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-rw-r--r-- | Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml | 103 |
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diff --git a/Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml b/Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml new file mode 100644 index 000000000..f0ff66c4c --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/nxp,pcf8575.yaml @@ -0,0 +1,103 @@ +# 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-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>; + }; + }; |