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