Re: [PATCH v4 1/6] dt-bindings: arm: qcom: Document QCM8550, QCS8550 SoC and board

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On Tue, 20 Feb 2024 at 11:09, Aiqun Yu (Maria) <quic_aiquny@quicinc.com> wrote:
>
>
>
> On 2/5/2024 9:48 PM, Dmitry Baryshkov wrote:
> > On Mon, 5 Feb 2024 at 12:21, Tengfei Fan <quic_tengfan@quicinc.com> wrote:
> >>
> >>
> >>
> >> On 2/5/2024 12:29 AM, Dmitry Baryshkov wrote:
> >>> On Fri, 19 Jan 2024 at 11:07, Tengfei Fan <quic_tengfan@quicinc.com> wrote:
> >>>>
> >>>> Document QCM8550, QCS8550 SoC and the AIM300 AIoT board bindings.
> >>>> QCS8550 and QCM8550 processor combines powerful computing, extreme edge
> >>>> AI processing, Wi-Fi 7, and robust video and graphics for a wide range
> >>>> of use cases for the Internet of Things (IoT). QCS8550 is a QCS version
> >>>> for QCM8550. Modem RF only in QCM8550 but not in QCS8550.
> >>>> AIM300 Series is a highly optimized family of modules designed to
> >>>> support AIoT applications. The module is mounted onto Qualcomm AIoT
> >>>> carrier board to support verification, evaluation and development. It
> >>>> integrates QCS8550 SoC, UFS and PMIC chip etc.
> >>>> AIM stands for Artificial Intelligence Module. AIoT stands for AI IoT.
> >>>>
> >>>> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> >>>> Signed-off-by: Tengfei Fan <quic_tengfan@quicinc.com>
> >>>> ---
> >>>>    Documentation/devicetree/bindings/arm/qcom.yaml | 11 +++++++++++
> >>>>    1 file changed, 11 insertions(+)
> >>>>
> >>>> diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
> >>>> index 1a5fb889a444..9cee874a8eae 100644
> >>>> --- a/Documentation/devicetree/bindings/arm/qcom.yaml
> >>>> +++ b/Documentation/devicetree/bindings/arm/qcom.yaml
> >>>> @@ -49,8 +49,10 @@ description: |
> >>>>            msm8996
> >>>>            msm8998
> >>>>            qcs404
> >>>> +        qcs8550
> >>>>            qcm2290
> >>>>            qcm6490
> >>>> +        qcm8550
> >>>
> >>> Drop
> >>
> >> we want to introduce qcm8550 here.
> >
> > What for. It either had to be introduced beforehand, or it should be
> > introduced when one adds support for an actual qcm8550 device.
> >
> >> qcm8550.dtsi has been introduced and qcs8550-aim300.dtsi include
> >> qcm8550.dtsi directly.
> >>
> >> qcs8550 is a QCS version for qcm8550. qcs8550 is a sub-series of
> >> qcm8550. qcm8550 will be a firmware release series from qualcomm.
> >
> > All three names refer to the different kinds of the same platform. The
> > base chip name is sm8550, so it is the last one. Other than that,
> > there is no need to include any SoC compatibles other than the actual
> > SoC name. See existing qrb devices for an inspiration.
> >
> >>
> >> here is the qcm8550/qcs8550 detailed spec:
> >> https://docs.qualcomm.com/bundle/publicresource/87-61717-1_REV_A_Qualcomm_QCS8550_QCM8550_Processors_Product_Brief.pdf
> >>
> >> here is the sm8550 detailed spec:
> >> https://docs.qualcomm.com/bundle/publicresource/87-71408-1_REV_C_Snapdragon_8_gen_3_Mobile_Platform_Product_Brief.pdf
> >
> > Can you please summarise the _actual_ difference between qcm8550,
> > qcs8550 and sm8550? Are they fully soft compatible? Soft compatible
> > except the modem? Pin compatible?
>
> we can remove the qcm8550 compatible for now, and rename current dtsi
> back for qcs8550.dtsi, and only introduce qcm8550 later when there is
> qcm8550 board public-ed.

Yes, please.

>
>  From software point of view, currently it is single firmware image
> release for both qcm8550 and qcs8550, and the firmware is not grantee
> for sm8550 software compatible.

I assume that modem.mbn is different for qcm and qcs devices. Or does
qcs completely miss the modem DSP?

>
>  From hardware point of view, qcm8550, qcs8550, sm8550 are different
> hardware socs, qcm8550, qcs8550 is derived from sm8550. We can only
> share the public document about those soc descriptions [1]. For soc
> itself, it is all similar difference for QCS and QCM version.
> Currently(in current development stage) there is not notable software
> difference needed other than memory map in kernel side needed to be
> differentiate from qcm8550 qcs8550 to sm8550.
>
> [1]
> https://docs.qualcomm.com/bundle/publicresource/87-61717-1_REV_A_Qualcomm_QCS8550_QCM8550_Processors_Product_Brief.pdf
>
> >
> >>
> >>>
> >>>>            qdu1000
> >>>>            qrb2210
> >>>>            qrb4210
> >>>> @@ -93,6 +95,7 @@ description: |
> >>>>      The 'board' element must be one of the following strings:
> >>>>
> >>>>            adp
> >>>> +        aim300-aiot
> >>>
> >>> We probably need to drop this list, it doesn't surve its purposes.
> >>
> >> I am a little confused, do you expect to just remove this "aim300-aiot"
> >> or do you want to introduce a new patch and remove the whole list?
> >
> > If you were following the list, you would have seen the patch
> > reworking the bindings.
> >
> >>
> >>>
> >>>>            cdp
> >>>>            dragonboard
> >>>>            idp
> >>>> @@ -904,6 +907,14 @@ properties:
> >>>>              - const: qcom,qcs404-evb
> >>>>              - const: qcom,qcs404
> >>>>
> >>>> +      - items:
> >>>> +          - enum:
> >>>> +              - qcom,qcs8550-aim300-aiot
> >>>> +          - const: qcom,qcs8550-aim300
> >>>> +          - const: qcom,qcs8550
> >>>> +          - const: qcom,qcm8550
> >>>
> >>> In the review comments for v3 you have been asked to add qcom,sm8550.
> >>> But not the qcom,qcm8550. I don't think that there is any need to
> >>> mention qcm8550 here.
> >>
> >> qcm8550 and sm8550 are different, they have different firmware release.
> >>
> >> AIM300 AIoT board depend on qcs8550, qcs8550 is a QCS version for
> >> qcm8550. Modem RF only in qcm8550 but not in qcs8550.
> >
> > There are no 'dependecies' here. The thing is about declaring compatibility.
> > In my opinion, the qcm8550 is an unnecesary part of the equation. You
> > declare compatibility with the board itself,  with the SoM, with the
> > actual SoC and with the base of the series. Anybody caring for the
> > difference between QCM, QCS and SM will have to check for both
> > qcom,qcs8550 and qcom,qcm8550 anyway, as there are differences on the
> > modem side.
> >
> >>>> +          - const: qcom,sm8550
> >>>> +
> >>>>          - items:
> >>>>              - enum:
> >>>>                  - qcom,sa8155p-adp
> >>>> --
> >
>
> --
> Thx and BRs,
> Aiqun(Maria) Yu



-- 
With best wishes
Dmitry