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/smp_lock.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 static int major = CONFIG_SND_MAJOR;
38 int snd_major;
39 EXPORT_SYMBOL(snd_major);
40
41 static int cards_limit = 1;
42
43 MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
44 MODULE_DESCRIPTION("Advanced Linux Sound Architecture driver for soundcards.");
45 MODULE_LICENSE("GPL");
46 module_param(major, int, 0444);
47 MODULE_PARM_DESC(major, "Major # for sound driver.");
48 module_param(cards_limit, int, 0444);
49 MODULE_PARM_DESC(cards_limit, "Count of auto-loadable soundcards.");
50 MODULE_ALIAS_CHARDEV_MAJOR(CONFIG_SND_MAJOR);
51
52 /* this one holds the actual max. card number currently available.
53 * as default, it's identical with cards_limit option. when more
54 * modules are loaded manually, this limit number increases, too.
55 */
56 int snd_ecards_limit;
57 EXPORT_SYMBOL(snd_ecards_limit);
58
59 static struct snd_minor *snd_minors[SNDRV_OS_MINORS];
60 static DEFINE_MUTEX(sound_mutex);
61
62 #ifdef CONFIG_MODULES
63
64 /**
65 * snd_request_card - try to load the card module
66 * @card: the card number
67 *
68 * Tries to load the module "snd-card-X" for the given card number
69 * via request_module. Returns immediately if already loaded.
70 */
71 void snd_request_card(int card)
72 {
73 if (snd_card_locked(card))
74 return;
75 if (card < 0 || card >= cards_limit)
76 return;
77 request_module("snd-card-%i", card);
78 }
79
80 EXPORT_SYMBOL(snd_request_card);
81
82 static void snd_request_other(int minor)
83 {
84 char *str;
85
86 switch (minor) {
87 case SNDRV_MINOR_SEQUENCER: str = "snd-seq"; break;
88 case SNDRV_MINOR_TIMER: str = "snd-timer"; break;
89 default: return;
90 }
91 request_module(str);
92 }
93
94 #endif /* modular kernel */
95
96 /**
97 * snd_lookup_minor_data - get user data of a registered device
98 * @minor: the minor number
99 * @type: device type (SNDRV_DEVICE_TYPE_XXX)
100 *
101 * Checks that a minor device with the specified type is registered, and returns
102 * its user data pointer.
103 */
104 void *snd_lookup_minor_data(unsigned int minor, int type)
105 {
106 struct snd_minor *mreg;
107 void *private_data;
108
109 if (minor >= ARRAY_SIZE(snd_minors))
110 return NULL;
111 mutex_lock(&sound_mutex);
112 mreg = snd_minors[minor];
113 if (mreg && mreg->type == type)
114 private_data = mreg->private_data;
115 else
116 private_data = NULL;
117 mutex_unlock(&sound_mutex);
118 return private_data;
119 }
120
121 EXPORT_SYMBOL(snd_lookup_minor_data);
122
123 static int __snd_open(struct inode *inode, struct file *file)
124 {
125 unsigned int minor = iminor(inode);
126 struct snd_minor *mptr = NULL;
127 const struct file_operations *old_fops;
128 int err = 0;
129
130 if (minor >= ARRAY_SIZE(snd_minors))
131 return -ENODEV;
132 mptr = snd_minors[minor];
133 if (mptr == NULL) {
134 #ifdef CONFIG_MODULES
135 int 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 #ifndef CONFIG_SND_DYNAMIC_MINORS
146 /* /dev/snd/{controlC?,seq} */
147 mptr = snd_minors[minor];
148 if (mptr == NULL)
149 #endif
150 #endif
151 return -ENODEV;
152 }
153 old_fops = file->f_op;
154 file->f_op = fops_get(mptr->f_ops);
155 if (file->f_op == NULL) {
156 file->f_op = old_fops;
157 return -ENODEV;
158 }
159 if (file->f_op->open)
160 err = file->f_op->open(inode, file);
161 if (err) {
162 fops_put(file->f_op);
163 file->f_op = fops_get(old_fops);
164 }
165 fops_put(old_fops);
166 return err;
167 }
168
169
170 /* BKL pushdown: nasty #ifdef avoidance wrapper */
171 static int snd_open(struct inode *inode, struct file *file)
172 {
173 int ret;
174
175 lock_kernel();
176 ret = __snd_open(inode, file);
177 unlock_kernel();
178 return ret;
179 }
180
181 static const struct file_operations snd_fops =
182 {
183 .owner = THIS_MODULE,
184 .open = snd_open
185 };
186
187 #ifdef CONFIG_SND_DYNAMIC_MINORS
188 static int snd_find_free_minor(void)
189 {
190 int minor;
191
192 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor) {
193 /* skip minors still used statically for autoloading devices */
194 if (SNDRV_MINOR_DEVICE(minor) == SNDRV_MINOR_CONTROL ||
195 minor == SNDRV_MINOR_SEQUENCER)
196 continue;
197 if (!snd_minors[minor])
198 return minor;
199 }
200 return -EBUSY;
201 }
202 #else
203 static int snd_kernel_minor(int type, struct snd_card *card, int dev)
204 {
205 int minor;
206
207 switch (type) {
208 case SNDRV_DEVICE_TYPE_SEQUENCER:
209 case SNDRV_DEVICE_TYPE_TIMER:
210 minor = type;
211 break;
212 case SNDRV_DEVICE_TYPE_CONTROL:
213 if (snd_BUG_ON(!card))
214 return -EINVAL;
215 minor = SNDRV_MINOR(card->number, type);
216 break;
217 case SNDRV_DEVICE_TYPE_HWDEP:
218 case SNDRV_DEVICE_TYPE_RAWMIDI:
219 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
220 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
221 if (snd_BUG_ON(!card))
222 return -EINVAL;
223 minor = SNDRV_MINOR(card->number, type + dev);
224 break;
225 default:
226 return -EINVAL;
227 }
228 if (snd_BUG_ON(minor < 0 || minor >= SNDRV_OS_MINORS))
229 return -EINVAL;
230 return minor;
231 }
232 #endif
233
234 /**
235 * snd_register_device_for_dev - Register the ALSA device file for the card
236 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
237 * @card: the card instance
238 * @dev: the device index
239 * @f_ops: the file operations
240 * @private_data: user pointer for f_ops->open()
241 * @name: the device file name
242 * @device: the &struct device to link this new device to
243 *
244 * Registers an ALSA device file for the given card.
245 * The operators have to be set in reg parameter.
246 *
247 * Returns zero if successful, or a negative error code on failure.
248 */
249 int snd_register_device_for_dev(int type, struct snd_card *card, int dev,
250 const struct file_operations *f_ops,
251 void *private_data,
252 const char *name, struct device *device)
253 {
254 int minor;
255 struct snd_minor *preg;
256
257 if (snd_BUG_ON(!name))
258 return -EINVAL;
259 preg = kmalloc(sizeof *preg, GFP_KERNEL);
260 if (preg == NULL)
261 return -ENOMEM;
262 preg->type = type;
263 preg->card = card ? card->number : -1;
264 preg->device = dev;
265 preg->f_ops = f_ops;
266 preg->private_data = private_data;
267 mutex_lock(&sound_mutex);
268 #ifdef CONFIG_SND_DYNAMIC_MINORS
269 minor = snd_find_free_minor();
270 #else
271 minor = snd_kernel_minor(type, card, dev);
272 if (minor >= 0 && snd_minors[minor])
273 minor = -EBUSY;
274 #endif
275 if (minor < 0) {
276 mutex_unlock(&sound_mutex);
277 kfree(preg);
278 return minor;
279 }
280 snd_minors[minor] = preg;
281 preg->dev = device_create(sound_class, device, MKDEV(major, minor),
282 private_data, "%s", name);
283 if (IS_ERR(preg->dev)) {
284 snd_minors[minor] = NULL;
285 mutex_unlock(&sound_mutex);
286 minor = PTR_ERR(preg->dev);
287 kfree(preg);
288 return minor;
289 }
290
291 mutex_unlock(&sound_mutex);
292 return 0;
293 }
294
295 EXPORT_SYMBOL(snd_register_device_for_dev);
296
297 /* find the matching minor record
298 * return the index of snd_minor, or -1 if not found
299 */
300 static int find_snd_minor(int type, struct snd_card *card, int dev)
301 {
302 int cardnum, minor;
303 struct snd_minor *mptr;
304
305 cardnum = card ? card->number : -1;
306 for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
307 if ((mptr = snd_minors[minor]) != NULL &&
308 mptr->type == type &&
309 mptr->card == cardnum &&
310 mptr->device == dev)
311 return minor;
312 return -1;
313 }
314
315 /**
316 * snd_unregister_device - unregister the device on the given card
317 * @type: the device type, SNDRV_DEVICE_TYPE_XXX
318 * @card: the card instance
319 * @dev: the device index
320 *
321 * Unregisters the device file already registered via
322 * snd_register_device().
323 *
324 * Returns zero if sucecessful, or a negative error code on failure
325 */
326 int snd_unregister_device(int type, struct snd_card *card, int dev)
327 {
328 int minor;
329
330 mutex_lock(&sound_mutex);
331 minor = find_snd_minor(type, card, dev);
332 if (minor < 0) {
333 mutex_unlock(&sound_mutex);
334 return -EINVAL;
335 }
336
337 device_destroy(sound_class, MKDEV(major, minor));
338
339 kfree(snd_minors[minor]);
340 snd_minors[minor] = NULL;
341 mutex_unlock(&sound_mutex);
342 return 0;
343 }
344
345 EXPORT_SYMBOL(snd_unregister_device);
346
347 int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
348 struct device_attribute *attr)
349 {
350 int minor, ret = -EINVAL;
351 struct device *d;
352
353 mutex_lock(&sound_mutex);
354 minor = find_snd_minor(type, card, dev);
355 if (minor >= 0 && (d = snd_minors[minor]->dev) != NULL)
356 ret = device_create_file(d, attr);
357 mutex_unlock(&sound_mutex);
358 return ret;
359
360 }
361
362 EXPORT_SYMBOL(snd_add_device_sysfs_file);
363
364 #ifdef CONFIG_PROC_FS
365 /*
366 * INFO PART
367 */
368
369 static struct snd_info_entry *snd_minor_info_entry;
370
371 static const char *snd_device_type_name(int type)
372 {
373 switch (type) {
374 case SNDRV_DEVICE_TYPE_CONTROL:
375 return "control";
376 case SNDRV_DEVICE_TYPE_HWDEP:
377 return "hardware dependent";
378 case SNDRV_DEVICE_TYPE_RAWMIDI:
379 return "raw midi";
380 case SNDRV_DEVICE_TYPE_PCM_PLAYBACK:
381 return "digital audio playback";
382 case SNDRV_DEVICE_TYPE_PCM_CAPTURE:
383 return "digital audio capture";
384 case SNDRV_DEVICE_TYPE_SEQUENCER:
385 return "sequencer";
386 case SNDRV_DEVICE_TYPE_TIMER:
387 return "timer";
388 default:
389 return "?";
390 }
391 }
392
393 static void snd_minor_info_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
394 {
395 int minor;
396 struct snd_minor *mptr;
397
398 mutex_lock(&sound_mutex);
399 for (minor = 0; minor < SNDRV_OS_MINORS; ++minor) {
400 if (!(mptr = snd_minors[minor]))
401 continue;
402 if (mptr->card >= 0) {
403 if (mptr->device >= 0)
404 snd_iprintf(buffer, "%3i: [%2i-%2i]: %s\n",
405 minor, mptr->card, mptr->device,
406 snd_device_type_name(mptr->type));
407 else
408 snd_iprintf(buffer, "%3i: [%2i] : %s\n",
409 minor, mptr->card,
410 snd_device_type_name(mptr->type));
411 } else
412 snd_iprintf(buffer, "%3i: : %s\n", minor,
413 snd_device_type_name(mptr->type));
414 }
415 mutex_unlock(&sound_mutex);
416 }
417
418 int __init snd_minor_info_init(void)
419 {
420 struct snd_info_entry *entry;
421
422 entry = snd_info_create_module_entry(THIS_MODULE, "devices", NULL);
423 if (entry) {
424 entry->c.text.read = snd_minor_info_read;
425 if (snd_info_register(entry) < 0) {
426 snd_info_free_entry(entry);
427 entry = NULL;
428 }
429 }
430 snd_minor_info_entry = entry;
431 return 0;
432 }
433
434 int __exit snd_minor_info_done(void)
435 {
436 snd_info_free_entry(snd_minor_info_entry);
437 return 0;
438 }
439 #endif /* CONFIG_PROC_FS */
440
441 /*
442 * INIT PART
443 */
444
445 static int __init alsa_sound_init(void)
446 {
447 snd_major = major;
448 snd_ecards_limit = cards_limit;
449 if (register_chrdev(major, "alsa", &snd_fops)) {
450 snd_printk(KERN_ERR "unable to register native major device number %d\n", major);
451 return -EIO;
452 }
453 if (snd_info_init() < 0) {
454 unregister_chrdev(major, "alsa");
455 return -ENOMEM;
456 }
457 snd_info_minor_register();
458 #ifndef MODULE
459 printk(KERN_INFO "Advanced Linux Sound Architecture Driver Version " CONFIG_SND_VERSION CONFIG_SND_DATE ".\n");
460 #endif
461 return 0;
462 }
463
464 static void __exit alsa_sound_exit(void)
465 {
466 snd_info_minor_unregister();
467 snd_info_done();
468 unregister_chrdev(major, "alsa");
469 }
470
471 module_init(alsa_sound_init)
472 module_exit(alsa_sound_exit)
473
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