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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Advanced Linux Sound Architecture
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5 */
6
7#include <linux/init.h>
8#include <linux/slab.h>
9#include <linux/time.h>
10#include <linux/device.h>
11#include <linux/module.h>
12#include <linux/debugfs.h>
13#include <sound/core.h>
14#include <sound/minors.h>
15#include <sound/info.h>
16#include <sound/control.h>
17#include <sound/initval.h>
18#include <linux/kmod.h>
19#include <linux/mutex.h>
20
21static int major = CONFIG_SND_MAJOR;
22int snd_major;
23EXPORT_SYMBOL(snd_major);
24
25static int cards_limit = 1;
26
27MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
28MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
29MODULE_LICENSE("GPL");
30module_param(major, int, 0444);
31MODULE_PARM_DESC(major, "Major # for sound driver.");
32module_param(cards_limit, int, 0444);
33MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
34MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
35
36/* this one holds the actual max. card number currently available.
37 * as default, it's identical with cards_limit option. when more
38 * modules are loaded manually, this limit number increases, too.
39 */
40int snd_ecards_limit;
41EXPORT_SYMBOL(snd_ecards_limit);
42
43#ifdef CONFIG_SND_DEBUG
44struct dentry *sound_debugfs_root;
45EXPORT_SYMBOL_GPL(sound_debugfs_root);
46#endif
47
48static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
49static DEFINE_MUTEX(sound_mutex);
50
51#ifdef CONFIG_MODULES
52
53/**
54 * snd_request_card - try to load the card module
55 * @card: the card number
56 *
57 * Tries to load the module "snd-card-X" for the given card number
58 * via request_module. Returns immediately if already loaded.
59 */
60void snd_request_card(int card)
61{
62 if (snd_card_locked(card))
63 return;
64 if (card < 0 || card >= cards_limit)
65 return;
66 request_module("snd-card-%i", card);
67}
68EXPORT_SYMBOL(snd_request_card);
69
70static void snd_request_other(int minor)
71{
72 char *str;
73
74 switch (minor) {
75 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
76 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
77 default: return;
78 }
79 request_module(str);
80}
81
82#endif /* modular kernel */
83
84/**
85 * snd_lookup_minor_data - get user data of a registered device
86 * @minor: the minor number
87 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
88 *
89 * Checks that a minor device with the specified type is registered, and returns
90 * its user data pointer.
91 *
92 * This function increments the reference counter of the card instance
93 * if an associated instance with the given minor number and type is found.
94 * The caller must call snd_card_unref() appropriately later.
95 *
96 * Return: The user data pointer if the specified device is found. %NULL
97 * otherwise.
98 */
99void *snd_lookup_minor_data(unsigned int minor, int type)
100{
101 struct snd_minor *mreg;
102 void *private_data;
103
104 if (minor >= ARRAY_SIZE(snd_minors))
105 return NULL;
106 guard(mutex)(&sound_mutex);
107 mreg = snd_minors[minor];
108 if (mreg && mreg->type == type) {
109 private_data = mreg->private_data;
110 if (private_data && mreg->card_ptr)
111 get_device(&mreg->card_ptr->card_dev);
112 } else
113 private_data = NULL;
114 return private_data;
115}
116EXPORT_SYMBOL(snd_lookup_minor_data);
117
118#ifdef CONFIG_MODULES
119static struct snd_minor *autoload_device(unsigned int minor)
120{
121 int dev;
122 mutex_unlock(&sound_mutex); /* release lock temporarily */
123 dev = SNDRV_MINOR_DEVICE(minor);
124 if (dev == SNDRV_MINOR_CONTROL) {
125 /* /dev/aloadC? */
126 int card = SNDRV_MINOR_CARD(minor);
127 struct snd_card *ref = snd_card_ref(card);
128 if (!ref)
129 snd_request_card(card);
130 else
131 snd_card_unref(ref);
132 } else if (dev == SNDRV_MINOR_GLOBAL) {
133 /* /dev/aloadSEQ */
134 snd_request_other(minor);
135 }
136 mutex_lock(&sound_mutex); /* reacquire lock */
137 return snd_minors[minor];
138}
139#else /* !CONFIG_MODULES */
140#define autoload_device(minor) NULL
141#endif /* CONFIG_MODULES */
142
143static int snd_open(struct inode *inode, struct file *file)
144{
145 unsigned int minor = iminor(inode);
146 struct snd_minor *mptr = NULL;
147 const struct file_operations *new_fops;
148 int err = 0;
149
150 if (minor >= ARRAY_SIZE(snd_minors))
151 return -ENODEV;
152 scoped_guard(mutex, &sound_mutex) {
153 mptr = snd_minors[minor];
154 if (mptr == NULL) {
155 mptr = autoload_device(minor);
156 if (!mptr)
157 return -ENODEV;
158 }
159 new_fops = fops_get(mptr->f_ops);
160 }
161 if (!new_fops)
162 return -ENODEV;
163 replace_fops(file, new_fops);
164
165 if (file->f_op->open)
166 err = file->f_op->open(inode, file);
167 return err;
168}
169
170static const struct file_operations snd_fops =
171{
172 .owner = THIS_MODULE,
173 .open = snd_open,
174 .llseek = noop_llseek,
175};
176
177#ifdef CONFIG_SND_DYNAMIC_MINORS
178static int snd_find_free_minor(int type, struct snd_card *card, int dev)
179{
180 int minor;
181
182 /* static minors for module auto loading */
183 if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
184 return SNDRV_MINOR_SEQUENCER;
185 if (type == SNDRV_DEVICE_TYPE_TIMER)
186 return SNDRV_MINOR_TIMER;
187
188 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
189 /* skip static minors still used for module auto loading */
190 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
191 continue;
192 if (minor == SNDRV_MINOR_SEQUENCER ||
193 minor == SNDRV_MINOR_TIMER)
194 continue;
195 if (!snd_minors[minor])
196 return minor;
197 }
198 return -EBUSY;
199}
200#else
201static int snd_find_free_minor(int type, struct snd_card *card, int dev)
202{
203 int minor;
204
205 switch (type) {
206 case SNDRV_DEVICE_TYPE_SEQUENCER:
207 case SNDRV_DEVICE_TYPE_TIMER:
208 minor = type;
209 break;
210 case SNDRV_DEVICE_TYPE_CONTROL:
211 if (snd_BUG_ON(!card))
212 return -EINVAL;
213 minor = SNDRV_MINOR(card->number, type);
214 break;
215 case SNDRV_DEVICE_TYPE_HWDEP:
216 case SNDRV_DEVICE_TYPE_RAWMIDI:
217 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
218 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
219 case SNDRV_DEVICE_TYPE_COMPRESS:
220 if (snd_BUG_ON(!card))
221 return -EINVAL;
222 minor = SNDRV_MINOR(card->number, type + dev);
223 break;
224 default:
225 return -EINVAL;
226 }
227 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
228 return -EINVAL;
229 if (snd_minors[minor])
230 return -EBUSY;
231 return minor;
232}
233#endif
234
235/**
236 * snd_register_device - Register the ALSA device file for the card
237 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
238 * @card: the card instance
239 * @dev: the device index
240 * @f_ops: the file operations
241 * @private_data: user pointer for f_ops->open()
242 * @device: the device to register
243 *
244 * Registers an ALSA device file for the given card.
245 * The operators have to be set in reg parameter.
246 *
247 * Return: Zero if successful, or a negative error code on failure.
248 */
249int snd_register_device(int type, struct snd_card *card, int dev,
250 const struct file_operations *f_ops,
251 void *private_data, struct device *device)
252{
253 int minor;
254 int err = 0;
255 struct snd_minor *preg;
256
257 if (snd_BUG_ON(!device))
258 return -EINVAL;
259
260 preg = kmalloc(sizeof *preg, GFP_KERNEL);
261 if (preg == NULL)
262 return -ENOMEM;
263 preg->type = type;
264 preg->card = card ? card->number : -1;
265 preg->device = dev;
266 preg->f_ops = f_ops;
267 preg->private_data = private_data;
268 preg->card_ptr = card;
269 guard(mutex)(&sound_mutex);
270 minor = snd_find_free_minor(type, card, dev);
271 if (minor < 0) {
272 err = minor;
273 goto error;
274 }
275
276 preg->dev = device;
277 device->devt = MKDEV(major, minor);
278 err = device_add(device);
279 if (err < 0)
280 goto error;
281
282 snd_minors[minor] = preg;
283 error:
284 if (err < 0)
285 kfree(preg);
286 return err;
287}
288EXPORT_SYMBOL(snd_register_device);
289
290/**
291 * snd_unregister_device - unregister the device on the given card
292 * @dev: the device instance
293 *
294 * Unregisters the device file already registered via
295 * snd_register_device().
296 *
297 * Return: Zero if successful, or a negative error code on failure.
298 */
299int snd_unregister_device(struct device *dev)
300{
301 int minor;
302 struct snd_minor *preg;
303
304 guard(mutex)(&sound_mutex);
305 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
306 preg = snd_minors[minor];
307 if (preg && preg->dev == dev) {
308 snd_minors[minor] = NULL;
309 device_del(dev);
310 kfree(preg);
311 break;
312 }
313 }
314 if (minor >= ARRAY_SIZE(snd_minors))
315 return -ENOENT;
316 return 0;
317}
318EXPORT_SYMBOL(snd_unregister_device);
319
320#ifdef CONFIG_SND_PROC_FS
321/*
322 * INFO PART
323 */
324static const char *snd_device_type_name(int type)
325{
326 switch (type) {
327 case SNDRV_DEVICE_TYPE_CONTROL:
328 return "control";
329 case SNDRV_DEVICE_TYPE_HWDEP:
330 return "hardware dependent";
331 case SNDRV_DEVICE_TYPE_RAWMIDI:
332 return "raw midi";
333 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
334 return "digital audio playback";
335 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
336 return "digital audio capture";
337 case SNDRV_DEVICE_TYPE_SEQUENCER:
338 return "sequencer";
339 case SNDRV_DEVICE_TYPE_TIMER:
340 return "timer";
341 case SNDRV_DEVICE_TYPE_COMPRESS:
342 return "compress";
343 default:
344 return "?";
345 }
346}
347
348static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
349{
350 int minor;
351 struct snd_minor *mptr;
352
353 guard(mutex)(&sound_mutex);
354 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
355 mptr = snd_minors[minor];
356 if (!mptr)
357 continue;
358 if (mptr->card >= 0) {
359 if (mptr->device >= 0)
360 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
361 minor, mptr->card, mptr->device,
362 snd_device_type_name(mptr->type));
363 else
364 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
365 minor, mptr->card,
366 snd_device_type_name(mptr->type));
367 } else
368 snd_iprintf(buffer, "%3i: : %s\n", minor,
369 snd_device_type_name(mptr->type));
370 }
371}
372
373int __init snd_minor_info_init(void)
374{
375 struct snd_info_entry *entry;
376
377 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
378 if (!entry)
379 return -ENOMEM;
380 entry->c.text.read = snd_minor_info_read;
381 return snd_info_register(entry); /* freed in error path */
382}
383#endif /* CONFIG_SND_PROC_FS */
384
385/*
386 * INIT PART
387 */
388
389static int __init alsa_sound_init(void)
390{
391 snd_major = major;
392 snd_ecards_limit = cards_limit;
393 if (register_chrdev(major, "alsa", &snd_fops)) {
394 pr_err("ALSA core: unable to register native major device number %d\n", major);
395 return -EIO;
396 }
397 if (snd_info_init() < 0) {
398 unregister_chrdev(major, "alsa");
399 return -ENOMEM;
400 }
401
402#ifdef CONFIG_SND_DEBUG
403 sound_debugfs_root = debugfs_create_dir("sound", NULL);
404#endif
405#ifndef MODULE
406 pr_info("Advanced Linux Sound Architecture Driver Initialized.\n");
407#endif
408 return 0;
409}
410
411static void __exit alsa_sound_exit(void)
412{
413#ifdef CONFIG_SND_DEBUG
414 debugfs_remove(sound_debugfs_root);
415#endif
416 snd_info_done();
417 unregister_chrdev(major, "alsa");
418}
419
420subsys_initcall(alsa_sound_init);
421module_exit(alsa_sound_exit);
1/*
2 * Advanced Linux Sound Architecture
3 * Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/init.h>
23#include <linux/slab.h>
24#include <linux/time.h>
25#include <linux/device.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/mutex.h>
35
36static int major = CONFIG_SND_MAJOR;
37int snd_major;
38EXPORT_SYMBOL(snd_major);
39
40static int cards_limit = 1;
41
42MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
43MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
44MODULE_LICENSE("GPL");
45module_param(major, int, 0444);
46MODULE_PARM_DESC(major, "Major # for sound driver.");
47module_param(cards_limit, int, 0444);
48MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
49MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
50
51/* this one holds the actual max. card number currently available.
52 * as default, it's identical with cards_limit option. when more
53 * modules are loaded manually, this limit number increases, too.
54 */
55int snd_ecards_limit;
56EXPORT_SYMBOL(snd_ecards_limit);
57
58static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
59static DEFINE_MUTEX(sound_mutex);
60
61#ifdef CONFIG_MODULES
62
63/**
64 * snd_request_card - try to load the card module
65 * @card: the card number
66 *
67 * Tries to load the module "snd-card-X" for the given card number
68 * via request_module. Returns immediately if already loaded.
69 */
70void snd_request_card(int card)
71{
72 if (snd_card_locked(card))
73 return;
74 if (card < 0 || card >= cards_limit)
75 return;
76 request_module("snd-card-%i", card);
77}
78
79EXPORT_SYMBOL(snd_request_card);
80
81static void snd_request_other(int minor)
82{
83 char *str;
84
85 switch (minor) {
86 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
87 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
88 default: return;
89 }
90 request_module(str);
91}
92
93#endif /* modular kernel */
94
95/**
96 * snd_lookup_minor_data - get user data of a registered device
97 * @minor: the minor number
98 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
99 *
100 * Checks that a minor device with the specified type is registered, and returns
101 * its user data pointer.
102 */
103void *snd_lookup_minor_data(unsigned int minor, int type)
104{
105 struct snd_minor *mreg;
106 void *private_data;
107
108 if (minor >= ARRAY_SIZE(snd_minors))
109 return NULL;
110 mutex_lock(&sound_mutex);
111 mreg = snd_minors[minor];
112 if (mreg && mreg->type == type)
113 private_data = mreg->private_data;
114 else
115 private_data = NULL;
116 mutex_unlock(&sound_mutex);
117 return private_data;
118}
119
120EXPORT_SYMBOL(snd_lookup_minor_data);
121
122#ifdef CONFIG_MODULES
123static struct snd_minor *autoload_device(unsigned int minor)
124{
125 int dev;
126 mutex_unlock(&sound_mutex); /* release lock temporarily */
127 dev = SNDRV_MINOR_DEVICE(minor);
128 if (dev == SNDRV_MINOR_CONTROL) {
129 /* /dev/aloadC? */
130 int card = SNDRV_MINOR_CARD(minor);
131 if (snd_cards[card] == NULL)
132 snd_request_card(card);
133 } else if (dev == SNDRV_MINOR_GLOBAL) {
134 /* /dev/aloadSEQ */
135 snd_request_other(minor);
136 }
137 mutex_lock(&sound_mutex); /* reacuire lock */
138 return snd_minors[minor];
139}
140#else /* !CONFIG_MODULES */
141#define autoload_device(minor) NULL
142#endif /* CONFIG_MODULES */
143
144static int snd_open(struct inode *inode, struct file *file)
145{
146 unsigned int minor = iminor(inode);
147 struct snd_minor *mptr = NULL;
148 const struct file_operations *old_fops;
149 int err = 0;
150
151 if (minor >= ARRAY_SIZE(snd_minors))
152 return -ENODEV;
153 mutex_lock(&sound_mutex);
154 mptr = snd_minors[minor];
155 if (mptr == NULL) {
156 mptr = autoload_device(minor);
157 if (!mptr) {
158 mutex_unlock(&sound_mutex);
159 return -ENODEV;
160 }
161 }
162 old_fops = file->f_op;
163 file->f_op = fops_get(mptr->f_ops);
164 if (file->f_op == NULL) {
165 file->f_op = old_fops;
166 err = -ENODEV;
167 }
168 mutex_unlock(&sound_mutex);
169 if (err < 0)
170 return err;
171
172 if (file->f_op->open) {
173 err = file->f_op->open(inode, file);
174 if (err) {
175 fops_put(file->f_op);
176 file->f_op = fops_get(old_fops);
177 }
178 }
179 fops_put(old_fops);
180 return err;
181}
182
183static const struct file_operations snd_fops =
184{
185 .owner = THIS_MODULE,
186 .open = snd_open,
187 .llseek = noop_llseek,
188};
189
190#ifdef CONFIG_SND_DYNAMIC_MINORS
191static int snd_find_free_minor(int type)
192{
193 int minor;
194
195 /* static minors for module auto loading */
196 if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
197 return SNDRV_MINOR_SEQUENCER;
198 if (type == SNDRV_DEVICE_TYPE_TIMER)
199 return SNDRV_MINOR_TIMER;
200
201 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
202 /* skip static minors still used for module auto loading */
203 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
204 continue;
205 if (minor == SNDRV_MINOR_SEQUENCER ||
206 minor == SNDRV_MINOR_TIMER)
207 continue;
208 if (!snd_minors[minor])
209 return minor;
210 }
211 return -EBUSY;
212}
213#else
214static int snd_kernel_minor(int type, struct snd_card *card, int dev)
215{
216 int minor;
217
218 switch (type) {
219 case SNDRV_DEVICE_TYPE_SEQUENCER:
220 case SNDRV_DEVICE_TYPE_TIMER:
221 minor = type;
222 break;
223 case SNDRV_DEVICE_TYPE_CONTROL:
224 if (snd_BUG_ON(!card))
225 return -EINVAL;
226 minor = SNDRV_MINOR(card->number, type);
227 break;
228 case SNDRV_DEVICE_TYPE_HWDEP:
229 case SNDRV_DEVICE_TYPE_RAWMIDI:
230 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
231 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
232 if (snd_BUG_ON(!card))
233 return -EINVAL;
234 minor = SNDRV_MINOR(card->number, type + dev);
235 break;
236 default:
237 return -EINVAL;
238 }
239 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
240 return -EINVAL;
241 return minor;
242}
243#endif
244
245/**
246 * snd_register_device_for_dev - Register the ALSA device file for the card
247 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
248 * @card: the card instance
249 * @dev: the device index
250 * @f_ops: the file operations
251 * @private_data: user pointer for f_ops->open()
252 * @name: the device file name
253 * @device: the &struct device to link this new device to
254 *
255 * Registers an ALSA device file for the given card.
256 * The operators have to be set in reg parameter.
257 *
258 * Returns zero if successful, or a negative error code on failure.
259 */
260int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
261 const struct file_operations *f_ops,
262 void *private_data,
263 const char *name, struct device *device)
264{
265 int minor;
266 struct snd_minor *preg;
267
268 if (snd_BUG_ON(!name))
269 return -EINVAL;
270 preg = kmalloc(sizeof *preg, GFP_KERNEL);
271 if (preg == NULL)
272 return -ENOMEM;
273 preg->type = type;
274 preg->card = card ? card->number : -1;
275 preg->device = dev;
276 preg->f_ops = f_ops;
277 preg->private_data = private_data;
278 mutex_lock(&sound_mutex);
279#ifdef CONFIG_SND_DYNAMIC_MINORS
280 minor = snd_find_free_minor(type);
281#else
282 minor = snd_kernel_minor(type, card, dev);
283 if (minor >= 0 && snd_minors[minor])
284 minor = -EBUSY;
285#endif
286 if (minor < 0) {
287 mutex_unlock(&sound_mutex);
288 kfree(preg);
289 return minor;
290 }
291 snd_minors[minor] = preg;
292 preg->dev = device_create(sound_class, device, MKDEV(major, minor),
293 private_data, "%s", name);
294 if (IS_ERR(preg->dev)) {
295 snd_minors[minor] = NULL;
296 mutex_unlock(&sound_mutex);
297 minor = PTR_ERR(preg->dev);
298 kfree(preg);
299 return minor;
300 }
301
302 mutex_unlock(&sound_mutex);
303 return 0;
304}
305
306EXPORT_SYMBOL(snd_register_device_for_dev);
307
308/* find the matching minor record
309 * return the index of snd_minor, or -1 if not found
310 */
311static int find_snd_minor(int type, struct snd_card *card, int dev)
312{
313 int cardnum, minor;
314 struct snd_minor *mptr;
315
316 cardnum = card ? card->number : -1;
317 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
318 if ((mptr = snd_minors[minor]) != NULL &&
319 mptr->type == type &&
320 mptr->card == cardnum &&
321 mptr->device == dev)
322 return minor;
323 return -1;
324}
325
326/**
327 * snd_unregister_device - unregister the device on the given card
328 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
329 * @card: the card instance
330 * @dev: the device index
331 *
332 * Unregisters the device file already registered via
333 * snd_register_device().
334 *
335 * Returns zero if sucecessful, or a negative error code on failure
336 */
337int snd_unregister_device(int type, struct snd_card *card, int dev)
338{
339 int minor;
340
341 mutex_lock(&sound_mutex);
342 minor = find_snd_minor(type, card, dev);
343 if (minor < 0) {
344 mutex_unlock(&sound_mutex);
345 return -EINVAL;
346 }
347
348 device_destroy(sound_class, MKDEV(major, minor));
349
350 kfree(snd_minors[minor]);
351 snd_minors[minor] = NULL;
352 mutex_unlock(&sound_mutex);
353 return 0;
354}
355
356EXPORT_SYMBOL(snd_unregister_device);
357
358int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
359 struct device_attribute *attr)
360{
361 int minor, ret = -EINVAL;
362 struct device *d;
363
364 mutex_lock(&sound_mutex);
365 minor = find_snd_minor(type, card, dev);
366 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
367 ret = device_create_file(d, attr);
368 mutex_unlock(&sound_mutex);
369 return ret;
370
371}
372
373EXPORT_SYMBOL(snd_add_device_sysfs_file);
374
375#ifdef CONFIG_PROC_FS
376/*
377 * INFO PART
378 */
379
380static struct snd_info_entry *snd_minor_info_entry;
381
382static const char *snd_device_type_name(int type)
383{
384 switch (type) {
385 case SNDRV_DEVICE_TYPE_CONTROL:
386 return "control";
387 case SNDRV_DEVICE_TYPE_HWDEP:
388 return "hardware dependent";
389 case SNDRV_DEVICE_TYPE_RAWMIDI:
390 return "raw midi";
391 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
392 return "digital audio playback";
393 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
394 return "digital audio capture";
395 case SNDRV_DEVICE_TYPE_SEQUENCER:
396 return "sequencer";
397 case SNDRV_DEVICE_TYPE_TIMER:
398 return "timer";
399 default:
400 return "?";
401 }
402}
403
404static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
405{
406 int minor;
407 struct snd_minor *mptr;
408
409 mutex_lock(&sound_mutex);
410 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
411 if (!(mptr = snd_minors[minor]))
412 continue;
413 if (mptr->card >= 0) {
414 if (mptr->device >= 0)
415 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
416 minor, mptr->card, mptr->device,
417 snd_device_type_name(mptr->type));
418 else
419 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
420 minor, mptr->card,
421 snd_device_type_name(mptr->type));
422 } else
423 snd_iprintf(buffer, "%3i: : %s\n", minor,
424 snd_device_type_name(mptr->type));
425 }
426 mutex_unlock(&sound_mutex);
427}
428
429int __init snd_minor_info_init(void)
430{
431 struct snd_info_entry *entry;
432
433 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
434 if (entry) {
435 entry->c.text.read = snd_minor_info_read;
436 if (snd_info_register(entry) < 0) {
437 snd_info_free_entry(entry);
438 entry = NULL;
439 }
440 }
441 snd_minor_info_entry = entry;
442 return 0;
443}
444
445int __exit snd_minor_info_done(void)
446{
447 snd_info_free_entry(snd_minor_info_entry);
448 return 0;
449}
450#endif /* CONFIG_PROC_FS */
451
452/*
453 * INIT PART
454 */
455
456static int __init alsa_sound_init(void)
457{
458 snd_major = major;
459 snd_ecards_limit = cards_limit;
460 if (register_chrdev(major, "alsa", &snd_fops)) {
461 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
462 return -EIO;
463 }
464 if (snd_info_init() < 0) {
465 unregister_chrdev(major, "alsa");
466 return -ENOMEM;
467 }
468 snd_info_minor_register();
469#ifndef MODULE
470 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
471#endif
472 return 0;
473}
474
475static void __exit alsa_sound_exit(void)
476{
477 snd_info_minor_unregister();
478 snd_info_done();
479 unregister_chrdev(major, "alsa");
480}
481
482subsys_initcall(alsa_sound_init);
483module_exit(alsa_sound_exit);