Re: [PATCH v3 net-next 2/2] net: airoha: Introduce ethernet support for EN7581 SoC

Benjamin Larsson
2024-06-24T19:27:19Z

On 24/06/2024 17:45, Andrew Lunn wrote:
>> https://mirror2.openwrt.org/docs/MT7981B_Wi-Fi6_Platform_Datasheet_Open_V1.0.pdf
>>
>> page 107 (text for 9.1.1 is relevant but not a complete match). In the
>> EN7581 case there is a 5 port switch in the place of GMAC1 (one switch port
>> is connected to GDM1).
> The typical DSA architecture is that the SoC MAC is connected to a
> switch MAC port. You say here, the switch is directly connected to the
> GGM1. So there is no GMAC involved? If there is no MAC, you don't need
> a MAC driver.
>
> It seems more likely there is a GMAC, and the SGMII interface, or
> something similar is connected to the switch?
>
> Andrew
>
Hi, the Mediatek MT7988A SoC block diagram is similar to the EN7581 as
it also have a built in switch (MT7531). MT7988A manual can be found here:

wiki.banana-pi.org/Banana_Pi_BPI-R4

drive.google.com/drive/folders/1XiVchy0a4syYFVlTndhVCETNJ9x7KOYi

MT7988A_Wi-Fi7_Platform_Datasheet_Open_V0.1.pdf

with page 125 containing the block diagram.

Per my understanding the MT7530 switch port connecting to the SoC in the
EN7581 has a direct connection to the GDM1 port. There seem to not be
any SGMII and MAC in this data path. How it actually is connected
internally is unknown to me but packets seem to transfer automatically
between the GDM1 port and the MT7530 switch soc port.

And as mentioned before there are high speed MACs capable of
HSGMII/USXGMII connected to the other GDM ports.

So there will be MACs involved just not for the connection to the MT7530
switch.

MvH

Benjamin Larsson