PCI: xilinx: Add Xilinx AXI PCIe Host Bridge IP driver

This is the driver for Xilinx AXI PCIe Host Bridge Soft IP.

[bhelgaas: minor whitespace fixes]
Signed-off-by: Srikanth Thokala <sthokal@xilinx.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

Documentation/devicetree/bindings/pci/xilinx-pcie.txt

+* Xilinx 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 "xlnx,axi-pcie-host-1.00.a"
+- reg: Should contain AXI PCIe registers location and length
+- device_type: must be "pci"
+- interrupts: Should contain AXI PCIe interrupt
+- interrupt-map-mask,
+  interrupt-map: standard PCI properties to define the mapping of the
+	PCI interface to interrupt numbers.
+- ranges: ranges for the PCI memory regions (I/O space region is not
+	supported by hardware)
+	Please refer to the standard PCI bus binding document for a more
+	detailed explanation
+
+Optional properties:
+- bus-range: PCI bus numbers covered
+
+Interrupt controller child node
++++++++++++++++++++++++++++++++
+Required properties:
+- 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.
+
+NOTE:
+The core provides a single interrupt for both INTx/MSI messages. So,
+created a interrupt controller node to support 'interrupt-map' DT
+functionality.  The driver will create an IRQ domain for this map, decode
+the four INTx interrupts in ISR and route them to this domain.
+
+
+Example:
+++++++++
+
+	pci_express: axi-pcie@50000000 {
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		compatible = "xlnx,axi-pcie-host-1.00.a";
+		reg = < 0x50000000 0x10000000 >;
+		device_type = "pci";
+		interrupts = < 0 52 4 >;
+		interrupt-map-mask = <0 0 0 7>;
+		interrupt-map = <0 0 0 1 &pcie_intc 1>,
+				<0 0 0 2 &pcie_intc 2>,
+				<0 0 0 3 &pcie_intc 3>,
+				<0 0 0 4 &pcie_intc 4>;
+		ranges = < 0x02000000 0 0x60000000 0x60000000 0 0x10000000 >;
+
+		pcie_intc: interrupt-controller {
+			interrupt-controller;
+			#address-cells = <0>;
+			#interrupt-cells = <1>;
+		}
+	};

drivers/pci/host/Kconfig

@@ -63,4 +63,11 @@ config PCIE_SPEAR13XX
 	help
 	  Say Y here if you want PCIe support on SPEAr13XX SoCs.
 
+config PCIE_XILINX
+	bool "Xilinx AXI PCIe host bridge support"
+	depends on ARCH_ZYNQ
+	help
+	  Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
+	  Host Bridge driver.
+
 endmenu

drivers/pci/host/Makefile

@@ -8,3 +8,4 @@ obj-$(CONFIG_PCI_RCAR_GEN2) += pci-rcar-gen2.o
 obj-$(CONFIG_PCI_RCAR_GEN2_PCIE) += pcie-rcar.o
 obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
+obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o