ALSA: when card identification is changed, change also /proc/asound symlink
[linux-2.6.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/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/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 = 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                 va_list ap;
124                 va_copy(ap, args);
125                 res = vsnprintf(buffer->buffer + buffer->curr, len, fmt, ap);
126                 va_end(ap);
127                 if (res < len)
128                         break;
129                 err = resize_info_buffer(buffer, buffer->len + PAGE_SIZE);
130                 if (err < 0)
131                         break;
132                 len = buffer->len - buffer->size;
133         }
134         va_end(args);
135
136         if (err < 0)
137                 return err;
138         buffer->curr += res;
139         buffer->size += res;
140         return res;
141 }
142
143 EXPORT_SYMBOL(snd_iprintf);
144
145 /*
146
147  */
148
149 static struct proc_dir_entry *snd_proc_root;
150 struct snd_info_entry *snd_seq_root;
151 EXPORT_SYMBOL(snd_seq_root);
152
153 #ifdef CONFIG_SND_OSSEMUL
154 struct snd_info_entry *snd_oss_root;
155 #endif
156
157 static inline void snd_info_entry_prepare(struct proc_dir_entry *de)
158 {
159         de->owner = THIS_MODULE;
160 }
161
162 static void snd_remove_proc_entry(struct proc_dir_entry *parent,
163                                   struct proc_dir_entry *de)
164 {
165         if (de)
166                 remove_proc_entry(de->name, parent);
167 }
168
169 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
170 {
171         struct snd_info_private_data *data;
172         struct snd_info_entry *entry;
173         loff_t ret;
174
175         data = file->private_data;
176         entry = data->entry;
177         lock_kernel();
178         switch (entry->content) {
179         case SNDRV_INFO_CONTENT_TEXT:
180                 switch (orig) {
181                 case SEEK_SET:
182                         file->f_pos = offset;
183                         ret = file->f_pos;
184                         goto out;
185                 case SEEK_CUR:
186                         file->f_pos += offset;
187                         ret = file->f_pos;
188                         goto out;
189                 case SEEK_END:
190                 default:
191                         ret = -EINVAL;
192                         goto out;
193                 }
194                 break;
195         case SNDRV_INFO_CONTENT_DATA:
196                 if (entry->c.ops->llseek) {
197                         ret = entry->c.ops->llseek(entry,
198                                                     data->file_private_data,
199                                                     file, offset, orig);
200                         goto out;
201                 }
202                 break;
203         }
204         ret = -ENXIO;
205 out:
206         unlock_kernel();
207         return ret;
208 }
209
210 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
211                                    size_t count, loff_t * offset)
212 {
213         struct snd_info_private_data *data;
214         struct snd_info_entry *entry;
215         struct snd_info_buffer *buf;
216         size_t size = 0;
217         loff_t pos;
218
219         data = file->private_data;
220         if (snd_BUG_ON(!data))
221                 return -ENXIO;
222         pos = *offset;
223         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
224                 return -EIO;
225         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
226                 return -EIO;
227         entry = data->entry;
228         switch (entry->content) {
229         case SNDRV_INFO_CONTENT_TEXT:
230                 buf = data->rbuffer;
231                 if (buf == NULL)
232                         return -EIO;
233                 if (pos >= buf->size)
234                         return 0;
235                 size = buf->size - pos;
236                 size = min(count, size);
237                 if (copy_to_user(buffer, buf->buffer + pos, size))
238                         return -EFAULT;
239                 break;
240         case SNDRV_INFO_CONTENT_DATA:
241                 if (entry->c.ops->read)
242                         size = entry->c.ops->read(entry,
243                                                   data->file_private_data,
244                                                   file, buffer, count, pos);
245                 break;
246         }
247         if ((ssize_t) size > 0)
248                 *offset = pos + size;
249         return size;
250 }
251
252 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
253                                     size_t count, loff_t * offset)
254 {
255         struct snd_info_private_data *data;
256         struct snd_info_entry *entry;
257         struct snd_info_buffer *buf;
258         ssize_t size = 0;
259         loff_t pos;
260
261         data = file->private_data;
262         if (snd_BUG_ON(!data))
263                 return -ENXIO;
264         entry = data->entry;
265         pos = *offset;
266         if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
267                 return -EIO;
268         if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
269                 return -EIO;
270         switch (entry->content) {
271         case SNDRV_INFO_CONTENT_TEXT:
272                 buf = data->wbuffer;
273                 if (buf == NULL)
274                         return -EIO;
275                 mutex_lock(&entry->access);
276                 if (pos + count >= buf->len) {
277                         if (resize_info_buffer(buf, pos + count)) {
278                                 mutex_unlock(&entry->access);
279                                 return -ENOMEM;
280                         }
281                 }
282                 if (copy_from_user(buf->buffer + pos, buffer, count)) {
283                         mutex_unlock(&entry->access);
284                         return -EFAULT;
285                 }
286                 buf->size = pos + count;
287                 mutex_unlock(&entry->access);
288                 size = count;
289                 break;
290         case SNDRV_INFO_CONTENT_DATA:
291                 if (entry->c.ops->write)
292                         size = entry->c.ops->write(entry,
293                                                    data->file_private_data,
294                                                    file, buffer, count, pos);
295                 break;
296         }
297         if ((ssize_t) size > 0)
298                 *offset = pos + size;
299         return size;
300 }
301
302 static int snd_info_entry_open(struct inode *inode, struct file *file)
303 {
304         struct snd_info_entry *entry;
305         struct snd_info_private_data *data;
306         struct snd_info_buffer *buffer;
307         struct proc_dir_entry *p;
308         int mode, err;
309
310         mutex_lock(&info_mutex);
311         p = PDE(inode);
312         entry = p == NULL ? NULL : (struct snd_info_entry *)p->data;
313         if (entry == NULL || ! entry->p) {
314                 mutex_unlock(&info_mutex);
315                 return -ENODEV;
316         }
317         if (!try_module_get(entry->module)) {
318                 err = -EFAULT;
319                 goto __error1;
320         }
321         mode = file->f_flags & O_ACCMODE;
322         if (mode == O_RDONLY || mode == O_RDWR) {
323                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
324                      entry->c.ops->read == NULL)) {
325                         err = -ENODEV;
326                         goto __error;
327                 }
328         }
329         if (mode == O_WRONLY || mode == O_RDWR) {
330                 if ((entry->content == SNDRV_INFO_CONTENT_DATA &&
331                      entry->c.ops->write == NULL)) {
332                         err = -ENODEV;
333                         goto __error;
334                 }
335         }
336         data = kzalloc(sizeof(*data), GFP_KERNEL);
337         if (data == NULL) {
338                 err = -ENOMEM;
339                 goto __error;
340         }
341         data->entry = entry;
342         switch (entry->content) {
343         case SNDRV_INFO_CONTENT_TEXT:
344                 if (mode == O_RDONLY || mode == O_RDWR) {
345                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
346                         if (buffer == NULL)
347                                 goto __nomem;
348                         data->rbuffer = buffer;
349                         buffer->len = PAGE_SIZE;
350                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
351                         if (buffer->buffer == NULL)
352                                 goto __nomem;
353                 }
354                 if (mode == O_WRONLY || mode == O_RDWR) {
355                         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
356                         if (buffer == NULL)
357                                 goto __nomem;
358                         data->wbuffer = buffer;
359                         buffer->len = PAGE_SIZE;
360                         buffer->buffer = kmalloc(buffer->len, GFP_KERNEL);
361                         if (buffer->buffer == NULL)
362                                 goto __nomem;
363                 }
364                 break;
365         case SNDRV_INFO_CONTENT_DATA:   /* data */
366                 if (entry->c.ops->open) {
367                         if ((err = entry->c.ops->open(entry, mode,
368                                                       &data->file_private_data)) < 0) {
369                                 kfree(data);
370                                 goto __error;
371                         }
372                 }
373                 break;
374         }
375         file->private_data = data;
376         mutex_unlock(&info_mutex);
377         if (entry->content == SNDRV_INFO_CONTENT_TEXT &&
378             (mode == O_RDONLY || mode == O_RDWR)) {
379                 if (entry->c.text.read) {
380                         mutex_lock(&entry->access);
381                         entry->c.text.read(entry, data->rbuffer);
382                         mutex_unlock(&entry->access);
383                 }
384         }
385         return 0;
386
387  __nomem:
388         if (data->rbuffer) {
389                 kfree(data->rbuffer->buffer);
390                 kfree(data->rbuffer);
391         }
392         if (data->wbuffer) {
393                 kfree(data->wbuffer->buffer);
394                 kfree(data->wbuffer);
395         }
396         kfree(data);
397         err = -ENOMEM;
398       __error:
399         module_put(entry->module);
400       __error1:
401         mutex_unlock(&info_mutex);
402         return err;
403 }
404
405 static int snd_info_entry_release(struct inode *inode, struct file *file)
406 {
407         struct snd_info_entry *entry;
408         struct snd_info_private_data *data;
409         int mode;
410
411         mode = file->f_flags & O_ACCMODE;
412         data = file->private_data;
413         entry = data->entry;
414         switch (entry->content) {
415         case SNDRV_INFO_CONTENT_TEXT:
416                 if (data->rbuffer) {
417                         kfree(data->rbuffer->buffer);
418                         kfree(data->rbuffer);
419                 }
420                 if (data->wbuffer) {
421                         if (entry->c.text.write) {
422                                 entry->c.text.write(entry, data->wbuffer);
423                                 if (data->wbuffer->error) {
424                                         snd_printk(KERN_WARNING "data write error to %s (%i)\n",
425                                                 entry->name,
426                                                 data->wbuffer->error);
427                                 }
428                         }
429                         kfree(data->wbuffer->buffer);
430                         kfree(data->wbuffer);
431                 }
432                 break;
433         case SNDRV_INFO_CONTENT_DATA:
434                 if (entry->c.ops->release)
435                         entry->c.ops->release(entry, mode,
436                                               data->file_private_data);
437                 break;
438         }
439         module_put(entry->module);
440         kfree(data);
441         return 0;
442 }
443
444 static unsigned int snd_info_entry_poll(struct file *file, poll_table * wait)
445 {
446         struct snd_info_private_data *data;
447         struct snd_info_entry *entry;
448         unsigned int mask;
449
450         data = file->private_data;
451         if (data == NULL)
452                 return 0;
453         entry = data->entry;
454         mask = 0;
455         switch (entry->content) {
456         case SNDRV_INFO_CONTENT_DATA:
457                 if (entry->c.ops->poll)
458                         return entry->c.ops->poll(entry,
459                                                   data->file_private_data,
460                                                   file, wait);
461                 if (entry->c.ops->read)
462                         mask |= POLLIN | POLLRDNORM;
463                 if (entry->c.ops->write)
464                         mask |= POLLOUT | POLLWRNORM;
465                 break;
466         }
467         return mask;
468 }
469
470 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
471                                 unsigned long arg)
472 {
473         struct snd_info_private_data *data;
474         struct snd_info_entry *entry;
475
476         data = file->private_data;
477         if (data == NULL)
478                 return 0;
479         entry = data->entry;
480         switch (entry->content) {
481         case SNDRV_INFO_CONTENT_DATA:
482                 if (entry->c.ops->ioctl)
483                         return entry->c.ops->ioctl(entry,
484                                                    data->file_private_data,
485                                                    file, cmd, arg);
486                 break;
487         }
488         return -ENOTTY;
489 }
490
491 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
492 {
493         struct inode *inode = file->f_path.dentry->d_inode;
494         struct snd_info_private_data *data;
495         struct snd_info_entry *entry;
496
497         data = file->private_data;
498         if (data == NULL)
499                 return 0;
500         entry = data->entry;
501         switch (entry->content) {
502         case SNDRV_INFO_CONTENT_DATA:
503                 if (entry->c.ops->mmap)
504                         return entry->c.ops->mmap(entry,
505                                                   data->file_private_data,
506                                                   inode, file, vma);
507                 break;
508         }
509         return -ENXIO;
510 }
511
512 static const struct file_operations snd_info_entry_operations =
513 {
514         .owner =                THIS_MODULE,
515         .llseek =               snd_info_entry_llseek,
516         .read =                 snd_info_entry_read,
517         .write =                snd_info_entry_write,
518         .poll =                 snd_info_entry_poll,
519         .unlocked_ioctl =       snd_info_entry_ioctl,
520         .mmap =                 snd_info_entry_mmap,
521         .open =                 snd_info_entry_open,
522         .release =              snd_info_entry_release,
523 };
524
525 /**
526  * snd_create_proc_entry - create a procfs entry
527  * @name: the name of the proc file
528  * @mode: the file permission bits, S_Ixxx
529  * @parent: the parent proc-directory entry
530  *
531  * Creates a new proc file entry with the given name and permission
532  * on the given directory.
533  *
534  * Returns the pointer of new instance or NULL on failure.
535  */
536 static struct proc_dir_entry *snd_create_proc_entry(const char *name, mode_t mode,
537                                                     struct proc_dir_entry *parent)
538 {
539         struct proc_dir_entry *p;
540         p = create_proc_entry(name, mode, parent);
541         if (p)
542                 snd_info_entry_prepare(p);
543         return p;
544 }
545
546 int __init snd_info_init(void)
547 {
548         struct proc_dir_entry *p;
549
550         p = snd_create_proc_entry("asound", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
551         if (p == NULL)
552                 return -ENOMEM;
553         snd_proc_root = p;
554 #ifdef CONFIG_SND_OSSEMUL
555         {
556                 struct snd_info_entry *entry;
557                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "oss", NULL)) == NULL)
558                         return -ENOMEM;
559                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
560                 if (snd_info_register(entry) < 0) {
561                         snd_info_free_entry(entry);
562                         return -ENOMEM;
563                 }
564                 snd_oss_root = entry;
565         }
566 #endif
567 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
568         {
569                 struct snd_info_entry *entry;
570                 if ((entry = snd_info_create_module_entry(THIS_MODULE, "seq", NULL)) == NULL)
571                         return -ENOMEM;
572                 entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
573                 if (snd_info_register(entry) < 0) {
574                         snd_info_free_entry(entry);
575                         return -ENOMEM;
576                 }
577                 snd_seq_root = entry;
578         }
579 #endif
580         snd_info_version_init();
581         snd_minor_info_init();
582         snd_minor_info_oss_init();
583         snd_card_info_init();
584         return 0;
585 }
586
587 int __exit snd_info_done(void)
588 {
589         snd_card_info_done();
590         snd_minor_info_oss_done();
591         snd_minor_info_done();
592         snd_info_version_done();
593         if (snd_proc_root) {
594 #if defined(CONFIG_SND_SEQUENCER) || defined(CONFIG_SND_SEQUENCER_MODULE)
595                 snd_info_free_entry(snd_seq_root);
596 #endif
597 #ifdef CONFIG_SND_OSSEMUL
598                 snd_info_free_entry(snd_oss_root);
599 #endif
600                 snd_remove_proc_entry(NULL, snd_proc_root);
601         }
602         return 0;
603 }
604
605 /*
606
607  */
608
609
610 /*
611  * create a card proc file
612  * called from init.c
613  */
614 int snd_info_card_create(struct snd_card *card)
615 {
616         char str[8];
617         struct snd_info_entry *entry;
618
619         if (snd_BUG_ON(!card))
620                 return -ENXIO;
621
622         sprintf(str, "card%i", card->number);
623         if ((entry = snd_info_create_module_entry(card->module, str, NULL)) == NULL)
624                 return -ENOMEM;
625         entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
626         if (snd_info_register(entry) < 0) {
627                 snd_info_free_entry(entry);
628                 return -ENOMEM;
629         }
630         card->proc_root = entry;
631         return 0;
632 }
633
634 /*
635  * register the card proc file
636  * called from init.c
637  */
638 int snd_info_card_register(struct snd_card *card)
639 {
640         struct proc_dir_entry *p;
641
642         if (snd_BUG_ON(!card))
643                 return -ENXIO;
644
645         if (!strcmp(card->id, card->proc_root->name))
646                 return 0;
647
648         p = proc_symlink(card->id, snd_proc_root, card->proc_root->name);
649         if (p == NULL)
650                 return -ENOMEM;
651         card->proc_root_link = p;
652         return 0;
653 }
654
655 /*
656  * called on card->id change
657  */
658 void snd_info_card_id_change(struct snd_card *card)
659 {
660         mutex_lock(&info_mutex);
661         if (card->proc_root_link) {
662                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
663                 card->proc_root_link = NULL;
664         }
665         if (strcmp(card->id, card->proc_root->name))
666                 card->proc_root_link = proc_symlink(card->id,
667                                                     snd_proc_root,
668                                                     card->proc_root->name);
669         mutex_unlock(&info_mutex);
670 }
671
672 /*
673  * de-register the card proc file
674  * called from init.c
675  */
676 void snd_info_card_disconnect(struct snd_card *card)
677 {
678         if (!card)
679                 return;
680         mutex_lock(&info_mutex);
681         if (card->proc_root_link) {
682                 snd_remove_proc_entry(snd_proc_root, card->proc_root_link);
683                 card->proc_root_link = NULL;
684         }
685         if (card->proc_root)
686                 snd_info_disconnect(card->proc_root);
687         mutex_unlock(&info_mutex);
688 }
689
690 /*
691  * release the card proc file resources
692  * called from init.c
693  */
694 int snd_info_card_free(struct snd_card *card)
695 {
696         if (!card)
697                 return 0;
698         snd_info_free_entry(card->proc_root);
699         card->proc_root = NULL;
700         return 0;
701 }
702
703
704 /**
705  * snd_info_get_line - read one line from the procfs buffer
706  * @buffer: the procfs buffer
707  * @line: the buffer to store
708  * @len: the max. buffer size - 1
709  *
710  * Reads one line from the buffer and stores the string.
711  *
712  * Returns zero if successful, or 1 if error or EOF.
713  */
714 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
715 {
716         int c = -1;
717
718         if (len <= 0 || buffer->stop || buffer->error)
719                 return 1;
720         while (--len > 0) {
721                 c = buffer->buffer[buffer->curr++];
722                 if (c == '\n') {
723                         if (buffer->curr >= buffer->size)
724                                 buffer->stop = 1;
725                         break;
726                 }
727                 *line++ = c;
728                 if (buffer->curr >= buffer->size) {
729                         buffer->stop = 1;
730                         break;
731                 }
732         }
733         while (c != '\n' && !buffer->stop) {
734                 c = buffer->buffer[buffer->curr++];
735                 if (buffer->curr >= buffer->size)
736                         buffer->stop = 1;
737         }
738         *line = '\0';
739         return 0;
740 }
741
742 EXPORT_SYMBOL(snd_info_get_line);
743
744 /**
745  * snd_info_get_str - parse a string token
746  * @dest: the buffer to store the string token
747  * @src: the original string
748  * @len: the max. length of token - 1
749  *
750  * Parses the original string and copy a token to the given
751  * string buffer.
752  *
753  * Returns the updated pointer of the original string so that
754  * it can be used for the next call.
755  */
756 char *snd_info_get_str(char *dest, char *src, int len)
757 {
758         int c;
759
760         while (*src == ' ' || *src == '\t')
761                 src++;
762         if (*src == '"' || *src == '\'') {
763                 c = *src++;
764                 while (--len > 0 && *src && *src != c) {
765                         *dest++ = *src++;
766                 }
767                 if (*src == c)
768                         src++;
769         } else {
770                 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
771                         *dest++ = *src++;
772                 }
773         }
774         *dest = 0;
775         while (*src == ' ' || *src == '\t')
776                 src++;
777         return src;
778 }
779
780 EXPORT_SYMBOL(snd_info_get_str);
781
782 /**
783  * snd_info_create_entry - create an info entry
784  * @name: the proc file name
785  *
786  * Creates an info entry with the given file name and initializes as
787  * the default state.
788  *
789  * Usually called from other functions such as
790  * snd_info_create_card_entry().
791  *
792  * Returns the pointer of the new instance, or NULL on failure.
793  */
794 static struct snd_info_entry *snd_info_create_entry(const char *name)
795 {
796         struct snd_info_entry *entry;
797         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
798         if (entry == NULL)
799                 return NULL;
800         entry->name = kstrdup(name, GFP_KERNEL);
801         if (entry->name == NULL) {
802                 kfree(entry);
803                 return NULL;
804         }
805         entry->mode = S_IFREG | S_IRUGO;
806         entry->content = SNDRV_INFO_CONTENT_TEXT;
807         mutex_init(&entry->access);
808         INIT_LIST_HEAD(&entry->children);
809         INIT_LIST_HEAD(&entry->list);
810         return entry;
811 }
812
813 /**
814  * snd_info_create_module_entry - create an info entry for the given module
815  * @module: the module pointer
816  * @name: the file name
817  * @parent: the parent directory
818  *
819  * Creates a new info entry and assigns it to the given module.
820  *
821  * Returns the pointer of the new instance, or NULL on failure.
822  */
823 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
824                                                const char *name,
825                                                struct snd_info_entry *parent)
826 {
827         struct snd_info_entry *entry = snd_info_create_entry(name);
828         if (entry) {
829                 entry->module = module;
830                 entry->parent = parent;
831         }
832         return entry;
833 }
834
835 EXPORT_SYMBOL(snd_info_create_module_entry);
836
837 /**
838  * snd_info_create_card_entry - create an info entry for the given card
839  * @card: the card instance
840  * @name: the file name
841  * @parent: the parent directory
842  *
843  * Creates a new info entry and assigns it to the given card.
844  *
845  * Returns the pointer of the new instance, or NULL on failure.
846  */
847 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
848                                              const char *name,
849                                              struct snd_info_entry * parent)
850 {
851         struct snd_info_entry *entry = snd_info_create_entry(name);
852         if (entry) {
853                 entry->module = card->module;
854                 entry->card = card;
855                 entry->parent = parent;
856         }
857         return entry;
858 }
859
860 EXPORT_SYMBOL(snd_info_create_card_entry);
861
862 static void snd_info_disconnect(struct snd_info_entry *entry)
863 {
864         struct list_head *p, *n;
865         struct proc_dir_entry *root;
866
867         list_for_each_safe(p, n, &entry->children) {
868                 snd_info_disconnect(list_entry(p, struct snd_info_entry, list));
869         }
870
871         if (! entry->p)
872                 return;
873         list_del_init(&entry->list);
874         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
875         snd_BUG_ON(!root);
876         snd_remove_proc_entry(root, entry->p);
877         entry->p = NULL;
878 }
879
880 static int snd_info_dev_free_entry(struct snd_device *device)
881 {
882         struct snd_info_entry *entry = device->device_data;
883         snd_info_free_entry(entry);
884         return 0;
885 }
886
887 static int snd_info_dev_register_entry(struct snd_device *device)
888 {
889         struct snd_info_entry *entry = device->device_data;
890         return snd_info_register(entry);
891 }
892
893 /**
894  * snd_card_proc_new - create an info entry for the given card
895  * @card: the card instance
896  * @name: the file name
897  * @entryp: the pointer to store the new info entry
898  *
899  * Creates a new info entry and assigns it to the given card.
900  * Unlike snd_info_create_card_entry(), this function registers the
901  * info entry as an ALSA device component, so that it can be
902  * unregistered/released without explicit call.
903  * Also, you don't have to register this entry via snd_info_register(),
904  * since this will be registered by snd_card_register() automatically.
905  *
906  * The parent is assumed as card->proc_root.
907  *
908  * For releasing this entry, use snd_device_free() instead of
909  * snd_info_free_entry(). 
910  *
911  * Returns zero if successful, or a negative error code on failure.
912  */
913 int snd_card_proc_new(struct snd_card *card, const char *name,
914                       struct snd_info_entry **entryp)
915 {
916         static struct snd_device_ops ops = {
917                 .dev_free = snd_info_dev_free_entry,
918                 .dev_register = snd_info_dev_register_entry,
919                 /* disconnect is done via snd_info_card_disconnect() */
920         };
921         struct snd_info_entry *entry;
922         int err;
923
924         entry = snd_info_create_card_entry(card, name, card->proc_root);
925         if (! entry)
926                 return -ENOMEM;
927         if ((err = snd_device_new(card, SNDRV_DEV_INFO, entry, &ops)) < 0) {
928                 snd_info_free_entry(entry);
929                 return err;
930         }
931         if (entryp)
932                 *entryp = entry;
933         return 0;
934 }
935
936 EXPORT_SYMBOL(snd_card_proc_new);
937
938 /**
939  * snd_info_free_entry - release the info entry
940  * @entry: the info entry
941  *
942  * Releases the info entry.  Don't call this after registered.
943  */
944 void snd_info_free_entry(struct snd_info_entry * entry)
945 {
946         if (entry == NULL)
947                 return;
948         if (entry->p) {
949                 mutex_lock(&info_mutex);
950                 snd_info_disconnect(entry);
951                 mutex_unlock(&info_mutex);
952         }
953         kfree(entry->name);
954         if (entry->private_free)
955                 entry->private_free(entry);
956         kfree(entry);
957 }
958
959 EXPORT_SYMBOL(snd_info_free_entry);
960
961 /**
962  * snd_info_register - register the info entry
963  * @entry: the info entry
964  *
965  * Registers the proc info entry.
966  *
967  * Returns zero if successful, or a negative error code on failure.
968  */
969 int snd_info_register(struct snd_info_entry * entry)
970 {
971         struct proc_dir_entry *root, *p = NULL;
972
973         if (snd_BUG_ON(!entry))
974                 return -ENXIO;
975         root = entry->parent == NULL ? snd_proc_root : entry->parent->p;
976         mutex_lock(&info_mutex);
977         p = snd_create_proc_entry(entry->name, entry->mode, root);
978         if (!p) {
979                 mutex_unlock(&info_mutex);
980                 return -ENOMEM;
981         }
982         p->owner = entry->module;
983         if (!S_ISDIR(entry->mode))
984                 p->proc_fops = &snd_info_entry_operations;
985         p->size = entry->size;
986         p->data = entry;
987         entry->p = p;
988         if (entry->parent)
989                 list_add_tail(&entry->list, &entry->parent->children);
990         mutex_unlock(&info_mutex);
991         return 0;
992 }
993
994 EXPORT_SYMBOL(snd_info_register);
995
996 /*
997
998  */
999
1000 static struct snd_info_entry *snd_info_version_entry;
1001
1002 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
1003 {
1004         snd_iprintf(buffer,
1005                     "Advanced Linux Sound Architecture Driver Version "
1006                     CONFIG_SND_VERSION CONFIG_SND_DATE ".\n"
1007                    );
1008 }
1009
1010 static int __init snd_info_version_init(void)
1011 {
1012         struct snd_info_entry *entry;
1013
1014         entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
1015         if (entry == NULL)
1016                 return -ENOMEM;
1017         entry->c.text.read = snd_info_version_read;
1018         if (snd_info_register(entry) < 0) {
1019                 snd_info_free_entry(entry);
1020                 return -ENOMEM;
1021         }
1022         snd_info_version_entry = entry;
1023         return 0;
1024 }
1025
1026 static int __exit snd_info_version_done(void)
1027 {
1028         snd_info_free_entry(snd_info_version_entry);
1029         return 0;
1030 }
1031
1032 #endif /* CONFIG_PROC_FS */