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/time.h>
25 #include <linux/device.h>
26 #include <linux/module.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>
36 static int major = CONFIG_SND_MAJOR;
38 EXPORT_SYMBOL(snd_major);
40 static int cards_limit = 1;
42 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
43 MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
44 MODULE_LICENSE("GPL");
45 module_param(major, int, 0444);
46 MODULE_PARM_DESC(major, "Major # for sound driver.");
47 module_param(cards_limit, int, 0444);
48 MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
49 MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
51 /* this one holds the actual max. card number currently available.
52 * as default, it's identical with cards_limit option. when more
53 * modules are loaded manually, this limit number increases, too.
56 EXPORT_SYMBOL(snd_ecards_limit);
58 static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
59 static DEFINE_MUTEX(sound_mutex);
64 * snd_request_card - try to load the card module
65 * @card: the card number
67 * Tries to load the module "snd-card-X" for the given card number
68 * via request_module. Returns immediately if already loaded.
70 void snd_request_card(int card)
72 if (snd_card_locked(card))
74 if (card < 0 || card >= cards_limit)
76 request_module("snd-card-%i", card);
79 EXPORT_SYMBOL(snd_request_card);
81 static void snd_request_other(int minor)
86 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
87 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
93 #endif /* modular kernel */
96 * snd_lookup_minor_data - get user data of a registered device
97 * @minor: the minor number
98 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
100 * Checks that a minor device with the specified type is registered, and returns
101 * its user data pointer.
103 * This function increments the reference counter of the card instance
104 * if an associated instance with the given minor number and type is found.
105 * The caller must call snd_card_unref() appropriately later.
107 void *snd_lookup_minor_data(unsigned int minor, int type)
109 struct snd_minor *mreg;
112 if (minor >= ARRAY_SIZE(snd_minors))
114 mutex_lock(&sound_mutex);
115 mreg = snd_minors[minor];
116 if (mreg && mreg->type == type) {
117 private_data = mreg->private_data;
118 if (private_data && mreg->card_ptr)
119 atomic_inc(&mreg->card_ptr->refcount);
122 mutex_unlock(&sound_mutex);
126 EXPORT_SYMBOL(snd_lookup_minor_data);
128 #ifdef CONFIG_MODULES
129 static struct snd_minor *autoload_device(unsigned int minor)
132 mutex_unlock(&sound_mutex); /* release lock temporarily */
133 dev = SNDRV_MINOR_DEVICE(minor);
134 if (dev == SNDRV_MINOR_CONTROL) {
136 int card = SNDRV_MINOR_CARD(minor);
137 if (snd_cards[card] == NULL)
138 snd_request_card(card);
139 } else if (dev == SNDRV_MINOR_GLOBAL) {
141 snd_request_other(minor);
143 mutex_lock(&sound_mutex); /* reacuire lock */
144 return snd_minors[minor];
146 #else /* !CONFIG_MODULES */
147 #define autoload_device(minor) NULL
148 #endif /* CONFIG_MODULES */
150 static int snd_open(struct inode *inode, struct file *file)
152 unsigned int minor = iminor(inode);
153 struct snd_minor *mptr = NULL;
154 const struct file_operations *old_fops;
157 if (minor >= ARRAY_SIZE(snd_minors))
159 mutex_lock(&sound_mutex);
160 mptr = snd_minors[minor];
162 mptr = autoload_device(minor);
164 mutex_unlock(&sound_mutex);
168 old_fops = file->f_op;
169 file->f_op = fops_get(mptr->f_ops);
170 if (file->f_op == NULL) {
171 file->f_op = old_fops;
174 mutex_unlock(&sound_mutex);
178 if (file->f_op->open) {
179 err = file->f_op->open(inode, file);
181 fops_put(file->f_op);
182 file->f_op = fops_get(old_fops);
189 static const struct file_operations snd_fops =
191 .owner = THIS_MODULE,
193 .llseek = noop_llseek,
196 #ifdef CONFIG_SND_DYNAMIC_MINORS
197 static int snd_find_free_minor(int type)
201 /* static minors for module auto loading */
202 if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
203 return SNDRV_MINOR_SEQUENCER;
204 if (type == SNDRV_DEVICE_TYPE_TIMER)
205 return SNDRV_MINOR_TIMER;
207 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
208 /* skip static minors still used for module auto loading */
209 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
211 if (minor == SNDRV_MINOR_SEQUENCER ||
212 minor == SNDRV_MINOR_TIMER)
214 if (!snd_minors[minor])
220 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
225 case SNDRV_DEVICE_TYPE_SEQUENCER:
226 case SNDRV_DEVICE_TYPE_TIMER:
229 case SNDRV_DEVICE_TYPE_CONTROL:
230 if (snd_BUG_ON(!card))
232 minor = SNDRV_MINOR(card->number, type);
234 case SNDRV_DEVICE_TYPE_HWDEP:
235 case SNDRV_DEVICE_TYPE_RAWMIDI:
236 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
237 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
238 if (snd_BUG_ON(!card))
240 minor = SNDRV_MINOR(card->number, type + dev);
245 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
252 * snd_register_device_for_dev - Register the ALSA device file for the card
253 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
254 * @card: the card instance
255 * @dev: the device index
256 * @f_ops: the file operations
257 * @private_data: user pointer for f_ops->open()
258 * @name: the device file name
259 * @device: the &struct device to link this new device to
261 * Registers an ALSA device file for the given card.
262 * The operators have to be set in reg parameter.
264 * Returns zero if successful, or a negative error code on failure.
266 int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
267 const struct file_operations *f_ops,
269 const char *name, struct device *device)
272 struct snd_minor *preg;
274 if (snd_BUG_ON(!name))
276 preg = kmalloc(sizeof *preg, GFP_KERNEL);
280 preg->card = card ? card->number : -1;
283 preg->private_data = private_data;
284 preg->card_ptr = card;
285 mutex_lock(&sound_mutex);
286 #ifdef CONFIG_SND_DYNAMIC_MINORS
287 minor = snd_find_free_minor(type);
289 minor = snd_kernel_minor(type, card, dev);
290 if (minor >= 0 && snd_minors[minor])
294 mutex_unlock(&sound_mutex);
298 snd_minors[minor] = preg;
299 preg->dev = device_create(sound_class, device, MKDEV(major, minor),
300 private_data, "%s", name);
301 if (IS_ERR(preg->dev)) {
302 snd_minors[minor] = NULL;
303 mutex_unlock(&sound_mutex);
304 minor = PTR_ERR(preg->dev);
309 mutex_unlock(&sound_mutex);
313 EXPORT_SYMBOL(snd_register_device_for_dev);
315 /* find the matching minor record
316 * return the index of snd_minor, or -1 if not found
318 static int find_snd_minor(int type, struct snd_card *card, int dev)
321 struct snd_minor *mptr;
323 cardnum = card ? card->number : -1;
324 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
325 if ((mptr = snd_minors[minor]) != NULL &&
326 mptr->type == type &&
327 mptr->card == cardnum &&
334 * snd_unregister_device - unregister the device on the given card
335 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
336 * @card: the card instance
337 * @dev: the device index
339 * Unregisters the device file already registered via
340 * snd_register_device().
342 * Returns zero if sucecessful, or a negative error code on failure
344 int snd_unregister_device(int type, struct snd_card *card, int dev)
348 mutex_lock(&sound_mutex);
349 minor = find_snd_minor(type, card, dev);
351 mutex_unlock(&sound_mutex);
355 device_destroy(sound_class, MKDEV(major, minor));
357 kfree(snd_minors[minor]);
358 snd_minors[minor] = NULL;
359 mutex_unlock(&sound_mutex);
363 EXPORT_SYMBOL(snd_unregister_device);
365 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
366 struct device_attribute *attr)
368 int minor, ret = -EINVAL;
371 mutex_lock(&sound_mutex);
372 minor = find_snd_minor(type, card, dev);
373 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
374 ret = device_create_file(d, attr);
375 mutex_unlock(&sound_mutex);
380 EXPORT_SYMBOL(snd_add_device_sysfs_file);
382 #ifdef CONFIG_PROC_FS
387 static struct snd_info_entry *snd_minor_info_entry;
389 static const char *snd_device_type_name(int type)
392 case SNDRV_DEVICE_TYPE_CONTROL:
394 case SNDRV_DEVICE_TYPE_HWDEP:
395 return "hardware dependent";
396 case SNDRV_DEVICE_TYPE_RAWMIDI:
398 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
399 return "digital audio playback";
400 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
401 return "digital audio capture";
402 case SNDRV_DEVICE_TYPE_SEQUENCER:
404 case SNDRV_DEVICE_TYPE_TIMER:
411 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
414 struct snd_minor *mptr;
416 mutex_lock(&sound_mutex);
417 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
418 if (!(mptr = snd_minors[minor]))
420 if (mptr->card >= 0) {
421 if (mptr->device >= 0)
422 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
423 minor, mptr->card, mptr->device,
424 snd_device_type_name(mptr->type));
426 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
428 snd_device_type_name(mptr->type));
430 snd_iprintf(buffer, "%3i: : %s\n", minor,
431 snd_device_type_name(mptr->type));
433 mutex_unlock(&sound_mutex);
436 int __init snd_minor_info_init(void)
438 struct snd_info_entry *entry;
440 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
442 entry->c.text.read = snd_minor_info_read;
443 if (snd_info_register(entry) < 0) {
444 snd_info_free_entry(entry);
448 snd_minor_info_entry = entry;
452 int __exit snd_minor_info_done(void)
454 snd_info_free_entry(snd_minor_info_entry);
457 #endif /* CONFIG_PROC_FS */
463 static int __init alsa_sound_init(void)
466 snd_ecards_limit = cards_limit;
467 if (register_chrdev(major, "alsa", &snd_fops)) {
468 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
471 if (snd_info_init() < 0) {
472 unregister_chrdev(major, "alsa");
475 snd_info_minor_register();
477 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
482 static void __exit alsa_sound_exit(void)
484 snd_info_minor_unregister();
486 unregister_chrdev(major, "alsa");
489 subsys_initcall(alsa_sound_init);
490 module_exit(alsa_sound_exit);