hwmon: ADT7461 Thermal Sensor driver

Bug 782954

Original-Change-Id: I142e9b3684830e5a10b506d320dbddb71efa57d3
Reviewed-on: http://git-master/r/18018
Reviewed-by: Varun Colbert <vcolbert@nvidia.com>
Tested-by: Varun Colbert <vcolbert@nvidia.com>

Rebase-Id: R333643df9c31076bc29d356d5835012dd8740862

3 files changed, 667 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 0b62c3c6b7ce..42e077c4dfeb 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -179,6 +179,16 @@ config SENSORS_ADT7411
 	  This driver can also be built as a module. If so, the module
 	  will be called adt7411.
 
+config SENSORS_ADT7461
+	tristate "Analog Devices ADT7461"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the Analog Devices
+	  ADT7461 temperature monitoring chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called adt7461.
+
 config SENSORS_ADT7462
 	tristate "Analog Devices ADT7462"
 	depends on I2C && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 3c9ccefea791..665a82fd1f91 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_SENSORS_ADS1015)	+= ads1015.o
 obj-$(CONFIG_SENSORS_ADS7828)	+= ads7828.o
 obj-$(CONFIG_SENSORS_ADS7871)	+= ads7871.o
 obj-$(CONFIG_SENSORS_ADT7411)	+= adt7411.o
+obj-$(CONFIG_SENSORS_ADT7461)	+= adt7461.o
 obj-$(CONFIG_SENSORS_ADT7462)	+= adt7462.o
 obj-$(CONFIG_SENSORS_ADT7470)	+= adt7470.o
 obj-$(CONFIG_SENSORS_ADT7475)	+= adt7475.o
diff --git a/drivers/hwmon/adt7461.c b/drivers/hwmon/adt7461.c
new file mode 100644
index 000000000000..50e50ee9e424
--- /dev/null
+++ b/drivers/hwmon/adt7461.c
@@ -0,0 +1,656 @@
+/*
+ * adt7461.c - Linux kernel modules for hardware
+ *          monitoring
+ * Copyright (C) 2003-2010  Jean Delvare <khali@linux-fr.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/regulator/consumer.h>
+#include <linux/i2c.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/hwmon.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+#include <linux/delay.h>
+
+/*
+ * The ADT7461 registers
+ */
+
+#define ADT7461_REG_R_MAN_ID			0xFE
+#define ADT7461_REG_R_CHIP_ID			0xFF
+#define ADT7461_REG_R_CONFIG1			0x03
+#define ADT7461_REG_W_CONFIG1			0x09
+#define ADT7461_REG_R_CONVRATE			0x04
+#define ADT7461_REG_W_CONVRATE			0x0A
+#define ADT7461_REG_R_STATUS			0x02
+#define ADT7461_REG_R_LOCAL_TEMP		0x00
+#define ADT7461_REG_R_LOCAL_HIGH		0x05
+#define ADT7461_REG_W_LOCAL_HIGH		0x0B
+#define ADT7461_REG_R_LOCAL_LOW			0x06
+#define ADT7461_REG_W_LOCAL_LOW			0x0C
+#define ADT7461_REG_R_LOCAL_CRIT		0x20
+#define ADT7461_REG_W_LOCAL_CRIT		0x20
+#define ADT7461_REG_R_REMOTE_TEMPH		0x01
+#define ADT7461_REG_R_REMOTE_TEMPL		0x10
+#define ADT7461_REG_R_REMOTE_OFFSH		0x11
+#define ADT7461_REG_W_REMOTE_OFFSH		0x11
+#define ADT7461_REG_R_REMOTE_OFFSL		0x12
+#define ADT7461_REG_W_REMOTE_OFFSL		0x12
+#define ADT7461_REG_R_REMOTE_HIGHH		0x07
+#define ADT7461_REG_W_REMOTE_HIGHH		0x0D
+#define ADT7461_REG_R_REMOTE_HIGHL		0x13
+#define ADT7461_REG_W_REMOTE_HIGHL		0x13
+#define ADT7461_REG_R_REMOTE_LOWH		0x08
+#define ADT7461_REG_W_REMOTE_LOWH		0x0E
+#define ADT7461_REG_R_REMOTE_LOWL		0x14
+#define ADT7461_REG_W_REMOTE_LOWL		0x14
+#define ADT7461_REG_R_REMOTE_CRIT		0x19
+#define ADT7461_REG_W_REMOTE_CRIT		0x19
+#define ADT7461_REG_R_TCRIT_HYST		0x21
+#define ADT7461_REG_W_TCRIT_HYST		0x21
+
+/*
+ * Device flags
+ */
+#define ADT7461_FLAG_ADT7461_EXT		0x01	/* ADT7461 extended mode */
+
+/*
+ * Client data
+ */
+
+struct adt7461_data {
+	struct device *hwmon_dev;
+	struct mutex update_lock;
+	struct regulator *regulator;
+	char valid; /* zero until following fields are valid */
+	unsigned long last_updated; /* in jiffies */
+	int flags;
+
+	u8 config_orig;		/* Original configuration register value */
+	u8 alert_alarms;	/* Which alarm bits trigger ALERT# */
+
+	/* registers values */
+	s8 temp8[4];	/* 0: local low limit
+			   1: local high limit
+			   2: local critical limit
+			   3: remote critical limit */
+	s16 temp11[5];	/* 0: remote input
+			   1: remote low limit
+			   2: remote high limit
+			   3: remote offset
+			   4: local input */
+	u8 temp_hyst;
+	u8 alarms; /* bitvector */
+};
+
+/*
+ * Conversions
+ */
+
+static inline int temp_from_s8(s8 val)
+{
+	return val * 1000;
+}
+
+static u8 hyst_to_reg(long val)
+{
+	if (val <= 0)
+		return 0;
+	if (val >= 30500)
+		return 31;
+	return (val + 500) / 1000;
+}
+
+/*
+ * ADT7461 attempts to write values that are outside the range
+ * 0 < temp < 127 are treated as the boundary value.
+ *
+ * ADT7461 in "extended mode" operation uses unsigned integers offset by
+ * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
+ */
+static inline int temp_from_u8(struct adt7461_data *data, u8 val)
+{
+	if (data->flags & ADT7461_FLAG_ADT7461_EXT)
+		return (val - 64) * 1000;
+	else
+		return temp_from_s8(val);
+}
+
+static inline int temp_from_u16(struct adt7461_data *data, u16 val)
+{
+	if (data->flags & ADT7461_FLAG_ADT7461_EXT)
+		return (val - 0x4000) / 64 * 250;
+	else
+		return val / 32 * 125;
+}
+
+static u8 temp_to_u8(struct adt7461_data *data, long val)
+{
+	if (data->flags & ADT7461_FLAG_ADT7461_EXT) {
+		if (val <= -64000)
+			return 0;
+		if (val >= 191000)
+			return 0xFF;
+		return (val + 500 + 64000) / 1000;
+	} else {
+		if (val <= 0)
+			return 0;
+		if (val >= 127000)
+			return 127;
+		return (val + 500) / 1000;
+	}
+}
+
+static u16 temp_to_u16(struct adt7461_data *data, long val)
+{
+	if (data->flags & ADT7461_FLAG_ADT7461_EXT) {
+		if (val <= -64000)
+			return 0;
+		if (val >= 191750)
+			return 0xFFC0;
+		return (val + 64000 + 125) / 250 * 64;
+	} else {
+		if (val <= 0)
+			return 0;
+		if (val >= 127750)
+			return 0x7FC0;
+		return (val + 125) / 250 * 64;
+	}
+}
+
+static int adt7461_read_reg(struct i2c_client* client, u8 reg, u8 *value)
+{
+	int err;
+
+	err = i2c_smbus_read_byte_data(client, reg);
+	if (err < 0) {
+		pr_err("adt7461_read_reg:Register %#02x read failed (%d)\n",
+			 reg, err);
+		return err;
+	}
+	*value = err;
+
+	return 0;
+}
+
+static int adt7461_read16(struct i2c_client *client, u8 regh, u8 regl,
+			u16 *value)
+{
+	int err;
+	u8 oldh, newh, l;
+
+	/*
+	 * There is a trick here. We have to read two registers to have the
+	 * sensor temperature, but we have to beware a conversion could occur
+	 * inbetween the readings. The datasheet says we should either use
+	 * the one-shot conversion register, which we don't want to do
+	 * (disables hardware monitoring) or monitor the busy bit, which is
+	 * impossible (we can't read the values and monitor that bit at the
+	 * exact same time). So the solution used here is to read the high
+	 * byte once, then the low byte, then the high byte again. If the new
+	 * high byte matches the old one, then we have a valid reading. Else
+	 * we have to read the low byte again, and now we believe we have a
+	 * correct reading.
+	 */
+	if ((err = adt7461_read_reg(client, regh, &oldh))
+	 || (err = adt7461_read_reg(client, regl, &l))
+	 || (err = adt7461_read_reg(client, regh, &newh)))
+		return err;
+	if (oldh != newh) {
+		err = adt7461_read_reg(client, regl, &l);
+		if (err)
+			return err;
+	}
+	*value = (newh << 8) | l;
+
+	return 0;
+}
+
+static struct adt7461_data *adt7461_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7461_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ / 2 + HZ / 10)
+	 || !data->valid) {
+		u8 h, l;
+
+		pr_err("adt7461_update_device:Updating adt7461 data.\n");
+		adt7461_read_reg(client, ADT7461_REG_R_LOCAL_LOW, &data->temp8[0]);
+		adt7461_read_reg(client, ADT7461_REG_R_LOCAL_HIGH, &data->temp8[1]);
+		adt7461_read_reg(client, ADT7461_REG_R_LOCAL_CRIT, &data->temp8[2]);
+		adt7461_read_reg(client, ADT7461_REG_R_REMOTE_CRIT, &data->temp8[3]);
+		adt7461_read_reg(client, ADT7461_REG_R_TCRIT_HYST, &data->temp_hyst);
+
+		if (adt7461_read_reg(client, ADT7461_REG_R_LOCAL_TEMP, &h) == 0)
+			data->temp11[4] = h << 8;
+
+		adt7461_read16(client, ADT7461_REG_R_REMOTE_TEMPH,
+				ADT7461_REG_R_REMOTE_TEMPL, &data->temp11[0]);
+
+		if (adt7461_read_reg(client, ADT7461_REG_R_REMOTE_LOWH, &h) == 0) {
+			data->temp11[1] = h << 8;
+			if (adt7461_read_reg(client, ADT7461_REG_R_REMOTE_LOWL, &l) == 0)
+				data->temp11[1] |= l;
+		}
+		if (adt7461_read_reg(client, ADT7461_REG_R_REMOTE_HIGHH, &h) == 0) {
+			data->temp11[2] = h << 8;
+			if (adt7461_read_reg(client, ADT7461_REG_R_REMOTE_HIGHL, &l) == 0)
+				data->temp11[2] |= l;
+		}
+
+		if (adt7461_read_reg(client, ADT7461_REG_R_REMOTE_OFFSH,
+					&h) == 0
+		 && adt7461_read_reg(client, ADT7461_REG_R_REMOTE_OFFSL,
+					&l) == 0)
+			data->temp11[3] = (h << 8) | l;
+		adt7461_read_reg(client, ADT7461_REG_R_STATUS, &data->alarms);
+
+		/* Re-enable ALERT# output if it was originally enabled and
+		 * relevant alarms are all clear */
+		if ((data->config_orig & 0x80) == 0
+		 && (data->alarms & data->alert_alarms) == 0) {
+			u8 config;
+
+			adt7461_read_reg(client, ADT7461_REG_R_CONFIG1, &config);
+			if (config & 0x80) {
+				pr_err("adt7461_update_device:Re-enabling ALERT#\n");
+				i2c_smbus_write_byte_data(client,
+							ADT7461_REG_W_CONFIG1,
+							config & ~0x80);
+			}
+		}
+
+		data->last_updated = jiffies;
+		data->valid = 1;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+/*
+ * Sysfs stuff
+ */
+
+static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
+			  char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7461_data *data = adt7461_update_device(dev);
+	int temp;
+
+	temp = temp_from_u8(data, data->temp8[attr->index]);
+
+	return sprintf(buf, "%d\n", temp);
+}
+
+static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
+			 const char *buf, size_t count)
+{
+	static const u8 reg[4] = {
+		ADT7461_REG_W_LOCAL_LOW,
+		ADT7461_REG_W_LOCAL_HIGH,
+		ADT7461_REG_W_LOCAL_CRIT,
+		ADT7461_REG_W_REMOTE_CRIT,
+	};
+
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7461_data *data = i2c_get_clientdata(client);
+	long val = simple_strtol(buf, NULL, 10);
+	int nr = attr->index;
+
+	mutex_lock(&data->update_lock);
+	data->temp8[nr] = temp_to_u8(data, val);
+	i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
+			  char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7461_data *data = adt7461_update_device(dev);
+	int temp;
+
+	temp = temp_from_u16(data, data->temp11[attr->index]);
+
+	return sprintf(buf, "%d\n", temp);
+}
+
+static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
+			  const char *buf, size_t count)
+{
+	static const u8 reg[6] = {
+		ADT7461_REG_W_REMOTE_LOWH,
+		ADT7461_REG_W_REMOTE_LOWL,
+		ADT7461_REG_W_REMOTE_HIGHH,
+		ADT7461_REG_W_REMOTE_HIGHL,
+		ADT7461_REG_W_REMOTE_OFFSH,
+		ADT7461_REG_W_REMOTE_OFFSL,
+	};
+
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7461_data *data = i2c_get_clientdata(client);
+	long val = simple_strtol(buf, NULL, 10);
+	int nr = attr->index;
+
+	mutex_lock(&data->update_lock);
+	data->temp11[nr] = temp_to_u16(data, val);
+
+	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
+				  data->temp11[nr] >> 8);
+	i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
+				  data->temp11[nr] & 0xff);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t show_temphyst(struct device *dev,
+		struct device_attribute *devattr,
+		char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7461_data *data = adt7461_update_device(dev);
+	int temp;
+
+	temp = temp_from_u8(data, data->temp8[attr->index]);
+
+	return sprintf(buf, "%d\n", temp - temp_from_s8(data->temp_hyst));
+}
+
+static ssize_t set_temphyst(struct device *dev, struct device_attribute *dummy,
+			 const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct adt7461_data *data = i2c_get_clientdata(client);
+	long val = simple_strtol(buf, NULL, 10);
+	int temp;
+
+	mutex_lock(&data->update_lock);
+	temp = temp_from_u8(data, data->temp8[2]);
+	data->temp_hyst = hyst_to_reg(temp - val);
+	i2c_smbus_write_byte_data(client, ADT7461_REG_W_TCRIT_HYST,
+				  data->temp_hyst);
+	mutex_unlock(&data->update_lock);
+	return count;
+}
+
+static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
+			 char *buf)
+{
+	struct adt7461_data *data = adt7461_update_device(dev);
+	return sprintf(buf, "%d\n", data->alarms);
+}
+
+static ssize_t show_alarm(struct device *dev, struct device_attribute
+			  *devattr, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct adt7461_data *data = adt7461_update_device(dev);
+	int bitnr = attr->index;
+
+	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp11, NULL, 4);
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp8,
+	set_temp8, 0);
+static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
+	set_temp11, 1);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp8,
+	set_temp8, 1);
+static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
+	set_temp11, 2);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp8,
+	set_temp8, 2);
+static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
+	set_temp8, 3);
+static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
+	set_temphyst, 2);
+static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
+	set_temp11, 3);
+
+/* Individual alarm files */
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
+static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
+/* Raw alarm file for compatibility */
+static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
+
+static struct attribute *adt7461_attributes[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp2_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_min.dev_attr.attr,
+	&sensor_dev_attr_temp2_min.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp2_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp2_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
+
+	&sensor_dev_attr_temp1_crit_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_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+	&dev_attr_alarms.attr,
+	NULL
+};
+
+static const struct attribute_group adt7461_group = {
+	.attrs = adt7461_attributes,
+};
+
+static void adt7461_regulator_enable(struct i2c_client *client)
+{
+	struct adt7461_data *data = i2c_get_clientdata(client);
+
+	data->regulator = regulator_get(NULL, "vdd_vcore_temp");
+	if (IS_ERR_OR_NULL(data->regulator)) {
+		pr_err("adt7461_regulator_enable:Couldn't get regulator vdd_vcore_temp\n");
+		data->regulator = NULL;
+	}
+	else {
+		regulator_enable(data->regulator);
+		/* Optimal time to get the regulator turned on
+		 * before initializing adt7461 chip*/
+		mdelay(5);
+	}
+}
+
+static void adt7461_regulator_disable(struct i2c_client *client)
+{
+	struct adt7461_data *data = i2c_get_clientdata(client);
+	struct regulator *adt7461_reg = data->regulator;
+	int ret;
+
+	if (adt7461_reg) {
+		ret = regulator_is_enabled(adt7461_reg);
+		if (ret > 0)
+			regulator_disable(adt7461_reg);
+		regulator_put(adt7461_reg);
+	}
+	data->regulator = NULL;
+}
+
+static void adt7461_init_client(struct i2c_client *client)
+{
+	u8 config;
+	struct adt7461_data *data = i2c_get_clientdata(client);
+
+	adt7461_regulator_enable(client);
+	/* Start the conversions. */
+	i2c_smbus_write_byte_data(client, ADT7461_REG_W_CONVRATE,
+				5); /* 2 Hz */
+	if (adt7461_read_reg(client, ADT7461_REG_R_CONFIG1, &config) < 0) {
+		pr_err("adt7461_init_client:Initialization failed!\n");
+		return;
+	}
+	data->config_orig = config;
+
+	/* Check Temperature Range Select */
+	if (config & 0x04)
+		data->flags |= ADT7461_FLAG_ADT7461_EXT;
+
+	config &= 0xBF;	/* run */
+	if (config != data->config_orig) /* Only write if changed */
+		i2c_smbus_write_byte_data(client, ADT7461_REG_W_CONFIG1, config);
+}
+
+static int adt7461_probe(struct i2c_client *new_client,
+		  const struct i2c_device_id *id)
+{
+	struct adt7461_data *data;
+	int err;
+
+	data = kzalloc(sizeof(struct adt7461_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	i2c_set_clientdata(new_client, data);
+	mutex_init(&data->update_lock);
+
+	data->alert_alarms = 0x7c;
+
+	/* Initialize the ADT7461 chip */
+	adt7461_init_client(new_client);
+
+	/* Register sysfs hooks */
+	if ((err = sysfs_create_group(&new_client->dev.kobj, &adt7461_group)))
+		goto exit_free;
+	if ((err = device_create_file(&new_client->dev,
+			&sensor_dev_attr_temp2_offset.dev_attr)))
+		goto exit_remove_files;
+
+	data->hwmon_dev = hwmon_device_register(&new_client->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove_files;
+	}
+
+	return 0;
+
+exit_remove_files:
+	sysfs_remove_group(&new_client->dev.kobj, &adt7461_group);
+exit_free:
+	kfree(data);
+	return err;
+}
+
+static int adt7461_remove(struct i2c_client *client)
+{
+	struct adt7461_data *data = i2c_get_clientdata(client);
+
+	adt7461_regulator_disable(client);
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&client->dev.kobj, &adt7461_group);
+	device_remove_file(&client->dev,
+			&sensor_dev_attr_temp2_offset.dev_attr);
+
+	/* Restore initial configuration */
+	i2c_smbus_write_byte_data(client, ADT7461_REG_W_CONFIG1,
+				data->config_orig);
+
+	kfree(data);
+	return 0;
+}
+
+static void adt7461_alert(struct i2c_client *client, unsigned int flag)
+{
+	struct adt7461_data *data = i2c_get_clientdata(client);
+	u8 config, alarms;
+
+	adt7461_read_reg(client, ADT7461_REG_R_STATUS, &alarms);
+	if ((alarms & 0x7f) == 0) {
+		pr_err("adt7461_alert:Everything OK\n");
+	} else {
+		if (alarms & 0x61)
+			pr_err("adt7461_alert:temp%d out of range, please check!\n", 1);
+		if (alarms & 0x1a)
+			pr_err("adt7461_alert:temp%d out of range, please check!\n", 2);
+		if (alarms & 0x04)
+			pr_err("adt7461_alert:temp%d diode open, please check!\n", 2);
+
+		/* Disable ALERT# output, because these chips don't implement
+		  SMBus alert correctly; they should only hold the alert line
+		  low briefly. */
+		if (alarms & data->alert_alarms) {
+			pr_err("adt7461_alert:Disabling ALERT#\n");
+			adt7461_read_reg(client, ADT7461_REG_R_CONFIG1, &config);
+			i2c_smbus_write_byte_data(client, ADT7461_REG_W_CONFIG1,
+					config | 0x80);
+		}
+	}
+}
+
+/*
+ * Driver data
+ */
+static const struct i2c_device_id adt7461_id[] = {
+	{ "adt7461", 0 },
+};
+
+MODULE_DEVICE_TABLE(i2c, adt7461_id);
+
+static struct i2c_driver adt7461_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "adt7461",
+	},
+	.probe		= adt7461_probe,
+	.remove		= adt7461_remove,
+	.alert		= adt7461_alert,
+	.id_table	= adt7461_id,
+};
+
+static int __init sensors_adt7461_init(void)
+{
+	return i2c_add_driver(&adt7461_driver);
+}
+
+static void __exit sensors_adt7461_exit(void)
+{
+	i2c_del_driver(&adt7461_driver);
+}
+
+MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
+MODULE_DESCRIPTION("ADT7461 driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_adt7461_init);
+module_exit(sensors_adt7461_exit);