hwmon: add support for adt7470

New driver to expose temperature and fan controls attached to Analog
Devices ADT7470 hwmon chips.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

3 files changed, 1061 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 7317793..da15d53 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -133,6 +133,16 @@ config SENSORS_ADM9240
 	  This driver can also be built as a module.  If so, the module
 	  will be called adm9240.
 
+config SENSORS_ADT7470
+	tristate "Analog Devices ADT7470"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the Analog Devices
+	  ADT7470 temperature monitoring chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called adt7470.
+
 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 6e9fdc2..fb4e0d8 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_SENSORS_ADM1026)	+= adm1026.o
 obj-$(CONFIG_SENSORS_ADM1029)	+= adm1029.o
 obj-$(CONFIG_SENSORS_ADM1031)	+= adm1031.o
 obj-$(CONFIG_SENSORS_ADM9240)	+= adm9240.o
+obj-$(CONFIG_SENSORS_ADT7470)	+= adt7470.o
 obj-$(CONFIG_SENSORS_APPLESMC)	+= applesmc.o
 obj-$(CONFIG_SENSORS_AMS)	+= ams/
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
new file mode 100644
index 0000000..c4dc205
--- /dev/null
+++ b/drivers/hwmon/adt7470.c
@@ -0,0 +1,1050 @@
+/*
+ * A hwmon driver for the Analog Devices ADT7470
+ * Copyright (C) 2007 IBM
+ *
+ * Author: Darrick J. Wong <djwong@us.ibm.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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.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>
+#include <linux/delay.h>
+#include <linux/log2.h>
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x2C, 0x2E, 0x2F, I2C_CLIENT_END };
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(adt7470);
+
+/* ADT7470 registers */
+#define ADT7470_REG_BASE_ADDR			0x20
+#define ADT7470_REG_TEMP_BASE_ADDR		0x20
+#define ADT7470_REG_TEMP_MAX_ADDR		0x29
+#define ADT7470_REG_FAN_BASE_ADDR		0x2A
+#define ADT7470_REG_FAN_MAX_ADDR		0x31
+#define ADT7470_REG_PWM_BASE_ADDR		0x32
+#define ADT7470_REG_PWM_MAX_ADDR		0x35
+#define ADT7470_REG_PWM_MAX_BASE_ADDR		0x38
+#define ADT7470_REG_PWM_MAX_MAX_ADDR		0x3B
+#define ADT7470_REG_CFG				0x40
+#define		ADT7470_FSPD_MASK		0x04
+#define ADT7470_REG_ALARM1			0x41
+#define ADT7470_REG_ALARM2			0x42
+#define ADT7470_REG_TEMP_LIMITS_BASE_ADDR	0x44
+#define ADT7470_REG_TEMP_LIMITS_MAX_ADDR	0x57
+#define ADT7470_REG_FAN_MIN_BASE_ADDR		0x58
+#define ADT7470_REG_FAN_MIN_MAX_ADDR		0x5F
+#define ADT7470_REG_FAN_MAX_BASE_ADDR		0x60
+#define ADT7470_REG_FAN_MAX_MAX_ADDR		0x67
+#define ADT7470_REG_PWM_CFG_BASE_ADDR		0x68
+#define ADT7470_REG_PWM12_CFG			0x68
+#define		ADT7470_PWM2_AUTO_MASK		0x40
+#define		ADT7470_PWM1_AUTO_MASK		0x80
+#define ADT7470_REG_PWM34_CFG			0x69
+#define		ADT7470_PWM3_AUTO_MASK		0x40
+#define		ADT7470_PWM4_AUTO_MASK		0x80
+#define	ADT7470_REG_PWM_MIN_BASE_ADDR		0x6A
+#define ADT7470_REG_PWM_MIN_MAX_ADDR		0x6D
+#define ADT7470_REG_PWM_TEMP_MIN_BASE_ADDR	0x6E
+#define ADT7470_REG_PWM_TEMP_MIN_MAX_ADDR	0x71
+#define ADT7470_REG_ACOUSTICS12			0x75
+#define ADT7470_REG_ACOUSTICS34			0x76
+#define ADT7470_REG_DEVICE			0x3D
+#define ADT7470_REG_VENDOR			0x3E
+#define ADT7470_REG_REVISION			0x3F
+#define ADT7470_REG_ALARM1_MASK			0x72
+#define ADT7470_REG_ALARM2_MASK			0x73
+#define ADT7470_REG_PWM_AUTO_TEMP_BASE_ADDR	0x7C
+#define ADT7470_REG_PWM_AUTO_TEMP_MAX_ADDR	0x7D
+#define ADT7470_REG_MAX_ADDR			0x81
+
+#define ADT7470_TEMP_COUNT	10
+#define ADT7470_TEMP_REG(x)	(ADT7470_REG_TEMP_BASE_ADDR + (x))
+#define ADT7470_TEMP_MIN_REG(x) (ADT7470_REG_TEMP_LIMITS_BASE_ADDR + ((x) * 2))
+#define ADT7470_TEMP_MAX_REG(x) (ADT7470_REG_TEMP_LIMITS_BASE_ADDR + \
+				((x) * 2) + 1)
+
+#define ADT7470_FAN_COUNT	4
+#define ADT7470_REG_FAN(x)	(ADT7470_REG_FAN_BASE_ADDR + ((x) * 2))
+#define ADT7470_REG_FAN_MIN(x)	(ADT7470_REG_FAN_MIN_BASE_ADDR + ((x) * 2))
+#define ADT7470_REG_FAN_MAX(x)	(ADT7470_REG_FAN_MAX_BASE_ADDR + ((x) * 2))
+
+#define ADT7470_PWM_COUNT	4
+#define ADT7470_REG_PWM(x)	(ADT7470_REG_PWM_BASE_ADDR + (x))
+#define ADT7470_REG_PWM_MAX(x)	(ADT7470_REG_PWM_MAX_BASE_ADDR + (x))
+#define ADT7470_REG_PWM_MIN(x)	(ADT7470_REG_PWM_MIN_BASE_ADDR + (x))
+#define ADT7470_REG_PWM_TMIN(x)	(ADT7470_REG_PWM_TEMP_MIN_BASE_ADDR + (x))
+#define ADT7470_REG_PWM_CFG(x)	(ADT7470_REG_PWM_CFG_BASE_ADDR + ((x) / 2))
+#define ADT7470_REG_PWM_AUTO_TEMP(x)	(ADT7470_REG_PWM_AUTO_TEMP_BASE_ADDR + \
+					((x) / 2))
+
+#define ADT7470_VENDOR		0x41
+#define ADT7470_DEVICE		0x70
+/* datasheet only mentions a revision 2 */
+#define ADT7470_REVISION	0x02
+
+/* "all temps" according to hwmon sysfs interface spec */
+#define ADT7470_PWM_ALL_TEMPS	0x3FF
+
+/* How often do we reread sensors values? (In jiffies) */
+#define SENSOR_REFRESH_INTERVAL	(5 * HZ)
+
+/* How often do we reread sensor limit values? (In jiffies) */
+#define LIMIT_REFRESH_INTERVAL	(60 * HZ)
+
+/* sleep 1s while gathering temperature data */
+#define TEMP_COLLECTION_TIME	1000
+
+#define power_of_2(x)	(((x) & ((x) - 1)) == 0)
+
+/* datasheet says to divide this number by the fan reading to get fan rpm */
+#define FAN_PERIOD_TO_RPM(x)	((90000 * 60) / (x))
+#define FAN_RPM_TO_PERIOD	FAN_PERIOD_TO_RPM
+#define FAN_PERIOD_INVALID	65535
+#define FAN_DATA_VALID(x)	((x) && (x) != FAN_PERIOD_INVALID)
+
+struct adt7470_data {
+	struct i2c_client	client;
+	struct class_device	*class_dev;
+	struct attribute_group	attrs;
+	struct mutex		lock;
+	char			sensors_valid;
+	char			limits_valid;
+	unsigned long		sensors_last_updated;	/* In jiffies */
+	unsigned long		limits_last_updated;	/* In jiffies */
+
+	s8			temp[ADT7470_TEMP_COUNT];
+	s8			temp_min[ADT7470_TEMP_COUNT];
+	s8			temp_max[ADT7470_TEMP_COUNT];
+	u16			fan[ADT7470_FAN_COUNT];
+	u16			fan_min[ADT7470_FAN_COUNT];
+	u16			fan_max[ADT7470_FAN_COUNT];
+	u16			alarms, alarms_mask;
+	u8			force_pwm_max;
+	u8			pwm[ADT7470_PWM_COUNT];
+	u8			pwm_max[ADT7470_PWM_COUNT];
+	u8			pwm_automatic[ADT7470_PWM_COUNT];
+	u8			pwm_min[ADT7470_PWM_COUNT];
+	s8			pwm_tmin[ADT7470_PWM_COUNT];
+	u8			pwm_auto_temp[ADT7470_PWM_COUNT];
+};
+
+static int adt7470_attach_adapter(struct i2c_adapter *adapter);
+static int adt7470_detect(struct i2c_adapter *adapter, int address, int kind);
+static int adt7470_detach_client(struct i2c_client *client);
+
+static struct i2c_driver adt7470_driver = {
+	.driver = {
+		.name	= "adt7470",
+	},
+	.attach_adapter	= adt7470_attach_adapter,
+	.detach_client	= adt7470_detach_client,
+};
+
+/*
+ * 16-bit registers on the ADT7470 are low-byte first.  The data sheet says
+ * that the low byte must be read before the high byte.
+ */
+static inline int adt7470_read_word_data(struct i2c_client *client, u8 reg)
+{
+	u16 foo;
+	foo = i2c_smbus_read_byte_data(client, reg);
+	foo |= ((u16)i2c_smbus_read_byte_data(client, reg + 1) << 8);
+	return foo;
+}
+
+static inline int adt7470_write_word_data(struct i2c_client *client, u8 reg,
+					  u16 value)
+{
+	return i2c_smbus_write_byte_data(client, reg, value & 0xFF)
+	       && i2c_smbus_write_byte_data(client, reg + 1, value >> 8);
+}
+
+static void adt7470_init_client(struct i2c_client *client)
+{
+	int reg = i2c_smbus_read_byte_data(client, ADT7470_REG_CFG);
+
+	if (reg < 0) {
+		dev_err(&client->dev, "cannot read configuration register\n");
+	} else {
+		/* start monitoring (and do a self-test) */
+		i2c_smbus_write_byte_data(client, ADT7470_REG_CFG, reg | 3);
+	}
+}
+
+static struct adt7470_data *adt7470_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	unsigned long local_jiffies = jiffies;
+	u8 cfg;
+	int i;
+
+	mutex_lock(&data->lock);
+	if (time_before(local_jiffies, data->sensors_last_updated +
+		SENSOR_REFRESH_INTERVAL)
+		&& data->sensors_valid)
+		goto no_sensor_update;
+
+	/* start reading temperature sensors */
+	cfg = i2c_smbus_read_byte_data(client, ADT7470_REG_CFG);
+	cfg |= 0x80;
+	i2c_smbus_write_byte_data(client, ADT7470_REG_CFG, cfg);
+
+	/*
+	 * Delay is 200ms * number of tmp05 sensors.  Too bad
+	 * there's no way to figure out how many are connected.
+	 * For now, assume 1s will work.
+	 */
+	msleep(TEMP_COLLECTION_TIME);
+
+	/* done reading temperature sensors */
+	cfg = i2c_smbus_read_byte_data(client, ADT7470_REG_CFG);
+	cfg &= ~0x80;
+	i2c_smbus_write_byte_data(client, ADT7470_REG_CFG, cfg);
+
+	for (i = 0; i < ADT7470_TEMP_COUNT; i++)
+		data->temp[i] = i2c_smbus_read_byte_data(client,
+						ADT7470_TEMP_REG(i));
+
+	for (i = 0; i < ADT7470_FAN_COUNT; i++)
+		data->fan[i] = adt7470_read_word_data(client,
+						ADT7470_REG_FAN(i));
+
+	for (i = 0; i < ADT7470_PWM_COUNT; i++) {
+		int reg;
+		int reg_mask;
+
+		data->pwm[i] = i2c_smbus_read_byte_data(client,
+						ADT7470_REG_PWM(i));
+
+		if (i % 2)
+			reg_mask = ADT7470_PWM2_AUTO_MASK;
+		else
+			reg_mask = ADT7470_PWM1_AUTO_MASK;
+
+		reg = ADT7470_REG_PWM_CFG(i);
+		if (i2c_smbus_read_byte_data(client, reg) & reg_mask)
+			data->pwm_automatic[i] = 1;
+		else
+			data->pwm_automatic[i] = 0;
+
+		reg = ADT7470_REG_PWM_AUTO_TEMP(i);
+		cfg = i2c_smbus_read_byte_data(client, reg);
+		if (!(i % 2))
+			data->pwm_auto_temp[i] = cfg >> 4;
+		else
+			data->pwm_auto_temp[i] = cfg & 0xF;
+	}
+
+	if (i2c_smbus_read_byte_data(client, ADT7470_REG_CFG) &
+	    ADT7470_FSPD_MASK)
+		data->force_pwm_max = 1;
+	else
+		data->force_pwm_max = 0;
+
+	data->alarms = adt7470_read_word_data(client, ADT7470_REG_ALARM1);
+	data->alarms_mask = adt7470_read_word_data(client,
+						   ADT7470_REG_ALARM1_MASK);
+
+	data->sensors_last_updated = local_jiffies;
+	data->sensors_valid = 1;
+
+no_sensor_update:
+	if (time_before(local_jiffies, data->limits_last_updated +
+		LIMIT_REFRESH_INTERVAL)
+		&& data->limits_valid)
+		goto out;
+
+	for (i = 0; i < ADT7470_TEMP_COUNT; i++) {
+		data->temp_min[i] = i2c_smbus_read_byte_data(client,
+						ADT7470_TEMP_MIN_REG(i));
+		data->temp_max[i] = i2c_smbus_read_byte_data(client,
+						ADT7470_TEMP_MAX_REG(i));
+	}
+
+	for (i = 0; i < ADT7470_FAN_COUNT; i++) {
+		data->fan_min[i] = adt7470_read_word_data(client,
+						ADT7470_REG_FAN_MIN(i));
+		data->fan_max[i] = adt7470_read_word_data(client,
+						ADT7470_REG_FAN_MAX(i));
+	}
+
+	for (i = 0; i < ADT7470_PWM_COUNT; i++) {
+		data->pwm_max[i] = i2c_smbus_read_byte_data(client,
+						ADT7470_REG_PWM_MAX(i));
+		data->pwm_min[i] = i2c_smbus_read_byte_data(client,
+						ADT7470_REG_PWM_MIN(i));
+		data->pwm_tmin[i] = i2c_smbus_read_byte_data(client,
+						ADT7470_REG_PWM_TMIN(i));
+	}
+
+	data->limits_last_updated = local_jiffies;
+	data->limits_valid = 1;
+
+out:
+	mutex_unlock(&data->lock);
+	return data;
+}
+
+static ssize_t show_temp_min(struct device *dev,
+			     struct device_attribute *devattr,
+			     char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", 1000 * data->temp_min[attr->index]);
+}
+
+static ssize_t set_temp_min(struct device *dev,
+			    struct device_attribute *devattr,
+			    const char *buf,
+			    size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10) / 1000;
+
+	mutex_lock(&data->lock);
+	data->temp_min[attr->index] = temp;
+	i2c_smbus_write_byte_data(client, ADT7470_TEMP_MIN_REG(attr->index),
+				  temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_temp_max(struct device *dev,
+			     struct device_attribute *devattr,
+			     char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", 1000 * data->temp_max[attr->index]);
+}
+
+static ssize_t set_temp_max(struct device *dev,
+			    struct device_attribute *devattr,
+			    const char *buf,
+			    size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10) / 1000;
+
+	mutex_lock(&data->lock);
+	data->temp_max[attr->index] = temp;
+	i2c_smbus_write_byte_data(client, ADT7470_TEMP_MAX_REG(attr->index),
+				  temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
+			 char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", 1000 * data->temp[attr->index]);
+}
+
+static ssize_t show_alarms(struct device *dev,
+			   struct device_attribute *devattr,
+			   char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+
+	if (attr->index)
+		return sprintf(buf, "%x\n", data->alarms);
+	else
+		return sprintf(buf, "%x\n", data->alarms_mask);
+}
+
+static ssize_t show_fan_max(struct device *dev,
+			    struct device_attribute *devattr,
+			    char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+
+	if (FAN_DATA_VALID(data->fan_max[attr->index]))
+		return sprintf(buf, "%d\n",
+			       FAN_PERIOD_TO_RPM(data->fan_max[attr->index]));
+	else
+		return sprintf(buf, "0\n");
+}
+
+static ssize_t set_fan_max(struct device *dev,
+			   struct device_attribute *devattr,
+			   const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+
+	if (!temp)
+		return -EINVAL;
+	temp = FAN_RPM_TO_PERIOD(temp);
+
+	mutex_lock(&data->lock);
+	data->fan_max[attr->index] = temp;
+	adt7470_write_word_data(client, ADT7470_REG_FAN_MAX(attr->index), temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_fan_min(struct device *dev,
+			    struct device_attribute *devattr,
+			    char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+
+	if (FAN_DATA_VALID(data->fan_min[attr->index]))
+		return sprintf(buf, "%d\n",
+			       FAN_PERIOD_TO_RPM(data->fan_min[attr->index]));
+	else
+		return sprintf(buf, "0\n");
+}
+
+static ssize_t set_fan_min(struct device *dev,
+			   struct device_attribute *devattr,
+			   const char *buf, size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+
+	if (!temp)
+		return -EINVAL;
+	temp = FAN_RPM_TO_PERIOD(temp);
+
+	mutex_lock(&data->lock);
+	data->fan_min[attr->index] = temp;
+	adt7470_write_word_data(client, ADT7470_REG_FAN_MIN(attr->index), temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_fan(struct device *dev, struct device_attribute *devattr,
+			char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+
+	if (FAN_DATA_VALID(data->fan[attr->index]))
+		return sprintf(buf, "%d\n",
+			       FAN_PERIOD_TO_RPM(data->fan[attr->index]));
+	else
+		return sprintf(buf, "0\n");
+}
+
+static ssize_t show_force_pwm_max(struct device *dev,
+				  struct device_attribute *devattr,
+				  char *buf)
+{
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", data->force_pwm_max);
+}
+
+static ssize_t set_force_pwm_max(struct device *dev,
+				 struct device_attribute *devattr,
+				 const char *buf,
+				 size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+	u8 reg;
+
+	mutex_lock(&data->lock);
+	data->force_pwm_max = temp;
+	reg = i2c_smbus_read_byte_data(client, ADT7470_REG_CFG);
+	if (temp)
+		reg |= ADT7470_FSPD_MASK;
+	else
+		reg &= ~ADT7470_FSPD_MASK;
+	i2c_smbus_write_byte_data(client, ADT7470_REG_CFG, reg);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_pwm(struct device *dev, struct device_attribute *devattr,
+			char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", data->pwm[attr->index]);
+}
+
+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 i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+
+	mutex_lock(&data->lock);
+	data->pwm[attr->index] = temp;
+	i2c_smbus_write_byte_data(client, ADT7470_REG_PWM(attr->index), temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_pwm_max(struct device *dev,
+			    struct device_attribute *devattr,
+			    char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", data->pwm_max[attr->index]);
+}
+
+static ssize_t set_pwm_max(struct device *dev,
+			   struct device_attribute *devattr,
+			   const char *buf,
+			   size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+
+	mutex_lock(&data->lock);
+	data->pwm_max[attr->index] = temp;
+	i2c_smbus_write_byte_data(client, ADT7470_REG_PWM_MAX(attr->index),
+				  temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_pwm_min(struct device *dev,
+			    struct device_attribute *devattr,
+			    char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", data->pwm_min[attr->index]);
+}
+
+static ssize_t set_pwm_min(struct device *dev,
+			   struct device_attribute *devattr,
+			   const char *buf,
+			   size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+
+	mutex_lock(&data->lock);
+	data->pwm_min[attr->index] = temp;
+	i2c_smbus_write_byte_data(client, ADT7470_REG_PWM_MIN(attr->index),
+				  temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_pwm_tmax(struct device *dev,
+			     struct device_attribute *devattr,
+			     char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	/* the datasheet says that tmax = tmin + 20C */
+	return sprintf(buf, "%d\n", 1000 * (20 + data->pwm_tmin[attr->index]));
+}
+
+static ssize_t show_pwm_tmin(struct device *dev,
+			     struct device_attribute *devattr,
+			     char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", 1000 * data->pwm_tmin[attr->index]);
+}
+
+static ssize_t set_pwm_tmin(struct device *dev,
+			    struct device_attribute *devattr,
+			    const char *buf,
+			    size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10) / 1000;
+
+	mutex_lock(&data->lock);
+	data->pwm_tmin[attr->index] = temp;
+	i2c_smbus_write_byte_data(client, ADT7470_REG_PWM_TMIN(attr->index),
+				  temp);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_pwm_auto(struct device *dev,
+			     struct device_attribute *devattr,
+			     char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	return sprintf(buf, "%d\n", 1 + data->pwm_automatic[attr->index]);
+}
+
+static ssize_t set_pwm_auto(struct device *dev,
+			    struct device_attribute *devattr,
+			    const char *buf,
+			    size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = simple_strtol(buf, NULL, 10);
+	int pwm_auto_reg = ADT7470_REG_PWM_CFG(attr->index);
+	int pwm_auto_reg_mask;
+	u8 reg;
+
+	if (attr->index % 2)
+		pwm_auto_reg_mask = ADT7470_PWM2_AUTO_MASK;
+	else
+		pwm_auto_reg_mask = ADT7470_PWM1_AUTO_MASK;
+
+	if (temp != 2 && temp != 1)
+		return -EINVAL;
+	temp--;
+
+	mutex_lock(&data->lock);
+	data->pwm_automatic[attr->index] = temp;
+	reg = i2c_smbus_read_byte_data(client, pwm_auto_reg);
+	if (temp)
+		reg |= pwm_auto_reg_mask;
+	else
+		reg &= ~pwm_auto_reg_mask;
+	i2c_smbus_write_byte_data(client, pwm_auto_reg, reg);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static ssize_t show_pwm_auto_temp(struct device *dev,
+				  struct device_attribute *devattr,
+				  char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7470_data *data = adt7470_update_device(dev);
+	u8 ctrl = data->pwm_auto_temp[attr->index];
+
+	if (ctrl)
+		return sprintf(buf, "%d\n", 1 << (ctrl - 1));
+	else
+		return sprintf(buf, "%d\n", ADT7470_PWM_ALL_TEMPS);
+}
+
+static int cvt_auto_temp(int input)
+{
+	if (input == ADT7470_PWM_ALL_TEMPS)
+		return 0;
+	if (input < 1 || !power_of_2(input))
+		return -EINVAL;
+	return ilog2(input) + 1;
+}
+
+static ssize_t set_pwm_auto_temp(struct device *dev,
+				 struct device_attribute *devattr,
+				 const char *buf,
+				 size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7470_data *data = i2c_get_clientdata(client);
+	int temp = cvt_auto_temp(simple_strtol(buf, NULL, 10));
+	int pwm_auto_reg = ADT7470_REG_PWM_AUTO_TEMP(attr->index);
+	u8 reg;
+
+	if (temp < 0)
+		return temp;
+
+	mutex_lock(&data->lock);
+	data->pwm_automatic[attr->index] = temp;
+	reg = i2c_smbus_read_byte_data(client, pwm_auto_reg);
+
+	if (!(attr->index % 2)) {
+		reg &= 0xF;
+		reg |= (temp << 4) & 0xF0;
+	} else {
+		reg &= 0xF0;
+		reg |= temp & 0xF;
+	}
+
+	i2c_smbus_write_byte_data(client, pwm_auto_reg, reg);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static SENSOR_DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL, 0);
+static SENSOR_DEVICE_ATTR(alarm_mask, S_IRUGO, show_alarms, NULL, 1);
+
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 0);
+static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 1);
+static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 2);
+static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 3);
+static SENSOR_DEVICE_ATTR(temp5_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 4);
+static SENSOR_DEVICE_ATTR(temp6_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 5);
+static SENSOR_DEVICE_ATTR(temp7_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 6);
+static SENSOR_DEVICE_ATTR(temp8_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 7);
+static SENSOR_DEVICE_ATTR(temp9_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 8);
+static SENSOR_DEVICE_ATTR(temp10_max, S_IWUSR | S_IRUGO, show_temp_max,
+		    set_temp_max, 9);
+
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 0);
+static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 1);
+static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 2);
+static SENSOR_DEVICE_ATTR(temp4_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 3);
+static SENSOR_DEVICE_ATTR(temp5_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 4);
+static SENSOR_DEVICE_ATTR(temp6_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 5);
+static SENSOR_DEVICE_ATTR(temp7_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 6);
+static SENSOR_DEVICE_ATTR(temp8_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 7);
+static SENSOR_DEVICE_ATTR(temp9_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 8);
+static SENSOR_DEVICE_ATTR(temp10_min, S_IWUSR | S_IRUGO, show_temp_min,
+		    set_temp_min, 9);
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_temp, NULL, 4);
+static SENSOR_DEVICE_ATTR(temp6_input, S_IRUGO, show_temp, NULL, 5);
+static SENSOR_DEVICE_ATTR(temp7_input, S_IRUGO, show_temp, NULL, 6);
+static SENSOR_DEVICE_ATTR(temp8_input, S_IRUGO, show_temp, NULL, 7);
+static SENSOR_DEVICE_ATTR(temp9_input, S_IRUGO, show_temp, NULL, 8);
+static SENSOR_DEVICE_ATTR(temp10_input, S_IRUGO, show_temp, NULL, 9);
+
+static SENSOR_DEVICE_ATTR(fan1_max, S_IWUSR | S_IRUGO, show_fan_max,
+		    set_fan_max, 0);
+static SENSOR_DEVICE_ATTR(fan2_max, S_IWUSR | S_IRUGO, show_fan_max,
+		    set_fan_max, 1);
+static SENSOR_DEVICE_ATTR(fan3_max, S_IWUSR | S_IRUGO, show_fan_max,
+		    set_fan_max, 2);
+static SENSOR_DEVICE_ATTR(fan4_max, S_IWUSR | S_IRUGO, show_fan_max,
+		    set_fan_max, 3);
+
+static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan_min,
+		    set_fan_min, 0);
+static SENSOR_DEVICE_ATTR(fan2_min, S_IWUSR | S_IRUGO, show_fan_min,
+		    set_fan_min, 1);
+static SENSOR_DEVICE_ATTR(fan3_min, S_IWUSR | S_IRUGO, show_fan_min,
+		    set_fan_min, 2);
+static SENSOR_DEVICE_ATTR(fan4_min, S_IWUSR | S_IRUGO, show_fan_min,
+		    set_fan_min, 3);
+
+static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0);
+static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1);
+static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, show_fan, NULL, 2);
+static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, show_fan, NULL, 3);
+
+static SENSOR_DEVICE_ATTR(force_pwm_max, S_IWUSR | S_IRUGO,
+		    show_force_pwm_max, set_force_pwm_max, 0);
+
+static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 0);
+static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 1);
+static SENSOR_DEVICE_ATTR(pwm3, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 2);
+static SENSOR_DEVICE_ATTR(pwm4, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 3);
+
+static SENSOR_DEVICE_ATTR(pwm1_auto_point1_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_min, set_pwm_min, 0);
+static SENSOR_DEVICE_ATTR(pwm2_auto_point1_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_min, set_pwm_min, 1);
+static SENSOR_DEVICE_ATTR(pwm3_auto_point1_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_min, set_pwm_min, 2);
+static SENSOR_DEVICE_ATTR(pwm4_auto_point1_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_min, set_pwm_min, 3);
+
+static SENSOR_DEVICE_ATTR(pwm1_auto_point2_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_max, set_pwm_max, 0);
+static SENSOR_DEVICE_ATTR(pwm2_auto_point2_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_max, set_pwm_max, 1);
+static SENSOR_DEVICE_ATTR(pwm3_auto_point2_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_max, set_pwm_max, 2);
+static SENSOR_DEVICE_ATTR(pwm4_auto_point2_pwm, S_IWUSR | S_IRUGO,
+		    show_pwm_max, set_pwm_max, 3);
+
+static SENSOR_DEVICE_ATTR(pwm1_auto_point1_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_tmin, set_pwm_tmin, 0);
+static SENSOR_DEVICE_ATTR(pwm2_auto_point1_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_tmin, set_pwm_tmin, 1);
+static SENSOR_DEVICE_ATTR(pwm3_auto_point1_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_tmin, set_pwm_tmin, 2);
+static SENSOR_DEVICE_ATTR(pwm4_auto_point1_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_tmin, set_pwm_tmin, 3);
+
+static SENSOR_DEVICE_ATTR(pwm1_auto_point2_temp, S_IRUGO, show_pwm_tmax,
+		    NULL, 0);
+static SENSOR_DEVICE_ATTR(pwm2_auto_point2_temp, S_IRUGO, show_pwm_tmax,
+		    NULL, 1);
+static SENSOR_DEVICE_ATTR(pwm3_auto_point2_temp, S_IRUGO, show_pwm_tmax,
+		    NULL, 2);
+static SENSOR_DEVICE_ATTR(pwm4_auto_point2_temp, S_IRUGO, show_pwm_tmax,
+		    NULL, 3);
+
+static SENSOR_DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, show_pwm_auto,
+		    set_pwm_auto, 0);
+static SENSOR_DEVICE_ATTR(pwm2_enable, S_IWUSR | S_IRUGO, show_pwm_auto,
+		    set_pwm_auto, 1);
+static SENSOR_DEVICE_ATTR(pwm3_enable, S_IWUSR | S_IRUGO, show_pwm_auto,
+		    set_pwm_auto, 2);
+static SENSOR_DEVICE_ATTR(pwm4_enable, S_IWUSR | S_IRUGO, show_pwm_auto,
+		    set_pwm_auto, 3);
+
+static SENSOR_DEVICE_ATTR(pwm1_auto_channels_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_auto_temp, set_pwm_auto_temp, 0);
+static SENSOR_DEVICE_ATTR(pwm2_auto_channels_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_auto_temp, set_pwm_auto_temp, 1);
+static SENSOR_DEVICE_ATTR(pwm3_auto_channels_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_auto_temp, set_pwm_auto_temp, 2);
+static SENSOR_DEVICE_ATTR(pwm4_auto_channels_temp, S_IWUSR | S_IRUGO,
+		    show_pwm_auto_temp, set_pwm_auto_temp, 3);
+
+static struct attribute *adt7470_attr[] =
+{
+	&sensor_dev_attr_alarms.dev_attr.attr,
+	&sensor_dev_attr_alarm_mask.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp2_max.dev_attr.attr,
+	&sensor_dev_attr_temp3_max.dev_attr.attr,
+	&sensor_dev_attr_temp4_max.dev_attr.attr,
+	&sensor_dev_attr_temp5_max.dev_attr.attr,
+	&sensor_dev_attr_temp6_max.dev_attr.attr,
+	&sensor_dev_attr_temp7_max.dev_attr.attr,
+	&sensor_dev_attr_temp8_max.dev_attr.attr,
+	&sensor_dev_attr_temp9_max.dev_attr.attr,
+	&sensor_dev_attr_temp10_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+	&sensor_dev_attr_temp2_min.dev_attr.attr,
+	&sensor_dev_attr_temp3_min.dev_attr.attr,
+	&sensor_dev_attr_temp4_min.dev_attr.attr,
+	&sensor_dev_attr_temp5_min.dev_attr.attr,
+	&sensor_dev_attr_temp6_min.dev_attr.attr,
+	&sensor_dev_attr_temp7_min.dev_attr.attr,
+	&sensor_dev_attr_temp8_min.dev_attr.attr,
+	&sensor_dev_attr_temp9_min.dev_attr.attr,
+	&sensor_dev_attr_temp10_min.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp3_input.dev_attr.attr,
+	&sensor_dev_attr_temp4_input.dev_attr.attr,
+	&sensor_dev_attr_temp5_input.dev_attr.attr,
+	&sensor_dev_attr_temp6_input.dev_attr.attr,
+	&sensor_dev_attr_temp7_input.dev_attr.attr,
+	&sensor_dev_attr_temp8_input.dev_attr.attr,
+	&sensor_dev_attr_temp9_input.dev_attr.attr,
+	&sensor_dev_attr_temp10_input.dev_attr.attr,
+	&sensor_dev_attr_fan1_max.dev_attr.attr,
+	&sensor_dev_attr_fan2_max.dev_attr.attr,
+	&sensor_dev_attr_fan3_max.dev_attr.attr,
+	&sensor_dev_attr_fan4_max.dev_attr.attr,
+	&sensor_dev_attr_fan1_min.dev_attr.attr,
+	&sensor_dev_attr_fan2_min.dev_attr.attr,
+	&sensor_dev_attr_fan3_min.dev_attr.attr,
+	&sensor_dev_attr_fan4_min.dev_attr.attr,
+	&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_force_pwm_max.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_pwm1_auto_point1_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm3_auto_point1_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm4_auto_point1_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm3_auto_point2_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm4_auto_point2_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_point1_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm3_auto_point1_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm4_auto_point1_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_point2_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm3_auto_point2_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm4_auto_point2_temp.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_pwm1_auto_channels_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm3_auto_channels_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm4_auto_channels_temp.dev_attr.attr,
+	NULL
+};
+
+static int adt7470_attach_adapter(struct i2c_adapter *adapter)
+{
+	if (!(adapter->class & I2C_CLASS_HWMON))
+		return 0;
+	return i2c_probe(adapter, &addr_data, adt7470_detect);
+}
+
+static int adt7470_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+	struct i2c_client *client;
+	struct adt7470_data *data;
+	int err = 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		goto exit;
+
+	if (!(data = kzalloc(sizeof(struct adt7470_data), GFP_KERNEL))) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	client = &data->client;
+	client->addr = address;
+	client->adapter = adapter;
+	client->driver = &adt7470_driver;
+
+	i2c_set_clientdata(client, data);
+
+	mutex_init(&data->lock);
+
+	if (kind <= 0) {
+		int vendor, device, revision;
+
+		vendor = i2c_smbus_read_byte_data(client, ADT7470_REG_VENDOR);
+		if (vendor != ADT7470_VENDOR) {
+			err = -ENODEV;
+			goto exit_free;
+		}
+
+		device = i2c_smbus_read_byte_data(client, ADT7470_REG_DEVICE);
+		if (device != ADT7470_DEVICE) {
+			err = -ENODEV;
+			goto exit_free;
+		}
+
+		revision = i2c_smbus_read_byte_data(client,
+						    ADT7470_REG_REVISION);
+		if (revision != ADT7470_REVISION) {
+			err = -ENODEV;
+			goto exit_free;
+		}
+	} else
+		dev_dbg(&adapter->dev, "detection forced\n");
+
+	strlcpy(client->name, "adt7470", I2C_NAME_SIZE);
+
+	if ((err = i2c_attach_client(client)))
+		goto exit_free;
+
+	dev_info(&client->dev, "%s chip found\n", client->name);
+
+	/* Initialize the ADT7470 chip */
+	adt7470_init_client(client);
+
+	/* Register sysfs hooks */
+	data->attrs.attrs = adt7470_attr;
+	if ((err = sysfs_create_group(&client->dev.kobj, &data->attrs)))
+		goto exit_detach;
+
+	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:
+	sysfs_remove_group(&client->dev.kobj, &data->attrs);
+exit_detach:
+	i2c_detach_client(client);
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int adt7470_detach_client(struct i2c_client *client)
+{
+	struct adt7470_data *data = i2c_get_clientdata(client);
+
+	hwmon_device_unregister(data->class_dev);
+	sysfs_remove_group(&client->dev.kobj, &data->attrs);
+	i2c_detach_client(client);
+	kfree(data);
+	return 0;
+}
+
+static int __init adt7470_init(void)
+{
+	return i2c_add_driver(&adt7470_driver);
+}
+
+static void __exit adt7470_exit(void)
+{
+	i2c_del_driver(&adt7470_driver);
+}
+
+MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
+MODULE_DESCRIPTION("ADT7470 driver");
+MODULE_LICENSE("GPL");
+
+module_init(adt7470_init);
+module_exit(adt7470_exit);