RE: [PATCH v5 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver

[Bharat Kumar Gogada <bharatku@xilinx.com>]

Thanks Bjorn.

Hi Lorenzo and Andrew, please let me know if you have any further queries.

> -----Original Message-----
> From: Bjorn Helgaas <helgaas@kernel.org>
> Sent: Tuesday, February 18, 2020 5:26 AM
> To: Bharat Kumar Gogada <bharatku@xilinx.com>
> Cc: linux-pci@vger.kernel.org; linux-kernel@vger.kernel.org; Ravikiran
> Gummaluri <rgummal@xilinx.com>; lorenzo.pieralisi@arm.com; Andrew Murray
> <amurray@thegoodpenguin.co.uk>
> Subject: Re: [PATCH v5 2/2] PCI: xilinx-cpm: Add Versal CPM Root Port driver
> 
> Lorenzo and Andrew take care of drivers/pci/controllers/*.  I'm sure this is on
> their radar already but I cc'd them for good measure.
> 
> On Thu, Jan 30, 2020 at 09:42:51PM +0530, Bharat Kumar Gogada wrote:
> > - 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.
> > - CPM Versal uses GICv3 ITS feature for achieving 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 v5:
> > - Removed xilinx_cpm_pcie_valid_device function
> 
> I don't include this sort of history in the commit log because it's not really of
> enduring interest.  Lorenzo will probably take it out for you, so no need to
> repost just for that.
> 
> > Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
> > ---
> >  drivers/pci/controller/Kconfig           |   8 +
> >  drivers/pci/controller/Makefile          |   1 +
> >  drivers/pci/controller/pcie-xilinx-cpm.c | 491
> > +++++++++++++++++++++++++++++++
> >  3 files changed, 500 insertions(+)
> >  create mode 100644 drivers/pci/controller/pcie-xilinx-cpm.c
> >
> > diff --git a/drivers/pci/controller/Kconfig
> > b/drivers/pci/controller/Kconfig index c77069c..362f4db 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
> 
> I would consider making this PCIE_XILINX_CPM_HOST because many of these
> chips can be either a host or an endpoint, and if you add _HOST now there is
> room for a future endpoint driver.  E.g., see CONFIG_PCI_DRA7XX_HOST and
> CONFIG_PCI_DRA7XX_EP.
> 
> > +	bool "Xilinx Versal CPM host bridge support"
> > +	depends on ARCH_ZYNQMP || COMPILE_TEST
> > +	help
> > +	  Say 'Y' here if you want kernel support for the
> > +	  Xilinx Versal CPM host bridge. 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..4e4c0f0
> > --- /dev/null
> > +++ b/drivers/pci/controller/pcie-xilinx-cpm.c
> > @@ -0,0 +1,491 @@
> > +// 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 System Level Control and Status Register(SLCR) 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_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;
> > +
> > +	relbus = (bus->number << ECAM_BUS_NUM_SHIFT) |
> > +		 (devfn << ECAM_DEV_NUM_SHIFT);
> > +
> > +	return port->reg_base + relbus + where;
> 
> I *think* this is exactly pci_ecam_map_bus(), so maybe you could just use
> pci_generic_ecam_ops instead of defining xilinx_cpm_pcie_ops?  If so,
> congratulations, you've achieved what seems to be almost impossible.
> 
> > +}
> > +
> > +/* 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 = 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);
> > +
> > +	/*
> > +	 * XILINX_CPM_PCIE_MISC_IR_STATUS register is mapped to
> > +	 * CPM SLCR block.
> > +	 */
> > +	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);
> > +
> > +	/*
> > +	 * 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);
> > +}
> > +
> > +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 platform_device *pdev = to_platform_device(dev);
> > +	struct resource *res;
> > +	int err;
> > +
> > +	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);
> > --
> > 2.7.4
> >