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hwmon: (isl28022) Fix current reading calculation 

According to the ISL28022 datasheet, bit15 of the current register is
representing -32768. Fix the calculation to properly handle this bit,
ensuring correct measurements for negative values.

Signed-off-by: Yikai Tsai <yikai.tsai.wiwynn@gmail.com>
Link: https://lore.kernel.org/r/20250519084055.3787-2-yikai.tsai.wiwynn@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
pull/1285/head
Yikai Tsai 2025-05-19 16:40:51 +08:00 committed by Guenter Roeck
parent 0ddce55490
commit b2446a16db
1 changed files with 4 additions and 2 deletions
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6
drivers/hwmon/isl28022.c
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@ -154,6 +154,7 @@ static int isl28022_read_current(struct device *dev, u32 attr, long *val)
struct isl28022_data *data = dev_get_drvdata(dev);
unsigned int regval;
int err;
u16 sign_bit;
switch (attr) {
case hwmon_curr_input:
@ -161,8 +162,9 @@ static int isl28022_read_current(struct device *dev, u32 attr, long *val)
ISL28022_REG_CURRENT, &regval);
if (err < 0)
return err;
*val = ((long)regval * 1250L * (long)data->gain) /
(long)data->shunt;
sign_bit = (regval >> 15) & 0x01;
*val = (((long)(((u16)regval) & 0x7FFF) - (sign_bit * 32768)) *
1250L * (long)data->gain) / (long)data->shunt;
break;
default:
return -EOPNOTSUPP;