sound/core/sound.c

   1 /*
   2  *  Advanced Linux Sound Architecture
   3  *  Copyright (c) by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
  23 #include <linux/init.h>
  24 #include <linux/slab.h>
  25 #include <linux/time.h>
  26 #include <linux/device.h>
  27 #include <linux/moduleparam.h>
  28 #include <sound/core.h>
  29 #include <sound/minors.h>
  30 #include <sound/info.h>
  31 #include <sound/version.h>
  32 #include <sound/control.h>
  33 #include <sound/initval.h>
  34 #include <linux/kmod.h>
  35 #include <linux/devfs_fs_kernel.h>
  36
  37 #define SNDRV_OS_MINORS 256
  38
  39 static int major = CONFIG_SND_MAJOR;
  40 int snd_major;
  41 static int cards_limit = 1;
  42 static int device_mode = S_IFCHR | S_IRUGO | S_IWUGO;
  43
  44 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
  45 MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
  46 MODULE_LICENSE("GPL");
  47 module_param(major, int, 0444);
  48 MODULE_PARM_DESC(major, "Major # for sound driver.");
  49 module_param(cards_limit, int, 0444);
  50 MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
  51 #ifdef CONFIG_DEVFS_FS
  52 module_param(device_mode, int, 0444);
  53 MODULE_PARM_DESC(device_mode, "Device file permission mask for devfs.");
  54 #endif
  55 MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
  56
  57 /* this one holds the actual max. card number currently available.
  58  * as default, it's identical with cards_limit option.  when more
  59  * modules are loaded manually, this limit number increases, too.
  60  */
  61 int snd_ecards_limit;
  62
  63 static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
  64 static DECLARE_MUTEX(sound_mutex);
  65
  66 extern struct class *sound_class;
  67
  68
  69 #ifdef CONFIG_KMOD
  70
  71 /**
  72  * snd_request_card - try to load the card module
  73  * @card: the card number
  74  *
  75  * Tries to load the module "snd-card-X" for the given card number
  76  * via KMOD.  Returns immediately if already loaded.
  77  */
  78 void snd_request_card(int card)
  79 {
  80         int locked;
  81
  82         if (! current->fs->root)
  83                 return;
  84         read_lock(&snd_card_rwlock);
  85         locked = snd_cards_lock & (1 << card);
  86         read_unlock(&snd_card_rwlock);
  87         if (locked)
  88                 return;
  89         if (card < 0 || card >= cards_limit)
  90                 return;
  91         request_module("snd-card-%i", card);
  92 }
  93
  94 static void snd_request_other(int minor)
  95 {
  96         char *str;
  97
  98         if (! current->fs->root)
  99                 return;
 100         switch (minor) {
 101         case SNDRV_MINOR_SEQUENCER:     str = "snd-seq";        break;
 102         case SNDRV_MINOR_TIMER:         str = "snd-timer";      break;
 103         default:                        return;
 104         }
 105         request_module(str);
 106 }
 107
 108 #endif                          /* request_module support */
 109
 110 /**
 111  * snd_lookup_minor_data - get user data of a registered device
 112  * @minor: the minor number
 113  * @type: device type (SNDRV_DEVICE_TYPE_XXX)
 114  *
 115  * Checks that a minor device with the specified type is registered, and returns
 116  * its user data pointer.
 117  */
 118 void *snd_lookup_minor_data(unsigned int minor, int type)
 119 {
 120         struct snd_minor *mreg;
 121         void *private_data;
 122
 123         if (minor > ARRAY_SIZE(snd_minors))
 124                 return NULL;
 125         down(&sound_mutex);
 126         mreg = snd_minors[minor];
 127         if (mreg && mreg->type == type)
 128                 private_data = mreg->private_data;
 129         else
 130                 private_data = NULL;
 131         up(&sound_mutex);
 132         return private_data;
 133 }
 134
 135 static int snd_open(struct inode *inode, struct file *file)
 136 {
 137         unsigned int minor = iminor(inode);
 138         struct snd_minor *mptr = NULL;
 139         struct file_operations *old_fops;
 140         int err = 0;
 141
 142         if (minor > ARRAY_SIZE(snd_minors))
 143                 return -ENODEV;
 144         mptr = snd_minors[minor];
 145         if (mptr == NULL) {
 146 #ifdef CONFIG_KMOD
 147                 int dev = SNDRV_MINOR_DEVICE(minor);
 148                 if (dev == SNDRV_MINOR_CONTROL) {
 149                         /* /dev/aloadC? */
 150                         int card = SNDRV_MINOR_CARD(minor);
 151                         if (snd_cards[card] == NULL)
 152                                 snd_request_card(card);
 153                 } else if (dev == SNDRV_MINOR_GLOBAL) {
 154                         /* /dev/aloadSEQ */
 155                         snd_request_other(minor);
 156                 }
 157 #ifndef CONFIG_SND_DYNAMIC_MINORS
 158                 /* /dev/snd/{controlC?,seq} */
 159                 mptr = snd_minors[minor];
 160                 if (mptr == NULL)
 161 #endif
 162 #endif
 163                         return -ENODEV;
 164         }
 165         old_fops = file->f_op;
 166         file->f_op = fops_get(mptr->f_ops);
 167         if (file->f_op->open)
 168                 err = file->f_op->open(inode, file);
 169         if (err) {
 170                 fops_put(file->f_op);
 171                 file->f_op = fops_get(old_fops);
 172         }
 173         fops_put(old_fops);
 174         return err;
 175 }
 176
 177 static struct file_operations snd_fops =
 178 {
 179         .owner =        THIS_MODULE,
 180         .open =         snd_open
 181 };
 182
 183 #ifdef CONFIG_SND_DYNAMIC_MINORS
 184 static int snd_find_free_minor(void)
 185 {
 186         int minor;
 187
 188         for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
 189                 /* skip minors still used statically for autoloading devices */
 190                 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
 191                     minor == SNDRV_MINOR_SEQUENCER)
 192                         continue;
 193                 if (!snd_minors[minor])
 194                         return minor;
 195         }
 196         return -EBUSY;
 197 }
 198 #else
 199 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
 200 {
 201         int minor;
 202
 203         switch (type) {
 204         case SNDRV_DEVICE_TYPE_SEQUENCER:
 205         case SNDRV_DEVICE_TYPE_TIMER:
 206                 minor = type;
 207                 break;
 208         case SNDRV_DEVICE_TYPE_CONTROL:
 209                 snd_assert(card != NULL, return -EINVAL);
 210                 minor = SNDRV_MINOR(card->number, type);
 211                 break;
 212         case SNDRV_DEVICE_TYPE_HWDEP:
 213         case SNDRV_DEVICE_TYPE_RAWMIDI:
 214         case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
 215         case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
 216                 snd_assert(card != NULL, return -EINVAL);
 217                 minor = SNDRV_MINOR(card->number, type + dev);
 218                 break;
 219         default:
 220                 return -EINVAL;
 221         }
 222         snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
 223         return minor;
 224 }
 225 #endif
 226
 227 /**
 228  * snd_register_device - Register the ALSA device file for the card
 229  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
 230  * @card: the card instance
 231  * @dev: the device index
 232  * @f_ops: the file operations
 233  * @private_data: user pointer for f_ops->open()
 234  * @name: the device file name
 235  *
 236  * Registers an ALSA device file for the given card.
 237  * The operators have to be set in reg parameter.
 238  *
 239  * Retrurns zero if successful, or a negative error code on failure.
 240  */
 241 int snd_register_device(int type, struct snd_card *card, int dev,
 242                         struct file_operations *f_ops, void *private_data,
 243                         const char *name)
 244 {
 245         int minor;
 246         struct snd_minor *preg;
 247         struct device *device = NULL;
 248
 249         snd_assert(name, return -EINVAL);
 250         preg = kmalloc(sizeof(struct snd_minor) + strlen(name) + 1, GFP_KERNEL);
 251         if (preg == NULL)
 252                 return -ENOMEM;
 253         preg->type = type;
 254         preg->card = card ? card->number : -1;
 255         preg->device = dev;
 256         preg->f_ops = f_ops;
 257         preg->private_data = private_data;
 258         strcpy(preg->name, name);
 259         down(&sound_mutex);
 260 #ifdef CONFIG_SND_DYNAMIC_MINORS
 261         minor = snd_find_free_minor();
 262 #else
 263         minor = snd_kernel_minor(type, card, dev);
 264         if (minor >= 0 && snd_minors[minor])
 265                 minor = -EBUSY;
 266 #endif
 267         if (minor < 0) {
 268                 up(&sound_mutex);
 269                 kfree(preg);
 270                 return minor;
 271         }
 272         snd_minors[minor] = preg;
 273         if (type != SNDRV_DEVICE_TYPE_CONTROL || preg->card >= cards_limit)
 274                 devfs_mk_cdev(MKDEV(major, minor), S_IFCHR | device_mode, "snd/%s", name);
 275         if (card)
 276                 device = card->dev;
 277         class_device_create(sound_class, NULL, MKDEV(major, minor), device, "%s", name);
 278
 279         up(&sound_mutex);
 280         return 0;
 281 }
 282
 283 /**
 284  * snd_unregister_device - unregister the device on the given card
 285  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
 286  * @card: the card instance
 287  * @dev: the device index
 288  *
 289  * Unregisters the device file already registered via
 290  * snd_register_device().
 291  *
 292  * Returns zero if sucecessful, or a negative error code on failure
 293  */
 294 int snd_unregister_device(int type, struct snd_card *card, int dev)
 295 {
 296         int cardnum, minor;
 297         struct snd_minor *mptr;
 298
 299         cardnum = card ? card->number : -1;
 300         down(&sound_mutex);
 301         for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
 302                 if ((mptr = snd_minors[minor]) != NULL &&
 303                     mptr->type == type &&
 304                     mptr->card == cardnum &&
 305                     mptr->device == dev)
 306                         break;
 307         if (minor == ARRAY_SIZE(snd_minors)) {
 308                 up(&sound_mutex);
 309                 return -EINVAL;
 310         }
 311
 312         if (mptr->type != SNDRV_DEVICE_TYPE_CONTROL ||
 313             mptr->card >= cards_limit)                  /* created in sound.c */
 314                 devfs_remove("snd/%s", mptr->name);
 315         class_device_destroy(sound_class, MKDEV(major, minor));
 316
 317         snd_minors[minor] = NULL;
 318         up(&sound_mutex);
 319         kfree(mptr);
 320         return 0;
 321 }
 322
 323 #ifdef CONFIG_PROC_FS
 324 /*
 325  *  INFO PART
 326  */
 327
 328 static struct snd_info_entry *snd_minor_info_entry = NULL;
 329
 330 static const char *snd_device_type_name(int type)
 331 {
 332         switch (type) {
 333         case SNDRV_DEVICE_TYPE_CONTROL:
 334                 return "control";
 335         case SNDRV_DEVICE_TYPE_HWDEP:
 336                 return "hardware dependent";
 337         case SNDRV_DEVICE_TYPE_RAWMIDI:
 338                 return "raw midi";
 339         case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
 340                 return "digital audio playback";
 341         case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
 342                 return "digital audio capture";
 343         case SNDRV_DEVICE_TYPE_SEQUENCER:
 344                 return "sequencer";
 345         case SNDRV_DEVICE_TYPE_TIMER:
 346                 return "timer";
 347         default:
 348                 return "?";
 349         }
 350 }
 351
 352 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 353 {
 354         int minor;
 355         struct snd_minor *mptr;
 356
 357         down(&sound_mutex);
 358         for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
 359                 if (!(mptr = snd_minors[minor]))
 360                         continue;
 361                 if (mptr->card >= 0) {
 362                         if (mptr->device >= 0)
 363                                 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
 364                                             minor, mptr->card, mptr->device,
 365                                             snd_device_type_name(mptr->type));
 366                         else
 367                                 snd_iprintf(buffer, "%3i: [%2i]   : %s\n",
 368                                             minor, mptr->card,
 369                                             snd_device_type_name(mptr->type));
 370                 } else
 371                         snd_iprintf(buffer, "%3i:        : %s\n", minor,
 372                                     snd_device_type_name(mptr->type));
 373         }
 374         up(&sound_mutex);
 375 }
 376
 377 int __init snd_minor_info_init(void)
 378 {
 379         struct snd_info_entry *entry;
 380
 381         entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
 382         if (entry) {
 383                 entry->c.text.read_size = PAGE_SIZE;
 384                 entry->c.text.read = snd_minor_info_read;
 385                 if (snd_info_register(entry) < 0) {
 386                         snd_info_free_entry(entry);
 387                         entry = NULL;
 388                 }
 389         }
 390         snd_minor_info_entry = entry;
 391         return 0;
 392 }
 393
 394 int __exit snd_minor_info_done(void)
 395 {
 396         if (snd_minor_info_entry)
 397                 snd_info_unregister(snd_minor_info_entry);
 398         return 0;
 399 }
 400 #endif /* CONFIG_PROC_FS */
 401
 402 /*
 403  *  INIT PART
 404  */
 405
 406 static int __init alsa_sound_init(void)
 407 {
 408         short controlnum;
 409
 410         snd_major = major;
 411         snd_ecards_limit = cards_limit;
 412         devfs_mk_dir("snd");
 413         if (register_chrdev(major, "alsa", &snd_fops)) {
 414                 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
 415                 devfs_remove("snd");
 416                 return -EIO;
 417         }
 418         if (snd_info_init() < 0) {
 419                 unregister_chrdev(major, "alsa");
 420                 devfs_remove("snd");
 421                 return -ENOMEM;
 422         }
 423         snd_info_minor_register();
 424         for (controlnum = 0; controlnum < cards_limit; controlnum++)
 425                 devfs_mk_cdev(MKDEV(major, controlnum<<5), S_IFCHR | device_mode, "snd/controlC%d", controlnum);
 426 #ifndef MODULE
 427         printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
 428 #endif
 429         return 0;
 430 }
 431
 432 static void __exit alsa_sound_exit(void)
 433 {
 434         short controlnum;
 435
 436         for (controlnum = 0; controlnum < cards_limit; controlnum++)
 437                 devfs_remove("snd/controlC%d", controlnum);
 438
 439         snd_info_minor_unregister();
 440         snd_info_done();
 441         if (unregister_chrdev(major, "alsa") != 0)
 442                 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major);
 443         devfs_remove("snd");
 444 }
 445
 446 module_init(alsa_sound_init)
 447 module_exit(alsa_sound_exit)
 448
 449   /* sound.c */
 450 EXPORT_SYMBOL(snd_major);
 451 EXPORT_SYMBOL(snd_ecards_limit);
 452 #if defined(CONFIG_KMOD)
 453 EXPORT_SYMBOL(snd_request_card);
 454 #endif
 455 EXPORT_SYMBOL(snd_register_device);
 456 EXPORT_SYMBOL(snd_unregister_device);
 457 EXPORT_SYMBOL(snd_lookup_minor_data);
 458 #if defined(CONFIG_SND_OSSEMUL)
 459 EXPORT_SYMBOL(snd_register_oss_device);
 460 EXPORT_SYMBOL(snd_unregister_oss_device);
 461 EXPORT_SYMBOL(snd_lookup_oss_minor_data);
 462 #endif
 463   /* memory.c */
 464 EXPORT_SYMBOL(copy_to_user_fromio);
 465 EXPORT_SYMBOL(copy_from_user_toio);
 466   /* init.c */
 467 EXPORT_SYMBOL(snd_cards);
 468 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 469 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
 470 #endif
 471 EXPORT_SYMBOL(snd_card_new);
 472 EXPORT_SYMBOL(snd_card_disconnect);
 473 EXPORT_SYMBOL(snd_card_free);
 474 EXPORT_SYMBOL(snd_card_free_in_thread);
 475 EXPORT_SYMBOL(snd_card_register);
 476 EXPORT_SYMBOL(snd_component_add);
 477 EXPORT_SYMBOL(snd_card_file_add);
 478 EXPORT_SYMBOL(snd_card_file_remove);
 479 #ifdef CONFIG_PM
 480 EXPORT_SYMBOL(snd_power_wait);
 481 #endif
 482   /* device.c */
 483 EXPORT_SYMBOL(snd_device_new);
 484 EXPORT_SYMBOL(snd_device_register);
 485 EXPORT_SYMBOL(snd_device_free);
 486   /* isadma.c */
 487 #ifdef CONFIG_ISA_DMA_API
 488 EXPORT_SYMBOL(snd_dma_program);
 489 EXPORT_SYMBOL(snd_dma_disable);
 490 EXPORT_SYMBOL(snd_dma_pointer);
 491 #endif
 492   /* info.c */
 493 #ifdef CONFIG_PROC_FS
 494 EXPORT_SYMBOL(snd_seq_root);
 495 EXPORT_SYMBOL(snd_iprintf);
 496 EXPORT_SYMBOL(snd_info_get_line);
 497 EXPORT_SYMBOL(snd_info_get_str);
 498 EXPORT_SYMBOL(snd_info_create_module_entry);
 499 EXPORT_SYMBOL(snd_info_create_card_entry);
 500 EXPORT_SYMBOL(snd_info_free_entry);
 501 EXPORT_SYMBOL(snd_info_register);
 502 EXPORT_SYMBOL(snd_info_unregister);
 503 EXPORT_SYMBOL(snd_card_proc_new);
 504 #endif
 505   /* info_oss.c */
 506 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
 507 EXPORT_SYMBOL(snd_oss_info_register);
 508 #endif
 509   /* control.c */
 510 EXPORT_SYMBOL(snd_ctl_new);
 511 EXPORT_SYMBOL(snd_ctl_new1);
 512 EXPORT_SYMBOL(snd_ctl_free_one);
 513 EXPORT_SYMBOL(snd_ctl_add);
 514 EXPORT_SYMBOL(snd_ctl_remove);
 515 EXPORT_SYMBOL(snd_ctl_remove_id);
 516 EXPORT_SYMBOL(snd_ctl_rename_id);
 517 EXPORT_SYMBOL(snd_ctl_find_numid);
 518 EXPORT_SYMBOL(snd_ctl_find_id);
 519 EXPORT_SYMBOL(snd_ctl_notify);
 520 EXPORT_SYMBOL(snd_ctl_register_ioctl);
 521 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
 522 #ifdef CONFIG_COMPAT
 523 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
 524 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
 525 #endif
 526 EXPORT_SYMBOL(snd_ctl_elem_read);
 527 EXPORT_SYMBOL(snd_ctl_elem_write);
 528   /* misc.c */
 529 EXPORT_SYMBOL(release_and_free_resource);
 530 #ifdef CONFIG_SND_VERBOSE_PRINTK
 531 EXPORT_SYMBOL(snd_verbose_printk);
 532 #endif
 533 #if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_VERBOSE_PRINTK)
 534 EXPORT_SYMBOL(snd_verbose_printd);
 535 #endif