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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Advanced Linux Sound Architecture | |
c1017a4c | 4 | * Copyright (c) by Jaroslav Kysela <perex@perex.cz> |
1da177e4 LT |
5 | */ |
6 | ||
1da177e4 LT |
7 | #include <linux/init.h> |
8 | #include <linux/slab.h> | |
9 | #include <linux/time.h> | |
9a1a2a1d | 10 | #include <linux/device.h> |
65a77217 | 11 | #include <linux/module.h> |
2d670ea2 | 12 | #include <linux/debugfs.h> |
1da177e4 LT |
13 | #include <sound/core.h> |
14 | #include <sound/minors.h> | |
15 | #include <sound/info.h> | |
1da177e4 LT |
16 | #include <sound/control.h> |
17 | #include <sound/initval.h> | |
18 | #include <linux/kmod.h> | |
1a60d4c5 | 19 | #include <linux/mutex.h> |
1da177e4 | 20 | |
1da177e4 LT |
21 | static int major = CONFIG_SND_MAJOR; |
22 | int snd_major; | |
c0d3fb39 TI |
23 | EXPORT_SYMBOL(snd_major); |
24 | ||
1da177e4 | 25 | static int cards_limit = 1; |
1da177e4 | 26 | |
c1017a4c | 27 | MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>"); |
1da177e4 LT |
28 | MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards."); |
29 | MODULE_LICENSE("GPL"); | |
30 | module_param(major, int, 0444); | |
31 | MODULE_PARM_DESC(major, "Major # for sound driver."); | |
32 | module_param(cards_limit, int, 0444); | |
33 | MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards."); | |
1da177e4 LT |
34 | MODULE_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 | */ | |
40 | int snd_ecards_limit; | |
c0d3fb39 | 41 | EXPORT_SYMBOL(snd_ecards_limit); |
1da177e4 | 42 | |
2d670ea2 HW |
43 | #ifdef CONFIG_SND_DEBUG |
44 | struct dentry *sound_debugfs_root; | |
45 | EXPORT_SYMBOL_GPL(sound_debugfs_root); | |
46 | #endif | |
47 | ||
6983b724 | 48 | static struct snd_minor *snd_minors[SNDRV_OS_MINORS]; |
1a60d4c5 | 49 | static DEFINE_MUTEX(sound_mutex); |
1da177e4 | 50 | |
ee2da997 | 51 | #ifdef CONFIG_MODULES |
1da177e4 LT |
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 | |
ee2da997 | 58 | * via request_module. Returns immediately if already loaded. |
1da177e4 LT |
59 | */ |
60 | void snd_request_card(int card) | |
61 | { | |
746df948 | 62 | if (snd_card_locked(card)) |
1da177e4 LT |
63 | return; |
64 | if (card < 0 || card >= cards_limit) | |
65 | return; | |
66 | request_module("snd-card-%i", card); | |
67 | } | |
c0d3fb39 TI |
68 | EXPORT_SYMBOL(snd_request_card); |
69 | ||
1da177e4 LT |
70 | static void snd_request_other(int minor) |
71 | { | |
72 | char *str; | |
73 | ||
1da177e4 LT |
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 | ||
ee2da997 | 82 | #endif /* modular kernel */ |
1da177e4 | 83 | |
f87135f5 CL |
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. | |
a0830dbd TI |
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. | |
eb7c06e8 YB |
95 | * |
96 | * Return: The user data pointer if the specified device is found. %NULL | |
97 | * otherwise. | |
f87135f5 CL |
98 | */ |
99 | void *snd_lookup_minor_data(unsigned int minor, int type) | |
100 | { | |
101 | struct snd_minor *mreg; | |
102 | void *private_data; | |
103 | ||
3a63e444 | 104 | if (minor >= ARRAY_SIZE(snd_minors)) |
f87135f5 | 105 | return NULL; |
1a60d4c5 | 106 | mutex_lock(&sound_mutex); |
f87135f5 | 107 | mreg = snd_minors[minor]; |
a0830dbd | 108 | if (mreg && mreg->type == type) { |
f87135f5 | 109 | private_data = mreg->private_data; |
8bb4d9ce | 110 | if (private_data && mreg->card_ptr) |
f2464064 | 111 | get_device(&mreg->card_ptr->card_dev); |
a0830dbd | 112 | } else |
f87135f5 | 113 | private_data = NULL; |
1a60d4c5 | 114 | mutex_unlock(&sound_mutex); |
f87135f5 CL |
115 | return private_data; |
116 | } | |
c0d3fb39 TI |
117 | EXPORT_SYMBOL(snd_lookup_minor_data); |
118 | ||
4cf19b84 TI |
119 | #ifdef CONFIG_MODULES |
120 | static 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); | |
f4fa9689 TI |
128 | struct snd_card *ref = snd_card_ref(card); |
129 | if (!ref) | |
4cf19b84 | 130 | snd_request_card(card); |
f4fa9689 TI |
131 | else |
132 | snd_card_unref(ref); | |
4cf19b84 TI |
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 | ||
144 | static int snd_open(struct inode *inode, struct file *file) | |
1da177e4 | 145 | { |
332682b1 | 146 | unsigned int minor = iminor(inode); |
512bbd6a | 147 | struct snd_minor *mptr = NULL; |
e84f9e57 | 148 | const struct file_operations *new_fops; |
1da177e4 LT |
149 | int err = 0; |
150 | ||
3a63e444 | 151 | if (minor >= ARRAY_SIZE(snd_minors)) |
332682b1 | 152 | return -ENODEV; |
4cf19b84 | 153 | mutex_lock(&sound_mutex); |
332682b1 CL |
154 | mptr = snd_minors[minor]; |
155 | if (mptr == NULL) { | |
4cf19b84 TI |
156 | mptr = autoload_device(minor); |
157 | if (!mptr) { | |
158 | mutex_unlock(&sound_mutex); | |
332682b1 | 159 | return -ENODEV; |
4cf19b84 | 160 | } |
1da177e4 | 161 | } |
e84f9e57 | 162 | new_fops = fops_get(mptr->f_ops); |
4cf19b84 | 163 | mutex_unlock(&sound_mutex); |
e84f9e57 AV |
164 | if (!new_fops) |
165 | return -ENODEV; | |
166 | replace_fops(file, new_fops); | |
4cf19b84 | 167 | |
e84f9e57 | 168 | if (file->f_op->open) |
1da177e4 | 169 | err = file->f_op->open(inode, file); |
1da177e4 LT |
170 | return err; |
171 | } | |
172 | ||
9c2e08c5 | 173 | static const struct file_operations snd_fops = |
1da177e4 LT |
174 | { |
175 | .owner = THIS_MODULE, | |
6038f373 AB |
176 | .open = snd_open, |
177 | .llseek = noop_llseek, | |
1da177e4 LT |
178 | }; |
179 | ||
332682b1 | 180 | #ifdef CONFIG_SND_DYNAMIC_MINORS |
38ebb703 | 181 | static int snd_find_free_minor(int type, struct snd_card *card, int dev) |
332682b1 CL |
182 | { |
183 | int minor; | |
184 | ||
03cfe6f5 KS |
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 | ||
332682b1 | 191 | for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) { |
03cfe6f5 KS |
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) | |
332682b1 CL |
197 | continue; |
198 | if (!snd_minors[minor]) | |
199 | return minor; | |
200 | } | |
201 | return -EBUSY; | |
202 | } | |
203 | #else | |
38ebb703 | 204 | static int snd_find_free_minor(int type, struct snd_card *card, int dev) |
1da177e4 LT |
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: | |
7eaa943c TI |
214 | if (snd_BUG_ON(!card)) |
215 | return -EINVAL; | |
1da177e4 LT |
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: | |
3eafc959 | 222 | case SNDRV_DEVICE_TYPE_COMPRESS: |
7eaa943c TI |
223 | if (snd_BUG_ON(!card)) |
224 | return -EINVAL; | |
1da177e4 LT |
225 | minor = SNDRV_MINOR(card->number, type + dev); |
226 | break; | |
227 | default: | |
228 | return -EINVAL; | |
229 | } | |
7eaa943c TI |
230 | if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS)) |
231 | return -EINVAL; | |
38ebb703 TI |
232 | if (snd_minors[minor]) |
233 | return -EBUSY; | |
1da177e4 LT |
234 | return minor; |
235 | } | |
332682b1 | 236 | #endif |
1da177e4 LT |
237 | |
238 | /** | |
40a4b263 | 239 | * snd_register_device - Register the ALSA device file for the card |
1da177e4 LT |
240 | * @type: the device type, SNDRV_DEVICE_TYPE_XXX |
241 | * @card: the card instance | |
242 | * @dev: the device index | |
2af677fc | 243 | * @f_ops: the file operations |
f87135f5 | 244 | * @private_data: user pointer for f_ops->open() |
40a4b263 | 245 | * @device: the device to register |
1da177e4 LT |
246 | * |
247 | * Registers an ALSA device file for the given card. | |
248 | * The operators have to be set in reg parameter. | |
249 | * | |
eb7c06e8 | 250 | * Return: Zero if successful, or a negative error code on failure. |
1da177e4 | 251 | */ |
40a4b263 TI |
252 | int 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) | |
1da177e4 | 255 | { |
332682b1 | 256 | int minor; |
92b7952d | 257 | int err = 0; |
512bbd6a | 258 | struct snd_minor *preg; |
1da177e4 | 259 | |
40a4b263 TI |
260 | if (snd_BUG_ON(!device)) |
261 | return -EINVAL; | |
262 | ||
562b590d | 263 | preg = kmalloc(sizeof *preg, GFP_KERNEL); |
1da177e4 LT |
264 | if (preg == NULL) |
265 | return -ENOMEM; | |
2af677fc | 266 | preg->type = type; |
6983b724 | 267 | preg->card = card ? card->number : -1; |
1da177e4 | 268 | preg->device = dev; |
2af677fc | 269 | preg->f_ops = f_ops; |
f87135f5 | 270 | preg->private_data = private_data; |
a0830dbd | 271 | preg->card_ptr = card; |
1a60d4c5 | 272 | mutex_lock(&sound_mutex); |
38ebb703 | 273 | minor = snd_find_free_minor(type, card, dev); |
332682b1 | 274 | if (minor < 0) { |
92b7952d TI |
275 | err = minor; |
276 | goto error; | |
1da177e4 | 277 | } |
92b7952d | 278 | |
40a4b263 TI |
279 | preg->dev = device; |
280 | device->devt = MKDEV(major, minor); | |
281 | err = device_add(device); | |
92b7952d TI |
282 | if (err < 0) |
283 | goto error; | |
2469049e | 284 | |
92b7952d TI |
285 | snd_minors[minor] = preg; |
286 | error: | |
1a60d4c5 | 287 | mutex_unlock(&sound_mutex); |
92b7952d TI |
288 | if (err < 0) |
289 | kfree(preg); | |
290 | return err; | |
1da177e4 | 291 | } |
40a4b263 | 292 | EXPORT_SYMBOL(snd_register_device); |
c0d3fb39 | 293 | |
1da177e4 LT |
294 | /** |
295 | * snd_unregister_device - unregister the device on the given card | |
40a4b263 | 296 | * @dev: the device instance |
1da177e4 LT |
297 | * |
298 | * Unregisters the device file already registered via | |
299 | * snd_register_device(). | |
300 | * | |
eb7c06e8 | 301 | * Return: Zero if successful, or a negative error code on failure. |
1da177e4 | 302 | */ |
40a4b263 | 303 | int snd_unregister_device(struct device *dev) |
1da177e4 | 304 | { |
9d19f48c | 305 | int minor; |
92b7952d | 306 | struct snd_minor *preg; |
1da177e4 | 307 | |
1a60d4c5 | 308 | mutex_lock(&sound_mutex); |
40a4b263 TI |
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 | } | |
1da177e4 | 317 | } |
1a60d4c5 | 318 | mutex_unlock(&sound_mutex); |
40a4b263 TI |
319 | if (minor >= ARRAY_SIZE(snd_minors)) |
320 | return -ENOENT; | |
1da177e4 LT |
321 | return 0; |
322 | } | |
c0d3fb39 TI |
323 | EXPORT_SYMBOL(snd_unregister_device); |
324 | ||
cd6a6503 | 325 | #ifdef CONFIG_SND_PROC_FS |
1da177e4 LT |
326 | /* |
327 | * INFO PART | |
328 | */ | |
2af677fc CL |
329 | static 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"; | |
2c28156d JK |
346 | case SNDRV_DEVICE_TYPE_COMPRESS: |
347 | return "compress"; | |
2af677fc CL |
348 | default: |
349 | return "?"; | |
350 | } | |
351 | } | |
352 | ||
512bbd6a | 353 | static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) |
1da177e4 | 354 | { |
6983b724 | 355 | int minor; |
512bbd6a | 356 | struct snd_minor *mptr; |
1da177e4 | 357 | |
1a60d4c5 | 358 | mutex_lock(&sound_mutex); |
6983b724 CL |
359 | for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) { |
360 | if (!(mptr = snd_minors[minor])) | |
361 | continue; | |
362 | if (mptr->card >= 0) { | |
363 | if (mptr->device >= 0) | |
d001544d | 364 | snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n", |
6983b724 CL |
365 | minor, mptr->card, mptr->device, |
366 | snd_device_type_name(mptr->type)); | |
367 | else | |
d001544d | 368 | snd_iprintf(buffer, "%3i: [%2i] : %s\n", |
6983b724 CL |
369 | minor, mptr->card, |
370 | snd_device_type_name(mptr->type)); | |
371 | } else | |
d001544d | 372 | snd_iprintf(buffer, "%3i: : %s\n", minor, |
6983b724 | 373 | snd_device_type_name(mptr->type)); |
1da177e4 | 374 | } |
1a60d4c5 | 375 | mutex_unlock(&sound_mutex); |
1da177e4 LT |
376 | } |
377 | ||
378 | int __init snd_minor_info_init(void) | |
379 | { | |
512bbd6a | 380 | struct snd_info_entry *entry; |
1da177e4 LT |
381 | |
382 | entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL); | |
b591b6e9 TI |
383 | if (!entry) |
384 | return -ENOMEM; | |
385 | entry->c.text.read = snd_minor_info_read; | |
386 | return snd_info_register(entry); /* freed in error path */ | |
1da177e4 | 387 | } |
cd6a6503 | 388 | #endif /* CONFIG_SND_PROC_FS */ |
1da177e4 LT |
389 | |
390 | /* | |
391 | * INIT PART | |
392 | */ | |
393 | ||
394 | static int __init alsa_sound_init(void) | |
395 | { | |
1da177e4 LT |
396 | snd_major = major; |
397 | snd_ecards_limit = cards_limit; | |
1da177e4 | 398 | if (register_chrdev(major, "alsa", &snd_fops)) { |
f2f9307a | 399 | pr_err("ALSA core: unable to register native major device number %d\n", major); |
1da177e4 LT |
400 | return -EIO; |
401 | } | |
1da177e4 | 402 | if (snd_info_init() < 0) { |
1da177e4 | 403 | unregister_chrdev(major, "alsa"); |
1da177e4 LT |
404 | return -ENOMEM; |
405 | } | |
2d670ea2 HW |
406 | |
407 | #ifdef CONFIG_SND_DEBUG | |
408 | sound_debugfs_root = debugfs_create_dir("sound", NULL); | |
409 | #endif | |
1da177e4 | 410 | #ifndef MODULE |
f2f9307a | 411 | pr_info("Advanced Linux Sound Architecture Driver Initialized.\n"); |
1da177e4 LT |
412 | #endif |
413 | return 0; | |
414 | } | |
415 | ||
416 | static void __exit alsa_sound_exit(void) | |
417 | { | |
2d670ea2 HW |
418 | #ifdef CONFIG_SND_DEBUG |
419 | debugfs_remove(sound_debugfs_root); | |
420 | #endif | |
1da177e4 | 421 | snd_info_done(); |
68fc4fab | 422 | unregister_chrdev(major, "alsa"); |
1da177e4 LT |
423 | } |
424 | ||
c181a13a TLSC |
425 | subsys_initcall(alsa_sound_init); |
426 | module_exit(alsa_sound_exit); |