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/moduleparam.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 void *snd_lookup_minor_data(unsigned int minor, int type)
105 struct snd_minor *mreg;
108 if (minor >= ARRAY_SIZE(snd_minors))
110 mutex_lock(&sound_mutex);
111 mreg = snd_minors[minor];
112 if (mreg && mreg->type == type)
113 private_data = mreg->private_data;
116 mutex_unlock(&sound_mutex);
120 EXPORT_SYMBOL(snd_lookup_minor_data);
122 #ifdef CONFIG_MODULES
123 static struct snd_minor *autoload_device(unsigned int minor)
126 mutex_unlock(&sound_mutex); /* release lock temporarily */
127 dev = SNDRV_MINOR_DEVICE(minor);
128 if (dev == SNDRV_MINOR_CONTROL) {
130 int card = SNDRV_MINOR_CARD(minor);
131 if (snd_cards[card] == NULL)
132 snd_request_card(card);
133 } else if (dev == SNDRV_MINOR_GLOBAL) {
135 snd_request_other(minor);
137 mutex_lock(&sound_mutex); /* reacuire lock */
138 return snd_minors[minor];
140 #else /* !CONFIG_MODULES */
141 #define autoload_device(minor) NULL
142 #endif /* CONFIG_MODULES */
144 static int snd_open(struct inode *inode, struct file *file)
146 unsigned int minor = iminor(inode);
147 struct snd_minor *mptr = NULL;
148 const struct file_operations *old_fops;
151 if (minor >= ARRAY_SIZE(snd_minors))
153 mutex_lock(&sound_mutex);
154 mptr = snd_minors[minor];
156 mptr = autoload_device(minor);
158 mutex_unlock(&sound_mutex);
162 old_fops = file->f_op;
163 file->f_op = fops_get(mptr->f_ops);
164 if (file->f_op == NULL) {
165 file->f_op = old_fops;
168 mutex_unlock(&sound_mutex);
172 if (file->f_op->open) {
173 err = file->f_op->open(inode, file);
175 fops_put(file->f_op);
176 file->f_op = fops_get(old_fops);
183 static const struct file_operations snd_fops =
185 .owner = THIS_MODULE,
187 .llseek = noop_llseek,
190 #ifdef CONFIG_SND_DYNAMIC_MINORS
191 static int snd_find_free_minor(void)
195 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
196 /* skip minors still used statically for autoloading devices */
197 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
198 minor == SNDRV_MINOR_SEQUENCER)
200 if (!snd_minors[minor])
206 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
211 case SNDRV_DEVICE_TYPE_SEQUENCER:
212 case SNDRV_DEVICE_TYPE_TIMER:
215 case SNDRV_DEVICE_TYPE_CONTROL:
216 if (snd_BUG_ON(!card))
218 minor = SNDRV_MINOR(card->number, type);
220 case SNDRV_DEVICE_TYPE_HWDEP:
221 case SNDRV_DEVICE_TYPE_RAWMIDI:
222 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
223 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
224 if (snd_BUG_ON(!card))
226 minor = SNDRV_MINOR(card->number, type + dev);
231 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
238 * snd_register_device_for_dev - Register the ALSA device file for the card
239 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
240 * @card: the card instance
241 * @dev: the device index
242 * @f_ops: the file operations
243 * @private_data: user pointer for f_ops->open()
244 * @name: the device file name
245 * @device: the &struct device to link this new device to
247 * Registers an ALSA device file for the given card.
248 * The operators have to be set in reg parameter.
250 * Returns zero if successful, or a negative error code on failure.
252 int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
253 const struct file_operations *f_ops,
255 const char *name, struct device *device)
258 struct snd_minor *preg;
260 if (snd_BUG_ON(!name))
262 preg = kmalloc(sizeof *preg, GFP_KERNEL);
266 preg->card = card ? card->number : -1;
269 preg->private_data = private_data;
270 mutex_lock(&sound_mutex);
271 #ifdef CONFIG_SND_DYNAMIC_MINORS
272 minor = snd_find_free_minor();
274 minor = snd_kernel_minor(type, card, dev);
275 if (minor >= 0 && snd_minors[minor])
279 mutex_unlock(&sound_mutex);
283 snd_minors[minor] = preg;
284 preg->dev = device_create(sound_class, device, MKDEV(major, minor),
285 private_data, "%s", name);
286 if (IS_ERR(preg->dev)) {
287 snd_minors[minor] = NULL;
288 mutex_unlock(&sound_mutex);
289 minor = PTR_ERR(preg->dev);
294 mutex_unlock(&sound_mutex);
298 EXPORT_SYMBOL(snd_register_device_for_dev);
300 /* find the matching minor record
301 * return the index of snd_minor, or -1 if not found
303 static int find_snd_minor(int type, struct snd_card *card, int dev)
306 struct snd_minor *mptr;
308 cardnum = card ? card->number : -1;
309 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
310 if ((mptr = snd_minors[minor]) != NULL &&
311 mptr->type == type &&
312 mptr->card == cardnum &&
319 * snd_unregister_device - unregister the device on the given card
320 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
321 * @card: the card instance
322 * @dev: the device index
324 * Unregisters the device file already registered via
325 * snd_register_device().
327 * Returns zero if sucecessful, or a negative error code on failure
329 int snd_unregister_device(int type, struct snd_card *card, int dev)
333 mutex_lock(&sound_mutex);
334 minor = find_snd_minor(type, card, dev);
336 mutex_unlock(&sound_mutex);
340 device_destroy(sound_class, MKDEV(major, minor));
342 kfree(snd_minors[minor]);
343 snd_minors[minor] = NULL;
344 mutex_unlock(&sound_mutex);
348 EXPORT_SYMBOL(snd_unregister_device);
350 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
351 struct device_attribute *attr)
353 int minor, ret = -EINVAL;
356 mutex_lock(&sound_mutex);
357 minor = find_snd_minor(type, card, dev);
358 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
359 ret = device_create_file(d, attr);
360 mutex_unlock(&sound_mutex);
365 EXPORT_SYMBOL(snd_add_device_sysfs_file);
367 #ifdef CONFIG_PROC_FS
372 static struct snd_info_entry *snd_minor_info_entry;
374 static const char *snd_device_type_name(int type)
377 case SNDRV_DEVICE_TYPE_CONTROL:
379 case SNDRV_DEVICE_TYPE_HWDEP:
380 return "hardware dependent";
381 case SNDRV_DEVICE_TYPE_RAWMIDI:
383 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
384 return "digital audio playback";
385 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
386 return "digital audio capture";
387 case SNDRV_DEVICE_TYPE_SEQUENCER:
389 case SNDRV_DEVICE_TYPE_TIMER:
396 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
399 struct snd_minor *mptr;
401 mutex_lock(&sound_mutex);
402 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
403 if (!(mptr = snd_minors[minor]))
405 if (mptr->card >= 0) {
406 if (mptr->device >= 0)
407 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
408 minor, mptr->card, mptr->device,
409 snd_device_type_name(mptr->type));
411 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
413 snd_device_type_name(mptr->type));
415 snd_iprintf(buffer, "%3i: : %s\n", minor,
416 snd_device_type_name(mptr->type));
418 mutex_unlock(&sound_mutex);
421 int __init snd_minor_info_init(void)
423 struct snd_info_entry *entry;
425 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
427 entry->c.text.read = snd_minor_info_read;
428 if (snd_info_register(entry) < 0) {
429 snd_info_free_entry(entry);
433 snd_minor_info_entry = entry;
437 int __exit snd_minor_info_done(void)
439 snd_info_free_entry(snd_minor_info_entry);
442 #endif /* CONFIG_PROC_FS */
448 static int __init alsa_sound_init(void)
451 snd_ecards_limit = cards_limit;
452 if (register_chrdev(major, "alsa", &snd_fops)) {
453 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
456 if (snd_info_init() < 0) {
457 unregister_chrdev(major, "alsa");
460 snd_info_minor_register();
462 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
467 static void __exit alsa_sound_exit(void)
469 snd_info_minor_unregister();
471 unregister_chrdev(major, "alsa");
474 subsys_initcall(alsa_sound_init);
475 module_exit(alsa_sound_exit);