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