Re: [PATCH 1/2] dt-bindings: power: Add Spreadtrum SC27XX fuel gauge unit documentation

[Baolin Wang]

Hi Rob,

On 17 September 2018 at 11:26, Rob Herring <robh@xxxxxxxxxx> wrote:
> On Wed, Sep 12, 2018 at 03:29:38PM +0800, Baolin Wang wrote:
>> This patch adds the binding documentation for Spreadtrum SC27XX series PMICs
>> fuel gauge unit device, which is used to calculate the battery capacity.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
>> ---
>>  .../devicetree/bindings/power/supply/sc27xx-fg.txt |   55 ++++++++++++++++++++
>>  1 file changed, 55 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/power/supply/sc27xx-fg.txt
>>
>> diff --git a/Documentation/devicetree/bindings/power/supply/sc27xx-fg.txt b/Documentation/devicetree/bindings/power/supply/sc27xx-fg.txt
>> new file mode 100644
>> index 0000000..7447bae
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/power/supply/sc27xx-fg.txt
>> @@ -0,0 +1,55 @@
>> +Spreadtrum SC27XX PMICs Fuel Gauge Unit Power Supply Bindings
>> +
>> +Required properties:
>> +- compatible: Should be one of the following:
>> +  "sprd,sc2720-fgu",
>> +  "sprd,sc2721-fgu",
>> +  "sprd,sc2723-fgu",
>> +  "sprd,sc2730-fgu",
>> +  "sprd,sc2731-fgu".
>> +- reg: The address offset of fuel gauge unit.
>> +- bat-detect-gpio: GPIO for battery detection.
>
> We already have sbs,battery-detect-gpios, let's drop the 'sbs,' and copy
> that.

Sure.

>
>> +- io-channels: Specify the IIO ADC channel to get temperature.
>> +- io-channel-names: Should be "bat-temp".
>> +- sprd,inner-resist: Specify the the battery inner resistance (mOhm).
>
> If this is a property of the battery, then why a sprd vendor prefix?
> This should perhaps be a common property.
>
> Minimally, it needs a unit suffix as defined in property-units.txt.

Right. As Sebastian pointed out previously we should add one common
property to describe the battery  inner resistance.

>
>> +- sprd,ocv-cap-table: Provide the battery capacity percent with corresponding
>> +  open circuit voltage (ocv) of the battery, which is used to look up current
>> +  battery capacity according to current baterry ocv values.
>
> Sounds like another battery property.

Yes.

>
>> +- monitored-battery: Phandle of battery characteristics devicetree node.
>
> If the battery is represented in another node, why are properties of the
> battery in this node.

Sure. I can remove these properties which are belonging to the battery
node. Thanks.

>
>> +  The fuel gauge uses the following battery properties:
>> +- charge-full-design-microamp-hours: battery design capacity.
>> +- constant-charge-voltage-max-microvolt: maximum constant input voltage.
>> +  See Documentation/devicetree/bindings/power/supply/battery.txt
>> +
>> +Example:
>> +
>> +     bat: battery {
>> +             compatible = "simple-battery";
>> +             charge-full-design-microamp-hours = <1900000>;
>> +             constant-charge-voltage-max-microvolt = <4350000>;
>> +             ......
>> +     };
>> +
>> +     sc2731_pmic: pmic@0 {
>> +             compatible = "sprd,sc2731";
>> +             reg = <0>;
>> +             spi-max-frequency = <26000000>;
>> +             interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
>> +             interrupt-controller;
>> +             #interrupt-cells = <2>;
>> +             #address-cells = <1>;
>> +             #size-cells = <0>;
>> +
>> +             fgu@a00 {
>> +                     compatible = "sprd,sc2731-fgu";
>> +                     reg = <0xa00>;
>> +                     bat-detect-gpio = <&pmic_eic 9 GPIO_ACTIVE_HIGH>;
>> +                     io-channels = <&pmic_adc 5>;
>> +                     io-channel-names = "bat-temp";
>> +                     sprd,inner-resist = <250>;
>> +                     sprd,ocv-cap-table = <4185 100>, <4113 95>, <4066 90>, <4022 85>, <3983 80>, <3949 75>, <3917 70>,
>> +                             <3889 65>, <3864 60>, <3835 55>, <3805 50>, <3787 45>, <3777 40>, <3773 35>, <3770 30>,
>> +                             <3765 25>, <3752 20>, <3724 15>, <3680 10>, <3605 5>, <3400 0>;
>> +                     monitored-battery = <&bat>;
>> +             };
>> +     };
>> --
>> 1.7.9.5
>>
>



-- 
Baolin Wang
Best Regards