hwmon: Driver for Maxim MAX31790
authorIl Han <corone.il.han@gmail.com>
Sun, 30 Aug 2015 11:44:26 +0000 (20:44 +0900)
committerGuenter Roeck <linux@roeck-us.net>
Wed, 14 Oct 2015 14:57:14 +0000 (07:57 -0700)
The driver supports the Maxim MAX31790.

Signed-off-by: Il Han <corone.il.han@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Documentation/hwmon/max31790 [new file with mode: 0644]
drivers/hwmon/Kconfig
drivers/hwmon/Makefile
drivers/hwmon/max31790.c [new file with mode: 0644]

diff --git a/Documentation/hwmon/max31790 b/Documentation/hwmon/max31790
new file mode 100644 (file)
index 0000000..855e624
--- /dev/null
@@ -0,0 +1,37 @@
+Kernel driver max31790
+======================
+
+Supported chips:
+  * Maxim MAX31790
+    Prefix: 'max31790'
+    Addresses scanned: -
+    Datasheet: http://pdfserv.maximintegrated.com/en/ds/MAX31790.pdf
+
+Author: Il Han <corone.il.han@gmail.com>
+
+
+Description
+-----------
+
+This driver implements support for the Maxim MAX31790 chip.
+
+The MAX31790 controls the speeds of up to six fans using six independent
+PWM outputs. The desired fan speeds (or PWM duty cycles) are written
+through the I2C interface. The outputs drive "4-wire" fans directly,
+or can be used to modulate the fan's power terminals using an external
+pass transistor.
+
+Tachometer inputs monitor fan tachometer logic outputs for precise (+/-1%)
+monitoring and control of fan RPM as well as detection of fan failure.
+Six pins are dedicated tachometer inputs. Any of the six PWM outputs can
+also be configured to serve as tachometer inputs.
+
+
+Sysfs entries
+-------------
+
+fan[1-12]_input    RO  fan tachometer speed in RPM
+fan[1-12]_fault    RO  fan experienced fault
+fan[1-6]_target    RW  desired fan speed in RPM
+pwm[1-6]_enable    RW  regulator mode, 0=disabled, 1=manual mode, 2=rpm mode
+pwm[1-6]           RW  fan target duty cycle (0-255)
index e13c902e8966977581f1959155b3f83774e94aa5..796569eeaf1d762c9d0283165b132c7a196d0e30 100644 (file)
@@ -840,6 +840,16 @@ config SENSORS_MAX6697
          This driver can also be built as a module.  If so, the module
          will be called max6697.
 
+config SENSORS_MAX31790
+       tristate "Maxim MAX31790 sensor chip"
+       depends on I2C
+       help
+         If you say yes here you get support for 6-Channel PWM-Output
+         Fan RPM Controller.
+
+         This driver can also be built as a module.  If so, the module
+         will be called max31790.
+
 config SENSORS_HTU21
        tristate "Measurement Specialties HTU21D humidity/temperature sensors"
        depends on I2C
index 9e0f3dd2841daaa1531acd3897c9077b2d18a09d..01855ee641d1d358dd01ed035ce6b20c0cbd080f 100644 (file)
@@ -115,6 +115,7 @@ obj-$(CONFIG_SENSORS_MAX6639)       += max6639.o
 obj-$(CONFIG_SENSORS_MAX6642)  += max6642.o
 obj-$(CONFIG_SENSORS_MAX6650)  += max6650.o
 obj-$(CONFIG_SENSORS_MAX6697)  += max6697.o
+obj-$(CONFIG_SENSORS_MAX31790) += max31790.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
 obj-$(CONFIG_SENSORS_MCP3021)  += mcp3021.o
 obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
new file mode 100644 (file)
index 0000000..f129668
--- /dev/null
@@ -0,0 +1,603 @@
+/*
+ * max31790.c - Part of lm_sensors, Linux kernel modules for hardware
+ *             monitoring.
+ *
+ * (C) 2015 by Il Han <corone.il.han@gmail.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.
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/* MAX31790 registers */
+#define MAX31790_REG_GLOBAL_CONFIG     0x00
+#define MAX31790_REG_FAN_CONFIG(ch)    (0x02 + (ch))
+#define MAX31790_REG_FAN_DYNAMICS(ch)  (0x08 + (ch))
+#define MAX31790_REG_FAN_FAULT_STATUS2 0x10
+#define MAX31790_REG_FAN_FAULT_STATUS1 0x11
+#define MAX31790_REG_TACH_COUNT(ch)    (0x18 + (ch) * 2)
+#define MAX31790_REG_PWM_DUTY_CYCLE(ch)        (0x30 + (ch) * 2)
+#define MAX31790_REG_PWMOUT(ch)                (0x40 + (ch) * 2)
+#define MAX31790_REG_TARGET_COUNT(ch)  (0x50 + (ch) * 2)
+
+/* Fan Config register bits */
+#define MAX31790_FAN_CFG_RPM_MODE      0x80
+#define MAX31790_FAN_CFG_TACH_INPUT_EN 0x08
+#define MAX31790_FAN_CFG_TACH_INPUT    0x01
+
+/* Fan Dynamics register bits */
+#define MAX31790_FAN_DYN_SR_SHIFT      5
+#define MAX31790_FAN_DYN_SR_MASK       0xE0
+#define SR_FROM_REG(reg)               (((reg) & MAX31790_FAN_DYN_SR_MASK) \
+                                        >> MAX31790_FAN_DYN_SR_SHIFT)
+
+#define FAN_RPM_MIN                    120
+#define FAN_RPM_MAX                    7864320
+
+#define RPM_FROM_REG(reg, sr)          (((reg) >> 4) ? \
+                                        ((60 * (sr) * 8192) / ((reg) >> 4)) : \
+                                        FAN_RPM_MAX)
+#define RPM_TO_REG(rpm, sr)            ((60 * (sr) * 8192) / ((rpm) * 2))
+
+#define NR_CHANNEL                     6
+
+/*
+ * Client data (each client gets its own)
+ */
+struct max31790_data {
+       struct i2c_client *client;
+       struct mutex update_lock;
+       bool valid; /* zero until following fields are valid */
+       unsigned long last_updated; /* in jiffies */
+
+       /* register values */
+       u8 fan_config[NR_CHANNEL];
+       u8 fan_dynamics[NR_CHANNEL];
+       u16 fault_status;
+       u16 tach[NR_CHANNEL * 2];
+       u16 pwm[NR_CHANNEL];
+       u16 target_count[NR_CHANNEL];
+};
+
+static struct max31790_data *max31790_update_device(struct device *dev)
+{
+       struct max31790_data *data = dev_get_drvdata(dev);
+       struct i2c_client *client = data->client;
+       struct max31790_data *ret = data;
+       int i;
+       int rv;
+
+       mutex_lock(&data->update_lock);
+
+       if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+               rv = i2c_smbus_read_byte_data(client,
+                               MAX31790_REG_FAN_FAULT_STATUS1);
+               if (rv < 0)
+                       goto abort;
+               data->fault_status = rv & 0x3F;
+
+               rv = i2c_smbus_read_byte_data(client,
+                               MAX31790_REG_FAN_FAULT_STATUS2);
+               if (rv < 0)
+                       goto abort;
+               data->fault_status |= (rv & 0x3F) << 6;
+
+               for (i = 0; i < NR_CHANNEL; i++) {
+                       rv = i2c_smbus_read_word_swapped(client,
+                                       MAX31790_REG_TACH_COUNT(i));
+                       if (rv < 0)
+                               goto abort;
+                       data->tach[i] = rv;
+
+                       if (data->fan_config[i]
+                           & MAX31790_FAN_CFG_TACH_INPUT) {
+                               rv = i2c_smbus_read_word_swapped(client,
+                                       MAX31790_REG_TACH_COUNT(NR_CHANNEL
+                                                               + i));
+                               if (rv < 0)
+                                       goto abort;
+                               data->tach[NR_CHANNEL + i] = rv;
+                       } else {
+                               rv = i2c_smbus_read_word_swapped(client,
+                                               MAX31790_REG_PWMOUT(i));
+                               if (rv < 0)
+                                       goto abort;
+                               data->pwm[i] = rv;
+
+                               rv = i2c_smbus_read_word_swapped(client,
+                                               MAX31790_REG_TARGET_COUNT(i));
+                               if (rv < 0)
+                                       goto abort;
+                               data->target_count[i] = rv;
+                       }
+               }
+
+               data->last_updated = jiffies;
+               data->valid = true;
+       }
+       goto done;
+
+abort:
+       data->valid = false;
+       ret = ERR_PTR(rv);
+
+done:
+       mutex_unlock(&data->update_lock);
+
+       return ret;
+}
+
+static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };
+
+static u8 get_tach_period(u8 fan_dynamics)
+{
+       return tach_period[SR_FROM_REG(fan_dynamics)];
+}
+
+static u8 bits_for_tach_period(int rpm)
+{
+       u8 bits;
+
+       if (rpm < 500)
+               bits = 0x0;
+       else if (rpm < 1000)
+               bits = 0x1;
+       else if (rpm < 2000)
+               bits = 0x2;
+       else if (rpm < 4000)
+               bits = 0x3;
+       else if (rpm < 8000)
+               bits = 0x4;
+       else
+               bits = 0x5;
+
+       return bits;
+}
+
+static ssize_t get_fan(struct device *dev,
+                      struct device_attribute *devattr, char *buf)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = max31790_update_device(dev);
+       int sr = get_tach_period(data->fan_dynamics[attr->index]);
+       int rpm;
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       rpm = RPM_FROM_REG(data->tach[attr->index], sr);
+
+       return sprintf(buf, "%d\n", rpm);
+}
+
+static ssize_t get_fan_target(struct device *dev,
+                             struct device_attribute *devattr, char *buf)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = max31790_update_device(dev);
+       int sr = get_tach_period(data->fan_dynamics[attr->index]);
+       int rpm;
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       rpm = RPM_FROM_REG(data->target_count[attr->index], sr);
+
+       return sprintf(buf, "%d\n", rpm);
+}
+
+static ssize_t set_fan_target(struct device *dev,
+                             struct device_attribute *devattr,
+                             const char *buf, size_t count)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = dev_get_drvdata(dev);
+       struct i2c_client *client = data->client;
+       u8 bits;
+       int sr;
+       int target_count;
+       unsigned long rpm;
+       int err;
+
+       err = kstrtoul(buf, 10, &rpm);
+       if (err)
+               return err;
+
+       mutex_lock(&data->update_lock);
+
+       rpm = clamp_val(rpm, FAN_RPM_MIN, FAN_RPM_MAX);
+       bits = bits_for_tach_period(rpm);
+       data->fan_dynamics[attr->index] =
+                       ((data->fan_dynamics[attr->index]
+                         & ~MAX31790_FAN_DYN_SR_MASK)
+                        | (bits << MAX31790_FAN_DYN_SR_SHIFT));
+       err = i2c_smbus_write_byte_data(client,
+                       MAX31790_REG_FAN_DYNAMICS(attr->index),
+                       data->fan_dynamics[attr->index]);
+
+       if (err < 0) {
+               mutex_unlock(&data->update_lock);
+               return err;
+       }
+
+       sr = get_tach_period(data->fan_dynamics[attr->index]);
+       target_count = RPM_TO_REG(rpm, sr);
+       target_count = clamp_val(target_count, 0x1, 0x7FF);
+
+       data->target_count[attr->index] = target_count << 5;
+
+       err = i2c_smbus_write_word_swapped(client,
+                       MAX31790_REG_TARGET_COUNT(attr->index),
+                       data->target_count[attr->index]);
+
+       mutex_unlock(&data->update_lock);
+
+       if (err < 0)
+               return err;
+
+       return count;
+}
+
+static ssize_t get_pwm(struct device *dev,
+                      struct device_attribute *devattr, char *buf)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = max31790_update_device(dev);
+       int pwm;
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       pwm = data->pwm[attr->index] >> 8;
+
+       return sprintf(buf, "%d\n", pwm);
+}
+
+static ssize_t set_pwm(struct device *dev,
+                      struct device_attribute *devattr,
+                      const char *buf, size_t count)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = dev_get_drvdata(dev);
+       struct i2c_client *client = data->client;
+       unsigned long pwm;
+       int err;
+
+       err = kstrtoul(buf, 10, &pwm);
+       if (err)
+               return err;
+
+       if (pwm > 255)
+               return -EINVAL;
+
+       mutex_lock(&data->update_lock);
+
+       data->pwm[attr->index] = pwm << 8;
+       err = i2c_smbus_write_word_swapped(client,
+                       MAX31790_REG_PWMOUT(attr->index),
+                       data->pwm[attr->index]);
+
+       mutex_unlock(&data->update_lock);
+
+       if (err < 0)
+               return err;
+
+       return count;
+}
+
+static ssize_t get_pwm_enable(struct device *dev,
+                             struct device_attribute *devattr, char *buf)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = max31790_update_device(dev);
+       int mode;
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       if (data->fan_config[attr->index] & MAX31790_FAN_CFG_RPM_MODE)
+               mode = 2;
+       else if (data->fan_config[attr->index] & MAX31790_FAN_CFG_TACH_INPUT_EN)
+               mode = 1;
+       else
+               mode = 0;
+
+       return sprintf(buf, "%d\n", mode);
+}
+
+static ssize_t set_pwm_enable(struct device *dev,
+                             struct device_attribute *devattr,
+                             const char *buf, size_t count)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = dev_get_drvdata(dev);
+       struct i2c_client *client = data->client;
+       unsigned long mode;
+       int err;
+
+       err = kstrtoul(buf, 10, &mode);
+       if (err)
+               return err;
+
+       switch (mode) {
+       case 0:
+               data->fan_config[attr->index] =
+                       data->fan_config[attr->index]
+                       & ~(MAX31790_FAN_CFG_TACH_INPUT_EN
+                           | MAX31790_FAN_CFG_RPM_MODE);
+               break;
+       case 1:
+               data->fan_config[attr->index] =
+                       (data->fan_config[attr->index]
+                        | MAX31790_FAN_CFG_TACH_INPUT_EN)
+                       & ~MAX31790_FAN_CFG_RPM_MODE;
+               break;
+       case 2:
+               data->fan_config[attr->index] =
+                       data->fan_config[attr->index]
+                       | MAX31790_FAN_CFG_TACH_INPUT_EN
+                       | MAX31790_FAN_CFG_RPM_MODE;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       mutex_lock(&data->update_lock);
+
+       err = i2c_smbus_write_byte_data(client,
+                       MAX31790_REG_FAN_CONFIG(attr->index),
+                       data->fan_config[attr->index]);
+
+       mutex_unlock(&data->update_lock);
+
+       if (err < 0)
+               return err;
+
+       return count;
+}
+
+static ssize_t get_fan_fault(struct device *dev,
+                            struct device_attribute *devattr, char *buf)
+{
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct max31790_data *data = max31790_update_device(dev);
+       int fault;
+
+       if (IS_ERR(data))
+               return PTR_ERR(data);
+
+       fault = !!(data->fault_status & (1 << attr->index));
+
+       return sprintf(buf, "%d\n", fault);
+}
+
+static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
+static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
+static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
+static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3);
+static SENSOR_DEVICE_ATTR(fan5_input, S_IRUGO, get_fan, NULL, 4);
+static SENSOR_DEVICE_ATTR(fan6_input, S_IRUGO, get_fan, NULL, 5);
+
+static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan_fault, NULL, 0);
+static SENSOR_DEVICE_ATTR(fan2_fault, S_IRUGO, get_fan_fault, NULL, 1);
+static SENSOR_DEVICE_ATTR(fan3_fault, S_IRUGO, get_fan_fault, NULL, 2);
+static SENSOR_DEVICE_ATTR(fan4_fault, S_IRUGO, get_fan_fault, NULL, 3);
+static SENSOR_DEVICE_ATTR(fan5_fault, S_IRUGO, get_fan_fault, NULL, 4);
+static SENSOR_DEVICE_ATTR(fan6_fault, S_IRUGO, get_fan_fault, NULL, 5);
+
+static SENSOR_DEVICE_ATTR(fan7_input, S_IRUGO, get_fan, NULL, 6);
+static SENSOR_DEVICE_ATTR(fan8_input, S_IRUGO, get_fan, NULL, 7);
+static SENSOR_DEVICE_ATTR(fan9_input, S_IRUGO, get_fan, NULL, 8);
+static SENSOR_DEVICE_ATTR(fan10_input, S_IRUGO, get_fan, NULL, 9);
+static SENSOR_DEVICE_ATTR(fan11_input, S_IRUGO, get_fan, NULL, 10);
+static SENSOR_DEVICE_ATTR(fan12_input, S_IRUGO, get_fan, NULL, 11);
+
+static SENSOR_DEVICE_ATTR(fan7_fault, S_IRUGO, get_fan_fault, NULL, 6);
+static SENSOR_DEVICE_ATTR(fan8_fault, S_IRUGO, get_fan_fault, NULL, 7);
+static SENSOR_DEVICE_ATTR(fan9_fault, S_IRUGO, get_fan_fault, NULL, 8);
+static SENSOR_DEVICE_ATTR(fan10_fault, S_IRUGO, get_fan_fault, NULL, 9);
+static SENSOR_DEVICE_ATTR(fan11_fault, S_IRUGO, get_fan_fault, NULL, 10);
+static SENSOR_DEVICE_ATTR(fan12_fault, S_IRUGO, get_fan_fault, NULL, 11);
+
+static SENSOR_DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO,
+               get_fan_target, set_fan_target, 0);
+static SENSOR_DEVICE_ATTR(fan2_target, S_IWUSR | S_IRUGO,
+               get_fan_target, set_fan_target, 1);
+static SENSOR_DEVICE_ATTR(fan3_target, S_IWUSR | S_IRUGO,
+               get_fan_target, set_fan_target, 2);
+static SENSOR_DEVICE_ATTR(fan4_target, S_IWUSR | S_IRUGO,
+               get_fan_target, set_fan_target, 3);
+static SENSOR_DEVICE_ATTR(fan5_target, S_IWUSR | S_IRUGO,
+               get_fan_target, set_fan_target, 4);
+static SENSOR_DEVICE_ATTR(fan6_target, S_IWUSR | S_IRUGO,
+               get_fan_target, set_fan_target, 5);
+
+static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 0);
+static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 1);
+static SENSOR_DEVICE_ATTR(pwm3, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 2);
+static SENSOR_DEVICE_ATTR(pwm4, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 3);
+static SENSOR_DEVICE_ATTR(pwm5, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 4);
+static SENSOR_DEVICE_ATTR(pwm6, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 5);
+
+static SENSOR_DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
+               get_pwm_enable, set_pwm_enable, 0);
+static SENSOR_DEVICE_ATTR(pwm2_enable, S_IWUSR | S_IRUGO,
+               get_pwm_enable, set_pwm_enable, 1);
+static SENSOR_DEVICE_ATTR(pwm3_enable, S_IWUSR | S_IRUGO,
+               get_pwm_enable, set_pwm_enable, 2);
+static SENSOR_DEVICE_ATTR(pwm4_enable, S_IWUSR | S_IRUGO,
+               get_pwm_enable, set_pwm_enable, 3);
+static SENSOR_DEVICE_ATTR(pwm5_enable, S_IWUSR | S_IRUGO,
+               get_pwm_enable, set_pwm_enable, 4);
+static SENSOR_DEVICE_ATTR(pwm6_enable, S_IWUSR | S_IRUGO,
+               get_pwm_enable, set_pwm_enable, 5);
+
+static struct attribute *max31790_attrs[] = {
+       &sensor_dev_attr_fan1_input.dev_attr.attr,
+       &sensor_dev_attr_fan2_input.dev_attr.attr,
+       &sensor_dev_attr_fan3_input.dev_attr.attr,
+       &sensor_dev_attr_fan4_input.dev_attr.attr,
+       &sensor_dev_attr_fan5_input.dev_attr.attr,
+       &sensor_dev_attr_fan6_input.dev_attr.attr,
+
+       &sensor_dev_attr_fan1_fault.dev_attr.attr,
+       &sensor_dev_attr_fan2_fault.dev_attr.attr,
+       &sensor_dev_attr_fan3_fault.dev_attr.attr,
+       &sensor_dev_attr_fan4_fault.dev_attr.attr,
+       &sensor_dev_attr_fan5_fault.dev_attr.attr,
+       &sensor_dev_attr_fan6_fault.dev_attr.attr,
+
+       &sensor_dev_attr_fan7_input.dev_attr.attr,
+       &sensor_dev_attr_fan8_input.dev_attr.attr,
+       &sensor_dev_attr_fan9_input.dev_attr.attr,
+       &sensor_dev_attr_fan10_input.dev_attr.attr,
+       &sensor_dev_attr_fan11_input.dev_attr.attr,
+       &sensor_dev_attr_fan12_input.dev_attr.attr,
+
+       &sensor_dev_attr_fan7_fault.dev_attr.attr,
+       &sensor_dev_attr_fan8_fault.dev_attr.attr,
+       &sensor_dev_attr_fan9_fault.dev_attr.attr,
+       &sensor_dev_attr_fan10_fault.dev_attr.attr,
+       &sensor_dev_attr_fan11_fault.dev_attr.attr,
+       &sensor_dev_attr_fan12_fault.dev_attr.attr,
+
+       &sensor_dev_attr_fan1_target.dev_attr.attr,
+       &sensor_dev_attr_fan2_target.dev_attr.attr,
+       &sensor_dev_attr_fan3_target.dev_attr.attr,
+       &sensor_dev_attr_fan4_target.dev_attr.attr,
+       &sensor_dev_attr_fan5_target.dev_attr.attr,
+       &sensor_dev_attr_fan6_target.dev_attr.attr,
+
+       &sensor_dev_attr_pwm1.dev_attr.attr,
+       &sensor_dev_attr_pwm2.dev_attr.attr,
+       &sensor_dev_attr_pwm3.dev_attr.attr,
+       &sensor_dev_attr_pwm4.dev_attr.attr,
+       &sensor_dev_attr_pwm5.dev_attr.attr,
+       &sensor_dev_attr_pwm6.dev_attr.attr,
+
+       &sensor_dev_attr_pwm1_enable.dev_attr.attr,
+       &sensor_dev_attr_pwm2_enable.dev_attr.attr,
+       &sensor_dev_attr_pwm3_enable.dev_attr.attr,
+       &sensor_dev_attr_pwm4_enable.dev_attr.attr,
+       &sensor_dev_attr_pwm5_enable.dev_attr.attr,
+       &sensor_dev_attr_pwm6_enable.dev_attr.attr,
+       NULL
+};
+
+static umode_t max31790_attrs_visible(struct kobject *kobj,
+                                    struct attribute *a, int n)
+{
+       struct device *dev = container_of(kobj, struct device, kobj);
+       struct max31790_data *data = dev_get_drvdata(dev);
+       struct device_attribute *devattr =
+                       container_of(a, struct device_attribute, attr);
+       int index = to_sensor_dev_attr(devattr)->index % NR_CHANNEL;
+       u8 fan_config;
+
+       fan_config = data->fan_config[index];
+
+       if (n >= NR_CHANNEL * 2 && n < NR_CHANNEL * 4 &&
+           !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
+               return 0;
+       if (n >= NR_CHANNEL * 4 && (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
+               return 0;
+
+       return a->mode;
+}
+
+static const struct attribute_group max31790_group = {
+       .attrs = max31790_attrs,
+       .is_visible = max31790_attrs_visible,
+};
+__ATTRIBUTE_GROUPS(max31790);
+
+static int max31790_init_client(struct i2c_client *client,
+                               struct max31790_data *data)
+{
+       int i, rv;
+
+       for (i = 0; i < NR_CHANNEL; i++) {
+               rv = i2c_smbus_read_byte_data(client,
+                               MAX31790_REG_FAN_CONFIG(i));
+               if (rv < 0)
+                       return rv;
+               data->fan_config[i] = rv;
+
+               rv = i2c_smbus_read_byte_data(client,
+                               MAX31790_REG_FAN_DYNAMICS(i));
+               if (rv < 0)
+                       return rv;
+               data->fan_dynamics[i] = rv;
+       }
+
+       return 0;
+}
+
+static int max31790_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+       struct i2c_adapter *adapter = client->adapter;
+       struct device *dev = &client->dev;
+       struct max31790_data *data;
+       struct device *hwmon_dev;
+       int err;
+
+       if (!i2c_check_functionality(adapter,
+                       I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
+               return -ENODEV;
+
+       data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       data->client = client;
+       mutex_init(&data->update_lock);
+
+       /*
+        * Initialize the max31790 chip
+        */
+       err = max31790_init_client(client, data);
+       if (err)
+               return err;
+
+       hwmon_dev = devm_hwmon_device_register_with_groups(dev,
+                       client->name, data, max31790_groups);
+
+       return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id max31790_id[] = {
+       { "max31790", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, max31790_id);
+
+static struct i2c_driver max31790_driver = {
+       .class          = I2C_CLASS_HWMON,
+       .probe          = max31790_probe,
+       .driver = {
+               .name   = "max31790",
+       },
+       .id_table       = max31790_id,
+};
+
+module_i2c_driver(max31790_driver);
+
+MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>");
+MODULE_DESCRIPTION("MAX31790 sensor driver");
+MODULE_LICENSE("GPL");