Re: [PATCH v2 1/2] dt-bindings: display: bridge: tc358867: Document default DP preemphasis

Conor Dooley
2024-06-22T11:56:10Z

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On Fri, Jun 21, 2024 at 05:53:53PM +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@denx.de>
> ---
> Cc: Andrzej Hajda <andrzej.hajda@intel.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
> Cc: Jonas Karlman <jonas@kwiboo.se>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
> Cc: Lucas Stach <l.stach@pengutronix.de>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Neil Armstrong <neil.armstrong@linaro.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Robert Foss <rfoss@kernel.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: devicetree@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: kernel@dh-electronics.com
> ---
> V2: - Fix the type to u8 array
> - Fix the enum items to match what they represent
> ---
> .../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..6287eb2b40908 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:
> + description:
> + Display port output Pre-Emphasis settings for both ports.

Why here and not in the port nodes?

> + $ref: /schemas/types.yaml#/definitions/uint8-array
> + minItems: 2
> + maxItems: 2
> + items:
> + enum:
> + - 0 # No pre-emphasis
> + - 1 # 3.5dB pre-emphasis
> + - 2 # 6dB pre-emphasis

I'd love to say please make this -bB and put this in units, but that'd
require it being a string..

> +
> oneOf:
> - required:
> - port@0
> --
> 2.43.0
>

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