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