Re: [PATCH 2/2] ARM: dts: exynos: tiny4412: add proper panel node

Frank Lee
2020-01-07T19:07:39Z

On Tue, Jan 7, 2020 at 5:04 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On Mon, Jan 06, 2020 at 07:10:03PM +0000, Yangtao Li wrote:
> > This patch add at070tn92 panel for tiny4412 board.
>
> Please fix description as in patch 1.
>
> >
> > Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> > ---
> > arch/arm/boot/dts/exynos4412-tiny4412.dts | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/exynos4412-tiny4412.dts b/arch/arm/boot/dts/exynos4412-tiny4412.dts
> > index 2b62cb27420c..57f9d09233ad 100644
> > --- a/arch/arm/boot/dts/exynos4412-tiny4412.dts
> > +++ b/arch/arm/boot/dts/exynos4412-tiny4412.dts
> > @@ -66,6 +66,16 @@
> > clock-frequency = <24000000>;
> > };
> > };
> > +
> > + panel {
> > + compatible = "innolux,at070tn92";
> > +
> > + port {
> > + panel_input: endpoint {
> > + remote-endpoint = <&lcdc_output>;
> > + };
> > + };
> > + };
> > };
> >
> > &fimd {
> > @@ -74,6 +84,12 @@
> > #address-cells = <1>;
> > #size-cells = <0>;
> > status = "okay";
>
> One empty space here.
>
> > + port@3 {
> > + reg = <3>;
>
> Why starting from "3"? Why this is port@3, not just "port"?

From samsung-fimd.txt:
---
The device node can contain 'port' child nodes according to the bindings defined
in [2]. The following are properties specific to those nodes:
- reg: (required) port index, can be:
0 - for CAMIF0 input,
1 - for CAMIF1 input,
2 - for CAMIF2 input,
3 - for parallel output,
4 - for write-back interface
---

I guess it is influenced here.
https://elixir.bootlin.com/linux/v5.5-rc5/source/drivers/gpu/drm/exynos/exynos_drm_dpi.c#L170
Without it, lcd is completely black.

Your,
Yangtao

>
> Best regards,
> Krzysztof
>