Linux v2.6.18-rc5

[pohmelfs.git] / drivers / hwmon / asb100.c

/*
    asb100.c - Part of lm_sensors, Linux kernel modules for hardware
                monitoring

    Copyright (C) 2004 Mark M. Hoffman <mhoffman@lightlink.com>

        (derived from w83781d.c)

    Copyright (C) 1998 - 2003  Frodo Looijaard <frodol@dds.nl>,
    Philip Edelbrock <phil@netroedge.com>, and
    Mark Studebaker <mdsxyz123@yahoo.com>

    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.
*/

/*
    This driver supports the hardware sensor chips: Asus ASB100 and
    ASB100-A "BACH".

    ASB100-A supports pwm1, while plain ASB100 does not.  There is no known
    way for the driver to tell which one is there.

    Chip        #vin    #fanin  #pwm    #temp   wchipid vendid  i2c     ISA
    asb100      7       3       1       4       0x31    0x0694  yes     no
*/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-vid.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/mutex.h>
#include "lm75.h"

/*
        HISTORY:
        2003-12-29      1.0.0   Ported from lm_sensors project for kernel 2.6
*/
#define ASB100_VERSION "1.0.0"

/* I2C addresses to scan */
static unsigned short normal_i2c[] = { 0x2d, I2C_CLIENT_END };

/* Insmod parameters */
I2C_CLIENT_INSMOD_1(asb100);
I2C_CLIENT_MODULE_PARM(force_subclients, "List of subclient addresses: "
        "{bus, clientaddr, subclientaddr1, subclientaddr2}");

/* Voltage IN registers 0-6 */
#define ASB100_REG_IN(nr)       (0x20 + (nr))
#define ASB100_REG_IN_MAX(nr)   (0x2b + (nr * 2))
#define ASB100_REG_IN_MIN(nr)   (0x2c + (nr * 2))

/* FAN IN registers 1-3 */
#define ASB100_REG_FAN(nr)      (0x28 + (nr))
#define ASB100_REG_FAN_MIN(nr)  (0x3b + (nr))

/* TEMPERATURE registers 1-4 */
static const u16 asb100_reg_temp[]      = {0, 0x27, 0x150, 0x250, 0x17};
static const u16 asb100_reg_temp_max[]  = {0, 0x39, 0x155, 0x255, 0x18};
static const u16 asb100_reg_temp_hyst[] = {0, 0x3a, 0x153, 0x253, 0x19};

#define ASB100_REG_TEMP(nr) (asb100_reg_temp[nr])
#define ASB100_REG_TEMP_MAX(nr) (asb100_reg_temp_max[nr])
#define ASB100_REG_TEMP_HYST(nr) (asb100_reg_temp_hyst[nr])

#define ASB100_REG_TEMP2_CONFIG 0x0152
#define ASB100_REG_TEMP3_CONFIG 0x0252


#define ASB100_REG_CONFIG       0x40
#define ASB100_REG_ALARM1       0x41
#define ASB100_REG_ALARM2       0x42
#define ASB100_REG_SMIM1        0x43
#define ASB100_REG_SMIM2        0x44
#define ASB100_REG_VID_FANDIV   0x47
#define ASB100_REG_I2C_ADDR     0x48
#define ASB100_REG_CHIPID       0x49
#define ASB100_REG_I2C_SUBADDR  0x4a
#define ASB100_REG_PIN          0x4b
#define ASB100_REG_IRQ          0x4c
#define ASB100_REG_BANK         0x4e
#define ASB100_REG_CHIPMAN      0x4f

#define ASB100_REG_WCHIPID      0x58

/* bit 7 -> enable, bits 0-3 -> duty cycle */
#define ASB100_REG_PWM1         0x59

/* CONVERSIONS
   Rounding and limit checking is only done on the TO_REG variants. */

/* These constants are a guess, consistent w/ w83781d */
#define ASB100_IN_MIN (   0)
#define ASB100_IN_MAX (4080)

/* IN: 1/1000 V (0V to 4.08V)
   REG: 16mV/bit */
static u8 IN_TO_REG(unsigned val)
{
        unsigned nval = SENSORS_LIMIT(val, ASB100_IN_MIN, ASB100_IN_MAX);
        return (nval + 8) / 16;
}

static unsigned IN_FROM_REG(u8 reg)
{
        return reg * 16;
}

static u8 FAN_TO_REG(long rpm, int div)
{
        if (rpm == -1)
                return 0;
        if (rpm == 0)
                return 255;
        rpm = SENSORS_LIMIT(rpm, 1, 1000000);
        return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
}

static int FAN_FROM_REG(u8 val, int div)
{
        return val==0 ? -1 : val==255 ? 0 : 1350000/(val*div);
}

/* These constants are a guess, consistent w/ w83781d */
#define ASB100_TEMP_MIN (-128000)
#define ASB100_TEMP_MAX ( 127000)

/* TEMP: 0.001C/bit (-128C to +127C)
   REG: 1C/bit, two's complement */
static u8 TEMP_TO_REG(int temp)
{
        int ntemp = SENSORS_LIMIT(temp, ASB100_TEMP_MIN, ASB100_TEMP_MAX);
        ntemp += (ntemp<0 ? -500 : 500);
        return (u8)(ntemp / 1000);
}

static int TEMP_FROM_REG(u8 reg)
{
        return (s8)reg * 1000;
}

/* PWM: 0 - 255 per sensors documentation
   REG: (6.25% duty cycle per bit) */
static u8 ASB100_PWM_TO_REG(int pwm)
{
        pwm = SENSORS_LIMIT(pwm, 0, 255);
        return (u8)(pwm / 16);
}

static int ASB100_PWM_FROM_REG(u8 reg)
{
        return reg * 16;
}

#define DIV_FROM_REG(val) (1 << (val))

/* FAN DIV: 1, 2, 4, or 8 (defaults to 2)
   REG: 0, 1, 2, or 3 (respectively) (defaults to 1) */
static u8 DIV_TO_REG(long val)
{
        return val==8 ? 3 : val==4 ? 2 : val==1 ? 0 : 1;
}

/* For each registered client, we need to keep some data in memory. That
   data is pointed to by client->data. The structure itself is
   dynamically allocated, at the same time the client itself is allocated. */
struct asb100_data {
        struct i2c_client client;
        struct class_device *class_dev;
        struct mutex lock;
        enum chips type;

        struct mutex update_lock;
        unsigned long last_updated;     /* In jiffies */

        /* array of 2 pointers to subclients */
        struct i2c_client *lm75[2];

        char valid;             /* !=0 if following fields are valid */
        u8 in[7];               /* Register value */
        u8 in_max[7];           /* Register value */
        u8 in_min[7];           /* Register value */
        u8 fan[3];              /* Register value */
        u8 fan_min[3];          /* Register value */
        u16 temp[4];            /* Register value (0 and 3 are u8 only) */
        u16 temp_max[4];        /* Register value (0 and 3 are u8 only) */
        u16 temp_hyst[4];       /* Register value (0 and 3 are u8 only) */
        u8 fan_div[3];          /* Register encoding, right justified */
        u8 pwm;                 /* Register encoding */
        u8 vid;                 /* Register encoding, combined */
        u32 alarms;             /* Register encoding, combined */
        u8 vrm;
};

static int asb100_read_value(struct i2c_client *client, u16 reg);
static void asb100_write_value(struct i2c_client *client, u16 reg, u16 val);

static int asb100_attach_adapter(struct i2c_adapter *adapter);
static int asb100_detect(struct i2c_adapter *adapter, int address, int kind);
static int asb100_detach_client(struct i2c_client *client);
static struct asb100_data *asb100_update_device(struct device *dev);
static void asb100_init_client(struct i2c_client *client);

static struct i2c_driver asb100_driver = {
        .driver = {
                .name   = "asb100",
        },
        .id             = I2C_DRIVERID_ASB100,
        .attach_adapter = asb100_attach_adapter,
        .detach_client  = asb100_detach_client,
};

/* 7 Voltages */
#define show_in_reg(reg) \
static ssize_t show_##reg (struct device *dev, char *buf, int nr) \
{ \
        struct asb100_data *data = asb100_update_device(dev); \
        return sprintf(buf, "%d\n", IN_FROM_REG(data->reg[nr])); \
}

show_in_reg(in)
show_in_reg(in_min)
show_in_reg(in_max)

#define set_in_reg(REG, reg) \
static ssize_t set_in_##reg(struct device *dev, const char *buf, \
                size_t count, int nr) \
{ \
        struct i2c_client *client = to_i2c_client(dev); \
        struct asb100_data *data = i2c_get_clientdata(client); \
        unsigned long val = simple_strtoul(buf, NULL, 10); \
 \
        mutex_lock(&data->update_lock); \
        data->in_##reg[nr] = IN_TO_REG(val); \
        asb100_write_value(client, ASB100_REG_IN_##REG(nr), \
                data->in_##reg[nr]); \
        mutex_unlock(&data->update_lock); \
        return count; \
}

set_in_reg(MIN, min)
set_in_reg(MAX, max)

#define sysfs_in(offset) \
static ssize_t \
        show_in##offset (struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_in(dev, buf, offset); \
} \
static DEVICE_ATTR(in##offset##_input, S_IRUGO, \
                show_in##offset, NULL); \
static ssize_t \
        show_in##offset##_min (struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_in_min(dev, buf, offset); \
} \
static ssize_t \
        show_in##offset##_max (struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_in_max(dev, buf, offset); \
} \
static ssize_t set_in##offset##_min (struct device *dev, struct device_attribute *attr, \
                const char *buf, size_t count) \
{ \
        return set_in_min(dev, buf, count, offset); \
} \
static ssize_t set_in##offset##_max (struct device *dev, struct device_attribute *attr, \
                const char *buf, size_t count) \
{ \
        return set_in_max(dev, buf, count, offset); \
} \
static DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR, \
                show_in##offset##_min, set_in##offset##_min); \
static DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR, \
                show_in##offset##_max, set_in##offset##_max);

sysfs_in(0);
sysfs_in(1);
sysfs_in(2);
sysfs_in(3);
sysfs_in(4);
sysfs_in(5);
sysfs_in(6);

#define device_create_file_in(client, offset) do { \
        device_create_file(&client->dev, &dev_attr_in##offset##_input); \
        device_create_file(&client->dev, &dev_attr_in##offset##_min); \
        device_create_file(&client->dev, &dev_attr_in##offset##_max); \
} while (0)

/* 3 Fans */
static ssize_t show_fan(struct device *dev, char *buf, int nr)
{
        struct asb100_data *data = asb100_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, char *buf, int nr)
{
        struct asb100_data *data = asb100_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, char *buf, int nr)
{
        struct asb100_data *data = asb100_update_device(dev);
        return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
}

static ssize_t set_fan_min(struct device *dev, const char *buf,
                                size_t count, int nr)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct asb100_data *data = i2c_get_clientdata(client);
        u32 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]));
        asb100_write_value(client, ASB100_REG_FAN_MIN(nr), data->fan_min[nr]);
        mutex_unlock(&data->update_lock);
        return count;
}

/* Note: we save and restore the fan minimum here, because its value is
   determined in part by the fan divisor.  This follows the principle of
   least surprise; the user doesn't expect the fan minimum to change just
   because the divisor changed. */
static ssize_t set_fan_div(struct device *dev, const char *buf,
                                size_t count, int nr)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct asb100_data *data = i2c_get_clientdata(client);
        unsigned long min;
        unsigned long val = simple_strtoul(buf, NULL, 10);
        int reg;
        
        mutex_lock(&data->update_lock);

        min = FAN_FROM_REG(data->fan_min[nr],
                        DIV_FROM_REG(data->fan_div[nr]));
        data->fan_div[nr] = DIV_TO_REG(val);

        switch(nr) {
        case 0: /* fan 1 */
                reg = asb100_read_value(client, ASB100_REG_VID_FANDIV);
                reg = (reg & 0xcf) | (data->fan_div[0] << 4);
                asb100_write_value(client, ASB100_REG_VID_FANDIV, reg);
                break;

        case 1: /* fan 2 */
                reg = asb100_read_value(client, ASB100_REG_VID_FANDIV);
                reg = (reg & 0x3f) | (data->fan_div[1] << 6);
                asb100_write_value(client, ASB100_REG_VID_FANDIV, reg);
                break;

        case 2: /* fan 3 */
                reg = asb100_read_value(client, ASB100_REG_PIN);
                reg = (reg & 0x3f) | (data->fan_div[2] << 6);
                asb100_write_value(client, ASB100_REG_PIN, reg);
                break;
        }

        data->fan_min[nr] =
                FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
        asb100_write_value(client, ASB100_REG_FAN_MIN(nr), data->fan_min[nr]);

        mutex_unlock(&data->update_lock);

        return count;
}

#define sysfs_fan(offset) \
static ssize_t show_fan##offset(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_fan(dev, buf, offset - 1); \
} \
static ssize_t show_fan##offset##_min(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_fan_min(dev, buf, offset - 1); \
} \
static ssize_t show_fan##offset##_div(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_fan_div(dev, buf, offset - 1); \
} \
static ssize_t set_fan##offset##_min(struct device *dev, struct device_attribute *attr, const char *buf, \
                                        size_t count) \
{ \
        return set_fan_min(dev, buf, count, offset - 1); \
} \
static ssize_t set_fan##offset##_div(struct device *dev, struct device_attribute *attr, const char *buf, \
                                        size_t count) \
{ \
        return set_fan_div(dev, buf, count, offset - 1); \
} \
static DEVICE_ATTR(fan##offset##_input, S_IRUGO, \
                show_fan##offset, NULL); \
static DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR, \
                show_fan##offset##_min, set_fan##offset##_min); \
static DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR, \
                show_fan##offset##_div, set_fan##offset##_div);

sysfs_fan(1);
sysfs_fan(2);
sysfs_fan(3);

#define device_create_file_fan(client, offset) do { \
        device_create_file(&client->dev, &dev_attr_fan##offset##_input); \
        device_create_file(&client->dev, &dev_attr_fan##offset##_min); \
        device_create_file(&client->dev, &dev_attr_fan##offset##_div); \
} while (0)

/* 4 Temp. Sensors */
static int sprintf_temp_from_reg(u16 reg, char *buf, int nr)
{
        int ret = 0;

        switch (nr) {
        case 1: case 2:
                ret = sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(reg));
                break;
        case 0: case 3: default:
                ret = sprintf(buf, "%d\n", TEMP_FROM_REG(reg));
                break;
        }
        return ret;
}
                        
#define show_temp_reg(reg) \
static ssize_t show_##reg(struct device *dev, char *buf, int nr) \
{ \
        struct asb100_data *data = asb100_update_device(dev); \
        return sprintf_temp_from_reg(data->reg[nr], buf, nr); \
}

show_temp_reg(temp);
show_temp_reg(temp_max);
show_temp_reg(temp_hyst);

#define set_temp_reg(REG, reg) \
static ssize_t set_##reg(struct device *dev, const char *buf, \
                        size_t count, int nr) \
{ \
        struct i2c_client *client = to_i2c_client(dev); \
        struct asb100_data *data = i2c_get_clientdata(client); \
        unsigned long val = simple_strtoul(buf, NULL, 10); \
 \
        mutex_lock(&data->update_lock); \
        switch (nr) { \
        case 1: case 2: \
                data->reg[nr] = LM75_TEMP_TO_REG(val); \
                break; \
        case 0: case 3: default: \
                data->reg[nr] = TEMP_TO_REG(val); \
                break; \
        } \
        asb100_write_value(client, ASB100_REG_TEMP_##REG(nr+1), \
                        data->reg[nr]); \
        mutex_unlock(&data->update_lock); \
        return count; \
}

set_temp_reg(MAX, temp_max);
set_temp_reg(HYST, temp_hyst);

#define sysfs_temp(num) \
static ssize_t show_temp##num(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_temp(dev, buf, num-1); \
} \
static DEVICE_ATTR(temp##num##_input, S_IRUGO, show_temp##num, NULL); \
static ssize_t show_temp_max##num(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_temp_max(dev, buf, num-1); \
} \
static ssize_t set_temp_max##num(struct device *dev, struct device_attribute *attr, const char *buf, \
                                        size_t count) \
{ \
        return set_temp_max(dev, buf, count, num-1); \
} \
static DEVICE_ATTR(temp##num##_max, S_IRUGO | S_IWUSR, \
                show_temp_max##num, set_temp_max##num); \
static ssize_t show_temp_hyst##num(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
        return show_temp_hyst(dev, buf, num-1); \
} \
static ssize_t set_temp_hyst##num(struct device *dev, struct device_attribute *attr, const char *buf, \
                                        size_t count) \
{ \
        return set_temp_hyst(dev, buf, count, num-1); \
} \
static DEVICE_ATTR(temp##num##_max_hyst, S_IRUGO | S_IWUSR, \
                show_temp_hyst##num, set_temp_hyst##num);

sysfs_temp(1);
sysfs_temp(2);
sysfs_temp(3);
sysfs_temp(4);

/* VID */
#define device_create_file_temp(client, num) do { \
        device_create_file(&client->dev, &dev_attr_temp##num##_input); \
        device_create_file(&client->dev, &dev_attr_temp##num##_max); \
        device_create_file(&client->dev, &dev_attr_temp##num##_max_hyst); \
} while (0)

static ssize_t show_vid(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct asb100_data *data = asb100_update_device(dev);
        return sprintf(buf, "%d\n", vid_from_reg(data->vid, data->vrm));
}

static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);
#define device_create_file_vid(client) \
device_create_file(&client->dev, &dev_attr_cpu0_vid)

/* VRM */
static ssize_t show_vrm(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct asb100_data *data = asb100_update_device(dev);
        return sprintf(buf, "%d\n", data->vrm);
}

static ssize_t set_vrm(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct asb100_data *data = i2c_get_clientdata(client);
        unsigned long val = simple_strtoul(buf, NULL, 10);
        data->vrm = val;
        return count;
}

/* Alarms */
static DEVICE_ATTR(vrm, S_IRUGO | S_IWUSR, show_vrm, set_vrm);
#define device_create_file_vrm(client) \
device_create_file(&client->dev, &dev_attr_vrm);

static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct asb100_data *data = asb100_update_device(dev);
        return sprintf(buf, "%u\n", data->alarms);
}

static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
#define device_create_file_alarms(client) \
device_create_file(&client->dev, &dev_attr_alarms)

/* 1 PWM */
static ssize_t show_pwm1(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct asb100_data *data = asb100_update_device(dev);
        return sprintf(buf, "%d\n", ASB100_PWM_FROM_REG(data->pwm & 0x0f));
}

static ssize_t set_pwm1(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct asb100_data *data = i2c_get_clientdata(client);
        unsigned long val = simple_strtoul(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->pwm &= 0x80; /* keep the enable bit */
        data->pwm |= (0x0f & ASB100_PWM_TO_REG(val));
        asb100_write_value(client, ASB100_REG_PWM1, data->pwm);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t show_pwm_enable1(struct device *dev, struct device_attribute *attr, char *buf)
{
        struct asb100_data *data = asb100_update_device(dev);
        return sprintf(buf, "%d\n", (data->pwm & 0x80) ? 1 : 0);
}

static ssize_t set_pwm_enable1(struct device *dev, struct device_attribute *attr, const char *buf,
                                size_t count)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct asb100_data *data = i2c_get_clientdata(client);
        unsigned long val = simple_strtoul(buf, NULL, 10);

        mutex_lock(&data->update_lock);
        data->pwm &= 0x0f; /* keep the duty cycle bits */
        data->pwm |= (val ? 0x80 : 0x00);
        asb100_write_value(client, ASB100_REG_PWM1, data->pwm);
        mutex_unlock(&data->update_lock);
        return count;
}

static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm1, set_pwm1);
static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
                show_pwm_enable1, set_pwm_enable1);
#define device_create_file_pwm1(client) do { \
        device_create_file(&new_client->dev, &dev_attr_pwm1); \
        device_create_file(&new_client->dev, &dev_attr_pwm1_enable); \
} while (0)

/* This function is called when:
        asb100_driver is inserted (when this module is loaded), for each
                available adapter
        when a new adapter is inserted (and asb100_driver is still present)
 */
static int asb100_attach_adapter(struct i2c_adapter *adapter)
{
        if (!(adapter->class & I2C_CLASS_HWMON))
                return 0;
        return i2c_probe(adapter, &addr_data, asb100_detect);
}

static int asb100_detect_subclients(struct i2c_adapter *adapter, int address,
                int kind, struct i2c_client *new_client)
{
        int i, id, err;
        struct asb100_data *data = i2c_get_clientdata(new_client);

        data->lm75[0] = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
        if (!(data->lm75[0])) {
                err = -ENOMEM;
                goto ERROR_SC_0;
        }

        data->lm75[1] = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
        if (!(data->lm75[1])) {
                err = -ENOMEM;
                goto ERROR_SC_1;
        }

        id = i2c_adapter_id(adapter);

        if (force_subclients[0] == id && force_subclients[1] == address) {
                for (i = 2; i <= 3; i++) {
                        if (force_subclients[i] < 0x48 ||
                            force_subclients[i] > 0x4f) {
                                dev_err(&new_client->dev, "invalid subclient "
                                        "address %d; must be 0x48-0x4f\n",
                                        force_subclients[i]);
                                err = -ENODEV;
                                goto ERROR_SC_2;
                        }
                }
                asb100_write_value(new_client, ASB100_REG_I2C_SUBADDR,
                                        (force_subclients[2] & 0x07) |
                                        ((force_subclients[3] & 0x07) <<4));
                data->lm75[0]->addr = force_subclients[2];
                data->lm75[1]->addr = force_subclients[3];
        } else {
                int val = asb100_read_value(new_client, ASB100_REG_I2C_SUBADDR);
                data->lm75[0]->addr = 0x48 + (val & 0x07);
                data->lm75[1]->addr = 0x48 + ((val >> 4) & 0x07);
        }

        if(data->lm75[0]->addr == data->lm75[1]->addr) {
                dev_err(&new_client->dev, "duplicate addresses 0x%x "
                                "for subclients\n", data->lm75[0]->addr);
                err = -ENODEV;
                goto ERROR_SC_2;
        }

        for (i = 0; i <= 1; i++) {
                i2c_set_clientdata(data->lm75[i], NULL);
                data->lm75[i]->adapter = adapter;
                data->lm75[i]->driver = &asb100_driver;
                data->lm75[i]->flags = 0;
                strlcpy(data->lm75[i]->name, "asb100 subclient", I2C_NAME_SIZE);
        }

        if ((err = i2c_attach_client(data->lm75[0]))) {
                dev_err(&new_client->dev, "subclient %d registration "
                        "at address 0x%x failed.\n", i, data->lm75[0]->addr);
                goto ERROR_SC_2;
        }

        if ((err = i2c_attach_client(data->lm75[1]))) {
                dev_err(&new_client->dev, "subclient %d registration "
                        "at address 0x%x failed.\n", i, data->lm75[1]->addr);
                goto ERROR_SC_3;
        }

        return 0;

/* Undo inits in case of errors */
ERROR_SC_3:
        i2c_detach_client(data->lm75[0]);
ERROR_SC_2:
        kfree(data->lm75[1]);
ERROR_SC_1:
        kfree(data->lm75[0]);
ERROR_SC_0:
        return err;
}

static int asb100_detect(struct i2c_adapter *adapter, int address, int kind)
{
        int err;
        struct i2c_client *new_client;
        struct asb100_data *data;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
                pr_debug("asb100.o: detect failed, "
                                "smbus byte data not supported!\n");
                err = -ENODEV;
                goto ERROR0;
        }

        /* OK. For now, we presume we have a valid client. We now create the
           client structure, even though we cannot fill it completely yet.
           But it allows us to access asb100_{read,write}_value. */

        if (!(data = kzalloc(sizeof(struct asb100_data), GFP_KERNEL))) {
                pr_debug("asb100.o: detect failed, kzalloc failed!\n");
                err = -ENOMEM;
                goto ERROR0;
        }

        new_client = &data->client;
        mutex_init(&data->lock);
        i2c_set_clientdata(new_client, data);
        new_client->addr = address;
        new_client->adapter = adapter;
        new_client->driver = &asb100_driver;
        new_client->flags = 0;

        /* Now, we do the remaining detection. */

        /* The chip may be stuck in some other bank than bank 0. This may
           make reading other information impossible. Specify a force=... or
           force_*=... parameter, and the chip will be reset to the right
           bank. */
        if (kind < 0) {

                int val1 = asb100_read_value(new_client, ASB100_REG_BANK);
                int val2 = asb100_read_value(new_client, ASB100_REG_CHIPMAN);

                /* If we're in bank 0 */
                if ( (!(val1 & 0x07)) &&
                                /* Check for ASB100 ID (low byte) */
                                ( ((!(val1 & 0x80)) && (val2 != 0x94)) ||
                                /* Check for ASB100 ID (high byte ) */
                                ((val1 & 0x80) && (val2 != 0x06)) ) ) {
                        pr_debug("asb100.o: detect failed, "
                                        "bad chip id 0x%02x!\n", val2);
                        err = -ENODEV;
                        goto ERROR1;
                }

        } /* kind < 0 */

        /* We have either had a force parameter, or we have already detected
           Winbond. Put it now into bank 0 and Vendor ID High Byte */
        asb100_write_value(new_client, ASB100_REG_BANK,
                (asb100_read_value(new_client, ASB100_REG_BANK) & 0x78) | 0x80);

        /* Determine the chip type. */
        if (kind <= 0) {
                int val1 = asb100_read_value(new_client, ASB100_REG_WCHIPID);
                int val2 = asb100_read_value(new_client, ASB100_REG_CHIPMAN);

                if ((val1 == 0x31) && (val2 == 0x06))
                        kind = asb100;
                else {
                        if (kind == 0)
                                dev_warn(&new_client->dev, "ignoring "
                                        "'force' parameter for unknown chip "
                                        "at adapter %d, address 0x%02x.\n",
                                        i2c_adapter_id(adapter), address);
                        err = -ENODEV;
                        goto ERROR1;
                }
        }

        /* Fill in remaining client fields and put it into the global list */
        strlcpy(new_client->name, "asb100", I2C_NAME_SIZE);
        data->type = kind;

        data->valid = 0;
        mutex_init(&data->update_lock);

        /* Tell the I2C layer a new client has arrived */
        if ((err = i2c_attach_client(new_client)))
                goto ERROR1;

        /* Attach secondary lm75 clients */
        if ((err = asb100_detect_subclients(adapter, address, kind,
                        new_client)))
                goto ERROR2;

        /* Initialize the chip */
        asb100_init_client(new_client);

        /* A few vars need to be filled upon startup */
        data->fan_min[0] = asb100_read_value(new_client, ASB100_REG_FAN_MIN(0));
        data->fan_min[1] = asb100_read_value(new_client, ASB100_REG_FAN_MIN(1));
        data->fan_min[2] = asb100_read_value(new_client, ASB100_REG_FAN_MIN(2));

        /* Register sysfs hooks */
        data->class_dev = hwmon_device_register(&new_client->dev);
        if (IS_ERR(data->class_dev)) {
                err = PTR_ERR(data->class_dev);
                goto ERROR3;
        }

        device_create_file_in(new_client, 0);
        device_create_file_in(new_client, 1);
        device_create_file_in(new_client, 2);
        device_create_file_in(new_client, 3);
        device_create_file_in(new_client, 4);
        device_create_file_in(new_client, 5);
        device_create_file_in(new_client, 6);

        device_create_file_fan(new_client, 1);
        device_create_file_fan(new_client, 2);
        device_create_file_fan(new_client, 3);

        device_create_file_temp(new_client, 1);
        device_create_file_temp(new_client, 2);
        device_create_file_temp(new_client, 3);
        device_create_file_temp(new_client, 4);

        device_create_file_vid(new_client);
        device_create_file_vrm(new_client);

        device_create_file_alarms(new_client);

        device_create_file_pwm1(new_client);

        return 0;

ERROR3:
        i2c_detach_client(data->lm75[1]);
        i2c_detach_client(data->lm75[0]);
        kfree(data->lm75[1]);
        kfree(data->lm75[0]);
ERROR2:
        i2c_detach_client(new_client);
ERROR1:
        kfree(data);
ERROR0:
        return err;
}

static int asb100_detach_client(struct i2c_client *client)
{
        struct asb100_data *data = i2c_get_clientdata(client);
        int err;

        /* main client */
        if (data)
                hwmon_device_unregister(data->class_dev);

        if ((err = i2c_detach_client(client)))
                return err;

        /* main client */
        if (data)
                kfree(data);

        /* subclient */
        else
                kfree(client);

        return 0;
}

/* The SMBus locks itself, usually, but nothing may access the chip between
   bank switches. */
static int asb100_read_value(struct i2c_client *client, u16 reg)
{
        struct asb100_data *data = i2c_get_clientdata(client);
        struct i2c_client *cl;
        int res, bank;

        mutex_lock(&data->lock);

        bank = (reg >> 8) & 0x0f;
        if (bank > 2)
                /* switch banks */
                i2c_smbus_write_byte_data(client, ASB100_REG_BANK, bank);

        if (bank == 0 || bank > 2) {
                res = i2c_smbus_read_byte_data(client, reg & 0xff);
        } else {
                /* switch to subclient */
                cl = data->lm75[bank - 1];

                /* convert from ISA to LM75 I2C addresses */
                switch (reg & 0xff) {
                case 0x50: /* TEMP */
                        res = swab16(i2c_smbus_read_word_data (cl, 0));
                        break;
                case 0x52: /* CONFIG */
                        res = i2c_smbus_read_byte_data(cl, 1);
                        break;
                case 0x53: /* HYST */
                        res = swab16(i2c_smbus_read_word_data (cl, 2));
                        break;
                case 0x55: /* MAX */
                default:
                        res = swab16(i2c_smbus_read_word_data (cl, 3));
                        break;
                }
        }

        if (bank > 2)
                i2c_smbus_write_byte_data(client, ASB100_REG_BANK, 0);

        mutex_unlock(&data->lock);

        return res;
}

static void asb100_write_value(struct i2c_client *client, u16 reg, u16 value)
{
        struct asb100_data *data = i2c_get_clientdata(client);
        struct i2c_client *cl;
        int bank;

        mutex_lock(&data->lock);

        bank = (reg >> 8) & 0x0f;
        if (bank > 2)
                /* switch banks */
                i2c_smbus_write_byte_data(client, ASB100_REG_BANK, bank);

        if (bank == 0 || bank > 2) {
                i2c_smbus_write_byte_data(client, reg & 0xff, value & 0xff);
        } else {
                /* switch to subclient */
                cl = data->lm75[bank - 1];

                /* convert from ISA to LM75 I2C addresses */
                switch (reg & 0xff) {
                case 0x52: /* CONFIG */
                        i2c_smbus_write_byte_data(cl, 1, value & 0xff);
                        break;
                case 0x53: /* HYST */
                        i2c_smbus_write_word_data(cl, 2, swab16(value));
                        break;
                case 0x55: /* MAX */
                        i2c_smbus_write_word_data(cl, 3, swab16(value));
                        break;
                }
        }

        if (bank > 2)
                i2c_smbus_write_byte_data(client, ASB100_REG_BANK, 0);

        mutex_unlock(&data->lock);
}

static void asb100_init_client(struct i2c_client *client)
{
        struct asb100_data *data = i2c_get_clientdata(client);
        int vid = 0;

        vid = asb100_read_value(client, ASB100_REG_VID_FANDIV) & 0x0f;
        vid |= (asb100_read_value(client, ASB100_REG_CHIPID) & 0x01) << 4;
        data->vrm = vid_which_vrm();
        vid = vid_from_reg(vid, data->vrm);

        /* Start monitoring */
        asb100_write_value(client, ASB100_REG_CONFIG, 
                (asb100_read_value(client, ASB100_REG_CONFIG) & 0xf7) | 0x01);
}

static struct asb100_data *asb100_update_device(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct asb100_data *data = i2c_get_clientdata(client);
        int i;

        mutex_lock(&data->update_lock);

        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
                || !data->valid) {

                dev_dbg(&client->dev, "starting device update...\n");

                /* 7 voltage inputs */
                for (i = 0; i < 7; i++) {
                        data->in[i] = asb100_read_value(client,
                                ASB100_REG_IN(i));
                        data->in_min[i] = asb100_read_value(client,
                                ASB100_REG_IN_MIN(i));
                        data->in_max[i] = asb100_read_value(client,
                                ASB100_REG_IN_MAX(i));
                }

                /* 3 fan inputs */
                for (i = 0; i < 3; i++) {
                        data->fan[i] = asb100_read_value(client,
                                        ASB100_REG_FAN(i));
                        data->fan_min[i] = asb100_read_value(client,
                                        ASB100_REG_FAN_MIN(i));
                }

                /* 4 temperature inputs */
                for (i = 1; i <= 4; i++) {
                        data->temp[i-1] = asb100_read_value(client,
                                        ASB100_REG_TEMP(i));
                        data->temp_max[i-1] = asb100_read_value(client,
                                        ASB100_REG_TEMP_MAX(i));
                        data->temp_hyst[i-1] = asb100_read_value(client,
                                        ASB100_REG_TEMP_HYST(i));
                }

                /* VID and fan divisors */
                i = asb100_read_value(client, ASB100_REG_VID_FANDIV);
                data->vid = i & 0x0f;
                data->vid |= (asb100_read_value(client,
                                ASB100_REG_CHIPID) & 0x01) << 4;
                data->fan_div[0] = (i >> 4) & 0x03;
                data->fan_div[1] = (i >> 6) & 0x03;
                data->fan_div[2] = (asb100_read_value(client,
                                ASB100_REG_PIN) >> 6) & 0x03;

                /* PWM */
                data->pwm = asb100_read_value(client, ASB100_REG_PWM1);

                /* alarms */
                data->alarms = asb100_read_value(client, ASB100_REG_ALARM1) +
                        (asb100_read_value(client, ASB100_REG_ALARM2) << 8);

                data->last_updated = jiffies;
                data->valid = 1;

                dev_dbg(&client->dev, "... device update complete\n");
        }

        mutex_unlock(&data->update_lock);

        return data;
}

static int __init asb100_init(void)
{
        return i2c_add_driver(&asb100_driver);
}

static void __exit asb100_exit(void)
{
        i2c_del_driver(&asb100_driver);
}

MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
MODULE_DESCRIPTION("ASB100 Bach driver");
MODULE_LICENSE("GPL");

module_init(asb100_init);
module_exit(asb100_exit);