[PATCH v10 07/14] iio: afe: rescale: use s64 for temporary scale calculations

Liam Beguin
2021-12-19T22:40:23Z

All four scaling coefficients can take signed values.
Make tmp a signed 64-bit integer and switch to div_s64() to preserve
signs during 64-bit divisions.

Signed-off-by: Liam Beguin <lvb@xiphos.com>
---
drivers/iio/afe/iio-rescale.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c
index e88b63747a46..e3680998565e 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c
@@ -22,7 +22,7 @@
int rescale_process_scale(struct rescale *rescale, int scale_type,
int *val, int *val2)
{
- unsigned long long tmp;
+ s64 tmp;
s32 rem;
u32 mult;
u32 neg;
@@ -39,10 +39,10 @@ int rescale_process_scale(struct rescale *rescale, int scale_type,
*val2 = rescale->denominator;
return IIO_VAL_FRACTIONAL;
case IIO_VAL_FRACTIONAL_LOG2:
- tmp = *val * 1000000000LL;
- do_div(tmp, rescale->denominator);
+ tmp = (s64)*val * 1000000000LL;
+ tmp = div_s64(tmp, rescale->denominator);
tmp *= rescale->numerator;
- do_div(tmp, 1000000000LL);
+ tmp = div_s64(tmp, 1000000000LL);
*val = tmp;
return scale_type;
case IIO_VAL_INT_PLUS_NANO:
--
2.34.0