sound/core/pcm.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/time.h>
  26 #include <linux/mutex.h>
  27 #include <linux/device.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/pcm.h>
  31 #include <sound/control.h>
  32 #include <sound/info.h>
  33
  34 #include "pcm_local.h"
  35
  36 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  37 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  38 MODULE_LICENSE("GPL");
  39
  40 static LIST_HEAD(snd_pcm_devices);
  41 static DEFINE_MUTEX(register_mutex);
  42 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  43 static LIST_HEAD(snd_pcm_notify_list);
  44 #endif
  45
  46 static int snd_pcm_free(struct snd_pcm *pcm);
  47 static int snd_pcm_dev_free(struct snd_device *device);
  48 static int snd_pcm_dev_register(struct snd_device *device);
  49 static int snd_pcm_dev_disconnect(struct snd_device *device);
  50
  51 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  52 {
  53         struct snd_pcm *pcm;
  54
  55         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  56                 if (pcm->card == card && pcm->device == device)
  57                         return pcm;
  58         }
  59         return NULL;
  60 }
  61
  62 static int snd_pcm_next(struct snd_card *card, int device)
  63 {
  64         struct snd_pcm *pcm;
  65
  66         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  67                 if (pcm->card == card && pcm->device > device)
  68                         return pcm->device;
  69                 else if (pcm->card->number > card->number)
  70                         return -1;
  71         }
  72         return -1;
  73 }
  74
  75 static int snd_pcm_add(struct snd_pcm *newpcm)
  76 {
  77         struct snd_pcm *pcm;
  78
  79         if (newpcm->internal)
  80                 return 0;
  81
  82         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  83                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  84                         return -EBUSY;
  85                 if (pcm->card->number > newpcm->card->number ||
  86                                 (pcm->card == newpcm->card &&
  87                                 pcm->device > newpcm->device)) {
  88                         list_add(&newpcm->list, pcm->list.prev);
  89                         return 0;
  90                 }
  91         }
  92         list_add_tail(&newpcm->list, &snd_pcm_devices);
  93         return 0;
  94 }
  95
  96 static int snd_pcm_control_ioctl(struct snd_card *card,
  97                                  struct snd_ctl_file *control,
  98                                  unsigned int cmd, unsigned long arg)
  99 {
 100         switch (cmd) {
 101         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
 102                 {
 103                         int device;
 104
 105                         if (get_user(device, (int __user *)arg))
 106                                 return -EFAULT;
 107                         mutex_lock(&register_mutex);
 108                         device = snd_pcm_next(card, device);
 109                         mutex_unlock(&register_mutex);
 110                         if (put_user(device, (int __user *)arg))
 111                                 return -EFAULT;
 112                         return 0;
 113                 }
 114         case SNDRV_CTL_IOCTL_PCM_INFO:
 115                 {
 116                         struct snd_pcm_info __user *info;
 117                         unsigned int device, subdevice;
 118                         int stream;
 119                         struct snd_pcm *pcm;
 120                         struct snd_pcm_str *pstr;
 121                         struct snd_pcm_substream *substream;
 122                         int err;
 123
 124                         info = (struct snd_pcm_info __user *)arg;
 125                         if (get_user(device, &info->device))
 126                                 return -EFAULT;
 127                         if (get_user(stream, &info->stream))
 128                                 return -EFAULT;
 129                         if (stream < 0 || stream > 1)
 130                                 return -EINVAL;
 131                         if (get_user(subdevice, &info->subdevice))
 132                                 return -EFAULT;
 133                         mutex_lock(&register_mutex);
 134                         pcm = snd_pcm_get(card, device);
 135                         if (pcm == NULL) {
 136                                 err = -ENXIO;
 137                                 goto _error;
 138                         }
 139                         pstr = &pcm->streams[stream];
 140                         if (pstr->substream_count == 0) {
 141                                 err = -ENOENT;
 142                                 goto _error;
 143                         }
 144                         if (subdevice >= pstr->substream_count) {
 145                                 err = -ENXIO;
 146                                 goto _error;
 147                         }
 148                         for (substream = pstr->substream; substream;
 149                              substream = substream->next)
 150                                 if (substream->number == (int)subdevice)
 151                                         break;
 152                         if (substream == NULL) {
 153                                 err = -ENXIO;
 154                                 goto _error;
 155                         }
 156                         err = snd_pcm_info_user(substream, info);
 157                 _error:
 158                         mutex_unlock(&register_mutex);
 159                         return err;
 160                 }
 161         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 162                 {
 163                         int val;
 164
 165                         if (get_user(val, (int __user *)arg))
 166                                 return -EFAULT;
 167                         control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
 168                         return 0;
 169                 }
 170         }
 171         return -ENOIOCTLCMD;
 172 }
 173
 174 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 175
 176 static char *snd_pcm_format_names[] = {
 177         FORMAT(S8),
 178         FORMAT(U8),
 179         FORMAT(S16_LE),
 180         FORMAT(S16_BE),
 181         FORMAT(U16_LE),
 182         FORMAT(U16_BE),
 183         FORMAT(S24_LE),
 184         FORMAT(S24_BE),
 185         FORMAT(U24_LE),
 186         FORMAT(U24_BE),
 187         FORMAT(S32_LE),
 188         FORMAT(S32_BE),
 189         FORMAT(U32_LE),
 190         FORMAT(U32_BE),
 191         FORMAT(FLOAT_LE),
 192         FORMAT(FLOAT_BE),
 193         FORMAT(FLOAT64_LE),
 194         FORMAT(FLOAT64_BE),
 195         FORMAT(IEC958_SUBFRAME_LE),
 196         FORMAT(IEC958_SUBFRAME_BE),
 197         FORMAT(MU_LAW),
 198         FORMAT(A_LAW),
 199         FORMAT(IMA_ADPCM),
 200         FORMAT(MPEG),
 201         FORMAT(GSM),
 202         FORMAT(SPECIAL),
 203         FORMAT(S24_3LE),
 204         FORMAT(S24_3BE),
 205         FORMAT(U24_3LE),
 206         FORMAT(U24_3BE),
 207         FORMAT(S20_3LE),
 208         FORMAT(S20_3BE),
 209         FORMAT(U20_3LE),
 210         FORMAT(U20_3BE),
 211         FORMAT(S18_3LE),
 212         FORMAT(S18_3BE),
 213         FORMAT(U18_3LE),
 214         FORMAT(U18_3BE),
 215         FORMAT(G723_24),
 216         FORMAT(G723_24_1B),
 217         FORMAT(G723_40),
 218         FORMAT(G723_40_1B),
 219         FORMAT(DSD_U8),
 220         FORMAT(DSD_U16_LE),
 221         FORMAT(DSD_U32_LE),
 222         FORMAT(DSD_U16_BE),
 223         FORMAT(DSD_U32_BE),
 224 };
 225
 226 /**
 227  * snd_pcm_format_name - Return a name string for the given PCM format
 228  * @format: PCM format
 229  */
 230 const char *snd_pcm_format_name(snd_pcm_format_t format)
 231 {
 232         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 233                 return "Unknown";
 234         return snd_pcm_format_names[(__force unsigned int)format];
 235 }
 236 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 237
 238 #ifdef CONFIG_SND_VERBOSE_PROCFS
 239
 240 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 241 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 242 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 243 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 244 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 245 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 246 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 247 #define START(v) [SNDRV_PCM_START_##v] = #v
 248 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 249
 250 static char *snd_pcm_stream_names[] = {
 251         STREAM(PLAYBACK),
 252         STREAM(CAPTURE),
 253 };
 254
 255 static char *snd_pcm_state_names[] = {
 256         STATE(OPEN),
 257         STATE(SETUP),
 258         STATE(PREPARED),
 259         STATE(RUNNING),
 260         STATE(XRUN),
 261         STATE(DRAINING),
 262         STATE(PAUSED),
 263         STATE(SUSPENDED),
 264 };
 265
 266 static char *snd_pcm_access_names[] = {
 267         ACCESS(MMAP_INTERLEAVED),
 268         ACCESS(MMAP_NONINTERLEAVED),
 269         ACCESS(MMAP_COMPLEX),
 270         ACCESS(RW_INTERLEAVED),
 271         ACCESS(RW_NONINTERLEAVED),
 272 };
 273
 274 static char *snd_pcm_subformat_names[] = {
 275         SUBFORMAT(STD),
 276 };
 277
 278 static char *snd_pcm_tstamp_mode_names[] = {
 279         TSTAMP(NONE),
 280         TSTAMP(ENABLE),
 281 };
 282
 283 static const char *snd_pcm_stream_name(int stream)
 284 {
 285         return snd_pcm_stream_names[stream];
 286 }
 287
 288 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 289 {
 290         return snd_pcm_access_names[(__force int)access];
 291 }
 292
 293 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 294 {
 295         return snd_pcm_subformat_names[(__force int)subformat];
 296 }
 297
 298 static const char *snd_pcm_tstamp_mode_name(int mode)
 299 {
 300         return snd_pcm_tstamp_mode_names[mode];
 301 }
 302
 303 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 304 {
 305         return snd_pcm_state_names[(__force int)state];
 306 }
 307
 308 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 309 #include <linux/soundcard.h>
 310
 311 static const char *snd_pcm_oss_format_name(int format)
 312 {
 313         switch (format) {
 314         case AFMT_MU_LAW:
 315                 return "MU_LAW";
 316         case AFMT_A_LAW:
 317                 return "A_LAW";
 318         case AFMT_IMA_ADPCM:
 319                 return "IMA_ADPCM";
 320         case AFMT_U8:
 321                 return "U8";
 322         case AFMT_S16_LE:
 323                 return "S16_LE";
 324         case AFMT_S16_BE:
 325                 return "S16_BE";
 326         case AFMT_S8:
 327                 return "S8";
 328         case AFMT_U16_LE:
 329                 return "U16_LE";
 330         case AFMT_U16_BE:
 331                 return "U16_BE";
 332         case AFMT_MPEG:
 333                 return "MPEG";
 334         default:
 335                 return "unknown";
 336         }
 337 }
 338 #endif
 339
 340 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 341                                    struct snd_info_buffer *buffer)
 342 {
 343         struct snd_pcm_info *info;
 344         int err;
 345
 346         if (! substream)
 347                 return;
 348
 349         info = kmalloc(sizeof(*info), GFP_KERNEL);
 350         if (!info)
 351                 return;
 352
 353         err = snd_pcm_info(substream, info);
 354         if (err < 0) {
 355                 snd_iprintf(buffer, "error %d\n", err);
 356                 kfree(info);
 357                 return;
 358         }
 359         snd_iprintf(buffer, "card: %d\n", info->card);
 360         snd_iprintf(buffer, "device: %d\n", info->device);
 361         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 362         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 363         snd_iprintf(buffer, "id: %s\n", info->id);
 364         snd_iprintf(buffer, "name: %s\n", info->name);
 365         snd_iprintf(buffer, "subname: %s\n", info->subname);
 366         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 367         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 368         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 369         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 370         kfree(info);
 371 }
 372
 373 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 374                                           struct snd_info_buffer *buffer)
 375 {
 376         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 377                                buffer);
 378 }
 379
 380 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 381                                              struct snd_info_buffer *buffer)
 382 {
 383         snd_pcm_proc_info_read(entry->private_data, buffer);
 384 }
 385
 386 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 387                                                   struct snd_info_buffer *buffer)
 388 {
 389         struct snd_pcm_substream *substream = entry->private_data;
 390         struct snd_pcm_runtime *runtime;
 391
 392         mutex_lock(&substream->pcm->open_mutex);
 393         runtime = substream->runtime;
 394         if (!runtime) {
 395                 snd_iprintf(buffer, "closed\n");
 396                 goto unlock;
 397         }
 398         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 399                 snd_iprintf(buffer, "no setup\n");
 400                 goto unlock;
 401         }
 402         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 403         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 404         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 405         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 406         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 407         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 408         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 409 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 410         if (substream->oss.oss) {
 411                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 412                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 413                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 414                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 415                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 416                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 417         }
 418 #endif
 419  unlock:
 420         mutex_unlock(&substream->pcm->open_mutex);
 421 }
 422
 423 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 424                                                   struct snd_info_buffer *buffer)
 425 {
 426         struct snd_pcm_substream *substream = entry->private_data;
 427         struct snd_pcm_runtime *runtime;
 428
 429         mutex_lock(&substream->pcm->open_mutex);
 430         runtime = substream->runtime;
 431         if (!runtime) {
 432                 snd_iprintf(buffer, "closed\n");
 433                 goto unlock;
 434         }
 435         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 436                 snd_iprintf(buffer, "no setup\n");
 437                 goto unlock;
 438         }
 439         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 440         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 441         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 442         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 443         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 444         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 445         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 446         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 447  unlock:
 448         mutex_unlock(&substream->pcm->open_mutex);
 449 }
 450
 451 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 452                                                struct snd_info_buffer *buffer)
 453 {
 454         struct snd_pcm_substream *substream = entry->private_data;
 455         struct snd_pcm_runtime *runtime;
 456         struct snd_pcm_status status;
 457         int err;
 458
 459         mutex_lock(&substream->pcm->open_mutex);
 460         runtime = substream->runtime;
 461         if (!runtime) {
 462                 snd_iprintf(buffer, "closed\n");
 463                 goto unlock;
 464         }
 465         memset(&status, 0, sizeof(status));
 466         err = snd_pcm_status(substream, &status);
 467         if (err < 0) {
 468                 snd_iprintf(buffer, "error %d\n", err);
 469                 goto unlock;
 470         }
 471         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 472         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 473         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 474                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 475         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 476                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 477         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 478         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 479         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 480         snd_iprintf(buffer, "-----\n");
 481         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 482         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 483  unlock:
 484         mutex_unlock(&substream->pcm->open_mutex);
 485 }
 486
 487 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 488 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 489                                          struct snd_info_buffer *buffer)
 490 {
 491         struct snd_pcm_substream *substream = entry->private_data;
 492         struct snd_pcm_runtime *runtime;
 493
 494         snd_pcm_stream_lock_irq(substream);
 495         runtime = substream->runtime;
 496         if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
 497                 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 498         snd_pcm_stream_unlock_irq(substream);
 499 }
 500
 501 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 502                                     struct snd_info_buffer *buffer)
 503 {
 504         struct snd_pcm_str *pstr = entry->private_data;
 505         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 506 }
 507
 508 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 509                                      struct snd_info_buffer *buffer)
 510 {
 511         struct snd_pcm_str *pstr = entry->private_data;
 512         char line[64];
 513         if (!snd_info_get_line(buffer, line, sizeof(line)))
 514                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 515 }
 516 #endif
 517
 518 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 519 {
 520         struct snd_pcm *pcm = pstr->pcm;
 521         struct snd_info_entry *entry;
 522         char name[16];
 523
 524         sprintf(name, "pcm%i%c", pcm->device,
 525                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 526         entry = snd_info_create_card_entry(pcm->card, name,
 527                                            pcm->card->proc_root);
 528         if (!entry)
 529                 return -ENOMEM;
 530         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 531         if (snd_info_register(entry) < 0) {
 532                 snd_info_free_entry(entry);
 533                 return -ENOMEM;
 534         }
 535         pstr->proc_root = entry;
 536         entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root);
 537         if (entry) {
 538                 snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
 539                 if (snd_info_register(entry) < 0) {
 540                         snd_info_free_entry(entry);
 541                         entry = NULL;
 542                 }
 543         }
 544         pstr->proc_info_entry = entry;
 545
 546 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 547         entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
 548                                            pstr->proc_root);
 549         if (entry) {
 550                 entry->c.text.read = snd_pcm_xrun_debug_read;
 551                 entry->c.text.write = snd_pcm_xrun_debug_write;
 552                 entry->mode |= S_IWUSR;
 553                 entry->private_data = pstr;
 554                 if (snd_info_register(entry) < 0) {
 555                         snd_info_free_entry(entry);
 556                         entry = NULL;
 557                 }
 558         }
 559         pstr->proc_xrun_debug_entry = entry;
 560 #endif
 561         return 0;
 562 }
 563
 564 static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
 565 {
 566 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 567         snd_info_free_entry(pstr->proc_xrun_debug_entry);
 568         pstr->proc_xrun_debug_entry = NULL;
 569 #endif
 570         snd_info_free_entry(pstr->proc_info_entry);
 571         pstr->proc_info_entry = NULL;
 572         snd_info_free_entry(pstr->proc_root);
 573         pstr->proc_root = NULL;
 574         return 0;
 575 }
 576
 577 static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
 578 {
 579         struct snd_info_entry *entry;
 580         struct snd_card *card;
 581         char name[16];
 582
 583         card = substream->pcm->card;
 584
 585         sprintf(name, "sub%i", substream->number);
 586         entry = snd_info_create_card_entry(card, name,
 587                                            substream->pstr->proc_root);
 588         if (!entry)
 589                 return -ENOMEM;
 590         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
 591         if (snd_info_register(entry) < 0) {
 592                 snd_info_free_entry(entry);
 593                 return -ENOMEM;
 594         }
 595         substream->proc_root = entry;
 596         entry = snd_info_create_card_entry(card, "info", substream->proc_root);
 597         if (entry) {
 598                 snd_info_set_text_ops(entry, substream,
 599                                       snd_pcm_substream_proc_info_read);
 600                 if (snd_info_register(entry) < 0) {
 601                         snd_info_free_entry(entry);
 602                         entry = NULL;
 603                 }
 604         }
 605         substream->proc_info_entry = entry;
 606         entry = snd_info_create_card_entry(card, "hw_params",
 607                                            substream->proc_root);
 608         if (entry) {
 609                 snd_info_set_text_ops(entry, substream,
 610                                       snd_pcm_substream_proc_hw_params_read);
 611                 if (snd_info_register(entry) < 0) {
 612                         snd_info_free_entry(entry);
 613                         entry = NULL;
 614                 }
 615         }
 616         substream->proc_hw_params_entry = entry;
 617         entry = snd_info_create_card_entry(card, "sw_params",
 618                                            substream->proc_root);
 619         if (entry) {
 620                 snd_info_set_text_ops(entry, substream,
 621                                       snd_pcm_substream_proc_sw_params_read);
 622                 if (snd_info_register(entry) < 0) {
 623                         snd_info_free_entry(entry);
 624                         entry = NULL;
 625                 }
 626         }
 627         substream->proc_sw_params_entry = entry;
 628         entry = snd_info_create_card_entry(card, "status",
 629                                            substream->proc_root);
 630         if (entry) {
 631                 snd_info_set_text_ops(entry, substream,
 632                                       snd_pcm_substream_proc_status_read);
 633                 if (snd_info_register(entry) < 0) {
 634                         snd_info_free_entry(entry);
 635                         entry = NULL;
 636                 }
 637         }
 638         substream->proc_status_entry = entry;
 639
 640 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 641         entry = snd_info_create_card_entry(card, "xrun_injection",
 642                                            substream->proc_root);
 643         if (entry) {
 644                 entry->private_data = substream;
 645                 entry->c.text.read = NULL;
 646                 entry->c.text.write = snd_pcm_xrun_injection_write;
 647                 entry->mode = S_IFREG | S_IWUSR;
 648                 if (snd_info_register(entry) < 0) {
 649                         snd_info_free_entry(entry);
 650                         entry = NULL;
 651                 }
 652         }
 653         substream->proc_xrun_injection_entry = entry;
 654 #endif /* CONFIG_SND_PCM_XRUN_DEBUG */
 655
 656         return 0;
 657 }
 658
 659 static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
 660 {
 661         snd_info_free_entry(substream->proc_info_entry);
 662         substream->proc_info_entry = NULL;
 663         snd_info_free_entry(substream->proc_hw_params_entry);
 664         substream->proc_hw_params_entry = NULL;
 665         snd_info_free_entry(substream->proc_sw_params_entry);
 666         substream->proc_sw_params_entry = NULL;
 667         snd_info_free_entry(substream->proc_status_entry);
 668         substream->proc_status_entry = NULL;
 669 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 670         snd_info_free_entry(substream->proc_xrun_injection_entry);
 671         substream->proc_xrun_injection_entry = NULL;
 672 #endif
 673         snd_info_free_entry(substream->proc_root);
 674         substream->proc_root = NULL;
 675         return 0;
 676 }
 677 #else /* !CONFIG_SND_VERBOSE_PROCFS */
 678 static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
 679 static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
 680 static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
 681 static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
 682 #endif /* CONFIG_SND_VERBOSE_PROCFS */
 683
 684 static const struct attribute_group *pcm_dev_attr_groups[];
 685
 686 /**
 687  * snd_pcm_new_stream - create a new PCM stream
 688  * @pcm: the pcm instance
 689  * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 690  * @substream_count: the number of substreams
 691  *
 692  * Creates a new stream for the pcm.
 693  * The corresponding stream on the pcm must have been empty before
 694  * calling this, i.e. zero must be given to the argument of
 695  * snd_pcm_new().
 696  *
 697  * Return: Zero if successful, or a negative error code on failure.
 698  */
 699 int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 700 {
 701         int idx, err;
 702         struct snd_pcm_str *pstr = &pcm->streams[stream];
 703         struct snd_pcm_substream *substream, *prev;
 704
 705 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 706         mutex_init(&pstr->oss.setup_mutex);
 707 #endif
 708         pstr->stream = stream;
 709         pstr->pcm = pcm;
 710         pstr->substream_count = substream_count;
 711         if (!substream_count)
 712                 return 0;
 713
 714         snd_device_initialize(&pstr->dev, pcm->card);
 715         pstr->dev.groups = pcm_dev_attr_groups;
 716         dev_set_name(&pstr->dev, "pcmC%iD%i%c", pcm->card->number, pcm->device,
 717                      stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 718
 719         if (!pcm->internal) {
 720                 err = snd_pcm_stream_proc_init(pstr);
 721                 if (err < 0) {
 722                         pcm_err(pcm, "Error in snd_pcm_stream_proc_init\n");
 723                         return err;
 724                 }
 725         }
 726         prev = NULL;
 727         for (idx = 0, prev = NULL; idx < substream_count; idx++) {
 728                 substream = kzalloc(sizeof(*substream), GFP_KERNEL);
 729                 if (!substream)
 730                         return -ENOMEM;
 731                 substream->pcm = pcm;
 732                 substream->pstr = pstr;
 733                 substream->number = idx;
 734                 substream->stream = stream;
 735                 sprintf(substream->name, "subdevice #%i", idx);
 736                 substream->buffer_bytes_max = UINT_MAX;
 737                 if (prev == NULL)
 738                         pstr->substream = substream;
 739                 else
 740                         prev->next = substream;
 741
 742                 if (!pcm->internal) {
 743                         err = snd_pcm_substream_proc_init(substream);
 744                         if (err < 0) {
 745                                 pcm_err(pcm,
 746                                         "Error in snd_pcm_stream_proc_init\n");
 747                                 if (prev == NULL)
 748                                         pstr->substream = NULL;
 749                                 else
 750                                         prev->next = NULL;
 751                                 kfree(substream);
 752                                 return err;
 753                         }
 754                 }
 755                 substream->group = &substream->self_group;
 756                 spin_lock_init(&substream->self_group.lock);
 757                 mutex_init(&substream->self_group.mutex);
 758                 INIT_LIST_HEAD(&substream->self_group.substreams);
 759                 list_add_tail(&substream->link_list, &substream->self_group.substreams);
 760                 atomic_set(&substream->mmap_count, 0);
 761                 prev = substream;
 762         }
 763         return 0;
 764 }
 765 EXPORT_SYMBOL(snd_pcm_new_stream);
 766
 767 static int _snd_pcm_new(struct snd_card *card, const char *id, int device,
 768                 int playback_count, int capture_count, bool internal,
 769                 struct snd_pcm **rpcm)
 770 {
 771         struct snd_pcm *pcm;
 772         int err;
 773         static struct snd_device_ops ops = {
 774                 .dev_free = snd_pcm_dev_free,
 775                 .dev_register = snd_pcm_dev_register,
 776                 .dev_disconnect = snd_pcm_dev_disconnect,
 777         };
 778         static struct snd_device_ops internal_ops = {
 779                 .dev_free = snd_pcm_dev_free,
 780         };
 781
 782         if (snd_BUG_ON(!card))
 783                 return -ENXIO;
 784         if (rpcm)
 785                 *rpcm = NULL;
 786         pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
 787         if (!pcm)
 788                 return -ENOMEM;
 789         pcm->card = card;
 790         pcm->device = device;
 791         pcm->internal = internal;
 792         mutex_init(&pcm->open_mutex);
 793         init_waitqueue_head(&pcm->open_wait);
 794         INIT_LIST_HEAD(&pcm->list);
 795         if (id)
 796                 strlcpy(pcm->id, id, sizeof(pcm->id));
 797
 798         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 799                                  playback_count);
 800         if (err < 0)
 801                 goto free_pcm;
 802
 803         err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count);
 804         if (err < 0)
 805                 goto free_pcm;
 806
 807         err = snd_device_new(card, SNDRV_DEV_PCM, pcm,
 808                              internal ? &internal_ops : &ops);
 809         if (err < 0)
 810                 goto free_pcm;
 811
 812         if (rpcm)
 813                 *rpcm = pcm;
 814         return 0;
 815
 816 free_pcm:
 817         snd_pcm_free(pcm);
 818         return err;
 819 }
 820
 821 /**
 822  * snd_pcm_new - create a new PCM instance
 823  * @card: the card instance
 824  * @id: the id string
 825  * @device: the device index (zero based)
 826  * @playback_count: the number of substreams for playback
 827  * @capture_count: the number of substreams for capture
 828  * @rpcm: the pointer to store the new pcm instance
 829  *
 830  * Creates a new PCM instance.
 831  *
 832  * The pcm operators have to be set afterwards to the new instance
 833  * via snd_pcm_set_ops().
 834  *
 835  * Return: Zero if successful, or a negative error code on failure.
 836  */
 837 int snd_pcm_new(struct snd_card *card, const char *id, int device,
 838                 int playback_count, int capture_count, struct snd_pcm **rpcm)
 839 {
 840         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 841                         false, rpcm);
 842 }
 843 EXPORT_SYMBOL(snd_pcm_new);
 844
 845 /**
 846  * snd_pcm_new_internal - create a new internal PCM instance
 847  * @card: the card instance
 848  * @id: the id string
 849  * @device: the device index (zero based - shared with normal PCMs)
 850  * @playback_count: the number of substreams for playback
 851  * @capture_count: the number of substreams for capture
 852  * @rpcm: the pointer to store the new pcm instance
 853  *
 854  * Creates a new internal PCM instance with no userspace device or procfs
 855  * entries. This is used by ASoC Back End PCMs in order to create a PCM that
 856  * will only be used internally by kernel drivers. i.e. it cannot be opened
 857  * by userspace. It provides existing ASoC components drivers with a substream
 858  * and access to any private data.
 859  *
 860  * The pcm operators have to be set afterwards to the new instance
 861  * via snd_pcm_set_ops().
 862  *
 863  * Return: Zero if successful, or a negative error code on failure.
 864  */
 865 int snd_pcm_new_internal(struct snd_card *card, const char *id, int device,
 866         int playback_count, int capture_count,
 867         struct snd_pcm **rpcm)
 868 {
 869         return _snd_pcm_new(card, id, device, playback_count, capture_count,
 870                         true, rpcm);
 871 }
 872 EXPORT_SYMBOL(snd_pcm_new_internal);
 873
 874 static void free_chmap(struct snd_pcm_str *pstr)
 875 {
 876         if (pstr->chmap_kctl) {
 877                 snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
 878                 pstr->chmap_kctl = NULL;
 879         }
 880 }
 881
 882 static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
 883 {
 884         struct snd_pcm_substream *substream, *substream_next;
 885 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 886         struct snd_pcm_oss_setup *setup, *setupn;
 887 #endif
 888         substream = pstr->substream;
 889         while (substream) {
 890                 substream_next = substream->next;
 891                 snd_pcm_timer_done(substream);
 892                 snd_pcm_substream_proc_done(substream);
 893                 kfree(substream);
 894                 substream = substream_next;
 895         }
 896         snd_pcm_stream_proc_done(pstr);
 897 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 898         for (setup = pstr->oss.setup_list; setup; setup = setupn) {
 899                 setupn = setup->next;
 900                 kfree(setup->task_name);
 901                 kfree(setup);
 902         }
 903 #endif
 904         free_chmap(pstr);
 905         if (pstr->substream_count)
 906                 put_device(&pstr->dev);
 907 }
 908
 909 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 910 #define pcm_call_notify(pcm, call)                                      \
 911         do {                                                            \
 912                 struct snd_pcm_notify *_notify;                         \
 913                 list_for_each_entry(_notify, &snd_pcm_notify_list, list) \
 914                         _notify->call(pcm);                             \
 915         } while (0)
 916 #else
 917 #define pcm_call_notify(pcm, call) do {} while (0)
 918 #endif
 919
 920 static int snd_pcm_free(struct snd_pcm *pcm)
 921 {
 922         if (!pcm)
 923                 return 0;
 924         if (!pcm->internal)
 925                 pcm_call_notify(pcm, n_unregister);
 926         if (pcm->private_free)
 927                 pcm->private_free(pcm);
 928         snd_pcm_lib_preallocate_free_for_all(pcm);
 929         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 930         snd_pcm_free_stream(&pcm->streams[SNDRV_PCM_STREAM_CAPTURE]);
 931         kfree(pcm);
 932         return 0;
 933 }
 934
 935 static int snd_pcm_dev_free(struct snd_device *device)
 936 {
 937         struct snd_pcm *pcm = device->device_data;
 938         return snd_pcm_free(pcm);
 939 }
 940
 941 int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 942                              struct file *file,
 943                              struct snd_pcm_substream **rsubstream)
 944 {
 945         struct snd_pcm_str * pstr;
 946         struct snd_pcm_substream *substream;
 947         struct snd_pcm_runtime *runtime;
 948         struct snd_card *card;
 949         int prefer_subdevice;
 950         size_t size;
 951
 952         if (snd_BUG_ON(!pcm || !rsubstream))
 953                 return -ENXIO;
 954         if (snd_BUG_ON(stream != SNDRV_PCM_STREAM_PLAYBACK &&
 955                        stream != SNDRV_PCM_STREAM_CAPTURE))
 956                 return -EINVAL;
 957         *rsubstream = NULL;
 958         pstr = &pcm->streams[stream];
 959         if (pstr->substream == NULL || pstr->substream_count == 0)
 960                 return -ENODEV;
 961
 962         card = pcm->card;
 963         prefer_subdevice = snd_ctl_get_preferred_subdevice(card, SND_CTL_SUBDEV_PCM);
 964
 965         if (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX) {
 966                 int opposite = !stream;
 967
 968                 for (substream = pcm->streams[opposite].substream; substream;
 969                      substream = substream->next) {
 970                         if (SUBSTREAM_BUSY(substream))
 971                                 return -EAGAIN;
 972                 }
 973         }
 974
 975         if (file->f_flags & O_APPEND) {
 976                 if (prefer_subdevice < 0) {
 977                         if (pstr->substream_count > 1)
 978                                 return -EINVAL; /* must be unique */
 979                         substream = pstr->substream;
 980                 } else {
 981                         for (substream = pstr->substream; substream;
 982                              substream = substream->next)
 983                                 if (substream->number == prefer_subdevice)
 984                                         break;
 985                 }
 986                 if (! substream)
 987                         return -ENODEV;
 988                 if (! SUBSTREAM_BUSY(substream))
 989                         return -EBADFD;
 990                 substream->ref_count++;
 991                 *rsubstream = substream;
 992                 return 0;
 993         }
 994
 995         for (substream = pstr->substream; substream; substream = substream->next) {
 996                 if (!SUBSTREAM_BUSY(substream) &&
 997                     (prefer_subdevice == -1 ||
 998                      substream->number == prefer_subdevice))
 999                         break;
1000         }
1001         if (substream == NULL)
1002                 return -EAGAIN;
1003
1004         runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
1005         if (runtime == NULL)
1006                 return -ENOMEM;
1007
1008         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status));
1009         runtime->status = snd_malloc_pages(size, GFP_KERNEL);
1010         if (runtime->status == NULL) {
1011                 kfree(runtime);
1012                 return -ENOMEM;
1013         }
1014         memset((void*)runtime->status, 0, size);
1015
1016         size = PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control));
1017         runtime->control = snd_malloc_pages(size, GFP_KERNEL);
1018         if (runtime->control == NULL) {
1019                 snd_free_pages((void*)runtime->status,
1020                                PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1021                 kfree(runtime);
1022                 return -ENOMEM;
1023         }
1024         memset((void*)runtime->control, 0, size);
1025
1026         init_waitqueue_head(&runtime->sleep);
1027         init_waitqueue_head(&runtime->tsleep);
1028
1029         runtime->status->state = SNDRV_PCM_STATE_OPEN;
1030
1031         substream->runtime = runtime;
1032         substream->private_data = pcm->private_data;
1033         substream->ref_count = 1;
1034         substream->f_flags = file->f_flags;
1035         substream->pid = get_pid(task_pid(current));
1036         pstr->substream_opened++;
1037         *rsubstream = substream;
1038         return 0;
1039 }
1040
1041 void snd_pcm_detach_substream(struct snd_pcm_substream *substream)
1042 {
1043         struct snd_pcm_runtime *runtime;
1044
1045         if (PCM_RUNTIME_CHECK(substream))
1046                 return;
1047         runtime = substream->runtime;
1048         if (runtime->private_free != NULL)
1049                 runtime->private_free(runtime);
1050         snd_free_pages((void*)runtime->status,
1051                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_status)));
1052         snd_free_pages((void*)runtime->control,
1053                        PAGE_ALIGN(sizeof(struct snd_pcm_mmap_control)));
1054         kfree(runtime->hw_constraints.rules);
1055         kfree(runtime);
1056         substream->runtime = NULL;
1057         put_pid(substream->pid);
1058         substream->pid = NULL;
1059         substream->pstr->substream_opened--;
1060 }
1061
1062 static ssize_t show_pcm_class(struct device *dev,
1063                               struct device_attribute *attr, char *buf)
1064 {
1065         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1066         struct snd_pcm *pcm = pstr->pcm;
1067         const char *str;
1068         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1069                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1070                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1071                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1072                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1073         };
1074
1075         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1076                 str = "none";
1077         else
1078                 str = strs[pcm->dev_class];
1079         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1080 }
1081
1082 static DEVICE_ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
1083 static struct attribute *pcm_dev_attrs[] = {
1084         &dev_attr_pcm_class.attr,
1085         NULL
1086 };
1087
1088 static const struct attribute_group pcm_dev_attr_group = {
1089         .attrs  = pcm_dev_attrs,
1090 };
1091
1092 static const struct attribute_group *pcm_dev_attr_groups[] = {
1093         &pcm_dev_attr_group,
1094         NULL
1095 };
1096
1097 static int snd_pcm_dev_register(struct snd_device *device)
1098 {
1099         int cidx, err;
1100         struct snd_pcm_substream *substream;
1101         struct snd_pcm *pcm;
1102
1103         if (snd_BUG_ON(!device || !device->device_data))
1104                 return -ENXIO;
1105         pcm = device->device_data;
1106
1107         mutex_lock(&register_mutex);
1108         err = snd_pcm_add(pcm);
1109         if (err)
1110                 goto unlock;
1111         for (cidx = 0; cidx < 2; cidx++) {
1112                 int devtype = -1;
1113                 if (pcm->streams[cidx].substream == NULL)
1114                         continue;
1115                 switch (cidx) {
1116                 case SNDRV_PCM_STREAM_PLAYBACK:
1117                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1118                         break;
1119                 case SNDRV_PCM_STREAM_CAPTURE:
1120                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1121                         break;
1122                 }
1123                 /* register pcm */
1124                 err = snd_register_device(devtype, pcm->card, pcm->device,
1125                                           &snd_pcm_f_ops[cidx], pcm,
1126                                           &pcm->streams[cidx].dev);
1127                 if (err < 0) {
1128                         list_del_init(&pcm->list);
1129                         goto unlock;
1130                 }
1131
1132                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1133                         snd_pcm_timer_init(substream);
1134         }
1135
1136         pcm_call_notify(pcm, n_register);
1137
1138  unlock:
1139         mutex_unlock(&register_mutex);
1140         return err;
1141 }
1142
1143 static int snd_pcm_dev_disconnect(struct snd_device *device)
1144 {
1145         struct snd_pcm *pcm = device->device_data;
1146         struct snd_pcm_substream *substream;
1147         int cidx;
1148
1149         mutex_lock(&register_mutex);
1150         mutex_lock(&pcm->open_mutex);
1151         wake_up(&pcm->open_wait);
1152         list_del_init(&pcm->list);
1153         for (cidx = 0; cidx < 2; cidx++) {
1154                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1155                         snd_pcm_stream_lock_irq(substream);
1156                         if (substream->runtime) {
1157                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1158                                 wake_up(&substream->runtime->sleep);
1159                                 wake_up(&substream->runtime->tsleep);
1160                         }
1161                         snd_pcm_stream_unlock_irq(substream);
1162                 }
1163         }
1164
1165         pcm_call_notify(pcm, n_disconnect);
1166         for (cidx = 0; cidx < 2; cidx++) {
1167                 snd_unregister_device(&pcm->streams[cidx].dev);
1168                 free_chmap(&pcm->streams[cidx]);
1169         }
1170         mutex_unlock(&pcm->open_mutex);
1171         mutex_unlock(&register_mutex);
1172         return 0;
1173 }
1174
1175 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1176 /**
1177  * snd_pcm_notify - Add/remove the notify list
1178  * @notify: PCM notify list
1179  * @nfree: 0 = register, 1 = unregister
1180  *
1181  * This adds the given notifier to the global list so that the callback is
1182  * called for each registered PCM devices.  This exists only for PCM OSS
1183  * emulation, so far.
1184  */
1185 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1186 {
1187         struct snd_pcm *pcm;
1188
1189         if (snd_BUG_ON(!notify ||
1190                        !notify->n_register ||
1191                        !notify->n_unregister ||
1192                        !notify->n_disconnect))
1193                 return -EINVAL;
1194         mutex_lock(&register_mutex);
1195         if (nfree) {
1196                 list_del(&notify->list);
1197                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1198                         notify->n_unregister(pcm);
1199         } else {
1200                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1201                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1202                         notify->n_register(pcm);
1203         }
1204         mutex_unlock(&register_mutex);
1205         return 0;
1206 }
1207 EXPORT_SYMBOL(snd_pcm_notify);
1208 #endif /* CONFIG_SND_PCM_OSS */
1209
1210 #ifdef CONFIG_SND_PROC_FS
1211 /*
1212  *  Info interface
1213  */
1214
1215 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1216                               struct snd_info_buffer *buffer)
1217 {
1218         struct snd_pcm *pcm;
1219
1220         mutex_lock(&register_mutex);
1221         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1222                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1223                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1224                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1225                         snd_iprintf(buffer, " : playback %i",
1226                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1227                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1228                         snd_iprintf(buffer, " : capture %i",
1229                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1230                 snd_iprintf(buffer, "\n");
1231         }
1232         mutex_unlock(&register_mutex);
1233 }
1234
1235 static struct snd_info_entry *snd_pcm_proc_entry;
1236
1237 static void snd_pcm_proc_init(void)
1238 {
1239         struct snd_info_entry *entry;
1240
1241         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1242         if (entry) {
1243                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1244                 if (snd_info_register(entry) < 0) {
1245                         snd_info_free_entry(entry);
1246                         entry = NULL;
1247                 }
1248         }
1249         snd_pcm_proc_entry = entry;
1250 }
1251
1252 static void snd_pcm_proc_done(void)
1253 {
1254         snd_info_free_entry(snd_pcm_proc_entry);
1255 }
1256
1257 #else /* !CONFIG_SND_PROC_FS */
1258 #define snd_pcm_proc_init()
1259 #define snd_pcm_proc_done()
1260 #endif /* CONFIG_SND_PROC_FS */
1261
1262
1263 /*
1264  *  ENTRY functions
1265  */
1266
1267 static int __init alsa_pcm_init(void)
1268 {
1269         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1270         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1271         snd_pcm_proc_init();
1272         return 0;
1273 }
1274
1275 static void __exit alsa_pcm_exit(void)
1276 {
1277         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1278         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1279         snd_pcm_proc_done();
1280 }
1281
1282 module_init(alsa_pcm_init)
1283 module_exit(alsa_pcm_exit)