77 lines
3.1 KiB
Plaintext
77 lines
3.1 KiB
Plaintext
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Battery Characteristics
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The devicetree battery node provides static battery characteristics.
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In smart batteries, these are typically stored in non-volatile memory
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on a fuel gauge chip. The battery node should be used where there is
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no appropriate non-volatile memory, or it is unprogrammed/incorrect.
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Upstream dts files should not include battery nodes, unless the battery
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represented cannot easily be replaced in the system by one of a
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different type. This prevents unpredictable, potentially harmful,
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behavior should a replacement that changes the battery type occur
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without a corresponding update to the dtb.
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Required Properties:
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- compatible: Must be "simple-battery"
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Optional Properties:
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- voltage-min-design-microvolt: drained battery voltage
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- voltage-max-design-microvolt: fully charged battery voltage
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- energy-full-design-microwatt-hours: battery design energy
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- charge-full-design-microamp-hours: battery design capacity
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- precharge-current-microamp: current for pre-charge phase
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- charge-term-current-microamp: current for charge termination phase
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- constant-charge-current-max-microamp: maximum constant input current
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- constant-charge-voltage-max-microvolt: maximum constant input voltage
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- factory-internal-resistance-micro-ohms: battery factory internal resistance
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- ocv-capacity-table-0: An array providing the open circuit voltage (OCV)
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of the battery and corresponding battery capacity percent, which is used
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to look up battery capacity according to current OCV value. And the open
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circuit voltage unit is microvolt.
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- ocv-capacity-table-1: Same as ocv-capacity-table-0
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......
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- ocv-capacity-table-n: Same as ocv-capacity-table-0
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- ocv-capacity-celsius: An array containing the temperature in degree Celsius,
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for each of the battery capacity lookup table. The first temperature value
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specifies the OCV table 0, and the second temperature value specifies the
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OCV table 1, and so on.
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Battery properties are named, where possible, for the corresponding
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elements in enum power_supply_property, defined in
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https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/power_supply.h
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Batteries must be referenced by chargers and/or fuel-gauges
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using a phandle. The phandle's property should be named
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"monitored-battery".
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Example:
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bat: battery {
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compatible = "simple-battery";
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voltage-min-design-microvolt = <3200000>;
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voltage-max-design-microvolt = <4200000>;
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energy-full-design-microwatt-hours = <5290000>;
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charge-full-design-microamp-hours = <1430000>;
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precharge-current-microamp = <256000>;
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charge-term-current-microamp = <128000>;
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constant-charge-current-max-microamp = <900000>;
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constant-charge-voltage-max-microvolt = <4200000>;
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factory-internal-resistance-micro-ohms = <250000>;
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ocv-capacity-celsius = <(-10) 0 10>;
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ocv-capacity-table-0 = <4185000 100>, <4113000 95>, <4066000 90>, ...;
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ocv-capacity-table-1 = <4200000 100>, <4185000 95>, <4113000 90>, ...;
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ocv-capacity-table-2 = <4250000 100>, <4200000 95>, <4185000 90>, ...;
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};
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charger: charger@11 {
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....
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monitored-battery = <&bat>;
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...
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};
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fuel_gauge: fuel-gauge@22 {
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....
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monitored-battery = <&bat>;
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...
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};
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