OpenWrt support for Cudy C200P (MT7621AT + IP804AR)

For Developers
1

The Cudy C200P is a Gigabit PoE router with five ports (1xWAN, 4xLAN).

Techdata: https://openwrt.org/toh/hwdata/cudy/cudy_c200p

Initial support was added to OpenWrt 24.10.5 with this commit: https://github.com/openwrt/openwrt/commit/2b7fffa963bb2d45a0d13e75cb882308937a61d5

The commit comment describes how to install OpenWrt.

Currently no support for PoE due to lack of support of IP804AR chip (note typo on tech page, should be IP804AR not IP804R).

The IP804AR chip is connected by I2C to the MediaTek MT7621AT.

I found some info that might be helpful for development of an IP804AR driver:

This post is mostly intended to document the results of my evaluation of the state of OpenWrt support of the device. I'm not going to look any further into the C200P.

2

I think you'd be better to target mainline linux for the pse-pd driver framework, rather than targetting the Realtek PoE.

As part of getting the Hasivo HS104 pse-pd chip in, we're looking at some netlink pse-pd enhancements to ubus (just a 'netlink.ethtool.pse' topic, exposing the ethtool pse 'stuff').

Do any of the LEDs on the Cudy C200P rely on PoE state?
The linux kernel pse-pd doesn't yet have any LED trigger integration, so we'd likely end up carrying some out of branch patches for that.

3

that part was easy to fix :wink:

2 Likes
4

Thanks for pointing out pse-pd. It indeed looks promising.

It appears that the IP804AR chip has its own LED interface (see chapter 5.11 of the datasheet). Of course, it would be a good idea to check (e.g. by looking at the PCB) that the relevant LEDs are indeed connected to the PSE chip and not controlled through some other port.