dt-bindings: clock: renesas: rcar-usb2-clock-sel: Convert bindings to json-schema

* Renesas R-Car USB 2.0 clock selector

This file provides information on what the device node for the R-Car USB 2.0

clock selector.

If you connect an external clock to the USB_EXTAL pin only, you should set

the clock rate to "usb_extal" node only.

If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module

is not needed because this is default setting. (Of course, you can set the

clock rates to both "usb_extal" and "usb_xtal" nodes.

Case 1: An external clock connects to R-Car SoC

	+----------+   +--- R-Car ---------------------+

	|External  |---|USB_EXTAL ---> all usb channels|

	|clock     |   |USB_XTAL                       |

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

In this case, we need this driver with "usb_extal" clock.

Case 2: An oscillator connects to R-Car SoC

	+----------+   +--- R-Car ---------------------+

	|Oscillator|---|USB_EXTAL -+-> all usb channels|

	|          |---|USB_XTAL --+                   |

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

In this case, we don't need this selector.

Required properties:

- compatible: "renesas,r8a7795-rcar-usb2-clock-sel" if the device is a part of

	      an R8A7795 SoC.

	      "renesas,r8a7796-rcar-usb2-clock-sel" if the device if a part of

	      an R8A77960 SoC.

	      "renesas,r8a77961-rcar-usb2-clock-sel" if the device if a part of

	      an R8A77961 SoC.

	      "renesas,rcar-gen3-usb2-clock-sel" for a generic R-Car Gen3

	      compatible device.

	      When compatible with the generic version, nodes must list the

	      SoC-specific version corresponding to the platform first

	      followed by the generic version.

- reg: offset and length of the USB 2.0 clock selector register block.

- clocks: A list of phandles and specifier pairs.

- clock-names: Name of the clocks.

 - The functional clock of USB 2.0 host side must be "ehci_ohci"

 - The functional clock of HS-USB side must be "hs-usb-if"

 - The USB_EXTAL clock pin must be "usb_extal"

 - The USB_XTAL clock pin must be "usb_xtal"

- #clock-cells: Must be 0

- power-domains: A phandle and symbolic PM domain specifier.

                 See power/renesas,rcar-sysc.yaml.

- resets: A list of phandles and specifier pairs.

- reset-names: Name of the resets.

 - The reset of USB 2.0 host side must be "ehci_ohci"

 - The reset of HS-USB side must be "hs-usb-if"

Example (R-Car H3):

	usb2_clksel: clock-controller@e6590630 {

		compatible = "renesas,r8a7795-rcar-usb2-clock-sel",

			     "renesas,rcar-gen3-usb2-clock-sel";

		reg = <0 0xe6590630 0 0x02>;

		clocks = <&cpg CPG_MOD 703>, <&cpg CPG_MOD 704>,

			 <&usb_extal>, <&usb_xtal>;

		clock-names = "ehci_ohci", "hs-usb-if", "usb_extal", "usb_xtal";

		#clock-cells = <0>;

		power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;

		resets = <&cpg 703>, <&cpg 704>;

		reset-names = "ehci_ohci", "hs-usb-if";

	};

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

%YAML 1.2

---

$id: "http://devicetree.org/schemas/clock/renesas,rcar-usb2-clock-sel.yaml#"

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

title: Renesas R-Car USB 2.0 clock selector

maintainers:

  - Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

description: |

  If you connect an external clock to the USB_EXTAL pin only, you should set

  the clock rate to "usb_extal" node only.

  If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module

  is not needed because this is default setting. (Of course, you can set the

  clock rates to both "usb_extal" and "usb_xtal" nodes.

  Case 1: An external clock connects to R-Car SoC

    +----------+   +--- R-Car ---------------------+

    |External  |---|USB_EXTAL ---> all usb channels|

    |clock     |   |USB_XTAL                       |

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

  In this case, we need this driver with "usb_extal" clock.

  Case 2: An oscillator connects to R-Car SoC

    +----------+   +--- R-Car ---------------------+

    |Oscillator|---|USB_EXTAL -+-> all usb channels|

    |          |---|USB_XTAL --+                   |

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

  In this case, we don't need this selector.

properties:

  compatible:

    items:

      - enum:

          - renesas,r8a7795-rcar-usb2-clock-sel  # R-Car H3

          - renesas,r8a7796-rcar-usb2-clock-sel  # R-Car M3-W

          - renesas,r8a77961-rcar-usb2-clock-sel # R-Car M3-W+

      - const: renesas,rcar-gen3-usb2-clock-sel

  reg:

    maxItems: 1

  clocks:

    minItems: 4

    maxItems: 4

  clock-names:

    items:

      - const: ehci_ohci

      - const: hs-usb-if

      - const: usb_extal

      - const: usb_xtal

  '#clock-cells':

    const: 0

  power-domains:

    maxItems: 1

  resets:

    minItems: 2

    maxItems: 2

  reset-names:

    items:

      - const: ehci_ohci

      - const: hs-usb-if

required:

  - compatible

  - reg

  - clocks

  - clock-names

  - '#clock-cells'

  - power-domains

  - resets

  - reset-names

additionalProperties: false

examples:

  - |

    #include <dt-bindings/clock/r8a7795-cpg-mssr.h>

    #include <dt-bindings/power/r8a7795-sysc.h>

    usb2_clksel: clock-controller@e6590630 {

        compatible = "renesas,r8a7795-rcar-usb2-clock-sel",

                     "renesas,rcar-gen3-usb2-clock-sel";

        reg = <0xe6590630 0x02>;

        clocks = <&cpg CPG_MOD 703>, <&cpg CPG_MOD 704>,

                 <&usb_extal>, <&usb_xtal>;

        clock-names = "ehci_ohci", "hs-usb-if", "usb_extal", "usb_xtal";

        #clock-cells = <0>;

        power-domains = <&sysc R8A7795_PD_ALWAYS_ON>;

        resets = <&cpg 703>, <&cpg 704>;

        reset-names = "ehci_ohci", "hs-usb-if";

    };