Re: [PATCH V3 4/5] arm64: dts: qcom: x1-crd: Add Embedded controller node

[Dmitry Baryshkov]

On Mon, Mar 09, 2026 at 04:21:50PM +0530, Sibi Sankar wrote:
> 
> On 3/9/2026 2:39 PM, Krzysztof Kozlowski wrote:
> > On 09/03/2026 10:03, Sibi Sankar wrote:
> > > On 3/9/2026 12:55 PM, Krzysztof Kozlowski wrote:
> > > > On Mon, Mar 09, 2026 at 05:06:45AM +0530, Sibi Sankar wrote:
> > > > > Add embedded controller node for Hamoa/Purwa CRDs which adds fan control,
> > > > > temperature sensors, access to EC internal state changes and suspend
> > > > > entry/exit notifications to the EC.
> > > > > 
> > > > > Signed-off-by: Sibi Sankar <sibi.sankar@xxxxxxxxxxxxxxxx>
> > > > > ---
> > > > >    arch/arm64/boot/dts/qcom/x1-crd.dtsi | 16 ++++++++++++++++
> > > > >    1 file changed, 16 insertions(+)
> > > > > 
> > > > > diff --git a/arch/arm64/boot/dts/qcom/x1-crd.dtsi b/arch/arm64/boot/dts/qcom/x1-crd.dtsi
> > > > > index ded96fb43489..29a1aeb98353 100644
> > > > > --- a/arch/arm64/boot/dts/qcom/x1-crd.dtsi
> > > > > +++ b/arch/arm64/boot/dts/qcom/x1-crd.dtsi
> > > > > @@ -1042,6 +1042,16 @@ eusb6_repeater: redriver@4f {
> > > > >    		#phy-cells = <0>;
> > > > >    	};
> > > > > +
> > > > > +	embedded-controller@76 {
> > > > > +		compatible = "qcom,hamoa-it8987-ec", "qcom,hamoa-ec";
> > > > I don't see updates to other x1e boards, thus my arguments from v2 stay
> > > > valid. It's wrong to call it "hamoa-ec" since only one Hamoa board has
> > > > it. All of other Hamoa boards apparently do not have it.
> > > 
> > > Hey Krzysztof,
> > > Thanks for taking time to review the series :)
> > > 
> > > What other Hamoa boards are you referring to? The series
> > > mentions that the driver and bindings is meant for Qualcomm
> > > Hamoa/Purwa/Glymur "reference" devices, so it only covers
> > > CRD and IOT-EVK. It definitely does not cover all Hamoa boards
> > > boards like you are assuming.
> > hamoa-ec compatible implies that and that's something I raised in v2
> > already. You need a specific compatible.
> 
> 
> Hamoa/Glymur reference devices can have different EC MCUs
> depending on the SKU. This introduces the need to deal with
> possibility of quirks and bugs introduced by these differences.
> Hamoa/Purwa CRDs and IOT EVK runs on IT8987, while Glymur
> reference devices run on NPCX498/488. This pretty much was
> the rationale to make the MCU part of the compatible. Anyway
> I can keep it as qcom,hamoa-ec and qcom,glymur-ec for now
> and add specific compatibles when we upstream those boards?

Why do you need a generic compat at all? Glancing at the database, at
least the following laptops seem to have similar protocol (I might be
wrong, this is based on a very quick glance):

acer-sfa14-11
asus-vivobook-s-15
asus-vivobook-s15-q5507
asus-vivobook-s15-s5507
honor-magicbook-art-14
honor-mro-521
hp-elitebook-6-g1q
hp-omnibook-5-14-he0xxx
lenovo-ideacentre-01q8x10
lenovo-ideapad-slim3x-15q8x10-WCN7850
lenovo-thinkpad-t14s-120hz-64gb
lenovo-thinkpad-t14s
lenovo-yoga-slim-7x
medion-14-s1-elite-sprchrgd
medion-14-s1-sprchrgd
qualcomm-snapdragon-dev-kit
tuxedo-elite-14-gen1

I assume that some of them might be false positives and others will use
vendor (or device) extensions to your protocol.

I'd suggest implicitly using "qcom,hamoa-crd-ec" / "qcom,glymyr-crd-ec",
because then we can use something like "asus,vivobook-s15-ec" to
identify the EC on VivoBook S15.

> 
> > 
> > 
> > Best regards,
> > Krzysztof

-- 
With best wishes
Dmitry