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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/module.h>
27#include <sound/core.h>
28#include <sound/minors.h>
29#include <sound/info.h>
30#include <sound/control.h>
31#include <sound/initval.h>
32#include <linux/kmod.h>
33#include <linux/mutex.h>
34
35static int major = CONFIG_SND_MAJOR;
36int snd_major;
37EXPORT_SYMBOL(snd_major);
38
39static int cards_limit = 1;
40
41MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
42MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
43MODULE_LICENSE("GPL");
44module_param(major, int, 0444);
45MODULE_PARM_DESC(major, "Major # for sound driver.");
46module_param(cards_limit, int, 0444);
47MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
48MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
49
50/* this one holds the actual max. card number currently available.
51 * as default, it's identical with cards_limit option. when more
52 * modules are loaded manually, this limit number increases, too.
53 */
54int snd_ecards_limit;
55EXPORT_SYMBOL(snd_ecards_limit);
56
57static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
58static DEFINE_MUTEX(sound_mutex);
59
60#ifdef CONFIG_MODULES
61
62/**
63 * snd_request_card - try to load the card module
64 * @card: the card number
65 *
66 * Tries to load the module "snd-card-X" for the given card number
67 * via request_module. Returns immediately if already loaded.
68 */
69void snd_request_card(int card)
70{
71 if (snd_card_locked(card))
72 return;
73 if (card < 0 || card >= cards_limit)
74 return;
75 request_module("snd-card-%i", card);
76}
77
78EXPORT_SYMBOL(snd_request_card);
79
80static void snd_request_other(int minor)
81{
82 char *str;
83
84 switch (minor) {
85 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
86 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
87 default: return;
88 }
89 request_module(str);
90}
91
92#endif /* modular kernel */
93
94/**
95 * snd_lookup_minor_data - get user data of a registered device
96 * @minor: the minor number
97 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
98 *
99 * Checks that a minor device with the specified type is registered, and returns
100 * its user data pointer.
101 *
102 * This function increments the reference counter of the card instance
103 * if an associated instance with the given minor number and type is found.
104 * The caller must call snd_card_unref() appropriately later.
105 *
106 * Return: The user data pointer if the specified device is found. %NULL
107 * otherwise.
108 */
109void *snd_lookup_minor_data(unsigned int minor, int type)
110{
111 struct snd_minor *mreg;
112 void *private_data;
113
114 if (minor >= ARRAY_SIZE(snd_minors))
115 return NULL;
116 mutex_lock(&sound_mutex);
117 mreg = snd_minors[minor];
118 if (mreg && mreg->type == type) {
119 private_data = mreg->private_data;
120 if (private_data && mreg->card_ptr)
121 get_device(&mreg->card_ptr->card_dev);
122 } else
123 private_data = NULL;
124 mutex_unlock(&sound_mutex);
125 return private_data;
126}
127
128EXPORT_SYMBOL(snd_lookup_minor_data);
129
130#ifdef CONFIG_MODULES
131static struct snd_minor *autoload_device(unsigned int minor)
132{
133 int dev;
134 mutex_unlock(&sound_mutex); /* release lock temporarily */
135 dev = SNDRV_MINOR_DEVICE(minor);
136 if (dev == SNDRV_MINOR_CONTROL) {
137 /* /dev/aloadC? */
138 int card = SNDRV_MINOR_CARD(minor);
139 if (snd_cards[card] == NULL)
140 snd_request_card(card);
141 } else if (dev == SNDRV_MINOR_GLOBAL) {
142 /* /dev/aloadSEQ */
143 snd_request_other(minor);
144 }
145 mutex_lock(&sound_mutex); /* reacuire lock */
146 return snd_minors[minor];
147}
148#else /* !CONFIG_MODULES */
149#define autoload_device(minor) NULL
150#endif /* CONFIG_MODULES */
151
152static int snd_open(struct inode *inode, struct file *file)
153{
154 unsigned int minor = iminor(inode);
155 struct snd_minor *mptr = NULL;
156 const struct file_operations *new_fops;
157 int err = 0;
158
159 if (minor >= ARRAY_SIZE(snd_minors))
160 return -ENODEV;
161 mutex_lock(&sound_mutex);
162 mptr = snd_minors[minor];
163 if (mptr == NULL) {
164 mptr = autoload_device(minor);
165 if (!mptr) {
166 mutex_unlock(&sound_mutex);
167 return -ENODEV;
168 }
169 }
170 new_fops = fops_get(mptr->f_ops);
171 mutex_unlock(&sound_mutex);
172 if (!new_fops)
173 return -ENODEV;
174 replace_fops(file, new_fops);
175
176 if (file->f_op->open)
177 err = file->f_op->open(inode, file);
178 return err;
179}
180
181static const struct file_operations snd_fops =
182{
183 .owner = THIS_MODULE,
184 .open = snd_open,
185 .llseek = noop_llseek,
186};
187
188#ifdef CONFIG_SND_DYNAMIC_MINORS
189static int snd_find_free_minor(int type)
190{
191 int minor;
192
193 /* static minors for module auto loading */
194 if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
195 return SNDRV_MINOR_SEQUENCER;
196 if (type == SNDRV_DEVICE_TYPE_TIMER)
197 return SNDRV_MINOR_TIMER;
198
199 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
200 /* skip static minors still used for module auto loading */
201 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
202 continue;
203 if (minor == SNDRV_MINOR_SEQUENCER ||
204 minor == SNDRV_MINOR_TIMER)
205 continue;
206 if (!snd_minors[minor])
207 return minor;
208 }
209 return -EBUSY;
210}
211#else
212static int snd_kernel_minor(int type, struct snd_card *card, int dev)
213{
214 int minor;
215
216 switch (type) {
217 case SNDRV_DEVICE_TYPE_SEQUENCER:
218 case SNDRV_DEVICE_TYPE_TIMER:
219 minor = type;
220 break;
221 case SNDRV_DEVICE_TYPE_CONTROL:
222 if (snd_BUG_ON(!card))
223 return -EINVAL;
224 minor = SNDRV_MINOR(card->number, type);
225 break;
226 case SNDRV_DEVICE_TYPE_HWDEP:
227 case SNDRV_DEVICE_TYPE_RAWMIDI:
228 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
229 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
230 case SNDRV_DEVICE_TYPE_COMPRESS:
231 if (snd_BUG_ON(!card))
232 return -EINVAL;
233 minor = SNDRV_MINOR(card->number, type + dev);
234 break;
235 default:
236 return -EINVAL;
237 }
238 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
239 return -EINVAL;
240 return minor;
241}
242#endif
243
244/**
245 * snd_register_device_for_dev - Register the ALSA device file for the card
246 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
247 * @card: the card instance
248 * @dev: the device index
249 * @f_ops: the file operations
250 * @private_data: user pointer for f_ops->open()
251 * @name: the device file name
252 * @device: the &struct device to link this new device to
253 *
254 * Registers an ALSA device file for the given card.
255 * The operators have to be set in reg parameter.
256 *
257 * Return: Zero if successful, or a negative error code on failure.
258 */
259int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
260 const struct file_operations *f_ops,
261 void *private_data,
262 const char *name, struct device *device)
263{
264 int minor;
265 struct snd_minor *preg;
266
267 if (snd_BUG_ON(!name))
268 return -EINVAL;
269 preg = kmalloc(sizeof *preg, GFP_KERNEL);
270 if (preg == NULL)
271 return -ENOMEM;
272 preg->type = type;
273 preg->card = card ? card->number : -1;
274 preg->device = dev;
275 preg->f_ops = f_ops;
276 preg->private_data = private_data;
277 preg->card_ptr = card;
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 * Return: Zero if successful, 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
358/* get the assigned device to the given type and device number;
359 * the caller needs to release it via put_device() after using it
360 */
361struct device *snd_get_device(int type, struct snd_card *card, int dev)
362{
363 int minor;
364 struct device *d = NULL;
365
366 mutex_lock(&sound_mutex);
367 minor = find_snd_minor(type, card, dev);
368 if (minor >= 0) {
369 d = snd_minors[minor]->dev;
370 if (d)
371 get_device(d);
372 }
373 mutex_unlock(&sound_mutex);
374 return d;
375}
376EXPORT_SYMBOL(snd_get_device);
377
378#ifdef CONFIG_PROC_FS
379/*
380 * INFO PART
381 */
382
383static struct snd_info_entry *snd_minor_info_entry;
384
385static const char *snd_device_type_name(int type)
386{
387 switch (type) {
388 case SNDRV_DEVICE_TYPE_CONTROL:
389 return "control";
390 case SNDRV_DEVICE_TYPE_HWDEP:
391 return "hardware dependent";
392 case SNDRV_DEVICE_TYPE_RAWMIDI:
393 return "raw midi";
394 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
395 return "digital audio playback";
396 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
397 return "digital audio capture";
398 case SNDRV_DEVICE_TYPE_SEQUENCER:
399 return "sequencer";
400 case SNDRV_DEVICE_TYPE_TIMER:
401 return "timer";
402 default:
403 return "?";
404 }
405}
406
407static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
408{
409 int minor;
410 struct snd_minor *mptr;
411
412 mutex_lock(&sound_mutex);
413 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
414 if (!(mptr = snd_minors[minor]))
415 continue;
416 if (mptr->card >= 0) {
417 if (mptr->device >= 0)
418 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
419 minor, mptr->card, mptr->device,
420 snd_device_type_name(mptr->type));
421 else
422 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
423 minor, mptr->card,
424 snd_device_type_name(mptr->type));
425 } else
426 snd_iprintf(buffer, "%3i: : %s\n", minor,
427 snd_device_type_name(mptr->type));
428 }
429 mutex_unlock(&sound_mutex);
430}
431
432int __init snd_minor_info_init(void)
433{
434 struct snd_info_entry *entry;
435
436 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
437 if (entry) {
438 entry->c.text.read = snd_minor_info_read;
439 if (snd_info_register(entry) < 0) {
440 snd_info_free_entry(entry);
441 entry = NULL;
442 }
443 }
444 snd_minor_info_entry = entry;
445 return 0;
446}
447
448int __exit snd_minor_info_done(void)
449{
450 snd_info_free_entry(snd_minor_info_entry);
451 return 0;
452}
453#endif /* CONFIG_PROC_FS */
454
455/*
456 * INIT PART
457 */
458
459static int __init alsa_sound_init(void)
460{
461 snd_major = major;
462 snd_ecards_limit = cards_limit;
463 if (register_chrdev(major, "alsa", &snd_fops)) {
464 pr_err("ALSA core: unable to register native major device number %d\n", major);
465 return -EIO;
466 }
467 if (snd_info_init() < 0) {
468 unregister_chrdev(major, "alsa");
469 return -ENOMEM;
470 }
471 snd_info_minor_register();
472#ifndef MODULE
473 pr_info("Advanced Linux Sound Architecture Driver Initialized.\n");
474#endif
475 return 0;
476}
477
478static void __exit alsa_sound_exit(void)
479{
480 snd_info_minor_unregister();
481 snd_info_done();
482 unregister_chrdev(major, "alsa");
483}
484
485subsys_initcall(alsa_sound_init);
486module_exit(alsa_sound_exit);