powerpc/mpc85xx: Add Cyrus P5040 device tree source

[Scott Wood]

On Wed, 2020-05-13 at 23:02 +0100, Darren Stevens wrote:
> Hello Scott
> 
> On 08/05/2020, Scott Wood wrote:
> > On Thu, 2020-05-07 at 22:30 +0100, Darren Stevens wrote:
> > > 
> > > +/include/ "p5040si-pre.dtsi"
> > > +
> > > +/ {
> > > +    model = "varisys,CYRUS5040";
> > > +    compatible = "varisys,CYRUS";
> > 
> > Is this board 100% compatible with the Cyrus P5020 board, down to every
> > last
> > quirk, except for the SoC plugged into it?  If not, they shouldn't have
> > the
> > same compatible.  If they are, then couldn't everything in this file but
> > the
> > SoC include be moved to a dtsi shared with cyrus_p5020.dts?
> 
> It's not 100% compatible, the mdio ports map to different fman ports, but
> both as are 'corenet generic' boards, I added varisys,CYRUS so it would be
> detected in corenet_generic.c - support for the 5020 was added by Andy
> Flemming, I've just tried to copy what he did.
> 
> I can add another entry to the table, but do we realy want a separate entry
> in the table for every supported board rather than using the device tree for
> similar boards?

A separate compatible for each board is generally what we've done, as it
allows for the possibility of board-specific quirks.  At least it's just a
table entry; back in the day it used to be a separate file. :-P

That said, if you're pretty sure that all potentially relevant differences are
described elsewhere in the device tree, I wouldn't mind too much if it
becomes:
	compatible = "varisys,CYRUS5040", "varisys,CYRUS";

-Scott