On Thu, Dec 21, 2023 at 07:50:47AM +0100, Christoph Winklhofer wrote: > Add device tree binding for UART 1-wire bus. > > Signed-off-by: Christoph Winklhofer <cj.winklhofer@xxxxxxxxx> > --- > .../devicetree/bindings/w1/w1-uart.yaml | 44 +++++++++++++++++++ > 1 file changed, 44 insertions(+) > create mode 100644 Documentation/devicetree/bindings/w1/w1-uart.yaml > > diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml > new file mode 100644 > index 000000000000..93d83c42c407 > --- /dev/null > +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml > @@ -0,0 +1,44 @@ > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause > +%YAML 1.2 > +--- > +$id: http://devicetree.org/schemas/w1/w1-uart.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: UART 1-Wire Bus > + > +maintainers: > + - Christoph Winklhofer <cj.winklhofer@xxxxxxxxx> > + > +description: | > + UART 1-wire bus. Utilizes the UART interface via the Serial Device Bus > + to create the 1-Wire timing patterns. > + > + The UART peripheral must support full-duplex and operate in open-drain > + mode. The timing patterns are generated by a specific combination of > + baud-rate and transmitted byte, which corresponds to a 1-Wire read bit, > + write bit or reset pulse. > + > + The default baud-rate for reset and presence detection is 9600 and for > + a 1-Wire read or write operation 115200. In case the actual baud-rate > + is different from the requested one, the transmitted byte is adapted > + to generate the 1-Wire timing patterns. > + > + https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html > + > + > +properties: > + compatible: > + const: w1-uart > + > +required: > + - compatible > + > +additionalProperties: false > + > +examples: > + - | > + serial { > + onewire { Have you tried this in an actual DT? Assuming the UART node has a schema, it should be a warning because child node names are explicit in serial.yaml unfortunately. IOW, you need to add "onewire" to serial.yaml. > + compatible = "w1-uart"; > + }; > + }; > -- > 2.43.0 >
