* Renesas RZ Clock Pulse Generator (CPG)

The CPG generates core clocks for the RZ SoCs. It includes the PLL, variable
CPU and GPU clocks, and several fixed ratio dividers.
The CPG also provides a Clock Domain for SoC devices, in combination with the
CPG Module Stop (MSTP) Clocks.

Required Properties:

  - compatible: Must be one of
    - "renesas,r7s72100-cpg-clocks" for the r7s72100 CPG
    and "renesas,rz-cpg-clocks" as a fallback.
  - reg: Base address and length of the memory resource used by the CPG
  - clocks: References to possible parent clocks. Order must match clock modes
    in the datasheet. For the r7s72100, this is extal, usb_x1.
  - #clock-cells: Must be 1
  - clock-output-names: The names of the clocks. Supported clocks are "pll",
    "i", and "g"
  - #power-domain-cells: Must be 0

SoC devices that are part of the CPG/MSTP Clock Domain and can be power-managed
through an MSTP clock should refer to the CPG device node in their
"power-domains" property, as documented by the generic PM domain bindings in
Documentation/devicetree/bindings/power/power_domain.txt.


Examples
--------

  - CPG device node:

	cpg_clocks: cpg_clocks@fcfe0000 {
		#clock-cells = <1>;
		compatible = "renesas,r7s72100-cpg-clocks",
			     "renesas,rz-cpg-clocks";
		reg = <0xfcfe0000 0x18>;
		clocks = <&extal_clk>, <&usb_x1_clk>;
		clock-output-names = "pll", "i", "g";
		#power-domain-cells = <0>;
	};


  - CPG/MSTP Clock Domain member device node:

	mtu2: timer@fcff0000 {
		compatible = "renesas,mtu2-r7s72100", "renesas,mtu2";
		reg = <0xfcff0000 0x400>;
		interrupts = <0 107 IRQ_TYPE_LEVEL_HIGH>;
		interrupt-names = "tgi0a";
		clocks = <&mstp3_clks R7S72100_CLK_MTU2>;
		clock-names = "fck";
		power-domains = <&cpg_clocks>;
		status = "disabled";
	};