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
 496         snd_pcm_stop_xrun(substream);
 497 }
 498
 499 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 500                                     struct snd_info_buffer *buffer)
 501 {
 502         struct snd_pcm_str *pstr = entry->private_data;
 503         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 504 }
 505
 506 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 507                                      struct snd_info_buffer *buffer)
 508 {
 509         struct snd_pcm_str *pstr = entry->private_data;
 510         char line[64];
 511         if (!snd_info_get_line(buffer, line, sizeof(line)))
 512                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 513 }
 514 #endif
 515
 516 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 517 {
 518         struct snd_pcm *pcm = pstr->pcm;
 519         struct snd_info_entry *entry;
 520         char name[16];
 521
 522         sprintf(name, "pcm%i%c", pcm->device,
 523                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 524         entry = snd_info_create_card_entry(pcm->card, name,
 525                                            pcm->card->proc_root);
 526         if (!entry)
 527                 return -ENOMEM;
 528         entry->mode = S_IFDIR | 0555;
 529         if (snd_info_register(entry) < 0) {
 530                 snd_info_free_entry(entry);
 531                 return -ENOMEM;
 532         }
 533         pstr->proc_root = entry;
 534         entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
 535         if (entry) {
 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         entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 546                                            pstr->proc_root);
 547         if (entry) {
 548                 entry->c.text.read = snd_pcm_xrun_debug_read;
 549                 entry->c.text.write = snd_pcm_xrun_debug_write;
 550                 entry->mode |= 0200;
 551                 entry->private_data = pstr;
 552                 if (snd_info_register(entry) < 0) {
 553                         snd_info_free_entry(entry);
 554                         entry = NULL;
 555                 }
 556         }
 557         pstr->proc_xrun_debug_entry = entry;
 558 #endif
 559         return 0;
 560 }
 561
 562 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 563 {
 564 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 565         snd_info_free_entry(pstr->proc_xrun_debug_entry);
 566         pstr->proc_xrun_debug_entry = NULL;
 567 #endif
 568         snd_info_free_entry(pstr->proc_info_entry);
 569         pstr->proc_info_entry = NULL;
 570         snd_info_free_entry(pstr->proc_root);
 571         pstr->proc_root = NULL;
 572         return 0;
 573 }
 574
 575 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 576 {
 577         struct snd_info_entry *entry;
 578         struct snd_card *card;
 579         char name[16];
 580
 581         card = substream->pcm->card;
 582
 583         sprintf(name, "sub%i", substream->number);
 584         entry = snd_info_create_card_entry(card, name,
 585                                            substream->pstr->proc_root);
 586         if (!entry)
 587                 return -ENOMEM;
 588         entry->mode = S_IFDIR | 0555;
 589         if (snd_info_register(entry) < 0) {
 590                 snd_info_free_entry(entry);
 591                 return -ENOMEM;
 592         }
 593         substream->proc_root = entry;
 594         entry = snd_info_create_card_entry(card, "info", substream->proc_root);
 595         if (entry) {
 596                 snd_info_set_text_ops(entry, substream,
 597                                       snd_pcm_substream_proc_info_read);
 598                 if (snd_info_register(entry) < 0) {
 599                         snd_info_free_entry(entry);
 600                         entry = NULL;
 601                 }
 602         }
 603         substream->proc_info_entry = entry;
 604         entry = snd_info_create_card_entry(card, "hw_params",
 605                                            substream->proc_root);
 606         if (entry) {
 607                 snd_info_set_text_ops(entry, substream,
 608                                       snd_pcm_substream_proc_hw_params_read);
 609                 if (snd_info_register(entry) < 0) {
 610                         snd_info_free_entry(entry);
 611                         entry = NULL;
 612                 }
 613         }
 614         substream->proc_hw_params_entry = entry;
 615         entry = snd_info_create_card_entry(card, "sw_params",
 616                                            substream->proc_root);
 617         if (entry) {
 618                 snd_info_set_text_ops(entry, substream,
 619                                       snd_pcm_substream_proc_sw_params_read);
 620                 if (snd_info_register(entry) < 0) {
 621                         snd_info_free_entry(entry);
 622                         entry = NULL;
 623                 }
 624         }
 625         substream->proc_sw_params_entry = entry;
 626         entry = snd_info_create_card_entry(card, "status",
 627                                            substream->proc_root);
 628         if (entry) {
 629                 snd_info_set_text_ops(entry, substream,
 630                                       snd_pcm_substream_proc_status_read);
 631                 if (snd_info_register(entry) < 0) {
 632                         snd_info_free_entry(entry);
 633                         entry = NULL;
 634                 }
 635         }
 636         substream->proc_status_entry = entry;
 637
 638 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 639         entry = snd_info_create_card_entry(card, "xrun_injection",
 640                                            substream->proc_root);
 641         if (entry) {
 642                 entry->private_data = substream;
 643                 entry->c.text.read = NULL;
 644                 entry->c.text.write = snd_pcm_xrun_injection_write;
 645                 entry->mode = S_IFREG | 0200;
 646                 if (snd_info_register(entry) < 0) {
 647                         snd_info_free_entry(entry);
 648                         entry = NULL;
 649                 }
 650         }
 651         substream->proc_xrun_injection_entry = entry;
 652 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 653
 654         return 0;
 655 }
 656
 657 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
 658 {
 659         snd_info_free_entry(substream->proc_info_entry);
 660         substream->proc_info_entry = NULL;
 661         snd_info_free_entry(substream->proc_hw_params_entry);
 662         substream->proc_hw_params_entry = NULL;
 663         snd_info_free_entry(substream->proc_sw_params_entry);
 664         substream->proc_sw_params_entry = NULL;
 665         snd_info_free_entry(substream->proc_status_entry);
 666         substream->proc_status_entry = NULL;
 667 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 668         snd_info_free_entry(substream->proc_xrun_injection_entry);
 669         substream->proc_xrun_injection_entry = NULL;
 670 #endif
 671         snd_info_free_entry(substream->proc_root);
 672         substream->proc_root = NULL;
 673         return 0;
 674 }
 675 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 676 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 677 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 678 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 679 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 680 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 681
 682 static const struct attribute_group *pcm_dev_attr_groups[];
 683
 684 /**
 685  * snd_pcm_new_stream - create a new PCM stream
 686  * @pcm: the pcm instance
 687  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 688  * @substream_count: the number of substreams
 689  *
 690  * Creates a new stream for the pcm.
 691  * The corresponding stream on the pcm must have been empty before
 692  * calling this, i.e. zero must be given to the argument of
 693  * snd_pcm_new().
 694  *
 695  * Return: Zero if successful, or a negative error code on failure.
 696  */
 697 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 698 {
 699         int idx, err;
 700         struct snd_pcm_str *pstr = &pcm->streams[stream];
 701         struct snd_pcm_substream *substream, *prev;
 702
 703 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 704         mutex_init(&pstr->oss.setup_mutex);
 705 #endif
 706         pstr->stream = stream;
 707         pstr->pcm = pcm;
 708         pstr->substream_count = substream_count;
 709         if (!substream_count)
 710                 return 0;
 711
 712         snd_device_initialize(&pstr->dev, pcm->card);
 713         pstr->dev.groups = pcm_dev_attr_groups;
 714         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 715                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 716
 717         if (!pcm->internal) {
 718                 err = snd_pcm_stream_proc_init(pstr);
 719                 if (err < 0) {
 720                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 721                         return err;
 722                 }
 723         }
 724         prev = NULL;
 725         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 726                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 727                 if (!substream)
 728                         return -ENOMEM;
 729                 substream->pcm = pcm;
 730                 substream->pstr = pstr;
 731                 substream->number = idx;
 732                 substream->stream = stream;
 733                 sprintf(substream->name, "subdevice #%i", idx);
 734                 substream->buffer_bytes_max = UINT_MAX;
 735                 if (prev == NULL)
 736                         pstr->substream = substream;
 737                 else
 738                         prev->next = substream;
 739
 740                 if (!pcm->internal) {
 741                         err = snd_pcm_substream_proc_init(substream);
 742                         if (err < 0) {
 743                                 pcm_err(pcm,
 744                                         "Error in snd_pcm_stream_proc_init\n");
 745                                 if (prev == NULL)
 746                                         pstr->substream = NULL;
 747                                 else
 748                                         prev->next = NULL;
 749                                 kfree(substream);
 750                                 return err;
 751                         }
 752                 }
 753                 substream->group = &substream->self_group;
 754                 spin_lock_init(&substream->self_group.lock);
 755                 mutex_init(&substream->self_group.mutex);
 756                 INIT_LIST_HEAD(&substream->self_group.substreams);
 757                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 758                 atomic_set(&substream->mmap_count, 0);
 759                 prev = substream;
 760         }
 761         return 0;
 762 }
 763 EXPORT_SYMBOL(snd_pcm_new_stream);
 764
 765 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 766                 int playback_count, int capture_count, bool internal,
 767                 struct snd_pcm **rpcm)
 768 {
 769         struct snd_pcm *pcm;
 770         int err;
 771         static struct snd_device_ops ops = {
 772                 .dev_free = snd_pcm_dev_free,
 773                 .dev_register = snd_pcm_dev_register,
 774                 .dev_disconnect = snd_pcm_dev_disconnect,
 775         };
 776         static struct snd_device_ops internal_ops = {
 777                 .dev_free = snd_pcm_dev_free,
 778         };
 779
 780         if (snd_BUG_ON(!card))
 781                 return -ENXIO;
 782         if (rpcm)
 783                 *rpcm = NULL;
 784         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 785         if (!pcm)
 786                 return -ENOMEM;
 787         pcm->card = card;
 788         pcm->device = device;
 789         pcm->internal = internal;
 790         mutex_init(&pcm->open_mutex);
 791         init_waitqueue_head(&pcm->open_wait);
 792         INIT_LIST_HEAD(&pcm->list);
 793         if (id)
 794                 strlcpy(pcm->id, id, sizeof(pcm->id));
 795
 796         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 797                                  playback_count);
 798         if (err < 0)
 799                 goto free_pcm;
 800
 801         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
 802         if (err < 0)
 803                 goto free_pcm;
 804
 805         err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
 806                              internal ? &internal_ops : &ops);
 807         if (err < 0)
 808                 goto free_pcm;
 809
 810         if (rpcm)
 811                 *rpcm = pcm;
 812         return 0;
 813
 814 free_pcm:
 815         snd_pcm_free(pcm);
 816         return err;
 817 }
 818
 819 /**
 820  * snd_pcm_new - create a new PCM instance
 821  * @card: the card instance
 822  * @id: the id string
 823  * @device: the device index (zero based)
 824  * @playback_count: the number of substreams for playback
 825  * @capture_count: the number of substreams for capture
 826  * @rpcm: the pointer to store the new pcm instance
 827  *
 828  * Creates a new PCM instance.
 829  *
 830  * The pcm operators have to be set afterwards to the new instance
 831  * via snd_pcm_set_ops().
 832  *
 833  * Return: Zero if successful, or a negative error code on failure.
 834  */
 835 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 836                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 837 {
 838         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 839                         false, rpcm);
 840 }
 841 EXPORT_SYMBOL(snd_pcm_new);
 842
 843 /**
 844  * snd_pcm_new_internal - create a new internal PCM instance
 845  * @card: the card instance
 846  * @id: the id string
 847  * @device: the device index (zero based - shared with normal PCMs)
 848  * @playback_count: the number of substreams for playback
 849  * @capture_count: the number of substreams for capture
 850  * @rpcm: the pointer to store the new pcm instance
 851  *
 852  * Creates a new internal PCM instance with no userspace device or procfs
 853  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 854  * will only be used internally by kernel drivers. i.e. it cannot be opened
 855  * by userspace. It provides existing ASoC components drivers with a substream
 856  * and access to any private data.
 857  *
 858  * The pcm operators have to be set afterwards to the new instance
 859  * via snd_pcm_set_ops().
 860  *
 861  * Return: Zero if successful, or a negative error code on failure.
 862  */
 863 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 864         int playback_count, int capture_count,
 865         struct snd_pcm **rpcm)
 866 {
 867         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 868                         true, rpcm);
 869 }
 870 EXPORT_SYMBOL(snd_pcm_new_internal);
 871
 872 static void free_chmap(struct snd_pcm_str *pstr)
 873 {
 874         if (pstr->chmap_kctl) {
 875                 snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
 876                 pstr->chmap_kctl = NULL;
 877         }
 878 }
 879
 880 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 881 {
 882         struct snd_pcm_substream *substream, *substream_next;
 883 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 884         struct snd_pcm_oss_setup *setup, *setupn;
 885 #endif
 886         substream = pstr->substream;
 887         while (substream) {
 888                 substream_next = substream->next;
 889                 snd_pcm_timer_done(substream);
 890                 snd_pcm_substream_proc_done(substream);
 891                 kfree(substream);
 892                 substream = substream_next;
 893         }
 894         snd_pcm_stream_proc_done(pstr);
 895 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 896         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 897                 setupn = setup->next;
 898                 kfree(setup->task_name);
 899                 kfree(setup);
 900         }
 901 #endif
 902         free_chmap(pstr);
 903         if (pstr->substream_count)
 904                 put_device(&pstr->dev);
 905 }
 906
 907 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 908 #define pcm_call_notify(pcm, call)                                      \
 909         do {                                                            \
 910                 struct snd_pcm_notify *_notify;                         \
 911                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 912                         _notify->call(pcm);                             \
 913         } while (0)
 914 #else
 915 #define pcm_call_notify(pcm, call) do {} while (0)
 916 #endif
 917
 918 static int snd_pcm_free(struct snd_pcm *pcm)
 919 {
 920         if (!pcm)
 921                 return 0;
 922         if (!pcm->internal)
 923                 pcm_call_notify(pcm, n_unregister);
 924         if (pcm->private_free)
 925                 pcm->private_free(pcm);
 926         snd_pcm_lib_preallocate_free_for_all(pcm);
 927         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 928         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 929         kfree(pcm);
 930         return 0;
 931 }
 932
 933 static int snd_pcm_dev_free(struct snd_device *device)
 934 {
 935         struct snd_pcm *pcm = device->device_data;
 936         return snd_pcm_free(pcm);
 937 }
 938
 939 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 940                              struct file *file,
 941                              struct snd_pcm_substream **rsubstream)
 942 {
 943         struct snd_pcm_str * pstr;
 944         struct snd_pcm_substream *substream;
 945         struct snd_pcm_runtime *runtime;
 946         struct snd_card *card;
 947         int prefer_subdevice;
 948         size_t size;
 949
 950         if (snd_BUG_ON(!pcm || !rsubstream))
 951                 return -ENXIO;
 952         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 953                        stream != SNDRV_PCM_STREAM_CAPTURE))
 954                 return -EINVAL;
 955         *rsubstream = NULL;
 956         pstr = &pcm->streams[stream];
 957         if (pstr->substream == NULL || pstr->substream_count == 0)
 958                 return -ENODEV;
 959
 960         card = pcm->card;
 961         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 962
 963         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 964                 int opposite = !stream;
 965
 966                 for (substream = pcm->streams[opposite].substream; substream;
 967                      substream = substream->next) {
 968                         if (SUBSTREAM_BUSY(substream))
 969                                 return -EAGAIN;
 970                 }
 971         }
 972
 973         if (file->f_flags & O_APPEND) {
 974                 if (prefer_subdevice < 0) {
 975                         if (pstr->substream_count > 1)
 976                                 return -EINVAL; /* must be unique */
 977                         substream = pstr->substream;
 978                 } else {
 979                         for (substream = pstr->substream; substream;
 980                              substream = substream->next)
 981                                 if (substream->number == prefer_subdevice)
 982                                         break;
 983                 }
 984                 if (! substream)
 985                         return -ENODEV;
 986                 if (! SUBSTREAM_BUSY(substream))
 987                         return -EBADFD;
 988                 substream->ref_count++;
 989                 *rsubstream = substream;
 990                 return 0;
 991         }
 992
 993         for (substream = pstr->substream; substream; substream = substream->next) {
 994                 if (!SUBSTREAM_BUSY(substream) &&
 995                     (prefer_subdevice == -1 ||
 996                      substream->number == prefer_subdevice))
 997                         break;
 998         }
 999         if (substream == NULL)
1000                 return -EAGAIN;
1001
1002         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
1003         if (runtime == NULL)
1004                 return -ENOMEM;
1005
1006         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
1007         runtime->status = snd_malloc_pages(size, GFP_KERNEL);
1008         if (runtime->status == NULL) {
1009                 kfree(runtime);
1010                 return -ENOMEM;
1011         }
1012         memset((void*)runtime->status, 0, size);
1013
1014         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
1015         runtime->control = snd_malloc_pages(size, GFP_KERNEL);
1016         if (runtime->control == NULL) {
1017                 snd_free_pages((void*)runtime->status,
1018                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1019                 kfree(runtime);
1020                 return -ENOMEM;
1021         }
1022         memset((void*)runtime->control, 0, size);
1023
1024         init_waitqueue_head(&runtime->sleep);
1025         init_waitqueue_head(&runtime->tsleep);
1026
1027         runtime->status->state = SNDRV_PCM_STATE_OPEN;
1028
1029         substream->runtime = runtime;
1030         substream->private_data = pcm->private_data;
1031         substream->ref_count = 1;
1032         substream->f_flags = file->f_flags;
1033         substream->pid = get_pid(task_pid(current));
1034         pstr->substream_opened++;
1035         *rsubstream = substream;
1036         return 0;
1037 }
1038
1039 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1040 {
1041         struct snd_pcm_runtime *runtime;
1042
1043         if (PCM_RUNTIME_CHECK(substream))
1044                 return;
1045         runtime = substream->runtime;
1046         if (runtime->private_free != NULL)
1047                 runtime->private_free(runtime);
1048         snd_free_pages((void*)runtime->status,
1049                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1050         snd_free_pages((void*)runtime->control,
1051                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1052         kfree(runtime->hw_constraints.rules);
1053         /* Avoid concurrent access to runtime via PCM timer interface */
1054         if (substream->timer)
1055                 spin_lock_irq(&substream->timer->lock);
1056         substream->runtime = NULL;
1057         if (substream->timer)
1058                 spin_unlock_irq(&substream->timer->lock);
1059         kfree(runtime);
1060         put_pid(substream->pid);
1061         substream->pid = NULL;
1062         substream->pstr->substream_opened--;
1063 }
1064
1065 static ssize_t show_pcm_class(struct device *dev,
1066                               struct device_attribute *attr, char *buf)
1067 {
1068         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1069         struct snd_pcm *pcm = pstr->pcm;
1070         const char *str;
1071         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1072                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1073                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1074                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1075                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1076         };
1077
1078         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1079                 str = "none";
1080         else
1081                 str = strs[pcm->dev_class];
1082         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1083 }
1084
1085 static DEVICE_ATTR(pcm_class, 0444, show_pcm_class, NULL);
1086 static struct attribute *pcm_dev_attrs[] = {
1087         &dev_attr_pcm_class.attr,
1088         NULL
1089 };
1090
1091 static const struct attribute_group pcm_dev_attr_group = {
1092         .attrs  = pcm_dev_attrs,
1093 };
1094
1095 static const struct attribute_group *pcm_dev_attr_groups[] = {
1096         &pcm_dev_attr_group,
1097         NULL
1098 };
1099
1100 static int snd_pcm_dev_register(struct snd_device *device)
1101 {
1102         int cidx, err;
1103         struct snd_pcm_substream *substream;
1104         struct snd_pcm *pcm;
1105
1106         if (snd_BUG_ON(!device || !device->device_data))
1107                 return -ENXIO;
1108         pcm = device->device_data;
1109
1110         mutex_lock(&register_mutex);
1111         err = snd_pcm_add(pcm);
1112         if (err)
1113                 goto unlock;
1114         for (cidx = 0; cidx < 2; cidx++) {
1115                 int devtype = -1;
1116                 if (pcm->streams[cidx].substream == NULL)
1117                         continue;
1118                 switch (cidx) {
1119                 case SNDRV_PCM_STREAM_PLAYBACK:
1120                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1121                         break;
1122                 case SNDRV_PCM_STREAM_CAPTURE:
1123                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1124                         break;
1125                 }
1126                 /* register pcm */
1127                 err = snd_register_device(devtype, pcm->card, pcm->device,
1128                                           &snd_pcm_f_ops[cidx], pcm,
1129                                           &pcm->streams[cidx].dev);
1130                 if (err < 0) {
1131                         list_del_init(&pcm->list);
1132                         goto unlock;
1133                 }
1134
1135                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1136                         snd_pcm_timer_init(substream);
1137         }
1138
1139         pcm_call_notify(pcm, n_register);
1140
1141  unlock:
1142         mutex_unlock(&register_mutex);
1143         return err;
1144 }
1145
1146 static int snd_pcm_dev_disconnect(struct snd_device *device)
1147 {
1148         struct snd_pcm *pcm = device->device_data;
1149         struct snd_pcm_substream *substream;
1150         int cidx;
1151
1152         mutex_lock(&register_mutex);
1153         mutex_lock(&pcm->open_mutex);
1154         wake_up(&pcm->open_wait);
1155         list_del_init(&pcm->list);
1156         for (cidx = 0; cidx < 2; cidx++) {
1157                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1158                         snd_pcm_stream_lock_irq(substream);
1159                         if (substream->runtime) {
1160                                 if (snd_pcm_running(substream))
1161                                         snd_pcm_stop(substream,
1162                                                      SNDRV_PCM_STATE_DISCONNECTED);
1163                                 /* to be sure, set the state unconditionally */
1164                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1165                                 wake_up(&substream->runtime->sleep);
1166                                 wake_up(&substream->runtime->tsleep);
1167                         }
1168                         snd_pcm_stream_unlock_irq(substream);
1169                 }
1170         }
1171
1172         pcm_call_notify(pcm, n_disconnect);
1173         for (cidx = 0; cidx < 2; cidx++) {
1174                 snd_unregister_device(&pcm->streams[cidx].dev);
1175                 free_chmap(&pcm->streams[cidx]);
1176         }
1177         mutex_unlock(&pcm->open_mutex);
1178         mutex_unlock(&register_mutex);
1179         return 0;
1180 }
1181
1182 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1183 /**
1184  * snd_pcm_notify - Add/remove the notify list
1185  * @notify: PCM notify list
1186  * @nfree: 0 = register, 1 = unregister
1187  *
1188  * This adds the given notifier to the global list so that the callback is
1189  * called for each registered PCM devices.  This exists only for PCM OSS
1190  * emulation, so far.
1191  */
1192 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1193 {
1194         struct snd_pcm *pcm;
1195
1196         if (snd_BUG_ON(!notify ||
1197                        !notify->n_register ||
1198                        !notify->n_unregister ||
1199                        !notify->n_disconnect))
1200                 return -EINVAL;
1201         mutex_lock(&register_mutex);
1202         if (nfree) {
1203                 list_del(&notify->list);
1204                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1205                         notify->n_unregister(pcm);
1206         } else {
1207                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1208                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1209                         notify->n_register(pcm);
1210         }
1211         mutex_unlock(&register_mutex);
1212         return 0;
1213 }
1214 EXPORT_SYMBOL(snd_pcm_notify);
1215 #endif /* CONFIG_SND_PCM_OSS */
1216
1217 #ifdef CONFIG_SND_PROC_FS
1218 /*
1219  *  Info interface
1220  */
1221
1222 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1223                               struct snd_info_buffer *buffer)
1224 {
1225         struct snd_pcm *pcm;
1226
1227         mutex_lock(&register_mutex);
1228         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1229                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1230                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1231                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1232                         snd_iprintf(buffer, " : playback %i",
1233                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1234                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1235                         snd_iprintf(buffer, " : capture %i",
1236                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1237                 snd_iprintf(buffer, "\n");
1238         }
1239         mutex_unlock(&register_mutex);
1240 }
1241
1242 static struct snd_info_entry *snd_pcm_proc_entry;
1243
1244 static void snd_pcm_proc_init(void)
1245 {
1246         struct snd_info_entry *entry;
1247
1248         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1249         if (entry) {
1250                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1251                 if (snd_info_register(entry) < 0) {
1252                         snd_info_free_entry(entry);
1253                         entry = NULL;
1254                 }
1255         }
1256         snd_pcm_proc_entry = entry;
1257 }
1258
1259 static void snd_pcm_proc_done(void)
1260 {
1261         snd_info_free_entry(snd_pcm_proc_entry);
1262 }
1263
1264 #else /* !CONFIG_SND_PROC_FS */
1265 #define snd_pcm_proc_init()
1266 #define snd_pcm_proc_done()
1267 #endif /* CONFIG_SND_PROC_FS */
1268
1269
1270 /*
1271  *  ENTRY functions
1272  */
1273
1274 static int __init alsa_pcm_init(void)
1275 {
1276         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1277         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1278         snd_pcm_proc_init();
1279         return 0;
1280 }
1281
1282 static void __exit alsa_pcm_exit(void)
1283 {
1284         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1285         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1286         snd_pcm_proc_done();
1287 }
1288
1289 module_init(alsa_pcm_init)
1290 module_exit(alsa_pcm_exit)