Re: [PATCH RFC 3/3] arm64: dts: ti: grove: Add Grove Sunlight Sensor overlay

[Geert Uytterhoeven]

Hi Andrew,

On Thu, Jul 4, 2024 at 6:56 PM Andrew Davis <afd@xxxxxx> wrote:
> The issue then is the overlay mechanism is not complete. We
> can add properties to nodes, and add nodes to nodes, and append
> properties to nodes, but cannot append values to existing properties,
> only replace them completely. This gap in the overlay system will
> prevent a general solution. So I've started to work on adding
> that property appending ability to the overlay system. I should
> have some patches posted against the upstream dtc/libfdt here
> in the next week or so.

This is not limited to overlays, but also true for plain dts.
We have /delete-node/ and /delete-property/, but lack /append-property/.

Hence we end up having to repeat all existing values when appending
to a property (e.g. see [1] appending to clocks from [2]).

[2] https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/renesas/r8a77951-salvator-xs.dts#L39
[1] https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/renesas/r8a77951.dtsi#L3334

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