Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Sound core handling. Breaks out sound functions to submodules | |
3 | * | |
4 | * Author: Alan Cox <alan.cox@linux.org> | |
5 | * | |
6 | * Fixes: | |
7 | * | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | * | |
14 | * -------------------- | |
15 | * | |
16 | * Top level handler for the sound subsystem. Various devices can | |
17 | * plug into this. The fact they don't all go via OSS doesn't mean | |
18 | * they don't have to implement the OSS API. There is a lot of logic | |
19 | * to keeping much of the OSS weight out of the code in a compatibility | |
20 | * module, but it's up to the driver to rember to load it... | |
21 | * | |
22 | * The code provides a set of functions for registration of devices | |
23 | * by type. This is done rather than providing a single call so that | |
24 | * we can hide any future changes in the internals (eg when we go to | |
25 | * 32bit dev_t) from the modules and their interface. | |
26 | * | |
27 | * Secondly we need to allocate the dsp, dsp16 and audio devices as | |
28 | * one. Thus we misuse the chains a bit to simplify this. | |
29 | * | |
30 | * Thirdly to make it more fun and for 2.3.x and above we do all | |
31 | * of this using fine grained locking. | |
32 | * | |
33 | * FIXME: we have to resolve modules and fine grained load/unload | |
34 | * locking at some point in 2.3.x. | |
35 | */ | |
36 | ||
1da177e4 LT |
37 | #include <linux/module.h> |
38 | #include <linux/init.h> | |
39 | #include <linux/slab.h> | |
78a3c3d7 | 40 | #include <linux/smp_lock.h> |
1da177e4 LT |
41 | #include <linux/types.h> |
42 | #include <linux/kernel.h> | |
43 | #include <linux/fs.h> | |
44 | #include <linux/sound.h> | |
45 | #include <linux/major.h> | |
46 | #include <linux/kmod.h> | |
1da177e4 LT |
47 | #include <linux/device.h> |
48 | ||
49 | #define SOUND_STEP 16 | |
50 | ||
51 | ||
52 | struct sound_unit | |
53 | { | |
54 | int unit_minor; | |
99ac48f5 | 55 | const struct file_operations *unit_fops; |
1da177e4 LT |
56 | struct sound_unit *next; |
57 | char name[32]; | |
58 | }; | |
59 | ||
60 | #ifdef CONFIG_SOUND_MSNDCLAS | |
61 | extern int msnd_classic_init(void); | |
62 | #endif | |
63 | #ifdef CONFIG_SOUND_MSNDPIN | |
64 | extern int msnd_pinnacle_init(void); | |
65 | #endif | |
66 | ||
619e666b | 67 | struct class *sound_class; |
1da177e4 LT |
68 | EXPORT_SYMBOL(sound_class); |
69 | ||
70 | /* | |
71 | * Low level list operator. Scan the ordered list, find a hole and | |
72 | * join into it. Called with the lock asserted | |
73 | */ | |
74 | ||
99ac48f5 | 75 | static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top) |
1da177e4 LT |
76 | { |
77 | int n=low; | |
78 | ||
79 | if (index < 0) { /* first free */ | |
80 | ||
81 | while (*list && (*list)->unit_minor<n) | |
82 | list=&((*list)->next); | |
83 | ||
84 | while(n<top) | |
85 | { | |
86 | /* Found a hole ? */ | |
87 | if(*list==NULL || (*list)->unit_minor>n) | |
88 | break; | |
89 | list=&((*list)->next); | |
90 | n+=SOUND_STEP; | |
91 | } | |
92 | ||
93 | if(n>=top) | |
94 | return -ENOENT; | |
95 | } else { | |
96 | n = low+(index*16); | |
97 | while (*list) { | |
98 | if ((*list)->unit_minor==n) | |
99 | return -EBUSY; | |
100 | if ((*list)->unit_minor>n) | |
101 | break; | |
102 | list=&((*list)->next); | |
103 | } | |
104 | } | |
105 | ||
106 | /* | |
107 | * Fill it in | |
108 | */ | |
109 | ||
110 | s->unit_minor=n; | |
111 | s->unit_fops=fops; | |
112 | ||
113 | /* | |
114 | * Link it | |
115 | */ | |
116 | ||
117 | s->next=*list; | |
118 | *list=s; | |
119 | ||
120 | ||
121 | return n; | |
122 | } | |
123 | ||
124 | /* | |
125 | * Remove a node from the chain. Called with the lock asserted | |
126 | */ | |
127 | ||
128 | static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit) | |
129 | { | |
130 | while(*list) | |
131 | { | |
132 | struct sound_unit *p=*list; | |
133 | if(p->unit_minor==unit) | |
134 | { | |
135 | *list=p->next; | |
136 | return p; | |
137 | } | |
138 | list=&(p->next); | |
139 | } | |
140 | printk(KERN_ERR "Sound device %d went missing!\n", unit); | |
141 | return NULL; | |
142 | } | |
143 | ||
144 | /* | |
145 | * This lock guards the sound loader list. | |
146 | */ | |
147 | ||
148 | static DEFINE_SPINLOCK(sound_loader_lock); | |
149 | ||
150 | /* | |
151 | * Allocate the controlling structure and add it to the sound driver | |
152 | * list. Acquires locks as needed | |
153 | */ | |
154 | ||
99ac48f5 | 155 | 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) |
1da177e4 LT |
156 | { |
157 | struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL); | |
158 | int r; | |
159 | ||
160 | if (!s) | |
161 | return -ENOMEM; | |
162 | ||
163 | spin_lock(&sound_loader_lock); | |
164 | r = __sound_insert_unit(s, list, fops, index, low, top); | |
165 | spin_unlock(&sound_loader_lock); | |
166 | ||
167 | if (r < 0) | |
168 | goto fail; | |
169 | else if (r < SOUND_STEP) | |
170 | sprintf(s->name, "sound/%s", name); | |
171 | else | |
172 | sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP); | |
173 | ||
d80f19fa GKH |
174 | device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor), |
175 | s->name+6); | |
1da177e4 LT |
176 | return r; |
177 | ||
178 | fail: | |
179 | kfree(s); | |
180 | return r; | |
181 | } | |
182 | ||
183 | /* | |
184 | * Remove a unit. Acquires locks as needed. The drivers MUST have | |
185 | * completed the removal before their file operations become | |
186 | * invalid. | |
187 | */ | |
188 | ||
189 | static void sound_remove_unit(struct sound_unit **list, int unit) | |
190 | { | |
191 | struct sound_unit *p; | |
192 | ||
193 | spin_lock(&sound_loader_lock); | |
194 | p = __sound_remove_unit(list, unit); | |
195 | spin_unlock(&sound_loader_lock); | |
196 | if (p) { | |
d80f19fa | 197 | device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor)); |
1da177e4 LT |
198 | kfree(p); |
199 | } | |
200 | } | |
201 | ||
202 | /* | |
203 | * Allocations | |
204 | * | |
205 | * 0 *16 Mixers | |
206 | * 1 *8 Sequencers | |
207 | * 2 *16 Midi | |
208 | * 3 *16 DSP | |
209 | * 4 *16 SunDSP | |
210 | * 5 *16 DSP16 | |
211 | * 6 -- sndstat (obsolete) | |
212 | * 7 *16 unused | |
213 | * 8 -- alternate sequencer (see above) | |
214 | * 9 *16 raw synthesizer access | |
215 | * 10 *16 unused | |
216 | * 11 *16 unused | |
217 | * 12 *16 unused | |
218 | * 13 *16 unused | |
219 | * 14 *16 unused | |
220 | * 15 *16 unused | |
221 | */ | |
222 | ||
223 | static struct sound_unit *chains[SOUND_STEP]; | |
224 | ||
225 | /** | |
d568121c | 226 | * register_sound_special_device - register a special sound node |
1da177e4 LT |
227 | * @fops: File operations for the driver |
228 | * @unit: Unit number to allocate | |
d568121c | 229 | * @dev: device pointer |
1da177e4 LT |
230 | * |
231 | * Allocate a special sound device by minor number from the sound | |
232 | * subsystem. The allocated number is returned on succes. On failure | |
233 | * a negative error code is returned. | |
234 | */ | |
235 | ||
99ac48f5 | 236 | int register_sound_special_device(const struct file_operations *fops, int unit, |
d568121c | 237 | struct device *dev) |
1da177e4 LT |
238 | { |
239 | const int chain = unit % SOUND_STEP; | |
240 | int max_unit = 128 + chain; | |
241 | const char *name; | |
242 | char _name[16]; | |
243 | ||
244 | switch (chain) { | |
245 | case 0: | |
246 | name = "mixer"; | |
247 | break; | |
248 | case 1: | |
249 | name = "sequencer"; | |
250 | if (unit >= SOUND_STEP) | |
251 | goto __unknown; | |
252 | max_unit = unit + 1; | |
253 | break; | |
254 | case 2: | |
255 | name = "midi"; | |
256 | break; | |
257 | case 3: | |
258 | name = "dsp"; | |
259 | break; | |
260 | case 4: | |
261 | name = "audio"; | |
262 | break; | |
263 | case 8: | |
264 | name = "sequencer2"; | |
265 | if (unit >= SOUND_STEP) | |
266 | goto __unknown; | |
267 | max_unit = unit + 1; | |
268 | break; | |
269 | case 9: | |
270 | name = "dmmidi"; | |
271 | break; | |
272 | case 10: | |
273 | name = "dmfm"; | |
274 | break; | |
275 | case 12: | |
276 | name = "adsp"; | |
277 | break; | |
278 | case 13: | |
279 | name = "amidi"; | |
280 | break; | |
281 | case 14: | |
282 | name = "admmidi"; | |
283 | break; | |
284 | default: | |
285 | { | |
286 | __unknown: | |
287 | sprintf(_name, "unknown%d", chain); | |
288 | if (unit >= SOUND_STEP) | |
289 | strcat(_name, "-"); | |
290 | name = _name; | |
291 | } | |
292 | break; | |
293 | } | |
294 | return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit, | |
d568121c | 295 | name, S_IRUSR | S_IWUSR, dev); |
1da177e4 LT |
296 | } |
297 | ||
d568121c TI |
298 | EXPORT_SYMBOL(register_sound_special_device); |
299 | ||
99ac48f5 | 300 | int register_sound_special(const struct file_operations *fops, int unit) |
d568121c TI |
301 | { |
302 | return register_sound_special_device(fops, unit, NULL); | |
303 | } | |
304 | ||
1da177e4 LT |
305 | EXPORT_SYMBOL(register_sound_special); |
306 | ||
307 | /** | |
308 | * register_sound_mixer - register a mixer device | |
309 | * @fops: File operations for the driver | |
310 | * @dev: Unit number to allocate | |
311 | * | |
312 | * Allocate a mixer device. Unit is the number of the mixer requested. | |
313 | * Pass -1 to request the next free mixer unit. On success the allocated | |
314 | * number is returned, on failure a negative error code is returned. | |
315 | */ | |
316 | ||
99ac48f5 | 317 | int register_sound_mixer(const struct file_operations *fops, int dev) |
1da177e4 LT |
318 | { |
319 | return sound_insert_unit(&chains[0], fops, dev, 0, 128, | |
d568121c | 320 | "mixer", S_IRUSR | S_IWUSR, NULL); |
1da177e4 LT |
321 | } |
322 | ||
323 | EXPORT_SYMBOL(register_sound_mixer); | |
324 | ||
325 | /** | |
326 | * register_sound_midi - register a midi device | |
327 | * @fops: File operations for the driver | |
328 | * @dev: Unit number to allocate | |
329 | * | |
330 | * Allocate a midi device. Unit is the number of the midi device requested. | |
331 | * Pass -1 to request the next free midi unit. On success the allocated | |
332 | * number is returned, on failure a negative error code is returned. | |
333 | */ | |
334 | ||
99ac48f5 | 335 | int register_sound_midi(const struct file_operations *fops, int dev) |
1da177e4 LT |
336 | { |
337 | return sound_insert_unit(&chains[2], fops, dev, 2, 130, | |
d568121c | 338 | "midi", S_IRUSR | S_IWUSR, NULL); |
1da177e4 LT |
339 | } |
340 | ||
341 | EXPORT_SYMBOL(register_sound_midi); | |
342 | ||
343 | /* | |
344 | * DSP's are registered as a triple. Register only one and cheat | |
345 | * in open - see below. | |
346 | */ | |
347 | ||
348 | /** | |
349 | * register_sound_dsp - register a DSP device | |
350 | * @fops: File operations for the driver | |
351 | * @dev: Unit number to allocate | |
352 | * | |
353 | * Allocate a DSP device. Unit is the number of the DSP requested. | |
354 | * Pass -1 to request the next free DSP unit. On success the allocated | |
355 | * number is returned, on failure a negative error code is returned. | |
356 | * | |
357 | * This function allocates both the audio and dsp device entries together | |
358 | * and will always allocate them as a matching pair - eg dsp3/audio3 | |
359 | */ | |
360 | ||
99ac48f5 | 361 | int register_sound_dsp(const struct file_operations *fops, int dev) |
1da177e4 LT |
362 | { |
363 | return sound_insert_unit(&chains[3], fops, dev, 3, 131, | |
d568121c | 364 | "dsp", S_IWUSR | S_IRUSR, NULL); |
1da177e4 LT |
365 | } |
366 | ||
367 | EXPORT_SYMBOL(register_sound_dsp); | |
368 | ||
1da177e4 LT |
369 | /** |
370 | * unregister_sound_special - unregister a special sound device | |
371 | * @unit: unit number to allocate | |
372 | * | |
373 | * Release a sound device that was allocated with | |
374 | * register_sound_special(). The unit passed is the return value from | |
375 | * the register function. | |
376 | */ | |
377 | ||
378 | ||
379 | void unregister_sound_special(int unit) | |
380 | { | |
381 | sound_remove_unit(&chains[unit % SOUND_STEP], unit); | |
382 | } | |
383 | ||
384 | EXPORT_SYMBOL(unregister_sound_special); | |
385 | ||
386 | /** | |
387 | * unregister_sound_mixer - unregister a mixer | |
388 | * @unit: unit number to allocate | |
389 | * | |
390 | * Release a sound device that was allocated with register_sound_mixer(). | |
391 | * The unit passed is the return value from the register function. | |
392 | */ | |
393 | ||
394 | void unregister_sound_mixer(int unit) | |
395 | { | |
396 | sound_remove_unit(&chains[0], unit); | |
397 | } | |
398 | ||
399 | EXPORT_SYMBOL(unregister_sound_mixer); | |
400 | ||
401 | /** | |
402 | * unregister_sound_midi - unregister a midi device | |
403 | * @unit: unit number to allocate | |
404 | * | |
405 | * Release a sound device that was allocated with register_sound_midi(). | |
406 | * The unit passed is the return value from the register function. | |
407 | */ | |
408 | ||
409 | void unregister_sound_midi(int unit) | |
410 | { | |
411 | return sound_remove_unit(&chains[2], unit); | |
412 | } | |
413 | ||
414 | EXPORT_SYMBOL(unregister_sound_midi); | |
415 | ||
416 | /** | |
417 | * unregister_sound_dsp - unregister a DSP device | |
418 | * @unit: unit number to allocate | |
419 | * | |
420 | * Release a sound device that was allocated with register_sound_dsp(). | |
421 | * The unit passed is the return value from the register function. | |
422 | * | |
423 | * Both of the allocated units are released together automatically. | |
424 | */ | |
425 | ||
426 | void unregister_sound_dsp(int unit) | |
427 | { | |
428 | return sound_remove_unit(&chains[3], unit); | |
429 | } | |
430 | ||
431 | ||
432 | EXPORT_SYMBOL(unregister_sound_dsp); | |
433 | ||
1da177e4 LT |
434 | /* |
435 | * Now our file operations | |
436 | */ | |
437 | ||
438 | static int soundcore_open(struct inode *, struct file *); | |
439 | ||
9c2e08c5 | 440 | static const struct file_operations soundcore_fops= |
1da177e4 LT |
441 | { |
442 | /* We must have an owner or the module locking fails */ | |
443 | .owner = THIS_MODULE, | |
444 | .open = soundcore_open, | |
445 | }; | |
446 | ||
447 | static struct sound_unit *__look_for_unit(int chain, int unit) | |
448 | { | |
449 | struct sound_unit *s; | |
450 | ||
451 | s=chains[chain]; | |
452 | while(s && s->unit_minor <= unit) | |
453 | { | |
454 | if(s->unit_minor==unit) | |
455 | return s; | |
456 | s=s->next; | |
457 | } | |
458 | return NULL; | |
459 | } | |
460 | ||
461 | int soundcore_open(struct inode *inode, struct file *file) | |
462 | { | |
463 | int chain; | |
464 | int unit = iminor(inode); | |
465 | struct sound_unit *s; | |
99ac48f5 | 466 | const struct file_operations *new_fops = NULL; |
1da177e4 | 467 | |
78a3c3d7 JC |
468 | lock_kernel (); |
469 | ||
1da177e4 LT |
470 | chain=unit&0x0F; |
471 | if(chain==4 || chain==5) /* dsp/audio/dsp16 */ | |
472 | { | |
473 | unit&=0xF0; | |
474 | unit|=3; | |
475 | chain=3; | |
476 | } | |
477 | ||
478 | spin_lock(&sound_loader_lock); | |
479 | s = __look_for_unit(chain, unit); | |
480 | if (s) | |
481 | new_fops = fops_get(s->unit_fops); | |
482 | if (!new_fops) { | |
483 | spin_unlock(&sound_loader_lock); | |
484 | /* | |
485 | * Please, don't change this order or code. | |
486 | * For ALSA slot means soundcard and OSS emulation code | |
487 | * comes as add-on modules which aren't depend on | |
488 | * ALSA toplevel modules for soundcards, thus we need | |
489 | * load them at first. [Jaroslav Kysela <perex@jcu.cz>] | |
490 | */ | |
491 | request_module("sound-slot-%i", unit>>4); | |
492 | request_module("sound-service-%i-%i", unit>>4, chain); | |
493 | spin_lock(&sound_loader_lock); | |
494 | s = __look_for_unit(chain, unit); | |
495 | if (s) | |
496 | new_fops = fops_get(s->unit_fops); | |
497 | } | |
498 | if (new_fops) { | |
499 | /* | |
500 | * We rely upon the fact that we can't be unloaded while the | |
501 | * subdriver is there, so if ->open() is successful we can | |
502 | * safely drop the reference counter and if it is not we can | |
503 | * revert to old ->f_op. Ugly, indeed, but that's the cost of | |
504 | * switching ->f_op in the first place. | |
505 | */ | |
506 | int err = 0; | |
99ac48f5 | 507 | const struct file_operations *old_fops = file->f_op; |
1da177e4 LT |
508 | file->f_op = new_fops; |
509 | spin_unlock(&sound_loader_lock); | |
510 | if(file->f_op->open) | |
511 | err = file->f_op->open(inode,file); | |
512 | if (err) { | |
513 | fops_put(file->f_op); | |
514 | file->f_op = fops_get(old_fops); | |
515 | } | |
516 | fops_put(old_fops); | |
78a3c3d7 | 517 | unlock_kernel(); |
1da177e4 LT |
518 | return err; |
519 | } | |
520 | spin_unlock(&sound_loader_lock); | |
78a3c3d7 | 521 | unlock_kernel(); |
1da177e4 LT |
522 | return -ENODEV; |
523 | } | |
524 | ||
1da177e4 LT |
525 | MODULE_DESCRIPTION("Core sound module"); |
526 | MODULE_AUTHOR("Alan Cox"); | |
527 | MODULE_LICENSE("GPL"); | |
528 | MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR); | |
529 | ||
530 | static void __exit cleanup_soundcore(void) | |
531 | { | |
532 | /* We have nothing to really do here - we know the lists must be | |
533 | empty */ | |
534 | unregister_chrdev(SOUND_MAJOR, "sound"); | |
619e666b | 535 | class_destroy(sound_class); |
1da177e4 LT |
536 | } |
537 | ||
538 | static int __init init_soundcore(void) | |
539 | { | |
540 | if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) { | |
541 | printk(KERN_ERR "soundcore: sound device already in use.\n"); | |
542 | return -EBUSY; | |
543 | } | |
619e666b | 544 | sound_class = class_create(THIS_MODULE, "sound"); |
1da177e4 LT |
545 | if (IS_ERR(sound_class)) |
546 | return PTR_ERR(sound_class); | |
547 | ||
548 | return 0; | |
549 | } | |
550 | ||
551 | module_init(init_soundcore); | |
552 | module_exit(cleanup_soundcore); |