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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/Documentation/devicetree/bindings/gpio/gpio-line-mux.yaml
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# 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/gpio-line-mux.yaml#

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$schema: http://devicetree.org/meta-schemas/core.yaml#

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title: GPIO line mux

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maintainers:

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  - Jonas Jelonek <jelonek.jonas@gmail.com>

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description: |

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  A GPIO controller to provide virtual GPIOs for a 1-to-many input-only mapping

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  backed by a single shared GPIO and a multiplexer. A simple illustrated

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  example is:

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            +----- A

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    IN     /

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    <-----o------- B

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        / |\

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        | | +----- C

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        | |  \

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        | |   +--- D

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        | |

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       M1 M0

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    MUX CONTROL

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     M1 M0   IN

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      0  0   A

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      0  1   B

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      1  0   C

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      1  1   D

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  This can be used in case a real GPIO is connected to multiple inputs and

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  controlled by a multiplexer, and another subsystem/driver does not work

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  directly with the multiplexer subsystem.

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properties:

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  compatible:

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    const: gpio-line-mux

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  gpio-controller: true

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  "#gpio-cells":

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    const: 2

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  gpio-line-mux-states:

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    description: Mux states corresponding to the virtual GPIOs.

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    $ref: /schemas/types.yaml#/definitions/uint32-array

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  gpio-line-names: true

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  mux-controls:

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    maxItems: 1

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    description:

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      Phandle to the multiplexer to control access to the GPIOs.

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  ngpios: false

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  muxed-gpios:

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    maxItems: 1

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    description:

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      GPIO which is the '1' in 1-to-many and is shared by the virtual GPIOs

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      and controlled via the mux.

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required:

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  - compatible

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  - gpio-controller

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  - gpio-line-mux-states

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  - mux-controls

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  - muxed-gpios

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additionalProperties: false

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examples:

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  - |

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    #include <dt-bindings/gpio/gpio.h>

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    #include <dt-bindings/mux/mux.h>

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    sfp_gpio_mux: mux-controller-1 {

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        compatible = "gpio-mux";

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        mux-gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>,

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                    <&gpio0 1 GPIO_ACTIVE_HIGH>;

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        #mux-control-cells = <0>;

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        idle-state = <MUX_IDLE_AS_IS>;

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    };

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    sfp1_gpio: sfp-gpio-1 {

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        compatible = "gpio-line-mux";

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        gpio-controller;

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        #gpio-cells = <2>;

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        mux-controls = <&sfp_gpio_mux>;

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        muxed-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;

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        gpio-line-mux-states = <0>, <1>, <3>;

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    };

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    sfp1: sfp-p1 {

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        compatible = "sff,sfp";

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        i2c-bus = <&sfp1_i2c>;

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        los-gpios = <&sfp1_gpio 0 GPIO_ACTIVE_HIGH>;

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        mod-def0-gpios = <&sfp1_gpio 1 GPIO_ACTIVE_LOW>;

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        tx-fault-gpios = <&sfp1_gpio 2 GPIO_ACTIVE_HIGH>;

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    };

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