The kernel has a helper function for linear interpolation so use it. It incidentally makes the code easier to read as well. Cc: Peter Rosin <peda@xxxxxxxxxx> Cc: Chris Lesiak <chris.lesiak@xxxxxxxxx> Cc: linux-iio@xxxxxxxxxxxxxxx Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> --- drivers/hwmon/ntc_thermistor.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c index 8587189c7f15..61bd0e074ec9 100644 --- a/drivers/hwmon/ntc_thermistor.c +++ b/drivers/hwmon/ntc_thermistor.c @@ -14,6 +14,7 @@ #include <linux/err.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/fixp-arith.h> #include <linux/platform_data/ntc_thermistor.h> @@ -557,10 +558,12 @@ static int get_temp_mc(struct ntc_data *data, unsigned int ohm) /* Unable to use linear approximation */ temp = data->comp[low].temp_c * 1000; } else { - temp = data->comp[low].temp_c * 1000 + - ((data->comp[high].temp_c - data->comp[low].temp_c) * - 1000 * ((int)ohm - (int)data->comp[low].ohm)) / - ((int)data->comp[high].ohm - (int)data->comp[low].ohm); + temp = fixp_linear_interpolate(data->comp[low].ohm, + data->comp[low].temp_c, + data->comp[high].ohm, + data->comp[high].temp_c, + ohm); + temp *= 1000; } return temp; } -- 2.31.1