* Rockchip AXI PCIe Root Port Bridge DT description

Required properties:
- #address-cells: Address representation for root ports, set to <3>
- #size-cells: Size representation for root ports, set to <2>
- #interrupt-cells: specifies the number of cells needed to encode an
		interrupt source. The value must be 1.
- compatible: Should contain "rockchip,rk3399-pcie"
- reg: Two register ranges as listed in the reg-names property
- reg-names: Must include the following names
	- "axi-base"
	- "apb-base"
- clocks: Must contain an entry for each entry in clock-names.
		See ../clocks/clock-bindings.txt for details.
- clock-names: Must include the following entries:
	- "aclk"
	- "aclk-perf"
	- "hclk"
	- "pm"
- msi-map: Maps a Requester ID to an MSI controller and associated
	msi-specifier data. See ./pci-msi.txt
- interrupts: Three interrupt entries must be specified.
- interrupt-names: Must include the following names
	- "sys"
	- "legacy"
	- "client"
- resets: Must contain seven entries for each entry in reset-names.
	   See ../reset/reset.txt for details.
- reset-names: Must include the following names
	- "core"
	- "mgmt"
	- "mgmt-sticky"
	- "pipe"
	- "pm"
	- "aclk"
	- "pclk"
- pinctrl-names : The pin control state names
- pinctrl-0: The "default" pinctrl state
- #interrupt-cells: specifies the number of cells needed to encode an
	interrupt source. The value must be 1.
- interrupt-map-mask and interrupt-map: standard PCI properties

Required properties for legacy PHY model (deprecated):
- phys: From PHY bindings: Phandle for the Generic PHY for PCIe.
- phy-names:  MUST be "pcie-phy".

Required properties for per-lane PHY model (preferred):
- phys: Must contain an phandle to a PHY for each entry in phy-names.
- phy-names: Must include 4 entries for all 4 lanes even if some of
  them won't be used for your cases. Entries are of the form "pcie-phy-N":
  where N ranges from 0 to 3.
  (see example below and you MUST also refer to ../phy/rockchip-pcie-phy.txt
  for changing the #phy-cells of phy node to support it)

Optional Property:
- aspm-no-l0s: RC won't support ASPM L0s. This property is needed if
	using 24MHz OSC for RC's PHY.
- ep-gpios: contain the entry for pre-reset gpio
- num-lanes: number of lanes to use
- vpcie12v-supply: The phandle to the 12v regulator to use for PCIe.
- vpcie3v3-supply: The phandle to the 3.3v regulator to use for PCIe.
- vpcie1v8-supply: The phandle to the 1.8v regulator to use for PCIe.
- vpcie0v9-supply: The phandle to the 0.9v regulator to use for PCIe.

*Interrupt controller child node*
The core controller provides a single interrupt for legacy INTx. The PCIe node
should contain an interrupt controller node as a target for the PCI
'interrupt-map' property. This node represents the domain at which the four
INTx interrupts are decoded and routed.


Required properties for Interrupt controller child node:
- interrupt-controller: identifies the node as an interrupt controller
- #address-cells: specifies the number of cells needed to encode an
	address. The value must be 0.
- #interrupt-cells: specifies the number of cells needed to encode an
	interrupt source. The value must be 1.

Example:

pcie0: pcie@f8000000 {
	compatible = "rockchip,rk3399-pcie";
	#address-cells = <3>;
	#size-cells = <2>;
	clocks = <&cru ACLK_PCIE>, <&cru ACLK_PERF_PCIE>,
		 <&cru PCLK_PCIE>, <&cru SCLK_PCIE_PM>;
	clock-names = "aclk", "aclk-perf",
		      "hclk", "pm";
	bus-range = <0x0 0x1>;
	interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH 0>,
		     <GIC_SPI 50 IRQ_TYPE_LEVEL_HIGH 0>,
		     <GIC_SPI 51 IRQ_TYPE_LEVEL_HIGH 0>;
	interrupt-names = "sys", "legacy", "client";
	assigned-clocks = <&cru SCLK_PCIEPHY_REF>;
	assigned-clock-parents = <&cru SCLK_PCIEPHY_REF100M>;
	assigned-clock-rates = <100000000>;
	ep-gpios = <&gpio3 13 GPIO_ACTIVE_HIGH>;
	ranges = <0x83000000 0x0 0xfa000000 0x0 0xfa000000 0x0 0x600000
		  0x81000000 0x0 0xfa600000 0x0 0xfa600000 0x0 0x100000>;
	num-lanes = <4>;
	msi-map = <0x0 &its 0x0 0x1000>;
	reg = <0x0 0xf8000000 0x0 0x2000000>, <0x0 0xfd000000 0x0 0x1000000>;
	reg-names = "axi-base", "apb-base";
	resets = <&cru SRST_PCIE_CORE>, <&cru SRST_PCIE_MGMT>,
		 <&cru SRST_PCIE_MGMT_STICKY>, <&cru SRST_PCIE_PIPE> ,
		 <&cru SRST_PCIE_PM>, <&cru SRST_P_PCIE>, <&cru SRST_A_PCIE>;
	reset-names = "core", "mgmt", "mgmt-sticky", "pipe",
		      "pm", "pclk", "aclk";
	/* deprecated legacy PHY model */
	phys = <&pcie_phy>;
	phy-names = "pcie-phy";
	pinctrl-names = "default";
	pinctrl-0 = <&pcie_clkreq>;
	#interrupt-cells = <1>;
	interrupt-map-mask = <0 0 0 7>;
	interrupt-map = <0 0 0 1 &pcie0_intc 0>,
			<0 0 0 2 &pcie0_intc 1>,
			<0 0 0 3 &pcie0_intc 2>,
			<0 0 0 4 &pcie0_intc 3>;
	pcie0_intc: interrupt-controller {
		interrupt-controller;
		#address-cells = <0>;
		#interrupt-cells = <1>;
	};
};

pcie0: pcie@f8000000 {
	...

	/* preferred per-lane PHY model */
	phys = <&pcie_phy 0>, <&pcie_phy 1>, <&pcie_phy 2>, <&pcie_phy 3>;
	phy-names = "pcie-phy-0", "pcie-phy-1", "pcie-phy-2", "pcie-phy-3";

	...
};