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
              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 <asm/io.h>

#define DRVNAME "it87"

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

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 */
#define GPIO	0x07	/* The device with the IT8718F VID value in it */
#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 IT8726F_DEVID 0x8726
#define IT87_ACT_REG  0x30
#define IT87_BASE_REG 0x60

/* Logical device 7 registers (IT8712F and later) */
#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 has 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)>0x80?(val)-0x100:(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;
};

/* 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 */
	u8 temp[3];		/* Register value */
	u8 temp_high[3];	/* Register value */
	u8 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 */
	u8 manual_pwm_ctl[3];   /* manual PWM value set by user */
};

static inline int has_16bit_fans(const struct it87_data *data)
{
	/* IT8712F Datasheet 0.9.1, section 8.3.5 indicates 7h == Version I.
	   This is the first revision with 16bit tachometer support. */
	return (data->type == it8712 && data->revision >= 0x07)
	    || data->type == it8716
	    || data->type == it8718;
}

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, "2\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);
	/* 3 = thermal diode; 2 = thermistor; 0 = disabled */
	if (val == 3)
	    data->sensor |= 1 << nr;
	else if (val == 2)
	    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 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", (data->fan_main_ctrl & (1 << nr)) ? 1 : 0);
}
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", data->manual_pwm_ctl[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);

	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) {
		/* set SmartGuardian mode */
		data->fan_main_ctrl |= (1 << nr);
		it87_write_value(data, IT87_REG_FAN_MAIN_CTRL, data->fan_main_ctrl);
		/* set saved pwm value, clear FAN_CTLX PWM mode bit */
		it87_write_value(data, IT87_REG_PWM(nr), PWM_TO_REG(data->manual_pwm_ctl[nr]));
	} else {
		mutex_unlock(&data->update_lock);
		return -EINVAL;
	}

	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->manual_pwm_ctl[nr] = val;
	if (data->fan_main_ctrl & (1 << nr))
		it87_write_value(data, IT87_REG_PWM(nr), PWM_TO_REG(data->manual_pwm_ctl[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;
}

#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));

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_opt[] = {
	&sensor_dev_attr_fan1_input16.dev_attr.attr,
	&sensor_dev_attr_fan1_min16.dev_attr.attr,
	&sensor_dev_attr_fan2_input16.dev_attr.attr,
	&sensor_dev_attr_fan2_min16.dev_attr.attr,
	&sensor_dev_attr_fan3_input16.dev_attr.attr,
	&sensor_dev_attr_fan3_min16.dev_attr.attr,
	&sensor_dev_attr_fan4_input16.dev_attr.attr,
	&sensor_dev_attr_fan4_min16.dev_attr.attr,
	&sensor_dev_attr_fan5_input16.dev_attr.attr,
	&sensor_dev_attr_fan5_min16.dev_attr.attr,

	&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_fan2_input.dev_attr.attr,
	&sensor_dev_attr_fan2_min.dev_attr.attr,
	&sensor_dev_attr_fan2_div.dev_attr.attr,
	&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_fan1_alarm.dev_attr.attr,
	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
	&sensor_dev_attr_fan4_alarm.dev_attr.attr,
	&sensor_dev_attr_fan5_alarm.dev_attr.attr,

	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
	&sensor_dev_attr_pwm1.dev_attr.attr,
	&sensor_dev_attr_pwm2.dev_attr.attr,
	&sensor_dev_attr_pwm3.dev_attr.attr,
	&dev_attr_pwm1_freq.attr,
	&dev_attr_pwm2_freq.attr,
	&dev_attr_pwm3_freq.attr,

	&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;

	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 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 (chip_type != IT8705F_DEVID) {
		int reg;

		superio_select(GPIO);
		if (chip_type == it8718)
			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");
	}

exit:
	superio_exit();
	return err;
}

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;
	int err = 0;
	int enable_pwm_interface;
	static const char *names[] = {
		"it87",
		"it8712",
		"it8716",
		"it8718",
	};

	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 */
	if (has_16bit_fans(data)) {
		/* 16-bit tachometers */
		if (data->has_fan & (1 << 0)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan1_input16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan1_min16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan1_alarm.dev_attr)))
				goto ERROR4;
		}
		if (data->has_fan & (1 << 1)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan2_input16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan2_min16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan2_alarm.dev_attr)))
				goto ERROR4;
		}
		if (data->has_fan & (1 << 2)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan3_input16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan3_min16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan3_alarm.dev_attr)))
				goto ERROR4;
		}
		if (data->has_fan & (1 << 3)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan4_input16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan4_min16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan4_alarm.dev_attr)))
				goto ERROR4;
		}
		if (data->has_fan & (1 << 4)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan5_input16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan5_min16.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan5_alarm.dev_attr)))
				goto ERROR4;
		}
	} else {
		/* 8-bit tachometers with clock divider */
		if (data->has_fan & (1 << 0)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan1_input.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan1_min.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan1_div.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan1_alarm.dev_attr)))
				goto ERROR4;
		}
		if (data->has_fan & (1 << 1)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan2_input.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan2_min.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan2_div.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan2_alarm.dev_attr)))
				goto ERROR4;
		}
		if (data->has_fan & (1 << 2)) {
			if ((err = device_create_file(dev,
			     &sensor_dev_attr_fan3_input.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan3_min.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan3_div.dev_attr))
			 || (err = device_create_file(dev,
			     &sensor_dev_attr_fan3_alarm.dev_attr)))
				goto ERROR4;
		}
	}

	if (enable_pwm_interface) {
		if ((err = device_create_file(dev,
		     &sensor_dev_attr_pwm1_enable.dev_attr))
		 || (err = device_create_file(dev,
		     &sensor_dev_attr_pwm2_enable.dev_attr))
		 || (err = device_create_file(dev,
		     &sensor_dev_attr_pwm3_enable.dev_attr))
		 || (err = device_create_file(dev,
		     &sensor_dev_attr_pwm1.dev_attr))
		 || (err = device_create_file(dev,
		     &sensor_dev_attr_pwm2.dev_attr))
		 || (err = device_create_file(dev,
		     &sensor_dev_attr_pwm3.dev_attr))
		 || (err = device_create_file(dev,
		     &dev_attr_pwm1_freq))
		 || (err = device_create_file(dev,
		     &dev_attr_pwm2_freq))
		 || (err = device_create_file(dev,
		     &dev_attr_pwm3_freq)))
			goto ERROR4;
	}

	if (data->type == it8712 || data->type == it8716
	 || data->type == it8718) {
		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:
	sysfs_remove_group(&dev->kobj, &it87_group);
	sysfs_remove_group(&dev->kobj, &it87_group_opt);
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);
	sysfs_remove_group(&pdev->dev.kobj, &it87_group);
	sysfs_remove_group(&pdev->dev.kobj, &it87_group_opt);

	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_data *data = platform_get_drvdata(pdev);
	int tmp, i;

	/* initialize to sane defaults:
	 * - if the chip is in manual pwm mode, this will be overwritten with
	 *   the actual settings on the chip (so in this case, initialization
	 *   is not needed)
	 * - if in automatic or on/off mode, we could switch to manual mode,
	 *   read the registers and set manual_pwm_ctl accordingly, but currently
	 *   this is not implemented, so we initialize to something sane */
	for (i = 0; i < 3; i++) {
		data->manual_pwm_ctl[i] = 0xff;
	}

	/* 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 channnels 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 */
	data->fan_main_ctrl = it87_read_value(data, IT87_REG_FAN_MAIN_CTRL);
	if ((data->fan_main_ctrl & 0x70) == 0) {
		/* Enable all fan tachometers */
		data->fan_main_ctrl |= 0x70;
		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);
		}
		if (tmp & (1 << 4))
			data->has_fan |= (1 << 3);	/* fan4 enabled */
		if (tmp & (1 << 5))
			data->has_fan |= (1 << 4);	/* fan5 enabled */
	}

	/* Set current fan mode registers and the default settings for the
	 * other mode registers */
	for (i = 0; i < 3; i++) {
		if (data->fan_main_ctrl & (1 << i)) {
			/* pwm mode */
			tmp = it87_read_value(data, IT87_REG_PWM(i));
			if (tmp & 0x80) {
				/* automatic pwm - not yet implemented, but
				 * leave the settings made by the BIOS alone
				 * until a change is requested via the sysfs
				 * interface */
			} else {
				/* manual pwm */
				data->manual_pwm_ctl[i] = PWM_FROM_REG(tmp);
			}
		}
 	}

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

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);

		data->sensor = it87_read_value(data, IT87_REG_TEMP_ENABLE);
		/* The 8705 does not have VID capability.
		   The 8718 does not 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;

	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;

	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/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);