* Rockchip DMC(Dynamic Memory Controller) device

Required properties:
- compatible: Should be one of the following.
  - "rockchip,px30-dmc" - for PX30 SoCs.
  - "rockchip,rk1808-dmc" - for RK1808 SoCs.
  - "rockchip,rk3128-dmc" - for RK3128 SoCs.
  - "rockchip,rk3228-dmc" - for RK3228 SoCs.
  - "rockchip,rk3288-dmc" - for RK3288 SoCs.
  - "rockchip,rk3308-dmc" - for RK3308 SoCs.
  - "rockchip,rk3328-dmc" - for RK3328 SoCs.
  - "rockchip,rk3399-dmc" - for RK3399 SoCs.
  - "rockchip,rk3528-dmc" - for RK3528 SoCs.
  - "rockchip,rk3562-dmc" - for RK3562 SoCs.
  - "rockchip,rk3568-dmc" - for RK3568 SoCs.
  - "rockchip,rk3588-dmc" - for RK3588 SoCs.
  - "rockchip,rv1126-dmc" - for RV1126 SoCs.
- devfreq-events: Node to get DDR loading, Refer to
		  Documentation/devicetree/bindings/devfreq/rockchip-dfi.txt
- interrupts: The interrupt number to the CPU. The interrupt specifier format
	      depends on the interrupt controller. It should be DCF interrupts,
	      when DDR dvfs finish, it will happen.
- clocks: Phandles for clock specified in "clock-names" property
- clock-names : The name of clock used by the DFI, must be "pclk_ddr_mon";
- operating-points-v2: Refer to Documentation/devicetree/bindings/power/opp.txt
		       for details.
- center-supply: DMC supply node.
- status: Marks the node enabled/disabled.

Optional properties:
- ddr_timing:  DDR timing need to pass to arm trust firmware
- upthreshold: The upthreshold to simpleondeamnd policy
- downdifferential: The downdifferential to simpleondeamnd policy
- vop-bw-dmc-freq: The property is an array of 3-tuples items, and
		   each item consists of bandwidth and frequency like
		   <min-bandwidth max-bandwidth frequency>.
		   min-bandwidth: minimum ddr bandwidth in Mbyte/sec.
		   max-bandwidth: maximum ddr bandwidth in Mbyte/sec.
		   frequency: ddr frequency in KHz.
- #cooling-cells: This property indicates dmc can work as a cooling device
- ddr_power_model: Sets power model parameters.
	- dynamic-power-coefficient: A u32 value that represents the running time dynamic
	  power coefficient in units of mW/MHz/uVolt^2. The coefficient can either be
	  calculated from power measurements or derived by analysis.
	- static-power-coefficient: A u32 value that represents the static power
	  coefficient.
	- ts: An array containing coefficients for the temperature scaling factor.
	  Used as : tsf = ts[3]*T^3 + ts[2]*T^2 + ts[1]*T + ts[0], where T = temperature
	- thermal-zone: A string identifying the thermal zone used for the dmc

Example:

	ddr_timing: ddr_timing {
		compatible = "rockchip,ddr-timing";
		ddr3_speed_bin = <21>;
		pd_idle = <0>;
		sr_idle = <0>;
		sr_mc_gate_idle = <0>;
		srpd_lite_idle  = <0>;
		standby_idle = <0>;
		dram_dll_dis_freq = <300>;
		phy_dll_dis_freq = <125>;

		ddr3_odt_dis_freq = <333>;
		ddr3_drv = <DDR3_DS_40ohm>;
		ddr3_odt = <DDR3_ODT_120ohm>;
		phy_ddr3_ca_drv = <PHY_DRV_ODT_40>;
		phy_ddr3_dq_drv = <PHY_DRV_ODT_40>;
		phy_ddr3_odt = <PHY_DRV_ODT_240>;

		lpddr3_odt_dis_freq = <333>;
		lpddr3_drv = <LP3_DS_34ohm>;
		lpddr3_odt = <LP3_ODT_240ohm>;
		phy_lpddr3_ca_drv = <PHY_DRV_ODT_40>;
		phy_lpddr3_dq_drv = <PHY_DRV_ODT_40>;
		phy_lpddr3_odt = <PHY_DRV_ODT_240>;

		lpddr4_odt_dis_freq = <333>;
		lpddr4_drv = <LP4_PDDS_60ohm>;
		lpddr4_dq_odt = <LP4_DQ_ODT_40ohm>;
		lpddr4_ca_odt = <LP4_CA_ODT_40ohm>;
		phy_lpddr4_ca_drv = <PHY_DRV_ODT_40>;
		phy_lpddr4_ck_cs_drv = <PHY_DRV_ODT_80>;
		phy_lpddr4_dq_drv = <PHY_DRV_ODT_80>;
		phy_lpddr4_odt = <PHY_DRV_ODT_60>;
	};

	dmc_opp_table: dmc_opp_table {
		compatible = "operating-points-v2";

		opp00 {
			opp-hz = /bits/ 64 <300000000>;
			opp-microvolt = <900000>;
		};
		opp01 {
			opp-hz = /bits/ 64 <666000000>;
			opp-microvolt = <900000>;
		};
	};

	dmc: dmc {
		compatible = "rockchip,rk3399-dmc";
		devfreq-events = <&dfi>;
		interrupts = <GIC_SPI 1 IRQ_TYPE_LEVEL_HIGH>;
		clocks = <&cru SCLK_DDRCLK>;
		clock-names = "dmc_clk";
		ddr_timing = <&ddr_timing>;
		operating-points-v2 = <&dmc_opp_table>;
		center-supply = <&ppvar_centerlogic>;
		upthreshold = <15>;
		downdifferential = <10>;
		#cooling-cells = <2>;
		ddr_power_model: ddr_power_model {
			dynamic-power-coefficient = <120>;
			static-power-coefficient = <300>;
			ts = <32000 4700 (-80) 2>;
			thermal-zone = "soc-thermal";
		}
		status = "disabled";
	};