On Wed, Sep 18, 2024 at 11:29:31AM +1200, Chris Packham wrote: > An extension of the RTL9300 SoC is to support multiplexing by selecting > the SDA pins that are being used dynamically. Add a binding that allows > us to describe hardware that makes use of this. > > Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx> > --- > .../bindings/i2c/realtek,rtl9300-i2c-mux.yaml | 82 +++++++++++++++++++ > MAINTAINERS | 1 + > 2 files changed, 83 insertions(+) > create mode 100644 Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml > > diff --git a/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml b/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml > new file mode 100644 > index 000000000000..a64879d0fda7 > --- /dev/null > +++ b/Documentation/devicetree/bindings/i2c/realtek,rtl9300-i2c-mux.yaml > @@ -0,0 +1,82 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/i2c/realtek,rtl9300-i2c-mux.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Realtek RTL I2C Multiplexer > + > +maintainers: > + - Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx> > + > +description: | > + The I2C controllers on the RTL9300 support a level of multiplexing. In the > + simple case the rtl9300-i2c binding can provide a single SDA pin per > + controller. This binding allows a more than one SDA line to be used per > + controller providing a level of multiplexing. > + > +properties: > + compatible: > + const: realtek,rtl9300-i2c-mux > + > + i2c-parent: > + description: phandle of the I2C bus controller that this multiplexer > + operates on. > + $ref: /schemas/types.yaml#/definitions/phandle The mux isn't a separate device, so I think this should just be part of the i2c parent: i2c-mux@36c { i2c@0 { ... }; i2c@1 { ... }; ... }; And then you can get rid of the SDA pin property. If you only use 1 pin, then there is just 1 'i2c' child node with an address matching the SDA pin. Rob