/*
   * w83l786ng.c - Linux kernel driver for hardware monitoring
   * Copyright (c) 2007 Kevin Lo <kevlo@kevlo.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 - version 2.
   *
   * 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., 51 Franklin Street, Fifth Floor, Boston, MA
   * 02110-1301 USA.
   */
  
  /*
   * Supports following chips:
   *
   * Chip		#vin	#fanin	#pwm	#temp	wchipid	vendid	i2c	ISA
   * w83l786ng	3	2	2	2	0x7b	0x5ca3	yes	no
   */
  
  #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>
  #include <linux/jiffies.h>
  
  /* Addresses to scan */
  static const unsigned short normal_i2c[] = { 0x2e, 0x2f, I2C_CLIENT_END };
  
  /* Insmod parameters */
  
  static bool reset;
  module_param(reset, bool, 0);
  MODULE_PARM_DESC(reset, "Set to 1 to reset chip, not recommended");
  
  #define W83L786NG_REG_IN_MIN(nr)	(0x2C + (nr) * 2)
  #define W83L786NG_REG_IN_MAX(nr)	(0x2B + (nr) * 2)
  #define W83L786NG_REG_IN(nr)		((nr) + 0x20)
  
  #define W83L786NG_REG_FAN(nr)		((nr) + 0x28)
  #define W83L786NG_REG_FAN_MIN(nr)	((nr) + 0x3B)
  
  #define W83L786NG_REG_CONFIG		0x40
  #define W83L786NG_REG_ALARM1		0x41
  #define W83L786NG_REG_ALARM2		0x42
  #define W83L786NG_REG_GPIO_EN		0x47
  #define W83L786NG_REG_MAN_ID2		0x4C
  #define W83L786NG_REG_MAN_ID1		0x4D
  #define W83L786NG_REG_CHIP_ID		0x4E
  
  #define W83L786NG_REG_DIODE		0x53
  #define W83L786NG_REG_FAN_DIV		0x54
  #define W83L786NG_REG_FAN_CFG		0x80
  
  #define W83L786NG_REG_TOLERANCE		0x8D
  
  static const u8 W83L786NG_REG_TEMP[2][3] = {
  	{ 0x25,		/* TEMP 0 in DataSheet */
  	  0x35,		/* TEMP 0 Over in DataSheet */
  	  0x36 },	/* TEMP 0 Hyst in DataSheet */
  	{ 0x26,		/* TEMP 1 in DataSheet */
  	  0x37,		/* TEMP 1 Over in DataSheet */
  	  0x38 }	/* TEMP 1 Hyst in DataSheet */
  };
  
  static const u8 W83L786NG_PWM_MODE_SHIFT[] = {6, 7};
  static const u8 W83L786NG_PWM_ENABLE_SHIFT[] = {2, 4};
  
  /* FAN Duty Cycle, be used to control */
  static const u8 W83L786NG_REG_PWM[] = {0x81, 0x87};
  
  
  static inline u8
  FAN_TO_REG(long rpm, int div)
  {
  	if (rpm == 0)
  		return 255;
  	rpm = clamp_val(rpm, 1, 1000000);
  	return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
  }
  
  #define FAN_FROM_REG(val, div)	((val) == 0   ? -1 : \
  				((val) == 255 ? 0 : \
  				1350000 / ((val) * (div))))
  
  /* for temp */
  #define TEMP_TO_REG(val)	(clamp_val(((val) < 0 ? (val) + 0x100 * 1000 \
  						      : (val)) / 1000, 0, 0xff))
  #define TEMP_FROM_REG(val)	(((val) & 0x80 ? \
  				  (val) - 0x100 : (val)) * 1000)
  
  /*
   * The analog voltage inputs have 8mV LSB. Since the sysfs output is
   * in mV as would be measured on the chip input pin, need to just
   * multiply/divide by 8 to translate from/to register values.
   */
  #define IN_TO_REG(val)		(clamp_val((((val) + 4) / 8), 0, 255))
  #define IN_FROM_REG(val)	((val) * 8)
  
  #define DIV_FROM_REG(val)	(1 << (val))
  
  static inline u8
  DIV_TO_REG(long val)
  {
  	int i;
  	val = clamp_val(val, 1, 128) >> 1;
  	for (i = 0; i < 7; i++) {
  		if (val == 0)
  			break;
  		val >>= 1;
  	}
  	return (u8)i;
  }
  
  struct w83l786ng_data {
  	struct device *hwmon_dev;
  	struct mutex update_lock;
  	char valid;			/* !=0 if following fields are valid */
  	unsigned long last_updated;	/* In jiffies */
  	unsigned long last_nonvolatile;	/* In jiffies, last time we update the
  					 * nonvolatile registers */
  
  	u8 in[3];
  	u8 in_max[3];
  	u8 in_min[3];
  	u8 fan[2];
  	u8 fan_div[2];
  	u8 fan_min[2];
  	u8 temp_type[2];
  	u8 temp[2][3];
  	u8 pwm[2];
  	u8 pwm_mode[2];	/* 0->DC variable voltage
  			 * 1->PWM variable duty cycle */
  
  	u8 pwm_enable[2]; /* 1->manual
  			   * 2->thermal cruise (also called SmartFan I) */
  	u8 tolerance[2];
  };
  
  static int w83l786ng_probe(struct i2c_client *client,
  			   const struct i2c_device_id *id);
  static int w83l786ng_detect(struct i2c_client *client,
  			    struct i2c_board_info *info);
  static int w83l786ng_remove(struct i2c_client *client);
  static void w83l786ng_init_client(struct i2c_client *client);
  static struct w83l786ng_data *w83l786ng_update_device(struct device *dev);
  
  static const struct i2c_device_id w83l786ng_id[] = {
  	{ "w83l786ng", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, w83l786ng_id);
  
  static struct i2c_driver w83l786ng_driver = {
  	.class		= I2C_CLASS_HWMON,
  	.driver = {
  		   .name = "w83l786ng",
  	},
  	.probe		= w83l786ng_probe,
  	.remove		= w83l786ng_remove,
  	.id_table	= w83l786ng_id,
  	.detect		= w83l786ng_detect,
  	.address_list	= normal_i2c,
  };
  
  static u8
  w83l786ng_read_value(struct i2c_client *client, u8 reg)
  {
  	return i2c_smbus_read_byte_data(client, reg);
  }
  
  static int
  w83l786ng_write_value(struct i2c_client *client, u8 reg, u8 value)
  {
  	return i2c_smbus_write_byte_data(client, reg, value);
  }
  
  /* 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) \
  { \
  	int nr = to_sensor_dev_attr(attr)->index; \
  	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
  	return sprintf(buf, "%d
  ", 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) \
  { \
  	int nr = to_sensor_dev_attr(attr)->index; \
  	struct i2c_client *client = to_i2c_client(dev); \
  	struct w83l786ng_data *data = i2c_get_clientdata(client); \
  	unsigned long val; \
  	int err = kstrtoul(buf, 10, &val); \
  	if (err) \
  		return err; \
  	mutex_lock(&data->update_lock); \
  	data->in_##reg[nr] = IN_TO_REG(val); \
  	w83l786ng_write_value(client, W83L786NG_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),
  };
  
  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),
  };
  
  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),
  };
  
  #define show_fan_reg(reg) \
  static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
  			  char *buf) \
  { \
  	int nr = to_sensor_dev_attr(attr)->index; \
  	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
  	return sprintf(buf, "%d
  ", \
  		FAN_FROM_REG(data->fan[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)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
  	w83l786ng_write_value(client, W83L786NG_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)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct w83l786ng_data *data = w83l786ng_update_device(dev);
  	return sprintf(buf, "%u
  ", 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 surprise; 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)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  
  	unsigned long min;
  	u8 tmp_fan_div;
  	u8 fan_div_reg;
  	u8 keep_mask = 0;
  	u8 new_shift = 0;
  
  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  
  	/* Save fan_min */
  	mutex_lock(&data->update_lock);
  	min = FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr]));
  
  	data->fan_div[nr] = DIV_TO_REG(val);
  
  	switch (nr) {
  	case 0:
  		keep_mask = 0xf8;
  		new_shift = 0;
  		break;
  	case 1:
  		keep_mask = 0x8f;
  		new_shift = 4;
  		break;
  	}
  
  	fan_div_reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV)
  					   & keep_mask;
  
  	tmp_fan_div = (data->fan_div[nr] << new_shift) & ~keep_mask;
  
  	w83l786ng_write_value(client, W83L786NG_REG_FAN_DIV,
  			      fan_div_reg | tmp_fan_div);
  
  	/* Restore fan_min */
  	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
  	w83l786ng_write_value(client, W83L786NG_REG_FAN_MIN(nr),
  			      data->fan_min[nr]);
  	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),
  };
  
  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),
  };
  
  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),
  };
  
  
  /* read/write the temperature, includes measured value and limits */
  
  static ssize_t
  show_temp(struct device *dev, struct device_attribute *attr, char *buf)
  {
  	struct sensor_device_attribute_2 *sensor_attr =
  	    to_sensor_dev_attr_2(attr);
  	int nr = sensor_attr->nr;
  	int index = sensor_attr->index;
  	struct w83l786ng_data *data = w83l786ng_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp[nr][index]));
  }
  
  static ssize_t
  store_temp(struct device *dev, struct device_attribute *attr,
  	   const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *sensor_attr =
  	    to_sensor_dev_attr_2(attr);
  	int nr = sensor_attr->nr;
  	int index = sensor_attr->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  	long val;
  	int err;
  
  	err = kstrtol(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	data->temp[nr][index] = TEMP_TO_REG(val);
  	w83l786ng_write_value(client, W83L786NG_REG_TEMP[nr][index],
  			      data->temp[nr][index]);
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }
  
  static struct sensor_device_attribute_2 sda_temp_input[] = {
  	SENSOR_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0),
  	SENSOR_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 1, 0),
  };
  
  static struct sensor_device_attribute_2 sda_temp_max[] = {
  	SENSOR_ATTR_2(temp1_max, S_IRUGO | S_IWUSR,
  		      show_temp, store_temp, 0, 1),
  	SENSOR_ATTR_2(temp2_max, S_IRUGO | S_IWUSR,
  		      show_temp, store_temp, 1, 1),
  };
  
  static struct sensor_device_attribute_2 sda_temp_max_hyst[] = {
  	SENSOR_ATTR_2(temp1_max_hyst, S_IRUGO | S_IWUSR,
  		      show_temp, store_temp, 0, 2),
  	SENSOR_ATTR_2(temp2_max_hyst, S_IRUGO | S_IWUSR,
  		      show_temp, store_temp, 1, 2),
  };
  
  #define show_pwm_reg(reg) \
  static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
  			  char *buf) \
  { \
  	struct w83l786ng_data *data = w83l786ng_update_device(dev); \
  	int nr = to_sensor_dev_attr(attr)->index; \
  	return sprintf(buf, "%d
  ", data->reg[nr]); \
  }
  
  show_pwm_reg(pwm_mode)
  show_pwm_reg(pwm_enable)
  show_pwm_reg(pwm)
  
  static ssize_t
  store_pwm_mode(struct device *dev, struct device_attribute *attr,
  	       const char *buf, size_t count)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  	u8 reg;
  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  
  	if (val > 1)
  		return -EINVAL;
  	mutex_lock(&data->update_lock);
  	data->pwm_mode[nr] = val;
  	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
  	reg &= ~(1 << W83L786NG_PWM_MODE_SHIFT[nr]);
  	if (!val)
  		reg |= 1 << W83L786NG_PWM_MODE_SHIFT[nr];
  	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static ssize_t
  store_pwm(struct device *dev, struct device_attribute *attr,
  	  const char *buf, size_t count)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  	val = clamp_val(val, 0, 255);
  	val = DIV_ROUND_CLOSEST(val, 0x11);
  
  	mutex_lock(&data->update_lock);
  	data->pwm[nr] = val * 0x11;
  	val |= w83l786ng_read_value(client, W83L786NG_REG_PWM[nr]) & 0xf0;
  	w83l786ng_write_value(client, W83L786NG_REG_PWM[nr], val);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static ssize_t
  store_pwm_enable(struct device *dev, struct device_attribute *attr,
  		 const char *buf, size_t count)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  	u8 reg;
  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  
  	if (!val || val > 2)  /* only modes 1 and 2 are supported */
  		return -EINVAL;
  
  	mutex_lock(&data->update_lock);
  	reg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
  	data->pwm_enable[nr] = val;
  	reg &= ~(0x03 << W83L786NG_PWM_ENABLE_SHIFT[nr]);
  	reg |= (val - 1) << W83L786NG_PWM_ENABLE_SHIFT[nr];
  	w83l786ng_write_value(client, W83L786NG_REG_FAN_CFG, reg);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static struct sensor_device_attribute sda_pwm[] = {
  	SENSOR_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 0),
  	SENSOR_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, store_pwm, 1),
  };
  
  static struct sensor_device_attribute sda_pwm_mode[] = {
  	SENSOR_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
  		    store_pwm_mode, 0),
  	SENSOR_ATTR(pwm2_mode, S_IWUSR | S_IRUGO, show_pwm_mode,
  		    store_pwm_mode, 1),
  };
  
  static struct sensor_device_attribute sda_pwm_enable[] = {
  	SENSOR_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
  		    store_pwm_enable, 0),
  	SENSOR_ATTR(pwm2_enable, S_IWUSR | S_IRUGO, show_pwm_enable,
  		    store_pwm_enable, 1),
  };
  
  /* For Smart Fan I/Thermal Cruise and Smart Fan II */
  static ssize_t
  show_tolerance(struct device *dev, struct device_attribute *attr, char *buf)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct w83l786ng_data *data = w83l786ng_update_device(dev);
  	return sprintf(buf, "%ld
  ", (long)data->tolerance[nr]);
  }
  
  static ssize_t
  store_tolerance(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  	u8 tol_tmp, tol_mask;
  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	tol_mask = w83l786ng_read_value(client,
  	    W83L786NG_REG_TOLERANCE) & ((nr == 1) ? 0x0f : 0xf0);
  	tol_tmp = clamp_val(val, 0, 15);
  	tol_tmp &= 0x0f;
  	data->tolerance[nr] = tol_tmp;
  	if (nr == 1)
  		tol_tmp <<= 4;
  
  	w83l786ng_write_value(client, W83L786NG_REG_TOLERANCE,
  			      tol_mask | tol_tmp);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static struct sensor_device_attribute sda_tolerance[] = {
  	SENSOR_ATTR(pwm1_tolerance, S_IWUSR | S_IRUGO,
  		    show_tolerance, store_tolerance, 0),
  	SENSOR_ATTR(pwm2_tolerance, S_IWUSR | S_IRUGO,
  		    show_tolerance, store_tolerance, 1),
  };
  
  
  #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
  
  #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
  
  #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
  
  #define PWM_UNIT_ATTRS(X)	\
  	&sda_pwm[X].dev_attr.attr,		\
  	&sda_pwm_mode[X].dev_attr.attr,		\
  	&sda_pwm_enable[X].dev_attr.attr
  
  #define TOLERANCE_UNIT_ATTRS(X)	\
  	&sda_tolerance[X].dev_attr.attr
  
  static struct attribute *w83l786ng_attributes[] = {
  	IN_UNIT_ATTRS(0),
  	IN_UNIT_ATTRS(1),
  	IN_UNIT_ATTRS(2),
  	FAN_UNIT_ATTRS(0),
  	FAN_UNIT_ATTRS(1),
  	TEMP_UNIT_ATTRS(0),
  	TEMP_UNIT_ATTRS(1),
  	PWM_UNIT_ATTRS(0),
  	PWM_UNIT_ATTRS(1),
  	TOLERANCE_UNIT_ATTRS(0),
  	TOLERANCE_UNIT_ATTRS(1),
  	NULL
  };
  
  static const struct attribute_group w83l786ng_group = {
  	.attrs = w83l786ng_attributes,
  };
  
  static int
  w83l786ng_detect(struct i2c_client *client, struct i2c_board_info *info)
  {
  	struct i2c_adapter *adapter = client->adapter;
  	u16 man_id;
  	u8 chip_id;
  
  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  		return -ENODEV;
  
  	/* Detection */
  	if ((w83l786ng_read_value(client, W83L786NG_REG_CONFIG) & 0x80)) {
  		dev_dbg(&adapter->dev, "W83L786NG detection failed at 0x%02x
  ",
  			client->addr);
  		return -ENODEV;
  	}
  
  	/* Identification */
  	man_id = (w83l786ng_read_value(client, W83L786NG_REG_MAN_ID1) << 8) +
  		 w83l786ng_read_value(client, W83L786NG_REG_MAN_ID2);
  	chip_id = w83l786ng_read_value(client, W83L786NG_REG_CHIP_ID);
  
  	if (man_id != 0x5CA3 ||		/* Winbond */
  	    chip_id != 0x80) {		/* W83L786NG */
  		dev_dbg(&adapter->dev,
  			"Unsupported chip (man_id=0x%04X, chip_id=0x%02X)
  ",
  			man_id, chip_id);
  		return -ENODEV;
  	}
  
  	strlcpy(info->type, "w83l786ng", I2C_NAME_SIZE);
  
  	return 0;
  }
  
  static int
  w83l786ng_probe(struct i2c_client *client, const struct i2c_device_id *id)
  {
  	struct device *dev = &client->dev;
  	struct w83l786ng_data *data;
  	int i, err = 0;
  	u8 reg_tmp;
  
  	data = devm_kzalloc(&client->dev, sizeof(struct w83l786ng_data),
  			    GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	i2c_set_clientdata(client, data);
  	mutex_init(&data->update_lock);
  
  	/* Initialize the chip */
  	w83l786ng_init_client(client);
  
  	/* A few vars need to be filled upon startup */
  	for (i = 0; i < 2; i++) {
  		data->fan_min[i] = w83l786ng_read_value(client,
  		    W83L786NG_REG_FAN_MIN(i));
  	}
  
  	/* Update the fan divisor */
  	reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
  	data->fan_div[0] = reg_tmp & 0x07;
  	data->fan_div[1] = (reg_tmp >> 4) & 0x07;
  
  	/* Register sysfs hooks */
  	err = sysfs_create_group(&client->dev.kobj, &w83l786ng_group);
  	if (err)
  		goto exit_remove;
  
  	data->hwmon_dev = hwmon_device_register(dev);
  	if (IS_ERR(data->hwmon_dev)) {
  		err = PTR_ERR(data->hwmon_dev);
  		goto exit_remove;
  	}
  
  	return 0;
  
  	/* Unregister sysfs hooks */
  
  exit_remove:
  	sysfs_remove_group(&client->dev.kobj, &w83l786ng_group);
  	return err;
  }
  
  static int
  w83l786ng_remove(struct i2c_client *client)
  {
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  
  	hwmon_device_unregister(data->hwmon_dev);
  	sysfs_remove_group(&client->dev.kobj, &w83l786ng_group);
  
  	return 0;
  }
  
  static void
  w83l786ng_init_client(struct i2c_client *client)
  {
  	u8 tmp;
  
  	if (reset)
  		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, 0x80);
  
  	/* Start monitoring */
  	tmp = w83l786ng_read_value(client, W83L786NG_REG_CONFIG);
  	if (!(tmp & 0x01))
  		w83l786ng_write_value(client, W83L786NG_REG_CONFIG, tmp | 0x01);
  }
  
  static struct w83l786ng_data *w83l786ng_update_device(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct w83l786ng_data *data = i2c_get_clientdata(client);
  	int i, j;
  	u8 reg_tmp, pwmcfg;
  
  	mutex_lock(&data->update_lock);
  	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
  	    || !data->valid) {
  		dev_dbg(&client->dev, "Updating w83l786ng data.
  ");
  
  		/* Update the voltages measured value and limits */
  		for (i = 0; i < 3; i++) {
  			data->in[i] = w83l786ng_read_value(client,
  			    W83L786NG_REG_IN(i));
  			data->in_min[i] = w83l786ng_read_value(client,
  			    W83L786NG_REG_IN_MIN(i));
  			data->in_max[i] = w83l786ng_read_value(client,
  			    W83L786NG_REG_IN_MAX(i));
  		}
  
  		/* Update the fan counts and limits */
  		for (i = 0; i < 2; i++) {
  			data->fan[i] = w83l786ng_read_value(client,
  			    W83L786NG_REG_FAN(i));
  			data->fan_min[i] = w83l786ng_read_value(client,
  			    W83L786NG_REG_FAN_MIN(i));
  		}
  
  		/* Update the fan divisor */
  		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_FAN_DIV);
  		data->fan_div[0] = reg_tmp & 0x07;
  		data->fan_div[1] = (reg_tmp >> 4) & 0x07;
  
  		pwmcfg = w83l786ng_read_value(client, W83L786NG_REG_FAN_CFG);
  		for (i = 0; i < 2; i++) {
  			data->pwm_mode[i] =
  			    ((pwmcfg >> W83L786NG_PWM_MODE_SHIFT[i]) & 1)
  			    ? 0 : 1;
  			data->pwm_enable[i] =
  			    ((pwmcfg >> W83L786NG_PWM_ENABLE_SHIFT[i]) & 3) + 1;
  			data->pwm[i] =
  			    (w83l786ng_read_value(client, W83L786NG_REG_PWM[i])
  			     & 0x0f) * 0x11;
  		}
  
  
  		/* Update the temperature sensors */
  		for (i = 0; i < 2; i++) {
  			for (j = 0; j < 3; j++) {
  				data->temp[i][j] = w83l786ng_read_value(client,
  				    W83L786NG_REG_TEMP[i][j]);
  			}
  		}
  
  		/* Update Smart Fan I/II tolerance */
  		reg_tmp = w83l786ng_read_value(client, W83L786NG_REG_TOLERANCE);
  		data->tolerance[0] = reg_tmp & 0x0f;
  		data->tolerance[1] = (reg_tmp >> 4) & 0x0f;
  
  		data->last_updated = jiffies;
  		data->valid = 1;
  
  	}
  
  	mutex_unlock(&data->update_lock);
  
  	return data;
  }
  
  module_i2c_driver(w83l786ng_driver);
  
  MODULE_AUTHOR("Kevin Lo");
  MODULE_DESCRIPTION("w83l786ng driver");
  MODULE_LICENSE("GPL");