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 list_head snd_minors_hash[SNDRV_CARDS];
  63
  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 static struct snd_minor *snd_minor_search(int minor)
 111 {
 112         struct list_head *list;
 113         struct snd_minor *mptr;
 114
 115         list_for_each(list, &snd_minors_hash[SNDRV_MINOR_CARD(minor)]) {
 116                 mptr = list_entry(list, struct snd_minor, list);
 117                 if (mptr->number == minor)
 118                         return mptr;
 119         }
 120         return NULL;
 121 }
 122
 123 static int snd_open(struct inode *inode, struct file *file)
 124 {
 125         int minor = iminor(inode);
 126         int card = SNDRV_MINOR_CARD(minor);
 127         int dev = SNDRV_MINOR_DEVICE(minor);
 128         struct snd_minor *mptr = NULL;
 129         struct file_operations *old_fops;
 130         int err = 0;
 131
 132         if (dev != SNDRV_MINOR_GLOBAL) {
 133                 if (snd_cards[card] == NULL) {
 134 #ifdef CONFIG_KMOD
 135                         snd_request_card(card);
 136                         if (snd_cards[card] == NULL)
 137 #endif
 138                                 return -ENODEV;
 139                 }
 140         } else {
 141 #ifdef CONFIG_KMOD
 142                 if ((mptr = snd_minor_search(minor)) == NULL)
 143                         snd_request_other(minor);
 144 #endif
 145         }
 146         if (mptr == NULL && (mptr = snd_minor_search(minor)) == NULL)
 147                 return -ENODEV;
 148         old_fops = file->f_op;
 149         file->f_op = fops_get(mptr->f_ops);
 150         if (file->f_op->open)
 151                 err = file->f_op->open(inode, file);
 152         if (err) {
 153                 fops_put(file->f_op);
 154                 file->f_op = fops_get(old_fops);
 155         }
 156         fops_put(old_fops);
 157         return err;
 158 }
 159
 160 static struct file_operations snd_fops =
 161 {
 162         .owner =        THIS_MODULE,
 163         .open =         snd_open
 164 };
 165
 166 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
 167 {
 168         int minor;
 169
 170         switch (type) {
 171         case SNDRV_DEVICE_TYPE_SEQUENCER:
 172         case SNDRV_DEVICE_TYPE_TIMER:
 173                 minor = type;
 174                 break;
 175         case SNDRV_DEVICE_TYPE_CONTROL:
 176                 snd_assert(card != NULL, return -EINVAL);
 177                 minor = SNDRV_MINOR(card->number, type);
 178                 break;
 179         case SNDRV_DEVICE_TYPE_HWDEP:
 180         case SNDRV_DEVICE_TYPE_RAWMIDI:
 181         case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
 182         case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
 183                 snd_assert(card != NULL, return -EINVAL);
 184                 minor = SNDRV_MINOR(card->number, type + dev);
 185                 break;
 186         default:
 187                 return -EINVAL;
 188         }
 189         snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
 190         return minor;
 191 }
 192
 193 /**
 194  * snd_register_device - Register the ALSA device file for the card
 195  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
 196  * @card: the card instance
 197  * @dev: the device index
 198  * @f_ops: the file operations
 199  * @name: the device file name
 200  *
 201  * Registers an ALSA device file for the given card.
 202  * The operators have to be set in reg parameter.
 203  *
 204  * Retrurns zero if successful, or a negative error code on failure.
 205  */
 206 int snd_register_device(int type, struct snd_card *card, int dev,
 207                         struct file_operations *f_ops, const char *name)
 208 {
 209         int minor = snd_kernel_minor(type, card, dev);
 210         struct snd_minor *preg;
 211         struct device *device = NULL;
 212
 213         if (minor < 0)
 214                 return minor;
 215         snd_assert(name, return -EINVAL);
 216         preg = kzalloc(sizeof(struct snd_minor) + strlen(name) + 1, GFP_KERNEL);
 217         if (preg == NULL)
 218                 return -ENOMEM;
 219         preg->number = minor;
 220         preg->type = type;
 221         preg->device = dev;
 222         preg->f_ops = f_ops;
 223         strcpy(preg->name, name);
 224         down(&sound_mutex);
 225         if (snd_minor_search(minor)) {
 226                 up(&sound_mutex);
 227                 kfree(preg);
 228                 return -EBUSY;
 229         }
 230         list_add_tail(&preg->list, &snd_minors_hash[SNDRV_MINOR_CARD(minor)]);
 231         if (strncmp(name, "controlC", 8) || card->number >= cards_limit)
 232                 devfs_mk_cdev(MKDEV(major, minor), S_IFCHR | device_mode, "snd/%s", name);
 233         if (card)
 234                 device = card->dev;
 235         class_device_create(sound_class, NULL, MKDEV(major, minor), device, "%s", name);
 236
 237         up(&sound_mutex);
 238         return 0;
 239 }
 240
 241 /**
 242  * snd_unregister_device - unregister the device on the given card
 243  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
 244  * @card: the card instance
 245  * @dev: the device index
 246  *
 247  * Unregisters the device file already registered via
 248  * snd_register_device().
 249  *
 250  * Returns zero if sucecessful, or a negative error code on failure
 251  */
 252 int snd_unregister_device(int type, struct snd_card *card, int dev)
 253 {
 254         int minor = snd_kernel_minor(type, card, dev);
 255         struct snd_minor *mptr;
 256
 257         if (minor < 0)
 258                 return minor;
 259         down(&sound_mutex);
 260         if ((mptr = snd_minor_search(minor)) == NULL) {
 261                 up(&sound_mutex);
 262                 return -EINVAL;
 263         }
 264
 265         if (strncmp(mptr->name, "controlC", 8) || card->number >= cards_limit) /* created in sound.c */
 266                 devfs_remove("snd/%s", mptr->name);
 267         class_device_destroy(sound_class, MKDEV(major, minor));
 268
 269         list_del(&mptr->list);
 270         up(&sound_mutex);
 271         kfree(mptr);
 272         return 0;
 273 }
 274
 275 /*
 276  *  INFO PART
 277  */
 278
 279 static struct snd_info_entry *snd_minor_info_entry = NULL;
 280
 281 static const char *snd_device_type_name(int type)
 282 {
 283         switch (type) {
 284         case SNDRV_DEVICE_TYPE_CONTROL:
 285                 return "control";
 286         case SNDRV_DEVICE_TYPE_HWDEP:
 287                 return "hardware dependent";
 288         case SNDRV_DEVICE_TYPE_RAWMIDI:
 289                 return "raw midi";
 290         case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
 291                 return "digital audio playback";
 292         case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
 293                 return "digital audio capture";
 294         case SNDRV_DEVICE_TYPE_SEQUENCER:
 295                 return "sequencer";
 296         case SNDRV_DEVICE_TYPE_TIMER:
 297                 return "timer";
 298         default:
 299                 return "?";
 300         }
 301 }
 302
 303 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 304 {
 305         int card, device;
 306         struct list_head *list;
 307         struct snd_minor *mptr;
 308
 309         down(&sound_mutex);
 310         for (card = 0; card < SNDRV_CARDS; card++) {
 311                 list_for_each(list, &snd_minors_hash[card]) {
 312                         mptr = list_entry(list, struct snd_minor, list);
 313                         if (SNDRV_MINOR_DEVICE(mptr->number) != SNDRV_MINOR_GLOBAL) {
 314                                 if ((device = mptr->device) >= 0)
 315                                         snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", mptr->number, card, device, snd_device_type_name(mptr->type));
 316                                 else
 317                                         snd_iprintf(buffer, "%3i: [%i]   : %s\n", mptr->number, card, snd_device_type_name(mptr->type));
 318                         } else {
 319                                 snd_iprintf(buffer, "%3i:       : %s\n", mptr->number, snd_device_type_name(mptr->type));
 320                         }
 321                 }
 322         }
 323         up(&sound_mutex);
 324 }
 325
 326 int __init snd_minor_info_init(void)
 327 {
 328         struct snd_info_entry *entry;
 329
 330         entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
 331         if (entry) {
 332                 entry->c.text.read_size = PAGE_SIZE;
 333                 entry->c.text.read = snd_minor_info_read;
 334                 if (snd_info_register(entry) < 0) {
 335                         snd_info_free_entry(entry);
 336                         entry = NULL;
 337                 }
 338         }
 339         snd_minor_info_entry = entry;
 340         return 0;
 341 }
 342
 343 int __exit snd_minor_info_done(void)
 344 {
 345         if (snd_minor_info_entry)
 346                 snd_info_unregister(snd_minor_info_entry);
 347         return 0;
 348 }
 349
 350 /*
 351  *  INIT PART
 352  */
 353
 354 static int __init alsa_sound_init(void)
 355 {
 356         short controlnum;
 357         int err;
 358         int card;
 359
 360         snd_major = major;
 361         snd_ecards_limit = cards_limit;
 362         for (card = 0; card < SNDRV_CARDS; card++)
 363                 INIT_LIST_HEAD(&snd_minors_hash[card]);
 364         if ((err = snd_oss_init_module()) < 0)
 365                 return err;
 366         devfs_mk_dir("snd");
 367         if (register_chrdev(major, "alsa", &snd_fops)) {
 368                 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
 369                 devfs_remove("snd");
 370                 return -EIO;
 371         }
 372         if (snd_info_init() < 0) {
 373                 unregister_chrdev(major, "alsa");
 374                 devfs_remove("snd");
 375                 return -ENOMEM;
 376         }
 377         snd_info_minor_register();
 378         for (controlnum = 0; controlnum < cards_limit; controlnum++)
 379                 devfs_mk_cdev(MKDEV(major, controlnum<<5), S_IFCHR | device_mode, "snd/controlC%d", controlnum);
 380 #ifndef MODULE
 381         printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
 382 #endif
 383         return 0;
 384 }
 385
 386 static void __exit alsa_sound_exit(void)
 387 {
 388         short controlnum;
 389
 390         for (controlnum = 0; controlnum < cards_limit; controlnum++)
 391                 devfs_remove("snd/controlC%d", controlnum);
 392
 393         snd_info_minor_unregister();
 394         snd_info_done();
 395         if (unregister_chrdev(major, "alsa") != 0)
 396                 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major);
 397         devfs_remove("snd");
 398 }
 399
 400 module_init(alsa_sound_init)
 401 module_exit(alsa_sound_exit)
 402
 403   /* sound.c */
 404 EXPORT_SYMBOL(snd_major);
 405 EXPORT_SYMBOL(snd_ecards_limit);
 406 #if defined(CONFIG_KMOD)
 407 EXPORT_SYMBOL(snd_request_card);
 408 #endif
 409 EXPORT_SYMBOL(snd_register_device);
 410 EXPORT_SYMBOL(snd_unregister_device);
 411 #if defined(CONFIG_SND_OSSEMUL)
 412 EXPORT_SYMBOL(snd_register_oss_device);
 413 EXPORT_SYMBOL(snd_unregister_oss_device);
 414 #endif
 415   /* memory.c */
 416 EXPORT_SYMBOL(copy_to_user_fromio);
 417 EXPORT_SYMBOL(copy_from_user_toio);
 418   /* init.c */
 419 EXPORT_SYMBOL(snd_cards);
 420 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
 421 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
 422 #endif
 423 EXPORT_SYMBOL(snd_card_new);
 424 EXPORT_SYMBOL(snd_card_disconnect);
 425 EXPORT_SYMBOL(snd_card_free);
 426 EXPORT_SYMBOL(snd_card_free_in_thread);
 427 EXPORT_SYMBOL(snd_card_register);
 428 EXPORT_SYMBOL(snd_component_add);
 429 EXPORT_SYMBOL(snd_card_file_add);
 430 EXPORT_SYMBOL(snd_card_file_remove);
 431 #ifdef CONFIG_PM
 432 EXPORT_SYMBOL(snd_power_wait);
 433 #endif
 434   /* device.c */
 435 EXPORT_SYMBOL(snd_device_new);
 436 EXPORT_SYMBOL(snd_device_register);
 437 EXPORT_SYMBOL(snd_device_free);
 438   /* isadma.c */
 439 #ifdef CONFIG_ISA_DMA_API
 440 EXPORT_SYMBOL(snd_dma_program);
 441 EXPORT_SYMBOL(snd_dma_disable);
 442 EXPORT_SYMBOL(snd_dma_pointer);
 443 #endif
 444   /* info.c */
 445 #ifdef CONFIG_PROC_FS
 446 EXPORT_SYMBOL(snd_seq_root);
 447 EXPORT_SYMBOL(snd_iprintf);
 448 EXPORT_SYMBOL(snd_info_get_line);
 449 EXPORT_SYMBOL(snd_info_get_str);
 450 EXPORT_SYMBOL(snd_info_create_module_entry);
 451 EXPORT_SYMBOL(snd_info_create_card_entry);
 452 EXPORT_SYMBOL(snd_info_free_entry);
 453 EXPORT_SYMBOL(snd_info_register);
 454 EXPORT_SYMBOL(snd_info_unregister);
 455 EXPORT_SYMBOL(snd_card_proc_new);
 456 #endif
 457   /* info_oss.c */
 458 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
 459 EXPORT_SYMBOL(snd_oss_info_register);
 460 #endif
 461   /* control.c */
 462 EXPORT_SYMBOL(snd_ctl_new);
 463 EXPORT_SYMBOL(snd_ctl_new1);
 464 EXPORT_SYMBOL(snd_ctl_free_one);
 465 EXPORT_SYMBOL(snd_ctl_add);
 466 EXPORT_SYMBOL(snd_ctl_remove);
 467 EXPORT_SYMBOL(snd_ctl_remove_id);
 468 EXPORT_SYMBOL(snd_ctl_rename_id);
 469 EXPORT_SYMBOL(snd_ctl_find_numid);
 470 EXPORT_SYMBOL(snd_ctl_find_id);
 471 EXPORT_SYMBOL(snd_ctl_notify);
 472 EXPORT_SYMBOL(snd_ctl_register_ioctl);
 473 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
 474 #ifdef CONFIG_COMPAT
 475 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
 476 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
 477 #endif
 478 EXPORT_SYMBOL(snd_ctl_elem_read);
 479 EXPORT_SYMBOL(snd_ctl_elem_write);
 480   /* misc.c */
 481 EXPORT_SYMBOL(release_and_free_resource);
 482 #ifdef CONFIG_SND_VERBOSE_PRINTK
 483 EXPORT_SYMBOL(snd_verbose_printk);
 484 #endif
 485 #if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_VERBOSE_PRINTK)
 486 EXPORT_SYMBOL(snd_verbose_printd);
 487 #endif