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 EXPORT_SYMBOL(snd_major);
  43
  44 static int cards_limit = 1;
  45 static int device_mode = S_IFCHR | S_IRUGO | S_IWUGO;
  46
  47 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
  48 MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
  49 MODULE_LICENSE("GPL");
  50 module_param(major, int, 0444);
  51 MODULE_PARM_DESC(major, "Major # for sound driver.");
  52 module_param(cards_limit, int, 0444);
  53 MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
  54 #ifdef CONFIG_DEVFS_FS
  55 module_param(device_mode, int, 0444);
  56 MODULE_PARM_DESC(device_mode, "Device file permission mask for devfs.");
  57 #endif
  58 MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
  59
  60 /* this one holds the actual max. card number currently available.
  61  * as default, it's identical with cards_limit option.  when more
  62  * modules are loaded manually, this limit number increases, too.
  63  */
  64 int snd_ecards_limit;
  65 EXPORT_SYMBOL(snd_ecards_limit);
  66
  67 static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
  68 static DEFINE_MUTEX(sound_mutex);
  69
  70 extern struct class *sound_class;
  71
  72
  73 #ifdef CONFIG_KMOD
  74
  75 /**
  76  * snd_request_card - try to load the card module
  77  * @card: the card number
  78  *
  79  * Tries to load the module "snd-card-X" for the given card number
  80  * via KMOD.  Returns immediately if already loaded.
  81  */
  82 void snd_request_card(int card)
  83 {
  84         if (! current->fs->root)
  85                 return;
  86         if (snd_card_locked(card))
  87                 return;
  88         if (card < 0 || card >= cards_limit)
  89                 return;
  90         request_module("snd-card-%i", card);
  91 }
  92
  93 EXPORT_SYMBOL(snd_request_card);
  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 EXPORT_SYMBOL(snd_lookup_minor_data);
 137
 138 static int snd_open(struct inode *inode, struct file *file)
 139 {
 140         unsigned int minor = iminor(inode);
 141         struct snd_minor *mptr = NULL;
 142         const struct file_operations *old_fops;
 143         int err = 0;
 144
 145         if (minor >= ARRAY_SIZE(snd_minors))
 146                 return -ENODEV;
 147         mptr = snd_minors[minor];
 148         if (mptr == NULL) {
 149 #ifdef CONFIG_KMOD
 150                 int dev = SNDRV_MINOR_DEVICE(minor);
 151                 if (dev == SNDRV_MINOR_CONTROL) {
 152                         /* /dev/aloadC? */
 153                         int card = SNDRV_MINOR_CARD(minor);
 154                         if (snd_cards[card] == NULL)
 155                                 snd_request_card(card);
 156                 } else if (dev == SNDRV_MINOR_GLOBAL) {
 157                         /* /dev/aloadSEQ */
 158                         snd_request_other(minor);
 159                 }
 160 #ifndef CONFIG_SND_DYNAMIC_MINORS
 161                 /* /dev/snd/{controlC?,seq} */
 162                 mptr = snd_minors[minor];
 163                 if (mptr == NULL)
 164 #endif
 165 #endif
 166                         return -ENODEV;
 167         }
 168         old_fops = file->f_op;
 169         file->f_op = fops_get(mptr->f_ops);
 170         if (file->f_op->open)
 171                 err = file->f_op->open(inode, file);
 172         if (err) {
 173                 fops_put(file->f_op);
 174                 file->f_op = fops_get(old_fops);
 175         }
 176         fops_put(old_fops);
 177         return err;
 178 }
 179
 180 static struct file_operations snd_fops =
 181 {
 182         .owner =        THIS_MODULE,
 183         .open =         snd_open
 184 };
 185
 186 #ifdef CONFIG_SND_DYNAMIC_MINORS
 187 static int snd_find_free_minor(void)
 188 {
 189         int minor;
 190
 191         for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
 192                 /* skip minors still used statically for autoloading devices */
 193                 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
 194                     minor == SNDRV_MINOR_SEQUENCER)
 195                         continue;
 196                 if (!snd_minors[minor])
 197                         return minor;
 198         }
 199         return -EBUSY;
 200 }
 201 #else
 202 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
 203 {
 204         int minor;
 205
 206         switch (type) {
 207         case SNDRV_DEVICE_TYPE_SEQUENCER:
 208         case SNDRV_DEVICE_TYPE_TIMER:
 209                 minor = type;
 210                 break;
 211         case SNDRV_DEVICE_TYPE_CONTROL:
 212                 snd_assert(card != NULL, return -EINVAL);
 213                 minor = SNDRV_MINOR(card->number, type);
 214                 break;
 215         case SNDRV_DEVICE_TYPE_HWDEP:
 216         case SNDRV_DEVICE_TYPE_RAWMIDI:
 217         case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
 218         case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
 219                 snd_assert(card != NULL, return -EINVAL);
 220                 minor = SNDRV_MINOR(card->number, type + dev);
 221                 break;
 222         default:
 223                 return -EINVAL;
 224         }
 225         snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
 226         return minor;
 227 }
 228 #endif
 229
 230 /**
 231  * snd_register_device - Register the ALSA device file for the card
 232  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
 233  * @card: the card instance
 234  * @dev: the device index
 235  * @f_ops: the file operations
 236  * @private_data: user pointer for f_ops->open()
 237  * @name: the device file name
 238  *
 239  * Registers an ALSA device file for the given card.
 240  * The operators have to be set in reg parameter.
 241  *
 242  * Retrurns zero if successful, or a negative error code on failure.
 243  */
 244 int snd_register_device(int type, struct snd_card *card, int dev,
 245                         const struct file_operations *f_ops, void *private_data,
 246                         const char *name)
 247 {
 248         int minor;
 249         struct snd_minor *preg;
 250         struct device *device = NULL;
 251
 252         snd_assert(name, return -EINVAL);
 253         preg = kmalloc(sizeof(struct snd_minor) + strlen(name) + 1, GFP_KERNEL);
 254         if (preg == NULL)
 255                 return -ENOMEM;
 256         preg->type = type;
 257         preg->card = card ? card->number : -1;
 258         preg->device = dev;
 259         preg->f_ops = f_ops;
 260         preg->private_data = private_data;
 261         strcpy(preg->name, name);
 262         mutex_lock(&sound_mutex);
 263 #ifdef CONFIG_SND_DYNAMIC_MINORS
 264         minor = snd_find_free_minor();
 265 #else
 266         minor = snd_kernel_minor(type, card, dev);
 267         if (minor >= 0 && snd_minors[minor])
 268                 minor = -EBUSY;
 269 #endif
 270         if (minor < 0) {
 271                 mutex_unlock(&sound_mutex);
 272                 kfree(preg);
 273                 return minor;
 274         }
 275         snd_minors[minor] = preg;
 276         if (type != SNDRV_DEVICE_TYPE_CONTROL || preg->card >= cards_limit)
 277                 devfs_mk_cdev(MKDEV(major, minor), S_IFCHR | device_mode, "snd/%s", name);
 278         if (card)
 279                 device = card->dev;
 280         class_device_create(sound_class, NULL, MKDEV(major, minor), device, "%s", name);
 281
 282         mutex_unlock(&sound_mutex);
 283         return 0;
 284 }
 285
 286 EXPORT_SYMBOL(snd_register_device);
 287
 288 /**
 289  * snd_unregister_device - unregister the device on the given card
 290  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
 291  * @card: the card instance
 292  * @dev: the device index
 293  *
 294  * Unregisters the device file already registered via
 295  * snd_register_device().
 296  *
 297  * Returns zero if sucecessful, or a negative error code on failure
 298  */
 299 int snd_unregister_device(int type, struct snd_card *card, int dev)
 300 {
 301         int cardnum, minor;
 302         struct snd_minor *mptr;
 303
 304         cardnum = card ? card->number : -1;
 305         mutex_lock(&sound_mutex);
 306         for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
 307                 if ((mptr = snd_minors[minor]) != NULL &&
 308                     mptr->type == type &&
 309                     mptr->card == cardnum &&
 310                     mptr->device == dev)
 311                         break;
 312         if (minor == ARRAY_SIZE(snd_minors)) {
 313                 mutex_unlock(&sound_mutex);
 314                 return -EINVAL;
 315         }
 316
 317         if (mptr->type != SNDRV_DEVICE_TYPE_CONTROL ||
 318             mptr->card >= cards_limit)                  /* created in sound.c */
 319                 devfs_remove("snd/%s", mptr->name);
 320         class_device_destroy(sound_class, MKDEV(major, minor));
 321
 322         snd_minors[minor] = NULL;
 323         mutex_unlock(&sound_mutex);
 324         kfree(mptr);
 325         return 0;
 326 }
 327
 328 EXPORT_SYMBOL(snd_unregister_device);
 329
 330 #ifdef CONFIG_PROC_FS
 331 /*
 332  *  INFO PART
 333  */
 334
 335 static struct snd_info_entry *snd_minor_info_entry;
 336
 337 static const char *snd_device_type_name(int type)
 338 {
 339         switch (type) {
 340         case SNDRV_DEVICE_TYPE_CONTROL:
 341                 return "control";
 342         case SNDRV_DEVICE_TYPE_HWDEP:
 343                 return "hardware dependent";
 344         case SNDRV_DEVICE_TYPE_RAWMIDI:
 345                 return "raw midi";
 346         case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
 347                 return "digital audio playback";
 348         case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
 349                 return "digital audio capture";
 350         case SNDRV_DEVICE_TYPE_SEQUENCER:
 351                 return "sequencer";
 352         case SNDRV_DEVICE_TYPE_TIMER:
 353                 return "timer";
 354         default:
 355                 return "?";
 356         }
 357 }
 358
 359 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
 360 {
 361         int minor;
 362         struct snd_minor *mptr;
 363
 364         mutex_lock(&sound_mutex);
 365         for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
 366                 if (!(mptr = snd_minors[minor]))
 367                         continue;
 368                 if (mptr->card >= 0) {
 369                         if (mptr->device >= 0)
 370                                 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
 371                                             minor, mptr->card, mptr->device,
 372                                             snd_device_type_name(mptr->type));
 373                         else
 374                                 snd_iprintf(buffer, "%3i: [%2i]   : %s\n",
 375                                             minor, mptr->card,
 376                                             snd_device_type_name(mptr->type));
 377                 } else
 378                         snd_iprintf(buffer, "%3i:        : %s\n", minor,
 379                                     snd_device_type_name(mptr->type));
 380         }
 381         mutex_unlock(&sound_mutex);
 382 }
 383
 384 int __init snd_minor_info_init(void)
 385 {
 386         struct snd_info_entry *entry;
 387
 388         entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
 389         if (entry) {
 390                 entry->c.text.read = snd_minor_info_read;
 391                 if (snd_info_register(entry) < 0) {
 392                         snd_info_free_entry(entry);
 393                         entry = NULL;
 394                 }
 395         }
 396         snd_minor_info_entry = entry;
 397         return 0;
 398 }
 399
 400 int __exit snd_minor_info_done(void)
 401 {
 402         if (snd_minor_info_entry)
 403                 snd_info_unregister(snd_minor_info_entry);
 404         return 0;
 405 }
 406 #endif /* CONFIG_PROC_FS */
 407
 408 /*
 409  *  INIT PART
 410  */
 411
 412 static int __init alsa_sound_init(void)
 413 {
 414         short controlnum;
 415
 416         snd_major = major;
 417         snd_ecards_limit = cards_limit;
 418         devfs_mk_dir("snd");
 419         if (register_chrdev(major, "alsa", &snd_fops)) {
 420                 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
 421                 devfs_remove("snd");
 422                 return -EIO;
 423         }
 424         if (snd_info_init() < 0) {
 425                 unregister_chrdev(major, "alsa");
 426                 devfs_remove("snd");
 427                 return -ENOMEM;
 428         }
 429         snd_info_minor_register();
 430         for (controlnum = 0; controlnum < cards_limit; controlnum++)
 431                 devfs_mk_cdev(MKDEV(major, controlnum<<5), S_IFCHR | device_mode, "snd/controlC%d", controlnum);
 432 #ifndef MODULE
 433         printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
 434 #endif
 435         return 0;
 436 }
 437
 438 static void __exit alsa_sound_exit(void)
 439 {
 440         short controlnum;
 441
 442         for (controlnum = 0; controlnum < cards_limit; controlnum++)
 443                 devfs_remove("snd/controlC%d", controlnum);
 444
 445         snd_info_minor_unregister();
 446         snd_info_done();
 447         if (unregister_chrdev(major, "alsa") != 0)
 448                 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major);
 449         devfs_remove("snd");
 450 }
 451
 452 module_init(alsa_sound_init)
 453 module_exit(alsa_sound_exit)