August 20 2015 10:49 PM, "Hartmut Knaack" <knaack.h@xxxxxx> wrote: > Nicola Corna schrieb am 20.08.2015 um 16:11: > >> 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). > > Hmm, I guess the mask should have been applied for bits 13:2, but your > solution confirms better to the data sheet. Just one essential detail: > The raw sensor data has already been divided by 4 when you do the boundary > check. So, you need to divide the boundaries, as well. > Btw, you can make this a one-liner using clamp_val, check it out: [1] > > [1]http://lxr.free-electrons.com/source/include/linux/kernel.h#L795 > Yes, you're right. Thanks. Forgive me for my ignorance, but do I have now to upload the [PATCH v2] for all the three patches? >> 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) -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
