6.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yikai Tsai yikai.tsai.wiwynn@gmail.com
[ Upstream commit b2446a16dbf2347a07af0cf994ca36576d94df77 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/isl28022.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/isl28022.c b/drivers/hwmon/isl28022.c index 1fb9864635db9..1b4fb0824d6c0 100644 --- a/drivers/hwmon/isl28022.c +++ b/drivers/hwmon/isl28022.c @@ -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, ®val); 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;