diff mbox series

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

Message ID 1637650813-16654-2-git-send-email-rnayak@codeaurora.org (mailing list archive)
State Changes Requested
Headers show
Series arm64: dts: qcom: Add support for the sc7280 CRD board | expand

Commit Message

Rajendra Nayak Nov. 23, 2021, 7 a.m. UTC
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(+)

Comments

Matthias Kaehlcke Nov. 23, 2021, 2:53 p.m. UTC | #1
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.
Rajendra Nayak Nov. 24, 2021, 11:47 a.m. UTC | #2
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
diff mbox series

Patch

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
               - google,piglin
               - google,senor
           - const: qcom,sc7280