From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Nicola Corna To: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald Cc: linux-iio@vger.kernel.org, Nicola Corna Subject: [PATCH 1/3] iio:humidity:si7020: replaced bitmask on humidity values with range check Date: Thu, 20 Aug 2015 16:11:47 +0200 Message-Id: <1440079909-1337-1-git-send-email-nicola@corna.info> List-ID: 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 --- 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