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 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 (preg->dev) 270 dev_set_drvdata(preg->dev, private_data); 271 272 mutex_unlock(&sound_mutex); 273 return 0; 274 } 275 276 EXPORT_SYMBOL(snd_register_device_for_dev); 277 278 /* find the matching minor record 279 * return the index of snd_minor, or -1 if not found 280 */ 281 static int find_snd_minor(int type, struct snd_card *card, int dev) 282 { 283 int cardnum, minor; 284 struct snd_minor *mptr; 285 286 cardnum = card ? card->number : -1; 287 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) 288 if ((mptr = snd_minors[minor]) != NULL && 289 mptr->type == type && 290 mptr->card == cardnum && 291 mptr->device == dev) 292 return minor; 293 return -1; 294 } 295 296 /** 297 * snd_unregister_device - unregister the device on the given card 298 * @type: the device type, SNDRV_DEVICE_TYPE_XXX 299 * @card: the card instance 300 * @dev: the device index 301 * 302 * Unregisters the device file already registered via 303 * snd_register_device(). 304 * 305 * Returns zero if sucecessful, or a negative error code on failure 306 */ 307 int snd_unregister_device(int type, struct snd_card *card, int dev) 308 { 309 int minor; 310 311 mutex_lock(&sound_mutex); 312 minor = find_snd_minor(type, card, dev); 313 if (minor < 0) { 314 mutex_unlock(&sound_mutex); 315 return -EINVAL; 316 } 317 318 device_destroy(sound_class, MKDEV(major, minor)); 319 320 kfree(snd_minors[minor]); 321 snd_minors[minor] = NULL; 322 mutex_unlock(&sound_mutex); 323 return 0; 324 } 325 326 EXPORT_SYMBOL(snd_unregister_device); 327 328 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev, 329 struct device_attribute *attr) 330 { 331 int minor, ret = -EINVAL; 332 struct device *d; 333 334 mutex_lock(&sound_mutex); 335 minor = find_snd_minor(type, card, dev); 336 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL) 337 ret = device_create_file(d, attr); 338 mutex_unlock(&sound_mutex); 339 return ret; 340 341 } 342 343 EXPORT_SYMBOL(snd_add_device_sysfs_file); 344 345 #ifdef CONFIG_PROC_FS 346 /* 347 * INFO PART 348 */ 349 350 static struct snd_info_entry *snd_minor_info_entry; 351 352 static const char *snd_device_type_name(int type) 353 { 354 switch (type) { 355 case SNDRV_DEVICE_TYPE_CONTROL: 356 return "control"; 357 case SNDRV_DEVICE_TYPE_HWDEP: 358 return "hardware dependent"; 359 case SNDRV_DEVICE_TYPE_RAWMIDI: 360 return "raw midi"; 361 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: 362 return "digital audio playback"; 363 case SNDRV_DEVICE_TYPE_PCM_CAPTURE: 364 return "digital audio capture"; 365 case SNDRV_DEVICE_TYPE_SEQUENCER: 366 return "sequencer"; 367 case SNDRV_DEVICE_TYPE_TIMER: 368 return "timer"; 369 default: 370 return "?"; 371 } 372 } 373 374 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) 375 { 376 int minor; 377 struct snd_minor *mptr; 378 379 mutex_lock(&sound_mutex); 380 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) { 381 if (!(mptr = snd_minors[minor])) 382 continue; 383 if (mptr->card >= 0) { 384 if (mptr->device >= 0) 385 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n", 386 minor, mptr->card, mptr->device, 387 snd_device_type_name(mptr->type)); 388 else 389 snd_iprintf(buffer, "%3i: [%2i] : %s\n", 390 minor, mptr->card, 391 snd_device_type_name(mptr->type)); 392 } else 393 snd_iprintf(buffer, "%3i: : %s\n", minor, 394 snd_device_type_name(mptr->type)); 395 } 396 mutex_unlock(&sound_mutex); 397 } 398 399 int __init snd_minor_info_init(void) 400 { 401 struct snd_info_entry *entry; 402 403 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL); 404 if (entry) { 405 entry->c.text.read = snd_minor_info_read; 406 if (snd_info_register(entry) < 0) { 407 snd_info_free_entry(entry); 408 entry = NULL; 409 } 410 } 411 snd_minor_info_entry = entry; 412 return 0; 413 } 414 415 int __exit snd_minor_info_done(void) 416 { 417 snd_info_free_entry(snd_minor_info_entry); 418 return 0; 419 } 420 #endif /* CONFIG_PROC_FS */ 421 422 /* 423 * INIT PART 424 */ 425 426 static int __init alsa_sound_init(void) 427 { 428 snd_major = major; 429 snd_ecards_limit = cards_limit; 430 if (register_chrdev(major, "alsa", &snd_fops)) { 431 snd_printk(KERN_ERR "unable to register native major device number %d\n", major); 432 return -EIO; 433 } 434 if (snd_info_init() < 0) { 435 unregister_chrdev(major, "alsa"); 436 return -ENOMEM; 437 } 438 snd_info_minor_register(); 439 #ifndef MODULE 440 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"); 441 #endif 442 return 0; 443 } 444 445 static void __exit alsa_sound_exit(void) 446 { 447 snd_info_minor_unregister(); 448 snd_info_done(); 449 if (unregister_chrdev(major, "alsa") != 0) 450 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major); 451 } 452 453 module_init(alsa_sound_init) 454 module_exit(alsa_sound_exit) 455