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