Re: [PATCH v4 3/5] dt-bindings: arm: qcom: Add sc7180 Chromebook board bindings

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 23/05/2022 18:16, Doug Anderson wrote:
> Hi,
> 
> On Sun, May 22, 2022 at 12:57 AM Krzysztof Kozlowski
> <krzysztof.kozlowski@linaro.org> wrote:
>>
>> On 20/05/2022 23:38, Douglas Anderson wrote:
>>> This copy-pastes compatibles from sc7180-based boards from the device
>>> trees to the yaml file so that `make dtbs_check` will be happy.
>>>
>>> NOTES:
>>> - I make no attempt to try to share an "item" for all sc7180 based
>>>   Chromebooks. Because of the revision matching scheme used by the
>>>   Chromebook bootloader, at times we need a different number of
>>>   revisions listed.
>>> - Some of the odd entries in here (like google,homestar-rev23 or the
>>>   fact that "Google Lazor Limozeen without Touchscreen" changed from
>>>   sku5 to sku6) are not typos but simply reflect reality.
>>> - Many revisions of boards here never actually went to consumers, but
>>>   they are still in use within various companies that were involved in
>>>   Chromebook development. Since Chromebooks are developed with an
>>>   "upstream first" methodology, having these revisions supported with
>>>   upstream Linux is important. Making it easy for Chromebooks to be
>>>   developed with an "upstream first" methodology is valuable to the
>>>   upstream community because it improves the quality of upstream and
>>>   gets Chromebooks supported with vanilla upstream faster.
>>>
>>> One other note here is that, though the bootloader effectively treats
>>> the list of compatibles in a given device tree as unordered, some
>>> people would prefer future boards to list higher-numbered revisions
>>> first in the list. Chromebooks here are not changing and typically
>>> list lower revisions first just to avoid churn.
>>>
>>> Signed-off-by: Douglas Anderson <dianders@chromium.org>
>>> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
>>> ---
>>>
>>> (no changes since v3)
>>>
>>> Changes in v3:
>>> - Split link to Chromebook boot doc into a separate patch.
>>> - Added a note to desc about revision ordering within a device tree.
>>>
>>> Changes in v2:
>>> - Add link to doc about how Chromebook devicetrees work.
>>> - Use a "description" instead of a comment for each item.
>>> - Use the marketing name instead of the code name where possible.
>>>
>>>  .../devicetree/bindings/arm/qcom.yaml         | 182 +++++++++++++++++-
>>>  1 file changed, 181 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
>>> index 5ac28e11ea7b..01e40ea40724 100644
>>> --- a/Documentation/devicetree/bindings/arm/qcom.yaml
>>> +++ b/Documentation/devicetree/bindings/arm/qcom.yaml
>>> @@ -219,11 +219,191 @@ properties:
>>>                - qcom,ipq8074-hk10-c2
>>>            - const: qcom,ipq8074
>>>
>>> -      - items:
>>> +      - description: Qualcomm Technologies, Inc. SC7180 IDP
>>> +        items:
>>>            - enum:
>>>                - qcom,sc7180-idp
>>>            - const: qcom,sc7180
>>>
>>> +      - description: HP Chromebook x2 11c (rev1 - 2)
>>> +        items:
>>> +          - const: google,coachz-rev1
>>> +          - const: google,coachz-rev2
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: HP Chromebook x2 11c (newest rev)
>>> +        items:
>>> +          - const: google,coachz
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: HP Chromebook x2 11c with LTE (rev1 - 2)
>>> +        items:
>>> +          - const: google,coachz-rev1-sku0
>>> +          - const: google,coachz-rev2-sku0
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: HP Chromebook x2 11c with LTE (newest rev)
>>> +        items:
>>> +          - const: google,coachz-sku0
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Lenovo Chromebook Duet 5 13 (rev2)
>>> +        items:
>>> +          - const: google,homestar-rev2
>>> +          - const: google,homestar-rev23
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Lenovo Chromebook Duet 5 13 (rev3)
>>> +        items:
>>> +          - const: google,homestar-rev3
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Lenovo Chromebook Duet 5 13 (newest rev)
>>> +        items:
>>> +          - const: google,homestar
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 (rev0)
>>> +        items:
>>> +          - const: google,lazor-rev0
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 (rev1 - 2)
>>> +        items:
>>> +          - const: google,lazor-rev1
>>> +          - const: google,lazor-rev2
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 (rev3 - 8)
>>> +        items:
>>> +          - const: google,lazor-rev3
>>> +          - const: google,lazor-rev4
>>> +          - const: google,lazor-rev5
>>> +          - const: google,lazor-rev6
>>> +          - const: google,lazor-rev7
>>> +          - const: google,lazor-rev8
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 (newest rev)
>>> +        items:
>>> +          - const: google,lazor
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 with KB Backlight (rev1 - 2)
>>> +        items:
>>> +          - const: google,lazor-rev1-sku2
>>> +          - const: google,lazor-rev2-sku2
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 with KB Backlight (rev3 - 8)
>>> +        items:
>>> +          - const: google,lazor-rev3-sku2
>>> +          - const: google,lazor-rev4-sku2
>>> +          - const: google,lazor-rev5-sku2
>>> +          - const: google,lazor-rev6-sku2
>>> +          - const: google,lazor-rev7-sku2
>>> +          - const: google,lazor-rev8-sku2
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 with KB Backlight (newest rev)
>>> +        items:
>>> +          - const: google,lazor-sku2
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 with LTE (rev1 - 2)
>>> +        items:
>>> +          - const: google,lazor-rev1-sku0
>>> +          - const: google,lazor-rev2-sku0
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 with LTE (rev3 - 8)
>>> +        items:
>>> +          - const: google,lazor-rev3-sku0
>>> +          - const: google,lazor-rev4-sku0
>>> +          - const: google,lazor-rev5-sku0
>>> +          - const: google,lazor-rev6-sku0
>>> +          - const: google,lazor-rev7-sku0
>>> +          - const: google,lazor-rev8-sku0
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook Spin 513 with LTE (newest rev)
>>> +        items:
>>> +          - const: google,lazor-sku0
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook 511 (rev4 - rev8)
>>> +        items:
>>> +          - const: google,lazor-rev4-sku4
>>> +          - const: google,lazor-rev5-sku4
>>> +          - const: google,lazor-rev6-sku4
>>> +          - const: google,lazor-rev7-sku4
>>> +          - const: google,lazor-rev8-sku4
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook 511 (newest rev)
>>> +        items:
>>> +          - const: google,lazor-sku4
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook 511 without Touchscreen (rev4)
>>> +        items:
>>> +          - const: google,lazor-rev4-sku5
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook 511 without Touchscreen (rev5 - rev8)
>>> +        items:
>>> +          - const: google,lazor-rev5-sku5
>>> +          - const: google,lazor-rev5-sku6
>>> +          - const: google,lazor-rev6-sku6
>>> +          - const: google,lazor-rev7-sku6
>>> +          - const: google,lazor-rev8-sku6
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Acer Chromebook 511 without Touchscreen (newest rev)
>>> +        items:
>>> +          - const: google,lazor-sku6
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Sharp Dynabook Chromebook C1 (rev1)
>>> +        items:
>>> +          - const: google,pompom-rev1
>>> +          - const: qcom,sc7180
>>> +
>>> +      - description: Sharp Dynabook Chromebook C1 (rev2)
>>> +        items:
>>> +          - const: google,pompom-rev2
>>
>> I understand why you do not share "item" (your first notes) for some of
>> boards, but I don't get why "google,pompom-rev1" cannot be combined with
>> "google,pompom-rev2". Do you see any chances to alter the bindings for
>> these two boards?
>>
>> The same for other such cases (not newest revision).
> 
> Yeah, I thought about it when I was writing the file and decided
> against it. I guess it's just a style decision. If we combine these
> two then I guess it raises the question: do we only combine entries
> that list a single revision if they're the same board, or do we have
> one uber entry at the end of the list that combines all
> single-revision sc7180 Chromebooks? ...and in either case, what should
> the description be?
> 
> Personally, though it takes up more lines of code, I prefer the
> simplicity of having each entry here correspond to a single dts file.
> 
> Unless you feel really strongly about it, I'd tend to leave the
> decision here to Bjorn.

Sure. I would prefer to combine such obvious entries, so not everything
into one, but the same boards with revision/SKU difference.

For both cases:
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>



Best regards,
Krzysztof