| Message ID | 20220130161101.1067691-3-liambeguin@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iio: afe: add temperature rescaling support | expand |
Hi! On 2022-01-30 17:10, Liam Beguin wrote: > Some ADCs use IIO_VAL_INT_PLUS_{NANO,MICRO} scale types. > Add support for these to allow using the iio-rescaler with them. > > Signed-off-by: Liam Beguin <liambeguin@gmail.com> > Reviewed-by: Peter Rosin <peda@axentia.se> > --- > drivers/iio/afe/iio-rescale.c | 35 +++++++++++++++++++++++++++++++++++ > 1 file changed, 35 insertions(+) > > diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c > index 65832dd09249..f833eb38f8bb 100644 > --- a/drivers/iio/afe/iio-rescale.c > +++ b/drivers/iio/afe/iio-rescale.c > @@ -14,6 +14,7 @@ > #include <linux/of_device.h> > #include <linux/platform_device.h> > #include <linux/property.h> > +#include <linux/units.h> This include should be moved to the first patch that uses stuff from it. Cheers, Peter *snip*
Hi Peter, On Wed, Feb 02, 2022 at 06:04:25PM +0100, Peter Rosin wrote: > Hi! > > On 2022-01-30 17:10, Liam Beguin wrote: > > Some ADCs use IIO_VAL_INT_PLUS_{NANO,MICRO} scale types. > > Add support for these to allow using the iio-rescaler with them. > > > > Signed-off-by: Liam Beguin <liambeguin@gmail.com> > > Reviewed-by: Peter Rosin <peda@axentia.se> > > --- > > drivers/iio/afe/iio-rescale.c | 35 +++++++++++++++++++++++++++++++++++ > > 1 file changed, 35 insertions(+) > > > > diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c > > index 65832dd09249..f833eb38f8bb 100644 > > --- a/drivers/iio/afe/iio-rescale.c > > +++ b/drivers/iio/afe/iio-rescale.c > > @@ -14,6 +14,7 @@ > > #include <linux/of_device.h> > > #include <linux/platform_device.h> > > #include <linux/property.h> > > +#include <linux/units.h> > > This include should be moved to the first patch that uses stuff from > it. Some defines are used a bit further down in mult (copied back from the original message): > > case IIO_VAL_INT_PLUS_NANO: > > case IIO_VAL_INT_PLUS_MICRO: > > mult = scale_type == IIO_VAL_INT_PLUS_NANO ? GIGA : MEGA; > Cheers, > Peter > > *snip* Cheers, Liam
diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c index 65832dd09249..f833eb38f8bb 100644 --- a/drivers/iio/afe/iio-rescale.c +++ b/drivers/iio/afe/iio-rescale.c @@ -14,6 +14,7 @@ #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/property.h> +#include <linux/units.h> #include <linux/iio/afe/rescale.h> #include <linux/iio/consumer.h> @@ -23,6 +24,9 @@ int rescale_process_scale(struct rescale *rescale, int scale_type, int *val, int *val2) { s64 tmp; + s32 rem; + u32 mult; + u32 neg; switch (scale_type) { case IIO_VAL_FRACTIONAL: @@ -41,6 +45,37 @@ int rescale_process_scale(struct rescale *rescale, int scale_type, tmp *= rescale->numerator; tmp = div_s64(tmp, 1000000000LL); *val = tmp; + return scale_type; + case IIO_VAL_INT_PLUS_NANO: + case IIO_VAL_INT_PLUS_MICRO: + mult = scale_type == IIO_VAL_INT_PLUS_NANO ? GIGA : MEGA; + + /* + * For IIO_VAL_INT_PLUS_{MICRO,NANO} scale types if either *val + * OR *val2 is negative the schan scale is negative, i.e. + * *val = 1 and *val2 = -0.5 yields -1.5 not -0.5. + */ + neg = *val < 0 || *val2 < 0; + + tmp = (s64)abs(*val) * abs(rescale->numerator); + *val = div_s64_rem(tmp, abs(rescale->denominator), &rem); + + tmp = (s64)rem * mult + (s64)abs(*val2) * abs(rescale->numerator); + tmp = div_s64(tmp, abs(rescale->denominator)); + + *val += div_s64_rem(tmp, mult, val2); + + /* + * If only one of the rescaler elements or the schan scale is + * negative, the combined scale is negative. + */ + if (neg ^ ((rescale->numerator < 0) ^ (rescale->denominator < 0))) { + if (*val) + *val = -*val; + else + *val2 = -*val2; + } + return scale_type; default: return -EOPNOTSUPP;
Some ADCs use IIO_VAL_INT_PLUS_{NANO,MICRO} scale types. Add support for these to allow using the iio-rescaler with them. Signed-off-by: Liam Beguin <liambeguin@gmail.com> Reviewed-by: Peter Rosin <peda@axentia.se> --- drivers/iio/afe/iio-rescale.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)