rtc: pcf2123: fix negative offset rounding

Using result = (value + divisor/2) / divisor is rounding values up and only
works well for positive values. Instead use DIV_ROUND_CLOSEST which does
the correct thing.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Alexandre Belloni 2019-06-19 15:17:53 +02:00
parent e32e60a2d5
commit fedc459a3d

View File

@ -161,7 +161,7 @@ static int pcf2123_set_offset(struct device *dev, long offset)
else if (offset < OFFSET_STEP * -128)
reg = -128;
else
reg = (s8)((offset + (OFFSET_STEP >> 1)) / OFFSET_STEP);
reg = DIV_ROUND_CLOSEST(offset, OFFSET_STEP);
/* choose fine offset only for odd values in the normal range */
if (reg & 1 && reg <= 63 && reg >= -64) {