The coulomb counter calibration is not CCO, it's CCM. And the CCM is nine bits wide signed register, so let's use sign_extend32() for it. Cc: Pavel Machek <pavel@xxxxxx> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> --- drivers/power/supply/cpcap-battery.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c --- a/drivers/power/supply/cpcap-battery.c +++ b/drivers/power/supply/cpcap-battery.c @@ -84,7 +84,7 @@ struct cpcap_battery_config { struct cpcap_coulomb_counter_data { s32 sample; /* 24 or 32 bits */ s32 accumulator; - s16 offset; /* 10-bits */ + s16 offset; /* 9 bits */ }; enum cpcap_battery_state { @@ -224,8 +224,6 @@ static int cpcap_battery_cc_raw_div(struct cpcap_battery_ddata *ddata, if (!divider) return 0; - offset &= 0x7ff; /* 10-bits, signed */ - switch (ddata->vendor) { case CPCAP_VENDOR_ST: cc_lsb = 95374; /* μAms per LSB */ @@ -318,12 +316,12 @@ cpcap_battery_read_accumulated(struct cpcap_battery_ddata *ddata, ccd->accumulator = ((s16)buf[3]) << 16; ccd->accumulator |= buf[2]; - /* Offset value CPCAP_REG_CCO */ - ccd->offset = buf[5]; - - /* Adjust offset based on mode value CPCAP_REG_CCM? */ - if (buf[4] >= 0x200) - ccd->offset |= 0xfc00; + /* + * Coulomb counter calibration offset is CPCAP_REG_CCM, + * REG_CCO seems unused + */ + ccd->offset = buf[4]; + ccd->offset = sign_extend32(ccd->offset, 9); return cpcap_battery_cc_to_uah(ddata, ccd->sample, -- 2.21.0