Re: [PATCH v2 3/4] arm64: dts: renesas: rcar-gen3: Add reset control properties for display

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Geert,

On Wed, Feb 19, 2020 at 04:55:52PM +0100, Geert Uytterhoeven wrote:
> On Wed, Feb 19, 2020 at 4:33 PM Laurent Pinchart wrote:
> > On Tue, Feb 18, 2020 at 02:30:18PM +0100, Geert Uytterhoeven wrote:
> > > Add reset control properties to the device nodes for the Display Units
> > > on all supported R-Car Gen3 SoCs.  Note that on these SoCs, there is
> > > only a single reset for each pair of DU channels.
> > >
> > > The display nodes on R-Car V3M and V3H already had "resets" properties,
> > > but lacked the corresponding "reset-names" properties.
> > >
> > > Join the clocks lines while at it, to increase uniformity.
> > >
> > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
> > > --- a/arch/arm64/boot/dts/renesas/r8a77965.dtsi
> > > +++ b/arch/arm64/boot/dts/renesas/r8a77965.dtsi
> > > @@ -2503,10 +2503,11 @@
> > >                       interrupts = <GIC_SPI 256 IRQ_TYPE_LEVEL_HIGH>,
> > >                                    <GIC_SPI 268 IRQ_TYPE_LEVEL_HIGH>,
> > >                                    <GIC_SPI 270 IRQ_TYPE_LEVEL_HIGH>;
> > > -                     clocks = <&cpg CPG_MOD 724>,
> > > -                              <&cpg CPG_MOD 723>,
> > > +                     clocks = <&cpg CPG_MOD 724>, <&cpg CPG_MOD 723>,
> > >                                <&cpg CPG_MOD 721>;
> > >                       clock-names = "du.0", "du.1", "du.3";
> > > +                     resets = <&cpg 724>, <&cpg 722>;
> > > +                     reset-names = "du.0", "du.3";
> >
> > I wonder if this should be du.2, especially given that 722 corresponds
> > to the non-existing DU2 channel. It's a bit of a mess at the hardware
> 
> Just following the bindings: "du.3" is the lowest channel that is affected
> by the reset.

Yes I was looking at that, and replied to the DT bindings patch. If the
outcome of the discussion there is to keep the bindings as-is, you can
have my

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

for this whole series.

> > level :-S
> 
> Note that supporting R-Car H3-N will make your^H^H^H^Hthe rcar-du device
> driver writer's life even more miserable, as suddenly there is no longer
> a DU2, while the single unified Display Unit node prevents the DTS
> writer from not setting the DU2's status to "okay" in the board DTS
> file. But you might look at the ports submode?

This will require a separate compatible string I'm afraid.

-- 
Regards,

Laurent Pinchart