@@ -877,27 +877,38 @@ static int ab8500_fg_uncomp_volt_to_capacity(struct ab8500_fg *di)
/**
* ab8500_fg_battery_resistance() - Returns the battery inner resistance
* @di: pointer to the ab8500_fg structure
+ * @vbat_uncomp_uv: Uncompensated VBAT voltage
*
* Returns battery inner resistance added with the fuel gauge resistor value
* to get the total resistance in the whole link from gnd to bat+ node
* in milliohm.
*/
-static int ab8500_fg_battery_resistance(struct ab8500_fg *di)
+static int ab8500_fg_battery_resistance(struct ab8500_fg *di, int vbat_uncomp_uv)
{
struct power_supply_battery_info *bi = di->bm->bi;
int resistance_percent = 0;
int resistance;
- resistance_percent = power_supply_temp2resist_simple(bi->resist_table,
- bi->resist_table_size,
- di->bat_temp / 10);
/*
- * We get a percentage of factory resistance here so first get
- * the factory resistance in milliohms then calculate how much
- * resistance we have at this temperature.
+ * Determine the resistance at this voltage. First try VBAT-to-Ri else
+ * just infer it from the surrounding temperature, if nothing works just
+ * use the internal resistance.
*/
- resistance = (bi->factory_internal_resistance_uohm / 1000);
- resistance = resistance * resistance_percent / 100;
+ if (power_supply_supports_vbat2ri(bi)) {
+ resistance = power_supply_vbat2ri(bi, vbat_uncomp_uv, di->flags.charging);
+ /* Convert to milliohm */
+ resistance = resistance / 1000;
+ } else if (power_supply_supports_temp2ri(bi)) {
+ resistance_percent = power_supply_temp2resist_simple(bi->resist_table,
+ bi->resist_table_size,
+ di->bat_temp / 10);
+ /* Convert to milliohm */
+ resistance = bi->factory_internal_resistance_uohm / 1000;
+ resistance = resistance * resistance_percent / 100;
+ } else {
+ /* Last fallback */
+ resistance = bi->factory_internal_resistance_uohm / 1000;
+ }
dev_dbg(di->dev, "%s Temp: %d battery internal resistance: %d"
" fg resistance %d, total: %d (mOhm)\n",
@@ -955,7 +966,7 @@ static int ab8500_load_comp_fg_bat_voltage(struct ab8500_fg *di, bool always)
vbat_uv = vbat_uv / i;
/* Next we apply voltage compensation from internal resistance */
- rcomp = ab8500_fg_battery_resistance(di);
+ rcomp = ab8500_fg_battery_resistance(di, vbat_uv);
vbat_uv = vbat_uv - (di->inst_curr_ua * rcomp) / 1000;
/* Always keep this state at latest measurement */
Augment the AB8500 fuel gauge to use the VBAT-to-Ri method of estimating the internal resistance if possible. Else fall back to using the temperature-to-Ri or just the default Ri. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - No changes --- drivers/power/supply/ab8500_fg.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-)