// 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_hw(write_support, bool, other, 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);