Re: [PATCH v5 2/3] arm64: dts: qcom: Introduce sa8255p SoC

From: Konrad Dybcio

Date: Wed Mar 11 2026 - 09:46:56 EST


On 3/5/26 5:28 AM, Deepti Jaggi wrote:
> From: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
>
> Introduce base device tree support for sa8255p Qualcomm's automotive
> infotainment SoC. The base dt file describes core SoC components- CPUs,
> CPU map, ipcc, QUP, geni UART, interrupt controller, TLMM, reserved
> memory, SMMU, firmware scm, scmi, watchdog, SRAM, PSCI, ufs, pcie, pmu
> nodes and enable booting to shell with ramdisk.
>
> The Qualcomm automotive sa8255p SoC utilizes firmware to configure
> platform resources such as clocks, interconnects, and TLMM. Device drivers
> request these resources through the SCMI power,reset and performance
> protocols. Assign each device driver a dedicated SCMI channel and Tx/Rx
> doorbells to support parallel resource requests and aggregation in the
> SCMI platform server. Operate the SCMI server stack in an SMP-enabled VM,
> using the Qualcomm SMC/HVC transport driver for communication.
>
> Group resource operations to improve abstraction and reduce the number of
> SCMI requests. Follow the SCMI-based resource management approach
> demonstrated by Qualcomm at LinaroConnect 2024.[1]
>
> Limit initial support to basic platform resources, serial console, ufs
> and pcie.Defer enabling USB, and Ethernet to subsequent updates.
>
> [1]: https://resources.linaro.org/en/resource/wfnfEwBhRjLV1PEAJoDDte
>
> Co-developed-by: Shazad Hussain <shazad.hussain@xxxxxxxxxxxxxxxx>
> Signed-off-by: Shazad Hussain <shazad.hussain@xxxxxxxxxxxxxxxx>
> Signed-off-by: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
> Co-developed-by: Deepti Jaggi <deepti.jaggi@xxxxxxxxxxxxxxxx>
> Signed-off-by: Deepti Jaggi <deepti.jaggi@xxxxxxxxxxxxxxxx>
> ---

[...]

> + tsens2: thermal-sensor@c251000 {
> + compatible = "qcom,sa8255p-tsens", "qcom,tsens-v2";
> + reg = <0x0 0x0c251000 0x0 0x1ff>,
> + <0x0 0x0c224000 0x0 0x8>;

All TSENS regions are 0x1000-long

[...]

> + tlmm: pinctrl@f000000 {
> + compatible = "qcom,sa8255p-tlmm", "qcom,sa8775p-tlmm";
> + reg = <0x0 0x0f000000 0x0 0x1000000>;
> + interrupts = <GIC_SPI 208 IRQ_TYPE_LEVEL_HIGH>;
> + gpio-controller;
> + #gpio-cells = <2>;
> + interrupt-controller;
> + #interrupt-cells = <2>;
> + gpio-ranges = <&tlmm 0 0 149>;
> + wakeup-parent = <&pdc>;
> + };

Praveen suggested GPIOs are not controlled by Linux:

https://lore.kernel.org/linux-arm-msm/12063990-70fe-4faf-89fa-c74c7bd97f42@xxxxxxxxxxxxxxxx/

Could you comment on this?

[...]

> + aoss-0-thermal {
> + thermal-sensors = <&tsens0 0>;

Is Linux going to act on any of these thermal trips?

Konrad