Re: [PATCH net-next v4 2/2] net:dsa:microchip: add property to select

From: Ante Knezic
Date: Mon Oct 23 2023 - 04:22:45 EST


On Mon, 23 Oct 2023 09:58:48 +0200, Oleksij Rempel wrote:

> If I see it correctly, KSZ9897R supports RMII on two ports (6 and 7)
> with configurable clock direction. See page 124 "5.2.3.2 XMII Port Control 1
> Register"
> http://ww1.microchip.com/downloads/en/DeviceDoc/00002330B.pdf

Clock direction is possible I guess with other devices as well, but I don't see
this specific property (routing REFCLKO to REFCLKI internally when switch is
used as clock provider) for any other, including KSZ9897?
I am no expert on micrel switches, but this to me looks like something specific
only to KSZ88X3 devices as the clocking seems a bit different on KSZ9897 and
alike. KSZ88X3 may generate clock to REFCLKO but still needs this clock fed
back to REFCLKI (or will be routed internally with the "microchip-rmii-internal"
property). This is managed differently on KSZ9897?