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Tom Rini6bb92fc2024-05-20 09:54:58 -06001# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/w1/w1-uart.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: UART 1-Wire Bus
8
9maintainers:
10 - Christoph Winklhofer <cj.winklhofer@gmail.com>
11
12description: |
13 UART 1-wire bus. Utilizes the UART interface via the Serial Device Bus
14 to create the 1-Wire timing patterns.
15
16 The UART peripheral must support full-duplex and operate in open-drain
17 mode. The timing patterns are generated by a specific combination of
18 baud-rate and transmitted byte, which corresponds to a 1-Wire read bit,
19 write bit or reset pulse.
20
21 The default baud-rate for reset and presence detection is 9600 and for
22 a 1-Wire read or write operation 115200. In case the actual baud-rate
23 is different from the requested one, the transmitted byte is adapted
24 to generate the 1-Wire timing patterns.
25
26 https://www.analog.com/en/technical-articles/using-a-uart-to-implement-a-1wire-bus-master.html
27
28properties:
29 compatible:
30 const: w1-uart
31
32 reset-bps:
33 default: 9600
34 description:
35 The baud rate for the 1-Wire reset and presence detect.
36
37 write-0-bps:
38 default: 115200
39 description:
40 The baud rate for the 1-Wire write-0 cycle.
41
42 write-1-bps:
43 default: 115200
44 description:
45 The baud rate for the 1-Wire write-1 and read cycle.
46
47required:
48 - compatible
49
50additionalProperties:
51 type: object
52
53examples:
54 - |
55 serial {
56 onewire {
57 compatible = "w1-uart";
58 };
59 };