pci: add common Designware PCIe functions

With the introduction of pcie_dw_rockchip, and need to support the DW PCIe in the
Amlogic AXG & G12 SoCs, most of the DW PCIe helpers would be duplicated.

This introduce a "common" DW PCIe helpers file with common code merged from the
dw_ti and dw_rockchip drivers and adapted to fit with the upcoming dw_meson.

The following changes will switch the dw_ti and dw_rockchip to use these helpers.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Green Wan <green.wan@sifive.com>
[bmeng: remove the blank line at EOF of drivers/pci/pcie_dw_common.c]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

4 files changed, 525 insertions, 0 deletions

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index ba41787f64..ab5a5e7ed6 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -258,6 +258,10 @@ config PCI_MVEBU
 	  Say Y here if you want to enable PCIe controller support on
 	  Armada XP/38x SoCs.
 
+config PCIE_DW_COMMON
+	bool
+	select DM_PCI
+
 config PCI_KEYSTONE
 	bool "TI Keystone PCIe controller"
 	depends on DM_PCI
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 5ed94bc95c..e3ca8b27e4 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_PCIE_LAYERSCAPE_GEN4) += pcie_layerscape_gen4.o \
 obj-$(CONFIG_PCI_XILINX) += pcie_xilinx.o
 obj-$(CONFIG_PCI_PHYTIUM) += pcie_phytium.o
 obj-$(CONFIG_PCIE_INTEL_FPGA) += pcie_intel_fpga.o
+obj-$(CONFIG_PCIE_DW_COMMON) += pcie_dw_common.o
 obj-$(CONFIG_PCI_KEYSTONE) += pcie_dw_ti.o
 obj-$(CONFIG_PCIE_MEDIATEK) += pcie_mediatek.o
 obj-$(CONFIG_PCIE_ROCKCHIP) += pcie_rockchip.o
diff --git a/drivers/pci/pcie_dw_common.c b/drivers/pci/pcie_dw_common.c
new file mode 100644
index 0000000000..785fd3aad0
--- /dev/null
+++ b/drivers/pci/pcie_dw_common.c
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * Copyright (c) 2021 Rockchip, Inc.
+ *
+ * Copyright (C) 2018 Texas Instruments, Inc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <log.h>
+#include <pci.h>
+#include <dm/device_compat.h>
+#include <asm/io.h>
+#include <linux/delay.h>
+#include "pcie_dw_common.h"
+
+int pcie_dw_get_link_speed(struct pcie_dw *pci)
+{
+	return (readl(pci->dbi_base + PCIE_LINK_STATUS_REG) &
+		PCIE_LINK_STATUS_SPEED_MASK) >> PCIE_LINK_STATUS_SPEED_OFF;
+}
+
+int pcie_dw_get_link_width(struct pcie_dw *pci)
+{
+	return (readl(pci->dbi_base + PCIE_LINK_STATUS_REG) &
+		PCIE_LINK_STATUS_WIDTH_MASK) >> PCIE_LINK_STATUS_WIDTH_OFF;
+}
+
+static void dw_pcie_writel_ob_unroll(struct pcie_dw *pci, u32 index, u32 reg,
+				     u32 val)
+{
+	u32 offset = PCIE_GET_ATU_OUTB_UNR_REG_OFFSET(index);
+	void __iomem *base = pci->atu_base;
+
+	writel(val, base + offset + reg);
+}
+
+static u32 dw_pcie_readl_ob_unroll(struct pcie_dw *pci, u32 index, u32 reg)
+{
+	u32 offset = PCIE_GET_ATU_OUTB_UNR_REG_OFFSET(index);
+	void __iomem *base = pci->atu_base;
+
+	return readl(base + offset + reg);
+}
+
+/**
+ * pcie_dw_prog_outbound_atu_unroll() - Configure ATU for outbound accesses
+ *
+ * @pcie: Pointer to the PCI controller state
+ * @index: ATU region index
+ * @type: ATU accsess type
+ * @cpu_addr: the physical address for the translation entry
+ * @pci_addr: the pcie bus address for the translation entry
+ * @size: the size of the translation entry
+ *
+ * Return: 0 is successful and -1 is failure
+ */
+int pcie_dw_prog_outbound_atu_unroll(struct pcie_dw *pci, int index,
+				     int type, u64 cpu_addr,
+					     u64 pci_addr, u32 size)
+{
+	u32 retries, val;
+
+	dev_dbg(pci->dev, "ATU programmed with: index: %d, type: %d, cpu addr: %8llx, pci addr: %8llx, size: %8x\n",
+		index, type, cpu_addr, pci_addr, size);
+
+	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_LOWER_BASE,
+				 lower_32_bits(cpu_addr));
+	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_BASE,
+				 upper_32_bits(cpu_addr));
+	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_LIMIT,
+				 lower_32_bits(cpu_addr + size - 1));
+	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_LOWER_TARGET,
+				 lower_32_bits(pci_addr));
+	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_TARGET,
+				 upper_32_bits(pci_addr));
+	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1,
+				 type);
+	dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL2,
+				 PCIE_ATU_ENABLE);
+
+	/*
+	 * Make sure ATU enable takes effect before any subsequent config
+	 * and I/O accesses.
+	 */
+	for (retries = 0; retries < LINK_WAIT_MAX_IATU_RETRIES; retries++) {
+		val = dw_pcie_readl_ob_unroll(pci, index,
+					      PCIE_ATU_UNR_REGION_CTRL2);
+		if (val & PCIE_ATU_ENABLE)
+			return 0;
+
+		udelay(LINK_WAIT_IATU);
+	}
+	dev_err(pci->dev, "outbound iATU is not being enabled\n");
+
+	return -1;
+}
+
+/**
+ * set_cfg_address() - Configure the PCIe controller config space access
+ *
+ * @pcie: Pointer to the PCI controller state
+ * @d: PCI device to access
+ * @where: Offset in the configuration space
+ *
+ * Configures the PCIe controller to access the configuration space of
+ * a specific PCIe device and returns the address to use for this
+ * access.
+ *
+ * Return: Address that can be used to access the configation space
+ *         of the requested device / offset
+ */
+static uintptr_t set_cfg_address(struct pcie_dw *pcie,
+				 pci_dev_t d, uint where)
+{
+	int bus = PCI_BUS(d) - pcie->first_busno;
+	uintptr_t va_address;
+	u32 atu_type;
+	int ret;
+
+	/* Use dbi_base for own configuration read and write */
+	if (!bus) {
+		va_address = (uintptr_t)pcie->dbi_base;
+		goto out;
+	}
+
+	if (bus == 1)
+		/*
+		 * For local bus whose primary bus number is root bridge,
+		 * change TLP Type field to 4.
+		 */
+		atu_type = PCIE_ATU_TYPE_CFG0;
+	else
+		/* Otherwise, change TLP Type field to 5. */
+		atu_type = PCIE_ATU_TYPE_CFG1;
+
+	/*
+	 * Not accessing root port configuration space?
+	 * Region #0 is used for Outbound CFG space access.
+	 * Direction = Outbound
+	 * Region Index = 0
+	 */
+	d = PCI_MASK_BUS(d);
+	d = PCI_ADD_BUS(bus, d);
+	ret = pcie_dw_prog_outbound_atu_unroll(pcie, PCIE_ATU_REGION_INDEX1,
+					       atu_type, (u64)pcie->cfg_base,
+						d << 8, pcie->cfg_size);
+	if (ret)
+		return (uintptr_t)ret;
+
+	va_address = (uintptr_t)pcie->cfg_base;
+
+out:
+	va_address += where & ~0x3;
+
+	return va_address;
+}
+
+/**
+ * pcie_dw_addr_valid() - Check for valid bus address
+ *
+ * @d: The PCI device to access
+ * @first_busno: Bus number of the PCIe controller root complex
+ *
+ * Return 1 (true) if the PCI device can be accessed by this controller.
+ *
+ * Return: 1 on valid, 0 on invalid
+ */
+static int pcie_dw_addr_valid(pci_dev_t d, int first_busno)
+{
+	if ((PCI_BUS(d) == first_busno) && (PCI_DEV(d) > 0))
+		return 0;
+	if ((PCI_BUS(d) == first_busno + 1) && (PCI_DEV(d) > 0))
+		return 0;
+
+	return 1;
+}
+
+/**
+ * pcie_dw_read_config() - Read from configuration space
+ *
+ * @bus: Pointer to the PCI bus
+ * @bdf: Identifies the PCIe device to access
+ * @offset: The offset into the device's configuration space
+ * @valuep: A pointer at which to store the read value
+ * @size: Indicates the size of access to perform
+ *
+ * Read a value of size @size from offset @offset within the configuration
+ * space of the device identified by the bus, device & function numbers in @bdf
+ * on the PCI bus @bus.
+ *
+ * Return: 0 on success
+ */
+int pcie_dw_read_config(const struct udevice *bus, pci_dev_t bdf,
+			uint offset, ulong *valuep,
+			enum pci_size_t size)
+{
+	struct pcie_dw *pcie = dev_get_priv(bus);
+	uintptr_t va_address;
+	ulong value;
+
+	dev_dbg(pcie->dev, "PCIE CFG read: bdf=%2x:%2x:%2x ",
+		PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
+
+	if (!pcie_dw_addr_valid(bdf, pcie->first_busno)) {
+		debug("- out of range\n");
+		*valuep = pci_get_ff(size);
+		return 0;
+	}
+
+	va_address = set_cfg_address(pcie, bdf, offset);
+
+	value = readl(va_address);
+
+	debug("(addr,val)=(0x%04x, 0x%08lx)\n", offset, value);
+	*valuep = pci_conv_32_to_size(value, offset, size);
+
+	return pcie_dw_prog_outbound_atu_unroll(pcie, PCIE_ATU_REGION_INDEX1,
+						 PCIE_ATU_TYPE_IO, pcie->io.phys_start,
+						 pcie->io.bus_start, pcie->io.size);
+}
+
+/**
+ * pcie_dw_write_config() - Write to configuration space
+ *
+ * @bus: Pointer to the PCI bus
+ * @bdf: Identifies the PCIe device to access
+ * @offset: The offset into the device's configuration space
+ * @value: The value to write
+ * @size: Indicates the size of access to perform
+ *
+ * Write the value @value of size @size from offset @offset within the
+ * configuration space of the device identified by the bus, device & function
+ * numbers in @bdf on the PCI bus @bus.
+ *
+ * Return: 0 on success
+ */
+int pcie_dw_write_config(struct udevice *bus, pci_dev_t bdf,
+			 uint offset, ulong value,
+			 enum pci_size_t size)
+{
+	struct pcie_dw *pcie = dev_get_priv(bus);
+	uintptr_t va_address;
+	ulong old;
+
+	dev_dbg(pcie->dev, "PCIE CFG write: (b,d,f)=(%2d,%2d,%2d) ",
+		PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf));
+	dev_dbg(pcie->dev, "(addr,val)=(0x%04x, 0x%08lx)\n", offset, value);
+
+	if (!pcie_dw_addr_valid(bdf, pcie->first_busno)) {
+		debug("- out of range\n");
+		return 0;
+	}
+
+	va_address = set_cfg_address(pcie, bdf, offset);
+
+	old = readl(va_address);
+	value = pci_conv_size_to_32(old, value, offset, size);
+	writel(value, va_address);
+
+	return pcie_dw_prog_outbound_atu_unroll(pcie, PCIE_ATU_REGION_INDEX1,
+						 PCIE_ATU_TYPE_IO, pcie->io.phys_start,
+						 pcie->io.bus_start, pcie->io.size);
+}
+
+/**
+ * pcie_dw_setup_host() - Setup the PCIe controller for RC opertaion
+ *
+ * @pcie: Pointer to the PCI controller state
+ *
+ * Configure the host BARs of the PCIe controller root port so that
+ * PCI(e) devices may access the system memory.
+ */
+void pcie_dw_setup_host(struct pcie_dw *pci)
+{
+	struct udevice *ctlr = pci_get_controller(pci->dev);
+	struct pci_controller *hose = dev_get_uclass_priv(ctlr);
+	u32 ret;
+
+	if (!pci->atu_base)
+		pci->atu_base = pci->dbi_base + DEFAULT_DBI_ATU_OFFSET;
+
+	/* setup RC BARs */
+	writel(PCI_BASE_ADDRESS_MEM_TYPE_64,
+	       pci->dbi_base + PCI_BASE_ADDRESS_0);
+	writel(0x0, pci->dbi_base + PCI_BASE_ADDRESS_1);
+
+	/* setup interrupt pins */
+	clrsetbits_le32(pci->dbi_base + PCI_INTERRUPT_LINE,
+			0xff00, 0x100);
+
+	/* setup bus numbers */
+	clrsetbits_le32(pci->dbi_base + PCI_PRIMARY_BUS,
+			0xffffff, 0x00ff0100);
+
+	/* setup command register */
+	clrsetbits_le32(pci->dbi_base + PCI_PRIMARY_BUS,
+			0xffff,
+			PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
+			PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
+
+	/* Enable write permission for the DBI read-only register */
+	dw_pcie_dbi_write_enable(pci, true);
+	/* program correct class for RC */
+	writew(PCI_CLASS_BRIDGE_PCI, pci->dbi_base + PCI_CLASS_DEVICE);
+	/* Better disable write permission right after the update */
+	dw_pcie_dbi_write_enable(pci, false);
+
+	setbits_le32(pci->dbi_base + PCIE_LINK_WIDTH_SPEED_CONTROL,
+		     PORT_LOGIC_SPEED_CHANGE);
+
+	for (ret = 0; ret < hose->region_count; ret++) {
+		if (hose->regions[ret].flags == PCI_REGION_IO) {
+			pci->io.phys_start = hose->regions[ret].phys_start; /* IO base */
+			pci->io.bus_start = hose->regions[ret].bus_start;  /* IO_bus_addr */
+			pci->io.size = hose->regions[ret].size;      /* IO size */
+		} else if (hose->regions[ret].flags == PCI_REGION_MEM) {
+			pci->mem.phys_start = hose->regions[ret].phys_start; /* MEM base */
+			pci->mem.bus_start = hose->regions[ret].bus_start;  /* MEM_bus_addr */
+			pci->mem.size = hose->regions[ret].size;	    /* MEM size */
+		} else if (hose->regions[ret].flags == PCI_REGION_PREFETCH) {
+			pci->prefetch.phys_start = hose->regions[ret].phys_start; /* PREFETCH base */
+			pci->prefetch.bus_start = hose->regions[ret].bus_start;  /* PREFETCH_bus_addr */
+			pci->prefetch.size = hose->regions[ret].size;	    /* PREFETCH size */
+		} else if (hose->regions[ret].flags == PCI_REGION_SYS_MEMORY) {
+			pci->cfg_base = (void *)(pci->io.phys_start - pci->io.size);
+			pci->cfg_size = pci->io.size;
+		} else {
+			dev_err(pci->dev, "invalid flags type!\n");
+		}
+	}
+
+	dev_dbg(pci->dev, "Config space: [0x%p - 0x%p, size 0x%llx]\n",
+		pci->cfg_base, pci->cfg_base + pci->cfg_size,
+		pci->cfg_size);
+
+	dev_dbg(pci->dev, "IO space: [0x%llx - 0x%llx, size 0x%lx]\n",
+		pci->io.phys_start, pci->io.phys_start + pci->io.size,
+		pci->io.size);
+
+	dev_dbg(pci->dev, "IO bus:   [0x%lx - 0x%lx, size 0x%lx]\n",
+		pci->io.bus_start, pci->io.bus_start + pci->io.size,
+		pci->io.size);
+
+	dev_dbg(pci->dev, "MEM space: [0x%llx - 0x%llx, size 0x%lx]\n",
+		pci->mem.phys_start, pci->mem.phys_start + pci->mem.size,
+		pci->mem.size);
+
+	dev_dbg(pci->dev, "MEM bus:   [0x%lx - 0x%lx, size 0x%lx]\n",
+		pci->mem.bus_start, pci->mem.bus_start + pci->mem.size,
+		pci->mem.size);
+
+	if (pci->prefetch.size) {
+		dev_dbg(pci->dev, "PREFETCH space: [0x%llx - 0x%llx, size 0x%lx]\n",
+			pci->prefetch.phys_start, pci->prefetch.phys_start + pci->prefetch.size,
+			pci->prefetch.size);
+
+		dev_dbg(pci->dev, "PREFETCH bus:   [0x%lx - 0x%lx, size 0x%lx]\n",
+			pci->prefetch.bus_start, pci->prefetch.bus_start + pci->prefetch.size,
+			pci->prefetch.size);
+	}
+}
diff --git a/drivers/pci/pcie_dw_common.h b/drivers/pci/pcie_dw_common.h
new file mode 100644
index 0000000000..6b701645af
--- /dev/null
+++ b/drivers/pci/pcie_dw_common.h
@@ -0,0 +1,155 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2021 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * Copyright (c) 2021 Rockchip, Inc.
+ *
+ * Copyright (C) 2018 Texas Instruments, Inc
+ */
+
+#ifndef PCIE_DW_COMMON_H
+#define PCIE_DW_COMMON_H
+
+#define DEFAULT_DBI_ATU_OFFSET (0x3 << 20)
+
+/* PCI DBICS registers */
+#define PCIE_LINK_STATUS_REG		0x80
+#define PCIE_LINK_STATUS_SPEED_OFF	16
+#define PCIE_LINK_STATUS_SPEED_MASK	(0xf << PCIE_LINK_STATUS_SPEED_OFF)
+#define PCIE_LINK_STATUS_WIDTH_OFF	20
+#define PCIE_LINK_STATUS_WIDTH_MASK	(0xf << PCIE_LINK_STATUS_WIDTH_OFF)
+
+/*
+ * iATU Unroll-specific register definitions
+ * From 4.80 core version the address translation will be made by unroll.
+ * The registers are offset from atu_base
+ */
+#define PCIE_ATU_UNR_REGION_CTRL1	0x00
+#define PCIE_ATU_UNR_REGION_CTRL2	0x04
+#define PCIE_ATU_UNR_LOWER_BASE		0x08
+#define PCIE_ATU_UNR_UPPER_BASE		0x0c
+#define PCIE_ATU_UNR_LIMIT		0x10
+#define PCIE_ATU_UNR_LOWER_TARGET	0x14
+#define PCIE_ATU_UNR_UPPER_TARGET	0x18
+
+#define PCIE_ATU_REGION_INDEX1		(0x1 << 0)
+#define PCIE_ATU_REGION_INDEX0		(0x0 << 0)
+#define PCIE_ATU_TYPE_MEM		(0x0 << 0)
+#define PCIE_ATU_TYPE_IO		(0x2 << 0)
+#define PCIE_ATU_TYPE_CFG0		(0x4 << 0)
+#define PCIE_ATU_TYPE_CFG1		(0x5 << 0)
+#define PCIE_ATU_ENABLE			(0x1 << 31)
+#define PCIE_ATU_BAR_MODE_ENABLE	(0x1 << 30)
+#define PCIE_ATU_BUS(x)			(((x) & 0xff) << 24)
+#define PCIE_ATU_DEV(x)			(((x) & 0x1f) << 19)
+#define PCIE_ATU_FUNC(x)		(((x) & 0x7) << 16)
+
+/* Register address builder */
+#define PCIE_GET_ATU_OUTB_UNR_REG_OFFSET(region)	((region) << 9)
+
+/* Parameters for the waiting for iATU enabled routine */
+#define LINK_WAIT_MAX_IATU_RETRIES	5
+#define LINK_WAIT_IATU_US		10000
+
+/* PCI DBICS registers */
+#define PCIE_LINK_STATUS_REG		0x80
+#define PCIE_LINK_STATUS_SPEED_OFF	16
+#define PCIE_LINK_STATUS_SPEED_MASK	(0xf << PCIE_LINK_STATUS_SPEED_OFF)
+#define PCIE_LINK_STATUS_WIDTH_OFF	20
+#define PCIE_LINK_STATUS_WIDTH_MASK	(0xf << PCIE_LINK_STATUS_WIDTH_OFF)
+
+#define PCIE_LINK_CAPABILITY		0x7c
+#define PCIE_LINK_CTL_2			0xa0
+#define TARGET_LINK_SPEED_MASK		0xf
+#define LINK_SPEED_GEN_1		0x1
+#define LINK_SPEED_GEN_2		0x2
+#define LINK_SPEED_GEN_3		0x3
+
+/* Synopsys-specific PCIe configuration registers */
+#define PCIE_PORT_LINK_CONTROL		0x710
+#define PORT_LINK_DLL_LINK_EN		BIT(5)
+#define PORT_LINK_FAST_LINK_MODE	BIT(7)
+#define PORT_LINK_MODE_MASK		GENMASK(21, 16)
+#define PORT_LINK_MODE(n)		FIELD_PREP(PORT_LINK_MODE_MASK, n)
+#define PORT_LINK_MODE_1_LANES		PORT_LINK_MODE(0x1)
+#define PORT_LINK_MODE_2_LANES		PORT_LINK_MODE(0x3)
+#define PORT_LINK_MODE_4_LANES		PORT_LINK_MODE(0x7)
+#define PORT_LINK_MODE_8_LANES		PORT_LINK_MODE(0xf)
+
+#define PCIE_LINK_WIDTH_SPEED_CONTROL	0x80C
+#define PORT_LOGIC_N_FTS_MASK		GENMASK(7, 0)
+#define PORT_LOGIC_SPEED_CHANGE		BIT(17)
+#define PORT_LOGIC_LINK_WIDTH_MASK	GENMASK(12, 8)
+#define PORT_LOGIC_LINK_WIDTH(n)	FIELD_PREP(PORT_LOGIC_LINK_WIDTH_MASK, n)
+#define PORT_LOGIC_LINK_WIDTH_1_LANES	PORT_LOGIC_LINK_WIDTH(0x1)
+#define PORT_LOGIC_LINK_WIDTH_2_LANES	PORT_LOGIC_LINK_WIDTH(0x2)
+#define PORT_LOGIC_LINK_WIDTH_4_LANES	PORT_LOGIC_LINK_WIDTH(0x4)
+#define PORT_LOGIC_LINK_WIDTH_8_LANES	PORT_LOGIC_LINK_WIDTH(0x8)
+
+#define PCIE_MISC_CONTROL_1_OFF		0x8bc
+#define PCIE_DBI_RO_WR_EN		BIT(0)
+
+/* Parameters for the waiting for iATU enabled routine */
+#define LINK_WAIT_MAX_IATU_RETRIES	5
+#define LINK_WAIT_IATU			10000
+
+/**
+ * struct pcie_dw - DW PCIe controller state
+ *
+ * @dbi_base: The base address of dbi register space
+ * @cfg_base: The base address of configuration space
+ * @atu_base: The base address of ATU space
+ * @cfg_size: The size of the configuration space which is needed
+ *            as it gets written into the PCIE_ATU_LIMIT register
+ * @first_busno: This driver supports multiple PCIe controllers.
+ *               first_busno stores the bus number of the PCIe root-port
+ *               number which may vary depending on the PCIe setup
+ *               (PEX switches etc).
+ * @io: The IO space for EP's BAR
+ * @mem: The memory space for EP's BAR
+ * @prefetch: The prefetch space for EP's BAR
+ */
+struct pcie_dw {
+	struct udevice	*dev;
+	void __iomem *dbi_base;
+	void __iomem *cfg_base;
+	void __iomem *atu_base;
+	fdt_size_t cfg_size;
+
+	int first_busno;
+
+	/* IO, MEM & PREFETCH PCI regions */
+	struct pci_region io;
+	struct pci_region mem;
+	struct pci_region prefetch;
+};
+
+int pcie_dw_get_link_speed(struct pcie_dw *pci);
+
+int pcie_dw_get_link_width(struct pcie_dw *pci);
+
+int pcie_dw_prog_outbound_atu_unroll(struct pcie_dw *pci, int index, int type, u64 cpu_addr,
+				     u64 pci_addr, u32 size);
+
+int pcie_dw_read_config(const struct udevice *bus, pci_dev_t bdf, uint offset, ulong *valuep,
+			enum pci_size_t size);
+
+int pcie_dw_write_config(struct udevice *bus, pci_dev_t bdf, uint offset, ulong value,
+			 enum pci_size_t size);
+
+static inline void dw_pcie_dbi_write_enable(struct pcie_dw *pci, bool en)
+{
+	u32 val;
+
+	val = readl(pci->dbi_base + PCIE_MISC_CONTROL_1_OFF);
+	if (en)
+		val |= PCIE_DBI_RO_WR_EN;
+	else
+		val &= ~PCIE_DBI_RO_WR_EN;
+	writel(val, pci->dbi_base + PCIE_MISC_CONTROL_1_OFF);
+}
+
+void pcie_dw_setup_host(struct pcie_dw *pci);
+
+#endif