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 extern struct class *sound_class; 65 66 67 #ifdef CONFIG_KMOD 68 69 /** 70 * snd_request_card - try to load the card module 71 * @card: the card number 72 * 73 * Tries to load the module "snd-card-X" for the given card number 74 * via KMOD. Returns immediately if already loaded. 75 */ 76 void snd_request_card(int card) 77 { 78 if (! current->fs->root) 79 return; 80 if (snd_card_locked(card)) 81 return; 82 if (card < 0 || card >= cards_limit) 83 return; 84 request_module("snd-card-%i", card); 85 } 86 87 EXPORT_SYMBOL(snd_request_card); 88 89 static void snd_request_other(int minor) 90 { 91 char *str; 92 93 if (! current->fs->root) 94 return; 95 switch (minor) { 96 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break; 97 case SNDRV_MINOR_TIMER: str = "snd-timer"; break; 98 default: return; 99 } 100 request_module(str); 101 } 102 103 #endif /* request_module support */ 104 105 /** 106 * snd_lookup_minor_data - get user data of a registered device 107 * @minor: the minor number 108 * @type: device type (SNDRV_DEVICE_TYPE_XXX) 109 * 110 * Checks that a minor device with the specified type is registered, and returns 111 * its user data pointer. 112 */ 113 void *snd_lookup_minor_data(unsigned int minor, int type) 114 { 115 struct snd_minor *mreg; 116 void *private_data; 117 118 if (minor >= ARRAY_SIZE(snd_minors)) 119 return NULL; 120 mutex_lock(&sound_mutex); 121 mreg = snd_minors[minor]; 122 if (mreg && mreg->type == type) 123 private_data = mreg->private_data; 124 else 125 private_data = NULL; 126 mutex_unlock(&sound_mutex); 127 return private_data; 128 } 129 130 EXPORT_SYMBOL(snd_lookup_minor_data); 131 132 static int snd_open(struct inode *inode, struct file *file) 133 { 134 unsigned int minor = iminor(inode); 135 struct snd_minor *mptr = NULL; 136 const struct file_operations *old_fops; 137 int err = 0; 138 139 if (minor >= ARRAY_SIZE(snd_minors)) 140 return -ENODEV; 141 mptr = snd_minors[minor]; 142 if (mptr == NULL) { 143 #ifdef CONFIG_KMOD 144 int dev = SNDRV_MINOR_DEVICE(minor); 145 if (dev == SNDRV_MINOR_CONTROL) { 146 /* /dev/aloadC? */ 147 int card = SNDRV_MINOR_CARD(minor); 148 if (snd_cards[card] == NULL) 149 snd_request_card(card); 150 } else if (dev == SNDRV_MINOR_GLOBAL) { 151 /* /dev/aloadSEQ */ 152 snd_request_other(minor); 153 } 154 #ifndef CONFIG_SND_DYNAMIC_MINORS 155 /* /dev/snd/{controlC?,seq} */ 156 mptr = snd_minors[minor]; 157 if (mptr == NULL) 158 #endif 159 #endif 160 return -ENODEV; 161 } 162 old_fops = file->f_op; 163 file->f_op = fops_get(mptr->f_ops); 164 if (file->f_op->open) 165 err = file->f_op->open(inode, file); 166 if (err) { 167 fops_put(file->f_op); 168 file->f_op = fops_get(old_fops); 169 } 170 fops_put(old_fops); 171 return err; 172 } 173 174 static struct file_operations snd_fops = 175 { 176 .owner = THIS_MODULE, 177 .open = snd_open 178 }; 179 180 #ifdef CONFIG_SND_DYNAMIC_MINORS 181 static int snd_find_free_minor(void) 182 { 183 int minor; 184 185 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) { 186 /* skip minors still used statically for autoloading devices */ 187 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL || 188 minor == SNDRV_MINOR_SEQUENCER) 189 continue; 190 if (!snd_minors[minor]) 191 return minor; 192 } 193 return -EBUSY; 194 } 195 #else 196 static int snd_kernel_minor(int type, struct snd_card *card, int dev) 197 { 198 int minor; 199 200 switch (type) { 201 case SNDRV_DEVICE_TYPE_SEQUENCER: 202 case SNDRV_DEVICE_TYPE_TIMER: 203 minor = type; 204 break; 205 case SNDRV_DEVICE_TYPE_CONTROL: 206 snd_assert(card != NULL, return -EINVAL); 207 minor = SNDRV_MINOR(card->number, type); 208 break; 209 case SNDRV_DEVICE_TYPE_HWDEP: 210 case SNDRV_DEVICE_TYPE_RAWMIDI: 211 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: 212 case SNDRV_DEVICE_TYPE_PCM_CAPTURE: 213 snd_assert(card != NULL, return -EINVAL); 214 minor = SNDRV_MINOR(card->number, type + dev); 215 break; 216 default: 217 return -EINVAL; 218 } 219 snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL); 220 return minor; 221 } 222 #endif 223 224 /** 225 * snd_register_device - Register the ALSA device file for the card 226 * @type: the device type, SNDRV_DEVICE_TYPE_XXX 227 * @card: the card instance 228 * @dev: the device index 229 * @f_ops: the file operations 230 * @private_data: user pointer for f_ops->open() 231 * @name: the device file name 232 * 233 * Registers an ALSA device file for the given card. 234 * The operators have to be set in reg parameter. 235 * 236 * Retrurns zero if successful, or a negative error code on failure. 237 */ 238 int snd_register_device(int type, struct snd_card *card, int dev, 239 const struct file_operations *f_ops, void *private_data, 240 const char *name) 241 { 242 int minor; 243 struct snd_minor *preg; 244 struct device *device = NULL; 245 246 snd_assert(name, return -EINVAL); 247 preg = kmalloc(sizeof *preg, GFP_KERNEL); 248 if (preg == NULL) 249 return -ENOMEM; 250 preg->type = type; 251 preg->card = card ? card->number : -1; 252 preg->device = dev; 253 preg->f_ops = f_ops; 254 preg->private_data = private_data; 255 mutex_lock(&sound_mutex); 256 #ifdef CONFIG_SND_DYNAMIC_MINORS 257 minor = snd_find_free_minor(); 258 #else 259 minor = snd_kernel_minor(type, card, dev); 260 if (minor >= 0 && snd_minors[minor]) 261 minor = -EBUSY; 262 #endif 263 if (minor < 0) { 264 mutex_unlock(&sound_mutex); 265 kfree(preg); 266 return minor; 267 } 268 snd_minors[minor] = preg; 269 if (card) 270 device = card->dev; 271 class_device_create(sound_class, NULL, MKDEV(major, minor), device, "%s", name); 272 273 mutex_unlock(&sound_mutex); 274 return 0; 275 } 276 277 EXPORT_SYMBOL(snd_register_device); 278 279 /** 280 * snd_unregister_device - unregister the device on the given card 281 * @type: the device type, SNDRV_DEVICE_TYPE_XXX 282 * @card: the card instance 283 * @dev: the device index 284 * 285 * Unregisters the device file already registered via 286 * snd_register_device(). 287 * 288 * Returns zero if sucecessful, or a negative error code on failure 289 */ 290 int snd_unregister_device(int type, struct snd_card *card, int dev) 291 { 292 int cardnum, minor; 293 struct snd_minor *mptr; 294 295 cardnum = card ? card->number : -1; 296 mutex_lock(&sound_mutex); 297 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) 298 if ((mptr = snd_minors[minor]) != NULL && 299 mptr->type == type && 300 mptr->card == cardnum && 301 mptr->device == dev) 302 break; 303 if (minor == ARRAY_SIZE(snd_minors)) { 304 mutex_unlock(&sound_mutex); 305 return -EINVAL; 306 } 307 308 class_device_destroy(sound_class, MKDEV(major, minor)); 309 310 snd_minors[minor] = NULL; 311 mutex_unlock(&sound_mutex); 312 kfree(mptr); 313 return 0; 314 } 315 316 EXPORT_SYMBOL(snd_unregister_device); 317 318 #ifdef CONFIG_PROC_FS 319 /* 320 * INFO PART 321 */ 322 323 static struct snd_info_entry *snd_minor_info_entry; 324 325 static const char *snd_device_type_name(int type) 326 { 327 switch (type) { 328 case SNDRV_DEVICE_TYPE_CONTROL: 329 return "control"; 330 case SNDRV_DEVICE_TYPE_HWDEP: 331 return "hardware dependent"; 332 case SNDRV_DEVICE_TYPE_RAWMIDI: 333 return "raw midi"; 334 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK: 335 return "digital audio playback"; 336 case SNDRV_DEVICE_TYPE_PCM_CAPTURE: 337 return "digital audio capture"; 338 case SNDRV_DEVICE_TYPE_SEQUENCER: 339 return "sequencer"; 340 case SNDRV_DEVICE_TYPE_TIMER: 341 return "timer"; 342 default: 343 return "?"; 344 } 345 } 346 347 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) 348 { 349 int minor; 350 struct snd_minor *mptr; 351 352 mutex_lock(&sound_mutex); 353 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) { 354 if (!(mptr = snd_minors[minor])) 355 continue; 356 if (mptr->card >= 0) { 357 if (mptr->device >= 0) 358 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n", 359 minor, mptr->card, mptr->device, 360 snd_device_type_name(mptr->type)); 361 else 362 snd_iprintf(buffer, "%3i: [%2i] : %s\n", 363 minor, mptr->card, 364 snd_device_type_name(mptr->type)); 365 } else 366 snd_iprintf(buffer, "%3i: : %s\n", minor, 367 snd_device_type_name(mptr->type)); 368 } 369 mutex_unlock(&sound_mutex); 370 } 371 372 int __init snd_minor_info_init(void) 373 { 374 struct snd_info_entry *entry; 375 376 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL); 377 if (entry) { 378 entry->c.text.read = snd_minor_info_read; 379 if (snd_info_register(entry) < 0) { 380 snd_info_free_entry(entry); 381 entry = NULL; 382 } 383 } 384 snd_minor_info_entry = entry; 385 return 0; 386 } 387 388 int __exit snd_minor_info_done(void) 389 { 390 if (snd_minor_info_entry) 391 snd_info_unregister(snd_minor_info_entry); 392 return 0; 393 } 394 #endif /* CONFIG_PROC_FS */ 395 396 /* 397 * INIT PART 398 */ 399 400 static int __init alsa_sound_init(void) 401 { 402 snd_major = major; 403 snd_ecards_limit = cards_limit; 404 if (register_chrdev(major, "alsa", &snd_fops)) { 405 snd_printk(KERN_ERR "unable to register native major device number %d\n", major); 406 return -EIO; 407 } 408 if (snd_info_init() < 0) { 409 unregister_chrdev(major, "alsa"); 410 return -ENOMEM; 411 } 412 snd_info_minor_register(); 413 #ifndef MODULE 414 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"); 415 #endif 416 return 0; 417 } 418 419 static void __exit alsa_sound_exit(void) 420 { 421 snd_info_minor_unregister(); 422 snd_info_done(); 423 if (unregister_chrdev(major, "alsa") != 0) 424 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major); 425 } 426 427 module_init(alsa_sound_init) 428 module_exit(alsa_sound_exit) 429