Re: [PATCH 1/4] dt-bindings: arm: qcom: Document qcom,sc7280-crd board

Rajendra Nayak
2021-11-24T11:47:54Z

On 11/23/2021 8:23 PM, Matthias Kaehlcke wrote:
> On Tue, Nov 23, 2021 at 12:30:10PM +0530, Rajendra Nayak wrote:
>> Document the qcom,sc7280-crd board based off sc7280 SoC,
>> The board is also known as hoglin in the Chrome OS builds,
>> and given there would be multiple (at least one more) rev
>> of this board document the google,hoglin-rev0 compatible as well.
>>
>> Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
>> ---
>> Documentation/devicetree/bindings/arm/qcom.yaml | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
>> index c8808e0..2abfd28 100644
>> --- a/Documentation/devicetree/bindings/arm/qcom.yaml
>> +++ b/Documentation/devicetree/bindings/arm/qcom.yaml
>> @@ -203,6 +203,8 @@ properties:
>> - enum:
>> - qcom,sc7280-idp
>> - qcom,sc7280-idp2
>> + - qcom,sc7280-crd
>> + - google,hoglin-rev0
>
> I think we also want the generic 'google,hoglin' compatible string, analogous to
> for example 'google,lazor' and 'google,lazor-revN'. For lazor there are no
> explicit compatible entries for rev3 and above, there were no DT relevant
> hardware changes for rev > 3, hence the 'google,lazor' compatible string is
> used, without the need to modify the DT for each new HW revision.
>
> Also on my CRD the bootloader thinks it is running on a rev4:
>
> Compat preference: google,hoglin-rev4 google,hoglin
>
> The board still boots thanks to the 'google,hoglin' entry in my device tree,
> but it seems you need to add more revN entries, or start with rev4 if you
> don't really care about supporting older revisions. In the later case you
> coul only have 'google,hoglin' for now, and add 'rev4' when you add support
> for the next revision (supposing it has DT relevant hardware changes). The
> sc7180-trogdor boards can serve as an example on how to deal with board
> revisions.

Sure, i think i will perhaps go with just the google,hoglin compatible
for now and add revs as and when needed, the fact that these boards have
a few initial revs not used at all seem to make it really confusing