Re: [PATCH v2 3/3] ARM: dts: qcom: msm8960: expressatt: Add MAX17048 fuel gauge

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 4/1/26 10:28 AM, Rudraksha Gupta via B4 Relay wrote:
> From: Rudraksha Gupta <guptarud@gmail.com>
> 
> Add MAX17048 fuel gauge support.
> 
> Tested by comparing battery capacity readings between upstream (mainline
> max17040 driver) and downstream (Samsung max17048_fuelgauge driver)
> across a full discharge cycle. Upstream reads ~3% lower throughout. Both
> track the discharge curve correctly:
> 
>   Upstream:   95 92 88 87 86 87 83 82 80 68 60 55 50 45 40 35 30 20 16 10 10 5 5 1
>   Downstream: 95 94 92 91 91 89 87 86 84 73 64 59 51 48 43 38 33 23 17 14 12 8 6 3
> 
> Each pair of readings was collected by checking the upstream capacity
> first, then moving the battery to a second expressatt running downstream
> Android to check its capacity. The battery was then moved back to the
> upstream device for the next reading. This swap occasionally caused the
> upstream capacity to read slightly higher than the previous value
> (e.g. 86 -> 87). When this happened, the reading was retaken after the
> value settled.

Ha, nice procedure!

Older phones used to chew through batteries on bootup, so perhaps that
could have had measurable impact as well..

[...]

> +&gsbi5_i2c {
> +	status = "okay";
> +
> +	fuel-gauge@36 {
> +		compatible = "maxim,max17048";
> +		reg = <0x36>;
> +		maxim,double-soc;
> +		maxim,rcomp = /bits/ 8 <0x62>;
> +		maxim,alert-low-soc-level = <2>;
> +		interrupt-parent = <&tlmm>;
> +		interrupts = <67 IRQ_TYPE_EDGE_FALLING>;

interrupts-extended = <&tlmm 67 IRQ...>

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad