Re: [PATCH v1 4/4] arm64: dts: imx8-ss-conn: add PPS channel to the FEC nodes

[Francesco Dolcini <francesco@dolcini.it>]

Hello Frank,

+Rafael

On Wed, Aug 07, 2024 at 11:34:48AM -0400, Frank Li wrote:
> On Wed, Aug 07, 2024 at 04:43:49PM +0200, Francesco Dolcini wrote:
> > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> >
> > On i.MX8 the FEC PPS channel is routed to the instance 1, not to the
> > default 0.
> 
> According to my understand, it should be board level configuration. FEC
> support output pps to any one. choose which one by board design.

This seems different from the information we got from NXP some time ago,
unfortunately this was happening over some private email exchange and
not documented anywhere public. But the message was about SoC internal
routing, not something at the board level, at least for i.MX8 SoCs that
is what this patch is changing.

For example to use PPS on i.MX8QXP we need to have this

IMX8QM_ENET0_REFCLK_125M_25M_CONN_ENET0_PPS 0x06000020

pinctrl configuration _and_ use PPS channel 1. Same is for i.MX8QP.

Maybe Rafael can provide you some more details and the name of the
person that provided this information.

And maybe you can also try to double check this internally within NXP.

Depending on what we find out we can decide if this patch needs to be
dropped or not.

Francesco