/*
        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)
                return 0;
        return SENSORS_LIMIT(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 __devexit 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\n", ((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\n", ((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\n", (((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 = simple_strtoul(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->in_min[nr] = SENSORS_LIMIT(((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 = simple_strtoul(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->in_max[nr] = SENSORS_LIMIT(((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\n",
                (((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\n",
                (((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\n",
                (((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 = simple_strtoul(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->in_min[5] = SENSORS_LIMIT(((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 = simple_strtoul(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->in_max[5] = SENSORS_LIMIT(((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\n", 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\n", 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\n", 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);
        int val = simple_strtol(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->temp_max[0] = SENSORS_LIMIT((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);
        int val = simple_strtol(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->temp_min[0] = SENSORS_LIMIT((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\n", 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\n", 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\n", 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);
        int val = simple_strtol(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->temp_max[nr] = SENSORS_LIMIT(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);
        int val = simple_strtol(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->temp_min[nr] = SENSORS_LIMIT(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\n", 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\n", 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\n", 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);
        int val = simple_strtoul(buf, NULL, 10);

        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 = simple_strtoul(buf, NULL, 10);
        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]));

        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!\n", 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\n", 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\n", (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\n", 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 = __devexit_p(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 __devinit 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 (!request_region(res->start, VT8231_EXTENT,
                            vt8231_driver.driver.name)) {
                dev_err(&pdev->dev, "Region 0x%lx-0x%lx already in use!\n",
                        (unsigned long)res->start, (unsigned long)res->end);
                return -ENODEV;
        }

        if (!(data = kzalloc(sizeof(struct vt8231_data), GFP_KERNEL))) {
                err = -ENOMEM;
                goto exit_release;
        }

        platform_set_drvdata(pdev, data);
        data->addr = res->start;
        data->name = "vt8231";

        mutex_init(&data->update_lock);
        vt8231_init_device(data);

        /* Register sysfs hooks */
        if ((err = sysfs_create_group(&pdev->dev.kobj, &vt8231_group)))
                goto exit_free;

        /* 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)) {
                        if ((err = sysfs_create_group(&pdev->dev.kobj,
                                        &vt8231_group_temps[i])))
                                goto exit_remove_files;
                }
        }

        for (i = 0; i < ARRAY_SIZE(vt8231_group_volts); i++) {
                if (ISVOLT(i, data->uch_config)) {
                        if ((err = sysfs_create_group(&pdev->dev.kobj,
                                        &vt8231_group_volts[i])))
                                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);

exit_free:
        platform_set_drvdata(pdev, NULL);
        kfree(data);

exit_release:
        release_region(res->start, VT8231_EXTENT);
        return err;
}

static int __devexit 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);

        release_region(data->addr, VT8231_EXTENT);
        platform_set_drvdata(pdev, NULL);
        kfree(data);
        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 __devinit 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\n");
                goto exit;
        }

        err = platform_device_add_resources(pdev, &res, 1);
        if (err) {
                pr_err("Device resource addition failed (%d)\n", err);
                goto exit_device_put;
        }

        err = platform_device_add(pdev);
        if (err) {
                pr_err("Device addition failed (%d)\n", err);
                goto exit_device_put;
        }

        return 0;

exit_device_put:
        platform_device_put(pdev);
exit:
        return err;
}

static int __devinit 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\n",
                         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\n");
                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\n");
                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);