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authorNicola Corna <nicola@corna.info>2015-08-23 23:06:19 +0200
committerJonathan Cameron <jic23@kernel.org>2015-08-24 20:41:16 +0200
commitecf7e207a55d8760734a9de5fba1a974628b92e5 (patch)
tree1403fc200aa6d632046dcdd717a68ae45282ecc2 /drivers/iio/humidity
parentiio: adc: mcp320x: Set struct spi_driver .of_match_table (diff)
downloadlinux-ecf7e207a55d8760734a9de5fba1a974628b92e5.tar.xz
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iio: humidity: si7020: replaced bitmask on humidity values with range check
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 786 (0%RH) and the maximum at 13893 (99.998%RH). Signed-off-by: Nicola Corna <nicola@corna.info> Reviewed-by: Hartmut Knaack <knaack.h@gmx.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/humidity')
-rw-r--r--drivers/iio/humidity/si7020.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iio/humidity/si7020.c b/drivers/iio/humidity/si7020.c
index fa3b809aff5e..12128d1ca570 100644
--- a/drivers/iio/humidity/si7020.c
+++ b/drivers/iio/humidity/si7020.c
@@ -57,8 +57,12 @@ static int si7020_read_raw(struct iio_dev *indio_dev,
if (ret < 0)
return ret;
*val = ret >> 2;
+ /*
+ * Humidity values can slightly exceed the 0-100%RH
+ * range and should be corrected by software
+ */
if (chan->type == IIO_HUMIDITYRELATIVE)
- *val &= GENMASK(11, 0);
+ *val = clamp_val(*val, 786, 13893);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (chan->type == IIO_TEMP)