lm63: Enable digital filter to suppress noise
The LM96063 can filter out bad temperature readings caused by noise.
Enable the setting "Enhanced Filter (Filter with transient noise
clipping)".
Resolves b/24907914
Change-Id: I434d5176d8f06a13b8837ef15fb16d51f6fd8006
diff --git a/drivers/hwmon/lm63.c b/drivers/hwmon/lm63.c
index 9e6255f..eee3446 100644
--- a/drivers/hwmon/lm63.c
+++ b/drivers/hwmon/lm63.c
@@ -1000,6 +1000,7 @@
{
struct lm63_data *data = i2c_get_clientdata(client);
u8 convrate;
+ u8 config2;
data->config = lm63_i2c_smbus_read_byte_data(client, LM63_REG_CONFIG1);
data->config_fan = lm63_i2c_smbus_read_byte_data(client,
@@ -1012,6 +1013,19 @@
lm63_i2c_smbus_write_byte_data(client, LM63_REG_CONFIG1,
data->config);
}
+
+ /* Enable digital filter */
+ /* From the LM96063 datasheet:
+ * "In order to suppress erroneous remote temperature readings due to
+ * noise as well as increase the resolution of the temperature, the
+ * LM96063 incorporates a digital filter for remote temperature
+ * readings." */
+ config2 = lm63_i2c_smbus_read_byte_data(client, LM63_REG_CONFIG2);
+ config2 |= 0x6; /* Enhanced Filter (Filter with transient noise
+ clipping) */
+ lm63_i2c_smbus_write_byte_data(client, LM63_REG_CONFIG2,
+ config2);
+
/* Tachometer is always enabled on LM64 */
if (data->kind == lm64)
data->config |= 0x04;
