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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// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Sound core. This file is composed of two parts. sound_class
4 * which is common to both OSS and ALSA and OSS sound core which
5 * is used OSS or emulation of it.
6 */
7
8/*
9 * First, the common part.
10 */
11#include <linux/module.h>
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/kdev_t.h>
15#include <linux/major.h>
16#include <sound/core.h>
17
18#ifdef CONFIG_SOUND_OSS_CORE
19static int __init init_oss_soundcore(void);
20static void cleanup_oss_soundcore(void);
21#else
22static inline int init_oss_soundcore(void) { return 0; }
23static inline void cleanup_oss_soundcore(void) { }
24#endif
25
26struct class *sound_class;
27EXPORT_SYMBOL(sound_class);
28
29MODULE_DESCRIPTION("Core sound module");
30MODULE_AUTHOR("Alan Cox");
31MODULE_LICENSE("GPL");
32
33static char *sound_devnode(const struct device *dev, umode_t *mode)
34{
35 if (MAJOR(dev->devt) == SOUND_MAJOR)
36 return NULL;
37 return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
38}
39
40static int __init init_soundcore(void)
41{
42 int rc;
43
44 rc = init_oss_soundcore();
45 if (rc)
46 return rc;
47
48 sound_class = class_create(THIS_MODULE, "sound");
49 if (IS_ERR(sound_class)) {
50 cleanup_oss_soundcore();
51 return PTR_ERR(sound_class);
52 }
53
54 sound_class->devnode = sound_devnode;
55
56 return 0;
57}
58
59static void __exit cleanup_soundcore(void)
60{
61 cleanup_oss_soundcore();
62 class_destroy(sound_class);
63}
64
65subsys_initcall(init_soundcore);
66module_exit(cleanup_soundcore);
67
68
69#ifdef CONFIG_SOUND_OSS_CORE
70/*
71 * OSS sound core handling. Breaks out sound functions to submodules
72 *
73 * Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
74 *
75 * Fixes:
76 *
77 * --------------------
78 *
79 * Top level handler for the sound subsystem. Various devices can
80 * plug into this. The fact they don't all go via OSS doesn't mean
81 * they don't have to implement the OSS API. There is a lot of logic
82 * to keeping much of the OSS weight out of the code in a compatibility
83 * module, but it's up to the driver to rember to load it...
84 *
85 * The code provides a set of functions for registration of devices
86 * by type. This is done rather than providing a single call so that
87 * we can hide any future changes in the internals (eg when we go to
88 * 32bit dev_t) from the modules and their interface.
89 *
90 * Secondly we need to allocate the dsp, dsp16 and audio devices as
91 * one. Thus we misuse the chains a bit to simplify this.
92 *
93 * Thirdly to make it more fun and for 2.3.x and above we do all
94 * of this using fine grained locking.
95 *
96 * FIXME: we have to resolve modules and fine grained load/unload
97 * locking at some point in 2.3.x.
98 */
99
100#include <linux/init.h>
101#include <linux/slab.h>
102#include <linux/types.h>
103#include <linux/kernel.h>
104#include <linux/sound.h>
105#include <linux/kmod.h>
106
107#define SOUND_STEP 16
108
109struct sound_unit
110{
111 int unit_minor;
112 const struct file_operations *unit_fops;
113 struct sound_unit *next;
114 char name[32];
115};
116
117/*
118 * By default, OSS sound_core claims full legacy minor range (0-255)
119 * of SOUND_MAJOR to trap open attempts to any sound minor and
120 * requests modules using custom sound-slot/service-* module aliases.
121 * The only benefit of doing this is allowing use of custom module
122 * aliases instead of the standard char-major-* ones. This behavior
123 * prevents alternative OSS implementation and is scheduled to be
124 * removed.
125 *
126 * CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
127 * parameter are added to allow distros and developers to try and
128 * switch to alternative implementations without needing to rebuild
129 * the kernel in the meantime. If preclaim_oss is non-zero, the
130 * kernel will behave the same as before. All SOUND_MAJOR minors are
131 * preclaimed and the custom module aliases along with standard chrdev
132 * ones are emitted if a missing device is opened. If preclaim_oss is
133 * zero, sound_core only grabs what's actually in use and for missing
134 * devices only the standard chrdev aliases are requested.
135 *
136 * All these clutters are scheduled to be removed along with
137 * sound-slot/service-* module aliases.
138 */
139static int preclaim_oss = IS_ENABLED(CONFIG_SOUND_OSS_CORE_PRECLAIM);
140
141module_param(preclaim_oss, int, 0444);
142
143static int soundcore_open(struct inode *, struct file *);
144
145static const struct file_operations soundcore_fops =
146{
147 /* We must have an owner or the module locking fails */
148 .owner = THIS_MODULE,
149 .open = soundcore_open,
150 .llseek = noop_llseek,
151};
152
153/*
154 * Low level list operator. Scan the ordered list, find a hole and
155 * join into it. Called with the lock asserted
156 */
157
158static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
159{
160 int n=low;
161
162 if (index < 0) { /* first free */
163
164 while (*list && (*list)->unit_minor<n)
165 list=&((*list)->next);
166
167 while(n<top)
168 {
169 /* Found a hole ? */
170 if(*list==NULL || (*list)->unit_minor>n)
171 break;
172 list=&((*list)->next);
173 n+=SOUND_STEP;
174 }
175
176 if(n>=top)
177 return -ENOENT;
178 } else {
179 n = low+(index*16);
180 while (*list) {
181 if ((*list)->unit_minor==n)
182 return -EBUSY;
183 if ((*list)->unit_minor>n)
184 break;
185 list=&((*list)->next);
186 }
187 }
188
189 /*
190 * Fill it in
191 */
192
193 s->unit_minor=n;
194 s->unit_fops=fops;
195
196 /*
197 * Link it
198 */
199
200 s->next=*list;
201 *list=s;
202
203
204 return n;
205}
206
207/*
208 * Remove a node from the chain. Called with the lock asserted
209 */
210
211static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
212{
213 while(*list)
214 {
215 struct sound_unit *p=*list;
216 if(p->unit_minor==unit)
217 {
218 *list=p->next;
219 return p;
220 }
221 list=&(p->next);
222 }
223 printk(KERN_ERR "Sound device %d went missing!\n", unit);
224 return NULL;
225}
226
227/*
228 * This lock guards the sound loader list.
229 */
230
231static DEFINE_SPINLOCK(sound_loader_lock);
232
233/*
234 * Allocate the controlling structure and add it to the sound driver
235 * list. Acquires locks as needed
236 */
237
238static 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)
239{
240 struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
241 int r;
242
243 if (!s)
244 return -ENOMEM;
245
246 spin_lock(&sound_loader_lock);
247retry:
248 r = __sound_insert_unit(s, list, fops, index, low, top);
249 spin_unlock(&sound_loader_lock);
250
251 if (r < 0)
252 goto fail;
253 else if (r < SOUND_STEP)
254 sprintf(s->name, "sound/%s", name);
255 else
256 sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
257
258 if (!preclaim_oss) {
259 /*
260 * Something else might have grabbed the minor. If
261 * first free slot is requested, rescan with @low set
262 * to the next unit; otherwise, -EBUSY.
263 */
264 r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
265 &soundcore_fops);
266 if (r < 0) {
267 spin_lock(&sound_loader_lock);
268 __sound_remove_unit(list, s->unit_minor);
269 if (index < 0) {
270 low = s->unit_minor + SOUND_STEP;
271 goto retry;
272 }
273 spin_unlock(&sound_loader_lock);
274 r = -EBUSY;
275 goto fail;
276 }
277 }
278
279 device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
280 NULL, "%s", s->name+6);
281 return s->unit_minor;
282
283fail:
284 kfree(s);
285 return r;
286}
287
288/*
289 * Remove a unit. Acquires locks as needed. The drivers MUST have
290 * completed the removal before their file operations become
291 * invalid.
292 */
293
294static void sound_remove_unit(struct sound_unit **list, int unit)
295{
296 struct sound_unit *p;
297
298 spin_lock(&sound_loader_lock);
299 p = __sound_remove_unit(list, unit);
300 spin_unlock(&sound_loader_lock);
301 if (p) {
302 if (!preclaim_oss)
303 __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
304 p->name);
305 device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
306 kfree(p);
307 }
308}
309
310/*
311 * Allocations
312 *
313 * 0 *16 Mixers
314 * 1 *8 Sequencers
315 * 2 *16 Midi
316 * 3 *16 DSP
317 * 4 *16 SunDSP
318 * 5 *16 DSP16
319 * 6 -- sndstat (obsolete)
320 * 7 *16 unused
321 * 8 -- alternate sequencer (see above)
322 * 9 *16 raw synthesizer access
323 * 10 *16 unused
324 * 11 *16 unused
325 * 12 *16 unused
326 * 13 *16 unused
327 * 14 *16 unused
328 * 15 *16 unused
329 */
330
331static struct sound_unit *chains[SOUND_STEP];
332
333/**
334 * register_sound_special_device - register a special sound node
335 * @fops: File operations for the driver
336 * @unit: Unit number to allocate
337 * @dev: device pointer
338 *
339 * Allocate a special sound device by minor number from the sound
340 * subsystem.
341 *
342 * Return: The allocated number is returned on success. On failure,
343 * a negative error code is returned.
344 */
345
346int register_sound_special_device(const struct file_operations *fops, int unit,
347 struct device *dev)
348{
349 const int chain = unit % SOUND_STEP;
350 int max_unit = 256;
351 const char *name;
352 char _name[16];
353
354 switch (chain) {
355 case 0:
356 name = "mixer";
357 break;
358 case 1:
359 name = "sequencer";
360 if (unit >= SOUND_STEP)
361 goto __unknown;
362 max_unit = unit + 1;
363 break;
364 case 2:
365 name = "midi";
366 break;
367 case 3:
368 name = "dsp";
369 break;
370 case 4:
371 name = "audio";
372 break;
373 case 5:
374 name = "dspW";
375 break;
376 case 8:
377 name = "sequencer2";
378 if (unit >= SOUND_STEP)
379 goto __unknown;
380 max_unit = unit + 1;
381 break;
382 case 9:
383 name = "dmmidi";
384 break;
385 case 10:
386 name = "dmfm";
387 break;
388 case 12:
389 name = "adsp";
390 break;
391 case 13:
392 name = "amidi";
393 break;
394 case 14:
395 name = "admmidi";
396 break;
397 default:
398 {
399 __unknown:
400 sprintf(_name, "unknown%d", chain);
401 if (unit >= SOUND_STEP)
402 strcat(_name, "-");
403 name = _name;
404 }
405 break;
406 }
407 return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
408 name, 0600, dev);
409}
410
411EXPORT_SYMBOL(register_sound_special_device);
412
413int register_sound_special(const struct file_operations *fops, int unit)
414{
415 return register_sound_special_device(fops, unit, NULL);
416}
417
418EXPORT_SYMBOL(register_sound_special);
419
420/**
421 * register_sound_mixer - register a mixer device
422 * @fops: File operations for the driver
423 * @dev: Unit number to allocate
424 *
425 * Allocate a mixer device. Unit is the number of the mixer requested.
426 * Pass -1 to request the next free mixer unit.
427 *
428 * Return: On success, the allocated number is returned. On failure,
429 * a negative error code is returned.
430 */
431
432int register_sound_mixer(const struct file_operations *fops, int dev)
433{
434 return sound_insert_unit(&chains[0], fops, dev, 0, 128,
435 "mixer", 0600, NULL);
436}
437
438EXPORT_SYMBOL(register_sound_mixer);
439
440/*
441 * DSP's are registered as a triple. Register only one and cheat
442 * in open - see below.
443 */
444
445/**
446 * register_sound_dsp - register a DSP device
447 * @fops: File operations for the driver
448 * @dev: Unit number to allocate
449 *
450 * Allocate a DSP device. Unit is the number of the DSP requested.
451 * Pass -1 to request the next free DSP unit.
452 *
453 * This function allocates both the audio and dsp device entries together
454 * and will always allocate them as a matching pair - eg dsp3/audio3
455 *
456 * Return: On success, the allocated number is returned. On failure,
457 * a negative error code is returned.
458 */
459
460int register_sound_dsp(const struct file_operations *fops, int dev)
461{
462 return sound_insert_unit(&chains[3], fops, dev, 3, 131,
463 "dsp", 0600, NULL);
464}
465
466EXPORT_SYMBOL(register_sound_dsp);
467
468/**
469 * unregister_sound_special - unregister a special sound device
470 * @unit: unit number to allocate
471 *
472 * Release a sound device that was allocated with
473 * register_sound_special(). The unit passed is the return value from
474 * the register function.
475 */
476
477
478void unregister_sound_special(int unit)
479{
480 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
481}
482
483EXPORT_SYMBOL(unregister_sound_special);
484
485/**
486 * unregister_sound_mixer - unregister a mixer
487 * @unit: unit number to allocate
488 *
489 * Release a sound device that was allocated with register_sound_mixer().
490 * The unit passed is the return value from the register function.
491 */
492
493void unregister_sound_mixer(int unit)
494{
495 sound_remove_unit(&chains[0], unit);
496}
497
498EXPORT_SYMBOL(unregister_sound_mixer);
499
500/**
501 * unregister_sound_dsp - unregister a DSP device
502 * @unit: unit number to allocate
503 *
504 * Release a sound device that was allocated with register_sound_dsp().
505 * The unit passed is the return value from the register function.
506 *
507 * Both of the allocated units are released together automatically.
508 */
509
510void unregister_sound_dsp(int unit)
511{
512 sound_remove_unit(&chains[3], unit);
513}
514
515
516EXPORT_SYMBOL(unregister_sound_dsp);
517
518static struct sound_unit *__look_for_unit(int chain, int unit)
519{
520 struct sound_unit *s;
521
522 s=chains[chain];
523 while(s && s->unit_minor <= unit)
524 {
525 if(s->unit_minor==unit)
526 return s;
527 s=s->next;
528 }
529 return NULL;
530}
531
532static int soundcore_open(struct inode *inode, struct file *file)
533{
534 int chain;
535 int unit = iminor(inode);
536 struct sound_unit *s;
537 const struct file_operations *new_fops = NULL;
538
539 chain=unit&0x0F;
540 if(chain==4 || chain==5) /* dsp/audio/dsp16 */
541 {
542 unit&=0xF0;
543 unit|=3;
544 chain=3;
545 }
546
547 spin_lock(&sound_loader_lock);
548 s = __look_for_unit(chain, unit);
549 if (s)
550 new_fops = fops_get(s->unit_fops);
551 if (preclaim_oss && !new_fops) {
552 spin_unlock(&sound_loader_lock);
553
554 /*
555 * Please, don't change this order or code.
556 * For ALSA slot means soundcard and OSS emulation code
557 * comes as add-on modules which aren't depend on
558 * ALSA toplevel modules for soundcards, thus we need
559 * load them at first. [Jaroslav Kysela <perex@jcu.cz>]
560 */
561 request_module("sound-slot-%i", unit>>4);
562 request_module("sound-service-%i-%i", unit>>4, chain);
563
564 /*
565 * sound-slot/service-* module aliases are scheduled
566 * for removal in favor of the standard char-major-*
567 * module aliases. For the time being, generate both
568 * the legacy and standard module aliases to ease
569 * transition.
570 */
571 if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
572 request_module("char-major-%d", SOUND_MAJOR);
573
574 spin_lock(&sound_loader_lock);
575 s = __look_for_unit(chain, unit);
576 if (s)
577 new_fops = fops_get(s->unit_fops);
578 }
579 spin_unlock(&sound_loader_lock);
580
581 if (!new_fops)
582 return -ENODEV;
583
584 /*
585 * We rely upon the fact that we can't be unloaded while the
586 * subdriver is there.
587 */
588 replace_fops(file, new_fops);
589
590 if (!file->f_op->open)
591 return -ENODEV;
592
593 return file->f_op->open(inode, file);
594}
595
596MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
597
598static void cleanup_oss_soundcore(void)
599{
600 /* We have nothing to really do here - we know the lists must be
601 empty */
602 unregister_chrdev(SOUND_MAJOR, "sound");
603}
604
605static int __init init_oss_soundcore(void)
606{
607 if (preclaim_oss &&
608 register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) {
609 printk(KERN_ERR "soundcore: sound device already in use.\n");
610 return -EBUSY;
611 }
612
613 return 0;
614}
615
616#endif /* CONFIG_SOUND_OSS_CORE */