hwmon: Driver for Andigilog aSC7621 family monitoring chips

Hwmon driver for Andigilog aSC7621 family monitoring chips.

Signed-off-by: George Joseph <george.joseph@fairview5.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

3 files changed, 1269 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 77d032fb813d..b6d65aa20825 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -226,6 +226,19 @@ config SENSORS_ADT7475
           This driver can also be build as a module.  If so, the module
           will be called adt7475.
 
+config SENSORS_ASC7621
+        tristate "Andigilog aSC7621"
+        depends on HWMON && I2C
+        help
+          If you say yes here you get support for the aSC7621
+          family of SMBus sensors chip found on most Intel X48, X38, 975,
+          965 and 945 desktop boards.  Currently supported chips:
+          aSC7621
+          aSC7621a
+
+          This driver can also be built as a module.  If so, the module
+          will be called asc7621.
+
 config SENSORS_K8TEMP
         tristate "AMD Athlon64/FX or Opteron temperature sensor"
         depends on X86 && PCI && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 5fe67bf961b3..865da80f2b90 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_SENSORS_ADT7473)	+= adt7473.o
 obj-$(CONFIG_SENSORS_ADT7475)   += adt7475.o
 obj-$(CONFIG_SENSORS_APPLESMC)  += applesmc.o
 obj-$(CONFIG_SENSORS_AMS)       += ams/
+obj-$(CONFIG_SENSORS_ASC7621)   += asc7621.o
 obj-$(CONFIG_SENSORS_ATXP1)     += atxp1.o
 obj-$(CONFIG_SENSORS_CORETEMP)  += coretemp.o
 obj-$(CONFIG_SENSORS_DME1737)   += dme1737.o
diff --git a/drivers/hwmon/asc7621.c b/drivers/hwmon/asc7621.c
new file mode 100644
index 000000000000..7f948105d8ad
--- /dev/null
+++ b/drivers/hwmon/asc7621.c
@@ -0,0 +1,1255 @@
+/*
+ * 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 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;
+        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 (strict_strtol(buf, 10, &reqval))
+                return -EINVAL;
+
+        reqval = SENSORS_LIMIT(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 (strict_strtol(buf, 10, &reqval))
+                return -EINVAL;
+
+        reqval = SENSORS_LIMIT(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 (strict_strtol(buf, 10, &reqval))
+                return -EINVAL;
+
+        reqval =
+            (SENSORS_LIMIT((reqval) <= 0 ? 0 : 5400000 / (reqval), 0, 65534));
+
+        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.  This doesn't help us if we don't have a point of refernce.
+ * The data sheet however provides us with the full scale value for each
+ * 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 int asc7621_in_scaling[] = {
+        3320, 3000, 4380, 6640, 16000
+};
+
+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]] * asc7621_in_scaling[nr]) / 256;
+
+        /* The LSB value is a 2-bit scaling of the MSB's LSbit value.
+         * I.E.  If the maximim voltage for this input is 6640 millivolts then
+         * a MSB register value of 0 = 0mv and 255 = 6640mv.
+         * A 1 step change therefore represents 25.9mv (6640 / 256).
+         * The extra 2-bits therefore represent increments of 6.48mv.
+         */
+        regval += ((asc7621_in_scaling[nr] / 256) / 4) *
+            (data->reg[param->lsb[0]] >> 6);
+
+        mutex_unlock(&data->update_lock);
+
+        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]) / 256));
+}
+
+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 (strict_strtol(buf, 10, &reqval))
+                return -EINVAL;
+
+        reqval = SENSORS_LIMIT(reqval, 0, asc7621_in_scaling[nr]);
+
+        reqval = (reqval * 255 + 128) / asc7621_in_scaling[nr];
+
+        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 (strict_strtol(buf, 10, &reqval))
+                return -EINVAL;
+
+        reqval = SENSORS_LIMIT(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 (strict_strtol(buf, 10, &reqval))
+                return -EINVAL;
+
+        reqval = SENSORS_LIMIT(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 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[SENSORS_LIMIT(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 (strict_strtol(buf, 10, &reqval))
+                return -EINVAL;
+
+        mutex_lock(&data->update_lock);
+        auto_point1 = data->reg[param->msb[1]] * 1000;
+        reqval = SENSORS_LIMIT(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;
+        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[SENSORS_LIMIT(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;
+        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 (strict_strtoul(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 (strict_strtol(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 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 = SENSORS_LIMIT(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 (strict_strtoul(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 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 = SENSORS_LIMIT(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 (strict_strtol(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 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 = SENSORS_LIMIT(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 (strict_strtol(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_LOW, 0x41, 0, 0x01, 0, bitmask),
+        PREAD(in1_alarm, 1, PRI_LOW, 0x41, 0, 0x01, 1, bitmask),
+        PREAD(in2_alarm, 2, PRI_LOW, 0x41, 0, 0x01, 2, bitmask),
+        PREAD(in3_alarm, 3, PRI_LOW, 0x41, 0, 0x01, 3, bitmask),
+        PREAD(in4_alarm, 4, PRI_LOW, 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_LOW, 0x42, 0, 0x01, 0, bitmask),
+        PREAD(fan2_alarm, 1, PRI_LOW, 0x42, 0, 0x01, 1, bitmask),
+        PREAD(fan3_alarm, 2, PRI_LOW, 0x42, 0, 0x01, 2, bitmask),
+        PREAD(fan4_alarm, 3, PRI_LOW, 0x42, 0, 0x01, 3, 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_LOW, 0x41, 0, 0x01, 4, bitmask),
+        PREAD(temp2_alarm, 1, PRI_LOW, 0x41, 0, 0x01, 5, bitmask),
+        PREAD(temp3_alarm, 2, PRI_LOW, 0x41, 0, 0x01, 6, bitmask),
+        PREAD(temp4_alarm, 3, PRI_LOW, 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, 0x64, 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 = kzalloc(sizeof(struct asc7621_data), GFP_KERNEL);
+        if (data == NULL)
+                return -ENOMEM;
+
+        i2c_set_clientdata(client, data);
+        data->valid = 0;
+        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));
+        }
+
+        i2c_set_clientdata(client, NULL);
+        kfree(data);
+        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;
+        struct device *dev;
+
+        dev = &client->dev;
+
+        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(client->name, asc7621_chips[chip_index].name,
+                                I2C_NAME_SIZE);
+                        strlcpy(info->type, asc7621_chips[chip_index].name,
+                                I2C_NAME_SIZE);
+
+                        dev_info(&adapter->dev, "Matched %s\n",
+                                 asc7621_chips[chip_index].name);
+                        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));
+        }
+
+        i2c_set_clientdata(client, NULL);
+        kfree(data);
+        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);