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