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 <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/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_KMOD 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 KMOD. Returns immediately if already loaded. 72 */ 73 void snd_request_card(int card) 74 { 75 if (! current->fs->root) 76 return; 77 if (snd_card_locked(card)) 78 return; 79 if (card < 0 || card >= cards_limit) 80 return; 81 request_module("snd-card-%i", card); 82 } 83 84 EXPORT_SYMBOL(snd_request_card); 85 86 static void snd_request_other(int minor) 87 { 88 char *str; 89 90 if (! current->fs->root) 91 return; 92 switch (minor) { 93 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break; 94 case SNDRV_MINOR_TIMER: str = "snd-timer"; break; 95 default: return; 96 } 97 request_module(str); 98 } 99 100 #endif /* request_module support */ 101 102 /** 103 * snd_lookup_minor_data - get user data of a registered device 104 * @minor: the minor number 105 * @type: device type (SNDRV_DEVICE_TYPE_XXX) 106 * 107 * Checks that a minor device with the specified type is registered, and returns 108 * its user data pointer. 109 */ 110 void *snd_lookup_minor_data(unsigned int minor, int type) 111 { 112 struct snd_minor *mreg; 113 void *private_data; 114 115 if (minor >= ARRAY_SIZE(snd_minors)) 116 return NULL; 117 mutex_lock(&sound_mutex); 118 mreg = snd_minors[minor]; 119 if (mreg && mreg->type == type) 120 private_data = mreg->private_data; 121 else 122 private_data = NULL; 123 mutex_unlock(&sound_mutex); 124 return private_data; 125 } 126 127 EXPORT_SYMBOL(snd_lookup_minor_data); 128 129 static int snd_open(struct inode *inode, struct file *file) 130 { 131 unsigned int minor = iminor(inode); 132 struct snd_minor *mptr = NULL; 133 const struct file_operations *old_fops; 134 int err = 0; 135 136 if (minor >= ARRAY_SIZE(snd_minors)) 137 return -ENODEV; 138 mptr = snd_minors[minor]; 139 if (mptr == NULL) { 140 #ifdef CONFIG_KMOD 141 int dev = SNDRV_MINOR_DEVICE(minor); 142 if (dev == SNDRV_MINOR_CONTROL) { 143 /* /dev/aloadC? */ 144 int card = SNDRV_MINOR_CARD(minor); 145 if (snd_cards[card] == NULL) 146 snd_request_card(card); 147 } else if (dev == SNDRV_MINOR_GLOBAL) { 148 /* /dev/aloadSEQ */ 149 snd_request_other(minor); 150 } 151 #ifndef CONFIG_SND_DYNAMIC_MINORS 152 /* /dev/snd/{controlC?,seq} */ 153 mptr = snd_minors[minor]; 154 if (mptr == NULL) 155 #endif 156 #endif 157 return -ENODEV; 158 } 159 old_fops = file->f_op; 160 file->f_op = fops_get(mptr->f_ops); 161 if (file->f_op->open) 162 err = file->f_op->open(inode, file); 163 if (err) { 164 fops_put(file->f_op); 165 file->f_op = fops_get(old_fops); 166 } 167 fops_put(old_fops); 168 return err; 169 } 170 171 static const struct file_operations snd_fops = 172 { 173 .owner = THIS_MODULE, 174 .open = snd_open 175 }; 176 177 #ifdef CONFIG_SND_DYNAMIC_MINORS 178 static int snd_find_free_minor(void) 179 { 180 int minor; 181 182 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) { 183 /* skip minors still used statically for autoloading devices */ 184 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL || 185 minor == SNDRV_MINOR_SEQUENCER) 186 continue; 187 if (!snd_minors[minor]) 188 return minor; 189 } 190 return -EBUSY; 191 } 192 #else 193 static int snd_kernel_minor(int type, struct snd_card *card, int dev) 194 { 195 int minor; 196 197 switch (type) { 198 case SNDRV_DEVICE_TYPE_SEQUENCER: 199 case SNDRV_DEVICE_TYPE_TIMER: 200 minor = type; 201 break; 202 case SNDRV_DEVICE_TYPE_CONTROL: 203 snd_assert(card != NULL, return -EINVAL); 204 minor = SNDRV_MINOR(card->number, type); 205 break; 206 case SNDRV_DEVICE_TYPE_HWDEP: 207 case SNDRV_DEVICE_TYPE_RAWMIDI: 208 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: 209 case SNDRV_DEVICE_TYPE_PCM_CAPTURE: 210 snd_assert(card != NULL, return -EINVAL); 211 minor = SNDRV_MINOR(card->number, type + dev); 212 break; 213 default: 214 return -EINVAL; 215 } 216 snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL); 217 return minor; 218 } 219 #endif 220 221 /** 222 * snd_register_device_for_dev - Register the ALSA device file for the card 223 * @type: the device type, SNDRV_DEVICE_TYPE_XXX 224 * @card: the card instance 225 * @dev: the device index 226 * @f_ops: the file operations 227 * @private_data: user pointer for f_ops->open() 228 * @name: the device file name 229 * @device: the &struct device to link this new device to 230 * 231 * Registers an ALSA device file for the given card. 232 * The operators have to be set in reg parameter. 233 * 234 * Returns zero if successful, or a negative error code on failure. 235 */ 236 int snd_register_device_for_dev(int type, struct snd_card *card, int dev, 237 const struct file_operations *f_ops, 238 void *private_data, 239 const char *name, struct device *device) 240 { 241 int minor; 242 struct snd_minor *preg; 243 244 snd_assert(name, return -EINVAL); 245 preg = kmalloc(sizeof *preg, GFP_KERNEL); 246 if (preg == NULL) 247 return -ENOMEM; 248 preg->type = type; 249 preg->card = card ? card->number : -1; 250 preg->device = dev; 251 preg->f_ops = f_ops; 252 preg->private_data = private_data; 253 mutex_lock(&sound_mutex); 254 #ifdef CONFIG_SND_DYNAMIC_MINORS 255 minor = snd_find_free_minor(); 256 #else 257 minor = snd_kernel_minor(type, card, dev); 258 if (minor >= 0 && snd_minors[minor]) 259 minor = -EBUSY; 260 #endif 261 if (minor < 0) { 262 mutex_unlock(&sound_mutex); 263 kfree(preg); 264 return minor; 265 } 266 snd_minors[minor] = preg; 267 preg->dev = device_create(sound_class, device, MKDEV(major, minor), 268 "%s", name); 269 if (IS_ERR(preg->dev)) { 270 snd_minors[minor] = NULL; 271 mutex_unlock(&sound_mutex); 272 minor = PTR_ERR(preg->dev); 273 kfree(preg); 274 return minor; 275 } 276 277 if (preg->dev) 278 dev_set_drvdata(preg->dev, private_data); 279 280 mutex_unlock(&sound_mutex); 281 return 0; 282 } 283 284 EXPORT_SYMBOL(snd_register_device_for_dev); 285 286 /* find the matching minor record 287 * return the index of snd_minor, or -1 if not found 288 */ 289 static int find_snd_minor(int type, struct snd_card *card, int dev) 290 { 291 int cardnum, minor; 292 struct snd_minor *mptr; 293 294 cardnum = card ? card->number : -1; 295 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) 296 if ((mptr = snd_minors[minor]) != NULL && 297 mptr->type == type && 298 mptr->card == cardnum && 299 mptr->device == dev) 300 return minor; 301 return -1; 302 } 303 304 /** 305 * snd_unregister_device - unregister the device on the given card 306 * @type: the device type, SNDRV_DEVICE_TYPE_XXX 307 * @card: the card instance 308 * @dev: the device index 309 * 310 * Unregisters the device file already registered via 311 * snd_register_device(). 312 * 313 * Returns zero if sucecessful, or a negative error code on failure 314 */ 315 int snd_unregister_device(int type, struct snd_card *card, int dev) 316 { 317 int minor; 318 319 mutex_lock(&sound_mutex); 320 minor = find_snd_minor(type, card, dev); 321 if (minor < 0) { 322 mutex_unlock(&sound_mutex); 323 return -EINVAL; 324 } 325 326 device_destroy(sound_class, MKDEV(major, minor)); 327 328 kfree(snd_minors[minor]); 329 snd_minors[minor] = NULL; 330 mutex_unlock(&sound_mutex); 331 return 0; 332 } 333 334 EXPORT_SYMBOL(snd_unregister_device); 335 336 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev, 337 struct device_attribute *attr) 338 { 339 int minor, ret = -EINVAL; 340 struct device *d; 341 342 mutex_lock(&sound_mutex); 343 minor = find_snd_minor(type, card, dev); 344 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL) 345 ret = device_create_file(d, attr); 346 mutex_unlock(&sound_mutex); 347 return ret; 348 349 } 350 351 EXPORT_SYMBOL(snd_add_device_sysfs_file); 352 353 #ifdef CONFIG_PROC_FS 354 /* 355 * INFO PART 356 */ 357 358 static struct snd_info_entry *snd_minor_info_entry; 359 360 static const char *snd_device_type_name(int type) 361 { 362 switch (type) { 363 case SNDRV_DEVICE_TYPE_CONTROL: 364 return "control"; 365 case SNDRV_DEVICE_TYPE_HWDEP: 366 return "hardware dependent"; 367 case SNDRV_DEVICE_TYPE_RAWMIDI: 368 return "raw midi"; 369 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: 370 return "digital audio playback"; 371 case SNDRV_DEVICE_TYPE_PCM_CAPTURE: 372 return "digital audio capture"; 373 case SNDRV_DEVICE_TYPE_SEQUENCER: 374 return "sequencer"; 375 case SNDRV_DEVICE_TYPE_TIMER: 376 return "timer"; 377 default: 378 return "?"; 379 } 380 } 381 382 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) 383 { 384 int minor; 385 struct snd_minor *mptr; 386 387 mutex_lock(&sound_mutex); 388 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) { 389 if (!(mptr = snd_minors[minor])) 390 continue; 391 if (mptr->card >= 0) { 392 if (mptr->device >= 0) 393 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n", 394 minor, mptr->card, mptr->device, 395 snd_device_type_name(mptr->type)); 396 else 397 snd_iprintf(buffer, "%3i: [%2i] : %s\n", 398 minor, mptr->card, 399 snd_device_type_name(mptr->type)); 400 } else 401 snd_iprintf(buffer, "%3i: : %s\n", minor, 402 snd_device_type_name(mptr->type)); 403 } 404 mutex_unlock(&sound_mutex); 405 } 406 407 int __init snd_minor_info_init(void) 408 { 409 struct snd_info_entry *entry; 410 411 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL); 412 if (entry) { 413 entry->c.text.read = snd_minor_info_read; 414 if (snd_info_register(entry) < 0) { 415 snd_info_free_entry(entry); 416 entry = NULL; 417 } 418 } 419 snd_minor_info_entry = entry; 420 return 0; 421 } 422 423 int __exit snd_minor_info_done(void) 424 { 425 snd_info_free_entry(snd_minor_info_entry); 426 return 0; 427 } 428 #endif /* CONFIG_PROC_FS */ 429 430 /* 431 * INIT PART 432 */ 433 434 static int __init alsa_sound_init(void) 435 { 436 snd_major = major; 437 snd_ecards_limit = cards_limit; 438 if (register_chrdev(major, "alsa", &snd_fops)) { 439 snd_printk(KERN_ERR "unable to register native major device number %d\n", major); 440 return -EIO; 441 } 442 if (snd_info_init() < 0) { 443 unregister_chrdev(major, "alsa"); 444 return -ENOMEM; 445 } 446 snd_info_minor_register(); 447 #ifndef MODULE 448 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"); 449 #endif 450 return 0; 451 } 452 453 static void __exit alsa_sound_exit(void) 454 { 455 snd_info_minor_unregister(); 456 snd_info_done(); 457 unregister_chrdev(major, "alsa"); 458 } 459 460 module_init(alsa_sound_init) 461 module_exit(alsa_sound_exit) 462