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 . This is an endpoint property, not a port property, because the TC9595 datasheet does mention that the DP might operate in some sort of split mode, where each DP lane is used to feed one display, so in that case there might be two endpoints. Signed-off-by: Marek Vasut <marex@xxxxxxx> --- Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx> Cc: Conor Dooley <conor+dt@xxxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: David Airlie <airlied@xxxxxxxxx> Cc: Jernej Skrabec <jernej.skrabec@xxxxxxxxx> Cc: Jonas Karlman <jonas@xxxxxxxxx> Cc: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx> Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Maxime Ripard <mripard@xxxxxxxxxx> Cc: Neil Armstrong <neil.armstrong@xxxxxxxxxx> Cc: Rob Herring <robh@xxxxxxxxxx> Cc: Robert Foss <rfoss@xxxxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: kernel@xxxxxxxxxxxxxxxxxx --- V2: - Fix the type to u8 array - Fix the enum items to match what they represent V3: - Update commit message, expand on this being an endpoint property --- .../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..9490854c22f3b 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 DP lanes. + $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 + oneOf: - required: - port@0 -- 2.43.0