# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2 --- $id: http://devicetree.org/schemas/gpio/nxp,pcf8575.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# title: PCF857x-compatible I/O expanders maintainers: - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> description: The PCF857x-compatible chips have "quasi-bidirectional" I/O lines that can be driven high by a pull-up current source or driven low to ground. This combines the direction and output level into a single bit per line, which can't be read back. We can't actually know at initialization time whether a line is configured (a) as output and driving the signal low/high, or (b) as input and reporting a low/high value, without knowing the last value written since the chip came out of reset (if any). The only reliable solution for setting up line direction is thus to do it explicitly. properties: compatible: enum: - maxim,max7328 - maxim,max7329 - nxp,pca8574 - nxp,pca8575 - nxp,pca9670 - nxp,pca9671 - nxp,pca9672 - nxp,pca9673 - nxp,pca9674 - nxp,pca9675 - nxp,pcf8574 - nxp,pcf8574a - nxp,pcf8575 reg: maxItems: 1 gpio-line-names: minItems: 1 maxItems: 16 gpio-controller: true '#gpio-cells': const: 2 description: The first cell is the GPIO number and the second cell specifies GPIO flags, as defined in <dt-bindings/gpio/gpio.h>. Only the GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported. lines-initial-states: $ref: /schemas/types.yaml#/definitions/uint32 description: Bitmask that specifies the initial state of each line. When a bit is set to zero, the corresponding line will be initialized to the input (pulled-up) state. When the bit is set to one, the line will be initialized to the low-level output state. If the property is not specified all lines will be initialized to the input state. interrupts: maxItems: 1 interrupt-controller: true '#interrupt-cells': const: 2 wakeup-source: true patternProperties: "^(.+-hog(-[0-9]+)?)$": type: object required: - gpio-hog required: - compatible - reg - gpio-controller - '#gpio-cells' additionalProperties: false examples: - | i2c { #address-cells = <1>; #size-cells = <0>; pcf8575: gpio@20 { compatible = "nxp,pcf8575"; reg = <0x20>; interrupt-parent = <&irqpin2>; interrupts = <3 0>; gpio-controller; #gpio-cells = <2>; interrupt-controller; #interrupt-cells = <2>; }; };