xref: /linux/sound/core/info.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 /*
2  *  Information interface for ALSA driver
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/vmalloc.h>
25 #include <linux/time.h>
26 #include <linux/smp_lock.h>
27 #include <linux/string.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/info.h>
31 #include <sound/version.h>
32 #include <linux/proc_fs.h>
33 #include <linux/devfs_fs_kernel.h>
34 #include <linux/mutex.h>
35 #include <stdarg.h>
36 
37 /*
38  *
39  */
40 
41 #ifdef CONFIG_PROC_FS
42 
43 int snd_info_check_reserved_words(const char *str)
44 {
45 	static char *reserved[] =
46 	{
47 		"version",
48 		"meminfo",
49 		"memdebug",
50 		"detect",
51 		"devices",
52 		"oss",
53 		"cards",
54 		"timers",
55 		"synth",
56 		"pcm",
57 		"seq",
58 		NULL
59 	};
60 	char **xstr = reserved;
61 
62 	while (*xstr) {
63 		if (!strcmp(*xstr, str))
64 			return 0;
65 		xstr++;
66 	}
67 	if (!strncmp(str, "card", 4))
68 		return 0;
69 	return 1;
70 }
71 
72 static DEFINE_MUTEX(info_mutex);
73 
74 struct snd_info_private_data {
75 	struct snd_info_buffer *rbuffer;
76 	struct snd_info_buffer *wbuffer;
77 	struct snd_info_entry *entry;
78 	void *file_private_data;
79 };
80 
81 static int snd_info_version_init(void);
82 static int snd_info_version_done(void);
83 
84 
85 /**
86  * snd_iprintf - printf on the procfs buffer
87  * @buffer: the procfs buffer
88  * @fmt: the printf format
89  *
90  * Outputs the string on the procfs buffer just like printf().
91  *
92  * Returns the size of output string.
93  */
94 int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
95 {
96 	va_list args;
97 	int len, res;
98 
99 	if (buffer->stop || buffer->error)
100 		return 0;
101 	len = buffer->len - buffer->size;
102 	va_start(args, fmt);
103 	res = vsnprintf(buffer->curr, len, fmt, args);
104 	va_end(args);
105 	if (res >= len) {
106 		buffer->stop = 1;
107 		return 0;
108 	}
109 	buffer->curr += res;
110 	buffer->size += res;
111 	return res;
112 }
113 
114 /*
115 
116  */
117 
118 static struct proc_dir_entry *snd_proc_root = NULL;
119 struct snd_info_entry *snd_seq_root = NULL;
120 #ifdef CONFIG_SND_OSSEMUL
121 struct snd_info_entry *snd_oss_root = NULL;
122 #endif
123 
124 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
125 {
126 	de->owner = THIS_MODULE;
127 }
128 
129 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
130 				  struct proc_dir_entry *de)
131 {
132 	if (de)
133 		remove_proc_entry(de->name, parent);
134 }
135 
136 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
137 {
138 	struct snd_info_private_data *data;
139 	struct snd_info_entry *entry;
140 	loff_t ret;
141 
142 	data = file->private_data;
143 	entry = data->entry;
144 	lock_kernel();
145 	switch (entry->content) {
146 	case SNDRV_INFO_CONTENT_TEXT:
147 		switch (orig) {
148 		case 0:	/* SEEK_SET */
149 			file->f_pos = offset;
150 			ret = file->f_pos;
151 			goto out;
152 		case 1:	/* SEEK_CUR */
153 			file->f_pos += offset;
154 			ret = file->f_pos;
155 			goto out;
156 		case 2:	/* SEEK_END */
157 		default:
158 			ret = -EINVAL;
159 			goto out;
160 		}
161 		break;
162 	case SNDRV_INFO_CONTENT_DATA:
163 		if (entry->c.ops->llseek) {
164 			ret = entry->c.ops->llseek(entry,
165 						    data->file_private_data,
166 						    file, offset, orig);
167 			goto out;
168 		}
169 		break;
170 	}
171 	ret = -ENXIO;
172 out:
173 	unlock_kernel();
174 	return ret;
175 }
176 
177 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
178 				   size_t count, loff_t * offset)
179 {
180 	struct snd_info_private_data *data;
181 	struct snd_info_entry *entry;
182 	struct snd_info_buffer *buf;
183 	size_t size = 0;
184 	loff_t pos;
185 
186 	data = file->private_data;
187 	snd_assert(data != NULL, return -ENXIO);
188 	pos = *offset;
189 	if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
190 		return -EIO;
191 	if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
192 		return -EIO;
193 	entry = data->entry;
194 	switch (entry->content) {
195 	case SNDRV_INFO_CONTENT_TEXT:
196 		buf = data->rbuffer;
197 		if (buf == NULL)
198 			return -EIO;
199 		if (pos >= buf->size)
200 			return 0;
201 		size = buf->size - pos;
202 		size = min(count, size);
203 		if (copy_to_user(buffer, buf->buffer + pos, size))
204 			return -EFAULT;
205 		break;
206 	case SNDRV_INFO_CONTENT_DATA:
207 		if (entry->c.ops->read)
208 			size = entry->c.ops->read(entry,
209 						  data->file_private_data,
210 						  file, buffer, count, pos);
211 		break;
212 	}
213 	if ((ssize_t) size > 0)
214 		*offset = pos + size;
215 	return size;
216 }
217 
218 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
219 				    size_t count, loff_t * offset)
220 {
221 	struct snd_info_private_data *data;
222 	struct snd_info_entry *entry;
223 	struct snd_info_buffer *buf;
224 	size_t size = 0;
225 	loff_t pos;
226 
227 	data = file->private_data;
228 	snd_assert(data != NULL, return -ENXIO);
229 	entry = data->entry;
230 	pos = *offset;
231 	if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
232 		return -EIO;
233 	if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
234 		return -EIO;
235 	switch (entry->content) {
236 	case SNDRV_INFO_CONTENT_TEXT:
237 		buf = data->wbuffer;
238 		if (buf == NULL)
239 			return -EIO;
240 		if (pos >= buf->len)
241 			return -ENOMEM;
242 		size = buf->len - pos;
243 		size = min(count, size);
244 		if (copy_from_user(buf->buffer + pos, buffer, size))
245 			return -EFAULT;
246 		if ((long)buf->size < pos + size)
247 			buf->size = pos + size;
248 		break;
249 	case SNDRV_INFO_CONTENT_DATA:
250 		if (entry->c.ops->write)
251 			size = entry->c.ops->write(entry,
252 						   data->file_private_data,
253 						   file, buffer, count, pos);
254 		break;
255 	}
256 	if ((ssize_t) size > 0)
257 		*offset = pos + size;
258 	return size;
259 }
260 
261 static int snd_info_entry_open(struct inode *inode, struct file *file)
262 {
263 	struct snd_info_entry *entry;
264 	struct snd_info_private_data *data;
265 	struct snd_info_buffer *buffer;
266 	struct proc_dir_entry *p;
267 	int mode, err;
268 
269 	mutex_lock(&info_mutex);
270 	p = PDE(inode);
271 	entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
272 	if (entry == NULL || entry->disconnected) {
273 		mutex_unlock(&info_mutex);
274 		return -ENODEV;
275 	}
276 	if (!try_module_get(entry->module)) {
277 		err = -EFAULT;
278 		goto __error1;
279 	}
280 	mode = file->f_flags & O_ACCMODE;
281 	if (mode == O_RDONLY || mode == O_RDWR) {
282 		if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
283 		     !entry->c.text.read_size) ||
284 		    (entry->content == SNDRV_INFO_CONTENT_DATA &&
285 		     entry->c.ops->read == NULL)) {
286 		    	err = -ENODEV;
287 		    	goto __error;
288 		}
289 	}
290 	if (mode == O_WRONLY || mode == O_RDWR) {
291 		if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
292 		     !entry->c.text.write_size) ||
293 		    (entry->content == SNDRV_INFO_CONTENT_DATA &&
294 		     entry->c.ops->write == NULL)) {
295 		    	err = -ENODEV;
296 		    	goto __error;
297 		}
298 	}
299 	data = kzalloc(sizeof(*data), GFP_KERNEL);
300 	if (data == NULL) {
301 		err = -ENOMEM;
302 		goto __error;
303 	}
304 	data->entry = entry;
305 	switch (entry->content) {
306 	case SNDRV_INFO_CONTENT_TEXT:
307 		if (mode == O_RDONLY || mode == O_RDWR) {
308 			buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
309 			if (buffer == NULL) {
310 				kfree(data);
311 				err = -ENOMEM;
312 				goto __error;
313 			}
314 			buffer->len = (entry->c.text.read_size +
315 				      (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
316 			buffer->buffer = vmalloc(buffer->len);
317 			if (buffer->buffer == NULL) {
318 				kfree(buffer);
319 				kfree(data);
320 				err = -ENOMEM;
321 				goto __error;
322 			}
323 			buffer->curr = buffer->buffer;
324 			data->rbuffer = buffer;
325 		}
326 		if (mode == O_WRONLY || mode == O_RDWR) {
327 			buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
328 			if (buffer == NULL) {
329 				if (mode == O_RDWR) {
330 					vfree(data->rbuffer->buffer);
331 					kfree(data->rbuffer);
332 				}
333 				kfree(data);
334 				err = -ENOMEM;
335 				goto __error;
336 			}
337 			buffer->len = (entry->c.text.write_size +
338 				      (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
339 			buffer->buffer = vmalloc(buffer->len);
340 			if (buffer->buffer == NULL) {
341 				if (mode == O_RDWR) {
342 					vfree(data->rbuffer->buffer);
343 					kfree(data->rbuffer);
344 				}
345 				kfree(buffer);
346 				kfree(data);
347 				err = -ENOMEM;
348 				goto __error;
349 			}
350 			buffer->curr = buffer->buffer;
351 			data->wbuffer = buffer;
352 		}
353 		break;
354 	case SNDRV_INFO_CONTENT_DATA:	/* data */
355 		if (entry->c.ops->open) {
356 			if ((err = entry->c.ops->open(entry, mode,
357 						      &data->file_private_data)) < 0) {
358 				kfree(data);
359 				goto __error;
360 			}
361 		}
362 		break;
363 	}
364 	file->private_data = data;
365 	mutex_unlock(&info_mutex);
366 	if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
367 	    (mode == O_RDONLY || mode == O_RDWR)) {
368 		if (entry->c.text.read) {
369 			mutex_lock(&entry->access);
370 			entry->c.text.read(entry, data->rbuffer);
371 			mutex_unlock(&entry->access);
372 		}
373 	}
374 	return 0;
375 
376       __error:
377 	module_put(entry->module);
378       __error1:
379 	mutex_unlock(&info_mutex);
380 	return err;
381 }
382 
383 static int snd_info_entry_release(struct inode *inode, struct file *file)
384 {
385 	struct snd_info_entry *entry;
386 	struct snd_info_private_data *data;
387 	int mode;
388 
389 	mode = file->f_flags & O_ACCMODE;
390 	data = file->private_data;
391 	entry = data->entry;
392 	switch (entry->content) {
393 	case SNDRV_INFO_CONTENT_TEXT:
394 		if (mode == O_RDONLY || mode == O_RDWR) {
395 			vfree(data->rbuffer->buffer);
396 			kfree(data->rbuffer);
397 		}
398 		if (mode == O_WRONLY || mode == O_RDWR) {
399 			if (entry->c.text.write) {
400 				entry->c.text.write(entry, data->wbuffer);
401 				if (data->wbuffer->error) {
402 					snd_printk(KERN_WARNING "data write error to %s (%i)\n",
403 						entry->name,
404 						data->wbuffer->error);
405 				}
406 			}
407 			vfree(data->wbuffer->buffer);
408 			kfree(data->wbuffer);
409 		}
410 		break;
411 	case SNDRV_INFO_CONTENT_DATA:
412 		if (entry->c.ops->release)
413 			entry->c.ops->release(entry, mode,
414 					      data->file_private_data);
415 		break;
416 	}
417 	module_put(entry->module);
418 	kfree(data);
419 	return 0;
420 }
421 
422 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
423 {
424 	struct snd_info_private_data *data;
425 	struct snd_info_entry *entry;
426 	unsigned int mask;
427 
428 	data = file->private_data;
429 	if (data == NULL)
430 		return 0;
431 	entry = data->entry;
432 	mask = 0;
433 	switch (entry->content) {
434 	case SNDRV_INFO_CONTENT_DATA:
435 		if (entry->c.ops->poll)
436 			return entry->c.ops->poll(entry,
437 						  data->file_private_data,
438 						  file, wait);
439 		if (entry->c.ops->read)
440 			mask |= POLLIN | POLLRDNORM;
441 		if (entry->c.ops->write)
442 			mask |= POLLOUT | POLLWRNORM;
443 		break;
444 	}
445 	return mask;
446 }
447 
448 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
449 				unsigned long arg)
450 {
451 	struct snd_info_private_data *data;
452 	struct snd_info_entry *entry;
453 
454 	data = file->private_data;
455 	if (data == NULL)
456 		return 0;
457 	entry = data->entry;
458 	switch (entry->content) {
459 	case SNDRV_INFO_CONTENT_DATA:
460 		if (entry->c.ops->ioctl)
461 			return entry->c.ops->ioctl(entry,
462 						   data->file_private_data,
463 						   file, cmd, arg);
464 		break;
465 	}
466 	return -ENOTTY;
467 }
468 
469 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
470 {
471 	struct inode *inode = file->f_dentry->d_inode;
472 	struct snd_info_private_data *data;
473 	struct snd_info_entry *entry;
474 
475 	data = file->private_data;
476 	if (data == NULL)
477 		return 0;
478 	entry = data->entry;
479 	switch (entry->content) {
480 	case SNDRV_INFO_CONTENT_DATA:
481 		if (entry->c.ops->mmap)
482 			return entry->c.ops->mmap(entry,
483 						  data->file_private_data,
484 						  inode, file, vma);
485 		break;
486 	}
487 	return -ENXIO;
488 }
489 
490 static struct file_operations snd_info_entry_operations =
491 {
492 	.owner =		THIS_MODULE,
493 	.llseek =		snd_info_entry_llseek,
494 	.read =			snd_info_entry_read,
495 	.write =		snd_info_entry_write,
496 	.poll =			snd_info_entry_poll,
497 	.unlocked_ioctl =	snd_info_entry_ioctl,
498 	.mmap =			snd_info_entry_mmap,
499 	.open =			snd_info_entry_open,
500 	.release =		snd_info_entry_release,
501 };
502 
503 /**
504  * snd_create_proc_entry - create a procfs entry
505  * @name: the name of the proc file
506  * @mode: the file permission bits, S_Ixxx
507  * @parent: the parent proc-directory entry
508  *
509  * Creates a new proc file entry with the given name and permission
510  * on the given directory.
511  *
512  * Returns the pointer of new instance or NULL on failure.
513  */
514 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
515 						    struct proc_dir_entry *parent)
516 {
517 	struct proc_dir_entry *p;
518 	p = create_proc_entry(name, mode, parent);
519 	if (p)
520 		snd_info_entry_prepare(p);
521 	return p;
522 }
523 
524 int __init snd_info_init(void)
525 {
526 	struct proc_dir_entry *p;
527 
528 	p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
529 	if (p == NULL)
530 		return -ENOMEM;
531 	snd_proc_root = p;
532 #ifdef CONFIG_SND_OSSEMUL
533 	{
534 		struct snd_info_entry *entry;
535 		if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
536 			return -ENOMEM;
537 		entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
538 		if (snd_info_register(entry) < 0) {
539 			snd_info_free_entry(entry);
540 			return -ENOMEM;
541 		}
542 		snd_oss_root = entry;
543 	}
544 #endif
545 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
546 	{
547 		struct snd_info_entry *entry;
548 		if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
549 			return -ENOMEM;
550 		entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
551 		if (snd_info_register(entry) < 0) {
552 			snd_info_free_entry(entry);
553 			return -ENOMEM;
554 		}
555 		snd_seq_root = entry;
556 	}
557 #endif
558 	snd_info_version_init();
559 	snd_minor_info_init();
560 	snd_minor_info_oss_init();
561 	snd_card_info_init();
562 	return 0;
563 }
564 
565 int __exit snd_info_done(void)
566 {
567 	snd_card_info_done();
568 	snd_minor_info_oss_done();
569 	snd_minor_info_done();
570 	snd_info_version_done();
571 	if (snd_proc_root) {
572 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
573 		snd_info_unregister(snd_seq_root);
574 #endif
575 #ifdef CONFIG_SND_OSSEMUL
576 		snd_info_unregister(snd_oss_root);
577 #endif
578 		snd_remove_proc_entry(&proc_root, snd_proc_root);
579 	}
580 	return 0;
581 }
582 
583 /*
584 
585  */
586 
587 
588 /*
589  * create a card proc file
590  * called from init.c
591  */
592 int snd_info_card_create(struct snd_card *card)
593 {
594 	char str[8];
595 	struct snd_info_entry *entry;
596 
597 	snd_assert(card != NULL, return -ENXIO);
598 
599 	sprintf(str, "card%i", card->number);
600 	if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
601 		return -ENOMEM;
602 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
603 	if (snd_info_register(entry) < 0) {
604 		snd_info_free_entry(entry);
605 		return -ENOMEM;
606 	}
607 	card->proc_root = entry;
608 	return 0;
609 }
610 
611 /*
612  * register the card proc file
613  * called from init.c
614  */
615 int snd_info_card_register(struct snd_card *card)
616 {
617 	struct proc_dir_entry *p;
618 
619 	snd_assert(card != NULL, return -ENXIO);
620 
621 	if (!strcmp(card->id, card->proc_root->name))
622 		return 0;
623 
624 	p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
625 	if (p == NULL)
626 		return -ENOMEM;
627 	card->proc_root_link = p;
628 	return 0;
629 }
630 
631 /*
632  * de-register the card proc file
633  * called from init.c
634  */
635 int snd_info_card_free(struct snd_card *card)
636 {
637 	snd_assert(card != NULL, return -ENXIO);
638 	if (card->proc_root_link) {
639 		snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
640 		card->proc_root_link = NULL;
641 	}
642 	if (card->proc_root) {
643 		snd_info_unregister(card->proc_root);
644 		card->proc_root = NULL;
645 	}
646 	return 0;
647 }
648 
649 
650 /**
651  * snd_info_get_line - read one line from the procfs buffer
652  * @buffer: the procfs buffer
653  * @line: the buffer to store
654  * @len: the max. buffer size - 1
655  *
656  * Reads one line from the buffer and stores the string.
657  *
658  * Returns zero if successful, or 1 if error or EOF.
659  */
660 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
661 {
662 	int c = -1;
663 
664 	if (len <= 0 || buffer->stop || buffer->error)
665 		return 1;
666 	while (--len > 0) {
667 		c = *buffer->curr++;
668 		if (c == '\n') {
669 			if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
670 				buffer->stop = 1;
671 			}
672 			break;
673 		}
674 		*line++ = c;
675 		if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
676 			buffer->stop = 1;
677 			break;
678 		}
679 	}
680 	while (c != '\n' && !buffer->stop) {
681 		c = *buffer->curr++;
682 		if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
683 			buffer->stop = 1;
684 		}
685 	}
686 	*line = '\0';
687 	return 0;
688 }
689 
690 /**
691  * snd_info_get_str - parse a string token
692  * @dest: the buffer to store the string token
693  * @src: the original string
694  * @len: the max. length of token - 1
695  *
696  * Parses the original string and copy a token to the given
697  * string buffer.
698  *
699  * Returns the updated pointer of the original string so that
700  * it can be used for the next call.
701  */
702 char *snd_info_get_str(char *dest, char *src, int len)
703 {
704 	int c;
705 
706 	while (*src == ' ' || *src == '\t')
707 		src++;
708 	if (*src == '"' || *src == '\'') {
709 		c = *src++;
710 		while (--len > 0 && *src && *src != c) {
711 			*dest++ = *src++;
712 		}
713 		if (*src == c)
714 			src++;
715 	} else {
716 		while (--len > 0 && *src && *src != ' ' && *src != '\t') {
717 			*dest++ = *src++;
718 		}
719 	}
720 	*dest = 0;
721 	while (*src == ' ' || *src == '\t')
722 		src++;
723 	return src;
724 }
725 
726 /**
727  * snd_info_create_entry - create an info entry
728  * @name: the proc file name
729  *
730  * Creates an info entry with the given file name and initializes as
731  * the default state.
732  *
733  * Usually called from other functions such as
734  * snd_info_create_card_entry().
735  *
736  * Returns the pointer of the new instance, or NULL on failure.
737  */
738 static struct snd_info_entry *snd_info_create_entry(const char *name)
739 {
740 	struct snd_info_entry *entry;
741 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
742 	if (entry == NULL)
743 		return NULL;
744 	entry->name = kstrdup(name, GFP_KERNEL);
745 	if (entry->name == NULL) {
746 		kfree(entry);
747 		return NULL;
748 	}
749 	entry->mode = S_IFREG | S_IRUGO;
750 	entry->content = SNDRV_INFO_CONTENT_TEXT;
751 	mutex_init(&entry->access);
752 	return entry;
753 }
754 
755 /**
756  * snd_info_create_module_entry - create an info entry for the given module
757  * @module: the module pointer
758  * @name: the file name
759  * @parent: the parent directory
760  *
761  * Creates a new info entry and assigns it to the given module.
762  *
763  * Returns the pointer of the new instance, or NULL on failure.
764  */
765 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
766 					       const char *name,
767 					       struct snd_info_entry *parent)
768 {
769 	struct snd_info_entry *entry = snd_info_create_entry(name);
770 	if (entry) {
771 		entry->module = module;
772 		entry->parent = parent;
773 	}
774 	return entry;
775 }
776 
777 /**
778  * snd_info_create_card_entry - create an info entry for the given card
779  * @card: the card instance
780  * @name: the file name
781  * @parent: the parent directory
782  *
783  * Creates a new info entry and assigns it to the given card.
784  *
785  * Returns the pointer of the new instance, or NULL on failure.
786  */
787 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
788 					     const char *name,
789 					     struct snd_info_entry * parent)
790 {
791 	struct snd_info_entry *entry = snd_info_create_entry(name);
792 	if (entry) {
793 		entry->module = card->module;
794 		entry->card = card;
795 		entry->parent = parent;
796 	}
797 	return entry;
798 }
799 
800 static int snd_info_dev_free_entry(struct snd_device *device)
801 {
802 	struct snd_info_entry *entry = device->device_data;
803 	snd_info_free_entry(entry);
804 	return 0;
805 }
806 
807 static int snd_info_dev_register_entry(struct snd_device *device)
808 {
809 	struct snd_info_entry *entry = device->device_data;
810 	return snd_info_register(entry);
811 }
812 
813 static int snd_info_dev_disconnect_entry(struct snd_device *device)
814 {
815 	struct snd_info_entry *entry = device->device_data;
816 	entry->disconnected = 1;
817 	return 0;
818 }
819 
820 static int snd_info_dev_unregister_entry(struct snd_device *device)
821 {
822 	struct snd_info_entry *entry = device->device_data;
823 	return snd_info_unregister(entry);
824 }
825 
826 /**
827  * snd_card_proc_new - create an info entry for the given card
828  * @card: the card instance
829  * @name: the file name
830  * @entryp: the pointer to store the new info entry
831  *
832  * Creates a new info entry and assigns it to the given card.
833  * Unlike snd_info_create_card_entry(), this function registers the
834  * info entry as an ALSA device component, so that it can be
835  * unregistered/released without explicit call.
836  * Also, you don't have to register this entry via snd_info_register(),
837  * since this will be registered by snd_card_register() automatically.
838  *
839  * The parent is assumed as card->proc_root.
840  *
841  * For releasing this entry, use snd_device_free() instead of
842  * snd_info_free_entry().
843  *
844  * Returns zero if successful, or a negative error code on failure.
845  */
846 int snd_card_proc_new(struct snd_card *card, const char *name,
847 		      struct snd_info_entry **entryp)
848 {
849 	static struct snd_device_ops ops = {
850 		.dev_free = snd_info_dev_free_entry,
851 		.dev_register =	snd_info_dev_register_entry,
852 		.dev_disconnect = snd_info_dev_disconnect_entry,
853 		.dev_unregister = snd_info_dev_unregister_entry
854 	};
855 	struct snd_info_entry *entry;
856 	int err;
857 
858 	entry = snd_info_create_card_entry(card, name, card->proc_root);
859 	if (! entry)
860 		return -ENOMEM;
861 	if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
862 		snd_info_free_entry(entry);
863 		return err;
864 	}
865 	if (entryp)
866 		*entryp = entry;
867 	return 0;
868 }
869 
870 /**
871  * snd_info_free_entry - release the info entry
872  * @entry: the info entry
873  *
874  * Releases the info entry.  Don't call this after registered.
875  */
876 void snd_info_free_entry(struct snd_info_entry * entry)
877 {
878 	if (entry == NULL)
879 		return;
880 	kfree(entry->name);
881 	if (entry->private_free)
882 		entry->private_free(entry);
883 	kfree(entry);
884 }
885 
886 /**
887  * snd_info_register - register the info entry
888  * @entry: the info entry
889  *
890  * Registers the proc info entry.
891  *
892  * Returns zero if successful, or a negative error code on failure.
893  */
894 int snd_info_register(struct snd_info_entry * entry)
895 {
896 	struct proc_dir_entry *root, *p = NULL;
897 
898 	snd_assert(entry != NULL, return -ENXIO);
899 	root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
900 	mutex_lock(&info_mutex);
901 	p = snd_create_proc_entry(entry->name, entry->mode, root);
902 	if (!p) {
903 		mutex_unlock(&info_mutex);
904 		return -ENOMEM;
905 	}
906 	p->owner = entry->module;
907 	if (!S_ISDIR(entry->mode))
908 		p->proc_fops = &snd_info_entry_operations;
909 	p->size = entry->size;
910 	p->data = entry;
911 	entry->p = p;
912 	mutex_unlock(&info_mutex);
913 	return 0;
914 }
915 
916 /**
917  * snd_info_unregister - de-register the info entry
918  * @entry: the info entry
919  *
920  * De-registers the info entry and releases the instance.
921  *
922  * Returns zero if successful, or a negative error code on failure.
923  */
924 int snd_info_unregister(struct snd_info_entry * entry)
925 {
926 	struct proc_dir_entry *root;
927 
928 	if (! entry)
929 		return 0;
930 	snd_assert(entry->p != NULL, return -ENXIO);
931 	root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
932 	snd_assert(root, return -ENXIO);
933 	mutex_lock(&info_mutex);
934 	snd_remove_proc_entry(root, entry->p);
935 	mutex_unlock(&info_mutex);
936 	snd_info_free_entry(entry);
937 	return 0;
938 }
939 
940 /*
941 
942  */
943 
944 static struct snd_info_entry *snd_info_version_entry = NULL;
945 
946 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
947 {
948 	snd_iprintf(buffer,
949 		    "Advanced Linux Sound Architecture Driver Version "
950 		    CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
951 		   );
952 }
953 
954 static int __init snd_info_version_init(void)
955 {
956 	struct snd_info_entry *entry;
957 
958 	entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
959 	if (entry == NULL)
960 		return -ENOMEM;
961 	entry->c.text.read_size = 256;
962 	entry->c.text.read = snd_info_version_read;
963 	if (snd_info_register(entry) < 0) {
964 		snd_info_free_entry(entry);
965 		return -ENOMEM;
966 	}
967 	snd_info_version_entry = entry;
968 	return 0;
969 }
970 
971 static int __exit snd_info_version_done(void)
972 {
973 	if (snd_info_version_entry)
974 		snd_info_unregister(snd_info_version_entry);
975 	return 0;
976 }
977 
978 #endif /* CONFIG_PROC_FS */
979