| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Information interface for ALSA driver |
| * Copyright (c) by Jaroslav Kysela <perex@perex.cz> |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/time.h> |
| #include <linux/mm.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| #include <linux/module.h> |
| #include <sound/core.h> |
| #include <sound/minors.h> |
| #include <sound/info.h> |
| #include <linux/utsname.h> |
| #include <linux/proc_fs.h> |
| #include <linux/mutex.h> |
| #include <stdarg.h> |
| |
| int snd_info_check_reserved_words(const char *str) |
| { |
| static const char * const reserved[] = |
| { |
| "version", |
| "meminfo", |
| "memdebug", |
| "detect", |
| "devices", |
| "oss", |
| "cards", |
| "timers", |
| "synth", |
| "pcm", |
| "seq", |
| NULL |
| }; |
| const char * const *xstr = reserved; |
| |
| while (*xstr) { |
| if (!strcmp(*xstr, str)) |
| return 0; |
| xstr++; |
| } |
| if (!strncmp(str, "card", 4)) |
| return 0; |
| return 1; |
| } |
| |
| static DEFINE_MUTEX(info_mutex); |
| |
| struct snd_info_private_data { |
| struct snd_info_buffer *rbuffer; |
| struct snd_info_buffer *wbuffer; |
| struct snd_info_entry *entry; |
| void *file_private_data; |
| }; |
| |
| static int snd_info_version_init(void); |
| static void snd_info_disconnect(struct snd_info_entry *entry); |
| |
| /* |
| |
| */ |
| |
| static struct snd_info_entry *snd_proc_root; |
| struct snd_info_entry *snd_seq_root; |
| EXPORT_SYMBOL(snd_seq_root); |
| |
| #ifdef CONFIG_SND_OSSEMUL |
| struct snd_info_entry *snd_oss_root; |
| #endif |
| |
| static int alloc_info_private(struct snd_info_entry *entry, |
| struct snd_info_private_data **ret) |
| { |
| struct snd_info_private_data *data; |
| |
| if (!entry || !entry->p) |
| return -ENODEV; |
| if (!try_module_get(entry->module)) |
| return -EFAULT; |
| data = kzalloc(sizeof(*data), GFP_KERNEL); |
| if (!data) { |
| module_put(entry->module); |
| return -ENOMEM; |
| } |
| data->entry = entry; |
| *ret = data; |
| return 0; |
| } |
| |
| static bool valid_pos(loff_t pos, size_t count) |
| { |
| if (pos < 0 || (long) pos != pos || (ssize_t) count < 0) |
| return false; |
| if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos) |
| return false; |
| return true; |
| } |
| |
| /* |
| * file ops for binary proc files |
| */ |
| static loff_t snd_info_entry_llseek(struct file *file, loff_t offset, int orig) |
| { |
| struct snd_info_private_data *data; |
| struct snd_info_entry *entry; |
| loff_t ret = -EINVAL, size; |
| |
| data = file->private_data; |
| entry = data->entry; |
| mutex_lock(&entry->access); |
| if (entry->c.ops->llseek) { |
| offset = entry->c.ops->llseek(entry, |
| data->file_private_data, |
| file, offset, orig); |
| goto out; |
| } |
| |
| size = entry->size; |
| switch (orig) { |
| case SEEK_SET: |
| break; |
| case SEEK_CUR: |
| offset += file->f_pos; |
| break; |
| case SEEK_END: |
| if (!size) |
| goto out; |
| offset += size; |
| break; |
| default: |
| goto out; |
| } |
| if (offset < 0) |
| goto out; |
| if (size && offset > size) |
| offset = size; |
| file->f_pos = offset; |
| ret = offset; |
| out: |
| mutex_unlock(&entry->access); |
| return ret; |
| } |
| |
| static ssize_t snd_info_entry_read(struct file *file, char __user *buffer, |
| size_t count, loff_t * offset) |
| { |
| struct snd_info_private_data *data = file->private_data; |
| struct snd_info_entry *entry = data->entry; |
| size_t size; |
| loff_t pos; |
| |
| pos = *offset; |
| if (!valid_pos(pos, count)) |
| return -EIO; |
| if (pos >= entry->size) |
| return 0; |
| size = entry->size - pos; |
| size = min(count, size); |
| size = entry->c.ops->read(entry, data->file_private_data, |
| file, buffer, size, pos); |
| if ((ssize_t) size > 0) |
| *offset = pos + size; |
| return size; |
| } |
| |
| static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer, |
| size_t count, loff_t * offset) |
| { |
| struct snd_info_private_data *data = file->private_data; |
| struct snd_info_entry *entry = data->entry; |
| ssize_t size = 0; |
| loff_t pos; |
| |
| pos = *offset; |
| if (!valid_pos(pos, count)) |
| return -EIO; |
| if (count > 0) { |
| size_t maxsize = entry->size - pos; |
| count = min(count, maxsize); |
| size = entry->c.ops->write(entry, data->file_private_data, |
| file, buffer, count, pos); |
| } |
| if (size > 0) |
| *offset = pos + size; |
| return size; |
| } |
| |
| static __poll_t snd_info_entry_poll(struct file *file, poll_table *wait) |
| { |
| struct snd_info_private_data *data = file->private_data; |
| struct snd_info_entry *entry = data->entry; |
| __poll_t mask = 0; |
| |
| if (entry->c.ops->poll) |
| return entry->c.ops->poll(entry, |
| data->file_private_data, |
| file, wait); |
| if (entry->c.ops->read) |
| mask |= EPOLLIN | EPOLLRDNORM; |
| if (entry->c.ops->write) |
| mask |= EPOLLOUT | EPOLLWRNORM; |
| return mask; |
| } |
| |
| static long snd_info_entry_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct snd_info_private_data *data = file->private_data; |
| struct snd_info_entry *entry = data->entry; |
| |
| if (!entry->c.ops->ioctl) |
| return -ENOTTY; |
| return entry->c.ops->ioctl(entry, data->file_private_data, |
| file, cmd, arg); |
| } |
| |
| static int snd_info_entry_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| struct inode *inode = file_inode(file); |
| struct snd_info_private_data *data; |
| struct snd_info_entry *entry; |
| |
| data = file->private_data; |
| if (data == NULL) |
| return 0; |
| entry = data->entry; |
| if (!entry->c.ops->mmap) |
| return -ENXIO; |
| return entry->c.ops->mmap(entry, data->file_private_data, |
| inode, file, vma); |
| } |
| |
| static int snd_info_entry_open(struct inode *inode, struct file *file) |
| { |
| struct snd_info_entry *entry = PDE_DATA(inode); |
| struct snd_info_private_data *data; |
| int mode, err; |
| |
| mutex_lock(&info_mutex); |
| err = alloc_info_private(entry, &data); |
| if (err < 0) |
| goto unlock; |
| |
| mode = file->f_flags & O_ACCMODE; |
| if (((mode == O_RDONLY || mode == O_RDWR) && !entry->c.ops->read) || |
| ((mode == O_WRONLY || mode == O_RDWR) && !entry->c.ops->write)) { |
| err = -ENODEV; |
| goto error; |
| } |
| |
| if (entry->c.ops->open) { |
| err = entry->c.ops->open(entry, mode, &data->file_private_data); |
| if (err < 0) |
| goto error; |
| } |
| |
| file->private_data = data; |
| mutex_unlock(&info_mutex); |
| return 0; |
| |
| error: |
| kfree(data); |
| module_put(entry->module); |
| unlock: |
| mutex_unlock(&info_mutex); |
| return err; |
| } |
| |
| static int snd_info_entry_release(struct inode *inode, struct file *file) |
| { |
| struct snd_info_private_data *data = file->private_data; |
| struct snd_info_entry *entry = data->entry; |
| |
| if (entry->c.ops->release) |
| entry->c.ops->release(entry, file->f_flags & O_ACCMODE, |
| data->file_private_data); |
| module_put(entry->module); |
| kfree(data); |
| return 0; |
| } |
| |
| static const struct file_operations snd_info_entry_operations = |
| { |
| .owner = THIS_MODULE, |
| .llseek = snd_info_entry_llseek, |
| .read = snd_info_entry_read, |
| .write = snd_info_entry_write, |
| .poll = snd_info_entry_poll, |
| .unlocked_ioctl = snd_info_entry_ioctl, |
| .mmap = snd_info_entry_mmap, |
| .open = snd_info_entry_open, |
| .release = snd_info_entry_release, |
| }; |
| |
| /* |
| * file ops for text proc files |
| */ |
| static ssize_t snd_info_text_entry_write(struct file *file, |
| const char __user *buffer, |
| size_t count, loff_t *offset) |
| { |
| struct seq_file *m = file->private_data; |
| struct snd_info_private_data *data = m->private; |
| struct snd_info_entry *entry = data->entry; |
| struct snd_info_buffer *buf; |
| loff_t pos; |
| size_t next; |
| int err = 0; |
| |
| if (!entry->c.text.write) |
| return -EIO; |
| pos = *offset; |
| if (!valid_pos(pos, count)) |
| return -EIO; |
| next = pos + count; |
| /* don't handle too large text inputs */ |
| if (next > 16 * 1024) |
| return -EIO; |
| mutex_lock(&entry->access); |
| buf = data->wbuffer; |
| if (!buf) { |
| data->wbuffer = buf = kzalloc(sizeof(*buf), GFP_KERNEL); |
| if (!buf) { |
| err = -ENOMEM; |
| goto error; |
| } |
| } |
| if (next > buf->len) { |
| char *nbuf = kvzalloc(PAGE_ALIGN(next), GFP_KERNEL); |
| if (!nbuf) { |
| err = -ENOMEM; |
| goto error; |
| } |
| kvfree(buf->buffer); |
| buf->buffer = nbuf; |
| buf->len = PAGE_ALIGN(next); |
| } |
| if (copy_from_user(buf->buffer + pos, buffer, count)) { |
| err = -EFAULT; |
| goto error; |
| } |
| buf->size = next; |
| error: |
| mutex_unlock(&entry->access); |
| if (err < 0) |
| return err; |
| *offset = next; |
| return count; |
| } |
| |
| static int snd_info_seq_show(struct seq_file *seq, void *p) |
| { |
| struct snd_info_private_data *data = seq->private; |
| struct snd_info_entry *entry = data->entry; |
| |
| if (!entry->c.text.read) { |
| return -EIO; |
| } else { |
| data->rbuffer->buffer = (char *)seq; /* XXX hack! */ |
| entry->c.text.read(entry, data->rbuffer); |
| } |
| return 0; |
| } |
| |
| static int snd_info_text_entry_open(struct inode *inode, struct file *file) |
| { |
| struct snd_info_entry *entry = PDE_DATA(inode); |
| struct snd_info_private_data *data; |
| int err; |
| |
| mutex_lock(&info_mutex); |
| err = alloc_info_private(entry, &data); |
| if (err < 0) |
| goto unlock; |
| |
| data->rbuffer = kzalloc(sizeof(*data->rbuffer), GFP_KERNEL); |
| if (!data->rbuffer) { |
| err = -ENOMEM; |
| goto error; |
| } |
| if (entry->size) |
| err = single_open_size(file, snd_info_seq_show, data, |
| entry->size); |
| else |
| err = single_open(file, snd_info_seq_show, data); |
| if (err < 0) |
| goto error; |
| mutex_unlock(&info_mutex); |
| return 0; |
| |
| error: |
| kfree(data->rbuffer); |
| kfree(data); |
| module_put(entry->module); |
| unlock: |
| mutex_unlock(&info_mutex); |
| return err; |
| } |
| |
| static int snd_info_text_entry_release(struct inode *inode, struct file *file) |
| { |
| struct seq_file *m = file->private_data; |
| struct snd_info_private_data *data = m->private; |
| struct snd_info_entry *entry = data->entry; |
| |
| if (data->wbuffer && entry->c.text.write) |
| entry->c.text.write(entry, data->wbuffer); |
| |
| single_release(inode, file); |
| kfree(data->rbuffer); |
| if (data->wbuffer) { |
| kvfree(data->wbuffer->buffer); |
| kfree(data->wbuffer); |
| } |
| |
| module_put(entry->module); |
| kfree(data); |
| return 0; |
| } |
| |
| static const struct file_operations snd_info_text_entry_ops = |
| { |
| .owner = THIS_MODULE, |
| .open = snd_info_text_entry_open, |
| .release = snd_info_text_entry_release, |
| .write = snd_info_text_entry_write, |
| .llseek = seq_lseek, |
| .read = seq_read, |
| }; |
| |
| static struct snd_info_entry *create_subdir(struct module *mod, |
| const char *name) |
| { |
| struct snd_info_entry *entry; |
| |
| entry = snd_info_create_module_entry(mod, name, NULL); |
| if (!entry) |
| return NULL; |
| entry->mode = S_IFDIR | 0555; |
| if (snd_info_register(entry) < 0) { |
| snd_info_free_entry(entry); |
| return NULL; |
| } |
| return entry; |
| } |
| |
| static struct snd_info_entry * |
| snd_info_create_entry(const char *name, struct snd_info_entry *parent, |
| struct module *module); |
| |
| int __init snd_info_init(void) |
| { |
| snd_proc_root = snd_info_create_entry("asound", NULL, THIS_MODULE); |
| if (!snd_proc_root) |
| return -ENOMEM; |
| snd_proc_root->mode = S_IFDIR | 0555; |
| snd_proc_root->p = proc_mkdir("asound", NULL); |
| if (!snd_proc_root->p) |
| goto error; |
| #ifdef CONFIG_SND_OSSEMUL |
| snd_oss_root = create_subdir(THIS_MODULE, "oss"); |
| if (!snd_oss_root) |
| goto error; |
| #endif |
| #if IS_ENABLED(CONFIG_SND_SEQUENCER) |
| snd_seq_root = create_subdir(THIS_MODULE, "seq"); |
| if (!snd_seq_root) |
| goto error; |
| #endif |
| if (snd_info_version_init() < 0 || |
| snd_minor_info_init() < 0 || |
| snd_minor_info_oss_init() < 0 || |
| snd_card_info_init() < 0 || |
| snd_info_minor_register() < 0) |
| goto error; |
| return 0; |
| |
| error: |
| snd_info_free_entry(snd_proc_root); |
| return -ENOMEM; |
| } |
| |
| int __exit snd_info_done(void) |
| { |
| snd_info_free_entry(snd_proc_root); |
| return 0; |
| } |
| |
| static void snd_card_id_read(struct snd_info_entry *entry, |
| struct snd_info_buffer *buffer) |
| { |
| struct snd_card *card = entry->private_data; |
| |
| snd_iprintf(buffer, "%s\n", card->id); |
| } |
| |
| /* |
| * create a card proc file |
| * called from init.c |
| */ |
| int snd_info_card_create(struct snd_card *card) |
| { |
| char str[8]; |
| struct snd_info_entry *entry; |
| |
| if (snd_BUG_ON(!card)) |
| return -ENXIO; |
| |
| sprintf(str, "card%i", card->number); |
| entry = create_subdir(card->module, str); |
| if (!entry) |
| return -ENOMEM; |
| card->proc_root = entry; |
| |
| return snd_card_ro_proc_new(card, "id", card, snd_card_id_read); |
| } |
| |
| /* |
| * register the card proc file |
| * called from init.c |
| * can be called multiple times for reinitialization |
| */ |
| int snd_info_card_register(struct snd_card *card) |
| { |
| struct proc_dir_entry *p; |
| int err; |
| |
| if (snd_BUG_ON(!card)) |
| return -ENXIO; |
| |
| err = snd_info_register(card->proc_root); |
| if (err < 0) |
| return err; |
| |
| if (!strcmp(card->id, card->proc_root->name)) |
| return 0; |
| |
| if (card->proc_root_link) |
| return 0; |
| p = proc_symlink(card->id, snd_proc_root->p, card->proc_root->name); |
| if (!p) |
| return -ENOMEM; |
| card->proc_root_link = p; |
| return 0; |
| } |
| |
| /* |
| * called on card->id change |
| */ |
| void snd_info_card_id_change(struct snd_card *card) |
| { |
| mutex_lock(&info_mutex); |
| if (card->proc_root_link) { |
| proc_remove(card->proc_root_link); |
| card->proc_root_link = NULL; |
| } |
| if (strcmp(card->id, card->proc_root->name)) |
| card->proc_root_link = proc_symlink(card->id, |
| snd_proc_root->p, |
| card->proc_root->name); |
| mutex_unlock(&info_mutex); |
| } |
| |
| /* |
| * de-register the card proc file |
| * called from init.c |
| */ |
| void snd_info_card_disconnect(struct snd_card *card) |
| { |
| if (!card) |
| return; |
| mutex_lock(&info_mutex); |
| proc_remove(card->proc_root_link); |
| card->proc_root_link = NULL; |
| if (card->proc_root) |
| snd_info_disconnect(card->proc_root); |
| mutex_unlock(&info_mutex); |
| } |
| |
| /* |
| * release the card proc file resources |
| * called from init.c |
| */ |
| int snd_info_card_free(struct snd_card *card) |
| { |
| if (!card) |
| return 0; |
| snd_info_free_entry(card->proc_root); |
| card->proc_root = NULL; |
| return 0; |
| } |
| |
| |
| /** |
| * snd_info_get_line - read one line from the procfs buffer |
| * @buffer: the procfs buffer |
| * @line: the buffer to store |
| * @len: the max. buffer size |
| * |
| * Reads one line from the buffer and stores the string. |
| * |
| * Return: Zero if successful, or 1 if error or EOF. |
| */ |
| int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len) |
| { |
| int c = -1; |
| |
| if (snd_BUG_ON(!buffer || !buffer->buffer)) |
| return 1; |
| if (len <= 0 || buffer->stop || buffer->error) |
| return 1; |
| while (!buffer->stop) { |
| c = buffer->buffer[buffer->curr++]; |
| if (buffer->curr >= buffer->size) |
| buffer->stop = 1; |
| if (c == '\n') |
| break; |
| if (len > 1) { |
| len--; |
| *line++ = c; |
| } |
| } |
| *line = '\0'; |
| return 0; |
| } |
| EXPORT_SYMBOL(snd_info_get_line); |
| |
| /** |
| * snd_info_get_str - parse a string token |
| * @dest: the buffer to store the string token |
| * @src: the original string |
| * @len: the max. length of token - 1 |
| * |
| * Parses the original string and copy a token to the given |
| * string buffer. |
| * |
| * Return: The updated pointer of the original string so that |
| * it can be used for the next call. |
| */ |
| const char *snd_info_get_str(char *dest, const char *src, int len) |
| { |
| int c; |
| |
| while (*src == ' ' || *src == '\t') |
| src++; |
| if (*src == '"' || *src == '\'') { |
| c = *src++; |
| while (--len > 0 && *src && *src != c) { |
| *dest++ = *src++; |
| } |
| if (*src == c) |
| src++; |
| } else { |
| while (--len > 0 && *src && *src != ' ' && *src != '\t') { |
| *dest++ = *src++; |
| } |
| } |
| *dest = 0; |
| while (*src == ' ' || *src == '\t') |
| src++; |
| return src; |
| } |
| EXPORT_SYMBOL(snd_info_get_str); |
| |
| /* |
| * snd_info_create_entry - create an info entry |
| * @name: the proc file name |
| * @parent: the parent directory |
| * |
| * Creates an info entry with the given file name and initializes as |
| * the default state. |
| * |
| * Usually called from other functions such as |
| * snd_info_create_card_entry(). |
| * |
| * Return: The pointer of the new instance, or %NULL on failure. |
| */ |
| static struct snd_info_entry * |
| snd_info_create_entry(const char *name, struct snd_info_entry *parent, |
| struct module *module) |
| { |
| struct snd_info_entry *entry; |
| entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
| if (entry == NULL) |
| return NULL; |
| entry->name = kstrdup(name, GFP_KERNEL); |
| if (entry->name == NULL) { |
| kfree(entry); |
| return NULL; |
| } |
| entry->mode = S_IFREG | 0444; |
| entry->content = SNDRV_INFO_CONTENT_TEXT; |
| mutex_init(&entry->access); |
| INIT_LIST_HEAD(&entry->children); |
| INIT_LIST_HEAD(&entry->list); |
| entry->parent = parent; |
| entry->module = module; |
| if (parent) { |
| mutex_lock(&parent->access); |
| list_add_tail(&entry->list, &parent->children); |
| mutex_unlock(&parent->access); |
| } |
| return entry; |
| } |
| |
| /** |
| * snd_info_create_module_entry - create an info entry for the given module |
| * @module: the module pointer |
| * @name: the file name |
| * @parent: the parent directory |
| * |
| * Creates a new info entry and assigns it to the given module. |
| * |
| * Return: The pointer of the new instance, or %NULL on failure. |
| */ |
| struct snd_info_entry *snd_info_create_module_entry(struct module * module, |
| const char *name, |
| struct snd_info_entry *parent) |
| { |
| if (!parent) |
| parent = snd_proc_root; |
| return snd_info_create_entry(name, parent, module); |
| } |
| EXPORT_SYMBOL(snd_info_create_module_entry); |
| |
| /** |
| * snd_info_create_card_entry - create an info entry for the given card |
| * @card: the card instance |
| * @name: the file name |
| * @parent: the parent directory |
| * |
| * Creates a new info entry and assigns it to the given card. |
| * |
| * Return: The pointer of the new instance, or %NULL on failure. |
| */ |
| struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card, |
| const char *name, |
| struct snd_info_entry * parent) |
| { |
| if (!parent) |
| parent = card->proc_root; |
| return snd_info_create_entry(name, parent, card->module); |
| } |
| EXPORT_SYMBOL(snd_info_create_card_entry); |
| |
| static void snd_info_disconnect(struct snd_info_entry *entry) |
| { |
| struct snd_info_entry *p; |
| |
| if (!entry->p) |
| return; |
| list_for_each_entry(p, &entry->children, list) |
| snd_info_disconnect(p); |
| proc_remove(entry->p); |
| entry->p = NULL; |
| } |
| |
| /** |
| * snd_info_free_entry - release the info entry |
| * @entry: the info entry |
| * |
| * Releases the info entry. |
| */ |
| void snd_info_free_entry(struct snd_info_entry * entry) |
| { |
| struct snd_info_entry *p, *n; |
| |
| if (!entry) |
| return; |
| if (entry->p) { |
| mutex_lock(&info_mutex); |
| snd_info_disconnect(entry); |
| mutex_unlock(&info_mutex); |
| } |
| |
| /* free all children at first */ |
| list_for_each_entry_safe(p, n, &entry->children, list) |
| snd_info_free_entry(p); |
| |
| p = entry->parent; |
| if (p) { |
| mutex_lock(&p->access); |
| list_del(&entry->list); |
| mutex_unlock(&p->access); |
| } |
| kfree(entry->name); |
| if (entry->private_free) |
| entry->private_free(entry); |
| kfree(entry); |
| } |
| EXPORT_SYMBOL(snd_info_free_entry); |
| |
| static int __snd_info_register(struct snd_info_entry *entry) |
| { |
| struct proc_dir_entry *root, *p = NULL; |
| |
| if (snd_BUG_ON(!entry)) |
| return -ENXIO; |
| root = entry->parent == NULL ? snd_proc_root->p : entry->parent->p; |
| mutex_lock(&info_mutex); |
| if (entry->p || !root) |
| goto unlock; |
| if (S_ISDIR(entry->mode)) { |
| p = proc_mkdir_mode(entry->name, entry->mode, root); |
| if (!p) { |
| mutex_unlock(&info_mutex); |
| return -ENOMEM; |
| } |
| } else { |
| const struct file_operations *ops; |
| if (entry->content == SNDRV_INFO_CONTENT_DATA) |
| ops = &snd_info_entry_operations; |
| else |
| ops = &snd_info_text_entry_ops; |
| p = proc_create_data(entry->name, entry->mode, root, |
| ops, entry); |
| if (!p) { |
| mutex_unlock(&info_mutex); |
| return -ENOMEM; |
| } |
| proc_set_size(p, entry->size); |
| } |
| entry->p = p; |
| unlock: |
| mutex_unlock(&info_mutex); |
| return 0; |
| } |
| |
| /** |
| * snd_info_register - register the info entry |
| * @entry: the info entry |
| * |
| * Registers the proc info entry. |
| * The all children entries are registered recursively. |
| * |
| * Return: Zero if successful, or a negative error code on failure. |
| */ |
| int snd_info_register(struct snd_info_entry *entry) |
| { |
| struct snd_info_entry *p; |
| int err; |
| |
| if (!entry->p) { |
| err = __snd_info_register(entry); |
| if (err < 0) |
| return err; |
| } |
| |
| list_for_each_entry(p, &entry->children, list) { |
| err = snd_info_register(p); |
| if (err < 0) |
| return err; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(snd_info_register); |
| |
| /** |
| * snd_card_rw_proc_new - Create a read/write text proc file entry for the card |
| * @card: the card instance |
| * @name: the file name |
| * @private_data: the arbitrary private data |
| * @read: the read callback |
| * @write: the write callback, NULL for read-only |
| * |
| * This proc file entry will be registered via snd_card_register() call, and |
| * it will be removed automatically at the card removal, too. |
| */ |
| int snd_card_rw_proc_new(struct snd_card *card, const char *name, |
| void *private_data, |
| void (*read)(struct snd_info_entry *, |
| struct snd_info_buffer *), |
| void (*write)(struct snd_info_entry *entry, |
| struct snd_info_buffer *buffer)) |
| { |
| struct snd_info_entry *entry; |
| |
| entry = snd_info_create_card_entry(card, name, card->proc_root); |
| if (!entry) |
| return -ENOMEM; |
| snd_info_set_text_ops(entry, private_data, read); |
| if (write) { |
| entry->mode |= 0200; |
| entry->c.text.write = write; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(snd_card_rw_proc_new); |
| |
| /* |
| |
| */ |
| |
| static void snd_info_version_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer) |
| { |
| snd_iprintf(buffer, |
| "Advanced Linux Sound Architecture Driver Version k%s.\n", |
| init_utsname()->release); |
| } |
| |
| static int __init snd_info_version_init(void) |
| { |
| struct snd_info_entry *entry; |
| |
| entry = snd_info_create_module_entry(THIS_MODULE, "version", NULL); |
| if (entry == NULL) |
| return -ENOMEM; |
| entry->c.text.read = snd_info_version_read; |
| return snd_info_register(entry); /* freed in error path */ |
| } |