pci: PCIe driver for Marvell Armada 370/XP systems

This driver implements the support for the PCIe interfaces on the
Marvell Armada 370/XP ARM SoCs. In the future, it might be extended to
cover earlier families of Marvell SoCs, such as Dove, Orion and
Kirkwood.

The driver implements the hw_pci operations needed by the core ARM PCI
code to setup PCI devices and get their corresponding IRQs, and the
pci_ops operations that are used by the PCI core to read/write the
configuration space of PCI devices.

Since the PCIe interfaces of Marvell SoCs are completely separate and
not linked together in a bus, this driver sets up an emulated PCI host
bridge, with one PCI-to-PCI bridge as child for each hardware PCIe
interface.

In addition, this driver enumerates the different PCIe slots, and for
those having a device plugged in, it sets up the necessary address
decoding windows, using the mvebu-mbus driver.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

Documentation/devicetree/bindings/pci/mvebu-pci.txt

+* Marvell EBU PCIe interfaces
+
+Mandatory properties:
+- compatible: one of the following values:
+    marvell,armada-370-pcie
+    marvell,armada-xp-pcie
+- #address-cells, set to <3>
+- #size-cells, set to <2>
+- #interrupt-cells, set to <1>
+- bus-range: PCI bus numbers covered
+- device_type, set to "pci"
+- ranges: ranges for the PCI memory and I/O regions, as well as the
+  MMIO registers to control the PCIe interfaces.
+
+In addition, the Device Tree node must have sub-nodes describing each
+PCIe interface, having the following mandatory properties:
+- reg: used only for interrupt mapping, so only the first four bytes
+  are used to refer to the correct bus number and device number.
+- assigned-addresses: reference to the MMIO registers used to control
+  this PCIe interface.
+- clocks: the clock associated to this PCIe interface
+- marvell,pcie-port: the physical PCIe port number
+- status: either "disabled" or "okay"
+- device_type, set to "pci"
+- #address-cells, set to <3>
+- #size-cells, set to <2>
+- #interrupt-cells, set to <1>
+- ranges, empty property.
+- interrupt-map-mask and interrupt-map, standard PCI properties to
+  define the mapping of the PCIe interface to interrupt numbers.
+
+and the following optional properties:
+- marvell,pcie-lane: the physical PCIe lane number, for ports having
+  multiple lanes. If this property is not found, we assume that the
+  value is 0.
+
+Example:
+
+pcie-controller {
+	compatible = "marvell,armada-xp-pcie";
+	status = "disabled";
+	device_type = "pci";
+
+	#address-cells = <3>;
+	#size-cells = <2>;
+
+	bus-range = <0x00 0xff>;
+
+	ranges = <0x82000000 0 0xd0040000 0xd0040000 0 0x00002000   /* Port 0.0 registers */
+		  0x82000000 0 0xd0042000 0xd0042000 0 0x00002000   /* Port 2.0 registers */
+		  0x82000000 0 0xd0044000 0xd0044000 0 0x00002000   /* Port 0.1 registers */
+		  0x82000000 0 0xd0048000 0xd0048000 0 0x00002000   /* Port 0.2 registers */
+		  0x82000000 0 0xd004c000 0xd004c000 0 0x00002000   /* Port 0.3 registers */
+		  0x82000000 0 0xd0080000 0xd0080000 0 0x00002000   /* Port 1.0 registers */
+		  0x82000000 0 0xd0082000 0xd0082000 0 0x00002000   /* Port 3.0 registers */
+		  0x82000000 0 0xd0084000 0xd0084000 0 0x00002000   /* Port 1.1 registers */
+		  0x82000000 0 0xd0088000 0xd0088000 0 0x00002000   /* Port 1.2 registers */
+		  0x82000000 0 0xd008c000 0xd008c000 0 0x00002000   /* Port 1.3 registers */
+		  0x82000000 0 0xe0000000 0xe0000000 0 0x08000000   /* non-prefetchable memory */
+		  0x81000000 0 0	  0xe8000000 0 0x00100000>; /* downstream I/O */
+
+	pcie@1,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82000800 0 0xd0040000 0 0x2000>;
+		reg = <0x0800 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 58>;
+		marvell,pcie-port = <0>;
+		marvell,pcie-lane = <0>;
+		clocks = <&gateclk 5>;
+		status = "disabled";
+	};
+
+	pcie@2,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82001000 0 0xd0044000 0 0x2000>;
+		reg = <0x1000 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 59>;
+		marvell,pcie-port = <0>;
+		marvell,pcie-lane = <1>;
+		clocks = <&gateclk 6>;
+		status = "disabled";
+	};
+
+	pcie@3,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82001800 0 0xd0048000 0 0x2000>;
+		reg = <0x1800 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 60>;
+		marvell,pcie-port = <0>;
+		marvell,pcie-lane = <2>;
+		clocks = <&gateclk 7>;
+		status = "disabled";
+	};
+
+	pcie@4,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82002000 0 0xd004c000 0 0x2000>;
+		reg = <0x2000 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 61>;
+		marvell,pcie-port = <0>;
+		marvell,pcie-lane = <3>;
+		clocks = <&gateclk 8>;
+		status = "disabled";
+	};
+
+	pcie@5,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82002800 0 0xd0080000 0 0x2000>;
+		reg = <0x2800 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 62>;
+		marvell,pcie-port = <1>;
+		marvell,pcie-lane = <0>;
+		clocks = <&gateclk 9>;
+		status = "disabled";
+	};
+
+	pcie@6,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82003000 0 0xd0084000 0 0x2000>;
+		reg = <0x3000 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 63>;
+		marvell,pcie-port = <1>;
+		marvell,pcie-lane = <1>;
+		clocks = <&gateclk 10>;
+		status = "disabled";
+	};
+
+	pcie@7,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82003800 0 0xd0088000 0 0x2000>;
+		reg = <0x3800 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 64>;
+		marvell,pcie-port = <1>;
+		marvell,pcie-lane = <2>;
+		clocks = <&gateclk 11>;
+		status = "disabled";
+	};
+
+	pcie@8,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82004000 0 0xd008c000 0 0x2000>;
+		reg = <0x4000 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 65>;
+		marvell,pcie-port = <1>;
+		marvell,pcie-lane = <3>;
+		clocks = <&gateclk 12>;
+		status = "disabled";
+	};
+	pcie@9,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82004800 0 0xd0042000 0 0x2000>;
+		reg = <0x4800 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 99>;
+		marvell,pcie-port = <2>;
+		marvell,pcie-lane = <0>;
+		clocks = <&gateclk 26>;
+		status = "disabled";
+	};
+
+	pcie@10,0 {
+		device_type = "pci";
+		assigned-addresses = <0x82005000 0 0xd0082000 0 0x2000>;
+		reg = <0x5000 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		#interrupt-cells = <1>;
+		ranges;
+		interrupt-map-mask = <0 0 0 0>;
+		interrupt-map = <0 0 0 0 &mpic 103>;
+		marvell,pcie-port = <3>;
+		marvell,pcie-lane = <0>;
+		clocks = <&gateclk 27>;
+		status = "disabled";
+	};
+};

drivers/pci/Kconfig

@@ -119,3 +119,5 @@ config PCI_IOAPIC
 config PCI_LABEL
 	def_bool y if (DMI || ACPI)
 	select NLS
+
+source "drivers/pci/host/Kconfig"

drivers/pci/Makefile

@@ -67,3 +67,6 @@ obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o
 obj-$(CONFIG_OF) += of.o
 
 ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG
+
+# PCI host controller drivers
+obj-y += host/

drivers/pci/host/Kconfig

+menu "PCI host controller drivers"
+	depends on PCI
+
+config PCI_MVEBU
+	bool "Marvell EBU PCIe controller"
+	depends on ARCH_MVEBU
+
+endmenu

drivers/pci/host/Makefile

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

drivers/pci/host/pci-mvebu.c

+/*
+ * PCIe driver for Marvell Armada 370 and Armada XP SoCs
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/mbus.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+/*
+ * PCIe unit register offsets.
+ */
+#define PCIE_DEV_ID_OFF		0x0000
+#define PCIE_CMD_OFF		0x0004
+#define PCIE_DEV_REV_OFF	0x0008
+#define PCIE_BAR_LO_OFF(n)	(0x0010 + ((n) << 3))
+#define PCIE_BAR_HI_OFF(n)	(0x0014 + ((n) << 3))
+#define PCIE_HEADER_LOG_4_OFF	0x0128
+#define PCIE_BAR_CTRL_OFF(n)	(0x1804 + (((n) - 1) * 4))
+#define PCIE_WIN04_CTRL_OFF(n)	(0x1820 + ((n) << 4))
+#define PCIE_WIN04_BASE_OFF(n)	(0x1824 + ((n) << 4))
+#define PCIE_WIN04_REMAP_OFF(n)	(0x182c + ((n) << 4))
+#define PCIE_WIN5_CTRL_OFF	0x1880
+#define PCIE_WIN5_BASE_OFF	0x1884
+#define PCIE_WIN5_REMAP_OFF	0x188c
+#define PCIE_CONF_ADDR_OFF	0x18f8
+#define  PCIE_CONF_ADDR_EN		0x80000000
+#define  PCIE_CONF_REG(r)		((((r) & 0xf00) << 16) | ((r) & 0xfc))
+#define  PCIE_CONF_BUS(b)		(((b) & 0xff) << 16)
+#define  PCIE_CONF_DEV(d)		(((d) & 0x1f) << 11)
+#define  PCIE_CONF_FUNC(f)		(((f) & 0x7) << 8)
+#define  PCIE_CONF_ADDR(bus, devfn, where) \
+	(PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn))    | \
+	 PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where) | \
+	 PCIE_CONF_ADDR_EN)
+#define PCIE_CONF_DATA_OFF	0x18fc
+#define PCIE_MASK_OFF		0x1910
+#define  PCIE_MASK_ENABLE_INTS          0x0f000000
+#define PCIE_CTRL_OFF		0x1a00
+#define  PCIE_CTRL_X1_MODE		0x0001
+#define PCIE_STAT_OFF		0x1a04
+#define  PCIE_STAT_BUS                  0xff00
+#define  PCIE_STAT_LINK_DOWN		BIT(0)
+#define PCIE_DEBUG_CTRL         0x1a60
+#define  PCIE_DEBUG_SOFT_RESET		BIT(20)
+
+/*
+ * This product ID is registered by Marvell, and used when the Marvell
+ * SoC is not the root complex, but an endpoint on the PCIe bus. It is
+ * therefore safe to re-use this PCI ID for our emulated PCI-to-PCI
+ * bridge.
+ */
+#define MARVELL_EMULATED_PCI_PCI_BRIDGE_ID 0x7846
+
+/* PCI configuration space of a PCI-to-PCI bridge */
+struct mvebu_sw_pci_bridge {
+	u16 vendor;
+	u16 device;
+	u16 command;
+	u16 status;
+	u16 class;
+	u8 interface;
+	u8 revision;
+	u8 bist;
+	u8 header_type;
+	u8 latency_timer;
+	u8 cache_line_size;
+	u32 bar[2];
+	u8 primary_bus;
+	u8 secondary_bus;
+	u8 subordinate_bus;
+	u8 secondary_latency_timer;
+	u8 iobase;
+	u8 iolimit;
+	u16 secondary_status;
+	u16 membase;
+	u16 memlimit;
+	u16 prefmembase;
+	u16 prefmemlimit;
+	u32 prefbaseupper;
+	u32 preflimitupper;
+	u16 iobaseupper;
+	u16 iolimitupper;
+	u8 cappointer;
+	u8 reserved1;
+	u16 reserved2;
+	u32 romaddr;
+	u8 intline;
+	u8 intpin;
+	u16 bridgectrl;
+};
+
+struct mvebu_pcie_port;
+
+/* Structure representing all PCIe interfaces */
+struct mvebu_pcie {
+	struct platform_device *pdev;
+	struct mvebu_pcie_port *ports;
+	struct resource io;
+	struct resource realio;
+	struct resource mem;
+	struct resource busn;
+	int nports;
+};
+
+/* Structure representing one PCIe interface */
+struct mvebu_pcie_port {
+	char *name;
+	void __iomem *base;
+	spinlock_t conf_lock;
+	int haslink;
+	u32 port;
+	u32 lane;
+	int devfn;
+	struct clk *clk;
+	struct mvebu_sw_pci_bridge bridge;
+	struct device_node *dn;
+	struct mvebu_pcie *pcie;
+	phys_addr_t memwin_base;
+	size_t memwin_size;
+	phys_addr_t iowin_base;
+	size_t iowin_size;
+};
+
+static bool mvebu_pcie_link_up(struct mvebu_pcie_port *port)
+{
+	return !(readl(port->base + PCIE_STAT_OFF) & PCIE_STAT_LINK_DOWN);
+}
+
+static void mvebu_pcie_set_local_bus_nr(struct mvebu_pcie_port *port, int nr)
+{
+	u32 stat;
+
+	stat = readl(port->base + PCIE_STAT_OFF);
+	stat &= ~PCIE_STAT_BUS;
+	stat |= nr << 8;
+	writel(stat, port->base + PCIE_STAT_OFF);
+}
+
+/*
+ * Setup PCIE BARs and Address Decode Wins:
+ * BAR[0,2] -> disabled, BAR[1] -> covers all DRAM banks
+ * WIN[0-3] -> DRAM bank[0-3]
+ */
+static void __init mvebu_pcie_setup_wins(struct mvebu_pcie_port *port)
+{
+	const struct mbus_dram_target_info *dram;
+	u32 size;
+	int i;
+
+	dram = mv_mbus_dram_info();
+
+	/* First, disable and clear BARs and windows. */
+	for (i = 1; i < 3; i++) {
+		writel(0, port->base + PCIE_BAR_CTRL_OFF(i));
+		writel(0, port->base + PCIE_BAR_LO_OFF(i));
+		writel(0, port->base + PCIE_BAR_HI_OFF(i));
+	}
+
+	for (i = 0; i < 5; i++) {
+		writel(0, port->base + PCIE_WIN04_CTRL_OFF(i));
+		writel(0, port->base + PCIE_WIN04_BASE_OFF(i));
+		writel(0, port->base + PCIE_WIN04_REMAP_OFF(i));
+	}
+
+	writel(0, port->base + PCIE_WIN5_CTRL_OFF);
+	writel(0, port->base + PCIE_WIN5_BASE_OFF);
+	writel(0, port->base + PCIE_WIN5_REMAP_OFF);
+
+	/* Setup windows for DDR banks.  Count total DDR size on the fly. */
+	size = 0;
+	for (i = 0; i < dram->num_cs; i++) {
+		const struct mbus_dram_window *cs = dram->cs + i;
+
+		writel(cs->base & 0xffff0000,
+		       port->base + PCIE_WIN04_BASE_OFF(i));
+		writel(0, port->base + PCIE_WIN04_REMAP_OFF(i));
+		writel(((cs->size - 1) & 0xffff0000) |
+			(cs->mbus_attr << 8) |
+			(dram->mbus_dram_target_id << 4) | 1,
+		       port->base + PCIE_WIN04_CTRL_OFF(i));
+
+		size += cs->size;
+	}
+
+	/* Round up 'size' to the nearest power of two. */
+	if ((size & (size - 1)) != 0)
+		size = 1 << fls(size);
+
+	/* Setup BAR[1] to all DRAM banks. */
+	writel(dram->cs[0].base, port->base + PCIE_BAR_LO_OFF(1));
+	writel(0, port->base + PCIE_BAR_HI_OFF(1));
+	writel(((size - 1) & 0xffff0000) | 1,
+	       port->base + PCIE_BAR_CTRL_OFF(1));
+}
+
+static void __init mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
+{
+	u16 cmd;
+	u32 mask;
+
+	/* Point PCIe unit MBUS decode windows to DRAM space. */
+	mvebu_pcie_setup_wins(port);
+
+	/* Master + slave enable. */
+	cmd = readw(port->base + PCIE_CMD_OFF);
+	cmd |= PCI_COMMAND_IO;
+	cmd |= PCI_COMMAND_MEMORY;
+	cmd |= PCI_COMMAND_MASTER;
+	writew(cmd, port->base + PCIE_CMD_OFF);
+
+	/* Enable interrupt lines A-D. */
+	mask = readl(port->base + PCIE_MASK_OFF);
+	mask |= PCIE_MASK_ENABLE_INTS;
+	writel(mask, port->base + PCIE_MASK_OFF);
+}
+
+static int mvebu_pcie_hw_rd_conf(struct mvebu_pcie_port *port,
+				 struct pci_bus *bus,
+				 u32 devfn, int where, int size, u32 *val)
+{
+	writel(PCIE_CONF_ADDR(bus->number, devfn, where),
+	       port->base + PCIE_CONF_ADDR_OFF);
+
+	*val = readl(port->base + PCIE_CONF_DATA_OFF);
+
+	if (size == 1)
+		*val = (*val >> (8 * (where & 3))) & 0xff;
+	else if (size == 2)
+		*val = (*val >> (8 * (where & 3))) & 0xffff;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int mvebu_pcie_hw_wr_conf(struct mvebu_pcie_port *port,
+				 struct pci_bus *bus,
+				 u32 devfn, int where, int size, u32 val)
+{
+	int ret = PCIBIOS_SUCCESSFUL;
+
+	writel(PCIE_CONF_ADDR(bus->number, devfn, where),
+	       port->base + PCIE_CONF_ADDR_OFF);
+
+	if (size == 4)
+		writel(val, port->base + PCIE_CONF_DATA_OFF);
+	else if (size == 2)
+		writew(val, port->base + PCIE_CONF_DATA_OFF + (where & 3));
+	else if (size == 1)
+		writeb(val, port->base + PCIE_CONF_DATA_OFF + (where & 3));
+	else
+		ret = PCIBIOS_BAD_REGISTER_NUMBER;
+
+	return ret;
+}
+
+static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
+{
+	phys_addr_t iobase;
+
+	/* Are the new iobase/iolimit values invalid? */
+	if (port->bridge.iolimit < port->bridge.iobase ||
+	    port->bridge.iolimitupper < port->bridge.iobaseupper) {
+
+		/* If a window was configured, remove it */
+		if (port->iowin_base) {
+			mvebu_mbus_del_window(port->iowin_base,
+					      port->iowin_size);
+			port->iowin_base = 0;
+			port->iowin_size = 0;
+		}
+
+		return;
+	}
+
+	/*
+	 * We read the PCI-to-PCI bridge emulated registers, and
+	 * calculate the base address and size of the address decoding
+	 * window to setup, according to the PCI-to-PCI bridge
+	 * specifications. iobase is the bus address, port->iowin_base
+	 * is the CPU address.
+	 */
+	iobase = ((port->bridge.iobase & 0xF0) << 8) |
+		(port->bridge.iobaseupper << 16);
+	port->iowin_base = port->pcie->io.start + iobase;
+	port->iowin_size = ((0xFFF | ((port->bridge.iolimit & 0xF0) << 8) |
+			    (port->bridge.iolimitupper << 16)) -
+			    iobase);
+
+	mvebu_mbus_add_window_remap_flags(port->name, port->iowin_base,
+					  port->iowin_size,
+					  iobase,
+					  MVEBU_MBUS_PCI_IO);
+
+	pci_ioremap_io(iobase, port->iowin_base);
+}
+
+static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
+{
+	/* Are the new membase/memlimit values invalid? */
+	if (port->bridge.memlimit < port->bridge.membase) {
+
+		/* If a window was configured, remove it */
+		if (port->memwin_base) {
+			mvebu_mbus_del_window(port->memwin_base,
+					      port->memwin_size);
+			port->memwin_base = 0;
+			port->memwin_size = 0;
+		}
+
+		return;
+	}
+
+	/*
+	 * We read the PCI-to-PCI bridge emulated registers, and
+	 * calculate the base address and size of the address decoding
+	 * window to setup, according to the PCI-to-PCI bridge
+	 * specifications.
+	 */
+	port->memwin_base  = ((port->bridge.membase & 0xFFF0) << 16);
+	port->memwin_size  =
+		(((port->bridge.memlimit & 0xFFF0) << 16) | 0xFFFFF) -
+		port->memwin_base;
+
+	mvebu_mbus_add_window_remap_flags(port->name, port->memwin_base,
+					  port->memwin_size,
+					  MVEBU_MBUS_NO_REMAP,
+					  MVEBU_MBUS_PCI_MEM);
+}
+
+/*
+ * Initialize the configuration space of the PCI-to-PCI bridge
+ * associated with the given PCIe interface.
+ */
+static void mvebu_sw_pci_bridge_init(struct mvebu_pcie_port *port)
+{
+	struct mvebu_sw_pci_bridge *bridge = &port->bridge;
+
+	memset(bridge, 0, sizeof(struct mvebu_sw_pci_bridge));
+
+	bridge->status = PCI_STATUS_CAP_LIST;
+	bridge->class = PCI_CLASS_BRIDGE_PCI;
+	bridge->vendor = PCI_VENDOR_ID_MARVELL;
+	bridge->device = MARVELL_EMULATED_PCI_PCI_BRIDGE_ID;
+	bridge->header_type = PCI_HEADER_TYPE_BRIDGE;
+	bridge->cache_line_size = 0x10;
+
+	/* We support 32 bits I/O addressing */
+	bridge->iobase = PCI_IO_RANGE_TYPE_32;
+	bridge->iolimit = PCI_IO_RANGE_TYPE_32;
+}
+
+/*
+ * Read the configuration space of the PCI-to-PCI bridge associated to
+ * the given PCIe interface.
+ */
+static int mvebu_sw_pci_bridge_read(struct mvebu_pcie_port *port,
+				  unsigned int where, int size, u32 *value)
+{
+	struct mvebu_sw_pci_bridge *bridge = &port->bridge;
+
+	switch (where & ~3) {
+	case PCI_VENDOR_ID:
+		*value = bridge->device << 16 | bridge->vendor;
+		break;
+
+	case PCI_COMMAND:
+		*value = bridge->status << 16 | bridge->command;
+		break;
+
+	case PCI_CLASS_REVISION:
+		*value = bridge->class << 16 | bridge->interface << 8 |
+			 bridge->revision;
+		break;
+
+	case PCI_CACHE_LINE_SIZE:
+		*value = bridge->bist << 24 | bridge->header_type << 16 |
+			 bridge->latency_timer << 8 | bridge->cache_line_size;
+		break;
+
+	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1:
+		*value = bridge->bar[((where & ~3) - PCI_BASE_ADDRESS_0) / 4];
+		break;
+
+	case PCI_PRIMARY_BUS:
+		*value = (bridge->secondary_latency_timer << 24 |
+			  bridge->subordinate_bus         << 16 |
+			  bridge->secondary_bus           <<  8 |
+			  bridge->primary_bus);
+		break;
+
+	case PCI_IO_BASE:
+		*value = (bridge->secondary_status << 16 |
+			  bridge->iolimit          <<  8 |
+			  bridge->iobase);
+		break;
+
+	case PCI_MEMORY_BASE:
+		*value = (bridge->memlimit << 16 | bridge->membase);
+		break;
+
+	case PCI_PREF_MEMORY_BASE:
+		*value = (bridge->prefmemlimit << 16 | bridge->prefmembase);
+		break;
+
+	case PCI_PREF_BASE_UPPER32:
+		*value = bridge->prefbaseupper;
+		break;
+
+	case PCI_PREF_LIMIT_UPPER32:
+		*value = bridge->preflimitupper;
+		break;
+
+	case PCI_IO_BASE_UPPER16:
+		*value = (bridge->iolimitupper << 16 | bridge->iobaseupper);
+		break;
+
+	case PCI_ROM_ADDRESS1:
+		*value = 0;
+		break;
+
+	default:
+		*value = 0xffffffff;
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	if (size == 2)
+		*value = (*value >> (8 * (where & 3))) & 0xffff;
+	else if (size == 1)
+		*value = (*value >> (8 * (where & 3))) & 0xff;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+/* Write to the PCI-to-PCI bridge configuration space */
+static int mvebu_sw_pci_bridge_write(struct mvebu_pcie_port *port,
+				     unsigned int where, int size, u32 value)
+{
+	struct mvebu_sw_pci_bridge *bridge = &port->bridge;
+	u32 mask, reg;
+	int err;
+
+	if (size == 4)
+		mask = 0x0;
+	else if (size == 2)
+		mask = ~(0xffff << ((where & 3) * 8));
+	else if (size == 1)
+		mask = ~(0xff << ((where & 3) * 8));
+	else
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	err = mvebu_sw_pci_bridge_read(port, where & ~3, 4, &reg);
+	if (err)
+		return err;
+
+	value = (reg & mask) | value << ((where & 3) * 8);
+
+	switch (where & ~3) {
+	case PCI_COMMAND:
+		bridge->command = value & 0xffff;
+		bridge->status = value >> 16;
+		break;
+
+	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_1:
+		bridge->bar[((where & ~3) - PCI_BASE_ADDRESS_0) / 4] = value;
+		break;
+
+	case PCI_IO_BASE:
+		/*
+		 * We also keep bit 1 set, it is a read-only bit that
+		 * indicates we support 32 bits addressing for the
+		 * I/O
+		 */
+		bridge->iobase = (value & 0xff) | PCI_IO_RANGE_TYPE_32;
+		bridge->iolimit = ((value >> 8) & 0xff) | PCI_IO_RANGE_TYPE_32;
+		bridge->secondary_status = value >> 16;
+		mvebu_pcie_handle_iobase_change(port);
+		break;
+
+	case PCI_MEMORY_BASE:
+		bridge->membase = value & 0xffff;
+		bridge->memlimit = value >> 16;
+		mvebu_pcie_handle_membase_change(port);
+		break;
+
+	case PCI_PREF_MEMORY_BASE:
+		bridge->prefmembase = value & 0xffff;
+		bridge->prefmemlimit = value >> 16;
+		break;
+
+	case PCI_PREF_BASE_UPPER32:
+		bridge->prefbaseupper = value;
+		break;
+
+	case PCI_PREF_LIMIT_UPPER32:
+		bridge->preflimitupper = value;
+		break;
+
+	case PCI_IO_BASE_UPPER16:
+		bridge->iobaseupper = value & 0xffff;
+		bridge->iolimitupper = value >> 16;
+		mvebu_pcie_handle_iobase_change(port);
+		break;
+
+	case PCI_PRIMARY_BUS:
+		bridge->primary_bus             = value & 0xff;
+		bridge->secondary_bus           = (value >> 8) & 0xff;
+		bridge->subordinate_bus         = (value >> 16) & 0xff;
+		bridge->secondary_latency_timer = (value >> 24) & 0xff;
+		mvebu_pcie_set_local_bus_nr(port, bridge->secondary_bus);
+		break;
+
+	default:
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static inline struct mvebu_pcie *sys_to_pcie(struct pci_sys_data *sys)
+{
+	return sys->private_data;
+}
+
+static struct mvebu_pcie_port *
+mvebu_pcie_find_port(struct mvebu_pcie *pcie, struct pci_bus *bus,
+		     int devfn)
+{
+	int i;
+
+	for (i = 0; i < pcie->nports; i++) {
+		struct mvebu_pcie_port *port = &pcie->ports[i];
+		if (bus->number == 0 && port->devfn == devfn)
+			return port;
+		if (bus->number != 0 &&
+		    port->bridge.secondary_bus == bus->number)
+			return port;
+	}
+
+	return NULL;
+}
+
+/* PCI configuration space write function */
+static int mvebu_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
+			      int where, int size, u32 val)
+{
+	struct mvebu_pcie *pcie = sys_to_pcie(bus->sysdata);
+	struct mvebu_pcie_port *port;
+	unsigned long flags;
+	int ret;
+
+	port = mvebu_pcie_find_port(pcie, bus, devfn);
+	if (!port)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/* Access the emulated PCI-to-PCI bridge */
+	if (bus->number == 0)
+		return mvebu_sw_pci_bridge_write(port, where, size, val);
+
+	if (!port->haslink || PCI_SLOT(devfn) != 0)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/* Access the real PCIe interface */
+	spin_lock_irqsave(&port->conf_lock, flags);
+	ret = mvebu_pcie_hw_wr_conf(port, bus,
+				    PCI_DEVFN(1, PCI_FUNC(devfn)),
+				    where, size, val);
+	spin_unlock_irqrestore(&port->conf_lock, flags);
+
+	return ret;
+}
+
+/* PCI configuration space read function */
+static int mvebu_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
+			      int size, u32 *val)
+{
+	struct mvebu_pcie *pcie = sys_to_pcie(bus->sysdata);
+	struct mvebu_pcie_port *port;
+	unsigned long flags;
+	int ret;
+
+	port = mvebu_pcie_find_port(pcie, bus, devfn);
+	if (!port) {
+		*val = 0xffffffff;
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	}
+
+	/* Access the emulated PCI-to-PCI bridge */
+	if (bus->number == 0)
+		return mvebu_sw_pci_bridge_read(port, where, size, val);
+
+	if (!port->haslink || PCI_SLOT(devfn) != 0) {
+		*val = 0xffffffff;
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	}
+
+	/* Access the real PCIe interface */
+	spin_lock_irqsave(&port->conf_lock, flags);
+	ret = mvebu_pcie_hw_rd_conf(port, bus,
+				    PCI_DEVFN(1, PCI_FUNC(devfn)),
+				    where, size, val);
+	spin_unlock_irqrestore(&port->conf_lock, flags);
+
+	return ret;
+}
+
+static struct pci_ops mvebu_pcie_ops = {
+	.read = mvebu_pcie_rd_conf,
+	.write = mvebu_pcie_wr_conf,
+};
+
+static int __init mvebu_pcie_setup(int nr, struct pci_sys_data *sys)
+{
+	struct mvebu_pcie *pcie = sys_to_pcie(sys);
+	int i;
+
+	pci_add_resource_offset(&sys->resources, &pcie->realio, sys->io_offset);
+	pci_add_resource_offset(&sys->resources, &pcie->mem, sys->mem_offset);
+	pci_add_resource(&sys->resources, &pcie->busn);
+
+	for (i = 0; i < pcie->nports; i++) {
+		struct mvebu_pcie_port *port = &pcie->ports[i];
+		mvebu_pcie_setup_hw(port);
+	}
+
+	return 1;
+}
+
+static int __init mvebu_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct of_irq oirq;
+	int ret;
+
+	ret = of_irq_map_pci(dev, &oirq);
+	if (ret)
+		return ret;
+
+	return irq_create_of_mapping(oirq.controller, oirq.specifier,
+				     oirq.size);
+}
+
+static struct pci_bus *mvebu_pcie_scan_bus(int nr, struct pci_sys_data *sys)
+{
+	struct mvebu_pcie *pcie = sys_to_pcie(sys);
+	struct pci_bus *bus;
+
+	bus = pci_create_root_bus(&pcie->pdev->dev, sys->busnr,
+				  &mvebu_pcie_ops, sys, &sys->resources);
+	if (!bus)
+		return NULL;
+
+	pci_scan_child_bus(bus);
+
+	return bus;
+}
+
+resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
+					  const struct resource *res,
+					  resource_size_t start,
+					  resource_size_t size,
+					  resource_size_t align)
+{
+	if (dev->bus->number != 0)
+		return start;
+
+	/*
+	 * On the PCI-to-PCI bridge side, the I/O windows must have at
+	 * least a 64 KB size and be aligned on their size, and the
+	 * memory windows must have at least a 1 MB size and be
+	 * aligned on their size
+	 */
+	if (res->flags & IORESOURCE_IO)
+		return round_up(start, max((resource_size_t)SZ_64K, size));
+	else if (res->flags & IORESOURCE_MEM)
+		return round_up(start, max((resource_size_t)SZ_1M, size));
+	else
+		return start;
+}
+
+static void __init mvebu_pcie_enable(struct mvebu_pcie *pcie)
+{
+	struct hw_pci hw;
+
+	memset(&hw, 0, sizeof(hw));
+
+	hw.nr_controllers = 1;
+	hw.private_data   = (void **)&pcie;
+	hw.setup          = mvebu_pcie_setup;
+	hw.scan           = mvebu_pcie_scan_bus;
+	hw.map_irq        = mvebu_pcie_map_irq;
+	hw.ops            = &mvebu_pcie_ops;
+	hw.align_resource = mvebu_pcie_align_resource;
+
+	pci_common_init(&hw);
+}
+
+/*
+ * Looks up the list of register addresses encoded into the reg =
+ * <...> property for one that matches the given port/lane. Once
+ * found, maps it.
+ */
+static void __iomem * __init
+mvebu_pcie_map_registers(struct platform_device *pdev,
+			 struct device_node *np,
+			 struct mvebu_pcie_port *port)
+{
+	struct resource regs;
+	int ret = 0;
+
+	ret = of_address_to_resource(np, 0, &regs);
+	if (ret)
+		return NULL;
+
+	return devm_request_and_ioremap(&pdev->dev, &regs);
+}
+
+static int __init mvebu_pcie_probe(struct platform_device *pdev)
+{
+	struct mvebu_pcie *pcie;
+	struct device_node *np = pdev->dev.of_node;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	struct device_node *child;
+	int i, ret;
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_pcie),
+			    GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->pdev = pdev;
+
+	if (of_pci_range_parser_init(&parser, np))
+		return -EINVAL;
+
+	/* Get the I/O and memory ranges from DT */
+	for_each_of_pci_range(&parser, &range) {
+		unsigned long restype = range.flags & IORESOURCE_TYPE_BITS;
+		if (restype == IORESOURCE_IO) {
+			of_pci_range_to_resource(&range, np, &pcie->io);
+			of_pci_range_to_resource(&range, np, &pcie->realio);
+			pcie->io.name = "I/O";
+			pcie->realio.start = max_t(resource_size_t,
+						   PCIBIOS_MIN_IO,
+						   range.pci_addr);
+			pcie->realio.end = min_t(resource_size_t,
+						 IO_SPACE_LIMIT,
+						 range.pci_addr + range.size);
+		}
+		if (restype == IORESOURCE_MEM) {
+			of_pci_range_to_resource(&range, np, &pcie->mem);
+			pcie->mem.name = "MEM";
+		}
+	}
+
+	/* Get the bus range */
+	ret = of_pci_parse_bus_range(np, &pcie->busn);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to parse bus-range property: %d\n",
+			ret);
+		return ret;
+	}
+
+	for_each_child_of_node(pdev->dev.of_node, child) {
+		if (!of_device_is_available(child))
+			continue;
+		pcie->nports++;
+	}
+
+	pcie->ports = devm_kzalloc(&pdev->dev, pcie->nports *
+				   sizeof(struct mvebu_pcie_port),
+				   GFP_KERNEL);
+	if (!pcie->ports)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_child_of_node(pdev->dev.of_node, child) {
+		struct mvebu_pcie_port *port = &pcie->ports[i];
+
+		if (!of_device_is_available(child))
+			continue;
+
+		port->pcie = pcie;
+
+		if (of_property_read_u32(child, "marvell,pcie-port",
+					 &port->port)) {
+			dev_warn(&pdev->dev,
+				 "ignoring PCIe DT node, missing pcie-port property\n");
+			continue;
+		}
+
+		if (of_property_read_u32(child, "marvell,pcie-lane",
+					 &port->lane))
+			port->lane = 0;
+
+		port->name = kasprintf(GFP_KERNEL, "pcie%d.%d",
+				       port->port, port->lane);
+
+		port->devfn = of_pci_get_devfn(child);
+		if (port->devfn < 0)
+			continue;
+
+		port->base = mvebu_pcie_map_registers(pdev, child, port);
+		if (!port->base) {
+			dev_err(&pdev->dev, "PCIe%d.%d: cannot map registers\n",
+				port->port, port->lane);
+			continue;
+		}
+
+		if (mvebu_pcie_link_up(port)) {
+			port->haslink = 1;
+			dev_info(&pdev->dev, "PCIe%d.%d: link up\n",
+				 port->port, port->lane);
+		} else {
+			port->haslink = 0;
+			dev_info(&pdev->dev, "PCIe%d.%d: link down\n",
+				 port->port, port->lane);
+		}
+
+		port->clk = of_clk_get_by_name(child, NULL);
+		if (!port->clk) {
+			dev_err(&pdev->dev, "PCIe%d.%d: cannot get clock\n",
+			       port->port, port->lane);
+			iounmap(port->base);
+			port->haslink = 0;
+			continue;
+		}
+
+		port->dn = child;
+
+		clk_prepare_enable(port->clk);
+		spin_lock_init(&port->conf_lock);
+
+		mvebu_sw_pci_bridge_init(port);
+
+		i++;
+	}
+
+	mvebu_pcie_enable(pcie);
+
+	return 0;
+}
+
+static const struct of_device_id mvebu_pcie_of_match_table[] = {
+	{ .compatible = "marvell,armada-xp-pcie", },
+	{ .compatible = "marvell,armada-370-pcie", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mvebu_pcie_of_match_table);
+
+static struct platform_driver mvebu_pcie_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "mvebu-pcie",
+		.of_match_table =
+		   of_match_ptr(mvebu_pcie_of_match_table),
+	},
+};
+
+static int __init mvebu_pcie_init(void)
+{
+	return platform_driver_probe(&mvebu_pcie_driver,
+				     mvebu_pcie_probe);
+}
+
+subsys_initcall(mvebu_pcie_init);
+
+MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell EBU PCIe driver");
+MODULE_LICENSE("GPLv2");