RE: [PATCH 2/3] ARM: dts: r8a7743: Add CMT SoC specific support

From: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
To: Simon Horman <horms@verge.net.au>
Cc: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Russell King <linux@armlinux.org.uk>,
	Magnus Damm <magnus.damm@gmail.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	"linux-renesas-soc@vger.kernel.org"
	<linux-renesas-soc@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: RE: [PATCH 2/3] ARM: dts: r8a7743: Add CMT SoC specific support
Date: Wed, 13 Dec 2017 09:42:54 +0000	[thread overview]
Message-ID: <TY1PR06MB0895B34EFC2A48F49AFF0694C0350@TY1PR06MB0895.apcprd06.prod.outlook.com> (raw)
In-Reply-To: <20171213083829.ptdeggbon3szmko4@verge.net.au>

Hello Simon,

thank you for your feedback.

> On Tue, Dec 12, 2017 at 06:49:38PM +0000, Fabrizio Castro wrote:
> > Add CMT[01] support to SoC DT.
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
> > Reviewed-by: Biju Das <biju.das@bp.renesas.com>
> > ---
> >  arch/arm/boot/dts/r8a7743.dtsi | 30 ++++++++++++++++++++++++++++++
> >  1 file changed, 30 insertions(+)
>
> I was expecting the cmt nodes to be "disabled" in the SoC file
> and then enabled selectively in board files. Am I missing something?

Since this component is just a compare and match timer, I  thought there was no harm in enabling it by default in the SoC specific DT. The system will park it and leave its clock disabled until actually needed for something.
The user can still disable it in the board specific DT if he/she doesn't mean to even have the option to use it. Do you prefer I left it disabled by default?

Thanks,
Fab

>
> Otherwise this patch looks good to me.
>
> > diff --git a/arch/arm/boot/dts/r8a7743.dtsi b/arch/arm/boot/dts/r8a7743.dtsi
> > index 59860c8..0e2834a 100644
> > --- a/arch/arm/boot/dts/r8a7743.dtsi
> > +++ b/arch/arm/boot/dts/r8a7743.dtsi
> > @@ -262,6 +262,36 @@
> >    IRQ_TYPE_LEVEL_LOW)>;
> >  };
> >
> > +cmt0: timer@ffca0000 {
> > +compatible = "renesas,r8a7743-cmt0",
> > +     "renesas,rcar-gen2-cmt0";
> > +reg = <0 0xffca0000 0 0x1004>;
> > +interrupts = <GIC_SPI 142 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>;
> > +clocks = <&cpg CPG_MOD 124>;
> > +clock-names = "fck";
> > +power-domains = <&sysc R8A7743_PD_ALWAYS_ON>;
> > +resets = <&cpg 124>;
> > +};
> > +
> > +cmt1: timer@e6130000 {
> > +compatible = "renesas,r8a7743-cmt1",
> > +     "renesas,rcar-gen2-cmt1";
> > +reg = <0 0xe6130000 0 0x1004>;
> > +interrupts = <GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 122 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 124 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 126 IRQ_TYPE_LEVEL_HIGH>,
> > +     <GIC_SPI 127 IRQ_TYPE_LEVEL_HIGH>;
> > +clocks = <&cpg CPG_MOD 329>;
> > +clock-names = "fck";
> > +power-domains = <&sysc R8A7743_PD_ALWAYS_ON>;
> > +resets = <&cpg 329>;
> > +};
> > +
> >  cpg: clock-controller@e6150000 {
> >  compatible = "renesas,r8a7743-cpg-mssr";
> >  reg = <0 0xe6150000 0 0x1000>;
> > --
> > 2.7.4
> >

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