Re: [PATCH net-next v8 1/4] dt-bindings: net: pse-pd: add bindings for Realtek PSE MCU

[Kory Maincent]

On Wed, 15 Jul 2026 07:55:25 +0000
Jonas Jelonek <jelonek.jonas@xxxxxxxxx> wrote:

> Add a binding for the microcontroller (MCU) that fronts the PSE silicon
> on a range of managed Realtek-based switches. The host talks only to the
> MCU, over I2C/SMBus or UART, using a fixed message-based protocol; the
> PSE chips behind it never appear on the bus.
> 
> The device is the MCU together with its Realtek firmware: the firmware
> and its host protocol are what the binding describes, not the
> general-purpose microcontroller they run on. The PSE silicon behind the
> MCU (Realtek or Broadcom) is reported by the MCU and detected at runtime,
> so it is not described here - hence the 'realtek' vendor prefix.
> 
> Two protocol generations exist, both Realtek's, selected by the
> compatible: gen1 on older boards (fronting Broadcom PSE silicon) and gen2,
> the altered protocol used with Realtek's own PSE silicon. On an I2C
> attachment the framing the MCU firmware expects is part of the compatible
> as well - '-smbus' or raw '-i2c'; a UART attachment carries no framing
> suffix, as the transport is given by the parent serial node.
> 
> Each board additionally carries a device-specific compatible that falls
> back to one of the protocol compatibles above. Drivers bind on the
> protocol compatible; the device-specific string identifies the board and
> reserves a place for a future per-board quirk without having to retrofit
> device trees already in the field.
> 
> Signed-off-by: Jonas Jelonek <jelonek.jonas@xxxxxxxxx>
> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> Reviewed-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>

Reviewed-by: Kory Maincent <kory.maincent@xxxxxxxxxxx>

Thank you!

-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com