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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);
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 mutex_lock(&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 mutex_unlock(&sound_mutex);
115 return private_data;
116}
117EXPORT_SYMBOL(snd_lookup_minor_data);
118
119#ifdef CONFIG_MODULES
120static struct snd_minor *autoload_device(unsigned int minor)
121{
122 int dev;
123 mutex_unlock(&sound_mutex); /* release lock temporarily */
124 dev = SNDRV_MINOR_DEVICE(minor);
125 if (dev == SNDRV_MINOR_CONTROL) {
126 /* /dev/aloadC? */
127 int card = SNDRV_MINOR_CARD(minor);
128 struct snd_card *ref = snd_card_ref(card);
129 if (!ref)
130 snd_request_card(card);
131 else
132 snd_card_unref(ref);
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 *new_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 new_fops = fops_get(mptr->f_ops);
163 mutex_unlock(&sound_mutex);
164 if (!new_fops)
165 return -ENODEV;
166 replace_fops(file, new_fops);
167
168 if (file->f_op->open)
169 err = file->f_op->open(inode, file);
170 return err;
171}
172
173static const struct file_operations snd_fops =
174{
175 .owner = THIS_MODULE,
176 .open = snd_open,
177 .llseek = noop_llseek,
178};
179
180#ifdef CONFIG_SND_DYNAMIC_MINORS
181static int snd_find_free_minor(int type, struct snd_card *card, int dev)
182{
183 int minor;
184
185 /* static minors for module auto loading */
186 if (type == SNDRV_DEVICE_TYPE_SEQUENCER)
187 return SNDRV_MINOR_SEQUENCER;
188 if (type == SNDRV_DEVICE_TYPE_TIMER)
189 return SNDRV_MINOR_TIMER;
190
191 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
192 /* skip static minors still used for module auto loading */
193 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL)
194 continue;
195 if (minor == SNDRV_MINOR_SEQUENCER ||
196 minor == SNDRV_MINOR_TIMER)
197 continue;
198 if (!snd_minors[minor])
199 return minor;
200 }
201 return -EBUSY;
202}
203#else
204static int snd_find_free_minor(int type, struct snd_card *card, int dev)
205{
206 int minor;
207
208 switch (type) {
209 case SNDRV_DEVICE_TYPE_SEQUENCER:
210 case SNDRV_DEVICE_TYPE_TIMER:
211 minor = type;
212 break;
213 case SNDRV_DEVICE_TYPE_CONTROL:
214 if (snd_BUG_ON(!card))
215 return -EINVAL;
216 minor = SNDRV_MINOR(card->number, type);
217 break;
218 case SNDRV_DEVICE_TYPE_HWDEP:
219 case SNDRV_DEVICE_TYPE_RAWMIDI:
220 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
221 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
222 case SNDRV_DEVICE_TYPE_COMPRESS:
223 if (snd_BUG_ON(!card))
224 return -EINVAL;
225 minor = SNDRV_MINOR(card->number, type + dev);
226 break;
227 default:
228 return -EINVAL;
229 }
230 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
231 return -EINVAL;
232 if (snd_minors[minor])
233 return -EBUSY;
234 return minor;
235}
236#endif
237
238/**
239 * snd_register_device - Register the ALSA device file for the card
240 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
241 * @card: the card instance
242 * @dev: the device index
243 * @f_ops: the file operations
244 * @private_data: user pointer for f_ops->open()
245 * @device: the device to register
246 *
247 * Registers an ALSA device file for the given card.
248 * The operators have to be set in reg parameter.
249 *
250 * Return: Zero if successful, or a negative error code on failure.
251 */
252int snd_register_device(int type, struct snd_card *card, int dev,
253 const struct file_operations *f_ops,
254 void *private_data, struct device *device)
255{
256 int minor;
257 int err = 0;
258 struct snd_minor *preg;
259
260 if (snd_BUG_ON(!device))
261 return -EINVAL;
262
263 preg = kmalloc(sizeof *preg, GFP_KERNEL);
264 if (preg == NULL)
265 return -ENOMEM;
266 preg->type = type;
267 preg->card = card ? card->number : -1;
268 preg->device = dev;
269 preg->f_ops = f_ops;
270 preg->private_data = private_data;
271 preg->card_ptr = card;
272 mutex_lock(&sound_mutex);
273 minor = snd_find_free_minor(type, card, dev);
274 if (minor < 0) {
275 err = minor;
276 goto error;
277 }
278
279 preg->dev = device;
280 device->devt = MKDEV(major, minor);
281 err = device_add(device);
282 if (err < 0)
283 goto error;
284
285 snd_minors[minor] = preg;
286 error:
287 mutex_unlock(&sound_mutex);
288 if (err < 0)
289 kfree(preg);
290 return err;
291}
292EXPORT_SYMBOL(snd_register_device);
293
294/**
295 * snd_unregister_device - unregister the device on the given card
296 * @dev: the device instance
297 *
298 * Unregisters the device file already registered via
299 * snd_register_device().
300 *
301 * Return: Zero if successful, or a negative error code on failure.
302 */
303int snd_unregister_device(struct device *dev)
304{
305 int minor;
306 struct snd_minor *preg;
307
308 mutex_lock(&sound_mutex);
309 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
310 preg = snd_minors[minor];
311 if (preg && preg->dev == dev) {
312 snd_minors[minor] = NULL;
313 device_del(dev);
314 kfree(preg);
315 break;
316 }
317 }
318 mutex_unlock(&sound_mutex);
319 if (minor >= ARRAY_SIZE(snd_minors))
320 return -ENOENT;
321 return 0;
322}
323EXPORT_SYMBOL(snd_unregister_device);
324
325#ifdef CONFIG_SND_PROC_FS
326/*
327 * INFO PART
328 */
329static const char *snd_device_type_name(int type)
330{
331 switch (type) {
332 case SNDRV_DEVICE_TYPE_CONTROL:
333 return "control";
334 case SNDRV_DEVICE_TYPE_HWDEP:
335 return "hardware dependent";
336 case SNDRV_DEVICE_TYPE_RAWMIDI:
337 return "raw midi";
338 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
339 return "digital audio playback";
340 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
341 return "digital audio capture";
342 case SNDRV_DEVICE_TYPE_SEQUENCER:
343 return "sequencer";
344 case SNDRV_DEVICE_TYPE_TIMER:
345 return "timer";
346 case SNDRV_DEVICE_TYPE_COMPRESS:
347 return "compress";
348 default:
349 return "?";
350 }
351}
352
353static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
354{
355 int minor;
356 struct snd_minor *mptr;
357
358 mutex_lock(&sound_mutex);
359 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
360 mptr = snd_minors[minor];
361 if (!mptr)
362 continue;
363 if (mptr->card >= 0) {
364 if (mptr->device >= 0)
365 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
366 minor, mptr->card, mptr->device,
367 snd_device_type_name(mptr->type));
368 else
369 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
370 minor, mptr->card,
371 snd_device_type_name(mptr->type));
372 } else
373 snd_iprintf(buffer, "%3i: : %s\n", minor,
374 snd_device_type_name(mptr->type));
375 }
376 mutex_unlock(&sound_mutex);
377}
378
379int __init snd_minor_info_init(void)
380{
381 struct snd_info_entry *entry;
382
383 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
384 if (!entry)
385 return -ENOMEM;
386 entry->c.text.read = snd_minor_info_read;
387 return snd_info_register(entry); /* freed in error path */
388}
389#endif /* CONFIG_SND_PROC_FS */
390
391/*
392 * INIT PART
393 */
394
395static int __init alsa_sound_init(void)
396{
397 snd_major = major;
398 snd_ecards_limit = cards_limit;
399 if (register_chrdev(major, "alsa", &snd_fops)) {
400 pr_err("ALSA core: unable to register native major device number %d\n", major);
401 return -EIO;
402 }
403 if (snd_info_init() < 0) {
404 unregister_chrdev(major, "alsa");
405 return -ENOMEM;
406 }
407
408#ifdef CONFIG_SND_DEBUG
409 sound_debugfs_root = debugfs_create_dir("sound", NULL);
410#endif
411#ifndef MODULE
412 pr_info("Advanced Linux Sound Architecture Driver Initialized.\n");
413#endif
414 return 0;
415}
416
417static void __exit alsa_sound_exit(void)
418{
419#ifdef CONFIG_SND_DEBUG
420 debugfs_remove(sound_debugfs_root);
421#endif
422 snd_info_done();
423 unregister_chrdev(major, "alsa");
424}
425
426subsys_initcall(alsa_sound_init);
427module_exit(alsa_sound_exit);