1 /* 2 * Advanced Linux Sound Architecture 3 * Copyright (c) by Jaroslav Kysela <perex@suse.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@suse.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 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 - 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 * 230 * Registers an ALSA device file for the given card. 231 * The operators have to be set in reg parameter. 232 * 233 * Retrurns zero if successful, or a negative error code on failure. 234 */ 235 int snd_register_device(int type, struct snd_card *card, int dev, 236 const struct file_operations *f_ops, void *private_data, 237 const char *name) 238 { 239 int minor; 240 struct snd_minor *preg; 241 struct device *device = snd_card_get_device_link(card); 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 (preg->dev) 269 dev_set_drvdata(preg->dev, private_data); 270 271 mutex_unlock(&sound_mutex); 272 return 0; 273 } 274 275 EXPORT_SYMBOL(snd_register_device); 276 277 /* find the matching minor record 278 * return the index of snd_minor, or -1 if not found 279 */ 280 static int find_snd_minor(int type, struct snd_card *card, int dev) 281 { 282 int cardnum, minor; 283 struct snd_minor *mptr; 284 285 cardnum = card ? card->number : -1; 286 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) 287 if ((mptr = snd_minors[minor]) != NULL && 288 mptr->type == type && 289 mptr->card == cardnum && 290 mptr->device == dev) 291 return minor; 292 return -1; 293 } 294 295 /** 296 * snd_unregister_device - unregister the device on the given card 297 * @type: the device type, SNDRV_DEVICE_TYPE_XXX 298 * @card: the card instance 299 * @dev: the device index 300 * 301 * Unregisters the device file already registered via 302 * snd_register_device(). 303 * 304 * Returns zero if sucecessful, or a negative error code on failure 305 */ 306 int snd_unregister_device(int type, struct snd_card *card, int dev) 307 { 308 int minor; 309 310 mutex_lock(&sound_mutex); 311 minor = find_snd_minor(type, card, dev); 312 if (minor < 0) { 313 mutex_unlock(&sound_mutex); 314 return -EINVAL; 315 } 316 317 device_destroy(sound_class, MKDEV(major, minor)); 318 319 kfree(snd_minors[minor]); 320 snd_minors[minor] = NULL; 321 mutex_unlock(&sound_mutex); 322 return 0; 323 } 324 325 EXPORT_SYMBOL(snd_unregister_device); 326 327 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev, 328 struct device_attribute *attr) 329 { 330 int minor, ret = -EINVAL; 331 struct device *d; 332 333 mutex_lock(&sound_mutex); 334 minor = find_snd_minor(type, card, dev); 335 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL) 336 ret = device_create_file(d, attr); 337 mutex_unlock(&sound_mutex); 338 return ret; 339 340 } 341 342 EXPORT_SYMBOL(snd_add_device_sysfs_file); 343 344 #ifdef CONFIG_PROC_FS 345 /* 346 * INFO PART 347 */ 348 349 static struct snd_info_entry *snd_minor_info_entry; 350 351 static const char *snd_device_type_name(int type) 352 { 353 switch (type) { 354 case SNDRV_DEVICE_TYPE_CONTROL: 355 return "control"; 356 case SNDRV_DEVICE_TYPE_HWDEP: 357 return "hardware dependent"; 358 case SNDRV_DEVICE_TYPE_RAWMIDI: 359 return "raw midi"; 360 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: 361 return "digital audio playback"; 362 case SNDRV_DEVICE_TYPE_PCM_CAPTURE: 363 return "digital audio capture"; 364 case SNDRV_DEVICE_TYPE_SEQUENCER: 365 return "sequencer"; 366 case SNDRV_DEVICE_TYPE_TIMER: 367 return "timer"; 368 default: 369 return "?"; 370 } 371 } 372 373 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) 374 { 375 int minor; 376 struct snd_minor *mptr; 377 378 mutex_lock(&sound_mutex); 379 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) { 380 if (!(mptr = snd_minors[minor])) 381 continue; 382 if (mptr->card >= 0) { 383 if (mptr->device >= 0) 384 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n", 385 minor, mptr->card, mptr->device, 386 snd_device_type_name(mptr->type)); 387 else 388 snd_iprintf(buffer, "%3i: [%2i] : %s\n", 389 minor, mptr->card, 390 snd_device_type_name(mptr->type)); 391 } else 392 snd_iprintf(buffer, "%3i: : %s\n", minor, 393 snd_device_type_name(mptr->type)); 394 } 395 mutex_unlock(&sound_mutex); 396 } 397 398 int __init snd_minor_info_init(void) 399 { 400 struct snd_info_entry *entry; 401 402 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL); 403 if (entry) { 404 entry->c.text.read = snd_minor_info_read; 405 if (snd_info_register(entry) < 0) { 406 snd_info_free_entry(entry); 407 entry = NULL; 408 } 409 } 410 snd_minor_info_entry = entry; 411 return 0; 412 } 413 414 int __exit snd_minor_info_done(void) 415 { 416 snd_info_free_entry(snd_minor_info_entry); 417 return 0; 418 } 419 #endif /* CONFIG_PROC_FS */ 420 421 /* 422 * INIT PART 423 */ 424 425 static int __init alsa_sound_init(void) 426 { 427 snd_major = major; 428 snd_ecards_limit = cards_limit; 429 if (register_chrdev(major, "alsa", &snd_fops)) { 430 snd_printk(KERN_ERR "unable to register native major device number %d\n", major); 431 return -EIO; 432 } 433 if (snd_info_init() < 0) { 434 unregister_chrdev(major, "alsa"); 435 return -ENOMEM; 436 } 437 snd_info_minor_register(); 438 #ifndef MODULE 439 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"); 440 #endif 441 return 0; 442 } 443 444 static void __exit alsa_sound_exit(void) 445 { 446 snd_info_minor_unregister(); 447 snd_info_done(); 448 if (unregister_chrdev(major, "alsa") != 0) 449 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major); 450 } 451 452 module_init(alsa_sound_init) 453 module_exit(alsa_sound_exit) 454