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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 26 Jan 2021 09:43:41 +0100
Message-ID: <CAMuHMdUmtMxucQ9DWvROVPVv2uGEzpRmtv1=jrjm09xU=gHHyw@mail.gmail.com>
Subject: Re: [PATCH] cmd_dtc: Enable generation of device tree symbols
To:     =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= <uwe@kleine-koenig.org>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        cyril@debamax.com, Arnd Bergmann <arnd@arndb.de>,
        Maxime Ripard <mripard@kernel.org>,
        DTML <devicetree@vger.kernel.org>, Rob Herring <robh@kernel.org>
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Hi Uwe,

On Tue, Jan 26, 2021 at 8:21 AM Uwe Kleine-König <uwe@kleine-koenig.org> wrote:
> And then I learned with hints from Rob and Geert that symbols are not
> really necessary for overlays, you just cannot use named labels. But
> using
>
>         target-path = "/soc/i2c@23473245";
>
> or
>
>         target = <&{/soc/i2c@23473245}>;
>
> instead of
>
>         target = <&i2c1>;
>
> works fine. (And if you need to add a phandle the &{/path/to/node}
> construct should work, too (but I didn't test).) Using labels is a tad
> nicer, but the problem I wanted to address with my patch now has a known
> different solution.

Please don't use "target" and "target-path".  Since the introduction of
sugar syntax support in v4.15[1], you can just use "&label", like in a normal
DTS file.  Paths do need the special "&{/path/to/node}" syntax instead
of "/path/to/node", though.

As usual, you can find lots of examples of DT overlays in my repo[2].

[1] commit 4201d057ea91c3d6 ("scripts/dtc: Update to upstream version
v1.4.5-3-gb1a60033c110")
[2] https://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git/log/?h=topic/renesas-overlays

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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