Re: [PATCH] arm64: dts: qcom: sdm845-oneplus: fix fuel gauge compatible

[David Heidelberg <david@ixit.cz>]

On 27/08/2026 01:38, Rinat Muhamedgaliev wrote:
> The fuel gauge at I2C address 0x55 on OnePlus 6T (fajita) reports
> DeviceType 0x0541, identifying it as a TI bq27541 rather than bq27411.
> 
> Binding it as bq27411 selects the wrong register map and produces
> invalid voltage, state-of-charge, and temperature readings. Use the
> bq27541 compatible and rename the shared label along with its fajita
> and enchilada consumers.
> 
> Tested on OnePlus 6T (fajita): queried DeviceType directly over I2C,
> built the DTB, booted it once with fastboot boot, then installed a
> locally built postmarketOS kernel package. Before the change, readings
> included about 65 V, over 10000% SOC, and -273.1 C. Afterward, the
> bq27xxx driver bound as ti,bq27541 and reported 3.835 V, 42% SOC, and
> 33.3 C.
> 
> Fixes: 12dfb002ca01 ("arm64: dts: qcom: sdm845-oneplus-*: add fuel gauge")
> Closes: https://gitlab.com/sdm845-mainline/linux/-/issues/36
> Link: https://gitlab.com/sdm845-mainline/linux/-/merge_requests/148
> Signed-off-by: Rinat Muhamedgaliev <rinat.muhamedgaliev@gmail.com>
> ---
>   arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi   | 4 ++--
>   arch/arm64/boot/dts/qcom/sdm845-oneplus-enchilada.dts | 2 +-
>   arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dts    | 2 +-
>   3 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
> index 948a0dd18..0c6203fa8 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-common.dtsi
> @@ -790,8 +790,8 @@ &i2c10 {
>   	status = "okay";
>   	clock-frequency = <100000>;
>   
> -	bq27441_fg: bq27441-battery@55 {
> -		compatible = "ti,bq27411";
> +	bq27541_fg: bq27541-battery@55 {
> +		compatible = "ti,bq27541";

Original OP6/6T has bq27411, replacements (or later series) bq27541.

This change is no-go as is, would be great thou to have auto-detection and use 
something such as:

compatible = "ti,bq27xxx";

and adding logic to detect chip id (and maybe also non-sense values)?

We could also multiply device-trees (fajita + enchilada) x2 (bq27411 + bq27541) 
and let u-boot decide, but it seems a bit overkill for a battery chip from the 
same generation and vendor.

Thanks
David


>   		status = "okay";
>   		reg = <0x55>;
>   	};
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-enchilada.dts b/arch/arm64/boot/dts/qcom/sdm845-oneplus-enchilada.dts
> index 5f01115e2..21ebd3f67 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-enchilada.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-enchilada.dts
> @@ -44,7 +44,7 @@ main_cam_ois: main-cam-ois-regulator {
>   	};
>   };
>   
> -&bq27441_fg {
> +&bq27541_fg {
>   	monitored-battery = <&battery>;
>   };
>   
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dts b/arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dts
> index 7ffcad24d..d640b38b5 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-oneplus-fajita.dts
> @@ -67,7 +67,7 @@ tfa9894_codec: tfa9894@34 {
>   
>   };
>   
> -&bq27441_fg {
> +&bq27541_fg {
>   	monitored-battery = <&battery>;
>   };
>