pci: Add PCIe driver for Samsung Exynos

Exynos5440 has a PCIe controller which can be used as Root Complex.
This driver supports a PCIe controller as Root Complex mode.
Signed-off-by: Surendranath Gurivireddy Balla <suren.reddy@samsung.com>
Signed-off-by: Siva Reddy Kallam <siva.kallam@samsung.com>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Pratyush Anand <pratyush.anand@st.com>
Cc: Mohit KUMAR <Mohit.KUMAR@st.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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

+* Synopsis Designware PCIe interface
+
+Required properties:
+- compatible: should contain "snps,dw-pcie" to identify the
+	core, plus an identifier for the specific instance, such
+	as "samsung,exynos5440-pcie".
+- reg: base addresses and lengths of the pcie controller,
+	the phy controller, additional register for the phy controller.
+- interrupts: interrupt values for level interrupt,
+	pulse interrupt, special interrupt.
+- clocks: from common clock binding: handle to pci clock.
+- clock-names: from common clock binding: should be "pcie" and "pcie_bus".
+- #address-cells: set to <3>
+- #size-cells: set to <2>
+- device_type: set to "pci"
+- ranges: ranges for the PCI memory and I/O regions
+- #interrupt-cells: set to <1>
+- interrupt-map-mask and interrupt-map: standard PCI properties
+	to define the mapping of the PCIe interface to interrupt
+	numbers.
+- reset-gpio: gpio pin number of power good signal
+
+Example:
+
+SoC specific DT Entry:
+
+	pcie@290000 {
+		compatible = "samsung,exynos5440-pcie", "snps,dw-pcie";
+		reg = <0x290000 0x1000
+			0x270000 0x1000
+			0x271000 0x40>;
+		interrupts = <0 20 0>, <0 21 0>, <0 22 0>;
+		clocks = <&clock 28>, <&clock 27>;
+		clock-names = "pcie", "pcie_bus";
+		#address-cells = <3>;
+		#size-cells = <2>;
+		device_type = "pci";
+		ranges = <0x00000800 0 0x40000000 0x40000000 0 0x00001000   /* configuration space */
+			  0x81000000 0 0	  0x40001000 0 0x00010000   /* downstream I/O */
+			  0x82000000 0 0x40011000 0x40011000 0 0x1ffef000>; /* non-prefetchable memory */
+		#interrupt-cells = <1>;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0x0 0 &gic 53>;
+	};
+
+	pcie@2a0000 {
+		compatible = "samsung,exynos5440-pcie", "snps,dw-pcie";
+		reg = <0x2a0000 0x1000
+			0x272000 0x1000
+			0x271040 0x40>;
+		interrupts = <0 23 0>, <0 24 0>, <0 25 0>;
+		clocks = <&clock 29>, <&clock 27>;
+		clock-names = "pcie", "pcie_bus";
+		#address-cells = <3>;
+		#size-cells = <2>;
+		device_type = "pci";
+		ranges = <0x00000800 0 0x60000000 0x60000000 0 0x00001000   /* configuration space */
+			  0x81000000 0 0	  0x60001000 0 0x00010000   /* downstream I/O */
+			  0x82000000 0 0x60011000 0x60011000 0 0x1ffef000>; /* non-prefetchable memory */
+		#interrupt-cells = <1>;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0x0 0 &gic 56>;
+	};
+
+Board specific DT Entry:
+
+	pcie@290000 {
+		reset-gpio = <&pin_ctrl 5 0>;
+	};
+
+	pcie@2a0000 {
+		reset-gpio = <&pin_ctrl 22 0>;
+	};

drivers/pci/host/Kconfig

@@ -5,4 +5,13 @@ config PCI_MVEBU
 	bool "Marvell EBU PCIe controller"
 	depends on ARCH_MVEBU || ARCH_KIRKWOOD
 
+config PCIE_DW
+	bool
+
+config PCI_EXYNOS
+	bool "Samsung Exynos PCIe controller"
+	depends on SOC_EXYNOS5440
+	select PCIEPORTBUS
+	select PCIE_DW
+
 endmenu

drivers/pci/host/Makefile

 obj-$(CONFIG_PCI_MVEBU) += pci-mvebu.o
+obj-$(CONFIG_PCIE_DW) += pcie-designware.o