Re: [PATCH v4 2/9] spi: dt-bindings: add spi-{tx,rx}-lane-map properties

From: Rob Herring
Date: Thu Jan 08 2026 - 09:46:02 EST


On Thu, Jan 8, 2026 at 6:28 AM Marcelo Schmitt
<marcelo.schmitt1@xxxxxxxxx> wrote:
>
> On 12/19, David Lechner wrote:
> > Add spi-tx-lane-map and spi-rx-lane-map properties to the SPI peripheral
> > device tree binding. These properties allow specifying the mapping of
> > peripheral data lanes to controller data lanes. This is needed e.g. when
> > some lanes are skipped on the controller side so that the controller
> > can correctly route data to/from the peripheral.
> >
> > Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
> > ---
> >
> > v4 changes:
> > - This replaces the data-lanes property from the previous revision. Now
> > there are separate properties for tx and rx lane maps. And instead of
> > being the primary property for determining the number of lanes, this
> > is only needed in special cases where the mapping is non-trivial.
> > ---
> > .../devicetree/bindings/spi/spi-peripheral-props.yaml | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
> > index 59ddead7da14..2f278f145f78 100644
> > --- a/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
> > +++ b/Documentation/devicetree/bindings/spi/spi-peripheral-props.yaml
> > @@ -75,6 +75,13 @@ properties:
> > enum: [0, 1, 2, 4, 8]
> > default: [1]
> >
> > + spi-rx-lane-map:
> > + description: Mapping of peripheral RX lanes to controller RX lanes.
> > + Each index in the array represents a peripheral RX lane, and the value
> > + at that index represents the corresponding controller RX lane.
> These are peripheral props so I guess RX is from peripheral perspective.
> In that case, those would be routed to controller TX lanes, no?

I'm pretty sure it's the input to the controller like the other rx
properties. Like rx-delay is for reads.

I guess "peripheral RX lanes to controller RX lanes" is a bit oddly worded.

Rob