The maximum possible value for the relative humidity is 55575 (100%RH).
This value, if shifted right by 2 bits, uses 14 bits and masking it with
a 12 bit mask removes 2 meaningful bits.
The masking has been replaced with a range check that sets the minimum
value at 3194 (0%RH) and the maximum at 55575 (100%RH).
Signed-off-by: Nicola Corna <nicola@xxxxxxxxxx>
---
drivers/iio/humidity/si7020.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/humidity/si7020.c b/drivers/iio/humidity/si7020.c
index fa3b809..62fdbcf 100644
--- a/drivers/iio/humidity/si7020.c
+++ b/drivers/iio/humidity/si7020.c
@@ -57,8 +57,16 @@ static int si7020_read_raw(struct iio_dev *indio_dev,
if (ret < 0)
return ret;
*val = ret >> 2;
- if (chan->type == IIO_HUMIDITYRELATIVE)
- *val &= GENMASK(11, 0);
+ /*
+ * Humidity values can sligthly exceed the 0-100%RH
+ * range and should be corrected by software
+ */
+ if (chan->type == IIO_HUMIDITYRELATIVE) {
+ if (*val < 3194) /* 0%RH */
+ *val = 3194;
+ else if (*val > 55575) /* 100%RH */
+ *val = 55575;
+ }
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (chan->type == IIO_TEMP)
--
2.5.0
--
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