via686a.c

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/*
 * via686a.c - Part of lm_sensors, Linux kernel modules
 *         for hardware monitoring
 *
 * Copyright (c) 1998 - 2002  Frodo Looijaard <[email protected]>,
 *                Kyösti Mälkki <[email protected]>,
 *                Mark Studebaker <[email protected]>,
 *                and Bob Dougherty <[email protected]>
 *
 * (Some conversion-factor data were contributed by Jonathan Teh Soon Yew
 * <[email protected]> and Alex van Kaam <[email protected]>.)
 *
 * 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 the Via VT82C686A, VT82C686B south bridges.
 * Reports all as a 686A.
 * Warning - only supports a single device.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.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/err.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/acpi.h>
#include <linux/io.h>


/*
 * If force_addr is set to anything different from 0, we forcibly enable
 * the device at the given address.
 */
static unsigned short force_addr;
module_param(force_addr, ushort, 0);
MODULE_PARM_DESC(force_addr,
         "Initialize the base address of the sensors");

static struct platform_device *pdev;

/*
 * The Via 686a southbridge has a LM78-like chip integrated on the same IC.
 * This driver is a customized copy of lm78.c
 */

/* Many VIA686A constants specified below */

/* Length of ISA address segment */
#define VIA686A_EXTENT      0x80
#define VIA686A_BASE_REG    0x70
#define VIA686A_ENABLE_REG  0x74

/* The VIA686A registers */
/* ins numbered 0-4 */
#define VIA686A_REG_IN_MAX(nr)  (0x2b + ((nr) * 2))
#define VIA686A_REG_IN_MIN(nr)  (0x2c + ((nr) * 2))
#define VIA686A_REG_IN(nr)  (0x22 + (nr))

/* fans numbered 1-2 */
#define VIA686A_REG_FAN_MIN(nr) (0x3a + (nr))
#define VIA686A_REG_FAN(nr) (0x28 + (nr))

/* temps numbered 1-3 */
static const u8 VIA686A_REG_TEMP[]  = { 0x20, 0x21, 0x1f };
static const u8 VIA686A_REG_TEMP_OVER[] = { 0x39, 0x3d, 0x1d };
static const u8 VIA686A_REG_TEMP_HYST[] = { 0x3a, 0x3e, 0x1e };
/* bits 7-6 */
#define VIA686A_REG_TEMP_LOW1   0x4b
/* 2 = bits 5-4, 3 = bits 7-6 */
#define VIA686A_REG_TEMP_LOW23  0x49

#define VIA686A_REG_ALARM1  0x41
#define VIA686A_REG_ALARM2  0x42
#define VIA686A_REG_FANDIV  0x47
#define VIA686A_REG_CONFIG  0x40
/*
 * The following register sets temp interrupt mode (bits 1-0 for temp1,
 * 3-2 for temp2, 5-4 for temp3).  Modes are:
 * 00 interrupt stays as long as value is out-of-range
 * 01 interrupt is cleared once register is read (default)
 * 10 comparator mode- like 00, but ignores hysteresis
 * 11 same as 00
 */
#define VIA686A_REG_TEMP_MODE       0x4b
/* We'll just assume that you want to set all 3 simultaneously: */
#define VIA686A_TEMP_MODE_MASK      0x3F
#define VIA686A_TEMP_MODE_CONTINUOUS    0x00

/*
 * Conversions. Limit checking is only done on the TO_REG
 * variants.
 *
 ******** VOLTAGE CONVERSIONS (Bob Dougherty) ********
 * From HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew):
 * voltagefactor[0]=1.25/2628; (2628/1.25=2102.4)   // Vccp
 * voltagefactor[1]=1.25/2628; (2628/1.25=2102.4)   // +2.5V
 * voltagefactor[2]=1.67/2628; (2628/1.67=1573.7)   // +3.3V
 * voltagefactor[3]=2.6/2628;  (2628/2.60=1010.8)   // +5V
 * voltagefactor[4]=6.3/2628;  (2628/6.30=417.14)   // +12V
 * in[i]=(data[i+2]*25.0+133)*voltagefactor[i];
 * That is:
 * volts = (25*regVal+133)*factor
 * regVal = (volts/factor-133)/25
 * (These conversions were contributed by Jonathan Teh Soon Yew
 * <[email protected]>)
 */
static inline u8 IN_TO_REG(long val, int inNum)
{
    /*
     * To avoid floating point, we multiply constants by 10 (100 for +12V).
     * Rounding is done (120500 is actually 133000 - 12500).
     * Remember that val is expressed in 0.001V/bit, which is why we divide
     * by an additional 10000 (100000 for +12V): 1000 for val and 10 (100)
     * for the constants.
     */
    if (inNum <= 1)
        return (u8)
            SENSORS_LIMIT((val * 21024 - 1205000) / 250000, 0, 255);
    else if (inNum == 2)
        return (u8)
            SENSORS_LIMIT((val * 15737 - 1205000) / 250000, 0, 255);
    else if (inNum == 3)
        return (u8)
            SENSORS_LIMIT((val * 10108 - 1205000) / 250000, 0, 255);
    else
        return (u8)
            SENSORS_LIMIT((val * 41714 - 12050000) / 2500000, 0, 255);
}

static inline long IN_FROM_REG(u8 val, int inNum)
{
    /*
     * To avoid floating point, we multiply constants by 10 (100 for +12V).
     * We also multiply them by 1000 because we want 0.001V/bit for the
     * output value. Rounding is done.
     */
    if (inNum <= 1)
        return (long) ((250000 * val + 1330000 + 21024 / 2) / 21024);
    else if (inNum == 2)
        return (long) ((250000 * val + 1330000 + 15737 / 2) / 15737);
    else if (inNum == 3)
        return (long) ((250000 * val + 1330000 + 10108 / 2) / 10108);
    else
        return (long) ((2500000 * val + 13300000 + 41714 / 2) / 41714);
}

/********* FAN RPM CONVERSIONS ********/
/*
 * Higher register values = slower fans (the fan's strobe gates a counter).
 * But this chip saturates back at 0, not at 255 like all the other chips.
 * So, 0 means 0 RPM
 */
static inline u8 FAN_TO_REG(long rpm, int div)
{
    if (rpm == 0)
        return 0;
    rpm = SENSORS_LIMIT(rpm, 1, 1000000);
    return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 255);
}

#define FAN_FROM_REG(val, div) ((val) == 0 ? 0 : (val) == 255 ? 0 : 1350000 / \
                ((val) * (div)))

/******** TEMP CONVERSIONS (Bob Dougherty) *********/
/*
 * linear fits from HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew)
 *  if(temp<169)
 *      return double(temp)*0.427-32.08;
 *  else if(temp>=169 && temp<=202)
 *      return double(temp)*0.582-58.16;
 *  else
 *      return double(temp)*0.924-127.33;
 *
 * A fifth-order polynomial fits the unofficial data (provided by Alex van
 * Kaam <[email protected]>) a bit better.  It also give more reasonable
 * numbers on my machine (ie. they agree with what my BIOS tells me).
 * Here's the fifth-order fit to the 8-bit data:
 * temp = 1.625093e-10*val^5 - 1.001632e-07*val^4 + 2.457653e-05*val^3 -
 *  2.967619e-03*val^2 + 2.175144e-01*val - 7.090067e+0.
 *
 * (2000-10-25- RFD: thanks to Uwe Andersen <[email protected]> for
 * finding my typos in this formula!)
 *
 * Alas, none of the elegant function-fit solutions will work because we
 * aren't allowed to use floating point in the kernel and doing it with
 * integers doesn't provide enough precision.  So we'll do boring old
 * look-up table stuff.  The unofficial data (see below) have effectively
 * 7-bit resolution (they are rounded to the nearest degree).  I'm assuming
 * that the transfer function of the device is monotonic and smooth, so a
 * smooth function fit to the data will allow us to get better precision.
 * I used the 5th-order poly fit described above and solved for
 * VIA register values 0-255.  I *10 before rounding, so we get tenth-degree
 * precision.  (I could have done all 1024 values for our 10-bit readings,
 * but the function is very linear in the useful range (0-80 deg C), so
 * we'll just use linear interpolation for 10-bit readings.)  So, tempLUT
 * is the temp at via register values 0-255:
 */
static const s16 tempLUT[] = {
    -709, -688, -667, -646, -627, -607, -589, -570, -553, -536, -519,
    -503, -487, -471, -456, -442, -428, -414, -400, -387, -375,
    -362, -350, -339, -327, -316, -305, -295, -285, -275, -265,
    -255, -246, -237, -229, -220, -212, -204, -196, -188, -180,
    -173, -166, -159, -152, -145, -139, -132, -126, -120, -114,
    -108, -102, -96, -91, -85, -80, -74, -69, -64, -59, -54, -49,
    -44, -39, -34, -29, -25, -20, -15, -11, -6, -2, 3, 7, 12, 16,
    20, 25, 29, 33, 37, 42, 46, 50, 54, 59, 63, 67, 71, 75, 79, 84,
    88, 92, 96, 100, 104, 109, 113, 117, 121, 125, 130, 134, 138,
    142, 146, 151, 155, 159, 163, 168, 172, 176, 181, 185, 189,
    193, 198, 202, 206, 211, 215, 219, 224, 228, 232, 237, 241,
    245, 250, 254, 259, 263, 267, 272, 276, 281, 285, 290, 294,
    299, 303, 307, 312, 316, 321, 325, 330, 334, 339, 344, 348,
    353, 357, 362, 366, 371, 376, 380, 385, 390, 395, 399, 404,
    409, 414, 419, 423, 428, 433, 438, 443, 449, 454, 459, 464,
    469, 475, 480, 486, 491, 497, 502, 508, 514, 520, 526, 532,
    538, 544, 551, 557, 564, 571, 578, 584, 592, 599, 606, 614,
    621, 629, 637, 645, 654, 662, 671, 680, 689, 698, 708, 718,
    728, 738, 749, 759, 770, 782, 793, 805, 818, 830, 843, 856,
    870, 883, 898, 912, 927, 943, 958, 975, 991, 1008, 1026, 1044,
    1062, 1081, 1101, 1121, 1141, 1162, 1184, 1206, 1229, 1252,
    1276, 1301, 1326, 1352, 1378, 1406, 1434, 1462
};

/*
 * the original LUT values from Alex van Kaam <[email protected]>
 * (for via register values 12-240):
 * {-50,-49,-47,-45,-43,-41,-39,-38,-37,-35,-34,-33,-32,-31,
 * -30,-29,-28,-27,-26,-25,-24,-24,-23,-22,-21,-20,-20,-19,-18,-17,-17,-16,-15,
 * -15,-14,-14,-13,-12,-12,-11,-11,-10,-9,-9,-8,-8,-7,-7,-6,-6,-5,-5,-4,-4,-3,
 * -3,-2,-2,-1,-1,0,0,1,1,1,3,3,3,4,4,4,5,5,5,6,6,7,7,8,8,9,9,9,10,10,11,11,12,
 * 12,12,13,13,13,14,14,15,15,16,16,16,17,17,18,18,19,19,20,20,21,21,21,22,22,
 * 22,23,23,24,24,25,25,26,26,26,27,27,27,28,28,29,29,30,30,30,31,31,32,32,33,
 * 33,34,34,35,35,35,36,36,37,37,38,38,39,39,40,40,41,41,42,42,43,43,44,44,45,
 * 45,46,46,47,48,48,49,49,50,51,51,52,52,53,53,54,55,55,56,57,57,58,59,59,60,
 * 61,62,62,63,64,65,66,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,83,84,
 * 85,86,88,89,91,92,94,96,97,99,101,103,105,107,109,110};
 *
 *
 * Here's the reverse LUT.  I got it by doing a 6-th order poly fit (needed
 * an extra term for a good fit to these inverse data!) and then
 * solving for each temp value from -50 to 110 (the useable range for
 * this chip).  Here's the fit:
 * viaRegVal = -1.160370e-10*val^6 +3.193693e-08*val^5 - 1.464447e-06*val^4
 * - 2.525453e-04*val^3 + 1.424593e-02*val^2 + 2.148941e+00*val +7.275808e+01)
 * Note that n=161:
 */
static const u8 viaLUT[] = {
    12, 12, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 22, 23,
    23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 40,
    41, 43, 45, 46, 48, 49, 51, 53, 55, 57, 59, 60, 62, 64, 66,
    69, 71, 73, 75, 77, 79, 82, 84, 86, 88, 91, 93, 95, 98, 100,
    103, 105, 107, 110, 112, 115, 117, 119, 122, 124, 126, 129,
    131, 134, 136, 138, 140, 143, 145, 147, 150, 152, 154, 156,
    158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180,
    182, 183, 185, 187, 188, 190, 192, 193, 195, 196, 198, 199,
    200, 202, 203, 205, 206, 207, 208, 209, 210, 211, 212, 213,
    214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 223, 224,
    225, 226, 226, 227, 228, 228, 229, 230, 230, 231, 232, 232,
    233, 233, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239,
    239, 240
};

/*
 * Converting temps to (8-bit) hyst and over registers
 * No interpolation here.
 * The +50 is because the temps start at -50
 */
static inline u8 TEMP_TO_REG(long val)
{
    return viaLUT[val <= -50000 ? 0 : val >= 110000 ? 160 :
              (val < 0 ? val - 500 : val + 500) / 1000 + 50];
}

/* for 8-bit temperature hyst and over registers */
#define TEMP_FROM_REG(val)  ((long)tempLUT[val] * 100)

/* for 10-bit temperature readings */
static inline long TEMP_FROM_REG10(u16 val)
{
    u16 eightBits = val >> 2;
    u16 twoBits = val & 3;

    /* no interpolation for these */
    if (twoBits == 0 || eightBits == 255)
        return TEMP_FROM_REG(eightBits);

    /* do some linear interpolation */
    return (tempLUT[eightBits] * (4 - twoBits) +
        tempLUT[eightBits + 1] * twoBits) * 25;
}

#define DIV_FROM_REG(val) (1 << (val))
#define DIV_TO_REG(val) ((val) == 8 ? 3 : (val) == 4 ? 2 : (val) == 1 ? 0 : 1)

/*
 * For each registered chip, we need to keep some data in memory.
 * The structure is dynamically allocated.
 */
struct via686a_data {
    unsigned short addr;
    const char *name;
    struct device *hwmon_dev;
    struct mutex update_lock;
    char valid;     /* !=0 if following fields are valid */
    unsigned long last_updated; /* In jiffies */

    u8 in[5];       /* Register value */
    u8 in_max[5];       /* Register value */
    u8 in_min[5];       /* Register value */
    u8 fan[2];      /* Register value */
    u8 fan_min[2];      /* Register value */
    u16 temp[3];        /* Register value 10 bit */
    u8 temp_over[3];    /* Register value */
    u8 temp_hyst[3];    /* Register value */
    u8 fan_div[2];      /* Register encoding, shifted right */
    u16 alarms;     /* Register encoding, combined */
};

static struct pci_dev *s_bridge;    /* pointer to the (only) via686a */

static int via686a_probe(struct platform_device *pdev);
static int __devexit via686a_remove(struct platform_device *pdev);

static inline int via686a_read_value(struct via686a_data *data, u8 reg)
{
    return inb_p(data->addr + reg);
}

static inline void via686a_write_value(struct via686a_data *data, u8 reg,
                       u8 value)
{
    outb_p(value, data->addr + reg);
}

static struct via686a_data *via686a_update_device(struct device *dev);
static void via686a_init_device(struct via686a_data *data);

/* following are the sysfs callback functions */

/* 7 voltage sensors */
static ssize_t show_in(struct device *dev, struct device_attribute *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    return sprintf(buf, "%ld\n", IN_FROM_REG(data->in[nr], nr));
}

static ssize_t show_in_min(struct device *dev, struct device_attribute *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_min[nr], nr));
}

static ssize_t show_in_max(struct device *dev, struct device_attribute *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_max[nr], nr));
}

static ssize_t set_in_min(struct device *dev, struct device_attribute *da,
        const char *buf, size_t count) {
    struct via686a_data *data = dev_get_drvdata(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    unsigned long val;
    int err;

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

    mutex_lock(&data->update_lock);
    data->in_min[nr] = IN_TO_REG(val, nr);
    via686a_write_value(data, VIA686A_REG_IN_MIN(nr),
            data->in_min[nr]);
    mutex_unlock(&data->update_lock);
    return count;
}
static ssize_t set_in_max(struct device *dev, struct device_attribute *da,
        const char *buf, size_t count) {
    struct via686a_data *data = dev_get_drvdata(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    unsigned long val;
    int err;

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

    mutex_lock(&data->update_lock);
    data->in_max[nr] = IN_TO_REG(val, nr);
    via686a_write_value(data, VIA686A_REG_IN_MAX(nr),
            data->in_max[nr]);
    mutex_unlock(&data->update_lock);
    return count;
}
#define show_in_offset(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);

show_in_offset(0);
show_in_offset(1);
show_in_offset(2);
show_in_offset(3);
show_in_offset(4);

/* 3 temperatures */
static ssize_t show_temp(struct device *dev, struct device_attribute *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    return sprintf(buf, "%ld\n", TEMP_FROM_REG10(data->temp[nr]));
}
static ssize_t show_temp_over(struct device *dev, struct device_attribute *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_over[nr]));
}
static ssize_t show_temp_hyst(struct device *dev, struct device_attribute *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_hyst[nr]));
}
static ssize_t set_temp_over(struct device *dev, struct device_attribute *da,
        const char *buf, size_t count) {
    struct via686a_data *data = dev_get_drvdata(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    long val;
    int err;

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

    mutex_lock(&data->update_lock);
    data->temp_over[nr] = TEMP_TO_REG(val);
    via686a_write_value(data, VIA686A_REG_TEMP_OVER[nr],
                data->temp_over[nr]);
    mutex_unlock(&data->update_lock);
    return count;
}
static ssize_t set_temp_hyst(struct device *dev, struct device_attribute *da,
        const char *buf, size_t count) {
    struct via686a_data *data = dev_get_drvdata(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    long val;
    int err;

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

    mutex_lock(&data->update_lock);
    data->temp_hyst[nr] = TEMP_TO_REG(val);
    via686a_write_value(data, VIA686A_REG_TEMP_HYST[nr],
                data->temp_hyst[nr]);
    mutex_unlock(&data->update_lock);
    return count;
}
#define show_temp_offset(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_over, set_temp_over, offset - 1);     \
static SENSOR_DEVICE_ATTR(temp##offset##_max_hyst, S_IRUGO | S_IWUSR,   \
        show_temp_hyst, set_temp_hyst, offset - 1);

show_temp_offset(1);
show_temp_offset(2);
show_temp_offset(3);

/* 2 Fans */
static ssize_t show_fan(struct device *dev, struct device_attribute *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    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 *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    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 *da,
        char *buf) {
    struct via686a_data *data = via686a_update_device(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
}
static ssize_t set_fan_min(struct device *dev, struct device_attribute *da,
        const char *buf, size_t count) {
    struct via686a_data *data = dev_get_drvdata(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    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]));
    via686a_write_value(data, VIA686A_REG_FAN_MIN(nr+1), data->fan_min[nr]);
    mutex_unlock(&data->update_lock);
    return count;
}
static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
        const char *buf, size_t count) {
    struct via686a_data *data = dev_get_drvdata(dev);
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    int nr = attr->index;
    int old;
    unsigned long val;
    int err;

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

    mutex_lock(&data->update_lock);
    old = via686a_read_value(data, VIA686A_REG_FANDIV);
    data->fan_div[nr] = DIV_TO_REG(val);
    old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
    via686a_write_value(data, VIA686A_REG_FANDIV, old);
    mutex_unlock(&data->update_lock);
    return count;
}

#define show_fan_offset(offset)                     \
static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,         \
        show_fan, 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);

show_fan_offset(1);
show_fan_offset(2);

/* Alarms */
static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
               char *buf)
{
    struct via686a_data *data = via686a_update_device(dev);
    return sprintf(buf, "%u\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 via686a_data *data = via686a_update_device(dev);
    return sprintf(buf, "%u\n", (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(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, 15);
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 via686a_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 *via686a_attributes[] = {
    &sensor_dev_attr_in0_input.dev_attr.attr,
    &sensor_dev_attr_in1_input.dev_attr.attr,
    &sensor_dev_attr_in2_input.dev_attr.attr,
    &sensor_dev_attr_in3_input.dev_attr.attr,
    &sensor_dev_attr_in4_input.dev_attr.attr,
    &sensor_dev_attr_in0_min.dev_attr.attr,
    &sensor_dev_attr_in1_min.dev_attr.attr,
    &sensor_dev_attr_in2_min.dev_attr.attr,
    &sensor_dev_attr_in3_min.dev_attr.attr,
    &sensor_dev_attr_in4_min.dev_attr.attr,
    &sensor_dev_attr_in0_max.dev_attr.attr,
    &sensor_dev_attr_in1_max.dev_attr.attr,
    &sensor_dev_attr_in2_max.dev_attr.attr,
    &sensor_dev_attr_in3_max.dev_attr.attr,
    &sensor_dev_attr_in4_max.dev_attr.attr,
    &sensor_dev_attr_in0_alarm.dev_attr.attr,
    &sensor_dev_attr_in1_alarm.dev_attr.attr,
    &sensor_dev_attr_in2_alarm.dev_attr.attr,
    &sensor_dev_attr_in3_alarm.dev_attr.attr,
    &sensor_dev_attr_in4_alarm.dev_attr.attr,

    &sensor_dev_attr_temp1_input.dev_attr.attr,
    &sensor_dev_attr_temp2_input.dev_attr.attr,
    &sensor_dev_attr_temp3_input.dev_attr.attr,
    &sensor_dev_attr_temp1_max.dev_attr.attr,
    &sensor_dev_attr_temp2_max.dev_attr.attr,
    &sensor_dev_attr_temp3_max.dev_attr.attr,
    &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
    &sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
    &sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
    &sensor_dev_attr_temp1_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_alarm.dev_attr.attr,
    &sensor_dev_attr_temp3_alarm.dev_attr.attr,

    &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 via686a_group = {
    .attrs = via686a_attributes,
};

static struct platform_driver via686a_driver = {
    .driver = {
        .owner  = THIS_MODULE,
        .name   = "via686a",
    },
    .probe      = via686a_probe,
    .remove     = __devexit_p(via686a_remove),
};


/* This is called when the module is loaded */
static int __devinit via686a_probe(struct platform_device *pdev)
{
    struct via686a_data *data;
    struct resource *res;
    int err;

    /* Reserve the ISA region */
    res = platform_get_resource(pdev, IORESOURCE_IO, 0);
    if (!devm_request_region(&pdev->dev, res->start, VIA686A_EXTENT,
                 via686a_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;
    }

    data = devm_kzalloc(&pdev->dev, sizeof(struct via686a_data),
                GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    platform_set_drvdata(pdev, data);
    data->addr = res->start;
    data->name = "via686a";
    mutex_init(&data->update_lock);

    /* Initialize the VIA686A chip */
    via686a_init_device(data);

    /* Register sysfs hooks */
    err = sysfs_create_group(&pdev->dev.kobj, &via686a_group);
    if (err)
        return err;

    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:
    sysfs_remove_group(&pdev->dev.kobj, &via686a_group);
    return err;
}

static int __devexit via686a_remove(struct platform_device *pdev)
{
    struct via686a_data *data = platform_get_drvdata(pdev);

    hwmon_device_unregister(data->hwmon_dev);
    sysfs_remove_group(&pdev->dev.kobj, &via686a_group);

    return 0;
}

static void via686a_update_fan_div(struct via686a_data *data)
{
    int reg = via686a_read_value(data, VIA686A_REG_FANDIV);
    data->fan_div[0] = (reg >> 4) & 0x03;
    data->fan_div[1] = reg >> 6;
}

static void __devinit via686a_init_device(struct via686a_data *data)
{
    u8 reg;

    /* Start monitoring */
    reg = via686a_read_value(data, VIA686A_REG_CONFIG);
    via686a_write_value(data, VIA686A_REG_CONFIG, (reg | 0x01) & 0x7F);

    /* Configure temp interrupt mode for continuous-interrupt operation */
    reg = via686a_read_value(data, VIA686A_REG_TEMP_MODE);
    via686a_write_value(data, VIA686A_REG_TEMP_MODE,
                (reg & ~VIA686A_TEMP_MODE_MASK)
                | VIA686A_TEMP_MODE_CONTINUOUS);

    /* Pre-read fan clock divisor values */
    via686a_update_fan_div(data);
}

static struct via686a_data *via686a_update_device(struct device *dev)
{
    struct via686a_data *data = dev_get_drvdata(dev);
    int i;

    mutex_lock(&data->update_lock);

    if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
        || !data->valid) {
        for (i = 0; i <= 4; i++) {
            data->in[i] =
                via686a_read_value(data, VIA686A_REG_IN(i));
            data->in_min[i] = via686a_read_value(data,
                                 VIA686A_REG_IN_MIN
                                 (i));
            data->in_max[i] =
                via686a_read_value(data, VIA686A_REG_IN_MAX(i));
        }
        for (i = 1; i <= 2; i++) {
            data->fan[i - 1] =
                via686a_read_value(data, VIA686A_REG_FAN(i));
            data->fan_min[i - 1] = via686a_read_value(data,
                             VIA686A_REG_FAN_MIN(i));
        }
        for (i = 0; i <= 2; i++) {
            data->temp[i] = via686a_read_value(data,
                         VIA686A_REG_TEMP[i]) << 2;
            data->temp_over[i] =
                via686a_read_value(data,
                           VIA686A_REG_TEMP_OVER[i]);
            data->temp_hyst[i] =
                via686a_read_value(data,
                           VIA686A_REG_TEMP_HYST[i]);
        }
        /*
         * add in lower 2 bits
         * temp1 uses bits 7-6 of VIA686A_REG_TEMP_LOW1
         * temp2 uses bits 5-4 of VIA686A_REG_TEMP_LOW23
         * temp3 uses bits 7-6 of VIA686A_REG_TEMP_LOW23
         */
        data->temp[0] |= (via686a_read_value(data,
                             VIA686A_REG_TEMP_LOW1)
                  & 0xc0) >> 6;
        data->temp[1] |=
            (via686a_read_value(data, VIA686A_REG_TEMP_LOW23) &
             0x30) >> 4;
        data->temp[2] |=
            (via686a_read_value(data, VIA686A_REG_TEMP_LOW23) &
             0xc0) >> 6;

        via686a_update_fan_div(data);
        data->alarms =
            via686a_read_value(data,
                       VIA686A_REG_ALARM1) |
            (via686a_read_value(data, VIA686A_REG_ALARM2) << 8);
        data->last_updated = jiffies;
        data->valid = 1;
    }

    mutex_unlock(&data->update_lock);

    return data;
}

static DEFINE_PCI_DEVICE_TABLE(via686a_pci_ids) = {
    { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4) },
    { }
};
MODULE_DEVICE_TABLE(pci, via686a_pci_ids);

static int __devinit via686a_device_add(unsigned short address)
{
    struct resource res = {
        .start  = address,
        .end    = address + VIA686A_EXTENT - 1,
        .name   = "via686a",
        .flags  = IORESOURCE_IO,
    };
    int err;

    err = acpi_check_resource_conflict(&res);
    if (err)
        goto exit;

    pdev = platform_device_alloc("via686a", 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 via686a_pci_probe(struct pci_dev *dev,
                       const struct pci_device_id *id)
{
    u16 address, val;

    if (force_addr) {
        address = force_addr & ~(VIA686A_EXTENT - 1);
        dev_warn(&dev->dev, "Forcing ISA address 0x%x\n", address);
        if (PCIBIOS_SUCCESSFUL !=
            pci_write_config_word(dev, VIA686A_BASE_REG, address | 1))
            return -ENODEV;
    }
    if (PCIBIOS_SUCCESSFUL !=
        pci_read_config_word(dev, VIA686A_BASE_REG, &val))
        return -ENODEV;

    address = val & ~(VIA686A_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, VIA686A_ENABLE_REG, &val))
        return -ENODEV;
    if (!(val & 0x0001)) {
        if (!force_addr) {
            dev_warn(&dev->dev, "Sensors disabled, enable "
                 "with force_addr=0x%x\n", address);
            return -ENODEV;
        }

        dev_warn(&dev->dev, "Enabling sensors\n");
        if (PCIBIOS_SUCCESSFUL !=
            pci_write_config_word(dev, VIA686A_ENABLE_REG,
                      val | 0x0001))
            return -ENODEV;
    }

    if (platform_driver_register(&via686a_driver))
        goto exit;

    /* Sets global pdev as a side effect */
    if (via686a_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.
     */
    s_bridge = pci_dev_get(dev);
    return -ENODEV;

exit_unregister:
    platform_driver_unregister(&via686a_driver);
exit:
    return -ENODEV;
}

static struct pci_driver via686a_pci_driver = {
    .name       = "via686a",
    .id_table   = via686a_pci_ids,
    .probe      = via686a_pci_probe,
};

static int __init sm_via686a_init(void)
{
    return pci_register_driver(&via686a_pci_driver);
}

static void __exit sm_via686a_exit(void)
{
    pci_unregister_driver(&via686a_pci_driver);
    if (s_bridge != NULL) {
        platform_device_unregister(pdev);
        platform_driver_unregister(&via686a_driver);
        pci_dev_put(s_bridge);
        s_bridge = NULL;
    }
}

MODULE_AUTHOR("Kyösti Mälkki <[email protected]>, "
          "Mark Studebaker <[email protected]> "
          "and Bob Dougherty <[email protected]>");
MODULE_DESCRIPTION("VIA 686A Sensor device");
MODULE_LICENSE("GPL");

module_init(sm_via686a_init);
module_exit(sm_via686a_exit);