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