ec_sys.c
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/*
* ec_sys.c
*
* Copyright (C) 2010 SUSE Products GmbH/Novell
* Author:
* Thomas Renninger <trenn@suse.de>
*
* This work is licensed under the terms of the GNU GPL, version 2.
*/
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include "internal.h"
MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>");
MODULE_DESCRIPTION("ACPI EC sysfs access driver");
MODULE_LICENSE("GPL");
static bool write_support;
module_param(write_support, bool, 0644);
MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may "
"be needed.");
#define EC_SPACE_SIZE 256
static struct dentry *acpi_ec_debugfs_dir;
static ssize_t acpi_ec_read_io(struct file *f, char __user *buf,
size_t count, loff_t *off)
{
/* Use this if support reading/writing multiple ECs exists in ec.c:
* struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;
*/
unsigned int size = EC_SPACE_SIZE;
loff_t init_off = *off;
int err = 0;
if (*off >= size)
return 0;
if (*off + count >= size) {
size -= *off;
count = size;
} else
size = count;
while (size) {
u8 byte_read;
err = ec_read(*off, &byte_read);
if (err)
return err;
if (put_user(byte_read, buf + *off - init_off)) {
if (*off - init_off)
return *off - init_off; /* partial read */
return -EFAULT;
}
*off += 1;
size--;
}
return count;
}
static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf,
size_t count, loff_t *off)
{
/* Use this if support reading/writing multiple ECs exists in ec.c:
* struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;
*/
unsigned int size = count;
loff_t init_off = *off;
int err = 0;
if (*off >= EC_SPACE_SIZE)
return 0;
if (*off + count >= EC_SPACE_SIZE) {
size = EC_SPACE_SIZE - *off;
count = size;
}
while (size) {
u8 byte_write;
if (get_user(byte_write, buf + *off - init_off)) {
if (*off - init_off)
return *off - init_off; /* partial write */
return -EFAULT;
}
err = ec_write(*off, byte_write);
if (err)
return err;
*off += 1;
size--;
}
return count;
}
static const struct file_operations acpi_ec_io_ops = {
.owner = THIS_MODULE,
.open = simple_open,
.read = acpi_ec_read_io,
.write = acpi_ec_write_io,
.llseek = default_llseek,
};
static int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count)
{
struct dentry *dev_dir;
char name[64];
umode_t mode = 0400;
if (ec_device_count == 0) {
acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL);
if (!acpi_ec_debugfs_dir)
return -ENOMEM;
}
sprintf(name, "ec%u", ec_device_count);
dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir);
if (!dev_dir) {
if (ec_device_count != 0)
goto error;
return -ENOMEM;
}
if (!debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe))
goto error;
if (!debugfs_create_bool("use_global_lock", 0444, dev_dir,
&first_ec->global_lock))
goto error;
if (write_support)
mode = 0600;
if (!debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops))
goto error;
return 0;
error:
debugfs_remove_recursive(acpi_ec_debugfs_dir);
return -ENOMEM;
}
static int __init acpi_ec_sys_init(void)
{
int err = 0;
if (first_ec)
err = acpi_ec_add_debugfs(first_ec, 0);
else
err = -ENODEV;
return err;
}
static void __exit acpi_ec_sys_exit(void)
{
debugfs_remove_recursive(acpi_ec_debugfs_dir);
}
module_init(acpi_ec_sys_init);
module_exit(acpi_ec_sys_exit);