path: root/drivers/hwmon/dell-smm-hwmon.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * dell-smm-hwmon.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
 *
 * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
 *
 * Hwmon integration:
 * Copyright (C) 2011  Jean Delvare <jdelvare@suse.de>
 * Copyright (C) 2013, 2014  Guenter Roeck <linux@roeck-us.net>
 * Copyright (C) 2014, 2015  Pali Rohár <pali@kernel.org>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/dmi.h>
#include <linux/capability.h>
#include <linux/mutex.h>
#include <linux/hwmon.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/smp.h>

#include <linux/i8k.h>

#define I8K_SMM_FN_STATUS	0x0025
#define I8K_SMM_POWER_STATUS	0x0069
#define I8K_SMM_SET_FAN		0x01a3
#define I8K_SMM_GET_FAN		0x00a3
#define I8K_SMM_GET_SPEED	0x02a3
#define I8K_SMM_GET_FAN_TYPE	0x03a3
#define I8K_SMM_GET_NOM_SPEED	0x04a3
#define I8K_SMM_GET_TEMP	0x10a3
#define I8K_SMM_GET_TEMP_TYPE	0x11a3
#define I8K_SMM_GET_DELL_SIG1	0xfea3
#define I8K_SMM_GET_DELL_SIG2	0xffa3

#define I8K_FAN_MULT		30
#define I8K_FAN_MAX_RPM		30000
#define I8K_MAX_TEMP		127

#define I8K_FN_NONE		0x00
#define I8K_FN_UP		0x01
#define I8K_FN_DOWN		0x02
#define I8K_FN_MUTE		0x04
#define I8K_FN_MASK		0x07
#define I8K_FN_SHIFT		8

#define I8K_POWER_AC		0x05
#define I8K_POWER_BATTERY	0x01

#define DELL_SMM_NO_TEMP	10
#define DELL_SMM_NO_FANS	3

struct dell_smm_data {
	struct mutex i8k_mutex; /* lock for sensors writes */
	char bios_version[4];
	char bios_machineid[16];
	uint i8k_fan_mult;
	uint i8k_pwm_mult;
	uint i8k_fan_max;
	bool disallow_fan_type_call;
	bool disallow_fan_support;
	unsigned int manual_fan;
	unsigned int auto_fan;
	int temp_type[DELL_SMM_NO_TEMP];
	bool fan[DELL_SMM_NO_FANS];
	int fan_type[DELL_SMM_NO_FANS];
};

MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("i8k");

static bool force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force, "Force loading without checking for supported models");

static bool ignore_dmi;
module_param(ignore_dmi, bool, 0);
MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");

#if IS_ENABLED(CONFIG_I8K)
static bool restricted = true;
module_param(restricted, bool, 0);
MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");

static bool power_status;
module_param(power_status, bool, 0600);
MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
#endif

static uint fan_mult;
module_param(fan_mult, uint, 0);
MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");

static uint fan_max;
module_param(fan_max, uint, 0);
MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autode