xref: /openbmc/linux/sound/core/info.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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 <stdarg.h>
35 
36 /*
37  *
38  */
39 
40 int snd_info_check_reserved_words(const char *str)
41 {
42 	static char *reserved[] =
43 	{
44 		"version",
45 		"meminfo",
46 		"memdebug",
47 		"detect",
48 		"devices",
49 		"oss",
50 		"cards",
51 		"timers",
52 		"synth",
53 		"pcm",
54 		"seq",
55 		NULL
56 	};
57 	char **xstr = reserved;
58 
59 	while (*xstr) {
60 		if (!strcmp(*xstr, str))
61 			return 0;
62 		xstr++;
63 	}
64 	if (!strncmp(str, "card", 4))
65 		return 0;
66 	return 1;
67 }
68 
69 #ifdef CONFIG_PROC_FS
70 
71 static DECLARE_MUTEX(info_mutex);
72 
73 typedef struct _snd_info_private_data {
74 	snd_info_buffer_t *rbuffer;
75 	snd_info_buffer_t *wbuffer;
76 	snd_info_entry_t *entry;
77 	void *file_private_data;
78 } snd_info_private_data_t;
79 
80 static int snd_info_version_init(void);
81 static int snd_info_version_done(void);
82 
83 
84 /**
85  * snd_iprintf - printf on the procfs buffer
86  * @buffer: the procfs buffer
87  * @fmt: the printf format
88  *
89  * Outputs the string on the procfs buffer just like printf().
90  *
91  * Returns the size of output string.
92  */
93 int snd_iprintf(snd_info_buffer_t * buffer, char *fmt,...)
94 {
95 	va_list args;
96 	int len, res;
97 
98 	if (buffer->stop || buffer->error)
99 		return 0;
100 	len = buffer->len - buffer->size;
101 	va_start(args, fmt);
102 	res = vsnprintf(buffer->curr, len, fmt, args);
103 	va_end(args);
104 	if (res >= len) {
105 		buffer->stop = 1;
106 		return 0;
107 	}
108 	buffer->curr += res;
109 	buffer->size += res;
110 	return res;
111 }
112 
113 /*
114 
115  */
116 
117 static struct proc_dir_entry *snd_proc_root = NULL;
118 snd_info_entry_t *snd_seq_root = NULL;
119 #ifdef CONFIG_SND_OSSEMUL
120 snd_info_entry_t *snd_oss_root = NULL;
121 #endif
122 
123 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
124 {
125 	de->owner = THIS_MODULE;
126 }
127 
128 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
129 				  struct proc_dir_entry *de)
130 {
131 	if (de)
132 		remove_proc_entry(de->name, parent);
133 }
134 
135 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
136 {
137 	snd_info_private_data_t *data;
138 	struct snd_info_entry *entry;
139 	loff_t ret;
140 
141 	data = file->private_data;
142 	entry = data->entry;
143 	lock_kernel();
144 	switch (entry->content) {
145 	case SNDRV_INFO_CONTENT_TEXT:
146 		switch (orig) {
147 		case 0:	/* SEEK_SET */
148 			file->f_pos = offset;
149 			ret = file->f_pos;
150 			goto out;
151 		case 1:	/* SEEK_CUR */
152 			file->f_pos += offset;
153 			ret = file->f_pos;
154 			goto out;
155 		case 2:	/* SEEK_END */
156 		default:
157 			ret = -EINVAL;
158 			goto out;
159 		}
160 		break;
161 	case SNDRV_INFO_CONTENT_DATA:
162 		if (entry->c.ops->llseek) {
163 			ret = entry->c.ops->llseek(entry,
164 						    data->file_private_data,
165 						    file, offset, orig);
166 			goto out;
167 		}
168 		break;
169 	}
170 	ret = -ENXIO;
171 out:
172 	unlock_kernel();
173 	return ret;
174 }
175 
176 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
177 				   size_t count, loff_t * offset)
178 {
179 	snd_info_private_data_t *data;
180 	struct snd_info_entry *entry;
181 	snd_info_buffer_t *buf;
182 	size_t size = 0;
183 	loff_t pos;
184 
185 	data = file->private_data;
186 	snd_assert(data != NULL, return -ENXIO);
187 	pos = *offset;
188 	if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
189 		return -EIO;
190 	if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
191 		return -EIO;
192 	entry = data->entry;
193 	switch (entry->content) {
194 	case SNDRV_INFO_CONTENT_TEXT:
195 		buf = data->rbuffer;
196 		if (buf == NULL)
197 			return -EIO;
198 		if (pos >= buf->size)
199 			return 0;
200 		size = buf->size - pos;
201 		size = min(count, size);
202 		if (copy_to_user(buffer, buf->buffer + pos, size))
203 			return -EFAULT;
204 		break;
205 	case SNDRV_INFO_CONTENT_DATA:
206 		if (entry->c.ops->read)
207 			size = entry->c.ops->read(entry,
208 						  data->file_private_data,
209 						  file, buffer, count, pos);
210 		break;
211 	}
212 	if ((ssize_t) size > 0)
213 		*offset = pos + size;
214 	return size;
215 }
216 
217 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
218 				    size_t count, loff_t * offset)
219 {
220 	snd_info_private_data_t *data;
221 	struct snd_info_entry *entry;
222 	snd_info_buffer_t *buf;
223 	size_t size = 0;
224 	loff_t pos;
225 
226 	data = file->private_data;
227 	snd_assert(data != NULL, return -ENXIO);
228 	entry = data->entry;
229 	pos = *offset;
230 	if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
231 		return -EIO;
232 	if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
233 		return -EIO;
234 	switch (entry->content) {
235 	case SNDRV_INFO_CONTENT_TEXT:
236 		buf = data->wbuffer;
237 		if (buf == NULL)
238 			return -EIO;
239 		if (pos >= buf->len)
240 			return -ENOMEM;
241 		size = buf->len - pos;
242 		size = min(count, size);
243 		if (copy_from_user(buf->buffer + pos, buffer, size))
244 			return -EFAULT;
245 		if ((long)buf->size < pos + size)
246 			buf->size = pos + size;
247 		break;
248 	case SNDRV_INFO_CONTENT_DATA:
249 		if (entry->c.ops->write)
250 			size = entry->c.ops->write(entry,
251 						   data->file_private_data,
252 						   file, buffer, count, pos);
253 		break;
254 	}
255 	if ((ssize_t) size > 0)
256 		*offset = pos + size;
257 	return size;
258 }
259 
260 static int snd_info_entry_open(struct inode *inode, struct file *file)
261 {
262 	snd_info_entry_t *entry;
263 	snd_info_private_data_t *data;
264 	snd_info_buffer_t *buffer;
265 	struct proc_dir_entry *p;
266 	int mode, err;
267 
268 	down(&info_mutex);
269 	p = PDE(inode);
270 	entry = p == NULL ? NULL : (snd_info_entry_t *)p->data;
271 	if (entry == NULL || entry->disconnected) {
272 		up(&info_mutex);
273 		return -ENODEV;
274 	}
275 	if (!try_module_get(entry->module)) {
276 		err = -EFAULT;
277 		goto __error1;
278 	}
279 	mode = file->f_flags & O_ACCMODE;
280 	if (mode == O_RDONLY || mode == O_RDWR) {
281 		if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
282 		     !entry->c.text.read_size) ||
283 		    (entry->content == SNDRV_INFO_CONTENT_DATA &&
284 		     entry->c.ops->read == NULL)) {
285 		    	err = -ENODEV;
286 		    	goto __error;
287 		}
288 	}
289 	if (mode == O_WRONLY || mode == O_RDWR) {
290 		if ((entry->content == SNDRV_INFO_CONTENT_TEXT &&
291 		     !entry->c.text.write_size) ||
292 		    (entry->content == SNDRV_INFO_CONTENT_DATA &&
293 		     entry->c.ops->write == NULL)) {
294 		    	err = -ENODEV;
295 		    	goto __error;
296 		}
297 	}
298 	data = kzalloc(sizeof(*data), GFP_KERNEL);
299 	if (data == NULL) {
300 		err = -ENOMEM;
301 		goto __error;
302 	}
303 	data->entry = entry;
304 	switch (entry->content) {
305 	case SNDRV_INFO_CONTENT_TEXT:
306 		if (mode == O_RDONLY || mode == O_RDWR) {
307 			buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
308 			if (buffer == NULL) {
309 				kfree(data);
310 				err = -ENOMEM;
311 				goto __error;
312 			}
313 			buffer->len = (entry->c.text.read_size +
314 				      (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
315 			buffer->buffer = vmalloc(buffer->len);
316 			if (buffer->buffer == NULL) {
317 				kfree(buffer);
318 				kfree(data);
319 				err = -ENOMEM;
320 				goto __error;
321 			}
322 			buffer->curr = buffer->buffer;
323 			data->rbuffer = buffer;
324 		}
325 		if (mode == O_WRONLY || mode == O_RDWR) {
326 			buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
327 			if (buffer == NULL) {
328 				if (mode == O_RDWR) {
329 					vfree(data->rbuffer->buffer);
330 					kfree(data->rbuffer);
331 				}
332 				kfree(data);
333 				err = -ENOMEM;
334 				goto __error;
335 			}
336 			buffer->len = (entry->c.text.write_size +
337 				      (PAGE_SIZE - 1)) & ~(PAGE_SIZE - 1);
338 			buffer->buffer = vmalloc(buffer->len);
339 			if (buffer->buffer == NULL) {
340 				if (mode == O_RDWR) {
341 					vfree(data->rbuffer->buffer);
342 					kfree(data->rbuffer);
343 				}
344 				kfree(buffer);
345 				kfree(data);
346 				err = -ENOMEM;
347 				goto __error;
348 			}
349 			buffer->curr = buffer->buffer;
350 			data->wbuffer = buffer;
351 		}
352 		break;
353 	case SNDRV_INFO_CONTENT_DATA:	/* data */
354 		if (entry->c.ops->open) {
355 			if ((err = entry->c.ops->open(entry, mode,
356 						      &data->file_private_data)) < 0) {
357 				kfree(data);
358 				goto __error;
359 			}
360 		}
361 		break;
362 	}
363 	file->private_data = data;
364 	up(&info_mutex);
365 	if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
366 	    (mode == O_RDONLY || mode == O_RDWR)) {
367 		if (entry->c.text.read) {
368 			down(&entry->access);
369 			entry->c.text.read(entry, data->rbuffer);
370 			up(&entry->access);
371 		}
372 	}
373 	return 0;
374 
375       __error:
376 	module_put(entry->module);
377       __error1:
378 	up(&info_mutex);
379 	return err;
380 }
381 
382 static int snd_info_entry_release(struct inode *inode, struct file *file)
383 {
384 	snd_info_entry_t *entry;
385 	snd_info_private_data_t *data;
386 	int mode;
387 
388 	mode = file->f_flags & O_ACCMODE;
389 	data = file->private_data;
390 	entry = data->entry;
391 	switch (entry->content) {
392 	case SNDRV_INFO_CONTENT_TEXT:
393 		if (mode == O_RDONLY || mode == O_RDWR) {
394 			vfree(data->rbuffer->buffer);
395 			kfree(data->rbuffer);
396 		}
397 		if (mode == O_WRONLY || mode == O_RDWR) {
398 			if (entry->c.text.write) {
399 				entry->c.text.write(entry, data->wbuffer);
400 				if (data->wbuffer->error) {
401 					snd_printk(KERN_WARNING "data write error to %s (%i)\n",
402 						entry->name,
403 						data->wbuffer->error);
404 				}
405 			}
406 			vfree(data->wbuffer->buffer);
407 			kfree(data->wbuffer);
408 		}
409 		break;
410 	case SNDRV_INFO_CONTENT_DATA:
411 		if (entry->c.ops->release)
412 			entry->c.ops->release(entry, mode,
413 					      data->file_private_data);
414 		break;
415 	}
416 	module_put(entry->module);
417 	kfree(data);
418 	return 0;
419 }
420 
421 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
422 {
423 	snd_info_private_data_t *data;
424 	struct snd_info_entry *entry;
425 	unsigned int mask;
426 
427 	data = file->private_data;
428 	if (data == NULL)
429 		return 0;
430 	entry = data->entry;
431 	mask = 0;
432 	switch (entry->content) {
433 	case SNDRV_INFO_CONTENT_DATA:
434 		if (entry->c.ops->poll)
435 			return entry->c.ops->poll(entry,
436 						  data->file_private_data,
437 						  file, wait);
438 		if (entry->c.ops->read)
439 			mask |= POLLIN | POLLRDNORM;
440 		if (entry->c.ops->write)
441 			mask |= POLLOUT | POLLWRNORM;
442 		break;
443 	}
444 	return mask;
445 }
446 
447 static inline int _snd_info_entry_ioctl(struct inode *inode, struct file *file,
448 					unsigned int cmd, unsigned long arg)
449 {
450 	snd_info_private_data_t *data;
451 	struct snd_info_entry *entry;
452 
453 	data = file->private_data;
454 	if (data == NULL)
455 		return 0;
456 	entry = data->entry;
457 	switch (entry->content) {
458 	case SNDRV_INFO_CONTENT_DATA:
459 		if (entry->c.ops->ioctl)
460 			return entry->c.ops->ioctl(entry,
461 						   data->file_private_data,
462 						   file, cmd, arg);
463 		break;
464 	}
465 	return -ENOTTY;
466 }
467 
468 /* FIXME: need to unlock BKL to allow preemption */
469 static int snd_info_entry_ioctl(struct inode *inode, struct file *file,
470 				unsigned int cmd, unsigned long arg)
471 {
472 	int err;
473 	unlock_kernel();
474 	err = _snd_info_entry_ioctl(inode, file, cmd, arg);
475 	lock_kernel();
476 	return err;
477 }
478 
479 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
480 {
481 	struct inode *inode = file->f_dentry->d_inode;
482 	snd_info_private_data_t *data;
483 	struct snd_info_entry *entry;
484 
485 	data = file->private_data;
486 	if (data == NULL)
487 		return 0;
488 	entry = data->entry;
489 	switch (entry->content) {
490 	case SNDRV_INFO_CONTENT_DATA:
491 		if (entry->c.ops->mmap)
492 			return entry->c.ops->mmap(entry,
493 						  data->file_private_data,
494 						  inode, file, vma);
495 		break;
496 	}
497 	return -ENXIO;
498 }
499 
500 static struct file_operations snd_info_entry_operations =
501 {
502 	.owner =	THIS_MODULE,
503 	.llseek =	snd_info_entry_llseek,
504 	.read =		snd_info_entry_read,
505 	.write =	snd_info_entry_write,
506 	.poll =		snd_info_entry_poll,
507 	.ioctl =	snd_info_entry_ioctl,
508 	.mmap =		snd_info_entry_mmap,
509 	.open =		snd_info_entry_open,
510 	.release =	snd_info_entry_release,
511 };
512 
513 /**
514  * snd_create_proc_entry - create a procfs entry
515  * @name: the name of the proc file
516  * @mode: the file permission bits, S_Ixxx
517  * @parent: the parent proc-directory entry
518  *
519  * Creates a new proc file entry with the given name and permission
520  * on the given directory.
521  *
522  * Returns the pointer of new instance or NULL on failure.
523  */
524 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
525 						    struct proc_dir_entry *parent)
526 {
527 	struct proc_dir_entry *p;
528 	p = create_proc_entry(name, mode, parent);
529 	if (p)
530 		snd_info_entry_prepare(p);
531 	return p;
532 }
533 
534 int __init snd_info_init(void)
535 {
536 	struct proc_dir_entry *p;
537 
538 	p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
539 	if (p == NULL)
540 		return -ENOMEM;
541 	snd_proc_root = p;
542 #ifdef CONFIG_SND_OSSEMUL
543 	{
544 		snd_info_entry_t *entry;
545 		if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
546 			return -ENOMEM;
547 		entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
548 		if (snd_info_register(entry) < 0) {
549 			snd_info_free_entry(entry);
550 			return -ENOMEM;
551 		}
552 		snd_oss_root = entry;
553 	}
554 #endif
555 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
556 	{
557 		snd_info_entry_t *entry;
558 		if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
559 			return -ENOMEM;
560 		entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
561 		if (snd_info_register(entry) < 0) {
562 			snd_info_free_entry(entry);
563 			return -ENOMEM;
564 		}
565 		snd_seq_root = entry;
566 	}
567 #endif
568 	snd_info_version_init();
569 	snd_memory_info_init();
570 	snd_minor_info_init();
571 	snd_minor_info_oss_init();
572 	snd_card_info_init();
573 	return 0;
574 }
575 
576 int __exit snd_info_done(void)
577 {
578 	snd_card_info_done();
579 	snd_minor_info_oss_done();
580 	snd_minor_info_done();
581 	snd_memory_info_done();
582 	snd_info_version_done();
583 	if (snd_proc_root) {
584 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
585 		if (snd_seq_root)
586 			snd_info_unregister(snd_seq_root);
587 #endif
588 #ifdef CONFIG_SND_OSSEMUL
589 		if (snd_oss_root)
590 			snd_info_unregister(snd_oss_root);
591 #endif
592 		snd_remove_proc_entry(&proc_root, snd_proc_root);
593 	}
594 	return 0;
595 }
596 
597 /*
598 
599  */
600 
601 
602 /*
603  * create a card proc file
604  * called from init.c
605  */
606 int snd_info_card_create(snd_card_t * card)
607 {
608 	char str[8];
609 	snd_info_entry_t *entry;
610 
611 	snd_assert(card != NULL, return -ENXIO);
612 
613 	sprintf(str, "card%i", card->number);
614 	if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
615 		return -ENOMEM;
616 	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
617 	if (snd_info_register(entry) < 0) {
618 		snd_info_free_entry(entry);
619 		return -ENOMEM;
620 	}
621 	card->proc_root = entry;
622 	return 0;
623 }
624 
625 /*
626  * register the card proc file
627  * called from init.c
628  */
629 int snd_info_card_register(snd_card_t * card)
630 {
631 	struct proc_dir_entry *p;
632 
633 	snd_assert(card != NULL, return -ENXIO);
634 
635 	if (!strcmp(card->id, card->proc_root->name))
636 		return 0;
637 
638 	p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
639 	if (p == NULL)
640 		return -ENOMEM;
641 	card->proc_root_link = p;
642 	return 0;
643 }
644 
645 /*
646  * de-register the card proc file
647  * called from init.c
648  */
649 int snd_info_card_free(snd_card_t * card)
650 {
651 	snd_assert(card != NULL, return -ENXIO);
652 	if (card->proc_root_link) {
653 		snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
654 		card->proc_root_link = NULL;
655 	}
656 	if (card->proc_root) {
657 		snd_info_unregister(card->proc_root);
658 		card->proc_root = NULL;
659 	}
660 	return 0;
661 }
662 
663 
664 /**
665  * snd_info_get_line - read one line from the procfs buffer
666  * @buffer: the procfs buffer
667  * @line: the buffer to store
668  * @len: the max. buffer size - 1
669  *
670  * Reads one line from the buffer and stores the string.
671  *
672  * Returns zero if successful, or 1 if error or EOF.
673  */
674 int snd_info_get_line(snd_info_buffer_t * buffer, char *line, int len)
675 {
676 	int c = -1;
677 
678 	if (len <= 0 || buffer->stop || buffer->error)
679 		return 1;
680 	while (--len > 0) {
681 		c = *buffer->curr++;
682 		if (c == '\n') {
683 			if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
684 				buffer->stop = 1;
685 			}
686 			break;
687 		}
688 		*line++ = c;
689 		if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
690 			buffer->stop = 1;
691 			break;
692 		}
693 	}
694 	while (c != '\n' && !buffer->stop) {
695 		c = *buffer->curr++;
696 		if ((buffer->curr - buffer->buffer) >= (long)buffer->size) {
697 			buffer->stop = 1;
698 		}
699 	}
700 	*line = '\0';
701 	return 0;
702 }
703 
704 /**
705  * snd_info_get_str - parse a string token
706  * @dest: the buffer to store the string token
707  * @src: the original string
708  * @len: the max. length of token - 1
709  *
710  * Parses the original string and copy a token to the given
711  * string buffer.
712  *
713  * Returns the updated pointer of the original string so that
714  * it can be used for the next call.
715  */
716 char *snd_info_get_str(char *dest, char *src, int len)
717 {
718 	int c;
719 
720 	while (*src == ' ' || *src == '\t')
721 		src++;
722 	if (*src == '"' || *src == '\'') {
723 		c = *src++;
724 		while (--len > 0 && *src && *src != c) {
725 			*dest++ = *src++;
726 		}
727 		if (*src == c)
728 			src++;
729 	} else {
730 		while (--len > 0 && *src && *src != ' ' && *src != '\t') {
731 			*dest++ = *src++;
732 		}
733 	}
734 	*dest = 0;
735 	while (*src == ' ' || *src == '\t')
736 		src++;
737 	return src;
738 }
739 
740 /**
741  * snd_info_create_entry - create an info entry
742  * @name: the proc file name
743  *
744  * Creates an info entry with the given file name and initializes as
745  * the default state.
746  *
747  * Usually called from other functions such as
748  * snd_info_create_card_entry().
749  *
750  * Returns the pointer of the new instance, or NULL on failure.
751  */
752 static snd_info_entry_t *snd_info_create_entry(const char *name)
753 {
754 	snd_info_entry_t *entry;
755 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
756 	if (entry == NULL)
757 		return NULL;
758 	entry->name = kstrdup(name, GFP_KERNEL);
759 	if (entry->name == NULL) {
760 		kfree(entry);
761 		return NULL;
762 	}
763 	entry->mode = S_IFREG | S_IRUGO;
764 	entry->content = SNDRV_INFO_CONTENT_TEXT;
765 	init_MUTEX(&entry->access);
766 	return entry;
767 }
768 
769 /**
770  * snd_info_create_module_entry - create an info entry for the given module
771  * @module: the module pointer
772  * @name: the file name
773  * @parent: the parent directory
774  *
775  * Creates a new info entry and assigns it to the given module.
776  *
777  * Returns the pointer of the new instance, or NULL on failure.
778  */
779 snd_info_entry_t *snd_info_create_module_entry(struct module * module,
780 					       const char *name,
781 					       snd_info_entry_t *parent)
782 {
783 	snd_info_entry_t *entry = snd_info_create_entry(name);
784 	if (entry) {
785 		entry->module = module;
786 		entry->parent = parent;
787 	}
788 	return entry;
789 }
790 
791 /**
792  * snd_info_create_card_entry - create an info entry for the given card
793  * @card: the card instance
794  * @name: the file name
795  * @parent: the parent directory
796  *
797  * Creates a new info entry and assigns it to the given card.
798  *
799  * Returns the pointer of the new instance, or NULL on failure.
800  */
801 snd_info_entry_t *snd_info_create_card_entry(snd_card_t * card,
802 					     const char *name,
803 					     snd_info_entry_t * parent)
804 {
805 	snd_info_entry_t *entry = snd_info_create_entry(name);
806 	if (entry) {
807 		entry->module = card->module;
808 		entry->card = card;
809 		entry->parent = parent;
810 	}
811 	return entry;
812 }
813 
814 static int snd_info_dev_free_entry(snd_device_t *device)
815 {
816 	snd_info_entry_t *entry = device->device_data;
817 	snd_info_free_entry(entry);
818 	return 0;
819 }
820 
821 static int snd_info_dev_register_entry(snd_device_t *device)
822 {
823 	snd_info_entry_t *entry = device->device_data;
824 	return snd_info_register(entry);
825 }
826 
827 static int snd_info_dev_disconnect_entry(snd_device_t *device)
828 {
829 	snd_info_entry_t *entry = device->device_data;
830 	entry->disconnected = 1;
831 	return 0;
832 }
833 
834 static int snd_info_dev_unregister_entry(snd_device_t *device)
835 {
836 	snd_info_entry_t *entry = device->device_data;
837 	return snd_info_unregister(entry);
838 }
839 
840 /**
841  * snd_card_proc_new - create an info entry for the given card
842  * @card: the card instance
843  * @name: the file name
844  * @entryp: the pointer to store the new info entry
845  *
846  * Creates a new info entry and assigns it to the given card.
847  * Unlike snd_info_create_card_entry(), this function registers the
848  * info entry as an ALSA device component, so that it can be
849  * unregistered/released without explicit call.
850  * Also, you don't have to register this entry via snd_info_register(),
851  * since this will be registered by snd_card_register() automatically.
852  *
853  * The parent is assumed as card->proc_root.
854  *
855  * For releasing this entry, use snd_device_free() instead of
856  * snd_info_free_entry().
857  *
858  * Returns zero if successful, or a negative error code on failure.
859  */
860 int snd_card_proc_new(snd_card_t *card, const char *name,
861 		      snd_info_entry_t **entryp)
862 {
863 	static snd_device_ops_t ops = {
864 		.dev_free = snd_info_dev_free_entry,
865 		.dev_register =	snd_info_dev_register_entry,
866 		.dev_disconnect = snd_info_dev_disconnect_entry,
867 		.dev_unregister = snd_info_dev_unregister_entry
868 	};
869 	snd_info_entry_t *entry;
870 	int err;
871 
872 	entry = snd_info_create_card_entry(card, name, card->proc_root);
873 	if (! entry)
874 		return -ENOMEM;
875 	if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
876 		snd_info_free_entry(entry);
877 		return err;
878 	}
879 	if (entryp)
880 		*entryp = entry;
881 	return 0;
882 }
883 
884 /**
885  * snd_info_free_entry - release the info entry
886  * @entry: the info entry
887  *
888  * Releases the info entry.  Don't call this after registered.
889  */
890 void snd_info_free_entry(snd_info_entry_t * entry)
891 {
892 	if (entry == NULL)
893 		return;
894 	kfree(entry->name);
895 	if (entry->private_free)
896 		entry->private_free(entry);
897 	kfree(entry);
898 }
899 
900 /**
901  * snd_info_register - register the info entry
902  * @entry: the info entry
903  *
904  * Registers the proc info entry.
905  *
906  * Returns zero if successful, or a negative error code on failure.
907  */
908 int snd_info_register(snd_info_entry_t * entry)
909 {
910 	struct proc_dir_entry *root, *p = NULL;
911 
912 	snd_assert(entry != NULL, return -ENXIO);
913 	root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
914 	down(&info_mutex);
915 	p = snd_create_proc_entry(entry->name, entry->mode, root);
916 	if (!p) {
917 		up(&info_mutex);
918 		return -ENOMEM;
919 	}
920 	p->owner = entry->module;
921 	if (!S_ISDIR(entry->mode))
922 		p->proc_fops = &snd_info_entry_operations;
923 	p->size = entry->size;
924 	p->data = entry;
925 	entry->p = p;
926 	up(&info_mutex);
927 	return 0;
928 }
929 
930 /**
931  * snd_info_unregister - de-register the info entry
932  * @entry: the info entry
933  *
934  * De-registers the info entry and releases the instance.
935  *
936  * Returns zero if successful, or a negative error code on failure.
937  */
938 int snd_info_unregister(snd_info_entry_t * entry)
939 {
940 	struct proc_dir_entry *root;
941 
942 	snd_assert(entry != NULL, return -ENXIO);
943 	snd_assert(entry->p != NULL, return -ENXIO);
944 	root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
945 	snd_assert(root, return -ENXIO);
946 	down(&info_mutex);
947 	snd_remove_proc_entry(root, entry->p);
948 	up(&info_mutex);
949 	snd_info_free_entry(entry);
950 	return 0;
951 }
952 
953 /*
954 
955  */
956 
957 static snd_info_entry_t *snd_info_version_entry = NULL;
958 
959 static void snd_info_version_read(snd_info_entry_t *entry, snd_info_buffer_t * buffer)
960 {
961 	snd_iprintf(buffer,
962 		    "Advanced Linux Sound Architecture Driver Version "
963 		    CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
964 		   );
965 }
966 
967 static int __init snd_info_version_init(void)
968 {
969 	snd_info_entry_t *entry;
970 
971 	entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
972 	if (entry == NULL)
973 		return -ENOMEM;
974 	entry->c.text.read_size = 256;
975 	entry->c.text.read = snd_info_version_read;
976 	if (snd_info_register(entry) < 0) {
977 		snd_info_free_entry(entry);
978 		return -ENOMEM;
979 	}
980 	snd_info_version_entry = entry;
981 	return 0;
982 }
983 
984 static int __exit snd_info_version_done(void)
985 {
986 	if (snd_info_version_entry)
987 		snd_info_unregister(snd_info_version_entry);
988 	return 0;
989 }
990 
991 #endif /* CONFIG_PROC_FS */
992