Merge branch 'net-airoha-preliminary-patches-to-support-multiple-net_devices-connecte...

Lorenzo Bianconi says:

====================
net: airoha: Preliminary patches to support multiple net_devices connected to the same GDM port

EN7581 or AN7583 SoCs support connecting multiple external SerDes (e.g.
Ethernet or USB SerDes) to GDM3 or GDM4 ports via a hw arbiter that
manages the traffic in a TDM manner. As a result multiple net_devices can
connect to the same GDM{3,4} port and there is a theoretical "1:n"
relation between GDM ports and net_devices.

           ┌─────────────────────────────────┐
           │                                 │    ┌──────┐
           │                         P1 GDM1 ├────►MT7530│
           │                                 │    └──────┘
           │                                 │      ETH0 (DSA conduit)
           │                                 │
           │              PSE/FE             │
           │                                 │
           │                                 │
           │                                 │    ┌─────┐
           │                         P0 CDM1 ├────►QDMA0│
           │  P4                     P9 GDM4 │    └─────┘
           └──┬─────────────────────────┬────┘
              │                         │
           ┌──▼──┐                 ┌────▼────┐
           │ PPE │                 │   ARB   │
           └─────┘                 └─┬─────┬─┘
                                     │     │
                                  ┌──▼──┐┌─▼───┐
                                  │ ETH ││ USB │
                                  └─────┘└─────┘
                                   ETH1   ETH2

This is a preliminary series to introduce support for multiple net_devices
connected to the same Frame Engine (FE) GDM port (GDM3 or GDM4) via an
external hw arbiter.
====================

Link: https://patch.msgid.link/20260527-airoha-eth-multi-serdes-preliminary-v1-0-ec6ed73ef7fc@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>