Thread (39 messages) 39 messages, 4 authors, 2021-09-11
STALE1723d
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[PATCH v8 07/14] iio: afe: rescale: use s64 for temporary scale calculations

From: Liam Beguin <hidden>
Date: 2021-08-20 19:18:19
Also in: linux-devicetree, lkml
Subsystem: iio subsystem and drivers, iio unit converter, the rest · Maintainers: Jonathan Cameron, Peter Rosin, Linus Torvalds

From: Liam Beguin <redacted>

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 <redacted>
---
 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 48a8096f68ca..809e966f7058 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c
@@ -21,7 +21,7 @@
 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;
@@ -38,10 +38,10 @@ 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:
-- 
2.32.0.452.g940fe202adcb
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