hwmon: (adt7411) set bit 3 in CFG1 register

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@walle.cc>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
index d9299dee37d17b9a4cdedc9fdd1f7427e693244c..dddaa161aadbfc87c7669ecd08d19a11f1321236 100644 (file)
--- 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;