linux/drivers/base/regmap/regmap-debugfs.c

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/*
* Register map access API - debugfs
*
* Copyright 2011 Wolfson Microelectronics plc
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*
* 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.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include "internal.h"
static struct dentry *regmap_debugfs_root;
static int regmap_map_open_file(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
int reg_len, val_len, tot_len;
size_t buf_pos = 0;
loff_t p = 0;
ssize_t ret;
int i;
struct regmap *map = file->private_data;
char *buf;
unsigned int val;
if (*ppos < 0 || !count)
return -EINVAL;
buf = kmalloc(count, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/* Calculate the length of a fixed format */
snprintf(buf, count, "%x", map->max_register);
reg_len = strlen(buf);
val_len = 2 * map->format.val_bytes;
tot_len = reg_len + val_len + 3; /* : \n */
for (i = 0; i < map->max_register; i++) {
if (map->readable_reg &&
!map->readable_reg(map->dev, i))
continue;
if (map->precious_reg &&
map->precious_reg(map->dev, i))
continue;
/* If we're in the region the user is trying to read */
if (p >= *ppos) {
/* ...but not beyond it */
if (buf_pos >= count - 1 - tot_len)
break;
/* Format the register */
snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
reg_len, i);
buf_pos += reg_len + 2;
/* Format the value, write all X if we can't read */
ret = regmap_read(map, i, &val);
if (ret == 0)
snprintf(buf + buf_pos, count - buf_pos,
"%.*x", val_len, val);
else
memset(buf + buf_pos, 'X', val_len);
buf_pos += 2 * map->format.val_bytes;
buf[buf_pos++] = '\n';
}
p += tot_len;
}
ret = buf_pos;
if (copy_to_user(user_buf, buf, buf_pos)) {
ret = -EFAULT;
goto out;
}
*ppos += buf_pos;
out:
kfree(buf);
return ret;
}
static const struct file_operations regmap_map_fops = {
.open = regmap_map_open_file,
.read = regmap_map_read_file,
.llseek = default_llseek,
};
void regmap_debugfs_init(struct regmap *map)
{
map->debugfs = debugfs_create_dir(dev_name(map->dev),
regmap_debugfs_root);
if (!map->debugfs) {
dev_warn(map->dev, "Failed to create debugfs directory\n");
return;
}
if (map->max_register)
debugfs_create_file("registers", 0400, map->debugfs,
map, &regmap_map_fops);
}
void regmap_debugfs_exit(struct regmap *map)
{
debugfs_remove_recursive(map->debugfs);
}
void regmap_debugfs_initcall(void)
{
regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
if (!regmap_debugfs_root) {
pr_warn("regmap: Failed to create debugfs root\n");
return;
}
}