2 * Advanced Linux Sound Architecture
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/smp_lock.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>
37 static int major = CONFIG_SND_MAJOR;
39 EXPORT_SYMBOL(snd_major);
41 static int cards_limit = 1;
43 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
44 MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
45 MODULE_LICENSE("GPL");
46 module_param(major, int, 0444);
47 MODULE_PARM_DESC(major, "Major # for sound driver.");
48 module_param(cards_limit, int, 0444);
49 MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
50 MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
52 /* this one holds the actual max. card number currently available.
53 * as default, it's identical with cards_limit option. when more
54 * modules are loaded manually, this limit number increases, too.
57 EXPORT_SYMBOL(snd_ecards_limit);
59 static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
60 static DEFINE_MUTEX(sound_mutex);
65 * snd_request_card - try to load the card module
66 * @card: the card number
68 * Tries to load the module "snd-card-X" for the given card number
69 * via request_module. Returns immediately if already loaded.
71 void snd_request_card(int card)
73 if (snd_card_locked(card))
75 if (card < 0 || card >= cards_limit)
77 request_module("snd-card-%i", card);
80 EXPORT_SYMBOL(snd_request_card);
82 static void snd_request_other(int minor)
87 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
88 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
94 #endif /* modular kernel */
97 * snd_lookup_minor_data - get user data of a registered device
98 * @minor: the minor number
99 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
101 * Checks that a minor device with the specified type is registered, and returns
102 * its user data pointer.
104 void *snd_lookup_minor_data(unsigned int minor, int type)
106 struct snd_minor *mreg;
109 if (minor >= ARRAY_SIZE(snd_minors))
111 mutex_lock(&sound_mutex);
112 mreg = snd_minors[minor];
113 if (mreg && mreg->type == type)
114 private_data = mreg->private_data;
117 mutex_unlock(&sound_mutex);
121 EXPORT_SYMBOL(snd_lookup_minor_data);
123 #ifdef CONFIG_MODULES
124 static struct snd_minor *autoload_device(unsigned int minor)
127 mutex_unlock(&sound_mutex); /* release lock temporarily */
128 dev = SNDRV_MINOR_DEVICE(minor);
129 if (dev == SNDRV_MINOR_CONTROL) {
131 int card = SNDRV_MINOR_CARD(minor);
132 if (snd_cards[card] == NULL)
133 snd_request_card(card);
134 } else if (dev == SNDRV_MINOR_GLOBAL) {
136 snd_request_other(minor);
138 mutex_lock(&sound_mutex); /* reacuire lock */
139 return snd_minors[minor];
141 #else /* !CONFIG_MODULES */
142 #define autoload_device(minor) NULL
143 #endif /* CONFIG_MODULES */
145 static int snd_open(struct inode *inode, struct file *file)
147 unsigned int minor = iminor(inode);
148 struct snd_minor *mptr = NULL;
149 const struct file_operations *old_fops;
152 if (minor >= ARRAY_SIZE(snd_minors))
154 mutex_lock(&sound_mutex);
155 mptr = snd_minors[minor];
157 mptr = autoload_device(minor);
159 mutex_unlock(&sound_mutex);
163 old_fops = file->f_op;
164 file->f_op = fops_get(mptr->f_ops);
165 if (file->f_op == NULL) {
166 file->f_op = old_fops;
169 mutex_unlock(&sound_mutex);
173 if (file->f_op->open) {
174 err = file->f_op->open(inode, file);
176 fops_put(file->f_op);
177 file->f_op = fops_get(old_fops);
184 static const struct file_operations snd_fops =
186 .owner = THIS_MODULE,
188 .llseek = noop_llseek,
191 #ifdef CONFIG_SND_DYNAMIC_MINORS
192 static int snd_find_free_minor(void)
196 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
197 /* skip minors still used statically for autoloading devices */
198 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
199 minor == SNDRV_MINOR_SEQUENCER)
201 if (!snd_minors[minor])
207 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
212 case SNDRV_DEVICE_TYPE_SEQUENCER:
213 case SNDRV_DEVICE_TYPE_TIMER:
216 case SNDRV_DEVICE_TYPE_CONTROL:
217 if (snd_BUG_ON(!card))
219 minor = SNDRV_MINOR(card->number, type);
221 case SNDRV_DEVICE_TYPE_HWDEP:
222 case SNDRV_DEVICE_TYPE_RAWMIDI:
223 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
224 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
225 if (snd_BUG_ON(!card))
227 minor = SNDRV_MINOR(card->number, type + dev);
232 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
239 * snd_register_device_for_dev - Register the ALSA device file for the card
240 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
241 * @card: the card instance
242 * @dev: the device index
243 * @f_ops: the file operations
244 * @private_data: user pointer for f_ops->open()
245 * @name: the device file name
246 * @device: the &struct device to link this new device to
248 * Registers an ALSA device file for the given card.
249 * The operators have to be set in reg parameter.
251 * Returns zero if successful, or a negative error code on failure.
253 int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
254 const struct file_operations *f_ops,
256 const char *name, struct device *device)
259 struct snd_minor *preg;
261 if (snd_BUG_ON(!name))
263 preg = kmalloc(sizeof *preg, GFP_KERNEL);
267 preg->card = card ? card->number : -1;
270 preg->private_data = private_data;
271 mutex_lock(&sound_mutex);
272 #ifdef CONFIG_SND_DYNAMIC_MINORS
273 minor = snd_find_free_minor();
275 minor = snd_kernel_minor(type, card, dev);
276 if (minor >= 0 && snd_minors[minor])
280 mutex_unlock(&sound_mutex);
284 snd_minors[minor] = preg;
285 preg->dev = device_create(sound_class, device, MKDEV(major, minor),
286 private_data, "%s", name);
287 if (IS_ERR(preg->dev)) {
288 snd_minors[minor] = NULL;
289 mutex_unlock(&sound_mutex);
290 minor = PTR_ERR(preg->dev);
295 mutex_unlock(&sound_mutex);
299 EXPORT_SYMBOL(snd_register_device_for_dev);
301 /* find the matching minor record
302 * return the index of snd_minor, or -1 if not found
304 static int find_snd_minor(int type, struct snd_card *card, int dev)
307 struct snd_minor *mptr;
309 cardnum = card ? card->number : -1;
310 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
311 if ((mptr = snd_minors[minor]) != NULL &&
312 mptr->type == type &&
313 mptr->card == cardnum &&
320 * snd_unregister_device - unregister the device on the given card
321 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
322 * @card: the card instance
323 * @dev: the device index
325 * Unregisters the device file already registered via
326 * snd_register_device().
328 * Returns zero if sucecessful, or a negative error code on failure
330 int snd_unregister_device(int type, struct snd_card *card, int dev)
334 mutex_lock(&sound_mutex);
335 minor = find_snd_minor(type, card, dev);
337 mutex_unlock(&sound_mutex);
341 device_destroy(sound_class, MKDEV(major, minor));
343 kfree(snd_minors[minor]);
344 snd_minors[minor] = NULL;
345 mutex_unlock(&sound_mutex);
349 EXPORT_SYMBOL(snd_unregister_device);
351 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
352 struct device_attribute *attr)
354 int minor, ret = -EINVAL;
357 mutex_lock(&sound_mutex);
358 minor = find_snd_minor(type, card, dev);
359 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
360 ret = device_create_file(d, attr);
361 mutex_unlock(&sound_mutex);
366 EXPORT_SYMBOL(snd_add_device_sysfs_file);
368 #ifdef CONFIG_PROC_FS
373 static struct snd_info_entry *snd_minor_info_entry;
375 static const char *snd_device_type_name(int type)
378 case SNDRV_DEVICE_TYPE_CONTROL:
380 case SNDRV_DEVICE_TYPE_HWDEP:
381 return "hardware dependent";
382 case SNDRV_DEVICE_TYPE_RAWMIDI:
384 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
385 return "digital audio playback";
386 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
387 return "digital audio capture";
388 case SNDRV_DEVICE_TYPE_SEQUENCER:
390 case SNDRV_DEVICE_TYPE_TIMER:
397 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
400 struct snd_minor *mptr;
402 mutex_lock(&sound_mutex);
403 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
404 if (!(mptr = snd_minors[minor]))
406 if (mptr->card >= 0) {
407 if (mptr->device >= 0)
408 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
409 minor, mptr->card, mptr->device,
410 snd_device_type_name(mptr->type));
412 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
414 snd_device_type_name(mptr->type));
416 snd_iprintf(buffer, "%3i: : %s\n", minor,
417 snd_device_type_name(mptr->type));
419 mutex_unlock(&sound_mutex);
422 int __init snd_minor_info_init(void)
424 struct snd_info_entry *entry;
426 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
428 entry->c.text.read = snd_minor_info_read;
429 if (snd_info_register(entry) < 0) {
430 snd_info_free_entry(entry);
434 snd_minor_info_entry = entry;
438 int __exit snd_minor_info_done(void)
440 snd_info_free_entry(snd_minor_info_entry);
443 #endif /* CONFIG_PROC_FS */
449 static int __init alsa_sound_init(void)
452 snd_ecards_limit = cards_limit;
453 if (register_chrdev(major, "alsa", &snd_fops)) {
454 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
457 if (snd_info_init() < 0) {
458 unregister_chrdev(major, "alsa");
461 snd_info_minor_register();
463 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
468 static void __exit alsa_sound_exit(void)
470 snd_info_minor_unregister();
472 unregister_chrdev(major, "alsa");
475 subsys_initcall(alsa_sound_init);
476 module_exit(alsa_sound_exit);