PCI: xilinx-cpm: Add Versal CPM Root Port driver

Add support for Versal CPM as Root Port.

The Versal ACAP devices include CCIX-PCIe Module (CPM). The integrated
block for CPM along with the integrated bridge can function as PCIe Root
Port.

Bridge error and legacy interrupts in Versal CPM are handled using Versal
CPM specific interrupt line.

[bhelgaas: fold in kerneldoc fix from
https://lore.kernel.org/linux-acpi/20200729201224.26799-7-krzk@kernel.org/]
Link: https://lore.kernel.org/r/1592312214-9347-3-git-send-email-bharat.kumar.gogada@xilinx.comSigned-off-by: NBharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRob Herring <robh@kernel.org>

drivers/pci/controller/Kconfig

@@ -99,6 +99,14 @@ config PCIE_XILINX
 	  Say 'Y' here if you want kernel to support the Xilinx AXI PCIe
 	  Host Bridge driver.
 
+config PCIE_XILINX_CPM
+	bool "Xilinx Versal CPM host bridge support"
+	depends on ARCH_ZYNQMP || COMPILE_TEST
+	select PCI_HOST_COMMON
+	help
+	  Say 'Y' here if you want kernel support for the
+	  Xilinx Versal CPM host bridge.
+
 config PCI_XGENE
 	bool "X-Gene PCIe controller"
 	depends on ARM64 || COMPILE_TEST

drivers/pci/controller/Makefile

@@ -13,6 +13,7 @@ obj-$(CONFIG_PCI_HOST_COMMON) += pci-host-common.o
 obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
 obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
+obj-$(CONFIG_PCIE_XILINX_CPM) += pcie-xilinx-cpm.o
 obj-$(CONFIG_PCI_V3_SEMI) += pci-v3-semi.o
 obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o
 obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o

drivers/pci/controller/pcie-xilinx-cpm.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCIe host controller driver for Xilinx Versal CPM DMA Bridge
+ *
+ * (C) Copyright 2019 - 2020, Xilinx, Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/pci-ecam.h>
+
+#include "../pci.h"
+
+/* Register definitions */
+#define XILINX_CPM_PCIE_REG_IDR		0x00000E10
+#define XILINX_CPM_PCIE_REG_IMR		0x00000E14
+#define XILINX_CPM_PCIE_REG_PSCR	0x00000E1C
+#define XILINX_CPM_PCIE_REG_RPSC	0x00000E20
+#define XILINX_CPM_PCIE_REG_RPEFR	0x00000E2C
+#define XILINX_CPM_PCIE_REG_IDRN	0x00000E38
+#define XILINX_CPM_PCIE_REG_IDRN_MASK	0x00000E3C
+#define XILINX_CPM_PCIE_MISC_IR_STATUS	0x00000340
+#define XILINX_CPM_PCIE_MISC_IR_ENABLE	0x00000348
+#define XILINX_CPM_PCIE_MISC_IR_LOCAL	BIT(1)
+
+/* Interrupt registers definitions */
+#define XILINX_CPM_PCIE_INTR_LINK_DOWN		0
+#define XILINX_CPM_PCIE_INTR_HOT_RESET		3
+#define XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT	4
+#define XILINX_CPM_PCIE_INTR_CFG_TIMEOUT	8
+#define XILINX_CPM_PCIE_INTR_CORRECTABLE	9
+#define XILINX_CPM_PCIE_INTR_NONFATAL		10
+#define XILINX_CPM_PCIE_INTR_FATAL		11
+#define XILINX_CPM_PCIE_INTR_CFG_ERR_POISON	12
+#define XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD	15
+#define XILINX_CPM_PCIE_INTR_INTX		16
+#define XILINX_CPM_PCIE_INTR_PM_PME_RCVD	17
+#define XILINX_CPM_PCIE_INTR_SLV_UNSUPP		20
+#define XILINX_CPM_PCIE_INTR_SLV_UNEXP		21
+#define XILINX_CPM_PCIE_INTR_SLV_COMPL		22
+#define XILINX_CPM_PCIE_INTR_SLV_ERRP		23
+#define XILINX_CPM_PCIE_INTR_SLV_CMPABT		24
+#define XILINX_CPM_PCIE_INTR_SLV_ILLBUR		25
+#define XILINX_CPM_PCIE_INTR_MST_DECERR		26
+#define XILINX_CPM_PCIE_INTR_MST_SLVERR		27
+#define XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT	28
+
+#define IMR(x) BIT(XILINX_CPM_PCIE_INTR_ ##x)
+
+#define XILINX_CPM_PCIE_IMR_ALL_MASK			\
+	(						\
+		IMR(LINK_DOWN)		|		\
+		IMR(HOT_RESET)		|		\
+		IMR(CFG_PCIE_TIMEOUT)	|		\
+		IMR(CFG_TIMEOUT)	|		\
+		IMR(CORRECTABLE)	|		\
+		IMR(NONFATAL)		|		\
+		IMR(FATAL)		|		\
+		IMR(CFG_ERR_POISON)	|		\
+		IMR(PME_TO_ACK_RCVD)	|		\
+		IMR(INTX)		|		\
+		IMR(PM_PME_RCVD)	|		\
+		IMR(SLV_UNSUPP)		|		\
+		IMR(SLV_UNEXP)		|		\
+		IMR(SLV_COMPL)		|		\
+		IMR(SLV_ERRP)		|		\
+		IMR(SLV_CMPABT)		|		\
+		IMR(SLV_ILLBUR)		|		\
+		IMR(MST_DECERR)		|		\
+		IMR(MST_SLVERR)		|		\
+		IMR(SLV_PCIE_TIMEOUT)			\
+	)
+
+#define XILINX_CPM_PCIE_IDR_ALL_MASK		0xFFFFFFFF
+#define XILINX_CPM_PCIE_IDRN_MASK		GENMASK(19, 16)
+#define XILINX_CPM_PCIE_IDRN_SHIFT		16
+
+/* Root Port Error FIFO Read Register definitions */
+#define XILINX_CPM_PCIE_RPEFR_ERR_VALID		BIT(18)
+#define XILINX_CPM_PCIE_RPEFR_REQ_ID		GENMASK(15, 0)
+#define XILINX_CPM_PCIE_RPEFR_ALL_MASK		0xFFFFFFFF
+
+/* Root Port Status/control Register definitions */
+#define XILINX_CPM_PCIE_REG_RPSC_BEN		BIT(0)
+
+/* Phy Status/Control Register definitions */
+#define XILINX_CPM_PCIE_REG_PSCR_LNKUP		BIT(11)
+
+/**
+ * struct xilinx_cpm_pcie_port - PCIe port information
+ * @reg_base: Bridge Register Base
+ * @cpm_base: CPM System Level Control and Status Register(SLCR) Base
+ * @dev: Device pointer
+ * @intx_domain: Legacy IRQ domain pointer
+ * @cpm_domain: CPM IRQ domain pointer
+ * @cfg: Holds mappings of config space window
+ * @intx_irq: legacy interrupt number
+ * @irq: Error interrupt number
+ * @lock: lock protecting shared register access
+ */
+struct xilinx_cpm_pcie_port {
+	void __iomem			*reg_base;
+	void __iomem			*cpm_base;
+	struct device			*dev;
+	struct irq_domain		*intx_domain;
+	struct irq_domain		*cpm_domain;
+	struct pci_config_window	*cfg;
+	int				intx_irq;
+	int				irq;
+	raw_spinlock_t			lock;
+};
+
+static u32 pcie_read(struct xilinx_cpm_pcie_port *port, u32 reg)
+{
+	return readl_relaxed(port->reg_base + reg);
+}
+
+static void pcie_write(struct xilinx_cpm_pcie_port *port,
+		       u32 val, u32 reg)
+{
+	writel_relaxed(val, port->reg_base + reg);
+}
+
+static bool cpm_pcie_link_up(struct xilinx_cpm_pcie_port *port)
+{
+	return (pcie_read(port, XILINX_CPM_PCIE_REG_PSCR) &
+		XILINX_CPM_PCIE_REG_PSCR_LNKUP);
+}
+
+static void cpm_pcie_clear_err_interrupts(struct xilinx_cpm_pcie_port *port)
+{
+	unsigned long val = pcie_read(port, XILINX_CPM_PCIE_REG_RPEFR);
+
+	if (val & XILINX_CPM_PCIE_RPEFR_ERR_VALID) {
+		dev_dbg(port->dev, "Requester ID %lu\n",
+			val & XILINX_CPM_PCIE_RPEFR_REQ_ID);
+		pcie_write(port, XILINX_CPM_PCIE_RPEFR_ALL_MASK,
+			   XILINX_CPM_PCIE_REG_RPEFR);
+	}
+}
+
+static void xilinx_cpm_mask_leg_irq(struct irq_data *data)
+{
+	struct xilinx_cpm_pcie_port *port = irq_data_get_irq_chip_data(data);
+	unsigned long flags;
+	u32 mask;
+	u32 val;
+
+	mask = BIT(data->hwirq + XILINX_CPM_PCIE_IDRN_SHIFT);
+	raw_spin_lock_irqsave(&port->lock, flags);
+	val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN_MASK);
+	pcie_write(port, (val & (~mask)), XILINX_CPM_PCIE_REG_IDRN_MASK);
+	raw_spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void xilinx_cpm_unmask_leg_irq(struct irq_data *data)
+{
+	struct xilinx_cpm_pcie_port *port = irq_data_get_irq_chip_data(data);
+	unsigned long flags;
+	u32 mask;
+	u32 val;
+
+	mask = BIT(data->hwirq + XILINX_CPM_PCIE_IDRN_SHIFT);
+	raw_spin_lock_irqsave(&port->lock, flags);
+	val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN_MASK);
+	pcie_write(port, (val | mask), XILINX_CPM_PCIE_REG_IDRN_MASK);
+	raw_spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static struct irq_chip xilinx_cpm_leg_irq_chip = {
+	.name		= "INTx",
+	.irq_mask	= xilinx_cpm_mask_leg_irq,
+	.irq_unmask	= xilinx_cpm_unmask_leg_irq,
+};
+
+/**
+ * xilinx_cpm_pcie_intx_map - Set the handler for the INTx and mark IRQ as valid
+ * @domain: IRQ domain
+ * @irq: Virtual IRQ number
+ * @hwirq: HW interrupt number
+ *
+ * Return: Always returns 0.
+ */
+static int xilinx_cpm_pcie_intx_map(struct irq_domain *domain,
+				    unsigned int irq, irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &xilinx_cpm_leg_irq_chip,
+				 handle_level_irq);
+	irq_set_chip_data(irq, domain->host_data);
+	irq_set_status_flags(irq, IRQ_LEVEL);
+
+	return 0;
+}
+
+/* INTx IRQ Domain operations */
+static const struct irq_domain_ops intx_domain_ops = {
+	.map = xilinx_cpm_pcie_intx_map,
+};
+
+static void xilinx_cpm_pcie_intx_flow(struct irq_desc *desc)
+{
+	struct xilinx_cpm_pcie_port *port = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned long val;
+	int i;
+
+	chained_irq_enter(chip, desc);
+
+	val = FIELD_GET(XILINX_CPM_PCIE_IDRN_MASK,
+			pcie_read(port, XILINX_CPM_PCIE_REG_IDRN));
+
+	for_each_set_bit(i, &val, PCI_NUM_INTX)
+		generic_handle_irq(irq_find_mapping(port->intx_domain, i));
+
+	chained_irq_exit(chip, desc);
+}
+
+static void xilinx_cpm_mask_event_irq(struct irq_data *d)
+{
+	struct xilinx_cpm_pcie_port *port = irq_data_get_irq_chip_data(d);
+	u32 val;
+
+	raw_spin_lock(&port->lock);
+	val = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
+	val &= ~BIT(d->hwirq);
+	pcie_write(port, val, XILINX_CPM_PCIE_REG_IMR);
+	raw_spin_unlock(&port->lock);
+}
+
+static void xilinx_cpm_unmask_event_irq(struct irq_data *d)
+{
+	struct xilinx_cpm_pcie_port *port = irq_data_get_irq_chip_data(d);
+	u32 val;
+
+	raw_spin_lock(&port->lock);
+	val = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
+	val |= BIT(d->hwirq);
+	pcie_write(port, val, XILINX_CPM_PCIE_REG_IMR);
+	raw_spin_unlock(&port->lock);
+}
+
+static struct irq_chip xilinx_cpm_event_irq_chip = {
+	.name		= "RC-Event",
+	.irq_mask	= xilinx_cpm_mask_event_irq,
+	.irq_unmask	= xilinx_cpm_unmask_event_irq,
+};
+
+static int xilinx_cpm_pcie_event_map(struct irq_domain *domain,
+				     unsigned int irq, irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &xilinx_cpm_event_irq_chip,
+				 handle_level_irq);
+	irq_set_chip_data(irq, domain->host_data);
+	irq_set_status_flags(irq, IRQ_LEVEL);
+	return 0;
+}
+
+static const struct irq_domain_ops event_domain_ops = {
+	.map = xilinx_cpm_pcie_event_map,
+};
+
+static void xilinx_cpm_pcie_event_flow(struct irq_desc *desc)
+{
+	struct xilinx_cpm_pcie_port *port = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned long val;
+	int i;
+
+	chained_irq_enter(chip, desc);
+	val =  pcie_read(port, XILINX_CPM_PCIE_REG_IDR);
+	val &= pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
+	for_each_set_bit(i, &val, 32)
+		generic_handle_irq(irq_find_mapping(port->cpm_domain, i));
+	pcie_write(port, val, XILINX_CPM_PCIE_REG_IDR);
+
+	/*
+	 * XILINX_CPM_PCIE_MISC_IR_STATUS register is mapped to
+	 * CPM SLCR block.
+	 */
+	val = readl_relaxed(port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
+	if (val)
+		writel_relaxed(val,
+			       port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
+
+	chained_irq_exit(chip, desc);
+}
+
+#define _IC(x, s)                              \
+	[XILINX_CPM_PCIE_INTR_ ## x] = { __stringify(x), s }
+
+static const struct {
+	const char      *sym;
+	const char      *str;
+} intr_cause[32] = {
+	_IC(LINK_DOWN,		"Link Down"),
+	_IC(HOT_RESET,		"Hot reset"),
+	_IC(CFG_TIMEOUT,	"ECAM access timeout"),
+	_IC(CORRECTABLE,	"Correctable error message"),
+	_IC(NONFATAL,		"Non fatal error message"),
+	_IC(FATAL,		"Fatal error message"),
+	_IC(SLV_UNSUPP,		"Slave unsupported request"),
+	_IC(SLV_UNEXP,		"Slave unexpected completion"),
+	_IC(SLV_COMPL,		"Slave completion timeout"),
+	_IC(SLV_ERRP,		"Slave Error Poison"),
+	_IC(SLV_CMPABT,		"Slave Completer Abort"),
+	_IC(SLV_ILLBUR,		"Slave Illegal Burst"),
+	_IC(MST_DECERR,		"Master decode error"),
+	_IC(MST_SLVERR,		"Master slave error"),
+	_IC(CFG_PCIE_TIMEOUT,	"PCIe ECAM access timeout"),
+	_IC(CFG_ERR_POISON,	"ECAM poisoned completion received"),
+	_IC(PME_TO_ACK_RCVD,	"PME_TO_ACK message received"),
+	_IC(PM_PME_RCVD,	"PM_PME message received"),
+	_IC(SLV_PCIE_TIMEOUT,	"PCIe completion timeout received"),
+};
+
+static irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *dev_id)
+{
+	struct xilinx_cpm_pcie_port *port = dev_id;
+	struct device *dev = port->dev;
+	struct irq_data *d;
+
+	d = irq_domain_get_irq_data(port->cpm_domain, irq);
+
+	switch (d->hwirq) {
+	case XILINX_CPM_PCIE_INTR_CORRECTABLE:
+	case XILINX_CPM_PCIE_INTR_NONFATAL:
+	case XILINX_CPM_PCIE_INTR_FATAL:
+		cpm_pcie_clear_err_interrupts(port);
+		fallthrough;
+
+	default:
+		if (intr_cause[d->hwirq].str)
+			dev_warn(dev, "%s\n", intr_cause[d->hwirq].str);
+		else
+			dev_warn(dev, "Unknown IRQ %ld\n", d->hwirq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void xilinx_cpm_free_irq_domains(struct xilinx_cpm_pcie_port *port)
+{
+	if (port->intx_domain) {
+		irq_domain_remove(port->intx_domain);
+		port->intx_domain = NULL;
+	}
+
+	if (port->cpm_domain) {
+		irq_domain_remove(port->cpm_domain);
+		port->cpm_domain = NULL;
+	}
+}
+
+/**
+ * xilinx_cpm_pcie_init_irq_domain - Initialize IRQ domain
+ * @port: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_cpm_pcie_init_irq_domain(struct xilinx_cpm_pcie_port *port)
+{
+	struct device *dev = port->dev;
+	struct device_node *node = dev->of_node;
+	struct device_node *pcie_intc_node;
+
+	/* Setup INTx */
+	pcie_intc_node = of_get_next_child(node, NULL);
+	if (!pcie_intc_node) {
+		dev_err(dev, "No PCIe Intc node found\n");
+		return -EINVAL;
+	}
+
+	port->cpm_domain = irq_domain_add_linear(pcie_intc_node, 32,
+						 &event_domain_ops,
+						 port);
+	if (!port->cpm_domain)
+		goto out;
+
+	irq_domain_update_bus_token(port->cpm_domain, DOMAIN_BUS_NEXUS);
+
+	port->intx_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX,
+						  &intx_domain_ops,
+						  port);
+	if (!port->intx_domain)
+		goto out;
+
+	irq_domain_update_bus_token(port->intx_domain, DOMAIN_BUS_WIRED);
+
+	of_node_put(pcie_intc_node);
+	raw_spin_lock_init(&port->lock);
+
+	return 0;
+out:
+	xilinx_cpm_free_irq_domains(port);
+	dev_err(dev, "Failed to allocate IRQ domains\n");
+
+	return -ENOMEM;
+}
+
+static int xilinx_cpm_setup_irq(struct xilinx_cpm_pcie_port *port)
+{
+	struct device *dev = port->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	int i, irq;
+
+	port->irq = platform_get_irq(pdev, 0);
+	if (port->irq < 0)
+		return port->irq;
+
+	for (i = 0; i < ARRAY_SIZE(intr_cause); i++) {
+		int err;
+
+		if (!intr_cause[i].str)
+			continue;
+
+		irq = irq_create_mapping(port->cpm_domain, i);
+		if (!irq) {
+			dev_err(dev, "Failed to map interrupt\n");
+			return -ENXIO;
+		}
+
+		err = devm_request_irq(dev, irq, xilinx_cpm_pcie_intr_handler,
+				       0, intr_cause[i].sym, port);
+		if (err) {
+			dev_err(dev, "Failed to request IRQ %d\n", irq);
+			return err;
+		}
+	}
+
+	port->intx_irq = irq_create_mapping(port->cpm_domain,
+					    XILINX_CPM_PCIE_INTR_INTX);
+	if (!port->intx_irq) {
+		dev_err(dev, "Failed to map INTx interrupt\n");
+		return -ENXIO;
+	}
+
+	/* Plug the INTx chained handler */
+	irq_set_chained_handler_and_data(port->intx_irq,
+					 xilinx_cpm_pcie_intx_flow, port);
+
+	/* Plug the main event chained handler */
+	irq_set_chained_handler_and_data(port->irq,
+					 xilinx_cpm_pcie_event_flow, port);
+
+	return 0;
+}
+
+/**
+ * xilinx_cpm_pcie_init_port - Initialize hardware
+ * @port: PCIe port information
+ */
+static void xilinx_cpm_pcie_init_port(struct xilinx_cpm_pcie_port *port)
+{
+	if (cpm_pcie_link_up(port))
+		dev_info(port->dev, "PCIe Link is UP\n");
+	else
+		dev_info(port->dev, "PCIe Link is DOWN\n");
+
+	/* Disable all interrupts */
+	pcie_write(port, ~XILINX_CPM_PCIE_IDR_ALL_MASK,
+		   XILINX_CPM_PCIE_REG_IMR);
+
+	/* Clear pending interrupts */
+	pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_IDR) &
+		   XILINX_CPM_PCIE_IMR_ALL_MASK,
+		   XILINX_CPM_PCIE_REG_IDR);
+
+	/*
+	 * XILINX_CPM_PCIE_MISC_IR_ENABLE register is mapped to
+	 * CPM SLCR block.
+	 */
+	writel(XILINX_CPM_PCIE_MISC_IR_LOCAL,
+	       port->cpm_base + XILINX_CPM_PCIE_MISC_IR_ENABLE);
+	/* Enable the Bridge enable bit */
+	pcie_write(port, pcie_read(port, XILINX_CPM_PCIE_REG_RPSC) |
+		   XILINX_CPM_PCIE_REG_RPSC_BEN,
+		   XILINX_CPM_PCIE_REG_RPSC);
+}
+
+/**
+ * xilinx_cpm_pcie_parse_dt - Parse Device tree
+ * @port: PCIe port information
+ * @bus_range: Bus resource
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_cpm_pcie_parse_dt(struct xilinx_cpm_pcie_port *port,
+				    struct resource *bus_range)
+{
+	struct device *dev = port->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	struct resource *res;
+
+	port->cpm_base = devm_platform_ioremap_resource_byname(pdev,
+							       "cpm_slcr");
+	if (IS_ERR(port->cpm_base))
+		return PTR_ERR(port->cpm_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+	if (!res)
+		return -ENXIO;
+
+	port->cfg = pci_ecam_create(dev, res, bus_range,
+				    &pci_generic_ecam_ops);
+	if (IS_ERR(port->cfg))
+		return PTR_ERR(port->cfg);
+
+	port->reg_base = port->cfg->win;
+
+	return 0;
+}
+
+static void xilinx_cpm_free_interrupts(struct xilinx_cpm_pcie_port *port)
+{
+	irq_set_chained_handler_and_data(port->intx_irq, NULL, NULL);
+	irq_set_chained_handler_and_data(port->irq, NULL, NULL);
+}
+
+/**
+ * xilinx_cpm_pcie_probe - Probe function
+ * @pdev: Platform device pointer
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_cpm_pcie_probe(struct platform_device *pdev)
+{
+	struct xilinx_cpm_pcie_port *port;
+	struct device *dev = &pdev->dev;
+	struct pci_host_bridge *bridge;
+	struct resource *bus_range;
+	int err;
+
+	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*port));
+	if (!bridge)
+		return -ENODEV;
+
+	port = pci_host_bridge_priv(bridge);
+
+	port->dev = dev;
+
+	err = pci_parse_request_of_pci_ranges(dev, &bridge->windows,
+					      &bridge->dma_ranges, &bus_range);
+	if (err) {
+		dev_err(dev, "Getting bridge resources failed\n");
+		return err;
+	}
+
+	err = xilinx_cpm_pcie_init_irq_domain(port);
+	if (err)
+		return err;
+
+	err = xilinx_cpm_pcie_parse_dt(port, bus_range);
+	if (err) {
+		dev_err(dev, "Parsing DT failed\n");
+		goto err_parse_dt;
+	}
+
+	xilinx_cpm_pcie_init_port(port);
+
+	err = xilinx_cpm_setup_irq(port);
+	if (err) {
+		dev_err(dev, "Failed to set up interrupts\n");
+		goto err_setup_irq;
+	}
+
+	bridge->dev.parent = dev;
+	bridge->sysdata = port->cfg;
+	bridge->busnr = port->cfg->busr.start;
+	bridge->ops = (struct pci_ops *)&pci_generic_ecam_ops.pci_ops;
+	bridge->map_irq = of_irq_parse_and_map_pci;
+	bridge->swizzle_irq = pci_common_swizzle;
+
+	err = pci_host_probe(bridge);
+	if (err < 0)
+		goto err_host_bridge;
+
+	return 0;
+
+err_host_bridge:
+	xilinx_cpm_free_interrupts(port);
+err_setup_irq:
+	pci_ecam_free(port->cfg);
+err_parse_dt:
+	xilinx_cpm_free_irq_domains(port);
+	return err;
+}
+
+static const struct of_device_id xilinx_cpm_pcie_of_match[] = {
+	{ .compatible = "xlnx,versal-cpm-host-1.00", },
+	{}
+};
+
+static struct platform_driver xilinx_cpm_pcie_driver = {
+	.driver = {
+		.name = "xilinx-cpm-pcie",
+		.of_match_table = xilinx_cpm_pcie_of_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = xilinx_cpm_pcie_probe,
+};
+
+builtin_platform_driver(xilinx_cpm_pcie_driver);