| Message ID | 20240430131330.1555849-1-marc.ferland@sonatest.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | iio: dac: ad5592r: fix temperature scale | expand |
On Tue, 30 Apr 2024 09:13:30 -0400 marc.ferland@gmail.com wrote: > From: Marc Ferland <marc.ferland@sonatest.com> > > For temperature readings, the remainder is returned as nano Celsius > _but_ we mark it as IIO_VAL_INT_PLUS_MICRO. This results in incorrect > temperature reporting through hwmon for example. I have a board here > which reports the following when running 'sensors': > > iio_hwmon-isa-0000 > Adapter: ISA adapter > temp1: +93.3°C > > With the patch applied, it returns the correct temperature: > > iio_hwmon-isa-0000 > Adapter: ISA adapter > temp1: +30.5°C > > Signed-off-by: Marc Ferland <marc.ferland@sonatest.com> IIO temperature units are milli celcius, so I'm not following the argument here. The driver might be reporting in pico celcius I suppose? Call out that this is the scale factor though, so it corresponds to 1LSB hence a small number is certainly plausible.. Reasonable to argue it's taking the integer and dividing by 10^9 hence INT_PLUS_NANO is the right answer, but it isn't nano celsius. Jonathan > --- > drivers/iio/dac/ad5592r-base.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c > index 076bc9ecfb49..4763402dbcd6 100644 > --- a/drivers/iio/dac/ad5592r-base.c > +++ b/drivers/iio/dac/ad5592r-base.c > @@ -415,7 +415,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev, > s64 tmp = *val * (3767897513LL / 25LL); > *val = div_s64_rem(tmp, 1000000000LL, val2); > > - return IIO_VAL_INT_PLUS_MICRO; > + return IIO_VAL_INT_PLUS_NANO; > } > > mutex_lock(&st->lock); > > base-commit: 98369dccd2f8e16bf4c6621053af7aa4821dcf8e
On Tue, Apr 30, 2024 at 9:59 AM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > On Tue, 30 Apr 2024 09:13:30 -0400 > marc.ferland@gmail.com wrote: > > > From: Marc Ferland <marc.ferland@sonatest.com> > > > > For temperature readings, the remainder is returned as nano Celsius > > _but_ we mark it as IIO_VAL_INT_PLUS_MICRO. This results in incorrect > > temperature reporting through hwmon for example. I have a board here > > which reports the following when running 'sensors': > > > > iio_hwmon-isa-0000 > > Adapter: ISA adapter > > temp1: +93.3°C > > > > With the patch applied, it returns the correct temperature: > > > > iio_hwmon-isa-0000 > > Adapter: ISA adapter > > temp1: +30.5°C > > > > Signed-off-by: Marc Ferland <marc.ferland@sonatest.com> > > IIO temperature units are milli celcius, so I'm not following > the argument here. The driver might be reporting in pico celcius > I suppose? Call out that this is the scale factor though, so > it corresponds to 1LSB hence a small number is certainly plausible.. > > Reasonable to argue it's taking the integer and dividing by 10^9 hence > INT_PLUS_NANO is the right answer, but it isn't nano celsius. > Oups! you're obviously right. I'll update my commit message and resend. Marc
diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c index 076bc9ecfb49..4763402dbcd6 100644 --- a/drivers/iio/dac/ad5592r-base.c +++ b/drivers/iio/dac/ad5592r-base.c @@ -415,7 +415,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev, s64 tmp = *val * (3767897513LL / 25LL); *val = div_s64_rem(tmp, 1000000000LL, val2); - return IIO_VAL_INT_PLUS_MICRO; + return IIO_VAL_INT_PLUS_NANO; } mutex_lock(&st->lock);