Commit 8b82b841 authored by Thierry Reding's avatar Thierry Reding Committed by Rob Herring
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dt-bindings: i2c: i2c-mux-pinctrl: Convert to json-schema 



Convert the pinctrl-based I2C mux bindings from the free-form text
format to json-schema.

Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211217165658.2650677-2-thierry.reding@gmail.com
parent f10a9b72

Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.txt

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Pinctrl-based I2C Bus Mux



This binding describes an I2C bus multiplexer that uses pin multiplexing to

route the I2C signals, and represents the pin multiplexing configuration

using the pinctrl device tree bindings.



                                 +-----+  +-----+

                                 | dev |  | dev |

    +------------------------+   +-----+  +-----+

    | SoC                    |      |        |

    |                   /----|------+--------+

    |   +---+   +------+     | child bus A, on first set of pins

    |   |I2C|---|Pinmux|     |

    |   +---+   +------+     | child bus B, on second set of pins

    |                   \----|------+--------+--------+

    |                        |      |        |        |

    +------------------------+  +-----+  +-----+  +-----+

                                | dev |  | dev |  | dev |

                                +-----+  +-----+  +-----+



Required properties:

- compatible: i2c-mux-pinctrl

- i2c-parent: The phandle of the I2C bus that this multiplexer's master-side

  port is connected to.



Also required are:



* Standard pinctrl properties that specify the pin mux state for each child

  bus. See ../pinctrl/pinctrl-bindings.txt.



* Standard I2C mux properties. See i2c-mux.yaml in this directory.



* I2C child bus nodes. See i2c-mux.yaml in this directory.



For each named state defined in the pinctrl-names property, an I2C child bus

will be created. I2C child bus numbers are assigned based on the index into

the pinctrl-names property.



The only exception is that no bus will be created for a state named "idle". If

such a state is defined, it must be the last entry in pinctrl-names. For

example:



	pinctrl-names = "ddc", "pta", "idle"  ->  ddc = bus 0, pta = bus 1

	pinctrl-names = "ddc", "idle", "pta"  ->  Invalid ("idle" not last)

	pinctrl-names = "idle", "ddc", "pta"  ->  Invalid ("idle" not last)



Whenever an access is made to a device on a child bus, the relevant pinctrl

state will be programmed into hardware.



If an idle state is defined, whenever an access is not being made to a device

on a child bus, the idle pinctrl state will be programmed into hardware.



If an idle state is not defined, the most recently used pinctrl state will be

left programmed into hardware whenever no access is being made of a device on

a child bus.



Example:



	i2cmux {

		compatible = "i2c-mux-pinctrl";

		#address-cells = <1>;

		#size-cells = <0>;



		i2c-parent = <&i2c1>;



		pinctrl-names = "ddc", "pta", "idle";

		pinctrl-0 = <&state_i2cmux_ddc>;

		pinctrl-1 = <&state_i2cmux_pta>;

		pinctrl-2 = <&state_i2cmux_idle>;



		i2c@0 {

			reg = <0>;

			#address-cells = <1>;

			#size-cells = <0>;



			eeprom {

				compatible = "eeprom";

				reg = <0x50>;

			};

		};



		i2c@1 {

			reg = <1>;

			#address-cells = <1>;

			#size-cells = <0>;



			eeprom {

				compatible = "eeprom";

				reg = <0x50>;

			};

		};

	};

Documentation/devicetree/bindings/i2c/i2c-mux-pinctrl.yaml

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# SPDX-License-Identifier: GPL-2.0-only

%YAML 1.2

---

$id: http://devicetree.org/schemas/i2c/i2c-mux-pinctrl.yaml#

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



title: Pinctrl-based I2C Bus Mux



maintainers:

  - Wolfram Sang <wsa@kernel.org>



description: |

  This binding describes an I2C bus multiplexer that uses pin multiplexing to route the I2C

  signals, and represents the pin multiplexing configuration using the pinctrl device tree

  bindings.



                                 +-----+  +-----+

                                 | dev |  | dev |

    +------------------------+   +-----+  +-----+

    | SoC                    |      |        |

    |                   /----|------+--------+

    |   +---+   +------+     | child bus A, on first set of pins

    |   |I2C|---|Pinmux|     |

    |   +---+   +------+     | child bus B, on second set of pins

    |                   \----|------+--------+--------+

    |                        |      |        |        |

    +------------------------+  +-----+  +-----+  +-----+

                                | dev |  | dev |  | dev |

                                +-----+  +-----+  +-----+



  For each named state defined in the pinctrl-names property, an I2C child bus will be created.

  I2C child bus numbers are assigned based on the index into the pinctrl-names property.



  The only exception is that no bus will be created for a state named "idle". If such a state is

  defined, it must be the last entry in pinctrl-names. For example:



    pinctrl-names = "ddc", "pta", "idle"  ->  ddc = bus 0, pta = bus 1

    pinctrl-names = "ddc", "idle", "pta"  ->  Invalid ("idle" not last)

    pinctrl-names = "idle", "ddc", "pta"  ->  Invalid ("idle" not last)



  Whenever an access is made to a device on a child bus, the relevant pinctrl state will be

  programmed into hardware.



  If an idle state is defined, whenever an access is not being made to a device on a child bus,

  the idle pinctrl state will be programmed into hardware.



  If an idle state is not defined, the most recently used pinctrl state will be left programmed

  into hardware whenever no access is being made of a device on a child bus.



properties:

  compatible:

    const: i2c-mux-pinctrl



  i2c-parent:

    $ref: /schemas/types.yaml#/definitions/phandle

    description: The phandle of the I2C bus that this multiplexer's master-side port is connected

      to.



allOf:

  - $ref: i2c-mux.yaml



unevaluatedProperties: false



required:

  - compatible

  - i2c-parent



examples:

  - |

    i2cmux {

      compatible = "i2c-mux-pinctrl";

      #address-cells = <1>;

      #size-cells = <0>;



      i2c-parent = <&i2c1>;



      pinctrl-names = "ddc", "pta", "idle";

      pinctrl-0 = <&state_i2cmux_ddc>;

      pinctrl-1 = <&state_i2cmux_pta>;

      pinctrl-2 = <&state_i2cmux_idle>;



      i2c@0 {

        reg = <0>;

        #address-cells = <1>;

        #size-cells = <0>;



        eeprom@50 {

          compatible = "atmel,24c02";

          reg = <0x50>;

        };

      };



      i2c@1 {

        reg = <1>;

        #address-cells = <1>;

        #size-cells = <0>;



        eeprom@50 {

          compatible = "atmel,24c02";

          reg = <0x50>;

        };

      };

    };