Re: [PATCH v2 1/9] dt-bindings: interrupt-controller: renesas,rzg2l-irqc: Document RZ/G2UL SoC

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Marc Zyngier <maz@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Magnus Damm <magnus.damm@gmail.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	linux-renesas-soc@vger.kernel.org, linux-gpio@vger.kernel.org,
	Biju Das <biju.das.jz@bp.renesas.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: Re: [PATCH v2 1/9] dt-bindings: interrupt-controller: renesas,rzg2l-irqc: Document RZ/G2UL SoC
Date: Thu, 22 Dec 2022 09:19:14 +0100	[thread overview]
Message-ID: <CAMuHMdXDbfadxJsrEvQMwQKvxtBxQRA_Bx4+FY90N9v_XVirOA@mail.gmail.com> (raw)
In-Reply-To: <CA+V-a8tqvY+Nj391j+zJO21Q=47pyFR1SkDLH-hmJephcorY3g@mail.gmail.com>

Hi Prabhakar,

On Wed, Dec 21, 2022 at 10:06 PM Lad, Prabhakar
<prabhakar.csengg@gmail.com> wrote:
> On Wed, Dec 21, 2022 at 12:37 PM Geert Uytterhoeven
> <geert@linux-m68k.org> wrote:
> > On Wed, Dec 21, 2022 at 1:03 AM Prabhakar <prabhakar.csengg@gmail.com> wrote:
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > >
> > > Document RZ/G2UL (R9A07G043U) IRQC bindings. The IRQC block on RZ/G2UL SoC
> > > is almost identical to one found on the RZ/G2L SoC the only difference
> > > being it can support BUS_ERR_INT for which it has additional registers.
> > > Hence new generic compatible string "renesas,rzg2ul-irqc" is added for
> > > RZ/G2UL SoC.
> > >
> > > Now that we have additional interrupt for RZ/G2UL and RZ/Five SoC
> > > interrupt-names property is added so that we can parse them based on
> > > names.
> > >
> > > While at it updated the example node to four spaces and added
> > > interrupt-names property.
> > >
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > > v1- > v2
> > > * Dropped RB tags
> > > * Added generic compatible string for rzg2ul
> > > * Added interrupt-names
> > > * Added checks for RZ/G2UL to make sure interrupts are 42 and interrupt-names
> > > * Updated example node with interrupt-names
> > > * Used 4 spaces for example node
> >
> > Thanks for the update!
> >
> > > --- a/Documentation/devicetree/bindings/interrupt-controller/renesas,rzg2l-irqc.yaml
> > > +++ b/Documentation/devicetree/bindings/interrupt-controller/renesas,rzg2l-irqc.yaml
> > > @@ -19,16 +19,19 @@ description: |
> > >      - NMI edge select (NMI is not treated as NMI exception and supports fall edge and
> > >        stand-up edge detection interrupts)
> > >
> > > -allOf:
> > > -  - $ref: /schemas/interrupt-controller.yaml#
> > > -
> > >  properties:
> > >    compatible:
> > > -    items:
> > > -      - enum:
> > > -          - renesas,r9a07g044-irqc    # RZ/G2{L,LC}
> > > -          - renesas,r9a07g054-irqc    # RZ/V2L
> > > -      - const: renesas,rzg2l-irqc
> > > +    oneOf:
> > > +      - items:
> > > +          - enum:
> > > +              - renesas,r9a07g044-irqc    # RZ/G2{L,LC}
> > > +              - renesas,r9a07g054-irqc    # RZ/V2L
> > > +          - const: renesas,rzg2l-irqc
> > > +
> > > +      - items:
> > > +          - enum:
> > > +              - renesas,r9a07g043u-irqc   # RZ/G2UL
> > > +          - const: renesas,rzg2ul-irqc
> >
> > I'm not sure it's worth splitting into RZ/G2L and RZ/G2UL alike
> > variants, and adding the "renesas,rzg2ul-irqc" family-specific
> > compatible value.  You can easily handle the difference by the presence
> > (or absence) of the "bus-err" interrupt source.
> >
> Yes, the only reason to add "renesas,rzg2ul-irqc" is to differentiate
> RZ/Five later. I have not worked out on how this driver will work in
> case of RZ/Five yet with PLIC (as we sifive plic driver as a chained
> handler and then we have the RISC-V intc driver). If you insist I can
> drop it for now and then later when we add RZ/FIve we could add a
> check for compat string maybe?

Given you already use "renesas,r9a07g043u-irqc" (note the "u") here,
you will have "renesas,r9a07g043f-irqc" to handle the (minor)
differences.

> > I understand there "renesas,r9a07g043f-irqc" will be added later to
> > support RZ/Five?
> >
> Yes.

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