On Sun, Jan 29, 2017 at 6:39 PM, Sebastian Reichel <sre@xxxxxxxxxx> wrote:
> Hi,
>
> On Sun, Jan 29, 2017 at 03:32:10PM -0800, Liam Breck wrote:
>> On Sun, Jan 29, 2017 at 10:06 AM, Sebastian Reichel <sre@xxxxxxxxxx> wrote:
>> > On Sun, Jan 22, 2017 at 02:22:12PM -0800, Liam Breck wrote:
>> ...
>> >> +Batteries must be referenced by chargers and/or fuel-gauges
>> >> +using a phandle. The phandle's property should be named
>> >> +"monitored-battery".
>> >> +
>> >> +Example:
>> >> +
>> >> + bat: battery {
>> >> + compatible = "fixed-battery";
>> >> + terminate-microvolt = <3700000>;
>> >> + design-microwatt-hours = <5290000>;
>> >> + design-microamp-hours = <1430000>;
>> >> + };
>> >> +
>> >> + charger: charger@0 {
>> >> + ....
>> >> + monitored-battery = <&bat>;
>> >> + ...
>> >> + };
>> >> +
>> >> + fuel_gauge: fuel_gauge@0 {
>> >> + ....
>> >> + monitored-battery = <&bat>;
>> >> + ...
>> >> + };
>> >
>> > The charger stuff does does not integrate well with
>> > pre-existing support for power-supplies property
>> > described in
>> > Documentation/devicetree/bindings/power/supply/power_supply.txt
>> >
>> > I think the proper chain would be:
>> >
>> > bat: battery {
>> > compatible = "fixed-battery";
>> > terminate-microvolt = <3700000>;
>> > design-microwatt-hours = <5290000>;
>> > design-microamp-hours = <1430000>;
>> > };
>> >
>> > fuel_gauge: fuel_gauge@0 {
>> > ...
>> > monitored-battery = <&bat>;
>> > power-supplies = <&charger>;
>> > ...
>> > };
>> >
>> > charger: charger@0 {
>> > ...
>> > };
>> >
>> > I added the power-supplies node to the fuel-gauge instead of the battery,
>> > since fuel-gauge + fixed-battery is basically a smart battery.
>>
>> BQ24190 charger will need other params from a battery node. How does
>> it get them in this scenario?
>
> It should be able to get all required properties from the bq27xxx.
> Otherwise supporting smart batteries is impossible. What properties
> do you need?
These two, at a minimum:
- precharge-microamps: maximum charge current during precharge
phase (typically 20% of battery capacity)
- termination-microamps: a charge cycle terminates when the
battery voltage is above recharge threshold, and the current is below
this setting (typically 10% of battery capacity)
Sorry, I'm not seeing how the charger will obtain these from the fuel
gauge. Could you clarify with a code snippet?
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