/*
   * vt8231.c - Part of lm_sensors, Linux kernel modules
   *	      for hardware monitoring
   *
   * Copyright (c) 2005 Roger Lucas <vt8231@hiddenengine.co.uk>
   * Copyright (c) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
   *		      Aaron M. Marsh <amarsh@sdf.lonestar.org>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; 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.
   */
  
  /*
   * Supports VIA VT8231 South Bridge embedded sensors
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/pci.h>
  #include <linux/jiffies.h>
  #include <linux/platform_device.h>
  #include <linux/hwmon.h>
  #include <linux/hwmon-sysfs.h>
  #include <linux/hwmon-vid.h>
  #include <linux/err.h>
  #include <linux/mutex.h>
  #include <linux/acpi.h>
  #include <linux/io.h>
  
  static int force_addr;
  module_param(force_addr, int, 0);
  MODULE_PARM_DESC(force_addr, "Initialize the base address of the sensors");
  
  static struct platform_device *pdev;
  
  #define VT8231_EXTENT 0x80
  #define VT8231_BASE_REG 0x70
  #define VT8231_ENABLE_REG 0x74
  
  /*
   * The VT8231 registers
   *
   * The reset value for the input channel configuration is used (Reg 0x4A=0x07)
   * which sets the selected inputs marked with '*' below if multiple options are
   * possible:
   *
   *		    Voltage Mode	  Temperature Mode
   *	Sensor	      Linux Id	      Linux Id	      VIA Id
   *	--------      --------	      --------	      ------
   *	CPU Diode	N/A		temp1		0
   *	UIC1		in0		temp2 *		1
   *	UIC2		in1 *		temp3		2
   *	UIC3		in2 *		temp4		3
   *	UIC4		in3 *		temp5		4
   *	UIC5		in4 *		temp6		5
   *	3.3V		in5		N/A
   *
   * Note that the BIOS may set the configuration register to a different value
   * to match the motherboard configuration.
   */
  
  /* fans numbered 0-1 */
  #define VT8231_REG_FAN_MIN(nr)	(0x3b + (nr))
  #define VT8231_REG_FAN(nr)	(0x29 + (nr))
  
  /* Voltage inputs numbered 0-5 */
  
  static const u8 regvolt[]    = { 0x21, 0x22, 0x23, 0x24, 0x25, 0x26 };
  static const u8 regvoltmax[] = { 0x3d, 0x2b, 0x2d, 0x2f, 0x31, 0x33 };
  static const u8 regvoltmin[] = { 0x3e, 0x2c, 0x2e, 0x30, 0x32, 0x34 };
  
  /*
   * Temperatures are numbered 1-6 according to the Linux kernel specification.
   *
   * In the VIA datasheet, however, the temperatures are numbered from zero.
   * Since it is important that this driver can easily be compared to the VIA
   * datasheet, we will use the VIA numbering within this driver and map the
   * kernel sysfs device name to the VIA number in the sysfs callback.
   */
  
  #define VT8231_REG_TEMP_LOW01	0x49
  #define VT8231_REG_TEMP_LOW25	0x4d
  
  static const u8 regtemp[]    = { 0x1f, 0x21, 0x22, 0x23, 0x24, 0x25 };
  static const u8 regtempmax[] = { 0x39, 0x3d, 0x2b, 0x2d, 0x2f, 0x31 };
  static const u8 regtempmin[] = { 0x3a, 0x3e, 0x2c, 0x2e, 0x30, 0x32 };
  
  #define TEMP_FROM_REG(reg)		(((253 * 4 - (reg)) * 550 + 105) / 210)
  #define TEMP_MAXMIN_FROM_REG(reg)	(((253 - (reg)) * 2200 + 105) / 210)
  #define TEMP_MAXMIN_TO_REG(val)		(253 - ((val) * 210 + 1100) / 2200)
  
  #define VT8231_REG_CONFIG 0x40
  #define VT8231_REG_ALARM1 0x41
  #define VT8231_REG_ALARM2 0x42
  #define VT8231_REG_FANDIV 0x47
  #define VT8231_REG_UCH_CONFIG 0x4a
  #define VT8231_REG_TEMP1_CONFIG 0x4b
  #define VT8231_REG_TEMP2_CONFIG 0x4c
  
  /*
   * temps 0-5 as numbered in VIA datasheet - see later for mapping to Linux
   * numbering
   */
  #define ISTEMP(i, ch_config) ((i) == 0 ? 1 : \
  			      ((ch_config) >> ((i)+1)) & 0x01)
  /* voltages 0-5 */
  #define ISVOLT(i, ch_config) ((i) == 5 ? 1 : \
  			      !(((ch_config) >> ((i)+2)) & 0x01))
  
  #define DIV_FROM_REG(val) (1 << (val))
  
  /*
   * NB  The values returned here are NOT temperatures.  The calibration curves
   *     for the thermistor curves are board-specific and must go in the
   *     sensors.conf file.  Temperature sensors are actually ten bits, but the
   *     VIA datasheet only considers the 8 MSBs obtained from the regtemp[]
   *     register.  The temperature value returned should have a magnitude of 3,
   *     so we use the VIA scaling as the "true" scaling and use the remaining 2
   *     LSBs as fractional precision.
   *
   *     All the on-chip hardware temperature comparisons for the alarms are only
   *     8-bits wide, and compare against the 8 MSBs of the temperature.  The bits
   *     in the registers VT8231_REG_TEMP_LOW01 and VT8231_REG_TEMP_LOW25 are
   *     ignored.
   */
  
  /*
   ****** FAN RPM CONVERSIONS ********
   * This chip saturates back at 0, not at 255 like many the other chips.
   * So, 0 means 0 RPM
   */
  static inline u8 FAN_TO_REG(long rpm, int div)
  {
  	if (rpm <= 0 || rpm > 1310720)
  		return 0;
  	return clamp_val(1310720 / (rpm * div), 1, 255);
  }
  
  #define FAN_FROM_REG(val, div) ((val) == 0 ? 0 : 1310720 / ((val) * (div)))
  
  struct vt8231_data {
  	unsigned short addr;
  	const char *name;
  
  	struct mutex update_lock;
  	struct device *hwmon_dev;
  	char valid;		/* !=0 if following fields are valid */
  	unsigned long last_updated;	/* In jiffies */
  
  	u8 in[6];		/* Register value */
  	u8 in_max[6];		/* Register value */
  	u8 in_min[6];		/* Register value */
  	u16 temp[6];		/* Register value 10 bit, right aligned */
  	u8 temp_max[6];		/* Register value */
  	u8 temp_min[6];		/* Register value */
  	u8 fan[2];		/* Register value */
  	u8 fan_min[2];		/* Register value */
  	u8 fan_div[2];		/* Register encoding, shifted right */
  	u16 alarms;		/* Register encoding */
  	u8 uch_config;
  };
  
  static struct pci_dev *s_bridge;
  static int vt8231_probe(struct platform_device *pdev);
  static int vt8231_remove(struct platform_device *pdev);
  static struct vt8231_data *vt8231_update_device(struct device *dev);
  static void vt8231_init_device(struct vt8231_data *data);
  
  static inline int vt8231_read_value(struct vt8231_data *data, u8 reg)
  {
  	return inb_p(data->addr + reg);
  }
  
  static inline void vt8231_write_value(struct vt8231_data *data, u8 reg,
  					u8 value)
  {
  	outb_p(value, data->addr + reg);
  }
  
  /* following are the sysfs callback functions */
  static ssize_t show_in(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  
  	return sprintf(buf, "%d
  ", ((data->in[nr] - 3) * 10000) / 958);
  }
  
  static ssize_t show_in_min(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  
  	return sprintf(buf, "%d
  ", ((data->in_min[nr] - 3) * 10000) / 958);
  }
  
  static ssize_t show_in_max(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  
  	return sprintf(buf, "%d
  ", (((data->in_max[nr] - 3) * 10000) / 958));
  }
  
  static ssize_t set_in_min(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_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[nr] = clamp_val(((val * 958) / 10000) + 3, 0, 255);
  	vt8231_write_value(data, regvoltmin[nr], 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 sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_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[nr] = clamp_val(((val * 958) / 10000) + 3, 0, 255);
  	vt8231_write_value(data, regvoltmax[nr], data->in_max[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  /* Special case for input 5 as this has 3.3V scaling built into the chip */
  static ssize_t show_in5(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct vt8231_data *data = vt8231_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		(((data->in[5] - 3) * 10000 * 54) / (958 * 34)));
  }
  
  static ssize_t show_in5_min(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct vt8231_data *data = vt8231_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		(((data->in_min[5] - 3) * 10000 * 54) / (958 * 34)));
  }
  
  static ssize_t show_in5_max(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct vt8231_data *data = vt8231_update_device(dev);
  
  	return sprintf(buf, "%d
  ",
  		(((data->in_max[5] - 3) * 10000 * 54) / (958 * 34)));
  }
  
  static ssize_t set_in5_min(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct vt8231_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[5] = clamp_val(((val * 958 * 34) / (10000 * 54)) + 3,
  				    0, 255);
  	vt8231_write_value(data, regvoltmin[5], data->in_min[5]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static ssize_t set_in5_max(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct vt8231_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[5] = clamp_val(((val * 958 * 34) / (10000 * 54)) + 3,
  				    0, 255);
  	vt8231_write_value(data, regvoltmax[5], data->in_max[5]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  #define define_voltage_sysfs(offset)				\
  static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
  		show_in, 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)
  
  define_voltage_sysfs(0);
  define_voltage_sysfs(1);
  define_voltage_sysfs(2);
  define_voltage_sysfs(3);
  define_voltage_sysfs(4);
  
  static DEVICE_ATTR(in5_input, S_IRUGO, show_in5, NULL);
  static DEVICE_ATTR(in5_min, S_IRUGO | S_IWUSR, show_in5_min, set_in5_min);
  static DEVICE_ATTR(in5_max, S_IRUGO | S_IWUSR, show_in5_max, set_in5_max);
  
  /* Temperatures */
  static ssize_t show_temp0(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", data->temp[0] * 250);
  }
  
  static ssize_t show_temp0_max(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", data->temp_max[0] * 1000);
  }
  
  static ssize_t show_temp0_min(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", data->temp_min[0] * 1000);
  }
  
  static ssize_t set_temp0_max(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct vt8231_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[0] = clamp_val((val + 500) / 1000, 0, 255);
  	vt8231_write_value(data, regtempmax[0], data->temp_max[0]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  static ssize_t set_temp0_min(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct vt8231_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_min[0] = clamp_val((val + 500) / 1000, 0, 255);
  	vt8231_write_value(data, regtempmin[0], data->temp_min[0]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static ssize_t show_temp(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp[nr]));
  }
  
  static ssize_t show_temp_max(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_MAXMIN_FROM_REG(data->temp_max[nr]));
  }
  
  static ssize_t show_temp_min(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_MAXMIN_FROM_REG(data->temp_min[nr]));
  }
  
  static ssize_t set_temp_max(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_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[nr] = clamp_val(TEMP_MAXMIN_TO_REG(val), 0, 255);
  	vt8231_write_value(data, regtempmax[nr], data->temp_max[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  static ssize_t set_temp_min(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_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_min[nr] = clamp_val(TEMP_MAXMIN_TO_REG(val), 0, 255);
  	vt8231_write_value(data, regtempmin[nr], data->temp_min[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  /*
   * Note that these map the Linux temperature sensor numbering (1-6) to the VIA
   * temperature sensor numbering (0-5)
   */
  #define define_temperature_sysfs(offset)				\
  static SENSOR_DEVICE_ATTR(temp##offset##_input, S_IRUGO,		\
  		show_temp, NULL, offset - 1);				\
  static SENSOR_DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR,	\
  		show_temp_max, set_temp_max, offset - 1);		\
  static SENSOR_DEVICE_ATTR(temp##offset##_max_hyst, S_IRUGO | S_IWUSR,	\
  		show_temp_min, set_temp_min, offset - 1)
  
  static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp0, NULL);
  static DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, show_temp0_max, set_temp0_max);
  static DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR, show_temp0_min,
  		   set_temp0_min);
  
  define_temperature_sysfs(2);
  define_temperature_sysfs(3);
  define_temperature_sysfs(4);
  define_temperature_sysfs(5);
  define_temperature_sysfs(6);
  
  /* Fans */
  static ssize_t show_fan(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", FAN_FROM_REG(data->fan[nr],
  				DIV_FROM_REG(data->fan_div[nr])));
  }
  
  static ssize_t show_fan_min(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", FAN_FROM_REG(data->fan_min[nr],
  			DIV_FROM_REG(data->fan_div[nr])));
  }
  
  static ssize_t show_fan_div(struct device *dev, struct device_attribute *attr,
  		char *buf)
  {
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", 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 sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	int nr = sensor_attr->index;
  	struct vt8231_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->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
  	vt8231_write_value(data, VT8231_REG_FAN_MIN(nr), data->fan_min[nr]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
  		const char *buf, size_t count)
  {
  	struct vt8231_data *data = dev_get_drvdata(dev);
  	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
  	unsigned long val;
  	int nr = sensor_attr->index;
  	int old = vt8231_read_value(data, VT8231_REG_FANDIV);
  	long min = FAN_FROM_REG(data->fan_min[nr],
  				 DIV_FROM_REG(data->fan_div[nr]));
  	int err;
  
  	err = kstrtoul(buf, 10, &val);
  	if (err)
  		return err;
  
  	mutex_lock(&data->update_lock);
  	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:
  		dev_err(dev,
  			"fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!
  ",
  			val);
  		mutex_unlock(&data->update_lock);
  		return -EINVAL;
  	}
  
  	/* Correct the fan minimum speed */
  	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
  	vt8231_write_value(data, VT8231_REG_FAN_MIN(nr), data->fan_min[nr]);
  
  	old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
  	vt8231_write_value(data, VT8231_REG_FANDIV, old);
  	mutex_unlock(&data->update_lock);
  	return count;
  }
  
  
  #define define_fan_sysfs(offset)					\
  static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,			\
  		show_fan, NULL, offset - 1);				\
  static SENSOR_DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR,		\
  		show_fan_div, set_fan_div, offset - 1);			\
  static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,		\
  		show_fan_min, set_fan_min, offset - 1)
  
  define_fan_sysfs(1);
  define_fan_sysfs(2);
  
  /* Alarms */
  static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
  			   char *buf)
  {
  	struct vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%d
  ", 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 vt8231_data *data = vt8231_update_device(dev);
  	return sprintf(buf, "%u
  ", (data->alarms >> bitnr) & 1);
  }
  static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
  static SENSOR_DEVICE_ATTR(temp2_alarm, S_IRUGO, show_alarm, NULL, 11);
  static SENSOR_DEVICE_ATTR(temp3_alarm, S_IRUGO, show_alarm, NULL, 0);
  static SENSOR_DEVICE_ATTR(temp4_alarm, S_IRUGO, show_alarm, NULL, 1);
  static SENSOR_DEVICE_ATTR(temp5_alarm, S_IRUGO, show_alarm, NULL, 3);
  static SENSOR_DEVICE_ATTR(temp6_alarm, S_IRUGO, show_alarm, NULL, 8);
  static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 11);
  static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 0);
  static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 1);
  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, 2);
  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 ssize_t show_name(struct device *dev, struct device_attribute
  			 *devattr, char *buf)
  {
  	struct vt8231_data *data = dev_get_drvdata(dev);
  	return sprintf(buf, "%s
  ", data->name);
  }
  static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
  
  static struct attribute *vt8231_attributes_temps[6][5] = {
  	{
  		&dev_attr_temp1_input.attr,
  		&dev_attr_temp1_max_hyst.attr,
  		&dev_attr_temp1_max.attr,
  		&sensor_dev_attr_temp1_alarm.dev_attr.attr,
  		NULL
  	}, {
  		&sensor_dev_attr_temp2_input.dev_attr.attr,
  		&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
  		&sensor_dev_attr_temp2_max.dev_attr.attr,
  		&sensor_dev_attr_temp2_alarm.dev_attr.attr,
  		NULL
  	}, {
  		&sensor_dev_attr_temp3_input.dev_attr.attr,
  		&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
  		&sensor_dev_attr_temp3_max.dev_attr.attr,
  		&sensor_dev_attr_temp3_alarm.dev_attr.attr,
  		NULL
  	}, {
  		&sensor_dev_attr_temp4_input.dev_attr.attr,
  		&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
  		&sensor_dev_attr_temp4_max.dev_attr.attr,
  		&sensor_dev_attr_temp4_alarm.dev_attr.attr,
  		NULL
  	}, {
  		&sensor_dev_attr_temp5_input.dev_attr.attr,
  		&sensor_dev_attr_temp5_max_hyst.dev_attr.attr,
  		&sensor_dev_attr_temp5_max.dev_attr.attr,
  		&sensor_dev_attr_temp5_alarm.dev_attr.attr,
  		NULL
  	}, {
  		&sensor_dev_attr_temp6_input.dev_attr.attr,
  		&sensor_dev_attr_temp6_max_hyst.dev_attr.attr,
  		&sensor_dev_attr_temp6_max.dev_attr.attr,
  		&sensor_dev_attr_temp6_alarm.dev_attr.attr,
  		NULL
  	}
  };
  
  static const struct attribute_group vt8231_group_temps[6] = {
  	{ .attrs = vt8231_attributes_temps[0] },
  	{ .attrs = vt8231_attributes_temps[1] },
  	{ .attrs = vt8231_attributes_temps[2] },
  	{ .attrs = vt8231_attributes_temps[3] },
  	{ .attrs = vt8231_attributes_temps[4] },
  	{ .attrs = vt8231_attributes_temps[5] },
  };
  
  static struct attribute *vt8231_attributes_volts[6][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,
  		NULL
  	}, {
  		&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,
  		NULL
  	}, {
  		&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,
  		NULL
  	}, {
  		&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,
  		NULL
  	}, {
  		&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,
  		NULL
  	}, {
  		&dev_attr_in5_input.attr,
  		&dev_attr_in5_min.attr,
  		&dev_attr_in5_max.attr,
  		&sensor_dev_attr_in5_alarm.dev_attr.attr,
  		NULL
  	}
  };
  
  static const struct attribute_group vt8231_group_volts[6] = {
  	{ .attrs = vt8231_attributes_volts[0] },
  	{ .attrs = vt8231_attributes_volts[1] },
  	{ .attrs = vt8231_attributes_volts[2] },
  	{ .attrs = vt8231_attributes_volts[3] },
  	{ .attrs = vt8231_attributes_volts[4] },
  	{ .attrs = vt8231_attributes_volts[5] },
  };
  
  static struct attribute *vt8231_attributes[] = {
  	&sensor_dev_attr_fan1_input.dev_attr.attr,
  	&sensor_dev_attr_fan2_input.dev_attr.attr,
  	&sensor_dev_attr_fan1_min.dev_attr.attr,
  	&sensor_dev_attr_fan2_min.dev_attr.attr,
  	&sensor_dev_attr_fan1_div.dev_attr.attr,
  	&sensor_dev_attr_fan2_div.dev_attr.attr,
  	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
  	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
  	&dev_attr_alarms.attr,
  	&dev_attr_name.attr,
  	NULL
  };
  
  static const struct attribute_group vt8231_group = {
  	.attrs = vt8231_attributes,
  };
  
  static struct platform_driver vt8231_driver = {
  	.driver = {
  		.owner	= THIS_MODULE,
  		.name	= "vt8231",
  	},
  	.probe	= vt8231_probe,
  	.remove	= vt8231_remove,
  };
  
  static const struct pci_device_id vt8231_pci_ids[] = {
  	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4) },
  	{ 0, }
  };
  
  MODULE_DEVICE_TABLE(pci, vt8231_pci_ids);
  
  static int vt8231_pci_probe(struct pci_dev *dev,
  				      const struct pci_device_id *id);
  
  static struct pci_driver vt8231_pci_driver = {
  	.name		= "vt8231",
  	.id_table	= vt8231_pci_ids,
  	.probe		= vt8231_pci_probe,
  };
  
  static int vt8231_probe(struct platform_device *pdev)
  {
  	struct resource *res;
  	struct vt8231_data *data;
  	int err = 0, i;
  
  	/* Reserve the ISA region */
  	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
  	if (!devm_request_region(&pdev->dev, res->start, VT8231_EXTENT,
  				 vt8231_driver.driver.name)) {
  		dev_err(&pdev->dev, "Region 0x%lx-0x%lx already in use!
  ",
  			(unsigned long)res->start, (unsigned long)res->end);
  		return -ENODEV;
  	}
  
  	data = devm_kzalloc(&pdev->dev, sizeof(struct vt8231_data), GFP_KERNEL);
  	if (!data)
  		return -ENOMEM;
  
  	platform_set_drvdata(pdev, data);
  	data->addr = res->start;
  	data->name = "vt8231";
  
  	mutex_init(&data->update_lock);
  	vt8231_init_device(data);
  
  	/* Register sysfs hooks */
  	err = sysfs_create_group(&pdev->dev.kobj, &vt8231_group);
  	if (err)
  		return err;
  
  	/* Must update device information to find out the config field */
  	data->uch_config = vt8231_read_value(data, VT8231_REG_UCH_CONFIG);
  
  	for (i = 0; i < ARRAY_SIZE(vt8231_group_temps); i++) {
  		if (ISTEMP(i, data->uch_config)) {
  			err = sysfs_create_group(&pdev->dev.kobj,
  						 &vt8231_group_temps[i]);
  			if (err)
  				goto exit_remove_files;
  		}
  	}
  
  	for (i = 0; i < ARRAY_SIZE(vt8231_group_volts); i++) {
  		if (ISVOLT(i, data->uch_config)) {
  			err = sysfs_create_group(&pdev->dev.kobj,
  						 &vt8231_group_volts[i]);
  			if (err)
  				goto exit_remove_files;
  		}
  	}
  
  	data->hwmon_dev = hwmon_device_register(&pdev->dev);
  	if (IS_ERR(data->hwmon_dev)) {
  		err = PTR_ERR(data->hwmon_dev);
  		goto exit_remove_files;
  	}
  	return 0;
  
  exit_remove_files:
  	for (i = 0; i < ARRAY_SIZE(vt8231_group_volts); i++)
  		sysfs_remove_group(&pdev->dev.kobj, &vt8231_group_volts[i]);
  
  	for (i = 0; i < ARRAY_SIZE(vt8231_group_temps); i++)
  		sysfs_remove_group(&pdev->dev.kobj, &vt8231_group_temps[i]);
  
  	sysfs_remove_group(&pdev->dev.kobj, &vt8231_group);
  	return err;
  }
  
  static int vt8231_remove(struct platform_device *pdev)
  {
  	struct vt8231_data *data = platform_get_drvdata(pdev);
  	int i;
  
  	hwmon_device_unregister(data->hwmon_dev);
  
  	for (i = 0; i < ARRAY_SIZE(vt8231_group_volts); i++)
  		sysfs_remove_group(&pdev->dev.kobj, &vt8231_group_volts[i]);
  
  	for (i = 0; i < ARRAY_SIZE(vt8231_group_temps); i++)
  		sysfs_remove_group(&pdev->dev.kobj, &vt8231_group_temps[i]);
  
  	sysfs_remove_group(&pdev->dev.kobj, &vt8231_group);
  
  	return 0;
  }
  
  static void vt8231_init_device(struct vt8231_data *data)
  {
  	vt8231_write_value(data, VT8231_REG_TEMP1_CONFIG, 0);
  	vt8231_write_value(data, VT8231_REG_TEMP2_CONFIG, 0);
  }
  
  static struct vt8231_data *vt8231_update_device(struct device *dev)
  {
  	struct vt8231_data *data = dev_get_drvdata(dev);
  	int i;
  	u16 low;
  
  	mutex_lock(&data->update_lock);
  
  	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
  	    || !data->valid) {
  		for (i = 0; i < 6; i++) {
  			if (ISVOLT(i, data->uch_config)) {
  				data->in[i] = vt8231_read_value(data,
  						regvolt[i]);
  				data->in_min[i] = vt8231_read_value(data,
  						regvoltmin[i]);
  				data->in_max[i] = vt8231_read_value(data,
  						regvoltmax[i]);
  			}
  		}
  		for (i = 0; i < 2; i++) {
  			data->fan[i] = vt8231_read_value(data,
  						VT8231_REG_FAN(i));
  			data->fan_min[i] = vt8231_read_value(data,
  						VT8231_REG_FAN_MIN(i));
  		}
  
  		low = vt8231_read_value(data, VT8231_REG_TEMP_LOW01);
  		low = (low >> 6) | ((low & 0x30) >> 2)
  		    | (vt8231_read_value(data, VT8231_REG_TEMP_LOW25) << 4);
  		for (i = 0; i < 6; i++) {
  			if (ISTEMP(i, data->uch_config)) {
  				data->temp[i] = (vt8231_read_value(data,
  						       regtemp[i]) << 2)
  						| ((low >> (2 * i)) & 0x03);
  				data->temp_max[i] = vt8231_read_value(data,
  						      regtempmax[i]);
  				data->temp_min[i] = vt8231_read_value(data,
  						      regtempmin[i]);
  			}
  		}
  
  		i = vt8231_read_value(data, VT8231_REG_FANDIV);
  		data->fan_div[0] = (i >> 4) & 0x03;
  		data->fan_div[1] = i >> 6;
  		data->alarms = vt8231_read_value(data, VT8231_REG_ALARM1) |
  			(vt8231_read_value(data, VT8231_REG_ALARM2) << 8);
  
  		/* Set alarm flags correctly */
  		if (!data->fan[0] && data->fan_min[0])
  			data->alarms |= 0x40;
  		else if (data->fan[0] && !data->fan_min[0])
  			data->alarms &= ~0x40;
  
  		if (!data->fan[1] && data->fan_min[1])
  			data->alarms |= 0x80;
  		else if (data->fan[1] && !data->fan_min[1])
  			data->alarms &= ~0x80;
  
  		data->last_updated = jiffies;
  		data->valid = 1;
  	}
  
  	mutex_unlock(&data->update_lock);
  
  	return data;
  }
  
  static int vt8231_device_add(unsigned short address)
  {
  	struct resource res = {
  		.start	= address,
  		.end	= address + VT8231_EXTENT - 1,
  		.name	= "vt8231",
  		.flags	= IORESOURCE_IO,
  	};
  	int err;
  
  	err = acpi_check_resource_conflict(&res);
  	if (err)
  		goto exit;
  
  	pdev = platform_device_alloc("vt8231", address);
  	if (!pdev) {
  		err = -ENOMEM;
  		pr_err("Device allocation failed
  ");
  		goto exit;
  	}
  
  	err = platform_device_add_resources(pdev, &res, 1);
  	if (err) {
  		pr_err("Device resource addition failed (%d)
  ", err);
  		goto exit_device_put;
  	}
  
  	err = platform_device_add(pdev);
  	if (err) {
  		pr_err("Device addition failed (%d)
  ", err);
  		goto exit_device_put;
  	}
  
  	return 0;
  
  exit_device_put:
  	platform_device_put(pdev);
  exit:
  	return err;
  }
  
  static int vt8231_pci_probe(struct pci_dev *dev,
  				const struct pci_device_id *id)
  {
  	u16 address, val;
  	if (force_addr) {
  		address = force_addr & 0xff00;
  		dev_warn(&dev->dev, "Forcing ISA address 0x%x
  ",
  			 address);
  
  		if (PCIBIOS_SUCCESSFUL !=
  		    pci_write_config_word(dev, VT8231_BASE_REG, address | 1))
  			return -ENODEV;
  	}
  
  	if (PCIBIOS_SUCCESSFUL != pci_read_config_word(dev, VT8231_BASE_REG,
  							&val))
  		return -ENODEV;
  
  	address = val & ~(VT8231_EXTENT - 1);
  	if (address == 0) {
  		dev_err(&dev->dev, "base address not set - upgrade BIOS or use force_addr=0xaddr
  ");
  		return -ENODEV;
  	}
  
  	if (PCIBIOS_SUCCESSFUL != pci_read_config_word(dev, VT8231_ENABLE_REG,
  							&val))
  		return -ENODEV;
  
  	if (!(val & 0x0001)) {
  		dev_warn(&dev->dev, "enabling sensors
  ");
  		if (PCIBIOS_SUCCESSFUL !=
  			pci_write_config_word(dev, VT8231_ENABLE_REG,
  							val | 0x0001))
  			return -ENODEV;
  	}
  
  	if (platform_driver_register(&vt8231_driver))
  		goto exit;
  
  	/* Sets global pdev as a side effect */
  	if (vt8231_device_add(address))
  		goto exit_unregister;
  
  	/*
  	 * Always return failure here.  This is to allow other drivers to bind
  	 * to this pci device.  We don't really want to have control over the
  	 * pci device, we only wanted to read as few register values from it.
  	 */
  
  	/*
  	 * We do, however, mark ourselves as using the PCI device to stop it
  	 * getting unloaded.
  	 */
  	s_bridge = pci_dev_get(dev);
  	return -ENODEV;
  
  exit_unregister:
  	platform_driver_unregister(&vt8231_driver);
  exit:
  	return -ENODEV;
  }
  
  static int __init sm_vt8231_init(void)
  {
  	return pci_register_driver(&vt8231_pci_driver);
  }
  
  static void __exit sm_vt8231_exit(void)
  {
  	pci_unregister_driver(&vt8231_pci_driver);
  	if (s_bridge != NULL) {
  		platform_device_unregister(pdev);
  		platform_driver_unregister(&vt8231_driver);
  		pci_dev_put(s_bridge);
  		s_bridge = NULL;
  	}
  }
  
  MODULE_AUTHOR("Roger Lucas <vt8231@hiddenengine.co.uk>");
  MODULE_DESCRIPTION("VT8231 sensors");
  MODULE_LICENSE("GPL");
  
  module_init(sm_vt8231_init);
  module_exit(sm_vt8231_exit);