Re: [PATCH v11 3/4] arm64: dts: qcom: Add HAMOA-IOT-SOM platform

[Stephan Gerhold <stephan.gerhold@linaro.org>]

yOn Mon, Sep 15, 2025 at 05:46:09PM +0800, Yijie Yang wrote:
> 
> 
> On 2025-09-15 16:52, Stephan Gerhold wrote:
> > On Mon, Sep 15, 2025 at 10:12:15AM +0800, Yijie Yang wrote:
> > > 
> > > 
> > > On 2025-09-12 16:48, Stephan Gerhold wrote:
> > > > On Wed, Sep 10, 2025 at 05:02:11PM +0800, Yijie Yang wrote:
> > > > > The HAMOA-IOT-SOM is a compact computing module that integrates a System
> > > > > on Chip (SoC) — specifically the x1e80100 — along with essential
> > > > > components optimized for IoT applications. It is designed to be mounted on
> > > > > carrier boards, enabling the development of complete embedded systems.
> > > > > 
> > > > > Make the following peripherals on the SOM enabled:
> > > > > - Regulators on the SOM
> > > > > - Reserved memory regions
> > > > > - PCIe6a and its PHY
> > > > > - PCIe4 and its PHY
> > > > > - USB0 through USB6 and their PHYs
> > > > > - ADSP, CDSP
> > > > > - Graphic
> > > > > - Video
> > > > > 
> > > > > Written in collaboration with Yingying Tang (PCIe4)
> > > > > <quic_yintang@quicinc.com> and Wangao Wang (Video)
> > > > > <quic_wangaow@quicinc.com>.
> > > > 
> > > > This looks like you should have Co-developed-by: tags together with
> > > > their Signed-off-by: tags.
> > > 
> > > We’ve agreed on this as the preferred method for marking collaboration, as
> > > discussed earlier in this thread.
> > > 
> > 
> > I can't say I agree with Bjorn there, but ok, he's the maintainer. :-)
> > 
> > > > 
> > > > > 
> > > > > Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> > > > > Signed-off-by: Yijie Yang <yijie.yang@oss.qualcomm.com>
> > > > > ---
> > > > >    arch/arm64/boot/dts/qcom/hamoa-iot-som.dtsi | 621 ++++++++++++++++++++++++++++
> > > > >    1 file changed, 621 insertions(+)
> > > > > 
> > > > > diff --git a/arch/arm64/boot/dts/qcom/hamoa-iot-som.dtsi b/arch/arm64/boot/dts/qcom/hamoa-iot-som.dtsi
> > > > > new file mode 100644
> > > > > index 000000000000..c7c3a167eb6a
> > > > > --- /dev/null
> > > > > +++ b/arch/arm64/boot/dts/qcom/hamoa-iot-som.dtsi
> > > > > @@ -0,0 +1,621 @@
> > > > > +// SPDX-License-Identifier: BSD-3-Clause
> > > > > +/*
> > > > > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> > > > > + */
> > > > > +
> > > > > +#include "x1e80100.dtsi"
> > > > > +#include "x1e80100-pmics.dtsi"
> > > > > +#include <dt-bindings/gpio/gpio.h>
> > > > > +#include <dt-bindings/regulator/qcom,rpmh-regulator.h>
> > > > > +
> > > > > +/ {
> > > > > +	compatible = "hamoa-iot-som", "qcom,x1e80100";
> > > > 
> > > > Undocumented compatible (without "qcom," prefix). I think you can just
> > > > drop this?
> > > 
> > > This compatible string was also discussed previously and is the preferred
> > > choice. I’ll add the missing 'qcom,' prefix.
> > > 
> > 
> > Even compatible = "qcom,hamoa-iot-som", "qcom,x1e80100"; is not
> > documented. And it doesn't make much sense to document it either, each
> > of the boards using the SoM should have a more specific compatible and
> > therefore needs to override this property. I think you can really just
> > drop this line.
> 
> Patch 1/4 documents this compatible. It’s another requirement that SoC/SoM
> should follow, which Krzysztof pointed out in v2:
> https://lore.kernel.org/all/aee74e0f-c957-437d-ab48-3977013c3116@kernel.org/
> 

I'm not saying you should drop the "qcom,hamoa-iot-som" compatible. My
point is that only the compatible list you use in hamoa-iot-evk.dts is
documented in PATCH 1/4:

compatible = "qcom,hamoa-iot-evk", "qcom,hamoa-iot-som", "qcom,x1e80100";

The compatible list you are using in hamoa-iot-som.dtsi is *not*
documented:

compatible = "(qcom,)hamoa-iot-som", "qcom,x1e80100";

because the board-specific compatible string (e.g. "qcom,hamoa-iot-evk")
is missing.

The compatible property you have in hamoa-iot-som.dtsi is redundant,
because you override it with the valid one in hamoa-iot-evk.dts. And
every other board using the SoM should do the same.

I would expect that you can just drop this line in hamoa-iot-som.dtsi.

Thanks,
Stephan