fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / sound / core / sound.c
blob7b486c4d70db7c9c21d19a416b6a8db017b5ceb9
1 /*
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 <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>
37 #define SNDRV_OS_MINORS 256
39 static int major = CONFIG_SND_MAJOR;
40 int snd_major;
41 EXPORT_SYMBOL(snd_major);
43 static int cards_limit = 1;
45 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.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);
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.
58 int snd_ecards_limit;
59 EXPORT_SYMBOL(snd_ecards_limit);
61 static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
62 static DEFINE_MUTEX(sound_mutex);
64 #ifdef CONFIG_KMOD
66 /**
67 * snd_request_card - try to load the card module
68 * @card: the card number
70 * Tries to load the module "snd-card-X" for the given card number
71 * via KMOD. Returns immediately if already loaded.
73 void snd_request_card(int card)
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);
84 EXPORT_SYMBOL(snd_request_card);
86 static void snd_request_other(int minor)
88 char *str;
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;
97 request_module(str);
100 #endif /* request_module support */
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)
107 * Checks that a minor device with the specified type is registered, and returns
108 * its user data pointer.
110 void *snd_lookup_minor_data(unsigned int minor, int type)
112 struct snd_minor *mreg;
113 void *private_data;
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;
127 EXPORT_SYMBOL(snd_lookup_minor_data);
129 static int snd_open(struct inode *inode, struct file *file)
131 unsigned int minor = iminor(inode);
132 struct snd_minor *mptr = NULL;
133 const struct file_operations *old_fops;
134 int err = 0;
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);
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;
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);
167 fops_put(old_fops);
168 return err;
171 static const struct file_operations snd_fops =
173 .owner = THIS_MODULE,
174 .open = snd_open
177 #ifdef CONFIG_SND_DYNAMIC_MINORS
178 static int snd_find_free_minor(void)
180 int minor;
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;
190 return -EBUSY;
192 #else
193 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
195 int minor;
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;
216 snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
217 return minor;
219 #endif
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
231 * Registers an ALSA device file for the given card.
232 * The operators have to be set in reg parameter.
234 * Returns zero if successful, or a negative error code on failure.
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)
241 int minor;
242 struct snd_minor *preg;
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;
266 snd_minors[minor] = preg;
267 preg->dev = device_create(sound_class, device, MKDEV(major, minor),
268 "%s", name);
269 if (IS_ERR(preg->dev)) {
270 snd_minors[minor] = NULL;
271 mutex_unlock(&sound_mutex);
272 minor = PTR_ERR(preg->dev);
273 kfree(preg);
274 return minor;
277 if (preg->dev)
278 dev_set_drvdata(preg->dev, private_data);
280 mutex_unlock(&sound_mutex);
281 return 0;
284 EXPORT_SYMBOL(snd_register_device_for_dev);
286 /* find the matching minor record
287 * return the index of snd_minor, or -1 if not found
289 static int find_snd_minor(int type, struct snd_card *card, int dev)
291 int cardnum, minor;
292 struct snd_minor *mptr;
294 cardnum = card ? card->number : -1;
295 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
296 if ((mptr = snd_minors[minor]) != NULL &&
297 mptr->type == type &&
298 mptr->card == cardnum &&
299 mptr->device == dev)
300 return minor;
301 return -1;
305 * snd_unregister_device - unregister the device on the given card
306 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
307 * @card: the card instance
308 * @dev: the device index
310 * Unregisters the device file already registered via
311 * snd_register_device().
313 * Returns zero if sucecessful, or a negative error code on failure
315 int snd_unregister_device(int type, struct snd_card *card, int dev)
317 int minor;
319 mutex_lock(&sound_mutex);
320 minor = find_snd_minor(type, card, dev);
321 if (minor < 0) {
322 mutex_unlock(&sound_mutex);
323 return -EINVAL;
326 device_destroy(sound_class, MKDEV(major, minor));
328 kfree(snd_minors[minor]);
329 snd_minors[minor] = NULL;
330 mutex_unlock(&sound_mutex);
331 return 0;
334 EXPORT_SYMBOL(snd_unregister_device);
336 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
337 struct device_attribute *attr)
339 int minor, ret = -EINVAL;
340 struct device *d;
342 mutex_lock(&sound_mutex);
343 minor = find_snd_minor(type, card, dev);
344 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
345 ret = device_create_file(d, attr);
346 mutex_unlock(&sound_mutex);
347 return ret;
351 EXPORT_SYMBOL(snd_add_device_sysfs_file);
353 #ifdef CONFIG_PROC_FS
355 * INFO PART
358 static struct snd_info_entry *snd_minor_info_entry;
360 static const char *snd_device_type_name(int type)
362 switch (type) {
363 case SNDRV_DEVICE_TYPE_CONTROL:
364 return "control";
365 case SNDRV_DEVICE_TYPE_HWDEP:
366 return "hardware dependent";
367 case SNDRV_DEVICE_TYPE_RAWMIDI:
368 return "raw midi";
369 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
370 return "digital audio playback";
371 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
372 return "digital audio capture";
373 case SNDRV_DEVICE_TYPE_SEQUENCER:
374 return "sequencer";
375 case SNDRV_DEVICE_TYPE_TIMER:
376 return "timer";
377 default:
378 return "?";
382 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
384 int minor;
385 struct snd_minor *mptr;
387 mutex_lock(&sound_mutex);
388 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
389 if (!(mptr = snd_minors[minor]))
390 continue;
391 if (mptr->card >= 0) {
392 if (mptr->device >= 0)
393 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
394 minor, mptr->card, mptr->device,
395 snd_device_type_name(mptr->type));
396 else
397 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
398 minor, mptr->card,
399 snd_device_type_name(mptr->type));
400 } else
401 snd_iprintf(buffer, "%3i: : %s\n", minor,
402 snd_device_type_name(mptr->type));
404 mutex_unlock(&sound_mutex);
407 int __init snd_minor_info_init(void)
409 struct snd_info_entry *entry;
411 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
412 if (entry) {
413 entry->c.text.read = snd_minor_info_read;
414 if (snd_info_register(entry) < 0) {
415 snd_info_free_entry(entry);
416 entry = NULL;
419 snd_minor_info_entry = entry;
420 return 0;
423 int __exit snd_minor_info_done(void)
425 snd_info_free_entry(snd_minor_info_entry);
426 return 0;
428 #endif /* CONFIG_PROC_FS */
431 * INIT PART
434 static int __init alsa_sound_init(void)
436 snd_major = major;
437 snd_ecards_limit = cards_limit;
438 if (register_chrdev(major, "alsa", &snd_fops)) {
439 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
440 return -EIO;
442 if (snd_info_init() < 0) {
443 unregister_chrdev(major, "alsa");
444 return -ENOMEM;
446 snd_info_minor_register();
447 #ifndef MODULE
448 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
449 #endif
450 return 0;
453 static void __exit alsa_sound_exit(void)
455 snd_info_minor_unregister();
456 snd_info_done();
457 unregister_chrdev(major, "alsa");
460 module_init(alsa_sound_init)
461 module_exit(alsa_sound_exit)