Loading...
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(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 */
139#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
140static int preclaim_oss = 1;
141#else
142static int preclaim_oss = 0;
143#endif
144
145module_param(preclaim_oss, int, 0444);
146
147static int soundcore_open(struct inode *, struct file *);
148
149static const struct file_operations soundcore_fops =
150{
151 /* We must have an owner or the module locking fails */
152 .owner = THIS_MODULE,
153 .open = soundcore_open,
154 .llseek = noop_llseek,
155};
156
157/*
158 * Low level list operator. Scan the ordered list, find a hole and
159 * join into it. Called with the lock asserted
160 */
161
162static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
163{
164 int n=low;
165
166 if (index < 0) { /* first free */
167
168 while (*list && (*list)->unit_minor<n)
169 list=&((*list)->next);
170
171 while(n<top)
172 {
173 /* Found a hole ? */
174 if(*list==NULL || (*list)->unit_minor>n)
175 break;
176 list=&((*list)->next);
177 n+=SOUND_STEP;
178 }
179
180 if(n>=top)
181 return -ENOENT;
182 } else {
183 n = low+(index*16);
184 while (*list) {
185 if ((*list)->unit_minor==n)
186 return -EBUSY;
187 if ((*list)->unit_minor>n)
188 break;
189 list=&((*list)->next);
190 }
191 }
192
193 /*
194 * Fill it in
195 */
196
197 s->unit_minor=n;
198 s->unit_fops=fops;
199
200 /*
201 * Link it
202 */
203
204 s->next=*list;
205 *list=s;
206
207
208 return n;
209}
210
211/*
212 * Remove a node from the chain. Called with the lock asserted
213 */
214
215static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
216{
217 while(*list)
218 {
219 struct sound_unit *p=*list;
220 if(p->unit_minor==unit)
221 {
222 *list=p->next;
223 return p;
224 }
225 list=&(p->next);
226 }
227 printk(KERN_ERR "Sound device %d went missing!\n", unit);
228 return NULL;
229}
230
231/*
232 * This lock guards the sound loader list.
233 */
234
235static DEFINE_SPINLOCK(sound_loader_lock);
236
237/*
238 * Allocate the controlling structure and add it to the sound driver
239 * list. Acquires locks as needed
240 */
241
242static 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)
243{
244 struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
245 int r;
246
247 if (!s)
248 return -ENOMEM;
249
250 spin_lock(&sound_loader_lock);
251retry:
252 r = __sound_insert_unit(s, list, fops, index, low, top);
253 spin_unlock(&sound_loader_lock);
254
255 if (r < 0)
256 goto fail;
257 else if (r < SOUND_STEP)
258 sprintf(s->name, "sound/%s", name);
259 else
260 sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
261
262 if (!preclaim_oss) {
263 /*
264 * Something else might have grabbed the minor. If
265 * first free slot is requested, rescan with @low set
266 * to the next unit; otherwise, -EBUSY.
267 */
268 r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
269 &soundcore_fops);
270 if (r < 0) {
271 spin_lock(&sound_loader_lock);
272 __sound_remove_unit(list, s->unit_minor);
273 if (index < 0) {
274 low = s->unit_minor + SOUND_STEP;
275 goto retry;
276 }
277 spin_unlock(&sound_loader_lock);
278 r = -EBUSY;
279 goto fail;
280 }
281 }
282
283 device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
284 NULL, "%s", s->name+6);
285 return s->unit_minor;
286
287fail:
288 kfree(s);
289 return r;
290}
291
292/*
293 * Remove a unit. Acquires locks as needed. The drivers MUST have
294 * completed the removal before their file operations become
295 * invalid.
296 */
297
298static void sound_remove_unit(struct sound_unit **list, int unit)
299{
300 struct sound_unit *p;
301
302 spin_lock(&sound_loader_lock);
303 p = __sound_remove_unit(list, unit);
304 spin_unlock(&sound_loader_lock);
305 if (p) {
306 if (!preclaim_oss)
307 __unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
308 p->name);
309 device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
310 kfree(p);
311 }
312}
313
314/*
315 * Allocations
316 *
317 * 0 *16 Mixers
318 * 1 *8 Sequencers
319 * 2 *16 Midi
320 * 3 *16 DSP
321 * 4 *16 SunDSP
322 * 5 *16 DSP16
323 * 6 -- sndstat (obsolete)
324 * 7 *16 unused
325 * 8 -- alternate sequencer (see above)
326 * 9 *16 raw synthesizer access
327 * 10 *16 unused
328 * 11 *16 unused
329 * 12 *16 unused
330 * 13 *16 unused
331 * 14 *16 unused
332 * 15 *16 unused
333 */
334
335static struct sound_unit *chains[SOUND_STEP];
336
337/**
338 * register_sound_special_device - register a special sound node
339 * @fops: File operations for the driver
340 * @unit: Unit number to allocate
341 * @dev: device pointer
342 *
343 * Allocate a special sound device by minor number from the sound
344 * subsystem.
345 *
346 * Return: The allocated number is returned on success. On failure,
347 * a negative error code is returned.
348 */
349
350int register_sound_special_device(const struct file_operations *fops, int unit,
351 struct device *dev)
352{
353 const int chain = unit % SOUND_STEP;
354 int max_unit = 256;
355 const char *name;
356 char _name[16];
357
358 switch (chain) {
359 case 0:
360 name = "mixer";
361 break;
362 case 1:
363 name = "sequencer";
364 if (unit >= SOUND_STEP)
365 goto __unknown;
366 max_unit = unit + 1;
367 break;
368 case 2:
369 name = "midi";
370 break;
371 case 3:
372 name = "dsp";
373 break;
374 case 4:
375 name = "audio";
376 break;
377 case 5:
378 name = "dspW";
379 break;
380 case 8:
381 name = "sequencer2";
382 if (unit >= SOUND_STEP)
383 goto __unknown;
384 max_unit = unit + 1;
385 break;
386 case 9:
387 name = "dmmidi";
388 break;
389 case 10:
390 name = "dmfm";
391 break;
392 case 12:
393 name = "adsp";
394 break;
395 case 13:
396 name = "amidi";
397 break;
398 case 14:
399 name = "admmidi";
400 break;
401 default:
402 {
403 __unknown:
404 sprintf(_name, "unknown%d", chain);
405 if (unit >= SOUND_STEP)
406 strcat(_name, "-");
407 name = _name;
408 }
409 break;
410 }
411 return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
412 name, 0600, dev);
413}
414
415EXPORT_SYMBOL(register_sound_special_device);
416
417int register_sound_special(const struct file_operations *fops, int unit)
418{
419 return register_sound_special_device(fops, unit, NULL);
420}
421
422EXPORT_SYMBOL(register_sound_special);
423
424/**
425 * register_sound_mixer - register a mixer device
426 * @fops: File operations for the driver
427 * @dev: Unit number to allocate
428 *
429 * Allocate a mixer device. Unit is the number of the mixer requested.
430 * Pass -1 to request the next free mixer unit.
431 *
432 * Return: On success, the allocated number is returned. On failure,
433 * a negative error code is returned.
434 */
435
436int register_sound_mixer(const struct file_operations *fops, int dev)
437{
438 return sound_insert_unit(&chains[0], fops, dev, 0, 128,
439 "mixer", 0600, NULL);
440}
441
442EXPORT_SYMBOL(register_sound_mixer);
443
444/*
445 * DSP's are registered as a triple. Register only one and cheat
446 * in open - see below.
447 */
448
449/**
450 * register_sound_dsp - register a DSP device
451 * @fops: File operations for the driver
452 * @dev: Unit number to allocate
453 *
454 * Allocate a DSP device. Unit is the number of the DSP requested.
455 * Pass -1 to request the next free DSP unit.
456 *
457 * This function allocates both the audio and dsp device entries together
458 * and will always allocate them as a matching pair - eg dsp3/audio3
459 *
460 * Return: On success, the allocated number is returned. On failure,
461 * a negative error code is returned.
462 */
463
464int register_sound_dsp(const struct file_operations *fops, int dev)
465{
466 return sound_insert_unit(&chains[3], fops, dev, 3, 131,
467 "dsp", 0600, NULL);
468}
469
470EXPORT_SYMBOL(register_sound_dsp);
471
472/**
473 * unregister_sound_special - unregister a special sound device
474 * @unit: unit number to allocate
475 *
476 * Release a sound device that was allocated with
477 * register_sound_special(). The unit passed is the return value from
478 * the register function.
479 */
480
481
482void unregister_sound_special(int unit)
483{
484 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
485}
486
487EXPORT_SYMBOL(unregister_sound_special);
488
489/**
490 * unregister_sound_mixer - unregister a mixer
491 * @unit: unit number to allocate
492 *
493 * Release a sound device that was allocated with register_sound_mixer().
494 * The unit passed is the return value from the register function.
495 */
496
497void unregister_sound_mixer(int unit)
498{
499 sound_remove_unit(&chains[0], unit);
500}
501
502EXPORT_SYMBOL(unregister_sound_mixer);
503
504/**
505 * unregister_sound_dsp - unregister a DSP device
506 * @unit: unit number to allocate
507 *
508 * Release a sound device that was allocated with register_sound_dsp().
509 * The unit passed is the return value from the register function.
510 *
511 * Both of the allocated units are released together automatically.
512 */
513
514void unregister_sound_dsp(int unit)
515{
516 sound_remove_unit(&chains[3], unit);
517}
518
519
520EXPORT_SYMBOL(unregister_sound_dsp);
521
522static struct sound_unit *__look_for_unit(int chain, int unit)
523{
524 struct sound_unit *s;
525
526 s=chains[chain];
527 while(s && s->unit_minor <= unit)
528 {
529 if(s->unit_minor==unit)
530 return s;
531 s=s->next;
532 }
533 return NULL;
534}
535
536static int soundcore_open(struct inode *inode, struct file *file)
537{
538 int chain;
539 int unit = iminor(inode);
540 struct sound_unit *s;
541 const struct file_operations *new_fops = NULL;
542
543 chain=unit&0x0F;
544 if(chain==4 || chain==5) /* dsp/audio/dsp16 */
545 {
546 unit&=0xF0;
547 unit|=3;
548 chain=3;
549 }
550
551 spin_lock(&sound_loader_lock);
552 s = __look_for_unit(chain, unit);
553 if (s)
554 new_fops = fops_get(s->unit_fops);
555 if (preclaim_oss && !new_fops) {
556 spin_unlock(&sound_loader_lock);
557
558 /*
559 * Please, don't change this order or code.
560 * For ALSA slot means soundcard and OSS emulation code
561 * comes as add-on modules which aren't depend on
562 * ALSA toplevel modules for soundcards, thus we need
563 * load them at first. [Jaroslav Kysela <perex@jcu.cz>]
564 */
565 request_module("sound-slot-%i", unit>>4);
566 request_module("sound-service-%i-%i", unit>>4, chain);
567
568 /*
569 * sound-slot/service-* module aliases are scheduled
570 * for removal in favor of the standard char-major-*
571 * module aliases. For the time being, generate both
572 * the legacy and standard module aliases to ease
573 * transition.
574 */
575 if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
576 request_module("char-major-%d", SOUND_MAJOR);
577
578 spin_lock(&sound_loader_lock);
579 s = __look_for_unit(chain, unit);
580 if (s)
581 new_fops = fops_get(s->unit_fops);
582 }
583 spin_unlock(&sound_loader_lock);
584 if (new_fops) {
585 /*
586 * We rely upon the fact that we can't be unloaded while the
587 * subdriver is there.
588 */
589 int err = 0;
590 replace_fops(file, new_fops);
591
592 if (file->f_op->open)
593 err = file->f_op->open(inode,file);
594
595 return err;
596 }
597 return -ENODEV;
598}
599
600MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
601
602static void cleanup_oss_soundcore(void)
603{
604 /* We have nothing to really do here - we know the lists must be
605 empty */
606 unregister_chrdev(SOUND_MAJOR, "sound");
607}
608
609static int __init init_oss_soundcore(void)
610{
611 if (preclaim_oss &&
612 register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) < 0) {
613 printk(KERN_ERR "soundcore: sound device already in use.\n");
614 return -EBUSY;
615 }
616
617 return 0;
618}
619
620#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 */