Re: [PATCH v7 1/9] devicetree: power: Add battery.txt
From: Andrew F. Davis <hidden>
Date: 2017-02-22 20:05:48
Also in:
linux-pm
On 02/21/2017 03:30 PM, Liam Breck wrote:
quoted hunk
From: Liam Breck <redacted> Documentation of static battery characteristics that can be defined for batteries which cannot self-identify. This information is required by fuel-gauge and charger chips for proper handling of the battery. Cc: Rob Herring <redacted> Cc: devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Matt Ranostay <redacted> Signed-off-by: Liam Breck <redacted> --- .../devicetree/bindings/power/supply/battery.txt | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/supply/battery.txtdiff --git a/Documentation/devicetree/bindings/power/supply/battery.txt b/Documentation/devicetree/bindings/power/supply/battery.txt new file mode 100644 index 0000000..3d916bd --- /dev/null +++ b/Documentation/devicetree/bindings/power/supply/battery.txt@@ -0,0 +1,42 @@ +Battery Characteristics + +Required Properties: + - compatible: Must be "fixed-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 + +Future Properties must be named for the corresponding elements in +enum power_supply_property, defined in 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". + +Driver code should call power_supply_get_battery_info() to obtain +battery properties via monitored-battery. For details see: + drivers/power/supply/power_supply_core.c + drivers/power/supply/bq27xxx_battery.c + +Example: + + bat: battery { + compatible = "fixed-battery"; + voltage-min-design-microvolt = <3200000>; + energy-full-design-microwatt-hours = <5290000>; + charge-full-design-microamp-hours = <1430000>; + }; +
Still not sure what a non-fixed-battery would be. I guess it would be a battery with an integrated fuel-gauge pre-programmed with this design info. So then the charger node would want to point to a fuel-gauge node, and the fuel-gauge can optionally point to a fixed-battery if that info is not pre-programmable. The issues then is for chargers with an integrated fuel-gauge, or systems without a fuel-gauge, that may get a bit messy, so I have no issues with this current binding.
+ charger: charger@11 {
+ ....
+ monitored-battery = <&bat>;
+ ...
+ };
+
+ fuel_gauge: fuel-gauge@22 {
+ ....
+ monitored-battery = <&bat>;
+ ...
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