ixgbe: add missing supported filters to get_ts_info
[linux-2.6/cjktty.git] / sound / sound_core.c
blobbb23009edc8d748e138c4a44fdd6da0079f24158
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 */
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>
17 #ifdef CONFIG_SOUND_OSS_CORE
18 static int __init init_oss_soundcore(void);
19 static void cleanup_oss_soundcore(void);
20 #else
21 static inline int init_oss_soundcore(void) { return 0; }
22 static inline void cleanup_oss_soundcore(void) { }
23 #endif
25 struct class *sound_class;
26 EXPORT_SYMBOL(sound_class);
28 MODULE_DESCRIPTION("Core sound module");
29 MODULE_AUTHOR("Alan Cox");
30 MODULE_LICENSE("GPL");
32 static char *sound_devnode(struct device *dev, umode_t *mode)
34 if (MAJOR(dev->devt) == SOUND_MAJOR)
35 return NULL;
36 return kasprintf(GFP_KERNEL, "snd/%s", dev_name(dev));
39 static int __init init_soundcore(void)
41 int rc;
43 rc = init_oss_soundcore();
44 if (rc)
45 return rc;
47 sound_class = class_create(THIS_MODULE, "sound");
48 if (IS_ERR(sound_class)) {
49 cleanup_oss_soundcore();
50 return PTR_ERR(sound_class);
53 sound_class->devnode = sound_devnode;
55 return 0;
58 static void __exit cleanup_soundcore(void)
60 cleanup_oss_soundcore();
61 class_destroy(sound_class);
64 subsys_initcall(init_soundcore);
65 module_exit(cleanup_soundcore);
68 #ifdef CONFIG_SOUND_OSS_CORE
70 * OSS sound core handling. Breaks out sound functions to submodules
72 * Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
74 * Fixes:
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.
82 * --------------------
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...
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.
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.
98 * Thirdly to make it more fun and for 2.3.x and above we do all
99 * of this using fine grained locking.
101 * FIXME: we have to resolve modules and fine grained load/unload
102 * locking at some point in 2.3.x.
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>
112 #define SOUND_STEP 16
114 struct sound_unit
116 int unit_minor;
117 const struct file_operations *unit_fops;
118 struct sound_unit *next;
119 char name[32];
122 #ifdef CONFIG_SOUND_MSNDCLAS
123 extern int msnd_classic_init(void);
124 #endif
125 #ifdef CONFIG_SOUND_MSNDPIN
126 extern int msnd_pinnacle_init(void);
127 #endif
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.
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.
148 * All these clutters are scheduled to be removed along with
149 * sound-slot/service-* module aliases.
151 #ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
152 static int preclaim_oss = 1;
153 #else
154 static int preclaim_oss = 0;
155 #endif
157 module_param(preclaim_oss, int, 0444);
159 static int soundcore_open(struct inode *, struct file *);
161 static const struct file_operations soundcore_fops =
163 /* We must have an owner or the module locking fails */
164 .owner = THIS_MODULE,
165 .open = soundcore_open,
166 .llseek = noop_llseek,
170 * Low level list operator. Scan the ordered list, find a hole and
171 * join into it. Called with the lock asserted
174 static int __sound_insert_unit(struct sound_unit * s, struct sound_unit **list, const struct file_operations *fops, int index, int low, int top)
176 int n=low;
178 if (index < 0) { /* first free */
180 while (*list && (*list)->unit_minor<n)
181 list=&((*list)->next);
183 while(n<top)
185 /* Found a hole ? */
186 if(*list==NULL || (*list)->unit_minor>n)
187 break;
188 list=&((*list)->next);
189 n+=SOUND_STEP;
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);
206 * Fill it in
209 s->unit_minor=n;
210 s->unit_fops=fops;
213 * Link it
216 s->next=*list;
217 *list=s;
220 return n;
224 * Remove a node from the chain. Called with the lock asserted
227 static struct sound_unit *__sound_remove_unit(struct sound_unit **list, int unit)
229 while(*list)
231 struct sound_unit *p=*list;
232 if(p->unit_minor==unit)
234 *list=p->next;
235 return p;
237 list=&(p->next);
239 printk(KERN_ERR "Sound device %d went missing!\n", unit);
240 return NULL;
244 * This lock guards the sound loader list.
247 static DEFINE_SPINLOCK(sound_loader_lock);
250 * Allocate the controlling structure and add it to the sound driver
251 * list. Acquires locks as needed
254 static int sound_insert_unit(struct sound_unit **list, const struct file_operations *fops, int index, int low, int top, const char *name, umode_t mode, struct device *dev)
256 struct sound_unit *s = kmalloc(sizeof(*s), GFP_KERNEL);
257 int r;
259 if (!s)
260 return -ENOMEM;
262 spin_lock(&sound_loader_lock);
263 retry:
264 r = __sound_insert_unit(s, list, fops, index, low, top);
265 spin_unlock(&sound_loader_lock);
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);
274 if (!preclaim_oss) {
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.
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;
289 spin_unlock(&sound_loader_lock);
290 return -EBUSY;
294 device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
295 NULL, s->name+6);
296 return s->unit_minor;
298 fail:
299 kfree(s);
300 return r;
304 * Remove a unit. Acquires locks as needed. The drivers MUST have
305 * completed the removal before their file operations become
306 * invalid.
309 static void sound_remove_unit(struct sound_unit **list, int unit)
311 struct sound_unit *p;
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);
326 * Allocations
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
346 static struct sound_unit *chains[SOUND_STEP];
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
354 * Allocate a special sound device by minor number from the sound
355 * subsystem. The allocated number is returned on success. On failure
356 * a negative error code is returned.
359 int register_sound_special_device(const struct file_operations *fops, int unit,
360 struct device *dev)
362 const int chain = unit % SOUND_STEP;
363 int max_unit = 256;
364 const char *name;
365 char _name[16];
367 switch (chain) {
368 case 0:
369 name = "mixer";
370 break;
371 case 1:
372 name = "sequencer";
373 if (unit >= SOUND_STEP)
374 goto __unknown;
375 max_unit = unit + 1;
376 break;
377 case 2:
378 name = "midi";
379 break;
380 case 3:
381 name = "dsp";
382 break;
383 case 4:
384 name = "audio";
385 break;
386 case 5:
387 name = "dspW";
388 break;
389 case 8:
390 name = "sequencer2";
391 if (unit >= SOUND_STEP)
392 goto __unknown;
393 max_unit = unit + 1;
394 break;
395 case 9:
396 name = "dmmidi";
397 break;
398 case 10:
399 name = "dmfm";
400 break;
401 case 12:
402 name = "adsp";
403 break;
404 case 13:
405 name = "amidi";
406 break;
407 case 14:
408 name = "admmidi";
409 break;
410 default:
412 __unknown:
413 sprintf(_name, "unknown%d", chain);
414 if (unit >= SOUND_STEP)
415 strcat(_name, "-");
416 name = _name;
418 break;
420 return sound_insert_unit(&chains[chain], fops, -1, unit, max_unit,
421 name, S_IRUSR | S_IWUSR, dev);
424 EXPORT_SYMBOL(register_sound_special_device);
426 int register_sound_special(const struct file_operations *fops, int unit)
428 return register_sound_special_device(fops, unit, NULL);
431 EXPORT_SYMBOL(register_sound_special);
434 * register_sound_mixer - register a mixer device
435 * @fops: File operations for the driver
436 * @dev: Unit number to allocate
438 * Allocate a mixer device. Unit is the number of the mixer requested.
439 * Pass -1 to request the next free mixer unit. On success the allocated
440 * number is returned, on failure a negative error code is returned.
443 int register_sound_mixer(const struct file_operations *fops, int dev)
445 return sound_insert_unit(&chains[0], fops, dev, 0, 128,
446 "mixer", S_IRUSR | S_IWUSR, NULL);
449 EXPORT_SYMBOL(register_sound_mixer);
452 * register_sound_midi - register a midi device
453 * @fops: File operations for the driver
454 * @dev: Unit number to allocate
456 * Allocate a midi device. Unit is the number of the midi device requested.
457 * Pass -1 to request the next free midi unit. On success the allocated
458 * number is returned, on failure a negative error code is returned.
461 int register_sound_midi(const struct file_operations *fops, int dev)
463 return sound_insert_unit(&chains[2], fops, dev, 2, 130,
464 "midi", S_IRUSR | S_IWUSR, NULL);
467 EXPORT_SYMBOL(register_sound_midi);
470 * DSP's are registered as a triple. Register only one and cheat
471 * in open - see below.
475 * register_sound_dsp - register a DSP device
476 * @fops: File operations for the driver
477 * @dev: Unit number to allocate
479 * Allocate a DSP device. Unit is the number of the DSP requested.
480 * Pass -1 to request the next free DSP unit. On success the allocated
481 * number is returned, on failure a negative error code is returned.
483 * This function allocates both the audio and dsp device entries together
484 * and will always allocate them as a matching pair - eg dsp3/audio3
487 int register_sound_dsp(const struct file_operations *fops, int dev)
489 return sound_insert_unit(&chains[3], fops, dev, 3, 131,
490 "dsp", S_IWUSR | S_IRUSR, NULL);
493 EXPORT_SYMBOL(register_sound_dsp);
496 * unregister_sound_special - unregister a special sound device
497 * @unit: unit number to allocate
499 * Release a sound device that was allocated with
500 * register_sound_special(). The unit passed is the return value from
501 * the register function.
505 void unregister_sound_special(int unit)
507 sound_remove_unit(&chains[unit % SOUND_STEP], unit);
510 EXPORT_SYMBOL(unregister_sound_special);
513 * unregister_sound_mixer - unregister a mixer
514 * @unit: unit number to allocate
516 * Release a sound device that was allocated with register_sound_mixer().
517 * The unit passed is the return value from the register function.
520 void unregister_sound_mixer(int unit)
522 sound_remove_unit(&chains[0], unit);
525 EXPORT_SYMBOL(unregister_sound_mixer);
528 * unregister_sound_midi - unregister a midi device
529 * @unit: unit number to allocate
531 * Release a sound device that was allocated with register_sound_midi().
532 * The unit passed is the return value from the register function.
535 void unregister_sound_midi(int unit)
537 sound_remove_unit(&chains[2], unit);
540 EXPORT_SYMBOL(unregister_sound_midi);
543 * unregister_sound_dsp - unregister a DSP device
544 * @unit: unit number to allocate
546 * Release a sound device that was allocated with register_sound_dsp().
547 * The unit passed is the return value from the register function.
549 * Both of the allocated units are released together automatically.
552 void unregister_sound_dsp(int unit)
554 sound_remove_unit(&chains[3], unit);
558 EXPORT_SYMBOL(unregister_sound_dsp);
560 static struct sound_unit *__look_for_unit(int chain, int unit)
562 struct sound_unit *s;
564 s=chains[chain];
565 while(s && s->unit_minor <= unit)
567 if(s->unit_minor==unit)
568 return s;
569 s=s->next;
571 return NULL;
574 static int soundcore_open(struct inode *inode, struct file *file)
576 int chain;
577 int unit = iminor(inode);
578 struct sound_unit *s;
579 const struct file_operations *new_fops = NULL;
581 chain=unit&0x0F;
582 if(chain==4 || chain==5) /* dsp/audio/dsp16 */
584 unit&=0xF0;
585 unit|=3;
586 chain=3;
589 spin_lock(&sound_loader_lock);
590 s = __look_for_unit(chain, unit);
591 if (s)
592 new_fops = fops_get(s->unit_fops);
593 if (preclaim_oss && !new_fops) {
594 spin_unlock(&sound_loader_lock);
597 * Please, don't change this order or code.
598 * For ALSA slot means soundcard and OSS emulation code
599 * comes as add-on modules which aren't depend on
600 * ALSA toplevel modules for soundcards, thus we need
601 * load them at first. [Jaroslav Kysela <perex@jcu.cz>]
603 request_module("sound-slot-%i", unit>>4);
604 request_module("sound-service-%i-%i", unit>>4, chain);
607 * sound-slot/service-* module aliases are scheduled
608 * for removal in favor of the standard char-major-*
609 * module aliases. For the time being, generate both
610 * the legacy and standard module aliases to ease
611 * transition.
613 if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
614 request_module("char-major-%d", SOUND_MAJOR);
616 spin_lock(&sound_loader_lock);
617 s = __look_for_unit(chain, unit);
618 if (s)
619 new_fops = fops_get(s->unit_fops);
621 if (new_fops) {
623 * We rely upon the fact that we can't be unloaded while the
624 * subdriver is there, so if ->open() is successful we can
625 * safely drop the reference counter and if it is not we can
626 * revert to old ->f_op. Ugly, indeed, but that's the cost of
627 * switching ->f_op in the first place.
629 int err = 0;
630 const struct file_operations *old_fops = file->f_op;
631 file->f_op = new_fops;
632 spin_unlock(&sound_loader_lock);
634 if (file->f_op->open)
635 err = file->f_op->open(inode,file);
637 if (err) {
638 fops_put(file->f_op);
639 file->f_op = fops_get(old_fops);
642 fops_put(old_fops);
643 return err;
645 spin_unlock(&sound_loader_lock);
646 return -ENODEV;
649 MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);
651 static void cleanup_oss_soundcore(void)
653 /* We have nothing to really do here - we know the lists must be
654 empty */
655 unregister_chrdev(SOUND_MAJOR, "sound");
658 static int __init init_oss_soundcore(void)
660 if (preclaim_oss &&
661 register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) {
662 printk(KERN_ERR "soundcore: sound device already in use.\n");
663 return -EBUSY;
666 return 0;
669 #endif /* CONFIG_SOUND_OSS_CORE */