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

  /*
   * 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

   */
  
  #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>

  #include <linux/jiffies.h>

  #include <linux/regmap.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)
  {

  	val = clamp_val(val, 0, nom_mv[n] * 255 / 192);
  	return SCALE(val, 192, nom_mv[n]);

  }
  
  /* temperature range: -40..125, 127 disables temperature alarm */
  static inline s8 TEMP_TO_REG(long val)
  {

  	val = clamp_val(val, -40000, 127000);
  	return SCALE(val, 1, 1000);

  }
  
  /* 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)
  {

  	val = clamp_val(val, 0, 1250);
  	return SCALE(val, 255, 1250);

  }
  
  static inline unsigned int AOUT_FROM_REG(u8 reg)
  {
  	return SCALE(reg, 1250, 255);
  }

  /* per client data */
  struct adm9240_data {

  	struct i2c_client *client;

  	struct regmap *regmap;

  	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 */
  };

  /* write new fan div, callers must hold data->update_lock */

  static int adm9240_write_fan_div(struct adm9240_data *data, int nr,

  		u8 fan_div)
  {

  	unsigned int reg, old, shift = (nr + 2) * 2;
  	int err;

  	err = regmap_read(data->regmap, ADM9240_REG_VID_FAN_DIV, &reg);
  	if (err < 0)
  		return err;

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

  	err = regmap_write(data->regmap, ADM9240_REG_VID_FAN_DIV, reg);
  	if (err < 0)
  		return err;
  	dev_dbg(&data->client->dev,

  		"fan%d clock divider changed from %u to %u
  ",
  		nr + 1, 1 << old, 1 << fan_div);

  
  	return 0;

  }

  static int adm9240_update_measure(struct adm9240_data *data)
  {

  	unsigned int val;
  	u8 regs[2];
  	int err;

  	int i;

  	err = regmap_bulk_read(data->regmap, ADM9240_REG_IN(0), &data->in[0], 6);
  	if (err < 0)
  		return err;
  	err = regmap_bulk_read(data->regmap, ADM9240_REG_INT(0), &regs, 2);
  	if (err < 0)
  		return err;
  
  	data->alarms = regs[0] | regs[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
  	 */

  	err = regmap_read(data->regmap, ADM9240_REG_TEMP, &val);
  	if (err < 0)
  		return err;
  	data->temp = val << 8;
  	err = regmap_read(data->regmap, ADM9240_REG_TEMP_CONF, &val);
  	if (err < 0)
  		return err;
  	data->temp |= val;

  	err = regmap_bulk_read(data->regmap, ADM9240_REG_FAN(0),
  			       &data->fan[0], 2);
  	if (err < 0)
  		return err;

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

  		/* adjust fan clock divider on overflow */
  		if (data->valid && data->fan[i] == 255 &&
  				data->fan_div[i] < 3) {

  			err = adm9240_write_fan_div(data, i,

  					++data->fan_div[i]);

  			if (err < 0)
  				return err;

  
  			/* 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;
  		}
  	}
  
  	return 0;
  }
  
  static int adm9240_update_config(struct adm9240_data *data)

  {

  	unsigned int val;

  	int i;

  	int err;

  	for (i = 0; i < 6; i++) {

  		err = regmap_raw_read(data->regmap, ADM9240_REG_IN_MIN(i),
  				      &data->in_min[i], 1);
  		if (err < 0)
  			return err;
  		err = regmap_raw_read(data->regmap, ADM9240_REG_IN_MAX(i),
  				      &data->in_max[i], 1);
  		if (err < 0)
  			return err;

  	}

  	err = regmap_bulk_read(data->regmap, ADM9240_REG_FAN_MIN(0),
  				      &data->fan_min[0], 2);
  	if (err < 0)
  		return err;
  	err = regmap_bulk_read(data->regmap, ADM9240_REG_TEMP_MAX(0),
  				      &data->temp_max[0], 2);
  	if (err < 0)
  		return err;

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

  	err = regmap_read(data->regmap, ADM9240_REG_VID_FAN_DIV, &val);
  	if (err < 0)
  		return err;
  	data->fan_div[0] = (val >> 4) & 3;
  	data->fan_div[1] = (val >> 6) & 3;
  	data->vid = val & 0x0f;
  	err = regmap_read(data->regmap, ADM9240_REG_VID4, &val);
  	if (err < 0)
  		return err;
  	data->vid |= (val & 1) << 4;

  	/* read analog out */

  	err = regmap_raw_read(data->regmap, ADM9240_REG_ANALOG_OUT,
  			      &data->aout, 1);

  	return err;

  }
  
  static struct adm9240_data *adm9240_update_device(struct device *dev)
  {
  	struct adm9240_data *data = dev_get_drvdata(dev);
  	int err;

  	mutex_lock(&data->update_lock);
  
  	/* minimum measurement cycle: 1.75 seconds */
  	if (time_after(jiffies, data->last_updated_measure + (HZ * 7 / 4))
  			|| !data->valid) {

  		err = adm9240_update_measure(data);
  		if (err < 0) {
  			data->valid = 0;
  			mutex_unlock(&data->update_lock);
  			return ERR_PTR(err);

  		}
  		data->last_updated_measure = jiffies;
  	}
  
  	/* minimum config reading cycle: 300 seconds */
  	if (time_after(jiffies, data->last_updated_config + (HZ * 300))
  			|| !data->valid) {

  		err = adm9240_update_config(data);
  		if (err < 0) {
  			data->valid = 0;
  			mutex_unlock(&data->update_lock);
  			return ERR_PTR(err);

  		}

  		data->last_updated_config = jiffies;
  		data->valid = 1;
  	}
  	mutex_unlock(&data->update_lock);
  	return data;
  }

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

  static ssize_t temp1_input_show(struct device *dev,
  				struct device_attribute *dummy, char *buf)

  {
  	struct adm9240_data *data = adm9240_update_device(dev);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

  	return sprintf(buf, "%d
  ", data->temp / 128 * 500); /* 9-bit value */

  }

  static ssize_t max_show(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);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

  	return sprintf(buf, "%d
  ", data->temp_max[attr->index] * 1000);
  }

  static ssize_t max_store(struct device *dev, struct device_attribute *devattr,
  			 const char *buf, size_t count)

  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = dev_get_drvdata(dev);

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

  	mutex_lock(&data->update_lock);

  	data->temp_max[attr->index] = TEMP_TO_REG(val);

  	err = regmap_write(data->regmap, ADM9240_REG_TEMP_MAX(attr->index),
  			   data->temp_max[attr->index]);

  	mutex_unlock(&data->update_lock);

  	return err < 0 ? err : count;

  }

  static DEVICE_ATTR_RO(temp1_input);

  static SENSOR_DEVICE_ATTR_RW(temp1_max, max, 0);
  static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, max, 1);

  
  /* voltage */

  static ssize_t in_show(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);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  }

  static ssize_t in_min_show(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);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  }

  static ssize_t in_max_show(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);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  }

  static ssize_t in_min_store(struct device *dev,
  			    struct device_attribute *devattr, const char *buf,
  			    size_t count)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = dev_get_drvdata(dev);

  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;

  	mutex_lock(&data->update_lock);

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

  	err = regmap_write(data->regmap, ADM9240_REG_IN_MIN(attr->index),
  			   data->in_min[attr->index]);

  	mutex_unlock(&data->update_lock);

  	return err < 0 ? err : count;

  }

  static ssize_t in_max_store(struct device *dev,
  			    struct device_attribute *devattr, const char *buf,
  			    size_t count)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = dev_get_drvdata(dev);

  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;

  	mutex_lock(&data->update_lock);

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

  	err = regmap_write(data->regmap, ADM9240_REG_IN_MAX(attr->index),
  			   data->in_max[attr->index]);

  	mutex_unlock(&data->update_lock);

  	return err < 0 ? err : count;

  }

  static SENSOR_DEVICE_ATTR_RO(in0_input, in, 0);
  static SENSOR_DEVICE_ATTR_RW(in0_min, in_min, 0);
  static SENSOR_DEVICE_ATTR_RW(in0_max, in_max, 0);
  static SENSOR_DEVICE_ATTR_RO(in1_input, in, 1);
  static SENSOR_DEVICE_ATTR_RW(in1_min, in_min, 1);
  static SENSOR_DEVICE_ATTR_RW(in1_max, in_max, 1);
  static SENSOR_DEVICE_ATTR_RO(in2_input, in, 2);
  static SENSOR_DEVICE_ATTR_RW(in2_min, in_min, 2);
  static SENSOR_DEVICE_ATTR_RW(in2_max, in_max, 2);
  static SENSOR_DEVICE_ATTR_RO(in3_input, in, 3);
  static SENSOR_DEVICE_ATTR_RW(in3_min, in_min, 3);
  static SENSOR_DEVICE_ATTR_RW(in3_max, in_max, 3);
  static SENSOR_DEVICE_ATTR_RO(in4_input, in, 4);
  static SENSOR_DEVICE_ATTR_RW(in4_min, in_min, 4);
  static SENSOR_DEVICE_ATTR_RW(in4_max, in_max, 4);
  static SENSOR_DEVICE_ATTR_RO(in5_input, in, 5);
  static SENSOR_DEVICE_ATTR_RW(in5_min, in_min, 5);
  static SENSOR_DEVICE_ATTR_RW(in5_max, in_max, 5);

  
  /* fans */

  static ssize_t fan_show(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);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  }

  static ssize_t fan_min_show(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);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  }

  static ssize_t fan_div_show(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);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  }

  /*

   * 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 fan_min_store(struct device *dev,
  			     struct device_attribute *devattr,
  			     const char *buf, size_t count)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	struct adm9240_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	int nr = attr->index;

  	u8 new_div;

  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;

  	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(data, nr, new_div);

  	}

  	err = regmap_write(data->regmap, ADM9240_REG_FAN_MIN(nr),
  			   data->fan_min[nr]);

  	mutex_unlock(&data->update_lock);

  	return err < 0 ? err : count;

  }

  static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
  static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0);
  static SENSOR_DEVICE_ATTR_RO(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_RO(fan2_div, fan_div, 1);

  
  /* alarms */

  static ssize_t alarms_show(struct device *dev,

  		struct device_attribute *attr, char *buf)

  {
  	struct adm9240_data *data = adm9240_update_device(dev);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  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 adm9240_data *data = adm9240_update_device(dev);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

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

  static SENSOR_DEVICE_ATTR_RO(in0_alarm, alarm, 0);
  static SENSOR_DEVICE_ATTR_RO(in1_alarm, alarm, 1);
  static SENSOR_DEVICE_ATTR_RO(in2_alarm, alarm, 2);
  static SENSOR_DEVICE_ATTR_RO(in3_alarm, alarm, 3);
  static SENSOR_DEVICE_ATTR_RO(in4_alarm, alarm, 8);
  static SENSOR_DEVICE_ATTR_RO(in5_alarm, alarm, 9);
  static SENSOR_DEVICE_ATTR_RO(temp1_alarm, alarm, 4);
  static SENSOR_DEVICE_ATTR_RO(fan1_alarm, alarm, 6);
  static SENSOR_DEVICE_ATTR_RO(fan2_alarm, alarm, 7);

  /* vid */

  static ssize_t cpu0_vid_show(struct device *dev,
  			     struct device_attribute *attr, char *buf)

  {
  	struct adm9240_data *data = adm9240_update_device(dev);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

  	return sprintf(buf, "%d
  ", vid_from_reg(data->vid, data->vrm));
  }

  static DEVICE_ATTR_RO(cpu0_vid);

  
  /* analog output */

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

  {
  	struct adm9240_data *data = adm9240_update_device(dev);

  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

  	return sprintf(buf, "%d
  ", AOUT_FROM_REG(data->aout));
  }

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

  {

  	struct adm9240_data *data = dev_get_drvdata(dev);

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

  	mutex_lock(&data->update_lock);

  	data->aout = AOUT_TO_REG(val);

  	err = regmap_write(data->regmap, ADM9240_REG_ANALOG_OUT, data->aout);

  	mutex_unlock(&data->update_lock);

  	return err < 0 ? err : count;

  }

  static DEVICE_ATTR_RW(aout_output);

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

  {

  	struct adm9240_data *data = dev_get_drvdata(dev);

  	unsigned long val;

  	int err;

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

  		return -EINVAL;
  
  	mutex_lock(&data->update_lock);

  	err = regmap_write(data->regmap, ADM9240_REG_CHASSIS_CLEAR, 0x80);

  	data->valid = 0;		/* Force cache refresh */
  	mutex_unlock(&data->update_lock);

  	if (err < 0)
  		return err;
  	dev_dbg(&data->client->dev, "chassis intrusion latch cleared
  ");

  
  	return count;
  }

  static SENSOR_DEVICE_ATTR_RW(intrusion0_alarm, alarm, 12);

  static struct attribute *adm9240_attrs[] = {

  	&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,

  	&sensor_dev_attr_intrusion0_alarm.dev_attr.attr,

  	&dev_attr_cpu0_vid.attr,
  	NULL
  };

  ATTRIBUTE_GROUPS(adm9240);

  /*** 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_init_client(struct i2c_client *client, struct adm9240_data *data)

  {

  	u8 conf, mode;
  	int err;
  
  	err = regmap_raw_read(data->regmap, ADM9240_REG_CONFIG, &conf, 1);
  	if (err < 0)
  		return err;
  	err = regmap_raw_read(data->regmap, ADM9240_REG_TEMP_CONF, &mode, 1);
  	if (err < 0)
  		return err;
  	mode &= 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++) {

  			err = regmap_write(data->regmap,
  					   ADM9240_REG_IN_MIN(i), 0);
  			if (err < 0)
  				return err;
  			err = regmap_write(data->regmap,
  					   ADM9240_REG_IN_MAX(i), 255);
  			if (err < 0)
  				return err;

  		}

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

  			err = regmap_write(data->regmap,

  					ADM9240_REG_FAN_MIN(i), 255);

  			if (err < 0)
  				return err;

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

  			err = regmap_write(data->regmap,

  					ADM9240_REG_TEMP_MAX(i), 127);

  			if (err < 0)
  				return err;

  		}

  
  		/* start measurement cycle */

  		err = regmap_write(data->regmap, ADM9240_REG_CONFIG, 1);
  		if (err < 0)
  			return err;

  		dev_info(&client->dev,
  			 "cold start: config was 0x%02x mode %u
  ", conf, mode);

  	}

  
  	return 0;

  }

  static const struct regmap_config adm9240_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,
  	.use_single_read = true,
  	.use_single_write = true,
  };

  static int adm9240_probe(struct i2c_client *new_client)

  {

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

  	struct adm9240_data *data;

  	int err;

  	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);

  	if (!data)
  		return -ENOMEM;

  	data->client = new_client;

  	mutex_init(&data->update_lock);

  	data->regmap = devm_regmap_init_i2c(new_client, &adm9240_regmap_config);
  	if (IS_ERR(data->regmap))
  		return PTR_ERR(data->regmap);

  	err = adm9240_init_client(new_client, data);
  	if (err < 0)
  		return err;

  	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
  							   new_client->name,
  							   data,
  							   adm9240_groups);
  	return PTR_ERR_OR_ZERO(hwmon_dev);

  }

  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_new	= adm9240_probe,

  	.id_table	= adm9240_id,
  	.detect		= adm9240_detect,
  	.address_list	= normal_i2c,
  };

  module_i2c_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");