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