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authorLuuk Paulussen <luuk.paulussen@alliedtelesis.co.nz>2019-12-06 02:16:59 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-29 17:02:37 +0300
commit6090ac18fcc58ed264ffdd00f6fdd6042475b6a4 (patch)
tree3b0222626e880ab73f844088f0ad3bc3cc902066 /drivers/hwmon
parente841252840c48e9a0e5add9d82796b1d55c0f653 (diff)
downloadlinux-6090ac18fcc58ed264ffdd00f6fdd6042475b6a4.tar.xz
hwmon: (adt7475) Make volt2reg return same reg as reg2volt input
commit cf3ca1877574a306c0207cbf7fdf25419d9229df upstream. reg2volt returns the voltage that matches a given register value. Converting this back the other way with volt2reg didn't return the same register value because it used truncation instead of rounding. This meant that values read from sysfs could not be written back to sysfs to set back the same register value. With this change, volt2reg will return the same value for every voltage previously returned by reg2volt (for the set of possible input values) Signed-off-by: Luuk Paulussen <luuk.paulussen@alliedtelesis.co.nz> Link: https://lore.kernel.org/r/20191205231659.1301-1-luuk.paulussen@alliedtelesis.co.nz cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/adt7475.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 37db2eb66ed7..d7d1f2467100 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -297,9 +297,10 @@ static inline u16 volt2reg(int channel, long volt, u8 bypass_attn)
long reg;
if (bypass_attn & (1 << channel))
- reg = (volt * 1024) / 2250;
+ reg = DIV_ROUND_CLOSEST(volt * 1024, 2250);
else
- reg = (volt * r[1] * 1024) / ((r[0] + r[1]) * 2250);
+ reg = DIV_ROUND_CLOSEST(volt * r[1] * 1024,
+ (r[0] + r[1]) * 2250);
return clamp_val(reg, 0, 1023) & (0xff << 2);
}