Subject: Re: [PATCH v10 5/6] arm64: dts: allwinner: a64: Add MIPI DSI pipeline

From: Maxime Ripard <[email-masked]>
Date: Thu, 17 Oct 2019 11:52:25 +0200

On Wed, Oct 16, 2019 at 02:19:44PM +0530, Jagan Teki wrote:
> On Wed, Oct 16, 2019 at 1:33 PM Maxime Ripard <[email-masked]> wrote:
> >
> > On Mon, Oct 14, 2019 at 05:37:50PM +0530, Jagan Teki wrote:
> > > On Mon, Oct 7, 2019 at 4:27 PM Maxime Ripard <[email-masked]> wrote:
> > > >
> > > > On Sat, Oct 05, 2019 at 07:49:12PM +0530, Jagan Teki wrote:
> > > > > Add MIPI DSI pipeline for Allwinner A64.
> > > > >
> > > > > - dsi node, with A64 compatible since it doesn't support
> > > > >   DSI_SCLK gating unlike A33
> > > > > - dphy node, with A64 compatible with A33 fallback since
> > > > >   DPHY on A64 and A33 is similar
> > > > > - finally, attach the dsi_in to tcon0 for complete MIPI DSI
> > > > >
> > > > > Signed-off-by: Jagan Teki <[email-masked]>
> > > > > Tested-by: Merlijn Wajer <[email-masked]>
> > > > > ---
> > > > >  arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 38 +++++++++++++++++++
> > > > >  1 file changed, 38 insertions(+)
> > > > >
> > > > > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
> > > > > index 69128a6dfc46..ad4170b8aee0 100644
> > > > > --- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
> > > > > +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
> > > > > @@ -382,6 +382,12 @@
> > > > >                                       #address-cells = <1>;
> > > > >                                       #size-cells = <0>;
> > > > >                                       reg = <1>;
> > > > > +
> > > > > +                                     tcon0_out_dsi: endpoint@1 {
> > > > > +                                             reg = <1>;
> > > > > +                                             remote-endpoint = <&dsi_in_tcon0>;
> > > > > +                                             allwinner,tcon-channel = <1>;
> > > > > +                                     };
> > > > >                               };
> > > > >                       };
> > > > >               };
> > > > > @@ -1003,6 +1009,38 @@
> > > > >                       status = "disabled";
> > > > >               };
> > > > >
> > > > > +             dsi: dsi@1ca0000 {
> > > > > +                     compatible = "allwinner,sun50i-a64-mipi-dsi";
> > > > > +                     reg = <0x01ca0000 0x1000>;
> > > > > +                     interrupts = <GIC_SPI 89 IRQ_TYPE_LEVEL_HIGH>;
> > > > > +                     clocks = <&ccu CLK_BUS_MIPI_DSI>;
> > > > > +                     clock-names = "bus";
> > > >
> > > > This won't validate with the bindings you have either here, since it
> > > > still expects bus and mod.
> > > >
> > > > I guess in that cas, we can just drop clock-names, which will require
> > > > a bit of work on the driver side as well.
> > >
> > > Okay.
> > > mod clock is not required for a64, ie reason we have has_mod_clk quirk
> > > patch. Adjust the clock-names: on dt-bindings would make sense here,
> > > what do you think?
> >
> > I'm confused, what are you suggesting?
>
> Sorry for the confusion.
>
> The mod clock is not required for A64 and we have a patch for handling
> mod clock using has_mod_clk quirk(on the series), indeed the mod clock
> is available in A31 and not needed for A64. So, to satisfy this
> requirement the clock-names on dt-bindings can update to make mod
> clock-name is optional and bus clock is required.

No, the bus clock name is not needed if there's only one clock.

> I'm not exactly sure, this is correct but trying to understand if it
> is possible or not? something like
>
>    clocks:
>       minItems: 1
>       maxItems: 2
>      items:
>        - description: Bus Clock
>        - description: Module Clock

That's correct.

>    clock-names:
>       minItems: 1
>       maxItems: 2
>      items:
>        - const: bus
>        - const: mod

Here, just keep the current clock-names definition, and make it
required only for SoCs that are not the A64

Maxime
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