From: Christoph Winklhofer <cj.winklhofer@xxxxxxxxx> Add device tree binding for UART 1-Wire bus. Reviewed-by: Rob Herring <robh@xxxxxxxxxx> Signed-off-by: Christoph Winklhofer <cj.winklhofer@xxxxxxxxx> --- Documentation/devicetree/bindings/w1/w1-uart.yaml | 60 +++++++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/Documentation/devicetree/bindings/w1/w1-uart.yaml b/Documentation/devicetree/bindings/w1/w1-uart.yaml new file mode 100644 index 000000000000..7173820c78f9 --- /dev/null +++ b/Documentation/devicetree/bindings/w1/w1-uart.yaml @@ -0,0 +1,60 @@ +# 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 + + reset-bps: + default: 9600 + description: + The baud rate for the 1-Wire reset and presence detect. + + write-0-bps: + default: 115200 + description: + The baud rate for the 1-Wire write-0 cycle. + + write-1-bps: + default: 115200 + description: + The baud rate for the 1-Wire write-1 and read cycle. + +required: + - compatible + +additionalProperties: + type: object + +examples: + - | + serial { + onewire { + compatible = "w1-uart"; + }; + }; -- 2.43.0
