| 1 | /* |
| 2 | * Advanced Linux Sound Architecture |
| 3 | * Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/init.h> |
| 23 | #include <linux/slab.h> |
| 24 | #include <linux/time.h> |
| 25 | #include <linux/device.h> |
| 26 | #include <linux/module.h> |
| 27 | #include <sound/core.h> |
| 28 | #include <sound/minors.h> |
| 29 | #include <sound/info.h> |
| 30 | #include <sound/control.h> |
| 31 | #include <sound/initval.h> |
| 32 | #include <linux/kmod.h> |
| 33 | #include <linux/mutex.h> |
| 34 | |
| 35 | static int major = CONFIG_SND_MAJOR; |
| 36 | int snd_major; |
| 37 | EXPORT_SYMBOL(snd_major); |
| 38 | |
| 39 | static int cards_limit = 1; |
| 40 | |
| 41 | MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>"); |
| 42 | MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards."); |
| 43 | MODULE_LICENSE("GPL"); |
| 44 | module_param(major, int, 0444); |
| 45 | MODULE_PARM_DESC(major, "Major # for sound driver."); |
| 46 | module_param(cards_limit, int, 0444); |
| 47 | MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards."); |
| 48 | MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR); |
| 49 | |
| 50 | /* this one holds the actual max. card number currently available. |
| 51 | * as default, it's identical with cards_limit option. when more |
| 52 | * modules are loaded manually, this limit number increases, too. |
| 53 | */ |
| 54 | int snd_ecards_limit; |
| 55 | EXPORT_SYMBOL(snd_ecards_limit); |
| 56 | |
| 57 | static struct snd_minor *snd_minors[SNDRV_OS_MINORS]; |
| 58 | static DEFINE_MUTEX(sound_mutex); |
| 59 | |
| 60 | #ifdef CONFIG_MODULES |
| 61 | |
| 62 | /** |
| 63 | * snd_request_card - try to load the card module |
| 64 | * @card: the card number |
| 65 | * |
| 66 | * Tries to load the module "snd-card-X" for the given card number |
| 67 | * via request_module. Returns immediately if already loaded. |
| 68 | */ |
| 69 | void snd_request_card(int card) |
| 70 | { |
| 71 | if (snd_card_locked(card)) |
| 72 | return; |
| 73 | if (card < 0 || card >= cards_limit) |
| 74 | return; |
| 75 | request_module("snd-card-%i", card); |
| 76 | } |
| 77 | |
| 78 | EXPORT_SYMBOL(snd_request_card); |
| 79 | |
| 80 | static void snd_request_other(int minor) |
| 81 | { |
| 82 | char *str; |
| 83 | |
| 84 | switch (minor) { |
| 85 | case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break; |
| 86 | case SNDRV_MINOR_TIMER: str = "snd-timer"; break; |
| 87 | default: return; |
| 88 | } |
| 89 | request_module(str); |
| 90 | } |
| 91 | |
| 92 | #endif /* modular kernel */ |
| 93 | |
| 94 | /** |
| 95 | * snd_lookup_minor_data - get user data of a registered device |
| 96 | * @minor: the minor number |
| 97 | * @type: device type (SNDRV_DEVICE_TYPE_XXX) |
| 98 | * |
| 99 | * Checks that a minor device with the specified type is registered, and returns |
| 100 | * its user data pointer. |
| 101 | * |
| 102 | * This function increments the reference counter of the card instance |
| 103 | * if an associated instance with the given minor number and type is found. |
| 104 | * The caller must call snd_card_unref() appropriately later. |
| 105 | */ |
| 106 | void *snd_lookup_minor_data(unsigned int minor, int type) |
| 107 | { |
| 108 | struct snd_minor *mreg; |
| 109 | void *private_data; |
| 110 | |
| 111 | if (minor >= ARRAY_SIZE(snd_minors)) |
| 112 | return NULL; |
| 113 | mutex_lock(&sound_mutex); |
| 114 | mreg = snd_minors[minor]; |
| 115 | if (mreg && mreg->type == type) { |
| 116 | private_data = mreg->private_data; |
| 117 | if (private_data && mreg->card_ptr) |
| 118 | atomic_inc(&mreg->card_ptr->refcount); |
| 119 | } else |
| 120 | private_data = NULL; |
| 121 | mutex_unlock(&sound_mutex); |
| 122 | return private_data; |
| 123 | } |
| 124 | |
| 125 | EXPORT_SYMBOL(snd_lookup_minor_data); |
| 126 | |
| 127 | #ifdef CONFIG_MODULES |
| 128 | static struct snd_minor *autoload_device(unsigned int minor) |
| 129 | { |
| 130 | int dev; |
| 131 | mutex_unlock(&sound_mutex); /* release lock temporarily */ |
| 132 | dev = SNDRV_MINOR_DEVICE(minor); |
| 133 | if (dev == SNDRV_MINOR_CONTROL) { |
| 134 | /* /dev/aloadC? */ |
| 135 | int card = SNDRV_MINOR_CARD(minor); |
| 136 | if (snd_cards[card] == NULL) |
| 137 | snd_request_card(card); |
| 138 | } else if (dev == SNDRV_MINOR_GLOBAL) { |
| 139 | /* /dev/aloadSEQ */ |
| 140 | snd_request_other(minor); |
| 141 | } |
| 142 | mutex_lock(&sound_mutex); /* reacuire lock */ |
| 143 | return snd_minors[minor]; |
| 144 | } |
| 145 | #else /* !CONFIG_MODULES */ |
| 146 | #define autoload_device(minor) NULL |
| 147 | #endif /* CONFIG_MODULES */ |
| 148 | |
| 149 | static int snd_open(struct inode *inode, struct file *file) |
| 150 | { |
| 151 | unsigned int minor = iminor(inode); |
| 152 | struct snd_minor *mptr = NULL; |
| 153 | const struct file_operations *old_fops; |
| 154 | int err = 0; |
| 155 | |
| 156 | if (minor >= ARRAY_SIZE(snd_minors)) |
| 157 | return -ENODEV; |
| 158 | mutex_lock(&sound_mutex); |
| 159 | mptr = snd_minors[minor]; |
| 160 | if (mptr == NULL) { |
| 161 | mptr = autoload_device(minor); |
| 162 | if (!mptr) { |
| 163 | mutex_unlock(&sound_mutex); |
| 164 | return -ENODEV; |
| 165 | } |
| 166 | } |
| 167 | old_fops = file->f_op; |
| 168 | file->f_op = fops_get(mptr->f_ops); |
| 169 | if (file->f_op == NULL) { |
| 170 | file->f_op = old_fops; |
| 171 | err = -ENODEV; |
| 172 | } |
| 173 | mutex_unlock(&sound_mutex); |
| 174 | if (err < 0) |
| 175 | return err; |
| 176 | |
| 177 | if (file->f_op->open) { |
| 178 | err = file->f_op->open(inode, file); |
| 179 | if (err) { |
| 180 | fops_put(file->f_op); |
| 181 | file->f_op = fops_get(old_fops); |
| 182 | } |
| 183 | } |
| 184 | fops_put(old_fops); |
| 185 | return err; |
| 186 | } |
| 187 | |
| 188 | static const struct file_operations snd_fops = |
| 189 | { |
| 190 | .owner = THIS_MODULE, |
| 191 | .open = snd_open, |
| 192 | .llseek = noop_llseek, |
| 193 | }; |
| 194 | |
| 195 | #ifdef CONFIG_SND_DYNAMIC_MINORS |
| 196 | static int snd_find_free_minor(int type) |
| 197 | { |
| 198 | int minor; |
| 199 | |
| 200 | /* static minors for module auto loading */ |
| 201 | if (type == SNDRV_DEVICE_TYPE_SEQUENCER) |
| 202 | return SNDRV_MINOR_SEQUENCER; |
| 203 | if (type == SNDRV_DEVICE_TYPE_TIMER) |
| 204 | return SNDRV_MINOR_TIMER; |
| 205 | |
| 206 | for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) { |
| 207 | /* skip static minors still used for module auto loading */ |
| 208 | if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL) |
| 209 | continue; |
| 210 | if (minor == SNDRV_MINOR_SEQUENCER || |
| 211 | minor == SNDRV_MINOR_TIMER) |
| 212 | continue; |
| 213 | if (!snd_minors[minor]) |
| 214 | return minor; |
| 215 | } |
| 216 | return -EBUSY; |
| 217 | } |
| 218 | #else |
| 219 | static int snd_kernel_minor(int type, struct snd_card *card, int dev) |
| 220 | { |
| 221 | int minor; |
| 222 | |
| 223 | switch (type) { |
| 224 | case SNDRV_DEVICE_TYPE_SEQUENCER: |
| 225 | case SNDRV_DEVICE_TYPE_TIMER: |
| 226 | minor = type; |
| 227 | break; |
| 228 | case SNDRV_DEVICE_TYPE_CONTROL: |
| 229 | if (snd_BUG_ON(!card)) |
| 230 | return -EINVAL; |
| 231 | minor = SNDRV_MINOR(card->number, type); |
| 232 | break; |
| 233 | case SNDRV_DEVICE_TYPE_HWDEP: |
| 234 | case SNDRV_DEVICE_TYPE_RAWMIDI: |
| 235 | case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: |
| 236 | case SNDRV_DEVICE_TYPE_PCM_CAPTURE: |
| 237 | case SNDRV_DEVICE_TYPE_COMPRESS: |
| 238 | if (snd_BUG_ON(!card)) |
| 239 | return -EINVAL; |
| 240 | minor = SNDRV_MINOR(card->number, type + dev); |
| 241 | break; |
| 242 | default: |
| 243 | return -EINVAL; |
| 244 | } |
| 245 | if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS)) |
| 246 | return -EINVAL; |
| 247 | return minor; |
| 248 | } |
| 249 | #endif |
| 250 | |
| 251 | /** |
| 252 | * snd_register_device_for_dev - Register the ALSA device file for the card |
| 253 | * @type: the device type, SNDRV_DEVICE_TYPE_XXX |
| 254 | * @card: the card instance |
| 255 | * @dev: the device index |
| 256 | * @f_ops: the file operations |
| 257 | * @private_data: user pointer for f_ops->open() |
| 258 | * @name: the device file name |
| 259 | * @device: the &struct device to link this new device to |
| 260 | * |
| 261 | * Registers an ALSA device file for the given card. |
| 262 | * The operators have to be set in reg parameter. |
| 263 | * |
| 264 | * Returns zero if successful, or a negative error code on failure. |
| 265 | */ |
| 266 | int snd_register_device_for_dev(int type, struct snd_card *card, int dev, |
| 267 | const struct file_operations *f_ops, |
| 268 | void *private_data, |
| 269 | const char *name, struct device *device) |
| 270 | { |
| 271 | int minor; |
| 272 | struct snd_minor *preg; |
| 273 | |
| 274 | if (snd_BUG_ON(!name)) |
| 275 | return -EINVAL; |
| 276 | preg = kmalloc(sizeof *preg, GFP_KERNEL); |
| 277 | if (preg == NULL) |
| 278 | return -ENOMEM; |
| 279 | preg->type = type; |
| 280 | preg->card = card ? card->number : -1; |
| 281 | preg->device = dev; |
| 282 | preg->f_ops = f_ops; |
| 283 | preg->private_data = private_data; |
| 284 | preg->card_ptr = card; |
| 285 | mutex_lock(&sound_mutex); |
| 286 | #ifdef CONFIG_SND_DYNAMIC_MINORS |
| 287 | minor = snd_find_free_minor(type); |
| 288 | #else |
| 289 | minor = snd_kernel_minor(type, card, dev); |
| 290 | if (minor >= 0 && snd_minors[minor]) |
| 291 | minor = -EBUSY; |
| 292 | #endif |
| 293 | if (minor < 0) { |
| 294 | mutex_unlock(&sound_mutex); |
| 295 | kfree(preg); |
| 296 | return minor; |
| 297 | } |
| 298 | snd_minors[minor] = preg; |
| 299 | preg->dev = device_create(sound_class, device, MKDEV(major, minor), |
| 300 | private_data, "%s", name); |
| 301 | if (IS_ERR(preg->dev)) { |
| 302 | snd_minors[minor] = NULL; |
| 303 | mutex_unlock(&sound_mutex); |
| 304 | minor = PTR_ERR(preg->dev); |
| 305 | kfree(preg); |
| 306 | return minor; |
| 307 | } |
| 308 | |
| 309 | mutex_unlock(&sound_mutex); |
| 310 | return 0; |
| 311 | } |
| 312 | |
| 313 | EXPORT_SYMBOL(snd_register_device_for_dev); |
| 314 | |
| 315 | /* find the matching minor record |
| 316 | * return the index of snd_minor, or -1 if not found |
| 317 | */ |
| 318 | static int find_snd_minor(int type, struct snd_card *card, int dev) |
| 319 | { |
| 320 | int cardnum, minor; |
| 321 | struct snd_minor *mptr; |
| 322 | |
| 323 | cardnum = card ? card->number : -1; |
| 324 | for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) |
| 325 | if ((mptr = snd_minors[minor]) != NULL && |
| 326 | mptr->type == type && |
| 327 | mptr->card == cardnum && |
| 328 | mptr->device == dev) |
| 329 | return minor; |
| 330 | return -1; |
| 331 | } |
| 332 | |
| 333 | /** |
| 334 | * snd_unregister_device - unregister the device on the given card |
| 335 | * @type: the device type, SNDRV_DEVICE_TYPE_XXX |
| 336 | * @card: the card instance |
| 337 | * @dev: the device index |
| 338 | * |
| 339 | * Unregisters the device file already registered via |
| 340 | * snd_register_device(). |
| 341 | * |
| 342 | * Returns zero if sucecessful, or a negative error code on failure |
| 343 | */ |
| 344 | int snd_unregister_device(int type, struct snd_card *card, int dev) |
| 345 | { |
| 346 | int minor; |
| 347 | |
| 348 | mutex_lock(&sound_mutex); |
| 349 | minor = find_snd_minor(type, card, dev); |
| 350 | if (minor < 0) { |
| 351 | mutex_unlock(&sound_mutex); |
| 352 | return -EINVAL; |
| 353 | } |
| 354 | |
| 355 | device_destroy(sound_class, MKDEV(major, minor)); |
| 356 | |
| 357 | kfree(snd_minors[minor]); |
| 358 | snd_minors[minor] = NULL; |
| 359 | mutex_unlock(&sound_mutex); |
| 360 | return 0; |
| 361 | } |
| 362 | |
| 363 | EXPORT_SYMBOL(snd_unregister_device); |
| 364 | |
| 365 | int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev, |
| 366 | struct device_attribute *attr) |
| 367 | { |
| 368 | int minor, ret = -EINVAL; |
| 369 | struct device *d; |
| 370 | |
| 371 | mutex_lock(&sound_mutex); |
| 372 | minor = find_snd_minor(type, card, dev); |
| 373 | if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL) |
| 374 | ret = device_create_file(d, attr); |
| 375 | mutex_unlock(&sound_mutex); |
| 376 | return ret; |
| 377 | |
| 378 | } |
| 379 | |
| 380 | EXPORT_SYMBOL(snd_add_device_sysfs_file); |
| 381 | |
| 382 | #ifdef CONFIG_PROC_FS |
| 383 | /* |
| 384 | * INFO PART |
| 385 | */ |
| 386 | |
| 387 | static struct snd_info_entry *snd_minor_info_entry; |
| 388 | |
| 389 | static const char *snd_device_type_name(int type) |
| 390 | { |
| 391 | switch (type) { |
| 392 | case SNDRV_DEVICE_TYPE_CONTROL: |
| 393 | return "control"; |
| 394 | case SNDRV_DEVICE_TYPE_HWDEP: |
| 395 | return "hardware dependent"; |
| 396 | case SNDRV_DEVICE_TYPE_RAWMIDI: |
| 397 | return "raw midi"; |
| 398 | case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: |
| 399 | return "digital audio playback"; |
| 400 | case SNDRV_DEVICE_TYPE_PCM_CAPTURE: |
| 401 | return "digital audio capture"; |
| 402 | case SNDRV_DEVICE_TYPE_SEQUENCER: |
| 403 | return "sequencer"; |
| 404 | case SNDRV_DEVICE_TYPE_TIMER: |
| 405 | return "timer"; |
| 406 | default: |
| 407 | return "?"; |
| 408 | } |
| 409 | } |
| 410 | |
| 411 | static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) |
| 412 | { |
| 413 | int minor; |
| 414 | struct snd_minor *mptr; |
| 415 | |
| 416 | mutex_lock(&sound_mutex); |
| 417 | for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) { |
| 418 | if (!(mptr = snd_minors[minor])) |
| 419 | continue; |
| 420 | if (mptr->card >= 0) { |
| 421 | if (mptr->device >= 0) |
| 422 | snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n", |
| 423 | minor, mptr->card, mptr->device, |
| 424 | snd_device_type_name(mptr->type)); |
| 425 | else |
| 426 | snd_iprintf(buffer, "%3i: [%2i] : %s\n", |
| 427 | minor, mptr->card, |
| 428 | snd_device_type_name(mptr->type)); |
| 429 | } else |
| 430 | snd_iprintf(buffer, "%3i: : %s\n", minor, |
| 431 | snd_device_type_name(mptr->type)); |
| 432 | } |
| 433 | mutex_unlock(&sound_mutex); |
| 434 | } |
| 435 | |
| 436 | int __init snd_minor_info_init(void) |
| 437 | { |
| 438 | struct snd_info_entry *entry; |
| 439 | |
| 440 | entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL); |
| 441 | if (entry) { |
| 442 | entry->c.text.read = snd_minor_info_read; |
| 443 | if (snd_info_register(entry) < 0) { |
| 444 | snd_info_free_entry(entry); |
| 445 | entry = NULL; |
| 446 | } |
| 447 | } |
| 448 | snd_minor_info_entry = entry; |
| 449 | return 0; |
| 450 | } |
| 451 | |
| 452 | int __exit snd_minor_info_done(void) |
| 453 | { |
| 454 | snd_info_free_entry(snd_minor_info_entry); |
| 455 | return 0; |
| 456 | } |
| 457 | #endif /* CONFIG_PROC_FS */ |
| 458 | |
| 459 | /* |
| 460 | * INIT PART |
| 461 | */ |
| 462 | |
| 463 | static int __init alsa_sound_init(void) |
| 464 | { |
| 465 | snd_major = major; |
| 466 | snd_ecards_limit = cards_limit; |
| 467 | if (register_chrdev(major, "alsa", &snd_fops)) { |
| 468 | snd_printk(KERN_ERR "unable to register native major device number %d\n", major); |
| 469 | return -EIO; |
| 470 | } |
| 471 | if (snd_info_init() < 0) { |
| 472 | unregister_chrdev(major, "alsa"); |
| 473 | return -ENOMEM; |
| 474 | } |
| 475 | snd_info_minor_register(); |
| 476 | #ifndef MODULE |
| 477 | printk(KERN_INFO "Advanced Linux Sound Architecture Driver Initialized.\n"); |
| 478 | #endif |
| 479 | return 0; |
| 480 | } |
| 481 | |
| 482 | static void __exit alsa_sound_exit(void) |
| 483 | { |
| 484 | snd_info_minor_unregister(); |
| 485 | snd_info_done(); |
| 486 | unregister_chrdev(major, "alsa"); |
| 487 | } |
| 488 | |
| 489 | subsys_initcall(alsa_sound_init); |
| 490 | module_exit(alsa_sound_exit); |