Re: [PATCH 2/5] arm64: dts: qcom: sc8180x: Add Microsoft Surface Pro X

[Haipeng Lin <jimmie.lin@gmail.com>]

On 11/4/26 2:04 AM, Val Packett wrote:
> From: Maximilian Luz <luzmaximilian@gmail.com>
> 
> Introduce a device tree for the Surface Pro X tablet in all 3 variants
> (SQ1 with cellular, SQ1 Wi-Fi only, SQ2 with cellular).
[...]

I believe there is also a Wi-Fi only SQ2 variant. Looking at the WoA
drivers for 8180_CAS (Caspar, Wi-Fi only)
https://github.com/WOA-Project/Qualcomm-Reference-Drivers/tree/master/Surface/8180_CAS/200.0.31.0

This variant is the only that has both SurfaceSMF_SQ1.cab and 
SurfaceSMF_SQ2.cab. Only 8180_CAS MPSS INF maps the no-modem subsystem
ID (SUBSYS_MSNM8180 -> qcmpss8180_nm.mbn), the 8180_CAR (Carina) only
lists the cellular MSWW/MSJP/MSCN IDs.

My SQ2 Wi-Fi boots with the caspar dts in this patch fine but the
gold cluster is pinned at SQ1's top clocks because the 3.072 / 3.1488
GHz OPPs are only in carina.dts.

> diff --git a/arch/arm64/boot/dts/qcom/sc8180x-microsoft-carina.dts b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-carina.dts
> new file mode 100644
> index 000000000000..5d155c69907a
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-carina.dts
> @@ -0,0 +1,50 @@
> +// SPDX-License-Identifier: BSD-3-Clause
> +
> +/dts-v1/;
> +
> +#include "sc8180x-microsoft-surface-pro-x.dtsi"
> +
> +/ {
> +	model = "Microsoft Surface Pro X (SQ2)";
> +	compatible = "microsoft,carina", "qcom,sc8180x";
> +};
> +
> +&cpu4_opp_table {
> +	opp-3072000000 {
> +		opp-hz = /bits/ 64 <3072000000>;
> +		opp-peak-kBps = <8368000 51609600>;
> +	};
> +
> +	opp-3148800000 {
> +		opp-hz = /bits/ 64 <3148800000>;
> +		opp-peak-kBps = <8368000 51609600>;
> +	};
> +};
> +
[...]

Would it make sense to move opp-3072000000 and opp-3148800000 into the
shared sc8180x-microsoft-surface-pro-x.dtsi? qcom-cpufreq-hw disables
all DT OPPs first and only re-enables freqs present in the hardware LUT
so this would work for SQ1 and caspar.dtb will cover both the SQ1 and
SQ2 Wi-Fi models out of the box and carina.dts won't need its own
&cpu4_opp_table override.
> diff --git a/arch/arm64/boot/dts/qcom/sc8180x-microsoft-surface-pro-x.dtsi b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-surface-pro-x.dtsi
> new file mode 100644
> index 000000000000..17fb01c6b164
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-surface-pro-x.dtsi
[...]
> +&smb2351_2 {
> +	status = "disabled";
> +};
> +
> +&smb2351_a {
> +	status = "disabled";
> +};

Confirmed on hardware that labeling pmic@2 and pmic@a in
sc8180x-pmics.dtsi fixes the dtc build failure here.

[...]> +&uart13 {
> +	pinctrl-0 = <&uart13_state>;
> +	pinctrl-names = "default";
> +
> +	status = "okay";
[...]

On linux-surface, ad1bb617a15a from Maximilian Luz had

&qupv3_id_2 {
  status = "okay";
};

Would it be helpful to add here? I confirmed on hardware that adding it
allows uart13 (WCN3998 Bluetooth) and uart15 (SAM EC) to populate and
probe properly.

Thanks,
Haipeng