Re: [PATCH v5 03/12] dt-bindings: display: sun4i-drm: Add LVDS properties

From: Jernej Åkrabec
Date: Sat Dec 30 2017 - 06:51:45 EST


Hi Maxime,

Dne Äetrtek, 21. december 2017 ob 12:02:29 CET je Maxime Ripard napisal(a):
> Some clocks and resets supposed to drive the LVDS logic in the display
> engine have been overlooked when the driver was first introduced.
>
> Add those additional resources to the binding, and we'll deal with the ABI
> stability in the code.
>
> Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxx>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt | 9 +++++++-
> 1 file changed, 9 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
> b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt index
> 50cc72ee1168..1e21cfaac9e2 100644
> --- a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
> +++ b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
> @@ -121,6 +121,15 @@ Required properties:
> On SoCs other than the A33 and V3s, there is one more clock required:
> - 'tcon-ch1': The clock driving the TCON channel 1
>
> +On SoCs that support LVDS (all SoCs but the A13, H3, H5 and V3s), you
> +need one more reset line:
> + - 'lvds': The reset line driving the LVDS logic
> +
> +And on the SoCs newer than the A31 (sun6i and sun8i families), you
> +need one more clock line:
> + - 'lvds-alt': An alternative clock source, separate from the TCON
> channel 0 + clock, that can be used to drive the LVDS clock

I think this wording is imprecise, since A83T is part of the sun8i family, but
from the code (patch 7) and DT changes (patch 9) you do, it doesn't need this
property.

Maybe it would be just easier to enumerate all compatibles which needs this
property?

Best regards,
Jernej