[ALSA] Insert might_sleep() in snd_iprintf()
[linux-2.6.git] / sound / core / info.c
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/time.h>
25 #include <linux/smp_lock.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/devfs_fs_kernel.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
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 = kmalloc(nsize, GFP_KERNEL);
92         if (! nbuf)
93                 return -ENOMEM;
94
95         memcpy(nbuf, buffer->buffer, buffer->len);
96         kfree(buffer->buffer);
97         buffer->buffer = nbuf;
98         buffer->len = nsize;
99         return 0;
100 }
101
102 /**
103  * snd_iprintf - printf on the procfs buffer
104  * @buffer: the procfs buffer
105  * @fmt: the printf format
106  *
107  * Outputs the string on the procfs buffer just like printf().
108  *
109  * Returns the size of output string.
110  */
111 int snd_iprintf(struct snd_info_buffer *buffer, char *fmt,...)
112 {
113         va_list args;
114         int len, res;
115         int err = 0;
116
117         might_sleep();
118         if (buffer->stop || buffer->error)
119                 return 0;
120         len = buffer->len - buffer->size;
121         va_start(args, fmt);
122         for (;;) {
123                 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, args);
124                 if (res < len)
125                         break;
126                 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
127                 if (err < 0)
128                         break;
129                 len = buffer->len - buffer->size;
130         }
131         va_end(args);
132
133         if (err < 0)
134                 return err;
135         buffer->curr += res;
136         buffer->size += res;
137         return res;
138 }
139
140 EXPORT_SYMBOL(snd_iprintf);
141
142 /*
143
144  */
145
146 static struct proc_dir_entry *snd_proc_root = NULL;
147 struct snd_info_entry *snd_seq_root = NULL;
148 EXPORT_SYMBOL(snd_seq_root);
149
150 #ifdef CONFIG_SND_OSSEMUL
151 struct snd_info_entry *snd_oss_root = NULL;
152 #endif
153
154 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
155 {
156         de->owner = THIS_MODULE;
157 }
158
159 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
160                                   struct proc_dir_entry *de)
161 {
162         if (de)
163                 remove_proc_entry(de->name, parent);
164 }
165
166 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
167 {
168         struct snd_info_private_data *data;
169         struct snd_info_entry *entry;
170         loff_t ret;
171
172         data = file->private_data;
173         entry = data->entry;
174         lock_kernel();
175         switch (entry->content) {
176         case SNDRV_INFO_CONTENT_TEXT:
177                 switch (orig) {
178                 case 0: /* SEEK_SET */
179                         file->f_pos = offset;
180                         ret = file->f_pos;
181                         goto out;
182                 case 1: /* SEEK_CUR */
183                         file->f_pos += offset;
184                         ret = file->f_pos;
185                         goto out;
186                 case 2: /* SEEK_END */
187                 default:
188                         ret = -EINVAL;
189                         goto out;
190                 }
191                 break;
192         case SNDRV_INFO_CONTENT_DATA:
193                 if (entry->c.ops->llseek) {
194                         ret = entry->c.ops->llseek(entry,
195                                                     data->file_private_data,
196                                                     file, offset, orig);
197                         goto out;
198                 }
199                 break;
200         }
201         ret = -ENXIO;
202 out:
203         unlock_kernel();
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         snd_assert(data != NULL, return -ENXIO);
218         pos = *offset;
219         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
220                 return -EIO;
221         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
222                 return -EIO;
223         entry = data->entry;
224         switch (entry->content) {
225         case SNDRV_INFO_CONTENT_TEXT:
226                 buf = data->rbuffer;
227                 if (buf == NULL)
228                         return -EIO;
229                 if (pos >= buf->size)
230                         return 0;
231                 size = buf->size - pos;
232                 size = min(count, size);
233                 if (copy_to_user(buffer, buf->buffer + pos, size))
234                         return -EFAULT;
235                 break;
236         case SNDRV_INFO_CONTENT_DATA:
237                 if (entry->c.ops->read)
238                         size = entry->c.ops->read(entry,
239                                                   data->file_private_data,
240                                                   file, buffer, count, pos);
241                 break;
242         }
243         if ((ssize_t) size > 0)
244                 *offset = pos + size;
245         return size;
246 }
247
248 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
249                                     size_t count, loff_t * offset)
250 {
251         struct snd_info_private_data *data;
252         struct snd_info_entry *entry;
253         struct snd_info_buffer *buf;
254         ssize_t size = 0;
255         loff_t pos;
256
257         data = file->private_data;
258         snd_assert(data != NULL, return -ENXIO);
259         entry = data->entry;
260         pos = *offset;
261         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
262                 return -EIO;
263         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
264                 return -EIO;
265         switch (entry->content) {
266         case SNDRV_INFO_CONTENT_TEXT:
267                 buf = data->wbuffer;
268                 if (buf == NULL)
269                         return -EIO;
270                 mutex_unlock(&entry->access);
271                 if (pos + count >= buf->len) {
272                         if (resize_info_buffer(buf, pos + count)) {
273                                 mutex_unlock(&entry->access);
274                                 return -ENOMEM;
275                         }
276                 }
277                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
278                         mutex_unlock(&entry->access);
279                         return -EFAULT;
280                 }
281                 buf->size = pos + count;
282                 mutex_unlock(&entry->access);
283                 size = count;
284                 break;
285         case SNDRV_INFO_CONTENT_DATA:
286                 if (entry->c.ops->write)
287                         size = entry->c.ops->write(entry,
288                                                    data->file_private_data,
289                                                    file, buffer, count, pos);
290                 break;
291         }
292         if ((ssize_t) size > 0)
293                 *offset = pos + size;
294         return size;
295 }
296
297 static int snd_info_entry_open(struct inode *inode, struct file *file)
298 {
299         struct snd_info_entry *entry;
300         struct snd_info_private_data *data;
301         struct snd_info_buffer *buffer;
302         struct proc_dir_entry *p;
303         int mode, err;
304
305         mutex_lock(&info_mutex);
306         p = PDE(inode);
307         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
308         if (entry == NULL || entry->disconnected) {
309                 mutex_unlock(&info_mutex);
310                 return -ENODEV;
311         }
312         if (!try_module_get(entry->module)) {
313                 err = -EFAULT;
314                 goto __error1;
315         }
316         mode = file->f_flags & O_ACCMODE;
317         if (mode == O_RDONLY || mode == O_RDWR) {
318                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
319                      entry->c.ops->read == NULL)) {
320                         err = -ENODEV;
321                         goto __error;
322                 }
323         }
324         if (mode == O_WRONLY || mode == O_RDWR) {
325                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
326                      entry->c.ops->write == NULL)) {
327                         err = -ENODEV;
328                         goto __error;
329                 }
330         }
331         data = kzalloc(sizeof(*data), GFP_KERNEL);
332         if (data == NULL) {
333                 err = -ENOMEM;
334                 goto __error;
335         }
336         data->entry = entry;
337         switch (entry->content) {
338         case SNDRV_INFO_CONTENT_TEXT:
339                 if (mode == O_RDONLY || mode == O_RDWR) {
340                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
341                         if (buffer == NULL)
342                                 goto __nomem;
343                         data->rbuffer = buffer;
344                         buffer->len = PAGE_SIZE;
345                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
346                         if (buffer->buffer == NULL)
347                                 goto __nomem;
348                 }
349                 if (mode == O_WRONLY || mode == O_RDWR) {
350                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
351                         if (buffer == NULL)
352                                 goto __nomem;
353                         data->wbuffer = buffer;
354                         buffer->len = PAGE_SIZE;
355                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
356                         if (buffer->buffer == NULL)
357                                 goto __nomem;
358                 }
359                 break;
360         case SNDRV_INFO_CONTENT_DATA:   /* data */
361                 if (entry->c.ops->open) {
362                         if ((err = entry->c.ops->open(entry, mode,
363                                                       &data->file_private_data)) < 0) {
364                                 kfree(data);
365                                 goto __error;
366                         }
367                 }
368                 break;
369         }
370         file->private_data = data;
371         mutex_unlock(&info_mutex);
372         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
373             (mode == O_RDONLY || mode == O_RDWR)) {
374                 if (entry->c.text.read) {
375                         mutex_lock(&entry->access);
376                         entry->c.text.read(entry, data->rbuffer);
377                         mutex_unlock(&entry->access);
378                 }
379         }
380         return 0;
381
382  __nomem:
383         if (data->rbuffer) {
384                 kfree(data->rbuffer->buffer);
385                 kfree(data->rbuffer);
386         }
387         if (data->wbuffer) {
388                 kfree(data->wbuffer->buffer);
389                 kfree(data->wbuffer);
390         }
391         kfree(data);
392         err = -ENOMEM;
393       __error:
394         module_put(entry->module);
395       __error1:
396         mutex_unlock(&info_mutex);
397         return err;
398 }
399
400 static int snd_info_entry_release(struct inode *inode, struct file *file)
401 {
402         struct snd_info_entry *entry;
403         struct snd_info_private_data *data;
404         int mode;
405
406         mode = file->f_flags & O_ACCMODE;
407         data = file->private_data;
408         entry = data->entry;
409         switch (entry->content) {
410         case SNDRV_INFO_CONTENT_TEXT:
411                 if (data->rbuffer) {
412                         kfree(data->rbuffer->buffer);
413                         kfree(data->rbuffer);
414                 }
415                 if (data->wbuffer) {
416                         if (entry->c.text.write) {
417                                 entry->c.text.write(entry, data->wbuffer);
418                                 if (data->wbuffer->error) {
419                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
420                                                 entry->name,
421                                                 data->wbuffer->error);
422                                 }
423                         }
424                         kfree(data->wbuffer->buffer);
425                         kfree(data->wbuffer);
426                 }
427                 break;
428         case SNDRV_INFO_CONTENT_DATA:
429                 if (entry->c.ops->release)
430                         entry->c.ops->release(entry, mode,
431                                               data->file_private_data);
432                 break;
433         }
434         module_put(entry->module);
435         kfree(data);
436         return 0;
437 }
438
439 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
440 {
441         struct snd_info_private_data *data;
442         struct snd_info_entry *entry;
443         unsigned int mask;
444
445         data = file->private_data;
446         if (data == NULL)
447                 return 0;
448         entry = data->entry;
449         mask = 0;
450         switch (entry->content) {
451         case SNDRV_INFO_CONTENT_DATA:
452                 if (entry->c.ops->poll)
453                         return entry->c.ops->poll(entry,
454                                                   data->file_private_data,
455                                                   file, wait);
456                 if (entry->c.ops->read)
457                         mask |= POLLIN | POLLRDNORM;
458                 if (entry->c.ops->write)
459                         mask |= POLLOUT | POLLWRNORM;
460                 break;
461         }
462         return mask;
463 }
464
465 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
466                                 unsigned long arg)
467 {
468         struct snd_info_private_data *data;
469         struct snd_info_entry *entry;
470
471         data = file->private_data;
472         if (data == NULL)
473                 return 0;
474         entry = data->entry;
475         switch (entry->content) {
476         case SNDRV_INFO_CONTENT_DATA:
477                 if (entry->c.ops->ioctl)
478                         return entry->c.ops->ioctl(entry,
479                                                    data->file_private_data,
480                                                    file, cmd, arg);
481                 break;
482         }
483         return -ENOTTY;
484 }
485
486 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
487 {
488         struct inode *inode = file->f_dentry->d_inode;
489         struct snd_info_private_data *data;
490         struct snd_info_entry *entry;
491
492         data = file->private_data;
493         if (data == NULL)
494                 return 0;
495         entry = data->entry;
496         switch (entry->content) {
497         case SNDRV_INFO_CONTENT_DATA:
498                 if (entry->c.ops->mmap)
499                         return entry->c.ops->mmap(entry,
500                                                   data->file_private_data,
501                                                   inode, file, vma);
502                 break;
503         }
504         return -ENXIO;
505 }
506
507 static struct file_operations snd_info_entry_operations =
508 {
509         .owner =                THIS_MODULE,
510         .llseek =               snd_info_entry_llseek,
511         .read =                 snd_info_entry_read,
512         .write =                snd_info_entry_write,
513         .poll =                 snd_info_entry_poll,
514         .unlocked_ioctl =       snd_info_entry_ioctl,
515         .mmap =                 snd_info_entry_mmap,
516         .open =                 snd_info_entry_open,
517         .release =              snd_info_entry_release,
518 };
519
520 /**
521  * snd_create_proc_entry - create a procfs entry
522  * @name: the name of the proc file
523  * @mode: the file permission bits, S_Ixxx
524  * @parent: the parent proc-directory entry
525  *
526  * Creates a new proc file entry with the given name and permission
527  * on the given directory.
528  *
529  * Returns the pointer of new instance or NULL on failure.
530  */
531 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
532                                                     struct proc_dir_entry *parent)
533 {
534         struct proc_dir_entry *p;
535         p = create_proc_entry(name, mode, parent);
536         if (p)
537                 snd_info_entry_prepare(p);
538         return p;
539 }
540
541 int __init snd_info_init(void)
542 {
543         struct proc_dir_entry *p;
544
545         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, &proc_root);
546         if (p == NULL)
547                 return -ENOMEM;
548         snd_proc_root = p;
549 #ifdef CONFIG_SND_OSSEMUL
550         {
551                 struct snd_info_entry *entry;
552                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
553                         return -ENOMEM;
554                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
555                 if (snd_info_register(entry) < 0) {
556                         snd_info_free_entry(entry);
557                         return -ENOMEM;
558                 }
559                 snd_oss_root = entry;
560         }
561 #endif
562 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
563         {
564                 struct snd_info_entry *entry;
565                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
566                         return -ENOMEM;
567                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
568                 if (snd_info_register(entry) < 0) {
569                         snd_info_free_entry(entry);
570                         return -ENOMEM;
571                 }
572                 snd_seq_root = entry;
573         }
574 #endif
575         snd_info_version_init();
576         snd_minor_info_init();
577         snd_minor_info_oss_init();
578         snd_card_info_init();
579         return 0;
580 }
581
582 int __exit snd_info_done(void)
583 {
584         snd_card_info_done();
585         snd_minor_info_oss_done();
586         snd_minor_info_done();
587         snd_info_version_done();
588         if (snd_proc_root) {
589 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
590                 snd_info_unregister(snd_seq_root);
591 #endif
592 #ifdef CONFIG_SND_OSSEMUL
593                 snd_info_unregister(snd_oss_root);
594 #endif
595                 snd_remove_proc_entry(&proc_root, snd_proc_root);
596         }
597         return 0;
598 }
599
600 /*
601
602  */
603
604
605 /*
606  * create a card proc file
607  * called from init.c
608  */
609 int snd_info_card_create(struct snd_card *card)
610 {
611         char str[8];
612         struct snd_info_entry *entry;
613
614         snd_assert(card != NULL, return -ENXIO);
615
616         sprintf(str, "card%i", card->number);
617         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
618                 return -ENOMEM;
619         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
620         if (snd_info_register(entry) < 0) {
621                 snd_info_free_entry(entry);
622                 return -ENOMEM;
623         }
624         card->proc_root = entry;
625         return 0;
626 }
627
628 /*
629  * register the card proc file
630  * called from init.c
631  */
632 int snd_info_card_register(struct snd_card *card)
633 {
634         struct proc_dir_entry *p;
635
636         snd_assert(card != NULL, return -ENXIO);
637
638         if (!strcmp(card->id, card->proc_root->name))
639                 return 0;
640
641         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
642         if (p == NULL)
643                 return -ENOMEM;
644         card->proc_root_link = p;
645         return 0;
646 }
647
648 /*
649  * de-register the card proc file
650  * called from init.c
651  */
652 int snd_info_card_free(struct snd_card *card)
653 {
654         snd_assert(card != NULL, return -ENXIO);
655         if (card->proc_root_link) {
656                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
657                 card->proc_root_link = NULL;
658         }
659         if (card->proc_root) {
660                 snd_info_unregister(card->proc_root);
661                 card->proc_root = NULL;
662         }
663         return 0;
664 }
665
666
667 /**
668  * snd_info_get_line - read one line from the procfs buffer
669  * @buffer: the procfs buffer
670  * @line: the buffer to store
671  * @len: the max. buffer size - 1
672  *
673  * Reads one line from the buffer and stores the string.
674  *
675  * Returns zero if successful, or 1 if error or EOF.
676  */
677 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
678 {
679         int c = -1;
680
681         if (len <= 0 || buffer->stop || buffer->error)
682                 return 1;
683         while (--len > 0) {
684                 c = buffer->buffer[buffer->curr++];
685                 if (c == '\n') {
686                         if (buffer->curr >= buffer->size)
687                                 buffer->stop = 1;
688                         break;
689                 }
690                 *line++ = c;
691                 if (buffer->curr >= buffer->size) {
692                         buffer->stop = 1;
693                         break;
694                 }
695         }
696         while (c != '\n' && !buffer->stop) {
697                 c = buffer->buffer[buffer->curr++];
698                 if (buffer->curr >= buffer->size)
699                         buffer->stop = 1;
700         }
701         *line = '\0';
702         return 0;
703 }
704
705 EXPORT_SYMBOL(snd_info_get_line);
706
707 /**
708  * snd_info_get_str - parse a string token
709  * @dest: the buffer to store the string token
710  * @src: the original string
711  * @len: the max. length of token - 1
712  *
713  * Parses the original string and copy a token to the given
714  * string buffer.
715  *
716  * Returns the updated pointer of the original string so that
717  * it can be used for the next call.
718  */
719 char *snd_info_get_str(char *dest, char *src, int len)
720 {
721         int c;
722
723         while (*src == ' ' || *src == '\t')
724                 src++;
725         if (*src == '"' || *src == '\'') {
726                 c = *src++;
727                 while (--len > 0 && *src && *src != c) {
728                         *dest++ = *src++;
729                 }
730                 if (*src == c)
731                         src++;
732         } else {
733                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
734                         *dest++ = *src++;
735                 }
736         }
737         *dest = 0;
738         while (*src == ' ' || *src == '\t')
739                 src++;
740         return src;
741 }
742
743 EXPORT_SYMBOL(snd_info_get_str);
744
745 /**
746  * snd_info_create_entry - create an info entry
747  * @name: the proc file name
748  *
749  * Creates an info entry with the given file name and initializes as
750  * the default state.
751  *
752  * Usually called from other functions such as
753  * snd_info_create_card_entry().
754  *
755  * Returns the pointer of the new instance, or NULL on failure.
756  */
757 static struct snd_info_entry *snd_info_create_entry(const char *name)
758 {
759         struct snd_info_entry *entry;
760         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
761         if (entry == NULL)
762                 return NULL;
763         entry->name = kstrdup(name, GFP_KERNEL);
764         if (entry->name == NULL) {
765                 kfree(entry);
766                 return NULL;
767         }
768         entry->mode = S_IFREG | S_IRUGO;
769         entry->content = SNDRV_INFO_CONTENT_TEXT;
770         mutex_init(&entry->access);
771         return entry;
772 }
773
774 /**
775  * snd_info_create_module_entry - create an info entry for the given module
776  * @module: the module pointer
777  * @name: the file name
778  * @parent: the parent directory
779  *
780  * Creates a new info entry and assigns it to the given module.
781  *
782  * Returns the pointer of the new instance, or NULL on failure.
783  */
784 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
785                                                const char *name,
786                                                struct snd_info_entry *parent)
787 {
788         struct snd_info_entry *entry = snd_info_create_entry(name);
789         if (entry) {
790                 entry->module = module;
791                 entry->parent = parent;
792         }
793         return entry;
794 }
795
796 EXPORT_SYMBOL(snd_info_create_module_entry);
797
798 /**
799  * snd_info_create_card_entry - create an info entry for the given card
800  * @card: the card instance
801  * @name: the file name
802  * @parent: the parent directory
803  *
804  * Creates a new info entry and assigns it to the given card.
805  *
806  * Returns the pointer of the new instance, or NULL on failure.
807  */
808 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
809                                              const char *name,
810                                              struct snd_info_entry * parent)
811 {
812         struct snd_info_entry *entry = snd_info_create_entry(name);
813         if (entry) {
814                 entry->module = card->module;
815                 entry->card = card;
816                 entry->parent = parent;
817         }
818         return entry;
819 }
820
821 EXPORT_SYMBOL(snd_info_create_card_entry);
822
823 static int snd_info_dev_free_entry(struct snd_device *device)
824 {
825         struct snd_info_entry *entry = device->device_data;
826         snd_info_free_entry(entry);
827         return 0;
828 }
829
830 static int snd_info_dev_register_entry(struct snd_device *device)
831 {
832         struct snd_info_entry *entry = device->device_data;
833         return snd_info_register(entry);
834 }
835
836 static int snd_info_dev_disconnect_entry(struct snd_device *device)
837 {
838         struct snd_info_entry *entry = device->device_data;
839         entry->disconnected = 1;
840         return 0;
841 }
842
843 static int snd_info_dev_unregister_entry(struct snd_device *device)
844 {
845         struct snd_info_entry *entry = device->device_data;
846         return snd_info_unregister(entry);
847 }
848
849 /**
850  * snd_card_proc_new - create an info entry for the given card
851  * @card: the card instance
852  * @name: the file name
853  * @entryp: the pointer to store the new info entry
854  *
855  * Creates a new info entry and assigns it to the given card.
856  * Unlike snd_info_create_card_entry(), this function registers the
857  * info entry as an ALSA device component, so that it can be
858  * unregistered/released without explicit call.
859  * Also, you don't have to register this entry via snd_info_register(),
860  * since this will be registered by snd_card_register() automatically.
861  *
862  * The parent is assumed as card->proc_root.
863  *
864  * For releasing this entry, use snd_device_free() instead of
865  * snd_info_free_entry(). 
866  *
867  * Returns zero if successful, or a negative error code on failure.
868  */
869 int snd_card_proc_new(struct snd_card *card, const char *name,
870                       struct snd_info_entry **entryp)
871 {
872         static struct snd_device_ops ops = {
873                 .dev_free = snd_info_dev_free_entry,
874                 .dev_register = snd_info_dev_register_entry,
875                 .dev_disconnect = snd_info_dev_disconnect_entry,
876                 .dev_unregister = snd_info_dev_unregister_entry
877         };
878         struct snd_info_entry *entry;
879         int err;
880
881         entry = snd_info_create_card_entry(card, name, card->proc_root);
882         if (! entry)
883                 return -ENOMEM;
884         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
885                 snd_info_free_entry(entry);
886                 return err;
887         }
888         if (entryp)
889                 *entryp = entry;
890         return 0;
891 }
892
893 EXPORT_SYMBOL(snd_card_proc_new);
894
895 /**
896  * snd_info_free_entry - release the info entry
897  * @entry: the info entry
898  *
899  * Releases the info entry.  Don't call this after registered.
900  */
901 void snd_info_free_entry(struct snd_info_entry * entry)
902 {
903         if (entry == NULL)
904                 return;
905         kfree(entry->name);
906         if (entry->private_free)
907                 entry->private_free(entry);
908         kfree(entry);
909 }
910
911 EXPORT_SYMBOL(snd_info_free_entry);
912
913 /**
914  * snd_info_register - register the info entry
915  * @entry: the info entry
916  *
917  * Registers the proc info entry.
918  *
919  * Returns zero if successful, or a negative error code on failure.
920  */
921 int snd_info_register(struct snd_info_entry * entry)
922 {
923         struct proc_dir_entry *root, *p = NULL;
924
925         snd_assert(entry != NULL, return -ENXIO);
926         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
927         mutex_lock(&info_mutex);
928         p = snd_create_proc_entry(entry->name, entry->mode, root);
929         if (!p) {
930                 mutex_unlock(&info_mutex);
931                 return -ENOMEM;
932         }
933         p->owner = entry->module;
934         if (!S_ISDIR(entry->mode))
935                 p->proc_fops = &snd_info_entry_operations;
936         p->size = entry->size;
937         p->data = entry;
938         entry->p = p;
939         mutex_unlock(&info_mutex);
940         return 0;
941 }
942
943 EXPORT_SYMBOL(snd_info_register);
944
945 /**
946  * snd_info_unregister - de-register the info entry
947  * @entry: the info entry
948  *
949  * De-registers the info entry and releases the instance.
950  *
951  * Returns zero if successful, or a negative error code on failure.
952  */
953 int snd_info_unregister(struct snd_info_entry * entry)
954 {
955         struct proc_dir_entry *root;
956
957         if (! entry)
958                 return 0;
959         snd_assert(entry->p != NULL, return -ENXIO);
960         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
961         snd_assert(root, return -ENXIO);
962         mutex_lock(&info_mutex);
963         snd_remove_proc_entry(root, entry->p);
964         mutex_unlock(&info_mutex);
965         snd_info_free_entry(entry);
966         return 0;
967 }
968
969 EXPORT_SYMBOL(snd_info_unregister);
970
971 /*
972
973  */
974
975 static struct snd_info_entry *snd_info_version_entry = NULL;
976
977 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
978 {
979         snd_iprintf(buffer,
980                     "Advanced Linux Sound Architecture Driver Version "
981                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
982                    );
983 }
984
985 static int __init snd_info_version_init(void)
986 {
987         struct snd_info_entry *entry;
988
989         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
990         if (entry == NULL)
991                 return -ENOMEM;
992         entry->c.text.read = snd_info_version_read;
993         if (snd_info_register(entry) < 0) {
994                 snd_info_free_entry(entry);
995                 return -ENOMEM;
996         }
997         snd_info_version_entry = entry;
998         return 0;
999 }
1000
1001 static int __exit snd_info_version_done(void)
1002 {
1003         if (snd_info_version_entry)
1004                 snd_info_unregister(snd_info_version_entry);
1005         return 0;
1006 }
1007
1008 #endif /* CONFIG_PROC_FS */