2 * Information interface for ALSA driver
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
22 #include <linux/init.h>
23 #include <linux/time.h>
25 #include <linux/slab.h>
26 #include <linux/string.h>
27 #include <linux/module.h>
28 #include <sound/core.h>
29 #include <sound/minors.h>
30 #include <sound/info.h>
31 #include <linux/utsname.h>
32 #include <linux/proc_fs.h>
33 #include <linux/mutex.h>
36 int snd_info_check_reserved_words(const char *str)
38 static char *reserved[] =
53 char **xstr = reserved;
56 if (!strcmp(*xstr, str))
60 if (!strncmp(str, "card", 4))
65 static DEFINE_MUTEX(info_mutex);
67 struct snd_info_private_data {
68 struct snd_info_buffer *rbuffer;
69 struct snd_info_buffer *wbuffer;
70 struct snd_info_entry *entry;
71 void *file_private_data;
74 static int snd_info_version_init(void);
75 static void snd_info_disconnect(struct snd_info_entry *entry);
81 static struct snd_info_entry *snd_proc_root;
82 struct snd_info_entry *snd_seq_root;
83 EXPORT_SYMBOL(snd_seq_root);
85 #ifdef CONFIG_SND_OSSEMUL
86 struct snd_info_entry *snd_oss_root;
89 static int alloc_info_private(struct snd_info_entry *entry,
90 struct snd_info_private_data **ret)
92 struct snd_info_private_data *data;
94 if (!entry || !entry->p)
96 if (!try_module_get(entry->module))
98 data = kzalloc(sizeof(*data), GFP_KERNEL);
100 module_put(entry->module);
108 static bool valid_pos(loff_t pos, size_t count)
110 if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
112 if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
118 * file ops for binary proc files
120 static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig)
122 struct snd_info_private_data *data;
123 struct snd_info_entry *entry;
124 loff_t ret = -EINVAL, size;
126 data = file->private_data;
128 mutex_lock(&entry->access);
129 if (entry->c.ops->llseek) {
130 offset = entry->c.ops->llseek(entry,
131 data->file_private_data,
141 offset += file->f_pos;
153 if (size && offset > size)
155 file->f_pos = offset;
158 mutex_unlock(&entry->access);
162 static ssize_t snd_info_entry_read(struct file *file, char __user *buffer,
163 size_t count, loff_t * offset)
165 struct snd_info_private_data *data = file->private_data;
166 struct snd_info_entry *entry = data->entry;
171 if (!valid_pos(pos, count))
173 if (pos >= entry->size)
175 size = entry->size - pos;
176 size = min(count, size);
177 size = entry->c.ops->read(entry, data->file_private_data,
178 file, buffer, size, pos);
179 if ((ssize_t) size > 0)
180 *offset = pos + size;
184 static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer,
185 size_t count, loff_t * offset)
187 struct snd_info_private_data *data = file->private_data;
188 struct snd_info_entry *entry = data->entry;
193 if (!valid_pos(pos, count))
196 size_t maxsize = entry->size - pos;
197 count = min(count, maxsize);
198 size = entry->c.ops->write(entry, data->file_private_data,
199 file, buffer, count, pos);
202 *offset = pos + size;
206 static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait)
208 struct snd_info_private_data *data = file->private_data;
209 struct snd_info_entry *entry = data->entry;
212 if (entry->c.ops->poll)
213 return entry->c.ops->poll(entry,
214 data->file_private_data,
216 if (entry->c.ops->read)
217 mask |= EPOLLIN | EPOLLRDNORM;
218 if (entry->c.ops->write)
219 mask |= EPOLLOUT | EPOLLWRNORM;
223 static long snd_info_entry_ioctl(struct file *file, unsigned int cmd,
226 struct snd_info_private_data *data = file->private_data;
227 struct snd_info_entry *entry = data->entry;
229 if (!entry->c.ops->ioctl)
231 return entry->c.ops->ioctl(entry, data->file_private_data,
235 static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma)
237 struct inode *inode = file_inode(file);
238 struct snd_info_private_data *data;
239 struct snd_info_entry *entry;
241 data = file->private_data;
245 if (!entry->c.ops->mmap)
247 return entry->c.ops->mmap(entry, data->file_private_data,
251 static int snd_info_entry_open(struct inode *inode, struct file *file)
253 struct snd_info_entry *entry = PDE_DATA(inode);
254 struct snd_info_private_data *data;
257 mutex_lock(&info_mutex);
258 err = alloc_info_private(entry, &data);
262 mode = file->f_flags & O_ACCMODE;
263 if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) ||
264 ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) {
269 if (entry->c.ops->open) {
270 err = entry->c.ops->open(entry, mode, &data->file_private_data);
275 file->private_data = data;
276 mutex_unlock(&info_mutex);
281 module_put(entry->module);
283 mutex_unlock(&info_mutex);
287 static int snd_info_entry_release(struct inode *inode, struct file *file)
289 struct snd_info_private_data *data = file->private_data;
290 struct snd_info_entry *entry = data->entry;
292 if (entry->c.ops->release)
293 entry->c.ops->release(entry, file->f_flags & O_ACCMODE,
294 data->file_private_data);
295 module_put(entry->module);
300 static const struct file_operations snd_info_entry_operations =
302 .owner = THIS_MODULE,
303 .llseek = snd_info_entry_llseek,
304 .read = snd_info_entry_read,
305 .write = snd_info_entry_write,
306 .poll = snd_info_entry_poll,
307 .unlocked_ioctl = snd_info_entry_ioctl,
308 .mmap = snd_info_entry_mmap,
309 .open = snd_info_entry_open,
310 .release = snd_info_entry_release,
314 * file ops for text proc files
316 static ssize_t snd_info_text_entry_write(struct file *file,
317 const char __user *buffer,
318 size_t count, loff_t *offset)
320 struct seq_file *m = file->private_data;
321 struct snd_info_private_data *data = m->private;
322 struct snd_info_entry *entry = data->entry;
323 struct snd_info_buffer *buf;
328 if (!entry->c.text.write)
331 if (!valid_pos(pos, count))
334 /* don't handle too large text inputs */
335 if (next > 16 * 1024)
337 mutex_lock(&entry->access);
340 data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL);
346 if (next > buf->len) {
347 char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL);
354 buf->len = PAGE_ALIGN(next);
356 if (copy_from_user(buf->buffer + pos, buffer, count)) {
362 mutex_unlock(&entry->access);
369 static int snd_info_seq_show(struct seq_file *seq, void *p)
371 struct snd_info_private_data *data = seq->private;
372 struct snd_info_entry *entry = data->entry;
374 if (!entry->c.text.read) {
377 data->rbuffer->buffer = (char *)seq; /* XXX hack! */
378 entry->c.text.read(entry, data->rbuffer);
383 static int snd_info_text_entry_open(struct inode *inode, struct file *file)
385 struct snd_info_entry *entry = PDE_DATA(inode);
386 struct snd_info_private_data *data;
389 mutex_lock(&info_mutex);
390 err = alloc_info_private(entry, &data);
394 data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL);
395 if (!data->rbuffer) {
400 err = single_open_size(file, snd_info_seq_show, data,
403 err = single_open(file, snd_info_seq_show, data);
406 mutex_unlock(&info_mutex);
410 kfree(data->rbuffer);
412 module_put(entry->module);
414 mutex_unlock(&info_mutex);
418 static int snd_info_text_entry_release(struct inode *inode, struct file *file)
420 struct seq_file *m = file->private_data;
421 struct snd_info_private_data *data = m->private;
422 struct snd_info_entry *entry = data->entry;
424 if (data->wbuffer && entry->c.text.write)
425 entry->c.text.write(entry, data->wbuffer);
427 single_release(inode, file);
428 kfree(data->rbuffer);
430 kvfree(data->wbuffer->buffer);
431 kfree(data->wbuffer);
434 module_put(entry->module);
439 static const struct file_operations snd_info_text_entry_ops =
441 .owner = THIS_MODULE,
442 .open = snd_info_text_entry_open,
443 .release = snd_info_text_entry_release,
444 .write = snd_info_text_entry_write,
449 static struct snd_info_entry *create_subdir(struct module *mod,
452 struct snd_info_entry *entry;
454 entry = snd_info_create_module_entry(mod, name, NULL);
457 entry->mode = S_IFDIR | 0555;
458 if (snd_info_register(entry) < 0) {
459 snd_info_free_entry(entry);
465 static struct snd_info_entry *
466 snd_info_create_entry(const char *name, struct snd_info_entry *parent,
467 struct module *module);
469 int __init snd_info_init(void)
471 snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE);
474 snd_proc_root->mode = S_IFDIR | 0555;
475 snd_proc_root->p = proc_mkdir("asound", NULL);
476 if (!snd_proc_root->p)
478 #ifdef CONFIG_SND_OSSEMUL
479 snd_oss_root = create_subdir(THIS_MODULE, "oss");
483 #if IS_ENABLED(CONFIG_SND_SEQUENCER)
484 snd_seq_root = create_subdir(THIS_MODULE, "seq");
488 if (snd_info_version_init() < 0 ||
489 snd_minor_info_init() < 0 ||
490 snd_minor_info_oss_init() < 0 ||
491 snd_card_info_init() < 0 ||
492 snd_info_minor_register() < 0)
497 snd_info_free_entry(snd_proc_root);
501 int __exit snd_info_done(void)
503 snd_info_free_entry(snd_proc_root);
508 * create a card proc file
511 int snd_info_card_create(struct snd_card *card)
514 struct snd_info_entry *entry;
516 if (snd_BUG_ON(!card))
519 sprintf(str, "card%i", card->number);
520 entry = create_subdir(card->module, str);
523 card->proc_root = entry;
528 * register the card proc file
530 * can be called multiple times for reinitialization
532 int snd_info_card_register(struct snd_card *card)
534 struct proc_dir_entry *p;
537 if (snd_BUG_ON(!card))
540 err = snd_info_register(card->proc_root);
544 if (!strcmp(card->id, card->proc_root->name))
547 if (card->proc_root_link)
549 p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name);
552 card->proc_root_link = p;
557 * called on card->id change
559 void snd_info_card_id_change(struct snd_card *card)
561 mutex_lock(&info_mutex);
562 if (card->proc_root_link) {
563 proc_remove(card->proc_root_link);
564 card->proc_root_link = NULL;
566 if (strcmp(card->id, card->proc_root->name))
567 card->proc_root_link = proc_symlink(card->id,
569 card->proc_root->name);
570 mutex_unlock(&info_mutex);
574 * de-register the card proc file
577 void snd_info_card_disconnect(struct snd_card *card)
581 mutex_lock(&info_mutex);
582 proc_remove(card->proc_root_link);
583 card->proc_root_link = NULL;
585 snd_info_disconnect(card->proc_root);
586 mutex_unlock(&info_mutex);
590 * release the card proc file resources
593 int snd_info_card_free(struct snd_card *card)
597 snd_info_free_entry(card->proc_root);
598 card->proc_root = NULL;
604 * snd_info_get_line - read one line from the procfs buffer
605 * @buffer: the procfs buffer
606 * @line: the buffer to store
607 * @len: the max. buffer size
609 * Reads one line from the buffer and stores the string.
611 * Return: Zero if successful, or 1 if error or EOF.
613 int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
617 if (snd_BUG_ON(!buffer || !buffer->buffer))
619 if (len <= 0 || buffer->stop || buffer->error)
621 while (!buffer->stop) {
622 c = buffer->buffer[buffer->curr++];
623 if (buffer->curr >= buffer->size)
635 EXPORT_SYMBOL(snd_info_get_line);
638 * snd_info_get_str - parse a string token
639 * @dest: the buffer to store the string token
640 * @src: the original string
641 * @len: the max. length of token - 1
643 * Parses the original string and copy a token to the given
646 * Return: The updated pointer of the original string so that
647 * it can be used for the next call.
649 const char *snd_info_get_str(char *dest, const char *src, int len)
653 while (*src == ' ' || *src == '\t')
655 if (*src == '"' || *src == '\'') {
657 while (--len > 0 && *src && *src != c) {
663 while (--len > 0 && *src && *src != ' ' && *src != '\t') {
668 while (*src == ' ' || *src == '\t')
672 EXPORT_SYMBOL(snd_info_get_str);
675 * snd_info_create_entry - create an info entry
676 * @name: the proc file name
677 * @parent: the parent directory
679 * Creates an info entry with the given file name and initializes as
682 * Usually called from other functions such as
683 * snd_info_create_card_entry().
685 * Return: The pointer of the new instance, or %NULL on failure.
687 static struct snd_info_entry *
688 snd_info_create_entry(const char *name, struct snd_info_entry *parent,
689 struct module *module)
691 struct snd_info_entry *entry;
692 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
695 entry->name = kstrdup(name, GFP_KERNEL);
696 if (entry->name == NULL) {
700 entry->mode = S_IFREG | 0444;
701 entry->content = SNDRV_INFO_CONTENT_TEXT;
702 mutex_init(&entry->access);
703 INIT_LIST_HEAD(&entry->children);
704 INIT_LIST_HEAD(&entry->list);
705 entry->parent = parent;
706 entry->module = module;
708 list_add_tail(&entry->list, &parent->children);
713 * snd_info_create_module_entry - create an info entry for the given module
714 * @module: the module pointer
715 * @name: the file name
716 * @parent: the parent directory
718 * Creates a new info entry and assigns it to the given module.
720 * Return: The pointer of the new instance, or %NULL on failure.
722 struct snd_info_entry *snd_info_create_module_entry(struct module * module,
724 struct snd_info_entry *parent)
727 parent = snd_proc_root;
728 return snd_info_create_entry(name, parent, module);
730 EXPORT_SYMBOL(snd_info_create_module_entry);
733 * snd_info_create_card_entry - create an info entry for the given card
734 * @card: the card instance
735 * @name: the file name
736 * @parent: the parent directory
738 * Creates a new info entry and assigns it to the given card.
740 * Return: The pointer of the new instance, or %NULL on failure.
742 struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
744 struct snd_info_entry * parent)
747 parent = card->proc_root;
748 return snd_info_create_entry(name, parent, card->module);
750 EXPORT_SYMBOL(snd_info_create_card_entry);
752 static void snd_info_disconnect(struct snd_info_entry *entry)
754 struct snd_info_entry *p;
758 list_for_each_entry(p, &entry->children, list)
759 snd_info_disconnect(p);
760 proc_remove(entry->p);
765 * snd_info_free_entry - release the info entry
766 * @entry: the info entry
768 * Releases the info entry.
770 void snd_info_free_entry(struct snd_info_entry * entry)
772 struct snd_info_entry *p, *n;
777 mutex_lock(&info_mutex);
778 snd_info_disconnect(entry);
779 mutex_unlock(&info_mutex);
782 /* free all children at first */
783 list_for_each_entry_safe(p, n, &entry->children, list)
784 snd_info_free_entry(p);
786 list_del(&entry->list);
788 if (entry->private_free)
789 entry->private_free(entry);
792 EXPORT_SYMBOL(snd_info_free_entry);
794 static int __snd_info_register(struct snd_info_entry *entry)
796 struct proc_dir_entry *root, *p = NULL;
798 if (snd_BUG_ON(!entry))
800 root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p;
801 mutex_lock(&info_mutex);
802 if (entry->p || !root)
804 if (S_ISDIR(entry->mode)) {
805 p = proc_mkdir_mode(entry->name, entry->mode, root);
807 mutex_unlock(&info_mutex);
811 const struct file_operations *ops;
812 if (entry->content == SNDRV_INFO_CONTENT_DATA)
813 ops = &snd_info_entry_operations;
815 ops = &snd_info_text_entry_ops;
816 p = proc_create_data(entry->name, entry->mode, root,
819 mutex_unlock(&info_mutex);
822 proc_set_size(p, entry->size);
826 mutex_unlock(&info_mutex);
831 * snd_info_register - register the info entry
832 * @entry: the info entry
834 * Registers the proc info entry.
835 * The all children entries are registered recursively.
837 * Return: Zero if successful, or a negative error code on failure.
839 int snd_info_register(struct snd_info_entry *entry)
841 struct snd_info_entry *p;
845 err = __snd_info_register(entry);
850 list_for_each_entry(p, &entry->children, list) {
851 err = snd_info_register(p);
858 EXPORT_SYMBOL(snd_info_register);
861 * snd_card_rw_proc_new - Create a read/write text proc file entry for the card
862 * @card: the card instance
863 * @name: the file name
864 * @private_data: the arbitrary private data
865 * @read: the read callback
866 * @write: the write callback, NULL for read-only
868 * This proc file entry will be registered via snd_card_register() call, and
869 * it will be removed automatically at the card removal, too.
871 int snd_card_rw_proc_new(struct snd_card *card, const char *name,
873 void (*read)(struct snd_info_entry *,
874 struct snd_info_buffer *),
875 void (*write)(struct snd_info_entry *entry,
876 struct snd_info_buffer *buffer))
878 struct snd_info_entry *entry;
880 entry = snd_info_create_card_entry(card, name, card->proc_root);
883 snd_info_set_text_ops(entry, private_data, read);
886 entry->c.text.write = write;
890 EXPORT_SYMBOL_GPL(snd_card_rw_proc_new);
896 static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
899 "Advanced Linux Sound Architecture Driver Version k%s.\n",
900 init_utsname()->release);
903 static int __init snd_info_version_init(void)
905 struct snd_info_entry *entry;
907 entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL);
910 entry->c.text.read = snd_info_version_read;
911 return snd_info_register(entry); /* freed in error path */