sound/core/pcm.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/time.h>
  26 #include <linux/mutex.h>
  27 #include <linux/device.h>
  28 #include <linux/nospec.h>
  29 #include <sound/core.h>
  30 #include <sound/minors.h>
  31 #include <sound/pcm.h>
  32 #include <sound/timer.h>
  33 #include <sound/control.h>
  34 #include <sound/info.h>
  35
  36 #include "pcm_local.h"
  37
  38 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>, Abramo Bagnara <abramo@alsa-project.org>");
  39 MODULE_DESCRIPTION("Midlevel PCM code for ALSA.");
  40 MODULE_LICENSE("GPL");
  41
  42 static LIST_HEAD(snd_pcm_devices);
  43 static DEFINE_MUTEX(register_mutex);
  44 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
  45 static LIST_HEAD(snd_pcm_notify_list);
  46 #endif
  47
  48 static int snd_pcm_free(struct snd_pcm *pcm);
  49 static int snd_pcm_dev_free(struct snd_device *device);
  50 static int snd_pcm_dev_register(struct snd_device *device);
  51 static int snd_pcm_dev_disconnect(struct snd_device *device);
  52
  53 static struct snd_pcm *snd_pcm_get(struct snd_card *card, int device)
  54 {
  55         struct snd_pcm *pcm;
  56
  57         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  58                 if (pcm->card == card && pcm->device == device)
  59                         return pcm;
  60         }
  61         return NULL;
  62 }
  63
  64 static int snd_pcm_next(struct snd_card *card, int device)
  65 {
  66         struct snd_pcm *pcm;
  67
  68         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  69                 if (pcm->card == card && pcm->device > device)
  70                         return pcm->device;
  71                 else if (pcm->card->number > card->number)
  72                         return -1;
  73         }
  74         return -1;
  75 }
  76
  77 static int snd_pcm_add(struct snd_pcm *newpcm)
  78 {
  79         struct snd_pcm *pcm;
  80
  81         if (newpcm->internal)
  82                 return 0;
  83
  84         list_for_each_entry(pcm, &snd_pcm_devices, list) {
  85                 if (pcm->card == newpcm->card && pcm->device == newpcm->device)
  86                         return -EBUSY;
  87                 if (pcm->card->number > newpcm->card->number ||
  88                                 (pcm->card == newpcm->card &&
  89                                 pcm->device > newpcm->device)) {
  90                         list_add(&newpcm->list, pcm->list.prev);
  91                         return 0;
  92                 }
  93         }
  94         list_add_tail(&newpcm->list, &snd_pcm_devices);
  95         return 0;
  96 }
  97
  98 static int snd_pcm_control_ioctl(struct snd_card *card,
  99                                  struct snd_ctl_file *control,
 100                                  unsigned int cmd, unsigned long arg)
 101 {
 102         switch (cmd) {
 103         case SNDRV_CTL_IOCTL_PCM_NEXT_DEVICE:
 104                 {
 105                         int device;
 106
 107                         if (get_user(device, (int __user *)arg))
 108                                 return -EFAULT;
 109                         mutex_lock(&register_mutex);
 110                         device = snd_pcm_next(card, device);
 111                         mutex_unlock(&register_mutex);
 112                         if (put_user(device, (int __user *)arg))
 113                                 return -EFAULT;
 114                         return 0;
 115                 }
 116         case SNDRV_CTL_IOCTL_PCM_INFO:
 117                 {
 118                         struct snd_pcm_info __user *info;
 119                         unsigned int device, subdevice;
 120                         int stream;
 121                         struct snd_pcm *pcm;
 122                         struct snd_pcm_str *pstr;
 123                         struct snd_pcm_substream *substream;
 124                         int err;
 125
 126                         info = (struct snd_pcm_info __user *)arg;
 127                         if (get_user(device, &info->device))
 128                                 return -EFAULT;
 129                         if (get_user(stream, &info->stream))
 130                                 return -EFAULT;
 131                         if (stream < 0 || stream > 1)
 132                                 return -EINVAL;
 133                         stream = array_index_nospec(stream, 2);
 134                         if (get_user(subdevice, &info->subdevice))
 135                                 return -EFAULT;
 136                         mutex_lock(&register_mutex);
 137                         pcm = snd_pcm_get(card, device);
 138                         if (pcm == NULL) {
 139                                 err = -ENXIO;
 140                                 goto _error;
 141                         }
 142                         pstr = &pcm->streams[stream];
 143                         if (pstr->substream_count == 0) {
 144                                 err = -ENOENT;
 145                                 goto _error;
 146                         }
 147                         if (subdevice >= pstr->substream_count) {
 148                                 err = -ENXIO;
 149                                 goto _error;
 150                         }
 151                         for (substream = pstr->substream; substream;
 152                              substream = substream->next)
 153                                 if (substream->number == (int)subdevice)
 154                                         break;
 155                         if (substream == NULL) {
 156                                 err = -ENXIO;
 157                                 goto _error;
 158                         }
 159                         mutex_lock(&pcm->open_mutex);
 160                         err = snd_pcm_info_user(substream, info);
 161                         mutex_unlock(&pcm->open_mutex);
 162                 _error:
 163                         mutex_unlock(&register_mutex);
 164                         return err;
 165                 }
 166         case SNDRV_CTL_IOCTL_PCM_PREFER_SUBDEVICE:
 167                 {
 168                         int val;
 169
 170                         if (get_user(val, (int __user *)arg))
 171                                 return -EFAULT;
 172                         control->preferred_subdevice[SND_CTL_SUBDEV_PCM] = val;
 173                         return 0;
 174                 }
 175         }
 176         return -ENOIOCTLCMD;
 177 }
 178
 179 #define FORMAT(v) [SNDRV_PCM_FORMAT_##v] = #v
 180
 181 static char *snd_pcm_format_names[] = {
 182         FORMAT(S8),
 183         FORMAT(U8),
 184         FORMAT(S16_LE),
 185         FORMAT(S16_BE),
 186         FORMAT(U16_LE),
 187         FORMAT(U16_BE),
 188         FORMAT(S24_LE),
 189         FORMAT(S24_BE),
 190         FORMAT(U24_LE),
 191         FORMAT(U24_BE),
 192         FORMAT(S32_LE),
 193         FORMAT(S32_BE),
 194         FORMAT(U32_LE),
 195         FORMAT(U32_BE),
 196         FORMAT(FLOAT_LE),
 197         FORMAT(FLOAT_BE),
 198         FORMAT(FLOAT64_LE),
 199         FORMAT(FLOAT64_BE),
 200         FORMAT(IEC958_SUBFRAME_LE),
 201         FORMAT(IEC958_SUBFRAME_BE),
 202         FORMAT(MU_LAW),
 203         FORMAT(A_LAW),
 204         FORMAT(IMA_ADPCM),
 205         FORMAT(MPEG),
 206         FORMAT(GSM),
 207         FORMAT(SPECIAL),
 208         FORMAT(S24_3LE),
 209         FORMAT(S24_3BE),
 210         FORMAT(U24_3LE),
 211         FORMAT(U24_3BE),
 212         FORMAT(S20_3LE),
 213         FORMAT(S20_3BE),
 214         FORMAT(U20_3LE),
 215         FORMAT(U20_3BE),
 216         FORMAT(S18_3LE),
 217         FORMAT(S18_3BE),
 218         FORMAT(U18_3LE),
 219         FORMAT(U18_3BE),
 220         FORMAT(G723_24),
 221         FORMAT(G723_24_1B),
 222         FORMAT(G723_40),
 223         FORMAT(G723_40_1B),
 224         FORMAT(DSD_U8),
 225         FORMAT(DSD_U16_LE),
 226         FORMAT(DSD_U32_LE),
 227         FORMAT(DSD_U16_BE),
 228         FORMAT(DSD_U32_BE),
 229 };
 230
 231 /**
 232  * snd_pcm_format_name - Return a name string for the given PCM format
 233  * @format: PCM format
 234  */
 235 const char *snd_pcm_format_name(snd_pcm_format_t format)
 236 {
 237         if ((__force unsigned int)format >= ARRAY_SIZE(snd_pcm_format_names))
 238                 return "Unknown";
 239         return snd_pcm_format_names[(__force unsigned int)format];
 240 }
 241 EXPORT_SYMBOL_GPL(snd_pcm_format_name);
 242
 243 #ifdef CONFIG_SND_VERBOSE_PROCFS
 244
 245 #define STATE(v) [SNDRV_PCM_STATE_##v] = #v
 246 #define STREAM(v) [SNDRV_PCM_STREAM_##v] = #v
 247 #define READY(v) [SNDRV_PCM_READY_##v] = #v
 248 #define XRUN(v) [SNDRV_PCM_XRUN_##v] = #v
 249 #define SILENCE(v) [SNDRV_PCM_SILENCE_##v] = #v
 250 #define TSTAMP(v) [SNDRV_PCM_TSTAMP_##v] = #v
 251 #define ACCESS(v) [SNDRV_PCM_ACCESS_##v] = #v
 252 #define START(v) [SNDRV_PCM_START_##v] = #v
 253 #define SUBFORMAT(v) [SNDRV_PCM_SUBFORMAT_##v] = #v
 254
 255 static char *snd_pcm_stream_names[] = {
 256         STREAM(PLAYBACK),
 257         STREAM(CAPTURE),
 258 };
 259
 260 static char *snd_pcm_state_names[] = {
 261         STATE(OPEN),
 262         STATE(SETUP),
 263         STATE(PREPARED),
 264         STATE(RUNNING),
 265         STATE(XRUN),
 266         STATE(DRAINING),
 267         STATE(PAUSED),
 268         STATE(SUSPENDED),
 269 };
 270
 271 static char *snd_pcm_access_names[] = {
 272         ACCESS(MMAP_INTERLEAVED),
 273         ACCESS(MMAP_NONINTERLEAVED),
 274         ACCESS(MMAP_COMPLEX),
 275         ACCESS(RW_INTERLEAVED),
 276         ACCESS(RW_NONINTERLEAVED),
 277 };
 278
 279 static char *snd_pcm_subformat_names[] = {
 280         SUBFORMAT(STD),
 281 };
 282
 283 static char *snd_pcm_tstamp_mode_names[] = {
 284         TSTAMP(NONE),
 285         TSTAMP(ENABLE),
 286 };
 287
 288 static const char *snd_pcm_stream_name(int stream)
 289 {
 290         return snd_pcm_stream_names[stream];
 291 }
 292
 293 static const char *snd_pcm_access_name(snd_pcm_access_t access)
 294 {
 295         return snd_pcm_access_names[(__force int)access];
 296 }
 297
 298 static const char *snd_pcm_subformat_name(snd_pcm_subformat_t subformat)
 299 {
 300         return snd_pcm_subformat_names[(__force int)subformat];
 301 }
 302
 303 static const char *snd_pcm_tstamp_mode_name(int mode)
 304 {
 305         return snd_pcm_tstamp_mode_names[mode];
 306 }
 307
 308 static const char *snd_pcm_state_name(snd_pcm_state_t state)
 309 {
 310         return snd_pcm_state_names[(__force int)state];
 311 }
 312
 313 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 314 #include <linux/soundcard.h>
 315
 316 static const char *snd_pcm_oss_format_name(int format)
 317 {
 318         switch (format) {
 319         case AFMT_MU_LAW:
 320                 return "MU_LAW";
 321         case AFMT_A_LAW:
 322                 return "A_LAW";
 323         case AFMT_IMA_ADPCM:
 324                 return "IMA_ADPCM";
 325         case AFMT_U8:
 326                 return "U8";
 327         case AFMT_S16_LE:
 328                 return "S16_LE";
 329         case AFMT_S16_BE:
 330                 return "S16_BE";
 331         case AFMT_S8:
 332                 return "S8";
 333         case AFMT_U16_LE:
 334                 return "U16_LE";
 335         case AFMT_U16_BE:
 336                 return "U16_BE";
 337         case AFMT_MPEG:
 338                 return "MPEG";
 339         default:
 340                 return "unknown";
 341         }
 342 }
 343 #endif
 344
 345 static void snd_pcm_proc_info_read(struct snd_pcm_substream *substream,
 346                                    struct snd_info_buffer *buffer)
 347 {
 348         struct snd_pcm_info *info;
 349         int err;
 350
 351         if (! substream)
 352                 return;
 353
 354         info = kmalloc(sizeof(*info), GFP_KERNEL);
 355         if (!info)
 356                 return;
 357
 358         err = snd_pcm_info(substream, info);
 359         if (err < 0) {
 360                 snd_iprintf(buffer, "error %d\n", err);
 361                 kfree(info);
 362                 return;
 363         }
 364         snd_iprintf(buffer, "card: %d\n", info->card);
 365         snd_iprintf(buffer, "device: %d\n", info->device);
 366         snd_iprintf(buffer, "subdevice: %d\n", info->subdevice);
 367         snd_iprintf(buffer, "stream: %s\n", snd_pcm_stream_name(info->stream));
 368         snd_iprintf(buffer, "id: %s\n", info->id);
 369         snd_iprintf(buffer, "name: %s\n", info->name);
 370         snd_iprintf(buffer, "subname: %s\n", info->subname);
 371         snd_iprintf(buffer, "class: %d\n", info->dev_class);
 372         snd_iprintf(buffer, "subclass: %d\n", info->dev_subclass);
 373         snd_iprintf(buffer, "subdevices_count: %d\n", info->subdevices_count);
 374         snd_iprintf(buffer, "subdevices_avail: %d\n", info->subdevices_avail);
 375         kfree(info);
 376 }
 377
 378 static void snd_pcm_stream_proc_info_read(struct snd_info_entry *entry,
 379                                           struct snd_info_buffer *buffer)
 380 {
 381         snd_pcm_proc_info_read(((struct snd_pcm_str *)entry->private_data)->substream,
 382                                buffer);
 383 }
 384
 385 static void snd_pcm_substream_proc_info_read(struct snd_info_entry *entry,
 386                                              struct snd_info_buffer *buffer)
 387 {
 388         snd_pcm_proc_info_read(entry->private_data, buffer);
 389 }
 390
 391 static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 392                                                   struct snd_info_buffer *buffer)
 393 {
 394         struct snd_pcm_substream *substream = entry->private_data;
 395         struct snd_pcm_runtime *runtime;
 396
 397         mutex_lock(&substream->pcm->open_mutex);
 398         runtime = substream->runtime;
 399         if (!runtime) {
 400                 snd_iprintf(buffer, "closed\n");
 401                 goto unlock;
 402         }
 403         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 404                 snd_iprintf(buffer, "no setup\n");
 405                 goto unlock;
 406         }
 407         snd_iprintf(buffer, "access: %s\n", snd_pcm_access_name(runtime->access));
 408         snd_iprintf(buffer, "format: %s\n", snd_pcm_format_name(runtime->format));
 409         snd_iprintf(buffer, "subformat: %s\n", snd_pcm_subformat_name(runtime->subformat));
 410         snd_iprintf(buffer, "channels: %u\n", runtime->channels);
 411         snd_iprintf(buffer, "rate: %u (%u/%u)\n", runtime->rate, runtime->rate_num, runtime->rate_den);
 412         snd_iprintf(buffer, "period_size: %lu\n", runtime->period_size);
 413         snd_iprintf(buffer, "buffer_size: %lu\n", runtime->buffer_size);
 414 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
 415         if (substream->oss.oss) {
 416                 snd_iprintf(buffer, "OSS format: %s\n", snd_pcm_oss_format_name(runtime->oss.format));
 417                 snd_iprintf(buffer, "OSS channels: %u\n", runtime->oss.channels);
 418                 snd_iprintf(buffer, "OSS rate: %u\n", runtime->oss.rate);
 419                 snd_iprintf(buffer, "OSS period bytes: %lu\n", (unsigned long)runtime->oss.period_bytes);
 420                 snd_iprintf(buffer, "OSS periods: %u\n", runtime->oss.periods);
 421                 snd_iprintf(buffer, "OSS period frames: %lu\n", (unsigned long)runtime->oss.period_frames);
 422         }
 423 #endif
 424  unlock:
 425         mutex_unlock(&substream->pcm->open_mutex);
 426 }
 427
 428 static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 429                                                   struct snd_info_buffer *buffer)
 430 {
 431         struct snd_pcm_substream *substream = entry->private_data;
 432         struct snd_pcm_runtime *runtime;
 433
 434         mutex_lock(&substream->pcm->open_mutex);
 435         runtime = substream->runtime;
 436         if (!runtime) {
 437                 snd_iprintf(buffer, "closed\n");
 438                 goto unlock;
 439         }
 440         if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
 441                 snd_iprintf(buffer, "no setup\n");
 442                 goto unlock;
 443         }
 444         snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
 445         snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
 446         snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
 447         snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
 448         snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
 449         snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
 450         snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
 451         snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
 452  unlock:
 453         mutex_unlock(&substream->pcm->open_mutex);
 454 }
 455
 456 static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
 457                                                struct snd_info_buffer *buffer)
 458 {
 459         struct snd_pcm_substream *substream = entry->private_data;
 460         struct snd_pcm_runtime *runtime;
 461         struct snd_pcm_status status;
 462         int err;
 463
 464         mutex_lock(&substream->pcm->open_mutex);
 465         runtime = substream->runtime;
 466         if (!runtime) {
 467                 snd_iprintf(buffer, "closed\n");
 468                 goto unlock;
 469         }
 470         memset(&status, 0, sizeof(status));
 471         err = snd_pcm_status(substream, &status);
 472         if (err < 0) {
 473                 snd_iprintf(buffer, "error %d\n", err);
 474                 goto unlock;
 475         }
 476         snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
 477         snd_iprintf(buffer, "owner_pid   : %d\n", pid_vnr(substream->pid));
 478         snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
 479                 status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
 480         snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
 481                 status.tstamp.tv_sec, status.tstamp.tv_nsec);
 482         snd_iprintf(buffer, "delay       : %ld\n", status.delay);
 483         snd_iprintf(buffer, "avail       : %ld\n", status.avail);
 484         snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
 485         snd_iprintf(buffer, "-----\n");
 486         snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
 487         snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
 488  unlock:
 489         mutex_unlock(&substream->pcm->open_mutex);
 490 }
 491
 492 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 493 static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
 494                                          struct snd_info_buffer *buffer)
 495 {
 496         struct snd_pcm_substream *substream = entry->private_data;
 497
 498         snd_pcm_stop_xrun(substream);
 499 }
 500
 501 static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
 502                                     struct snd_info_buffer *buffer)
 503 {
 504         struct snd_pcm_str *pstr = entry->private_data;
 505         snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
 506 }
 507
 508 static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
 509                                      struct snd_info_buffer *buffer)
 510 {
 511         struct snd_pcm_str *pstr = entry->private_data;
 512         char line[64];
 513         if (!snd_info_get_line(buffer, line, sizeof(line)))
 514                 pstr->xrun_debug = simple_strtoul(line, NULL, 10);
 515 }
 516 #endif
 517
 518 static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
 519 {
 520         struct snd_pcm *pcm = pstr->pcm;
 521         struct snd_info_entry *entry;
 522         char name[16];
 523
 524         sprintf(name, "pcm%i%c", pcm->device,
 525                 pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
 526         entry = snd_info_create_card_entry(pcm->card, name,
 527                                            pcm->card->proc_root);
 528         if (!entry)
 529                 return -ENOMEM;
 530         entry->mode = S_IFDIR | 0555;
 531         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 |= 0200;
 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 | 0555;
 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 | 0200;
 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         /* Avoid concurrent access to runtime via PCM timer interface */
1056         if (substream->timer)
1057                 spin_lock_irq(&substream->timer->lock);
1058         substream->runtime = NULL;
1059         if (substream->timer)
1060                 spin_unlock_irq(&substream->timer->lock);
1061         kfree(runtime);
1062         put_pid(substream->pid);
1063         substream->pid = NULL;
1064         substream->pstr->substream_opened--;
1065 }
1066
1067 static ssize_t show_pcm_class(struct device *dev,
1068                               struct device_attribute *attr, char *buf)
1069 {
1070         struct snd_pcm_str *pstr = container_of(dev, struct snd_pcm_str, dev);
1071         struct snd_pcm *pcm = pstr->pcm;
1072         const char *str;
1073         static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
1074                 [SNDRV_PCM_CLASS_GENERIC] = "generic",
1075                 [SNDRV_PCM_CLASS_MULTI] = "multi",
1076                 [SNDRV_PCM_CLASS_MODEM] = "modem",
1077                 [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
1078         };
1079
1080         if (pcm->dev_class > SNDRV_PCM_CLASS_LAST)
1081                 str = "none";
1082         else
1083                 str = strs[pcm->dev_class];
1084         return snprintf(buf, PAGE_SIZE, "%s\n", str);
1085 }
1086
1087 static DEVICE_ATTR(pcm_class, 0444, show_pcm_class, NULL);
1088 static struct attribute *pcm_dev_attrs[] = {
1089         &dev_attr_pcm_class.attr,
1090         NULL
1091 };
1092
1093 static const struct attribute_group pcm_dev_attr_group = {
1094         .attrs  = pcm_dev_attrs,
1095 };
1096
1097 static const struct attribute_group *pcm_dev_attr_groups[] = {
1098         &pcm_dev_attr_group,
1099         NULL
1100 };
1101
1102 static int snd_pcm_dev_register(struct snd_device *device)
1103 {
1104         int cidx, err;
1105         struct snd_pcm_substream *substream;
1106         struct snd_pcm *pcm;
1107
1108         if (snd_BUG_ON(!device || !device->device_data))
1109                 return -ENXIO;
1110         pcm = device->device_data;
1111
1112         mutex_lock(&register_mutex);
1113         err = snd_pcm_add(pcm);
1114         if (err)
1115                 goto unlock;
1116         for (cidx = 0; cidx < 2; cidx++) {
1117                 int devtype = -1;
1118                 if (pcm->streams[cidx].substream == NULL)
1119                         continue;
1120                 switch (cidx) {
1121                 case SNDRV_PCM_STREAM_PLAYBACK:
1122                         devtype = SNDRV_DEVICE_TYPE_PCM_PLAYBACK;
1123                         break;
1124                 case SNDRV_PCM_STREAM_CAPTURE:
1125                         devtype = SNDRV_DEVICE_TYPE_PCM_CAPTURE;
1126                         break;
1127                 }
1128                 /* register pcm */
1129                 err = snd_register_device(devtype, pcm->card, pcm->device,
1130                                           &snd_pcm_f_ops[cidx], pcm,
1131                                           &pcm->streams[cidx].dev);
1132                 if (err < 0) {
1133                         list_del_init(&pcm->list);
1134                         goto unlock;
1135                 }
1136
1137                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
1138                         snd_pcm_timer_init(substream);
1139         }
1140
1141         pcm_call_notify(pcm, n_register);
1142
1143  unlock:
1144         mutex_unlock(&register_mutex);
1145         return err;
1146 }
1147
1148 static int snd_pcm_dev_disconnect(struct snd_device *device)
1149 {
1150         struct snd_pcm *pcm = device->device_data;
1151         struct snd_pcm_substream *substream;
1152         int cidx;
1153
1154         mutex_lock(&register_mutex);
1155         mutex_lock(&pcm->open_mutex);
1156         wake_up(&pcm->open_wait);
1157         list_del_init(&pcm->list);
1158         for (cidx = 0; cidx < 2; cidx++) {
1159                 for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) {
1160                         snd_pcm_stream_lock_irq(substream);
1161                         if (substream->runtime) {
1162                                 if (snd_pcm_running(substream))
1163                                         snd_pcm_stop(substream,
1164                                                      SNDRV_PCM_STATE_DISCONNECTED);
1165                                 /* to be sure, set the state unconditionally */
1166                                 substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
1167                                 wake_up(&substream->runtime->sleep);
1168                                 wake_up(&substream->runtime->tsleep);
1169                         }
1170                         snd_pcm_stream_unlock_irq(substream);
1171                 }
1172         }
1173
1174         pcm_call_notify(pcm, n_disconnect);
1175         for (cidx = 0; cidx < 2; cidx++) {
1176                 snd_unregister_device(&pcm->streams[cidx].dev);
1177                 free_chmap(&pcm->streams[cidx]);
1178         }
1179         mutex_unlock(&pcm->open_mutex);
1180         mutex_unlock(&register_mutex);
1181         return 0;
1182 }
1183
1184 #if IS_ENABLED(CONFIG_SND_PCM_OSS)
1185 /**
1186  * snd_pcm_notify - Add/remove the notify list
1187  * @notify: PCM notify list
1188  * @nfree: 0 = register, 1 = unregister
1189  *
1190  * This adds the given notifier to the global list so that the callback is
1191  * called for each registered PCM devices.  This exists only for PCM OSS
1192  * emulation, so far.
1193  */
1194 int snd_pcm_notify(struct snd_pcm_notify *notify, int nfree)
1195 {
1196         struct snd_pcm *pcm;
1197
1198         if (snd_BUG_ON(!notify ||
1199                        !notify->n_register ||
1200                        !notify->n_unregister ||
1201                        !notify->n_disconnect))
1202                 return -EINVAL;
1203         mutex_lock(&register_mutex);
1204         if (nfree) {
1205                 list_del(&notify->list);
1206                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1207                         notify->n_unregister(pcm);
1208         } else {
1209                 list_add_tail(&notify->list, &snd_pcm_notify_list);
1210                 list_for_each_entry(pcm, &snd_pcm_devices, list)
1211                         notify->n_register(pcm);
1212         }
1213         mutex_unlock(&register_mutex);
1214         return 0;
1215 }
1216 EXPORT_SYMBOL(snd_pcm_notify);
1217 #endif /* CONFIG_SND_PCM_OSS */
1218
1219 #ifdef CONFIG_SND_PROC_FS
1220 /*
1221  *  Info interface
1222  */
1223
1224 static void snd_pcm_proc_read(struct snd_info_entry *entry,
1225                               struct snd_info_buffer *buffer)
1226 {
1227         struct snd_pcm *pcm;
1228
1229         mutex_lock(&register_mutex);
1230         list_for_each_entry(pcm, &snd_pcm_devices, list) {
1231                 snd_iprintf(buffer, "%02i-%02i: %s : %s",
1232                             pcm->card->number, pcm->device, pcm->id, pcm->name);
1233                 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream)
1234                         snd_iprintf(buffer, " : playback %i",
1235                                     pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count);
1236                 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream)
1237                         snd_iprintf(buffer, " : capture %i",
1238                                     pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count);
1239                 snd_iprintf(buffer, "\n");
1240         }
1241         mutex_unlock(&register_mutex);
1242 }
1243
1244 static struct snd_info_entry *snd_pcm_proc_entry;
1245
1246 static void snd_pcm_proc_init(void)
1247 {
1248         struct snd_info_entry *entry;
1249
1250         entry = snd_info_create_module_entry(THIS_MODULE, "pcm", NULL);
1251         if (entry) {
1252                 snd_info_set_text_ops(entry, NULL, snd_pcm_proc_read);
1253                 if (snd_info_register(entry) < 0) {
1254                         snd_info_free_entry(entry);
1255                         entry = NULL;
1256                 }
1257         }
1258         snd_pcm_proc_entry = entry;
1259 }
1260
1261 static void snd_pcm_proc_done(void)
1262 {
1263         snd_info_free_entry(snd_pcm_proc_entry);
1264 }
1265
1266 #else /* !CONFIG_SND_PROC_FS */
1267 #define snd_pcm_proc_init()
1268 #define snd_pcm_proc_done()
1269 #endif /* CONFIG_SND_PROC_FS */
1270
1271
1272 /*
1273  *  ENTRY functions
1274  */
1275
1276 static int __init alsa_pcm_init(void)
1277 {
1278         snd_ctl_register_ioctl(snd_pcm_control_ioctl);
1279         snd_ctl_register_ioctl_compat(snd_pcm_control_ioctl);
1280         snd_pcm_proc_init();
1281         return 0;
1282 }
1283
1284 static void __exit alsa_pcm_exit(void)
1285 {
1286         snd_ctl_unregister_ioctl(snd_pcm_control_ioctl);
1287         snd_ctl_unregister_ioctl_compat(snd_pcm_control_ioctl);
1288         snd_pcm_proc_done();
1289 }
1290
1291 module_init(alsa_pcm_init)
1292 module_exit(alsa_pcm_exit)