xref: /freebsd/sys/contrib/device-tree/Bindings/w1/w1-uart.yaml (revision 01950c46b8155250f64374fb72fc11faa44bf099)

# 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@gmail.com>

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";
        };
    };