| Message ID | 20240531204339.277848-1-marex@denx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] dt-bindings: display: bridge: tc358867: Document default DP preemphasis | expand |
Hi Marek, Am Freitag, 31. Mai 2024, 22:42:03 CEST schrieb Marek Vasut: > 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 > --- > .../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: > + description: > + Display port output Pre-Emphasis settings for both ports. Is this a property of the port or the endpoint? > + $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 Is there a reason you reversed the notation here? de-emphasis <-> pre-emphasis. Commit message also says: > in range 0=0dB, 1=3.5dB, 2=6dB . Best regards, Alexander > + > oneOf: > - required: > - port@0 >
On 6/4/24 11:42 AM, Alexander Stein wrote: > Hi Marek, Hi, >> --- 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. > > Is this a property of the port or the endpoint? Endpoint I think. >> + $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 > > Is there a reason you reversed the notation here? de-emphasis <-> pre-emphasis. > Commit message also says: >> in range 0=0dB, 1=3.5dB, 2=6dB . Copy-paste error from Documentation/devicetree/bindings/usb/snps,dwc3.yaml , fixed in V2, thanks .
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@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 > --- > .../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@0 > -- > 2.43.0 >
On Tue, Jun 04, 2024 at 11:42:31AM +0200, Alexander Stein wrote: > Hi Marek, > > Am Freitag, 31. Mai 2024, 22:42:03 CEST schrieb Marek Vasut: > > 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 > > --- > > .../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: > > + description: > > + Display port output Pre-Emphasis settings for both ports. > > Is this a property of the port or the endpoint? What's the difference? Either is the same data path. The preference is custom properties in endpoint node, not port nodes. Rob
On 6/5/24 6:03 PM, Rob Herring wrote: Hi, >> 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). Fixed >> + description: >> + Display port output Pre-Emphasis settings for both ports. > > Both ports? This schema is for just port 2. 'lanes' is better here. The array can be used to configure each DP main link lane separately, the chip supports two lanes.
On 6/5/24 6:05 PM, Rob Herring wrote: >>> 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: >>> + description: >>> + Display port output Pre-Emphasis settings for both ports. >> >> Is this a property of the port or the endpoint? > > What's the difference? Either is the same data path. > > The preference is custom properties in endpoint node, not port nodes. Let's keep it in the endpoint node. There is some mention in the TC9595 datasheet that the DP might operate in some split mode, where each DP lane is used to feed one display (?), so I assume in that case there might be two endpoints (?), but that is not supported right now. If that is ever needed, I guess this array would have minItems 1 and maxItems 2 and another endpoint would be added to the schema for this port 2.
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: + description: + Display port output Pre-Emphasis settings for both ports. + $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@0
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 --- .../display/bridge/toshiba,tc358767.yaml | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)