On Mon, Nov 28, 2016 at 06:05:39PM +0200, Pantelis Antoniou wrote:
> There exists a syntactic sugar version of overlays which
> make them simpler to write for the trivial case of a single target.
>
> Document it in the device tree object internals.
>
> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
I'm with Frank that I think this, rather than being regarded mere
syntactic sugar, should be considered the primary way of describing
overlays.
Obviously we need to support the fully written out version as well.
> ---
> Documentation/dt-object-internal.txt | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/Documentation/dt-object-internal.txt b/Documentation/dt-object-internal.txt
> index 026d4ee..d5b841e 100644
> --- a/Documentation/dt-object-internal.txt
> +++ b/Documentation/dt-object-internal.txt
> @@ -300,3 +300,19 @@ local reference is being made. No matter how phandles are allocated from dtc
> the run time loader must apply an offset to each phandle in every dynamic
> DT object loaded. The __local_fixups__ node records the place of every
> local reference so that the loader can apply the offset.
> +
> +There is an alternative syntax to the expanded form for overlays with phandle
> +targets which makes the format similar to the one using in .dtsi include files.
> +
> +So for the &ocp target example above one can simply write:
> +
> +/dts-v1/ /plugin/;
> +&ocp {
> + /* bar peripheral */
> + bar {
> + compatible = "corp,bar";
> + ... /* various properties and child nodes */
> + }
> +};
> +
> +The resulting dtb object is identical.
--
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
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