[PATCH 3.12 46/84] hwmon: (adt7411) set bit 3 in CFG1 register

[Jiri Slaby]

From: Michael Walle <michael@xxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit b53893aae441a034bf4dbbad42fe218561d7d81f upstream.

According to the datasheet you should only write 1 to this bit. If it is
not set, at least AIN3 will return bad values on newer silicon revisions.

Fixes: d84ca5b345c2 ("hwmon: Add driver for ADT7411 voltage and temperature sensor")
Signed-off-by: Michael Walle <michael@xxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/hwmon/adt7411.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
index d9299dee37d1..dddaa161aadb 100644
--- a/drivers/hwmon/adt7411.c
+++ b/drivers/hwmon/adt7411.c
@@ -30,6 +30,7 @@
 
 #define ADT7411_REG_CFG1			0x18
 #define ADT7411_CFG1_START_MONITOR		(1 << 0)
+#define ADT7411_CFG1_RESERVED_BIT3		(1 << 3)
 
 #define ADT7411_REG_CFG2			0x19
 #define ADT7411_CFG2_DISABLE_AVG		(1 << 5)
@@ -292,8 +293,10 @@ static int adt7411_probe(struct i2c_client *client,
 	mutex_init(&data->device_lock);
 	mutex_init(&data->update_lock);
 
+	/* According to the datasheet, we must only write 1 to bit 3 */
 	ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
-				 ADT7411_CFG1_START_MONITOR, 1);
+				 ADT7411_CFG1_RESERVED_BIT3
+				 | ADT7411_CFG1_START_MONITOR, 1);
 	if (ret < 0)
 		return ret;
 
-- 
2.10.1