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