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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_nodename(struct device *dev) |
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->nodename = sound_nodename; |
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 | module_init(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/smp_lock.h> |
108 | #include <linux/types.h> |
109 | #include <linux/kernel.h> |
110 | #include <linux/sound.h> |
111 | #include <linux/kmod.h> |
112 | |
113 | #define SOUND_STEP 16 |
114 | |
115 | struct sound_unit |
116 | { |
117 | int unit_minor; |
118 | const struct file_operations *unit_fops; |
119 | struct sound_unit *next; |
120 | char name[32]; |
121 | }; |
122 | |
123 | #ifdef CONFIG_SOUND_MSNDCLAS |
124 | extern int msnd_classic_init(void); |
125 | #endif |
126 | #ifdef CONFIG_SOUND_MSNDPIN |
127 | extern int msnd_pinnacle_init(void); |
128 | #endif |
129 | |
130 | /* |
131 | * Low level list operator. Scan the ordered list, find a hole and |
132 | * join into it. Called with the lock asserted |
133 | */ |
134 | |
135 | static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top) |
136 | { |
137 | int n=low; |
138 | |
139 | if (index < 0) { /* first free */ |
140 | |
141 | while (*list && (*list)->unit_minor<n) |
142 | list=&((*list)->next); |
143 | |
144 | while(n<top) |
145 | { |
146 | /* Found a hole ? */ |
147 | if(*list==NULL || (*list)->unit_minor>n) |
148 | break; |
149 | list=&((*list)->next); |
150 | n+=SOUND_STEP; |
151 | } |
152 | |
153 | if(n>=top) |
154 | return -ENOENT; |
155 | } else { |
156 | n = low+(index*16); |
157 | while (*list) { |
158 | if ((*list)->unit_minor==n) |
159 | return -EBUSY; |
160 | if ((*list)->unit_minor>n) |
161 | break; |
162 | list=&((*list)->next); |
163 | } |
164 | } |
165 | |
166 | /* |
167 | * Fill it in |
168 | */ |
169 | |
170 | s->unit_minor=n; |
171 | s->unit_fops=fops; |
172 | |
173 | /* |
174 | * Link it |
175 | */ |
176 | |
177 | s->next=*list; |
178 | *list=s; |
179 | |
180 | |
181 | return n; |
182 | } |
183 | |
184 | /* |
185 | * Remove a node from the chain. Called with the lock asserted |
186 | */ |
187 | |
188 | static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit) |
189 | { |
190 | while(*list) |
191 | { |
192 | struct sound_unit *p=*list; |
193 | if(p->unit_minor==unit) |
194 | { |
195 | *list=p->next; |
196 | return p; |
197 | } |
198 | list=&(p->next); |
199 | } |
200 | printk(KERN_ERR "Sound device %d went missing!\n", unit); |
201 | return NULL; |
202 | } |
203 | |
204 | /* |
205 | * This lock guards the sound loader list. |
206 | */ |
207 | |
208 | static DEFINE_SPINLOCK(sound_loader_lock); |
209 | |
210 | /* |
211 | * Allocate the controlling structure and add it to the sound driver |
212 | * list. Acquires locks as needed |
213 | */ |
214 | |
215 | 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) |
216 | { |
217 | struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL); |
218 | int r; |
219 | |
220 | if (!s) |
221 | return -ENOMEM; |
222 | |
223 | spin_lock(&sound_loader_lock); |
224 | r = __sound_insert_unit(s, list, fops, index, low, top); |
225 | spin_unlock(&sound_loader_lock); |
226 | |
227 | if (r < 0) |
228 | goto fail; |
229 | else if (r < SOUND_STEP) |
230 | sprintf(s->name, "sound/%s", name); |
231 | else |
232 | sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP); |
233 | |
234 | device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor), |
235 | NULL, s->name+6); |
236 | return r; |
237 | |
238 | fail: |
239 | kfree(s); |
240 | return r; |
241 | } |
242 | |
243 | /* |
244 | * Remove a unit. Acquires locks as needed. The drivers MUST have |
245 | * completed the removal before their file operations become |
246 | * invalid. |
247 | */ |
248 | |
249 | static void sound_remove_unit(struct sound_unit **list, int unit) |
250 | { |
251 | struct sound_unit *p; |
252 | |
253 | spin_lock(&sound_loader_lock); |
254 | p = __sound_remove_unit(list, unit); |
255 | spin_unlock(&sound_loader_lock); |
256 | if (p) { |
257 | device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor)); |
258 | kfree(p); |
259 | } |
260 | } |
261 | |
262 | /* |
263 | * Allocations |
264 | * |
265 | * 0 *16 Mixers |
266 | * 1 *8 Sequencers |
267 | * 2 *16 Midi |
268 | * 3 *16 DSP |
269 | * 4 *16 SunDSP |
270 | * 5 *16 DSP16 |
271 | * 6 -- sndstat (obsolete) |
272 | * 7 *16 unused |
273 | * 8 -- alternate sequencer (see above) |
274 | * 9 *16 raw synthesizer access |
275 | * 10 *16 unused |
276 | * 11 *16 unused |
277 | * 12 *16 unused |
278 | * 13 *16 unused |
279 | * 14 *16 unused |
280 | * 15 *16 unused |
281 | */ |
282 | |
283 | static struct sound_unit *chains[SOUND_STEP]; |
284 | |
285 | /** |
286 | * register_sound_special_device - register a special sound node |
287 | * @fops: File operations for the driver |
288 | * @unit: Unit number to allocate |
289 | * @dev: device pointer |
290 | * |
291 | * Allocate a special sound device by minor number from the sound |
292 | * subsystem. The allocated number is returned on succes. On failure |
293 | * a negative error code is returned. |
294 | */ |
295 | |
296 | int register_sound_special_device(const struct file_operations *fops, int unit, |
297 | struct device *dev) |
298 | { |
299 | const int chain = unit % SOUND_STEP; |
300 | int max_unit = 128 + chain; |
301 | const char *name; |
302 | char _name[16]; |
303 | |
304 | switch (chain) { |
305 | case 0: |
306 | name = "mixer"; |
307 | break; |
308 | case 1: |
309 | name = "sequencer"; |
310 | if (unit >= SOUND_STEP) |
311 | goto __unknown; |
312 | max_unit = unit + 1; |
313 | break; |
314 | case 2: |
315 | name = "midi"; |
316 | break; |
317 | case 3: |
318 | name = "dsp"; |
319 | break; |
320 | case 4: |
321 | name = "audio"; |
322 | break; |
323 | case 8: |
324 | name = "sequencer2"; |
325 | if (unit >= SOUND_STEP) |
326 | goto __unknown; |
327 | max_unit = unit + 1; |
328 | break; |
329 | case 9: |
330 | name = "dmmidi"; |
331 | break; |
332 | case 10: |
333 | name = "dmfm"; |
334 | break; |
335 | case 12: |
336 | name = "adsp"; |
337 | break; |
338 | case 13: |
339 | name = "amidi"; |
340 | break; |
341 | case 14: |
342 | name = "admmidi"; |
343 | break; |
344 | default: |
345 | { |
346 | __unknown: |
347 | sprintf(_name, "unknown%d", chain); |
348 | if (unit >= SOUND_STEP) |
349 | strcat(_name, "-"); |
350 | name = _name; |
351 | } |
352 | break; |
353 | } |
354 | return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit, |
355 | name, S_IRUSR | S_IWUSR, dev); |
356 | } |
357 | |
358 | EXPORT_SYMBOL(register_sound_special_device); |
359 | |
360 | int register_sound_special(const struct file_operations *fops, int unit) |
361 | { |
362 | return register_sound_special_device(fops, unit, NULL); |
363 | } |
364 | |
365 | EXPORT_SYMBOL(register_sound_special); |
366 | |
367 | /** |
368 | * register_sound_mixer - register a mixer device |
369 | * @fops: File operations for the driver |
370 | * @dev: Unit number to allocate |
371 | * |
372 | * Allocate a mixer device. Unit is the number of the mixer requested. |
373 | * Pass -1 to request the next free mixer unit. On success the allocated |
374 | * number is returned, on failure a negative error code is returned. |
375 | */ |
376 | |
377 | int register_sound_mixer(const struct file_operations *fops, int dev) |
378 | { |
379 | return sound_insert_unit(&chains[0], fops, dev, 0, 128, |
380 | "mixer", S_IRUSR | S_IWUSR, NULL); |
381 | } |
382 | |
383 | EXPORT_SYMBOL(register_sound_mixer); |
384 | |
385 | /** |
386 | * register_sound_midi - register a midi device |
387 | * @fops: File operations for the driver |
388 | * @dev: Unit number to allocate |
389 | * |
390 | * Allocate a midi device. Unit is the number of the midi device requested. |
391 | * Pass -1 to request the next free midi unit. On success the allocated |
392 | * number is returned, on failure a negative error code is returned. |
393 | */ |
394 | |
395 | int register_sound_midi(const struct file_operations *fops, int dev) |
396 | { |
397 | return sound_insert_unit(&chains[2], fops, dev, 2, 130, |
398 | "midi", S_IRUSR | S_IWUSR, NULL); |
399 | } |
400 | |
401 | EXPORT_SYMBOL(register_sound_midi); |
402 | |
403 | /* |
404 | * DSP's are registered as a triple. Register only one and cheat |
405 | * in open - see below. |
406 | */ |
407 | |
408 | /** |
409 | * register_sound_dsp - register a DSP device |
410 | * @fops: File operations for the driver |
411 | * @dev: Unit number to allocate |
412 | * |
413 | * Allocate a DSP device. Unit is the number of the DSP requested. |
414 | * Pass -1 to request the next free DSP unit. On success the allocated |
415 | * number is returned, on failure a negative error code is returned. |
416 | * |
417 | * This function allocates both the audio and dsp device entries together |
418 | * and will always allocate them as a matching pair - eg dsp3/audio3 |
419 | */ |
420 | |
421 | int register_sound_dsp(const struct file_operations *fops, int dev) |
422 | { |
423 | return sound_insert_unit(&chains[3], fops, dev, 3, 131, |
424 | "dsp", S_IWUSR | S_IRUSR, NULL); |
425 | } |
426 | |
427 | EXPORT_SYMBOL(register_sound_dsp); |
428 | |
429 | /** |
430 | * unregister_sound_special - unregister a special sound device |
431 | * @unit: unit number to allocate |
432 | * |
433 | * Release a sound device that was allocated with |
434 | * register_sound_special(). The unit passed is the return value from |
435 | * the register function. |
436 | */ |
437 | |
438 | |
439 | void unregister_sound_special(int unit) |
440 | { |
441 | sound_remove_unit(&chains[unit % SOUND_STEP], unit); |
442 | } |
443 | |
444 | EXPORT_SYMBOL(unregister_sound_special); |
445 | |
446 | /** |
447 | * unregister_sound_mixer - unregister a mixer |
448 | * @unit: unit number to allocate |
449 | * |
450 | * Release a sound device that was allocated with register_sound_mixer(). |
451 | * The unit passed is the return value from the register function. |
452 | */ |
453 | |
454 | void unregister_sound_mixer(int unit) |
455 | { |
456 | sound_remove_unit(&chains[0], unit); |
457 | } |
458 | |
459 | EXPORT_SYMBOL(unregister_sound_mixer); |
460 | |
461 | /** |
462 | * unregister_sound_midi - unregister a midi device |
463 | * @unit: unit number to allocate |
464 | * |
465 | * Release a sound device that was allocated with register_sound_midi(). |
466 | * The unit passed is the return value from the register function. |
467 | */ |
468 | |
469 | void unregister_sound_midi(int unit) |
470 | { |
471 | sound_remove_unit(&chains[2], unit); |
472 | } |
473 | |
474 | EXPORT_SYMBOL(unregister_sound_midi); |
475 | |
476 | /** |
477 | * unregister_sound_dsp - unregister a DSP device |
478 | * @unit: unit number to allocate |
479 | * |
480 | * Release a sound device that was allocated with register_sound_dsp(). |
481 | * The unit passed is the return value from the register function. |
482 | * |
483 | * Both of the allocated units are released together automatically. |
484 | */ |
485 | |
486 | void unregister_sound_dsp(int unit) |
487 | { |
488 | sound_remove_unit(&chains[3], unit); |
489 | } |
490 | |
491 | |
492 | EXPORT_SYMBOL(unregister_sound_dsp); |
493 | |
494 | /* |
495 | * Now our file operations |
496 | */ |
497 | |
498 | static int soundcore_open(struct inode *, struct file *); |
499 | |
500 | static const struct file_operations soundcore_fops= |
501 | { |
502 | /* We must have an owner or the module locking fails */ |
503 | .owner = THIS_MODULE, |
504 | .open = soundcore_open, |
505 | }; |
506 | |
507 | static struct sound_unit *__look_for_unit(int chain, int unit) |
508 | { |
509 | struct sound_unit *s; |
510 | |
511 | s=chains[chain]; |
512 | while(s && s->unit_minor <= unit) |
513 | { |
514 | if(s->unit_minor==unit) |
515 | return s; |
516 | s=s->next; |
517 | } |
518 | return NULL; |
519 | } |
520 | |
521 | static int soundcore_open(struct inode *inode, struct file *file) |
522 | { |
523 | int chain; |
524 | int unit = iminor(inode); |
525 | struct sound_unit *s; |
526 | const struct file_operations *new_fops = NULL; |
527 | |
528 | lock_kernel (); |
529 | |
530 | chain=unit&0x0F; |
531 | if(chain==4 || chain==5) /* dsp/audio/dsp16 */ |
532 | { |
533 | unit&=0xF0; |
534 | unit|=3; |
535 | chain=3; |
536 | } |
537 | |
538 | spin_lock(&sound_loader_lock); |
539 | s = __look_for_unit(chain, unit); |
540 | if (s) |
541 | new_fops = fops_get(s->unit_fops); |
542 | if (!new_fops) { |
543 | spin_unlock(&sound_loader_lock); |
544 | /* |
545 | * Please, don't change this order or code. |
546 | * For ALSA slot means soundcard and OSS emulation code |
547 | * comes as add-on modules which aren't depend on |
548 | * ALSA toplevel modules for soundcards, thus we need |
549 | * load them at first. [Jaroslav Kysela <perex@jcu.cz>] |
550 | */ |
551 | request_module("sound-slot-%i", unit>>4); |
552 | request_module("sound-service-%i-%i", unit>>4, chain); |
553 | spin_lock(&sound_loader_lock); |
554 | s = __look_for_unit(chain, unit); |
555 | if (s) |
556 | new_fops = fops_get(s->unit_fops); |
557 | } |
558 | if (new_fops) { |
559 | /* |
560 | * We rely upon the fact that we can't be unloaded while the |
561 | * subdriver is there, so if ->open() is successful we can |
562 | * safely drop the reference counter and if it is not we can |
563 | * revert to old ->f_op. Ugly, indeed, but that's the cost of |
564 | * switching ->f_op in the first place. |
565 | */ |
566 | int err = 0; |
567 | const struct file_operations *old_fops = file->f_op; |
568 | file->f_op = new_fops; |
569 | spin_unlock(&sound_loader_lock); |
570 | if(file->f_op->open) |
571 | err = file->f_op->open(inode,file); |
572 | if (err) { |
573 | fops_put(file->f_op); |
574 | file->f_op = fops_get(old_fops); |
575 | } |
576 | fops_put(old_fops); |
577 | unlock_kernel(); |
578 | return err; |
579 | } |
580 | spin_unlock(&sound_loader_lock); |
581 | unlock_kernel(); |
582 | return -ENODEV; |
583 | } |
584 | |
585 | MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR); |
586 | |
587 | static void cleanup_oss_soundcore(void) |
588 | { |
589 | /* We have nothing to really do here - we know the lists must be |
590 | empty */ |
591 | unregister_chrdev(SOUND_MAJOR, "sound"); |
592 | } |
593 | |
594 | static int __init init_oss_soundcore(void) |
595 | { |
596 | if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) { |
597 | printk(KERN_ERR "soundcore: sound device already in use.\n"); |
598 | return -EBUSY; |
599 | } |
600 | |
601 | return 0; |
602 | } |
603 | |
604 | #endif /* CONFIG_SOUND_OSS_CORE */ |
605 |
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