Re: [PATCH v7 3/4] dt-bindings: power: supply: qcom_bms: Add bindings

[Craig <ctatlor97@gmail.com>]

On 20 September 2018 17:58:47 BST, Sebastian Reichel <sebastian.reichel@collabora.com> wrote:
>[Dropped a couple of people from CC, added Baolin]
>
>Hi Craig, Baolin and Rob,
>
>On Thu, Sep 20, 2018 at 03:32:29PM +0100, Craig wrote:
>> On 16 September 2018 13:10:45 BST, Sebastian Reichel
><sebastian.reichel@collabora.com> wrote:
>> >Sorry for my long delay in reviewing this. I like the binding,
>> >but the "qcom," specific properties should become common properties
>> >in
>> >
>> >Documentation/devicetree/bindings/power/supply/battery.txt
>> >and referenced via monitored-battery.
>
>> Thanks for the review, what bindings for ocv would you prefer? The
>> spreadtrum ones or mine?
>
>Most importantly I want to see only one generic binding supporting
>both use cases. As far as I can see there are two major differences:
>
>1. Qcom uses legend properties and SC27XX embedds this into data
>2. Qcom supports temperature based mapping
>
>The second point is easy: Not having temperature information can
>be a subset of the data with temperature info. The main thing to
>discuss are the legend properties. I suppose we have these
>proposals:
>
>Proposal A (from Qcom BMS binding):
>
>ocv-capacity-legend = /bits/ 8 <100 95 90 85 80 75 70 65 60 55 50 45
>...>;
>ocv-temp-legend-celsius = /bits/ 8 <(-10) 0 25 50 65>;
>ocv-lut-microvolt = <43050000 43050000 43030000 42990000
>
>Proposal B (from SC27XX binding):
>
>ocv-cap-table = <4185 100>, <4113 95>, <4066 90>, <4022 85> ...;
>
>I prefer the second binding (with mV -> uV), but I think it becomes
>messy when temperature is added. What do you think about the
>following proposal (derived from pinctrl style):
>
>Proposal C:
>
>ocv-capacity-table-temperatures = <(-10) 0 10>;
>ocv-capacity-table-0 = <4185000 100>, <4113000 95>, <4066000 90>, ...;
>ocv-capacity-table-1 = <4200000 100>, <4185000 95>, <4113000 90>, ...;
>ocv-capacity-table-2 = <4250000 100>, <4200000 95>, <4185000 90>, ...;
>
>-- Sebastian

C looks good to me however I do kinda think it should be millivolts as I don't think any hardware reads in microvolts and the zeroes make it look quite ugly