Document the lontium,dsi-port-b property for selecting DSI Port B as
the input source instead of the default Port A.

Signed-off-by: Hongyang Zhao <hongyang.zhao@thundersoft.com>
Reviewed-by: Roger Shimizu <rosh@debian.org>
---
 .../devicetree/bindings/display/bridge/lontium,lt9611.yaml          | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
index 655db8cfdc25..9b7dba4e114c 100644
--- a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
@@ -37,6 +37,12 @@ properties:
   vcc-supply:
     description: Regulator for 3.3V IO power.
 
+  lontium,dsi-port-b:
+    type: boolean
+    description:
+      Use DSI Port B as the input source instead of Port A or Port A + B.
+      Required when the DSI is physically connected to Port B.
+
   ports:
     $ref: /schemas/graph.yaml#/properties/ports
 

-- 
2.43.0

On 1/27/26 07:58, Hongyang Zhao wrote:
> Document the lontium,dsi-port-b property for selecting DSI Port B as
> the input source instead of the default Port A.
> 
> Signed-off-by: Hongyang Zhao <hongyang.zhao@thundersoft.com>
> Reviewed-by: Roger Shimizu <rosh@debian.org>
> ---
>   .../devicetree/bindings/display/bridge/lontium,lt9611.yaml          | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> index 655db8cfdc25..9b7dba4e114c 100644
> --- a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> @@ -37,6 +37,12 @@ properties:
>     vcc-supply:
>       description: Regulator for 3.3V IO power.
>   
> +  lontium,dsi-port-b:
> +    type: boolean
> +    description:
> +      Use DSI Port B as the input source instead of Port A or Port A + B.
> +      Required when the DSI is physically connected to Port B.

This is not how this should be solved, the ports links are here for this exact purpose.

port@0 represents port A, port@1 represent port B, so you need to describe the HW correctly
in the first place.

Populate only port1 and in the driver check which ports are population and change the
configuration.

Neil

> +
>     ports:
>       $ref: /schemas/graph.yaml#/properties/ports
>   
>

> On 1/27/26 07:58, Hongyang Zhao wrote:
> > Document the lontium,dsi-port-b property for selecting DSI Port B as
> > the input source instead of the default Port A.
> >
> > Signed-off-by: Hongyang Zhao <hongyang.zhao@thundersoft.com>
> > Reviewed-by: Roger Shimizu <rosh@debian.org>
> > ---
> >   .../devicetree/bindings/display/bridge/lontium,lt9611.yaml          | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> > index 655db8cfdc25..9b7dba4e114c 100644
> > --- a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> > +++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml
> > @@ -37,6 +37,12 @@ properties:
> >     vcc-supply:
> >       description: Regulator for 3.3V IO power.
> >
> > +  lontium,dsi-port-b:
> > +    type: boolean
> > +    description:
> > +      Use DSI Port B as the input source instead of Port A or Port A + B.
> > +      Required when the DSI is physically connected to Port B.
>
> This is not how this should be solved, the ports links are here for this exact purpose.
>
> port@0 represents port A, port@1 represent port B, so you need to describe the HW correctly
> in the first place.
>
> Populate only port1 and in the driver check which ports are population and change the
> configuration.
>
> Neil
>
> > +
> >     ports:
> >       $ref: /schemas/graph.yaml#/properties/ports
> >
> >

Hi Neil,

Thanks for the review. You're right - I'll use the ports to describe the
physical connection properly.

I'll update the patches to:
1. Make port@0 optional in the binding (require at least one of port@0 or port@1)
2. Update port descriptions to clarify port@0 = Port A, port@1 = Port B
3. Modify the driver to detect which port is populated and configure accordingly
4. Use port@1 in the RubikPi3 DTS since the DSI is physically connected to Port B

Will send v2 shortly.

Thanks,
Hongyang