dt-bindings: Add en7523-scu device tree binding documentation

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

%YAML 1.2

---

$id: http://devicetree.org/schemas/clock/airoha,en7523-scu.yaml#

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

title: EN7523 Clock Device Tree Bindings

maintainers:

  - Felix Fietkau <nbd@nbd.name>

  - John Crispin <nbd@nbd.name>

description: |

  This node defines the System Control Unit of the EN7523 SoC,

  a collection of registers configuring many different aspects of the SoC.

  The clock driver uses it to read and configure settings of the

  PLL controller, which provides clocks for the CPU, the bus and

  other SoC internal peripherals.

  Each clock is assigned an identifier and client nodes use this identifier

  to specify which clock they consume.

  All these identifiers can be found in:

  [1]: <include/dt-bindings/clock/en7523-clk.h>.

  The clocks are provided inside a system controller node.

properties:

  compatible:

    items:

      - const: airoha,en7523-scu

  reg:

    maxItems: 2

  "#clock-cells":

    description:

      The first cell indicates the clock number, see [1] for available

      clocks.

    const: 1

required:

  - compatible

  - reg

  - '#clock-cells'

additionalProperties: false

examples:

  - |

    #include <dt-bindings/clock/en7523-clk.h>

    scu: system-controller@1fa20000 {

      compatible = "airoha,en7523-scu";

      reg = <0x1fa20000 0x400>,

            <0x1fb00000 0x1000>;

      #clock-cells = <1>;

    };

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

#ifndef _DT_BINDINGS_CLOCK_AIROHA_EN7523_H_

#define _DT_BINDINGS_CLOCK_AIROHA_EN7523_H_

#define EN7523_CLK_GSW		0

#define EN7523_CLK_EMI		1

#define EN7523_CLK_BUS		2

#define EN7523_CLK_SLIC		3

#define EN7523_CLK_SPI		4

#define EN7523_CLK_NPU		5

#define EN7523_CLK_CRYPTO	6

#define EN7523_CLK_PCIE		7

#define EN7523_NUM_CLOCKS	8

#endif /* _DT_BINDINGS_CLOCK_AIROHA_EN7523_H_ */