dec behavior question

[David Gibson]

On Tue, Oct 25, 2011 at 10:10:03PM -0500, Kumar Gala wrote:
> 
> On Oct 25, 2011, at 6:36 PM, David Gibson wrote:
> 
> > On Tue, Oct 25, 2011 at 08:41:55AM -0500, Kumar Gala wrote:
> >> 
> >> On Oct 25, 2011, at 7:18 AM, Yoder Stuart-B08248 wrote:
> >> 
> >>> 
> >>> 
> >>>> -----Original Message-----
> >>>> From: devicetree-discuss-bounces+stuart.yoder=freescale.com at lists.ozlabs.org
> >>>> [mailto:devicetree-discuss-bounces+stuart.yoder=freescale.com at lists.ozlabs.org] On Behalf Of
> >>>> David Gibson
> >>>> Sent: Monday, October 24, 2011 6:15 PM
> >>>> To: Kumar Gala
> >>>> Cc: devicetree-discuss
> >>>> Subject: Re: dec behavior question
> >>>> 
> >>>> On Mon, Oct 24, 2011 at 09:01:49AM -0500, Kumar Gala wrote:
> >>>>> If I have something like:
> >>>>> 
> >>>>> ---------------------------------------
> >>>>> spi.dtsi:
> >>>>> 
> >>>>> &spi0 {
> >>>>>       #address-cells = <1>;
> >>>>>       #size-cells = <0>;
> >>>>>       compatible = "fsl,mpc8536-espi";
> >>>>>       reg = <0x7000 0x1000>;
> >>>>>       interrupts = <59 0x2 0 0>;
> >>>>> };
> >>>>> ---------------------------------------
> >>>>> 
> >>>>> foo.dts:
> >>>>> 
> >>>>> spi0: spi at f00bar {
> >>>>> 	compatible = "FOOBAR";
> >>>>> };
> >>>>> 
> >>>>> /include/ "spi.dtsi"
> >>>>> 
> >>>>> ---------------------------------------
> >>>>> 
> >>>>> What do you expect the resulting dtb to look like w/regards to the
> >>>>> compatible node?
> >>>> 
> >>>> It's always last tree wins.  So it will end up with compatible = "FOOBAR".
> >>> 
> >>> If last wins, then it would be the included file
> >>> (compatible = "fsl,mpc8536-espi"), no?
> > 
> > Uh, yes, sorry.  I misread and assumed the /include/ came first.
> > 
> >> I don't believe so because the include of spi.dtsi doesn't actually
> >> instantiate a node.  This is a little different than use of
> >> 'include' for merging of nodes.
> > 
> > No, it really isn't.  /include/ is just a textual include.  If a node
> > is defined multiple times, properties in the last definition always
> > win.
> 
> So than is there a way to do this?

No way to do what?  I don't see what it is you want that isn't what
you're getting.

> It seems that node references have to come after their use.  Not
> exactly sure why that would be the case.
> 
> ---- the following is invalid ----
> 
> /dts-v1/;
> 
> &spi0 {
>        compatible = "fsl,mpc8536-espi";
> };
> 
> /{
>         spi0: spi at 0 {
>               compatible = "kumar";
>         };
> };

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson