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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, mode_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. Please take a look at
150 * feature-removal-schedule.txt for details.
151 */
152#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
153static int preclaim_oss = 1;
154#else
155static int preclaim_oss = 0;
156#endif
157
158module_param(preclaim_oss, int, 0444);
159
160static int soundcore_open(struct inode *, struct file *);
161
162static const struct file_operations soundcore_fops =
163{
164 /* We must have an owner or the module locking fails */
165 .owner = THIS_MODULE,
166 .open = soundcore_open,
167 .llseek = noop_llseek,
168};
169
170/*
171 * Low level list operator. Scan the ordered list, find a hole and
172 * join into it. Called with the lock asserted
173 */
174
175static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
176{
177 int n=low;
178
179 if (index < 0) { /* first free */
180
181 while (*list && (*list)->unit_minor<n)
182 list=&((*list)->next);
183
184 while(n<top)
185 {
186 /* Found a hole ? */
187 if(*list==NULL || (*list)->unit_minor>n)
188 break;
189 list=&((*list)->next);
190 n+=SOUND_STEP;
191 }
192
193 if(n>=top)
194 return -ENOENT;
195 } else {
196 n = low+(index*16);
197 while (*list) {
198 if ((*list)->unit_minor==n)
199 return -EBUSY;
200 if ((*list)->unit_minor>n)
201 break;
202 list=&((*list)->next);
203 }
204 }
205
206 /*
207 * Fill it in
208 */
209
210 s->unit_minor=n;
211 s->unit_fops=fops;
212
213 /*
214 * Link it
215 */
216
217 s->next=*list;
218 *list=s;
219
220
221 return n;
222}
223
224/*
225 * Remove a node from the chain. Called with the lock asserted
226 */
227
228static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
229{
230 while(*list)
231 {
232 struct sound_unit *p=*list;
233 if(p->unit_minor==unit)
234 {
235 *list=p->next;
236 return p;
237 }
238 list=&(p->next);
239 }
240 printk(KERN_ERR "Sound device %d went missing!\n", unit);
241 return NULL;
242}
243
244/*
245 * This lock guards the sound loader list.
246 */
247
248static DEFINE_SPINLOCK(sound_loader_lock);
249
250/*
251 * Allocate the controlling structure and add it to the sound driver
252 * list. Acquires locks as needed
253 */
254
255static 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)
256{
257 struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
258 int r;
259
260 if (!s)
261 return -ENOMEM;
262
263 spin_lock(&sound_loader_lock);
264retry:
265 r = __sound_insert_unit(s, list, fops, index, low, top);
266 spin_unlock(&sound_loader_lock);
267
268 if (r < 0)
269 goto fail;
270 else if (r < SOUND_STEP)
271 sprintf(s->name, "sound/%s", name);
272 else
273 sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
274
275 if (!preclaim_oss) {
276 /*
277 * Something else might have grabbed the minor. If
278 * first free slot is requested, rescan with @low set
279 * to the next unit; otherwise, -EBUSY.
280 */
281 r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
282 &soundcore_fops);
283 if (r < 0) {
284 spin_lock(&sound_loader_lock);
285 __sound_remove_unit(list, s->unit_minor);
286 if (index < 0) {
287 low = s->unit_minor + SOUND_STEP;
288 goto retry;
289 }
290 spin_unlock(&sound_loader_lock);
291 return -EBUSY;
292 }
293 }
294
295 device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
296 NULL, s->name+6);
297 return s->unit_minor;
298
299fail:
300 kfree(s);
301 return r;
302}
303
304/*
305 * Remove a unit. Acquires locks as needed. The drivers MUST have
306 * completed the removal before their file operations become
307 * invalid.
308 */
309
310static void sound_remove_unit(struct sound_unit **list, int unit)
311{
312 struct sound_unit *p;
313
314 spin_lock(&sound_loader_lock);
315 p = __sound_remove_unit(list, unit);
316 spin_unlock(&sound_loader_lock);
317 if (p) {
318 if (!preclaim_oss)
319 __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
320 p->name);
321 device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
322 kfree(p);
323 }
324}
325
326/*
327 * Allocations
328 *
329 * 0 *16 Mixers
330 * 1 *8 Sequencers
331 * 2 *16 Midi
332 * 3 *16 DSP
333 * 4 *16 SunDSP
334 * 5 *16 DSP16
335 * 6 -- sndstat (obsolete)
336 * 7 *16 unused
337 * 8 -- alternate sequencer (see above)
338 * 9 *16 raw synthesizer access
339 * 10 *16 unused
340 * 11 *16 unused
341 * 12 *16 unused
342 * 13 *16 unused
343 * 14 *16 unused
344 * 15 *16 unused
345 */
346
347static struct sound_unit *chains[SOUND_STEP];
348
349/**
350 * register_sound_special_device - register a special sound node
351 * @fops: File operations for the driver
352 * @unit: Unit number to allocate
353 * @dev: device pointer
354 *
355 * Allocate a special sound device by minor number from the sound
356 * subsystem. The allocated number is returned on success. On failure
357 * a negative error code is returned.
358 */
359
360int register_sound_special_device(const struct file_operations *fops, int unit,
361 struct device *dev)
362{
363 const int chain = unit % SOUND_STEP;
364 int max_unit = 128 + chain;
365 const char *name;
366 char _name[16];
367
368 switch (chain) {
369 case 0:
370 name = "mixer";
371 break;
372 case 1:
373 name = "sequencer";
374 if (unit >= SOUND_STEP)
375 goto __unknown;
376 max_unit = unit + 1;
377 break;
378 case 2:
379 name = "midi";
380 break;
381 case 3:
382 name = "dsp";
383 break;
384 case 4:
385 name = "audio";
386 break;
387 case 5:
388 name = "dspW";
389 break;
390 case 8:
391 name = "sequencer2";
392 if (unit >= SOUND_STEP)
393 goto __unknown;
394 max_unit = unit + 1;
395 break;
396 case 9:
397 name = "dmmidi";
398 break;
399 case 10:
400 name = "dmfm";
401 break;
402 case 12:
403 name = "adsp";
404 break;
405 case 13:
406 name = "amidi";
407 break;
408 case 14:
409 name = "admmidi";
410 break;
411 default:
412 {
413 __unknown:
414 sprintf(_name, "unknown%d", chain);
415 if (unit >= SOUND_STEP)
416 strcat(_name, "-");
417 name = _name;
418 }
419 break;
420 }
421 return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
422 name, S_IRUSR | S_IWUSR, dev);
423}
424
425EXPORT_SYMBOL(register_sound_special_device);
426
427int register_sound_special(const struct file_operations *fops, int unit)
428{
429 return register_sound_special_device(fops, unit, NULL);
430}
431
432EXPORT_SYMBOL(register_sound_special);
433
434/**
435 * register_sound_mixer - register a mixer device
436 * @fops: File operations for the driver
437 * @dev: Unit number to allocate
438 *
439 * Allocate a mixer device. Unit is the number of the mixer requested.
440 * Pass -1 to request the next free mixer unit. On success the allocated
441 * number is returned, on failure a negative error code is returned.
442 */
443
444int register_sound_mixer(const struct file_operations *fops, int dev)
445{
446 return sound_insert_unit(&chains[0], fops, dev, 0, 128,
447 "mixer", S_IRUSR | S_IWUSR, NULL);
448}
449
450EXPORT_SYMBOL(register_sound_mixer);
451
452/**
453 * register_sound_midi - register a midi device
454 * @fops: File operations for the driver
455 * @dev: Unit number to allocate
456 *
457 * Allocate a midi device. Unit is the number of the midi device requested.
458 * Pass -1 to request the next free midi unit. On success the allocated
459 * number is returned, on failure a negative error code is returned.
460 */
461
462int register_sound_midi(const struct file_operations *fops, int dev)
463{
464 return sound_insert_unit(&chains[2], fops, dev, 2, 130,
465 "midi", S_IRUSR | S_IWUSR, NULL);
466}
467
468EXPORT_SYMBOL(register_sound_midi);
469
470/*
471 * DSP's are registered as a triple. Register only one and cheat
472 * in open - see below.
473 */
474
475/**
476 * register_sound_dsp - register a DSP device
477 * @fops: File operations for the driver
478 * @dev: Unit number to allocate
479 *
480 * Allocate a DSP device. Unit is the number of the DSP requested.
481 * Pass -1 to request the next free DSP unit. On success the allocated
482 * number is returned, on failure a negative error code is returned.
483 *
484 * This function allocates both the audio and dsp device entries together
485 * and will always allocate them as a matching pair - eg dsp3/audio3
486 */
487
488int register_sound_dsp(const struct file_operations *fops, int dev)
489{
490 return sound_insert_unit(&chains[3], fops, dev, 3, 131,
491 "dsp", S_IWUSR | S_IRUSR, NULL);
492}
493
494EXPORT_SYMBOL(register_sound_dsp);
495
496/**
497 * unregister_sound_special - unregister a special sound device
498 * @unit: unit number to allocate
499 *
500 * Release a sound device that was allocated with
501 * register_sound_special(). The unit passed is the return value from
502 * the register function.
503 */
504
505
506void unregister_sound_special(int unit)
507{
508 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
509}
510
511EXPORT_SYMBOL(unregister_sound_special);
512
513/**
514 * unregister_sound_mixer - unregister a mixer
515 * @unit: unit number to allocate
516 *
517 * Release a sound device that was allocated with register_sound_mixer().
518 * The unit passed is the return value from the register function.
519 */
520
521void unregister_sound_mixer(int unit)
522{
523 sound_remove_unit(&chains[0], unit);
524}
525
526EXPORT_SYMBOL(unregister_sound_mixer);
527
528/**
529 * unregister_sound_midi - unregister a midi device
530 * @unit: unit number to allocate
531 *
532 * Release a sound device that was allocated with register_sound_midi().
533 * The unit passed is the return value from the register function.
534 */
535
536void unregister_sound_midi(int unit)
537{
538 sound_remove_unit(&chains[2], unit);
539}
540
541EXPORT_SYMBOL(unregister_sound_midi);
542
543/**
544 * unregister_sound_dsp - unregister a DSP device
545 * @unit: unit number to allocate
546 *
547 * Release a sound device that was allocated with register_sound_dsp().
548 * The unit passed is the return value from the register function.
549 *
550 * Both of the allocated units are released together automatically.
551 */
552
553void unregister_sound_dsp(int unit)
554{
555 sound_remove_unit(&chains[3], unit);
556}
557
558
559EXPORT_SYMBOL(unregister_sound_dsp);
560
561static struct sound_unit *__look_for_unit(int chain, int unit)
562{
563 struct sound_unit *s;
564
565 s=chains[chain];
566 while(s && s->unit_minor <= unit)
567 {
568 if(s->unit_minor==unit)
569 return s;
570 s=s->next;
571 }
572 return NULL;
573}
574
575static int soundcore_open(struct inode *inode, struct file *file)
576{
577 int chain;
578 int unit = iminor(inode);
579 struct sound_unit *s;
580 const struct file_operations *new_fops = NULL;
581
582 chain=unit&0x0F;
583 if(chain==4 || chain==5) /* dsp/audio/dsp16 */
584 {
585 unit&=0xF0;
586 unit|=3;
587 chain=3;
588 }
589
590 spin_lock(&sound_loader_lock);
591 s = __look_for_unit(chain, unit);
592 if (s)
593 new_fops = fops_get(s->unit_fops);
594 if (preclaim_oss && !new_fops) {
595 spin_unlock(&sound_loader_lock);
596
597 /*
598 * Please, don't change this order or code.
599 * For ALSA slot means soundcard and OSS emulation code
600 * comes as add-on modules which aren't depend on
601 * ALSA toplevel modules for soundcards, thus we need
602 * load them at first. [Jaroslav Kysela <perex@jcu.cz>]
603 */
604 request_module("sound-slot-%i", unit>>4);
605 request_module("sound-service-%i-%i", unit>>4, chain);
606
607 /*
608 * sound-slot/service-* module aliases are scheduled
609 * for removal in favor of the standard char-major-*
610 * module aliases. For the time being, generate both
611 * the legacy and standard module aliases to ease
612 * transition.
613 */
614 if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
615 request_module("char-major-%d", SOUND_MAJOR);
616
617 spin_lock(&sound_loader_lock);
618 s = __look_for_unit(chain, unit);
619 if (s)
620 new_fops = fops_get(s->unit_fops);
621 }
622 if (new_fops) {
623 /*
624 * We rely upon the fact that we can't be unloaded while the
625 * subdriver is there, so if ->open() is successful we can
626 * safely drop the reference counter and if it is not we can
627 * revert to old ->f_op. Ugly, indeed, but that's the cost of
628 * switching ->f_op in the first place.
629 */
630 int err = 0;
631 const struct file_operations *old_fops = file->f_op;
632 file->f_op = new_fops;
633 spin_unlock(&sound_loader_lock);
634
635 if (file->f_op->open)
636 err = file->f_op->open(inode,file);
637
638 if (err) {
639 fops_put(file->f_op);
640 file->f_op = fops_get(old_fops);
641 }
642
643 fops_put(old_fops);
644 return err;
645 }
646 spin_unlock(&sound_loader_lock);
647 return -ENODEV;
648}
649
650MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
651
652static void cleanup_oss_soundcore(void)
653{
654 /* We have nothing to really do here - we know the lists must be
655 empty */
656 unregister_chrdev(SOUND_MAJOR, "sound");
657}
658
659static int __init init_oss_soundcore(void)
660{
661 if (preclaim_oss &&
662 register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) {
663 printk(KERN_ERR "soundcore: sound device already in use.\n");
664 return -EBUSY;
665 }
666
667 return 0;
668}
669
670#endif /* CONFIG_SOUND_OSS_CORE */