nxp,pcf8575.yaml

  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
  7title: PCF857x-compatible I/O expanders
  8
  9maintainers:
 10  - Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
 11
 12description:
 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
 22properties:
 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    $ref: /schemas/types.yaml#/definitions/uint32
 57    description:
 58      Bitmask that specifies the initial state of each line.
 59      When a bit is set to zero, the corresponding line will be initialized to
 60      the input (pulled-up) state.
 61      When the  bit is set to one, the line will be initialized to the
 62      low-level output state.
 63      If the property is not specified all lines will be initialized to the
 64      input state.
 65
 66  interrupts:
 67    maxItems: 1
 68
 69  interrupt-controller: true
 70
 71  '#interrupt-cells':
 72    const: 2
 73
 74  wakeup-source: true
 75
 76  reset-gpios:
 77    maxItems: 1
 78    description:
 79      GPIO controlling the (reset active LOW) RESET# pin.
 80
 81      The active polarity of the GPIO must translate to the low state of the
 82      RESET# pin on the IC, i.e. if a GPIO is directly routed to the RESET# pin
 83      without any inverter, GPIO_ACTIVE_LOW is expected.
 84
 85      Performing a reset makes all lines initialized to their input (pulled-up)
 86      state.
 87
 88allOf:
 89  - if:
 90      properties:
 91        compatible:
 92          not:
 93            contains:
 94              enum:
 95                - nxp,pca9670
 96                - nxp,pca9671
 97                - nxp,pca9672
 98                - nxp,pca9673
 99    then:
100      properties:
101        reset-gpios: false
102
103  # lines-initial-states XOR reset-gpios
104  # Performing a reset reinitializes all lines to a known state which
105  # may not match passed lines-initial-states
106  - if:
107      required:
108        - lines-initial-states
109    then:
110      properties:
111        reset-gpios: false
112
113patternProperties:
114  "^(.+-hog(-[0-9]+)?)$":
115    type: object
116
117    required:
118      - gpio-hog
119
120required:
121  - compatible
122  - reg
123  - gpio-controller
124  - '#gpio-cells'
125
126additionalProperties: false
127
128examples:
129  - |
130    i2c {
131        #address-cells = <1>;
132        #size-cells = <0>;
133
134        gpio@20 {
135            compatible = "nxp,pcf8575";
136            reg = <0x20>;
137            interrupt-parent = <&irqpin2>;
138            interrupts = <3 0>;
139            gpio-controller;
140            #gpio-cells = <2>;
141            interrupt-controller;
142            #interrupt-cells = <2>;
143        };
144    };