/*
    w83791d.c - Part of lm_sensors, Linux kernel modules for hardware
                monitoring

    Copyright (C) 2006-2007 Charles Spirakis <bezaur@gmail.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 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.
*/

/*
    Supports following chips:

    Chip	#vin	#fanin	#pwm	#temp	wchipid	vendid	i2c	ISA
    w83791d	10	5	3	3	0x71	0x5ca3	yes	no

    The w83791d chip appears to be part way between the 83781d and the
    83792d. Thus, this file is derived from both the w83792d.c and
    w83781d.c files.

    The w83791g chip is the same as the w83791d but lead-free.
*/

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-vid.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>

#define NUMBER_OF_VIN		10
#define NUMBER_OF_FANIN		5
#define NUMBER_OF_TEMPIN	3

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, 0x2f,
						I2C_CLIENT_END };

/* Insmod parameters */
I2C_CLIENT_INSMOD_1(w83791d);
I2C_CLIENT_MODULE_PARM(force_subclients, "List of subclient addresses: "
			"{bus, clientaddr, subclientaddr1, subclientaddr2}");

static int reset;
module_param(reset, bool, 0);
MODULE_PARM_DESC(reset, "Set to one to force a hardware chip reset");

static int init;
module_param(init, bool, 0);
MODULE_PARM_DESC(init, "Set to one to force extra software initialization");

/* The W83791D registers */
static const u8 W83791D_REG_IN[NUMBER_OF_VIN] = {
	0x20,			/* VCOREA in DataSheet */
	0x21,			/* VINR0 in DataSheet */
	0x22,			/* +3.3VIN in DataSheet */
	0x23,			/* VDD5V in DataSheet */
	0x24,			/* +12VIN in DataSheet */
	0x25,			/* -12VIN in DataSheet */
	0x26,			/* -5VIN in DataSheet */
	0xB0,			/* 5VSB in DataSheet */
	0xB1,			/* VBAT in DataSheet */
	0xB2			/* VINR1 in DataSheet */
};

static const u8 W83791D_REG_IN_MAX[NUMBER_OF_VIN] = {
	0x2B,			/* VCOREA High Limit in DataSheet */
	0x2D,			/* VINR0 High Limit in DataSheet */
	0x2F,			/* +3.3VIN High Limit in DataSheet */
	0x31,			/* VDD5V High Limit in DataSheet */
	0x33,			/* +12VIN High Limit in DataSheet */
	0x35,			/* -12VIN High Limit in DataSheet */
	0x37,			/* -5VIN High Limit in DataSheet */
	0xB4,			/* 5VSB High Limit in DataSheet */
	0xB6,			/* VBAT High Limit in DataSheet */
	0xB8			/* VINR1 High Limit in DataSheet */
};
static const u8 W83791D_REG_IN_MIN[NUMBER_OF_VIN] = {
	0x2C,			/* VCOREA Low Limit in DataSheet */
	0x2E,			/* VINR0 Low Limit in DataSheet */
	0x30,			/* +3.3VIN Low Limit in DataSheet */
	0x32,			/* VDD5V Low Limit in DataSheet */
	0x34,			/* +12VIN Low Limit in DataSheet */
	0x36,			/* -12VIN Low Limit in DataSheet */
	0x38,			/* -5VIN Low Limit in DataSheet */
	0xB5,			/* 5VSB Low Limit in DataSheet */
	0xB7,			/* VBAT Low Limit in DataSheet */
	0xB9			/* VINR1 Low Limit in DataSheet */
};
static const u8 W83791D_REG_FAN[NUMBER_OF_FANIN] = {
	0x28,			/* FAN 1 Count in DataSheet */
	0x29,			/* FAN 2 Count in DataSheet */
	0x2A,			/* FAN 3 Count in DataSheet */
	0xBA,			/* FAN 4 Count in DataSheet */
	0xBB,			/* FAN 5 Count in DataSheet */
};
static const u8 W83791D_REG_FAN_MIN[NUMBER_OF_FANIN] = {
	0x3B,			/* FAN 1 Count Low Limit in DataSheet */
	0x3C,			/* FAN 2 Count Low Limit in DataSheet */
	0x3D,			/* FAN 3 Count Low Limit in DataSheet */
	0xBC,			/* FAN 4 Count Low Limit in DataSheet */
	0xBD,			/* FAN 5 Count Low Limit in DataSheet */
};

static const u8 W83791D_REG_FAN_CFG[2] = {
	0x84,			/* FAN 1/2 configuration */
	0x95,			/* FAN 3 configuration */
};

static const u8 W83791D_REG_FAN_DIV[3] = {
	0x47,			/* contains FAN1 and FAN2 Divisor */
	0x4b,			/* contains FAN3 Divisor */
	0x5C,			/* contains FAN4 and FAN5 Divisor */
};

#define W83791D_REG_BANK		0x4E
#define W83791D_REG_TEMP2_CONFIG	0xC2
#define W83791D_REG_TEMP3_CONFIG	0xCA

static const u8 W83791D_REG_TEMP1[3] = {
	0x27,			/* TEMP 1 in DataSheet */
	0x39,			/* TEMP 1 Over in DataSheet */
	0x3A,			/* TEMP 1 Hyst in DataSheet */
};

static const u8 W83791D_REG_TEMP_ADD[2][6] = {
	{0xC0,			/* TEMP 2 in DataSheet */
	 0xC1,			/* TEMP 2(0.5 deg) in DataSheet */
	 0xC5,			/* TEMP 2 Over High part in DataSheet */
	 0xC6,			/* TEMP 2 Over Low part in DataSheet */
	 0xC3,			/* TEMP 2 Thyst High part in DataSheet */
	 0xC4},			/* TEMP 2 Thyst Low part in DataSheet */
	{0xC8,			/* TEMP 3 in DataSheet */
	 0xC9,			/* TEMP 3(0.5 deg) in DataSheet */
	 0xCD,			/* TEMP 3 Over High part in DataSheet */
	 0xCE,			/* TEMP 3 Over Low part in DataSheet */
	 0xCB,			/* TEMP 3 Thyst High part in DataSheet */
	 0xCC}			/* TEMP 3 Thyst Low part in DataSheet */
};

#define W83791D_REG_BEEP_CONFIG		0x4D

static const u8 W83791D_REG_BEEP_CTRL[3] = {
	0x56,			/* BEEP Control Register 1 */
	0x57,			/* BEEP Control Register 2 */
	0xA3,			/* BEEP Control Register 3 */
};

#define W83791D_REG_CONFIG		0x40
#define W83791D_REG_VID_FANDIV		0x47
#define W83791D_REG_DID_VID4		0x49
#define W83791D_REG_WCHIPID		0x58
#define W83791D_REG_CHIPMAN		0x4F
#define W83791D_REG_PIN			0x4B
#define W83791D_REG_I2C_SUBADDR		0x4A

#define W83791D_REG_ALARM1 0xA9	/* realtime status register1 */
#define W83791D_REG_ALARM2 0xAA	/* realtime status register2 */
#define W83791D_REG_ALARM3 0xAB	/* realtime status register3 */

#define W83791D_REG_VBAT		0x5D
#define W83791D_REG_I2C_ADDR		0x48

/* The SMBus locks itself. The Winbond W83791D has a bank select register
   (index 0x4e), but the driver only accesses registers in bank 0. Since
   we don't switch banks, we don't need any special code to handle
   locking access between bank switches */
static inline int w83791d_read(struct i2c_client *client, u8 reg)
{
	return i2c_smbus_read_byte_data(client, reg);
}

static inline int w83791d_write(struct i2c_client *client, u8 reg, u8 value)
{
	return i2c_smbus_write_byte_data(client, reg, value);
}

/* The analog voltage inputs have 16mV LSB. Since the sysfs output is
   in mV as would be measured on the chip input pin, need to just
   multiply/divide by 16 to translate from/to register values. */
#define IN_TO_REG(val)		(SENSORS_LIMIT((((val) + 8) / 16), 0, 255))
#define IN_FROM_REG(val)	((val) * 16)

static 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);
}

#define FAN_FROM_REG(val,div)	((val) == 0   ? -1 : \
				((val) == 255 ? 0 : \
					1350000 / ((val) * (div))))

/* for temp1 which is 8-bit resolution, LSB = 1 degree Celsius */
#define TEMP1_FROM_REG(val)	((val) * 1000)
#define TEMP1_TO_REG(val)	((val) <= -128000 ? -128 : \
				 (val) >= 127000 ? 127 : \
				 (val) < 0 ? ((val) - 500) / 1000 : \
				 ((val) + 500) / 1000)

/* for temp2 and temp3 which are 9-bit resolution, LSB = 0.5 degree Celsius
   Assumes the top 8 bits are the integral amount and the bottom 8 bits
   are the fractional amount. Since we only have 0.5 degree resolution,
   the bottom 7 bits will always be zero */
#define TEMP23_FROM_REG(val)	((val) / 128 * 500)
#define TEMP23_TO_REG(val)	((val) <= -128000 ? 0x8000 : \
				 (val) >= 127500 ? 0x7F80 : \
				 (val) < 0 ? ((val) - 250) / 500 * 128 : \
				 ((val) + 250) / 500 * 128)


#define BEEP_MASK_TO_REG(val)		((val) & 0xffffff)
#define BEEP_MASK_FROM_REG(val)		((val) & 0xffffff)

#define DIV_FROM_REG(val)		(1 << (val))

static u8 div_to_reg(int nr, long val)
{
	int i;
	int max;

	/* first three fan's divisor max out at 8, rest max out at 128 */
	max = (nr < 3) ? 8 : 128;
	val = SENSORS_LIMIT(val, 1, max) >> 1;
	for (i = 0; i < 7; i++) {
		if (val == 0)
			break;
		val >>= 1;
	}
	return (u8) i;
}

struct w83791d_data {
	struct i2c_client client;
	struct device *hwmon_dev;
	struct mutex update_lock;

	char valid;			/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	/* array of 2 pointers to subclients */
	struct i2c_client *lm75[2];

	/* volts */
	u8 in[NUMBER_OF_VIN];		/* Register value */
	u8 in_max[NUMBER_OF_VIN];	/* Register value */
	u8 in_min[NUMBER_OF_VIN];	/* Register value */

	/* fans */
	u8 fan[NUMBER_OF_FANIN];	/* Register value */
	u8 fan_min[NUMBER_OF_FANIN];	/* Register value */
	u8 fan_div[NUMBER_OF_FANIN];	/* Register encoding, shifted right */

	/* Temperature sensors */

	s8 temp1[3];		/* current, over, thyst */
	s16 temp_add[2][3];	/* fixed point value. Top 8 bits are the
				   integral part, bottom 8 bits are the
				   fractional part. We only use the top
				   9 bits as the resolution is only
				   to the 0.5 degree C...
				   two sensors with three values
				   (cur, over, hyst)  */

	/* Misc */
	u32 alarms;		/* realtime status register encoding,combined */
	u8 beep_enable;		/* Global beep enable */
	u32 beep_mask;		/* Mask off specific beeps */
	u8 vid;			/* Register encoding, combined */
	u8 vrm;			/* hwmon-vid */
};

static int w83791d_attach_adapter(struct i2c_adapter *adapter);
static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind);
static int w83791d_detach_client(struct i2c_client *client);

static int w83791d_read(struct i2c_client *client, u8 register);
static int w83791d_write(struct i2c_client *client, u8 register, u8 value);
static struct w83791d_data *w83791d_update_device(struct device *dev);

#ifdef DEBUG
static void w83791d_print_debug(struct w83791d_data *data, struct device *dev);
#endif

static void w83791d_init_client(struct i2c_client *client);

static struct i2c_driver w83791d_driver = {
	.driver = {
		.name = "w83791d",
	},
	.attach_adapter = w83791d_attach_adapter,
	.detach_client = w83791d_detach_client,
};

/* following are the sysfs callback functions */
#define show_in_reg(reg) \
static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
			char *buf) \
{ \
	struct sensor_device_attribute *sensor_attr = \
						to_sensor_dev_attr(attr); \
	struct w83791d_data *data = w83791d_update_device(dev); \
	int nr = sensor_attr->index; \
	return sprintf(buf,"%d\n", IN_FROM_REG(data->reg[nr])); \
}

show_in_reg(in);
show_in_reg(in_min);
show_in_reg(in_max);

#define store_in_reg(REG, reg) \
static ssize_t store_in_##reg(struct device *dev, \
				struct device_attribute *attr, \
				const char *buf, size_t count) \
{ \
	struct sensor_device_attribute *sensor_attr = \
						to_sensor_dev_attr(attr); \
	struct i2c_client *client = to_i2c_client(dev); \
	struct w83791d_data *data = i2c_get_clientdata(client); \
	unsigned long val = simple_strtoul(buf, NULL, 10); \
	int nr = sensor_attr->index; \
	 \
	mutex_lock(&data->update_lock); \
	data->in_##reg[nr] = IN_TO_REG(val); \
	w83791d_write(client, W83791D_REG_IN_##REG[nr], data->in_##reg[nr]); \
	mutex_unlock(&data->update_lock); \
	 \
	return count; \
}
store_in_reg(MIN, min);
store_in_reg(MAX, max);

static struct sensor_device_attribute sda_in_input[] = {
	SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
	SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
	SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
	SENSOR_ATTR(in3_input, S_IRUGO, show_in, NULL, 3),
	SENSOR_ATTR(in4_input, S_IRUGO, show_in, NULL, 4),
	SENSOR_ATTR(in5_input, S_IRUGO, show_in, NULL, 5),
	SENSOR_ATTR(in6_input, S_IRUGO, show_in, NULL, 6),
	SENSOR_ATTR(in7_input, S_IRUGO, show_in, NULL, 7),
	SENSOR_ATTR(in8_input, S_IRUGO, show_in, NULL, 8),
	SENSOR_ATTR(in9_input, S_IRUGO, show_in, NULL, 9),
};

static struct sensor_device_attribute sda_in_min[] = {
	SENSOR_ATTR(in0_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 0),
	SENSOR_ATTR(in1_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 1),
	SENSOR_ATTR(in2_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 2),
	SENSOR_ATTR(in3_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 3),
	SENSOR_ATTR(in4_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 4),
	SENSOR_ATTR(in5_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 5),
	SENSOR_ATTR(in6_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 6),
	SENSOR_ATTR(in7_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 7),
	SENSOR_ATTR(in8_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 8),
	SENSOR_ATTR(in9_min, S_IWUSR | S_IRUGO, show_in_min, store_in_min, 9),
};

static struct sensor_device_attribute sda_in_max[] = {
	SENSOR_ATTR(in0_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 0),
	SENSOR_ATTR(in1_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 1),
	SENSOR_ATTR(in2_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 2),
	SENSOR_ATTR(in3_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 3),
	SENSOR_ATTR(in4_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 4),
	SENSOR_ATTR(in5_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 5),
	SENSOR_ATTR(in6_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 6),
	SENSOR_ATTR(in7_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 7),
	SENSOR_ATTR(in8_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 8),
	SENSOR_ATTR(in9_max, S_IWUSR | S_IRUGO, show_in_max, store_in_max, 9),
};


static ssize_t show_beep(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	struct sensor_device_attribute *sensor_attr =
						to_sensor_dev_attr(attr);
	struct w83791d_data *data = w83791d_update_device(dev);
	int bitnr = sensor_attr->index;

	return sprintf(buf, "%d\n", (data->beep_mask >> bitnr) & 1);
}

static ssize_t store_beep(struct device *dev, struct device_attribute *attr,
			const char *buf, size_t count)
{
	struct sensor_device_attribute *sensor_attr =
						to_sensor_dev_attr(attr);
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	int bitnr = sensor_attr->index;
	int bytenr = bitnr / 8;
	long val = simple_strtol(buf, NULL, 10) ? 1 : 0;

	mutex_lock(&data->update_lock);

	data->beep_mask &= ~(0xff << (bytenr * 8));
	data->beep_mask |= w83791d_read(client, W83791D_REG_BEEP_CTRL[bytenr])
		<< (bytenr * 8);

	data->beep_mask &= ~(1 << bitnr);
	data->beep_mask |= val << bitnr;

	w83791d_write(client, W83791D_REG_BEEP_CTRL[bytenr],
		(data->beep_mask >> (bytenr * 8)) & 0xff);

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	struct sensor_device_attribute *sensor_attr =
						to_sensor_dev_attr(attr);
	struct w83791d_data *data = w83791d_update_device(dev);
	int bitnr = sensor_attr->index;

	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
}

/* Note: The bitmask for the beep enable/disable is different than
   the bitmask for the alarm. */
static struct sensor_device_attribute sda_in_beep[] = {
	SENSOR_ATTR(in0_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 0),
	SENSOR_ATTR(in1_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 13),
	SENSOR_ATTR(in2_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 2),
	SENSOR_ATTR(in3_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 3),
	SENSOR_ATTR(in4_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 8),
	SENSOR_ATTR(in5_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 9),
	SENSOR_ATTR(in6_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 10),
	SENSOR_ATTR(in7_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 16),
	SENSOR_ATTR(in8_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 17),
	SENSOR_ATTR(in9_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 14),
};

static struct sensor_device_attribute sda_in_alarm[] = {
	SENSOR_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0),
	SENSOR_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1),
	SENSOR_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2),
	SENSOR_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3),
	SENSOR_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 8),
	SENSOR_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 9),
	SENSOR_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 10),
	SENSOR_ATTR(in7_alarm, S_IRUGO, show_alarm, NULL, 19),
	SENSOR_ATTR(in8_alarm, S_IRUGO, show_alarm, NULL, 20),
	SENSOR_ATTR(in9_alarm, S_IRUGO, show_alarm, NULL, 14),
};

#define show_fan_reg(reg) \
static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
				char *buf) \
{ \
	struct sensor_device_attribute *sensor_attr = \
						to_sensor_dev_attr(attr); \
	struct w83791d_data *data = w83791d_update_device(dev); \
	int nr = sensor_attr->index; \
	return sprintf(buf,"%d\n", \
		FAN_FROM_REG(data->reg[nr], DIV_FROM_REG(data->fan_div[nr]))); \
}

show_fan_reg(fan);
show_fan_reg(fan_min);

static ssize_t store_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);
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	int nr = sensor_attr->index;

	mutex_lock(&data->update_lock);
	data->fan_min[nr] = fan_to_reg(val, DIV_FROM_REG(data->fan_div[nr]));
	w83791d_write(client, W83791D_REG_FAN_MIN[nr], data->fan_min[nr]);
	mutex_unlock(&data->update_lock);

	return count;
}

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 w83791d_data *data = w83791d_update_device(dev);
	return sprintf(buf, "%u\n", DIV_FROM_REG(data->fan_div[nr]));
}

/* Note: we save and restore the fan minimum here, because its value is
   determined in part by the fan divisor.  This follows the principle of
   least suprise; the user doesn't expect the fan minimum to change just
   because the divisor changed. */
static ssize_t store_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);
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	int nr = sensor_attr->index;
	unsigned long min;
	u8 tmp_fan_div;
	u8 fan_div_reg;
	int indx = 0;
	u8 keep_mask = 0;
	u8 new_shift = 0;

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

	mutex_lock(&data->update_lock);
	data->fan_div[nr] = div_to_reg(nr, simple_strtoul(buf, NULL, 10));

	switch (nr) {
	case 0:
		indx = 0;
		keep_mask = 0xcf;
		new_shift = 4;
		break;
	case 1:
		indx = 0;
		keep_mask = 0x3f;
		new_shift = 6;
		break;
	case 2:
		indx = 1;
		keep_mask = 0x3f;
		new_shift = 6;
		break;
	case 3:
		indx = 2;
		keep_mask = 0xf8;
		new_shift = 0;
		break;
	case 4:
		indx = 2;
		keep_mask = 0x8f;
		new_shift = 4;
		break;
#ifdef DEBUG
	default:
		dev_warn(dev, "store_fan_div: Unexpected nr seen: %d\n", nr);
		count = -EINVAL;
		goto err_exit;
#endif
	}

	fan_div_reg = w83791d_read(client, W83791D_REG_FAN_DIV[indx])
			& keep_mask;
	tmp_fan_div = (data->fan_div[nr] << new_shift) & ~keep_mask;

	w83791d_write(client, W83791D_REG_FAN_DIV[indx],
				fan_div_reg | tmp_fan_div);

	/* Restore fan_min */
	data->fan_min[nr] = fan_to_reg(min, DIV_FROM_REG(data->fan_div[nr]));
	w83791d_write(client, W83791D_REG_FAN_MIN[nr], data->fan_min[nr]);

#ifdef DEBUG
err_exit:
#endif
	mutex_unlock(&data->update_lock);

	return count;
}

static struct sensor_device_attribute sda_fan_input[] = {
	SENSOR_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0),
	SENSOR_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1),
	SENSOR_ATTR(fan3_input, S_IRUGO, show_fan, NULL, 2),
	SENSOR_ATTR(fan4_input, S_IRUGO, show_fan, NULL, 3),
	SENSOR_ATTR(fan5_input, S_IRUGO, show_fan, NULL, 4),
};

static struct sensor_device_attribute sda_fan_min[] = {
	SENSOR_ATTR(fan1_min, S_IWUSR | S_IRUGO,
			show_fan_min, store_fan_min, 0),
	SENSOR_ATTR(fan2_min, S_IWUSR | S_IRUGO,
			show_fan_min, store_fan_min, 1),
	SENSOR_ATTR(fan3_min, S_IWUSR | S_IRUGO,
			show_fan_min, store_fan_min, 2),
	SENSOR_ATTR(fan4_min, S_IWUSR | S_IRUGO,
			show_fan_min, store_fan_min, 3),
	SENSOR_ATTR(fan5_min, S_IWUSR | S_IRUGO,
			show_fan_min, store_fan_min, 4),
};

static struct sensor_device_attribute sda_fan_div[] = {
	SENSOR_ATTR(fan1_div, S_IWUSR | S_IRUGO,
			show_fan_div, store_fan_div, 0),
	SENSOR_ATTR(fan2_div, S_IWUSR | S_IRUGO,
			show_fan_div, store_fan_div, 1),
	SENSOR_ATTR(fan3_div, S_IWUSR | S_IRUGO,
			show_fan_div, store_fan_div, 2),
	SENSOR_ATTR(fan4_div, S_IWUSR | S_IRUGO,
			show_fan_div, store_fan_div, 3),
	SENSOR_ATTR(fan5_div, S_IWUSR | S_IRUGO,
			show_fan_div, store_fan_div, 4),
};

static struct sensor_device_attribute sda_fan_beep[] = {
	SENSOR_ATTR(fan1_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 6),
	SENSOR_ATTR(fan2_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 7),
	SENSOR_ATTR(fan3_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 11),
	SENSOR_ATTR(fan4_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 21),
	SENSOR_ATTR(fan5_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 22),
};

static struct sensor_device_attribute sda_fan_alarm[] = {
	SENSOR_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6),
	SENSOR_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7),
	SENSOR_ATTR(fan3_alarm, S_IRUGO, show_alarm, NULL, 11),
	SENSOR_ATTR(fan4_alarm, S_IRUGO, show_alarm, NULL, 21),
	SENSOR_ATTR(fan5_alarm, S_IRUGO, show_alarm, NULL, 22),
};

/* read/write the temperature1, includes measured value and limits */
static ssize_t show_temp1(struct device *dev, struct device_attribute *devattr,
				char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct w83791d_data *data = w83791d_update_device(dev);
	return sprintf(buf, "%d\n", TEMP1_FROM_REG(data->temp1[attr->index]));
}

static ssize_t store_temp1(struct device *dev, struct device_attribute *devattr,
				const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	int nr = attr->index;

	mutex_lock(&data->update_lock);
	data->temp1[nr] = TEMP1_TO_REG(val);
	w83791d_write(client, W83791D_REG_TEMP1[nr], data->temp1[nr]);
	mutex_unlock(&data->update_lock);
	return count;
}

/* read/write temperature2-3, includes measured value and limits */
static ssize_t show_temp23(struct device *dev, struct device_attribute *devattr,
				char *buf)
{
	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
	struct w83791d_data *data = w83791d_update_device(dev);
	int nr = attr->nr;
	int index = attr->index;
	return sprintf(buf, "%d\n", TEMP23_FROM_REG(data->temp_add[nr][index]));
}

static ssize_t store_temp23(struct device *dev,
				struct device_attribute *devattr,
				const char *buf, size_t count)
{
	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	int nr = attr->nr;
	int index = attr->index;

	mutex_lock(&data->update_lock);
	data->temp_add[nr][index] = TEMP23_TO_REG(val);
	w83791d_write(client, W83791D_REG_TEMP_ADD[nr][index * 2],
				data->temp_add[nr][index] >> 8);
	w83791d_write(client, W83791D_REG_TEMP_ADD[nr][index * 2 + 1],
				data->temp_add[nr][index] & 0x80);
	mutex_unlock(&data->update_lock);

	return count;
}

static struct sensor_device_attribute_2 sda_temp_input[] = {
	SENSOR_ATTR_2(temp1_input, S_IRUGO, show_temp1, NULL, 0, 0),
	SENSOR_ATTR_2(temp2_input, S_IRUGO, show_temp23, NULL, 0, 0),
	SENSOR_ATTR_2(temp3_input, S_IRUGO, show_temp23, NULL, 1, 0),
};

static struct sensor_device_attribute_2 sda_temp_max[] = {
	SENSOR_ATTR_2(temp1_max, S_IRUGO | S_IWUSR,
			show_temp1, store_temp1, 0, 1),
	SENSOR_ATTR_2(temp2_max, S_IRUGO | S_IWUSR,
			show_temp23, store_temp23, 0, 1),
	SENSOR_ATTR_2(temp3_max, S_IRUGO | S_IWUSR,
			show_temp23, store_temp23, 1, 1),
};

static struct sensor_device_attribute_2 sda_temp_max_hyst[] = {
	SENSOR_ATTR_2(temp1_max_hyst, S_IRUGO | S_IWUSR,
			show_temp1, store_temp1, 0, 2),
	SENSOR_ATTR_2(temp2_max_hyst, S_IRUGO | S_IWUSR,
			show_temp23, store_temp23, 0, 2),
	SENSOR_ATTR_2(temp3_max_hyst, S_IRUGO | S_IWUSR,
			show_temp23, store_temp23, 1, 2),
};

/* Note: The bitmask for the beep enable/disable is different than
   the bitmask for the alarm. */
static struct sensor_device_attribute sda_temp_beep[] = {
	SENSOR_ATTR(temp1_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 4),
	SENSOR_ATTR(temp2_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 5),
	SENSOR_ATTR(temp3_beep, S_IWUSR | S_IRUGO, show_beep, store_beep, 1),
};

static struct sensor_device_attribute sda_temp_alarm[] = {
	SENSOR_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4),
	SENSOR_ATTR(temp2_alarm, S_IRUGO, show_alarm, NULL, 5),
	SENSOR_ATTR(temp3_alarm, S_IRUGO, show_alarm, NULL, 13),
};

/* get reatime status of all sensors items: voltage, temp, fan */
static ssize_t show_alarms_reg(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct w83791d_data *data = w83791d_update_device(dev);
	return sprintf(buf, "%u\n", data->alarms);
}

static DEVICE_ATTR(alarms, S_IRUGO, show_alarms_reg, NULL);

/* Beep control */

#define GLOBAL_BEEP_ENABLE_SHIFT	15
#define GLOBAL_BEEP_ENABLE_MASK		(1 << GLOBAL_BEEP_ENABLE_SHIFT)

static ssize_t show_beep_enable(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct w83791d_data *data = w83791d_update_device(dev);
	return sprintf(buf, "%d\n", data->beep_enable);
}

static ssize_t show_beep_mask(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct w83791d_data *data = w83791d_update_device(dev);
	return sprintf(buf, "%d\n", BEEP_MASK_FROM_REG(data->beep_mask));
}


static ssize_t store_beep_mask(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);
	int i;

	mutex_lock(&data->update_lock);

	/* The beep_enable state overrides any enabling request from
	   the masks */
	data->beep_mask = BEEP_MASK_TO_REG(val) & ~GLOBAL_BEEP_ENABLE_MASK;
	data->beep_mask |= (data->beep_enable << GLOBAL_BEEP_ENABLE_SHIFT);

	val = data->beep_mask;

	for (i = 0; i < 3; i++) {
		w83791d_write(client, W83791D_REG_BEEP_CTRL[i], (val & 0xff));
		val >>= 8;
	}

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t store_beep_enable(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	long val = simple_strtol(buf, NULL, 10);

	mutex_lock(&data->update_lock);

	data->beep_enable = val ? 1 : 0;

	/* Keep the full mask value in sync with the current enable */
	data->beep_mask &= ~GLOBAL_BEEP_ENABLE_MASK;
	data->beep_mask |= (data->beep_enable << GLOBAL_BEEP_ENABLE_SHIFT);

	/* The global control is in the second beep control register
	   so only need to update that register */
	val = (data->beep_mask >> 8) & 0xff;

	w83791d_write(client, W83791D_REG_BEEP_CTRL[1], val);

	mutex_unlock(&data->update_lock);

	return count;
}

static struct sensor_device_attribute sda_beep_ctrl[] = {
	SENSOR_ATTR(beep_enable, S_IRUGO | S_IWUSR,
			show_beep_enable, store_beep_enable, 0),
	SENSOR_ATTR(beep_mask, S_IRUGO | S_IWUSR,
			show_beep_mask, store_beep_mask, 1)
};

/* cpu voltage regulation information */
static ssize_t show_vid_reg(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct w83791d_data *data = w83791d_update_device(dev);
	return sprintf(buf, "%d\n", vid_from_reg(data->vid, data->vrm));
}

static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid_reg, NULL);

static ssize_t show_vrm_reg(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct w83791d_data *data = dev_get_drvdata(dev);
	return sprintf(buf, "%d\n", data->vrm);
}

static ssize_t store_vrm_reg(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct w83791d_data *data = dev_get_drvdata(dev);

	/* No lock needed as vrm is internal to the driver
	   (not read from a chip register) and so is not
	   updated in w83791d_update_device() */
	data->vrm = simple_strtoul(buf, NULL, 10);

	return count;
}

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

#define IN_UNIT_ATTRS(X) \
	&sda_in_input[X].dev_attr.attr, \
	&sda_in_min[X].dev_attr.attr,   \
	&sda_in_max[X].dev_attr.attr,   \
	&sda_in_beep[X].dev_attr.attr,  \
	&sda_in_alarm[X].dev_attr.attr

#define FAN_UNIT_ATTRS(X) \
	&sda_fan_input[X].dev_attr.attr,        \
	&sda_fan_min[X].dev_attr.attr,          \
	&sda_fan_div[X].dev_attr.attr,          \
	&sda_fan_beep[X].dev_attr.attr,         \
	&sda_fan_alarm[X].dev_attr.attr

#define TEMP_UNIT_ATTRS(X) \
	&sda_temp_input[X].dev_attr.attr,       \
	&sda_temp_max[X].dev_attr.attr,         \
	&sda_temp_max_hyst[X].dev_attr.attr,    \
	&sda_temp_beep[X].dev_attr.attr,        \
	&sda_temp_alarm[X].dev_attr.attr

static struct attribute *w83791d_attributes[] = {
	IN_UNIT_ATTRS(0),
	IN_UNIT_ATTRS(1),
	IN_UNIT_ATTRS(2),
	IN_UNIT_ATTRS(3),
	IN_UNIT_ATTRS(4),
	IN_UNIT_ATTRS(5),
	IN_UNIT_ATTRS(6),
	IN_UNIT_ATTRS(7),
	IN_UNIT_ATTRS(8),
	IN_UNIT_ATTRS(9),
	FAN_UNIT_ATTRS(0),
	FAN_UNIT_ATTRS(1),
	FAN_UNIT_ATTRS(2),
	FAN_UNIT_ATTRS(3),
	FAN_UNIT_ATTRS(4),
	TEMP_UNIT_ATTRS(0),
	TEMP_UNIT_ATTRS(1),
	TEMP_UNIT_ATTRS(2),
	&dev_attr_alarms.attr,
	&sda_beep_ctrl[0].dev_attr.attr,
	&sda_beep_ctrl[1].dev_attr.attr,
	&dev_attr_cpu0_vid.attr,
	&dev_attr_vrm.attr,
	NULL
};

static const struct attribute_group w83791d_group = {
	.attrs = w83791d_attributes,
};

/* This function is called when:
     * w83791d_driver is inserted (when this module is loaded), for each
       available adapter
     * when a new adapter is inserted (and w83791d_driver is still present) */
static int w83791d_attach_adapter(struct i2c_adapter *adapter)
{
	if (!(adapter->class & I2C_CLASS_HWMON))
		return 0;
	return i2c_probe(adapter, &addr_data, w83791d_detect);
}


static int w83791d_create_subclient(struct i2c_adapter *adapter,
				struct i2c_client *client, int addr,
				struct i2c_client **sub_cli)
{
	int err;
	struct i2c_client *sub_client;

	(*sub_cli) = sub_client =
			kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
	if (!(sub_client)) {
		return -ENOMEM;
	}
	sub_client->addr = 0x48 + addr;
	i2c_set_clientdata(sub_client, NULL);
	sub_client->adapter = adapter;
	sub_client->driver = &w83791d_driver;
	strlcpy(sub_client->name, "w83791d subclient", I2C_NAME_SIZE);
	if ((err = i2c_attach_client(sub_client))) {
		dev_err(&client->dev, "subclient registration "
			"at address 0x%x failed\n", sub_client->addr);
		kfree(sub_client);
		return err;
	}
	return 0;
}


static int w83791d_detect_subclients(struct i2c_adapter *adapter, int address,
				int kind, struct i2c_client *client)
{
	struct w83791d_data *data = i2c_get_clientdata(client);
	int i, id, err;
	u8 val;

	id = i2c_adapter_id(adapter);
	if (force_subclients[0] == id && force_subclients[1] == address) {
		for (i = 2; i <= 3; i++) {
			if (force_subclients[i] < 0x48 ||
			    force_subclients[i] > 0x4f) {
				dev_err(&client->dev,
					"invalid subclient "
					"address %d; must be 0x48-0x4f\n",
					force_subclients[i]);
				err = -ENODEV;
				goto error_sc_0;
			}
		}
		w83791d_write(client, W83791D_REG_I2C_SUBADDR,
					(force_subclients[2] & 0x07) |
					((force_subclients[3] & 0x07) << 4));
	}

	val = w83791d_read(client, W83791D_REG_I2C_SUBADDR);
	if (!(val & 0x08)) {
		err = w83791d_create_subclient(adapter, client,
						val & 0x7, &data->lm75[0]);
		if (err < 0)
			goto error_sc_0;
	}
	if (!(val & 0x80)) {
		if ((data->lm75[0] != NULL) &&
				((val & 0x7) == ((val >> 4) & 0x7))) {
			dev_err(&client->dev,
				"duplicate addresses 0x%x, "
				"use force_subclient\n",
				data->lm75[0]->addr);
			err = -ENODEV;
			goto error_sc_1;
		}
		err = w83791d_create_subclient(adapter, client,
					(val >> 4) & 0x7, &data->lm75[1]);
		if (err < 0)
			goto error_sc_1;
	}

	return 0;

/* Undo inits in case of errors */

error_sc_1:
	if (data->lm75[0] != NULL) {
		i2c_detach_client(data->lm75[0]);
		kfree(data->lm75[0]);
	}
error_sc_0:
	return err;
}


static int w83791d_detect(struct i2c_adapter *adapter, int address, int kind)
{
	struct i2c_client *client;
	struct device *dev;
	struct w83791d_data *data;
	int i, val1, val2;
	int err = 0;
	const char *client_name = "";

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
		goto error0;
	}

	/* OK. For now, we presume we have a valid client. We now create the
	   client structure, even though we cannot fill it completely yet.
	   But it allows us to access w83791d_{read,write}_value. */
	if (!(data = kzalloc(sizeof(struct w83791d_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto error0;
	}

	client = &data->client;
	dev = &client->dev;
	i2c_set_clientdata(client, data);
	client->addr = address;
	client->adapter = adapter;
	client->driver = &w83791d_driver;
	mutex_init(&data->update_lock);

	/* Now, we do the remaining detection. */

	/* The w83791d may be stuck in some other bank than bank 0. This may
	   make reading other information impossible. Specify a force=...
	   parameter, and the Winbond will be reset to the right bank. */
	if (kind < 0) {
		if (w83791d_read(client, W83791D_REG_CONFIG) & 0x80) {
			dev_dbg(dev, "Detection failed at step 1\n");
			goto error1;
		}
		val1 = w83791d_read(client, W83791D_REG_BANK);
		val2 = w83791d_read(client, W83791D_REG_CHIPMAN);
		/* Check for Winbond ID if in bank 0 */
		if (!(val1 & 0x07)) {
			/* yes it is Bank0 */
			if (((!(val1 & 0x80)) && (val2 != 0xa3)) ||
			    ((val1 & 0x80) && (val2 != 0x5c))) {
				dev_dbg(dev, "Detection failed at step 2\n");
				goto error1;
			}
		}
		/* If Winbond chip, address of chip and W83791D_REG_I2C_ADDR
		   should match */
		if (w83791d_read(client, W83791D_REG_I2C_ADDR) != address) {
			dev_dbg(dev, "Detection failed at step 3\n");
			goto error1;
		}
	}

	/* We either have a force parameter or we have reason to
	   believe it is a Winbond chip. Either way, we want bank 0 and
	   Vendor ID high byte */
	val1 = w83791d_read(client, W83791D_REG_BANK) & 0x78;
	w83791d_write(client, W83791D_REG_BANK, val1 | 0x80);

	/* Verify it is a Winbond w83791d */
	if (kind <= 0) {
		/* get vendor ID */
		val2 = w83791d_read(client, W83791D_REG_CHIPMAN);
		if (val2 != 0x5c) {	/* the vendor is NOT Winbond */
			dev_dbg(dev, "Detection failed at step 4\n");
			goto error1;
		}
		val1 = w83791d_read(client, W83791D_REG_WCHIPID);
		if (val1 == 0x71) {
			kind = w83791d;
		} else {
			if (kind == 0)
				dev_warn(dev,
					"w83791d: Ignoring 'force' parameter "
					"for unknown chip at adapter %d, "
					"address 0x%02x\n",
					i2c_adapter_id(adapter), address);
			goto error1;
		}
	}

	if (kind == w83791d) {
		client_name = "w83791d";
	} else {
		dev_err(dev, "w83791d: Internal error: unknown kind (%d)?!?\n",
			kind);
		goto error1;
	}

#ifdef DEBUG
	val1 = w83791d_read(client, W83791D_REG_DID_VID4);
	dev_dbg(dev, "Device ID version: %d.%d (0x%02x)\n",
			(val1 >> 5) & 0x07, (val1 >> 1) & 0x0f, val1);
#endif

	/* Fill in the remaining client fields and put into the global list */
	strlcpy(client->name, client_name, I2C_NAME_SIZE);

	/* Tell the I2C layer a new client has arrived */
	if ((err = i2c_attach_client(client)))
		goto error1;

	if ((err = w83791d_detect_subclients(adapter, address, kind, client)))
		goto error2;

	/* Initialize the chip */
	w83791d_init_client(client);

	/* If the fan_div is changed, make sure there is a rational
	   fan_min in place */
	for (i = 0; i < NUMBER_OF_FANIN; i++) {
		data->fan_min[i] = w83791d_read(client, W83791D_REG_FAN_MIN[i]);
	}

	/* Register sysfs hooks */
	if ((err = sysfs_create_group(&client->dev.kobj, &w83791d_group)))
		goto error3;

	/* Everything is ready, now register the working device */
	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(&client->dev.kobj, &w83791d_group);
error3:
	if (data->lm75[0] != NULL) {
		i2c_detach_client(data->lm75[0]);
		kfree(data->lm75[0]);
	}
	if (data->lm75[1] != NULL) {
		i2c_detach_client(data->lm75[1]);
		kfree(data->lm75[1]);
	}
error2:
	i2c_detach_client(client);
error1:
	kfree(data);
error0:
	return err;
}

static int w83791d_detach_client(struct i2c_client *client)
{
	struct w83791d_data *data = i2c_get_clientdata(client);
	int err;

	/* main client */
	if (data) {
		hwmon_device_unregister(data->hwmon_dev);
		sysfs_remove_group(&client->dev.kobj, &w83791d_group);
	}

	if ((err = i2c_detach_client(client)))
		return err;

	/* main client */
	if (data)
		kfree(data);
	/* subclient */
	else
		kfree(client);

	return 0;
}

static void w83791d_init_client(struct i2c_client *client)
{
	struct w83791d_data *data = i2c_get_clientdata(client);
	u8 tmp;
	u8 old_beep;

	/* The difference between reset and init is that reset
	   does a hard reset of the chip via index 0x40, bit 7,
	   but init simply forces certain registers to have "sane"
	   values. The hope is that the BIOS has done the right
	   thing (which is why the default is reset=0, init=0),
	   but if not, reset is the hard hammer and init
	   is the soft mallet both of which are trying to whack
	   things into place...
	   NOTE: The data sheet makes a distinction between
	   "power on defaults" and "reset by MR". As far as I can tell,
	   the hard reset puts everything into a power-on state so I'm
	   not sure what "reset by MR" means or how it can happen.
	   */
	if (reset || init) {
		/* keep some BIOS settings when we... */
		old_beep = w83791d_read(client, W83791D_REG_BEEP_CONFIG);

		if (reset) {
			/* ... reset the chip and ... */
			w83791d_write(client, W83791D_REG_CONFIG, 0x80);
		}

		/* ... disable power-on abnormal beep */
		w83791d_write(client, W83791D_REG_BEEP_CONFIG, old_beep | 0x80);

		/* disable the global beep (not done by hard reset) */
		tmp = w83791d_read(client, W83791D_REG_BEEP_CTRL[1]);
		w83791d_write(client, W83791D_REG_BEEP_CTRL[1], tmp & 0xef);

		if (init) {
			/* Make sure monitoring is turned on for add-ons */
			tmp = w83791d_read(client, W83791D_REG_TEMP2_CONFIG);
			if (tmp & 1) {
				w83791d_write(client, W83791D_REG_TEMP2_CONFIG,
					tmp & 0xfe);
			}

			tmp = w83791d_read(client, W83791D_REG_TEMP3_CONFIG);
			if (tmp & 1) {
				w83791d_write(client, W83791D_REG_TEMP3_CONFIG,
					tmp & 0xfe);
			}

			/* Start monitoring */
			tmp = w83791d_read(client, W83791D_REG_CONFIG) & 0xf7;
			w83791d_write(client, W83791D_REG_CONFIG, tmp | 0x01);
		}
	}

	data->vrm = vid_which_vrm();
}

static struct w83791d_data *w83791d_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct w83791d_data *data = i2c_get_clientdata(client);
	int i, j;
	u8 reg_array_tmp[3];

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + (HZ * 3))
			|| !data->valid) {
		dev_dbg(dev, "Starting w83791d device update\n");

		/* Update the voltages measured value and limits */
		for (i = 0; i < NUMBER_OF_VIN; i++) {
			data->in[i] = w83791d_read(client,
						W83791D_REG_IN[i]);
			data->in_max[i] = w83791d_read(client,
						W83791D_REG_IN_MAX[i]);
			data->in_min[i] = w83791d_read(client,
						W83791D_REG_IN_MIN[i]);
		}

		/* Update the fan counts and limits */
		for (i = 0; i < NUMBER_OF_FANIN; i++) {
			/* Update the Fan measured value and limits */
			data->fan[i] = w83791d_read(client,
						W83791D_REG_FAN[i]);
			data->fan_min[i] = w83791d_read(client,
						W83791D_REG_FAN_MIN[i]);
		}

		/* Update the fan divisor */
		for (i = 0; i < 3; i++) {
			reg_array_tmp[i] = w83791d_read(client,
						W83791D_REG_FAN_DIV[i]);
		}
		data->fan_div[0] = (reg_array_tmp[0] >> 4) & 0x03;
		data->fan_div[1] = (reg_array_tmp[0] >> 6) & 0x03;
		data->fan_div[2] = (reg_array_tmp[1] >> 6) & 0x03;
		data->fan_div[3] = reg_array_tmp[2] & 0x07;
		data->fan_div[4] = (reg_array_tmp[2] >> 4) & 0x07;

		/* Update the first temperature sensor */
		for (i = 0; i < 3; i++) {
			data->temp1[i] = w83791d_read(client,
						W83791D_REG_TEMP1[i]);
		}

		/* Update the rest of the temperature sensors */
		for (i = 0; i < 2; i++) {
			for (j = 0; j < 3; j++) {
				data->temp_add[i][j] =
					(w83791d_read(client,
					W83791D_REG_TEMP_ADD[i][j * 2]) << 8) |
					w83791d_read(client,
					W83791D_REG_TEMP_ADD[i][j * 2 + 1]);
			}
		}

		/* Update the realtime status */
		data->alarms =
			w83791d_read(client, W83791D_REG_ALARM1) +
			(w83791d_read(client, W83791D_REG_ALARM2) << 8) +
			(w83791d_read(client, W83791D_REG_ALARM3) << 16);

		/* Update the beep configuration information */
		data->beep_mask =
			w83791d_read(client, W83791D_REG_BEEP_CTRL[0]) +
			(w83791d_read(client, W83791D_REG_BEEP_CTRL[1]) << 8) +
			(w83791d_read(client, W83791D_REG_BEEP_CTRL[2]) << 16);

		/* Extract global beep enable flag */
		data->beep_enable =
			(data->beep_mask >> GLOBAL_BEEP_ENABLE_SHIFT) & 0x01;

		/* Update the cpu voltage information */
		i = w83791d_read(client, W83791D_REG_VID_FANDIV);
		data->vid = i & 0x0f;
		data->vid |= (w83791d_read(client, W83791D_REG_DID_VID4) & 0x01)
				<< 4;

		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

#ifdef DEBUG
	w83791d_print_debug(data, dev);
#endif

	return data;
}

#ifdef DEBUG
static void w83791d_print_debug(struct w83791d_data *data, struct device *dev)
{
	int i = 0, j = 0;

	dev_dbg(dev, "======Start of w83791d debug values======\n");
	dev_dbg(dev, "%d set of Voltages: ===>\n", NUMBER_OF_VIN);
	for (i = 0; i < NUMBER_OF_VIN; i++) {
		dev_dbg(dev, "vin[%d] is:     0x%02x\n", i, data->in[i]);
		dev_dbg(dev, "vin[%d] min is: 0x%02x\n", i, data->in_min[i]);
		dev_dbg(dev, "vin[%d] max is: 0x%02x\n", i, data->in_max[i]);
	}
	dev_dbg(dev, "%d set of Fan Counts/Divisors: ===>\n", NUMBER_OF_FANIN);
	for (i = 0; i < NUMBER_OF_FANIN; i++) {
		dev_dbg(dev, "fan[%d] is:     0x%02x\n", i, data->fan[i]);
		dev_dbg(dev, "fan[%d] min is: 0x%02x\n", i, data->fan_min[i]);
		dev_dbg(dev, "fan_div[%d] is: 0x%02x\n", i, data->fan_div[i]);
	}

	/* temperature math is signed, but only print out the
	   bits that matter */
	dev_dbg(dev, "%d set of Temperatures: ===>\n", NUMBER_OF_TEMPIN);
	for (i = 0; i < 3; i++) {
		dev_dbg(dev, "temp1[%d] is: 0x%02x\n", i, (u8) data->temp1[i]);
	}
	for (i = 0; i < 2; i++) {
		for (j = 0; j < 3; j++) {
			dev_dbg(dev, "temp_add[%d][%d] is: 0x%04x\n", i, j,
				(u16) data->temp_add[i][j]);
		}
	}

	dev_dbg(dev, "Misc Information: ===>\n");
	dev_dbg(dev, "alarm is:     0x%08x\n", data->alarms);
	dev_dbg(dev, "beep_mask is: 0x%08x\n", data->beep_mask);
	dev_dbg(dev, "beep_enable is: %d\n", data->beep_enable);
	dev_dbg(dev, "vid is: 0x%02x\n", data->vid);
	dev_dbg(dev, "vrm is: 0x%02x\n", data->vrm);
	dev_dbg(dev, "=======End of w83791d debug values========\n");
	dev_dbg(dev, "\n");
}
#endif

static int __init sensors_w83791d_init(void)
{
	return i2c_add_driver(&w83791d_driver);
}

static void __exit sensors_w83791d_exit(void)
{
	i2c_del_driver(&w83791d_driver);
}

MODULE_AUTHOR("Charles Spirakis <bezaur@gmail.com>");
MODULE_DESCRIPTION("W83791D driver");
MODULE_LICENSE("GPL");

module_init(sensors_w83791d_init);
module_exit(sensors_w83791d_exit);