Re: [PATCH RFC v2 4/5] ARM: dts: qcom: msm8974: add HDMI nodes

Brian Masney
2019-10-09T06:05:24Z

On Tue, Oct 08, 2019 at 07:21:30PM -0700, Stephen Boyd wrote:
> Quoting Brian Masney (2019-10-06 18:45:08)
> > diff --git a/arch/arm/boot/dts/qcom-msm8974.dtsi b/arch/arm/boot/dts/qcom-msm8974.dtsi
> > index 7fc23e422cc5..af02eace14e2 100644
> > --- a/arch/arm/boot/dts/qcom-msm8974.dtsi
> > +++ b/arch/arm/boot/dts/qcom-msm8974.dtsi
> > @@ -1335,6 +1342,77 @@
> > clocks = <&mmcc MDSS_AHB_CLK>;
> > clock-names = "iface";
> > };
> > +
> > + hdmi: hdmi-tx@fd922100 {
> > + status = "disabled";
> > +
> > + compatible = "qcom,hdmi-tx-8974";
> > + reg = <0xfd922100 0x35c>,
> > + <0xfc4b8000 0x60f0>;
> > + reg-names = "core_physical",
> > + "qfprom_physical";
>
> Is this the qfprom "uncorrected" physical address? If so, why can't this
> node use an nvmem to read whatever it needs out of the qfprom?

The MSM HDMI code is configured to look for this reg-name here:

https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/msm/hdmi/hdmi.c#L582

There is a qcom,qfprom configured for this board in DTS, however its at
a different address range, so maybe there are multiple qfproms?

https://elixir.bootlin.com/linux/latest/source/arch/arm/boot/dts/qcom-msm8974.dtsi#L424

msm8996.dtsi has the same style of configuration:

https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/qcom/msm8996.dtsi#L956
https://elixir.bootlin.com/linux/latest/source/arch/arm64/boot/dts/qcom/msm8996.dtsi#L1736

Brian