Re: [PATCH v2 5/9] dt-bindings: riscv: Add bouffalolab bl808 board compatibles

[Krzysztof Kozlowski]

On 01/12/2022 12:14, Conor Dooley wrote:
> Hey Krzysztof,
> 
> On Thu, Dec 01, 2022 at 12:05:04PM +0100, Krzysztof Kozlowski wrote:
>> On 27/11/2022 14:24, Jisheng Zhang wrote:
>>> Several SoMs and boards are available that feature the Bouffalolab
>>> bl808 SoC. Document the compatible strings.
>>>
>>> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
>>> ---
>>>  .../bindings/riscv/bouffalolab.yaml           | 34 +++++++++++++++++++
>>>  1 file changed, 34 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/riscv/bouffalolab.yaml
>>>
>>> diff --git a/Documentation/devicetree/bindings/riscv/bouffalolab.yaml b/Documentation/devicetree/bindings/riscv/bouffalolab.yaml
>>> new file mode 100644
>>> index 000000000000..91ca9dbdc798
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/riscv/bouffalolab.yaml
>>> @@ -0,0 +1,34 @@
>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/riscv/bouffalolab.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: Bouffalo Lab Technology SoC-based boards
>>> +
>>> +maintainers:
>>> +  - Jisheng Zhang <jszhang@xxxxxxxxxx>
>>> +
>>> +description:
>>> +  Bouffalo Lab Technology SoC-based boards
>>> +
>>> +properties:
>>> +  $nodename:
>>> +    const: '/'
>>> +  compatible:
>>> +    oneOf:
>>> +      - description: Sipeed M1s SoM:
>>> +        items:
>>> +          - const: sipeed,m1s
>>> +          - const: bouffalolab,bl808
>>
>> I don't think that SoM is usable alone. It always needs a carrier, so
>> drop this entry.
> 
> For my own information, if a SoM is not capable of functioning without a
> carrier there is no merit in it having a compatible?
> Does this also apply if there are multiple possible carriers from
> different vendors?

Compatible makes sense anyway. There will be different boards using this
SoM (not only carriers, but final products) and they all will have
common piece - the SoM. It's the same for other SoM designs (e.g. for iMX).

Best regards,
Krzysztof