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ALSA: info - Check file position validity in common layer
[deliverable/linux.git] / sound / core / info.c
1 /*
2 * Information interface for ALSA driver
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/time.h>
24 #include <linux/mm.h>
25 #include <linux/slab.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/mutex.h>
34 #include <stdarg.h>
35
36 /*
37 *
38 */
39
40 #ifdef CONFIG_PROC_FS
41
42 int snd_info_check_reserved_words(const char *str)
43 {
44 static char *reserved[] =
45 {
46 "version",
47 "meminfo",
48 "memdebug",
49 "detect",
50 "devices",
51 "oss",
52 "cards",
53 "timers",
54 "synth",
55 "pcm",
56 "seq",
57 NULL
58 };
59 char **xstr = reserved;
60
61 while (*xstr) {
62 if (!strcmp(*xstr, str))
63 return 0;
64 xstr++;
65 }
66 if (!strncmp(str, "card", 4))
67 return 0;
68 return 1;
69 }
70
71 static DEFINE_MUTEX(info_mutex);
72
73 struct snd_info_private_data {
74 struct snd_info_buffer *rbuffer;
75 struct snd_info_buffer *wbuffer;
76 struct snd_info_entry *entry;
77 void *file_private_data;
78 };
79
80 static int snd_info_version_init(void);
81 static int snd_info_version_done(void);
82 static void snd_info_disconnect(struct snd_info_entry *entry);
83
84
85 /* resize the proc r/w buffer */
86 static int resize_info_buffer(struct snd_info_buffer *buffer,
87 unsigned int nsize)
88 {
89 char *nbuf;
90
91 nsize = PAGE_ALIGN(nsize);
92 nbuf = krealloc(buffer->buffer, nsize, GFP_KERNEL);
93 if (! nbuf)
94 return -ENOMEM;
95
96 buffer->buffer = nbuf;
97 buffer->len = nsize;
98 return 0;
99 }
100
101 /**
102 * snd_iprintf - printf on the procfs buffer
103 * @buffer: the procfs buffer
104 * @fmt: the printf format
105 *
106 * Outputs the string on the procfs buffer just like printf().
107 *
108 * Returns the size of output string.
109 */
110 int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
111 {
112 va_list args;
113 int len, res;
114 int err = 0;
115
116 might_sleep();
117 if (buffer->stop || buffer->error)
118 return 0;
119 len = buffer->len - buffer->size;
120 va_start(args, fmt);
121 for (;;) {
122 va_list ap;
123 va_copy(ap, args);
124 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
125 va_end(ap);
126 if (res < len)
127 break;
128 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
129 if (err < 0)
130 break;
131 len = buffer->len - buffer->size;
132 }
133 va_end(args);
134
135 if (err < 0)
136 return err;
137 buffer->curr += res;
138 buffer->size += res;
139 return res;
140 }
141
142 EXPORT_SYMBOL(snd_iprintf);
143
144 /*
145
146 */
147
148 static struct proc_dir_entry *snd_proc_root;
149 struct snd_info_entry *snd_seq_root;
150 EXPORT_SYMBOL(snd_seq_root);
151
152 #ifdef CONFIG_SND_OSSEMUL
153 struct snd_info_entry *snd_oss_root;
154 #endif
155
156 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
157 struct proc_dir_entry *de)
158 {
159 if (de)
160 remove_proc_entry(de->name, parent);
161 }
162
163 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
164 {
165 struct snd_info_private_data *data;
166 struct snd_info_entry *entry;
167 loff_t ret;
168
169 data = file->private_data;
170 entry = data->entry;
171 mutex_lock(&entry->access);
172 switch (entry->content) {
173 case SNDRV_INFO_CONTENT_TEXT:
174 switch (orig) {
175 case SEEK_SET:
176 file->f_pos = offset;
177 ret = file->f_pos;
178 goto out;
179 case SEEK_CUR:
180 file->f_pos += offset;
181 ret = file->f_pos;
182 goto out;
183 case SEEK_END:
184 default:
185 ret = -EINVAL;
186 goto out;
187 }
188 break;
189 case SNDRV_INFO_CONTENT_DATA:
190 if (entry->c.ops->llseek) {
191 ret = entry->c.ops->llseek(entry,
192 data->file_private_data,
193 file, offset, orig);
194 goto out;
195 }
196 break;
197 }
198 ret = -ENXIO;
199 out:
200 mutex_unlock(&entry->access);
201 return ret;
202 }
203
204 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
205 size_t count, loff_t * offset)
206 {
207 struct snd_info_private_data *data;
208 struct snd_info_entry *entry;
209 struct snd_info_buffer *buf;
210 size_t size = 0;
211 loff_t pos;
212
213 data = file->private_data;
214 if (snd_BUG_ON(!data))
215 return -ENXIO;
216 pos = *offset;
217 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
218 return -EIO;
219 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
220 return -EIO;
221 entry = data->entry;
222 switch (entry->content) {
223 case SNDRV_INFO_CONTENT_TEXT:
224 buf = data->rbuffer;
225 if (buf == NULL)
226 return -EIO;
227 if (pos >= buf->size)
228 return 0;
229 size = buf->size - pos;
230 size = min(count, size);
231 if (copy_to_user(buffer, buf->buffer + pos, size))
232 return -EFAULT;
233 break;
234 case SNDRV_INFO_CONTENT_DATA:
235 if (pos >= entry->size)
236 return 0;
237 if (entry->c.ops->read) {
238 size = entry->size - pos;
239 size = min(count, size);
240 size = entry->c.ops->read(entry,
241 data->file_private_data,
242 file, buffer, size, pos);
243 }
244 break;
245 }
246 if ((ssize_t) size > 0)
247 *offset = pos + size;
248 return size;
249 }
250
251 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
252 size_t count, loff_t * offset)
253 {
254 struct snd_info_private_data *data;
255 struct snd_info_entry *entry;
256 struct snd_info_buffer *buf;
257 ssize_t size = 0;
258 loff_t pos;
259
260 data = file->private_data;
261 if (snd_BUG_ON(!data))
262 return -ENXIO;
263 entry = data->entry;
264 pos = *offset;
265 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
266 return -EIO;
267 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
268 return -EIO;
269 switch (entry->content) {
270 case SNDRV_INFO_CONTENT_TEXT:
271 buf = data->wbuffer;
272 if (buf == NULL)
273 return -EIO;
274 mutex_lock(&entry->access);
275 if (pos + count >= buf->len) {
276 if (resize_info_buffer(buf, pos + count)) {
277 mutex_unlock(&entry->access);
278 return -ENOMEM;
279 }
280 }
281 if (copy_from_user(buf->buffer + pos, buffer, count)) {
282 mutex_unlock(&entry->access);
283 return -EFAULT;
284 }
285 buf->size = pos + count;
286 mutex_unlock(&entry->access);
287 size = count;
288 break;
289 case SNDRV_INFO_CONTENT_DATA:
290 if (entry->c.ops->write && count > 0) {
291 size_t maxsize = entry->size - pos;
292 count = min(count, maxsize);
293 size = entry->c.ops->write(entry,
294 data->file_private_data,
295 file, buffer, count, pos);
296 }
297 break;
298 }
299 if ((ssize_t) size > 0)
300 *offset = pos + size;
301 return size;
302 }
303
304 static int snd_info_entry_open(struct inode *inode, struct file *file)
305 {
306 struct snd_info_entry *entry;
307 struct snd_info_private_data *data;
308 struct snd_info_buffer *buffer;
309 struct proc_dir_entry *p;
310 int mode, err;
311
312 mutex_lock(&info_mutex);
313 p = PDE(inode);
314 entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
315 if (entry == NULL || ! entry->p) {
316 mutex_unlock(&info_mutex);
317 return -ENODEV;
318 }
319 if (!try_module_get(entry->module)) {
320 err = -EFAULT;
321 goto __error1;
322 }
323 mode = file->f_flags & O_ACCMODE;
324 if (mode == O_RDONLY || mode == O_RDWR) {
325 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
326 entry->c.ops->read == NULL)) {
327 err = -ENODEV;
328 goto __error;
329 }
330 }
331 if (mode == O_WRONLY || mode == O_RDWR) {
332 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
333 entry->c.ops->write == NULL)) {
334 err = -ENODEV;
335 goto __error;
336 }
337 }
338 data = kzalloc(sizeof(*data), GFP_KERNEL);
339 if (data == NULL) {
340 err = -ENOMEM;
341 goto __error;
342 }
343 data->entry = entry;
344 switch (entry->content) {
345 case SNDRV_INFO_CONTENT_TEXT:
346 if (mode == O_RDONLY || mode == O_RDWR) {
347 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
348 if (buffer == NULL)
349 goto __nomem;
350 data->rbuffer = buffer;
351 buffer->len = PAGE_SIZE;
352 buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
353 if (buffer->buffer == NULL)
354 goto __nomem;
355 }
356 if (mode == O_WRONLY || mode == O_RDWR) {
357 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
358 if (buffer == NULL)
359 goto __nomem;
360 data->wbuffer = buffer;
361 buffer->len = PAGE_SIZE;
362 buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
363 if (buffer->buffer == NULL)
364 goto __nomem;
365 }
366 break;
367 case SNDRV_INFO_CONTENT_DATA: /* data */
368 if (entry->c.ops->open) {
369 if ((err = entry->c.ops->open(entry, mode,
370 &data->file_private_data)) < 0) {
371 kfree(data);
372 goto __error;
373 }
374 }
375 break;
376 }
377 file->private_data = data;
378 mutex_unlock(&info_mutex);
379 if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
380 (mode == O_RDONLY || mode == O_RDWR)) {
381 if (entry->c.text.read) {
382 mutex_lock(&entry->access);
383 entry->c.text.read(entry, data->rbuffer);
384 mutex_unlock(&entry->access);
385 }
386 }
387 return 0;
388
389 __nomem:
390 if (data->rbuffer) {
391 kfree(data->rbuffer->buffer);
392 kfree(data->rbuffer);
393 }
394 if (data->wbuffer) {
395 kfree(data->wbuffer->buffer);
396 kfree(data->wbuffer);
397 }
398 kfree(data);
399 err = -ENOMEM;
400 __error:
401 module_put(entry->module);
402 __error1:
403 mutex_unlock(&info_mutex);
404 return err;
405 }
406
407 static int snd_info_entry_release(struct inode *inode, struct file *file)
408 {
409 struct snd_info_entry *entry;
410 struct snd_info_private_data *data;
411 int mode;
412
413 mode = file->f_flags & O_ACCMODE;
414 data = file->private_data;
415 entry = data->entry;
416 switch (entry->content) {
417 case SNDRV_INFO_CONTENT_TEXT:
418 if (data->rbuffer) {
419 kfree(data->rbuffer->buffer);
420 kfree(data->rbuffer);
421 }
422 if (data->wbuffer) {
423 if (entry->c.text.write) {
424 entry->c.text.write(entry, data->wbuffer);
425 if (data->wbuffer->error) {
426 snd_printk(KERN_WARNING "data write error to %s (%i)\n",
427 entry->name,
428 data->wbuffer->error);
429 }
430 }
431 kfree(data->wbuffer->buffer);
432 kfree(data->wbuffer);
433 }
434 break;
435 case SNDRV_INFO_CONTENT_DATA:
436 if (entry->c.ops->release)
437 entry->c.ops->release(entry, mode,
438 data->file_private_data);
439 break;
440 }
441 module_put(entry->module);
442 kfree(data);
443 return 0;
444 }
445
446 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
447 {
448 struct snd_info_private_data *data;
449 struct snd_info_entry *entry;
450 unsigned int mask;
451
452 data = file->private_data;
453 if (data == NULL)
454 return 0;
455 entry = data->entry;
456 mask = 0;
457 switch (entry->content) {
458 case SNDRV_INFO_CONTENT_DATA:
459 if (entry->c.ops->poll)
460 return entry->c.ops->poll(entry,
461 data->file_private_data,
462 file, wait);
463 if (entry->c.ops->read)
464 mask |= POLLIN | POLLRDNORM;
465 if (entry->c.ops->write)
466 mask |= POLLOUT | POLLWRNORM;
467 break;
468 }
469 return mask;
470 }
471
472 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
473 unsigned long arg)
474 {
475 struct snd_info_private_data *data;
476 struct snd_info_entry *entry;
477
478 data = file->private_data;
479 if (data == NULL)
480 return 0;
481 entry = data->entry;
482 switch (entry->content) {
483 case SNDRV_INFO_CONTENT_DATA:
484 if (entry->c.ops->ioctl)
485 return entry->c.ops->ioctl(entry,
486 data->file_private_data,
487 file, cmd, arg);
488 break;
489 }
490 return -ENOTTY;
491 }
492
493 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
494 {
495 struct inode *inode = file->f_path.dentry->d_inode;
496 struct snd_info_private_data *data;
497 struct snd_info_entry *entry;
498
499 data = file->private_data;
500 if (data == NULL)
501 return 0;
502 entry = data->entry;
503 switch (entry->content) {
504 case SNDRV_INFO_CONTENT_DATA:
505 if (entry->c.ops->mmap)
506 return entry->c.ops->mmap(entry,
507 data->file_private_data,
508 inode, file, vma);
509 break;
510 }
511 return -ENXIO;
512 }
513
514 static const struct file_operations snd_info_entry_operations =
515 {
516 .owner = THIS_MODULE,
517 .llseek = snd_info_entry_llseek,
518 .read = snd_info_entry_read,
519 .write = snd_info_entry_write,
520 .poll = snd_info_entry_poll,
521 .unlocked_ioctl = snd_info_entry_ioctl,
522 .mmap = snd_info_entry_mmap,
523 .open = snd_info_entry_open,
524 .release = snd_info_entry_release,
525 };
526
527 int __init snd_info_init(void)
528 {
529 struct proc_dir_entry *p;
530
531 p = create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
532 if (p == NULL)
533 return -ENOMEM;
534 snd_proc_root = p;
535 #ifdef CONFIG_SND_OSSEMUL
536 {
537 struct snd_info_entry *entry;
538 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
539 return -ENOMEM;
540 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
541 if (snd_info_register(entry) < 0) {
542 snd_info_free_entry(entry);
543 return -ENOMEM;
544 }
545 snd_oss_root = entry;
546 }
547 #endif
548 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
549 {
550 struct snd_info_entry *entry;
551 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
552 return -ENOMEM;
553 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
554 if (snd_info_register(entry) < 0) {
555 snd_info_free_entry(entry);
556 return -ENOMEM;
557 }
558 snd_seq_root = entry;
559 }
560 #endif
561 snd_info_version_init();
562 snd_minor_info_init();
563 snd_minor_info_oss_init();
564 snd_card_info_init();
565 return 0;
566 }
567
568 int __exit snd_info_done(void)
569 {
570 snd_card_info_done();
571 snd_minor_info_oss_done();
572 snd_minor_info_done();
573 snd_info_version_done();
574 if (snd_proc_root) {
575 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
576 snd_info_free_entry(snd_seq_root);
577 #endif
578 #ifdef CONFIG_SND_OSSEMUL
579 snd_info_free_entry(snd_oss_root);
580 #endif
581 snd_remove_proc_entry(NULL, snd_proc_root);
582 }
583 return 0;
584 }
585
586 /*
587
588 */
589
590
591 /*
592 * create a card proc file
593 * called from init.c
594 */
595 int snd_info_card_create(struct snd_card *card)
596 {
597 char str[8];
598 struct snd_info_entry *entry;
599
600 if (snd_BUG_ON(!card))
601 return -ENXIO;
602
603 sprintf(str, "card%i", card->number);
604 if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
605 return -ENOMEM;
606 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
607 if (snd_info_register(entry) < 0) {
608 snd_info_free_entry(entry);
609 return -ENOMEM;
610 }
611 card->proc_root = entry;
612 return 0;
613 }
614
615 /*
616 * register the card proc file
617 * called from init.c
618 */
619 int snd_info_card_register(struct snd_card *card)
620 {
621 struct proc_dir_entry *p;
622
623 if (snd_BUG_ON(!card))
624 return -ENXIO;
625
626 if (!strcmp(card->id, card->proc_root->name))
627 return 0;
628
629 p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
630 if (p == NULL)
631 return -ENOMEM;
632 card->proc_root_link = p;
633 return 0;
634 }
635
636 /*
637 * called on card->id change
638 */
639 void snd_info_card_id_change(struct snd_card *card)
640 {
641 mutex_lock(&info_mutex);
642 if (card->proc_root_link) {
643 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
644 card->proc_root_link = NULL;
645 }
646 if (strcmp(card->id, card->proc_root->name))
647 card->proc_root_link = proc_symlink(card->id,
648 snd_proc_root,
649 card->proc_root->name);
650 mutex_unlock(&info_mutex);
651 }
652
653 /*
654 * de-register the card proc file
655 * called from init.c
656 */
657 void snd_info_card_disconnect(struct snd_card *card)
658 {
659 if (!card)
660 return;
661 mutex_lock(&info_mutex);
662 if (card->proc_root_link) {
663 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
664 card->proc_root_link = NULL;
665 }
666 if (card->proc_root)
667 snd_info_disconnect(card->proc_root);
668 mutex_unlock(&info_mutex);
669 }
670
671 /*
672 * release the card proc file resources
673 * called from init.c
674 */
675 int snd_info_card_free(struct snd_card *card)
676 {
677 if (!card)
678 return 0;
679 snd_info_free_entry(card->proc_root);
680 card->proc_root = NULL;
681 return 0;
682 }
683
684
685 /**
686 * snd_info_get_line - read one line from the procfs buffer
687 * @buffer: the procfs buffer
688 * @line: the buffer to store
689 * @len: the max. buffer size - 1
690 *
691 * Reads one line from the buffer and stores the string.
692 *
693 * Returns zero if successful, or 1 if error or EOF.
694 */
695 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
696 {
697 int c = -1;
698
699 if (len <= 0 || buffer->stop || buffer->error)
700 return 1;
701 while (--len > 0) {
702 c = buffer->buffer[buffer->curr++];
703 if (c == '\n') {
704 if (buffer->curr >= buffer->size)
705 buffer->stop = 1;
706 break;
707 }
708 *line++ = c;
709 if (buffer->curr >= buffer->size) {
710 buffer->stop = 1;
711 break;
712 }
713 }
714 while (c != '\n' && !buffer->stop) {
715 c = buffer->buffer[buffer->curr++];
716 if (buffer->curr >= buffer->size)
717 buffer->stop = 1;
718 }
719 *line = '\0';
720 return 0;
721 }
722
723 EXPORT_SYMBOL(snd_info_get_line);
724
725 /**
726 * snd_info_get_str - parse a string token
727 * @dest: the buffer to store the string token
728 * @src: the original string
729 * @len: the max. length of token - 1
730 *
731 * Parses the original string and copy a token to the given
732 * string buffer.
733 *
734 * Returns the updated pointer of the original string so that
735 * it can be used for the next call.
736 */
737 const char *snd_info_get_str(char *dest, const char *src, int len)
738 {
739 int c;
740
741 while (*src == ' ' || *src == '\t')
742 src++;
743 if (*src == '"' || *src == '\'') {
744 c = *src++;
745 while (--len > 0 && *src && *src != c) {
746 *dest++ = *src++;
747 }
748 if (*src == c)
749 src++;
750 } else {
751 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
752 *dest++ = *src++;
753 }
754 }
755 *dest = 0;
756 while (*src == ' ' || *src == '\t')
757 src++;
758 return src;
759 }
760
761 EXPORT_SYMBOL(snd_info_get_str);
762
763 /**
764 * snd_info_create_entry - create an info entry
765 * @name: the proc file name
766 *
767 * Creates an info entry with the given file name and initializes as
768 * the default state.
769 *
770 * Usually called from other functions such as
771 * snd_info_create_card_entry().
772 *
773 * Returns the pointer of the new instance, or NULL on failure.
774 */
775 static struct snd_info_entry *snd_info_create_entry(const char *name)
776 {
777 struct snd_info_entry *entry;
778 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
779 if (entry == NULL)
780 return NULL;
781 entry->name = kstrdup(name, GFP_KERNEL);
782 if (entry->name == NULL) {
783 kfree(entry);
784 return NULL;
785 }
786 entry->mode = S_IFREG | S_IRUGO;
787 entry->content = SNDRV_INFO_CONTENT_TEXT;
788 mutex_init(&entry->access);
789 INIT_LIST_HEAD(&entry->children);
790 INIT_LIST_HEAD(&entry->list);
791 return entry;
792 }
793
794 /**
795 * snd_info_create_module_entry - create an info entry for the given module
796 * @module: the module pointer
797 * @name: the file name
798 * @parent: the parent directory
799 *
800 * Creates a new info entry and assigns it to the given module.
801 *
802 * Returns the pointer of the new instance, or NULL on failure.
803 */
804 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
805 const char *name,
806 struct snd_info_entry *parent)
807 {
808 struct snd_info_entry *entry = snd_info_create_entry(name);
809 if (entry) {
810 entry->module = module;
811 entry->parent = parent;
812 }
813 return entry;
814 }
815
816 EXPORT_SYMBOL(snd_info_create_module_entry);
817
818 /**
819 * snd_info_create_card_entry - create an info entry for the given card
820 * @card: the card instance
821 * @name: the file name
822 * @parent: the parent directory
823 *
824 * Creates a new info entry and assigns it to the given card.
825 *
826 * Returns the pointer of the new instance, or NULL on failure.
827 */
828 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
829 const char *name,
830 struct snd_info_entry * parent)
831 {
832 struct snd_info_entry *entry = snd_info_create_entry(name);
833 if (entry) {
834 entry->module = card->module;
835 entry->card = card;
836 entry->parent = parent;
837 }
838 return entry;
839 }
840
841 EXPORT_SYMBOL(snd_info_create_card_entry);
842
843 static void snd_info_disconnect(struct snd_info_entry *entry)
844 {
845 struct list_head *p, *n;
846 struct proc_dir_entry *root;
847
848 list_for_each_safe(p, n, &entry->children) {
849 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
850 }
851
852 if (! entry->p)
853 return;
854 list_del_init(&entry->list);
855 root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
856 snd_BUG_ON(!root);
857 snd_remove_proc_entry(root, entry->p);
858 entry->p = NULL;
859 }
860
861 static int snd_info_dev_free_entry(struct snd_device *device)
862 {
863 struct snd_info_entry *entry = device->device_data;
864 snd_info_free_entry(entry);
865 return 0;
866 }
867
868 static int snd_info_dev_register_entry(struct snd_device *device)
869 {
870 struct snd_info_entry *entry = device->device_data;
871 return snd_info_register(entry);
872 }
873
874 /**
875 * snd_card_proc_new - create an info entry for the given card
876 * @card: the card instance
877 * @name: the file name
878 * @entryp: the pointer to store the new info entry
879 *
880 * Creates a new info entry and assigns it to the given card.
881 * Unlike snd_info_create_card_entry(), this function registers the
882 * info entry as an ALSA device component, so that it can be
883 * unregistered/released without explicit call.
884 * Also, you don't have to register this entry via snd_info_register(),
885 * since this will be registered by snd_card_register() automatically.
886 *
887 * The parent is assumed as card->proc_root.
888 *
889 * For releasing this entry, use snd_device_free() instead of
890 * snd_info_free_entry().
891 *
892 * Returns zero if successful, or a negative error code on failure.
893 */
894 int snd_card_proc_new(struct snd_card *card, const char *name,
895 struct snd_info_entry **entryp)
896 {
897 static struct snd_device_ops ops = {
898 .dev_free = snd_info_dev_free_entry,
899 .dev_register = snd_info_dev_register_entry,
900 /* disconnect is done via snd_info_card_disconnect() */
901 };
902 struct snd_info_entry *entry;
903 int err;
904
905 entry = snd_info_create_card_entry(card, name, card->proc_root);
906 if (! entry)
907 return -ENOMEM;
908 if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
909 snd_info_free_entry(entry);
910 return err;
911 }
912 if (entryp)
913 *entryp = entry;
914 return 0;
915 }
916
917 EXPORT_SYMBOL(snd_card_proc_new);
918
919 /**
920 * snd_info_free_entry - release the info entry
921 * @entry: the info entry
922 *
923 * Releases the info entry. Don't call this after registered.
924 */
925 void snd_info_free_entry(struct snd_info_entry * entry)
926 {
927 if (entry == NULL)
928 return;
929 if (entry->p) {
930 mutex_lock(&info_mutex);
931 snd_info_disconnect(entry);
932 mutex_unlock(&info_mutex);
933 }
934 kfree(entry->name);
935 if (entry->private_free)
936 entry->private_free(entry);
937 kfree(entry);
938 }
939
940 EXPORT_SYMBOL(snd_info_free_entry);
941
942 /**
943 * snd_info_register - register the info entry
944 * @entry: the info entry
945 *
946 * Registers the proc info entry.
947 *
948 * Returns zero if successful, or a negative error code on failure.
949 */
950 int snd_info_register(struct snd_info_entry * entry)
951 {
952 struct proc_dir_entry *root, *p = NULL;
953
954 if (snd_BUG_ON(!entry))
955 return -ENXIO;
956 root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
957 mutex_lock(&info_mutex);
958 p = create_proc_entry(entry->name, entry->mode, root);
959 if (!p) {
960 mutex_unlock(&info_mutex);
961 return -ENOMEM;
962 }
963 if (!S_ISDIR(entry->mode))
964 p->proc_fops = &snd_info_entry_operations;
965 p->size = entry->size;
966 p->data = entry;
967 entry->p = p;
968 if (entry->parent)
969 list_add_tail(&entry->list, &entry->parent->children);
970 mutex_unlock(&info_mutex);
971 return 0;
972 }
973
974 EXPORT_SYMBOL(snd_info_register);
975
976 /*
977
978 */
979
980 static struct snd_info_entry *snd_info_version_entry;
981
982 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
983 {
984 snd_iprintf(buffer,
985 "Advanced Linux Sound Architecture Driver Version "
986 CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
987 );
988 }
989
990 static int __init snd_info_version_init(void)
991 {
992 struct snd_info_entry *entry;
993
994 entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
995 if (entry == NULL)
996 return -ENOMEM;
997 entry->c.text.read = snd_info_version_read;
998 if (snd_info_register(entry) < 0) {
999 snd_info_free_entry(entry);
1000 return -ENOMEM;
1001 }
1002 snd_info_version_entry = entry;
1003 return 0;
1004 }
1005
1006 static int __exit snd_info_version_done(void)
1007 {
1008 snd_info_free_entry(snd_info_version_entry);
1009 return 0;
1010 }
1011
1012 #endif /* CONFIG_PROC_FS */
Linux kernel - Deliverables
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