Messages in this thread Patch in this message | | | Date | Thu, 26 Nov 2020 12:09:40 +0200 | From | Matti Vaittinen <> | Subject | [RFC PATCH 1/2] power: supply: add cap2ocv batinfo helper |
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The power-supply core supports concept of OCV (Open Circuit Voltage) => SOC (State Of Charge) conversion tables. Usually these tables are used to estimate SOC based on OCV. Some systems use so called "Zero Adjust" where at the near end-of-battery condition the SOC from coulomb counter is used to retrieve the OCV - and OCV and VSYS difference is used to re-estimate the battery capacity.
Add helper to do look-up the other-way around and also get the OCV based on SOC
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> --- drivers/power/supply/power_supply_core.c | 51 ++++++++++++++++++++++++ include/linux/power_supply.h | 5 +++ 2 files changed, 56 insertions(+)
diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index 38e3aa642131..67258799ae2e 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -787,6 +787,43 @@ int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *t } EXPORT_SYMBOL_GPL(power_supply_temp2resist_simple); +/** + * power_supply_cap2ocv_simple() - find the battery OCV by capacity + * @table: Pointer to battery OCV/CAP lookup table + * @table_len: OCV/CAP table length + * @cap: Current cap value + * + * This helper function is used to look up battery OCV according to + * current capacity value from one OCV table, and the OCV table must be ordered + * descending. + * + * Return: the battery OCV. + */ +int power_supply_cap2ocv_simple(struct power_supply_battery_ocv_table *table, + int table_len, int cap) +{ + int i, ocv, tmp; + + for (i = 0; i < table_len; i++) + if (cap > table[i].capacity) + break; + + if (i > 0 && i < table_len) { + tmp = (table[i - 1].ocv - table[i].ocv) * + (cap - table[i].capacity); + + tmp /= table[i - 1].capacity - table[i].capacity; + ocv = tmp + table[i].ocv; + } else if (i == 0) { + ocv = table[0].ocv; + } else { + ocv = table[table_len - 1].ocv; + } + + return ocv; +} +EXPORT_SYMBOL_GPL(power_supply_cap2ocv_simple); + /** * power_supply_ocv2cap_simple() - find the battery capacity * @table: Pointer to battery OCV lookup table @@ -847,6 +884,20 @@ power_supply_find_ocv2cap_table(struct power_supply_battery_info *info, } EXPORT_SYMBOL_GPL(power_supply_find_ocv2cap_table); +int power_supply_batinfo_cap2ocv(struct power_supply_battery_info *info, + int cap, int temp) +{ + struct power_supply_battery_ocv_table *table; + int table_len; + + table = power_supply_find_ocv2cap_table(info, temp, &table_len); + if (!table) + return -EINVAL; + + return power_supply_cap2ocv_simple(table, table_len, cap); +} +EXPORT_SYMBOL_GPL(power_supply_batinfo_cap2ocv); + int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info, int ocv, int temp) { diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 81a55e974feb..bae98b628f92 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -403,11 +403,16 @@ extern void power_supply_put_battery_info(struct power_supply *psy, struct power_supply_battery_info *info); extern int power_supply_ocv2cap_simple(struct power_supply_battery_ocv_table *table, int table_len, int ocv); +int power_supply_cap2ocv_simple(struct power_supply_battery_ocv_table *table, + int table_len, int cap); + extern struct power_supply_battery_ocv_table * power_supply_find_ocv2cap_table(struct power_supply_battery_info *info, int temp, int *table_len); extern int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info, int ocv, int temp); +int power_supply_batinfo_cap2ocv(struct power_supply_battery_info *info, + int cap, int temp); extern int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table, int table_len, int temp); -- 2.25.4
-- Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =]
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