[v3,2/2] PCI: Versal CPM: Add support for Versal CPM Root Port driver
diff mbox series

Message ID 1578909821-10604-3-git-send-email-bharat.kumar.gogada@xilinx.com
State New
Headers show
Series
  • Adding support for Versal CPM as Root Port driver.
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Commit Message

Bharat Kumar Gogada Jan. 13, 2020, 10:03 a.m. UTC
- Adding 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.
- CPM Versal uses GICv3 ITS feature for acheiving assigning MSI/MSI-X
  vectors and handling MSI/MSI-X interrupts.
- Bridge error and legacy interrupts in Versal CPM are handled using
  Versal CPM specific MISC interrupt line.

Changes v3:
Fix warnings reported.

Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 drivers/pci/controller/Kconfig           |   8 +
 drivers/pci/controller/Makefile          |   1 +
 drivers/pci/controller/pcie-xilinx-cpm.c | 505 +++++++++++++++++++++++++++++++
 3 files changed, 514 insertions(+)
 create mode 100644 drivers/pci/controller/pcie-xilinx-cpm.c

Comments

Bjorn Helgaas Jan. 13, 2020, 10:34 p.m. UTC | #1
s/PCI: Versal CPM: .../PCI: xilinx-cpm: Add Versal CPM Root Port driver/

Format is "PCI: <driver-name>: Subject"

On Mon, Jan 13, 2020 at 03:33:41PM +0530, Bharat Kumar Gogada wrote:
> - Adding support for Versal CPM as Root Port.

s/- Adding/Add/

> - 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.
> - CPM Versal uses GICv3 ITS feature for acheiving assigning MSI/MSI-X
>   vectors and handling MSI/MSI-X interrupts.

s/acheiving//

> - Bridge error and legacy interrupts in Versal CPM are handled using
>   Versal CPM specific MISC interrupt line.
> 
> Changes v3:
> Fix warnings reported.
> 
> Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> Reported-by: kbuild test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

"Reported-by" is for bug reports.  This makes it look like the lack of
the driver is the bug, but it's not.  Personally, I'd thank Dan and
the kbuild robot, but not add "Reported-by" here.  It's like patch
reviews; I don't expect you to mention my feedback in the commit log.

> +config PCIE_XILINX_CPM
> +	bool "Xilinx Versal CPM host bridge support"
> +	depends on ARCH_ZYNQMP || COMPILE_TEST
> +	help
> +	  Say 'Y' here if you want kernel to enable support the
> +	  Xilinx Versal CPM host Bridge driver.The driver supports
> +	  MSI/MSI-X interrupts using GICv3 ITS feature.

s/kernel to enable support the/kernel support for the/
s/host Bridge driver./host bridge. /  (note space after period)

> + * xilinx_cpm_pcie_valid_device - Check if a valid device is present on bus

Technically this does not check if the device is present on the bus.
It checks whether it's *possible* for a device to be at this address.
For non-root bus devices in particular, it always returns true, and
you have to do a config read to see whether a device responds.

> + * @bus: PCI Bus structure
> + * @devfn: device/function
> + *
> + * Return: 'true' on success and 'false' if invalid device is found
> + */
> +static bool xilinx_cpm_pcie_valid_device(struct pci_bus *bus,
> +					 unsigned int devfn)
> +{
> +	struct xilinx_cpm_pcie_port *port = bus->sysdata;
> +
> +	/* Only one device down on each root port */
> +	if (bus->number == port->root_busno && devfn > 0)
> +		return false;
> +
> +	return true;
> +}

> +static irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *data)
> +{
> +	struct xilinx_cpm_pcie_port *port =
> +				(struct xilinx_cpm_pcie_port *)data;

No cast needed.

> +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);
> +
> +	/* Enable all interrupts */
> +	pcie_write(port, XILINX_CPM_PCIE_IMR_ALL_MASK,
> +		   XILINX_CPM_PCIE_REG_IMR);
> +	pcie_write(port, XILINX_CPM_PCIE_IDRN_MASK,
> +		   XILINX_CPM_PCIE_REG_IDRN_MASK);
> +
> +	writel(XILINX_CPM_PCIE_MISC_IR_LOCAL,
> +	       port->cpm_base + XILINX_CPM_PCIE_MISC_IR_ENABLE);

This lonely writel() in the middle of all the pcie_write() and
pcie_read() calls *looks* like a mistake.

I see that the writel() uses port->cpm_base, while pcie_write() uses
port->reg_base, so I don't think it *is* a mistake, but it's sure not
obvious.  A blank line after it and a comment at the _MISC_IR
definitions about them being in a different register set would be nice
hints.

> +	/* 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);
> +}

> +static int xilinx_cpm_pcie_parse_dt(struct xilinx_cpm_pcie_port *port)
> +{
> +	struct device *dev = port->dev;
> +	struct resource *res;
> +	int err;
> +	struct platform_device *pdev = to_platform_device(dev);

The "struct platform_device ..." line really should be first in the
list.  Not because of "reverse Christmas tree", but because "pdev" is
the first variable used in the code below.

> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
> +	port->reg_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(port->reg_base))
> +		return PTR_ERR(port->reg_base);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +					   "cpm_slcr");
> +	port->cpm_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(port->cpm_base))
> +		return PTR_ERR(port->cpm_base);

Bjorn
Bharat Kumar Gogada Jan. 27, 2020, 1:06 p.m. UTC | #2
> Subject: Re: [PATCH v3 2/2] PCI: Versal CPM: Add support for Versal CPM Root
> Port driver
> 
> s/PCI: Versal CPM: .../PCI: xilinx-cpm: Add Versal CPM Root Port driver/
> 
Thanks Bjorn, sorry for late response. 
> Format is "PCI: <driver-name>: Subject"
Accepted will change the subject.
> 
> On Mon, Jan 13, 2020 at 03:33:41PM +0530, Bharat Kumar Gogada wrote:
> > - Adding support for Versal CPM as Root Port.
> 
> s/- Adding/Add/
> 
> > - 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.
> > - CPM Versal uses GICv3 ITS feature for acheiving assigning MSI/MSI-X
> >   vectors and handling MSI/MSI-X interrupts.
> 
> s/acheiving//
> 
> > - Bridge error and legacy interrupts in Versal CPM are handled using
> >   Versal CPM specific MISC interrupt line.
> >
> > Changes v3:
> > Fix warnings reported.
> >
> > Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> > Reported-by: kbuild test robot <lkp@intel.com>
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> "Reported-by" is for bug reports.  This makes it look like the lack of the driver is
> the bug, but it's not.  Personally, I'd thank Dan and the kbuild robot, but not add
> "Reported-by" here.  It's like patch reviews; I don't expect you to mention my
> feedback in the commit log.
Accepted above comments will fix these in next patch.
> 
> > +config PCIE_XILINX_CPM
> > +	bool "Xilinx Versal CPM host bridge support"
> > +	depends on ARCH_ZYNQMP || COMPILE_TEST
> > +	help
> > +	  Say 'Y' here if you want kernel to enable support the
> > +	  Xilinx Versal CPM host Bridge driver.The driver supports
> > +	  MSI/MSI-X interrupts using GICv3 ITS feature.
> 
> s/kernel to enable support the/kernel support for the/ s/host Bridge driver./host
> bridge. /  (note space after period)
Accepted , will fix these in next patch.
> 
> > + * xilinx_cpm_pcie_valid_device - Check if a valid device is present
> > + on bus
> 
> Technically this does not check if the device is present on the bus.
> It checks whether it's *possible* for a device to be at this address.
> For non-root bus devices in particular, it always returns true, and you have to do
> a config read to see whether a device responds.
Accepted, will change the comments.
> 
> > + * @bus: PCI Bus structure
> > + * @devfn: device/function
> > + *
> > + * Return: 'true' on success and 'false' if invalid device is found
> > +*/ static bool xilinx_cpm_pcie_valid_device(struct pci_bus *bus,
> > +					 unsigned int devfn)
> > +{
> > +	struct xilinx_cpm_pcie_port *port = bus->sysdata;
> > +
> > +	/* Only one device down on each root port */
> > +	if (bus->number == port->root_busno && devfn > 0)
> > +		return false;
> > +
> > +	return true;
> > +}
> 
> > +static irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *data)
> > +{
> > +	struct xilinx_cpm_pcie_port *port =
> > +				(struct xilinx_cpm_pcie_port *)data;
> 
> No cast needed.
Accepted, will fix these in next patch.
> 
> > +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);
> > +
> > +	/* Enable all interrupts */
> > +	pcie_write(port, XILINX_CPM_PCIE_IMR_ALL_MASK,
> > +		   XILINX_CPM_PCIE_REG_IMR);
> > +	pcie_write(port, XILINX_CPM_PCIE_IDRN_MASK,
> > +		   XILINX_CPM_PCIE_REG_IDRN_MASK);
> > +
> > +	writel(XILINX_CPM_PCIE_MISC_IR_LOCAL,
> > +	       port->cpm_base + XILINX_CPM_PCIE_MISC_IR_ENABLE);
> 
> This lonely writel() in the middle of all the pcie_write() and
> pcie_read() calls *looks* like a mistake.
> 
> I see that the writel() uses port->cpm_base, while pcie_write() uses
> port->reg_base, so I don't think it *is* a mistake, but it's sure not
> obvious.  A blank line after it and a comment at the _MISC_IR definitions about
> them being in a different register set would be nice hints.
Accepted, will add comments.
> 
> > +	/* 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);
> > +}
> 
> > +static int xilinx_cpm_pcie_parse_dt(struct xilinx_cpm_pcie_port
> > +*port) {
> > +	struct device *dev = port->dev;
> > +	struct resource *res;
> > +	int err;
> > +	struct platform_device *pdev = to_platform_device(dev);
> 
> The "struct platform_device ..." line really should be first in the list.  Not because
> of "reverse Christmas tree", but because "pdev" is the first variable used in the
> code below.
Accepted, will fix these in next patch.
> 
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
> > +	port->reg_base = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(port->reg_base))
> > +		return PTR_ERR(port->reg_base);
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> > +					   "cpm_slcr");
> > +	port->cpm_base = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(port->cpm_base))
> > +		return PTR_ERR(port->cpm_base);
> 
Regards,
Bharat

Patch
diff mbox series

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index c77069c..eca496d 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -81,6 +81,14 @@  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
+	help
+	  Say 'Y' here if you want kernel to enable support the
+	  Xilinx Versal CPM host Bridge driver.The driver supports
+	  MSI/MSI-X interrupts using GICv3 ITS feature.
+
 config PCI_XGENE
 	bool "X-Gene PCIe controller"
 	depends on ARM64 || COMPILE_TEST
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index 3d4f597..6c936e9 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -12,6 +12,7 @@  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
diff --git a/drivers/pci/controller/pcie-xilinx-cpm.c b/drivers/pci/controller/pcie-xilinx-cpm.c
new file mode 100644
index 0000000..88ee93e
--- /dev/null
+++ b/drivers/pci/controller/pcie-xilinx-cpm.c
@@ -0,0 +1,505 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCIe host controller driver for Xilinx Versal CPM DMA Bridge
+ *
+ * (C) Copyright 2019 - 2020, Xilinx, Inc.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/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 "../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		BIT(0)
+#define XILINX_CPM_PCIE_INTR_HOT_RESET		BIT(3)
+#define XILINX_CPM_PCIE_INTR_CFG_TIMEOUT	BIT(8)
+#define XILINX_CPM_PCIE_INTR_CORRECTABLE	BIT(9)
+#define XILINX_CPM_PCIE_INTR_NONFATAL		BIT(10)
+#define XILINX_CPM_PCIE_INTR_FATAL		BIT(11)
+#define XILINX_CPM_PCIE_INTR_INTX		BIT(16)
+#define XILINX_CPM_PCIE_INTR_MSI		BIT(17)
+#define XILINX_CPM_PCIE_INTR_SLV_UNSUPP		BIT(20)
+#define XILINX_CPM_PCIE_INTR_SLV_UNEXP		BIT(21)
+#define XILINX_CPM_PCIE_INTR_SLV_COMPL		BIT(22)
+#define XILINX_CPM_PCIE_INTR_SLV_ERRP		BIT(23)
+#define XILINX_CPM_PCIE_INTR_SLV_CMPABT		BIT(24)
+#define XILINX_CPM_PCIE_INTR_SLV_ILLBUR		BIT(25)
+#define XILINX_CPM_PCIE_INTR_MST_DECERR		BIT(26)
+#define XILINX_CPM_PCIE_INTR_MST_SLVERR		BIT(27)
+#define XILINX_CPM_PCIE_IMR_ALL_MASK		0x1FF39FF9
+#define XILINX_CPM_PCIE_IDR_ALL_MASK		0xFFFFFFFF
+#define XILINX_CPM_PCIE_IDRN_MASK		GENMASK(19, 16)
+#define XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT	BIT(4)
+#define XILINX_CPM_PCIE_INTR_CFG_ERR_POISON	BIT(12)
+#define XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD	BIT(15)
+#define XILINX_CPM_PCIE_INTR_PM_PME_RCVD	BIT(17)
+#define XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT	BIT(28)
+#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)
+
+/* ECAM definitions */
+#define ECAM_BUS_NUM_SHIFT		20
+#define ECAM_DEV_NUM_SHIFT		12
+
+/**
+ * struct xilinx_cpm_pcie_port - PCIe port information
+ * @reg_base: Bridge Register Base
+ * @cpm_base: CPM SLCR Register Base
+ * @irq: Interrupt number
+ * @root_busno: Root Bus number
+ * @dev: Device pointer
+ * @leg_domain: Legacy IRQ domain pointer
+ * @irq_misc: Legacy and error interrupt number
+ */
+struct xilinx_cpm_pcie_port {
+	void __iomem *reg_base;
+	void __iomem *cpm_base;
+	u32 irq;
+	u8 root_busno;
+	struct device *dev;
+	struct irq_domain *leg_domain;
+	int irq_misc;
+};
+
+static inline u32 pcie_read(struct xilinx_cpm_pcie_port *port, u32 reg)
+{
+	return readl(port->reg_base + reg);
+}
+
+static inline void pcie_write(struct xilinx_cpm_pcie_port *port,
+			      u32 val, u32 reg)
+{
+	writel(val, port->reg_base + reg);
+}
+
+static inline 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) ? 1 : 0;
+}
+
+/**
+ * xilinx_cpm_pcie_clear_err_interrupts - Clear Error Interrupts
+ * @port: PCIe port information
+ */
+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);
+	}
+}
+
+/**
+ * xilinx_cpm_pcie_valid_device - Check if a valid device is present on bus
+ * @bus: PCI Bus structure
+ * @devfn: device/function
+ *
+ * Return: 'true' on success and 'false' if invalid device is found
+ */
+static bool xilinx_cpm_pcie_valid_device(struct pci_bus *bus,
+					 unsigned int devfn)
+{
+	struct xilinx_cpm_pcie_port *port = bus->sysdata;
+
+	/* Only one device down on each root port */
+	if (bus->number == port->root_busno && devfn > 0)
+		return false;
+
+	return true;
+}
+
+/**
+ * xilinx_cpm_pcie_map_bus - Get configuration base
+ * @bus: PCI Bus structure
+ * @devfn: Device/function
+ * @where: Offset from base
+ *
+ * Return: Base address of the configuration space needed to be
+ *	   accessed.
+ */
+static void __iomem *xilinx_cpm_pcie_map_bus(struct pci_bus *bus,
+					     unsigned int devfn, int where)
+{
+	struct xilinx_cpm_pcie_port *port = bus->sysdata;
+	int relbus;
+
+	if (!xilinx_cpm_pcie_valid_device(bus, devfn))
+		return NULL;
+
+	relbus = (bus->number << ECAM_BUS_NUM_SHIFT) |
+		 (devfn << ECAM_DEV_NUM_SHIFT);
+
+	return port->reg_base + relbus + where;
+}
+
+/* PCIe operations */
+static struct pci_ops xilinx_cpm_pcie_ops = {
+	.map_bus = xilinx_cpm_pcie_map_bus,
+	.read	= pci_generic_config_read,
+	.write	= pci_generic_config_write,
+};
+
+/**
+ * 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, &dummy_irq_chip, handle_simple_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,
+	.xlate = pci_irqd_intx_xlate,
+};
+
+/**
+ * xilinx_cpm_pcie_intr_handler - Interrupt Service Handler
+ * @irq: IRQ number
+ * @data: PCIe port information
+ *
+ * Return: IRQ_HANDLED on success and IRQ_NONE on failure
+ */
+static irqreturn_t xilinx_cpm_pcie_intr_handler(int irq, void *data)
+{
+	struct xilinx_cpm_pcie_port *port =
+				(struct xilinx_cpm_pcie_port *)data;
+	struct device *dev = port->dev;
+	u32 val, mask, status, bit;
+	unsigned long intr_val;
+
+	/* Read interrupt decode and mask registers */
+	val = pcie_read(port, XILINX_CPM_PCIE_REG_IDR);
+	mask = pcie_read(port, XILINX_CPM_PCIE_REG_IMR);
+
+	status = val & mask;
+	if (!status)
+		return IRQ_NONE;
+
+	if (status & XILINX_CPM_PCIE_INTR_LINK_DOWN)
+		dev_warn(dev, "Link Down\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_HOT_RESET)
+		dev_info(dev, "Hot reset\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_CFG_TIMEOUT)
+		dev_warn(dev, "ECAM access timeout\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_CORRECTABLE) {
+		dev_warn(dev, "Correctable error message\n");
+		cpm_pcie_clear_err_interrupts(port);
+	}
+
+	if (status & XILINX_CPM_PCIE_INTR_NONFATAL) {
+		dev_warn(dev, "Non fatal error message\n");
+		cpm_pcie_clear_err_interrupts(port);
+	}
+
+	if (status & XILINX_CPM_PCIE_INTR_FATAL) {
+		dev_warn(dev, "Fatal error message\n");
+		cpm_pcie_clear_err_interrupts(port);
+	}
+
+	if (status & XILINX_CPM_PCIE_INTR_INTX) {
+		/* Handle INTx Interrupt */
+		intr_val = pcie_read(port, XILINX_CPM_PCIE_REG_IDRN);
+		intr_val = intr_val >> XILINX_CPM_PCIE_IDRN_SHIFT;
+
+		for_each_set_bit(bit, &intr_val, PCI_NUM_INTX)
+			generic_handle_irq(irq_find_mapping(port->leg_domain,
+							    bit));
+	}
+
+	if (status & XILINX_CPM_PCIE_INTR_SLV_UNSUPP)
+		dev_warn(dev, "Slave unsupported request\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_SLV_UNEXP)
+		dev_warn(dev, "Slave unexpected completion\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_SLV_COMPL)
+		dev_warn(dev, "Slave completion timeout\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_SLV_ERRP)
+		dev_warn(dev, "Slave Error Poison\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_SLV_CMPABT)
+		dev_warn(dev, "Slave Completer Abort\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_SLV_ILLBUR)
+		dev_warn(dev, "Slave Illegal Burst\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_MST_DECERR)
+		dev_warn(dev, "Master decode error\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_MST_SLVERR)
+		dev_warn(dev, "Master slave error\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_CFG_PCIE_TIMEOUT)
+		dev_warn(dev, "PCIe ECAM access timeout\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_CFG_ERR_POISON)
+		dev_warn(dev, "ECAM poisoned completion received\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_PME_TO_ACK_RCVD)
+		dev_warn(dev, "PME_TO_ACK message received\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_PM_PME_RCVD)
+		dev_warn(dev, "PM_PME message received\n");
+
+	if (status & XILINX_CPM_PCIE_INTR_SLV_PCIE_TIMEOUT)
+		dev_warn(dev, "PCIe completion timeout received\n");
+
+	/* Clear the Interrupt Decode register */
+	pcie_write(port, status, XILINX_CPM_PCIE_REG_IDR);
+	val = readl(port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
+	if (val)
+		writel(val, port->cpm_base + XILINX_CPM_PCIE_MISC_IR_STATUS);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * 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->leg_domain = irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX,
+						 &intx_domain_ops,
+						 port);
+	if (!port->leg_domain) {
+		dev_err(dev, "Failed to get a INTx IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	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);
+
+	/* Enable all interrupts */
+	pcie_write(port, XILINX_CPM_PCIE_IMR_ALL_MASK,
+		   XILINX_CPM_PCIE_REG_IMR);
+	pcie_write(port, XILINX_CPM_PCIE_IDRN_MASK,
+		   XILINX_CPM_PCIE_REG_IDRN_MASK);
+
+	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);
+}
+
+static int xilinx_cpm_request_misc_irq(struct xilinx_cpm_pcie_port *port)
+{
+	struct device *dev = port->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	int err;
+
+	port->irq_misc = platform_get_irq_byname(pdev, "misc");
+	if (port->irq_misc <= 0) {
+		dev_err(dev, "Unable to find misc IRQ line\n");
+		return port->irq_misc;
+	}
+	err = devm_request_irq(dev, port->irq_misc,
+			       xilinx_cpm_pcie_intr_handler,
+			       IRQF_SHARED | IRQF_NO_THREAD,
+			       "xilinx-pcie", port);
+	if (err) {
+		dev_err(dev, "unable to request misc IRQ line %d\n",
+			port->irq_misc);
+		return err;
+	}
+
+	return 0;
+}
+
+/**
+ * xilinx_cpm_pcie_parse_dt - Parse Device tree
+ * @port: PCIe port information
+ *
+ * Return: '0' on success and error value on failure
+ */
+static int xilinx_cpm_pcie_parse_dt(struct xilinx_cpm_pcie_port *port)
+{
+	struct device *dev = port->dev;
+	struct resource *res;
+	int err;
+	struct platform_device *pdev = to_platform_device(dev);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
+	port->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(port->reg_base))
+		return PTR_ERR(port->reg_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					   "cpm_slcr");
+	port->cpm_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(port->cpm_base))
+		return PTR_ERR(port->cpm_base);
+
+	err = xilinx_cpm_request_misc_irq(port);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+/**
+ * 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_bus *bus;
+	struct pci_bus *child;
+	struct pci_host_bridge *bridge;
+	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 = xilinx_cpm_pcie_parse_dt(port);
+	if (err) {
+		dev_err(dev, "Parsing DT failed\n");
+		return err;
+	}
+
+	xilinx_cpm_pcie_init_port(port);
+
+	err = xilinx_cpm_pcie_init_irq_domain(port);
+	if (err) {
+		dev_err(dev, "Failed creating IRQ Domain\n");
+		return err;
+	}
+
+	err = pci_parse_request_of_pci_ranges(dev, &bridge->windows,
+					      &bridge->dma_ranges, NULL);
+	if (err) {
+		dev_err(dev, "Getting bridge resources failed\n");
+		return err;
+	}
+
+	bridge->dev.parent = dev;
+	bridge->sysdata = port;
+	bridge->busnr = port->root_busno;
+	bridge->ops = &xilinx_cpm_pcie_ops;
+	bridge->map_irq = of_irq_parse_and_map_pci;
+	bridge->swizzle_irq = pci_common_swizzle;
+
+	err = pci_scan_root_bus_bridge(bridge);
+	if (err)
+		return err;
+
+	bus = bridge->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);
+	return 0;
+}
+
+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);