ALSA: Kill snd_assert() in sound/core/*
[deliverable/linux.git] / sound / core / sound.c
CommitLineData
1da177e4
LT
1/*
2 * Advanced Linux Sound Architecture
c1017a4c 3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
1da177e4
LT
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
1da177e4
LT
22#include <linux/init.h>
23#include <linux/slab.h>
78a3c3d7 24#include <linux/smp_lock.h>
1da177e4 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>
1a60d4c5 35#include <linux/mutex.h>
1da177e4 36
1da177e4
LT
37static int major = CONFIG_SND_MAJOR;
38int snd_major;
c0d3fb39
TI
39EXPORT_SYMBOL(snd_major);
40
1da177e4 41static int cards_limit = 1;
1da177e4 42
c1017a4c 43MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
1da177e4
LT
44MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
45MODULE_LICENSE("GPL");
46module_param(major, int, 0444);
47MODULE_PARM_DESC(major, "Major # for sound driver.");
48module_param(cards_limit, int, 0444);
49MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
1da177e4
LT
50MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
51
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.
55 */
56int snd_ecards_limit;
c0d3fb39 57EXPORT_SYMBOL(snd_ecards_limit);
1da177e4 58
6983b724 59static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
1a60d4c5 60static DEFINE_MUTEX(sound_mutex);
1da177e4 61
ee2da997 62#ifdef CONFIG_MODULES
1da177e4
LT
63
64/**
65 * snd_request_card - try to load the card module
66 * @card: the card number
67 *
68 * Tries to load the module "snd-card-X" for the given card number
ee2da997 69 * via request_module. Returns immediately if already loaded.
1da177e4
LT
70 */
71void snd_request_card(int card)
72{
746df948 73 if (snd_card_locked(card))
1da177e4
LT
74 return;
75 if (card < 0 || card >= cards_limit)
76 return;
77 request_module("snd-card-%i", card);
78}
79
c0d3fb39
TI
80EXPORT_SYMBOL(snd_request_card);
81
1da177e4
LT
82static void snd_request_other(int minor)
83{
84 char *str;
85
1da177e4
LT
86 switch (minor) {
87 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
88 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
89 default: return;
90 }
91 request_module(str);
92}
93
ee2da997 94#endif /* modular kernel */
1da177e4 95
f87135f5
CL
96/**
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)
100 *
101 * Checks that a minor device with the specified type is registered, and returns
102 * its user data pointer.
103 */
104void *snd_lookup_minor_data(unsigned int minor, int type)
105{
106 struct snd_minor *mreg;
107 void *private_data;
108
3a63e444 109 if (minor >= ARRAY_SIZE(snd_minors))
f87135f5 110 return NULL;
1a60d4c5 111 mutex_lock(&sound_mutex);
f87135f5
CL
112 mreg = snd_minors[minor];
113 if (mreg && mreg->type == type)
114 private_data = mreg->private_data;
115 else
116 private_data = NULL;
1a60d4c5 117 mutex_unlock(&sound_mutex);
f87135f5
CL
118 return private_data;
119}
120
c0d3fb39
TI
121EXPORT_SYMBOL(snd_lookup_minor_data);
122
78a3c3d7 123static int __snd_open(struct inode *inode, struct file *file)
1da177e4 124{
332682b1 125 unsigned int minor = iminor(inode);
512bbd6a 126 struct snd_minor *mptr = NULL;
99ac48f5 127 const struct file_operations *old_fops;
1da177e4
LT
128 int err = 0;
129
3a63e444 130 if (minor >= ARRAY_SIZE(snd_minors))
332682b1
CL
131 return -ENODEV;
132 mptr = snd_minors[minor];
133 if (mptr == NULL) {
ee2da997 134#ifdef CONFIG_MODULES
332682b1
CL
135 int dev = SNDRV_MINOR_DEVICE(minor);
136 if (dev == SNDRV_MINOR_CONTROL) {
137 /* /dev/aloadC? */
138 int card = SNDRV_MINOR_CARD(minor);
1da177e4 139 if (snd_cards[card] == NULL)
332682b1
CL
140 snd_request_card(card);
141 } else if (dev == SNDRV_MINOR_GLOBAL) {
142 /* /dev/aloadSEQ */
1da177e4 143 snd_request_other(minor);
332682b1
CL
144 }
145#ifndef CONFIG_SND_DYNAMIC_MINORS
146 /* /dev/snd/{controlC?,seq} */
147 mptr = snd_minors[minor];
148 if (mptr == NULL)
149#endif
1da177e4 150#endif
332682b1 151 return -ENODEV;
1da177e4 152 }
1da177e4
LT
153 old_fops = file->f_op;
154 file->f_op = fops_get(mptr->f_ops);
155 if (file->f_op->open)
156 err = file->f_op->open(inode, file);
157 if (err) {
158 fops_put(file->f_op);
159 file->f_op = fops_get(old_fops);
160 }
161 fops_put(old_fops);
162 return err;
163}
164
78a3c3d7
JC
165
166/* BKL pushdown: nasty #ifdef avoidance wrapper */
167static int snd_open(struct inode *inode, struct file *file)
168{
169 int ret;
170
171 lock_kernel();
172 ret = __snd_open(inode, file);
173 unlock_kernel();
174 return ret;
175}
176
9c2e08c5 177static const struct file_operations snd_fops =
1da177e4
LT
178{
179 .owner = THIS_MODULE,
180 .open = snd_open
181};
182
332682b1
CL
183#ifdef CONFIG_SND_DYNAMIC_MINORS
184static int snd_find_free_minor(void)
185{
186 int minor;
187
188 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
189 /* skip minors still used statically for autoloading devices */
190 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
191 minor == SNDRV_MINOR_SEQUENCER)
192 continue;
193 if (!snd_minors[minor])
194 return minor;
195 }
196 return -EBUSY;
197}
198#else
512bbd6a 199static int snd_kernel_minor(int type, struct snd_card *card, int dev)
1da177e4
LT
200{
201 int minor;
202
203 switch (type) {
204 case SNDRV_DEVICE_TYPE_SEQUENCER:
205 case SNDRV_DEVICE_TYPE_TIMER:
206 minor = type;
207 break;
208 case SNDRV_DEVICE_TYPE_CONTROL:
7eaa943c
TI
209 if (snd_BUG_ON(!card))
210 return -EINVAL;
1da177e4
LT
211 minor = SNDRV_MINOR(card->number, type);
212 break;
213 case SNDRV_DEVICE_TYPE_HWDEP:
214 case SNDRV_DEVICE_TYPE_RAWMIDI:
215 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
216 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
7eaa943c
TI
217 if (snd_BUG_ON(!card))
218 return -EINVAL;
1da177e4
LT
219 minor = SNDRV_MINOR(card->number, type + dev);
220 break;
221 default:
222 return -EINVAL;
223 }
7eaa943c
TI
224 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
225 return -EINVAL;
1da177e4
LT
226 return minor;
227}
332682b1 228#endif
1da177e4
LT
229
230/**
12b131c4 231 * snd_register_device_for_dev - Register the ALSA device file for the card
1da177e4
LT
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 237 * @name: the device file name
12b131c4 238 * @device: the &struct device to link this new device to
1da177e4
LT
239 *
240 * Registers an ALSA device file for the given card.
241 * The operators have to be set in reg parameter.
242 *
12b131c4 243 * Returns zero if successful, or a negative error code on failure.
1da177e4 244 */
12b131c4
JB
245int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
246 const struct file_operations *f_ops,
247 void *private_data,
248 const char *name, struct device *device)
1da177e4 249{
332682b1 250 int minor;
512bbd6a 251 struct snd_minor *preg;
1da177e4 252
7eaa943c
TI
253 if (snd_BUG_ON(!name))
254 return -EINVAL;
562b590d 255 preg = kmalloc(sizeof *preg, GFP_KERNEL);
1da177e4
LT
256 if (preg == NULL)
257 return -ENOMEM;
2af677fc 258 preg->type = type;
6983b724 259 preg->card = card ? card->number : -1;
1da177e4 260 preg->device = dev;
2af677fc 261 preg->f_ops = f_ops;
f87135f5 262 preg->private_data = private_data;
1a60d4c5 263 mutex_lock(&sound_mutex);
332682b1
CL
264#ifdef CONFIG_SND_DYNAMIC_MINORS
265 minor = snd_find_free_minor();
266#else
267 minor = snd_kernel_minor(type, card, dev);
268 if (minor >= 0 && snd_minors[minor])
269 minor = -EBUSY;
270#endif
271 if (minor < 0) {
1a60d4c5 272 mutex_unlock(&sound_mutex);
1da177e4 273 kfree(preg);
332682b1 274 return minor;
1da177e4 275 }
6983b724 276 snd_minors[minor] = preg;
5d99a8b8
GKH
277 preg->dev = device_create_drvdata(sound_class, device,
278 MKDEV(major, minor),
279 private_data, "%s", name);
2469049e
MK
280 if (IS_ERR(preg->dev)) {
281 snd_minors[minor] = NULL;
282 mutex_unlock(&sound_mutex);
283 minor = PTR_ERR(preg->dev);
284 kfree(preg);
285 return minor;
286 }
287
1a60d4c5 288 mutex_unlock(&sound_mutex);
1da177e4
LT
289 return 0;
290}
291
12b131c4 292EXPORT_SYMBOL(snd_register_device_for_dev);
c0d3fb39 293
9d19f48c
TI
294/* find the matching minor record
295 * return the index of snd_minor, or -1 if not found
296 */
297static int find_snd_minor(int type, struct snd_card *card, int dev)
298{
299 int cardnum, minor;
300 struct snd_minor *mptr;
301
302 cardnum = card ? card->number : -1;
303 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
304 if ((mptr = snd_minors[minor]) != NULL &&
305 mptr->type == type &&
306 mptr->card == cardnum &&
307 mptr->device == dev)
308 return minor;
309 return -1;
310}
311
1da177e4
LT
312/**
313 * snd_unregister_device - unregister the device on the given card
314 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
315 * @card: the card instance
316 * @dev: the device index
317 *
318 * Unregisters the device file already registered via
319 * snd_register_device().
320 *
321 * Returns zero if sucecessful, or a negative error code on failure
322 */
512bbd6a 323int snd_unregister_device(int type, struct snd_card *card, int dev)
1da177e4 324{
9d19f48c 325 int minor;
1da177e4 326
1a60d4c5 327 mutex_lock(&sound_mutex);
9d19f48c
TI
328 minor = find_snd_minor(type, card, dev);
329 if (minor < 0) {
1a60d4c5 330 mutex_unlock(&sound_mutex);
1da177e4
LT
331 return -EINVAL;
332 }
333
d80f19fa 334 device_destroy(sound_class, MKDEV(major, minor));
1da177e4 335
9d19f48c 336 kfree(snd_minors[minor]);
6983b724 337 snd_minors[minor] = NULL;
1a60d4c5 338 mutex_unlock(&sound_mutex);
1da177e4
LT
339 return 0;
340}
341
c0d3fb39
TI
342EXPORT_SYMBOL(snd_unregister_device);
343
9d19f48c 344int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
d80f19fa 345 struct device_attribute *attr)
9d19f48c
TI
346{
347 int minor, ret = -EINVAL;
d80f19fa 348 struct device *d;
9d19f48c
TI
349
350 mutex_lock(&sound_mutex);
351 minor = find_snd_minor(type, card, dev);
d80f19fa
GKH
352 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
353 ret = device_create_file(d, attr);
9d19f48c
TI
354 mutex_unlock(&sound_mutex);
355 return ret;
356
357}
358
359EXPORT_SYMBOL(snd_add_device_sysfs_file);
360
e28563cc 361#ifdef CONFIG_PROC_FS
1da177e4
LT
362/*
363 * INFO PART
364 */
365
6581f4e7 366static struct snd_info_entry *snd_minor_info_entry;
1da177e4 367
2af677fc
CL
368static const char *snd_device_type_name(int type)
369{
370 switch (type) {
371 case SNDRV_DEVICE_TYPE_CONTROL:
372 return "control";
373 case SNDRV_DEVICE_TYPE_HWDEP:
374 return "hardware dependent";
375 case SNDRV_DEVICE_TYPE_RAWMIDI:
376 return "raw midi";
377 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
378 return "digital audio playback";
379 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
380 return "digital audio capture";
381 case SNDRV_DEVICE_TYPE_SEQUENCER:
382 return "sequencer";
383 case SNDRV_DEVICE_TYPE_TIMER:
384 return "timer";
385 default:
386 return "?";
387 }
388}
389
512bbd6a 390static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
1da177e4 391{
6983b724 392 int minor;
512bbd6a 393 struct snd_minor *mptr;
1da177e4 394
1a60d4c5 395 mutex_lock(&sound_mutex);
6983b724
CL
396 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
397 if (!(mptr = snd_minors[minor]))
398 continue;
399 if (mptr->card >= 0) {
400 if (mptr->device >= 0)
d001544d 401 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
6983b724
CL
402 minor, mptr->card, mptr->device,
403 snd_device_type_name(mptr->type));
404 else
d001544d 405 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
6983b724
CL
406 minor, mptr->card,
407 snd_device_type_name(mptr->type));
408 } else
d001544d 409 snd_iprintf(buffer, "%3i: : %s\n", minor,
6983b724 410 snd_device_type_name(mptr->type));
1da177e4 411 }
1a60d4c5 412 mutex_unlock(&sound_mutex);
1da177e4
LT
413}
414
415int __init snd_minor_info_init(void)
416{
512bbd6a 417 struct snd_info_entry *entry;
1da177e4
LT
418
419 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
420 if (entry) {
1da177e4
LT
421 entry->c.text.read = snd_minor_info_read;
422 if (snd_info_register(entry) < 0) {
423 snd_info_free_entry(entry);
424 entry = NULL;
425 }
426 }
427 snd_minor_info_entry = entry;
428 return 0;
429}
430
431int __exit snd_minor_info_done(void)
432{
746d4a02 433 snd_info_free_entry(snd_minor_info_entry);
1da177e4
LT
434 return 0;
435}
e28563cc 436#endif /* CONFIG_PROC_FS */
1da177e4
LT
437
438/*
439 * INIT PART
440 */
441
442static int __init alsa_sound_init(void)
443{
1da177e4
LT
444 snd_major = major;
445 snd_ecards_limit = cards_limit;
1da177e4
LT
446 if (register_chrdev(major, "alsa", &snd_fops)) {
447 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
1da177e4
LT
448 return -EIO;
449 }
1da177e4 450 if (snd_info_init() < 0) {
1da177e4 451 unregister_chrdev(major, "alsa");
1da177e4
LT
452 return -ENOMEM;
453 }
454 snd_info_minor_register();
1da177e4
LT
455#ifndef MODULE
456 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
457#endif
458 return 0;
459}
460
461static void __exit alsa_sound_exit(void)
462{
1da177e4
LT
463 snd_info_minor_unregister();
464 snd_info_done();
68fc4fab 465 unregister_chrdev(major, "alsa");
1da177e4
LT
466}
467
468module_init(alsa_sound_init)
469module_exit(alsa_sound_exit)
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