hwmon: Driver for Nuvoton NCT7802Y

NCT7802Y is an I2C based hardware monitoring chip from Nuvoton.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

3 files changed, 872 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5286d7ce1f9e..f893e0ff0081 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1123,6 +1123,17 @@ config SENSORS_NCT6775
           This driver can also be built as a module.  If so, the module
           will be called nct6775.
 
+config SENSORS_NCT7802
+        tristate "Nuvoton NCT7802Y"
+        depends on I2C
+        select REGMAP_I2C
+        help
+          If you say yes here you get support for the Nuvoton NCT7802Y
+          hardware monitoring chip.
+
+          This driver can also be built as a module.  If so, the module
+          will be called nct7802.
+
 config SENSORS_PCF8591
         tristate "Philips PCF8591 ADC/DAC"
         depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index c90a7611efaa..67280643bcf0 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -118,6 +118,7 @@ obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
 obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
 obj-$(CONFIG_SENSORS_NCT6683)   += nct6683.o
 obj-$(CONFIG_SENSORS_NCT6775)   += nct6775.o
+obj-$(CONFIG_SENSORS_NCT7802)   += nct7802.o
 obj-$(CONFIG_SENSORS_NTC_THERMISTOR)    += ntc_thermistor.o
 obj-$(CONFIG_SENSORS_PC87360)   += pc87360.o
 obj-$(CONFIG_SENSORS_PC87427)   += pc87427.o
diff --git a/drivers/hwmon/nct7802.c b/drivers/hwmon/nct7802.c
new file mode 100644
index 000000000000..ec5678289e4a
--- /dev/null
+++ b/drivers/hwmon/nct7802.c
@@ -0,0 +1,860 @@
+/*
+ * nct7802 - Driver for Nuvoton NCT7802Y
+ *
+ * Copyright (C) 2014  Guenter Roeck <linux@roeck-us.net>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define DRVNAME "nct7802"
+
+static const u8 REG_VOLTAGE[5] = { 0x09, 0x0a, 0x0c, 0x0d, 0x0e };
+
+static const u8 REG_VOLTAGE_LIMIT_LSB[2][5] = {
+        { 0x40, 0x00, 0x42, 0x44, 0x46 },
+        { 0x3f, 0x00, 0x41, 0x43, 0x45 },
+};
+
+static const u8 REG_VOLTAGE_LIMIT_MSB[5] = { 0x48, 0x00, 0x47, 0x47, 0x48 };
+
+static const u8 REG_VOLTAGE_LIMIT_MSB_SHIFT[2][5] = {
+        { 0, 0, 4, 0, 4 },
+        { 2, 0, 6, 2, 6 },
+};
+
+#define REG_BANK                0x00
+#define REG_TEMP_LSB            0x05
+#define REG_TEMP_PECI_LSB       0x08
+#define REG_VOLTAGE_LOW         0x0f
+#define REG_FANCOUNT_LOW        0x13
+#define REG_START               0x21
+#define REG_MODE                0x22
+#define REG_PECI_ENABLE         0x23
+#define REG_FAN_ENABLE          0x24
+#define REG_VMON_ENABLE         0x25
+#define REG_VENDOR_ID           0xfd
+#define REG_CHIP_ID             0xfe
+#define REG_VERSION_ID          0xff
+
+/*
+ * Data structures and manipulation thereof
+ */
+
+struct nct7802_data {
+        struct regmap *regmap;
+        struct mutex access_lock; /* for multi-byte read and write operations */
+};
+
+static int nct7802_read_temp(struct nct7802_data *data,
+                             u8 reg_temp, u8 reg_temp_low, int *temp)
+{
+        unsigned int t1, t2 = 0;
+        int err;
+
+        *temp = 0;
+
+        mutex_lock(&data->access_lock);
+        err = regmap_read(data->regmap, reg_temp, &t1);
+        if (err < 0)
+                goto abort;
+        t1 <<= 8;
+        if (reg_temp_low) {     /* 11 bit data */
+                err = regmap_read(data->regmap, reg_temp_low, &t2);
+                if (err < 0)
+                        goto abort;
+        }
+        t1 |= t2 & 0xe0;
+        *temp = (s16)t1 / 32 * 125;
+abort:
+        mutex_unlock(&data->access_lock);
+        return err;
+}
+
+static int nct7802_read_fan(struct nct7802_data *data, u8 reg_fan)
+{
+        unsigned int f1, f2;
+        int ret;
+
+        mutex_lock(&data->access_lock);
+        ret = regmap_read(data->regmap, reg_fan, &f1);
+        if (ret < 0)
+                goto abort;
+        ret = regmap_read(data->regmap, REG_FANCOUNT_LOW, &f2);
+        if (ret < 0)
+                goto abort;
+        ret = (f1 << 5) | (f2 >> 3);
+        /* convert fan count to rpm */
+        if (ret == 0x1fff)      /* maximum value, assume fan is stopped */
+                ret = 0;
+        else if (ret)
+                ret = DIV_ROUND_CLOSEST(1350000U, ret);
+abort:
+        mutex_unlock(&data->access_lock);
+        return ret;
+}
+
+static int nct7802_read_fan_min(struct nct7802_data *data, u8 reg_fan_low,
+                                u8 reg_fan_high)
+{
+        unsigned int f1, f2;
+        int ret;
+
+        mutex_lock(&data->access_lock);
+        ret = regmap_read(data->regmap, reg_fan_low, &f1);
+        if (ret < 0)
+                goto abort;
+        ret = regmap_read(data->regmap, reg_fan_high, &f2);
+        if (ret < 0)
+                goto abort;
+        ret = f1 | ((f2 & 0xf8) << 5);
+        /* convert fan count to rpm */
+        if (ret == 0x1fff)      /* maximum value, assume no limit */
+                ret = 0;
+        else if (ret)
+                ret = DIV_ROUND_CLOSEST(1350000U, ret);
+abort:
+        mutex_unlock(&data->access_lock);
+        return ret;
+}
+
+static int nct7802_write_fan_min(struct nct7802_data *data, u8 reg_fan_low,
+                                 u8 reg_fan_high, unsigned int limit)
+{
+        int err;
+
+        if (limit)
+                limit = DIV_ROUND_CLOSEST(1350000U, limit);
+        else
+                limit = 0x1fff;
+        limit = clamp_val(limit, 0, 0x1fff);
+
+        mutex_lock(&data->access_lock);
+        err = regmap_write(data->regmap, reg_fan_low, limit & 0xff);
+        if (err < 0)
+                goto abort;
+
+        err = regmap_write(data->regmap, reg_fan_high, (limit & 0x1f00) >> 5);
+abort:
+        mutex_unlock(&data->access_lock);
+        return err;
+}
+
+static u8 nct7802_vmul[] = { 4, 2, 2, 2, 2 };
+
+static int nct7802_read_voltage(struct nct7802_data *data, int nr, int index)
+{
+        unsigned int v1, v2;
+        int ret;
+
+        mutex_lock(&data->access_lock);
+        if (index == 0) {       /* voltage */
+                ret = regmap_read(data->regmap, REG_VOLTAGE[nr], &v1);
+                if (ret < 0)
+                        goto abort;
+                ret = regmap_read(data->regmap, REG_VOLTAGE_LOW, &v2);
+                if (ret < 0)
+                        goto abort;
+                ret = ((v1 << 2) | (v2 >> 6)) * nct7802_vmul[nr];
+        }  else {       /* limit */
+                int shift = 8 - REG_VOLTAGE_LIMIT_MSB_SHIFT[index - 1][nr];
+
+                ret = regmap_read(data->regmap,
+                                  REG_VOLTAGE_LIMIT_LSB[index - 1][nr], &v1);
+                if (ret < 0)
+                        goto abort;
+                ret = regmap_read(data->regmap, REG_VOLTAGE_LIMIT_MSB[nr],
+                                  &v2);
+                if (ret < 0)
+                        goto abort;
+                ret = (v1 | ((v2 << shift) & 0x300)) * nct7802_vmul[nr];
+        }
+abort:
+        mutex_unlock(&data->access_lock);
+        return ret;
+}
+
+static int nct7802_write_voltage(struct nct7802_data *data, int nr, int index,
+                                 unsigned int voltage)
+{
+        int shift = 8 - REG_VOLTAGE_LIMIT_MSB_SHIFT[index - 1][nr];
+        int err;
+
+        voltage = DIV_ROUND_CLOSEST(voltage, nct7802_vmul[nr]);
+        voltage = clamp_val(voltage, 0, 0x3ff);
+
+        mutex_lock(&data->access_lock);
+        err = regmap_write(data->regmap,
+                           REG_VOLTAGE_LIMIT_LSB[index - 1][nr],
+                           voltage & 0xff);
+        if (err < 0)
+                goto abort;
+
+        err = regmap_update_bits(data->regmap, REG_VOLTAGE_LIMIT_MSB[nr],
+                                 0x0300 >> shift, (voltage & 0x0300) >> shift);
+abort:
+        mutex_unlock(&data->access_lock);
+        return err;
+}
+
+static ssize_t show_in(struct device *dev, struct device_attribute *attr,
+                       char *buf)
+{
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        int voltage;
+
+        voltage = nct7802_read_voltage(data, sattr->nr, sattr->index);
+        if (voltage < 0)
+                return voltage;
+
+        return sprintf(buf, "%d\n", voltage);
+}
+
+static ssize_t store_in(struct device *dev, struct device_attribute *attr,
+                        const char *buf, size_t count)
+{
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        int index = sattr->index;
+        int nr = sattr->nr;
+        unsigned long val;
+        int err;
+
+        err = kstrtoul(buf, 10, &val);
+        if (err < 0)
+                return err;
+
+        err = nct7802_write_voltage(data, nr, index, val);
+        return err ? : count;
+}
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        int err, temp;
+
+        err = nct7802_read_temp(data, sattr->nr, sattr->index, &temp);
+        if (err < 0)
+                return err;
+
+        return sprintf(buf, "%d\n", temp);
+}
+
+static ssize_t store_temp(struct device *dev, struct device_attribute *attr,
+                          const char *buf, size_t count)
+{
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        int nr = sattr->nr;
+        long val;
+        int err;
+
+        err = kstrtol(buf, 10, &val);
+        if (err < 0)
+                return err;
+
+        val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
+
+        err = regmap_write(data->regmap, nr, val & 0xff);
+        return err ? : count;
+}
+
+static ssize_t show_fan(struct device *dev, struct device_attribute *attr,
+                        char *buf)
+{
+        struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        int speed;
+
+        speed = nct7802_read_fan(data, sattr->index);
+        if (speed < 0)
+                return speed;
+
+        return sprintf(buf, "%d\n", speed);
+}
+
+static ssize_t show_fan_min(struct device *dev, struct device_attribute *attr,
+                            char *buf)
+{
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        int speed;
+
+        speed = nct7802_read_fan_min(data, sattr->nr, sattr->index);
+        if (speed < 0)
+                return speed;
+
+        return sprintf(buf, "%d\n", speed);
+}
+
+static ssize_t store_fan_min(struct device *dev, struct device_attribute *attr,
+                             const char *buf, size_t count)
+{
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        unsigned long val;
+        int err;
+
+        err = kstrtoul(buf, 10, &val);
+        if (err < 0)
+                return err;
+
+        err = nct7802_write_fan_min(data, sattr->nr, sattr->index, val);
+        return err ? : count;
+}
+
+static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
+                          char *buf)
+{
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        int bit = sattr->index;
+        unsigned int val;
+        int ret;
+
+        ret = regmap_read(data->regmap, sattr->nr, &val);
+        if (ret < 0)
+                return ret;
+
+        return sprintf(buf, "%u\n", !!(val & (1 << bit)));
+}
+
+static ssize_t
+show_beep(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        unsigned int regval;
+        int err;
+
+        err = regmap_read(data->regmap, sattr->nr, &regval);
+        if (err)
+                return err;
+
+        return sprintf(buf, "%u\n", !!(regval & (1 << sattr->index)));
+}
+
+static ssize_t
+store_beep(struct device *dev, struct device_attribute *attr, const char *buf,
+           size_t count)
+{
+        struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        unsigned long val;
+        int err;
+
+        err = kstrtoul(buf, 10, &val);
+        if (err < 0)
+                return err;
+        if (val > 1)
+                return -EINVAL;
+
+        err = regmap_update_bits(data->regmap, sattr->nr, 1 << sattr->index,
+                                 val ? 1 << sattr->index : 0);
+        return err ? : count;
+}
+
+static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0x01,
+                            REG_TEMP_LSB);
+static SENSOR_DEVICE_ATTR_2(temp1_min, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x31, 0);
+static SENSOR_DEVICE_ATTR_2(temp1_max, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x30, 0);
+static SENSOR_DEVICE_ATTR_2(temp1_crit, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x3a, 0);
+
+static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 0x02,
+                            REG_TEMP_LSB);
+static SENSOR_DEVICE_ATTR_2(temp2_min, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x33, 0);
+static SENSOR_DEVICE_ATTR_2(temp2_max, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x32, 0);
+static SENSOR_DEVICE_ATTR_2(temp2_crit, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x3b, 0);
+
+static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp, NULL, 0x03,
+                            REG_TEMP_LSB);
+static SENSOR_DEVICE_ATTR_2(temp3_min, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x35, 0);
+static SENSOR_DEVICE_ATTR_2(temp3_max, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x34, 0);
+static SENSOR_DEVICE_ATTR_2(temp3_crit, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x3c, 0);
+
+static SENSOR_DEVICE_ATTR_2(temp4_input, S_IRUGO, show_temp, NULL, 0x04, 0);
+static SENSOR_DEVICE_ATTR_2(temp4_min, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x37, 0);
+static SENSOR_DEVICE_ATTR_2(temp4_max, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x36, 0);
+static SENSOR_DEVICE_ATTR_2(temp4_crit, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x3d, 0);
+
+static SENSOR_DEVICE_ATTR_2(temp5_input, S_IRUGO, show_temp, NULL, 0x06,
+                            REG_TEMP_PECI_LSB);
+static SENSOR_DEVICE_ATTR_2(temp5_min, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x39, 0);
+static SENSOR_DEVICE_ATTR_2(temp5_max, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x38, 0);
+static SENSOR_DEVICE_ATTR_2(temp5_crit, S_IRUGO | S_IWUSR, show_temp,
+                            store_temp, 0x3e, 0);
+
+static SENSOR_DEVICE_ATTR_2(temp6_input, S_IRUGO, show_temp, NULL, 0x07,
+                            REG_TEMP_PECI_LSB);
+
+static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
+                            0x18, 0);
+static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO, show_alarm, NULL,
+                            0x18, 1);
+static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO, show_alarm, NULL,
+                            0x18, 2);
+static SENSOR_DEVICE_ATTR_2(temp4_min_alarm, S_IRUGO, show_alarm, NULL,
+                            0x18, 3);
+static SENSOR_DEVICE_ATTR_2(temp5_min_alarm, S_IRUGO, show_alarm, NULL,
+                            0x18, 4);
+
+static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
+                            0x19, 0);
+static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO, show_alarm, NULL,
+                            0x19, 1);
+static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO, show_alarm, NULL,
+                            0x19, 2);
+static SENSOR_DEVICE_ATTR_2(temp4_max_alarm, S_IRUGO, show_alarm, NULL,
+                            0x19, 3);
+static SENSOR_DEVICE_ATTR_2(temp5_max_alarm, S_IRUGO, show_alarm, NULL,
+                            0x19, 4);
+
+static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
+                            0x1b, 0);
+static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
+                            0x1b, 1);
+static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO, show_alarm, NULL,
+                            0x1b, 2);
+static SENSOR_DEVICE_ATTR_2(temp4_crit_alarm, S_IRUGO, show_alarm, NULL,
+                            0x1b, 3);
+static SENSOR_DEVICE_ATTR_2(temp5_crit_alarm, S_IRUGO, show_alarm, NULL,
+                            0x1b, 4);
+
+static SENSOR_DEVICE_ATTR_2(temp1_fault, S_IRUGO, show_alarm, NULL, 0x17, 0);
+static SENSOR_DEVICE_ATTR_2(temp2_fault, S_IRUGO, show_alarm, NULL, 0x17, 1);
+static SENSOR_DEVICE_ATTR_2(temp3_fault, S_IRUGO, show_alarm, NULL, 0x17, 2);
+
+static SENSOR_DEVICE_ATTR_2(temp1_beep, S_IRUGO | S_IWUSR, show_beep,
+                            store_beep, 0x5c, 0);
+static SENSOR_DEVICE_ATTR_2(temp2_beep, S_IRUGO | S_IWUSR, show_beep,
+                            store_beep, 0x5c, 1);
+static SENSOR_DEVICE_ATTR_2(temp3_beep, S_IRUGO | S_IWUSR, show_beep,
+                            store_beep, 0x5c, 2);
+static SENSOR_DEVICE_ATTR_2(temp4_beep, S_IRUGO | S_IWUSR, show_beep,
+                            store_beep, 0x5c, 3);
+static SENSOR_DEVICE_ATTR_2(temp5_beep, S_IRUGO | S_IWUSR, show_beep,
+                            store_beep, 0x5c, 4);
+static SENSOR_DEVICE_ATTR_2(temp6_beep, S_IRUGO | S_IWUSR, show_beep,
+                            store_beep, 0x5c, 5);
+
+static struct attribute *nct7802_temp_attrs[] = {
+        &sensor_dev_attr_temp1_input.dev_attr.attr,
+        &sensor_dev_attr_temp1_min.dev_attr.attr,
+        &sensor_dev_attr_temp1_max.dev_attr.attr,
+        &sensor_dev_attr_temp1_crit.dev_attr.attr,
+        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_fault.dev_attr.attr,
+        &sensor_dev_attr_temp1_beep.dev_attr.attr,
+
+        &sensor_dev_attr_temp2_input.dev_attr.attr,             /* 9 */
+        &sensor_dev_attr_temp2_min.dev_attr.attr,
+        &sensor_dev_attr_temp2_max.dev_attr.attr,
+        &sensor_dev_attr_temp2_crit.dev_attr.attr,
+        &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp2_fault.dev_attr.attr,
+        &sensor_dev_attr_temp2_beep.dev_attr.attr,
+
+        &sensor_dev_attr_temp3_input.dev_attr.attr,             /* 18 */
+        &sensor_dev_attr_temp3_min.dev_attr.attr,
+        &sensor_dev_attr_temp3_max.dev_attr.attr,
+        &sensor_dev_attr_temp3_crit.dev_attr.attr,
+        &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp3_fault.dev_attr.attr,
+        &sensor_dev_attr_temp3_beep.dev_attr.attr,
+
+        &sensor_dev_attr_temp4_input.dev_attr.attr,             /* 27 */
+        &sensor_dev_attr_temp4_min.dev_attr.attr,
+        &sensor_dev_attr_temp4_max.dev_attr.attr,
+        &sensor_dev_attr_temp4_crit.dev_attr.attr,
+        &sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp4_beep.dev_attr.attr,
+
+        &sensor_dev_attr_temp5_input.dev_attr.attr,             /* 35 */
+        &sensor_dev_attr_temp5_min.dev_attr.attr,
+        &sensor_dev_attr_temp5_max.dev_attr.attr,
+        &sensor_dev_attr_temp5_crit.dev_attr.attr,
+        &sensor_dev_attr_temp5_min_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp5_max_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp5_crit_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp5_beep.dev_attr.attr,
+
+        &sensor_dev_attr_temp6_input.dev_attr.attr,             /* 43 */
+        &sensor_dev_attr_temp6_beep.dev_attr.attr,
+
+        NULL
+};
+
+static umode_t nct7802_temp_is_visible(struct kobject *kobj,
+                                       struct attribute *attr, int index)
+{
+        struct device *dev = container_of(kobj, struct device, kobj);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        unsigned int reg;
+        int err;
+
+        err = regmap_read(data->regmap, REG_MODE, &reg);
+        if (err < 0)
+                return 0;
+
+        if (index < 9 &&
+            (reg & 03) != 0x01 && (reg & 0x03) != 0x02)         /* RD1 */
+                return 0;
+        if (index >= 9 && index < 18 &&
+            (reg & 0x0c) != 0x04 && (reg & 0x0c) != 0x08)       /* RD2 */
+                return 0;
+        if (index >= 18 && index < 27 && (reg & 0x30) != 0x10)  /* RD3 */
+                return 0;
+        if (index >= 27 && index < 35)                          /* local */
+                return attr->mode;
+
+        err = regmap_read(data->regmap, REG_PECI_ENABLE, &reg);
+        if (err < 0)
+                return 0;
+
+        if (index >= 35 && index < 43 && !(reg & 0x01))         /* PECI 0 */
+                return 0;
+
+        if (index >= 0x43 && (!(reg & 0x02)))                   /* PECI 1 */
+                return 0;
+
+        return attr->mode;
+}
+
+static struct attribute_group nct7802_temp_group = {
+        .attrs = nct7802_temp_attrs,
+        .is_visible = nct7802_temp_is_visible,
+};
+
+static SENSOR_DEVICE_ATTR_2(in0_input, S_IRUGO, show_in, NULL, 0, 0);
+static SENSOR_DEVICE_ATTR_2(in0_min, S_IRUGO | S_IWUSR, show_in, store_in,
+                            0, 1);
+static SENSOR_DEVICE_ATTR_2(in0_max, S_IRUGO | S_IWUSR, show_in, store_in,
+                            0, 2);
+static SENSOR_DEVICE_ATTR_2(in0_alarm, S_IRUGO, show_alarm, NULL, 0x1e, 3);
+static SENSOR_DEVICE_ATTR_2(in0_beep, S_IRUGO | S_IWUSR, show_beep, store_beep,
+                            0x5a, 3);
+
+static SENSOR_DEVICE_ATTR_2(in1_input, S_IRUGO, show_in, NULL, 1, 0);
+
+static SENSOR_DEVICE_ATTR_2(in2_input, S_IRUGO, show_in, NULL, 2, 0);
+static SENSOR_DEVICE_ATTR_2(in2_min, S_IRUGO | S_IWUSR, show_in, store_in,
+                            2, 1);
+static SENSOR_DEVICE_ATTR_2(in2_max, S_IRUGO | S_IWUSR, show_in, store_in,
+                            2, 2);
+static SENSOR_DEVICE_ATTR_2(in2_alarm, S_IRUGO, show_alarm, NULL, 0x1e, 0);
+static SENSOR_DEVICE_ATTR_2(in2_beep, S_IRUGO | S_IWUSR, show_beep, store_beep,
+                            0x5a, 0);
+
+static SENSOR_DEVICE_ATTR_2(in3_input, S_IRUGO, show_in, NULL, 3, 0);
+static SENSOR_DEVICE_ATTR_2(in3_min, S_IRUGO | S_IWUSR, show_in, store_in,
+                            3, 1);
+static SENSOR_DEVICE_ATTR_2(in3_max, S_IRUGO | S_IWUSR, show_in, store_in,
+                            3, 2);
+static SENSOR_DEVICE_ATTR_2(in3_alarm, S_IRUGO, show_alarm, NULL, 0x1e, 1);
+static SENSOR_DEVICE_ATTR_2(in3_beep, S_IRUGO | S_IWUSR, show_beep, store_beep,
+                            0x5a, 1);
+
+static SENSOR_DEVICE_ATTR_2(in4_input, S_IRUGO, show_in, NULL, 4, 0);
+static SENSOR_DEVICE_ATTR_2(in4_min, S_IRUGO | S_IWUSR, show_in, store_in,
+                            4, 1);
+static SENSOR_DEVICE_ATTR_2(in4_max, S_IRUGO | S_IWUSR, show_in, store_in,
+                            4, 2);
+static SENSOR_DEVICE_ATTR_2(in4_alarm, S_IRUGO, show_alarm, NULL, 0x1e, 2);
+static SENSOR_DEVICE_ATTR_2(in4_beep, S_IRUGO | S_IWUSR, show_beep, store_beep,
+                            0x5a, 2);
+
+static struct attribute *nct7802_in_attrs[] = {
+        &sensor_dev_attr_in0_input.dev_attr.attr,
+        &sensor_dev_attr_in0_min.dev_attr.attr,
+        &sensor_dev_attr_in0_max.dev_attr.attr,
+        &sensor_dev_attr_in0_alarm.dev_attr.attr,
+        &sensor_dev_attr_in0_beep.dev_attr.attr,
+
+        &sensor_dev_attr_in1_input.dev_attr.attr,       /* 5 */
+
+        &sensor_dev_attr_in2_input.dev_attr.attr,       /* 6 */
+        &sensor_dev_attr_in2_min.dev_attr.attr,
+        &sensor_dev_attr_in2_max.dev_attr.attr,
+        &sensor_dev_attr_in2_alarm.dev_attr.attr,
+        &sensor_dev_attr_in2_beep.dev_attr.attr,
+
+        &sensor_dev_attr_in3_input.dev_attr.attr,       /* 11 */
+        &sensor_dev_attr_in3_min.dev_attr.attr,
+        &sensor_dev_attr_in3_max.dev_attr.attr,
+        &sensor_dev_attr_in3_alarm.dev_attr.attr,
+        &sensor_dev_attr_in3_beep.dev_attr.attr,
+
+        &sensor_dev_attr_in4_input.dev_attr.attr,       /* 17 */
+        &sensor_dev_attr_in4_min.dev_attr.attr,
+        &sensor_dev_attr_in4_max.dev_attr.attr,
+        &sensor_dev_attr_in4_alarm.dev_attr.attr,
+        &sensor_dev_attr_in4_beep.dev_attr.attr,
+
+        NULL,
+};
+
+static umode_t nct7802_in_is_visible(struct kobject *kobj,
+                                     struct attribute *attr, int index)
+{
+        struct device *dev = container_of(kobj, struct device, kobj);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        unsigned int reg;
+        int err;
+
+        if (index < 6)                                          /* VCC, VCORE */
+                return attr->mode;
+
+        err = regmap_read(data->regmap, REG_MODE, &reg);
+        if (err < 0)
+                return 0;
+
+        if (index >= 6 && index < 11 && (reg & 0x03) != 0x03)   /* VSEN1 */
+                return 0;
+        if (index >= 11 && index < 17 && (reg & 0x0c) != 0x0c)  /* VSEN2 */
+                return 0;
+        if (index >= 17 && (reg & 0x30) != 0x30)                /* VSEN3 */
+                return 0;
+
+        return attr->mode;
+}
+
+static struct attribute_group nct7802_in_group = {
+        .attrs = nct7802_in_attrs,
+        .is_visible = nct7802_in_is_visible,
+};
+
+static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0x10);
+static SENSOR_DEVICE_ATTR_2(fan1_min, S_IRUGO | S_IWUSR, show_fan_min,
+                            store_fan_min, 0x49, 0x4c);
+static SENSOR_DEVICE_ATTR_2(fan1_alarm, S_IRUGO, show_alarm, NULL, 0x1a, 0);
+static SENSOR_DEVICE_ATTR_2(fan1_beep, S_IRUGO | S_IWUSR, show_beep, store_beep,
+                            0x5b, 0);
+static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 0x11);
+static SENSOR_DEVICE_ATTR_2(fan2_min, S_IRUGO | S_IWUSR, show_fan_min,
+                            store_fan_min, 0x4a, 0x4d);
+static SENSOR_DEVICE_ATTR_2(fan2_alarm, S_IRUGO, show_alarm, NULL, 0x1a, 1);
+static SENSOR_DEVICE_ATTR_2(fan2_beep, S_IRUGO | S_IWUSR, show_beep, store_beep,
+                            0x5b, 1);
+static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, show_fan, NULL, 0x12);
+static SENSOR_DEVICE_ATTR_2(fan3_min, S_IRUGO | S_IWUSR, show_fan_min,
+                            store_fan_min, 0x4b, 0x4e);
+static SENSOR_DEVICE_ATTR_2(fan3_alarm, S_IRUGO, show_alarm, NULL, 0x1a, 2);
+static SENSOR_DEVICE_ATTR_2(fan3_beep, S_IRUGO | S_IWUSR, show_beep, store_beep,
+                            0x5b, 2);
+
+static struct attribute *nct7802_fan_attrs[] = {
+        &sensor_dev_attr_fan1_input.dev_attr.attr,
+        &sensor_dev_attr_fan1_min.dev_attr.attr,
+        &sensor_dev_attr_fan1_alarm.dev_attr.attr,
+        &sensor_dev_attr_fan1_beep.dev_attr.attr,
+        &sensor_dev_attr_fan2_input.dev_attr.attr,
+        &sensor_dev_attr_fan2_min.dev_attr.attr,
+        &sensor_dev_attr_fan2_alarm.dev_attr.attr,
+        &sensor_dev_attr_fan2_beep.dev_attr.attr,
+        &sensor_dev_attr_fan3_input.dev_attr.attr,
+        &sensor_dev_attr_fan3_min.dev_attr.attr,
+        &sensor_dev_attr_fan3_alarm.dev_attr.attr,
+        &sensor_dev_attr_fan3_beep.dev_attr.attr,
+
+        NULL
+};
+
+static umode_t nct7802_fan_is_visible(struct kobject *kobj,
+                                      struct attribute *attr, int index)
+{
+        struct device *dev = container_of(kobj, struct device, kobj);
+        struct nct7802_data *data = dev_get_drvdata(dev);
+        int fan = index / 4;    /* 4 attributes per fan */
+        unsigned int reg;
+        int err;
+
+        err = regmap_read(data->regmap, REG_FAN_ENABLE, &reg);
+        if (err < 0 || !(reg & (1 << fan)))
+                return 0;
+
+        return attr->mode;
+}
+
+static struct attribute_group nct7802_fan_group = {
+        .attrs = nct7802_fan_attrs,
+        .is_visible = nct7802_fan_is_visible,
+};
+
+static const struct attribute_group *nct7802_groups[] = {
+        &nct7802_temp_group,
+        &nct7802_in_group,
+        &nct7802_fan_group,
+        NULL
+};
+
+static int nct7802_detect(struct i2c_client *client,
+                          struct i2c_board_info *info)
+{
+        int reg;
+
+        /*
+         * Chip identification registers are only available in bank 0,
+         * so only attempt chip detection if bank 0 is selected
+         */
+        reg = i2c_smbus_read_byte_data(client, REG_BANK);
+        if (reg != 0x00)
+                return -ENODEV;
+
+        reg = i2c_smbus_read_byte_data(client, REG_VENDOR_ID);
+        if (reg != 0x50)
+                return -ENODEV;
+
+        reg = i2c_smbus_read_byte_data(client, REG_CHIP_ID);
+        if (reg != 0xc3)
+                return -ENODEV;
+
+        reg = i2c_smbus_read_byte_data(client, REG_VERSION_ID);
+        if (reg < 0 || (reg & 0xf0) != 0x20)
+                return -ENODEV;
+
+        /* Also validate lower bits of voltage and temperature registers */
+        reg = i2c_smbus_read_byte_data(client, REG_TEMP_LSB);
+        if (reg < 0 || (reg & 0x1f))
+                return -ENODEV;
+
+        reg = i2c_smbus_read_byte_data(client, REG_TEMP_PECI_LSB);
+        if (reg < 0 || (reg & 0x3f))
+                return -ENODEV;
+
+        reg = i2c_smbus_read_byte_data(client, REG_VOLTAGE_LOW);
+        if (reg < 0 || (reg & 0x3f))
+                return -ENODEV;
+
+        strlcpy(info->type, "nct7802", I2C_NAME_SIZE);
+        return 0;
+}
+
+static bool nct7802_regmap_is_volatile(struct device *dev, unsigned int reg)
+{
+        return reg != REG_BANK && reg <= 0x20;
+}
+
+static struct regmap_config nct7802_regmap_config = {
+        .reg_bits = 8,
+        .val_bits = 8,
+        .cache_type = REGCACHE_RBTREE,
+        .volatile_reg = nct7802_regmap_is_volatile,
+};
+
+static int nct7802_init_chip(struct nct7802_data *data)
+{
+        int err;
+
+        /* Enable ADC */
+        err = regmap_update_bits(data->regmap, REG_START, 0x01, 0x01);
+        if (err)
+                return err;
+
+        /* Enable local temperature sensor */
+        err = regmap_update_bits(data->regmap, REG_MODE, 0x40, 0x40);
+        if (err)
+                return err;
+
+        /* Enable Vcore and VCC voltage monitoring */
+        return regmap_update_bits(data->regmap, REG_VMON_ENABLE, 0x03, 0x03);
+}
+
+static int nct7802_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+        struct device *dev = &client->dev;
+        struct nct7802_data *data;
+        struct device *hwmon_dev;
+        int ret;
+
+        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+        if (data == NULL)
+                return -ENOMEM;
+
+        data->regmap = devm_regmap_init_i2c(client, &nct7802_regmap_config);
+        if (IS_ERR(data->regmap))
+                return PTR_ERR(data->regmap);
+
+        mutex_init(&data->access_lock);
+
+        ret = nct7802_init_chip(data);
+        if (ret < 0)
+                return ret;
+
+        hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+                                                           data,
+                                                           nct7802_groups);
+        return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const unsigned short nct7802_address_list[] = {
+        0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END
+};
+
+static const struct i2c_device_id nct7802_idtable[] = {
+        { "nct7802", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, nct7802_idtable);
+
+static struct i2c_driver nct7802_driver = {
+        .class = I2C_CLASS_HWMON,
+        .driver = {
+                .name = DRVNAME,
+        },
+        .detect = nct7802_detect,
+        .probe = nct7802_probe,
+        .id_table = nct7802_idtable,
+        .address_list = nct7802_address_list,
+};
+
+module_i2c_driver(nct7802_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("NCT7802Y Hardware Monitoring Driver");
+MODULE_LICENSE("GPL v2");