Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220929172356.301342-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
In-Reply-To: <20220929172356.301342-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 25 Oct 2022 14:40:45 +0200
Message-ID: <CAMuHMdVfExBuXNiRBaPRqaX9AvDprTHec7+1K-7Un6gDf6VWJA@mail.gmail.com>
Subject: Re: [RFC PATCH 0/2] RZ/G2UL separate out SoC specific parts
To:     Prabhakar <prabhakar.csengg@gmail.com>
Cc:     Magnus Damm <magnus.damm@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor.dooley@microchip.com>,
        Samuel Holland <samuel@sholland.org>,
        linux-riscv <linux-riscv@lists.infradead.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        DT <devicetree@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Biju Das <biju.das.jz@bp.renesas.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi Prabhakar,

On Thu, Sep 29, 2022 at 7:24 PM Prabhakar <prabhakar.csengg@gmail.com> wrote:
> This patch series aims to split up the RZ/G2UL SoC DTSI into common parts
> so that this can be shared with the RZ/Five SoC.
>
> Implementation is based on the discussion [0] where I have used option#2.
>
> The Renesas RZ/G2UL (ARM64) and RZ/Five (RISC-V) have almost the same
> identical blocks to avoid duplication a base SoC dtsi (r9a07g043.dtsi) is
> created which will be used by the RZ/G2UL (r9a07g043u.dtsi) and RZ/Five
> (r9a07g043F.dtsi)

Thanks for your series!

> r9a07g043f.dtsi will look something like below:
>
> #include <dt-bindings/interrupt-controller/irq.h>
>
> #define SOC_PERIPHERAL_IRQ_NUMBER(nr)   (nr + 32)
> #define SOC_PERIPHERAL_IRQ(nr, na)      SOC_PERIPHERAL_IRQ_NUMBER(nr) na

Originally, when I assumed incorrectly that dtc does not support
arithmetic, I used "nr" and "na" in the macro I proposed to mean RISC-V
("r") resp. ARM ("a") interrupt number.  Apparently the names stuck,
although the second parameter now has a completely different meaning ;-)

However, as the NCEPLIC does support interrupt flags, unlike the SiFive
PLIC, there is no need to have the flags parameter in the macro.

Moreover,  it looks like the SOC_PERIPHERAL_IRQ_NUMBER()
intermediate is not needed, so you can just write:

    #define SOC_PERIPHERAL_IRQ(nr)  (nr + 32)

> #include <arm64/renesas/r9a07g043.dtsi>
>
> / {
>    ...
>    ...
> };

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