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