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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
18static int __init init_oss_soundcore(void);
19static void cleanup_oss_soundcore(void);
20#else
21static inline int init_oss_soundcore(void) { return 0; }
22static inline void cleanup_oss_soundcore(void) { }
23#endif
24
25struct class *sound_class;
26EXPORT_SYMBOL(sound_class);
27
28MODULE_DESCRIPTION("Core sound module");
29MODULE_AUTHOR("Alan Cox");
30MODULE_LICENSE("GPL");
31
32static 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
39static 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
58static void __exit cleanup_soundcore(void)
59{
60 cleanup_oss_soundcore();
61 class_destroy(sound_class);
62}
63
64subsys_initcall(init_soundcore);
65module_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
114struct 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
123extern int msnd_classic_init(void);
124#endif
125#ifdef CONFIG_SOUND_MSNDPIN
126extern 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
152static int preclaim_oss = 1;
153#else
154static int preclaim_oss = 0;
155#endif
156
157module_param(preclaim_oss, int, 0444);
158
159static int soundcore_open(struct inode *, struct file *);
160
161static 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
174static 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
227static 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
247static 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
254static 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);
263retry:
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
298fail:
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
309static 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
346static 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
361int 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
426EXPORT_SYMBOL(register_sound_special_device);
427
428int register_sound_special(const struct file_operations *fops, int unit)
429{
430 return register_sound_special_device(fops, unit, NULL);
431}
432
433EXPORT_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
447int 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
453EXPORT_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
467int 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
473EXPORT_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
495int 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
501EXPORT_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
513void unregister_sound_special(int unit)
514{
515 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
516}
517
518EXPORT_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
528void unregister_sound_mixer(int unit)
529{
530 sound_remove_unit(&chains[0], unit);
531}
532
533EXPORT_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
543void unregister_sound_midi(int unit)
544{
545 sound_remove_unit(&chains[2], unit);
546}
547
548EXPORT_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
560void unregister_sound_dsp(int unit)
561{
562 sound_remove_unit(&chains[3], unit);
563}
564
565
566EXPORT_SYMBOL(unregister_sound_dsp);
567
568static 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
582static 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
646MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
647
648static 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
655static int __init init_oss_soundcore(void)
656{
657 if (preclaim_oss &&
658 register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) {
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 */
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
18static int __init init_oss_soundcore(void);
19static void cleanup_oss_soundcore(void);
20#else
21static inline int init_oss_soundcore(void) { return 0; }
22static inline void cleanup_oss_soundcore(void) { }
23#endif
24
25struct class *sound_class;
26EXPORT_SYMBOL(sound_class);
27
28MODULE_DESCRIPTION("Core sound module");
29MODULE_AUTHOR("Alan Cox");
30MODULE_LICENSE("GPL");
31
32static 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
39static 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
58static void __exit cleanup_soundcore(void)
59{
60 cleanup_oss_soundcore();
61 class_destroy(sound_class);
62}
63
64subsys_initcall(init_soundcore);
65module_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
114struct 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/*
123 * By default, OSS sound_core claims full legacy minor range (0-255)
124 * of SOUND_MAJOR to trap open attempts to any sound minor and
125 * requests modules using custom sound-slot/service-* module aliases.
126 * The only benefit of doing this is allowing use of custom module
127 * aliases instead of the standard char-major-* ones. This behavior
128 * prevents alternative OSS implementation and is scheduled to be
129 * removed.
130 *
131 * CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
132 * parameter are added to allow distros and developers to try and
133 * switch to alternative implementations without needing to rebuild
134 * the kernel in the meantime. If preclaim_oss is non-zero, the
135 * kernel will behave the same as before. All SOUND_MAJOR minors are
136 * preclaimed and the custom module aliases along with standard chrdev
137 * ones are emitted if a missing device is opened. If preclaim_oss is
138 * zero, sound_core only grabs what's actually in use and for missing
139 * devices only the standard chrdev aliases are requested.
140 *
141 * All these clutters are scheduled to be removed along with
142 * sound-slot/service-* module aliases.
143 */
144#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
145static int preclaim_oss = 1;
146#else
147static int preclaim_oss = 0;
148#endif
149
150module_param(preclaim_oss, int, 0444);
151
152static int soundcore_open(struct inode *, struct file *);
153
154static const struct file_operations soundcore_fops =
155{
156 /* We must have an owner or the module locking fails */
157 .owner = THIS_MODULE,
158 .open = soundcore_open,
159 .llseek = noop_llseek,
160};
161
162/*
163 * Low level list operator. Scan the ordered list, find a hole and
164 * join into it. Called with the lock asserted
165 */
166
167static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
168{
169 int n=low;
170
171 if (index < 0) { /* first free */
172
173 while (*list && (*list)->unit_minor<n)
174 list=&((*list)->next);
175
176 while(n<top)
177 {
178 /* Found a hole ? */
179 if(*list==NULL || (*list)->unit_minor>n)
180 break;
181 list=&((*list)->next);
182 n+=SOUND_STEP;
183 }
184
185 if(n>=top)
186 return -ENOENT;
187 } else {
188 n = low+(index*16);
189 while (*list) {
190 if ((*list)->unit_minor==n)
191 return -EBUSY;
192 if ((*list)->unit_minor>n)
193 break;
194 list=&((*list)->next);
195 }
196 }
197
198 /*
199 * Fill it in
200 */
201
202 s->unit_minor=n;
203 s->unit_fops=fops;
204
205 /*
206 * Link it
207 */
208
209 s->next=*list;
210 *list=s;
211
212
213 return n;
214}
215
216/*
217 * Remove a node from the chain. Called with the lock asserted
218 */
219
220static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
221{
222 while(*list)
223 {
224 struct sound_unit *p=*list;
225 if(p->unit_minor==unit)
226 {
227 *list=p->next;
228 return p;
229 }
230 list=&(p->next);
231 }
232 printk(KERN_ERR "Sound device %d went missing!\n", unit);
233 return NULL;
234}
235
236/*
237 * This lock guards the sound loader list.
238 */
239
240static DEFINE_SPINLOCK(sound_loader_lock);
241
242/*
243 * Allocate the controlling structure and add it to the sound driver
244 * list. Acquires locks as needed
245 */
246
247static 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)
248{
249 struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
250 int r;
251
252 if (!s)
253 return -ENOMEM;
254
255 spin_lock(&sound_loader_lock);
256retry:
257 r = __sound_insert_unit(s, list, fops, index, low, top);
258 spin_unlock(&sound_loader_lock);
259
260 if (r < 0)
261 goto fail;
262 else if (r < SOUND_STEP)
263 sprintf(s->name, "sound/%s", name);
264 else
265 sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
266
267 if (!preclaim_oss) {
268 /*
269 * Something else might have grabbed the minor. If
270 * first free slot is requested, rescan with @low set
271 * to the next unit; otherwise, -EBUSY.
272 */
273 r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
274 &soundcore_fops);
275 if (r < 0) {
276 spin_lock(&sound_loader_lock);
277 __sound_remove_unit(list, s->unit_minor);
278 if (index < 0) {
279 low = s->unit_minor + SOUND_STEP;
280 goto retry;
281 }
282 spin_unlock(&sound_loader_lock);
283 return -EBUSY;
284 }
285 }
286
287 device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
288 NULL, "%s", s->name+6);
289 return s->unit_minor;
290
291fail:
292 kfree(s);
293 return r;
294}
295
296/*
297 * Remove a unit. Acquires locks as needed. The drivers MUST have
298 * completed the removal before their file operations become
299 * invalid.
300 */
301
302static void sound_remove_unit(struct sound_unit **list, int unit)
303{
304 struct sound_unit *p;
305
306 spin_lock(&sound_loader_lock);
307 p = __sound_remove_unit(list, unit);
308 spin_unlock(&sound_loader_lock);
309 if (p) {
310 if (!preclaim_oss)
311 __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
312 p->name);
313 device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
314 kfree(p);
315 }
316}
317
318/*
319 * Allocations
320 *
321 * 0 *16 Mixers
322 * 1 *8 Sequencers
323 * 2 *16 Midi
324 * 3 *16 DSP
325 * 4 *16 SunDSP
326 * 5 *16 DSP16
327 * 6 -- sndstat (obsolete)
328 * 7 *16 unused
329 * 8 -- alternate sequencer (see above)
330 * 9 *16 raw synthesizer access
331 * 10 *16 unused
332 * 11 *16 unused
333 * 12 *16 unused
334 * 13 *16 unused
335 * 14 *16 unused
336 * 15 *16 unused
337 */
338
339static struct sound_unit *chains[SOUND_STEP];
340
341/**
342 * register_sound_special_device - register a special sound node
343 * @fops: File operations for the driver
344 * @unit: Unit number to allocate
345 * @dev: device pointer
346 *
347 * Allocate a special sound device by minor number from the sound
348 * subsystem.
349 *
350 * Return: The allocated number is returned on success. On failure,
351 * a negative error code is returned.
352 */
353
354int register_sound_special_device(const struct file_operations *fops, int unit,
355 struct device *dev)
356{
357 const int chain = unit % SOUND_STEP;
358 int max_unit = 256;
359 const char *name;
360 char _name[16];
361
362 switch (chain) {
363 case 0:
364 name = "mixer";
365 break;
366 case 1:
367 name = "sequencer";
368 if (unit >= SOUND_STEP)
369 goto __unknown;
370 max_unit = unit + 1;
371 break;
372 case 2:
373 name = "midi";
374 break;
375 case 3:
376 name = "dsp";
377 break;
378 case 4:
379 name = "audio";
380 break;
381 case 5:
382 name = "dspW";
383 break;
384 case 8:
385 name = "sequencer2";
386 if (unit >= SOUND_STEP)
387 goto __unknown;
388 max_unit = unit + 1;
389 break;
390 case 9:
391 name = "dmmidi";
392 break;
393 case 10:
394 name = "dmfm";
395 break;
396 case 12:
397 name = "adsp";
398 break;
399 case 13:
400 name = "amidi";
401 break;
402 case 14:
403 name = "admmidi";
404 break;
405 default:
406 {
407 __unknown:
408 sprintf(_name, "unknown%d", chain);
409 if (unit >= SOUND_STEP)
410 strcat(_name, "-");
411 name = _name;
412 }
413 break;
414 }
415 return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
416 name, S_IRUSR | S_IWUSR, dev);
417}
418
419EXPORT_SYMBOL(register_sound_special_device);
420
421int register_sound_special(const struct file_operations *fops, int unit)
422{
423 return register_sound_special_device(fops, unit, NULL);
424}
425
426EXPORT_SYMBOL(register_sound_special);
427
428/**
429 * register_sound_mixer - register a mixer device
430 * @fops: File operations for the driver
431 * @dev: Unit number to allocate
432 *
433 * Allocate a mixer device. Unit is the number of the mixer requested.
434 * Pass -1 to request the next free mixer unit.
435 *
436 * Return: On success, the allocated number is returned. On failure,
437 * a negative error code is returned.
438 */
439
440int register_sound_mixer(const struct file_operations *fops, int dev)
441{
442 return sound_insert_unit(&chains[0], fops, dev, 0, 128,
443 "mixer", S_IRUSR | S_IWUSR, NULL);
444}
445
446EXPORT_SYMBOL(register_sound_mixer);
447
448/*
449 * DSP's are registered as a triple. Register only one and cheat
450 * in open - see below.
451 */
452
453/**
454 * register_sound_dsp - register a DSP device
455 * @fops: File operations for the driver
456 * @dev: Unit number to allocate
457 *
458 * Allocate a DSP device. Unit is the number of the DSP requested.
459 * Pass -1 to request the next free DSP unit.
460 *
461 * This function allocates both the audio and dsp device entries together
462 * and will always allocate them as a matching pair - eg dsp3/audio3
463 *
464 * Return: On success, the allocated number is returned. On failure,
465 * a negative error code is returned.
466 */
467
468int register_sound_dsp(const struct file_operations *fops, int dev)
469{
470 return sound_insert_unit(&chains[3], fops, dev, 3, 131,
471 "dsp", S_IWUSR | S_IRUSR, NULL);
472}
473
474EXPORT_SYMBOL(register_sound_dsp);
475
476/**
477 * unregister_sound_special - unregister a special sound device
478 * @unit: unit number to allocate
479 *
480 * Release a sound device that was allocated with
481 * register_sound_special(). The unit passed is the return value from
482 * the register function.
483 */
484
485
486void unregister_sound_special(int unit)
487{
488 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
489}
490
491EXPORT_SYMBOL(unregister_sound_special);
492
493/**
494 * unregister_sound_mixer - unregister a mixer
495 * @unit: unit number to allocate
496 *
497 * Release a sound device that was allocated with register_sound_mixer().
498 * The unit passed is the return value from the register function.
499 */
500
501void unregister_sound_mixer(int unit)
502{
503 sound_remove_unit(&chains[0], unit);
504}
505
506EXPORT_SYMBOL(unregister_sound_mixer);
507
508/**
509 * unregister_sound_dsp - unregister a DSP device
510 * @unit: unit number to allocate
511 *
512 * Release a sound device that was allocated with register_sound_dsp().
513 * The unit passed is the return value from the register function.
514 *
515 * Both of the allocated units are released together automatically.
516 */
517
518void unregister_sound_dsp(int unit)
519{
520 sound_remove_unit(&chains[3], unit);
521}
522
523
524EXPORT_SYMBOL(unregister_sound_dsp);
525
526static struct sound_unit *__look_for_unit(int chain, int unit)
527{
528 struct sound_unit *s;
529
530 s=chains[chain];
531 while(s && s->unit_minor <= unit)
532 {
533 if(s->unit_minor==unit)
534 return s;
535 s=s->next;
536 }
537 return NULL;
538}
539
540static int soundcore_open(struct inode *inode, struct file *file)
541{
542 int chain;
543 int unit = iminor(inode);
544 struct sound_unit *s;
545 const struct file_operations *new_fops = NULL;
546
547 chain=unit&0x0F;
548 if(chain==4 || chain==5) /* dsp/audio/dsp16 */
549 {
550 unit&=0xF0;
551 unit|=3;
552 chain=3;
553 }
554
555 spin_lock(&sound_loader_lock);
556 s = __look_for_unit(chain, unit);
557 if (s)
558 new_fops = fops_get(s->unit_fops);
559 if (preclaim_oss && !new_fops) {
560 spin_unlock(&sound_loader_lock);
561
562 /*
563 * Please, don't change this order or code.
564 * For ALSA slot means soundcard and OSS emulation code
565 * comes as add-on modules which aren't depend on
566 * ALSA toplevel modules for soundcards, thus we need
567 * load them at first. [Jaroslav Kysela <perex@jcu.cz>]
568 */
569 request_module("sound-slot-%i", unit>>4);
570 request_module("sound-service-%i-%i", unit>>4, chain);
571
572 /*
573 * sound-slot/service-* module aliases are scheduled
574 * for removal in favor of the standard char-major-*
575 * module aliases. For the time being, generate both
576 * the legacy and standard module aliases to ease
577 * transition.
578 */
579 if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
580 request_module("char-major-%d", SOUND_MAJOR);
581
582 spin_lock(&sound_loader_lock);
583 s = __look_for_unit(chain, unit);
584 if (s)
585 new_fops = fops_get(s->unit_fops);
586 }
587 spin_unlock(&sound_loader_lock);
588 if (new_fops) {
589 /*
590 * We rely upon the fact that we can't be unloaded while the
591 * subdriver is there.
592 */
593 int err = 0;
594 replace_fops(file, new_fops);
595
596 if (file->f_op->open)
597 err = file->f_op->open(inode,file);
598
599 return err;
600 }
601 return -ENODEV;
602}
603
604MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
605
606static void cleanup_oss_soundcore(void)
607{
608 /* We have nothing to really do here - we know the lists must be
609 empty */
610 unregister_chrdev(SOUND_MAJOR, "sound");
611}
612
613static int __init init_oss_soundcore(void)
614{
615 if (preclaim_oss &&
616 register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) {
617 printk(KERN_ERR "soundcore: sound device already in use.\n");
618 return -EBUSY;
619 }
620
621 return 0;
622}
623
624#endif /* CONFIG_SOUND_OSS_CORE */