PCI: xilinx-nwl: Add support for Xilinx NWL PCIe Host Controller

Add PCIe Root Port driver for Xilinx PCIe NWL bridge IP.

[bhelgaas: wait for link like dw_pcie_wait_for_link(), simplify bitmap
error path, typos, whitespace, fold in Dan Carpenter's PTR_ERR() fix]
Signed-off-by: Bharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: Ravi Kiran Gummaluri <rgummal@xilinx.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Rob Herring <robh@kernel.org>

3 files changed, 892 insertions, 0 deletions

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 75a6054..c39989a 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -16,6 +16,16 @@ config PCI_MVEBU
 	depends on ARCH_MVEBU || ARCH_DOVE
 	depends on OF
 
+config PCIE_XILINX_NWL
+	bool "NWL PCIe Core"
+	depends on ARCH_ZYNQMP
+	select PCI_MSI_IRQ_DOMAIN if PCI_MSI
+	help
+	 Say 'Y' here if you want kernel support for Xilinx
+	 NWL PCIe controller. The controller can act as Root Port
+	 or End Point. The current option selection will only
+	 support root port enabling.
+
 config PCIE_DW
 	bool
 
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 7b2f20c..d0b7d85 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_PCI_HOST_GENERIC) += pci-host-generic.o
 obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
 obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
 obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
+obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
 obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
 obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o
 obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
diff --git a/drivers/pci/host/pcie-xilinx-nwl.c b/drivers/pci/host/pcie-xilinx-nwl.c
new file mode 100644
index 0000000..5139e64
--- /dev/null
+++ b/drivers/pci/host/pcie-xilinx-nwl.c
@@ -0,0 +1,881 @@
+/*
+ * PCIe host controller driver for NWL PCIe Bridge
+ * Based on pcie-xilinx.c, pci-tegra.c
+ *
+ * (C) Copyright 2014 - 2015, Xilinx, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/msi.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/irqchip/chained_irq.h>
+
+/* Bridge core config registers */
+#define BRCFG_PCIE_RX0			0x00000000
+#define BRCFG_INTERRUPT			0x00000010
+#define BRCFG_PCIE_RX_MSG_FILTER	0x00000020
+
+/* Egress - Bridge translation registers */
+#define E_BREG_CAPABILITIES		0x00000200
+#define E_BREG_CONTROL			0x00000208
+#define E_BREG_BASE_LO			0x00000210
+#define E_BREG_BASE_HI			0x00000214
+#define E_ECAM_CAPABILITIES		0x00000220
+#define E_ECAM_CONTROL			0x00000228
+#define E_ECAM_BASE_LO			0x00000230
+#define E_ECAM_BASE_HI			0x00000234
+
+/* Ingress - address translations */
+#define I_MSII_CAPABILITIES		0x00000300
+#define I_MSII_CONTROL			0x00000308
+#define I_MSII_BASE_LO			0x00000310
+#define I_MSII_BASE_HI			0x00000314
+
+#define I_ISUB_CONTROL			0x000003E8
+#define SET_ISUB_CONTROL		BIT(0)
+/* Rxed msg fifo  - Interrupt status registers */
+#define MSGF_MISC_STATUS		0x00000400
+#define MSGF_MISC_MASK			0x00000404
+#define MSGF_LEG_STATUS			0x00000420
+#define MSGF_LEG_MASK			0x00000424
+#define MSGF_MSI_STATUS_LO		0x00000440
+#define MSGF_MSI_STATUS_HI		0x00000444
+#define MSGF_MSI_MASK_LO		0x00000448
+#define MSGF_MSI_MASK_HI		0x0000044C
+
+/* Msg filter mask bits */
+#define CFG_ENABLE_PM_MSG_FWD		BIT(1)
+#define CFG_ENABLE_INT_MSG_FWD		BIT(2)
+#define CFG_ENABLE_ERR_MSG_FWD		BIT(3)
+#define CFG_ENABLE_SLT_MSG_FWD		BIT(5)
+#define CFG_ENABLE_VEN_MSG_FWD		BIT(7)
+#define CFG_ENABLE_OTH_MSG_FWD		BIT(13)
+#define CFG_ENABLE_VEN_MSG_EN		BIT(14)
+#define CFG_ENABLE_VEN_MSG_VEN_INV	BIT(15)
+#define CFG_ENABLE_VEN_MSG_VEN_ID	GENMASK(31, 16)
+#define CFG_ENABLE_MSG_FILTER_MASK	(CFG_ENABLE_PM_MSG_FWD | \
+					CFG_ENABLE_INT_MSG_FWD | \
+					CFG_ENABLE_ERR_MSG_FWD | \
+					CFG_ENABLE_SLT_MSG_FWD | \
+					CFG_ENABLE_VEN_MSG_FWD | \
+					CFG_ENABLE_OTH_MSG_FWD | \
+					CFG_ENABLE_VEN_MSG_EN | \
+					CFG_ENABLE_VEN_MSG_VEN_INV | \
+					CFG_ENABLE_VEN_MSG_VEN_ID)
+
+/* Misc interrupt status mask bits */
+#define MSGF_MISC_SR_RXMSG_AVAIL	BIT(0)
+#define MSGF_MISC_SR_RXMSG_OVER		BIT(1)
+#define MSGF_MISC_SR_SLAVE_ERR		BIT(4)
+#define MSGF_MISC_SR_MASTER_ERR		BIT(5)
+#define MSGF_MISC_SR_I_ADDR_ERR		BIT(6)
+#define MSGF_MISC_SR_E_ADDR_ERR		BIT(7)
+#define MSGF_MISC_SR_UR_DETECT          BIT(20)
+
+#define MSGF_MISC_SR_PCIE_CORE		GENMASK(18, 16)
+#define MSGF_MISC_SR_PCIE_CORE_ERR	GENMASK(31, 22)
+
+#define MSGF_MISC_SR_MASKALL		(MSGF_MISC_SR_RXMSG_AVAIL | \
+					MSGF_MISC_SR_RXMSG_OVER | \
+					MSGF_MISC_SR_SLAVE_ERR | \
+					MSGF_MISC_SR_MASTER_ERR | \
+					MSGF_MISC_SR_I_ADDR_ERR | \
+					MSGF_MISC_SR_E_ADDR_ERR | \
+					MSGF_MISC_SR_UR_DETECT | \
+					MSGF_MISC_SR_PCIE_CORE | \
+					MSGF_MISC_SR_PCIE_CORE_ERR)
+
+/* Legacy interrupt status mask bits */
+#define MSGF_LEG_SR_INTA		BIT(0)
+#define MSGF_LEG_SR_INTB		BIT(1)
+#define MSGF_LEG_SR_INTC		BIT(2)
+#define MSGF_LEG_SR_INTD		BIT(3)
+#define MSGF_LEG_SR_MASKALL		(MSGF_LEG_SR_INTA | MSGF_LEG_SR_INTB | \
+					MSGF_LEG_SR_INTC | MSGF_LEG_SR_INTD)
+
+/* MSI interrupt status mask bits */
+#define MSGF_MSI_SR_LO_MASK		BIT(0)
+#define MSGF_MSI_SR_HI_MASK		BIT(0)
+
+#define MSII_PRESENT			BIT(0)
+#define MSII_ENABLE			BIT(0)
+#define MSII_STATUS_ENABLE		BIT(15)
+
+/* Bridge config interrupt mask */
+#define BRCFG_INTERRUPT_MASK		BIT(0)
+#define BREG_PRESENT			BIT(0)
+#define BREG_ENABLE			BIT(0)
+#define BREG_ENABLE_FORCE		BIT(1)
+
+/* E_ECAM status mask bits */
+#define E_ECAM_PRESENT			BIT(0)
+#define E_ECAM_CR_ENABLE		BIT(0)
+#define E_ECAM_SIZE_LOC			GENMASK(20, 16)
+#define E_ECAM_SIZE_SHIFT		16
+#define ECAM_BUS_LOC_SHIFT		20
+#define ECAM_DEV_LOC_SHIFT		12
+#define NWL_ECAM_VALUE_DEFAULT		12
+
+#define CFG_DMA_REG_BAR			GENMASK(2, 0)
+
+#define INT_PCI_MSI_NR			(2 * 32)
+#define INTX_NUM			4
+
+/* Readin the PS_LINKUP */
+#define PS_LINKUP_OFFSET		0x00000238
+#define PCIE_PHY_LINKUP_BIT		BIT(0)
+#define PHY_RDY_LINKUP_BIT		BIT(1)
+
+/* Parameters for the waiting for link up routine */
+#define LINK_WAIT_MAX_RETRIES          10
+#define LINK_WAIT_USLEEP_MIN           90000
+#define LINK_WAIT_USLEEP_MAX           100000
+
+struct nwl_msi {			/* MSI information */
+	struct irq_domain *msi_domain;
+	unsigned long *bitmap;
+	struct irq_domain *dev_domain;
+	struct mutex lock;		/* protect bitmap variable */
+	int irq_msi0;
+	int irq_msi1;
+};
+
+struct nwl_pcie {
+	struct device *dev;
+	void __iomem *breg_base;
+	void __iomem *pcireg_base;
+	void __iomem *ecam_base;
+	phys_addr_t phys_breg_base;	/* Physical Bridge Register Base */
+	phys_addr_t phys_pcie_reg_base;	/* Physical PCIe Controller Base */
+	phys_addr_t phys_ecam_base;	/* Physical Configuration Base */
+	u32 breg_size;
+	u32 pcie_reg_size;
+	u32 ecam_size;
+	int irq_intx;
+	int irq_misc;
+	u32 ecam_value;
+	u8 last_busno;
+	u8 root_busno;
+	struct nwl_msi msi;
+	struct irq_domain *legacy_irq_domain;
+};
+
+static inline u32 nwl_bridge_readl(struct nwl_pcie *pcie, u32 off)
+{
+	return readl(pcie->breg_base + off);
+}
+
+static inline void nwl_bridge_writel(struct nwl_pcie *pcie, u32 val, u32 off)
+{
+	writel(val, pcie->breg_base + off);
+}
+
+static bool nwl_pcie_link_up(struct nwl_pcie *pcie)
+{
+	if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PCIE_PHY_LINKUP_BIT)
+		return true;
+	return false;
+}
+
+static bool nwl_phy_link_up(struct nwl_pcie *pcie)
+{
+	if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PHY_RDY_LINKUP_BIT)
+		return true;
+	return false;
+}
+
+static int nwl_wait_for_link(struct nwl_pcie *pcie)
+{
+	int retries;
+
+	/* check if the link is up or not */
+	for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
+		if (nwl_phy_link_up(pcie))
+			return 0;
+		usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
+	}
+
+	dev_err(pcie->dev, "PHY link never came up\n");
+	return -ETIMEDOUT;
+}
+
+static bool nwl_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
+{
+	struct nwl_pcie *pcie = bus->sysdata;
+
+	/* Check link before accessing downstream ports */
+	if (bus->number != pcie->root_busno) {
+		if (!nwl_pcie_link_up(pcie))
+			return false;
+	}
+
+	/* Only one device down on each root port */
+	if (bus->number == pcie->root_busno && devfn > 0)
+		return false;
+
+	return true;
+}
+
+/**
+ * nwl_pcie_map_bus - Get configuration base
+ *
+ * @bus: Bus structure of current bus
+ * @devfn: Device/function
+ * @where: Offset from base
+ *
+ * Return: Base address of the configuration space needed to be
+ *	   accessed.
+ */
+static void __iomem *nwl_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
+				      int where)
+{
+	struct nwl_pcie *pcie = bus->sysdata;
+	int relbus;
+
+	if (!nwl_pcie_valid_device(bus, devfn))
+		return NULL;
+
+	relbus = (bus->number << ECAM_BUS_LOC_SHIFT) |
+			(devfn << ECAM_DEV_LOC_SHIFT);
+
+	return pcie->ecam_base + relbus + where;
+}
+
+/* PCIe operations */
+static struct pci_ops nwl_pcie_ops = {
+	.map_bus = nwl_pcie_map_bus,
+	.read  = pci_generic_config_read,
+	.write = pci_generic_config_write,
+};
+
+static irqreturn_t nwl_pcie_misc_handler(int irq, void *data)
+{
+	struct nwl_pcie *pcie = data;
+	u32 misc_stat;
+
+	/* Checking for misc interrupts */
+	misc_stat = nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
+				     MSGF_MISC_SR_MASKALL;
+	if (!misc_stat)
+		return IRQ_NONE;
+
+	if (misc_stat & MSGF_MISC_SR_RXMSG_OVER)
+		dev_err(pcie->dev, "Received Message FIFO Overflow\n");
+
+	if (misc_stat & MSGF_MISC_SR_SLAVE_ERR)
+		dev_err(pcie->dev, "Slave error\n");
+
+	if (misc_stat & MSGF_MISC_SR_MASTER_ERR)
+		dev_err(pcie->dev, "Master error\n");
+
+	if (misc_stat & MSGF_MISC_SR_I_ADDR_ERR)
+		dev_err(pcie->dev,
+			"In Misc Ingress address translation error\n");
+
+	if (misc_stat & MSGF_MISC_SR_E_ADDR_ERR)
+		dev_err(pcie->dev,
+			"In Misc Egress address translation error\n");
+
+	if (misc_stat & MSGF_MISC_SR_PCIE_CORE_ERR)
+		dev_err(pcie->dev, "PCIe Core error\n");
+
+	/* Clear misc interrupt status */
+	nwl_bridge_writel(pcie, misc_stat, MSGF_MISC_STATUS);
+
+	return IRQ_HANDLED;
+}
+
+static void nwl_pcie_leg_handler(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct nwl_pcie *pcie;
+	unsigned long status;
+	u32 bit;
+	u32 virq;
+
+	chained_irq_enter(chip, desc);
+	pcie = irq_desc_get_handler_data(desc);
+
+	while ((status = nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
+				MSGF_LEG_SR_MASKALL) != 0) {
+		for_each_set_bit(bit, &status, INTX_NUM) {
+			virq = irq_find_mapping(pcie->legacy_irq_domain,
+						bit + 1);
+			if (virq)
+				generic_handle_irq(virq);
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void nwl_pcie_handle_msi_irq(struct nwl_pcie *pcie, u32 status_reg)
+{
+	struct nwl_msi *msi;
+	unsigned long status;
+	u32 bit;
+	u32 virq;
+
+	msi = &pcie->msi;
+
+	while ((status = nwl_bridge_readl(pcie, status_reg)) != 0) {
+		for_each_set_bit(bit, &status, 32) {
+			nwl_bridge_writel(pcie, 1 << bit, status_reg);
+			virq = irq_find_mapping(msi->dev_domain, bit);
+			if (virq)
+				generic_handle_irq(virq);
+		}
+	}
+}
+
+static void nwl_pcie_msi_handler_high(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct nwl_pcie *pcie = irq_desc_get_handler_data(desc);
+
+	chained_irq_enter(chip, desc);
+	nwl_pcie_handle_msi_irq(pcie, MSGF_MSI_STATUS_HI);
+	chained_irq_exit(chip, desc);
+}
+
+static void nwl_pcie_msi_handler_low(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct nwl_pcie *pcie = irq_desc_get_handler_data(desc);
+
+	chained_irq_enter(chip, desc);
+	nwl_pcie_handle_msi_irq(pcie, MSGF_MSI_STATUS_LO);
+	chained_irq_exit(chip, desc);
+}
+
+static int nwl_legacy_map(struct irq_domain *domain, unsigned int irq,
+			  irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+
+	return 0;
+}
+
+static const struct irq_domain_ops legacy_domain_ops = {
+	.map = nwl_legacy_map,
+};
+
+#ifdef CONFIG_PCI_MSI
+static struct irq_chip nwl_msi_irq_chip = {
+	.name = "nwl_pcie:msi",
+	.irq_enable = unmask_msi_irq,
+	.irq_disable = mask_msi_irq,
+	.irq_mask = mask_msi_irq,
+	.irq_unmask = unmask_msi_irq,
+
+};
+
+static struct msi_domain_info nwl_msi_domain_info = {
+	.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		  MSI_FLAG_MULTI_PCI_MSI),
+	.chip = &nwl_msi_irq_chip,
+};
+#endif
+
+static void nwl_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct nwl_pcie *pcie = irq_data_get_irq_chip_data(data);
+	phys_addr_t msi_addr = pcie->phys_pcie_reg_base;
+
+	msg->address_lo = lower_32_bits(msi_addr);
+	msg->address_hi = upper_32_bits(msi_addr);
+	msg->data = data->hwirq;
+}
+
+static int nwl_msi_set_affinity(struct irq_data *irq_data,
+				const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
+}
+
+static struct irq_chip nwl_irq_chip = {
+	.name = "Xilinx MSI",
+	.irq_compose_msi_msg = nwl_compose_msi_msg,
+	.irq_set_affinity = nwl_msi_set_affinity,
+};
+
+static int nwl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				unsigned int nr_irqs, void *args)
+{
+	struct nwl_pcie *pcie = domain->host_data;
+	struct nwl_msi *msi = &pcie->msi;
+	int bit;
+	int i;
+
+	mutex_lock(&msi->lock);
+	bit = bitmap_find_next_zero_area(msi->bitmap, INT_PCI_MSI_NR, 0,
+					 nr_irqs, 0);
+	if (bit >= INT_PCI_MSI_NR) {
+		mutex_unlock(&msi->lock);
+		return -ENOSPC;
+	}
+
+	bitmap_set(msi->bitmap, bit, nr_irqs);
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, bit + i, &nwl_irq_chip,
+				domain->host_data, handle_simple_irq,
+				NULL, NULL);
+	}
+	mutex_unlock(&msi->lock);
+	return 0;
+}
+
+static void nwl_irq_domain_free(struct irq_domain *domain, unsigned int virq,
+					unsigned int nr_irqs)
+{
+	struct irq_data *data = irq_domain_get_irq_data(domain, virq);
+	struct nwl_pcie *pcie = irq_data_get_irq_chip_data(data);
+	struct nwl_msi *msi = &pcie->msi;
+
+	mutex_lock(&msi->lock);
+	bitmap_clear(msi->bitmap, data->hwirq, nr_irqs);
+	mutex_unlock(&msi->lock);
+}
+
+static const struct irq_domain_ops dev_msi_domain_ops = {
+	.alloc  = nwl_irq_domain_alloc,
+	.free   = nwl_irq_domain_free,
+};
+
+static void nwl_msi_free_irq_domain(struct nwl_pcie *pcie)
+{
+	struct nwl_msi *msi = &pcie->msi;
+
+	if (msi->irq_msi0)
+		irq_set_chained_handler_and_data(msi->irq_msi0, NULL, NULL);
+	if (msi->irq_msi1)
+		irq_set_chained_handler_and_data(msi->irq_msi1, NULL, NULL);
+
+	if (msi->msi_domain)
+		irq_domain_remove(msi->msi_domain);
+	if (msi->dev_domain)
+		irq_domain_remove(msi->dev_domain);
+
+	kfree(msi->bitmap);
+	msi->bitmap = NULL;
+}
+
+static void nwl_pcie_free_irq_domain(struct nwl_pcie *pcie)
+{
+	int i;
+	u32 irq;
+
+	for (i = 0; i < INTX_NUM; i++) {
+		irq = irq_find_mapping(pcie->legacy_irq_domain, i + 1);
+		if (irq > 0)
+			irq_dispose_mapping(irq);
+	}
+	if (pcie->legacy_irq_domain)
+		irq_domain_remove(pcie->legacy_irq_domain);
+
+	nwl_msi_free_irq_domain(pcie);
+}
+
+static int nwl_pcie_init_msi_irq_domain(struct nwl_pcie *pcie)
+{
+#ifdef CONFIG_PCI_MSI
+	struct fwnode_handle *fwnode = of_node_to_fwnode(pcie->dev->of_node);
+	struct nwl_msi *msi = &pcie->msi;
+
+	msi->dev_domain = irq_domain_add_linear(NULL, INT_PCI_MSI_NR,
+						&dev_msi_domain_ops, pcie);
+	if (!msi->dev_domain) {
+		dev_err(pcie->dev, "failed to create dev IRQ domain\n");
+		return -ENOMEM;
+	}
+	msi->msi_domain = pci_msi_create_irq_domain(fwnode,
+						    &nwl_msi_domain_info,
+						    msi->dev_domain);
+	if (!msi->msi_domain) {
+		dev_err(pcie->dev, "failed to create msi IRQ domain\n");
+		irq_domain_remove(msi->dev_domain);
+		return -ENOMEM;
+	}
+#endif
+	return 0;
+}
+
+static int nwl_pcie_init_irq_domain(struct nwl_pcie *pcie)
+{
+	struct device_node *node = pcie->dev->of_node;
+	struct device_node *legacy_intc_node;
+
+	legacy_intc_node = of_get_next_child(node, NULL);
+	if (!legacy_intc_node) {
+		dev_err(pcie->dev, "No legacy intc node found\n");
+		return -EINVAL;
+	}
+
+	pcie->legacy_irq_domain = irq_domain_add_linear(legacy_intc_node,
+							INTX_NUM,
+							&legacy_domain_ops,
+							pcie);
+
+	if (!pcie->legacy_irq_domain) {
+		dev_err(pcie->dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	nwl_pcie_init_msi_irq_domain(pcie);
+	return 0;
+}
+
+static int nwl_pcie_enable_msi(struct nwl_pcie *pcie, struct pci_bus *bus)
+{
+	struct platform_device *pdev = to_platform_device(pcie->dev);
+	struct nwl_msi *msi = &pcie->msi;
+	unsigned long base;
+	int ret;
+	int size = BITS_TO_LONGS(INT_PCI_MSI_NR) * sizeof(long);
+
+	mutex_init(&msi->lock);
+
+	msi->bitmap = kzalloc(size, GFP_KERNEL);
+	if (!msi->bitmap)
+		return -ENOMEM;
+
+	/* Get msi_1 IRQ number */
+	msi->irq_msi1 = platform_get_irq_byname(pdev, "msi1");
+	if (msi->irq_msi1 < 0) {
+		dev_err(&pdev->dev, "failed to get IRQ#%d\n", msi->irq_msi1);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	irq_set_chained_handler_and_data(msi->irq_msi1,
+					 nwl_pcie_msi_handler_high, pcie);
+
+	/* Get msi_0 IRQ number */
+	msi->irq_msi0 = platform_get_irq_byname(pdev, "msi0");
+	if (msi->irq_msi0 < 0) {
+		dev_err(&pdev->dev, "failed to get IRQ#%d\n", msi->irq_msi0);
+		ret = -EINVAL;
+		goto err;
+	}
+
+	irq_set_chained_handler_and_data(msi->irq_msi0,
+					 nwl_pcie_msi_handler_low, pcie);
+
+	/* Check for msii_present bit */
+	ret = nwl_bridge_readl(pcie, I_MSII_CAPABILITIES) & MSII_PRESENT;
+	if (!ret) {
+		dev_err(pcie->dev, "MSI not present\n");
+		ret = -EIO;
+		goto err;
+	}
+
+	/* Enable MSII */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
+			  MSII_ENABLE, I_MSII_CONTROL);
+
+	/* Enable MSII status */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
+			  MSII_STATUS_ENABLE, I_MSII_CONTROL);
+
+	/* setup AFI/FPCI range */
+	base = pcie->phys_pcie_reg_base;
+	nwl_bridge_writel(pcie, lower_32_bits(base), I_MSII_BASE_LO);
+	nwl_bridge_writel(pcie, upper_32_bits(base), I_MSII_BASE_HI);
+
+	/*
+	 * For high range MSI interrupts: disable, clear any pending,
+	 * and enable
+	 */
+	nwl_bridge_writel(pcie, (u32)~MSGF_MSI_SR_HI_MASK, MSGF_MSI_MASK_HI);
+
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie,  MSGF_MSI_STATUS_HI) &
+			  MSGF_MSI_SR_HI_MASK, MSGF_MSI_STATUS_HI);
+
+	nwl_bridge_writel(pcie, MSGF_MSI_SR_HI_MASK, MSGF_MSI_MASK_HI);
+
+	/*
+	 * For low range MSI interrupts: disable, clear any pending,
+	 * and enable
+	 */
+	nwl_bridge_writel(pcie, (u32)~MSGF_MSI_SR_LO_MASK, MSGF_MSI_MASK_LO);
+
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MSI_STATUS_LO) &
+			  MSGF_MSI_SR_LO_MASK, MSGF_MSI_STATUS_LO);
+
+	nwl_bridge_writel(pcie, MSGF_MSI_SR_LO_MASK, MSGF_MSI_MASK_LO);
+
+	return 0;
+err:
+	kfree(msi->bitmap);
+	msi->bitmap = NULL;
+	return ret;
+}
+
+static int nwl_pcie_bridge_init(struct nwl_pcie *pcie)
+{
+	struct platform_device *pdev = to_platform_device(pcie->dev);
+	u32 breg_val, ecam_val, first_busno = 0;
+	int err;
+
+	breg_val = nwl_bridge_readl(pcie, E_BREG_CAPABILITIES) & BREG_PRESENT;
+	if (!breg_val) {
+		dev_err(pcie->dev, "BREG is not present\n");
+		return breg_val;
+	}
+
+	/* Write bridge_off to breg base */
+	nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_breg_base),
+			  E_BREG_BASE_LO);
+	nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_breg_base),
+			  E_BREG_BASE_HI);
+
+	/* Enable BREG */
+	nwl_bridge_writel(pcie, ~BREG_ENABLE_FORCE & BREG_ENABLE,
+			  E_BREG_CONTROL);
+
+	/* Disable DMA channel registers */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_PCIE_RX0) |
+			  CFG_DMA_REG_BAR, BRCFG_PCIE_RX0);
+
+	/* Enable Ingress subtractive decode translation */
+	nwl_bridge_writel(pcie, SET_ISUB_CONTROL, I_ISUB_CONTROL);
+
+	/* Enable msg filtering details */
+	nwl_bridge_writel(pcie, CFG_ENABLE_MSG_FILTER_MASK,
+			  BRCFG_PCIE_RX_MSG_FILTER);
+
+	err = nwl_wait_for_link(pcie);
+	if (err)
+		return err;
+
+	ecam_val = nwl_bridge_readl(pcie, E_ECAM_CAPABILITIES) & E_ECAM_PRESENT;
+	if (!ecam_val) {
+		dev_err(pcie->dev, "ECAM is not present\n");
+		return ecam_val;
+	}
+
+	/* Enable ECAM */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
+			  E_ECAM_CR_ENABLE, E_ECAM_CONTROL);
+
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
+			  (pcie->ecam_value << E_ECAM_SIZE_SHIFT),
+			  E_ECAM_CONTROL);
+
+	nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_ecam_base),
+			  E_ECAM_BASE_LO);
+	nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_ecam_base),
+			  E_ECAM_BASE_HI);
+
+	/* Get bus range */
+	ecam_val = nwl_bridge_readl(pcie, E_ECAM_CONTROL);
+	pcie->last_busno = (ecam_val & E_ECAM_SIZE_LOC) >> E_ECAM_SIZE_SHIFT;
+	/* Write primary, secondary and subordinate bus numbers */
+	ecam_val = first_busno;
+	ecam_val |= (first_busno + 1) << 8;
+	ecam_val |= (pcie->last_busno << E_ECAM_SIZE_SHIFT);
+	writel(ecam_val, (pcie->ecam_base + PCI_PRIMARY_BUS));
+
+	if (nwl_pcie_link_up(pcie))
+		dev_info(pcie->dev, "Link is UP\n");
+	else
+		dev_info(pcie->dev, "Link is DOWN\n");
+
+	/* Get misc IRQ number */
+	pcie->irq_misc = platform_get_irq_byname(pdev, "misc");
+	if (pcie->irq_misc < 0) {
+		dev_err(&pdev->dev, "failed to get misc IRQ %d\n",
+			pcie->irq_misc);
+		return -EINVAL;
+	}
+
+	err = devm_request_irq(pcie->dev, pcie->irq_misc,
+			       nwl_pcie_misc_handler, IRQF_SHARED,
+			       "nwl_pcie:misc", pcie);
+	if (err) {
+		dev_err(pcie->dev, "fail to register misc IRQ#%d\n",
+			pcie->irq_misc);
+		return err;
+	}
+
+	/* Disable all misc interrupts */
+	nwl_bridge_writel(pcie, (u32)~MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);
+
+	/* Clear pending misc interrupts */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
+			  MSGF_MISC_SR_MASKALL, MSGF_MISC_STATUS);
+
+	/* Enable all misc interrupts */
+	nwl_bridge_writel(pcie, MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);
+
+
+	/* Disable all legacy interrupts */
+	nwl_bridge_writel(pcie, (u32)~MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);
+
+	/* Clear pending legacy interrupts */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
+			  MSGF_LEG_SR_MASKALL, MSGF_LEG_STATUS);
+
+	/* Enable all legacy interrupts */
+	nwl_bridge_writel(pcie, MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);
+
+	/* Enable the bridge config interrupt */
+	nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_INTERRUPT) |
+			  BRCFG_INTERRUPT_MASK, BRCFG_INTERRUPT);
+
+	return 0;
+}
+
+static int nwl_pcie_parse_dt(struct nwl_pcie *pcie,
+			     struct platform_device *pdev)
+{
+	struct device_node *node = pcie->dev->of_node;
+	struct resource *res;
+	const char *type;
+
+	/* Check for device type */
+	type = of_get_property(node, "device_type", NULL);
+	if (!type || strcmp(type, "pci")) {
+		dev_err(pcie->dev, "invalid \"device_type\" %s\n", type);
+		return -EINVAL;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "breg");
+	pcie->breg_base = devm_ioremap_resource(pcie->dev, res);
+	if (IS_ERR(pcie->breg_base))
+		return PTR_ERR(pcie->breg_base);
+	pcie->phys_breg_base = res->start;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcireg");
+	pcie->pcireg_base = devm_ioremap_resource(pcie->dev, res);
+	if (IS_ERR(pcie->pcireg_base))
+		return PTR_ERR(pcie->pcireg_base);
+	pcie->phys_pcie_reg_base = res->start;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+	pcie->ecam_base = devm_ioremap_resource(pcie->dev, res);
+	if (IS_ERR(pcie->ecam_base))
+		return PTR_ERR(pcie->ecam_base);
+	pcie->phys_ecam_base = res->start;
+
+	/* Get intx IRQ number */
+	pcie->irq_intx = platform_get_irq_byname(pdev, "intx");
+	if (pcie->irq_intx < 0) {
+		dev_err(&pdev->dev, "failed to get intx IRQ %d\n",
+			pcie->irq_intx);
+		return -EINVAL;
+	}
+
+	irq_set_chained_handler_and_data(pcie->irq_intx,
+					 nwl_pcie_leg_handler, pcie);
+
+	return 0;
+}
+
+static const struct of_device_id nwl_pcie_of_match[] = {
+	{ .compatible = "xlnx,nwl-pcie-2.11", },
+	{}
+};
+
+static int nwl_pcie_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct nwl_pcie *pcie;
+	struct pci_bus *bus;
+	struct pci_bus *child;
+	int err;
+	resource_size_t iobase = 0;
+	LIST_HEAD(res);
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->dev = &pdev->dev;
+	pcie->ecam_value = NWL_ECAM_VALUE_DEFAULT;
+
+	err = nwl_pcie_parse_dt(pcie, pdev);
+	if (err) {
+		dev_err(pcie->dev, "Parsing DT failed\n");
+		return err;
+	}
+
+	err = nwl_pcie_bridge_init(pcie);
+	if (err) {
+		dev_err(pcie->dev, "HW Initalization failed\n");
+		return err;
+	}
+
+	err = of_pci_get_host_bridge_resources(node, 0, 0xff, &res, &iobase);
+	if (err) {
+		pr_err("Getting bridge resources failed\n");
+		return err;
+	}
+
+	err = nwl_pcie_init_irq_domain(pcie);
+	if (err) {
+		dev_err(pcie->dev, "Failed creating IRQ Domain\n");
+		return err;
+	}
+
+	bus = pci_create_root_bus(&pdev->dev, pcie->root_busno,
+				  &nwl_pcie_ops, pcie, &res);
+	if (!bus)
+		return -ENOMEM;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		err = nwl_pcie_enable_msi(pcie, bus);
+		if (err < 0) {
+			dev_err(&pdev->dev,
+				"failed to enable MSI support: %d\n", err);
+			return err;
+		}
+	}
+	pci_scan_child_bus(bus);
+	pci_assign_unassigned_bus_resources(bus);
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
+	pci_bus_add_devices(bus);
+	platform_set_drvdata(pdev, pcie);
+	return 0;
+}
+
+static int nwl_pcie_remove(struct platform_device *pdev)
+{
+	struct nwl_pcie *pcie = platform_get_drvdata(pdev);
+
+	nwl_pcie_free_irq_domain(pcie);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static struct platform_driver nwl_pcie_driver = {
+	.driver = {
+		.name = "nwl-pcie",
+		.of_match_table = nwl_pcie_of_match,
+	},
+	.probe = nwl_pcie_probe,
+	.remove = nwl_pcie_remove,
+};
+module_platform_driver(nwl_pcie_driver);
+
+MODULE_AUTHOR("Xilinx, Inc");
+MODULE_DESCRIPTION("NWL PCIe driver");
+MODULE_LICENSE("GPL");