[ALSA] sound/core/: possible cleanups
[linux-2.6.git] / sound / core / sound.c
1 /*
2  *  Advanced Linux Sound Architecture
3  *  Copyright (c) by Jaroslav Kysela <perex@suse.cz>
4  *
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
19  *
20  */
21
22 #include <sound/driver.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/time.h>
26 #include <linux/moduleparam.h>
27 #include <sound/core.h>
28 #include <sound/minors.h>
29 #include <sound/info.h>
30 #include <sound/version.h>
31 #include <sound/control.h>
32 #include <sound/initval.h>
33 #include <linux/kmod.h>
34 #include <linux/devfs_fs_kernel.h>
35 #include <linux/device.h>
36
37 #define SNDRV_OS_MINORS 256
38
39 static int major = CONFIG_SND_MAJOR;
40 int snd_major;
41 static int cards_limit = 1;
42 static int device_mode = S_IFCHR | S_IRUGO | S_IWUGO;
43
44 MODULE_AUTHOR("Jaroslav Kysela <perex@suse.cz>");
45 MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
46 MODULE_LICENSE("GPL");
47 module_param(major, int, 0444);
48 MODULE_PARM_DESC(major, "Major # for sound driver.");
49 module_param(cards_limit, int, 0444);
50 MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
51 #ifdef CONFIG_DEVFS_FS
52 module_param(device_mode, int, 0444);
53 MODULE_PARM_DESC(device_mode, "Device file permission mask for devfs.");
54 #endif
55 MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
56
57 /* this one holds the actual max. card number currently available.
58  * as default, it's identical with cards_limit option.  when more
59  * modules are loaded manually, this limit number increases, too.
60  */
61 int snd_ecards_limit;
62
63 static struct list_head snd_minors_hash[SNDRV_CARDS];
64
65 static DECLARE_MUTEX(sound_mutex);
66
67 extern struct class_simple *sound_class;
68
69
70 #ifdef CONFIG_KMOD
71
72 /**
73  * snd_request_card - try to load the card module
74  * @card: the card number
75  *
76  * Tries to load the module "snd-card-X" for the given card number
77  * via KMOD.  Returns immediately if already loaded.
78  */
79 void snd_request_card(int card)
80 {
81         int locked;
82
83         if (! current->fs->root)
84                 return;
85         read_lock(&snd_card_rwlock);
86         locked = snd_cards_lock & (1 << card);
87         read_unlock(&snd_card_rwlock);
88         if (locked)
89                 return;
90         if (card < 0 || card >= cards_limit)
91                 return;
92         request_module("snd-card-%i", card);
93 }
94
95 static void snd_request_other(int minor)
96 {
97         char *str;
98
99         if (! current->fs->root)
100                 return;
101         switch (minor) {
102         case SNDRV_MINOR_SEQUENCER:     str = "snd-seq";        break;
103         case SNDRV_MINOR_TIMER:         str = "snd-timer";      break;
104         default:                        return;
105         }
106         request_module(str);
107 }
108
109 #endif                          /* request_module support */
110
111 static snd_minor_t *snd_minor_search(int minor)
112 {
113         struct list_head *list;
114         snd_minor_t *mptr;
115
116         list_for_each(list, &snd_minors_hash[SNDRV_MINOR_CARD(minor)]) {
117                 mptr = list_entry(list, snd_minor_t, list);
118                 if (mptr->number == minor)
119                         return mptr;
120         }
121         return NULL;
122 }
123
124 static int snd_open(struct inode *inode, struct file *file)
125 {
126         int minor = iminor(inode);
127         int card = SNDRV_MINOR_CARD(minor);
128         int dev = SNDRV_MINOR_DEVICE(minor);
129         snd_minor_t *mptr = NULL;
130         struct file_operations *old_fops;
131         int err = 0;
132
133         if (dev != SNDRV_MINOR_SEQUENCER && dev != SNDRV_MINOR_TIMER) {
134                 if (snd_cards[card] == NULL) {
135 #ifdef CONFIG_KMOD
136                         snd_request_card(card);
137                         if (snd_cards[card] == NULL)
138 #endif
139                                 return -ENODEV;
140                 }
141         } else {
142 #ifdef CONFIG_KMOD
143                 if ((mptr = snd_minor_search(minor)) == NULL)
144                         snd_request_other(minor);
145 #endif
146         }
147         if (mptr == NULL && (mptr = snd_minor_search(minor)) == NULL)
148                 return -ENODEV;
149         old_fops = file->f_op;
150         file->f_op = fops_get(mptr->f_ops);
151         if (file->f_op->open)
152                 err = file->f_op->open(inode, file);
153         if (err) {
154                 fops_put(file->f_op);
155                 file->f_op = fops_get(old_fops);
156         }
157         fops_put(old_fops);
158         return err;
159 }
160
161 static struct file_operations snd_fops =
162 {
163         .owner =        THIS_MODULE,
164         .open =         snd_open
165 };
166
167 static int snd_kernel_minor(int type, snd_card_t * card, int dev)
168 {
169         int minor;
170
171         switch (type) {
172         case SNDRV_DEVICE_TYPE_SEQUENCER:
173         case SNDRV_DEVICE_TYPE_TIMER:
174                 minor = type;
175                 break;
176         case SNDRV_DEVICE_TYPE_CONTROL:
177                 snd_assert(card != NULL, return -EINVAL);
178                 minor = SNDRV_MINOR(card->number, type);
179                 break;
180         case SNDRV_DEVICE_TYPE_HWDEP:
181         case SNDRV_DEVICE_TYPE_RAWMIDI:
182         case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
183         case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
184                 snd_assert(card != NULL, return -EINVAL);
185                 minor = SNDRV_MINOR(card->number, type + dev);
186                 break;
187         default:
188                 return -EINVAL;
189         }
190         snd_assert(minor >= 0 && minor < SNDRV_OS_MINORS, return -EINVAL);
191         return minor;
192 }
193
194 /**
195  * snd_register_device - Register the ALSA device file for the card
196  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
197  * @card: the card instance
198  * @dev: the device index
199  * @reg: the snd_minor_t record
200  * @name: the device file name
201  *
202  * Registers an ALSA device file for the given card.
203  * The operators have to be set in reg parameter.
204  *
205  * Retrurns zero if successful, or a negative error code on failure.
206  */
207 int snd_register_device(int type, snd_card_t * card, int dev, snd_minor_t * reg, const char *name)
208 {
209         int minor = snd_kernel_minor(type, card, dev);
210         snd_minor_t *preg;
211         struct device *device = NULL;
212
213         if (minor < 0)
214                 return minor;
215         snd_assert(name, return -EINVAL);
216         preg = (snd_minor_t *)kmalloc(sizeof(snd_minor_t) + strlen(name) + 1, GFP_KERNEL);
217         if (preg == NULL)
218                 return -ENOMEM;
219         *preg = *reg;
220         preg->number = minor;
221         preg->device = dev;
222         strcpy(preg->name, name);
223         down(&sound_mutex);
224         if (snd_minor_search(minor)) {
225                 up(&sound_mutex);
226                 kfree(preg);
227                 return -EBUSY;
228         }
229         list_add_tail(&preg->list, &snd_minors_hash[SNDRV_MINOR_CARD(minor)]);
230         if (strncmp(name, "controlC", 8) || card->number >= cards_limit)
231                 devfs_mk_cdev(MKDEV(major, minor), S_IFCHR | device_mode, "snd/%s", name);
232         if (card)
233                 device = card->dev;
234         class_simple_device_add(sound_class, MKDEV(major, minor), device, name);
235
236         up(&sound_mutex);
237         return 0;
238 }
239
240 /**
241  * snd_unregister_device - unregister the device on the given card
242  * @type: the device type, SNDRV_DEVICE_TYPE_XXX
243  * @card: the card instance
244  * @dev: the device index
245  *
246  * Unregisters the device file already registered via
247  * snd_register_device().
248  *
249  * Returns zero if sucecessful, or a negative error code on failure
250  */
251 int snd_unregister_device(int type, snd_card_t * card, int dev)
252 {
253         int minor = snd_kernel_minor(type, card, dev);
254         snd_minor_t *mptr;
255
256         if (minor < 0)
257                 return minor;
258         down(&sound_mutex);
259         if ((mptr = snd_minor_search(minor)) == NULL) {
260                 up(&sound_mutex);
261                 return -EINVAL;
262         }
263
264         if (strncmp(mptr->name, "controlC", 8) || card->number >= cards_limit) /* created in sound.c */
265                 devfs_remove("snd/%s", mptr->name);
266         class_simple_device_remove(MKDEV(major, minor));
267
268         list_del(&mptr->list);
269         up(&sound_mutex);
270         kfree(mptr);
271         return 0;
272 }
273
274 /*
275  *  INFO PART
276  */
277
278 static snd_info_entry_t *snd_minor_info_entry = NULL;
279
280 static void snd_minor_info_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
281 {
282         int card, device;
283         struct list_head *list;
284         snd_minor_t *mptr;
285
286         down(&sound_mutex);
287         for (card = 0; card < SNDRV_CARDS; card++) {
288                 list_for_each(list, &snd_minors_hash[card]) {
289                         mptr = list_entry(list, snd_minor_t, list);
290                         if (SNDRV_MINOR_DEVICE(mptr->number) != SNDRV_MINOR_SEQUENCER) {
291                                 if ((device = mptr->device) >= 0)
292                                         snd_iprintf(buffer, "%3i: [%i-%2i]: %s\n", mptr->number, card, device, mptr->comment);
293                                 else
294                                         snd_iprintf(buffer, "%3i: [%i]   : %s\n", mptr->number, card, mptr->comment);
295                         } else {
296                                 snd_iprintf(buffer, "%3i:       : %s\n", mptr->number, mptr->comment);
297                         }
298                 }
299         }
300         up(&sound_mutex);
301 }
302
303 int __init snd_minor_info_init(void)
304 {
305         snd_info_entry_t *entry;
306
307         entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
308         if (entry) {
309                 entry->c.text.read_size = PAGE_SIZE;
310                 entry->c.text.read = snd_minor_info_read;
311                 if (snd_info_register(entry) < 0) {
312                         snd_info_free_entry(entry);
313                         entry = NULL;
314                 }
315         }
316         snd_minor_info_entry = entry;
317         return 0;
318 }
319
320 int __exit snd_minor_info_done(void)
321 {
322         if (snd_minor_info_entry)
323                 snd_info_unregister(snd_minor_info_entry);
324         return 0;
325 }
326
327 /*
328  *  INIT PART
329  */
330
331 static int __init alsa_sound_init(void)
332 {
333         short controlnum;
334         int err;
335         int card;
336
337         snd_major = major;
338         snd_ecards_limit = cards_limit;
339         for (card = 0; card < SNDRV_CARDS; card++)
340                 INIT_LIST_HEAD(&snd_minors_hash[card]);
341         if ((err = snd_oss_init_module()) < 0)
342                 return err;
343         devfs_mk_dir("snd");
344         if (register_chrdev(major, "alsa", &snd_fops)) {
345                 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
346                 devfs_remove("snd");
347                 return -EIO;
348         }
349         snd_memory_init();
350         if (snd_info_init() < 0) {
351                 snd_memory_done();
352                 unregister_chrdev(major, "alsa");
353                 devfs_remove("snd");
354                 return -ENOMEM;
355         }
356         snd_info_minor_register();
357         for (controlnum = 0; controlnum < cards_limit; controlnum++)
358                 devfs_mk_cdev(MKDEV(major, controlnum<<5), S_IFCHR | device_mode, "snd/controlC%d", controlnum);
359 #ifndef MODULE
360         printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
361 #endif
362         return 0;
363 }
364
365 static void __exit alsa_sound_exit(void)
366 {
367         short controlnum;
368
369         for (controlnum = 0; controlnum < cards_limit; controlnum++)
370                 devfs_remove("snd/controlC%d", controlnum);
371
372         snd_info_minor_unregister();
373         snd_info_done();
374         snd_memory_done();
375         if (unregister_chrdev(major, "alsa") != 0)
376                 snd_printk(KERN_ERR "unable to unregister major device number %d\n", major);
377         devfs_remove("snd");
378 }
379
380 module_init(alsa_sound_init)
381 module_exit(alsa_sound_exit)
382
383   /* sound.c */
384 EXPORT_SYMBOL(snd_major);
385 EXPORT_SYMBOL(snd_ecards_limit);
386 #if defined(CONFIG_KMOD)
387 EXPORT_SYMBOL(snd_request_card);
388 #endif
389 EXPORT_SYMBOL(snd_register_device);
390 EXPORT_SYMBOL(snd_unregister_device);
391 #if defined(CONFIG_SND_OSSEMUL)
392 EXPORT_SYMBOL(snd_register_oss_device);
393 EXPORT_SYMBOL(snd_unregister_oss_device);
394 #endif
395   /* memory.c */
396 #ifdef CONFIG_SND_DEBUG_MEMORY
397 EXPORT_SYMBOL(snd_hidden_kmalloc);
398 EXPORT_SYMBOL(snd_hidden_kcalloc);
399 EXPORT_SYMBOL(snd_hidden_kfree);
400 EXPORT_SYMBOL(snd_hidden_vmalloc);
401 EXPORT_SYMBOL(snd_hidden_vfree);
402 #endif
403 EXPORT_SYMBOL(snd_kmalloc_strdup);
404 EXPORT_SYMBOL(copy_to_user_fromio);
405 EXPORT_SYMBOL(copy_from_user_toio);
406   /* init.c */
407 EXPORT_SYMBOL(snd_cards);
408 #if defined(CONFIG_SND_MIXER_OSS) || defined(CONFIG_SND_MIXER_OSS_MODULE)
409 EXPORT_SYMBOL(snd_mixer_oss_notify_callback);
410 #endif
411 EXPORT_SYMBOL(snd_card_new);
412 EXPORT_SYMBOL(snd_card_disconnect);
413 EXPORT_SYMBOL(snd_card_free);
414 EXPORT_SYMBOL(snd_card_free_in_thread);
415 EXPORT_SYMBOL(snd_card_register);
416 EXPORT_SYMBOL(snd_component_add);
417 EXPORT_SYMBOL(snd_card_file_add);
418 EXPORT_SYMBOL(snd_card_file_remove);
419 #ifdef CONFIG_PM
420 EXPORT_SYMBOL(snd_power_wait);
421 EXPORT_SYMBOL(snd_card_set_pm_callback);
422 #if defined(CONFIG_PM) && defined(CONFIG_SND_GENERIC_PM)
423 EXPORT_SYMBOL(snd_card_set_generic_pm_callback);
424 #endif
425 #ifdef CONFIG_PCI
426 EXPORT_SYMBOL(snd_card_pci_suspend);
427 EXPORT_SYMBOL(snd_card_pci_resume);
428 #endif
429 #endif
430   /* device.c */
431 EXPORT_SYMBOL(snd_device_new);
432 EXPORT_SYMBOL(snd_device_register);
433 EXPORT_SYMBOL(snd_device_free);
434   /* isadma.c */
435 #ifdef CONFIG_ISA
436 EXPORT_SYMBOL(snd_dma_program);
437 EXPORT_SYMBOL(snd_dma_disable);
438 EXPORT_SYMBOL(snd_dma_pointer);
439 #endif
440   /* info.c */
441 #ifdef CONFIG_PROC_FS
442 EXPORT_SYMBOL(snd_seq_root);
443 EXPORT_SYMBOL(snd_iprintf);
444 EXPORT_SYMBOL(snd_info_get_line);
445 EXPORT_SYMBOL(snd_info_get_str);
446 EXPORT_SYMBOL(snd_info_create_module_entry);
447 EXPORT_SYMBOL(snd_info_create_card_entry);
448 EXPORT_SYMBOL(snd_info_free_entry);
449 EXPORT_SYMBOL(snd_info_register);
450 EXPORT_SYMBOL(snd_info_unregister);
451 EXPORT_SYMBOL(snd_card_proc_new);
452 #endif
453   /* info_oss.c */
454 #if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_PROC_FS)
455 EXPORT_SYMBOL(snd_oss_info_register);
456 #endif
457   /* control.c */
458 EXPORT_SYMBOL(snd_ctl_new);
459 EXPORT_SYMBOL(snd_ctl_new1);
460 EXPORT_SYMBOL(snd_ctl_free_one);
461 EXPORT_SYMBOL(snd_ctl_add);
462 EXPORT_SYMBOL(snd_ctl_remove);
463 EXPORT_SYMBOL(snd_ctl_remove_id);
464 EXPORT_SYMBOL(snd_ctl_rename_id);
465 EXPORT_SYMBOL(snd_ctl_find_numid);
466 EXPORT_SYMBOL(snd_ctl_find_id);
467 EXPORT_SYMBOL(snd_ctl_notify);
468 EXPORT_SYMBOL(snd_ctl_register_ioctl);
469 EXPORT_SYMBOL(snd_ctl_unregister_ioctl);
470 #ifdef CONFIG_COMPAT
471 EXPORT_SYMBOL(snd_ctl_register_ioctl_compat);
472 EXPORT_SYMBOL(snd_ctl_unregister_ioctl_compat);
473 #endif
474 EXPORT_SYMBOL(snd_ctl_elem_read);
475 EXPORT_SYMBOL(snd_ctl_elem_write);
476   /* misc.c */
477 EXPORT_SYMBOL(snd_task_name);
478 #ifdef CONFIG_SND_VERBOSE_PRINTK
479 EXPORT_SYMBOL(snd_verbose_printk);
480 #endif
481 #if defined(CONFIG_SND_DEBUG) && defined(CONFIG_SND_VERBOSE_PRINTK)
482 EXPORT_SYMBOL(snd_verbose_printd);
483 #endif
484   /* wrappers */
485 #ifdef CONFIG_SND_DEBUG_MEMORY
486 EXPORT_SYMBOL(snd_wrapper_kmalloc);
487 EXPORT_SYMBOL(snd_wrapper_kfree);
488 EXPORT_SYMBOL(snd_wrapper_vmalloc);
489 EXPORT_SYMBOL(snd_wrapper_vfree);
490 #endif