Hi Pantelis,
On Thu, Sep 21, 2017 at 10:51 AM, Pantelis Antoniou
<pantelis.antoniou@xxxxxxxxxxxx> wrote:
> On Wed, 2017-09-20 at 14:32 +0200, Geert Uytterhoeven wrote:
>> On Thu, Sep 14, 2017 at 4:18 PM, Vladimir Barinov
>> <vladimir.barinov@xxxxxxxxxxxxxxxxxx> wrote:
>> > +#include "ulcb-kf.dtsi"
>>
>> As the Kingfisher is actually an expansion board for H3ULCB (with R-Car H3
>> ES1.1 and ES2.0) and M3ULCB (with R-Car M3-W), turning ulcb-kf.dtsi into a
>> DT overlay would make sense.
>> That would also solve the issue of the 3 extra DTSes needed for all possible
>> combinations of ULCB and Kingfisher (r8a7795-es1-h3ulcb-kf.dts,
>> r8a7795-h3ulcb-kf.dts, r8a7796-h3ulcb-kf.dts (perhaps more to follow?)).
>>
>> But that's too premature, without upstream support for the easy loading of
>> DT overlays.
>>
>
> Sigh, yes.
>
>> > +/ {
>> > + model = "Renesas M3ULCB Kingfisher board based on r8a7796";
>> > + compatible = "shimafuji,kingfisher", "renesas,m3ulcb",
>> > + "renesas,r8a7796";
>> > +};
>>
>> And how to support from an overlay the addition of "shimafuji,kingfisher" to
>> (not replacement of!) the main compatible value?
>
> You can hack something in DT but it will be gross indeed.
>
> Ideally you'd want a += operator, but it's going to take a lot of
> changes starting from DTB blob format.
>
> In yaml we could easily do this with an append tag type
>
> compatible: [ "renesas,m3ulcb", "renesas,r8a7796" ]
>
> compatible: !append "shimafuji,kingfisher"
As we already have /delete-property/, we could add /append-property/ and
/prepend-property/? Would be useful for a .dts including and enhancing
an .dtsi, too.
That doesn't solve the DTB blob format issue yet, though.
> Are you going to be at ELCE? I have a bunch of thing to ask you about
> your DT usage patterns.
Yes, and registered for the Device Tree Workshop.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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