diff options
| author | Yikai Tsai <yikai.tsai.wiwynn@gmail.com> | 2025-05-19 16:40:51 +0800 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2025-05-19 21:56:18 -0700 |
| commit | b2446a16dbf2347a07af0cf994ca36576d94df77 (patch) | |
| tree | 18faac3c6c06e651eea16989b9a648dc6d71b9d6 | |
| parent | 0ddce5549012a3f3b9ddcf59822aa0d1be61e8e8 (diff) | |
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>
| -rw-r--r-- | drivers/hwmon/isl28022.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/hwmon/isl28022.c b/drivers/hwmon/isl28022.c index 0f27ac556f51..c2e559dde63f 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; |