blob: a75b289a5d78465c25ccf2aab83958e3e8a0a67d [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>
13
14#ifdef CONFIG_SOUND_OSS_CORE
15static int __init init_oss_soundcore(void);
Krzysztof Heltde30d362008-09-07 17:24:33 +020016static void cleanup_oss_soundcore(void);
Tejun Heod886e872008-08-28 16:42:51 +020017#else
18static inline int init_oss_soundcore(void) { return 0; }
19static inline void cleanup_oss_soundcore(void) { }
20#endif
21
22struct class *sound_class;
23EXPORT_SYMBOL(sound_class);
24
25MODULE_DESCRIPTION("Core sound module");
26MODULE_AUTHOR("Alan Cox");
27MODULE_LICENSE("GPL");
28
29static int __init init_soundcore(void)
30{
31 int rc;
32
33 rc = init_oss_soundcore();
34 if (rc)
35 return rc;
36
37 sound_class = class_create(THIS_MODULE, "sound");
38 if (IS_ERR(sound_class)) {
39 cleanup_oss_soundcore();
40 return PTR_ERR(sound_class);
41 }
42
43 return 0;
44}
45
46static void __exit cleanup_soundcore(void)
47{
48 cleanup_oss_soundcore();
49 class_destroy(sound_class);
50}
51
52module_init(init_soundcore);
53module_exit(cleanup_soundcore);
54
55
56#ifdef CONFIG_SOUND_OSS_CORE
57/*
58 * OSS sound core handling. Breaks out sound functions to submodules
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 *
Alan Cox2f1e5932008-10-27 15:21:19 +000060 * Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 *
62 * Fixes:
63 *
64 *
65 * This program is free software; you can redistribute it and/or
66 * modify it under the terms of the GNU General Public License
67 * as published by the Free Software Foundation; either version
68 * 2 of the License, or (at your option) any later version.
69 *
70 * --------------------
71 *
72 * Top level handler for the sound subsystem. Various devices can
73 * plug into this. The fact they don't all go via OSS doesn't mean
74 * they don't have to implement the OSS API. There is a lot of logic
75 * to keeping much of the OSS weight out of the code in a compatibility
76 * module, but it's up to the driver to rember to load it...
77 *
78 * The code provides a set of functions for registration of devices
79 * by type. This is done rather than providing a single call so that
80 * we can hide any future changes in the internals (eg when we go to
81 * 32bit dev_t) from the modules and their interface.
82 *
83 * Secondly we need to allocate the dsp, dsp16 and audio devices as
84 * one. Thus we misuse the chains a bit to simplify this.
85 *
86 * Thirdly to make it more fun and for 2.3.x and above we do all
87 * of this using fine grained locking.
88 *
89 * FIXME: we have to resolve modules and fine grained load/unload
90 * locking at some point in 2.3.x.
91 */
92
Linus Torvalds1da177e2005-04-16 15:20:36 -070093#include <linux/init.h>
94#include <linux/slab.h>
Jonathan Corbet78a3c3d2008-05-15 16:39:03 -060095#include <linux/smp_lock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070096#include <linux/types.h>
97#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070098#include <linux/sound.h>
99#include <linux/major.h>
100#include <linux/kmod.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
102#define SOUND_STEP 16
103
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104struct sound_unit
105{
106 int unit_minor;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800107 const struct file_operations *unit_fops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 struct sound_unit *next;
109 char name[32];
110};
111
112#ifdef CONFIG_SOUND_MSNDCLAS
113extern int msnd_classic_init(void);
114#endif
115#ifdef CONFIG_SOUND_MSNDPIN
116extern int msnd_pinnacle_init(void);
117#endif
118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119/*
120 * Low level list operator. Scan the ordered list, find a hole and
121 * join into it. Called with the lock asserted
122 */
123
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800124static 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 -0700125{
126 int n=low;
127
128 if (index < 0) { /* first free */
129
130 while (*list && (*list)->unit_minor<n)
131 list=&((*list)->next);
132
133 while(n<top)
134 {
135 /* Found a hole ? */
136 if(*list==NULL || (*list)->unit_minor>n)
137 break;
138 list=&((*list)->next);
139 n+=SOUND_STEP;
140 }
141
142 if(n>=top)
143 return -ENOENT;
144 } else {
145 n = low+(index*16);
146 while (*list) {
147 if ((*list)->unit_minor==n)
148 return -EBUSY;
149 if ((*list)->unit_minor>n)
150 break;
151 list=&((*list)->next);
152 }
153 }
154
155 /*
156 * Fill it in
157 */
158
159 s->unit_minor=n;
160 s->unit_fops=fops;
161
162 /*
163 * Link it
164 */
165
166 s->next=*list;
167 *list=s;
168
169
170 return n;
171}
172
173/*
174 * Remove a node from the chain. Called with the lock asserted
175 */
176
177static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
178{
179 while(*list)
180 {
181 struct sound_unit *p=*list;
182 if(p->unit_minor==unit)
183 {
184 *list=p->next;
185 return p;
186 }
187 list=&(p->next);
188 }
189 printk(KERN_ERR "Sound device %d went missing!\n", unit);
190 return NULL;
191}
192
193/*
194 * This lock guards the sound loader list.
195 */
196
197static DEFINE_SPINLOCK(sound_loader_lock);
198
199/*
200 * Allocate the controlling structure and add it to the sound driver
201 * list. Acquires locks as needed
202 */
203
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800204static 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 -0700205{
206 struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
207 int r;
208
209 if (!s)
210 return -ENOMEM;
211
212 spin_lock(&sound_loader_lock);
213 r = __sound_insert_unit(s, list, fops, index, low, top);
214 spin_unlock(&sound_loader_lock);
215
216 if (r < 0)
217 goto fail;
218 else if (r < SOUND_STEP)
219 sprintf(s->name, "sound/%s", name);
220 else
221 sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
222
Greg Kroah-Hartmanabe9ab82008-07-21 20:03:34 -0700223 device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
224 NULL, s->name+6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 return r;
226
227 fail:
228 kfree(s);
229 return r;
230}
231
232/*
233 * Remove a unit. Acquires locks as needed. The drivers MUST have
234 * completed the removal before their file operations become
235 * invalid.
236 */
237
238static void sound_remove_unit(struct sound_unit **list, int unit)
239{
240 struct sound_unit *p;
241
242 spin_lock(&sound_loader_lock);
243 p = __sound_remove_unit(list, unit);
244 spin_unlock(&sound_loader_lock);
245 if (p) {
Greg Kroah-Hartmand80f19f2006-08-07 22:19:37 -0700246 device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 kfree(p);
248 }
249}
250
251/*
252 * Allocations
253 *
254 * 0 *16 Mixers
255 * 1 *8 Sequencers
256 * 2 *16 Midi
257 * 3 *16 DSP
258 * 4 *16 SunDSP
259 * 5 *16 DSP16
260 * 6 -- sndstat (obsolete)
261 * 7 *16 unused
262 * 8 -- alternate sequencer (see above)
263 * 9 *16 raw synthesizer access
264 * 10 *16 unused
265 * 11 *16 unused
266 * 12 *16 unused
267 * 13 *16 unused
268 * 14 *16 unused
269 * 15 *16 unused
270 */
271
272static struct sound_unit *chains[SOUND_STEP];
273
274/**
Takashi Iwaid5681212005-08-30 08:58:37 +0200275 * register_sound_special_device - register a special sound node
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 * @fops: File operations for the driver
277 * @unit: Unit number to allocate
Takashi Iwaid5681212005-08-30 08:58:37 +0200278 * @dev: device pointer
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 *
280 * Allocate a special sound device by minor number from the sound
281 * subsystem. The allocated number is returned on succes. On failure
282 * a negative error code is returned.
283 */
284
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800285int register_sound_special_device(const struct file_operations *fops, int unit,
Takashi Iwaid5681212005-08-30 08:58:37 +0200286 struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287{
288 const int chain = unit % SOUND_STEP;
289 int max_unit = 128 + chain;
290 const char *name;
291 char _name[16];
292
293 switch (chain) {
294 case 0:
295 name = "mixer";
296 break;
297 case 1:
298 name = "sequencer";
299 if (unit >= SOUND_STEP)
300 goto __unknown;
301 max_unit = unit + 1;
302 break;
303 case 2:
304 name = "midi";
305 break;
306 case 3:
307 name = "dsp";
308 break;
309 case 4:
310 name = "audio";
311 break;
312 case 8:
313 name = "sequencer2";
314 if (unit >= SOUND_STEP)
315 goto __unknown;
316 max_unit = unit + 1;
317 break;
318 case 9:
319 name = "dmmidi";
320 break;
321 case 10:
322 name = "dmfm";
323 break;
324 case 12:
325 name = "adsp";
326 break;
327 case 13:
328 name = "amidi";
329 break;
330 case 14:
331 name = "admmidi";
332 break;
333 default:
334 {
335 __unknown:
336 sprintf(_name, "unknown%d", chain);
337 if (unit >= SOUND_STEP)
338 strcat(_name, "-");
339 name = _name;
340 }
341 break;
342 }
343 return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
Takashi Iwaid5681212005-08-30 08:58:37 +0200344 name, S_IRUSR | S_IWUSR, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345}
346
Takashi Iwaid5681212005-08-30 08:58:37 +0200347EXPORT_SYMBOL(register_sound_special_device);
348
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800349int register_sound_special(const struct file_operations *fops, int unit)
Takashi Iwaid5681212005-08-30 08:58:37 +0200350{
351 return register_sound_special_device(fops, unit, NULL);
352}
353
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354EXPORT_SYMBOL(register_sound_special);
355
356/**
357 * register_sound_mixer - register a mixer device
358 * @fops: File operations for the driver
359 * @dev: Unit number to allocate
360 *
361 * Allocate a mixer device. Unit is the number of the mixer requested.
362 * Pass -1 to request the next free mixer unit. On success the allocated
363 * number is returned, on failure a negative error code is returned.
364 */
365
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800366int register_sound_mixer(const struct file_operations *fops, int dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367{
368 return sound_insert_unit(&chains[0], fops, dev, 0, 128,
Takashi Iwaid5681212005-08-30 08:58:37 +0200369 "mixer", S_IRUSR | S_IWUSR, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370}
371
372EXPORT_SYMBOL(register_sound_mixer);
373
374/**
375 * register_sound_midi - register a midi device
376 * @fops: File operations for the driver
377 * @dev: Unit number to allocate
378 *
379 * Allocate a midi device. Unit is the number of the midi device requested.
380 * Pass -1 to request the next free midi unit. On success the allocated
381 * number is returned, on failure a negative error code is returned.
382 */
383
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800384int register_sound_midi(const struct file_operations *fops, int dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385{
386 return sound_insert_unit(&chains[2], fops, dev, 2, 130,
Takashi Iwaid5681212005-08-30 08:58:37 +0200387 "midi", S_IRUSR | S_IWUSR, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388}
389
390EXPORT_SYMBOL(register_sound_midi);
391
392/*
393 * DSP's are registered as a triple. Register only one and cheat
394 * in open - see below.
395 */
396
397/**
398 * register_sound_dsp - register a DSP device
399 * @fops: File operations for the driver
400 * @dev: Unit number to allocate
401 *
402 * Allocate a DSP device. Unit is the number of the DSP requested.
403 * Pass -1 to request the next free DSP unit. On success the allocated
404 * number is returned, on failure a negative error code is returned.
405 *
406 * This function allocates both the audio and dsp device entries together
407 * and will always allocate them as a matching pair - eg dsp3/audio3
408 */
409
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800410int register_sound_dsp(const struct file_operations *fops, int dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411{
412 return sound_insert_unit(&chains[3], fops, dev, 3, 131,
Takashi Iwaid5681212005-08-30 08:58:37 +0200413 "dsp", S_IWUSR | S_IRUSR, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414}
415
416EXPORT_SYMBOL(register_sound_dsp);
417
418/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 * unregister_sound_special - unregister a special sound device
420 * @unit: unit number to allocate
421 *
422 * Release a sound device that was allocated with
423 * register_sound_special(). The unit passed is the return value from
424 * the register function.
425 */
426
427
428void unregister_sound_special(int unit)
429{
430 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
431}
432
433EXPORT_SYMBOL(unregister_sound_special);
434
435/**
436 * unregister_sound_mixer - unregister a mixer
437 * @unit: unit number to allocate
438 *
439 * Release a sound device that was allocated with register_sound_mixer().
440 * The unit passed is the return value from the register function.
441 */
442
443void unregister_sound_mixer(int unit)
444{
445 sound_remove_unit(&chains[0], unit);
446}
447
448EXPORT_SYMBOL(unregister_sound_mixer);
449
450/**
451 * unregister_sound_midi - unregister a midi device
452 * @unit: unit number to allocate
453 *
454 * Release a sound device that was allocated with register_sound_midi().
455 * The unit passed is the return value from the register function.
456 */
457
458void unregister_sound_midi(int unit)
459{
460 return sound_remove_unit(&chains[2], unit);
461}
462
463EXPORT_SYMBOL(unregister_sound_midi);
464
465/**
466 * unregister_sound_dsp - unregister a DSP device
467 * @unit: unit number to allocate
468 *
469 * Release a sound device that was allocated with register_sound_dsp().
470 * The unit passed is the return value from the register function.
471 *
472 * Both of the allocated units are released together automatically.
473 */
474
475void unregister_sound_dsp(int unit)
476{
477 return sound_remove_unit(&chains[3], unit);
478}
479
480
481EXPORT_SYMBOL(unregister_sound_dsp);
482
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483/*
484 * Now our file operations
485 */
486
487static int soundcore_open(struct inode *, struct file *);
488
Arjan van de Ven9c2e08c2007-02-12 00:55:37 -0800489static const struct file_operations soundcore_fops=
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490{
491 /* We must have an owner or the module locking fails */
492 .owner = THIS_MODULE,
493 .open = soundcore_open,
494};
495
496static struct sound_unit *__look_for_unit(int chain, int unit)
497{
498 struct sound_unit *s;
499
500 s=chains[chain];
501 while(s && s->unit_minor <= unit)
502 {
503 if(s->unit_minor==unit)
504 return s;
505 s=s->next;
506 }
507 return NULL;
508}
509
510int soundcore_open(struct inode *inode, struct file *file)
511{
512 int chain;
513 int unit = iminor(inode);
514 struct sound_unit *s;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800515 const struct file_operations *new_fops = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
Jonathan Corbet78a3c3d2008-05-15 16:39:03 -0600517 lock_kernel ();
518
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 chain=unit&0x0F;
520 if(chain==4 || chain==5) /* dsp/audio/dsp16 */
521 {
522 unit&=0xF0;
523 unit|=3;
524 chain=3;
525 }
526
527 spin_lock(&sound_loader_lock);
528 s = __look_for_unit(chain, unit);
529 if (s)
530 new_fops = fops_get(s->unit_fops);
531 if (!new_fops) {
532 spin_unlock(&sound_loader_lock);
533 /*
534 * Please, don't change this order or code.
535 * For ALSA slot means soundcard and OSS emulation code
536 * comes as add-on modules which aren't depend on
537 * ALSA toplevel modules for soundcards, thus we need
538 * load them at first. [Jaroslav Kysela <perex@jcu.cz>]
539 */
540 request_module("sound-slot-%i", unit>>4);
541 request_module("sound-service-%i-%i", unit>>4, chain);
542 spin_lock(&sound_loader_lock);
543 s = __look_for_unit(chain, unit);
544 if (s)
545 new_fops = fops_get(s->unit_fops);
546 }
547 if (new_fops) {
548 /*
549 * We rely upon the fact that we can't be unloaded while the
550 * subdriver is there, so if ->open() is successful we can
551 * safely drop the reference counter and if it is not we can
552 * revert to old ->f_op. Ugly, indeed, but that's the cost of
553 * switching ->f_op in the first place.
554 */
555 int err = 0;
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800556 const struct file_operations *old_fops = file->f_op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 file->f_op = new_fops;
558 spin_unlock(&sound_loader_lock);
559 if(file->f_op->open)
560 err = file->f_op->open(inode,file);
561 if (err) {
562 fops_put(file->f_op);
563 file->f_op = fops_get(old_fops);
564 }
565 fops_put(old_fops);
Jonathan Corbet78a3c3d2008-05-15 16:39:03 -0600566 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 return err;
568 }
569 spin_unlock(&sound_loader_lock);
Jonathan Corbet78a3c3d2008-05-15 16:39:03 -0600570 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 return -ENODEV;
572}
573
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
575
Krzysztof Heltde30d362008-09-07 17:24:33 +0200576static void cleanup_oss_soundcore(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577{
578 /* We have nothing to really do here - we know the lists must be
579 empty */
580 unregister_chrdev(SOUND_MAJOR, "sound");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581}
582
Tejun Heod886e872008-08-28 16:42:51 +0200583static int __init init_oss_soundcore(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584{
585 if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) {
586 printk(KERN_ERR "soundcore: sound device already in use.\n");
587 return -EBUSY;
588 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589
590 return 0;
591}
592
Tejun Heod886e872008-08-28 16:42:51 +0200593#endif /* CONFIG_SOUND_OSS_CORE */