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