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