[PATCH] hwmon: Consider LM64 temperature offset

[Dirk Eibach <eibach@gdsys.de>]

LM64 has 16 degrees Celsius temperature offset on all
remote sensor registers.
This was not considered When LM64 support was added to lm63.c.

Signed-off-by: Dirk Eibach <eibach@gdsys.de>
---
 drivers/hwmon/lm63.c |   34 +++++++++++++++++++++++++++++-----
 1 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/hwmon/lm63.c b/drivers/hwmon/lm63.c
index 776aeb3..87bfefb 100644
--- a/drivers/hwmon/lm63.c
+++ b/drivers/hwmon/lm63.c
@@ -98,6 +98,9 @@ static const unsigned short normal_i2c[] = { 0x18, 0x4c, 0x4e, I2C_CLIENT_END };
  * value, it uses signed 8-bit values with LSB = 1 degree Celsius.
  * For remote temperature, low and high limits, it uses signed 11-bit values
  * with LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
+ * For LM64 the actual remote diode temperature is 16 degree Celsius higher
+ * than the register reading. Remote temperature setpoints have to be
+ * adapted accordingly.
  */
 
 #define FAN_FROM_REG(reg)	((reg) == 0xFFFC || (reg) == 0 ? 0 : \
@@ -180,6 +183,7 @@ struct lm63_data {
 			   2: remote high limit */
 	u8 temp2_crit_hyst;
 	u8 alarms;
+	bool is_lm64;
 };
 
 /*
@@ -255,6 +259,17 @@ static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
 	return sprintf(buf, "%d\n", TEMP8_FROM_REG(data->temp8[attr->index]));
 }
 
+static ssize_t show_remote_temp8(struct device *dev,
+				 struct device_attribute *devattr,
+				 char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct lm63_data *data = lm63_update_device(dev);
+	int offset = data->is_lm64 ? 16000 : 0;
+	return sprintf(buf, "%d\n",
+		       TEMP8_FROM_REG(data->temp8[attr->index]) + offset);
+}
+
 static ssize_t set_temp8(struct device *dev, struct device_attribute *dummy,
 			 const char *buf, size_t count)
 {
@@ -274,7 +289,9 @@ static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 	struct lm63_data *data = lm63_update_device(dev);
-	return sprintf(buf, "%d\n", TEMP11_FROM_REG(data->temp11[attr->index]));
+	int offset = data->is_lm64 ? 16000 : 0;
+	return sprintf(buf, "%d\n",
+		       TEMP11_FROM_REG(data->temp11[attr->index]) + offset);
 }
 
 static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
@@ -292,9 +309,10 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
 	struct lm63_data *data = i2c_get_clientdata(client);
 	long val = simple_strtol(buf, NULL, 10);
 	int nr = attr->index;
+	int offset = data->is_lm64 ? 16000 : 0;
 
 	mutex_lock(&data->update_lock);
-	data->temp11[nr] = TEMP11_TO_REG(val);
+	data->temp11[nr] = TEMP11_TO_REG(val - offset);
 	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],
@@ -309,7 +327,8 @@ static ssize_t show_temp2_crit_hyst(struct device *dev, struct device_attribute
 				    char *buf)
 {
 	struct lm63_data *data = lm63_update_device(dev);
-	return sprintf(buf, "%d\n", TEMP8_FROM_REG(data->temp8[2])
+	int offset = data->is_lm64 ? 16000 : 0;
+	return sprintf(buf, "%d\n", TEMP8_FROM_REG(data->temp8[2]) + offset
 		       - TEMP8_FROM_REG(data->temp2_crit_hyst));
 }
 
@@ -320,11 +339,12 @@ static ssize_t set_temp2_crit_hyst(struct device *dev, struct device_attribute *
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct lm63_data *data = i2c_get_clientdata(client);
+	int offset = data->is_lm64 ? 16000 : 0;
 	long val = simple_strtol(buf, NULL, 10);
 	long hyst;
 
 	mutex_lock(&data->update_lock);
-	hyst = TEMP8_FROM_REG(data->temp8[2]) - val;
+	hyst = TEMP8_FROM_REG(data->temp8[2]) + offset - val;
 	i2c_smbus_write_byte_data(client, LM63_REG_REMOTE_TCRIT_HYST,
 				  HYST_TO_REG(hyst));
 	mutex_unlock(&data->update_lock);
@@ -364,7 +384,7 @@ static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
 	set_temp11, 1);
 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
 	set_temp11, 2);
-static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp8, NULL, 2);
+static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_remote_temp8, NULL, 2);
 static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp2_crit_hyst,
 	set_temp2_crit_hyst);
 
@@ -466,6 +486,7 @@ static int lm63_detect(struct i2c_client *new_client,
 static int lm63_probe(struct i2c_client *new_client,
 		      const struct i2c_device_id *id)
 {
+	u8 chip_id;
 	struct lm63_data *data;
 	int err;
 
@@ -479,6 +500,9 @@ static int lm63_probe(struct i2c_client *new_client,
 	data->valid = 0;
 	mutex_init(&data->update_lock);
 
+	chip_id = i2c_smbus_read_byte_data(new_client, LM63_REG_CHIP_ID);
+	data->is_lm64 = (chip_id == 0x51);
+
 	/* Initialize the LM63 chip */
 	lm63_init_client(new_client);
 
-- 
1.5.6.5