linux-kernel - Re: [PATCH v2 3/3] arm64: dts: sc7180: Support Parade ps8640 edp bridge

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Message-ID: <CAD=FV=VfuxrrFbzZwCQr-6KYb2OXEPmrAH5y9UPr4V6Pud2h7g@mail.gmail.com>
Date:   Fri, 8 Oct 2021 16:12:54 -0700
From:   Doug Anderson <dianders@...omium.org>
To:     Philip Chen <philipchen@...omium.org>
Cc:     Stephen Boyd <swboyd@...omium.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>
Subject: Re: [PATCH v2 3/3] arm64: dts: sc7180: Support Parade ps8640 edp bridge

Hi,

On Fri, Oct 8, 2021 at 11:46 AM Philip Chen <philipchen@...omium.org> wrote:
>
> Hi
>
> On Thu, Oct 7, 2021 at 11:15 AM Philip Chen <philipchen@...omium.org> wrote:
> >
> > Hi,
> >
> > On Thu, Sep 30, 2021 at 9:22 AM Doug Anderson <dianders@...omium.org> wrote:
> > >
> > > Hi,
> > >
> > > On Wed, Sep 29, 2021 at 9:02 PM Stephen Boyd <swboyd@...omium.org> wrote:
> > > >
> > > > > +       pp3300_brij_ps8640: pp3300-brij-ps8640 {
> > > > > +               compatible = "regulator-fixed";
> > > > > +               status = "okay";
> > > > > +               regulator-name = "pp3300_brij_ps8640";
> > > > > +
> > > > > +               regulator-min-microvolt = <3300000>;
> > > > > +               regulator-max-microvolt = <3300000>;
> > > > > +
> > > > > +               gpio = <&tlmm 32 GPIO_ACTIVE_HIGH>;
> > > >
> > > > Doesn't this need
> > > >
> > > >                 enable-active-high;
> > >
> > > Looks like it. Without that it looks like it assumes active low.
> > Thanks for catching this.
> > I'll fix it in v3.
> >
> > >
> > >
> > > > > +
> > > > > +               pinctrl-names = "default";
> > > > > +               pinctrl-0 = <&en_pp3300_edp_brij_ps8640>;
> > > > > +
> > > > > +               vin-supply = <&pp3300_a>;
> > > > > +       };
> > > > > +};
> > > > > +
> > > > > +&dsi0_out {
> > > > > +       remote-endpoint = <&ps8640_in>;
> > > >
> > > > Should this also have data-lanes to be "complete"?
> > >
> > > That's still back in the main trogdor.dtsi, isn't it?
> > Yes, I think so.
> > Plus, ti-sn65 dts doesn't define data-lanes for input either.
> Sorry, I was wrong.
> ti-sn65 dts actually defines data-lanes for input.
> However, since ps8640 driver doesn't parse input data-lanes for now,
> it's not useful to add data-lanes here anyway.

Ah, right. This one _isn't_ in the dtsi. Looking closer, I agree with
you that it's not useful. Specifically it should be noted that, unlike
ti-sn65dsi86, this bridge part looks to only support 2-lanes of DP
traffic. If both of these two lanes are routed to the panel then
there's really nothing to specify--that should be the default
assumption of the driver if/when it ever adds support for data-lanes.

-Doug