// SPDX-License-Identifier: GPL-2.0-only /* * ec_sys.c * * Copyright (C) 2010 SUSE Products GmbH/Novell * Author: * Thomas Renninger <trenn@suse.de> */ #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);