Nicola Corna schrieb am 20.08.2015 um 23:57: > 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? > That's what we usually do. And since your third patch depends on this one, it needs to be updated as well. >>> 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 > -- 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
