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