[PATCH v2 1/2] dt-bindings: power: supply: Document max17040 extensions

[Iskren Chernev]

Maxim max17040 is a fuel gauge from a larger family utilising the Model
Gauge technology. Document all different compatible strings that the
max17040 driver recognizes.

Some devices in the wild report double the capacity. The
maxim,double-soc (from State-Of-Charge) property fixes that.

Complete device reset might lead to very inaccurate readings. Specify
maxim,skip-reset to avoid that.

To compensate for the battery chemistry and operating conditions the
chips support a compensation value. Specify one or two byte compensation
via the maxim,rcomp byte array.

Signed-off-by: Iskren Chernev <iskren.chernev@xxxxxxxxx>
---
v1: https://lkml.org/lkml/2020/6/8/682

Changes in v2:
- add maxim,skip-reset
- remove 2 byte rcomp from example, the specified compat string supports 1 byte
  rcomp

 .../power/supply/max17040_battery.txt         | 24 ++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
index 4e0186b8380fa..3ee91c295027f 100644
--- a/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
+++ b/Documentation/devicetree/bindings/power/supply/max17040_battery.txt
@@ -2,7 +2,9 @@ max17040_battery
 ~~~~~~~~~~~~~~~~
 
 Required properties :
- - compatible : "maxim,max17040" or "maxim,max77836-battery"
+ - compatible : "maxim,max17040", "maxim,max17041", "maxim,max17043",
+ 		"maxim,max17044", "maxim,max17048", "maxim,max17049",
+		"maxim,max17058", "maxim,max17059" or "maxim,max77836-battery"
  - reg: i2c slave address
 
 Optional properties :
@@ -11,6 +13,18 @@ Optional properties :
 				generated. Can be configured from 1 up to 32
 				(%). If skipped the power up default value of
 				4 (%) will be used.
+- maxim,double-soc : 		Certain devices return double the capacity.
+				Specify this boolean property to divide the
+				reported value in 2 and thus normalize it.
+				SOC == State of Charge == Capacity.
+- maxim,skip-reset :		Do not reset device on driver initialization.
+				Some devices report extremely inaccurately after
+				a hard reset.
+- maxim,rcomp :			A value to compensate readings for various
+				battery chemistries and operating temperatures.
+				max17040,41 have 2 byte rcomp, default to
+				0x97 0x00. All other devices have one byte
+				rcomp, default to 0x97.
 - interrupts : 			Interrupt line see Documentation/devicetree/
 				bindings/interrupt-controller/interrupts.txt
 - wakeup-source :		This device has wakeup capabilities. Use this
@@ -31,3 +45,11 @@ Example:
 		interrupts = <2 IRQ_TYPE_EDGE_FALLING>;
 		wakeup-source;
 	};
+
+	battery-fuel-gauge@36 {
+		compatible = "maxim,max17048";
+		reg = <0x36>;
+		maxim,rcomp = /bits/ 8 <0x97>;
+		maxim,alert-low-soc-level = <10>;
+		maxim,double-soc;
+	};

base-commit: 1713116fa907cc7290020f0d8632ec646d2936f8
-- 
2.27.0