Battery Characteristics
|
|
The devicetree battery node provides static battery characteristics.
|
In smart batteries, these are typically stored in non-volatile memory
|
on a fuel gauge chip. The battery node should be used where there is
|
no appropriate non-volatile memory, or it is unprogrammed/incorrect.
|
|
Upstream dts files should not include battery nodes, unless the battery
|
represented cannot easily be replaced in the system by one of a
|
different type. This prevents unpredictable, potentially harmful,
|
behavior should a replacement that changes the battery type occur
|
without a corresponding update to the dtb.
|
|
Required Properties:
|
- compatible: Must be "simple-battery"
|
|
Optional Properties:
|
- voltage-min-design-microvolt: drained battery voltage
|
- energy-full-design-microwatt-hours: battery design energy
|
- charge-full-design-microamp-hours: battery design capacity
|
- precharge-current-microamp: current for pre-charge phase
|
- charge-term-current-microamp: current for charge termination phase
|
- constant-charge-current-max-microamp: maximum constant input current
|
- constant-charge-voltage-max-microvolt: maximum constant input voltage
|
|
Battery properties are named, where possible, for the corresponding
|
elements in enum power_supply_property, defined in
|
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/power_supply.h
|
|
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 = "simple-battery";
|
voltage-min-design-microvolt = <3200000>;
|
energy-full-design-microwatt-hours = <5290000>;
|
charge-full-design-microamp-hours = <1430000>;
|
precharge-current-microamp = <256000>;
|
charge-term-current-microamp = <128000>;
|
constant-charge-current-max-microamp = <900000>;
|
constant-charge-voltage-max-microvolt = <4200000>;
|
};
|
|
charger: charger@11 {
|
....
|
monitored-battery = <&bat>;
|
...
|
};
|
|
fuel_gauge: fuel-gauge@22 {
|
....
|
monitored-battery = <&bat>;
|
...
|
};
|
