diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 716dae9ff0f771a3e54c90c394b3a9c975b528b3..d20130723d684600d7d9bac9fa3d5eae4123a95a 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -80,6 +80,8 @@
 
 #define REG_EXTEND1		0x76
 #define REG_EXTEND2		0x77
+
+#define REG_CONFIG3		0x78
 #define REG_CONFIG5		0x7C
 #define REG_CONFIG4		0x7D
 
@@ -88,6 +90,10 @@
 #define REG_VTT_MIN		0x84	/* ADT7490 only */
 #define REG_VTT_MAX		0x86	/* ADT7490 only */
 
+#define CONFIG3_SMBALERT	0x01
+#define CONFIG3_THERM		0x02
+
+#define CONFIG4_PINFUNC		0x03
 #define CONFIG4_MAXDUTY		0x08
 
 #define CONFIG5_TWOSCOMP	0x01
@@ -149,6 +155,8 @@ struct adt7475_data {
 	u8 config4;
 	u8 config5;
 	u8 has_voltage;
+	u8 has_pwm2:1;
+	u8 has_fan4:1;
 	u32 alarms;
 	u16 voltage[3][6];
 	u16 temp[7][3];
@@ -1025,21 +1033,12 @@ static struct attribute *adt7475_attrs[] = {
 	&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_fan4_input.dev_attr.attr,
-	&sensor_dev_attr_fan4_min.dev_attr.attr,
-	&sensor_dev_attr_fan4_alarm.dev_attr.attr,
 	&sensor_dev_attr_pwm1.dev_attr.attr,
 	&sensor_dev_attr_pwm1_freq.dev_attr.attr,
 	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
-	&sensor_dev_attr_pwm2.dev_attr.attr,
-	&sensor_dev_attr_pwm2_freq.dev_attr.attr,
-	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
-	&sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
-	&sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
-	&sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
 	&sensor_dev_attr_pwm3.dev_attr.attr,
 	&sensor_dev_attr_pwm3_freq.dev_attr.attr,
 	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
@@ -1050,12 +1049,33 @@ static struct attribute *adt7475_attrs[] = {
 	NULL,
 };
 
+static struct attribute *fan4_attrs[] = {
+	&sensor_dev_attr_fan4_input.dev_attr.attr,
+	&sensor_dev_attr_fan4_min.dev_attr.attr,
+	&sensor_dev_attr_fan4_alarm.dev_attr.attr,
+	NULL
+};
+
+static struct attribute *pwm2_attrs[] = {
+	&sensor_dev_attr_pwm2.dev_attr.attr,
+	&sensor_dev_attr_pwm2_freq.dev_attr.attr,
+	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
+	NULL
+};
+
 /* Attributes specific to the ADT7490 */
-static struct attribute *adt7490_attrs[] = {
+static struct attribute *in0_attrs[] = {
 	&sensor_dev_attr_in0_input.dev_attr.attr,
 	&sensor_dev_attr_in0_max.dev_attr.attr,
 	&sensor_dev_attr_in0_min.dev_attr.attr,
 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
+	NULL
+};
+
+static struct attribute *adt7490_attrs[] = {
 	&sensor_dev_attr_in3_input.dev_attr.attr,
 	&sensor_dev_attr_in3_max.dev_attr.attr,
 	&sensor_dev_attr_in3_min.dev_attr.attr,
@@ -1072,6 +1092,9 @@ static struct attribute *adt7490_attrs[] = {
 };
 
 static struct attribute_group adt7475_attr_group = { .attrs = adt7475_attrs };
+static struct attribute_group fan4_attr_group = { .attrs = fan4_attrs };
+static struct attribute_group pwm2_attr_group = { .attrs = pwm2_attrs };
+static struct attribute_group in0_attr_group = { .attrs = in0_attrs };
 static struct attribute_group adt7490_attr_group = { .attrs = adt7490_attrs };
 
 static int adt7475_detect(struct i2c_client *client, int kind,
@@ -1115,13 +1138,20 @@ static void adt7475_remove_files(struct i2c_client *client,
 	sysfs_remove_group(&client->dev.kobj, &adt7475_attr_group);
 	if (data->has_voltage & 0x39)
 		sysfs_remove_group(&client->dev.kobj, &adt7490_attr_group);
+	if (data->has_fan4)
+		sysfs_remove_group(&client->dev.kobj, &fan4_attr_group);
+	if (data->has_pwm2)
+		sysfs_remove_group(&client->dev.kobj, &pwm2_attr_group);
+	if (data->has_voltage & (1 << 0))
+		sysfs_remove_group(&client->dev.kobj, &in0_attr_group);
 }
 
 static int adt7475_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct adt7475_data *data;
-	int i, ret = 0;
+	int i, ret = 0, revision;
+	u8 config3;
 
 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (data == NULL)
@@ -1133,10 +1163,36 @@ static int adt7475_probe(struct i2c_client *client,
 	/* Initialize device-specific values */
 	switch (id->driver_data) {
 	case adt7490:
-		data->has_voltage = 0x3f;	/* in0 to in5 */
+		data->has_voltage = 0x3e;	/* in1 to in5 */
+		revision = adt7475_read(REG_DEVID2) & 0x03;
 		break;
 	default:
 		data->has_voltage = 0x06;	/* in1, in2 */
+		revision = adt7475_read(REG_DEVID2) & 0x07;
+	}
+
+	config3 = adt7475_read(REG_CONFIG3);
+	/* Pin PWM2 may alternatively be used for ALERT output */
+	if (!(config3 & CONFIG3_SMBALERT))
+		data->has_pwm2 = 1;
+	/* Meaning of this bit is inverted for the ADT7473-1 */
+	if (id->driver_data == adt7473 && revision >= 1)
+		data->has_pwm2 = !data->has_pwm2;
+
+	data->config4 = adt7475_read(REG_CONFIG4);
+	/* Pin TACH4 may alternatively be used for THERM */
+	if ((data->config4 & CONFIG4_PINFUNC) == 0x0)
+		data->has_fan4 = 1;
+
+	/* THERM configuration is more complex on the ADT7490, because 2
+	   different pins (TACH4 and +2.5 Vin) can be used for this function */
+	if (id->driver_data == adt7490) {
+		if ((data->config4 & CONFIG4_PINFUNC) == 0x1 &&
+		    !(config3 & CONFIG3_THERM))
+			data->has_fan4 = 1;
+		if (!(config3 & CONFIG3_THERM) ||
+		    (data->config4 & CONFIG4_PINFUNC) == 0x1)
+			data->has_voltage |= (1 << 0);		/* in0 */
 	}
 
 	/* Call adt7475_read_pwm for all pwm's as this will reprogram any
@@ -1155,6 +1211,23 @@ static int adt7475_probe(struct i2c_client *client,
 			goto eremove;
 	}
 
+	/* Features that can be disabled individually */
+	if (data->has_fan4) {
+		ret = sysfs_create_group(&client->dev.kobj, &fan4_attr_group);
+		if (ret)
+			goto eremove;
+	}
+	if (data->has_pwm2) {
+		ret = sysfs_create_group(&client->dev.kobj, &pwm2_attr_group);
+		if (ret)
+			goto eremove;
+	}
+	if (data->has_voltage & (1 << 0)) {
+		ret = sysfs_create_group(&client->dev.kobj, &in0_attr_group);
+		if (ret)
+			goto eremove;
+	}
+
 	data->hwmon_dev = hwmon_device_register(&client->dev);
 	if (IS_ERR(data->hwmon_dev)) {
 		ret = PTR_ERR(data->hwmon_dev);
@@ -1293,13 +1366,19 @@ static struct adt7475_data *adt7475_update_device(struct device *dev)
 				((ext >> 4) & 3);
 		}
 
-		for (i = 0; i < ADT7475_TACH_COUNT; i++)
+		for (i = 0; i < ADT7475_TACH_COUNT; i++) {
+			if (i == 3 && !data->has_fan4)
+				continue;
 			data->tach[INPUT][i] =
 				adt7475_read_word(client, TACH_REG(i));
+		}
 
 		/* Updated by hw when in auto mode */
-		for (i = 0; i < ADT7475_PWM_COUNT; i++)
+		for (i = 0; i < ADT7475_PWM_COUNT; i++) {
+			if (i == 1 && !data->has_pwm2)
+				continue;
 			data->pwm[INPUT][i] = adt7475_read(PWM_REG(i));
+		}
 
 		data->measure_updated = jiffies;
 	}
@@ -1340,11 +1419,16 @@ static struct adt7475_data *adt7475_update_device(struct device *dev)
 		}
 		adt7475_read_hystersis(client);
 
-		for (i = 0; i < ADT7475_TACH_COUNT; i++)
+		for (i = 0; i < ADT7475_TACH_COUNT; i++) {
+			if (i == 3 && !data->has_fan4)
+				continue;
 			data->tach[MIN][i] =
 				adt7475_read_word(client, TACH_MIN_REG(i));
+		}
 
 		for (i = 0; i < ADT7475_PWM_COUNT; i++) {
+			if (i == 1 && !data->has_pwm2)
+				continue;
 			data->pwm[MAX][i] = adt7475_read(PWM_MAX_REG(i));
 			data->pwm[MIN][i] = adt7475_read(PWM_MIN_REG(i));
 			/* Set the channel and control information */