Re: [PATCH net-next 1/2] dt-bindings: net: pse-pd: realtek,pse: add gen1 I2C transport

[Jonas Jelonek <jelonek.jonas@gmail.com>]

Hi,

On 20.10.26 09:27, Krzysztof Kozlowski wrote:
> On Sun, Oct 18, 2026 at 06:12:47PM +0200, Sander Vanheule wrote:
>> Like the gen2 protocol, the gen1 protocol can also be used over both a
>> raw I2C transport and an SMBUs transport. Add a compatible for the
>> former and the compatible for the Ubiquiti Unifi Switch Lite 16 PoE
>> device that uses it.
>>
>> Signed-off-by: Sander Vanheule <sander@svanheule.net>
>> ---
>>  .../bindings/net/pse-pd/realtek,pse-mcu-gen1.yaml          | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/net/pse-pd/realtek,pse-mcu-gen1.yaml b/Documentation/devicetree/bindings/net/pse-pd/realtek,pse-mcu-gen1.yaml
>> index 3bb32349c28c..526f8525bb4d 100644
>> --- a/Documentation/devicetree/bindings/net/pse-pd/realtek,pse-mcu-gen1.yaml
>> +++ b/Documentation/devicetree/bindings/net/pse-pd/realtek,pse-mcu-gen1.yaml
>> @@ -54,6 +54,12 @@ properties:
>>                - zyxel,gs1920-24hp-v2-pse
>>            - const: realtek,pse-mcu-gen1-smbus
>>  
>> +      # I2C, raw framing
>> +      - items:
>> +          - enum:
>> +              - ubnt,usw-lite-16-poe-pse
>> +          - const: realtek,pse-mcu-gen1-i2c
>> +
>>        # UART
>>        - items:
>>            - enum:
>> @@ -100,6 +106,7 @@ allOf:
>>            contains:
>>              enum:
>>                - realtek,pse-mcu-gen1-smbus
>> +              - realtek,pse-mcu-gen1-i2c
> That's the same device as smbus, no? Same device, same compatible.

Physically it's the same device/MCU but the baked-in firmware and configuration
differs. Same for the UART vs. SMBus.

> You can have property deciding about protocol, if this cannot be deduced
> from the clients.

This was the approach in the early versions of the driver when I sent it
to the list. Rob favored the current way [1] and I think Conor was ok
with it later on.

[1] https://lore.kernel.org/netdev/20260615212959.GA1679454-robh@kernel.org/

> Best regards,
> Krzysztof

Best,
Jonas