hwmon: Rename i8k driver to dell-smm-hwmon and move it to hwmon tree
authorPali Rohár <pali.rohar@gmail.com>
Thu, 14 May 2015 11:16:36 +0000 (13:16 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 24 May 2015 19:48:12 +0000 (12:48 -0700)
This commit moves i8k driver to hwmon tree under name dell-smm-hwmon which is
better name then abbreviation i8k. For backward compatibility is added macro
MODULE_ALIAS("i8k") so modprobe will load driver also old name i8k. CONFIG_I8K
compile option was not changed.

This commit also adds me as maintainer of this new dell-smm-hwmon driver and
remove Guenter Roeck from list who is implicit maintainer all hwmon drivers.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MAINTAINERS
drivers/char/Makefile
drivers/char/i8k.c [deleted file]
drivers/hwmon/Makefile
drivers/hwmon/dell-smm-hwmon.c [new file with mode: 0644]

index f8e0afb708b4fe2a60f3f6a3b697bd1dd60753d4..9201e140438ac4286f2852aee0c61bf8337ac39f 100644 (file)
@@ -3092,9 +3092,9 @@ S:        Maintained
 F:     drivers/platform/x86/dell-smo8800.c
 
 DELL LAPTOP SMM DRIVER
-M:     Guenter Roeck <linux@roeck-us.net>
+M:     Pali Rohár <pali.rohar@gmail.com>
 S:     Maintained
-F:     drivers/char/i8k.c
+F:     drivers/hwmon/dell-smm-hwmon.c
 F:     include/uapi/linux/i8k.h
 
 DELL SYSTEMS MANAGEMENT BASE DRIVER (dcdbas)
index 76cdfaa07cd5ed1eed7cbd6ca9ff8ef0ddc13e25..d8a7579300d2df1112446c3a69a29713fd2af163 100644 (file)
@@ -35,7 +35,6 @@ else
   obj-$(CONFIG_NVRAM)  += nvram.o
 endif
 obj-$(CONFIG_TOSHIBA)          += toshiba.o
-obj-$(CONFIG_I8K)              += i8k.o
 obj-$(CONFIG_DS1620)           += ds1620.o
 obj-$(CONFIG_HW_RANDOM)                += hw_random/
 obj-$(CONFIG_PPDEV)            += ppdev.o
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
deleted file mode 100644 (file)
index a43048b..0000000
+++ /dev/null
@@ -1,1007 +0,0 @@
-/*
- * i8k.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  Pali Rohár <pali.rohar@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2, or (at your option) any
- * later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/delay.h>
-#include <linux/module.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/hwmon-sysfs.h>
-#include <linux/uaccess.h>
-#include <linux/io.h>
-#include <linux/sched.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
-
-static DEFINE_MUTEX(i8k_mutex);
-static char bios_version[4];
-static struct device *i8k_hwmon_dev;
-static u32 i8k_hwmon_flags;
-static uint i8k_fan_mult = I8K_FAN_MULT;
-static uint i8k_pwm_mult;
-static uint i8k_fan_max = I8K_FAN_HIGH;
-
-#define I8K_HWMON_HAVE_TEMP1   (1 << 0)
-#define I8K_HWMON_HAVE_TEMP2   (1 << 1)
-#define I8K_HWMON_HAVE_TEMP3   (1 << 2)
-#define I8K_HWMON_HAVE_TEMP4   (1 << 3)
-#define I8K_HWMON_HAVE_FAN1    (1 << 4)
-#define I8K_HWMON_HAVE_FAN2    (1 << 5)
-
-MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
-MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
-MODULE_LICENSE("GPL");
-
-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");
-
-static bool restricted;
-module_param(restricted, bool, 0);
-MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
-
-static bool power_status;
-module_param(power_status, bool, 0600);
-MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
-
-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: autodetect)");
-
-static int i8k_open_fs(struct inode *inode, struct file *file);
-static long i8k_ioctl(struct file *, unsigned int, unsigned long);
-
-static const struct file_operations i8k_fops = {
-       .owner          = THIS_MODULE,
-       .open           = i8k_open_fs,
-       .read           = seq_read,
-       .llseek         = seq_lseek,
-       .release        = single_release,
-       .unlocked_ioctl = i8k_ioctl,
-};
-
-struct smm_regs {
-       unsigned int eax;
-       unsigned int ebx __packed;
-       unsigned int ecx __packed;
-       unsigned int edx __packed;
-       unsigned int esi __packed;
-       unsigned int edi __packed;
-};
-
-static inline const char *i8k_get_dmi_data(int field)
-{
-       const char *dmi_data = dmi_get_system_info(field);
-
-       return dmi_data && *dmi_data ? dmi_data : "?";
-}
-
-/*
- * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
- */
-static int i8k_smm(struct smm_regs *regs)
-{
-       int rc;
-       int eax = regs->eax;
-       cpumask_var_t old_mask;
-
-       /* SMM requires CPU 0 */
-       if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
-               return -ENOMEM;
-       cpumask_copy(old_mask, &current->cpus_allowed);
-       rc = set_cpus_allowed_ptr(current, cpumask_of(0));
-       if (rc)
-               goto out;
-       if (smp_processor_id() != 0) {
-               rc = -EBUSY;
-               goto out;
-       }
-
-#if defined(CONFIG_X86_64)
-       asm volatile("pushq %%rax\n\t"
-               "movl 0(%%rax),%%edx\n\t"
-               "pushq %%rdx\n\t"
-               "movl 4(%%rax),%%ebx\n\t"
-               "movl 8(%%rax),%%ecx\n\t"
-               "movl 12(%%rax),%%edx\n\t"
-               "movl 16(%%rax),%%esi\n\t"
-               "movl 20(%%rax),%%edi\n\t"
-               "popq %%rax\n\t"
-               "out %%al,$0xb2\n\t"
-               "out %%al,$0x84\n\t"
-               "xchgq %%rax,(%%rsp)\n\t"
-               "movl %%ebx,4(%%rax)\n\t"
-               "movl %%ecx,8(%%rax)\n\t"
-               "movl %%edx,12(%%rax)\n\t"
-               "movl %%esi,16(%%rax)\n\t"
-               "movl %%edi,20(%%rax)\n\t"
-               "popq %%rdx\n\t"
-               "movl %%edx,0(%%rax)\n\t"
-               "pushfq\n\t"
-               "popq %%rax\n\t"
-               "andl $1,%%eax\n"
-               : "=a"(rc)
-               :    "a"(regs)
-               :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
-#else
-       asm volatile("pushl %%eax\n\t"
-           "movl 0(%%eax),%%edx\n\t"
-           "push %%edx\n\t"
-           "movl 4(%%eax),%%ebx\n\t"
-           "movl 8(%%eax),%%ecx\n\t"
-           "movl 12(%%eax),%%edx\n\t"
-           "movl 16(%%eax),%%esi\n\t"
-           "movl 20(%%eax),%%edi\n\t"
-           "popl %%eax\n\t"
-           "out %%al,$0xb2\n\t"
-           "out %%al,$0x84\n\t"
-           "xchgl %%eax,(%%esp)\n\t"
-           "movl %%ebx,4(%%eax)\n\t"
-           "movl %%ecx,8(%%eax)\n\t"
-           "movl %%edx,12(%%eax)\n\t"
-           "movl %%esi,16(%%eax)\n\t"
-           "movl %%edi,20(%%eax)\n\t"
-           "popl %%edx\n\t"
-           "movl %%edx,0(%%eax)\n\t"
-           "lahf\n\t"
-           "shrl $8,%%eax\n\t"
-           "andl $1,%%eax\n"
-           : "=a"(rc)
-           :    "a"(regs)
-           :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
-#endif
-       if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
-               rc = -EINVAL;
-
-out:
-       set_cpus_allowed_ptr(current, old_mask);
-       free_cpumask_var(old_mask);
-       return rc;
-}
-
-/*
- * Read the Fn key status.
- */
-static int i8k_get_fn_status(void)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
-       int rc;
-
-       rc = i8k_smm(&regs);
-       if (rc < 0)
-               return rc;
-
-       switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
-       case I8K_FN_UP:
-               return I8K_VOL_UP;
-       case I8K_FN_DOWN:
-               return I8K_VOL_DOWN;
-       case I8K_FN_MUTE:
-               return I8K_VOL_MUTE;
-       default:
-               return 0;
-       }
-}
-
-/*
- * Read the power status.
- */
-static int i8k_get_power_status(void)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
-       int rc;
-
-       rc = i8k_smm(&regs);
-       if (rc < 0)
-               return rc;
-
-       return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
-}
-
-/*
- * Read the fan status.
- */
-static int i8k_get_fan_status(int fan)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
-
-       regs.ebx = fan & 0xff;
-       return i8k_smm(&regs) ? : regs.eax & 0xff;
-}
-
-/*
- * Read the fan speed in RPM.
- */
-static int i8k_get_fan_speed(int fan)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
-
-       regs.ebx = fan & 0xff;
-       return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
-}
-
-/*
- * Read the fan type.
- */
-static int i8k_get_fan_type(int fan)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
-
-       regs.ebx = fan & 0xff;
-       return i8k_smm(&regs) ? : regs.eax & 0xff;
-}
-
-/*
- * Read the fan nominal rpm for specific fan speed.
- */
-static int i8k_get_fan_nominal_speed(int fan, int speed)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
-
-       regs.ebx = (fan & 0xff) | (speed << 8);
-       return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
-}
-
-/*
- * Set the fan speed (off, low, high). Returns the new fan status.
- */
-static int i8k_set_fan(int fan, int speed)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
-
-       speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
-       regs.ebx = (fan & 0xff) | (speed << 8);
-
-       return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
-}
-
-static int i8k_get_temp_type(int sensor)
-{
-       struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
-
-       regs.ebx = sensor & 0xff;
-       return i8k_smm(&regs) ? : regs.eax & 0xff;
-}
-
-/*
- * Read the cpu temperature.
- */
-static int _i8k_get_temp(int sensor)
-{
-       struct smm_regs regs = {
-               .eax = I8K_SMM_GET_TEMP,
-               .ebx = sensor & 0xff,
-       };
-
-       return i8k_smm(&regs) ? : regs.eax & 0xff;
-}
-
-static int i8k_get_temp(int sensor)
-{
-       int temp = _i8k_get_temp(sensor);
-
-       /*
-        * Sometimes the temperature sensor returns 0x99, which is out of range.
-        * In this case we retry (once) before returning an error.
-        # 1003655137 00000058 00005a4b
-        # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
-        # 1003655139 00000054 00005c52
-        */
-       if (temp == 0x99) {
-               msleep(100);
-               temp = _i8k_get_temp(sensor);
-       }
-       /*
-        * Return -ENODATA for all invalid temperatures.
-        *
-        * Known instances are the 0x99 value as seen above as well as
-        * 0xc1 (193), which may be returned when trying to read the GPU
-        * temperature if the system supports a GPU and it is currently
-        * turned off.
-        */
-       if (temp > I8K_MAX_TEMP)
-               return -ENODATA;
-
-       return temp;
-}
-
-static int i8k_get_dell_signature(int req_fn)
-{
-       struct smm_regs regs = { .eax = req_fn, };
-       int rc;
-
-       rc = i8k_smm(&regs);
-       if (rc < 0)
-               return rc;
-
-       return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
-}
-
-static int
-i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
-{
-       int val = 0;
-       int speed;
-       unsigned char buff[16];
-       int __user *argp = (int __user *)arg;
-
-       if (!argp)
-               return -EINVAL;
-
-       switch (cmd) {
-       case I8K_BIOS_VERSION:
-               val = (bios_version[0] << 16) |
-                               (bios_version[1] << 8) | bios_version[2];
-               break;
-
-       case I8K_MACHINE_ID:
-               memset(buff, 0, 16);
-               strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
-                       sizeof(buff));
-               break;
-
-       case I8K_FN_STATUS:
-               val = i8k_get_fn_status();
-               break;
-
-       case I8K_POWER_STATUS:
-               val = i8k_get_power_status();
-               break;
-
-       case I8K_GET_TEMP:
-               val = i8k_get_temp(0);
-               break;
-
-       case I8K_GET_SPEED:
-               if (copy_from_user(&val, argp, sizeof(int)))
-                       return -EFAULT;
-
-               val = i8k_get_fan_speed(val);
-               break;
-
-       case I8K_GET_FAN:
-               if (copy_from_user(&val, argp, sizeof(int)))
-                       return -EFAULT;
-
-               val = i8k_get_fan_status(val);
-               break;
-
-       case I8K_SET_FAN:
-               if (restricted && !capable(CAP_SYS_ADMIN))
-                       return -EPERM;
-
-               if (copy_from_user(&val, argp, sizeof(int)))
-                       return -EFAULT;
-
-               if (copy_from_user(&speed, argp + 1, sizeof(int)))
-                       return -EFAULT;
-
-               val = i8k_set_fan(val, speed);
-               break;
-
-       default:
-               return -EINVAL;
-       }
-
-       if (val < 0)
-               return val;
-
-       switch (cmd) {
-       case I8K_BIOS_VERSION:
-               if (copy_to_user(argp, &val, 4))
-                       return -EFAULT;
-
-               break;
-       case I8K_MACHINE_ID:
-               if (copy_to_user(argp, buff, 16))
-                       return -EFAULT;
-
-               break;
-       default:
-               if (copy_to_user(argp, &val, sizeof(int)))
-                       return -EFAULT;
-
-               break;
-       }
-
-       return 0;
-}
-
-static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
-{
-       long ret;
-
-       mutex_lock(&i8k_mutex);
-       ret = i8k_ioctl_unlocked(fp, cmd, arg);
-       mutex_unlock(&i8k_mutex);
-
-       return ret;
-}
-
-/*
- * Print the information for /proc/i8k.
- */
-static int i8k_proc_show(struct seq_file *seq, void *offset)
-{
-       int fn_key, cpu_temp, ac_power;
-       int left_fan, right_fan, left_speed, right_speed;
-
-       cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
-       left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
-       right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
-       left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
-       right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
-       fn_key          = i8k_get_fn_status();                  /*   750 µs */
-       if (power_status)
-               ac_power = i8k_get_power_status();              /* 14700 µs */
-       else
-               ac_power = -1;
-
-       /*
-        * Info:
-        *
-        * 1)  Format version (this will change if format changes)
-        * 2)  BIOS version
-        * 3)  BIOS machine ID
-        * 4)  Cpu temperature
-        * 5)  Left fan status
-        * 6)  Right fan status
-        * 7)  Left fan speed
-        * 8)  Right fan speed
-        * 9)  AC power
-        * 10) Fn Key status
-        */
-       seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
-                  I8K_PROC_FMT,
-                  bios_version,
-                  i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
-                  cpu_temp,
-                  left_fan, right_fan, left_speed, right_speed,
-                  ac_power, fn_key);
-
-       return 0;
-}
-
-static int i8k_open_fs(struct inode *inode, struct file *file)
-{
-       return single_open(file, i8k_proc_show, NULL);
-}
-
-
-/*
- * Hwmon interface
- */
-
-static ssize_t i8k_hwmon_show_temp_label(struct device *dev,
-                                        struct device_attribute *devattr,
-                                        char *buf)
-{
-       static const char * const labels[] = {
-               "CPU",
-               "GPU",
-               "SODIMM",
-               "Other",
-               "Ambient",
-               "Other",
-       };
-       int index = to_sensor_dev_attr(devattr)->index;
-       int type;
-
-       type = i8k_get_temp_type(index);
-       if (type < 0)
-               return type;
-       if (type >= ARRAY_SIZE(labels))
-               type = ARRAY_SIZE(labels) - 1;
-       return sprintf(buf, "%s\n", labels[type]);
-}
-
-static ssize_t i8k_hwmon_show_temp(struct device *dev,
-                                  struct device_attribute *devattr,
-                                  char *buf)
-{
-       int index = to_sensor_dev_attr(devattr)->index;
-       int temp;
-
-       temp = i8k_get_temp(index);
-       if (temp < 0)
-               return temp;
-       return sprintf(buf, "%d\n", temp * 1000);
-}
-
-static ssize_t i8k_hwmon_show_fan_label(struct device *dev,
-                                       struct device_attribute *devattr,
-                                       char *buf)
-{
-       static const char * const labels[] = {
-               "Processor Fan",
-               "Motherboard Fan",
-               "Video Fan",
-               "Power Supply Fan",
-               "Chipset Fan",
-               "Other Fan",
-       };
-       int index = to_sensor_dev_attr(devattr)->index;
-       bool dock = false;
-       int type;
-
-       type = i8k_get_fan_type(index);
-       if (type < 0)
-               return type;
-
-       if (type & 0x10) {
-               dock = true;
-               type &= 0x0F;
-       }
-
-       if (type >= ARRAY_SIZE(labels))
-               type = (ARRAY_SIZE(labels) - 1);
-
-       return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
-}
-
-static ssize_t i8k_hwmon_show_fan(struct device *dev,
-                                 struct device_attribute *devattr,
-                                 char *buf)
-{
-       int index = to_sensor_dev_attr(devattr)->index;
-       int fan_speed;
-
-       fan_speed = i8k_get_fan_speed(index);
-       if (fan_speed < 0)
-               return fan_speed;
-       return sprintf(buf, "%d\n", fan_speed);
-}
-
-static ssize_t i8k_hwmon_show_pwm(struct device *dev,
-                                 struct device_attribute *devattr,
-                                 char *buf)
-{
-       int index = to_sensor_dev_attr(devattr)->index;
-       int status;
-
-       status = i8k_get_fan_status(index);
-       if (status < 0)
-               return -EIO;
-       return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
-}
-
-static ssize_t i8k_hwmon_set_pwm(struct device *dev,
-                                struct device_attribute *attr,
-                                const char *buf, size_t count)
-{
-       int index = to_sensor_dev_attr(attr)->index;
-       unsigned long val;
-       int err;
-
-       err = kstrtoul(buf, 10, &val);
-       if (err)
-               return err;
-       val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
-
-       mutex_lock(&i8k_mutex);
-       err = i8k_set_fan(index, val);
-       mutex_unlock(&i8k_mutex);
-
-       return err < 0 ? -EIO : count;
-}
-
-static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
-static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
-                         0);
-static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
-static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
-                         1);
-static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
-static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
-                         2);
-static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
-static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
-                         3);
-static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL, 0);
-static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
-                         0);
-static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
-                         i8k_hwmon_set_pwm, 0);
-static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
-                         1);
-static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
-                         1);
-static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
-                         i8k_hwmon_set_pwm, 1);
-
-static struct attribute *i8k_attrs[] = {
-       &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
-       &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
-       &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
-       &sensor_dev_attr_temp2_label.dev_attr.attr,     /* 3 */
-       &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 4 */
-       &sensor_dev_attr_temp3_label.dev_attr.attr,     /* 5 */
-       &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 6 */
-       &sensor_dev_attr_temp4_label.dev_attr.attr,     /* 7 */
-       &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 8 */
-       &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 9 */
-       &sensor_dev_attr_pwm1.dev_attr.attr,            /* 10 */
-       &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 11 */
-       &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 12 */
-       &sensor_dev_attr_pwm2.dev_attr.attr,            /* 13 */
-       NULL
-};
-
-static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
-                             int index)
-{
-       if (index >= 0 && index <= 1 &&
-           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
-               return 0;
-       if (index >= 2 && index <= 3 &&
-           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
-               return 0;
-       if (index >= 4 && index <= 5 &&
-           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
-               return 0;
-       if (index >= 6 && index <= 7 &&
-           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
-               return 0;
-       if (index >= 8 && index <= 10 &&
-           !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
-               return 0;
-       if (index >= 11 && index <= 13 &&
-           !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
-               return 0;
-
-       return attr->mode;
-}
-
-static const struct attribute_group i8k_group = {
-       .attrs = i8k_attrs,
-       .is_visible = i8k_is_visible,
-};
-__ATTRIBUTE_GROUPS(i8k);
-
-static int __init i8k_init_hwmon(void)
-{
-       int err;
-
-       i8k_hwmon_flags = 0;
-
-       /* CPU temperature attributes, if temperature type is OK */
-       err = i8k_get_temp_type(0);
-       if (err >= 0)
-               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
-       /* check for additional temperature sensors */
-       err = i8k_get_temp_type(1);
-       if (err >= 0)
-               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
-       err = i8k_get_temp_type(2);
-       if (err >= 0)
-               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
-       err = i8k_get_temp_type(3);
-       if (err >= 0)
-               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
-
-       /* First fan attributes, if fan type is OK */
-       err = i8k_get_fan_type(0);
-       if (err >= 0)
-               i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
-
-       /* Second fan attributes, if fan type is OK */
-       err = i8k_get_fan_type(1);
-       if (err >= 0)
-               i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
-
-       i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
-                                                         i8k_groups);
-       if (IS_ERR(i8k_hwmon_dev)) {
-               err = PTR_ERR(i8k_hwmon_dev);
-               i8k_hwmon_dev = NULL;
-               pr_err("hwmon registration failed (%d)\n", err);
-               return err;
-       }
-       return 0;
-}
-
-struct i8k_config_data {
-       uint fan_mult;
-       uint fan_max;
-};
-
-enum i8k_configs {
-       DELL_LATITUDE_D520,
-       DELL_PRECISION_490,
-       DELL_STUDIO,
-       DELL_XPS,
-};
-
-static const struct i8k_config_data i8k_config_data[] = {
-       [DELL_LATITUDE_D520] = {
-               .fan_mult = 1,
-               .fan_max = I8K_FAN_TURBO,
-       },
-       [DELL_PRECISION_490] = {
-               .fan_mult = 1,
-               .fan_max = I8K_FAN_TURBO,
-       },
-       [DELL_STUDIO] = {
-               .fan_mult = 1,
-               .fan_max = I8K_FAN_HIGH,
-       },
-       [DELL_XPS] = {
-               .fan_mult = 1,
-               .fan_max = I8K_FAN_HIGH,
-       },
-};
-
-static struct dmi_system_id i8k_dmi_table[] __initdata = {
-       {
-               .ident = "Dell Inspiron",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
-               },
-       },
-       {
-               .ident = "Dell Latitude",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
-               },
-       },
-       {
-               .ident = "Dell Inspiron 2",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
-               },
-       },
-       {
-               .ident = "Dell Latitude D520",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
-               },
-               .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
-       },
-       {
-               .ident = "Dell Latitude 2",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
-               },
-       },
-       {       /* UK Inspiron 6400  */
-               .ident = "Dell Inspiron 3",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
-               },
-       },
-       {
-               .ident = "Dell Inspiron 3",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
-               },
-       },
-       {
-               .ident = "Dell Precision 490",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME,
-                                 "Precision WorkStation 490"),
-               },
-               .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
-       },
-       {
-               .ident = "Dell Precision",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
-               },
-       },
-       {
-               .ident = "Dell Vostro",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
-               },
-       },
-       {
-               .ident = "Dell XPS421",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
-               },
-       },
-       {
-               .ident = "Dell Studio",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
-               },
-               .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
-       },
-       {
-               .ident = "Dell XPS 13",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
-               },
-               .driver_data = (void *)&i8k_config_data[DELL_XPS],
-       },
-       {
-               .ident = "Dell XPS M140",
-               .matches = {
-                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-                       DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
-               },
-               .driver_data = (void *)&i8k_config_data[DELL_XPS],
-       },
-       { }
-};
-
-MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
-
-/*
- * Probe for the presence of a supported laptop.
- */
-static int __init i8k_probe(void)
-{
-       const struct dmi_system_id *id;
-       int fan, ret;
-
-       /*
-        * Get DMI information
-        */
-       if (!dmi_check_system(i8k_dmi_table)) {
-               if (!ignore_dmi && !force)
-                       return -ENODEV;
-
-               pr_info("not running on a supported Dell system.\n");
-               pr_info("vendor=%s, model=%s, version=%s\n",
-                       i8k_get_dmi_data(DMI_SYS_VENDOR),
-                       i8k_get_dmi_data(DMI_PRODUCT_NAME),
-                       i8k_get_dmi_data(DMI_BIOS_VERSION));
-       }
-
-       strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
-               sizeof(bios_version));
-
-       /*
-        * Get SMM Dell signature
-        */
-       if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
-           i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
-               pr_err("unable to get SMM Dell signature\n");
-               if (!force)
-                       return -ENODEV;
-       }
-
-       /*
-        * Set fan multiplier and maximal fan speed from dmi config
-        * Values specified in module parameters override values from dmi
-        */
-       id = dmi_first_match(i8k_dmi_table);
-       if (id && id->driver_data) {
-               const struct i8k_config_data *conf = id->driver_data;
-               if (!fan_mult && conf->fan_mult)
-                       fan_mult = conf->fan_mult;
-               if (!fan_max && conf->fan_max)
-                       fan_max = conf->fan_max;
-       }
-
-       i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
-       i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
-
-       if (!fan_mult) {
-               /*
-                * Autodetect fan multiplier based on nominal rpm
-                * If fan reports rpm value too high then set multiplier to 1
-                */
-               for (fan = 0; fan < 2; ++fan) {
-                       ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
-                       if (ret < 0)
-                               continue;
-                       if (ret > I8K_FAN_MAX_RPM)
-                               i8k_fan_mult = 1;
-                       break;
-               }
-       } else {
-               /* Fan multiplier was specified in module param or in dmi */
-               i8k_fan_mult = fan_mult;
-       }
-
-       return 0;
-}
-
-static int __init i8k_init(void)
-{
-       struct proc_dir_entry *proc_i8k;
-       int err;
-
-       /* Are we running on an supported laptop? */
-       if (i8k_probe())
-               return -ENODEV;
-
-       /* Register the proc entry */
-       proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
-       if (!proc_i8k)
-               return -ENOENT;
-
-       err = i8k_init_hwmon();
-       if (err)
-               goto exit_remove_proc;
-
-       return 0;
-
- exit_remove_proc:
-       remove_proc_entry("i8k", NULL);
-       return err;
-}
-
-static void __exit i8k_exit(void)
-{
-       hwmon_device_unregister(i8k_hwmon_dev);
-       remove_proc_entry("i8k", NULL);
-}
-
-module_init(i8k_init);
-module_exit(i8k_exit);
index b4a40f17e2aa5211f767323f736cab872c16528d..51533acfa01e9722cfe3948b427e94edf0d9c513 100644 (file)
@@ -156,6 +156,7 @@ obj-$(CONFIG_SENSORS_W83L785TS)     += w83l785ts.o
 obj-$(CONFIG_SENSORS_W83L786NG)        += w83l786ng.o
 obj-$(CONFIG_SENSORS_WM831X)   += wm831x-hwmon.o
 obj-$(CONFIG_SENSORS_WM8350)   += wm8350-hwmon.o
+obj-$(CONFIG_I8K)              += dell-smm-hwmon.o
 
 obj-$(CONFIG_PMBUS)            += pmbus/
 
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
new file mode 100644 (file)
index 0000000..65d314b
--- /dev/null
@@ -0,0 +1,1009 @@
+/*
+ * 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.rohar@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/delay.h>
+#include <linux/module.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/hwmon-sysfs.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/sched.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
+
+static DEFINE_MUTEX(i8k_mutex);
+static char bios_version[4];
+static struct device *i8k_hwmon_dev;
+static u32 i8k_hwmon_flags;
+static uint i8k_fan_mult = I8K_FAN_MULT;
+static uint i8k_pwm_mult;
+static uint i8k_fan_max = I8K_FAN_HIGH;
+
+#define I8K_HWMON_HAVE_TEMP1   (1 << 0)
+#define I8K_HWMON_HAVE_TEMP2   (1 << 1)
+#define I8K_HWMON_HAVE_TEMP3   (1 << 2)
+#define I8K_HWMON_HAVE_TEMP4   (1 << 3)
+#define I8K_HWMON_HAVE_FAN1    (1 << 4)
+#define I8K_HWMON_HAVE_FAN2    (1 << 5)
+
+MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
+MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
+MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
+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");
+
+static bool restricted;
+module_param(restricted, bool, 0);
+MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
+
+static bool power_status;
+module_param(power_status, bool, 0600);
+MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
+
+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: autodetect)");
+
+static int i8k_open_fs(struct inode *inode, struct file *file);
+static long i8k_ioctl(struct file *, unsigned int, unsigned long);
+
+static const struct file_operations i8k_fops = {
+       .owner          = THIS_MODULE,
+       .open           = i8k_open_fs,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+       .unlocked_ioctl = i8k_ioctl,
+};
+
+struct smm_regs {
+       unsigned int eax;
+       unsigned int ebx __packed;
+       unsigned int ecx __packed;
+       unsigned int edx __packed;
+       unsigned int esi __packed;
+       unsigned int edi __packed;
+};
+
+static inline const char *i8k_get_dmi_data(int field)
+{
+       const char *dmi_data = dmi_get_system_info(field);
+
+       return dmi_data && *dmi_data ? dmi_data : "?";
+}
+
+/*
+ * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
+ */
+static int i8k_smm(struct smm_regs *regs)
+{
+       int rc;
+       int eax = regs->eax;
+       cpumask_var_t old_mask;
+
+       /* SMM requires CPU 0 */
+       if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
+               return -ENOMEM;
+       cpumask_copy(old_mask, &current->cpus_allowed);
+       rc = set_cpus_allowed_ptr(current, cpumask_of(0));
+       if (rc)
+               goto out;
+       if (smp_processor_id() != 0) {
+               rc = -EBUSY;
+               goto out;
+       }
+
+#if defined(CONFIG_X86_64)
+       asm volatile("pushq %%rax\n\t"
+               "movl 0(%%rax),%%edx\n\t"
+               "pushq %%rdx\n\t"
+               "movl 4(%%rax),%%ebx\n\t"
+               "movl 8(%%rax),%%ecx\n\t"
+               "movl 12(%%rax),%%edx\n\t"
+               "movl 16(%%rax),%%esi\n\t"
+               "movl 20(%%rax),%%edi\n\t"
+               "popq %%rax\n\t"
+               "out %%al,$0xb2\n\t"
+               "out %%al,$0x84\n\t"
+               "xchgq %%rax,(%%rsp)\n\t"
+               "movl %%ebx,4(%%rax)\n\t"
+               "movl %%ecx,8(%%rax)\n\t"
+               "movl %%edx,12(%%rax)\n\t"
+               "movl %%esi,16(%%rax)\n\t"
+               "movl %%edi,20(%%rax)\n\t"
+               "popq %%rdx\n\t"
+               "movl %%edx,0(%%rax)\n\t"
+               "pushfq\n\t"
+               "popq %%rax\n\t"
+               "andl $1,%%eax\n"
+               : "=a"(rc)
+               :    "a"(regs)
+               :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
+#else
+       asm volatile("pushl %%eax\n\t"
+           "movl 0(%%eax),%%edx\n\t"
+           "push %%edx\n\t"
+           "movl 4(%%eax),%%ebx\n\t"
+           "movl 8(%%eax),%%ecx\n\t"
+           "movl 12(%%eax),%%edx\n\t"
+           "movl 16(%%eax),%%esi\n\t"
+           "movl 20(%%eax),%%edi\n\t"
+           "popl %%eax\n\t"
+           "out %%al,$0xb2\n\t"
+           "out %%al,$0x84\n\t"
+           "xchgl %%eax,(%%esp)\n\t"
+           "movl %%ebx,4(%%eax)\n\t"
+           "movl %%ecx,8(%%eax)\n\t"
+           "movl %%edx,12(%%eax)\n\t"
+           "movl %%esi,16(%%eax)\n\t"
+           "movl %%edi,20(%%eax)\n\t"
+           "popl %%edx\n\t"
+           "movl %%edx,0(%%eax)\n\t"
+           "lahf\n\t"
+           "shrl $8,%%eax\n\t"
+           "andl $1,%%eax\n"
+           : "=a"(rc)
+           :    "a"(regs)
+           :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
+#endif
+       if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
+               rc = -EINVAL;
+
+out:
+       set_cpus_allowed_ptr(current, old_mask);
+       free_cpumask_var(old_mask);
+       return rc;
+}
+
+/*
+ * Read the Fn key status.
+ */
+static int i8k_get_fn_status(void)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
+       int rc;
+
+       rc = i8k_smm(&regs);
+       if (rc < 0)
+               return rc;
+
+       switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
+       case I8K_FN_UP:
+               return I8K_VOL_UP;
+       case I8K_FN_DOWN:
+               return I8K_VOL_DOWN;
+       case I8K_FN_MUTE:
+               return I8K_VOL_MUTE;
+       default:
+               return 0;
+       }
+}
+
+/*
+ * Read the power status.
+ */
+static int i8k_get_power_status(void)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
+       int rc;
+
+       rc = i8k_smm(&regs);
+       if (rc < 0)
+               return rc;
+
+       return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
+}
+
+/*
+ * Read the fan status.
+ */
+static int i8k_get_fan_status(int fan)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
+
+       regs.ebx = fan & 0xff;
+       return i8k_smm(&regs) ? : regs.eax & 0xff;
+}
+
+/*
+ * Read the fan speed in RPM.
+ */
+static int i8k_get_fan_speed(int fan)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
+
+       regs.ebx = fan & 0xff;
+       return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
+}
+
+/*
+ * Read the fan type.
+ */
+static int i8k_get_fan_type(int fan)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
+
+       regs.ebx = fan & 0xff;
+       return i8k_smm(&regs) ? : regs.eax & 0xff;
+}
+
+/*
+ * Read the fan nominal rpm for specific fan speed.
+ */
+static int i8k_get_fan_nominal_speed(int fan, int speed)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
+
+       regs.ebx = (fan & 0xff) | (speed << 8);
+       return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
+}
+
+/*
+ * Set the fan speed (off, low, high). Returns the new fan status.
+ */
+static int i8k_set_fan(int fan, int speed)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
+
+       speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
+       regs.ebx = (fan & 0xff) | (speed << 8);
+
+       return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
+}
+
+static int i8k_get_temp_type(int sensor)
+{
+       struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
+
+       regs.ebx = sensor & 0xff;
+       return i8k_smm(&regs) ? : regs.eax & 0xff;
+}
+
+/*
+ * Read the cpu temperature.
+ */
+static int _i8k_get_temp(int sensor)
+{
+       struct smm_regs regs = {
+               .eax = I8K_SMM_GET_TEMP,
+               .ebx = sensor & 0xff,
+       };
+
+       return i8k_smm(&regs) ? : regs.eax & 0xff;
+}
+
+static int i8k_get_temp(int sensor)
+{
+       int temp = _i8k_get_temp(sensor);
+
+       /*
+        * Sometimes the temperature sensor returns 0x99, which is out of range.
+        * In this case we retry (once) before returning an error.
+        # 1003655137 00000058 00005a4b
+        # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
+        # 1003655139 00000054 00005c52
+        */
+       if (temp == 0x99) {
+               msleep(100);
+               temp = _i8k_get_temp(sensor);
+       }
+       /*
+        * Return -ENODATA for all invalid temperatures.
+        *
+        * Known instances are the 0x99 value as seen above as well as
+        * 0xc1 (193), which may be returned when trying to read the GPU
+        * temperature if the system supports a GPU and it is currently
+        * turned off.
+        */
+       if (temp > I8K_MAX_TEMP)
+               return -ENODATA;
+
+       return temp;
+}
+
+static int i8k_get_dell_signature(int req_fn)
+{
+       struct smm_regs regs = { .eax = req_fn, };
+       int rc;
+
+       rc = i8k_smm(&regs);
+       if (rc < 0)
+               return rc;
+
+       return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
+}
+
+static int
+i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
+{
+       int val = 0;
+       int speed;
+       unsigned char buff[16];
+       int __user *argp = (int __user *)arg;
+
+       if (!argp)
+               return -EINVAL;
+
+       switch (cmd) {
+       case I8K_BIOS_VERSION:
+               val = (bios_version[0] << 16) |
+                               (bios_version[1] << 8) | bios_version[2];
+               break;
+
+       case I8K_MACHINE_ID:
+               memset(buff, 0, 16);
+               strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
+                       sizeof(buff));
+               break;
+
+       case I8K_FN_STATUS:
+               val = i8k_get_fn_status();
+               break;
+
+       case I8K_POWER_STATUS:
+               val = i8k_get_power_status();
+               break;
+
+       case I8K_GET_TEMP:
+               val = i8k_get_temp(0);
+               break;
+
+       case I8K_GET_SPEED:
+               if (copy_from_user(&val, argp, sizeof(int)))
+                       return -EFAULT;
+
+               val = i8k_get_fan_speed(val);
+               break;
+
+       case I8K_GET_FAN:
+               if (copy_from_user(&val, argp, sizeof(int)))
+                       return -EFAULT;
+
+               val = i8k_get_fan_status(val);
+               break;
+
+       case I8K_SET_FAN:
+               if (restricted && !capable(CAP_SYS_ADMIN))
+                       return -EPERM;
+
+               if (copy_from_user(&val, argp, sizeof(int)))
+                       return -EFAULT;
+
+               if (copy_from_user(&speed, argp + 1, sizeof(int)))
+                       return -EFAULT;
+
+               val = i8k_set_fan(val, speed);
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       if (val < 0)
+               return val;
+
+       switch (cmd) {
+       case I8K_BIOS_VERSION:
+               if (copy_to_user(argp, &val, 4))
+                       return -EFAULT;
+
+               break;
+       case I8K_MACHINE_ID:
+               if (copy_to_user(argp, buff, 16))
+                       return -EFAULT;
+
+               break;
+       default:
+               if (copy_to_user(argp, &val, sizeof(int)))
+                       return -EFAULT;
+
+               break;
+       }
+
+       return 0;
+}
+
+static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
+{
+       long ret;
+
+       mutex_lock(&i8k_mutex);
+       ret = i8k_ioctl_unlocked(fp, cmd, arg);
+       mutex_unlock(&i8k_mutex);
+
+       return ret;
+}
+
+/*
+ * Print the information for /proc/i8k.
+ */
+static int i8k_proc_show(struct seq_file *seq, void *offset)
+{
+       int fn_key, cpu_temp, ac_power;
+       int left_fan, right_fan, left_speed, right_speed;
+
+       cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
+       left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
+       right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
+       left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
+       right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
+       fn_key          = i8k_get_fn_status();                  /*   750 µs */
+       if (power_status)
+               ac_power = i8k_get_power_status();              /* 14700 µs */
+       else
+               ac_power = -1;
+
+       /*
+        * Info:
+        *
+        * 1)  Format version (this will change if format changes)
+        * 2)  BIOS version
+        * 3)  BIOS machine ID
+        * 4)  Cpu temperature
+        * 5)  Left fan status
+        * 6)  Right fan status
+        * 7)  Left fan speed
+        * 8)  Right fan speed
+        * 9)  AC power
+        * 10) Fn Key status
+        */
+       seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
+                  I8K_PROC_FMT,
+                  bios_version,
+                  i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
+                  cpu_temp,
+                  left_fan, right_fan, left_speed, right_speed,
+                  ac_power, fn_key);
+
+       return 0;
+}
+
+static int i8k_open_fs(struct inode *inode, struct file *file)
+{
+       return single_open(file, i8k_proc_show, NULL);
+}
+
+
+/*
+ * Hwmon interface
+ */
+
+static ssize_t i8k_hwmon_show_temp_label(struct device *dev,
+                                        struct device_attribute *devattr,
+                                        char *buf)
+{
+       static const char * const labels[] = {
+               "CPU",
+               "GPU",
+               "SODIMM",
+               "Other",
+               "Ambient",
+               "Other",
+       };
+       int index = to_sensor_dev_attr(devattr)->index;
+       int type;
+
+       type = i8k_get_temp_type(index);
+       if (type < 0)
+               return type;
+       if (type >= ARRAY_SIZE(labels))
+               type = ARRAY_SIZE(labels) - 1;
+       return sprintf(buf, "%s\n", labels[type]);
+}
+
+static ssize_t i8k_hwmon_show_temp(struct device *dev,
+                                  struct device_attribute *devattr,
+                                  char *buf)
+{
+       int index = to_sensor_dev_attr(devattr)->index;
+       int temp;
+
+       temp = i8k_get_temp(index);
+       if (temp < 0)
+               return temp;
+       return sprintf(buf, "%d\n", temp * 1000);
+}
+
+static ssize_t i8k_hwmon_show_fan_label(struct device *dev,
+                                       struct device_attribute *devattr,
+                                       char *buf)
+{
+       static const char * const labels[] = {
+               "Processor Fan",
+               "Motherboard Fan",
+               "Video Fan",
+               "Power Supply Fan",
+               "Chipset Fan",
+               "Other Fan",
+       };
+       int index = to_sensor_dev_attr(devattr)->index;
+       bool dock = false;
+       int type;
+
+       type = i8k_get_fan_type(index);
+       if (type < 0)
+               return type;
+
+       if (type & 0x10) {
+               dock = true;
+               type &= 0x0F;
+       }
+
+       if (type >= ARRAY_SIZE(labels))
+               type = (ARRAY_SIZE(labels) - 1);
+
+       return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
+}
+
+static ssize_t i8k_hwmon_show_fan(struct device *dev,
+                                 struct device_attribute *devattr,
+                                 char *buf)
+{
+       int index = to_sensor_dev_attr(devattr)->index;
+       int fan_speed;
+
+       fan_speed = i8k_get_fan_speed(index);
+       if (fan_speed < 0)
+               return fan_speed;
+       return sprintf(buf, "%d\n", fan_speed);
+}
+
+static ssize_t i8k_hwmon_show_pwm(struct device *dev,
+                                 struct device_attribute *devattr,
+                                 char *buf)
+{
+       int index = to_sensor_dev_attr(devattr)->index;
+       int status;
+
+       status = i8k_get_fan_status(index);
+       if (status < 0)
+               return -EIO;
+       return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
+}
+
+static ssize_t i8k_hwmon_set_pwm(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buf, size_t count)
+{
+       int index = to_sensor_dev_attr(attr)->index;
+       unsigned long val;
+       int err;
+
+       err = kstrtoul(buf, 10, &val);
+       if (err)
+               return err;
+       val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
+
+       mutex_lock(&i8k_mutex);
+       err = i8k_set_fan(index, val);
+       mutex_unlock(&i8k_mutex);
+
+       return err < 0 ? -EIO : count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
+                         0);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
+                         1);
+static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
+                         2);
+static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
+                         3);
+static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL, 0);
+static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
+                         0);
+static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
+                         i8k_hwmon_set_pwm, 0);
+static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
+                         1);
+static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
+                         1);
+static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
+                         i8k_hwmon_set_pwm, 1);
+
+static struct attribute *i8k_attrs[] = {
+       &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
+       &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
+       &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
+       &sensor_dev_attr_temp2_label.dev_attr.attr,     /* 3 */
+       &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 4 */
+       &sensor_dev_attr_temp3_label.dev_attr.attr,     /* 5 */
+       &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 6 */
+       &sensor_dev_attr_temp4_label.dev_attr.attr,     /* 7 */
+       &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 8 */
+       &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 9 */
+       &sensor_dev_attr_pwm1.dev_attr.attr,            /* 10 */
+       &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 11 */
+       &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 12 */
+       &sensor_dev_attr_pwm2.dev_attr.attr,            /* 13 */
+       NULL
+};
+
+static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
+                             int index)
+{
+       if (index >= 0 && index <= 1 &&
+           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
+               return 0;
+       if (index >= 2 && index <= 3 &&
+           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
+               return 0;
+       if (index >= 4 && index <= 5 &&
+           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
+               return 0;
+       if (index >= 6 && index <= 7 &&
+           !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
+               return 0;
+       if (index >= 8 && index <= 10 &&
+           !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
+               return 0;
+       if (index >= 11 && index <= 13 &&
+           !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
+               return 0;
+
+       return attr->mode;
+}
+
+static const struct attribute_group i8k_group = {
+       .attrs = i8k_attrs,
+       .is_visible = i8k_is_visible,
+};
+__ATTRIBUTE_GROUPS(i8k);
+
+static int __init i8k_init_hwmon(void)
+{
+       int err;
+
+       i8k_hwmon_flags = 0;
+
+       /* CPU temperature attributes, if temperature type is OK */
+       err = i8k_get_temp_type(0);
+       if (err >= 0)
+               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
+       /* check for additional temperature sensors */
+       err = i8k_get_temp_type(1);
+       if (err >= 0)
+               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
+       err = i8k_get_temp_type(2);
+       if (err >= 0)
+               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
+       err = i8k_get_temp_type(3);
+       if (err >= 0)
+               i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
+
+       /* First fan attributes, if fan type is OK */
+       err = i8k_get_fan_type(0);
+       if (err >= 0)
+               i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
+
+       /* Second fan attributes, if fan type is OK */
+       err = i8k_get_fan_type(1);
+       if (err >= 0)
+               i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
+
+       i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
+                                                         i8k_groups);
+       if (IS_ERR(i8k_hwmon_dev)) {
+               err = PTR_ERR(i8k_hwmon_dev);
+               i8k_hwmon_dev = NULL;
+               pr_err("hwmon registration failed (%d)\n", err);
+               return err;
+       }
+       return 0;
+}
+
+struct i8k_config_data {
+       uint fan_mult;
+       uint fan_max;
+};
+
+enum i8k_configs {
+       DELL_LATITUDE_D520,
+       DELL_PRECISION_490,
+       DELL_STUDIO,
+       DELL_XPS,
+};
+
+static const struct i8k_config_data i8k_config_data[] = {
+       [DELL_LATITUDE_D520] = {
+               .fan_mult = 1,
+               .fan_max = I8K_FAN_TURBO,
+       },
+       [DELL_PRECISION_490] = {
+               .fan_mult = 1,
+               .fan_max = I8K_FAN_TURBO,
+       },
+       [DELL_STUDIO] = {
+               .fan_mult = 1,
+               .fan_max = I8K_FAN_HIGH,
+       },
+       [DELL_XPS] = {
+               .fan_mult = 1,
+               .fan_max = I8K_FAN_HIGH,
+       },
+};
+
+static struct dmi_system_id i8k_dmi_table[] __initdata = {
+       {
+               .ident = "Dell Inspiron",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
+               },
+       },
+       {
+               .ident = "Dell Latitude",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
+               },
+       },
+       {
+               .ident = "Dell Inspiron 2",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
+               },
+       },
+       {
+               .ident = "Dell Latitude D520",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
+               },
+               .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
+       },
+       {
+               .ident = "Dell Latitude 2",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
+               },
+       },
+       {       /* UK Inspiron 6400  */
+               .ident = "Dell Inspiron 3",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
+               },
+       },
+       {
+               .ident = "Dell Inspiron 3",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
+               },
+       },
+       {
+               .ident = "Dell Precision 490",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME,
+                                 "Precision WorkStation 490"),
+               },
+               .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
+       },
+       {
+               .ident = "Dell Precision",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
+               },
+       },
+       {
+               .ident = "Dell Vostro",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
+               },
+       },
+       {
+               .ident = "Dell XPS421",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
+               },
+       },
+       {
+               .ident = "Dell Studio",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
+               },
+               .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
+       },
+       {
+               .ident = "Dell XPS 13",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
+               },
+               .driver_data = (void *)&i8k_config_data[DELL_XPS],
+       },
+       {
+               .ident = "Dell XPS M140",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
+               },
+               .driver_data = (void *)&i8k_config_data[DELL_XPS],
+       },
+       { }
+};
+
+MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
+
+/*
+ * Probe for the presence of a supported laptop.
+ */
+static int __init i8k_probe(void)
+{
+       const struct dmi_system_id *id;
+       int fan, ret;
+
+       /*
+        * Get DMI information
+        */
+       if (!dmi_check_system(i8k_dmi_table)) {
+               if (!ignore_dmi && !force)
+                       return -ENODEV;
+
+               pr_info("not running on a supported Dell system.\n");
+               pr_info("vendor=%s, model=%s, version=%s\n",
+                       i8k_get_dmi_data(DMI_SYS_VENDOR),
+                       i8k_get_dmi_data(DMI_PRODUCT_NAME),
+                       i8k_get_dmi_data(DMI_BIOS_VERSION));
+       }
+
+       strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
+               sizeof(bios_version));
+
+       /*
+        * Get SMM Dell signature
+        */
+       if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
+           i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
+               pr_err("unable to get SMM Dell signature\n");
+               if (!force)
+                       return -ENODEV;
+       }
+
+       /*
+        * Set fan multiplier and maximal fan speed from dmi config
+        * Values specified in module parameters override values from dmi
+        */
+       id = dmi_first_match(i8k_dmi_table);
+       if (id && id->driver_data) {
+               const struct i8k_config_data *conf = id->driver_data;
+               if (!fan_mult && conf->fan_mult)
+                       fan_mult = conf->fan_mult;
+               if (!fan_max && conf->fan_max)
+                       fan_max = conf->fan_max;
+       }
+
+       i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
+       i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
+
+       if (!fan_mult) {
+               /*
+                * Autodetect fan multiplier based on nominal rpm
+                * If fan reports rpm value too high then set multiplier to 1
+                */
+               for (fan = 0; fan < 2; ++fan) {
+                       ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
+                       if (ret < 0)
+                               continue;
+                       if (ret > I8K_FAN_MAX_RPM)
+                               i8k_fan_mult = 1;
+                       break;
+               }
+       } else {
+               /* Fan multiplier was specified in module param or in dmi */
+               i8k_fan_mult = fan_mult;
+       }
+
+       return 0;
+}
+
+static int __init i8k_init(void)
+{
+       struct proc_dir_entry *proc_i8k;
+       int err;
+
+       /* Are we running on an supported laptop? */
+       if (i8k_probe())
+               return -ENODEV;
+
+       /* Register the proc entry */
+       proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
+       if (!proc_i8k)
+               return -ENOENT;
+
+       err = i8k_init_hwmon();
+       if (err)
+               goto exit_remove_proc;
+
+       return 0;
+
+ exit_remove_proc:
+       remove_proc_entry("i8k", NULL);
+       return err;
+}
+
+static void __exit i8k_exit(void)
+{
+       hwmon_device_unregister(i8k_hwmon_dev);
+       remove_proc_entry("i8k", NULL);
+}
+
+module_init(i8k_init);
+module_exit(i8k_exit);