dt-bindings: serial: Convert i.MX uart to json-schema

* Freescale i.MX Universal Asynchronous Receiver/Transmitter (UART)

Required properties:

- compatible : Should be "fsl,<soc>-uart"

- reg : Address and length of the register set for the device

- interrupts : Should contain uart interrupt

Optional properties:

- fsl,dte-mode : Indicate the uart works in DTE mode. The uart works

                  in DCE mode by default.

- fsl,inverted-tx , fsl,inverted-rx : Indicate that the hardware attached

  to the peripheral inverts the signal transmitted or received,

  respectively, and that the peripheral should invert its output/input

  using the INVT/INVR registers.

- rs485-rts-delay, rs485-rts-active-low, rs485-rx-during-tx,

  linux,rs485-enabled-at-boot-time: see rs485.txt. Note that for RS485

  you must enable either the "uart-has-rtscts" or the "rts-gpios"

  properties. In case you use "uart-has-rtscts" the signal that controls

  the transceiver is actually CTS_B, not RTS_B. CTS_B is always output,

  and RTS_B is input, regardless of dte-mode.

Please check Documentation/devicetree/bindings/serial/serial.yaml

for the complete list of generic properties.

Note: Each uart controller should have an alias correctly numbered

in "aliases" node.

Example:

aliases {

	serial0 = &uart1;

};

uart1: serial@73fbc000 {

	compatible = "fsl,imx51-uart", "fsl,imx21-uart";

	reg = <0x73fbc000 0x4000>;

	interrupts = <31>;

	uart-has-rtscts;

	fsl,dte-mode;

};

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/serial/fsl-imx-uart.yaml#

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

title: Freescale i.MX Universal Asynchronous Receiver/Transmitter (UART)

maintainers:

  - Fabio Estevam <fabio.estevam@nxp.com>

allOf:

  - $ref: "serial.yaml"

  - $ref: "rs485.yaml"

properties:

  compatible:

    oneOf:

      - const: fsl,imx1-uart

      - const: fsl,imx21-uart

      - const: fsl,imx53-uart

      - const: fsl,imx6q-uart

      - items:

          - enum:

            - fsl,imx25-uart

            - fsl,imx27-uart

            - fsl,imx31-uart

            - fsl,imx35-uart

            - fsl,imx50-uart

            - fsl,imx51-uart

          - const: fsl,imx21-uart

      - items:

          - enum:

            - fsl,imx6sl-uart

            - fsl,imx6sll-uart

            - fsl,imx6sx-uart

            - fsl,imx6ul-uart

            - fsl,imx7d-uart

          - const: fsl,imx6q-uart

  reg:

    maxItems: 1

  interrupts:

    maxItems: 1

  fsl,dte-mode:

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

    description: |

      Indicate the uart works in DTE mode. The uart works in DCE mode by default.

  fsl,inverted-tx:

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

    description: |

      Indicate that the hardware attached to the peripheral inverts the signal

      transmitted, and that the peripheral should invert its output using the

      INVT registers.

  fsl,inverted-rx:

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

    description: |

      Indicate that the hardware attached to the peripheral inverts the signal

      received, and that the peripheral should invert its input using the

      INVR registers.

  uart-has-rtscts: true

  rs485-rts-delay: true

  rs485-rts-active-low: true

  rs485-rx-during-tx: true

  linux,rs485-enabled-at-boot-time: true

required:

  - compatible

  - reg

  - interrupts

unevaluatedProperties: false

examples:

  - |

    aliases {

        serial0 = &uart1;

    };

    uart1: serial@73fbc000 {

        compatible = "fsl,imx51-uart", "fsl,imx21-uart";

        reg = <0x73fbc000 0x4000>;

        interrupts = <31>;

        uart-has-rtscts;

        fsl,dte-mode;

    };