On Mon, Jun 22, 2026 at 05:31:36PM +0530, Mohit Dsor wrote: > On Thu, Jun 11, 2026 at 12:40:38PM +0200, Krzysztof Kozlowski wrote: > > On Thu, Jun 11, 2026 at 02:44:56AM +0530, Mohit Dsor wrote: > > > Add a new optional `lontium,port-select` property to describe the DSI > > > input port configuration for the LT9611C variant, which supports > > > single-port (A or B) and dual-port (A+B) operation. > > > > > > This property allows explicitly selecting the active DSI input port(s): > > > 0 = port A (default) > > > 1 = port B > > > 2 = ports A and B (dual-port) > > > > > > Signed-off-by: Mohit Dsor <[email protected]> > > > --- > > > .../devicetree/bindings/display/bridge/lontium,lt9611.yaml | 13 > > > +++++++++++++ > > > 1 file changed, 13 insertions(+) > > > > > > diff --git > > > a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml > > > b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml > > > index e0821a63d9d7..77220f893bf8 100644 > > > --- a/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml > > > +++ b/Documentation/devicetree/bindings/display/bridge/lontium,lt9611.yaml > > > @@ -41,6 +41,17 @@ properties: > > > vcc-supply: > > > description: Regulator for 3.3V IO power. > > > > > > + lontium,port-select: > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > + enum: [0, 1, 2] > > > + default: 0 > > > + description: | > > > + Selects which DSI input port(s) the bridge uses. Only relevant for > > > + the lontium,lt9611c compatible. > > > + 0 = PORT_SELECT_A - single DSI port A (default) > > > + 1 = PORT_SELECT_B - single DSI port B > > > + 2 = PORT_SELECT_AB - dual DSI ports A and B > > > > Why graph is not enough? Seems exactly duplicating the graph ports. > > > > Best regards, > > Krzysztof > > > Hi Krzysztof, > > Thanks for the review. > > The graph describes the physical connectivity between endpoints, > however it does not fully capture the internal mode of operation of > the LT9611C. This variant supports multiple functional configurations > (single-port A, single-port B, or dual-port A+B), which affect how the > hardware internally combines or selects DSI inputs. > > In particular: > - The graph can describe connections to both ports, but it does not > indicate whether the device should operate in single-port or dual-port > aggregation mode. > - For single-port use, both ports may be described in DT for board > consistency, while the driver still needs to know which port is > actively selected. > - Dual-port mode requires explicit configuration even when both > endpoints are present in the graph.
If both modes of operation are possible on a given board, then it sounds like the mode should be selected at runtime, not hardcoded in the device tree. > So, this property is not duplicating connectivity, but rather > describing the *operational mode* of the device, which cannot be > reliably inferred from the graph alone. -- Regards, Laurent Pinchart
