drivers/hwmon/it87.c

/*
    it87.c - Part of lm_sensors, Linux kernel modules for hardware
             monitoring.

    The IT8705F is an LPC-based Super I/O part that contains UARTs, a
    parallel port, an IR port, a MIDI port, a floppy controller, etc., in
    addition to an Environment Controller (Enhanced Hardware Monitor and
    Fan Controller)

    This driver supports only the Environment Controller in the IT8705F and
    similar parts.  The other devices are supported by different drivers.

    Supports: IT8705F  Super I/O chip w/LPC interface
              IT8712F  Super I/O chip w/LPC interface
              IT8716F  Super I/O chip w/LPC interface
              IT8718F  Super I/O chip w/LPC interface
              IT8720F  Super I/O chip w/LPC interface
              IT8726F  Super I/O chip w/LPC interface
              Sis950   A clone of the IT8705F

    Copyright (C) 2001 Chris Gauthron
    Copyright (C) 2005-2007 Jean Delvare <khali@linux-fr.org>

    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 of the License, 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.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/hwmon-vid.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/string.h>
#include <linux/dmi.h>
#include <linux/acpi.h>
#include <linux/io.h>

#define DRVNAME "it87"

enum chips { it87, it8712, it8716, it8718, it8720 };

static unsigned short force_id;
module_param(force_id, ushort, 0);
MODULE_PARM_DESC(force_id, "Override the detected device ID");

static struct platform_device *pdev;

#define	REG	0x2e	/* The register to read/write */
#define	DEV	0x07	/* Register: Logical device select */
#define	VAL	0x2f	/* The value to read/write */
#define PME	0x04	/* The device with the fan registers in it */

/* The device with the IT8718F/IT8720F VID value in it */
#define GPIO	0x07

#define	DEVID	0x20	/* Register: Device ID */
#define	DEVREV	0x22	/* Register: Device Revision */

static inline int
superio_inb(int reg)
{
	outb(reg, REG);
	return inb(VAL);
}

static int superio_inw(int reg)
{
	int val;
	outb(reg++, REG);
	val = inb(VAL) << 8;
	outb(reg, REG);
	val |= inb(VAL);
	return val;
}

static inline void
superio_select(int ldn)
{
	outb(DEV, REG);
	outb(ldn, VAL);
}

static inline void
superio_enter(void)
{
	outb(0x87, REG);
	outb(0x01, REG);
	outb(0x55, REG);
	outb(0x55, REG);
}

static inline void
superio_exit(void)
{
	outb(0x02, REG);
	outb(0x02, VAL);
}

/* Logical device 4 registers */
#define IT8712F_DEVID 0x8712
#define IT8705F_DEVID 0x8705
#define IT8716F_DEVID 0x8716
#define IT8718F_DEVID 0x8718
#define IT8720F_DEVID 0x8720
#define IT8726F_DEVID 0x8726
#define IT87_ACT_REG  0x30
#define IT87_BASE_REG 0x60

/* Logical device 7 registers (IT8712F and later) */
#define IT87_SIO_GPIO3_REG	0x27
#define IT87_SIO_GPIO5_REG	0x29
#define IT87_SIO_PINX2_REG	0x2c	/* Pin selection */
#define IT87_SIO_VID_REG	0xfc	/* VID value */

/* Update battery voltage after every reading if true */
static int update_vbat;

/* Not all BIOSes properly configure the PWM registers */
static int fix_pwm_polarity;

/* Many IT87 constants specified below */

/* Length of ISA address segment */
#define IT87_EXTENT 8

/* Length of ISA address segment for Environmental Controller */
#define IT87_EC_EXTENT 2

/* Offset of EC registers from ISA base address */
#define IT87_EC_OFFSET 5

/* Where are the ISA address/data registers relative to the EC base address */
#define IT87_ADDR_REG_OFFSET 0
#define IT87_DATA_REG_OFFSET 1

/*----- The IT87 registers -----*/

#define IT87_REG_CONFIG        0x00

#define IT87_REG_ALARM1        0x01
#define IT87_REG_ALARM2        0x02
#define IT87_REG_ALARM3        0x03

/* The IT8718F and IT8720F have the VID value in a different register, in
   Super-I/O configuration space. */
#define IT87_REG_VID           0x0a
/* The IT8705F and IT8712F earlier than revision 0x08 use register 0x0b
   for fan divisors. Later IT8712F revisions must use 16-bit tachometer
   mode. */
#define IT87_REG_FAN_DIV       0x0b
#define IT87_REG_FAN_16BIT     0x0c

/* Monitors: 9 voltage (0 to 7, battery), 3 temp (1 to 3), 3 fan (1 to 3) */

static const u8 IT87_REG_FAN[]		= { 0x0d, 0x0e, 0x0f, 0x80, 0x82 };
static const u8 IT87_REG_FAN_MIN[]	= { 0x10, 0x11, 0x12, 0x84, 0x86 };
static const u8 IT87_REG_FANX[]		= { 0x18, 0x19, 0x1a, 0x81, 0x83 };
static const u8 IT87_REG_FANX_MIN[]	= { 0x1b, 0x1c, 0x1d, 0x85, 0x87 };
#define IT87_REG_FAN_MAIN_CTRL 0x13
#define IT87_REG_FAN_CTL       0x14
#define IT87_REG_PWM(nr)       (0x15 + (nr))

#define IT87_REG_VIN(nr)       (0x20 + (nr))
#define IT87_REG_TEMP(nr)      (0x29 + (nr))

#define IT87_REG_VIN_MAX(nr)   (0x30 + (nr) * 2)
#define IT87_REG_VIN_MIN(nr)   (0x31 + (nr) * 2)
#define IT87_REG_TEMP_HIGH(nr) (0x40 + (nr) * 2)
#define IT87_REG_TEMP_LOW(nr)  (0x41 + (nr) * 2)

#define IT87_REG_VIN_ENABLE    0x50
#define IT87_REG_TEMP_ENABLE   0x51

#define IT87_REG_CHIPID        0x58

#define IN_TO_REG(val)  (SENSORS_LIMIT((((val) + 8)/16),0,255))
#define IN_FROM_REG(val) ((val) * 16)

static inline u8 FAN_TO_REG(long rpm, int div)
{
	if (rpm == 0)
		return 255;
	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1,
			     254);
}

static inline u16 FAN16_TO_REG(long rpm)
{
	if (rpm == 0)
		return 0xffff;
	return SENSORS_LIMIT((1350000 + rpm) / (rpm * 2), 1, 0xfffe);
}

#define FAN_FROM_REG(val,div) ((val)==0?-1:(val)==255?0:1350000/((val)*(div)))
/* The divider is fixed to 2 in 16-bit mode */
#define FAN16_FROM_REG(val) ((val)==0?-1:(val)==0xffff?0:1350000/((val)*2))

#define TEMP_TO_REG(val) (SENSORS_LIMIT(((val)<0?(((val)-500)/1000):\
					((val)+500)/1000),-128,127))
#define TEMP_FROM_REG(val) ((val) * 1000)

#define PWM_TO_REG(val)   ((val) >> 1)
#define PWM_FROM_REG(val) (((val)&0x7f) << 1)

static int DIV_TO_REG(int val)
{
	int answer = 0;
	while (answer < 7 && (val >>= 1))
		answer++;
	return answer;
}
#define DIV_FROM_REG(val) (1 << (val))

static const unsigned int pwm_freq[8] = {
	48000000 / 128,
	24000000 / 128,
	12000000 / 128,
	8000000 / 128,
	6000000 / 128,
	3000000 / 128,
	1500000 / 128,
	750000 / 128,
};


struct it87_sio_data {
	enum chips type;
	/* Values read from Super-I/O config space */
	u8 revision;
	u8 vid_value;
	/* Features skipped based on config or DMI */
	u8 skip_vid;
	u8 skip_fan;
	u8 skip_pwm;
};

/* For each registered chip, we need to keep some data in memory.
   The structure is dynamically allocated. */
struct it87_data {
	struct device *hwmon_dev;
	enum chips type;
	u8 revision;

	unsigned short addr;
	const char *name;
	struct mutex update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	u8 in[9];		/* Register value */
	u8 in_max[8];		/* Register value */
	u8 in_min[8];		/* Register value */
	u8 has_fan;		/* Bitfield, fans enabled */
	u16 fan[5];		/* Register values, possibly combined */
	u16 fan_min[5];		/* Register values, possibly combined */
	s8 temp[3];		/* Register value */
	s8 temp_high[3];	/* Register value */
	s8 temp_low[3];		/* Register value */
	u8 sensor;		/* Register value */
	u8 fan_div[3];		/* Register encoding, shifted right */
	u8 vid;			/* Register encoding, combined */
	u8 vrm;
	u32 alarms;		/* Register encoding, combined */
	u8 fan_main_ctrl;	/* Register value */
	u8 fan_ctl;		/* Register value */

	/* The following 3 arrays correspond to the same registers. The
	 * meaning of bits 6-0 depends on the value of bit 7, and we want
	 * to preserve settings on mode changes, so we have to track all
	 * values separately. */
	u8 pwm_ctrl[3];		/* Register value */
	u8 pwm_duty[3];		/* Manual PWM value set by user (bit 6-0) */
	u8 pwm_temp_map[3];	/* PWM to temp. chan. mapping (bits 1-0) */
};

static inline int has_16bit_fans(const struct it87_data *data)
{
	/* IT8705F Datasheet 0.4.1, 3h == Version G.
	   IT8712F Datasheet 0.9.1, section 8.3.5 indicates 8h == Version J.
	   These are the first revisions with 16bit tachometer support. */
	return (data->type == it87 && data->revision >= 0x03)
	    || (data->type == it8712 && data->revision >= 0x08)
	    || data->type == it8716
	    || data->type == it8718
	    || data->type == it8720;
}

static int it87_probe(struct platform_device *pdev);
static int __devexit it87_remove(struct platform_device *pdev);

static int it87_read_value(struct it87_data *data, u8 reg);
static void it87_write_value(struct it87_data *data, u8 reg, u8 value);
static struct it87_data *it87_update_device(struct device *dev);
static int it87_check_pwm(struct device *dev);
static void it87_init_device(struct platform_device *pdev);


static struct platform_driver it87_driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= DRVNAME,
	},
	.probe	= it87_probe,
	.remove	= __devexit_p(it87_remove),
};

static ssize_t show_in(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", IN_FROM_REG(data->in[nr]));
}

static ssize_t show_in_min(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_min[nr]));
}

static ssize_t show_in_max(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_max[nr]));
}

static ssize_t set_in_min(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	unsigned long val = simple_strtoul(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->in_min[nr] = IN_TO_REG(val);
	it87_write_value(data, IT87_REG_VIN_MIN(nr),
			data->in_min[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}
static ssize_t set_in_max(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	unsigned long val = simple_strtoul(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->in_max[nr] = IN_TO_REG(val);
	it87_write_value(data, IT87_REG_VIN_MAX(nr),
			data->in_max[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

#define show_in_offset(offset)					\
static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
		show_in, NULL, offset);

#define limit_in_offset(offset)					\
static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,	\
		show_in_min, set_in_min, offset);		\
static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,	\
		show_in_max, set_in_max, offset);

show_in_offset(0);
limit_in_offset(0);
show_in_offset(1);
limit_in_offset(1);
show_in_offset(2);
limit_in_offset(2);
show_in_offset(3);
limit_in_offset(3);
show_in_offset(4);
limit_in_offset(4);
show_in_offset(5);
limit_in_offset(5);
show_in_offset(6);
limit_in_offset(6);
show_in_offset(7);
limit_in_offset(7);
show_in_offset(8);

/* 3 temperatures */
static ssize_t show_temp(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[nr]));
}
static ssize_t show_temp_max(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_high[nr]));
}
static ssize_t show_temp_min(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_low[nr]));
}
static ssize_t set_temp_max(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	int val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->temp_high[nr] = TEMP_TO_REG(val);
	it87_write_value(data, IT87_REG_TEMP_HIGH(nr), data->temp_high[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}
static ssize_t set_temp_min(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	int val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->temp_low[nr] = TEMP_TO_REG(val);
	it87_write_value(data, IT87_REG_TEMP_LOW(nr), data->temp_low[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}
#define show_temp_offset(offset)					\
static SENSOR_DEVICE_ATTR(temp##offset##_input, S_IRUGO,		\
		show_temp, NULL, offset - 1);				\
static SENSOR_DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR,	\
		show_temp_max, set_temp_max, offset - 1);		\
static SENSOR_DEVICE_ATTR(temp##offset##_min, S_IRUGO | S_IWUSR,	\
		show_temp_min, set_temp_min, offset - 1);

show_temp_offset(1);
show_temp_offset(2);
show_temp_offset(3);

static ssize_t show_sensor(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	u8 reg = data->sensor; /* In case the value is updated while we use it */
	
	if (reg & (1 << nr))
		return sprintf(buf, "3\n");  /* thermal diode */
	if (reg & (8 << nr))
		return sprintf(buf, "4\n");  /* thermistor */
	return sprintf(buf, "0\n");      /* disabled */
}
static ssize_t set_sensor(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	int val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);

	data->sensor &= ~(1 << nr);
	data->sensor &= ~(8 << nr);
	if (val == 2) {	/* backwards compatibility */
		dev_warn(dev, "Sensor type 2 is deprecated, please use 4 "
			 "instead\n");
		val = 4;
	}
	/* 3 = thermal diode; 4 = thermistor; 0 = disabled */
	if (val == 3)
	    data->sensor |= 1 << nr;
	else if (val == 4)
	    data->sensor |= 8 << nr;
	else if (val != 0) {
		mutex_unlock(&data->update_lock);
		return -EINVAL;
	}
	it87_write_value(data, IT87_REG_TEMP_ENABLE, data->sensor);
	mutex_unlock(&data->update_lock);
	return count;
}
#define show_sensor_offset(offset)					\
static SENSOR_DEVICE_ATTR(temp##offset##_type, S_IRUGO | S_IWUSR,	\
		show_sensor, set_sensor, offset - 1);

show_sensor_offset(1);
show_sensor_offset(2);
show_sensor_offset(3);

/* 3 Fans */

static int pwm_mode(const struct it87_data *data, int nr)
{
	int ctrl = data->fan_main_ctrl & (1 << nr);

	if (ctrl == 0)					/* Full speed */
		return 0;
	if (data->pwm_ctrl[nr] & 0x80)			/* Automatic mode */
		return 2;
	else						/* Manual mode */
		return 1;
}

static ssize_t show_fan(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf,"%d\n", FAN_FROM_REG(data->fan[nr], 
				DIV_FROM_REG(data->fan_div[nr])));
}
static ssize_t show_fan_min(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf,"%d\n",
		FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr])));
}
static ssize_t show_fan_div(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
}
static ssize_t show_pwm_enable(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", pwm_mode(data, nr));
}
static ssize_t show_pwm(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", PWM_FROM_REG(data->pwm_duty[nr]));
}
static ssize_t show_pwm_freq(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct it87_data *data = it87_update_device(dev);
	int index = (data->fan_ctl >> 4) & 0x07;

	return sprintf(buf, "%u\n", pwm_freq[index]);
}
static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	int val = simple_strtol(buf, NULL, 10);
	u8 reg;

	mutex_lock(&data->update_lock);
	reg = it87_read_value(data, IT87_REG_FAN_DIV);
	switch (nr) {
	case 0: data->fan_div[nr] = reg & 0x07; break;
	case 1: data->fan_div[nr] = (reg >> 3) & 0x07; break;
	case 2: data->fan_div[nr] = (reg & 0x40) ? 3 : 1; break;
	}

	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
	it87_write_value(data, IT87_REG_FAN_MIN[nr], data->fan_min[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}
static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	int min;
	u8 old;

	mutex_lock(&data->update_lock);
	old = it87_read_value(data, IT87_REG_FAN_DIV);

	/* Save fan min limit */
	min = FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));

	switch (nr) {
	case 0:
	case 1:
		data->fan_div[nr] = DIV_TO_REG(val);
		break;
	case 2:
		if (val < 8)
			data->fan_div[nr] = 1;
		else
			data->fan_div[nr] = 3;
	}
	val = old & 0x80;
	val |= (data->fan_div[0] & 0x07);
	val |= (data->fan_div[1] & 0x07) << 3;
	if (data->fan_div[2] == 3)
		val |= 0x1 << 6;
	it87_write_value(data, IT87_REG_FAN_DIV, val);

	/* Restore fan min limit */
	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
	it87_write_value(data, IT87_REG_FAN_MIN[nr], data->fan_min[nr]);

	mutex_unlock(&data->update_lock);
	return count;
}
static ssize_t set_pwm_enable(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	int val = simple_strtol(buf, NULL, 10);

	if (val < 0 || val > 2)
		return -EINVAL;

	mutex_lock(&data->update_lock);

	if (val == 0) {
		int tmp;
		/* make sure the fan is on when in on/off mode */
		tmp = it87_read_value(data, IT87_REG_FAN_CTL);
		it87_write_value(data, IT87_REG_FAN_CTL, tmp | (1 << nr));
		/* set on/off mode */
		data->fan_main_ctrl &= ~(1 << nr);
		it87_write_value(data, IT87_REG_FAN_MAIN_CTRL, data->fan_main_ctrl);
	} else {
		if (val == 1)				/* Manual mode */
			data->pwm_ctrl[nr] = data->pwm_duty[nr];
		else					/* Automatic mode */
			data->pwm_ctrl[nr] = 0x80 | data->pwm_temp_map[nr];
		it87_write_value(data, IT87_REG_PWM(nr), data->pwm_ctrl[nr]);
		/* set SmartGuardian mode */
		data->fan_main_ctrl |= (1 << nr);
		it87_write_value(data, IT87_REG_FAN_MAIN_CTRL, data->fan_main_ctrl);
	}

	mutex_unlock(&data->update_lock);
	return count;
}
static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	int val = simple_strtol(buf, NULL, 10);

	if (val < 0 || val > 255)
		return -EINVAL;

	mutex_lock(&data->update_lock);
	data->pwm_duty[nr] = PWM_TO_REG(val);
	/* If we are in manual mode, write the duty cycle immediately;
	 * otherwise, just store it for later use. */
	if (!(data->pwm_ctrl[nr] & 0x80)) {
		data->pwm_ctrl[nr] = data->pwm_duty[nr];
		it87_write_value(data, IT87_REG_PWM(nr), data->pwm_ctrl[nr]);
	}
	mutex_unlock(&data->update_lock);
	return count;
}
static ssize_t set_pwm_freq(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct it87_data *data = dev_get_drvdata(dev);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	int i;

	/* Search for the nearest available frequency */
	for (i = 0; i < 7; i++) {
		if (val > (pwm_freq[i] + pwm_freq[i+1]) / 2)
			break;
	}

	mutex_lock(&data->update_lock);
	data->fan_ctl = it87_read_value(data, IT87_REG_FAN_CTL) & 0x8f;
	data->fan_ctl |= i << 4;
	it87_write_value(data, IT87_REG_FAN_CTL, data->fan_ctl);
	mutex_unlock(&data->update_lock);

	return count;
}
static ssize_t show_pwm_temp_map(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = it87_update_device(dev);
	int map;

	if (data->pwm_temp_map[nr] < 3)
		map = 1 << data->pwm_temp_map[nr];
	else
		map = 0;			/* Should never happen */
	return sprintf(buf, "%d\n", map);
}
static ssize_t set_pwm_temp_map(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;

	struct it87_data *data = dev_get_drvdata(dev);
	long val;
	u8 reg;

	if (strict_strtol(buf, 10, &val) < 0)
		return -EINVAL;

	switch (val) {
	case (1 << 0):
		reg = 0x00;
		break;
	case (1 << 1):
		reg = 0x01;
		break;
	case (1 << 2):
		reg = 0x02;
		break;
	default:
		return -EINVAL;
	}

	mutex_lock(&data->update_lock);
	data->pwm_temp_map[nr] = reg;
	/* If we are in automatic mode, write the temp mapping immediately;
	 * otherwise, just store it for later use. */
	if (data->pwm_ctrl[nr] & 0x80) {
		data->pwm_ctrl[nr] = 0x80 | data->pwm_temp_map[nr];
		it87_write_value(data, IT87_REG_PWM(nr), data->pwm_ctrl[nr]);
	}
	mutex_unlock(&data->update_lock);
	return count;
}

#define show_fan_offset(offset)					\
static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,		\
		show_fan, NULL, offset - 1);			\
static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR, \
		show_fan_min, set_fan_min, offset - 1);		\
static SENSOR_DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR, \
		show_fan_div, set_fan_div, offset - 1);

show_fan_offset(1);
show_fan_offset(2);
show_fan_offset(3);

#define show_pwm_offset(offset)						\
static SENSOR_DEVICE_ATTR(pwm##offset##_enable, S_IRUGO | S_IWUSR,	\
		show_pwm_enable, set_pwm_enable, offset - 1);		\
static SENSOR_DEVICE_ATTR(pwm##offset, S_IRUGO | S_IWUSR,		\
		show_pwm, set_pwm, offset - 1);				\
static DEVICE_ATTR(pwm##offset##_freq,					\
		(offset == 1 ? S_IRUGO | S_IWUSR : S_IRUGO),		\
		show_pwm_freq, (offset == 1 ? set_pwm_freq : NULL));	\
static SENSOR_DEVICE_ATTR(pwm##offset##_auto_channels_temp,		\
		S_IRUGO, show_pwm_temp_map, set_pwm_temp_map,		\
		offset - 1);

show_pwm_offset(1);
show_pwm_offset(2);
show_pwm_offset(3);

/* A different set of callbacks for 16-bit fans */
static ssize_t show_fan16(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;
	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", FAN16_FROM_REG(data->fan[nr]));
}

static ssize_t show_fan16_min(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;
	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%d\n", FAN16_FROM_REG(data->fan_min[nr]));
}

static ssize_t set_fan16_min(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
	int nr = sensor_attr->index;
	struct it87_data *data = dev_get_drvdata(dev);
	int val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	data->fan_min[nr] = FAN16_TO_REG(val);
	it87_write_value(data, IT87_REG_FAN_MIN[nr],
			 data->fan_min[nr] & 0xff);
	it87_write_value(data, IT87_REG_FANX_MIN[nr],
			 data->fan_min[nr] >> 8);
	mutex_unlock(&data->update_lock);
	return count;
}

/* We want to use the same sysfs file names as 8-bit fans, but we need
   different variable names, so we have to use SENSOR_ATTR instead of
   SENSOR_DEVICE_ATTR. */
#define show_fan16_offset(offset) \
static struct sensor_device_attribute sensor_dev_attr_fan##offset##_input16 \
	= SENSOR_ATTR(fan##offset##_input, S_IRUGO,		\
		show_fan16, NULL, offset - 1);			\
static struct sensor_device_attribute sensor_dev_attr_fan##offset##_min16 \
	= SENSOR_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,	\
		show_fan16_min, set_fan16_min, offset - 1)

show_fan16_offset(1);
show_fan16_offset(2);
show_fan16_offset(3);
show_fan16_offset(4);
show_fan16_offset(5);

/* Alarms */
static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%u\n", data->alarms);
}
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	int bitnr = to_sensor_dev_attr(attr)->index;
	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
}
static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 8);
static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 9);
static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 10);
static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 11);
static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 12);
static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 13);
static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 14);
static SENSOR_DEVICE_ATTR(in7_alarm, S_IRUGO, show_alarm, NULL, 15);
static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(fan3_alarm, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(fan4_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(fan5_alarm, S_IRUGO, show_alarm, NULL, 6);
static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 16);
static SENSOR_DEVICE_ATTR(temp2_alarm, S_IRUGO, show_alarm, NULL, 17);
static SENSOR_DEVICE_ATTR(temp3_alarm, S_IRUGO, show_alarm, NULL, 18);

static ssize_t
show_vrm_reg(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct it87_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%u\n", data->vrm);
}
static ssize_t
store_vrm_reg(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct it87_data *data = dev_get_drvdata(dev);
	u32 val;

	val = simple_strtoul(buf, NULL, 10);
	data->vrm = val;

	return count;
}
static DEVICE_ATTR(vrm, S_IRUGO | S_IWUSR, show_vrm_reg, store_vrm_reg);

static ssize_t
show_vid_reg(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct it87_data *data = it87_update_device(dev);
	return sprintf(buf, "%ld\n", (long) vid_from_reg(data->vid, data->vrm));
}
static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid_reg, NULL);

static ssize_t show_name(struct device *dev, struct device_attribute
			 *devattr, char *buf)
{
	struct it87_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%s\n", data->name);
}
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);

static struct attribute *it87_attributes[] = {
	&sensor_dev_attr_in0_input.dev_attr.attr,
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in3_input.dev_attr.attr,
	&sensor_dev_attr_in4_input.dev_attr.attr,
	&sensor_dev_attr_in5_input.dev_attr.attr,
	&sensor_dev_attr_in6_input.dev_attr.attr,
	&sensor_dev_attr_in7_input.dev_attr.attr,
	&sensor_dev_attr_in8_input.dev_attr.attr,
	&sensor_dev_attr_in0_min.dev_attr.attr,
	&sensor_dev_attr_in1_min.dev_attr.attr,
	&sensor_dev_attr_in2_min.dev_attr.attr,
	&sensor_dev_attr_in3_min.dev_attr.attr,
	&sensor_dev_attr_in4_min.dev_attr.attr,
	&sensor_dev_attr_in5_min.dev_attr.attr,
	&sensor_dev_attr_in6_min.dev_attr.attr,
	&sensor_dev_attr_in7_min.dev_attr.attr,
	&sensor_dev_attr_in0_max.dev_attr.attr,
	&sensor_dev_attr_in1_max.dev_attr.attr,
	&sensor_dev_attr_in2_max.dev_attr.attr,
	&sensor_dev_attr_in3_max.dev_attr.attr,
	&sensor_dev_attr_in4_max.dev_attr.attr,
	&sensor_dev_attr_in5_max.dev_attr.attr,
	&sensor_dev_attr_in6_max.dev_attr.attr,
	&sensor_dev_attr_in7_max.dev_attr.attr,
	&sensor_dev_attr_in0_alarm.dev_attr.attr,
	&sensor_dev_attr_in1_alarm.dev_attr.attr,
	&sensor_dev_attr_in2_alarm.dev_attr.attr,
	&sensor_dev_attr_in3_alarm.dev_attr.attr,
	&sensor_dev_attr_in4_alarm.dev_attr.attr,
	&sensor_dev_attr_in5_alarm.dev_attr.attr,
	&sensor_dev_attr_in6_alarm.dev_attr.attr,
	&sensor_dev_attr_in7_alarm.dev_attr.attr,

	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp3_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp3_max.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp3_min.dev_attr.attr,
	&sensor_dev_attr_temp1_type.dev_attr.attr,
	&sensor_dev_attr_temp2_type.dev_attr.attr,
	&sensor_dev_attr_temp3_type.dev_attr.attr,
	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_alarm.dev_attr.attr,
	&sensor_dev_attr_temp3_alarm.dev_attr.attr,

	&dev_attr_alarms.attr,
	&dev_attr_name.attr,
	NULL
};

static const struct attribute_group it87_group = {
	.attrs = it87_attributes,
};

static struct attribute *it87_attributes_fan16[5][3+1] = { {
	&sensor_dev_attr_fan1_input16.dev_attr.attr,
	&sensor_dev_attr_fan1_min16.dev_attr.attr,
	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_fan2_input16.dev_attr.attr,
	&sensor_dev_attr_fan2_min16.dev_attr.attr,
	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_fan3_input16.dev_attr.attr,
	&sensor_dev_attr_fan3_min16.dev_attr.attr,
	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_fan4_input16.dev_attr.attr,
	&sensor_dev_attr_fan4_min16.dev_attr.attr,
	&sensor_dev_attr_fan4_alarm.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_fan5_input16.dev_attr.attr,
	&sensor_dev_attr_fan5_min16.dev_attr.attr,
	&sensor_dev_attr_fan5_alarm.dev_attr.attr,
	NULL
} };

static const struct attribute_group it87_group_fan16[5] = {
	{ .attrs = it87_attributes_fan16[0] },
	{ .attrs = it87_attributes_fan16[1] },
	{ .attrs = it87_attributes_fan16[2] },
	{ .attrs = it87_attributes_fan16[3] },
	{ .attrs = it87_attributes_fan16[4] },
};

static struct attribute *it87_attributes_fan[3][4+1] = { {
	&sensor_dev_attr_fan1_input.dev_attr.attr,
	&sensor_dev_attr_fan1_min.dev_attr.attr,
	&sensor_dev_attr_fan1_div.dev_attr.attr,
	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_fan2_input.dev_attr.attr,
	&sensor_dev_attr_fan2_min.dev_attr.attr,
	&sensor_dev_attr_fan2_div.dev_attr.attr,
	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_fan3_input.dev_attr.attr,
	&sensor_dev_attr_fan3_min.dev_attr.attr,
	&sensor_dev_attr_fan3_div.dev_attr.attr,
	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
	NULL
} };

static const struct attribute_group it87_group_fan[3] = {
	{ .attrs = it87_attributes_fan[0] },
	{ .attrs = it87_attributes_fan[1] },
	{ .attrs = it87_attributes_fan[2] },
};

static const struct attribute_group *
it87_get_fan_group(const struct it87_data *data)
{
	return has_16bit_fans(data) ? it87_group_fan16 : it87_group_fan;
}

static struct attribute *it87_attributes_pwm[3][4+1] = { {
	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
	&sensor_dev_attr_pwm1.dev_attr.attr,
	&dev_attr_pwm1_freq.attr,
	&sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
	&sensor_dev_attr_pwm2.dev_attr.attr,
	&dev_attr_pwm2_freq.attr,
	&sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
	NULL
}, {
	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
	&sensor_dev_attr_pwm3.dev_attr.attr,
	&dev_attr_pwm3_freq.attr,
	&sensor_dev_attr_pwm3_auto_channels_temp.dev_attr.attr,
	NULL
} };

static const struct attribute_group it87_group_pwm[3] = {
	{ .attrs = it87_attributes_pwm[0] },
	{ .attrs = it87_attributes_pwm[1] },
	{ .attrs = it87_attributes_pwm[2] },
};

static struct attribute *it87_attributes_opt[] = {
	&dev_attr_vrm.attr,
	&dev_attr_cpu0_vid.attr,
	NULL
};

static const struct attribute_group it87_group_opt = {
	.attrs = it87_attributes_opt,
};

/* SuperIO detection - will change isa_address if a chip is found */
static int __init it87_find(unsigned short *address,
	struct it87_sio_data *sio_data)
{
	int err = -ENODEV;
	u16 chip_type;
	const char *board_vendor, *board_name;

	superio_enter();
	chip_type = force_id ? force_id : superio_inw(DEVID);

	switch (chip_type) {
	case IT8705F_DEVID:
		sio_data->type = it87;
		break;
	case IT8712F_DEVID:
		sio_data->type = it8712;
		break;
	case IT8716F_DEVID:
	case IT8726F_DEVID:
		sio_data->type = it8716;
		break;
	case IT8718F_DEVID:
		sio_data->type = it8718;
		break;
	case IT8720F_DEVID:
		sio_data->type = it8720;
		break;
	case 0xffff:	/* No device at all */
		goto exit;
	default:
		pr_debug(DRVNAME ": Unsupported chip (DEVID=0x%x)\n",
			 chip_type);
		goto exit;
	}

	superio_select(PME);
	if (!(superio_inb(IT87_ACT_REG) & 0x01)) {
		pr_info("it87: Device not activated, skipping\n");
		goto exit;
	}

	*address = superio_inw(IT87_BASE_REG) & ~(IT87_EXTENT - 1);
	if (*address == 0) {
		pr_info("it87: Base address not set, skipping\n");
		goto exit;
	}

	err = 0;
	sio_data->revision = superio_inb(DEVREV) & 0x0f;
	pr_info("it87: Found IT%04xF chip at 0x%x, revision %d\n",
		chip_type, *address, sio_data->revision);

	/* Read GPIO config and VID value from LDN 7 (GPIO) */
	if (sio_data->type == it87) {
		/* The IT8705F doesn't have VID pins at all */
		sio_data->skip_vid = 1;
	} else {
		int reg;

		superio_select(GPIO);
		/* We need at least 4 VID pins */
		reg = superio_inb(IT87_SIO_GPIO3_REG);
		if (reg & 0x0f) {
			pr_info("it87: VID is disabled (pins used for GPIO)\n");
			sio_data->skip_vid = 1;
		}

		/* Check if fan3 is there or not */
		if (reg & (1 << 6))
			sio_data->skip_pwm |= (1 << 2);
		if (reg & (1 << 7))
			sio_data->skip_fan |= (1 << 2);

		/* Check if fan2 is there or not */
		reg = superio_inb(IT87_SIO_GPIO5_REG);
		if (reg & (1 << 1))
			sio_data->skip_pwm |= (1 << 1);
		if (reg & (1 << 2))
			sio_data->skip_fan |= (1 << 1);

		if ((sio_data->type == it8718 || sio_data->type == it8720)
		 && !(sio_data->skip_vid))
			sio_data->vid_value = superio_inb(IT87_SIO_VID_REG);

		reg = superio_inb(IT87_SIO_PINX2_REG);
		if (reg & (1 << 0))
			pr_info("it87: in3 is VCC (+5V)\n");
		if (reg & (1 << 1))
			pr_info("it87: in7 is VCCH (+5V Stand-By)\n");
	}

	/* Disable specific features based on DMI strings */
	board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
	board_name = dmi_get_system_info(DMI_BOARD_NAME);
	if (board_vendor && board_name) {
		if (strcmp(board_vendor, "nVIDIA") == 0
		 && strcmp(board_name, "FN68PT") == 0) {
			/* On the Shuttle SN68PT, FAN_CTL2 is apparently not
			   connected to a fan, but to something else. One user
			   has reported instant system power-off when changing
			   the PWM2 duty cycle, so we disable it.
			   I use the board name string as the trigger in case
			   the same board is ever used in other systems. */
			pr_info("it87: Disabling pwm2 due to "
				"hardware constraints\n");
			sio_data->skip_pwm = (1 << 1);
		}
	}

exit:
	superio_exit();
	return err;
}

static void it87_remove_files(struct device *dev)
{
	struct it87_data *data = platform_get_drvdata(pdev);
	struct it87_sio_data *sio_data = dev->platform_data;
	const struct attribute_group *fan_group = it87_get_fan_group(data);
	int i;

	sysfs_remove_group(&dev->kobj, &it87_group);
	for (i = 0; i < 5; i++) {
		if (!(data->has_fan & (1 << i)))
			continue;
		sysfs_remove_group(&dev->kobj, &fan_group[i]);
	}
	for (i = 0; i < 3; i++) {
		if (sio_data->skip_pwm & (1 << 0))
			continue;
		sysfs_remove_group(&dev->kobj, &it87_group_pwm[i]);
	}
	sysfs_remove_group(&dev->kobj, &it87_group_opt);
}

static int __devinit it87_probe(struct platform_device *pdev)
{
	struct it87_data *data;
	struct resource *res;
	struct device *dev = &pdev->dev;
	struct it87_sio_data *sio_data = dev->platform_data;
	const struct attribute_group *fan_group;
	int err = 0, i;
	int enable_pwm_interface;
	static const char *names[] = {
		"it87",
		"it8712",
		"it8716",
		"it8718",
		"it8720",
	};

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!request_region(res->start, IT87_EC_EXTENT, DRVNAME)) {
		dev_err(dev, "Failed to request region 0x%lx-0x%lx\n",
			(unsigned long)res->start,
			(unsigned long)(res->start + IT87_EC_EXTENT - 1));
		err = -EBUSY;
		goto ERROR0;
	}

	if (!(data = kzalloc(sizeof(struct it87_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto ERROR1;
	}

	data->addr = res->start;
	data->type = sio_data->type;
	data->revision = sio_data->revision;
	data->name = names[sio_data->type];

	/* Now, we do the remaining detection. */
	if ((it87_read_value(data, IT87_REG_CONFIG) & 0x80)
	 || it87_read_value(data, IT87_REG_CHIPID) != 0x90) {
		err = -ENODEV;
		goto ERROR2;
	}

	platform_set_drvdata(pdev, data);

	mutex_init(&data->update_lock);

	/* Check PWM configuration */
	enable_pwm_interface = it87_check_pwm(dev);

	/* Initialize the IT87 chip */
	it87_init_device(pdev);

	/* Register sysfs hooks */
	if ((err = sysfs_create_group(&dev->kobj, &it87_group)))
		goto ERROR2;

	/* Do not create fan files for disabled fans */
	fan_group = it87_get_fan_group(data);
	for (i = 0; i < 5; i++) {
		if (!(data->has_fan & (1 << i)))
			continue;
		err = sysfs_create_group(&dev->kobj, &fan_group[i]);
		if (err)
			goto ERROR4;
	}

	if (enable_pwm_interface) {
		for (i = 0; i < 3; i++) {
			if (sio_data->skip_pwm & (1 << i))
				continue;
			err = sysfs_create_group(&dev->kobj,
						 &it87_group_pwm[i]);
			if (err)
				goto ERROR4;
		}
	}

	if (!sio_data->skip_vid) {
		data->vrm = vid_which_vrm();
		/* VID reading from Super-I/O config space if available */
		data->vid = sio_data->vid_value;
		if ((err = device_create_file(dev,
		     &dev_attr_vrm))
		 || (err = device_create_file(dev,
		     &dev_attr_cpu0_vid)))
			goto ERROR4;
	}

	data->hwmon_dev = hwmon_device_register(dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto ERROR4;
	}

	return 0;

ERROR4:
	it87_remove_files(dev);
ERROR2:
	platform_set_drvdata(pdev, NULL);
	kfree(data);
ERROR1:
	release_region(res->start, IT87_EC_EXTENT);
ERROR0:
	return err;
}

static int __devexit it87_remove(struct platform_device *pdev)
{
	struct it87_data *data = platform_get_drvdata(pdev);

	hwmon_device_unregister(data->hwmon_dev);
	it87_remove_files(&pdev->dev);

	release_region(data->addr, IT87_EC_EXTENT);
	platform_set_drvdata(pdev, NULL);
	kfree(data);

	return 0;
}

/* Must be called with data->update_lock held, except during initialization.
   We ignore the IT87 BUSY flag at this moment - it could lead to deadlocks,
   would slow down the IT87 access and should not be necessary. */
static int it87_read_value(struct it87_data *data, u8 reg)
{
	outb_p(reg, data->addr + IT87_ADDR_REG_OFFSET);
	return inb_p(data->addr + IT87_DATA_REG_OFFSET);
}

/* Must be called with data->update_lock held, except during initialization.
   We ignore the IT87 BUSY flag at this moment - it could lead to deadlocks,
   would slow down the IT87 access and should not be necessary. */
static void it87_write_value(struct it87_data *data, u8 reg, u8 value)
{
	outb_p(reg, data->addr + IT87_ADDR_REG_OFFSET);
	outb_p(value, data->addr + IT87_DATA_REG_OFFSET);
}

/* Return 1 if and only if the PWM interface is safe to use */
static int __devinit it87_check_pwm(struct device *dev)
{
	struct it87_data *data = dev_get_drvdata(dev);
	/* Some BIOSes fail to correctly configure the IT87 fans. All fans off
	 * and polarity set to active low is sign that this is the case so we
	 * disable pwm control to protect the user. */
	int tmp = it87_read_value(data, IT87_REG_FAN_CTL);
	if ((tmp & 0x87) == 0) {
		if (fix_pwm_polarity) {
			/* The user asks us to attempt a chip reconfiguration.
			 * This means switching to active high polarity and
			 * inverting all fan speed values. */
			int i;
			u8 pwm[3];

			for (i = 0; i < 3; i++)
				pwm[i] = it87_read_value(data,
							 IT87_REG_PWM(i));

			/* If any fan is in automatic pwm mode, the polarity
			 * might be correct, as suspicious as it seems, so we
			 * better don't change anything (but still disable the
			 * PWM interface). */
			if (!((pwm[0] | pwm[1] | pwm[2]) & 0x80)) {
				dev_info(dev, "Reconfiguring PWM to "
					 "active high polarity\n");
				it87_write_value(data, IT87_REG_FAN_CTL,
						 tmp | 0x87);
				for (i = 0; i < 3; i++)
					it87_write_value(data,
							 IT87_REG_PWM(i),
							 0x7f & ~pwm[i]);
				return 1;
			}

			dev_info(dev, "PWM configuration is "
				 "too broken to be fixed\n");
		}

		dev_info(dev, "Detected broken BIOS "
			 "defaults, disabling PWM interface\n");
		return 0;
	} else if (fix_pwm_polarity) {
		dev_info(dev, "PWM configuration looks "
			 "sane, won't touch\n");
	}

	return 1;
}

/* Called when we have found a new IT87. */
static void __devinit it87_init_device(struct platform_device *pdev)
{
	struct it87_sio_data *sio_data = pdev->dev.platform_data;
	struct it87_data *data = platform_get_drvdata(pdev);
	int tmp, i;
	u8 mask;

	/* For each PWM channel:
	 * - If it is in automatic mode, setting to manual mode should set
	 *   the fan to full speed by default.
	 * - If it is in manual mode, we need a mapping to temperature
	 *   channels to use when later setting to automatic mode later.
	 *   Use a 1:1 mapping by default (we are clueless.)
	 * In both cases, the value can (and should) be changed by the user
	 * prior to switching to a different mode. */
	for (i = 0; i < 3; i++) {
		data->pwm_temp_map[i] = i;
		data->pwm_duty[i] = 0x7f;	/* Full speed */
	}

	/* Some chips seem to have default value 0xff for all limit
	 * registers. For low voltage limits it makes no sense and triggers
	 * alarms, so change to 0 instead. For high temperature limits, it
	 * means -1 degree C, which surprisingly doesn't trigger an alarm,
	 * but is still confusing, so change to 127 degrees C. */
	for (i = 0; i < 8; i++) {
		tmp = it87_read_value(data, IT87_REG_VIN_MIN(i));
		if (tmp == 0xff)
			it87_write_value(data, IT87_REG_VIN_MIN(i), 0);
	}
	for (i = 0; i < 3; i++) {
		tmp = it87_read_value(data, IT87_REG_TEMP_HIGH(i));
		if (tmp == 0xff)
			it87_write_value(data, IT87_REG_TEMP_HIGH(i), 127);
	}

	/* Check if temperature channels are reset manually or by some reason */
	tmp = it87_read_value(data, IT87_REG_TEMP_ENABLE);
	if ((tmp & 0x3f) == 0) {
		/* Temp1,Temp3=thermistor; Temp2=thermal diode */
		tmp = (tmp & 0xc0) | 0x2a;
		it87_write_value(data, IT87_REG_TEMP_ENABLE, tmp);
	}
	data->sensor = tmp;

	/* Check if voltage monitors are reset manually or by some reason */
	tmp = it87_read_value(data, IT87_REG_VIN_ENABLE);
	if ((tmp & 0xff) == 0) {
		/* Enable all voltage monitors */
		it87_write_value(data, IT87_REG_VIN_ENABLE, 0xff);
	}

	/* Check if tachometers are reset manually or by some reason */
	mask = 0x70 & ~(sio_data->skip_fan << 4);
	data->fan_main_ctrl = it87_read_value(data, IT87_REG_FAN_MAIN_CTRL);
	if ((data->fan_main_ctrl & mask) == 0) {
		/* Enable all fan tachometers */
		data->fan_main_ctrl |= mask;
		it87_write_value(data, IT87_REG_FAN_MAIN_CTRL, data->fan_main_ctrl);
	}
	data->has_fan = (data->fan_main_ctrl >> 4) & 0x07;

	/* Set tachometers to 16-bit mode if needed */
	if (has_16bit_fans(data)) {
		tmp = it87_read_value(data, IT87_REG_FAN_16BIT);
		if (~tmp & 0x07 & data->has_fan) {
			dev_dbg(&pdev->dev,
				"Setting fan1-3 to 16-bit mode\n");
			it87_write_value(data, IT87_REG_FAN_16BIT,
					 tmp | 0x07);
		}
		/* IT8705F only supports three fans. */
		if (data->type != it87) {
			if (tmp & (1 << 4))
				data->has_fan |= (1 << 3); /* fan4 enabled */
			if (tmp & (1 << 5))
				data->has_fan |= (1 << 4); /* fan5 enabled */
		}
	}

	/* Fan input pins may be used for alternative functions */
	data->has_fan &= ~sio_data->skip_fan;

	/* Start monitoring */
	it87_write_value(data, IT87_REG_CONFIG,
			 (it87_read_value(data, IT87_REG_CONFIG) & 0x36)
			 | (update_vbat ? 0x41 : 0x01));
}

static void it87_update_pwm_ctrl(struct it87_data *data, int nr)
{
	data->pwm_ctrl[nr] = it87_read_value(data, IT87_REG_PWM(nr));
	if (data->pwm_ctrl[nr] & 0x80)	/* Automatic mode */
		data->pwm_temp_map[nr] = data->pwm_ctrl[nr] & 0x03;
	else				/* Manual mode */
		data->pwm_duty[nr] = data->pwm_ctrl[nr] & 0x7f;
}

static struct it87_data *it87_update_device(struct device *dev)
{
	struct it87_data *data = dev_get_drvdata(dev);
	int i;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	    || !data->valid) {

		if (update_vbat) {
			/* Cleared after each update, so reenable.  Value
		 	  returned by this read will be previous value */	
			it87_write_value(data, IT87_REG_CONFIG,
			   it87_read_value(data, IT87_REG_CONFIG) | 0x40);
		}
		for (i = 0; i <= 7; i++) {
			data->in[i] =
			    it87_read_value(data, IT87_REG_VIN(i));
			data->in_min[i] =
			    it87_read_value(data, IT87_REG_VIN_MIN(i));
			data->in_max[i] =
			    it87_read_value(data, IT87_REG_VIN_MAX(i));
		}
		/* in8 (battery) has no limit registers */
		data->in[8] =
		    it87_read_value(data, IT87_REG_VIN(8));

		for (i = 0; i < 5; i++) {
			/* Skip disabled fans */
			if (!(data->has_fan & (1 << i)))
				continue;

			data->fan_min[i] =
			    it87_read_value(data, IT87_REG_FAN_MIN[i]);
			data->fan[i] = it87_read_value(data,
				       IT87_REG_FAN[i]);
			/* Add high byte if in 16-bit mode */
			if (has_16bit_fans(data)) {
				data->fan[i] |= it87_read_value(data,
						IT87_REG_FANX[i]) << 8;
				data->fan_min[i] |= it87_read_value(data,
						IT87_REG_FANX_MIN[i]) << 8;
			}
		}
		for (i = 0; i < 3; i++) {
			data->temp[i] =
			    it87_read_value(data, IT87_REG_TEMP(i));
			data->temp_high[i] =
			    it87_read_value(data, IT87_REG_TEMP_HIGH(i));
			data->temp_low[i] =
			    it87_read_value(data, IT87_REG_TEMP_LOW(i));
		}

		/* Newer chips don't have clock dividers */
		if ((data->has_fan & 0x07) && !has_16bit_fans(data)) {
			i = it87_read_value(data, IT87_REG_FAN_DIV);
			data->fan_div[0] = i & 0x07;
			data->fan_div[1] = (i >> 3) & 0x07;
			data->fan_div[2] = (i & 0x40) ? 3 : 1;
		}

		data->alarms =
			it87_read_value(data, IT87_REG_ALARM1) |
			(it87_read_value(data, IT87_REG_ALARM2) << 8) |
			(it87_read_value(data, IT87_REG_ALARM3) << 16);

		data->fan_main_ctrl = it87_read_value(data,
				IT87_REG_FAN_MAIN_CTRL);
		data->fan_ctl = it87_read_value(data, IT87_REG_FAN_CTL);
		for (i = 0; i < 3; i++)
			it87_update_pwm_ctrl(data, i);

		data->sensor = it87_read_value(data, IT87_REG_TEMP_ENABLE);
		/* The 8705 does not have VID capability.
		   The 8718 and the 8720 don't use IT87_REG_VID for the
		   same purpose. */
		if (data->type == it8712 || data->type == it8716) {
			data->vid = it87_read_value(data, IT87_REG_VID);
			/* The older IT8712F revisions had only 5 VID pins,
			   but we assume it is always safe to read 6 bits. */
			data->vid &= 0x3f;
		}
		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

static int __init it87_device_add(unsigned short address,
				  const struct it87_sio_data *sio_data)
{
	struct resource res = {
		.start	= address + IT87_EC_OFFSET,
		.end	= address + IT87_EC_OFFSET + IT87_EC_EXTENT - 1,
		.name	= DRVNAME,
		.flags	= IORESOURCE_IO,
	};
	int err;

	err = acpi_check_resource_conflict(&res);
	if (err)
		goto exit;

	pdev = platform_device_alloc(DRVNAME, address);
	if (!pdev) {
		err = -ENOMEM;
		printk(KERN_ERR DRVNAME ": Device allocation failed\n");
		goto exit;
	}

	err = platform_device_add_resources(pdev, &res, 1);
	if (err) {
		printk(KERN_ERR DRVNAME ": Device resource addition failed "
		       "(%d)\n", err);
		goto exit_device_put;
	}

	err = platform_device_add_data(pdev, sio_data,
				       sizeof(struct it87_sio_data));
	if (err) {
		printk(KERN_ERR DRVNAME ": Platform data allocation failed\n");
		goto exit_device_put;
	}

	err = platform_device_add(pdev);
	if (err) {
		printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
		       err);
		goto exit_device_put;
	}

	return 0;

exit_device_put:
	platform_device_put(pdev);
exit:
	return err;
}

static int __init sm_it87_init(void)
{
	int err;
	unsigned short isa_address=0;
	struct it87_sio_data sio_data;

	memset(&sio_data, 0, sizeof(struct it87_sio_data));
	err = it87_find(&isa_address, &sio_data);
	if (err)
		return err;
	err = platform_driver_register(&it87_driver);
	if (err)
		return err;

	err = it87_device_add(isa_address, &sio_data);
	if (err){
		platform_driver_unregister(&it87_driver);
		return err;
	}

	return 0;
}

static void __exit sm_it87_exit(void)
{
	platform_device_unregister(pdev);
	platform_driver_unregister(&it87_driver);
}


MODULE_AUTHOR("Chris Gauthron, "
	      "Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("IT8705F/8712F/8716F/8718F/8720F/8726F, SiS950 driver");
module_param(update_vbat, bool, 0);
MODULE_PARM_DESC(update_vbat, "Update vbat if set else return powerup value");
module_param(fix_pwm_polarity, bool, 0);
MODULE_PARM_DESC(fix_pwm_polarity, "Force PWM polarity to active high (DANGEROUS)");
MODULE_LICENSE("GPL");

module_init(sm_it87_init);
module_exit(sm_it87_exit);