/*
   * adm9240.c	Part of lm_sensors, Linux kernel modules for hardware
   * 		monitoring
   *
   * Copyright (C) 1999	Frodo Looijaard <frodol@dds.nl>
   *			Philip Edelbrock <phil@netroedge.com>
   * Copyright (C) 2003	Michiel Rook <michiel@grendelproject.nl>

   * Copyright (C) 2005	Grant Coady <gcoady.lk@gmail.com> with valuable

   * 				guidance from Jean Delvare
   *
   * Driver supports	Analog Devices		ADM9240
   *			Dallas Semiconductor	DS1780
   *			National Semiconductor	LM81
   *
   * ADM9240 is the reference, DS1780 and LM81 are register compatibles
   *
   * Voltage	Six inputs are scaled by chip, VID also reported
   * Temperature	Chip temperature to 0.5'C, maximum and max_hysteris
   * Fans		2 fans, low speed alarm, automatic fan clock divider
   * Alarms	16-bit map of active alarms
   * Analog Out	0..1250 mV output
   *

   * Chassis Intrusion: clear CI latch with 'echo 0 > intrusion0_alarm'

   *
   * Test hardware: Intel SE440BX-2 desktop motherboard --Grant
   *
   * LM81 extended temp reading not implemented
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/i2c.h>

  #include <linux/hwmon-sysfs.h>

  #include <linux/hwmon.h>

  #include <linux/hwmon-vid.h>

  #include <linux/err.h>

  #include <linux/mutex.h>

  
  /* Addresses to scan */

  static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, 0x2f,

  					I2C_CLIENT_END };

  enum chips { adm9240, ds1780, lm81 };

  
  /* ADM9240 registers */
  #define ADM9240_REG_MAN_ID		0x3e
  #define ADM9240_REG_DIE_REV		0x3f
  #define ADM9240_REG_CONFIG		0x40
  
  #define ADM9240_REG_IN(nr)		(0x20 + (nr))   /* 0..5 */
  #define ADM9240_REG_IN_MAX(nr)		(0x2b + (nr) * 2)
  #define ADM9240_REG_IN_MIN(nr)		(0x2c + (nr) * 2)
  #define ADM9240_REG_FAN(nr)		(0x28 + (nr))   /* 0..1 */
  #define ADM9240_REG_FAN_MIN(nr)		(0x3b + (nr))
  #define ADM9240_REG_INT(nr)		(0x41 + (nr))
  #define ADM9240_REG_INT_MASK(nr)	(0x43 + (nr))
  #define ADM9240_REG_TEMP		0x27

  #define ADM9240_REG_TEMP_MAX(nr)	(0x39 + (nr)) /* 0, 1 = high, hyst */

  #define ADM9240_REG_ANALOG_OUT		0x19
  #define ADM9240_REG_CHASSIS_CLEAR	0x46
  #define ADM9240_REG_VID_FAN_DIV		0x47
  #define ADM9240_REG_I2C_ADDR		0x48
  #define ADM9240_REG_VID4		0x49
  #define ADM9240_REG_TEMP_CONF		0x4b
  
  /* generalised scaling with integer rounding */
  static inline int SCALE(long val, int mul, int div)
  {
  	if (val < 0)
  		return (val * mul - div / 2) / div;
  	else
  		return (val * mul + div / 2) / div;
  }
  
  /* adm9240 internally scales voltage measurements */
  static const u16 nom_mv[] = { 2500, 2700, 3300, 5000, 12000, 2700 };
  
  static inline unsigned int IN_FROM_REG(u8 reg, int n)
  {
  	return SCALE(reg, nom_mv[n], 192);
  }
  
  static inline u8 IN_TO_REG(unsigned long val, int n)
  {
  	return SENSORS_LIMIT(SCALE(val, 192, nom_mv[n]), 0, 255);
  }
  
  /* temperature range: -40..125, 127 disables temperature alarm */
  static inline s8 TEMP_TO_REG(long val)
  {
  	return SENSORS_LIMIT(SCALE(val, 1, 1000), -40, 127);
  }
  
  /* two fans, each with low fan speed limit */
  static inline unsigned int FAN_FROM_REG(u8 reg, u8 div)
  {
  	if (!reg) /* error */
  		return -1;
  
  	if (reg == 255)
  		return 0;
  
  	return SCALE(1350000, 1, reg * div);
  }
  
  /* analog out 0..1250mV */
  static inline u8 AOUT_TO_REG(unsigned long val)
  {
  	return SENSORS_LIMIT(SCALE(val, 255, 1250), 0, 255);
  }
  
  static inline unsigned int AOUT_FROM_REG(u8 reg)
  {
  	return SCALE(reg, 1250, 255);
  }

  static int adm9240_probe(struct i2c_client *client,
  			 const struct i2c_device_id *id);

  static int adm9240_detect(struct i2c_client *client,

  			  struct i2c_board_info *info);

  static void adm9240_init_client(struct i2c_client *client);

  static int adm9240_remove(struct i2c_client *client);

  static struct adm9240_data *adm9240_update_device(struct device *dev);
  
  /* driver data */

  static const struct i2c_device_id adm9240_id[] = {
  	{ "adm9240", adm9240 },
  	{ "ds1780", ds1780 },
  	{ "lm81", lm81 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, adm9240_id);

  static struct i2c_driver adm9240_driver = {

  	.class		= I2C_CLASS_HWMON,

  	.driver = {

  		.name	= "adm9240",
  	},

  	.probe		= adm9240_probe,
  	.remove		= adm9240_remove,
  	.id_table	= adm9240_id,
  	.detect		= adm9240_detect,

  	.address_list	= normal_i2c,

  };
  
  /* per client data */
  struct adm9240_data {

  	struct device *hwmon_dev;

  	struct mutex update_lock;

  	char valid;
  	unsigned long last_updated_measure;
  	unsigned long last_updated_config;
  
  	u8 in[6];		/* ro	in0_input */
  	u8 in_max[6];		/* rw	in0_max */
  	u8 in_min[6];		/* rw	in0_min */
  	u8 fan[2];		/* ro	fan1_input */
  	u8 fan_min[2];		/* rw	fan1_min */
  	u8 fan_div[2];		/* rw	fan1_div, read-only accessor */
  	s16 temp;		/* ro	temp1_input, 9-bit sign-extended */

  	s8 temp_max[2];		/* rw	0 -> temp_max, 1 -> temp_max_hyst */

  	u16 alarms;		/* ro	alarms */

  	u8 aout;		/* rw	aout_output */

  	u8 vid;			/* ro	vid */
  	u8 vrm;			/* --	vrm set on startup, no accessor */
  };

  /*** sysfs accessors ***/
  
  /* temperature */

  static ssize_t show_temp(struct device *dev, struct device_attribute *dummy,
  		char *buf)
  {
  	struct adm9240_data *data = adm9240_update_device(dev);
  	return sprintf(buf, "%d
  ", data->temp * 500); /* 9-bit value */
  }
  
  static ssize_t show_max(struct device *dev, struct device_attribute *devattr,
  		char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct adm9240_data *data = adm9240_update_device(dev);
  	return sprintf(buf, "%d
  ", data->temp_max[attr->index] * 1000);
  }
  
  static ssize_t set_max(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 adm9240_data *data = i2c_get_clientdata(client);
  	long val = simple_strtol(buf, NULL, 10);

  	mutex_lock(&data->update_lock);

  	data->temp_max[attr->index] = TEMP_TO_REG(val);
  	i2c_smbus_write_byte_data(client, ADM9240_REG_TEMP_MAX(attr->index),
  			data->temp_max[attr->index]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);

  static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
  		show_max, set_max, 0);
  static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
  		show_max, set_max, 1);

  
  /* voltage */

  static ssize_t show_in(struct device *dev, struct device_attribute *devattr,
  		char *buf)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = adm9240_update_device(dev);

  	return sprintf(buf, "%d
  ", IN_FROM_REG(data->in[attr->index],
  				attr->index));

  }

  static ssize_t show_in_min(struct device *dev,
  		struct device_attribute *devattr, char *buf)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = adm9240_update_device(dev);

  	return sprintf(buf, "%d
  ", IN_FROM_REG(data->in_min[attr->index],
  				attr->index));

  }

  static ssize_t show_in_max(struct device *dev,
  		struct device_attribute *devattr, char *buf)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = adm9240_update_device(dev);

  	return sprintf(buf, "%d
  ", IN_FROM_REG(data->in_max[attr->index],
  				attr->index));

  }

  static ssize_t set_in_min(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 adm9240_data *data = i2c_get_clientdata(client);
  	unsigned long val = simple_strtoul(buf, NULL, 10);

  	mutex_lock(&data->update_lock);

  	data->in_min[attr->index] = IN_TO_REG(val, attr->index);
  	i2c_smbus_write_byte_data(client, ADM9240_REG_IN_MIN(attr->index),
  			data->in_min[attr->index]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  static ssize_t set_in_max(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 adm9240_data *data = i2c_get_clientdata(client);
  	unsigned long val = simple_strtoul(buf, NULL, 10);

  	mutex_lock(&data->update_lock);

  	data->in_max[attr->index] = IN_TO_REG(val, attr->index);
  	i2c_smbus_write_byte_data(client, ADM9240_REG_IN_MAX(attr->index),
  			data->in_max[attr->index]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  #define vin(nr)							\
  static SENSOR_DEVICE_ATTR(in##nr##_input, S_IRUGO, 		\
  		show_in, NULL, nr);				\
  static SENSOR_DEVICE_ATTR(in##nr##_min, S_IRUGO | S_IWUSR,	\
  		show_in_min, set_in_min, nr);			\
  static SENSOR_DEVICE_ATTR(in##nr##_max, S_IRUGO | S_IWUSR,	\
  		show_in_max, set_in_max, nr);
  
  vin(0);
  vin(1);
  vin(2);
  vin(3);
  vin(4);
  vin(5);

  
  /* fans */

  static ssize_t show_fan(struct device *dev,
  		struct device_attribute *devattr, char *buf)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = adm9240_update_device(dev);

  	return sprintf(buf, "%d
  ", FAN_FROM_REG(data->fan[attr->index],
  				1 << data->fan_div[attr->index]));

  }

  static ssize_t show_fan_min(struct device *dev,
  		struct device_attribute *devattr, char *buf)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = adm9240_update_device(dev);

  	return sprintf(buf, "%d
  ", FAN_FROM_REG(data->fan_min[attr->index],
  				1 << data->fan_div[attr->index]));

  }

  static ssize_t show_fan_div(struct device *dev,
  		struct device_attribute *devattr, char *buf)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = adm9240_update_device(dev);

  	return sprintf(buf, "%d
  ", 1 << data->fan_div[attr->index]);

  }
  
  /* write new fan div, callers must hold data->update_lock */
  static void adm9240_write_fan_div(struct i2c_client *client, int nr,
  		u8 fan_div)
  {
  	u8 reg, old, shift = (nr + 2) * 2;

  	reg = i2c_smbus_read_byte_data(client, ADM9240_REG_VID_FAN_DIV);

  	old = (reg >> shift) & 3;
  	reg &= ~(3 << shift);
  	reg |= (fan_div << shift);

  	i2c_smbus_write_byte_data(client, ADM9240_REG_VID_FAN_DIV, reg);

  	dev_dbg(&client->dev, "fan%d clock divider changed from %u "
  			"to %u
  ", nr + 1, 1 << old, 1 << fan_div);
  }

  /*

   * set fan speed low limit:
   *
   * - value is zero: disable fan speed low limit alarm
   *
   * - value is below fan speed measurement range: enable fan speed low
   *   limit alarm to be asserted while fan speed too slow to measure
   *
   * - otherwise: select fan clock divider to suit fan speed low limit,
   *   measurement code may adjust registers to ensure fan speed reading
   */

  static ssize_t set_fan_min(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 adm9240_data *data = i2c_get_clientdata(client);
  	unsigned long val = simple_strtoul(buf, NULL, 10);

  	int nr = attr->index;

  	u8 new_div;

  	mutex_lock(&data->update_lock);

  
  	if (!val) {
  		data->fan_min[nr] = 255;
  		new_div = data->fan_div[nr];
  
  		dev_dbg(&client->dev, "fan%u low limit set disabled
  ",
  				nr + 1);
  
  	} else if (val < 1350000 / (8 * 254)) {
  		new_div = 3;
  		data->fan_min[nr] = 254;
  
  		dev_dbg(&client->dev, "fan%u low limit set minimum %u
  ",
  				nr + 1, FAN_FROM_REG(254, 1 << new_div));
  
  	} else {
  		unsigned int new_min = 1350000 / val;
  
  		new_div = 0;
  		while (new_min > 192 && new_div < 3) {
  			new_div++;
  			new_min /= 2;
  		}
  		if (!new_min) /* keep > 0 */
  			new_min++;
  
  		data->fan_min[nr] = new_min;
  
  		dev_dbg(&client->dev, "fan%u low limit set fan speed %u
  ",
  				nr + 1, FAN_FROM_REG(new_min, 1 << new_div));
  	}
  
  	if (new_div != data->fan_div[nr]) {
  		data->fan_div[nr] = new_div;
  		adm9240_write_fan_div(client, nr, new_div);
  	}

  	i2c_smbus_write_byte_data(client, ADM9240_REG_FAN_MIN(nr),

  			data->fan_min[nr]);

  	mutex_unlock(&data->update_lock);

  	return count;
  }

  #define fan(nr)							\
  static SENSOR_DEVICE_ATTR(fan##nr##_input, S_IRUGO,		\
  		show_fan, NULL, nr - 1);			\
  static SENSOR_DEVICE_ATTR(fan##nr##_div, S_IRUGO,		\
  		show_fan_div, NULL, nr - 1);			\
  static SENSOR_DEVICE_ATTR(fan##nr##_min, S_IRUGO | S_IWUSR,	\
  		show_fan_min, set_fan_min, nr - 1);
  
  fan(1);
  fan(2);

  
  /* alarms */

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

  {
  	struct adm9240_data *data = adm9240_update_device(dev);
  	return sprintf(buf, "%u
  ", data->alarms);
  }
  static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

  static ssize_t show_alarm(struct device *dev,
  		struct device_attribute *attr, char *buf)
  {
  	int bitnr = to_sensor_dev_attr(attr)->index;
  	struct adm9240_data *data = adm9240_update_device(dev);
  	return sprintf(buf, "%u
  ", (data->alarms >> bitnr) & 1);
  }
  static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
  static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
  static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
  static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
  static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 8);
  static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 9);
  static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
  static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6);
  static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7);

  /* vid */

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

  {
  	struct adm9240_data *data = adm9240_update_device(dev);
  	return sprintf(buf, "%d
  ", vid_from_reg(data->vid, data->vrm));
  }
  static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);
  
  /* analog output */

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

  {
  	struct adm9240_data *data = adm9240_update_device(dev);
  	return sprintf(buf, "%d
  ", AOUT_FROM_REG(data->aout));
  }

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

  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct adm9240_data *data = i2c_get_clientdata(client);
  	unsigned long val = simple_strtol(buf, NULL, 10);

  	mutex_lock(&data->update_lock);

  	data->aout = AOUT_TO_REG(val);

  	i2c_smbus_write_byte_data(client, ADM9240_REG_ANALOG_OUT, data->aout);

  	mutex_unlock(&data->update_lock);

  	return count;
  }
  static DEVICE_ATTR(aout_output, S_IRUGO | S_IWUSR, show_aout, set_aout);
  
  /* chassis_clear */

  static ssize_t chassis_clear_legacy(struct device *dev,

  		struct device_attribute *attr,
  		const char *buf, size_t count)

  {
  	struct i2c_client *client = to_i2c_client(dev);
  	unsigned long val = simple_strtol(buf, NULL, 10);

  	dev_warn(dev, "Attribute chassis_clear is deprecated, "
  		 "use intrusion0_alarm instead
  ");

  	if (val == 1) {

  		i2c_smbus_write_byte_data(client,
  				ADM9240_REG_CHASSIS_CLEAR, 0x80);

  		dev_dbg(&client->dev, "chassis intrusion latch cleared
  ");
  	}
  	return count;
  }

  static DEVICE_ATTR(chassis_clear, S_IWUSR, NULL, chassis_clear_legacy);
  
  static ssize_t chassis_clear(struct device *dev,
  		struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct adm9240_data *data = i2c_get_clientdata(client);
  	unsigned long val;

  	if (kstrtoul(buf, 10, &val) || val != 0)

  		return -EINVAL;
  
  	mutex_lock(&data->update_lock);
  	i2c_smbus_write_byte_data(client, ADM9240_REG_CHASSIS_CLEAR, 0x80);
  	data->valid = 0;		/* Force cache refresh */
  	mutex_unlock(&data->update_lock);
  	dev_dbg(&client->dev, "chassis intrusion latch cleared
  ");
  
  	return count;
  }
  static SENSOR_DEVICE_ATTR(intrusion0_alarm, S_IRUGO | S_IWUSR, show_alarm,
  		chassis_clear, 12);

  static struct attribute *adm9240_attributes[] = {
  	&sensor_dev_attr_in0_input.dev_attr.attr,
  	&sensor_dev_attr_in0_min.dev_attr.attr,
  	&sensor_dev_attr_in0_max.dev_attr.attr,

  	&sensor_dev_attr_in0_alarm.dev_attr.attr,

  	&sensor_dev_attr_in1_input.dev_attr.attr,
  	&sensor_dev_attr_in1_min.dev_attr.attr,
  	&sensor_dev_attr_in1_max.dev_attr.attr,

  	&sensor_dev_attr_in1_alarm.dev_attr.attr,

  	&sensor_dev_attr_in2_input.dev_attr.attr,
  	&sensor_dev_attr_in2_min.dev_attr.attr,
  	&sensor_dev_attr_in2_max.dev_attr.attr,

  	&sensor_dev_attr_in2_alarm.dev_attr.attr,

  	&sensor_dev_attr_in3_input.dev_attr.attr,
  	&sensor_dev_attr_in3_min.dev_attr.attr,
  	&sensor_dev_attr_in3_max.dev_attr.attr,

  	&sensor_dev_attr_in3_alarm.dev_attr.attr,

  	&sensor_dev_attr_in4_input.dev_attr.attr,
  	&sensor_dev_attr_in4_min.dev_attr.attr,
  	&sensor_dev_attr_in4_max.dev_attr.attr,

  	&sensor_dev_attr_in4_alarm.dev_attr.attr,

  	&sensor_dev_attr_in5_input.dev_attr.attr,
  	&sensor_dev_attr_in5_min.dev_attr.attr,
  	&sensor_dev_attr_in5_max.dev_attr.attr,

  	&sensor_dev_attr_in5_alarm.dev_attr.attr,

  	&dev_attr_temp1_input.attr,
  	&sensor_dev_attr_temp1_max.dev_attr.attr,
  	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,

  	&sensor_dev_attr_temp1_alarm.dev_attr.attr,

  	&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_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,

  	&dev_attr_alarms.attr,
  	&dev_attr_aout_output.attr,
  	&dev_attr_chassis_clear.attr,

  	&sensor_dev_attr_intrusion0_alarm.dev_attr.attr,

  	&dev_attr_cpu0_vid.attr,
  	NULL
  };
  
  static const struct attribute_group adm9240_group = {
  	.attrs = adm9240_attributes,
  };

  
  /*** sensor chip detect and driver install ***/

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

  static int adm9240_detect(struct i2c_client *new_client,

  			  struct i2c_board_info *info)

  {

  	struct i2c_adapter *adapter = new_client->adapter;

  	const char *name = "";

  	int address = new_client->addr;

  	u8 man_id, die_rev;
  
  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))

  		return -ENODEV;

  	/* verify chip: reg address should match i2c address */
  	if (i2c_smbus_read_byte_data(new_client, ADM9240_REG_I2C_ADDR)
  			!= address) {
  		dev_err(&adapter->dev, "detect fail: address match, 0x%02x
  ",
  			address);
  		return -ENODEV;

  	}

  	/* check known chip manufacturer */
  	man_id = i2c_smbus_read_byte_data(new_client, ADM9240_REG_MAN_ID);
  	if (man_id == 0x23) {

  		name = "adm9240";

  	} else if (man_id == 0xda) {

  		name = "ds1780";

  	} else if (man_id == 0x01) {

  		name = "lm81";

  	} else {
  		dev_err(&adapter->dev, "detect fail: unknown manuf, 0x%02x
  ",
  			man_id);
  		return -ENODEV;

  	}

  
  	/* successful detect, print chip info */
  	die_rev = i2c_smbus_read_byte_data(new_client, ADM9240_REG_DIE_REV);
  	dev_info(&adapter->dev, "found %s revision %u
  ",
  		 man_id == 0x23 ? "ADM9240" :
  		 man_id == 0xda ? "DS1780" : "LM81", die_rev);

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

  	return 0;
  }

  static int adm9240_probe(struct i2c_client *new_client,
  			 const struct i2c_device_id *id)
  {
  	struct adm9240_data *data;
  	int err;
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data) {
  		err = -ENOMEM;
  		goto exit;
  	}
  
  	i2c_set_clientdata(new_client, data);
  	mutex_init(&data->update_lock);

  
  	adm9240_init_client(new_client);
  
  	/* populate sysfs filesystem */

  	if ((err = sysfs_create_group(&new_client->dev.kobj, &adm9240_group)))

  		goto exit_free;

  	data->hwmon_dev = hwmon_device_register(&new_client->dev);
  	if (IS_ERR(data->hwmon_dev)) {
  		err = PTR_ERR(data->hwmon_dev);

  		goto exit_remove;

  	}

  	return 0;

  exit_remove:
  	sysfs_remove_group(&new_client->dev.kobj, &adm9240_group);

  exit_free:

  	kfree(data);

  exit:
  	return err;
  }

  static int adm9240_remove(struct i2c_client *client)

  {

  	struct adm9240_data *data = i2c_get_clientdata(client);

  	hwmon_device_unregister(data->hwmon_dev);

  	sysfs_remove_group(&client->dev.kobj, &adm9240_group);

  	kfree(data);

  	return 0;
  }
  
  static void adm9240_init_client(struct i2c_client *client)
  {
  	struct adm9240_data *data = i2c_get_clientdata(client);

  	u8 conf = i2c_smbus_read_byte_data(client, ADM9240_REG_CONFIG);
  	u8 mode = i2c_smbus_read_byte_data(client, ADM9240_REG_TEMP_CONF) & 3;

  	data->vrm = vid_which_vrm(); /* need this to report vid as mV */

  	dev_info(&client->dev, "Using VRM: %d.%d
  ", data->vrm / 10,
  			data->vrm % 10);

  	if (conf & 1) { /* measurement cycle running: report state */
  
  		dev_info(&client->dev, "status: config 0x%02x mode %u
  ",
  				conf, mode);
  
  	} else { /* cold start: open limits before starting chip */
  		int i;
  
  		for (i = 0; i < 6; i++)
  		{

  			i2c_smbus_write_byte_data(client,

  					ADM9240_REG_IN_MIN(i), 0);

  			i2c_smbus_write_byte_data(client,

  					ADM9240_REG_IN_MAX(i), 255);
  		}

  		i2c_smbus_write_byte_data(client,
  				ADM9240_REG_FAN_MIN(0), 255);
  		i2c_smbus_write_byte_data(client,
  				ADM9240_REG_FAN_MIN(1), 255);
  		i2c_smbus_write_byte_data(client,

  				ADM9240_REG_TEMP_MAX(0), 127);

  		i2c_smbus_write_byte_data(client,

  				ADM9240_REG_TEMP_MAX(1), 127);

  
  		/* start measurement cycle */

  		i2c_smbus_write_byte_data(client, ADM9240_REG_CONFIG, 1);

  
  		dev_info(&client->dev, "cold start: config was 0x%02x "
  				"mode %u
  ", conf, mode);
  	}
  }
  
  static struct adm9240_data *adm9240_update_device(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct adm9240_data *data = i2c_get_clientdata(client);
  	int i;

  	mutex_lock(&data->update_lock);

  
  	/* minimum measurement cycle: 1.75 seconds */
  	if (time_after(jiffies, data->last_updated_measure + (HZ * 7 / 4))
  			|| !data->valid) {
  
  		for (i = 0; i < 6; i++) /* read voltages */
  		{

  			data->in[i] = i2c_smbus_read_byte_data(client,

  					ADM9240_REG_IN(i));
  		}

  		data->alarms = i2c_smbus_read_byte_data(client,

  					ADM9240_REG_INT(0)) |

  					i2c_smbus_read_byte_data(client,

  					ADM9240_REG_INT(1)) << 8;
  
  		/* read temperature: assume temperature changes less than
  		 * 0.5'C per two measurement cycles thus ignore possible
  		 * but unlikely aliasing error on lsb reading. --Grant */

  		data->temp = ((i2c_smbus_read_byte_data(client,

  					ADM9240_REG_TEMP) << 8) |

  					i2c_smbus_read_byte_data(client,

  					ADM9240_REG_TEMP_CONF)) / 128;
  
  		for (i = 0; i < 2; i++) /* read fans */
  		{

  			data->fan[i] = i2c_smbus_read_byte_data(client,

  					ADM9240_REG_FAN(i));
  
  			/* adjust fan clock divider on overflow */
  			if (data->valid && data->fan[i] == 255 &&
  					data->fan_div[i] < 3) {
  
  				adm9240_write_fan_div(client, i,
  						++data->fan_div[i]);
  
  				/* adjust fan_min if active, but not to 0 */
  				if (data->fan_min[i] < 255 &&
  						data->fan_min[i] >= 2)
  					data->fan_min[i] /= 2;
  			}
  		}
  		data->last_updated_measure = jiffies;
  	}
  
  	/* minimum config reading cycle: 300 seconds */
  	if (time_after(jiffies, data->last_updated_config + (HZ * 300))
  			|| !data->valid) {
  
  		for (i = 0; i < 6; i++)
  		{

  			data->in_min[i] = i2c_smbus_read_byte_data(client,

  					ADM9240_REG_IN_MIN(i));

  			data->in_max[i] = i2c_smbus_read_byte_data(client,

  					ADM9240_REG_IN_MAX(i));
  		}
  		for (i = 0; i < 2; i++)
  		{

  			data->fan_min[i] = i2c_smbus_read_byte_data(client,

  					ADM9240_REG_FAN_MIN(i));
  		}

  		data->temp_max[0] = i2c_smbus_read_byte_data(client,
  				ADM9240_REG_TEMP_MAX(0));
  		data->temp_max[1] = i2c_smbus_read_byte_data(client,
  				ADM9240_REG_TEMP_MAX(1));

  
  		/* read fan divs and 5-bit VID */

  		i = i2c_smbus_read_byte_data(client, ADM9240_REG_VID_FAN_DIV);

  		data->fan_div[0] = (i >> 4) & 3;
  		data->fan_div[1] = (i >> 6) & 3;
  		data->vid = i & 0x0f;

  		data->vid |= (i2c_smbus_read_byte_data(client,

  					ADM9240_REG_VID4) & 1) << 4;
  		/* read analog out */

  		data->aout = i2c_smbus_read_byte_data(client,

  				ADM9240_REG_ANALOG_OUT);
  
  		data->last_updated_config = jiffies;
  		data->valid = 1;
  	}

  	mutex_unlock(&data->update_lock);

  	return data;
  }
  
  static int __init sensors_adm9240_init(void)
  {
  	return i2c_add_driver(&adm9240_driver);
  }
  
  static void __exit sensors_adm9240_exit(void)
  {
  	i2c_del_driver(&adm9240_driver);
  }
  
  MODULE_AUTHOR("Michiel Rook <michiel@grendelproject.nl>, "

  		"Grant Coady <gcoady.lk@gmail.com> and others");

  MODULE_DESCRIPTION("ADM9240/DS1780/LM81 driver");
  MODULE_LICENSE("GPL");
  
  module_init(sensors_adm9240_init);
  module_exit(sensors_adm9240_exit);