/*
* file.c - part of debugfs, a tiny little debug file system
*
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* debugfs is for people to use instead of /proc or /sys.
* See Documentation/DocBook/kernel-api for more details.
*
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/debugfs.h>
static ssize_t default_read_file(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
return 0;
}
static ssize_t default_write_file(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return count;
}
static int default_open(struct inode *inode, struct file *file)
{
if (inode->u.generic_ip)
file->private_data = inode->u.generic_ip;
return 0;
}
struct file_operations debugfs_file_operations = {
.read = default_read_file,
.write = default_write_file,
.open = default_open,
};
#define simple_type(type, format, temptype, strtolfn) \
static ssize_t read_file_##type(struct file *file, char __user *user_buf, \
size_t count, loff_t *ppos) \
{ \
char buf[32]; \
type *val = file->private_data; \
\
snprintf(buf, sizeof(buf), format "\n", *val); \
return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));\
} \
static ssize_t write_file_##type(struct file *file, const char __user *user_buf,\
size_t count, loff_t *ppos) \
{ \
char *endp; \
char buf[32]; \
int buf_size; \
type *val = file->private_data; \
temptype tmp; \
\
memset(buf, 0x00, sizeof(buf)); \
buf_size = min(count, (sizeof(buf)-1)); \
if (copy_from_user(buf, user_buf, buf_size)) \
return -EFAULT; \
\
tmp = strtolfn(buf, &endp, 0); \
if ((endp == buf) || ((type)tmp != tmp)) \
return -EINVAL; \
*val = tmp; \
return count; \
} \
static struct file_operations fops_##type = { \
.read = read_file_##type, \
.write = write_file_##type, \
.open = default_open, \
};
simple_type(u8, "%c", unsigned long, simple_strtoul);
simple_type(u16, "%hi", unsigned long, simple_strtoul);
simple_type(u32, "%i", unsigned long, simple_strtoul);
/**
* debugfs_create_u8 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this paramater is NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* NULL or !NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u8(const char *name, mode_t mode,
struct dentry *parent, u8 *value)
{
return debugfs_create_file(name, mode, parent, value, &fops_u8);
}
EXPORT_SYMBOL_GPL(debugfs_create_u8);
/**
* debugfs_create_u16 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this paramater is NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* NULL or !NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u16(const char *name, mode_t mode,
struct dentry *parent, u16 *value)
{
return debugfs_create_file(name, mode, parent, value, &fops_u16);
}
EXPORT_SYMBOL_GPL(debugfs_create_u16);
/**
* debugfs_create_u32 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value.
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this paramater is NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* NULL or !NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_u32(const char *name, mode_t mode,
struct dentry *parent, u32 *value)
{
return debugfs_create_file(name, mode, parent, value, &fops_u32);
}
EXPORT_SYMBOL_GPL(debugfs_create_u32);
static ssize_t read_file_bool(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
char buf[3];
u32 *val = file->private_data;
if (*val)
buf[0] = 'Y';
else
buf[0] = 'N';
buf[1] = '\n';
buf[2] = 0x00;
return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}
static ssize_t write_file_bool(struct file *file, const char __user *user_buf,
size_t count, loff_t *ppos)
{
char buf[32];
int buf_size;
u32 *val = file->private_data;
buf_size = min(count, (sizeof(buf)-1));
if (copy_from_user(buf, user_buf, buf_size))
return -EFAULT;
switch (buf[0]) {
case 'y':
case 'Y':
case '1':
*val = 1;
break;
case 'n':
case 'N':
case '0':
*val = 0;
break;
}
return count;
}
static struct file_operations fops_bool = {
.read = read_file_bool,
.write = write_file_bool,
.open = default_open,
};
/**
* debugfs_create_bool - create a file in the debugfs filesystem that is used to read and write a boolean value.
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this paramater is NULL, then the
* file will be created in the root of the debugfs filesystem.
* @value: a pointer to the variable that the file should read to and write
* from.
*
* This function creates a file in debugfs with the given name that
* contains the value of the variable @value. If the @mode variable is so
* set, it can be read from, and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here.) If an error occurs, NULL will be returned.
*
* If debugfs is not enabled in the kernel, the value -ENODEV will be
* returned. It is not wise to check for this value, but rather, check for
* NULL or !NULL instead as to eliminate the need for #ifdef in the calling
* code.
*/
struct dentry *debugfs_create_bool(const char *name, mode_t mode,
struct dentry *parent, u32 *value)
{
return debugfs_create_file(name, mode, parent, value, &fops_bool);
}
EXPORT_SYMBOL_GPL(debugfs_create_bool);
