36 lines
974 B
YAML
36 lines
974 B
YAML
# Copyright (c) 2023 Hudson C. Dalpra
|
|
# SPDX-License-Identifier: Apache-2.0
|
|
|
|
description: |
|
|
Zephyr W1 GPIO node
|
|
|
|
This defines a one-wire driver through GPIO bit-banging.
|
|
|
|
For example:
|
|
|
|
/ {
|
|
w1: w1 {
|
|
compatible = "zephyr,w1-gpio";
|
|
gpios = <&gpio0 13 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN | GPIO_PULL_UP)>;
|
|
};
|
|
};
|
|
|
|
Above:
|
|
- w1 is pin 13 on gpio0. The gpio is active when the pin is high, is
|
|
configured as an open-drain, and has a pull-up resistor.
|
|
|
|
Implementation details:
|
|
- Most drivers require the selected gpio to support open drain, this enables onewire
|
|
devices to lower the signal when the SOC set the signal high.
|
|
- Ensure pullup is strong enough (4.7K according to the specification). Standard pullup in
|
|
SOC are usually weak, and may not be strong enough.
|
|
|
|
compatible: "zephyr,w1-gpio"
|
|
|
|
include: [w1-master.yaml]
|
|
|
|
properties:
|
|
gpios:
|
|
type: phandle-array
|
|
required: true
|