0001 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/gpio/nxp,pcf8575.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: PCF857x-compatible I/O expanders
0008
0009 maintainers:
0010 - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
0011
0012 description:
0013 The PCF857x-compatible chips have "quasi-bidirectional" I/O lines that can be
0014 driven high by a pull-up current source or driven low to ground. This
0015 combines the direction and output level into a single bit per line, which
0016 can't be read back. We can't actually know at initialization time whether a
0017 line is configured (a) as output and driving the signal low/high, or (b) as
0018 input and reporting a low/high value, without knowing the last value written
0019 since the chip came out of reset (if any). The only reliable solution for
0020 setting up line direction is thus to do it explicitly.
0021
0022 properties:
0023 compatible:
0024 enum:
0025 - maxim,max7328
0026 - maxim,max7329
0027 - nxp,pca8574
0028 - nxp,pca8575
0029 - nxp,pca9670
0030 - nxp,pca9671
0031 - nxp,pca9672
0032 - nxp,pca9673
0033 - nxp,pca9674
0034 - nxp,pca9675
0035 - nxp,pcf8574
0036 - nxp,pcf8574a
0037 - nxp,pcf8575
0038
0039 reg:
0040 maxItems: 1
0041
0042 gpio-controller: true
0043
0044 '#gpio-cells':
0045 const: 2
0046 description:
0047 The first cell is the GPIO number and the second cell specifies GPIO
0048 flags, as defined in <dt-bindings/gpio/gpio.h>. Only the GPIO_ACTIVE_HIGH
0049 and GPIO_ACTIVE_LOW flags are supported.
0050
0051 lines-initial-states:
0052 $ref: /schemas/types.yaml#/definitions/uint32
0053 description:
0054 Bitmask that specifies the initial state of each line.
0055 When a bit is set to zero, the corresponding line will be initialized to
0056 the input (pulled-up) state.
0057 When the bit is set to one, the line will be initialized to the
0058 low-level output state.
0059 If the property is not specified all lines will be initialized to the
0060 input state.
0061
0062 interrupts:
0063 maxItems: 1
0064
0065 interrupt-controller: true
0066
0067 '#interrupt-cells':
0068 const: 2
0069
0070 wakeup-source: true
0071
0072 patternProperties:
0073 "^(.+-hog(-[0-9]+)?)$":
0074 type: object
0075
0076 required:
0077 - gpio-hog
0078
0079 required:
0080 - compatible
0081 - reg
0082 - gpio-controller
0083 - '#gpio-cells'
0084
0085 additionalProperties: false
0086
0087 examples:
0088 - |
0089 i2c {
0090 #address-cells = <1>;
0091 #size-cells = <0>;
0092
0093 pcf8575: gpio@20 {
0094 compatible = "nxp,pcf8575";
0095 reg = <0x20>;
0096 interrupt-parent = <&irqpin2>;
0097 interrupts = <3 0>;
0098 gpio-controller;
0099 #gpio-cells = <2>;
0100 interrupt-controller;
0101 #interrupt-cells = <2>;
0102 };
0103 };
