Re: [PATCH v4 6/7] dt-bindings: net: dsa: mediatek,mt7530: add EcoNet EN751221 switches

[Caleb James DeLisle <cjd@cjdns.fr>]

Hello,

Thanks for the review.

On 03/11/2026 12:08, Krzysztof Kozlowski wrote:
> On Thu, Oct 29, 2026 at 06:42:01PM +0000, Caleb James DeLisle wrote:
>> The EcoNet EN751221 MIPS SoC integrates an MT7530 switch memory-mapped
>> in the SoC register space. It is similar to the econet,en7528-switch
>> except that ports 0..3 are 10/100 only, port 4 has a gigabit PHY, and
>> port 5 has no PHY, but is in some implementations connected to a
>> downstream MT7530 multi-chip module via a TRGMII link.
>>
>> The downstream MT7530 is similar to the MT7621 multi-chip module and
>> has all gigabit ports.
>>
>> Add the econet,en751221-switch compatible with the same constraints as
>> the other built-in switches and also add the econet,en751221-gswitch
>> multi-chip-module switch whose port 6 is configured as a DSA link port.
>>
>> Signed-off-by: Caleb James DeLisle <cjd@cjdns.fr>
>> ---
>>   .../bindings/net/dsa/mediatek,mt7530.yaml     | 43 ++++++++++++++++++-
>>   1 file changed, 41 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml b/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
>> index f98b9113ad12..011c94ef9554 100644
>> --- a/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
>> +++ b/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml
>> @@ -29,6 +29,12 @@ description: |
>>     and the switch registers are directly mapped into SoC's memory map rather than
>>     using MDIO. The DSA driver currently doesn't support MT7620 variants.
>>   
>> +  EcoNet EN751221 SoCs have a memory mapped MT7530 with 3x 10/100 PHYs and 1x
>> +  gigabit PHY. Some EN751221 chips such as EN7513G and EN7526G have a multi-chip
>> +  module implementation of the MT7530 as well as the on-die switch. In these
>> +  packages, the multi-chip module is connected to port 5 of the on-die switch
>> +  via a TRGMII link and allows for 5 gigabit ports.
>> +
>>     There is only the standalone version of MT7531.
>>   
>>     Port 5 on MT7530 supports various configurations:
>> @@ -109,6 +115,14 @@ properties:
>>             Built-in switch of the EcoNet EN7528 SoC
>>           const: econet,en7528-switch
>>   
>> +      - description:
>> +          Built-in switch of EcoNet EN751221 SoC
> You can drop, pointless description, repeats the compatible.


Perhaps reword "On-die switch of EcoNet EN751221 SoC" to avoid confusion 
with MCM switch?


>
>> +        const: econet,en751221-switch
>> +
>> +      - description:
>> +          Multi-chip module gigabit MT7530 in EN751221 SoC
> Keep it in one line with description. No need to inflate it even more.


OK


>
>> +        const: econet,en751221-gswitch
> That's almost the same compatible, which makes me wonder if you describe
> the same device twice. Same device, same compatible.


Well, these are both MT7530 based, but one of them is on-die with the 
SoC and the other one is an MCM so for the driver they are very 
different - they're even loaded by different kmods. I think since one is 
MMIO and the other is MDIO, using the same compatible won't cause a 
driver problem - but I don't know if it's best practice to smooth over 
such a difference or not. Your advice here would be most appreciated.


Thanks,

Caleb


>
> Best regards,
> Krzysztof