blob: 99b73c675743661318ac5cf4bd3000e26e3627a7
1 | /* |
2 | * 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 | #include <linux/kdev_t.h> |
14 | #include <linux/major.h> |
15 | #include <sound/core.h> |
16 | |
17 | #ifdef CONFIG_SOUND_OSS_CORE |
18 | static int __init init_oss_soundcore(void); |
19 | static void cleanup_oss_soundcore(void); |
20 | #else |
21 | static inline int init_oss_soundcore(void) { return 0; } |
22 | static inline void cleanup_oss_soundcore(void) { } |
23 | #endif |
24 | |
25 | struct class *sound_class; |
26 | EXPORT_SYMBOL(sound_class); |
27 | |
28 | MODULE_DESCRIPTION("Core sound module"); |
29 | MODULE_AUTHOR("Alan Cox"); |
30 | MODULE_LICENSE("GPL"); |
31 | |
32 | static char *sound_devnode(struct device *dev, umode_t *mode) |
33 | { |
34 | if (MAJOR(dev->devt) == SOUND_MAJOR) |
35 | return NULL; |
36 | return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev)); |
37 | } |
38 | |
39 | static 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 | |
53 | sound_class->devnode = sound_devnode; |
54 | |
55 | return 0; |
56 | } |
57 | |
58 | static void __exit cleanup_soundcore(void) |
59 | { |
60 | cleanup_oss_soundcore(); |
61 | class_destroy(sound_class); |
62 | } |
63 | |
64 | subsys_initcall(init_soundcore); |
65 | module_exit(cleanup_soundcore); |
66 | |
67 | |
68 | #ifdef CONFIG_SOUND_OSS_CORE |
69 | /* |
70 | * OSS sound core handling. Breaks out sound functions to submodules |
71 | * |
72 | * Author: Alan Cox <alan@lxorguk.ukuu.org.uk> |
73 | * |
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 | |
105 | #include <linux/init.h> |
106 | #include <linux/slab.h> |
107 | #include <linux/types.h> |
108 | #include <linux/kernel.h> |
109 | #include <linux/sound.h> |
110 | #include <linux/kmod.h> |
111 | |
112 | #define SOUND_STEP 16 |
113 | |
114 | struct sound_unit |
115 | { |
116 | int unit_minor; |
117 | const struct file_operations *unit_fops; |
118 | struct sound_unit *next; |
119 | char name[32]; |
120 | }; |
121 | |
122 | #ifdef CONFIG_SOUND_MSNDCLAS |
123 | extern int msnd_classic_init(void); |
124 | #endif |
125 | #ifdef CONFIG_SOUND_MSNDPIN |
126 | extern int msnd_pinnacle_init(void); |
127 | #endif |
128 | |
129 | /* |
130 | * 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 |
149 | * sound-slot/service-* module aliases. |
150 | */ |
151 | #ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM |
152 | static int preclaim_oss = 1; |
153 | #else |
154 | static int preclaim_oss = 0; |
155 | #endif |
156 | |
157 | module_param(preclaim_oss, int, 0444); |
158 | |
159 | static int soundcore_open(struct inode *, struct file *); |
160 | |
161 | static 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, |
166 | .llseek = noop_llseek, |
167 | }; |
168 | |
169 | /* |
170 | * Low level list operator. Scan the ordered list, find a hole and |
171 | * join into it. Called with the lock asserted |
172 | */ |
173 | |
174 | static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top) |
175 | { |
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 | |
227 | static 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 | |
247 | static 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 | |
254 | static 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) |
255 | { |
256 | struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL); |
257 | int r; |
258 | |
259 | if (!s) |
260 | return -ENOMEM; |
261 | |
262 | spin_lock(&sound_loader_lock); |
263 | retry: |
264 | 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 | |
274 | 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 | |
294 | device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor), |
295 | NULL, "%s", s->name+6); |
296 | return s->unit_minor; |
297 | |
298 | fail: |
299 | 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 | |
309 | static 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) { |
317 | if (!preclaim_oss) |
318 | __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1, |
319 | p->name); |
320 | device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor)); |
321 | 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 | |
346 | static struct sound_unit *chains[SOUND_STEP]; |
347 | |
348 | /** |
349 | * register_sound_special_device - register a special sound node |
350 | * @fops: File operations for the driver |
351 | * @unit: Unit number to allocate |
352 | * @dev: device pointer |
353 | * |
354 | * Allocate a special sound device by minor number from the sound |
355 | * subsystem. |
356 | * |
357 | * Return: The allocated number is returned on success. On failure, |
358 | * a negative error code is returned. |
359 | */ |
360 | |
361 | int register_sound_special_device(const struct file_operations *fops, int unit, |
362 | struct device *dev) |
363 | { |
364 | const int chain = unit % SOUND_STEP; |
365 | int max_unit = 256; |
366 | 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; |
388 | case 5: |
389 | name = "dspW"; |
390 | break; |
391 | 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, |
423 | name, S_IRUSR | S_IWUSR, dev); |
424 | } |
425 | |
426 | EXPORT_SYMBOL(register_sound_special_device); |
427 | |
428 | int register_sound_special(const struct file_operations *fops, int unit) |
429 | { |
430 | return register_sound_special_device(fops, unit, NULL); |
431 | } |
432 | |
433 | EXPORT_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. |
441 | * 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. |
445 | */ |
446 | |
447 | int register_sound_mixer(const struct file_operations *fops, int dev) |
448 | { |
449 | return sound_insert_unit(&chains[0], fops, dev, 0, 128, |
450 | "mixer", S_IRUSR | S_IWUSR, NULL); |
451 | } |
452 | |
453 | EXPORT_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. |
461 | * 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. |
465 | */ |
466 | |
467 | int register_sound_midi(const struct file_operations *fops, int dev) |
468 | { |
469 | return sound_insert_unit(&chains[2], fops, dev, 2, 130, |
470 | "midi", S_IRUSR | S_IWUSR, NULL); |
471 | } |
472 | |
473 | EXPORT_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. |
486 | * Pass -1 to request the next free DSP unit. |
487 | * |
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 |
490 | * |
491 | * Return: On success, the allocated number is returned. On failure, |
492 | * a negative error code is returned. |
493 | */ |
494 | |
495 | int register_sound_dsp(const struct file_operations *fops, int dev) |
496 | { |
497 | return sound_insert_unit(&chains[3], fops, dev, 3, 131, |
498 | "dsp", S_IWUSR | S_IRUSR, NULL); |
499 | } |
500 | |
501 | EXPORT_SYMBOL(register_sound_dsp); |
502 | |
503 | /** |
504 | * 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 | |
513 | void unregister_sound_special(int unit) |
514 | { |
515 | sound_remove_unit(&chains[unit % SOUND_STEP], unit); |
516 | } |
517 | |
518 | EXPORT_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 | |
528 | void unregister_sound_mixer(int unit) |
529 | { |
530 | sound_remove_unit(&chains[0], unit); |
531 | } |
532 | |
533 | EXPORT_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 | |
543 | void unregister_sound_midi(int unit) |
544 | { |
545 | sound_remove_unit(&chains[2], unit); |
546 | } |
547 | |
548 | EXPORT_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 | |
560 | void unregister_sound_dsp(int unit) |
561 | { |
562 | sound_remove_unit(&chains[3], unit); |
563 | } |
564 | |
565 | |
566 | EXPORT_SYMBOL(unregister_sound_dsp); |
567 | |
568 | static 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 | |
582 | static int soundcore_open(struct inode *inode, struct file *file) |
583 | { |
584 | int chain; |
585 | int unit = iminor(inode); |
586 | struct sound_unit *s; |
587 | const struct file_operations *new_fops = NULL; |
588 | |
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); |
601 | if (preclaim_oss && !new_fops) { |
602 | spin_unlock(&sound_loader_lock); |
603 | |
604 | /* |
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); |
613 | |
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 | |
624 | 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 | spin_unlock(&sound_loader_lock); |
630 | if (new_fops) { |
631 | /* |
632 | * We rely upon the fact that we can't be unloaded while the |
633 | * subdriver is there. |
634 | */ |
635 | int err = 0; |
636 | replace_fops(file, new_fops); |
637 | |
638 | if (file->f_op->open) |
639 | err = file->f_op->open(inode,file); |
640 | |
641 | return err; |
642 | } |
643 | return -ENODEV; |
644 | } |
645 | |
646 | MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR); |
647 | |
648 | static void cleanup_oss_soundcore(void) |
649 | { |
650 | /* We have nothing to really do here - we know the lists must be |
651 | empty */ |
652 | unregister_chrdev(SOUND_MAJOR, "sound"); |
653 | } |
654 | |
655 | static int __init init_oss_soundcore(void) |
656 | { |
657 | if (preclaim_oss && |
658 | register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) { |
659 | printk(KERN_ERR "soundcore: sound device already in use.\n"); |
660 | return -EBUSY; |
661 | } |
662 | |
663 | return 0; |
664 | } |
665 | |
666 | #endif /* CONFIG_SOUND_OSS_CORE */ |
667 |