Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1159 insertions, 0 deletions

diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
new file mode 100644
index 000000000..2dc6890db
--- /dev/null
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -0,0 +1,1159 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe driver for Marvell Armada 370 and Armada XP SoCs
+ *
+ * Author: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/mbus.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+
+#include "../pci.h"
+#include "../pci-bridge-emul.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_CAP_PCIEXP		0x0060
+#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_DEV                  0x1f0000
+#define  PCIE_STAT_LINK_DOWN		BIT(0)
+#define PCIE_RC_RTSTA		0x1a14
+#define PCIE_DEBUG_CTRL         0x1a60
+#define  PCIE_DEBUG_SOFT_RESET		BIT(20)
+
+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;
+};
+
+struct mvebu_pcie_window {
+	phys_addr_t base;
+	phys_addr_t remap;
+	size_t size;
+};
+
+/* Structure representing one PCIe interface */
+struct mvebu_pcie_port {
+	char *name;
+	void __iomem *base;
+	u32 port;
+	u32 lane;
+	int devfn;
+	unsigned int mem_target;
+	unsigned int mem_attr;
+	unsigned int io_target;
+	unsigned int io_attr;
+	struct clk *clk;
+	struct gpio_desc *reset_gpio;
+	char *reset_name;
+	struct pci_bridge_emul bridge;
+	struct device_node *dn;
+	struct mvebu_pcie *pcie;
+	struct mvebu_pcie_window memwin;
+	struct mvebu_pcie_window iowin;
+	u32 saved_pcie_stat;
+	struct resource regs;
+};
+
+static inline void mvebu_writel(struct mvebu_pcie_port *port, u32 val, u32 reg)
+{
+	writel(val, port->base + reg);
+}
+
+static inline u32 mvebu_readl(struct mvebu_pcie_port *port, u32 reg)
+{
+	return readl(port->base + reg);
+}
+
+static inline bool mvebu_has_ioport(struct mvebu_pcie_port *port)
+{
+	return port->io_target != -1 && port->io_attr != -1;
+}
+
+static bool mvebu_pcie_link_up(struct mvebu_pcie_port *port)
+{
+	return !(mvebu_readl(port, 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 = mvebu_readl(port, PCIE_STAT_OFF);
+	stat &= ~PCIE_STAT_BUS;
+	stat |= nr << 8;
+	mvebu_writel(port, stat, PCIE_STAT_OFF);
+}
+
+static void mvebu_pcie_set_local_dev_nr(struct mvebu_pcie_port *port, int nr)
+{
+	u32 stat;
+
+	stat = mvebu_readl(port, PCIE_STAT_OFF);
+	stat &= ~PCIE_STAT_DEV;
+	stat |= nr << 16;
+	mvebu_writel(port, stat, PCIE_STAT_OFF);
+}
+
+/*
+ * Setup PCIE BARs and Address Decode Wins:
+ * BAR[0] -> internal registers (needed for MSI)
+ * BAR[1] -> covers all DRAM banks
+ * BAR[2] -> Disabled
+ * WIN[0-3] -> DRAM bank[0-3]
+ */
+static void 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++) {
+		mvebu_writel(port, 0, PCIE_BAR_CTRL_OFF(i));
+		mvebu_writel(port, 0, PCIE_BAR_LO_OFF(i));
+		mvebu_writel(port, 0, PCIE_BAR_HI_OFF(i));
+	}
+
+	for (i = 0; i < 5; i++) {
+		mvebu_writel(port, 0, PCIE_WIN04_CTRL_OFF(i));
+		mvebu_writel(port, 0, PCIE_WIN04_BASE_OFF(i));
+		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
+	}
+
+	mvebu_writel(port, 0, PCIE_WIN5_CTRL_OFF);
+	mvebu_writel(port, 0, PCIE_WIN5_BASE_OFF);
+	mvebu_writel(port, 0, 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;
+
+		mvebu_writel(port, cs->base & 0xffff0000,
+			     PCIE_WIN04_BASE_OFF(i));
+		mvebu_writel(port, 0, PCIE_WIN04_REMAP_OFF(i));
+		mvebu_writel(port,
+			     ((cs->size - 1) & 0xffff0000) |
+			     (cs->mbus_attr << 8) |
+			     (dram->mbus_dram_target_id << 4) | 1,
+			     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. */
+	mvebu_writel(port, dram->cs[0].base, PCIE_BAR_LO_OFF(1));
+	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(1));
+	mvebu_writel(port, ((size - 1) & 0xffff0000) | 1,
+		     PCIE_BAR_CTRL_OFF(1));
+
+	/*
+	 * Point BAR[0] to the device's internal registers.
+	 */
+	mvebu_writel(port, round_down(port->regs.start, SZ_1M), PCIE_BAR_LO_OFF(0));
+	mvebu_writel(port, 0, PCIE_BAR_HI_OFF(0));
+}
+
+static void mvebu_pcie_setup_hw(struct mvebu_pcie_port *port)
+{
+	u32 cmd, mask;
+
+	/* Point PCIe unit MBUS decode windows to DRAM space. */
+	mvebu_pcie_setup_wins(port);
+
+	/* Master + slave enable. */
+	cmd = mvebu_readl(port, PCIE_CMD_OFF);
+	cmd |= PCI_COMMAND_IO;
+	cmd |= PCI_COMMAND_MEMORY;
+	cmd |= PCI_COMMAND_MASTER;
+	mvebu_writel(port, cmd, PCIE_CMD_OFF);
+
+	/* Enable interrupt lines A-D. */
+	mask = mvebu_readl(port, PCIE_MASK_OFF);
+	mask |= PCIE_MASK_ENABLE_INTS;
+	mvebu_writel(port, mask, 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)
+{
+	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
+
+	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
+		     PCIE_CONF_ADDR_OFF);
+
+	switch (size) {
+	case 1:
+		*val = readb_relaxed(conf_data + (where & 3));
+		break;
+	case 2:
+		*val = readw_relaxed(conf_data + (where & 2));
+		break;
+	case 4:
+		*val = readl_relaxed(conf_data);
+		break;
+	}
+
+	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)
+{
+	void __iomem *conf_data = port->base + PCIE_CONF_DATA_OFF;
+
+	mvebu_writel(port, PCIE_CONF_ADDR(bus->number, devfn, where),
+		     PCIE_CONF_ADDR_OFF);
+
+	switch (size) {
+	case 1:
+		writeb(val, conf_data + (where & 3));
+		break;
+	case 2:
+		writew(val, conf_data + (where & 2));
+		break;
+	case 4:
+		writel(val, conf_data);
+		break;
+	default:
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+/*
+ * Remove windows, starting from the largest ones to the smallest
+ * ones.
+ */
+static void mvebu_pcie_del_windows(struct mvebu_pcie_port *port,
+				   phys_addr_t base, size_t size)
+{
+	while (size) {
+		size_t sz = 1 << (fls(size) - 1);
+
+		mvebu_mbus_del_window(base, sz);
+		base += sz;
+		size -= sz;
+	}
+}
+
+/*
+ * MBus windows can only have a power of two size, but PCI BARs do not
+ * have this constraint. Therefore, we have to split the PCI BAR into
+ * areas each having a power of two size. We start from the largest
+ * one (i.e highest order bit set in the size).
+ */
+static void mvebu_pcie_add_windows(struct mvebu_pcie_port *port,
+				   unsigned int target, unsigned int attribute,
+				   phys_addr_t base, size_t size,
+				   phys_addr_t remap)
+{
+	size_t size_mapped = 0;
+
+	while (size) {
+		size_t sz = 1 << (fls(size) - 1);
+		int ret;
+
+		ret = mvebu_mbus_add_window_remap_by_id(target, attribute, base,
+							sz, remap);
+		if (ret) {
+			phys_addr_t end = base + sz - 1;
+
+			dev_err(&port->pcie->pdev->dev,
+				"Could not create MBus window at [mem %pa-%pa]: %d\n",
+				&base, &end, ret);
+			mvebu_pcie_del_windows(port, base - size_mapped,
+					       size_mapped);
+			return;
+		}
+
+		size -= sz;
+		size_mapped += sz;
+		base += sz;
+		if (remap != MVEBU_MBUS_NO_REMAP)
+			remap += sz;
+	}
+}
+
+static void mvebu_pcie_set_window(struct mvebu_pcie_port *port,
+				  unsigned int target, unsigned int attribute,
+				  const struct mvebu_pcie_window *desired,
+				  struct mvebu_pcie_window *cur)
+{
+	if (desired->base == cur->base && desired->remap == cur->remap &&
+	    desired->size == cur->size)
+		return;
+
+	if (cur->size != 0) {
+		mvebu_pcie_del_windows(port, cur->base, cur->size);
+		cur->size = 0;
+		cur->base = 0;
+
+		/*
+		 * If something tries to change the window while it is enabled
+		 * the change will not be done atomically. That would be
+		 * difficult to do in the general case.
+		 */
+	}
+
+	if (desired->size == 0)
+		return;
+
+	mvebu_pcie_add_windows(port, target, attribute, desired->base,
+			       desired->size, desired->remap);
+	*cur = *desired;
+}
+
+static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
+{
+	struct mvebu_pcie_window desired = {};
+	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
+
+	/* Are the new iobase/iolimit values invalid? */
+	if (conf->iolimit < conf->iobase ||
+	    conf->iolimitupper < conf->iobaseupper ||
+	    !(conf->command & PCI_COMMAND_IO)) {
+		mvebu_pcie_set_window(port, port->io_target, port->io_attr,
+				      &desired, &port->iowin);
+		return;
+	}
+
+	if (!mvebu_has_ioport(port)) {
+		dev_WARN(&port->pcie->pdev->dev,
+			 "Attempt to set IO when IO is disabled\n");
+		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.
+	 */
+	desired.remap = ((conf->iobase & 0xF0) << 8) |
+			(conf->iobaseupper << 16);
+	desired.base = port->pcie->io.start + desired.remap;
+	desired.size = ((0xFFF | ((conf->iolimit & 0xF0) << 8) |
+			 (conf->iolimitupper << 16)) -
+			desired.remap) +
+		       1;
+
+	mvebu_pcie_set_window(port, port->io_target, port->io_attr, &desired,
+			      &port->iowin);
+}
+
+static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
+{
+	struct mvebu_pcie_window desired = {.remap = MVEBU_MBUS_NO_REMAP};
+	struct pci_bridge_emul_conf *conf = &port->bridge.conf;
+
+	/* Are the new membase/memlimit values invalid? */
+	if (conf->memlimit < conf->membase ||
+	    !(conf->command & PCI_COMMAND_MEMORY)) {
+		mvebu_pcie_set_window(port, port->mem_target, port->mem_attr,
+				      &desired, &port->memwin);
+		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.
+	 */
+	desired.base = ((conf->membase & 0xFFF0) << 16);
+	desired.size = (((conf->memlimit & 0xFFF0) << 16) | 0xFFFFF) -
+		       desired.base + 1;
+
+	mvebu_pcie_set_window(port, port->mem_target, port->mem_attr, &desired,
+			      &port->memwin);
+}
+
+static pci_bridge_emul_read_status_t
+mvebu_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
+				     int reg, u32 *value)
+{
+	struct mvebu_pcie_port *port = bridge->data;
+
+	switch (reg) {
+	case PCI_EXP_DEVCAP:
+		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCAP);
+		break;
+
+	case PCI_EXP_DEVCTL:
+		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL) &
+				 ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
+				   PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
+		break;
+
+	case PCI_EXP_LNKCAP:
+		/*
+		 * PCIe requires the clock power management capability to be
+		 * hard-wired to zero for downstream ports
+		 */
+		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCAP) &
+			 ~PCI_EXP_LNKCAP_CLKPM;
+		break;
+
+	case PCI_EXP_LNKCTL:
+		*value = mvebu_readl(port, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
+		break;
+
+	case PCI_EXP_SLTCTL:
+		*value = PCI_EXP_SLTSTA_PDS << 16;
+		break;
+
+	case PCI_EXP_RTSTA:
+		*value = mvebu_readl(port, PCIE_RC_RTSTA);
+		break;
+
+	default:
+		return PCI_BRIDGE_EMUL_NOT_HANDLED;
+	}
+
+	return PCI_BRIDGE_EMUL_HANDLED;
+}
+
+static void
+mvebu_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge,
+				      int reg, u32 old, u32 new, u32 mask)
+{
+	struct mvebu_pcie_port *port = bridge->data;
+	struct pci_bridge_emul_conf *conf = &bridge->conf;
+
+	switch (reg) {
+	case PCI_COMMAND:
+	{
+		if (!mvebu_has_ioport(port))
+			conf->command &= ~PCI_COMMAND_IO;
+
+		if ((old ^ new) & PCI_COMMAND_IO)
+			mvebu_pcie_handle_iobase_change(port);
+		if ((old ^ new) & PCI_COMMAND_MEMORY)
+			mvebu_pcie_handle_membase_change(port);
+
+		break;
+	}
+
+	case PCI_IO_BASE:
+		/*
+		 * We keep bit 1 set, it is a read-only bit that
+		 * indicates we support 32 bits addressing for the
+		 * I/O
+		 */
+		conf->iobase |= PCI_IO_RANGE_TYPE_32;
+		conf->iolimit |= PCI_IO_RANGE_TYPE_32;
+		mvebu_pcie_handle_iobase_change(port);
+		break;
+
+	case PCI_MEMORY_BASE:
+		mvebu_pcie_handle_membase_change(port);
+		break;
+
+	case PCI_IO_BASE_UPPER16:
+		mvebu_pcie_handle_iobase_change(port);
+		break;
+
+	case PCI_PRIMARY_BUS:
+		mvebu_pcie_set_local_bus_nr(port, conf->secondary_bus);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void
+mvebu_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
+				      int reg, u32 old, u32 new, u32 mask)
+{
+	struct mvebu_pcie_port *port = bridge->data;
+
+	switch (reg) {
+	case PCI_EXP_DEVCTL:
+		/*
+		 * Armada370 data says these bits must always
+		 * be zero when in root complex mode.
+		 */
+		new &= ~(PCI_EXP_DEVCTL_URRE | PCI_EXP_DEVCTL_FERE |
+			 PCI_EXP_DEVCTL_NFERE | PCI_EXP_DEVCTL_CERE);
+
+		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_DEVCTL);
+		break;
+
+	case PCI_EXP_LNKCTL:
+		/*
+		 * If we don't support CLKREQ, we must ensure that the
+		 * CLKREQ enable bit always reads zero.  Since we haven't
+		 * had this capability, and it's dependent on board wiring,
+		 * disable it for the time being.
+		 */
+		new &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
+
+		mvebu_writel(port, new, PCIE_CAP_PCIEXP + PCI_EXP_LNKCTL);
+		break;
+
+	case PCI_EXP_RTSTA:
+		mvebu_writel(port, new, PCIE_RC_RTSTA);
+		break;
+	}
+}
+
+static struct pci_bridge_emul_ops mvebu_pci_bridge_emul_ops = {
+	.write_base = mvebu_pci_bridge_emul_base_conf_write,
+	.read_pcie = mvebu_pci_bridge_emul_pcie_conf_read,
+	.write_pcie = mvebu_pci_bridge_emul_pcie_conf_write,
+};
+
+/*
+ * Initialize the configuration space of the PCI-to-PCI bridge
+ * associated with the given PCIe interface.
+ */
+static void mvebu_pci_bridge_emul_init(struct mvebu_pcie_port *port)
+{
+	struct pci_bridge_emul *bridge = &port->bridge;
+	u32 pcie_cap = mvebu_readl(port, PCIE_CAP_PCIEXP);
+	u8 pcie_cap_ver = ((pcie_cap >> 16) & PCI_EXP_FLAGS_VERS);
+
+	bridge->conf.vendor = PCI_VENDOR_ID_MARVELL;
+	bridge->conf.device = mvebu_readl(port, PCIE_DEV_ID_OFF) >> 16;
+	bridge->conf.class_revision =
+		mvebu_readl(port, PCIE_DEV_REV_OFF) & 0xff;
+
+	if (mvebu_has_ioport(port)) {
+		/* We support 32 bits I/O addressing */
+		bridge->conf.iobase = PCI_IO_RANGE_TYPE_32;
+		bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;
+	}
+
+	/*
+	 * Older mvebu hardware provides PCIe Capability structure only in
+	 * version 1. New hardware provides it in version 2.
+	 */
+	bridge->pcie_conf.cap = cpu_to_le16(pcie_cap_ver);
+
+	bridge->has_pcie = true;
+	bridge->data = port;
+	bridge->ops = &mvebu_pci_bridge_emul_ops;
+
+	pci_bridge_emul_init(bridge, PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR);
+}
+
+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 &&
+		    bus->number >= port->bridge.conf.secondary_bus &&
+		    bus->number <= port->bridge.conf.subordinate_bus)
+			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 = bus->sysdata;
+	struct mvebu_pcie_port *port;
+	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 pci_bridge_emul_conf_write(&port->bridge, where,
+						  size, val);
+
+	if (!mvebu_pcie_link_up(port))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/* Access the real PCIe interface */
+	ret = mvebu_pcie_hw_wr_conf(port, bus, devfn,
+				    where, size, val);
+
+	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 = bus->sysdata;
+	struct mvebu_pcie_port *port;
+	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 pci_bridge_emul_conf_read(&port->bridge, where,
+						 size, val);
+
+	if (!mvebu_pcie_link_up(port)) {
+		*val = 0xffffffff;
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	}
+
+	/* Access the real PCIe interface */
+	ret = mvebu_pcie_hw_rd_conf(port, bus, devfn,
+				    where, size, val);
+
+	return ret;
+}
+
+static struct pci_ops mvebu_pcie_ops = {
+	.read = mvebu_pcie_rd_conf,
+	.write = mvebu_pcie_wr_conf,
+};
+
+static 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 the memory windows must have at
+	 * least a 1 MB size. Moreover, MBus windows need to have a
+	 * base address aligned on their size, and their size must be
+	 * a power of two. This means that if the BAR doesn't have a
+	 * power of two size, several MBus windows will actually be
+	 * created. We need to ensure that the biggest MBus window
+	 * (which will be the first one) is aligned on its size, which
+	 * explains the rounddown_pow_of_two() being done here.
+	 */
+	if (res->flags & IORESOURCE_IO)
+		return round_up(start, max_t(resource_size_t, SZ_64K,
+					     rounddown_pow_of_two(size)));
+	else if (res->flags & IORESOURCE_MEM)
+		return round_up(start, max_t(resource_size_t, SZ_1M,
+					     rounddown_pow_of_two(size)));
+	else
+		return start;
+}
+
+static void __iomem *mvebu_pcie_map_registers(struct platform_device *pdev,
+					      struct device_node *np,
+					      struct mvebu_pcie_port *port)
+{
+	int ret = 0;
+
+	ret = of_address_to_resource(np, 0, &port->regs);
+	if (ret)
+		return (void __iomem *)ERR_PTR(ret);
+
+	return devm_ioremap_resource(&pdev->dev, &port->regs);
+}
+
+#define DT_FLAGS_TO_TYPE(flags)       (((flags) >> 24) & 0x03)
+#define    DT_TYPE_IO                 0x1
+#define    DT_TYPE_MEM32              0x2
+#define DT_CPUADDR_TO_TARGET(cpuaddr) (((cpuaddr) >> 56) & 0xFF)
+#define DT_CPUADDR_TO_ATTR(cpuaddr)   (((cpuaddr) >> 48) & 0xFF)
+
+static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
+			      unsigned long type,
+			      unsigned int *tgt,
+			      unsigned int *attr)
+{
+	const int na = 3, ns = 2;
+	const __be32 *range;
+	int rlen, nranges, rangesz, pna, i;
+
+	*tgt = -1;
+	*attr = -1;
+
+	range = of_get_property(np, "ranges", &rlen);
+	if (!range)
+		return -EINVAL;
+
+	pna = of_n_addr_cells(np);
+	rangesz = pna + na + ns;
+	nranges = rlen / sizeof(__be32) / rangesz;
+
+	for (i = 0; i < nranges; i++, range += rangesz) {
+		u32 flags = of_read_number(range, 1);
+		u32 slot = of_read_number(range + 1, 1);
+		u64 cpuaddr = of_read_number(range + na, pna);
+		unsigned long rtype;
+
+		if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
+			rtype = IORESOURCE_IO;
+		else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
+			rtype = IORESOURCE_MEM;
+		else
+			continue;
+
+		if (slot == PCI_SLOT(devfn) && type == rtype) {
+			*tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
+			*attr = DT_CPUADDR_TO_ATTR(cpuaddr);
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mvebu_pcie_suspend(struct device *dev)
+{
+	struct mvebu_pcie *pcie;
+	int i;
+
+	pcie = dev_get_drvdata(dev);
+	for (i = 0; i < pcie->nports; i++) {
+		struct mvebu_pcie_port *port = pcie->ports + i;
+		port->saved_pcie_stat = mvebu_readl(port, PCIE_STAT_OFF);
+	}
+
+	return 0;
+}
+
+static int mvebu_pcie_resume(struct device *dev)
+{
+	struct mvebu_pcie *pcie;
+	int i;
+
+	pcie = dev_get_drvdata(dev);
+	for (i = 0; i < pcie->nports; i++) {
+		struct mvebu_pcie_port *port = pcie->ports + i;
+		mvebu_writel(port, port->saved_pcie_stat, PCIE_STAT_OFF);
+		mvebu_pcie_setup_hw(port);
+	}
+
+	return 0;
+}
+#endif
+
+static void mvebu_pcie_port_clk_put(void *data)
+{
+	struct mvebu_pcie_port *port = data;
+
+	clk_put(port->clk);
+}
+
+static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie,
+	struct mvebu_pcie_port *port, struct device_node *child)
+{
+	struct device *dev = &pcie->pdev->dev;
+	enum of_gpio_flags flags;
+	int reset_gpio, ret;
+
+	port->pcie = pcie;
+
+	if (of_property_read_u32(child, "marvell,pcie-port", &port->port)) {
+		dev_warn(dev, "ignoring %pOF, missing pcie-port property\n",
+			 child);
+		goto skip;
+	}
+
+	if (of_property_read_u32(child, "marvell,pcie-lane", &port->lane))
+		port->lane = 0;
+
+	port->name = devm_kasprintf(dev, GFP_KERNEL, "pcie%d.%d", port->port,
+				    port->lane);
+	if (!port->name) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	port->devfn = of_pci_get_devfn(child);
+	if (port->devfn < 0)
+		goto skip;
+
+	ret = mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_MEM,
+				 &port->mem_target, &port->mem_attr);
+	if (ret < 0) {
+		dev_err(dev, "%s: cannot get tgt/attr for mem window\n",
+			port->name);
+		goto skip;
+	}
+
+	if (resource_size(&pcie->io) != 0) {
+		mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_IO,
+				   &port->io_target, &port->io_attr);
+	} else {
+		port->io_target = -1;
+		port->io_attr = -1;
+	}
+
+	reset_gpio = of_get_named_gpio_flags(child, "reset-gpios", 0, &flags);
+	if (reset_gpio == -EPROBE_DEFER) {
+		ret = reset_gpio;
+		goto err;
+	}
+
+	if (gpio_is_valid(reset_gpio)) {
+		unsigned long gpio_flags;
+
+		port->reset_name = devm_kasprintf(dev, GFP_KERNEL, "%s-reset",
+						  port->name);
+		if (!port->reset_name) {
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		if (flags & OF_GPIO_ACTIVE_LOW) {
+			dev_info(dev, "%pOF: reset gpio is active low\n",
+				 child);
+			gpio_flags = GPIOF_ACTIVE_LOW |
+				     GPIOF_OUT_INIT_LOW;
+		} else {
+			gpio_flags = GPIOF_OUT_INIT_HIGH;
+		}
+
+		ret = devm_gpio_request_one(dev, reset_gpio, gpio_flags,
+					    port->reset_name);
+		if (ret) {
+			if (ret == -EPROBE_DEFER)
+				goto err;
+			goto skip;
+		}
+
+		port->reset_gpio = gpio_to_desc(reset_gpio);
+	}
+
+	port->clk = of_clk_get_by_name(child, NULL);
+	if (IS_ERR(port->clk)) {
+		dev_err(dev, "%s: cannot get clock\n", port->name);
+		goto skip;
+	}
+
+	ret = devm_add_action(dev, mvebu_pcie_port_clk_put, port);
+	if (ret < 0) {
+		clk_put(port->clk);
+		goto err;
+	}
+
+	return 1;
+
+skip:
+	ret = 0;
+
+	/* In the case of skipping, we need to free these */
+	devm_kfree(dev, port->reset_name);
+	port->reset_name = NULL;
+	devm_kfree(dev, port->name);
+	port->name = NULL;
+
+err:
+	return ret;
+}
+
+/*
+ * Power up a PCIe port.  PCIe requires the refclk to be stable for 100µs
+ * prior to releasing PERST.  See table 2-4 in section 2.6.2 AC Specifications
+ * of the PCI Express Card Electromechanical Specification, 1.1.
+ */
+static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
+{
+	int ret;
+
+	ret = clk_prepare_enable(port->clk);
+	if (ret < 0)
+		return ret;
+
+	if (port->reset_gpio) {
+		u32 reset_udelay = PCI_PM_D3COLD_WAIT * 1000;
+
+		of_property_read_u32(port->dn, "reset-delay-us",
+				     &reset_udelay);
+
+		udelay(100);
+
+		gpiod_set_value_cansleep(port->reset_gpio, 0);
+		msleep(reset_udelay / 1000);
+	}
+
+	return 0;
+}
+
+/*
+ * Power down a PCIe port.  Strictly, PCIe requires us to place the card
+ * in D3hot state before asserting PERST#.
+ */
+static void mvebu_pcie_powerdown(struct mvebu_pcie_port *port)
+{
+	gpiod_set_value_cansleep(port->reset_gpio, 1);
+
+	clk_disable_unprepare(port->clk);
+}
+
+/*
+ * devm_of_pci_get_host_bridge_resources() only sets up translateable resources,
+ * so we need extra resource setup parsing our special DT properties encoding
+ * the MEM and IO apertures.
+ */
+static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
+{
+	struct device *dev = &pcie->pdev->dev;
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
+	int ret;
+
+	/* Get the PCIe memory aperture */
+	mvebu_mbus_get_pcie_mem_aperture(&pcie->mem);
+	if (resource_size(&pcie->mem) == 0) {
+		dev_err(dev, "invalid memory aperture size\n");
+		return -EINVAL;
+	}
+
+	pcie->mem.name = "PCI MEM";
+	pci_add_resource(&bridge->windows, &pcie->mem);
+	ret = devm_request_resource(dev, &iomem_resource, &pcie->mem);
+	if (ret)
+		return ret;
+
+	/* Get the PCIe IO aperture */
+	mvebu_mbus_get_pcie_io_aperture(&pcie->io);
+
+	if (resource_size(&pcie->io) != 0) {
+		pcie->realio.flags = pcie->io.flags;
+		pcie->realio.start = PCIBIOS_MIN_IO;
+		pcie->realio.end = min_t(resource_size_t,
+					 IO_SPACE_LIMIT - SZ_64K,
+					 resource_size(&pcie->io) - 1);
+		pcie->realio.name = "PCI I/O";
+
+		pci_add_resource(&bridge->windows, &pcie->realio);
+		ret = devm_request_resource(dev, &ioport_resource, &pcie->realio);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * This is a copy of pci_host_probe(), except that it does the I/O
+ * remap as the last step, once we are sure we won't fail.
+ *
+ * It should be removed once the I/O remap error handling issue has
+ * been sorted out.
+ */
+static int mvebu_pci_host_probe(struct pci_host_bridge *bridge)
+{
+	struct mvebu_pcie *pcie;
+	struct pci_bus *bus, *child;
+	int ret;
+
+	ret = pci_scan_root_bus_bridge(bridge);
+	if (ret < 0) {
+		dev_err(bridge->dev.parent, "Scanning root bridge failed");
+		return ret;
+	}
+
+	pcie = pci_host_bridge_priv(bridge);
+	if (resource_size(&pcie->io) != 0) {
+		unsigned int i;
+
+		for (i = 0; i < resource_size(&pcie->realio); i += SZ_64K)
+			pci_ioremap_io(i, pcie->io.start + i);
+	}
+
+	bus = bridge->bus;
+
+	/*
+	 * We insert PCI resources into the iomem_resource and
+	 * ioport_resource trees in either pci_bus_claim_resources()
+	 * or pci_bus_assign_resources().
+	 */
+	if (pci_has_flag(PCI_PROBE_ONLY)) {
+		pci_bus_claim_resources(bus);
+	} else {
+		pci_bus_size_bridges(bus);
+		pci_bus_assign_resources(bus);
+
+		list_for_each_entry(child, &bus->children, node)
+			pcie_bus_configure_settings(child);
+	}
+
+	pci_bus_add_devices(bus);
+	return 0;
+}
+
+static int mvebu_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mvebu_pcie *pcie;
+	struct pci_host_bridge *bridge;
+	struct device_node *np = dev->of_node;
+	struct device_node *child;
+	int num, i, ret;
+
+	bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct mvebu_pcie));
+	if (!bridge)
+		return -ENOMEM;
+
+	pcie = pci_host_bridge_priv(bridge);
+	pcie->pdev = pdev;
+	platform_set_drvdata(pdev, pcie);
+
+	ret = mvebu_pcie_parse_request_resources(pcie);
+	if (ret)
+		return ret;
+
+	num = of_get_available_child_count(np);
+
+	pcie->ports = devm_kcalloc(dev, num, sizeof(*pcie->ports), GFP_KERNEL);
+	if (!pcie->ports)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_available_child_of_node(np, child) {
+		struct mvebu_pcie_port *port = &pcie->ports[i];
+
+		ret = mvebu_pcie_parse_port(pcie, port, child);
+		if (ret < 0) {
+			of_node_put(child);
+			return ret;
+		} else if (ret == 0) {
+			continue;
+		}
+
+		port->dn = child;
+		i++;
+	}
+	pcie->nports = i;
+
+	for (i = 0; i < pcie->nports; i++) {
+		struct mvebu_pcie_port *port = &pcie->ports[i];
+
+		child = port->dn;
+		if (!child)
+			continue;
+
+		ret = mvebu_pcie_powerup(port);
+		if (ret < 0)
+			continue;
+
+		port->base = mvebu_pcie_map_registers(pdev, child, port);
+		if (IS_ERR(port->base)) {
+			dev_err(dev, "%s: cannot map registers\n", port->name);
+			port->base = NULL;
+			mvebu_pcie_powerdown(port);
+			continue;
+		}
+
+		mvebu_pcie_setup_hw(port);
+		mvebu_pcie_set_local_dev_nr(port, 1);
+		mvebu_pci_bridge_emul_init(port);
+	}
+
+	pcie->nports = i;
+
+	bridge->sysdata = pcie;
+	bridge->ops = &mvebu_pcie_ops;
+	bridge->align_resource = mvebu_pcie_align_resource;
+
+	return mvebu_pci_host_probe(bridge);
+}
+
+static const struct of_device_id mvebu_pcie_of_match_table[] = {
+	{ .compatible = "marvell,armada-xp-pcie", },
+	{ .compatible = "marvell,armada-370-pcie", },
+	{ .compatible = "marvell,dove-pcie", },
+	{ .compatible = "marvell,kirkwood-pcie", },
+	{},
+};
+
+static const struct dev_pm_ops mvebu_pcie_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mvebu_pcie_suspend, mvebu_pcie_resume)
+};
+
+static struct platform_driver mvebu_pcie_driver = {
+	.driver = {
+		.name = "mvebu-pcie",
+		.of_match_table = mvebu_pcie_of_match_table,
+		/* driver unloading/unbinding currently not supported */
+		.suppress_bind_attrs = true,
+		.pm = &mvebu_pcie_pm_ops,
+	},
+	.probe = mvebu_pcie_probe,
+};
+builtin_platform_driver(mvebu_pcie_driver);