BKL: remove extraneous #include <smp_lock.h>
[linux-3.10.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/string.h>
27 #include <sound/core.h>
28 #include <sound/minors.h>
29 #include <sound/info.h>
30 #include <sound/version.h>
31 #include <linux/proc_fs.h>
32 #include <linux/mutex.h>
33 #include <stdarg.h>
34
35 /*
36  *
37  */
38
39 #ifdef CONFIG_PROC_FS
40
41 int snd_info_check_reserved_words(const char *str)
42 {
43         static char *reserved[] =
44         {
45                 "version",
46                 "meminfo",
47                 "memdebug",
48                 "detect",
49                 "devices",
50                 "oss",
51                 "cards",
52                 "timers",
53                 "synth",
54                 "pcm",
55                 "seq",
56                 NULL
57         };
58         char **xstr = reserved;
59
60         while (*xstr) {
61                 if (!strcmp(*xstr, str))
62                         return 0;
63                 xstr++;
64         }
65         if (!strncmp(str, "card", 4))
66                 return 0;
67         return 1;
68 }
69
70 static DEFINE_MUTEX(info_mutex);
71
72 struct snd_info_private_data {
73         struct snd_info_buffer *rbuffer;
74         struct snd_info_buffer *wbuffer;
75         struct snd_info_entry *entry;
76         void *file_private_data;
77 };
78
79 static int snd_info_version_init(void);
80 static int snd_info_version_done(void);
81 static void snd_info_disconnect(struct snd_info_entry *entry);
82
83
84 /* resize the proc r/w buffer */
85 static int resize_info_buffer(struct snd_info_buffer *buffer,
86                               unsigned int nsize)
87 {
88         char *nbuf;
89
90         nsize = PAGE_ALIGN(nsize);
91         nbuf = krealloc(buffer->buffer, nsize, GFP_KERNEL);
92         if (! nbuf)
93                 return -ENOMEM;
94
95         buffer->buffer = nbuf;
96         buffer->len = nsize;
97         return 0;
98 }
99
100 /**
101  * snd_iprintf - printf on the procfs buffer
102  * @buffer: the procfs buffer
103  * @fmt: the printf format
104  *
105  * Outputs the string on the procfs buffer just like printf().
106  *
107  * Returns the size of output string.
108  */
109 int snd_iprintf(struct snd_info_buffer *buffer, const char *fmt, ...)
110 {
111         va_list args;
112         int len, res;
113         int err = 0;
114
115         might_sleep();
116         if (buffer->stop || buffer->error)
117                 return 0;
118         len = buffer->len - buffer->size;
119         va_start(args, fmt);
120         for (;;) {
121                 va_list ap;
122                 va_copy(ap, args);
123                 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
124                 va_end(ap);
125                 if (res < len)
126                         break;
127                 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
128                 if (err < 0)
129                         break;
130                 len = buffer->len - buffer->size;
131         }
132         va_end(args);
133
134         if (err < 0)
135                 return err;
136         buffer->curr += res;
137         buffer->size += res;
138         return res;
139 }
140
141 EXPORT_SYMBOL(snd_iprintf);
142
143 /*
144
145  */
146
147 static struct proc_dir_entry *snd_proc_root;
148 struct snd_info_entry *snd_seq_root;
149 EXPORT_SYMBOL(snd_seq_root);
150
151 #ifdef CONFIG_SND_OSSEMUL
152 struct snd_info_entry *snd_oss_root;
153 #endif
154
155 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
156                                   struct proc_dir_entry *de)
157 {
158         if (de)
159                 remove_proc_entry(de->name, parent);
160 }
161
162 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
163 {
164         struct snd_info_private_data *data;
165         struct snd_info_entry *entry;
166         loff_t ret = -EINVAL, size;
167
168         data = file->private_data;
169         entry = data->entry;
170         mutex_lock(&entry->access);
171         if (entry->content == SNDRV_INFO_CONTENT_DATA &&
172             entry->c.ops->llseek) {
173                 offset = entry->c.ops->llseek(entry,
174                                               data->file_private_data,
175                                               file, offset, orig);
176                 goto out;
177         }
178         if (entry->content == SNDRV_INFO_CONTENT_DATA)
179                 size = entry->size;
180         else
181                 size = 0;
182         switch (orig) {
183         case SEEK_SET:
184                 break;
185         case SEEK_CUR:
186                 offset += file->f_pos;
187                 break;
188         case SEEK_END:
189                 if (!size)
190                         goto out;
191                 offset += size;
192                 break;
193         default:
194                 goto out;
195         }
196         if (offset < 0)
197                 goto out;
198         if (size && offset > size)
199                 offset = size;
200         file->f_pos = offset;
201         ret = offset;
202  out:
203         mutex_unlock(&entry->access);
204         return ret;
205 }
206
207 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
208                                    size_t count, loff_t * offset)
209 {
210         struct snd_info_private_data *data;
211         struct snd_info_entry *entry;
212         struct snd_info_buffer *buf;
213         size_t size = 0;
214         loff_t pos;
215
216         data = file->private_data;
217         if (snd_BUG_ON(!data))
218                 return -ENXIO;
219         pos = *offset;
220         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
221                 return -EIO;
222         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
223                 return -EIO;
224         entry = data->entry;
225         switch (entry->content) {
226         case SNDRV_INFO_CONTENT_TEXT:
227                 buf = data->rbuffer;
228                 if (buf == NULL)
229                         return -EIO;
230                 if (pos >= buf->size)
231                         return 0;
232                 size = buf->size - pos;
233                 size = min(count, size);
234                 if (copy_to_user(buffer, buf->buffer + pos, size))
235                         return -EFAULT;
236                 break;
237         case SNDRV_INFO_CONTENT_DATA:
238                 if (pos >= entry->size)
239                         return 0;
240                 if (entry->c.ops->read) {
241                         size = entry->size - pos;
242                         size = min(count, size);
243                         size = entry->c.ops->read(entry,
244                                                   data->file_private_data,
245                                                   file, buffer, size, pos);
246                 }
247                 break;
248         }
249         if ((ssize_t) size > 0)
250                 *offset = pos + size;
251         return size;
252 }
253
254 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
255                                     size_t count, loff_t * offset)
256 {
257         struct snd_info_private_data *data;
258         struct snd_info_entry *entry;
259         struct snd_info_buffer *buf;
260         ssize_t size = 0;
261         loff_t pos;
262
263         data = file->private_data;
264         if (snd_BUG_ON(!data))
265                 return -ENXIO;
266         entry = data->entry;
267         pos = *offset;
268         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
269                 return -EIO;
270         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
271                 return -EIO;
272         switch (entry->content) {
273         case SNDRV_INFO_CONTENT_TEXT:
274                 buf = data->wbuffer;
275                 if (buf == NULL)
276                         return -EIO;
277                 mutex_lock(&entry->access);
278                 if (pos + count >= buf->len) {
279                         if (resize_info_buffer(buf, pos + count)) {
280                                 mutex_unlock(&entry->access);
281                                 return -ENOMEM;
282                         }
283                 }
284                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
285                         mutex_unlock(&entry->access);
286                         return -EFAULT;
287                 }
288                 buf->size = pos + count;
289                 mutex_unlock(&entry->access);
290                 size = count;
291                 break;
292         case SNDRV_INFO_CONTENT_DATA:
293                 if (entry->c.ops->write && count > 0) {
294                         size_t maxsize = entry->size - pos;
295                         count = min(count, maxsize);
296                         size = entry->c.ops->write(entry,
297                                                    data->file_private_data,
298                                                    file, buffer, count, pos);
299                 }
300                 break;
301         }
302         if ((ssize_t) size > 0)
303                 *offset = pos + size;
304         return size;
305 }
306
307 static int snd_info_entry_open(struct inode *inode, struct file *file)
308 {
309         struct snd_info_entry *entry;
310         struct snd_info_private_data *data;
311         struct snd_info_buffer *buffer;
312         struct proc_dir_entry *p;
313         int mode, err;
314
315         mutex_lock(&info_mutex);
316         p = PDE(inode);
317         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
318         if (entry == NULL || ! entry->p) {
319                 mutex_unlock(&info_mutex);
320                 return -ENODEV;
321         }
322         if (!try_module_get(entry->module)) {
323                 err = -EFAULT;
324                 goto __error1;
325         }
326         mode = file->f_flags & O_ACCMODE;
327         if (mode == O_RDONLY || mode == O_RDWR) {
328                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
329                      entry->c.ops->read == NULL)) {
330                         err = -ENODEV;
331                         goto __error;
332                 }
333         }
334         if (mode == O_WRONLY || mode == O_RDWR) {
335                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
336                      entry->c.ops->write == NULL)) {
337                         err = -ENODEV;
338                         goto __error;
339                 }
340         }
341         data = kzalloc(sizeof(*data), GFP_KERNEL);
342         if (data == NULL) {
343                 err = -ENOMEM;
344                 goto __error;
345         }
346         data->entry = entry;
347         switch (entry->content) {
348         case SNDRV_INFO_CONTENT_TEXT:
349                 if (mode == O_RDONLY || mode == O_RDWR) {
350                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
351                         if (buffer == NULL)
352                                 goto __nomem;
353                         data->rbuffer = buffer;
354                         buffer->len = PAGE_SIZE;
355                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
356                         if (buffer->buffer == NULL)
357                                 goto __nomem;
358                 }
359                 if (mode == O_WRONLY || mode == O_RDWR) {
360                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
361                         if (buffer == NULL)
362                                 goto __nomem;
363                         data->wbuffer = buffer;
364                         buffer->len = PAGE_SIZE;
365                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
366                         if (buffer->buffer == NULL)
367                                 goto __nomem;
368                 }
369                 break;
370         case SNDRV_INFO_CONTENT_DATA:   /* data */
371                 if (entry->c.ops->open) {
372                         if ((err = entry->c.ops->open(entry, mode,
373                                                       &data->file_private_data)) < 0) {
374                                 kfree(data);
375                                 goto __error;
376                         }
377                 }
378                 break;
379         }
380         file->private_data = data;
381         mutex_unlock(&info_mutex);
382         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
383             (mode == O_RDONLY || mode == O_RDWR)) {
384                 if (entry->c.text.read) {
385                         mutex_lock(&entry->access);
386                         entry->c.text.read(entry, data->rbuffer);
387                         mutex_unlock(&entry->access);
388                 }
389         }
390         return 0;
391
392  __nomem:
393         if (data->rbuffer) {
394                 kfree(data->rbuffer->buffer);
395                 kfree(data->rbuffer);
396         }
397         if (data->wbuffer) {
398                 kfree(data->wbuffer->buffer);
399                 kfree(data->wbuffer);
400         }
401         kfree(data);
402         err = -ENOMEM;
403       __error:
404         module_put(entry->module);
405       __error1:
406         mutex_unlock(&info_mutex);
407         return err;
408 }
409
410 static int snd_info_entry_release(struct inode *inode, struct file *file)
411 {
412         struct snd_info_entry *entry;
413         struct snd_info_private_data *data;
414         int mode;
415
416         mode = file->f_flags & O_ACCMODE;
417         data = file->private_data;
418         entry = data->entry;
419         switch (entry->content) {
420         case SNDRV_INFO_CONTENT_TEXT:
421                 if (data->rbuffer) {
422                         kfree(data->rbuffer->buffer);
423                         kfree(data->rbuffer);
424                 }
425                 if (data->wbuffer) {
426                         if (entry->c.text.write) {
427                                 entry->c.text.write(entry, data->wbuffer);
428                                 if (data->wbuffer->error) {
429                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
430                                                 entry->name,
431                                                 data->wbuffer->error);
432                                 }
433                         }
434                         kfree(data->wbuffer->buffer);
435                         kfree(data->wbuffer);
436                 }
437                 break;
438         case SNDRV_INFO_CONTENT_DATA:
439                 if (entry->c.ops->release)
440                         entry->c.ops->release(entry, mode,
441                                               data->file_private_data);
442                 break;
443         }
444         module_put(entry->module);
445         kfree(data);
446         return 0;
447 }
448
449 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
450 {
451         struct snd_info_private_data *data;
452         struct snd_info_entry *entry;
453         unsigned int mask;
454
455         data = file->private_data;
456         if (data == NULL)
457                 return 0;
458         entry = data->entry;
459         mask = 0;
460         switch (entry->content) {
461         case SNDRV_INFO_CONTENT_DATA:
462                 if (entry->c.ops->poll)
463                         return entry->c.ops->poll(entry,
464                                                   data->file_private_data,
465                                                   file, wait);
466                 if (entry->c.ops->read)
467                         mask |= POLLIN | POLLRDNORM;
468                 if (entry->c.ops->write)
469                         mask |= POLLOUT | POLLWRNORM;
470                 break;
471         }
472         return mask;
473 }
474
475 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
476                                 unsigned long arg)
477 {
478         struct snd_info_private_data *data;
479         struct snd_info_entry *entry;
480
481         data = file->private_data;
482         if (data == NULL)
483                 return 0;
484         entry = data->entry;
485         switch (entry->content) {
486         case SNDRV_INFO_CONTENT_DATA:
487                 if (entry->c.ops->ioctl)
488                         return entry->c.ops->ioctl(entry,
489                                                    data->file_private_data,
490                                                    file, cmd, arg);
491                 break;
492         }
493         return -ENOTTY;
494 }
495
496 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
497 {
498         struct inode *inode = file->f_path.dentry->d_inode;
499         struct snd_info_private_data *data;
500         struct snd_info_entry *entry;
501
502         data = file->private_data;
503         if (data == NULL)
504                 return 0;
505         entry = data->entry;
506         switch (entry->content) {
507         case SNDRV_INFO_CONTENT_DATA:
508                 if (entry->c.ops->mmap)
509                         return entry->c.ops->mmap(entry,
510                                                   data->file_private_data,
511                                                   inode, file, vma);
512                 break;
513         }
514         return -ENXIO;
515 }
516
517 static const struct file_operations snd_info_entry_operations =
518 {
519         .owner =                THIS_MODULE,
520         .llseek =               snd_info_entry_llseek,
521         .read =                 snd_info_entry_read,
522         .write =                snd_info_entry_write,
523         .poll =                 snd_info_entry_poll,
524         .unlocked_ioctl =       snd_info_entry_ioctl,
525         .mmap =                 snd_info_entry_mmap,
526         .open =                 snd_info_entry_open,
527         .release =              snd_info_entry_release,
528 };
529
530 int __init snd_info_init(void)
531 {
532         struct proc_dir_entry *p;
533
534         p = create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
535         if (p == NULL)
536                 return -ENOMEM;
537         snd_proc_root = p;
538 #ifdef CONFIG_SND_OSSEMUL
539         {
540                 struct snd_info_entry *entry;
541                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
542                         return -ENOMEM;
543                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
544                 if (snd_info_register(entry) < 0) {
545                         snd_info_free_entry(entry);
546                         return -ENOMEM;
547                 }
548                 snd_oss_root = entry;
549         }
550 #endif
551 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
552         {
553                 struct snd_info_entry *entry;
554                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
555                         return -ENOMEM;
556                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
557                 if (snd_info_register(entry) < 0) {
558                         snd_info_free_entry(entry);
559                         return -ENOMEM;
560                 }
561                 snd_seq_root = entry;
562         }
563 #endif
564         snd_info_version_init();
565         snd_minor_info_init();
566         snd_minor_info_oss_init();
567         snd_card_info_init();
568         return 0;
569 }
570
571 int __exit snd_info_done(void)
572 {
573         snd_card_info_done();
574         snd_minor_info_oss_done();
575         snd_minor_info_done();
576         snd_info_version_done();
577         if (snd_proc_root) {
578 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
579                 snd_info_free_entry(snd_seq_root);
580 #endif
581 #ifdef CONFIG_SND_OSSEMUL
582                 snd_info_free_entry(snd_oss_root);
583 #endif
584                 snd_remove_proc_entry(NULL, snd_proc_root);
585         }
586         return 0;
587 }
588
589 /*
590
591  */
592
593
594 /*
595  * create a card proc file
596  * called from init.c
597  */
598 int snd_info_card_create(struct snd_card *card)
599 {
600         char str[8];
601         struct snd_info_entry *entry;
602
603         if (snd_BUG_ON(!card))
604                 return -ENXIO;
605
606         sprintf(str, "card%i", card->number);
607         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
608                 return -ENOMEM;
609         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
610         if (snd_info_register(entry) < 0) {
611                 snd_info_free_entry(entry);
612                 return -ENOMEM;
613         }
614         card->proc_root = entry;
615         return 0;
616 }
617
618 /*
619  * register the card proc file
620  * called from init.c
621  */
622 int snd_info_card_register(struct snd_card *card)
623 {
624         struct proc_dir_entry *p;
625
626         if (snd_BUG_ON(!card))
627                 return -ENXIO;
628
629         if (!strcmp(card->id, card->proc_root->name))
630                 return 0;
631
632         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
633         if (p == NULL)
634                 return -ENOMEM;
635         card->proc_root_link = p;
636         return 0;
637 }
638
639 /*
640  * called on card->id change
641  */
642 void snd_info_card_id_change(struct snd_card *card)
643 {
644         mutex_lock(&info_mutex);
645         if (card->proc_root_link) {
646                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
647                 card->proc_root_link = NULL;
648         }
649         if (strcmp(card->id, card->proc_root->name))
650                 card->proc_root_link = proc_symlink(card->id,
651                                                     snd_proc_root,
652                                                     card->proc_root->name);
653         mutex_unlock(&info_mutex);
654 }
655
656 /*
657  * de-register the card proc file
658  * called from init.c
659  */
660 void snd_info_card_disconnect(struct snd_card *card)
661 {
662         if (!card)
663                 return;
664         mutex_lock(&info_mutex);
665         if (card->proc_root_link) {
666                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
667                 card->proc_root_link = NULL;
668         }
669         if (card->proc_root)
670                 snd_info_disconnect(card->proc_root);
671         mutex_unlock(&info_mutex);
672 }
673
674 /*
675  * release the card proc file resources
676  * called from init.c
677  */
678 int snd_info_card_free(struct snd_card *card)
679 {
680         if (!card)
681                 return 0;
682         snd_info_free_entry(card->proc_root);
683         card->proc_root = NULL;
684         return 0;
685 }
686
687
688 /**
689  * snd_info_get_line - read one line from the procfs buffer
690  * @buffer: the procfs buffer
691  * @line: the buffer to store
692  * @len: the max. buffer size - 1
693  *
694  * Reads one line from the buffer and stores the string.
695  *
696  * Returns zero if successful, or 1 if error or EOF.
697  */
698 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
699 {
700         int c = -1;
701
702         if (len <= 0 || buffer->stop || buffer->error)
703                 return 1;
704         while (--len > 0) {
705                 c = buffer->buffer[buffer->curr++];
706                 if (c == '\n') {
707                         if (buffer->curr >= buffer->size)
708                                 buffer->stop = 1;
709                         break;
710                 }
711                 *line++ = c;
712                 if (buffer->curr >= buffer->size) {
713                         buffer->stop = 1;
714                         break;
715                 }
716         }
717         while (c != '\n' && !buffer->stop) {
718                 c = buffer->buffer[buffer->curr++];
719                 if (buffer->curr >= buffer->size)
720                         buffer->stop = 1;
721         }
722         *line = '\0';
723         return 0;
724 }
725
726 EXPORT_SYMBOL(snd_info_get_line);
727
728 /**
729  * snd_info_get_str - parse a string token
730  * @dest: the buffer to store the string token
731  * @src: the original string
732  * @len: the max. length of token - 1
733  *
734  * Parses the original string and copy a token to the given
735  * string buffer.
736  *
737  * Returns the updated pointer of the original string so that
738  * it can be used for the next call.
739  */
740 const char *snd_info_get_str(char *dest, const char *src, int len)
741 {
742         int c;
743
744         while (*src == ' ' || *src == '\t')
745                 src++;
746         if (*src == '"' || *src == '\'') {
747                 c = *src++;
748                 while (--len > 0 && *src && *src != c) {
749                         *dest++ = *src++;
750                 }
751                 if (*src == c)
752                         src++;
753         } else {
754                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
755                         *dest++ = *src++;
756                 }
757         }
758         *dest = 0;
759         while (*src == ' ' || *src == '\t')
760                 src++;
761         return src;
762 }
763
764 EXPORT_SYMBOL(snd_info_get_str);
765
766 /**
767  * snd_info_create_entry - create an info entry
768  * @name: the proc file name
769  *
770  * Creates an info entry with the given file name and initializes as
771  * the default state.
772  *
773  * Usually called from other functions such as
774  * snd_info_create_card_entry().
775  *
776  * Returns the pointer of the new instance, or NULL on failure.
777  */
778 static struct snd_info_entry *snd_info_create_entry(const char *name)
779 {
780         struct snd_info_entry *entry;
781         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
782         if (entry == NULL)
783                 return NULL;
784         entry->name = kstrdup(name, GFP_KERNEL);
785         if (entry->name == NULL) {
786                 kfree(entry);
787                 return NULL;
788         }
789         entry->mode = S_IFREG | S_IRUGO;
790         entry->content = SNDRV_INFO_CONTENT_TEXT;
791         mutex_init(&entry->access);
792         INIT_LIST_HEAD(&entry->children);
793         INIT_LIST_HEAD(&entry->list);
794         return entry;
795 }
796
797 /**
798  * snd_info_create_module_entry - create an info entry for the given module
799  * @module: the module pointer
800  * @name: the file name
801  * @parent: the parent directory
802  *
803  * Creates a new info entry and assigns it to the given module.
804  *
805  * Returns the pointer of the new instance, or NULL on failure.
806  */
807 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
808                                                const char *name,
809                                                struct snd_info_entry *parent)
810 {
811         struct snd_info_entry *entry = snd_info_create_entry(name);
812         if (entry) {
813                 entry->module = module;
814                 entry->parent = parent;
815         }
816         return entry;
817 }
818
819 EXPORT_SYMBOL(snd_info_create_module_entry);
820
821 /**
822  * snd_info_create_card_entry - create an info entry for the given card
823  * @card: the card instance
824  * @name: the file name
825  * @parent: the parent directory
826  *
827  * Creates a new info entry and assigns it to the given card.
828  *
829  * Returns the pointer of the new instance, or NULL on failure.
830  */
831 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
832                                              const char *name,
833                                              struct snd_info_entry * parent)
834 {
835         struct snd_info_entry *entry = snd_info_create_entry(name);
836         if (entry) {
837                 entry->module = card->module;
838                 entry->card = card;
839                 entry->parent = parent;
840         }
841         return entry;
842 }
843
844 EXPORT_SYMBOL(snd_info_create_card_entry);
845
846 static void snd_info_disconnect(struct snd_info_entry *entry)
847 {
848         struct list_head *p, *n;
849         struct proc_dir_entry *root;
850
851         list_for_each_safe(p, n, &entry->children) {
852                 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
853         }
854
855         if (! entry->p)
856                 return;
857         list_del_init(&entry->list);
858         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
859         snd_BUG_ON(!root);
860         snd_remove_proc_entry(root, entry->p);
861         entry->p = NULL;
862 }
863
864 static int snd_info_dev_free_entry(struct snd_device *device)
865 {
866         struct snd_info_entry *entry = device->device_data;
867         snd_info_free_entry(entry);
868         return 0;
869 }
870
871 static int snd_info_dev_register_entry(struct snd_device *device)
872 {
873         struct snd_info_entry *entry = device->device_data;
874         return snd_info_register(entry);
875 }
876
877 /**
878  * snd_card_proc_new - create an info entry for the given card
879  * @card: the card instance
880  * @name: the file name
881  * @entryp: the pointer to store the new info entry
882  *
883  * Creates a new info entry and assigns it to the given card.
884  * Unlike snd_info_create_card_entry(), this function registers the
885  * info entry as an ALSA device component, so that it can be
886  * unregistered/released without explicit call.
887  * Also, you don't have to register this entry via snd_info_register(),
888  * since this will be registered by snd_card_register() automatically.
889  *
890  * The parent is assumed as card->proc_root.
891  *
892  * For releasing this entry, use snd_device_free() instead of
893  * snd_info_free_entry(). 
894  *
895  * Returns zero if successful, or a negative error code on failure.
896  */
897 int snd_card_proc_new(struct snd_card *card, const char *name,
898                       struct snd_info_entry **entryp)
899 {
900         static struct snd_device_ops ops = {
901                 .dev_free = snd_info_dev_free_entry,
902                 .dev_register = snd_info_dev_register_entry,
903                 /* disconnect is done via snd_info_card_disconnect() */
904         };
905         struct snd_info_entry *entry;
906         int err;
907
908         entry = snd_info_create_card_entry(card, name, card->proc_root);
909         if (! entry)
910                 return -ENOMEM;
911         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
912                 snd_info_free_entry(entry);
913                 return err;
914         }
915         if (entryp)
916                 *entryp = entry;
917         return 0;
918 }
919
920 EXPORT_SYMBOL(snd_card_proc_new);
921
922 /**
923  * snd_info_free_entry - release the info entry
924  * @entry: the info entry
925  *
926  * Releases the info entry.  Don't call this after registered.
927  */
928 void snd_info_free_entry(struct snd_info_entry * entry)
929 {
930         if (entry == NULL)
931                 return;
932         if (entry->p) {
933                 mutex_lock(&info_mutex);
934                 snd_info_disconnect(entry);
935                 mutex_unlock(&info_mutex);
936         }
937         kfree(entry->name);
938         if (entry->private_free)
939                 entry->private_free(entry);
940         kfree(entry);
941 }
942
943 EXPORT_SYMBOL(snd_info_free_entry);
944
945 /**
946  * snd_info_register - register the info entry
947  * @entry: the info entry
948  *
949  * Registers the proc info entry.
950  *
951  * Returns zero if successful, or a negative error code on failure.
952  */
953 int snd_info_register(struct snd_info_entry * entry)
954 {
955         struct proc_dir_entry *root, *p = NULL;
956
957         if (snd_BUG_ON(!entry))
958                 return -ENXIO;
959         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
960         mutex_lock(&info_mutex);
961         p = create_proc_entry(entry->name, entry->mode, root);
962         if (!p) {
963                 mutex_unlock(&info_mutex);
964                 return -ENOMEM;
965         }
966         if (!S_ISDIR(entry->mode))
967                 p->proc_fops = &snd_info_entry_operations;
968         p->size = entry->size;
969         p->data = entry;
970         entry->p = p;
971         if (entry->parent)
972                 list_add_tail(&entry->list, &entry->parent->children);
973         mutex_unlock(&info_mutex);
974         return 0;
975 }
976
977 EXPORT_SYMBOL(snd_info_register);
978
979 /*
980
981  */
982
983 static struct snd_info_entry *snd_info_version_entry;
984
985 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
986 {
987         snd_iprintf(buffer,
988                     "Advanced Linux Sound Architecture Driver Version "
989                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
990                    );
991 }
992
993 static int __init snd_info_version_init(void)
994 {
995         struct snd_info_entry *entry;
996
997         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
998         if (entry == NULL)
999                 return -ENOMEM;
1000         entry->c.text.read = snd_info_version_read;
1001         if (snd_info_register(entry) < 0) {
1002                 snd_info_free_entry(entry);
1003                 return -ENOMEM;
1004         }
1005         snd_info_version_entry = entry;
1006         return 0;
1007 }
1008
1009 static int __exit snd_info_version_done(void)
1010 {
1011         snd_info_free_entry(snd_info_version_entry);
1012         return 0;
1013 }
1014
1015 #endif /* CONFIG_PROC_FS */