Subject: Re: [0/14] Ebony support, 2nd spi

From: Segher Boessenkool <[email-masked]>
Date: Tue, 20 Feb 2007 16:25:00 +0100

>> And the ebony dts also has the a bus type of "ibm,opb" as well.
>
> We should really get a common name for these. I don't remember
> what the discussions were, but it seems we came up with different
> results for Axon and ppc4xx, which is very bad.

"Very bad"...  Well sure it's less than desirable, but
we have to deal with this problem anyway already.

> Using type "ibm,opb" rather than just "opb" makes sense to me,
> but I don't know if we already have shipping systems that use
> "opb" here.
>
> There is probably a similar problem with the nodes for "plb4",
> "plb5" and "ebc",

It makes sense for generic code to always if it is asked
to match for "vendor-code,some-name" also to match on
plain "some-name".  Well unless people start doing crazy
things like naming something "vendor-code,pci" which
isn't PCI compatible or something -- in that case there
could be a function that matches on exact name only, or
the caller can deal with it itself perhaps.

But in most cases the matching-without-prefix should work
fine.

> as well as the "compatible" property of the
> serial port, which, as you noted earlier is "ns16550" on
> ebony and "ns16750" on axon, although it is exactly the same
> macro.

So the "compatible" property should read ns16750, ns16550,
ns16450, i8250.  The kernel really only needs the device
to be compatible to the 8250; but since lots of device trees
mention only the newer UART types, you have to match on those
too.

Segher