/*
   * lm87.c
   *
   * Copyright (C) 2000       Frodo Looijaard <frodol@dds.nl>
   *                          Philip Edelbrock <phil@netroedge.com>
   *                          Stephen Rousset <stephen.rousset@rocketlogix.com>
   *                          Dan Eaton <dan.eaton@rocketlogix.com>
   * Copyright (C) 2004-2008  Jean Delvare <jdelvare@suse.de>
   *
   * Original port to Linux 2.6 by Jeff Oliver.
   *
   * The LM87 is a sensor chip made by National Semiconductor. It monitors up
   * to 8 voltages (including its own power source), up to three temperatures
   * (its own plus up to two external ones) and up to two fans. The default
   * configuration is 6 voltages, two temperatures and two fans (see below).
   * Voltages are scaled internally with ratios such that the nominal value of
   * each voltage correspond to a register value of 192 (which means a
   * resolution of about 0.5% of the nominal value). Temperature values are
   * reported with a 1 deg resolution and a 3-4 deg accuracy. Complete
   * datasheet can be obtained from National's website at:
   *   http://www.national.com/pf/LM/LM87.html
   *
   * Some functions share pins, so not all functions are available at the same
   * time. Which are depends on the hardware setup. This driver normally
   * assumes that firmware configured the chip correctly. Where this is not
   * the case, platform code must set the I2C client's platform_data to point
   * to a u8 value to be written to the channel register.
   * For reference, here is the list of exclusive functions:
   *  - in0+in5 (default) or temp3
   *  - fan1 (default) or in6
   *  - fan2 (default) or in7
   *  - VID lines (default) or IRQ lines (not handled by this driver)
   *
   * The LM87 additionally features an analog output, supposedly usable to
   * control the speed of a fan. All new chips use pulse width modulation
   * instead. The LM87 is the only hardware monitoring chipset I know of
   * which uses amplitude modulation. Be careful when using this feature.
   *
   * This driver also supports the ADM1024, a sensor chip made by Analog
   * Devices. That chip is fully compatible with the LM87. Complete
   * datasheet can be obtained from Analog's website at:
   *   http://www.analog.com/en/prod/0,2877,ADM1024,00.html
   *
   * 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/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/hwmon-vid.h>
  #include <linux/err.h>
  #include <linux/mutex.h>
  
  /*
   * Addresses to scan
   * LM87 has three possible addresses: 0x2c, 0x2d and 0x2e.
   */
  
  static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, I2C_CLIENT_END };
  
  enum chips { lm87, adm1024 };
  
  /*
   * The LM87 registers
   */
  
  /* nr in 0..5 */
  #define LM87_REG_IN(nr)			(0x20 + (nr))
  #define LM87_REG_IN_MAX(nr)		(0x2B + (nr) * 2)
  #define LM87_REG_IN_MIN(nr)		(0x2C + (nr) * 2)
  /* nr in 0..1 */
  #define LM87_REG_AIN(nr)		(0x28 + (nr))
  #define LM87_REG_AIN_MIN(nr)		(0x1A + (nr))
  #define LM87_REG_AIN_MAX(nr)		(0x3B + (nr))
  
  static u8 LM87_REG_TEMP[3] = { 0x27, 0x26, 0x20 };
  static u8 LM87_REG_TEMP_HIGH[3] = { 0x39, 0x37, 0x2B };
  static u8 LM87_REG_TEMP_LOW[3] = { 0x3A, 0x38, 0x2C };
  
  #define LM87_REG_TEMP_HW_INT_LOCK	0x13
  #define LM87_REG_TEMP_HW_EXT_LOCK	0x14
  #define LM87_REG_TEMP_HW_INT		0x17
  #define LM87_REG_TEMP_HW_EXT		0x18
  
  /* nr in 0..1 */
  #define LM87_REG_FAN(nr)		(0x28 + (nr))
  #define LM87_REG_FAN_MIN(nr)		(0x3B + (nr))
  #define LM87_REG_AOUT			0x19
  
  #define LM87_REG_CONFIG			0x40
  #define LM87_REG_CHANNEL_MODE		0x16
  #define LM87_REG_VID_FAN_DIV		0x47
  #define LM87_REG_VID4			0x49
  
  #define LM87_REG_ALARMS1		0x41
  #define LM87_REG_ALARMS2		0x42
  
  #define LM87_REG_COMPANY_ID		0x3E
  #define LM87_REG_REVISION		0x3F
  
  /*
   * Conversions and various macros
   * The LM87 uses signed 8-bit values for temperatures.
   */
  
  #define IN_FROM_REG(reg, scale)	(((reg) * (scale) + 96) / 192)
  #define IN_TO_REG(val, scale)	((val) <= 0 ? 0 : \
  				 (val) * 192 >= (scale) * 255 ? 255 : \
  				 ((val) * 192 + (scale) / 2) / (scale))
  
  #define TEMP_FROM_REG(reg)	((reg) * 1000)
  #define TEMP_TO_REG(val)	((val) <= -127500 ? -128 : \
  				 (val) >= 126500 ? 127 : \
  				 (((val) < 0 ? (val) - 500 : \
  				   (val) + 500) / 1000))
  
  #define FAN_FROM_REG(reg, div)	((reg) == 255 || (reg) == 0 ? 0 : \
  				 (1350000 + (reg)*(div) / 2) / ((reg) * (div)))
  #define FAN_TO_REG(val, div)	((val) * (div) * 255 <= 1350000 ? 255 : \
  				 (1350000 + (val)*(div) / 2) / ((val) * (div)))
  
  #define FAN_DIV_FROM_REG(reg)	(1 << (reg))
  
  /* analog out is 9.80mV/LSB */
  #define AOUT_FROM_REG(reg)	(((reg) * 98 + 5) / 10)
  #define AOUT_TO_REG(val)	((val) <= 0 ? 0 : \
  				 (val) >= 2500 ? 255 : \
  				 ((val) * 10 + 49) / 98)
  
  /* nr in 0..1 */
  #define CHAN_NO_FAN(nr)		(1 << (nr))
  #define CHAN_TEMP3		(1 << 2)
  #define CHAN_VCC_5V		(1 << 3)
  #define CHAN_NO_VID		(1 << 7)
  
  /*
   * Client data (each client gets its own)
   */
  
  struct lm87_data {
  	struct device *hwmon_dev;
  	struct mutex update_lock;
  	char valid; /* zero until following fields are valid */
  	unsigned long last_updated; /* In jiffies */
  
  	u8 channel;		/* register value */
  	u8 config;		/* original register value */
  
  	u8 in[8];		/* register value */
  	u8 in_max[8];		/* register value */
  	u8 in_min[8];		/* register value */
  	u16 in_scale[8];
  
  	s8 temp[3];		/* register value */
  	s8 temp_high[3];	/* register value */
  	s8 temp_low[3];		/* register value */
  	s8 temp_crit_int;	/* min of two register values */
  	s8 temp_crit_ext;	/* min of two register values */
  
  	u8 fan[2];		/* register value */
  	u8 fan_min[2];		/* register value */
  	u8 fan_div[2];		/* register value, shifted right */
  	u8 aout;		/* register value */
  
  	u16 alarms;		/* register values, combined */
  	u8 vid;			/* register values, combined */
  	u8 vrm;
  };
  
  static inline int lm87_read_value(struct i2c_client *client, u8 reg)
  {
  	return i2c_smbus_read_byte_data(client, reg);
  }
  
  static inline int lm87_write_value(struct i2c_client *client, u8 reg, u8 value)
  {
  	return i2c_smbus_write_byte_data(client, reg, value);
  }
  
  static struct lm87_data *lm87_update_device(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct lm87_data *data = i2c_get_clientdata(client);
  
  	mutex_lock(&data->update_lock);
  
  	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
  		int i, j;
  
  		dev_dbg(&client->dev, "Updating data.
  ");
  
  		i = (data->channel & CHAN_TEMP3) ? 1 : 0;
  		j = (data->channel & CHAN_TEMP3) ? 5 : 6;
  		for (; i < j; i++) {
  			data->in[i] = lm87_read_value(client,
  				      LM87_REG_IN(i));
  			data->in_min[i] = lm87_read_value(client,
  					  LM87_REG_IN_MIN(i));
  			data->in_max[i] = lm87_read_value(client,
  					  LM87_REG_IN_MAX(i));
  		}
  
  		for (i = 0; i < 2; i++) {
  			if (data->channel & CHAN_NO_FAN(i)) {
  				data->in[6+i] = lm87_read_value(client,
  						LM87_REG_AIN(i));
  				data->in_max[6+i] = lm87_read_value(client,
  						    LM87_REG_AIN_MAX(i));
  				data->in_min[6+i] = lm87_read_value(client,
  						    LM87_REG_AIN_MIN(i));
  
  			} else {
  				data->fan[i] = lm87_read_value(client,
  					       LM87_REG_FAN(i));
  				data->fan_min[i] = lm87_read_value(client,
  						   LM87_REG_FAN_MIN(i));
  			}
  		}
  
  		j = (data->channel & CHAN_TEMP3) ? 3 : 2;
  		for (i = 0 ; i < j; i++) {
  			data->temp[i] = lm87_read_value(client,
  					LM87_REG_TEMP[i]);
  			data->temp_high[i] = lm87_read_value(client,
  					     LM87_REG_TEMP_HIGH[i]);
  			data->temp_low[i] = lm87_read_value(client,
  					    LM87_REG_TEMP_LOW[i]);
  		}
  
  		i = lm87_read_value(client, LM87_REG_TEMP_HW_INT_LOCK);
  		j = lm87_read_value(client, LM87_REG_TEMP_HW_INT);
  		data->temp_crit_int = min(i, j);
  
  		i = lm87_read_value(client, LM87_REG_TEMP_HW_EXT_LOCK);
  		j = lm87_read_value(client, LM87_REG_TEMP_HW_EXT);
  		data->temp_crit_ext = min(i, j);
  
  		i = lm87_read_value(client, LM87_REG_VID_FAN_DIV);
  		data->fan_div[0] = (i >> 4) & 0x03;
  		data->fan_div[1] = (i >> 6) & 0x03;
  		data->vid = (i & 0x0F)
  			  | (lm87_read_value(client, LM87_REG_VID4) & 0x01)
  			     << 4;
  
  		data->alarms = lm87_read_value(client, LM87_REG_ALARMS1)
  			     | (lm87_read_value(client, LM87_REG_ALARMS2)
  				<< 8);
  		data->aout = lm87_read_value(client, LM87_REG_AOUT);
  
  		data->last_updated = jiffies;
  		data->valid = 1;
  	}
  
  	mutex_unlock(&data->update_lock);
  
  	return data;
  }
  
  /*
   * Sysfs stuff
   */
  
  static ssize_t show_in_input(struct device *dev, struct device_attribute *attr,
  			     char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%u
  ", IN_FROM_REG(data->in[nr],
  		       data->in_scale[nr]));
  }
  
  static ssize_t show_in_min(struct device *dev,
  				     struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%u
  ", IN_FROM_REG(data->in_min[nr],
  		       data->in_scale[nr]));
  }
  
  static ssize_t show_in_max(struct device *dev,
  				     struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%u
  ", IN_FROM_REG(data->in_max[nr],
  		       data->in_scale[nr]));
  }
  
  static ssize_t set_in_min(struct device *dev, struct device_attribute *attr,
  			  const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct lm87_data *data = i2c_get_clientdata(client);
  	int nr = to_sensor_dev_attr(attr)->index;
  	long val;
  	int err;
  
  	err = kstrtol(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	data->in_min[nr] = IN_TO_REG(val, data->in_scale[nr]);
  	lm87_write_value(client, nr < 6 ? LM87_REG_IN_MIN(nr) :
  			 LM87_REG_AIN_MIN(nr - 6), data->in_min[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static ssize_t set_in_max(struct device *dev,  struct device_attribute *attr,
  			  const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct lm87_data *data = i2c_get_clientdata(client);
  	int nr = to_sensor_dev_attr(attr)->index;
  	long val;
  	int err;
  
  	err = kstrtol(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	data->in_max[nr] = IN_TO_REG(val, data->in_scale[nr]);
  	lm87_write_value(client, nr < 6 ? LM87_REG_IN_MAX(nr) :
  			 LM87_REG_AIN_MAX(nr - 6), data->in_max[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  #define set_in(offset) \
  static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO, \
  		show_in_input, NULL, offset); \
  static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR, \
  		show_in_min, set_in_min, offset); \
  static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR, \
  		show_in_max, set_in_max, offset)
  set_in(0);
  set_in(1);
  set_in(2);
  set_in(3);
  set_in(4);
  set_in(5);
  set_in(6);
  set_in(7);
  
  static ssize_t show_temp_input(struct device *dev,
  			       struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp[nr]));
  }
  
  static ssize_t show_temp_low(struct device *dev,
  			     struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%d
  ",
  		       TEMP_FROM_REG(data->temp_low[nr]));
  }
  
  static ssize_t show_temp_high(struct device *dev,
  			      struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%d
  ",
  		       TEMP_FROM_REG(data->temp_high[nr]));
  }
  
  static ssize_t set_temp_low(struct device *dev, struct device_attribute *attr,
  			    const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct lm87_data *data = i2c_get_clientdata(client);
  	int nr = to_sensor_dev_attr(attr)->index;
  	long val;
  	int err;
  
  	err = kstrtol(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	data->temp_low[nr] = TEMP_TO_REG(val);
  	lm87_write_value(client, LM87_REG_TEMP_LOW[nr], data->temp_low[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static ssize_t set_temp_high(struct device *dev, struct device_attribute *attr,
  			     const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct lm87_data *data = i2c_get_clientdata(client);
  	int nr = to_sensor_dev_attr(attr)->index;
  	long val;
  	int err;
  
  	err = kstrtol(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	data->temp_high[nr] = TEMP_TO_REG(val);
  	lm87_write_value(client, LM87_REG_TEMP_HIGH[nr], data->temp_high[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  #define set_temp(offset) \
  static SENSOR_DEVICE_ATTR(temp##offset##_input, S_IRUGO, \
  		show_temp_input, NULL, offset - 1); \
  static SENSOR_DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR, \
  		show_temp_high, set_temp_high, offset - 1); \
  static SENSOR_DEVICE_ATTR(temp##offset##_min, S_IRUGO | S_IWUSR, \
  		show_temp_low, set_temp_low, offset - 1)
  set_temp(1);
  set_temp(2);
  set_temp(3);
  
  static ssize_t show_temp_crit_int(struct device *dev,
  				  struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp_crit_int));
  }
  
  static ssize_t show_temp_crit_ext(struct device *dev,
  				  struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp_crit_ext));
  }
  
  static DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp_crit_int, NULL);
  static DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp_crit_ext, NULL);
  static DEVICE_ATTR(temp3_crit, S_IRUGO, show_temp_crit_ext, NULL);
  
  static ssize_t show_fan_input(struct device *dev,
  			      struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%d
  ", FAN_FROM_REG(data->fan[nr],
  		       FAN_DIV_FROM_REG(data->fan_div[nr])));
  }
  
  static ssize_t show_fan_min(struct device *dev,
  			    struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%d
  ", FAN_FROM_REG(data->fan_min[nr],
  		       FAN_DIV_FROM_REG(data->fan_div[nr])));
  }
  
  static ssize_t show_fan_div(struct device *dev,
  			    struct device_attribute *attr, char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int nr = to_sensor_dev_attr(attr)->index;
  
  	return sprintf(buf, "%d
  ",
  		       FAN_DIV_FROM_REG(data->fan_div[nr]));
  }
  
  static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
  			   const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct lm87_data *data = i2c_get_clientdata(client);
  	int nr = to_sensor_dev_attr(attr)->index;
  	long val;
  	int err;
  
  	err = kstrtol(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	data->fan_min[nr] = FAN_TO_REG(val,
  			    FAN_DIV_FROM_REG(data->fan_div[nr]));
  	lm87_write_value(client, LM87_REG_FAN_MIN(nr), data->fan_min[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  /*
   * Note: we save and restore the fan minimum here, because its value is
   * determined in part by the fan clock divider.  This follows the principle
   * of least surprise; the user doesn't expect the fan minimum to change just
   * because the divider changed.
   */
  static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
  			   const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct lm87_data *data = i2c_get_clientdata(client);
  	int nr = to_sensor_dev_attr(attr)->index;
  	long val;
  	int err;
  	unsigned long min;
  	u8 reg;
  
  	err = kstrtol(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	min = FAN_FROM_REG(data->fan_min[nr],
  			   FAN_DIV_FROM_REG(data->fan_div[nr]));
  
  	switch (val) {
  	case 1:
  		data->fan_div[nr] = 0;
  		break;
  	case 2:
  		data->fan_div[nr] = 1;
  		break;
  	case 4:
  		data->fan_div[nr] = 2;
  		break;
  	case 8:
  		data->fan_div[nr] = 3;
  		break;
  	default:
  		mutex_unlock(&data->update_lock);
  		return -EINVAL;
  	}
  
  	reg = lm87_read_value(client, LM87_REG_VID_FAN_DIV);
  	switch (nr) {
  	case 0:
  	    reg = (reg & 0xCF) | (data->fan_div[0] << 4);
  	    break;
  	case 1:
  	    reg = (reg & 0x3F) | (data->fan_div[1] << 6);
  	    break;
  	}
  	lm87_write_value(client, LM87_REG_VID_FAN_DIV, reg);
  
  	data->fan_min[nr] = FAN_TO_REG(min, val);
  	lm87_write_value(client, LM87_REG_FAN_MIN(nr),
  			 data->fan_min[nr]);
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }
  
  #define set_fan(offset) \
  static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO, \
  		show_fan_input, NULL, offset - 1); \
  static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR, \
  		show_fan_min, set_fan_min, offset - 1); \
  static SENSOR_DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR, \
  		show_fan_div, set_fan_div, offset - 1)
  set_fan(1);
  set_fan(2);
  
  static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
  			   char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	return sprintf(buf, "%d
  ", data->alarms);
  }
  static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
  
  static ssize_t show_vid(struct device *dev, struct device_attribute *attr,
  			char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	return sprintf(buf, "%d
  ", vid_from_reg(data->vid, data->vrm));
  }
  static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);
  
  static ssize_t show_vrm(struct device *dev, struct device_attribute *attr,
  			char *buf)
  {
  	struct lm87_data *data = dev_get_drvdata(dev);
  	return sprintf(buf, "%d
  ", data->vrm);
  }
  static ssize_t set_vrm(struct device *dev, struct device_attribute *attr,
  		       const char *buf, size_t count)
  {
  	struct lm87_data *data = dev_get_drvdata(dev);
  	unsigned long val;
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  	data->vrm = val;
  	return count;
  }
  static DEVICE_ATTR(vrm, S_IRUGO | S_IWUSR, show_vrm, set_vrm);
  
  static ssize_t show_aout(struct device *dev, struct device_attribute *attr,
  			 char *buf)
  {
  	struct lm87_data *data = lm87_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 lm87_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->aout = AOUT_TO_REG(val);
  	lm87_write_value(client, LM87_REG_AOUT, data->aout);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  static DEVICE_ATTR(aout_output, S_IRUGO | S_IWUSR, show_aout, set_aout);
  
  static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
  			  char *buf)
  {
  	struct lm87_data *data = lm87_update_device(dev);
  	int bitnr = to_sensor_dev_attr(attr)->index;
  	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(in6_alarm, S_IRUGO, show_alarm, NULL, 6);
  static SENSOR_DEVICE_ATTR(in7_alarm, S_IRUGO, show_alarm, NULL, 7);
  static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
  static SENSOR_DEVICE_ATTR(temp2_alarm, S_IRUGO, show_alarm, NULL, 5);
  static SENSOR_DEVICE_ATTR(temp3_alarm, S_IRUGO, show_alarm, NULL, 5);
  static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6);
  static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7);
  static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 14);
  static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 15);
  
  /*
   * Real code
   */
  
  static struct attribute *lm87_attributes[] = {
  	&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_temp1_input.dev_attr.attr,
  	&sensor_dev_attr_temp1_max.dev_attr.attr,
  	&sensor_dev_attr_temp1_min.dev_attr.attr,
  	&dev_attr_temp1_crit.attr,
  	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_input.dev_attr.attr,
  	&sensor_dev_attr_temp2_max.dev_attr.attr,
  	&sensor_dev_attr_temp2_min.dev_attr.attr,
  	&dev_attr_temp2_crit.attr,
  	&sensor_dev_attr_temp2_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_fault.dev_attr.attr,
  
  	&dev_attr_alarms.attr,
  	&dev_attr_aout_output.attr,
  
  	NULL
  };
  
  static const struct attribute_group lm87_group = {
  	.attrs = lm87_attributes,
  };
  
  static struct attribute *lm87_attributes_in6[] = {
  	&sensor_dev_attr_in6_input.dev_attr.attr,
  	&sensor_dev_attr_in6_min.dev_attr.attr,
  	&sensor_dev_attr_in6_max.dev_attr.attr,
  	&sensor_dev_attr_in6_alarm.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group lm87_group_in6 = {
  	.attrs = lm87_attributes_in6,
  };
  
  static struct attribute *lm87_attributes_fan1[] = {
  	&sensor_dev_attr_fan1_input.dev_attr.attr,
  	&sensor_dev_attr_fan1_min.dev_attr.attr,
  	&sensor_dev_attr_fan1_div.dev_attr.attr,
  	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group lm87_group_fan1 = {
  	.attrs = lm87_attributes_fan1,
  };
  
  static struct attribute *lm87_attributes_in7[] = {
  	&sensor_dev_attr_in7_input.dev_attr.attr,
  	&sensor_dev_attr_in7_min.dev_attr.attr,
  	&sensor_dev_attr_in7_max.dev_attr.attr,
  	&sensor_dev_attr_in7_alarm.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group lm87_group_in7 = {
  	.attrs = lm87_attributes_in7,
  };
  
  static struct attribute *lm87_attributes_fan2[] = {
  	&sensor_dev_attr_fan2_input.dev_attr.attr,
  	&sensor_dev_attr_fan2_min.dev_attr.attr,
  	&sensor_dev_attr_fan2_div.dev_attr.attr,
  	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group lm87_group_fan2 = {
  	.attrs = lm87_attributes_fan2,
  };
  
  static struct attribute *lm87_attributes_temp3[] = {
  	&sensor_dev_attr_temp3_input.dev_attr.attr,
  	&sensor_dev_attr_temp3_max.dev_attr.attr,
  	&sensor_dev_attr_temp3_min.dev_attr.attr,
  	&dev_attr_temp3_crit.attr,
  	&sensor_dev_attr_temp3_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp3_fault.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group lm87_group_temp3 = {
  	.attrs = lm87_attributes_temp3,
  };
  
  static struct attribute *lm87_attributes_in0_5[] = {
  	&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_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,
  	NULL
  };
  
  static const struct attribute_group lm87_group_in0_5 = {
  	.attrs = lm87_attributes_in0_5,
  };
  
  static struct attribute *lm87_attributes_vid[] = {
  	&dev_attr_cpu0_vid.attr,
  	&dev_attr_vrm.attr,
  	NULL
  };
  
  static const struct attribute_group lm87_group_vid = {
  	.attrs = lm87_attributes_vid,
  };
  
  /* Return 0 if detection is successful, -ENODEV otherwise */
  static int lm87_detect(struct i2c_client *client, struct i2c_board_info *info)
  {
  	struct i2c_adapter *adapter = client->adapter;
  	const char *name;
  	u8 cid, rev;
  
  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  		return -ENODEV;
  
  	if (lm87_read_value(client, LM87_REG_CONFIG) & 0x80)
  		return -ENODEV;
  
  	/* Now, we do the remaining detection. */
  	cid = lm87_read_value(client, LM87_REG_COMPANY_ID);
  	rev = lm87_read_value(client, LM87_REG_REVISION);
  
  	if (cid == 0x02			/* National Semiconductor */
  	 && (rev >= 0x01 && rev <= 0x08))
  		name = "lm87";
  	else if (cid == 0x41		/* Analog Devices */
  	      && (rev & 0xf0) == 0x10)
  		name = "adm1024";
  	else {
  		dev_dbg(&adapter->dev, "LM87 detection failed at 0x%02x
  ",
  			client->addr);
  		return -ENODEV;
  	}
  
  	strlcpy(info->type, name, I2C_NAME_SIZE);
  
  	return 0;
  }
  
  static void lm87_remove_files(struct i2c_client *client)
  {
  	struct device *dev = &client->dev;
  
  	sysfs_remove_group(&dev->kobj, &lm87_group);
  	sysfs_remove_group(&dev->kobj, &lm87_group_in6);
  	sysfs_remove_group(&dev->kobj, &lm87_group_fan1);
  	sysfs_remove_group(&dev->kobj, &lm87_group_in7);
  	sysfs_remove_group(&dev->kobj, &lm87_group_fan2);
  	sysfs_remove_group(&dev->kobj, &lm87_group_temp3);
  	sysfs_remove_group(&dev->kobj, &lm87_group_in0_5);
  	sysfs_remove_group(&dev->kobj, &lm87_group_vid);
  }
  
  static void lm87_init_client(struct i2c_client *client)
  {
  	struct lm87_data *data = i2c_get_clientdata(client);
  
  	if (dev_get_platdata(&client->dev)) {
  		data->channel = *(u8 *)dev_get_platdata(&client->dev);
  		lm87_write_value(client,
  				 LM87_REG_CHANNEL_MODE, data->channel);
  	} else {
  		data->channel = lm87_read_value(client, LM87_REG_CHANNEL_MODE);
  	}
  	data->config = lm87_read_value(client, LM87_REG_CONFIG) & 0x6F;
  
  	if (!(data->config & 0x01)) {
  		int i;
  
  		/* Limits are left uninitialized after power-up */
  		for (i = 1; i < 6; i++) {
  			lm87_write_value(client, LM87_REG_IN_MIN(i), 0x00);
  			lm87_write_value(client, LM87_REG_IN_MAX(i), 0xFF);
  		}
  		for (i = 0; i < 2; i++) {
  			lm87_write_value(client, LM87_REG_TEMP_HIGH[i], 0x7F);
  			lm87_write_value(client, LM87_REG_TEMP_LOW[i], 0x00);
  			lm87_write_value(client, LM87_REG_AIN_MIN(i), 0x00);
  			lm87_write_value(client, LM87_REG_AIN_MAX(i), 0xFF);
  		}
  		if (data->channel & CHAN_TEMP3) {
  			lm87_write_value(client, LM87_REG_TEMP_HIGH[2], 0x7F);
  			lm87_write_value(client, LM87_REG_TEMP_LOW[2], 0x00);
  		} else {
  			lm87_write_value(client, LM87_REG_IN_MIN(0), 0x00);
  			lm87_write_value(client, LM87_REG_IN_MAX(0), 0xFF);
  		}
  	}
  
  	/* Make sure Start is set and INT#_Clear is clear */
  	if ((data->config & 0x09) != 0x01)
  		lm87_write_value(client, LM87_REG_CONFIG,
  				 (data->config & 0x77) | 0x01);
  }
  
  static int lm87_probe(struct i2c_client *client, const struct i2c_device_id *id)
  {
  	struct lm87_data *data;
  	int err;
  
  	data = devm_kzalloc(&client->dev, sizeof(struct lm87_data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	i2c_set_clientdata(client, data);
  	data->valid = 0;
  	mutex_init(&data->update_lock);
  
  	/* Initialize the LM87 chip */
  	lm87_init_client(client);
  
  	data->in_scale[0] = 2500;
  	data->in_scale[1] = 2700;
  	data->in_scale[2] = (data->channel & CHAN_VCC_5V) ? 5000 : 3300;
  	data->in_scale[3] = 5000;
  	data->in_scale[4] = 12000;
  	data->in_scale[5] = 2700;
  	data->in_scale[6] = 1875;
  	data->in_scale[7] = 1875;
  
  	/* Register sysfs hooks */
  	err = sysfs_create_group(&client->dev.kobj, &lm87_group);
  	if (err)
  		goto exit_stop;
  
  	if (data->channel & CHAN_NO_FAN(0)) {
  		err = sysfs_create_group(&client->dev.kobj, &lm87_group_in6);
  		if (err)
  			goto exit_remove;
  	} else {
  		err = sysfs_create_group(&client->dev.kobj, &lm87_group_fan1);
  		if (err)
  			goto exit_remove;
  	}
  
  	if (data->channel & CHAN_NO_FAN(1)) {
  		err = sysfs_create_group(&client->dev.kobj, &lm87_group_in7);
  		if (err)
  			goto exit_remove;
  	} else {
  		err = sysfs_create_group(&client->dev.kobj, &lm87_group_fan2);
  		if (err)
  			goto exit_remove;
  	}
  
  	if (data->channel & CHAN_TEMP3) {
  		err = sysfs_create_group(&client->dev.kobj, &lm87_group_temp3);
  		if (err)
  			goto exit_remove;
  	} else {
  		err = sysfs_create_group(&client->dev.kobj, &lm87_group_in0_5);
  		if (err)
  			goto exit_remove;
  	}
  
  	if (!(data->channel & CHAN_NO_VID)) {
  		data->vrm = vid_which_vrm();
  		err = sysfs_create_group(&client->dev.kobj, &lm87_group_vid);
  		if (err)
  			goto exit_remove;
  	}
  
  	data->hwmon_dev = hwmon_device_register(&client->dev);
  	if (IS_ERR(data->hwmon_dev)) {
  		err = PTR_ERR(data->hwmon_dev);
  		goto exit_remove;
  	}
  
  	return 0;
  
  exit_remove:
  	lm87_remove_files(client);
  exit_stop:
  	lm87_write_value(client, LM87_REG_CONFIG, data->config);
  	return err;
  }
  
  static int lm87_remove(struct i2c_client *client)
  {
  	struct lm87_data *data = i2c_get_clientdata(client);
  
  	hwmon_device_unregister(data->hwmon_dev);
  	lm87_remove_files(client);
  
  	lm87_write_value(client, LM87_REG_CONFIG, data->config);
  	return 0;
  }
  
  /*
   * Driver data (common to all clients)
   */
  
  static const struct i2c_device_id lm87_id[] = {
  	{ "lm87", lm87 },
  	{ "adm1024", adm1024 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, lm87_id);
  
  static struct i2c_driver lm87_driver = {
  	.class		= I2C_CLASS_HWMON,
  	.driver = {
  		.name	= "lm87",
  	},
  	.probe		= lm87_probe,
  	.remove		= lm87_remove,
  	.id_table	= lm87_id,
  	.detect		= lm87_detect,
  	.address_list	= normal_i2c,
  };
  
  module_i2c_driver(lm87_driver);
  
  MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de> and others");
  MODULE_DESCRIPTION("LM87 driver");
  MODULE_LICENSE("GPL");