blob: 359753fc24e161931bb0a95070331aba59c87aff [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Tejun Heod886e872008-08-28 16:42:51 +02002 * Sound core. This file is composed of two parts. sound_class
3 * which is common to both OSS and ALSA and OSS sound core which
4 * is used OSS or emulation of it.
5 */
6
7/*
8 * First, the common part.
9 */
10#include <linux/module.h>
11#include <linux/device.h>
12#include <linux/err.h>
Kay Sievers954a9732009-07-03 20:56:05 +020013#include <linux/kdev_t.h>
14#include <linux/major.h>
Mark Brown3d1ee372008-12-15 15:43:43 +000015#include <sound/core.h>
Tejun Heod886e872008-08-28 16:42:51 +020016
17#ifdef CONFIG_SOUND_OSS_CORE
18static int __init init_oss_soundcore(void);
Krzysztof Heltde30d362008-09-07 17:24:33 +020019static void cleanup_oss_soundcore(void);
Tejun Heod886e872008-08-28 16:42:51 +020020#else
21static inline int init_oss_soundcore(void) { return 0; }
22static inline void cleanup_oss_soundcore(void) { }
23#endif
24
25struct class *sound_class;
26EXPORT_SYMBOL(sound_class);
27
28MODULE_DESCRIPTION("Core sound module");
29MODULE_AUTHOR("Alan Cox");
30MODULE_LICENSE("GPL");
31
Al Viro2c9ede52011-07-23 20:24:48 -040032static char *sound_devnode(struct device *dev, umode_t *mode)
Kay Sievers7a9d56f2009-04-30 15:23:42 +020033{
Kay Sievers954a9732009-07-03 20:56:05 +020034 if (MAJOR(dev->devt) == SOUND_MAJOR)
35 return NULL;
Kay Sievers7a9d56f2009-04-30 15:23:42 +020036 return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
37}
38
Tejun Heod886e872008-08-28 16:42:51 +020039static int __init init_soundcore(void)
40{
41 int rc;
42
43 rc = init_oss_soundcore();
44 if (rc)
45 return rc;
46
47 sound_class = class_create(THIS_MODULE, "sound");
48 if (IS_ERR(sound_class)) {
49 cleanup_oss_soundcore();
50 return PTR_ERR(sound_class);
51 }
52
Kay Sieverse454cea2009-09-18 23:01:12 +020053 sound_class->devnode = sound_devnode;
Kay Sievers7a9d56f2009-04-30 15:23:42 +020054
Tejun Heod886e872008-08-28 16:42:51 +020055 return 0;
56}
57
58static void __exit cleanup_soundcore(void)
59{
60 cleanup_oss_soundcore();
61 class_destroy(sound_class);
62}
63
Thadeu Lima de Souza Cascardoc181a132010-01-12 20:20:39 -020064subsys_initcall(init_soundcore);
Tejun Heod886e872008-08-28 16:42:51 +020065module_exit(cleanup_soundcore);
66
67
68#ifdef CONFIG_SOUND_OSS_CORE
69/*
70 * OSS sound core handling. Breaks out sound functions to submodules
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 *
Alan Cox2f1e5932008-10-27 15:21:19 +000072 * Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 *
74 * Fixes:
75 *
76 *
77 * This program is free software; you can redistribute it and/or
78 * modify it under the terms of the GNU General Public License
79 * as published by the Free Software Foundation; either version
80 * 2 of the License, or (at your option) any later version.
81 *
82 * --------------------
83 *
84 * Top level handler for the sound subsystem. Various devices can
85 * plug into this. The fact they don't all go via OSS doesn't mean
86 * they don't have to implement the OSS API. There is a lot of logic
87 * to keeping much of the OSS weight out of the code in a compatibility
88 * module, but it's up to the driver to rember to load it...
89 *
90 * The code provides a set of functions for registration of devices
91 * by type. This is done rather than providing a single call so that
92 * we can hide any future changes in the internals (eg when we go to
93 * 32bit dev_t) from the modules and their interface.
94 *
95 * Secondly we need to allocate the dsp, dsp16 and audio devices as
96 * one. Thus we misuse the chains a bit to simplify this.
97 *
98 * Thirdly to make it more fun and for 2.3.x and above we do all
99 * of this using fine grained locking.
100 *
101 * FIXME: we have to resolve modules and fine grained load/unload
102 * locking at some point in 2.3.x.
103 */
104
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105#include <linux/init.h>
106#include <linux/slab.h>
107#include <linux/types.h>
108#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109#include <linux/sound.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110#include <linux/kmod.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
112#define SOUND_STEP 16
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114struct sound_unit
115{
116 int unit_minor;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800117 const struct file_operations *unit_fops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 struct sound_unit *next;
119 char name[32];
120};
121
122#ifdef CONFIG_SOUND_MSNDCLAS
123extern int msnd_classic_init(void);
124#endif
125#ifdef CONFIG_SOUND_MSNDPIN
126extern int msnd_pinnacle_init(void);
127#endif
128
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129/*
Tejun Heo93fe4482009-08-06 18:14:26 +0900130 * By default, OSS sound_core claims full legacy minor range (0-255)
131 * of SOUND_MAJOR to trap open attempts to any sound minor and
132 * requests modules using custom sound-slot/service-* module aliases.
133 * The only benefit of doing this is allowing use of custom module
134 * aliases instead of the standard char-major-* ones. This behavior
135 * prevents alternative OSS implementation and is scheduled to be
136 * removed.
137 *
138 * CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
139 * parameter are added to allow distros and developers to try and
140 * switch to alternative implementations without needing to rebuild
141 * the kernel in the meantime. If preclaim_oss is non-zero, the
142 * kernel will behave the same as before. All SOUND_MAJOR minors are
143 * preclaimed and the custom module aliases along with standard chrdev
144 * ones are emitted if a missing device is opened. If preclaim_oss is
145 * zero, sound_core only grabs what's actually in use and for missing
146 * devices only the standard chrdev aliases are requested.
147 *
148 * All these clutters are scheduled to be removed along with
Tao Ma8f6e6042012-12-17 15:59:37 -0800149 * sound-slot/service-* module aliases.
Tejun Heo93fe4482009-08-06 18:14:26 +0900150 */
151#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
152static int preclaim_oss = 1;
153#else
154static int preclaim_oss = 0;
155#endif
156
157module_param(preclaim_oss, int, 0444);
158
159static int soundcore_open(struct inode *, struct file *);
160
161static const struct file_operations soundcore_fops =
162{
163 /* We must have an owner or the module locking fails */
164 .owner = THIS_MODULE,
165 .open = soundcore_open,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200166 .llseek = noop_llseek,
Tejun Heo93fe4482009-08-06 18:14:26 +0900167};
168
169/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 * Low level list operator. Scan the ordered list, find a hole and
171 * join into it. Called with the lock asserted
172 */
173
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800174static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175{
176 int n=low;
177
178 if (index < 0) { /* first free */
179
180 while (*list && (*list)->unit_minor<n)
181 list=&((*list)->next);
182
183 while(n<top)
184 {
185 /* Found a hole ? */
186 if(*list==NULL || (*list)->unit_minor>n)
187 break;
188 list=&((*list)->next);
189 n+=SOUND_STEP;
190 }
191
192 if(n>=top)
193 return -ENOENT;
194 } else {
195 n = low+(index*16);
196 while (*list) {
197 if ((*list)->unit_minor==n)
198 return -EBUSY;
199 if ((*list)->unit_minor>n)
200 break;
201 list=&((*list)->next);
202 }
203 }
204
205 /*
206 * Fill it in
207 */
208
209 s->unit_minor=n;
210 s->unit_fops=fops;
211
212 /*
213 * Link it
214 */
215
216 s->next=*list;
217 *list=s;
218
219
220 return n;
221}
222
223/*
224 * Remove a node from the chain. Called with the lock asserted
225 */
226
227static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
228{
229 while(*list)
230 {
231 struct sound_unit *p=*list;
232 if(p->unit_minor==unit)
233 {
234 *list=p->next;
235 return p;
236 }
237 list=&(p->next);
238 }
239 printk(KERN_ERR "Sound device %d went missing!\n", unit);
240 return NULL;
241}
242
243/*
244 * This lock guards the sound loader list.
245 */
246
247static DEFINE_SPINLOCK(sound_loader_lock);
248
249/*
250 * Allocate the controlling structure and add it to the sound driver
251 * list. Acquires locks as needed
252 */
253
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800254static int sound_insert_unit(struct sound_unit **list, const struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode, struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255{
256 struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
257 int r;
258
259 if (!s)
260 return -ENOMEM;
Tejun Heo93fe4482009-08-06 18:14:26 +0900261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 spin_lock(&sound_loader_lock);
Tejun Heo93fe4482009-08-06 18:14:26 +0900263retry:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 r = __sound_insert_unit(s, list, fops, index, low, top);
265 spin_unlock(&sound_loader_lock);
266
267 if (r < 0)
268 goto fail;
269 else if (r < SOUND_STEP)
270 sprintf(s->name, "sound/%s", name);
271 else
272 sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
273
Tejun Heo93fe4482009-08-06 18:14:26 +0900274 if (!preclaim_oss) {
275 /*
276 * Something else might have grabbed the minor. If
277 * first free slot is requested, rescan with @low set
278 * to the next unit; otherwise, -EBUSY.
279 */
280 r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
281 &soundcore_fops);
282 if (r < 0) {
283 spin_lock(&sound_loader_lock);
284 __sound_remove_unit(list, s->unit_minor);
285 if (index < 0) {
286 low = s->unit_minor + SOUND_STEP;
287 goto retry;
288 }
289 spin_unlock(&sound_loader_lock);
290 return -EBUSY;
291 }
292 }
293
Greg Kroah-Hartmanabe9ab82008-07-21 20:03:34 -0700294 device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
295 NULL, s->name+6);
Tejun Heo93fe4482009-08-06 18:14:26 +0900296 return s->unit_minor;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
Tejun Heo93fe4482009-08-06 18:14:26 +0900298fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 kfree(s);
300 return r;
301}
302
303/*
304 * Remove a unit. Acquires locks as needed. The drivers MUST have
305 * completed the removal before their file operations become
306 * invalid.
307 */
308
309static void sound_remove_unit(struct sound_unit **list, int unit)
310{
311 struct sound_unit *p;
312
313 spin_lock(&sound_loader_lock);
314 p = __sound_remove_unit(list, unit);
315 spin_unlock(&sound_loader_lock);
316 if (p) {
Tejun Heo93fe4482009-08-06 18:14:26 +0900317 if (!preclaim_oss)
318 __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
319 p->name);
Greg Kroah-Hartmand80f19f2006-08-07 22:19:37 -0700320 device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 kfree(p);
322 }
323}
324
325/*
326 * Allocations
327 *
328 * 0 *16 Mixers
329 * 1 *8 Sequencers
330 * 2 *16 Midi
331 * 3 *16 DSP
332 * 4 *16 SunDSP
333 * 5 *16 DSP16
334 * 6 -- sndstat (obsolete)
335 * 7 *16 unused
336 * 8 -- alternate sequencer (see above)
337 * 9 *16 raw synthesizer access
338 * 10 *16 unused
339 * 11 *16 unused
340 * 12 *16 unused
341 * 13 *16 unused
342 * 14 *16 unused
343 * 15 *16 unused
344 */
345
346static struct sound_unit *chains[SOUND_STEP];
347
348/**
Takashi Iwaid5681212005-08-30 08:58:37 +0200349 * register_sound_special_device - register a special sound node
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 * @fops: File operations for the driver
351 * @unit: Unit number to allocate
Takashi Iwaid5681212005-08-30 08:58:37 +0200352 * @dev: device pointer
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 *
354 * Allocate a special sound device by minor number from the sound
Yacine Belkadieb7c06e2013-03-11 22:05:14 +0100355 * subsystem.
356 *
357 * Return: The allocated number is returned on success. On failure,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 * a negative error code is returned.
359 */
360
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800361int register_sound_special_device(const struct file_operations *fops, int unit,
Takashi Iwaid5681212005-08-30 08:58:37 +0200362 struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363{
364 const int chain = unit % SOUND_STEP;
Takashi Iwai2abb8012012-05-08 17:27:03 +0200365 int max_unit = 256;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 const char *name;
367 char _name[16];
368
369 switch (chain) {
370 case 0:
371 name = "mixer";
372 break;
373 case 1:
374 name = "sequencer";
375 if (unit >= SOUND_STEP)
376 goto __unknown;
377 max_unit = unit + 1;
378 break;
379 case 2:
380 name = "midi";
381 break;
382 case 3:
383 name = "dsp";
384 break;
385 case 4:
386 name = "audio";
387 break;
Takashi Iwai848669d2011-03-09 17:33:48 +0100388 case 5:
389 name = "dspW";
390 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 case 8:
392 name = "sequencer2";
393 if (unit >= SOUND_STEP)
394 goto __unknown;
395 max_unit = unit + 1;
396 break;
397 case 9:
398 name = "dmmidi";
399 break;
400 case 10:
401 name = "dmfm";
402 break;
403 case 12:
404 name = "adsp";
405 break;
406 case 13:
407 name = "amidi";
408 break;
409 case 14:
410 name = "admmidi";
411 break;
412 default:
413 {
414 __unknown:
415 sprintf(_name, "unknown%d", chain);
416 if (unit >= SOUND_STEP)
417 strcat(_name, "-");
418 name = _name;
419 }
420 break;
421 }
422 return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
Takashi Iwaid5681212005-08-30 08:58:37 +0200423 name, S_IRUSR | S_IWUSR, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424}
425
Takashi Iwaid5681212005-08-30 08:58:37 +0200426EXPORT_SYMBOL(register_sound_special_device);
427
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800428int register_sound_special(const struct file_operations *fops, int unit)
Takashi Iwaid5681212005-08-30 08:58:37 +0200429{
430 return register_sound_special_device(fops, unit, NULL);
431}
432
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433EXPORT_SYMBOL(register_sound_special);
434
435/**
436 * register_sound_mixer - register a mixer device
437 * @fops: File operations for the driver
438 * @dev: Unit number to allocate
439 *
440 * Allocate a mixer device. Unit is the number of the mixer requested.
Yacine Belkadieb7c06e2013-03-11 22:05:14 +0100441 * Pass -1 to request the next free mixer unit.
442 *
443 * Return: On success, the allocated number is returned. On failure,
444 * a negative error code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 */
446
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800447int register_sound_mixer(const struct file_operations *fops, int dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448{
449 return sound_insert_unit(&chains[0], fops, dev, 0, 128,
Takashi Iwaid5681212005-08-30 08:58:37 +0200450 "mixer", S_IRUSR | S_IWUSR, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451}
452
453EXPORT_SYMBOL(register_sound_mixer);
454
455/**
456 * register_sound_midi - register a midi device
457 * @fops: File operations for the driver
458 * @dev: Unit number to allocate
459 *
460 * Allocate a midi device. Unit is the number of the midi device requested.
Yacine Belkadieb7c06e2013-03-11 22:05:14 +0100461 * Pass -1 to request the next free midi unit.
462 *
463 * Return: On success, the allocated number is returned. On failure,
464 * a negative error code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 */
466
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800467int register_sound_midi(const struct file_operations *fops, int dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468{
469 return sound_insert_unit(&chains[2], fops, dev, 2, 130,
Takashi Iwaid5681212005-08-30 08:58:37 +0200470 "midi", S_IRUSR | S_IWUSR, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471}
472
473EXPORT_SYMBOL(register_sound_midi);
474
475/*
476 * DSP's are registered as a triple. Register only one and cheat
477 * in open - see below.
478 */
479
480/**
481 * register_sound_dsp - register a DSP device
482 * @fops: File operations for the driver
483 * @dev: Unit number to allocate
484 *
485 * Allocate a DSP device. Unit is the number of the DSP requested.
Yacine Belkadieb7c06e2013-03-11 22:05:14 +0100486 * Pass -1 to request the next free DSP unit.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 *
488 * This function allocates both the audio and dsp device entries together
489 * and will always allocate them as a matching pair - eg dsp3/audio3
Yacine Belkadieb7c06e2013-03-11 22:05:14 +0100490 *
491 * Return: On success, the allocated number is returned. On failure,
492 * a negative error code is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 */
494
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800495int register_sound_dsp(const struct file_operations *fops, int dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496{
497 return sound_insert_unit(&chains[3], fops, dev, 3, 131,
Takashi Iwaid5681212005-08-30 08:58:37 +0200498 "dsp", S_IWUSR | S_IRUSR, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499}
500
501EXPORT_SYMBOL(register_sound_dsp);
502
503/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 * unregister_sound_special - unregister a special sound device
505 * @unit: unit number to allocate
506 *
507 * Release a sound device that was allocated with
508 * register_sound_special(). The unit passed is the return value from
509 * the register function.
510 */
511
512
513void unregister_sound_special(int unit)
514{
515 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
516}
517
518EXPORT_SYMBOL(unregister_sound_special);
519
520/**
521 * unregister_sound_mixer - unregister a mixer
522 * @unit: unit number to allocate
523 *
524 * Release a sound device that was allocated with register_sound_mixer().
525 * The unit passed is the return value from the register function.
526 */
527
528void unregister_sound_mixer(int unit)
529{
530 sound_remove_unit(&chains[0], unit);
531}
532
533EXPORT_SYMBOL(unregister_sound_mixer);
534
535/**
536 * unregister_sound_midi - unregister a midi device
537 * @unit: unit number to allocate
538 *
539 * Release a sound device that was allocated with register_sound_midi().
540 * The unit passed is the return value from the register function.
541 */
542
543void unregister_sound_midi(int unit)
544{
Hannes Edera39c4ad2008-11-20 21:25:25 +0100545 sound_remove_unit(&chains[2], unit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546}
547
548EXPORT_SYMBOL(unregister_sound_midi);
549
550/**
551 * unregister_sound_dsp - unregister a DSP device
552 * @unit: unit number to allocate
553 *
554 * Release a sound device that was allocated with register_sound_dsp().
555 * The unit passed is the return value from the register function.
556 *
557 * Both of the allocated units are released together automatically.
558 */
559
560void unregister_sound_dsp(int unit)
561{
Hannes Edera39c4ad2008-11-20 21:25:25 +0100562 sound_remove_unit(&chains[3], unit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563}
564
565
566EXPORT_SYMBOL(unregister_sound_dsp);
567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568static struct sound_unit *__look_for_unit(int chain, int unit)
569{
570 struct sound_unit *s;
571
572 s=chains[chain];
573 while(s && s->unit_minor <= unit)
574 {
575 if(s->unit_minor==unit)
576 return s;
577 s=s->next;
578 }
579 return NULL;
580}
581
Hannes Edera39c4ad2008-11-20 21:25:25 +0100582static int soundcore_open(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583{
584 int chain;
585 int unit = iminor(inode);
586 struct sound_unit *s;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800587 const struct file_operations *new_fops = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588
589 chain=unit&0x0F;
590 if(chain==4 || chain==5) /* dsp/audio/dsp16 */
591 {
592 unit&=0xF0;
593 unit|=3;
594 chain=3;
595 }
596
597 spin_lock(&sound_loader_lock);
598 s = __look_for_unit(chain, unit);
599 if (s)
600 new_fops = fops_get(s->unit_fops);
Tejun Heo93fe4482009-08-06 18:14:26 +0900601 if (preclaim_oss && !new_fops) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 spin_unlock(&sound_loader_lock);
Tejun Heo0a848682009-08-06 18:13:58 +0900603
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 /*
605 * Please, don't change this order or code.
606 * For ALSA slot means soundcard and OSS emulation code
607 * comes as add-on modules which aren't depend on
608 * ALSA toplevel modules for soundcards, thus we need
609 * load them at first. [Jaroslav Kysela <perex@jcu.cz>]
610 */
611 request_module("sound-slot-%i", unit>>4);
612 request_module("sound-service-%i-%i", unit>>4, chain);
Tejun Heo0a848682009-08-06 18:13:58 +0900613
614 /*
615 * sound-slot/service-* module aliases are scheduled
616 * for removal in favor of the standard char-major-*
617 * module aliases. For the time being, generate both
618 * the legacy and standard module aliases to ease
619 * transition.
620 */
621 if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
622 request_module("char-major-%d", SOUND_MAJOR);
623
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 spin_lock(&sound_loader_lock);
625 s = __look_for_unit(chain, unit);
626 if (s)
627 new_fops = fops_get(s->unit_fops);
628 }
629 if (new_fops) {
630 /*
631 * We rely upon the fact that we can't be unloaded while the
632 * subdriver is there, so if ->open() is successful we can
633 * safely drop the reference counter and if it is not we can
634 * revert to old ->f_op. Ugly, indeed, but that's the cost of
635 * switching ->f_op in the first place.
636 */
637 int err = 0;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800638 const struct file_operations *old_fops = file->f_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 file->f_op = new_fops;
640 spin_unlock(&sound_loader_lock);
John Kacur171d9f72010-07-04 00:02:31 +0200641
Arnd Bergmann90dc7632010-07-11 12:16:36 +0200642 if (file->f_op->open)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 err = file->f_op->open(inode,file);
John Kacur171d9f72010-07-04 00:02:31 +0200644
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 if (err) {
646 fops_put(file->f_op);
647 file->f_op = fops_get(old_fops);
648 }
John Kacur171d9f72010-07-04 00:02:31 +0200649
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 fops_put(old_fops);
651 return err;
652 }
653 spin_unlock(&sound_loader_lock);
654 return -ENODEV;
655}
656
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
658
Krzysztof Heltde30d362008-09-07 17:24:33 +0200659static void cleanup_oss_soundcore(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660{
661 /* We have nothing to really do here - we know the lists must be
662 empty */
663 unregister_chrdev(SOUND_MAJOR, "sound");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664}
665
Tejun Heod886e872008-08-28 16:42:51 +0200666static int __init init_oss_soundcore(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667{
Tejun Heo93fe4482009-08-06 18:14:26 +0900668 if (preclaim_oss &&
669 register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 printk(KERN_ERR "soundcore: sound device already in use.\n");
671 return -EBUSY;
672 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
674 return 0;
675}
676
Tejun Heod886e872008-08-28 16:42:51 +0200677#endif /* CONFIG_SOUND_OSS_CORE */