Re: [PATCH RFC 1/2] dt-bindings: mfd: aspeed-lpc: Document lpcN alias for multi-instance SoCs

[YC Hsieh]

On Thu, 23 Jul 2026, Yu-Che Hsieh wrote:

>> Some SoCs (e.g. AST2700) expose more than one physical LPC controller
>> instance. Downstream devices such as KCS channels need a stable,
>> globally-unique index derived from which LPC controller instance they
>> belong to, so document the "lpcN" alias convention on the LPC
>> controller node that lets DT authors assign a fixed index per
>> instance, mirroring the existing alias-based numbering convention used
>> by mmc/i2c/spi/serial.
>>
>> Signed-off-by: Yu-Che Hsieh <yc_hsieh@xxxxxxxxxxxxxx>

> Why is this RFC?  What's stopping me from applying this now?

Thanks, there is no blocker. 

I marked it as RFC to gather feedback on the alias-based 
numbering convention for LPC controllers before submitting 
it as a regular patch.

If the approach looks acceptable, I'm happy to resend it 
without the RFC tag.

>> ---
>>  Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml b/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml
>> index cbc3a2485a2f..81c12e0fb312 100644
>> --- a/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml
>> +++ b/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml
>> @@ -35,6 +35,13 @@ description:
>>    configuration, therefore the host portion of the controller is exposed as a
>>    syscon as a means to arbitrate access.
>> 
>> +  On SoCs that expose more than one LPC controller instance, it is possible to
>> +  assign a fixed index to a given instance (and thus to downstream devices
>> +  such as KCS channels that must be uniquely identified system-wide) by
>> +  defining an "lpcN" alias for it in the /aliases device tree node. If no such
> +  alias is present, the SoC is treated as having a single LPC controller
>> +  instance.
>> +
>>  properties:
>>    compatible:
>>      items:
>>
>> --
>> 2.34.1
>>
--

Yu-Che