1 files changed, 25 insertions, 4 deletions

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 98b53b119c2a..960df9fa75af 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -41,7 +41,8 @@
  *   http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
  * Note that there is no easy way to differentiate between the three
  * variants. The extra address and features of the MAX6659 are not
- * supported by this driver.
+ * supported by this driver. These chips lack the remote temperature
+ * offset feature.
  *
  * This driver also supports the MAX6680 and MAX6681, two other sensor
  * chips made by Maxim. These are quite similar to the other Maxim
@@ -226,9 +227,10 @@ struct lm90_data {
                            2: local high limit
                            3: local critical limit
                            4: remote critical limit */
-        s16 temp11[3];  /* 0: remote input
+        s16 temp11[4];  /* 0: remote input
                            1: remote low limit
-                           2: remote high limit */
+                           2: remote high limit
+                           3: remote offset (except max6657) */
         u8 temp_hyst;
         u8 alarms; /* bitvector */
 };
@@ -282,11 +284,13 @@ static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
                           const char *buf, size_t count)
 {
-        static const u8 reg[4] = {
+        static const u8 reg[6] = {
                 LM90_REG_W_REMOTE_LOWH,
                 LM90_REG_W_REMOTE_LOWL,
                 LM90_REG_W_REMOTE_HIGHH,
                 LM90_REG_W_REMOTE_HIGHL,
+                LM90_REG_W_REMOTE_OFFSH,
+                LM90_REG_W_REMOTE_OFFSL,
         };
 
         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
@@ -367,6 +371,8 @@ static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp8,
 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temphyst,
         set_temphyst, 3);
 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_temphyst, NULL, 4);
+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);
@@ -652,6 +658,11 @@ static int lm90_detect(struct i2c_adapter *adapter, int address, int kind)
                                               &dev_attr_pec)))
                         goto exit_remove_files;
         }
+        if (data->kind != max6657) {
+                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)) {
@@ -710,6 +721,9 @@ static int lm90_detach_client(struct i2c_client *client)
         hwmon_device_unregister(data->hwmon_dev);
         sysfs_remove_group(&client->dev.kobj, &lm90_group);
         device_remove_file(&client->dev, &dev_attr_pec);
+        if (data->kind != max6657)
+                device_remove_file(&client->dev,
+                                   &sensor_dev_attr_temp2_offset.dev_attr);
 
         if ((err = i2c_detach_client(client)))
                 return err;
@@ -763,6 +777,13 @@ static struct lm90_data *lm90_update_device(struct device *dev)
                 if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &newh) == 0
                  && lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL, &l) == 0)
                         data->temp11[2] = (newh << 8) | l;
+                if (data->kind != max6657) {
+                        if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
+                                          &newh) == 0
+                         && lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
+                                          &l) == 0)
+                                data->temp11[3] = (newh << 8) | l;
+                }
                 lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);
 
                 data->last_updated = jiffies;