPEND) {
 979                 if (prefer_subdevice < 0) {
 980                         if (pstr->substream_count > 1)
 981                                 return -EINVAL; /* must be unique */
 982                         substream = pstr->substream;
 983                 } else {
 984                         for (substream = pstr->substream; substream;
 985                              substream = substream->next)
 986                                 if (substream->number == prefer_subdevice)
 987                                         break;
 988                 }
 989                 if (! substream)
 990                         return -ENODEV;
 991                 if (! SUBSTREAM_BUSY(substream))
 992                         return -EBADFD;
 993                 substream->ref_count++;
 994                 *rsubstream = substream;
 995                 return 0;
 996         }
 997
 998         for (substream = pstr->substream; substream; substream = substream->next) {
 999                 if (!SUBSTREAM_BUSY(substream) &&
1000                     (prefer_subdevice == -1 ||
1001                      substream->number == prefer_subdevice))
1002                         break;
1003         }
1004         if (substream == NULL)
1005                 return -EAGAIN;
1006
1007         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
1008         if (runtime == NULL)
1009                 return -ENOMEM;
1010
1011         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
1012         runtime->status = snd_malloc_pages(size, GFP_KERNEL);
1013         if (runtime->status == NULL) {
1014                 kfree(runtime);
1015                 return -ENOMEM;
1016         }
1017         memset((void*)runtime->status, 0, size);
1018
1019         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
1020         runtime->control = snd_malloc_pages(size, GFP_KERNEL);
1021         if (runtime->control == NULL) {
1022                 snd_free_pages((void*)runtime->status,
1023                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1024                 kfree(runtime);
1025                 return -ENOMEM;
1026         }
1027         memset((void*)runtime->control, 0, size);
1028
1029         init_waitqueue_head(&runtime->sleep);
1030         init_waitqueue_head(&runtime->tsleep);
1031
1032         runtime->status->state = SNDRV_PCM_STATE_OPEN;
1033
1034         substream->runtime = runtime;
1035         substream->private_data = pcm->private_data;
1036         substream->ref_count = 1;
1037         substream->f_flags = file->f_flags;
1038         substream->pid = get_pid(task_pid(current));
1039         pstr->substream_opened++;
1040         *rsubstream = substream;
1041         return 0;
1042 }
1043
1044 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1045 {
1046         struct snd_pcm_runtime *runtime;
1047
1048         if (PCM_RUNTIME_CHECK(substream))
1049                 return;
1050         runtime = substream->runtime;
1051         if (runtime->private_free != NULL)
1052                 runtime->private_free(runtime);
1053         snd_free_pages((void*)runtime->status,
1054                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1055         snd_free_pages((void*)runtime->control,
1056                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1057         kfree(runtime->hw_constraints.rules);
1058         /* Avoid concurrent access to runtime via PCM timer interface */
1059         if (substream->timer)
1060                 spin_lock_irq(&substream->timer->lock);
1061         substream->runtime = NULL;
1062         if (substream->timer)
1063                 spin_unlock_irq(&substream->timer->lock);
1064         kfree(runtime);
1065         put_pid(substream->pid);
1066         substream->pid = NULL;
1067         substream->pstr->substream_opened--;
1068 }
1069
1070 static ssize_t show_pcm_class(struct device *dev,
1071                               struct device_attribute *attr, char *buf)
1072 {
1073         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1074         struct snd_pcm *pcm = pstr->pcm;
1075         const char *str;
1076         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1077                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1078                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1079                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1080                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1081         };
1082
1083         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1084                 str = "none";
1085         else
1086                 str = strs[pcm->dev_class];
1087         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1088 }
1089
1090 static DEVICE_ATTR(pcm_class, 0444, show_pcm_class, NULL);
1091 static struct attribute *pcm_dev_attrs[] = {
1092         &dev_attr_pcm_class.attr,
1093         NULL
1094 };
1095
1096 static const struct attribute_group pcm_dev_attr_group = {
1097         .attrs  = pcm_dev_attrs,
1098 };
1099
1100 static const struct attribute_group *pcm_dev_attr_groups[] = {
1101         &pcm_dev_attr_group,
1102         NULL
1103 };
1104
1105 static int snd_pcm_dev_register(struct snd_device *device)
1106 {
1107         int cidx, err;
1108         struct snd_pcm_substream *substream;
1109         struct snd_pcm *pcm;
1110
1111         if (snd_BUG_ON(!device || !device->device_data))
1112                 return -ENXIO;
1113         pcm = device->device_data;
1114
1115         mutex_lock(&register_mutex);
1116         err = snd_pcm_add(pcm);
1117         if (err)
1118                 goto unlock;
1119         for (cidx = 0; cidx < 2; cidx++) {
1120                 int devtype = -1;
1121                 if (pcm->streams[cidx].substream == NULL)
1122                         continue;
1123                 switch (cidx) {
1124                 case SNDRV_PCM_STREAM_PLAYBACK:
1125                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1126                         break;
1127                 case SNDRV_PCM_STREAM_CAPTURE:
1128                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1129                         break;
1130                 }
1131                 /* register pcm */
1132                 err = snd_register_device(devtype, pcm->card, pcm->device,
1133                                           &snd_pcm_f_ops[cidx], pcm,
1134                                           &pcm->streams[cidx].dev);
1135                 if (err < 0) {
1136                         list_del_init(&pcm->list);
1137                         goto unlock;
1138                 }
1139
1140                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1141                         snd_pcm_timer_init(substream);
1142         }
1143
1144         pcm_call_notify(pcm, n_register);
1145
1146  unlock:
1147         mutex_unlock(&register_mutex);
1148         return err;
1149 }
1150
1151 static int snd_pcm_dev_disconnect(struct snd_device *device)
1152 {
1153         struct snd_pcm *pcm = device->device_data;
1154         struct snd_pcm_substream *substream;
1155         int cidx;
1156
1157         mutex_lock(&register_mutex);
1158         mutex_lock(&pcm->open_mutex);
1159         wake_up(&pcm->open_wait);
1160         list_del_init(&pcm->list);
1161         for (cidx = 0; cidx < 2; cidx++) {
1162                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1163                         snd_pcm_stream_lock_irq(substream);
1164                         if (substream->runtime) {
1165                                 if (snd_pcm_running(substream))
1166                                         snd_pcm_stop(substream,
1167                                                      SNDRV_PCM_STATE_DISCONNECTED);
1168                                 /* to be sure, set the state unconditionally */
1169                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1170                                 wake_up(&substream->runtime->sleep);
1171                                 wake_up(&substream->runtime->tsleep);
1172                         }
1173                         snd_pcm_stream_unlock_irq(substream);
1174                 }
1175         }
1176
1177         pcm_call_notify(pcm, n_disconnect);
1178         for (cidx = 0; cidx < 2; cidx++) {
1179                 snd_unregister_device(&pcm->streams[cidx].dev);
1180                 free_chmap(&pcm->streams[cidx]);
1181         }
1182         mutex_unlock(&pcm->open_mutex);
1183         mutex_unlock(&register_mutex);
1184         return 0;
1185 }
1186
1187 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1188 /**
1189  * snd_pcm_notify - Add/remove the notify list
1190  * @notify: PCM notify list
1191  * @nfree: 0 = register, 1 = unregister
1192  *
1193  * This adds the given notifier to the global list so that the callback is
1194  * called for each registered PCM devices.  This exists only for PCM OSS
1195  * emulation, so far.
1196  */
1197 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1198 {
1199         struct snd_pcm *pcm;
1200
1201         if (snd_BUG_ON(!notify ||
1202                        !notify->n_register ||
1203                        !notify->n_unregister ||
1204                        !notify->n_disconnect))
1205                 return -EINVAL;
1206         mutex_lock(&register_mutex);
1207         if (nfree) {
1208                 list_del(&notify->list);
1209                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1210                         notify->n_unregister(pcm);
1211         } else {
1212                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1213                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1214                         notify->n_register(pcm);
1215         }
1216         mutex_unlock(&register_mutex);
1217         return 0;
1218 }
1219 EXPORT_SYMBOL(snd_pcm_notify);
1220 #endif /* CONFIG_SND_PCM_OSS */
1221
1222 #ifdef CONFIG_SND_PROC_FS
1223 /*
1224  *  Info interface
1225  */
1226
1227 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1228                               struct snd_info_buffer *buffer)
1229 {
1230         struct snd_pcm *pcm;
1231
1232         mutex_lock(&register_mutex);
1233         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1234                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1235                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1236                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1237                         snd_iprintf(buffer, " : playback %i",
1238                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1239                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1240                         snd_iprintf(buffer, " : capture %i",
1241                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1242                 snd_iprintf(buffer, "\n");
1243         }
1244         mutex_unlock(&register_mutex);
1245 }
1246
1247 static struct snd_info_entry *snd_pcm_proc_entry;
1248
1249 static void snd_pcm_proc_init(void)
1250 {
1251         struct snd_info_entry *entry;
1252
1253         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1254         if (entry) {
1255                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1256                 if (snd_info_register(entry) < 0) {
1257                         snd_info_free_entry(entry);
1258                         entry = NULL;
1259                 }
1260         }
1261         snd_pcm_proc_entry = entry;
1262 }
1263
1264 static void snd_pcm_proc_done(void)
1265 {
1266         snd_info_free_entry(snd_pcm_proc_entry);
1267 }
1268
1269 #else /* !CONFIG_SND_PROC_FS */
1270 #define snd_pcm_proc_init()
1271 #define snd_pcm_proc_done()
1272 #endif /* CONFIG_SND_PROC_FS */
1273
1274
1275 /*
1276  *  ENTRY functions
1277  */
1278
1279 static int __init alsa_pcm_init(void)
1280 {
1281         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1282         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1283         snd_pcm_proc_init();
1284         return 0;
1285 }
1286
1287 static void __exit alsa_pcm_exit(void)
1288 {
1289         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1290         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1291         snd_pcm_proc_done();
1292 }
1293
1294 module_init(alsa_pcm_init)
1295 module_exit(alsa_pcm_exit)