diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2022-01-29 01:49:20 +0100 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2022-02-11 20:24:53 +0100 |
| commit | 965a990427b313a118865df1d33b82e30500c79a (patch) | |
| tree | 98bb05dc9c9df96ca9ce3bce7d95f50efc600b29 /drivers/power | |
| parent | 673b50322bb6e31f0e917eeb321648092528635a (diff) | |
power: supply: ab8500_fg: Safeguard compensated voltage
In some cases when the platform is dissapating more than
500mA the voltage measurements and compensation will become
instable. Add a parameter to bail out of the voltage
measurement if this happens.
This code was found in a Samsung vendor tree.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'drivers/power')
| -rw-r--r-- | drivers/power/supply/ab8500_fg.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/power/supply/ab8500_fg.c b/drivers/power/supply/ab8500_fg.c index 1797518c4b0e..c659fdc8babd 100644 --- a/drivers/power/supply/ab8500_fg.c +++ b/drivers/power/supply/ab8500_fg.c @@ -46,6 +46,8 @@ #define NBR_AVG_SAMPLES 20 #define WAIT_FOR_INST_CURRENT_MAX 70 +/* Currents higher than -500mA (dissipating) will make compensation unstable */ +#define IGNORE_VBAT_HIGHCUR -500000 #define LOW_BAT_CHECK_INTERVAL (HZ / 16) /* 62.5 ms */ @@ -911,12 +913,13 @@ static int ab8500_fg_battery_resistance(struct ab8500_fg *di) /** * ab8500_load_comp_fg_bat_voltage() - get load compensated battery voltage * @di: pointer to the ab8500_fg structure + * @always: always return a voltage, also uncompensated * * Returns compensated battery voltage (on success) else error code. * If always is specified, we always return a voltage but it may be * uncompensated. */ -static int ab8500_load_comp_fg_bat_voltage(struct ab8500_fg *di) +static int ab8500_load_comp_fg_bat_voltage(struct ab8500_fg *di, bool always) { int i = 0; int vbat_uv = 0; @@ -941,6 +944,14 @@ static int ab8500_load_comp_fg_bat_voltage(struct ab8500_fg *di) ab8500_fg_inst_curr_finalize(di, &di->inst_curr_ua); + /* + * If there is too high current dissipation, the compensation cannot be + * trusted so return an error unless we must return something here, as + * enforced by the "always" parameter. + */ + if (!always && di->inst_curr_ua < IGNORE_VBAT_HIGHCUR) + return -EINVAL; + vbat_uv = vbat_uv / i; /* Next we apply voltage compensation from internal resistance */ @@ -964,7 +975,7 @@ static int ab8500_fg_load_comp_volt_to_capacity(struct ab8500_fg *di) { int vbat_comp_uv; - vbat_comp_uv = ab8500_load_comp_fg_bat_voltage(di); + vbat_comp_uv = ab8500_load_comp_fg_bat_voltage(di, true); return ab8500_fg_volt_to_capacity(di, vbat_comp_uv); } |