Thread (1 message) 1 message, 1 author, 2017-02-22

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.txt
diff --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>;
+		...
+	};
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help