1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Information interface for ALSA driver
4 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
7 #include <linux/init.h>
8 #include <linux/time.h>
10 #include <linux/slab.h>
11 #include <linux/string.h>
12 #include <linux/module.h>
13 #include <sound/core.h>
14 #include <sound/minors.h>
15 #include <sound/info.h>
16 #include <linux/utsname.h>
17 #include <linux/proc_fs.h>
18 #include <linux/mutex.h>
21 int snd_info_check_reserved_words(const char *str
)
23 static const char * const reserved
[] =
38 const char * const *xstr
= reserved
;
41 if (!strcmp(*xstr
, str
))
45 if (!strncmp(str
, "card", 4))
50 static DEFINE_MUTEX(info_mutex
);
52 struct snd_info_private_data
{
53 struct snd_info_buffer
*rbuffer
;
54 struct snd_info_buffer
*wbuffer
;
55 struct snd_info_entry
*entry
;
56 void *file_private_data
;
59 static int snd_info_version_init(void);
60 static void snd_info_disconnect(struct snd_info_entry
*entry
);
66 static struct snd_info_entry
*snd_proc_root
;
67 struct snd_info_entry
*snd_seq_root
;
68 EXPORT_SYMBOL(snd_seq_root
);
70 #ifdef CONFIG_SND_OSSEMUL
71 struct snd_info_entry
*snd_oss_root
;
74 static int alloc_info_private(struct snd_info_entry
*entry
,
75 struct snd_info_private_data
**ret
)
77 struct snd_info_private_data
*data
;
79 if (!entry
|| !entry
->p
)
81 if (!try_module_get(entry
->module
))
83 data
= kzalloc(sizeof(*data
), GFP_KERNEL
);
85 module_put(entry
->module
);
93 static bool valid_pos(loff_t pos
, size_t count
)
95 if (pos
< 0 || (long) pos
!= pos
|| (ssize_t
) count
< 0)
97 if ((unsigned long) pos
+ (unsigned long) count
< (unsigned long) pos
)
103 * file ops for binary proc files
105 static loff_t
snd_info_entry_llseek(struct file
*file
, loff_t offset
, int orig
)
107 struct snd_info_private_data
*data
;
108 struct snd_info_entry
*entry
;
109 loff_t ret
= -EINVAL
, size
;
111 data
= file
->private_data
;
113 mutex_lock(&entry
->access
);
114 if (entry
->c
.ops
->llseek
) {
115 offset
= entry
->c
.ops
->llseek(entry
,
116 data
->file_private_data
,
126 offset
+= file
->f_pos
;
138 if (size
&& offset
> size
)
140 file
->f_pos
= offset
;
143 mutex_unlock(&entry
->access
);
147 static ssize_t
snd_info_entry_read(struct file
*file
, char __user
*buffer
,
148 size_t count
, loff_t
* offset
)
150 struct snd_info_private_data
*data
= file
->private_data
;
151 struct snd_info_entry
*entry
= data
->entry
;
156 if (!valid_pos(pos
, count
))
158 if (pos
>= entry
->size
)
160 size
= entry
->size
- pos
;
161 size
= min(count
, size
);
162 size
= entry
->c
.ops
->read(entry
, data
->file_private_data
,
163 file
, buffer
, size
, pos
);
164 if ((ssize_t
) size
> 0)
165 *offset
= pos
+ size
;
169 static ssize_t
snd_info_entry_write(struct file
*file
, const char __user
*buffer
,
170 size_t count
, loff_t
* offset
)
172 struct snd_info_private_data
*data
= file
->private_data
;
173 struct snd_info_entry
*entry
= data
->entry
;
178 if (!valid_pos(pos
, count
))
181 size_t maxsize
= entry
->size
- pos
;
182 count
= min(count
, maxsize
);
183 size
= entry
->c
.ops
->write(entry
, data
->file_private_data
,
184 file
, buffer
, count
, pos
);
187 *offset
= pos
+ size
;
191 static __poll_t
snd_info_entry_poll(struct file
*file
, poll_table
*wait
)
193 struct snd_info_private_data
*data
= file
->private_data
;
194 struct snd_info_entry
*entry
= data
->entry
;
197 if (entry
->c
.ops
->poll
)
198 return entry
->c
.ops
->poll(entry
,
199 data
->file_private_data
,
201 if (entry
->c
.ops
->read
)
202 mask
|= EPOLLIN
| EPOLLRDNORM
;
203 if (entry
->c
.ops
->write
)
204 mask
|= EPOLLOUT
| EPOLLWRNORM
;
208 static long snd_info_entry_ioctl(struct file
*file
, unsigned int cmd
,
211 struct snd_info_private_data
*data
= file
->private_data
;
212 struct snd_info_entry
*entry
= data
->entry
;
214 if (!entry
->c
.ops
->ioctl
)
216 return entry
->c
.ops
->ioctl(entry
, data
->file_private_data
,
220 static int snd_info_entry_mmap(struct file
*file
, struct vm_area_struct
*vma
)
222 struct inode
*inode
= file_inode(file
);
223 struct snd_info_private_data
*data
;
224 struct snd_info_entry
*entry
;
226 data
= file
->private_data
;
230 if (!entry
->c
.ops
->mmap
)
232 return entry
->c
.ops
->mmap(entry
, data
->file_private_data
,
236 static int snd_info_entry_open(struct inode
*inode
, struct file
*file
)
238 struct snd_info_entry
*entry
= PDE_DATA(inode
);
239 struct snd_info_private_data
*data
;
242 mutex_lock(&info_mutex
);
243 err
= alloc_info_private(entry
, &data
);
247 mode
= file
->f_flags
& O_ACCMODE
;
248 if (((mode
== O_RDONLY
|| mode
== O_RDWR
) && !entry
->c
.ops
->read
) ||
249 ((mode
== O_WRONLY
|| mode
== O_RDWR
) && !entry
->c
.ops
->write
)) {
254 if (entry
->c
.ops
->open
) {
255 err
= entry
->c
.ops
->open(entry
, mode
, &data
->file_private_data
);
260 file
->private_data
= data
;
261 mutex_unlock(&info_mutex
);
266 module_put(entry
->module
);
268 mutex_unlock(&info_mutex
);
272 static int snd_info_entry_release(struct inode
*inode
, struct file
*file
)
274 struct snd_info_private_data
*data
= file
->private_data
;
275 struct snd_info_entry
*entry
= data
->entry
;
277 if (entry
->c
.ops
->release
)
278 entry
->c
.ops
->release(entry
, file
->f_flags
& O_ACCMODE
,
279 data
->file_private_data
);
280 module_put(entry
->module
);
285 static const struct proc_ops snd_info_entry_operations
=
287 .proc_lseek
= snd_info_entry_llseek
,
288 .proc_read
= snd_info_entry_read
,
289 .proc_write
= snd_info_entry_write
,
290 .proc_poll
= snd_info_entry_poll
,
291 .proc_ioctl
= snd_info_entry_ioctl
,
292 .proc_mmap
= snd_info_entry_mmap
,
293 .proc_open
= snd_info_entry_open
,
294 .proc_release
= snd_info_entry_release
,
298 * file ops for text proc files
300 static ssize_t
snd_info_text_entry_write(struct file
*file
,
301 const char __user
*buffer
,
302 size_t count
, loff_t
*offset
)
304 struct seq_file
*m
= file
->private_data
;
305 struct snd_info_private_data
*data
= m
->private;
306 struct snd_info_entry
*entry
= data
->entry
;
307 struct snd_info_buffer
*buf
;
312 if (!entry
->c
.text
.write
)
315 if (!valid_pos(pos
, count
))
318 /* don't handle too large text inputs */
319 if (next
> 16 * 1024)
321 mutex_lock(&entry
->access
);
324 data
->wbuffer
= buf
= kzalloc(sizeof(*buf
), GFP_KERNEL
);
330 if (next
> buf
->len
) {
331 char *nbuf
= kvzalloc(PAGE_ALIGN(next
), GFP_KERNEL
);
338 buf
->len
= PAGE_ALIGN(next
);
340 if (copy_from_user(buf
->buffer
+ pos
, buffer
, count
)) {
346 mutex_unlock(&entry
->access
);
353 static int snd_info_seq_show(struct seq_file
*seq
, void *p
)
355 struct snd_info_private_data
*data
= seq
->private;
356 struct snd_info_entry
*entry
= data
->entry
;
358 if (!entry
->c
.text
.read
) {
361 data
->rbuffer
->buffer
= (char *)seq
; /* XXX hack! */
362 entry
->c
.text
.read(entry
, data
->rbuffer
);
367 static int snd_info_text_entry_open(struct inode
*inode
, struct file
*file
)
369 struct snd_info_entry
*entry
= PDE_DATA(inode
);
370 struct snd_info_private_data
*data
;
373 mutex_lock(&info_mutex
);
374 err
= alloc_info_private(entry
, &data
);
378 data
->rbuffer
= kzalloc(sizeof(*data
->rbuffer
), GFP_KERNEL
);
379 if (!data
->rbuffer
) {
384 err
= single_open_size(file
, snd_info_seq_show
, data
,
387 err
= single_open(file
, snd_info_seq_show
, data
);
390 mutex_unlock(&info_mutex
);
394 kfree(data
->rbuffer
);
396 module_put(entry
->module
);
398 mutex_unlock(&info_mutex
);
402 static int snd_info_text_entry_release(struct inode
*inode
, struct file
*file
)
404 struct seq_file
*m
= file
->private_data
;
405 struct snd_info_private_data
*data
= m
->private;
406 struct snd_info_entry
*entry
= data
->entry
;
408 if (data
->wbuffer
&& entry
->c
.text
.write
)
409 entry
->c
.text
.write(entry
, data
->wbuffer
);
411 single_release(inode
, file
);
412 kfree(data
->rbuffer
);
414 kvfree(data
->wbuffer
->buffer
);
415 kfree(data
->wbuffer
);
418 module_put(entry
->module
);
423 static const struct proc_ops snd_info_text_entry_ops
=
425 .proc_open
= snd_info_text_entry_open
,
426 .proc_release
= snd_info_text_entry_release
,
427 .proc_write
= snd_info_text_entry_write
,
428 .proc_lseek
= seq_lseek
,
429 .proc_read
= seq_read
,
432 static struct snd_info_entry
*create_subdir(struct module
*mod
,
435 struct snd_info_entry
*entry
;
437 entry
= snd_info_create_module_entry(mod
, name
, NULL
);
440 entry
->mode
= S_IFDIR
| 0555;
441 if (snd_info_register(entry
) < 0) {
442 snd_info_free_entry(entry
);
448 static struct snd_info_entry
*
449 snd_info_create_entry(const char *name
, struct snd_info_entry
*parent
,
450 struct module
*module
);
452 int __init
snd_info_init(void)
454 snd_proc_root
= snd_info_create_entry("asound", NULL
, THIS_MODULE
);
457 snd_proc_root
->mode
= S_IFDIR
| 0555;
458 snd_proc_root
->p
= proc_mkdir("asound", NULL
);
459 if (!snd_proc_root
->p
)
461 #ifdef CONFIG_SND_OSSEMUL
462 snd_oss_root
= create_subdir(THIS_MODULE
, "oss");
466 #if IS_ENABLED(CONFIG_SND_SEQUENCER)
467 snd_seq_root
= create_subdir(THIS_MODULE
, "seq");
471 if (snd_info_version_init() < 0 ||
472 snd_minor_info_init() < 0 ||
473 snd_minor_info_oss_init() < 0 ||
474 snd_card_info_init() < 0 ||
475 snd_info_minor_register() < 0)
480 snd_info_free_entry(snd_proc_root
);
484 int __exit
snd_info_done(void)
486 snd_info_free_entry(snd_proc_root
);
490 static void snd_card_id_read(struct snd_info_entry
*entry
,
491 struct snd_info_buffer
*buffer
)
493 struct snd_card
*card
= entry
->private_data
;
495 snd_iprintf(buffer
, "%s\n", card
->id
);
499 * create a card proc file
502 int snd_info_card_create(struct snd_card
*card
)
505 struct snd_info_entry
*entry
;
507 if (snd_BUG_ON(!card
))
510 sprintf(str
, "card%i", card
->number
);
511 entry
= create_subdir(card
->module
, str
);
514 card
->proc_root
= entry
;
516 return snd_card_ro_proc_new(card
, "id", card
, snd_card_id_read
);
520 * register the card proc file
522 * can be called multiple times for reinitialization
524 int snd_info_card_register(struct snd_card
*card
)
526 struct proc_dir_entry
*p
;
529 if (snd_BUG_ON(!card
))
532 err
= snd_info_register(card
->proc_root
);
536 if (!strcmp(card
->id
, card
->proc_root
->name
))
539 if (card
->proc_root_link
)
541 p
= proc_symlink(card
->id
, snd_proc_root
->p
, card
->proc_root
->name
);
544 card
->proc_root_link
= p
;
549 * called on card->id change
551 void snd_info_card_id_change(struct snd_card
*card
)
553 mutex_lock(&info_mutex
);
554 if (card
->proc_root_link
) {
555 proc_remove(card
->proc_root_link
);
556 card
->proc_root_link
= NULL
;
558 if (strcmp(card
->id
, card
->proc_root
->name
))
559 card
->proc_root_link
= proc_symlink(card
->id
,
561 card
->proc_root
->name
);
562 mutex_unlock(&info_mutex
);
566 * de-register the card proc file
569 void snd_info_card_disconnect(struct snd_card
*card
)
573 mutex_lock(&info_mutex
);
574 proc_remove(card
->proc_root_link
);
575 card
->proc_root_link
= NULL
;
577 snd_info_disconnect(card
->proc_root
);
578 mutex_unlock(&info_mutex
);
582 * release the card proc file resources
585 int snd_info_card_free(struct snd_card
*card
)
589 snd_info_free_entry(card
->proc_root
);
590 card
->proc_root
= NULL
;
596 * snd_info_get_line - read one line from the procfs buffer
597 * @buffer: the procfs buffer
598 * @line: the buffer to store
599 * @len: the max. buffer size
601 * Reads one line from the buffer and stores the string.
603 * Return: Zero if successful, or 1 if error or EOF.
605 int snd_info_get_line(struct snd_info_buffer
*buffer
, char *line
, int len
)
609 if (snd_BUG_ON(!buffer
))
613 if (len
<= 0 || buffer
->stop
|| buffer
->error
)
615 while (!buffer
->stop
) {
616 c
= buffer
->buffer
[buffer
->curr
++];
617 if (buffer
->curr
>= buffer
->size
)
629 EXPORT_SYMBOL(snd_info_get_line
);
632 * snd_info_get_str - parse a string token
633 * @dest: the buffer to store the string token
634 * @src: the original string
635 * @len: the max. length of token - 1
637 * Parses the original string and copy a token to the given
640 * Return: The updated pointer of the original string so that
641 * it can be used for the next call.
643 const char *snd_info_get_str(char *dest
, const char *src
, int len
)
647 while (*src
== ' ' || *src
== '\t')
649 if (*src
== '"' || *src
== '\'') {
651 while (--len
> 0 && *src
&& *src
!= c
) {
657 while (--len
> 0 && *src
&& *src
!= ' ' && *src
!= '\t') {
662 while (*src
== ' ' || *src
== '\t')
666 EXPORT_SYMBOL(snd_info_get_str
);
669 * snd_info_create_entry - create an info entry
670 * @name: the proc file name
671 * @parent: the parent directory
673 * Creates an info entry with the given file name and initializes as
676 * Usually called from other functions such as
677 * snd_info_create_card_entry().
679 * Return: The pointer of the new instance, or %NULL on failure.
681 static struct snd_info_entry
*
682 snd_info_create_entry(const char *name
, struct snd_info_entry
*parent
,
683 struct module
*module
)
685 struct snd_info_entry
*entry
;
686 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
689 entry
->name
= kstrdup(name
, GFP_KERNEL
);
690 if (entry
->name
== NULL
) {
694 entry
->mode
= S_IFREG
| 0444;
695 entry
->content
= SNDRV_INFO_CONTENT_TEXT
;
696 mutex_init(&entry
->access
);
697 INIT_LIST_HEAD(&entry
->children
);
698 INIT_LIST_HEAD(&entry
->list
);
699 entry
->parent
= parent
;
700 entry
->module
= module
;
702 mutex_lock(&parent
->access
);
703 list_add_tail(&entry
->list
, &parent
->children
);
704 mutex_unlock(&parent
->access
);
710 * snd_info_create_module_entry - create an info entry for the given module
711 * @module: the module pointer
712 * @name: the file name
713 * @parent: the parent directory
715 * Creates a new info entry and assigns it to the given module.
717 * Return: The pointer of the new instance, or %NULL on failure.
719 struct snd_info_entry
*snd_info_create_module_entry(struct module
* module
,
721 struct snd_info_entry
*parent
)
724 parent
= snd_proc_root
;
725 return snd_info_create_entry(name
, parent
, module
);
727 EXPORT_SYMBOL(snd_info_create_module_entry
);
730 * snd_info_create_card_entry - create an info entry for the given card
731 * @card: the card instance
732 * @name: the file name
733 * @parent: the parent directory
735 * Creates a new info entry and assigns it to the given card.
737 * Return: The pointer of the new instance, or %NULL on failure.
739 struct snd_info_entry
*snd_info_create_card_entry(struct snd_card
*card
,
741 struct snd_info_entry
* parent
)
744 parent
= card
->proc_root
;
745 return snd_info_create_entry(name
, parent
, card
->module
);
747 EXPORT_SYMBOL(snd_info_create_card_entry
);
749 static void snd_info_disconnect(struct snd_info_entry
*entry
)
751 struct snd_info_entry
*p
;
755 list_for_each_entry(p
, &entry
->children
, list
)
756 snd_info_disconnect(p
);
757 proc_remove(entry
->p
);
762 * snd_info_free_entry - release the info entry
763 * @entry: the info entry
765 * Releases the info entry.
767 void snd_info_free_entry(struct snd_info_entry
* entry
)
769 struct snd_info_entry
*p
, *n
;
774 mutex_lock(&info_mutex
);
775 snd_info_disconnect(entry
);
776 mutex_unlock(&info_mutex
);
779 /* free all children at first */
780 list_for_each_entry_safe(p
, n
, &entry
->children
, list
)
781 snd_info_free_entry(p
);
785 mutex_lock(&p
->access
);
786 list_del(&entry
->list
);
787 mutex_unlock(&p
->access
);
790 if (entry
->private_free
)
791 entry
->private_free(entry
);
794 EXPORT_SYMBOL(snd_info_free_entry
);
796 static int __snd_info_register(struct snd_info_entry
*entry
)
798 struct proc_dir_entry
*root
, *p
= NULL
;
800 if (snd_BUG_ON(!entry
))
802 root
= entry
->parent
== NULL
? snd_proc_root
->p
: entry
->parent
->p
;
803 mutex_lock(&info_mutex
);
804 if (entry
->p
|| !root
)
806 if (S_ISDIR(entry
->mode
)) {
807 p
= proc_mkdir_mode(entry
->name
, entry
->mode
, root
);
809 mutex_unlock(&info_mutex
);
813 const struct proc_ops
*ops
;
814 if (entry
->content
== SNDRV_INFO_CONTENT_DATA
)
815 ops
= &snd_info_entry_operations
;
817 ops
= &snd_info_text_entry_ops
;
818 p
= proc_create_data(entry
->name
, entry
->mode
, root
,
821 mutex_unlock(&info_mutex
);
824 proc_set_size(p
, entry
->size
);
828 mutex_unlock(&info_mutex
);
833 * snd_info_register - register the info entry
834 * @entry: the info entry
836 * Registers the proc info entry.
837 * The all children entries are registered recursively.
839 * Return: Zero if successful, or a negative error code on failure.
841 int snd_info_register(struct snd_info_entry
*entry
)
843 struct snd_info_entry
*p
;
847 err
= __snd_info_register(entry
);
852 list_for_each_entry(p
, &entry
->children
, list
) {
853 err
= snd_info_register(p
);
860 EXPORT_SYMBOL(snd_info_register
);
863 * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
864 * @card: the card instance
865 * @name: the file name
866 * @private_data: the arbitrary private data
867 * @read: the read callback
868 * @write: the write callback, NULL for read-only
870 * This proc file entry will be registered via snd_card_register() call, and
871 * it will be removed automatically at the card removal, too.
873 int snd_card_rw_proc_new(struct snd_card
*card
, const char *name
,
875 void (*read
)(struct snd_info_entry
*,
876 struct snd_info_buffer
*),
877 void (*write
)(struct snd_info_entry
*entry
,
878 struct snd_info_buffer
*buffer
))
880 struct snd_info_entry
*entry
;
882 entry
= snd_info_create_card_entry(card
, name
, card
->proc_root
);
885 snd_info_set_text_ops(entry
, private_data
, read
);
888 entry
->c
.text
.write
= write
;
892 EXPORT_SYMBOL_GPL(snd_card_rw_proc_new
);
898 static void snd_info_version_read(struct snd_info_entry
*entry
, struct snd_info_buffer
*buffer
)
901 "Advanced Linux Sound Architecture Driver Version k%s.\n",
902 init_utsname()->release
);
905 static int __init
snd_info_version_init(void)
907 struct snd_info_entry
*entry
;
909 entry
= snd_info_create_module_entry(THIS_MODULE
, "version", NULL
);
912 entry
->c
.text
.read
= snd_info_version_read
;
913 return snd_info_register(entry
); /* freed in error path */