1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 2010 SUSE Products GmbH/Novell
7 * Thomas Renninger <trenn@suse.de>
10 #include <linux/kernel.h>
11 #include <linux/acpi.h>
12 #include <linux/debugfs.h>
13 #include <linux/module.h>
14 #include <linux/uaccess.h>
17 MODULE_AUTHOR("Thomas Renninger <trenn@suse.de>");
18 MODULE_DESCRIPTION("ACPI EC sysfs access driver");
19 MODULE_LICENSE("GPL");
21 static bool write_support;
22 module_param(write_support, bool, 0644);
23 MODULE_PARM_DESC(write_support, "Dangerous, reboot and removal of battery may "
26 #define EC_SPACE_SIZE 256
28 static struct dentry *acpi_ec_debugfs_dir;
30 static ssize_t acpi_ec_read_io(struct file *f, char __user *buf,
31 size_t count, loff_t *off)
33 /* Use this if support reading/writing multiple ECs exists in ec.c:
34 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;
36 unsigned int size = EC_SPACE_SIZE;
37 loff_t init_off = *off;
42 if (*off + count >= size) {
50 err = ec_read(*off, &byte_read);
53 if (put_user(byte_read, buf + *off - init_off)) {
55 return *off - init_off; /* partial read */
64 static ssize_t acpi_ec_write_io(struct file *f, const char __user *buf,
65 size_t count, loff_t *off)
67 /* Use this if support reading/writing multiple ECs exists in ec.c:
68 * struct acpi_ec *ec = ((struct seq_file *)f->private_data)->private;
71 unsigned int size = count;
72 loff_t init_off = *off;
78 if (*off >= EC_SPACE_SIZE)
80 if (*off + count >= EC_SPACE_SIZE) {
81 size = EC_SPACE_SIZE - *off;
87 if (get_user(byte_write, buf + *off - init_off)) {
89 return *off - init_off; /* partial write */
92 err = ec_write(*off, byte_write);
102 static const struct file_operations acpi_ec_io_ops = {
103 .owner = THIS_MODULE,
105 .read = acpi_ec_read_io,
106 .write = acpi_ec_write_io,
107 .llseek = default_llseek,
110 static void acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count)
112 struct dentry *dev_dir;
116 if (ec_device_count == 0)
117 acpi_ec_debugfs_dir = debugfs_create_dir("ec", NULL);
119 sprintf(name, "ec%u", ec_device_count);
120 dev_dir = debugfs_create_dir(name, acpi_ec_debugfs_dir);
122 debugfs_create_x32("gpe", 0444, dev_dir, &first_ec->gpe);
123 debugfs_create_bool("use_global_lock", 0444, dev_dir,
124 &first_ec->global_lock);
128 debugfs_create_file("io", mode, dev_dir, ec, &acpi_ec_io_ops);
131 static int __init acpi_ec_sys_init(void)
134 acpi_ec_add_debugfs(first_ec, 0);
138 static void __exit acpi_ec_sys_exit(void)
140 debugfs_remove_recursive(acpi_ec_debugfs_dir);
143 module_init(acpi_ec_sys_init);
144 module_exit(acpi_ec_sys_exit);