Generic Linux PON framework RFC - looking for cross-vendor input

[Ziyou Xu]

Hi,

We recently started an RFC discussion on netdev about whether Linux
needs a small generic framework for PON devices:

   [RFC] net: towards a generic PON framework
   https://lore.kernel.org/netdev/20260926174601.1675-1-yhyxwgy@gmail.com/

The discussion started from existing work on Airoha AN7581/AN7583.
That implementation already has working PON MAC/activation support,
OMCI transport, GEM/T-CONT handling and an Ethernet datapath:

   https://github.com/pbs05/openwrt-pon-drivers
   https://github.com/pbs05/openwrt-pon-userspace

There is also ongoing OpenWrt work for older EcoNet/Airoha PON
hardware:

   https://github.com/openwrt/openwrt/pull/20104

The goal of the RFC is not to turn the current Airoha API into a
generic Linux API.

We are instead trying to determine which concepts, if any, are common
between different PON implementations before one vendor's model gets
frozen into a userspace ABI.

Some of the questions currently being discussed are:

   - whether Linux needs a common PON device/line object;
   - how Ethernet service netdevs relate to GEM/LLID bearers;
   - where the boundary between TC/VLAN classification and PON bearer
     mapping should be;
   - how raw OMCI PDUs should cross the kernel/userspace boundary;
   - which GEM/T-CONT/LLID state belongs in generic code versus a
     hardware driver;
   - how activation/PLOAM/MPCP state should be exposed;
   - how fixed PON optics should interact with PHY, hwmon and NVMEM.

The discussion has already shown that different working implementations 
make different choices about OMCI, activation and optical control, which 
is why another hardware family would be useful.

We would especially like to hear from people working on Realtek,
Lantiq/Intel/MaxLinear, Broadcom, or any other PON-capable SoCs.

Even a partially working port is useful. In particular, information
about how another PON MAC represents GEM/T-CONT/LLID resources,
service classification, OMCI transport and activation state would help
us identify which parts of the current Airoha designs are actually
generic and which are hardware-specific.

If you are working on xPON support in OpenWrt or Linux, please take a
look at the RFC and join the discussion on netdev. Replies here
pointing to existing code, vendor-open source trees or work-in-progress
ports would also be very useful.

Thanks,
Ziyou Xu