[ALSA] Remove zero-initialization of static variables
[deliverable/linux.git] / sound / core / sound.c
CommitLineData
1da177e4
LT
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>
9a1a2a1d 26#include <linux/device.h>
1da177e4
LT
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/devfs_fs_kernel.h>
1a60d4c5 36#include <linux/mutex.h>
1da177e4
LT
37
38#define SNDRV_OS_MINORS 256
39
40static int major = CONFIG_SND_MAJOR;
41int snd_major;
c0d3fb39
TI
42EXPORT_SYMBOL(snd_major);
43
1da177e4
LT
44static int cards_limit = 1;
45static int device_mode = S_IFCHR | S_IRUGO | S_IWUGO;
46
47MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
48MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
49MODULE_LICENSE("GPL");
50module_param(major, int, 0444);
51MODULE_PARM_DESC(major, "Major # for sound driver.");
52module_param(cards_limit, int, 0444);
53MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
54#ifdef CONFIG_DEVFS_FS
55module_param(device_mode, int, 0444);
56MODULE_PARM_DESC(device_mode, "Device file permission mask for devfs.");
57#endif
58MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
59
60/* this one holds the actual max. card number currently available.
61 * as default, it's identical with cards_limit option. when more
62 * modules are loaded manually, this limit number increases, too.
63 */
64int snd_ecards_limit;
c0d3fb39 65EXPORT_SYMBOL(snd_ecards_limit);
1da177e4 66
6983b724 67static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
1a60d4c5 68static DEFINE_MUTEX(sound_mutex);
1da177e4 69
619e666b 70extern struct class *sound_class;
1da177e4
LT
71
72
73#ifdef CONFIG_KMOD
74
75/**
76 * snd_request_card - try to load the card module
77 * @card: the card number
78 *
79 * Tries to load the module "snd-card-X" for the given card number
80 * via KMOD. Returns immediately if already loaded.
81 */
82void snd_request_card(int card)
83{
1da177e4
LT
84 if (! current->fs->root)
85 return;
746df948 86 if (snd_card_locked(card))
1da177e4
LT
87 return;
88 if (card < 0 || card >= cards_limit)
89 return;
90 request_module("snd-card-%i", card);
91}
92
c0d3fb39
TI
93EXPORT_SYMBOL(snd_request_card);
94
1da177e4
LT
95static void snd_request_other(int minor)
96{
97 char *str;
98
99 if (! current->fs->root)
100 return;
101 switch (minor) {
102 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
103 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
104 default: return;
105 }
106 request_module(str);
107}
108
109#endif /* request_module support */
110
f87135f5
CL
111/**
112 * snd_lookup_minor_data - get user data of a registered device
113 * @minor: the minor number
114 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
115 *
116 * Checks that a minor device with the specified type is registered, and returns
117 * its user data pointer.
118 */
119void *snd_lookup_minor_data(unsigned int minor, int type)
120{
121 struct snd_minor *mreg;
122 void *private_data;
123
3a63e444 124 if (minor >= ARRAY_SIZE(snd_minors))
f87135f5 125 return NULL;
1a60d4c5 126 mutex_lock(&sound_mutex);
f87135f5
CL
127 mreg = snd_minors[minor];
128 if (mreg && mreg->type == type)
129 private_data = mreg->private_data;
130 else
131 private_data = NULL;
1a60d4c5 132 mutex_unlock(&sound_mutex);
f87135f5
CL
133 return private_data;
134}
135
c0d3fb39
TI
136EXPORT_SYMBOL(snd_lookup_minor_data);
137
1da177e4
LT
138static int snd_open(struct inode *inode, struct file *file)
139{
332682b1 140 unsigned int minor = iminor(inode);
512bbd6a 141 struct snd_minor *mptr = NULL;
99ac48f5 142 const struct file_operations *old_fops;
1da177e4
LT
143 int err = 0;
144
3a63e444 145 if (minor >= ARRAY_SIZE(snd_minors))
332682b1
CL
146 return -ENODEV;
147 mptr = snd_minors[minor];
148 if (mptr == NULL) {
1da177e4 149#ifdef CONFIG_KMOD
332682b1
CL
150 int dev = SNDRV_MINOR_DEVICE(minor);
151 if (dev == SNDRV_MINOR_CONTROL) {
152 /* /dev/aloadC? */
153 int card = SNDRV_MINOR_CARD(minor);
1da177e4 154 if (snd_cards[card] == NULL)
332682b1
CL
155 snd_request_card(card);
156 } else if (dev == SNDRV_MINOR_GLOBAL) {
157 /* /dev/aloadSEQ */
1da177e4 158 snd_request_other(minor);
332682b1
CL
159 }
160#ifndef CONFIG_SND_DYNAMIC_MINORS
161 /* /dev/snd/{controlC?,seq} */
162 mptr = snd_minors[minor];
163 if (mptr == NULL)
164#endif
1da177e4 165#endif
332682b1 166 return -ENODEV;
1da177e4 167 }
1da177e4
LT
168 old_fops = file->f_op;
169 file->f_op = fops_get(mptr->f_ops);
170 if (file->f_op->open)
171 err = file->f_op->open(inode, file);
172 if (err) {
173 fops_put(file->f_op);
174 file->f_op = fops_get(old_fops);
175 }
176 fops_put(old_fops);
177 return err;
178}
179
180static struct file_operations snd_fops =
181{
182 .owner = THIS_MODULE,
183 .open = snd_open
184};
185
332682b1
CL
186#ifdef CONFIG_SND_DYNAMIC_MINORS
187static int snd_find_free_minor(void)
188{
189 int minor;
190
191 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
192 /* skip minors still used statically for autoloading devices */
193 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
194 minor == SNDRV_MINOR_SEQUENCER)
195 continue;
196 if (!snd_minors[minor])
197 return minor;
198 }
199 return -EBUSY;
200}
201#else
512bbd6a 202static int snd_kernel_minor(int type, struct snd_card *card, int dev)
1da177e4
LT
203{
204 int minor;
205
206 switch (type) {
207 case SNDRV_DEVICE_TYPE_SEQUENCER:
208 case SNDRV_DEVICE_TYPE_TIMER:
209 minor = type;
210 break;
211 case SNDRV_DEVICE_TYPE_CONTROL:
212 snd_assert(card != NULL, return -EINVAL);
213 minor = SNDRV_MINOR(card->number, type);
214 break;
215 case SNDRV_DEVICE_TYPE_HWDEP:
216 case SNDRV_DEVICE_TYPE_RAWMIDI:
217 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
218 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
219 snd_assert(card != NULL, return -EINVAL);
220 minor = SNDRV_MINOR(card->number, type + dev);
221 break;
222 default:
223 return -EINVAL;
224 }
225 snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
226 return minor;
227}
332682b1 228#endif
1da177e4
LT
229
230/**
231 * snd_register_device - Register the ALSA device file for the card
232 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
233 * @card: the card instance
234 * @dev: the device index
2af677fc 235 * @f_ops: the file operations
f87135f5 236 * @private_data: user pointer for f_ops->open()
1da177e4
LT
237 * @name: the device file name
238 *
239 * Registers an ALSA device file for the given card.
240 * The operators have to be set in reg parameter.
241 *
242 * Retrurns zero if successful, or a negative error code on failure.
243 */
2af677fc 244int snd_register_device(int type, struct snd_card *card, int dev,
99ac48f5 245 const struct file_operations *f_ops, void *private_data,
f87135f5 246 const char *name)
1da177e4 247{
332682b1 248 int minor;
512bbd6a 249 struct snd_minor *preg;
1da177e4
LT
250 struct device *device = NULL;
251
1da177e4 252 snd_assert(name, return -EINVAL);
6983b724 253 preg = kmalloc(sizeof(struct snd_minor) + strlen(name) + 1, GFP_KERNEL);
1da177e4
LT
254 if (preg == NULL)
255 return -ENOMEM;
2af677fc 256 preg->type = type;
6983b724 257 preg->card = card ? card->number : -1;
1da177e4 258 preg->device = dev;
2af677fc 259 preg->f_ops = f_ops;
f87135f5 260 preg->private_data = private_data;
1da177e4 261 strcpy(preg->name, name);
1a60d4c5 262 mutex_lock(&sound_mutex);
332682b1
CL
263#ifdef CONFIG_SND_DYNAMIC_MINORS
264 minor = snd_find_free_minor();
265#else
266 minor = snd_kernel_minor(type, card, dev);
267 if (minor >= 0 && snd_minors[minor])
268 minor = -EBUSY;
269#endif
270 if (minor < 0) {
1a60d4c5 271 mutex_unlock(&sound_mutex);
1da177e4 272 kfree(preg);
332682b1 273 return minor;
1da177e4 274 }
6983b724
CL
275 snd_minors[minor] = preg;
276 if (type != SNDRV_DEVICE_TYPE_CONTROL || preg->card >= cards_limit)
1da177e4 277 devfs_mk_cdev(MKDEV(major, minor), S_IFCHR | device_mode, "snd/%s", name);
3e23c658 278 if (card)
1da177e4 279 device = card->dev;
3e23c658 280 class_device_create(sound_class, NULL, MKDEV(major, minor), device, "%s", name);
1da177e4 281
1a60d4c5 282 mutex_unlock(&sound_mutex);
1da177e4
LT
283 return 0;
284}
285
c0d3fb39
TI
286EXPORT_SYMBOL(snd_register_device);
287
1da177e4
LT
288/**
289 * snd_unregister_device - unregister the device on the given card
290 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
291 * @card: the card instance
292 * @dev: the device index
293 *
294 * Unregisters the device file already registered via
295 * snd_register_device().
296 *
297 * Returns zero if sucecessful, or a negative error code on failure
298 */
512bbd6a 299int snd_unregister_device(int type, struct snd_card *card, int dev)
1da177e4 300{
f87135f5 301 int cardnum, minor;
512bbd6a 302 struct snd_minor *mptr;
1da177e4 303
f87135f5 304 cardnum = card ? card->number : -1;
1a60d4c5 305 mutex_lock(&sound_mutex);
f87135f5
CL
306 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
307 if ((mptr = snd_minors[minor]) != NULL &&
308 mptr->type == type &&
309 mptr->card == cardnum &&
310 mptr->device == dev)
311 break;
312 if (minor == ARRAY_SIZE(snd_minors)) {
1a60d4c5 313 mutex_unlock(&sound_mutex);
1da177e4
LT
314 return -EINVAL;
315 }
316
6983b724
CL
317 if (mptr->type != SNDRV_DEVICE_TYPE_CONTROL ||
318 mptr->card >= cards_limit) /* created in sound.c */
1da177e4 319 devfs_remove("snd/%s", mptr->name);
619e666b 320 class_device_destroy(sound_class, MKDEV(major, minor));
1da177e4 321
6983b724 322 snd_minors[minor] = NULL;
1a60d4c5 323 mutex_unlock(&sound_mutex);
1da177e4
LT
324 kfree(mptr);
325 return 0;
326}
327
c0d3fb39
TI
328EXPORT_SYMBOL(snd_unregister_device);
329
e28563cc 330#ifdef CONFIG_PROC_FS
1da177e4
LT
331/*
332 * INFO PART
333 */
334
6581f4e7 335static struct snd_info_entry *snd_minor_info_entry;
1da177e4 336
2af677fc
CL
337static const char *snd_device_type_name(int type)
338{
339 switch (type) {
340 case SNDRV_DEVICE_TYPE_CONTROL:
341 return "control";
342 case SNDRV_DEVICE_TYPE_HWDEP:
343 return "hardware dependent";
344 case SNDRV_DEVICE_TYPE_RAWMIDI:
345 return "raw midi";
346 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
347 return "digital audio playback";
348 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
349 return "digital audio capture";
350 case SNDRV_DEVICE_TYPE_SEQUENCER:
351 return "sequencer";
352 case SNDRV_DEVICE_TYPE_TIMER:
353 return "timer";
354 default:
355 return "?";
356 }
357}
358
512bbd6a 359static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
1da177e4 360{
6983b724 361 int minor;
512bbd6a 362 struct snd_minor *mptr;
1da177e4 363
1a60d4c5 364 mutex_lock(&sound_mutex);
6983b724
CL
365 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
366 if (!(mptr = snd_minors[minor]))
367 continue;
368 if (mptr->card >= 0) {
369 if (mptr->device >= 0)
d001544d 370 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
6983b724
CL
371 minor, mptr->card, mptr->device,
372 snd_device_type_name(mptr->type));
373 else
d001544d 374 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
6983b724
CL
375 minor, mptr->card,
376 snd_device_type_name(mptr->type));
377 } else
d001544d 378 snd_iprintf(buffer, "%3i: : %s\n", minor,
6983b724 379 snd_device_type_name(mptr->type));
1da177e4 380 }
1a60d4c5 381 mutex_unlock(&sound_mutex);
1da177e4
LT
382}
383
384int __init snd_minor_info_init(void)
385{
512bbd6a 386 struct snd_info_entry *entry;
1da177e4
LT
387
388 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
389 if (entry) {
1da177e4
LT
390 entry->c.text.read = snd_minor_info_read;
391 if (snd_info_register(entry) < 0) {
392 snd_info_free_entry(entry);
393 entry = NULL;
394 }
395 }
396 snd_minor_info_entry = entry;
397 return 0;
398}
399
400int __exit snd_minor_info_done(void)
401{
402 if (snd_minor_info_entry)
403 snd_info_unregister(snd_minor_info_entry);
404 return 0;
405}
e28563cc 406#endif /* CONFIG_PROC_FS */
1da177e4
LT
407
408/*
409 * INIT PART
410 */
411
412static int __init alsa_sound_init(void)
413{
414 short controlnum;
1da177e4
LT
415
416 snd_major = major;
417 snd_ecards_limit = cards_limit;
1da177e4
LT
418 devfs_mk_dir("snd");
419 if (register_chrdev(major, "alsa", &snd_fops)) {
420 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
421 devfs_remove("snd");
422 return -EIO;
423 }
1da177e4 424 if (snd_info_init() < 0) {
1da177e4
LT
425 unregister_chrdev(major, "alsa");
426 devfs_remove("snd");
427 return -ENOMEM;
428 }
429 snd_info_minor_register();
430 for (controlnum = 0; controlnum < cards_limit; controlnum++)
431 devfs_mk_cdev(MKDEV(major, controlnum<<5), S_IFCHR | device_mode, "snd/controlC%d", controlnum);
432#ifndef MODULE
433 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
434#endif
435 return 0;
436}
437
438static void __exit alsa_sound_exit(void)
439{
440 short controlnum;
441
442 for (controlnum = 0; controlnum < cards_limit; controlnum++)
443 devfs_remove("snd/controlC%d", controlnum);
444
445 snd_info_minor_unregister();
446 snd_info_done();
1da177e4
LT
447 if (unregister_chrdev(major, "alsa") != 0)
448 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major);
449 devfs_remove("snd");
450}
451
452module_init(alsa_sound_init)
453module_exit(alsa_sound_exit)
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