1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/gpio/nxp,pcf8575.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: PCF857x-compatible I/O expanders
8
9 maintainers:
10 - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
11
12 description:
13 The PCF857x-compatible chips have "quasi-bidirectional" I/O lines that can be
14 driven high by a pull-up current source or driven low to ground. This
15 combines the direction and output level into a single bit per line, which
16 can't be read back. We can't actually know at initialization time whether a
17 line is configured (a) as output and driving the signal low/high, or (b) as
18 input and reporting a low/high value, without knowing the last value written
19 since the chip came out of reset (if any). The only reliable solution for
20 setting up line direction is thus to do it explicitly.
21
22 properties:
23 compatible:
24 enum:
25 - maxim,max7328
26 - maxim,max7329
27 - nxp,pca8574
28 - nxp,pca8575
29 - nxp,pca9670
30 - nxp,pca9671
31 - nxp,pca9672
32 - nxp,pca9673
33 - nxp,pca9674
34 - nxp,pca9675
35 - nxp,pcf8574
36 - nxp,pcf8574a
37 - nxp,pcf8575
38
39 reg:
40 maxItems: 1
41
42 gpio-line-names:
43 minItems: 1
44 maxItems: 16
45
46 gpio-controller: true
47
48 '#gpio-cells':
49 const: 2
50 description:
51 The first cell is the GPIO number and the second cell specifies GPIO
52 flags, as defined in <dt-bindings/gpio/gpio.h>. Only the GPIO_ACTIVE_HIGH
53 and GPIO_ACTIVE_LOW flags are supported.
54
55 lines-initial-states:
56 $ref: /schemas/types.yaml#/definitions/uint32
57 description:
58 Bitmask that specifies the initial state of each line.
59 When a bit is set to zero, the corresponding line will be initialized to
60 the input (pulled-up) state.
61 When the bit is set to one, the line will be initialized to the
62 low-level output state.
63 If the property is not specified all lines will be initialized to the
64 input state.
65
66 interrupts:
67 maxItems: 1
68
69 interrupt-controller: true
70
71 '#interrupt-cells':
72 const: 2
73
74 wakeup-source: true
75
76 patternProperties:
77 "^(.+-hog(-[0-9]+)?)$":
78 type: object
79
80 required:
81 - gpio-hog
82
83 required:
84 - compatible
85 - reg
86 - gpio-controller
87 - '#gpio-cells'
88
89 additionalProperties: false
90
91 examples:
92 - |
93 i2c {
94 #address-cells = <1>;
95 #size-cells = <0>;
96
97 pcf8575: gpio@20 {
98 compatible = "nxp,pcf8575";
99 reg = <0x20>;
100 interrupt-parent = <&irqpin2>;
101 interrupts = <3 0>;
102 gpio-controller;
103 #gpio-cells = <2>;
104 interrupt-controller;
105 #interrupt-cells = <2>;
106 };
107 };
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