Tom Rini | 6bb92fc | 2024-05-20 09:54:58 -0600 | [diff] [blame] | 1 | # 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 | |
| 7 | title: UART 1-Wire Bus |
| 8 | |
| 9 | maintainers: |
| 10 | - Christoph Winklhofer <cj.winklhofer@gmail.com> |
| 11 | |
| 12 | description: | |
| 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 | |
| 28 | properties: |
| 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 | |
| 47 | required: |
| 48 | - compatible |
| 49 | |
| 50 | additionalProperties: |
| 51 | type: object |
| 52 | |
| 53 | examples: |
| 54 | - | |
| 55 | serial { |
| 56 | onewire { |
| 57 | compatible = "w1-uart"; |
| 58 | }; |
| 59 | }; |