// SPDX-License-Identifier: GPL-2.0-or-later

  /*

   * adm1031.c - Part of lm_sensors, Linux kernel modules for hardware
   *	       monitoring
   * Based on lm75.c and lm85.c
   * Supports adm1030 / adm1031
   * Copyright (C) 2004 Alexandre d'Alton <alex@alexdalton.org>

   * Reworked by Jean Delvare <jdelvare@suse.de>

   */

  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/jiffies.h>
  #include <linux/i2c.h>

  #include <linux/hwmon.h>

  #include <linux/hwmon-sysfs.h>

  #include <linux/err.h>

  #include <linux/mutex.h>

  
  /* Following macros takes channel parameter starting from 0 to 2 */
  #define ADM1031_REG_FAN_SPEED(nr)	(0x08 + (nr))

  #define ADM1031_REG_FAN_DIV(nr)		(0x20 + (nr))

  #define ADM1031_REG_PWM			(0x22)
  #define ADM1031_REG_FAN_MIN(nr)		(0x10 + (nr))

  #define ADM1031_REG_FAN_FILTER		(0x23)

  #define ADM1031_REG_TEMP_OFFSET(nr)	(0x0d + (nr))

  #define ADM1031_REG_TEMP_MAX(nr)	(0x14 + 4 * (nr))
  #define ADM1031_REG_TEMP_MIN(nr)	(0x15 + 4 * (nr))
  #define ADM1031_REG_TEMP_CRIT(nr)	(0x16 + 4 * (nr))

  #define ADM1031_REG_TEMP(nr)		(0x0a + (nr))

  #define ADM1031_REG_AUTO_TEMP(nr)	(0x24 + (nr))
  
  #define ADM1031_REG_STATUS(nr)		(0x2 + (nr))

  #define ADM1031_REG_CONF1		0x00
  #define ADM1031_REG_CONF2		0x01
  #define ADM1031_REG_EXT_TEMP		0x06

  
  #define ADM1031_CONF1_MONITOR_ENABLE	0x01	/* Monitoring enable */
  #define ADM1031_CONF1_PWM_INVERT	0x08	/* PWM Invert */
  #define ADM1031_CONF1_AUTO_MODE		0x80	/* Auto FAN */
  
  #define ADM1031_CONF2_PWM1_ENABLE	0x01
  #define ADM1031_CONF2_PWM2_ENABLE	0x02
  #define ADM1031_CONF2_TACH1_ENABLE	0x04
  #define ADM1031_CONF2_TACH2_ENABLE	0x08
  #define ADM1031_CONF2_TEMP_ENABLE(chan)	(0x10 << (chan))

  #define ADM1031_UPDATE_RATE_MASK	0x1c
  #define ADM1031_UPDATE_RATE_SHIFT	2

  /* Addresses to scan */

  static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, I2C_CLIENT_END };

  enum chips { adm1030, adm1031 };

  
  typedef u8 auto_chan_table_t[8][2];
  
  /* Each client has this additional data */
  struct adm1031_data {

  	struct i2c_client *client;
  	const struct attribute_group *groups[3];

  	struct mutex update_lock;

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

  	unsigned int update_interval;	/* In milliseconds */

  	/*
  	 * The chan_select_table contains the possible configurations for

  	 * auto fan control.
  	 */

  	const auto_chan_table_t *chan_select_table;

  	u16 alarm;
  	u8 conf1;
  	u8 conf2;
  	u8 fan[2];
  	u8 fan_div[2];
  	u8 fan_min[2];
  	u8 pwm[2];
  	u8 old_pwm[2];
  	s8 temp[3];
  	u8 ext_temp[3];
  	u8 auto_temp[3];
  	u8 auto_temp_min[3];
  	u8 auto_temp_off[3];
  	u8 auto_temp_max[3];

  	s8 temp_offset[3];

  	s8 temp_min[3];
  	s8 temp_max[3];
  	s8 temp_crit[3];
  };

  static inline u8 adm1031_read_value(struct i2c_client *client, u8 reg)
  {
  	return i2c_smbus_read_byte_data(client, reg);
  }
  
  static inline int
  adm1031_write_value(struct i2c_client *client, u8 reg, unsigned int value)
  {
  	return i2c_smbus_write_byte_data(client, reg, value);
  }

  static struct adm1031_data *adm1031_update_device(struct device *dev)
  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	unsigned long next_update;
  	int chan;
  
  	mutex_lock(&data->update_lock);
  
  	next_update = data->last_updated
  	  + msecs_to_jiffies(data->update_interval);
  	if (time_after(jiffies, next_update) || !data->valid) {
  
  		dev_dbg(&client->dev, "Starting adm1031 update
  ");
  		for (chan = 0;
  		     chan < ((data->chip_type == adm1031) ? 3 : 2); chan++) {
  			u8 oldh, newh;
  
  			oldh =
  			    adm1031_read_value(client, ADM1031_REG_TEMP(chan));
  			data->ext_temp[chan] =
  			    adm1031_read_value(client, ADM1031_REG_EXT_TEMP);
  			newh =
  			    adm1031_read_value(client, ADM1031_REG_TEMP(chan));
  			if (newh != oldh) {
  				data->ext_temp[chan] =
  				    adm1031_read_value(client,
  						       ADM1031_REG_EXT_TEMP);
  #ifdef DEBUG
  				oldh =
  				    adm1031_read_value(client,
  						       ADM1031_REG_TEMP(chan));
  
  				/* oldh is actually newer */
  				if (newh != oldh)
  					dev_warn(&client->dev,
  					  "Remote temperature may be wrong.
  ");
  #endif
  			}
  			data->temp[chan] = newh;
  
  			data->temp_offset[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_TEMP_OFFSET(chan));
  			data->temp_min[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_TEMP_MIN(chan));
  			data->temp_max[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_TEMP_MAX(chan));
  			data->temp_crit[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_TEMP_CRIT(chan));
  			data->auto_temp[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_AUTO_TEMP(chan));
  
  		}
  
  		data->conf1 = adm1031_read_value(client, ADM1031_REG_CONF1);
  		data->conf2 = adm1031_read_value(client, ADM1031_REG_CONF2);
  
  		data->alarm = adm1031_read_value(client, ADM1031_REG_STATUS(0))
  		    | (adm1031_read_value(client, ADM1031_REG_STATUS(1)) << 8);
  		if (data->chip_type == adm1030)
  			data->alarm &= 0xc0ff;
  
  		for (chan = 0; chan < (data->chip_type == adm1030 ? 1 : 2);
  		     chan++) {
  			data->fan_div[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_FAN_DIV(chan));
  			data->fan_min[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_FAN_MIN(chan));
  			data->fan[chan] =
  			    adm1031_read_value(client,
  					       ADM1031_REG_FAN_SPEED(chan));
  			data->pwm[chan] =
  			  (adm1031_read_value(client,
  					ADM1031_REG_PWM) >> (4 * chan)) & 0x0f;
  		}
  		data->last_updated = jiffies;
  		data->valid = 1;
  	}
  
  	mutex_unlock(&data->update_lock);
  
  	return data;
  }

  
  #define TEMP_TO_REG(val)		(((val) < 0 ? ((val - 500) / 1000) : \
  					((val + 500) / 1000)))
  
  #define TEMP_FROM_REG(val)		((val) * 1000)
  
  #define TEMP_FROM_REG_EXT(val, ext)	(TEMP_FROM_REG(val) + (ext) * 125)

  #define TEMP_OFFSET_TO_REG(val)		(TEMP_TO_REG(val) & 0x8f)
  #define TEMP_OFFSET_FROM_REG(val)	TEMP_FROM_REG((val) < 0 ? \
  						      (val) | 0x70 : (val))

  #define FAN_FROM_REG(reg, div)		((reg) ? \
  					 (11250 * 60) / ((reg) * (div)) : 0)

  
  static int FAN_TO_REG(int reg, int div)
  {
  	int tmp;

  	tmp = FAN_FROM_REG(clamp_val(reg, 0, 65535), div);

  	return tmp > 255 ? 255 : tmp;
  }
  
  #define FAN_DIV_FROM_REG(reg)		(1<<(((reg)&0xc0)>>6))

  #define PWM_TO_REG(val)			(clamp_val((val), 0, 255) >> 4)

  #define PWM_FROM_REG(val)		((val) << 4)
  
  #define FAN_CHAN_FROM_REG(reg)		(((reg) >> 5) & 7)
  #define FAN_CHAN_TO_REG(val, reg)	\
  	(((reg) & 0x1F) | (((val) << 5) & 0xe0))
  
  #define AUTO_TEMP_MIN_TO_REG(val, reg)	\

  	((((val) / 500) & 0xf8) | ((reg) & 0x7))
  #define AUTO_TEMP_RANGE_FROM_REG(reg)	(5000 * (1 << ((reg) & 0x7)))

  #define AUTO_TEMP_MIN_FROM_REG(reg)	(1000 * ((((reg) >> 3) & 0x1f) << 2))
  
  #define AUTO_TEMP_MIN_FROM_REG_DEG(reg)	((((reg) >> 3) & 0x1f) << 2)
  
  #define AUTO_TEMP_OFF_FROM_REG(reg)		\
  	(AUTO_TEMP_MIN_FROM_REG(reg) - 5000)
  
  #define AUTO_TEMP_MAX_FROM_REG(reg)		\
  	(AUTO_TEMP_RANGE_FROM_REG(reg) +	\
  	AUTO_TEMP_MIN_FROM_REG(reg))
  
  static int AUTO_TEMP_MAX_TO_REG(int val, int reg, int pwm)
  {
  	int ret;
  	int range = val - AUTO_TEMP_MIN_FROM_REG(reg);
  
  	range = ((val - AUTO_TEMP_MIN_FROM_REG(reg))*10)/(16 - pwm);
  	ret = ((reg & 0xf8) |
  	       (range < 10000 ? 0 :
  		range < 20000 ? 1 :
  		range < 40000 ? 2 : range < 80000 ? 3 : 4));
  	return ret;
  }
  
  /* FAN auto control */
  #define GET_FAN_AUTO_BITFIELD(data, idx)	\

  	(*(data)->chan_select_table)[FAN_CHAN_FROM_REG((data)->conf1)][idx % 2]

  /*
   * The tables below contains the possible values for the auto fan

   * control bitfields. the index in the table is the register value.
   * MSb is the auto fan control enable bit, so the four first entries
   * in the table disables auto fan control when both bitfields are zero.
   */

  static const auto_chan_table_t auto_channel_select_table_adm1031 = {
  	{ 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 },
  	{ 2 /* 0b010 */ , 4 /* 0b100 */ },
  	{ 2 /* 0b010 */ , 2 /* 0b010 */ },
  	{ 4 /* 0b100 */ , 4 /* 0b100 */ },
  	{ 7 /* 0b111 */ , 7 /* 0b111 */ },

  };

  static const auto_chan_table_t auto_channel_select_table_adm1030 = {
  	{ 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 },
  	{ 2 /* 0b10 */		, 0 },
  	{ 0xff /* invalid */	, 0 },
  	{ 0xff /* invalid */	, 0 },
  	{ 3 /* 0b11 */		, 0 },

  };

  /*
   * That function checks if a bitfield is valid and returns the other bitfield

   * nearest match if no exact match where found.
   */
  static int

  get_fan_auto_nearest(struct adm1031_data *data, int chan, u8 val, u8 reg)

  {
  	int i;
  	int first_match = -1, exact_match = -1;
  	u8 other_reg_val =
  	    (*data->chan_select_table)[FAN_CHAN_FROM_REG(reg)][chan ? 0 : 1];

  	if (val == 0)

  		return 0;

  
  	for (i = 0; i < 8; i++) {
  		if ((val == (*data->chan_select_table)[i][chan]) &&
  		    ((*data->chan_select_table)[i][chan ? 0 : 1] ==
  		     other_reg_val)) {
  			/* We found an exact match */
  			exact_match = i;
  			break;
  		} else if (val == (*data->chan_select_table)[i][chan] &&
  			   first_match == -1) {

  			/*
  			 * Save the first match in case of an exact match has

  			 * not been found

  			 */
  			first_match = i;
  		}
  	}

  	if (exact_match >= 0)

  		return exact_match;

  	else if (first_match >= 0)

  		return first_match;

  	return -EINVAL;

  }

  static ssize_t fan_auto_channel_show(struct device *dev,

  				     struct device_attribute *attr, char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", GET_FAN_AUTO_BITFIELD(data, nr));
  }
  
  static ssize_t

  fan_auto_channel_store(struct device *dev, struct device_attribute *attr,
  		       const char *buf, size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;

  	u8 reg;
  	int ret;
  	u8 old_fan_mode;

  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	old_fan_mode = data->conf1;

  	mutex_lock(&data->update_lock);

  	ret = get_fan_auto_nearest(data, nr, val, data->conf1);
  	if (ret < 0) {

  		mutex_unlock(&data->update_lock);

  		return ret;
  	}

  	reg = ret;

  	data->conf1 = FAN_CHAN_TO_REG(reg, data->conf1);
  	if ((data->conf1 & ADM1031_CONF1_AUTO_MODE) ^

  	    (old_fan_mode & ADM1031_CONF1_AUTO_MODE)) {

  		if (data->conf1 & ADM1031_CONF1_AUTO_MODE) {

  			/*
  			 * Switch to Auto Fan Mode

  			 * Save PWM registers

  			 * Set PWM registers to 33% Both
  			 */

  			data->old_pwm[0] = data->pwm[0];
  			data->old_pwm[1] = data->pwm[1];
  			adm1031_write_value(client, ADM1031_REG_PWM, 0x55);
  		} else {
  			/* Switch to Manual Mode */
  			data->pwm[0] = data->old_pwm[0];
  			data->pwm[1] = data->old_pwm[1];
  			/* Restore PWM registers */

  			adm1031_write_value(client, ADM1031_REG_PWM,

  					    data->pwm[0] | (data->pwm[1] << 4));
  		}
  	}
  	data->conf1 = FAN_CHAN_TO_REG(reg, data->conf1);
  	adm1031_write_value(client, ADM1031_REG_CONF1, data->conf1);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static SENSOR_DEVICE_ATTR_RW(auto_fan1_channel, fan_auto_channel, 0);
  static SENSOR_DEVICE_ATTR_RW(auto_fan2_channel, fan_auto_channel, 1);

  
  /* Auto Temps */

  static ssize_t auto_temp_off_show(struct device *dev,

  				  struct device_attribute *attr, char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);

  	return sprintf(buf, "%d
  ",

  		       AUTO_TEMP_OFF_FROM_REG(data->auto_temp[nr]));
  }

  static ssize_t auto_temp_min_show(struct device *dev,

  				  struct device_attribute *attr, char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ",
  		       AUTO_TEMP_MIN_FROM_REG(data->auto_temp[nr]));
  }
  static ssize_t

  auto_temp_min_store(struct device *dev, struct device_attribute *attr,
  		    const char *buf, size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	val = clamp_val(val, 0, 127000);

  	mutex_lock(&data->update_lock);

  	data->auto_temp[nr] = AUTO_TEMP_MIN_TO_REG(val, data->auto_temp[nr]);
  	adm1031_write_value(client, ADM1031_REG_AUTO_TEMP(nr),
  			    data->auto_temp[nr]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static ssize_t auto_temp_max_show(struct device *dev,

  				  struct device_attribute *attr, char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ",
  		       AUTO_TEMP_MAX_FROM_REG(data->auto_temp[nr]));
  }
  static ssize_t

  auto_temp_max_store(struct device *dev, struct device_attribute *attr,
  		    const char *buf, size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	val = clamp_val(val, 0, 127000);

  	mutex_lock(&data->update_lock);

  	data->temp_max[nr] = AUTO_TEMP_MAX_TO_REG(val, data->auto_temp[nr],
  						  data->pwm[nr]);

  	adm1031_write_value(client, ADM1031_REG_AUTO_TEMP(nr),
  			    data->temp_max[nr]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static SENSOR_DEVICE_ATTR_RO(auto_temp1_off, auto_temp_off, 0);
  static SENSOR_DEVICE_ATTR_RW(auto_temp1_min, auto_temp_min, 0);
  static SENSOR_DEVICE_ATTR_RW(auto_temp1_max, auto_temp_max, 0);
  static SENSOR_DEVICE_ATTR_RO(auto_temp2_off, auto_temp_off, 1);
  static SENSOR_DEVICE_ATTR_RW(auto_temp2_min, auto_temp_min, 1);
  static SENSOR_DEVICE_ATTR_RW(auto_temp2_max, auto_temp_max, 1);
  static SENSOR_DEVICE_ATTR_RO(auto_temp3_off, auto_temp_off, 2);
  static SENSOR_DEVICE_ATTR_RW(auto_temp3_min, auto_temp_min, 2);
  static SENSOR_DEVICE_ATTR_RW(auto_temp3_max, auto_temp_max, 2);

  
  /* pwm */

  static ssize_t pwm_show(struct device *dev, struct device_attribute *attr,
  			char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", PWM_FROM_REG(data->pwm[nr]));
  }

  static ssize_t pwm_store(struct device *dev, struct device_attribute *attr,
  			 const char *buf, size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret, reg;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	mutex_lock(&data->update_lock);

  	if ((data->conf1 & ADM1031_CONF1_AUTO_MODE) &&

  	    (((val>>4) & 0xf) != 5)) {
  		/* In automatic mode, the only PWM accepted is 33% */

  		mutex_unlock(&data->update_lock);

  		return -EINVAL;
  	}
  	data->pwm[nr] = PWM_TO_REG(val);
  	reg = adm1031_read_value(client, ADM1031_REG_PWM);
  	adm1031_write_value(client, ADM1031_REG_PWM,
  			    nr ? ((data->pwm[nr] << 4) & 0xf0) | (reg & 0xf)
  			    : (data->pwm[nr] & 0xf) | (reg & 0xf0));

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
  static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, 1);
  static SENSOR_DEVICE_ATTR_RW(auto_fan1_min_pwm, pwm, 0);
  static SENSOR_DEVICE_ATTR_RW(auto_fan2_min_pwm, pwm, 1);

  
  /* Fans */
  
  /*
   * That function checks the cases where the fan reading is not

   * relevant.  It is used to provide 0 as fan reading when the fan is

   * not supposed to run
   */
  static int trust_fan_readings(struct adm1031_data *data, int chan)
  {
  	int res = 0;
  
  	if (data->conf1 & ADM1031_CONF1_AUTO_MODE) {
  		switch (data->conf1 & 0x60) {

  		case 0x00:
  			/*
  			 * remote temp1 controls fan1,
  			 * remote temp2 controls fan2
  			 */

  			res = data->temp[chan+1] >=

  			    AUTO_TEMP_MIN_FROM_REG_DEG(data->auto_temp[chan+1]);

  			break;
  		case 0x20:	/* remote temp1 controls both fans */
  			res =
  			    data->temp[1] >=
  			    AUTO_TEMP_MIN_FROM_REG_DEG(data->auto_temp[1]);
  			break;
  		case 0x40:	/* remote temp2 controls both fans */
  			res =
  			    data->temp[2] >=
  			    AUTO_TEMP_MIN_FROM_REG_DEG(data->auto_temp[2]);
  			break;
  		case 0x60:	/* max controls both fans */
  			res =
  			    data->temp[0] >=
  			    AUTO_TEMP_MIN_FROM_REG_DEG(data->auto_temp[0])
  			    || data->temp[1] >=
  			    AUTO_TEMP_MIN_FROM_REG_DEG(data->auto_temp[1])

  			    || (data->chip_type == adm1031

  				&& data->temp[2] >=
  				AUTO_TEMP_MIN_FROM_REG_DEG(data->auto_temp[2]));
  			break;
  		}
  	} else {
  		res = data->pwm[chan] > 0;
  	}
  	return res;
  }

  static ssize_t fan_show(struct device *dev, struct device_attribute *attr,
  			char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	int value;
  
  	value = trust_fan_readings(data, nr) ? FAN_FROM_REG(data->fan[nr],
  				 FAN_DIV_FROM_REG(data->fan_div[nr])) : 0;
  	return sprintf(buf, "%d
  ", value);
  }

  static ssize_t fan_div_show(struct device *dev, struct device_attribute *attr,
  			    char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", FAN_DIV_FROM_REG(data->fan_div[nr]));
  }

  static ssize_t fan_min_show(struct device *dev, struct device_attribute *attr,
  			    char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ",
  		       FAN_FROM_REG(data->fan_min[nr],
  				    FAN_DIV_FROM_REG(data->fan_div[nr])));
  }

  static ssize_t fan_min_store(struct device *dev,
  			     struct device_attribute *attr, const char *buf,
  			     size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	mutex_lock(&data->update_lock);

  	if (val) {

  		data->fan_min[nr] =

  			FAN_TO_REG(val, FAN_DIV_FROM_REG(data->fan_div[nr]));
  	} else {
  		data->fan_min[nr] = 0xff;
  	}
  	adm1031_write_value(client, ADM1031_REG_FAN_MIN(nr), data->fan_min[nr]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static ssize_t fan_div_store(struct device *dev,
  			     struct device_attribute *attr, const char *buf,
  			     size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;

  	u8 tmp;
  	int old_div;
  	int new_min;

  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  
  	tmp = val == 8 ? 0xc0 :
  	      val == 4 ? 0x80 :

  	      val == 2 ? 0x40 :
  	      val == 1 ? 0x00 :

  	      0xff;
  	if (tmp == 0xff)
  		return -EINVAL;

  	mutex_lock(&data->update_lock);

  	/* Get fresh readings */
  	data->fan_div[nr] = adm1031_read_value(client,
  					       ADM1031_REG_FAN_DIV(nr));
  	data->fan_min[nr] = adm1031_read_value(client,
  					       ADM1031_REG_FAN_MIN(nr));
  
  	/* Write the new clock divider and fan min */

  	old_div = FAN_DIV_FROM_REG(data->fan_div[nr]);

  	data->fan_div[nr] = tmp | (0x3f & data->fan_div[nr]);
  	new_min = data->fan_min[nr] * old_div / val;

  	data->fan_min[nr] = new_min > 0xff ? 0xff : new_min;

  	adm1031_write_value(client, ADM1031_REG_FAN_DIV(nr),

  			    data->fan_div[nr]);

  	adm1031_write_value(client, ADM1031_REG_FAN_MIN(nr),

  			    data->fan_min[nr]);

  
  	/* Invalidate the cache: fan speed is no longer valid */
  	data->valid = 0;

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
  static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0);
  static SENSOR_DEVICE_ATTR_RW(fan1_div, fan_div, 0);
  static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1);
  static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1);
  static SENSOR_DEVICE_ATTR_RW(fan2_div, fan_div, 1);

  
  /* Temps */

  static ssize_t temp_show(struct device *dev, struct device_attribute *attr,
  			 char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	int ext;
  	ext = nr == 0 ?
  	    ((data->ext_temp[nr] >> 6) & 0x3) * 2 :
  	    (((data->ext_temp[nr] >> ((nr - 1) * 3)) & 7));
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG_EXT(data->temp[nr], ext));
  }

  static ssize_t temp_offset_show(struct device *dev,

  				struct device_attribute *attr, char *buf)
  {
  	int nr = to_sensor_dev_attr(attr)->index;
  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ",
  		       TEMP_OFFSET_FROM_REG(data->temp_offset[nr]));
  }

  static ssize_t temp_min_show(struct device *dev,

  			     struct device_attribute *attr, char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp_min[nr]));
  }

  static ssize_t temp_max_show(struct device *dev,

  			     struct device_attribute *attr, char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp_max[nr]));
  }

  static ssize_t temp_crit_show(struct device *dev,

  			      struct device_attribute *attr, char *buf)

  {

  	int nr = to_sensor_dev_attr(attr)->index;

  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp_crit[nr]));
  }

  static ssize_t temp_offset_store(struct device *dev,
  				 struct device_attribute *attr,
  				 const char *buf, size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	val = clamp_val(val, -15000, 15000);

  	mutex_lock(&data->update_lock);
  	data->temp_offset[nr] = TEMP_OFFSET_TO_REG(val);
  	adm1031_write_value(client, ADM1031_REG_TEMP_OFFSET(nr),
  			    data->temp_offset[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }

  static ssize_t temp_min_store(struct device *dev,
  			      struct device_attribute *attr, const char *buf,
  			      size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	val = clamp_val(val, -55000, 127000);

  	mutex_lock(&data->update_lock);

  	data->temp_min[nr] = TEMP_TO_REG(val);
  	adm1031_write_value(client, ADM1031_REG_TEMP_MIN(nr),
  			    data->temp_min[nr]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static ssize_t temp_max_store(struct device *dev,
  			      struct device_attribute *attr, const char *buf,
  			      size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	val = clamp_val(val, -55000, 127000);

  	mutex_lock(&data->update_lock);

  	data->temp_max[nr] = TEMP_TO_REG(val);
  	adm1031_write_value(client, ADM1031_REG_TEMP_MAX(nr),
  			    data->temp_max[nr]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static ssize_t temp_crit_store(struct device *dev,
  			       struct device_attribute *attr, const char *buf,
  			       size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = to_sensor_dev_attr(attr)->index;

  	long val;
  	int ret;
  
  	ret = kstrtol(buf, 10, &val);
  	if (ret)
  		return ret;

  	val = clamp_val(val, -55000, 127000);

  	mutex_lock(&data->update_lock);

  	data->temp_crit[nr] = TEMP_TO_REG(val);
  	adm1031_write_value(client, ADM1031_REG_TEMP_CRIT(nr),
  			    data->temp_crit[nr]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
  static SENSOR_DEVICE_ATTR_RW(temp1_offset, temp_offset, 0);
  static SENSOR_DEVICE_ATTR_RW(temp1_min, temp_min, 0);
  static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
  static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp_crit, 0);
  static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
  static SENSOR_DEVICE_ATTR_RW(temp2_offset, temp_offset, 1);
  static SENSOR_DEVICE_ATTR_RW(temp2_min, temp_min, 1);
  static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
  static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp_crit, 1);
  static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);
  static SENSOR_DEVICE_ATTR_RW(temp3_offset, temp_offset, 2);
  static SENSOR_DEVICE_ATTR_RW(temp3_min, temp_min, 2);
  static SENSOR_DEVICE_ATTR_RW(temp3_max, temp_max, 2);
  static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp_crit, 2);

  
  /* Alarms */

  static ssize_t alarms_show(struct device *dev, struct device_attribute *attr,

  			   char *buf)

  {
  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", data->alarm);
  }

  static DEVICE_ATTR_RO(alarms);

  static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
  			  char *buf)

  {
  	int bitnr = to_sensor_dev_attr(attr)->index;
  	struct adm1031_data *data = adm1031_update_device(dev);
  	return sprintf(buf, "%d
  ", (data->alarm >> bitnr) & 1);
  }

  static SENSOR_DEVICE_ATTR_RO(fan1_alarm, alarm, 0);
  static SENSOR_DEVICE_ATTR_RO(fan1_fault, alarm, 1);
  static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 2);
  static SENSOR_DEVICE_ATTR_RO(temp2_min_alarm, alarm, 3);
  static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 4);
  static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 5);
  static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
  static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 7);
  static SENSOR_DEVICE_ATTR_RO(fan2_alarm, alarm, 8);
  static SENSOR_DEVICE_ATTR_RO(fan2_fault, alarm, 9);
  static SENSOR_DEVICE_ATTR_RO(temp3_max_alarm, alarm, 10);
  static SENSOR_DEVICE_ATTR_RO(temp3_min_alarm, alarm, 11);
  static SENSOR_DEVICE_ATTR_RO(temp3_crit_alarm, alarm, 12);
  static SENSOR_DEVICE_ATTR_RO(temp3_fault, alarm, 13);
  static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 14);

  /* Update Interval */
  static const unsigned int update_intervals[] = {

  	16000, 8000, 4000, 2000, 1000, 500, 250, 125,
  };

  static ssize_t update_interval_show(struct device *dev,

  				    struct device_attribute *attr, char *buf)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);

  	return sprintf(buf, "%u
  ", data->update_interval);

  }

  static ssize_t update_interval_store(struct device *dev,
  				     struct device_attribute *attr,
  				     const char *buf, size_t count)

  {

  	struct adm1031_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	unsigned long val;
  	int i, err;
  	u8 reg;

  	err = kstrtoul(buf, 10, &val);

  	if (err)
  		return err;

  	/*
  	 * Find the nearest update interval from the table.
  	 * Use it to determine the matching update rate.
  	 */
  	for (i = 0; i < ARRAY_SIZE(update_intervals) - 1; i++) {
  		if (val >= update_intervals[i])

  			break;
  	}

  	/* if not found, we point to the last entry (lowest update interval) */

  
  	/* set the new update rate while preserving other settings */
  	reg = adm1031_read_value(client, ADM1031_REG_FAN_FILTER);
  	reg &= ~ADM1031_UPDATE_RATE_MASK;
  	reg |= i << ADM1031_UPDATE_RATE_SHIFT;
  	adm1031_write_value(client, ADM1031_REG_FAN_FILTER, reg);
  
  	mutex_lock(&data->update_lock);

  	data->update_interval = update_intervals[i];

  	mutex_unlock(&data->update_lock);
  
  	return count;
  }

  static DEVICE_ATTR_RW(update_interval);

  static struct attribute *adm1031_attributes[] = {

  	&sensor_dev_attr_fan1_input.dev_attr.attr,
  	&sensor_dev_attr_fan1_div.dev_attr.attr,
  	&sensor_dev_attr_fan1_min.dev_attr.attr,

  	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
  	&sensor_dev_attr_fan1_fault.dev_attr.attr,

  	&sensor_dev_attr_pwm1.dev_attr.attr,
  	&sensor_dev_attr_auto_fan1_channel.dev_attr.attr,
  	&sensor_dev_attr_temp1_input.dev_attr.attr,

  	&sensor_dev_attr_temp1_offset.dev_attr.attr,

  	&sensor_dev_attr_temp1_min.dev_attr.attr,

  	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,

  	&sensor_dev_attr_temp1_max.dev_attr.attr,

  	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,

  	&sensor_dev_attr_temp1_crit.dev_attr.attr,

  	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,

  	&sensor_dev_attr_temp2_input.dev_attr.attr,

  	&sensor_dev_attr_temp2_offset.dev_attr.attr,

  	&sensor_dev_attr_temp2_min.dev_attr.attr,

  	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,

  	&sensor_dev_attr_temp2_max.dev_attr.attr,

  	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,

  	&sensor_dev_attr_temp2_crit.dev_attr.attr,

  	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_fault.dev_attr.attr,

  
  	&sensor_dev_attr_auto_temp1_off.dev_attr.attr,
  	&sensor_dev_attr_auto_temp1_min.dev_attr.attr,
  	&sensor_dev_attr_auto_temp1_max.dev_attr.attr,
  
  	&sensor_dev_attr_auto_temp2_off.dev_attr.attr,
  	&sensor_dev_attr_auto_temp2_min.dev_attr.attr,
  	&sensor_dev_attr_auto_temp2_max.dev_attr.attr,
  
  	&sensor_dev_attr_auto_fan1_min_pwm.dev_attr.attr,

  	&dev_attr_update_interval.attr,

  	&dev_attr_alarms.attr,
  
  	NULL
  };
  
  static const struct attribute_group adm1031_group = {
  	.attrs = adm1031_attributes,
  };
  
  static struct attribute *adm1031_attributes_opt[] = {

  	&sensor_dev_attr_fan2_input.dev_attr.attr,
  	&sensor_dev_attr_fan2_div.dev_attr.attr,
  	&sensor_dev_attr_fan2_min.dev_attr.attr,

  	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
  	&sensor_dev_attr_fan2_fault.dev_attr.attr,

  	&sensor_dev_attr_pwm2.dev_attr.attr,
  	&sensor_dev_attr_auto_fan2_channel.dev_attr.attr,
  	&sensor_dev_attr_temp3_input.dev_attr.attr,

  	&sensor_dev_attr_temp3_offset.dev_attr.attr,

  	&sensor_dev_attr_temp3_min.dev_attr.attr,

  	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,

  	&sensor_dev_attr_temp3_max.dev_attr.attr,

  	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,

  	&sensor_dev_attr_temp3_crit.dev_attr.attr,

  	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp3_fault.dev_attr.attr,

  	&sensor_dev_attr_auto_temp3_off.dev_attr.attr,
  	&sensor_dev_attr_auto_temp3_min.dev_attr.attr,
  	&sensor_dev_attr_auto_temp3_max.dev_attr.attr,
  	&sensor_dev_attr_auto_fan2_min_pwm.dev_attr.attr,

  	NULL
  };
  
  static const struct attribute_group adm1031_group_opt = {
  	.attrs = adm1031_attributes_opt,
  };

  /* Return 0 if detection is successful, -ENODEV otherwise */

  static int adm1031_detect(struct i2c_client *client,

  			  struct i2c_board_info *info)

  {

  	struct i2c_adapter *adapter = client->adapter;

  	const char *name;
  	int id, co;

  
  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))

  		return -ENODEV;

  	id = i2c_smbus_read_byte_data(client, 0x3d);
  	co = i2c_smbus_read_byte_data(client, 0x3e);

  	if (!((id == 0x31 || id == 0x30) && co == 0x41))
  		return -ENODEV;
  	name = (id == 0x30) ? "adm1030" : "adm1031";

  	strlcpy(info->type, name, I2C_NAME_SIZE);

  	return 0;
  }

  static void adm1031_init_client(struct i2c_client *client)
  {
  	unsigned int read_val;
  	unsigned int mask;
  	int i;
  	struct adm1031_data *data = i2c_get_clientdata(client);
  
  	mask = (ADM1031_CONF2_PWM1_ENABLE | ADM1031_CONF2_TACH1_ENABLE);
  	if (data->chip_type == adm1031) {
  		mask |= (ADM1031_CONF2_PWM2_ENABLE |
  			ADM1031_CONF2_TACH2_ENABLE);
  	}
  	/* Initialize the ADM1031 chip (enables fan speed reading ) */
  	read_val = adm1031_read_value(client, ADM1031_REG_CONF2);
  	if ((read_val | mask) != read_val)
  		adm1031_write_value(client, ADM1031_REG_CONF2, read_val | mask);
  
  	read_val = adm1031_read_value(client, ADM1031_REG_CONF1);
  	if ((read_val | ADM1031_CONF1_MONITOR_ENABLE) != read_val) {
  		adm1031_write_value(client, ADM1031_REG_CONF1,
  				    read_val | ADM1031_CONF1_MONITOR_ENABLE);
  	}
  
  	/* Read the chip's update rate */
  	mask = ADM1031_UPDATE_RATE_MASK;
  	read_val = adm1031_read_value(client, ADM1031_REG_FAN_FILTER);
  	i = (read_val & mask) >> ADM1031_UPDATE_RATE_SHIFT;
  	/* Save it as update interval */
  	data->update_interval = update_intervals[i];
  }

  static const struct i2c_device_id adm1031_id[];
  
  static int adm1031_probe(struct i2c_client *client)

  {

  	struct device *dev = &client->dev;
  	struct device *hwmon_dev;

  	struct adm1031_data *data;

  	data = devm_kzalloc(dev, sizeof(struct adm1031_data), GFP_KERNEL);

  	if (!data)
  		return -ENOMEM;

  
  	i2c_set_clientdata(client, data);

  	data->client = client;

  	data->chip_type = i2c_match_id(adm1031_id, client)->driver_data;

  	mutex_init(&data->update_lock);

  	if (data->chip_type == adm1030)
  		data->chan_select_table = &auto_channel_select_table_adm1030;
  	else
  		data->chan_select_table = &auto_channel_select_table_adm1031;

  
  	/* Initialize the ADM1031 chip */

  	adm1031_init_client(client);

  	/* sysfs hooks */
  	data->groups[0] = &adm1031_group;
  	if (data->chip_type == adm1031)
  		data->groups[1] = &adm1031_group_opt;

  	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
  							   data, data->groups);
  	return PTR_ERR_OR_ZERO(hwmon_dev);

  }

  static const struct i2c_device_id adm1031_id[] = {
  	{ "adm1030", adm1030 },
  	{ "adm1031", adm1031 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, adm1031_id);

  static struct i2c_driver adm1031_driver = {
  	.class		= I2C_CLASS_HWMON,
  	.driver = {
  		.name = "adm1031",
  	},

  	.probe_new	= adm1031_probe,

  	.id_table	= adm1031_id,
  	.detect		= adm1031_detect,
  	.address_list	= normal_i2c,
  };

  module_i2c_driver(adm1031_driver);

  
  MODULE_AUTHOR("Alexandre d'Alton <alex@alexdalton.org>");
  MODULE_DESCRIPTION("ADM1031/ADM1030 driver");
  MODULE_LICENSE("GPL");