/*
 * asc7621.c - Part of lm_sensors, Linux kernel modules for hardware monitoring
 * Copyright (c) 2007, 2010 George Joseph  <george.joseph@fairview5.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.
 */

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

/* Addresses to scan */
static const unsigned short normal_i2c[] = {
        0x2c, 0x2d, 0x2e, I2C_CLIENT_END
};

enum asc7621_type {
        asc7621,
        asc7621a
};

#define INTERVAL_HIGH   (HZ + HZ / 2)
#define INTERVAL_LOW    (1 * 60 * HZ)
#define PRI_NONE        0
#define PRI_LOW         1
#define PRI_HIGH        2
#define FIRST_CHIP      asc7621
#define LAST_CHIP       asc7621a

struct asc7621_chip {
        char *name;
        enum asc7621_type chip_type;
        u8 company_reg;
        u8 company_id;
        u8 verstep_reg;
        u8 verstep_id;
        const unsigned short *addresses;
};

static struct asc7621_chip asc7621_chips[] = {
        {
                .name = "asc7621",
                .chip_type = asc7621,
                .company_reg = 0x3e,
                .company_id = 0x61,
                .verstep_reg = 0x3f,
                .verstep_id = 0x6c,
                .addresses = normal_i2c,
         },
        {
                .name = "asc7621a",
                .chip_type = asc7621a,
                .company_reg = 0x3e,
                .company_id = 0x61,
                .verstep_reg = 0x3f,
                .verstep_id = 0x6d,
                .addresses = normal_i2c,
         },
};

/*
 * Defines the highest register to be used, not the count.
 * The actual count will probably be smaller because of gaps
 * in the implementation (unused register locations).
 * This define will safely set the array size of both the parameter
 * and data arrays.
 * This comes from the data sheet register description table.
 */
#define LAST_REGISTER 0xff

struct asc7621_data {
        struct i2c_client client;
        struct device *class_dev;
        struct mutex update_lock;
        int valid;              /* !=0 if following fields are valid */
        unsigned long last_high_reading;        /* In jiffies */
        unsigned long last_low_reading;         /* In jiffies */
        /*
         * Registers we care about occupy the corresponding index
         * in the array.  Registers we don't care about are left
         * at 0.
         */
        u8 reg[LAST_REGISTER + 1];
};

/*
 * Macro to get the parent asc7621_param structure
 * from a sensor_device_attribute passed into the
 * show/store functions.
 */
#define to_asc7621_param(_sda) \
        container_of(_sda, struct asc7621_param, sda)

/*
 * Each parameter to be retrieved needs an asc7621_param structure
 * allocated.  It contains the sensor_device_attribute structure
 * and the control info needed to retrieve the value from the register map.
 */
struct asc7621_param {
        struct sensor_device_attribute sda;
        u8 priority;
        u8 msb[3];
        u8 lsb[3];
        u8 mask[3];
        u8 shift[3];
};

/*
 * This is the map that ultimately indicates whether we'll be
 * retrieving a register value or not, and at what frequency.
 */
static u8 asc7621_register_priorities[255];

static struct asc7621_data *asc7621_update_device(struct device *dev);

static inline u8 read_byte(struct i2c_client *client, u8 reg)
{
        int res = i2c_smbus_read_byte_data(client, reg);
        if (res < 0) {
                dev_err(&client->dev,
                        "Unable to read from register 0x%02x.\n", reg);
                return 0;
        }
        return res & 0xff;
}

static inline int write_byte(struct i2c_client *client, u8 reg, u8 data)
{
        int res = i2c_smbus_write_byte_data(client, reg, data);
        if (res < 0) {
                dev_err(&client->dev,
                        "Unable to write value 0x%02x to register 0x%02x.\n",
                        data, reg);
        }
        return res;
}

/*
 * Data Handlers
 * Each function handles the formatting, storage
 * and retrieval of like parameters.
 */

#define SETUP_SHOW_DATA_PARAM(d, a) \
        struct sensor_device_attribute *sda = to_sensor_dev_attr(a); \
        struct asc7621_data *data = asc7621_update_device(d); \
        struct asc7621_param *param = to_asc7621_param(sda)

#define SETUP_STORE_DATA_PARAM(d, a) \
        struct sensor_device_attribute *sda = to_sensor_dev_attr(a); \
        struct i2c_client *client = to_i2c_client(d); \
        struct asc7621_data *data = i2c_get_clientdata(client); \
        struct asc7621_param *param = to_asc7621_param(sda)

/*
 * u8 is just what it sounds like...an unsigned byte with no
 * special formatting.
 */
static ssize_t show_u8(struct device *dev, struct device_attribute *attr,
                       char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);

        return sprintf(buf, "%u\n", data->reg[param->msb[0]]);
}

static ssize_t store_u8(struct device *dev, struct device_attribute *attr,
                        const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        reqval = clamp_val(reqval, 0, 255);

        mutex_lock(&data->update_lock);
        data->reg[param->msb[0]] = reqval;
        write_byte(client, param->msb[0], reqval);
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * Many of the config values occupy only a few bits of a register.
 */
static ssize_t show_bitmask(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);

        return sprintf(buf, "%u\n",
                       (data->reg[param->msb[0]] >> param->
                        shift[0]) & param->mask[0]);
}

static ssize_t store_bitmask(struct device *dev,
                             struct device_attribute *attr,
                             const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;
        u8 currval;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        reqval = clamp_val(reqval, 0, param->mask[0]);

        reqval = (reqval & param->mask[0]) << param->shift[0];

        mutex_lock(&data->update_lock);
        currval = read_byte(client, param->msb[0]);
        reqval |= (currval & ~(param->mask[0] << param->shift[0]));
        data->reg[param->msb[0]] = reqval;
        write_byte(client, param->msb[0], reqval);
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * 16 bit fan rpm values
 * reported by the device as the number of 11.111us periods (90khz)
 * between full fan rotations.  Therefore...
 * RPM = (90000 * 60) / register value
 */
static ssize_t show_fan16(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u16 regval;

        mutex_lock(&data->update_lock);
        regval = (data->reg[param->msb[0]] << 8) | data->reg[param->lsb[0]];
        mutex_unlock(&data->update_lock);

        return sprintf(buf, "%u\n",
                       (regval == 0 ? -1 : (regval) ==
                        0xffff ? 0 : 5400000 / regval));
}

static ssize_t store_fan16(struct device *dev,
                           struct device_attribute *attr, const char *buf,
                           size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        /*
         * If a minimum RPM of zero is requested, then we set the register to
         * 0xffff. This value allows the fan to be stopped completely without
         * generating an alarm.
         */
        reqval =
            (reqval <= 0 ? 0xffff : clamp_val(5400000 / reqval, 0, 0xfffe));

        mutex_lock(&data->update_lock);
        data->reg[param->msb[0]] = (reqval >> 8) & 0xff;
        data->reg[param->lsb[0]] = reqval & 0xff;
        write_byte(client, param->msb[0], data->reg[param->msb[0]]);
        write_byte(client, param->lsb[0], data->reg[param->lsb[0]]);
        mutex_unlock(&data->update_lock);

        return count;
}

/*
 * Voltages are scaled in the device so that the nominal voltage
 * is 3/4ths of the 0-255 range (i.e. 192).
 * If all voltages are 'normal' then all voltage registers will
 * read 0xC0.
 *
 * The data sheet provides us with the 3/4 scale value for each voltage
 * which is stored in in_scaling.  The sda->index parameter value provides
 * the index into in_scaling.
 *
 * NOTE: The chip expects the first 2 inputs be 2.5 and 2.25 volts
 * respectively. That doesn't mean that's what the motherboard provides. :)
 */

static const int asc7621_in_scaling[] = {
        2500, 2250, 3300, 5000, 12000
};

static ssize_t show_in10(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u16 regval;
        u8 nr = sda->index;

        mutex_lock(&data->update_lock);
        regval = (data->reg[param->msb[0]] << 8) | (data->reg[param->lsb[0]]);
        mutex_unlock(&data->update_lock);

        /* The LSB value is a 2-bit scaling of the MSB's LSbit value. */
        regval = (regval >> 6) * asc7621_in_scaling[nr] / (0xc0 << 2);

        return sprintf(buf, "%u\n", regval);
}

/* 8 bit voltage values (the mins and maxs) */
static ssize_t show_in8(struct device *dev, struct device_attribute *attr,
                        char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 nr = sda->index;

        return sprintf(buf, "%u\n",
                       ((data->reg[param->msb[0]] *
                         asc7621_in_scaling[nr]) / 0xc0));
}

static ssize_t store_in8(struct device *dev, struct device_attribute *attr,
                         const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;
        u8 nr = sda->index;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        reqval = clamp_val(reqval, 0, 0xffff);

        reqval = reqval * 0xc0 / asc7621_in_scaling[nr];

        reqval = clamp_val(reqval, 0, 0xff);

        mutex_lock(&data->update_lock);
        data->reg[param->msb[0]] = reqval;
        write_byte(client, param->msb[0], reqval);
        mutex_unlock(&data->update_lock);

        return count;
}

static ssize_t show_temp8(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);

        return sprintf(buf, "%d\n", ((s8) data->reg[param->msb[0]]) * 1000);
}

static ssize_t store_temp8(struct device *dev,
                           struct device_attribute *attr, const char *buf,
                           size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;
        s8 temp;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        reqval = clamp_val(reqval, -127000, 127000);

        temp = reqval / 1000;

        mutex_lock(&data->update_lock);
        data->reg[param->msb[0]] = temp;
        write_byte(client, param->msb[0], temp);
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * Temperatures that occupy 2 bytes always have the whole
 * number of degrees in the MSB with some part of the LSB
 * indicating fractional degrees.
 */

/*   mmmmmmmm.llxxxxxx */
static ssize_t show_temp10(struct device *dev,
                           struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 msb, lsb;
        int temp;

        mutex_lock(&data->update_lock);
        msb = data->reg[param->msb[0]];
        lsb = (data->reg[param->lsb[0]] >> 6) & 0x03;
        temp = (((s8) msb) * 1000) + (lsb * 250);
        mutex_unlock(&data->update_lock);

        return sprintf(buf, "%d\n", temp);
}

/*   mmmmmm.ll */
static ssize_t show_temp62(struct device *dev,
                           struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 regval = data->reg[param->msb[0]];
        int temp = ((s8) (regval & 0xfc) * 1000) + ((regval & 0x03) * 250);

        return sprintf(buf, "%d\n", temp);
}

static ssize_t store_temp62(struct device *dev,
                            struct device_attribute *attr, const char *buf,
                            size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval, i, f;
        s8 temp;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        reqval = clamp_val(reqval, -32000, 31750);
        i = reqval / 1000;
        f = reqval - (i * 1000);
        temp = i << 2;
        temp |= f / 250;

        mutex_lock(&data->update_lock);
        data->reg[param->msb[0]] = temp;
        write_byte(client, param->msb[0], temp);
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * The aSC7621 doesn't provide an "auto_point2".  Instead, you
 * specify the auto_point1 and a range.  To keep with the sysfs
 * hwmon specs, we synthesize the auto_point_2 from them.
 */

static const u32 asc7621_range_map[] = {
        2000, 2500, 3330, 4000, 5000, 6670, 8000, 10000,
        13330, 16000, 20000, 26670, 32000, 40000, 53330, 80000,
};

static ssize_t show_ap2_temp(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        long auto_point1;
        u8 regval;
        int temp;

        mutex_lock(&data->update_lock);
        auto_point1 = ((s8) data->reg[param->msb[1]]) * 1000;
        regval =
            ((data->reg[param->msb[0]] >> param->shift[0]) & param->mask[0]);
        temp = auto_point1 + asc7621_range_map[clamp_val(regval, 0, 15)];
        mutex_unlock(&data->update_lock);

        return sprintf(buf, "%d\n", temp);

}

static ssize_t store_ap2_temp(struct device *dev,
                              struct device_attribute *attr,
                              const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval, auto_point1;
        int i;
        u8 currval, newval = 0;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        mutex_lock(&data->update_lock);
        auto_point1 = data->reg[param->msb[1]] * 1000;
        reqval = clamp_val(reqval, auto_point1 + 2000, auto_point1 + 80000);

        for (i = ARRAY_SIZE(asc7621_range_map) - 1; i >= 0; i--) {
                if (reqval >= auto_point1 + asc7621_range_map[i]) {
                        newval = i;
                        break;
                }
        }

        newval = (newval & param->mask[0]) << param->shift[0];
        currval = read_byte(client, param->msb[0]);
        newval |= (currval & ~(param->mask[0] << param->shift[0]));
        data->reg[param->msb[0]] = newval;
        write_byte(client, param->msb[0], newval);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t show_pwm_ac(struct device *dev,
                           struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 config, altbit, regval;
        const u8 map[] = {
                0x01, 0x02, 0x04, 0x1f, 0x00, 0x06, 0x07, 0x10,
                0x08, 0x0f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f
        };

        mutex_lock(&data->update_lock);
        config = (data->reg[param->msb[0]] >> param->shift[0]) & param->mask[0];
        altbit = (data->reg[param->msb[1]] >> param->shift[1]) & param->mask[1];
        regval = config | (altbit << 3);
        mutex_unlock(&data->update_lock);

        return sprintf(buf, "%u\n", map[clamp_val(regval, 0, 15)]);
}

static ssize_t store_pwm_ac(struct device *dev,
                            struct device_attribute *attr,
                            const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        unsigned long reqval;
        u8 currval, config, altbit, newval;
        const u16 map[] = {
                0x04, 0x00, 0x01, 0xff, 0x02, 0xff, 0x05, 0x06,
                0x08, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x0f,
                0x07, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x03,
        };

        if (kstrtoul(buf, 10, &reqval))
                return -EINVAL;

        if (reqval > 31)
                return -EINVAL;

        reqval = map[reqval];
        if (reqval == 0xff)
                return -EINVAL;

        config = reqval & 0x07;
        altbit = (reqval >> 3) & 0x01;

        config = (config & param->mask[0]) << param->shift[0];
        altbit = (altbit & param->mask[1]) << param->shift[1];

        mutex_lock(&data->update_lock);
        currval = read_byte(client, param->msb[0]);
        newval = config | (currval & ~(param->mask[0] << param->shift[0]));
        newval = altbit | (newval & ~(param->mask[1] << param->shift[1]));
        data->reg[param->msb[0]] = newval;
        write_byte(client, param->msb[0], newval);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t show_pwm_enable(struct device *dev,
                               struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 config, altbit, minoff, val, newval;

        mutex_lock(&data->update_lock);
        config = (data->reg[param->msb[0]] >> param->shift[0]) & param->mask[0];
        altbit = (data->reg[param->msb[1]] >> param->shift[1]) & param->mask[1];
        minoff = (data->reg[param->msb[2]] >> param->shift[2]) & param->mask[2];
        mutex_unlock(&data->update_lock);

        val = config | (altbit << 3);
        newval = 0;

        if (val == 3 || val >= 10)
                newval = 255;
        else if (val == 4)
                newval = 0;
        else if (val == 7)
                newval = 1;
        else if (minoff == 1)
                newval = 2;
        else
                newval = 3;

        return sprintf(buf, "%u\n", newval);
}

static ssize_t store_pwm_enable(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;
        u8 currval, config, altbit, newval, minoff = 255;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        switch (reqval) {
        case 0:
                newval = 0x04;
                break;
        case 1:
                newval = 0x07;
                break;
        case 2:
                newval = 0x00;
                minoff = 1;
                break;
        case 3:
                newval = 0x00;
                minoff = 0;
                break;
        case 255:
                newval = 0x03;
                break;
        default:
                return -EINVAL;
        }

        config = newval & 0x07;
        altbit = (newval >> 3) & 0x01;

        mutex_lock(&data->update_lock);
        config = (config & param->mask[0]) << param->shift[0];
        altbit = (altbit & param->mask[1]) << param->shift[1];
        currval = read_byte(client, param->msb[0]);
        newval = config | (currval & ~(param->mask[0] << param->shift[0]));
        newval = altbit | (newval & ~(param->mask[1] << param->shift[1]));
        data->reg[param->msb[0]] = newval;
        write_byte(client, param->msb[0], newval);
        if (minoff < 255) {
                minoff = (minoff & param->mask[2]) << param->shift[2];
                currval = read_byte(client, param->msb[2]);
                newval =
                    minoff | (currval & ~(param->mask[2] << param->shift[2]));
                data->reg[param->msb[2]] = newval;
                write_byte(client, param->msb[2], newval);
        }
        mutex_unlock(&data->update_lock);
        return count;
}

static const u32 asc7621_pwm_freq_map[] = {
        10, 15, 23, 30, 38, 47, 62, 94,
        23000, 24000, 25000, 26000, 27000, 28000, 29000, 30000
};

static ssize_t show_pwm_freq(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 regval =
            (data->reg[param->msb[0]] >> param->shift[0]) & param->mask[0];

        regval = clamp_val(regval, 0, 15);

        return sprintf(buf, "%u\n", asc7621_pwm_freq_map[regval]);
}

static ssize_t store_pwm_freq(struct device *dev,
                              struct device_attribute *attr,
                              const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        unsigned long reqval;
        u8 currval, newval = 255;
        int i;

        if (kstrtoul(buf, 10, &reqval))
                return -EINVAL;

        for (i = 0; i < ARRAY_SIZE(asc7621_pwm_freq_map); i++) {
                if (reqval == asc7621_pwm_freq_map[i]) {
                        newval = i;
                        break;
                }
        }
        if (newval == 255)
                return -EINVAL;

        newval = (newval & param->mask[0]) << param->shift[0];

        mutex_lock(&data->update_lock);
        currval = read_byte(client, param->msb[0]);
        newval |= (currval & ~(param->mask[0] << param->shift[0]));
        data->reg[param->msb[0]] = newval;
        write_byte(client, param->msb[0], newval);
        mutex_unlock(&data->update_lock);
        return count;
}

static const u32 asc7621_pwm_auto_spinup_map[] =  {
        0, 100, 250, 400, 700, 1000, 2000, 4000
};

static ssize_t show_pwm_ast(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 regval =
            (data->reg[param->msb[0]] >> param->shift[0]) & param->mask[0];

        regval = clamp_val(regval, 0, 7);

        return sprintf(buf, "%u\n", asc7621_pwm_auto_spinup_map[regval]);

}

static ssize_t store_pwm_ast(struct device *dev,
                             struct device_attribute *attr,
                             const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;
        u8 currval, newval = 255;
        u32 i;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        for (i = 0; i < ARRAY_SIZE(asc7621_pwm_auto_spinup_map); i++) {
                if (reqval == asc7621_pwm_auto_spinup_map[i]) {
                        newval = i;
                        break;
                }
        }
        if (newval == 255)
                return -EINVAL;

        newval = (newval & param->mask[0]) << param->shift[0];

        mutex_lock(&data->update_lock);
        currval = read_byte(client, param->msb[0]);
        newval |= (currval & ~(param->mask[0] << param->shift[0]));
        data->reg[param->msb[0]] = newval;
        write_byte(client, param->msb[0], newval);
        mutex_unlock(&data->update_lock);
        return count;
}

static const u32 asc7621_temp_smoothing_time_map[] = {
        35000, 17600, 11800, 7000, 4400, 3000, 1600, 800
};

static ssize_t show_temp_st(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        SETUP_SHOW_DATA_PARAM(dev, attr);
        u8 regval =
            (data->reg[param->msb[0]] >> param->shift[0]) & param->mask[0];
        regval = clamp_val(regval, 0, 7);

        return sprintf(buf, "%u\n", asc7621_temp_smoothing_time_map[regval]);
}

static ssize_t store_temp_st(struct device *dev,
                             struct device_attribute *attr,
                             const char *buf, size_t count)
{
        SETUP_STORE_DATA_PARAM(dev, attr);
        long reqval;
        u8 currval, newval = 255;
        u32 i;

        if (kstrtol(buf, 10, &reqval))
                return -EINVAL;

        for (i = 0; i < ARRAY_SIZE(asc7621_temp_smoothing_time_map); i++) {
                if (reqval == asc7621_temp_smoothing_time_map[i]) {
                        newval = i;
                        break;
                }
        }

        if (newval == 255)
                return -EINVAL;

        newval = (newval & param->mask[0]) << param->shift[0];

        mutex_lock(&data->update_lock);
        currval = read_byte(client, param->msb[0]);
        newval |= (currval & ~(param->mask[0] << param->shift[0]));
        data->reg[param->msb[0]] = newval;
        write_byte(client, param->msb[0], newval);
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * End of data handlers
 *
 * These defines do nothing more than make the table easier
 * to read when wrapped at column 80.
 */

/*
 * Creates a variable length array inititalizer.
 * VAA(1,3,5,7) would produce {1,3,5,7}
 */
#define VAA(args...) {args}

#define PREAD(name, n, pri, rm, rl, m, s, r) \
        {.sda = SENSOR_ATTR(name, S_IRUGO, show_##r, NULL, n), \
          .priority = pri, .msb[0] = rm, .lsb[0] = rl, .mask[0] = m, \
          .shift[0] = s,}

#define PWRITE(name, n, pri, rm, rl, m, s, r) \
        {.sda = SENSOR_ATTR(name, S_IRUGO | S_IWUSR, show_##r, store_##r, n), \
          .priority = pri, .msb[0] = rm, .lsb[0] = rl, .mask[0] = m, \
          .shift[0] = s,}

/*
 * PWRITEM assumes that the initializers for the .msb, .lsb, .mask and .shift
 * were created using the VAA macro.
 */
#define PWRITEM(name, n, pri, rm, rl, m, s, r) \
        {.sda = SENSOR_ATTR(name, S_IRUGO | S_IWUSR, show_##r, store_##r, n), \
          .priority = pri, .msb = rm, .lsb = rl, .mask = m, .shift = s,}

static struct asc7621_param asc7621_params[] = {
        PREAD(in0_input, 0, PRI_HIGH, 0x20, 0x13, 0, 0, in10),
        PREAD(in1_input, 1, PRI_HIGH, 0x21, 0x18, 0, 0, in10),
        PREAD(in2_input, 2, PRI_HIGH, 0x22, 0x11, 0, 0, in10),
        PREAD(in3_input, 3, PRI_HIGH, 0x23, 0x12, 0, 0, in10),
        PREAD(in4_input, 4, PRI_HIGH, 0x24, 0x14, 0, 0, in10),

        PWRITE(in0_min, 0, PRI_LOW, 0x44, 0, 0, 0, in8),
        PWRITE(in1_min, 1, PRI_LOW, 0x46, 0, 0, 0, in8),
        PWRITE(in2_min, 2, PRI_LOW, 0x48, 0, 0, 0, in8),
        PWRITE(in3_min, 3, PRI_LOW, 0x4a, 0, 0, 0, in8),
        PWRITE(in4_min, 4, PRI_LOW, 0x4c, 0, 0, 0, in8),

        PWRITE(in0_max, 0, PRI_LOW, 0x45, 0, 0, 0, in8),
        PWRITE(in1_max, 1, PRI_LOW, 0x47, 0, 0, 0, in8),
        PWRITE(in2_max, 2, PRI_LOW, 0x49, 0, 0, 0, in8),
        PWRITE(in3_max, 3, PRI_LOW, 0x4b, 0, 0, 0, in8),
        PWRITE(in4_max, 4, PRI_LOW, 0x4d, 0, 0, 0, in8),

        PREAD(in0_alarm, 0, PRI_HIGH, 0x41, 0, 0x01, 0, bitmask),
        PREAD(in1_alarm, 1, PRI_HIGH, 0x41, 0, 0x01, 1, bitmask),
        PREAD(in2_alarm, 2, PRI_HIGH, 0x41, 0, 0x01, 2, bitmask),
        PREAD(in3_alarm, 3, PRI_HIGH, 0x41, 0, 0x01, 3, bitmask),
        PREAD(in4_alarm, 4, PRI_HIGH, 0x42, 0, 0x01, 0, bitmask),

        PREAD(fan1_input, 0, PRI_HIGH, 0x29, 0x28, 0, 0, fan16),
        PREAD(fan2_input, 1, PRI_HIGH, 0x2b, 0x2a, 0, 0, fan16),
        PREAD(fan3_input, 2, PRI_HIGH, 0x2d, 0x2c, 0, 0, fan16),
        PREAD(fan4_input, 3, PRI_HIGH, 0x2f, 0x2e, 0, 0, fan16),

        PWRITE(fan1_min, 0, PRI_LOW, 0x55, 0x54, 0, 0, fan16),
        PWRITE(fan2_min, 1, PRI_LOW, 0x57, 0x56, 0, 0, fan16),
        PWRITE(fan3_min, 2, PRI_LOW, 0x59, 0x58, 0, 0, fan16),
        PWRITE(fan4_min, 3, PRI_LOW, 0x5b, 0x5a, 0, 0, fan16),

        PREAD(fan1_alarm, 0, PRI_HIGH, 0x42, 0, 0x01, 2, bitmask),
        PREAD(fan2_alarm, 1, PRI_HIGH, 0x42, 0, 0x01, 3, bitmask),
        PREAD(fan3_alarm, 2, PRI_HIGH, 0x42, 0, 0x01, 4, bitmask),
        PREAD(fan4_alarm, 3, PRI_HIGH, 0x42, 0, 0x01, 5, bitmask),

        PREAD(temp1_input, 0, PRI_HIGH, 0x25, 0x10, 0, 0, temp10),
        PREAD(temp2_input, 1, PRI_HIGH, 0x26, 0x15, 0, 0, temp10),
        PREAD(temp3_input, 2, PRI_HIGH, 0x27, 0x16, 0, 0, temp10),
        PREAD(temp4_input, 3, PRI_HIGH, 0x33, 0x17, 0, 0, temp10),
        PREAD(temp5_input, 4, PRI_HIGH, 0xf7, 0xf6, 0, 0, temp10),
        PREAD(temp6_input, 5, PRI_HIGH, 0xf9, 0xf8, 0, 0, temp10),
        PREAD(temp7_input, 6, PRI_HIGH, 0xfb, 0xfa, 0, 0, temp10),
        PREAD(temp8_input, 7, PRI_HIGH, 0xfd, 0xfc, 0, 0, temp10),

        PWRITE(temp1_min, 0, PRI_LOW, 0x4e, 0, 0, 0, temp8),
        PWRITE(temp2_min, 1, PRI_LOW, 0x50, 0, 0, 0, temp8),
        PWRITE(temp3_min, 2, PRI_LOW, 0x52, 0, 0, 0, temp8),
        PWRITE(temp4_min, 3, PRI_LOW, 0x34, 0, 0, 0, temp8),

        PWRITE(temp1_max, 0, PRI_LOW, 0x4f, 0, 0, 0, temp8),
        PWRITE(temp2_max, 1, PRI_LOW, 0x51, 0, 0, 0, temp8),
        PWRITE(temp3_max, 2, PRI_LOW, 0x53, 0, 0, 0, temp8),
        PWRITE(temp4_max, 3, PRI_LOW, 0x35, 0, 0, 0, temp8),

        PREAD(temp1_alarm, 0, PRI_HIGH, 0x41, 0, 0x01, 4, bitmask),
        PREAD(temp2_alarm, 1, PRI_HIGH, 0x41, 0, 0x01, 5, bitmask),
        PREAD(temp3_alarm, 2, PRI_HIGH, 0x41, 0, 0x01, 6, bitmask),
        PREAD(temp4_alarm, 3, PRI_HIGH, 0x43, 0, 0x01, 0, bitmask),

        PWRITE(temp1_source, 0, PRI_LOW, 0x02, 0, 0x07, 4, bitmask),
        PWRITE(temp2_source, 1, PRI_LOW, 0x02, 0, 0x07, 0, bitmask),
        PWRITE(temp3_source, 2, PRI_LOW, 0x03, 0, 0x07, 4, bitmask),
        PWRITE(temp4_source, 3, PRI_LOW, 0x03, 0, 0x07, 0, bitmask),

        PWRITE(temp1_smoothing_enable, 0, PRI_LOW, 0x62, 0, 0x01, 3, bitmask),
        PWRITE(temp2_smoothing_enable, 1, PRI_LOW, 0x63, 0, 0x01, 7, bitmask),
        PWRITE(temp3_smoothing_enable, 2, PRI_LOW, 0x63, 0, 0x01, 3, bitmask),
        PWRITE(temp4_smoothing_enable, 3, PRI_LOW, 0x3c, 0, 0x01, 3, bitmask),

        PWRITE(temp1_smoothing_time, 0, PRI_LOW, 0x62, 0, 0x07, 0, temp_st),
        PWRITE(temp2_smoothing_time, 1, PRI_LOW, 0x63, 0, 0x07, 4, temp_st),
        PWRITE(temp3_smoothing_time, 2, PRI_LOW, 0x63, 0, 0x07, 0, temp_st),
        PWRITE(temp4_smoothing_time, 3, PRI_LOW, 0x3c, 0, 0x07, 0, temp_st),

        PWRITE(temp1_auto_point1_temp_hyst, 0, PRI_LOW, 0x6d, 0, 0x0f, 4,
               bitmask),
        PWRITE(temp2_auto_point1_temp_hyst, 1, PRI_LOW, 0x6d, 0, 0x0f, 0,
               bitmask),
        PWRITE(temp3_auto_point1_temp_hyst, 2, PRI_LOW, 0x6e, 0, 0x0f, 4,
               bitmask),
        PWRITE(temp4_auto_point1_temp_hyst, 3, PRI_LOW, 0x6e, 0, 0x0f, 0,
               bitmask),

        PREAD(temp1_auto_point2_temp_hyst, 0, PRI_LOW, 0x6d, 0, 0x0f, 4,
              bitmask),
        PREAD(temp2_auto_point2_temp_hyst, 1, PRI_LOW, 0x6d, 0, 0x0f, 0,
              bitmask),
        PREAD(temp3_auto_point2_temp_hyst, 2, PRI_LOW, 0x6e, 0, 0x0f, 4,
              bitmask),
        PREAD(temp4_auto_point2_temp_hyst, 3, PRI_LOW, 0x6e, 0, 0x0f, 0,
              bitmask),

        PWRITE(temp1_auto_point1_temp, 0, PRI_LOW, 0x67, 0, 0, 0, temp8),
        PWRITE(temp2_auto_point1_temp, 1, PRI_LOW, 0x68, 0, 0, 0, temp8),
        PWRITE(temp3_auto_point1_temp, 2, PRI_LOW, 0x69, 0, 0, 0, temp8),
        PWRITE(temp4_auto_point1_temp, 3, PRI_LOW, 0x3b, 0, 0, 0, temp8),

        PWRITEM(temp1_auto_point2_temp, 0, PRI_LOW, VAA(0x5f, 0x67), VAA(0),
                VAA(0x0f), VAA(4), ap2_temp),
        PWRITEM(temp2_auto_point2_temp, 1, PRI_LOW, VAA(0x60, 0x68), VAA(0),
                VAA(0x0f), VAA(4), ap2_temp),
        PWRITEM(temp3_auto_point2_temp, 2, PRI_LOW, VAA(0x61, 0x69), VAA(0),
                VAA(0x0f), VAA(4), ap2_temp),
        PWRITEM(temp4_auto_point2_temp, 3, PRI_LOW, VAA(0x3c, 0x3b), VAA(0),
                VAA(0x0f), VAA(4), ap2_temp),

        PWRITE(temp1_crit, 0, PRI_LOW, 0x6a, 0, 0, 0, temp8),
        PWRITE(temp2_crit, 1, PRI_LOW, 0x6b, 0, 0, 0, temp8),
        PWRITE(temp3_crit, 2, PRI_LOW, 0x6c, 0, 0, 0, temp8),
        PWRITE(temp4_crit, 3, PRI_LOW, 0x3d, 0, 0, 0, temp8),

        PWRITE(temp5_enable, 4, PRI_LOW, 0x0e, 0, 0x01, 0, bitmask),
        PWRITE(temp6_enable, 5, PRI_LOW, 0x0e, 0, 0x01, 1, bitmask),
        PWRITE(temp7_enable, 6, PRI_LOW, 0x0e, 0, 0x01, 2, bitmask),
        PWRITE(temp8_enable, 7, PRI_LOW, 0x0e, 0, 0x01, 3, bitmask),

        PWRITE(remote1_offset, 0, PRI_LOW, 0x1c, 0, 0, 0, temp62),
        PWRITE(remote2_offset, 1, PRI_LOW, 0x1d, 0, 0, 0, temp62),

        PWRITE(pwm1, 0, PRI_HIGH, 0x30, 0, 0, 0, u8),
        PWRITE(pwm2, 1, PRI_HIGH, 0x31, 0, 0, 0, u8),
        PWRITE(pwm3, 2, PRI_HIGH, 0x32, 0, 0, 0, u8),

        PWRITE(pwm1_invert, 0, PRI_LOW, 0x5c, 0, 0x01, 4, bitmask),
        PWRITE(pwm2_invert, 1, PRI_LOW, 0x5d, 0, 0x01, 4, bitmask),
        PWRITE(pwm3_invert, 2, PRI_LOW, 0x5e, 0, 0x01, 4, bitmask),

        PWRITEM(pwm1_enable, 0, PRI_LOW, VAA(0x5c, 0x5c, 0x62), VAA(0, 0, 0),
                VAA(0x07, 0x01, 0x01), VAA(5, 3, 5), pwm_enable),
        PWRITEM(pwm2_enable, 1, PRI_LOW, VAA(0x5d, 0x5d, 0x62), VAA(0, 0, 0),
                VAA(0x07, 0x01, 0x01), VAA(5, 3, 6), pwm_enable),
        PWRITEM(pwm3_enable, 2, PRI_LOW, VAA(0x5e, 0x5e, 0x62), VAA(0, 0, 0),
                VAA(0x07, 0x01, 0x01), VAA(5, 3, 7), pwm_enable),

        PWRITEM(pwm1_auto_channels, 0, PRI_LOW, VAA(0x5c, 0x5c), VAA(0, 0),
                VAA(0x07, 0x01), VAA(5, 3), pwm_ac),
        PWRITEM(pwm2_auto_channels, 1, PRI_LOW, VAA(0x5d, 0x5d), VAA(0, 0),
                VAA(0x07, 0x01), VAA(5, 3), pwm_ac),
        PWRITEM(pwm3_auto_channels, 2, PRI_LOW, VAA(0x5e, 0x5e), VAA(0, 0),
                VAA(0x07, 0x01), VAA(5, 3), pwm_ac),

        PWRITE(pwm1_auto_point1_pwm, 0, PRI_LOW, 0x64, 0, 0, 0, u8),
        PWRITE(pwm2_auto_point1_pwm, 1, PRI_LOW, 0x65, 0, 0, 0, u8),
        PWRITE(pwm3_auto_point1_pwm, 2, PRI_LOW, 0x66, 0, 0, 0, u8),

        PWRITE(pwm1_auto_point2_pwm, 0, PRI_LOW, 0x38, 0, 0, 0, u8),
        PWRITE(pwm2_auto_point2_pwm, 1, PRI_LOW, 0x39, 0, 0, 0, u8),
        PWRITE(pwm3_auto_point2_pwm, 2, PRI_LOW, 0x3a, 0, 0, 0, u8),

        PWRITE(pwm1_freq, 0, PRI_LOW, 0x5f, 0, 0x0f, 0, pwm_freq),
        PWRITE(pwm2_freq, 1, PRI_LOW, 0x60, 0, 0x0f, 0, pwm_freq),
        PWRITE(pwm3_freq, 2, PRI_LOW, 0x61, 0, 0x0f, 0, pwm_freq),

        PREAD(pwm1_auto_zone_assigned, 0, PRI_LOW, 0, 0, 0x03, 2, bitmask),
        PREAD(pwm2_auto_zone_assigned, 1, PRI_LOW, 0, 0, 0x03, 4, bitmask),
        PREAD(pwm3_auto_zone_assigned, 2, PRI_LOW, 0, 0, 0x03, 6, bitmask),

        PWRITE(pwm1_auto_spinup_time, 0, PRI_LOW, 0x5c, 0, 0x07, 0, pwm_ast),
        PWRITE(pwm2_auto_spinup_time, 1, PRI_LOW, 0x5d, 0, 0x07, 0, pwm_ast),
        PWRITE(pwm3_auto_spinup_time, 2, PRI_LOW, 0x5e, 0, 0x07, 0, pwm_ast),

        PWRITE(peci_enable, 0, PRI_LOW, 0x40, 0, 0x01, 4, bitmask),
        PWRITE(peci_avg, 0, PRI_LOW, 0x36, 0, 0x07, 0, bitmask),
        PWRITE(peci_domain, 0, PRI_LOW, 0x36, 0, 0x01, 3, bitmask),
        PWRITE(peci_legacy, 0, PRI_LOW, 0x36, 0, 0x01, 4, bitmask),

        PWRITE(peci_diode, 0, PRI_LOW, 0x0e, 0, 0x07, 4, bitmask),
        PWRITE(peci_4domain, 0, PRI_LOW, 0x0e, 0, 0x01, 4, bitmask),

};

static struct asc7621_data *asc7621_update_device(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct asc7621_data *data = i2c_get_clientdata(client);
        int i;

/*
 * The asc7621 chips guarantee consistent reads of multi-byte values
 * regardless of the order of the reads.  No special logic is needed
 * so we can just read the registers in whatever  order they appear
 * in the asc7621_params array.
 */

        mutex_lock(&data->update_lock);

        /* Read all the high priority registers */

        if (!data->valid ||
            time_after(jiffies, data->last_high_reading + INTERVAL_HIGH)) {

                for (i = 0; i < ARRAY_SIZE(asc7621_register_priorities); i++) {
                        if (asc7621_register_priorities[i] == PRI_HIGH) {
                                data->reg[i] =
                                    i2c_smbus_read_byte_data(client, i) & 0xff;
                        }
                }
                data->last_high_reading = jiffies;
        }                       /* last_reading */

        /* Read all the low priority registers. */

        if (!data->valid ||
            time_after(jiffies, data->last_low_reading + INTERVAL_LOW)) {

                for (i = 0; i < ARRAY_SIZE(asc7621_params); i++) {
                        if (asc7621_register_priorities[i] == PRI_LOW) {
                                data->reg[i] =
                                    i2c_smbus_read_byte_data(client, i) & 0xff;
                        }
                }
                data->last_low_reading = jiffies;
        }                       /* last_reading */

        data->valid = 1;

        mutex_unlock(&data->update_lock);

        return data;
}

/*
 * Standard detection and initialization below
 *
 * Helper function that checks if an address is valid
 * for a particular chip.
 */

static inline int valid_address_for_chip(int chip_type, int address)
{
        int i;

        for (i = 0; asc7621_chips[chip_type].addresses[i] != I2C_CLIENT_END;
             i++) {
                if (asc7621_chips[chip_type].addresses[i] == address)
                        return 1;
        }
        return 0;
}

static void asc7621_init_client(struct i2c_client *client)
{
        int value;

        /* Warn if part was not "READY" */

        value = read_byte(client, 0x40);

        if (value & 0x02) {
                dev_err(&client->dev,
                        "Client (%d,0x%02x) config is locked.\n",
                        i2c_adapter_id(client->adapter), client->addr);
        }
        if (!(value & 0x04)) {
                dev_err(&client->dev, "Client (%d,0x%02x) is not ready.\n",
                        i2c_adapter_id(client->adapter), client->addr);
        }

/*
 * Start monitoring
 *
 * Try to clear LOCK, Set START, save everything else
 */
        value = (value & ~0x02) | 0x01;
        write_byte(client, 0x40, value & 0xff);

}

static int
asc7621_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
        struct asc7621_data *data;
        int i, err;

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -EIO;

        data = devm_kzalloc(&client->dev, sizeof(struct asc7621_data),
                            GFP_KERNEL);
        if (data == NULL)
                return -ENOMEM;

        i2c_set_clientdata(client, data);
        mutex_init(&data->update_lock);

        /* Initialize the asc7621 chip */
        asc7621_init_client(client);

        /* Create the sysfs entries */
        for (i = 0; i < ARRAY_SIZE(asc7621_params); i++) {
                err =
                    device_create_file(&client->dev,
                                       &(asc7621_params[i].sda.dev_attr));
                if (err)
                        goto exit_remove;
        }

        data->class_dev = hwmon_device_register(&client->dev);
        if (IS_ERR(data->class_dev)) {
                err = PTR_ERR(data->class_dev);
                goto exit_remove;
        }

        return 0;

exit_remove:
        for (i = 0; i < ARRAY_SIZE(asc7621_params); i++) {
                device_remove_file(&client->dev,
                                   &(asc7621_params[i].sda.dev_attr));
        }

        return err;
}

static int asc7621_detect(struct i2c_client *client,
                          struct i2c_board_info *info)
{
        struct i2c_adapter *adapter = client->adapter;
        int company, verstep, chip_index;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        for (chip_index = FIRST_CHIP; chip_index <= LAST_CHIP; chip_index++) {

                if (!valid_address_for_chip(chip_index, client->addr))
                        continue;

                company = read_byte(client,
                        asc7621_chips[chip_index].company_reg);
                verstep = read_byte(client,
                        asc7621_chips[chip_index].verstep_reg);

                if (company == asc7621_chips[chip_index].company_id &&
                    verstep == asc7621_chips[chip_index].verstep_id) {
                        strlcpy(info->type, asc7621_chips[chip_index].name,
                                I2C_NAME_SIZE);

                        dev_info(&adapter->dev, "Matched %s at 0x%02x\n",
                                 asc7621_chips[chip_index].name, client->addr);
                        return 0;
                }
        }

        return -ENODEV;
}

static int asc7621_remove(struct i2c_client *client)
{
        struct asc7621_data *data = i2c_get_clientdata(client);
        int i;

        hwmon_device_unregister(data->class_dev);

        for (i = 0; i < ARRAY_SIZE(asc7621_params); i++) {
                device_remove_file(&client->dev,
                                   &(asc7621_params[i].sda.dev_attr));
        }

        return 0;
}

static const struct i2c_device_id asc7621_id[] = {
        {"asc7621", asc7621},
        {"asc7621a", asc7621a},
        {},
};

MODULE_DEVICE_TABLE(i2c, asc7621_id);

static struct i2c_driver asc7621_driver = {
        .class = I2C_CLASS_HWMON,
        .driver = {
                .name = "asc7621",
        },
        .probe = asc7621_probe,
        .remove = asc7621_remove,
        .id_table = asc7621_id,
        .detect = asc7621_detect,
        .address_list = normal_i2c,
};

static int __init sm_asc7621_init(void)
{
        int i, j;
/*
 * Collect all the registers needed into a single array.
 * This way, if a register isn't actually used for anything,
 * we don't retrieve it.
 */

        for (i = 0; i < ARRAY_SIZE(asc7621_params); i++) {
                for (j = 0; j < ARRAY_SIZE(asc7621_params[i].msb); j++)
                        asc7621_register_priorities[asc7621_params[i].msb[j]] =
                            asc7621_params[i].priority;
                for (j = 0; j < ARRAY_SIZE(asc7621_params[i].lsb); j++)
                        asc7621_register_priorities[asc7621_params[i].lsb[j]] =
                            asc7621_params[i].priority;
        }
        return i2c_add_driver(&asc7621_driver);
}

static void __exit sm_asc7621_exit(void)
{
        i2c_del_driver(&asc7621_driver);
}

MODULE_LICENSE("GPL");
MODULE_AUTHOR("George Joseph");
MODULE_DESCRIPTION("Andigilog aSC7621 and aSC7621a driver");

module_init(sm_asc7621_init);
module_exit(sm_asc7621_exit);