On Fri, Dec 4, 2020 at 1:41 PM Matti Vaittinen <[email protected]> wrote:
> 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 <[email protected]> Overall a good idea! > +/** > + * 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. > + */ Spell out the abbreviations in the kerneldoc and not just the commit. These will be read much more than the commit message so I would move all the excellent info in the commit message into the kerneldoc and diet the commit message instead. > +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; This is some linear interpolation right? It's not immediately evident so insert some comment about what is going on. > /** > * 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, I suspect this kerneldoc could be improved in the process as well. Yours, Linus Walleij
