On Thu, 31 May 2018 10:06:50 +0800 Matt Ranostay <matt.ranostay@xxxxxxxxxxxx> wrote: > On Wed, May 30, 2018 at 10:23 PM, Tomasz Duszynski <tduszyns@xxxxxxxxx> wrote: > > On Wed, May 30, 2018 at 03:20:37PM +0800, Matt Ranostay wrote: > >> On Wed, May 30, 2018 at 1:05 PM, Matt Ranostay > >> <matt.ranostay@xxxxxxxxxxxx> wrote: > >> > On Wed, May 30, 2018 at 9:17 AM, Phil Reid <preid@xxxxxxxxxxxxxxxxx> wrote: > >> >> On 30/05/2018 08:44, Matt Ranostay wrote: > >> >>> > >> >>> On Mon, May 28, 2018 at 11:38 PM, Tomasz Duszynski <tduszyns@xxxxxxxxx> > >> >>> wrote: > >> >>>> > >> >>>> According to IIO ABI relative humidity reading should be > >> >>>> returned in milli percent. > >> >>>> > >> >>>> This patch addresses that by applying proper scaling and > >> >>>> returning integer instead of fractional format type specifier. > >> >>>> > >> >>> > >> >>> *sigh* seems this is my mistake, but good catch. Slight nitpick > >> >>> below.. otherwise looks good > >> >>> > >> >>>> Signed-off-by: Tomasz Duszynski <tduszyns@xxxxxxxxx> > >> >>>> --- > >> >>>> drivers/iio/pressure/bmp280-core.c | 5 ++--- > >> >>>> 1 file changed, 2 insertions(+), 3 deletions(-) > >> >>>> > >> >>>> diff --git a/drivers/iio/pressure/bmp280-core.c > >> >>>> b/drivers/iio/pressure/bmp280-core.c > >> >>>> index 5ec3e41b65f2..fe87d27779d9 100644 > >> >>>> --- a/drivers/iio/pressure/bmp280-core.c > >> >>>> +++ b/drivers/iio/pressure/bmp280-core.c > >> >>>> @@ -415,10 +415,9 @@ static int bmp280_read_humid(struct bmp280_data > >> >>>> *data, int *val, int *val2) > >> >>>> } > >> >>>> comp_humidity = bmp280_compensate_humidity(data, adc_humidity); > >> >>>> > >> >>>> - *val = comp_humidity; > >> >>>> - *val2 = 1024; > >> >>>> + *val = comp_humidity * 1000 / 1024; > >> >>> > >> >>> > >> >>> Minor nitpick that it would look cleaner as: (comp_humidity / 1024) * > >> >>> 1000 > >> >>> > >> >> be careful of integer division. > >> >> > >> > > >> > Ah yes good point. You will have to check if comp_humidity isn't zero > >> > or it is possible to have a divide-by-zero. > >> > >> D'oh actually divide by zero would be an issue. But you'll want to be > >> sure of possible overflows (doubt that would be an issue here). > > > > What kind of division-by-zero are you meaning? When would that happen > > in this case? > > > >> > >> However it may be better to just add the scaling factor of 1000 with > >> IIO_CHAN_INFO_SCALE and make the processed value now a raw one. > > > > Is measurement precision your concern here? I would not bother with that > > since the sensor is not a top-notch anyway. Even datasheet itself specifies > > error margin of +/-3% for relative humidity. > > As Phil mentioned the original patchset is okay as it is. Now I agree > with him after thinking it through. > > Acked-by: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx> Applied to the fixes-togreg branch of iio.git. Note this won't go upstream until after the merge window. It should also have had a relevant fixes tag. I added the original humidity one of Matt's though the patch won't apply that far back due to splitting of code when SPI support was added. I added a note to that effect. Jonathan > > > > > >> > >> > > >> > - Matt > >> > > >> >> > >> >>>> > >> >>>> - return IIO_VAL_FRACTIONAL; > >> >>>> + return IIO_VAL_INT; > >> >>>> } > >> >>>> > >> >>>> static int bmp280_read_raw(struct iio_dev *indio_dev, > >> >>>> -- > >> >>>> 2.17.0 > >> >> > >> >> > >> >>> > >> >> > >> >> > >> >> -- > >> >> Regards > >> >> Phil Reid > >> >> > -- > 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
