Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/sound/sound_core.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 13800 byte(s)
Tag kernel26-2.6.12-alx-r9
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 | |
37 | #include <linux/config.h> |
38 | #include <linux/module.h> |
39 | #include <linux/init.h> |
40 | #include <linux/slab.h> |
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> |
47 | #include <linux/devfs_fs_kernel.h> |
48 | #include <linux/device.h> |
49 | |
50 | #define SOUND_STEP 16 |
51 | |
52 | |
53 | struct sound_unit |
54 | { |
55 | int unit_minor; |
56 | struct file_operations *unit_fops; |
57 | struct sound_unit *next; |
58 | char name[32]; |
59 | }; |
60 | |
61 | #ifdef CONFIG_SOUND_MSNDCLAS |
62 | extern int msnd_classic_init(void); |
63 | #endif |
64 | #ifdef CONFIG_SOUND_MSNDPIN |
65 | extern int msnd_pinnacle_init(void); |
66 | #endif |
67 | |
68 | struct class_simple *sound_class; |
69 | EXPORT_SYMBOL(sound_class); |
70 | |
71 | /* |
72 | * Low level list operator. Scan the ordered list, find a hole and |
73 | * join into it. Called with the lock asserted |
74 | */ |
75 | |
76 | static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, struct file_operations *fops, int index, int low, int top) |
77 | { |
78 | int n=low; |
79 | |
80 | if (index < 0) { /* first free */ |
81 | |
82 | while (*list && (*list)->unit_minor<n) |
83 | list=&((*list)->next); |
84 | |
85 | while(n<top) |
86 | { |
87 | /* Found a hole ? */ |
88 | if(*list==NULL || (*list)->unit_minor>n) |
89 | break; |
90 | list=&((*list)->next); |
91 | n+=SOUND_STEP; |
92 | } |
93 | |
94 | if(n>=top) |
95 | return -ENOENT; |
96 | } else { |
97 | n = low+(index*16); |
98 | while (*list) { |
99 | if ((*list)->unit_minor==n) |
100 | return -EBUSY; |
101 | if ((*list)->unit_minor>n) |
102 | break; |
103 | list=&((*list)->next); |
104 | } |
105 | } |
106 | |
107 | /* |
108 | * Fill it in |
109 | */ |
110 | |
111 | s->unit_minor=n; |
112 | s->unit_fops=fops; |
113 | |
114 | /* |
115 | * Link it |
116 | */ |
117 | |
118 | s->next=*list; |
119 | *list=s; |
120 | |
121 | |
122 | return n; |
123 | } |
124 | |
125 | /* |
126 | * Remove a node from the chain. Called with the lock asserted |
127 | */ |
128 | |
129 | static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit) |
130 | { |
131 | while(*list) |
132 | { |
133 | struct sound_unit *p=*list; |
134 | if(p->unit_minor==unit) |
135 | { |
136 | *list=p->next; |
137 | return p; |
138 | } |
139 | list=&(p->next); |
140 | } |
141 | printk(KERN_ERR "Sound device %d went missing!\n", unit); |
142 | return NULL; |
143 | } |
144 | |
145 | /* |
146 | * This lock guards the sound loader list. |
147 | */ |
148 | |
149 | static DEFINE_SPINLOCK(sound_loader_lock); |
150 | |
151 | /* |
152 | * Allocate the controlling structure and add it to the sound driver |
153 | * list. Acquires locks as needed |
154 | */ |
155 | |
156 | static int sound_insert_unit(struct sound_unit **list, struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode) |
157 | { |
158 | struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL); |
159 | int r; |
160 | |
161 | if (!s) |
162 | return -ENOMEM; |
163 | |
164 | spin_lock(&sound_loader_lock); |
165 | r = __sound_insert_unit(s, list, fops, index, low, top); |
166 | spin_unlock(&sound_loader_lock); |
167 | |
168 | if (r < 0) |
169 | goto fail; |
170 | else if (r < SOUND_STEP) |
171 | sprintf(s->name, "sound/%s", name); |
172 | else |
173 | sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP); |
174 | |
175 | devfs_mk_cdev(MKDEV(SOUND_MAJOR, s->unit_minor), |
176 | S_IFCHR | mode, s->name); |
177 | class_simple_device_add(sound_class, MKDEV(SOUND_MAJOR, s->unit_minor), |
178 | NULL, s->name+6); |
179 | return r; |
180 | |
181 | fail: |
182 | kfree(s); |
183 | return r; |
184 | } |
185 | |
186 | /* |
187 | * Remove a unit. Acquires locks as needed. The drivers MUST have |
188 | * completed the removal before their file operations become |
189 | * invalid. |
190 | */ |
191 | |
192 | static void sound_remove_unit(struct sound_unit **list, int unit) |
193 | { |
194 | struct sound_unit *p; |
195 | |
196 | spin_lock(&sound_loader_lock); |
197 | p = __sound_remove_unit(list, unit); |
198 | spin_unlock(&sound_loader_lock); |
199 | if (p) { |
200 | devfs_remove(p->name); |
201 | class_simple_device_remove(MKDEV(SOUND_MAJOR, p->unit_minor)); |
202 | kfree(p); |
203 | } |
204 | } |
205 | |
206 | /* |
207 | * Allocations |
208 | * |
209 | * 0 *16 Mixers |
210 | * 1 *8 Sequencers |
211 | * 2 *16 Midi |
212 | * 3 *16 DSP |
213 | * 4 *16 SunDSP |
214 | * 5 *16 DSP16 |
215 | * 6 -- sndstat (obsolete) |
216 | * 7 *16 unused |
217 | * 8 -- alternate sequencer (see above) |
218 | * 9 *16 raw synthesizer access |
219 | * 10 *16 unused |
220 | * 11 *16 unused |
221 | * 12 *16 unused |
222 | * 13 *16 unused |
223 | * 14 *16 unused |
224 | * 15 *16 unused |
225 | */ |
226 | |
227 | static struct sound_unit *chains[SOUND_STEP]; |
228 | |
229 | /** |
230 | * register_sound_special - register a special sound node |
231 | * @fops: File operations for the driver |
232 | * @unit: Unit number to allocate |
233 | * |
234 | * Allocate a special sound device by minor number from the sound |
235 | * subsystem. The allocated number is returned on succes. On failure |
236 | * a negative error code is returned. |
237 | */ |
238 | |
239 | int register_sound_special(struct file_operations *fops, int unit) |
240 | { |
241 | const int chain = unit % SOUND_STEP; |
242 | int max_unit = 128 + chain; |
243 | const char *name; |
244 | char _name[16]; |
245 | |
246 | switch (chain) { |
247 | case 0: |
248 | name = "mixer"; |
249 | break; |
250 | case 1: |
251 | name = "sequencer"; |
252 | if (unit >= SOUND_STEP) |
253 | goto __unknown; |
254 | max_unit = unit + 1; |
255 | break; |
256 | case 2: |
257 | name = "midi"; |
258 | break; |
259 | case 3: |
260 | name = "dsp"; |
261 | break; |
262 | case 4: |
263 | name = "audio"; |
264 | break; |
265 | case 8: |
266 | name = "sequencer2"; |
267 | if (unit >= SOUND_STEP) |
268 | goto __unknown; |
269 | max_unit = unit + 1; |
270 | break; |
271 | case 9: |
272 | name = "dmmidi"; |
273 | break; |
274 | case 10: |
275 | name = "dmfm"; |
276 | break; |
277 | case 12: |
278 | name = "adsp"; |
279 | break; |
280 | case 13: |
281 | name = "amidi"; |
282 | break; |
283 | case 14: |
284 | name = "admmidi"; |
285 | break; |
286 | default: |
287 | { |
288 | __unknown: |
289 | sprintf(_name, "unknown%d", chain); |
290 | if (unit >= SOUND_STEP) |
291 | strcat(_name, "-"); |
292 | name = _name; |
293 | } |
294 | break; |
295 | } |
296 | return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit, |
297 | name, S_IRUSR | S_IWUSR); |
298 | } |
299 | |
300 | EXPORT_SYMBOL(register_sound_special); |
301 | |
302 | /** |
303 | * register_sound_mixer - register a mixer device |
304 | * @fops: File operations for the driver |
305 | * @dev: Unit number to allocate |
306 | * |
307 | * Allocate a mixer device. Unit is the number of the mixer requested. |
308 | * Pass -1 to request the next free mixer unit. On success the allocated |
309 | * number is returned, on failure a negative error code is returned. |
310 | */ |
311 | |
312 | int register_sound_mixer(struct file_operations *fops, int dev) |
313 | { |
314 | return sound_insert_unit(&chains[0], fops, dev, 0, 128, |
315 | "mixer", S_IRUSR | S_IWUSR); |
316 | } |
317 | |
318 | EXPORT_SYMBOL(register_sound_mixer); |
319 | |
320 | /** |
321 | * register_sound_midi - register a midi device |
322 | * @fops: File operations for the driver |
323 | * @dev: Unit number to allocate |
324 | * |
325 | * Allocate a midi device. Unit is the number of the midi device requested. |
326 | * Pass -1 to request the next free midi unit. On success the allocated |
327 | * number is returned, on failure a negative error code is returned. |
328 | */ |
329 | |
330 | int register_sound_midi(struct file_operations *fops, int dev) |
331 | { |
332 | return sound_insert_unit(&chains[2], fops, dev, 2, 130, |
333 | "midi", S_IRUSR | S_IWUSR); |
334 | } |
335 | |
336 | EXPORT_SYMBOL(register_sound_midi); |
337 | |
338 | /* |
339 | * DSP's are registered as a triple. Register only one and cheat |
340 | * in open - see below. |
341 | */ |
342 | |
343 | /** |
344 | * register_sound_dsp - register a DSP device |
345 | * @fops: File operations for the driver |
346 | * @dev: Unit number to allocate |
347 | * |
348 | * Allocate a DSP device. Unit is the number of the DSP requested. |
349 | * Pass -1 to request the next free DSP unit. On success the allocated |
350 | * number is returned, on failure a negative error code is returned. |
351 | * |
352 | * This function allocates both the audio and dsp device entries together |
353 | * and will always allocate them as a matching pair - eg dsp3/audio3 |
354 | */ |
355 | |
356 | int register_sound_dsp(struct file_operations *fops, int dev) |
357 | { |
358 | return sound_insert_unit(&chains[3], fops, dev, 3, 131, |
359 | "dsp", S_IWUSR | S_IRUSR); |
360 | } |
361 | |
362 | EXPORT_SYMBOL(register_sound_dsp); |
363 | |
364 | /** |
365 | * register_sound_synth - register a synth device |
366 | * @fops: File operations for the driver |
367 | * @dev: Unit number to allocate |
368 | * |
369 | * Allocate a synth device. Unit is the number of the synth device requested. |
370 | * Pass -1 to request the next free synth unit. On success the allocated |
371 | * number is returned, on failure a negative error code is returned. |
372 | */ |
373 | |
374 | |
375 | int register_sound_synth(struct file_operations *fops, int dev) |
376 | { |
377 | return sound_insert_unit(&chains[9], fops, dev, 9, 137, |
378 | "synth", S_IRUSR | S_IWUSR); |
379 | } |
380 | |
381 | EXPORT_SYMBOL(register_sound_synth); |
382 | |
383 | /** |
384 | * unregister_sound_special - unregister a special sound device |
385 | * @unit: unit number to allocate |
386 | * |
387 | * Release a sound device that was allocated with |
388 | * register_sound_special(). The unit passed is the return value from |
389 | * the register function. |
390 | */ |
391 | |
392 | |
393 | void unregister_sound_special(int unit) |
394 | { |
395 | sound_remove_unit(&chains[unit % SOUND_STEP], unit); |
396 | } |
397 | |
398 | EXPORT_SYMBOL(unregister_sound_special); |
399 | |
400 | /** |
401 | * unregister_sound_mixer - unregister a mixer |
402 | * @unit: unit number to allocate |
403 | * |
404 | * Release a sound device that was allocated with register_sound_mixer(). |
405 | * The unit passed is the return value from the register function. |
406 | */ |
407 | |
408 | void unregister_sound_mixer(int unit) |
409 | { |
410 | sound_remove_unit(&chains[0], unit); |
411 | } |
412 | |
413 | EXPORT_SYMBOL(unregister_sound_mixer); |
414 | |
415 | /** |
416 | * unregister_sound_midi - unregister a midi device |
417 | * @unit: unit number to allocate |
418 | * |
419 | * Release a sound device that was allocated with register_sound_midi(). |
420 | * The unit passed is the return value from the register function. |
421 | */ |
422 | |
423 | void unregister_sound_midi(int unit) |
424 | { |
425 | return sound_remove_unit(&chains[2], unit); |
426 | } |
427 | |
428 | EXPORT_SYMBOL(unregister_sound_midi); |
429 | |
430 | /** |
431 | * unregister_sound_dsp - unregister a DSP device |
432 | * @unit: unit number to allocate |
433 | * |
434 | * Release a sound device that was allocated with register_sound_dsp(). |
435 | * The unit passed is the return value from the register function. |
436 | * |
437 | * Both of the allocated units are released together automatically. |
438 | */ |
439 | |
440 | void unregister_sound_dsp(int unit) |
441 | { |
442 | return sound_remove_unit(&chains[3], unit); |
443 | } |
444 | |
445 | |
446 | EXPORT_SYMBOL(unregister_sound_dsp); |
447 | |
448 | /** |
449 | * unregister_sound_synth - unregister a synth device |
450 | * @unit: unit number to allocate |
451 | * |
452 | * Release a sound device that was allocated with register_sound_synth(). |
453 | * The unit passed is the return value from the register function. |
454 | */ |
455 | |
456 | void unregister_sound_synth(int unit) |
457 | { |
458 | return sound_remove_unit(&chains[9], unit); |
459 | } |
460 | |
461 | EXPORT_SYMBOL(unregister_sound_synth); |
462 | |
463 | /* |
464 | * Now our file operations |
465 | */ |
466 | |
467 | static int soundcore_open(struct inode *, struct file *); |
468 | |
469 | static struct file_operations soundcore_fops= |
470 | { |
471 | /* We must have an owner or the module locking fails */ |
472 | .owner = THIS_MODULE, |
473 | .open = soundcore_open, |
474 | }; |
475 | |
476 | static struct sound_unit *__look_for_unit(int chain, int unit) |
477 | { |
478 | struct sound_unit *s; |
479 | |
480 | s=chains[chain]; |
481 | while(s && s->unit_minor <= unit) |
482 | { |
483 | if(s->unit_minor==unit) |
484 | return s; |
485 | s=s->next; |
486 | } |
487 | return NULL; |
488 | } |
489 | |
490 | int soundcore_open(struct inode *inode, struct file *file) |
491 | { |
492 | int chain; |
493 | int unit = iminor(inode); |
494 | struct sound_unit *s; |
495 | struct file_operations *new_fops = NULL; |
496 | |
497 | chain=unit&0x0F; |
498 | if(chain==4 || chain==5) /* dsp/audio/dsp16 */ |
499 | { |
500 | unit&=0xF0; |
501 | unit|=3; |
502 | chain=3; |
503 | } |
504 | |
505 | spin_lock(&sound_loader_lock); |
506 | s = __look_for_unit(chain, unit); |
507 | if (s) |
508 | new_fops = fops_get(s->unit_fops); |
509 | if (!new_fops) { |
510 | spin_unlock(&sound_loader_lock); |
511 | /* |
512 | * Please, don't change this order or code. |
513 | * For ALSA slot means soundcard and OSS emulation code |
514 | * comes as add-on modules which aren't depend on |
515 | * ALSA toplevel modules for soundcards, thus we need |
516 | * load them at first. [Jaroslav Kysela <perex@jcu.cz>] |
517 | */ |
518 | request_module("sound-slot-%i", unit>>4); |
519 | request_module("sound-service-%i-%i", unit>>4, chain); |
520 | spin_lock(&sound_loader_lock); |
521 | s = __look_for_unit(chain, unit); |
522 | if (s) |
523 | new_fops = fops_get(s->unit_fops); |
524 | } |
525 | if (new_fops) { |
526 | /* |
527 | * We rely upon the fact that we can't be unloaded while the |
528 | * subdriver is there, so if ->open() is successful we can |
529 | * safely drop the reference counter and if it is not we can |
530 | * revert to old ->f_op. Ugly, indeed, but that's the cost of |
531 | * switching ->f_op in the first place. |
532 | */ |
533 | int err = 0; |
534 | struct file_operations *old_fops = file->f_op; |
535 | file->f_op = new_fops; |
536 | spin_unlock(&sound_loader_lock); |
537 | if(file->f_op->open) |
538 | err = file->f_op->open(inode,file); |
539 | if (err) { |
540 | fops_put(file->f_op); |
541 | file->f_op = fops_get(old_fops); |
542 | } |
543 | fops_put(old_fops); |
544 | return err; |
545 | } |
546 | spin_unlock(&sound_loader_lock); |
547 | return -ENODEV; |
548 | } |
549 | |
550 | extern int mod_firmware_load(const char *, char **); |
551 | EXPORT_SYMBOL(mod_firmware_load); |
552 | |
553 | |
554 | MODULE_DESCRIPTION("Core sound module"); |
555 | MODULE_AUTHOR("Alan Cox"); |
556 | MODULE_LICENSE("GPL"); |
557 | MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR); |
558 | |
559 | static void __exit cleanup_soundcore(void) |
560 | { |
561 | /* We have nothing to really do here - we know the lists must be |
562 | empty */ |
563 | unregister_chrdev(SOUND_MAJOR, "sound"); |
564 | devfs_remove("sound"); |
565 | class_simple_destroy(sound_class); |
566 | } |
567 | |
568 | static int __init init_soundcore(void) |
569 | { |
570 | if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) { |
571 | printk(KERN_ERR "soundcore: sound device already in use.\n"); |
572 | return -EBUSY; |
573 | } |
574 | devfs_mk_dir ("sound"); |
575 | sound_class = class_simple_create(THIS_MODULE, "sound"); |
576 | if (IS_ERR(sound_class)) |
577 | return PTR_ERR(sound_class); |
578 | |
579 | return 0; |
580 | } |
581 | |
582 | module_init(init_soundcore); |
583 | module_exit(cleanup_soundcore); |