linux/drivers/acpi/ec_sys.c
Greg Kroah-Hartman 9ec6dbfbdc ACPI: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-22 19:45:52 +01:00

146 lines
3.2 KiB
C

/*
* 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 (!write_support)
return -EINVAL;
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 void 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);
sprintf(name, "ec%u", ec_device_count);
dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir);
debugfs_create_x32("gpe", 0444, dev_dir, &first_ec->gpe);
debugfs_create_bool("use_global_lock", 0444, dev_dir,
&first_ec->global_lock);
if (write_support)
mode = 0600;
debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops);
}
static int __init acpi_ec_sys_init(void)
{
if (first_ec)
acpi_ec_add_debugfs(first_ec, 0);
return 0;
}
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);