From: Liam Breck <kernel@xxxxxxxxxxxxxxxxx> Documentation of static battery characteristics that can be defined for batteries that do not embed this data, which are required by fuel-gauge and charger chips for proper handling of the battery. The following properties are defined: voltage-min-design-microvolt charge-full-design-microamp-hours energy-full-design-microwatt-hours precharge-current-microamp charge-term-current-microamp constant-charge-current-max-microamp constant-charge-voltage-max-microamp Property names are derived from corresponding elements in enum power_supply_property from include/linux/power_supply.h https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/power_supply.h Cc: Rob Herring <robh@xxxxxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Signed-off-by: Matt Ranostay <matt@ranostay.consulting> Signed-off-by: Liam Breck <kernel@xxxxxxxxxxxxxxxxx> Acked-by: Rob Herring <robh@xxxxxxxxxx> --- .../devicetree/bindings/power/supply/battery.txt | 57 ++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/supply/battery.txt diff --git a/Documentation/devicetree/bindings/power/supply/battery.txt b/Documentation/devicetree/bindings/power/supply/battery.txt new file mode 100644 index 00000000..f4d3b4a1 --- /dev/null +++ b/Documentation/devicetree/bindings/power/supply/battery.txt @@ -0,0 +1,57 @@ +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>; + ... + }; -- 2.13.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
