[PATCH 1/2] dt-bindings: display: bridge: tc358867: Document default DP preemphasis

[Rob Herring]

On Fri, May 31, 2024 at 10:42:03PM +0200, Marek Vasut wrote:
> Document default DP port preemphasis configurable via new DT property
> "toshiba,pre-emphasis". This is useful in case the DP link properties
> are known and starting link training from preemphasis setting of 0 dB
> is not useful. The preemphasis can be set separately for both DP lanes
> in range 0=0dB, 1=3.5dB, 2=6dB .
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> Cc: Andrzej Hajda <andrzej.hajda at intel.com>
> Cc: Conor Dooley <conor+dt at kernel.org>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: David Airlie <airlied at gmail.com>
> Cc: Jernej Skrabec <jernej.skrabec at gmail.com>
> Cc: Jonas Karlman <jonas at kwiboo.se>
> Cc: Krzysztof Kozlowski <krzk+dt at kernel.org>
> Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
> Cc: Lucas Stach <l.stach at pengutronix.de>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Neil Armstrong <neil.armstrong at linaro.org>
> Cc: Rob Herring <robh at kernel.org>
> Cc: Robert Foss <rfoss at kernel.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: devicetree at vger.kernel.org
> Cc: dri-devel at lists.freedesktop.org
> Cc: kernel at dh-electronics.com
> ---
>  .../display/bridge/toshiba,tc358767.yaml       | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml
> index 2ad0cd6dd49e0..dcf56e996ee22 100644
> --- a/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358767.yaml
> @@ -98,6 +98,24 @@ properties:
>              reference to a valid eDP panel input endpoint node. This port is
>              optional, treated as DP panel if not defined
>  
> +        properties:
> +          endpoint:
> +            $ref: /schemas/media/video-interfaces.yaml#
> +            unevaluatedProperties: false
> +
> +            properties:
> +              toshiba,pre-emphasis:

You didn't test adding this property. You will find it isn't allowed. 
That's because 'properties/port' schema above doesn't allow extra 
properties (on the port and endpoint).

> +                description:
> +                  Display port output Pre-Emphasis settings for both ports.

Both ports? This schema is for just port 2.

> +                $ref: /schemas/types.yaml#/definitions/uint32-array
> +                minItems: 2
> +                maxItems: 2
> +                items:
> +                  enum:
> +                    - 0 # -6dB de-emphasis
> +                    - 1 # -3.5dB de-emphasis
> +                    - 2 # No de-emphasis
> +
>      oneOf:
>        - required:
>            - port at 0
> -- 
> 2.43.0
>