[PATCH v10 02/15] fixp-arith: add a linear interpolation function
From: Dmitry Baryshkov <hidden>
Date: 2020-12-04 02:56:46
Also in:
linux-arm-msm, linux-iio, linux-pm
Subsystem:
the rest · Maintainer:
Linus Torvalds
From: Craig Tatlor <redacted> Adds a function to interpolate against two points, this is carried arount as a helper function by tons of drivers. Signed-off-by: Craig Tatlor <redacted> Signed-off-by: Dmitry Baryshkov <redacted> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- include/linux/fixp-arith.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/include/linux/fixp-arith.h b/include/linux/fixp-arith.h
index 8396013785ef..281cb4f83dbe 100644
--- a/include/linux/fixp-arith.h
+++ b/include/linux/fixp-arith.h@@ -141,4 +141,23 @@ static inline s32 fixp_sin32_rad(u32 radians, u32 twopi) #define fixp_cos32_rad(rad, twopi) \ fixp_sin32_rad(rad + twopi / 4, twopi) +/** + * fixp_linear_interpolate() - interpolates a value from two known points + * + * @x0: x value of point 0 + * @y0: y value of point 0 + * @x1: x value of point 1 + * @y1: y value of point 1 + * @x: the linear interpolant + */ +static inline int fixp_linear_interpolate(int x0, int y0, int x1, int y1, int x) +{ + if (y0 == y1 || x == x0) + return y0; + if (x1 == x0 || x == x1) + return y1; + + return y0 + ((y1 - y0) * (x - x0) / (x1 - x0)); +} + #endif
--
2.29.2