drivers/pci/dwc/pci-keystone.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * PCIe host controller driver for Texas Instruments Keystone SoCs
  *
  * Copyright (C) 2013-2014 Texas Instruments., Ltd.
  *		http://www.ti.com
  *
  * Author: Murali Karicheri <m-karicheri2@ti.com>
  * Implementation based on pci-exynos.c and pcie-designware.c
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #include <linux/irqchip/chained_irq.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/irqdomain.h>
 #include <linux/init.h>
 #include <linux/msi.h>
 #include <linux/of_irq.h>
 #include <linux/of.h>
 #include <linux/of_pci.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
 #include <linux/resource.h>
 #include <linux/signal.h>

 #include "pcie-designware.h"
 #include "pci-keystone.h"

 #define DRIVER_NAME	"keystone-pcie"

 /* DEV_STAT_CTRL */
 #define PCIE_CAP_BASE		0x70

 /* PCIE controller device IDs */
 #define PCIE_RC_K2HK		0xb008
 #define PCIE_RC_K2E		0xb009
 #define PCIE_RC_K2L		0xb00a
 #define PCIE_RC_K2G		0xb00b

 #define to_keystone_pcie(x)	dev_get_drvdata((x)->dev)

 static void quirk_limit_mrrs(struct pci_dev *dev)
 {
 	struct pci_bus *bus = dev->bus;
 	struct pci_dev *bridge = bus->self;
 	static const struct pci_device_id rc_pci_devids[] = {
 		{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK),
 		 .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
 		{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E),
 		 .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
 		{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L),
 		 .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
 		{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2G),
 		 .class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
 		{ 0, },
 	};

 	if (pci_is_root_bus(bus))
 		return;

 	/* look for the host bridge */
 	while (!pci_is_root_bus(bus)) {
 		bridge = bus->self;
 		bus = bus->parent;
 	}

 	if (bridge) {
 		/*
 		 * Keystone PCI controller has a h/w limitation of
 		 * 256 bytes maximum read request size.  It can't handle
 		 * anything higher than this.  So force this limit on
 		 * all downstream devices.
 		 */
 		if (pci_match_id(rc_pci_devids, bridge)) {
 			if (pcie_get_readrq(dev) > 256) {
 				dev_info(&dev->dev, "limiting MRRS to 256\n");
 				pcie_set_readrq(dev, 256);
 			}
 		}
 	}
 }
 DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs);

 static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie)
 {
 	struct dw_pcie *pci = ks_pcie->pci;
 	struct pcie_port *pp = &pci->pp;
 	struct device *dev = pci->dev;
 	unsigned int retries;

 	dw_pcie_setup_rc(pp);

 	if (dw_pcie_link_up(pci)) {
 		dev_err(dev, "Link already up\n");
 		return 0;
 	}

 	/* check if the link is up or not */
 	for (retries = 0; retries < 5; retries++) {
 		ks_dw_pcie_initiate_link_train(ks_pcie);
 		if (!dw_pcie_wait_for_link(pci))
 			return 0;
 	}

 	dev_err(dev, "phy link never came up\n");
 	return -ETIMEDOUT;
 }

 static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
 {
 	unsigned int irq = irq_desc_get_irq(desc);
 	struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 	u32 offset = irq - ks_pcie->msi_host_irqs[0];
 	struct dw_pcie *pci = ks_pcie->pci;
 	struct device *dev = pci->dev;
 	struct irq_chip *chip = irq_desc_get_chip(desc);

 	dev_dbg(dev, "%s, irq %d\n", __func__, irq);

 	/*
 	 * The chained irq handler installation would have replaced normal
 	 * interrupt driver handler so we need to take care of mask/unmask and
 	 * ack operation.
 	 */
 	chained_irq_enter(chip, desc);
 	ks_dw_pcie_handle_msi_irq(ks_pcie, offset);
 	chained_irq_exit(chip, desc);
 }

 /**
  * ks_pcie_legacy_irq_handler() - Handle legacy interrupt
  * @irq: IRQ line for legacy interrupts
  * @desc: Pointer to irq descriptor
  *
  * Traverse through pending legacy interrupts and invoke handler for each. Also
  * takes care of interrupt controller level mask/ack operation.
  */
 static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
 {
 	unsigned int irq = irq_desc_get_irq(desc);
 	struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
 	struct dw_pcie *pci = ks_pcie->pci;
 	struct device *dev = pci->dev;
 	u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0];
 	struct irq_chip *chip = irq_desc_get_chip(desc);

 	dev_dbg(dev, ": Handling legacy irq %d\n", irq);

 	/*
 	 * The chained irq handler installation would have replaced normal
 	 * interrupt driver handler so we need to take care of mask/unmask and
 	 * ack operation.
 	 */
 	chained_irq_enter(chip, desc);
 	ks_dw_pcie_handle_legacy_irq(ks_pcie, irq_offset);
 	chained_irq_exit(chip, desc);
 }

 static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
 					   char *controller, int *num_irqs)
 {
 	int temp, max_host_irqs, legacy = 1, *host_irqs;
 	struct device *dev = ks_pcie->pci->dev;
 	struct device_node *np_pcie = dev->of_node, **np_temp;

 	if (!strcmp(controller, "msi-interrupt-controller"))
 		legacy = 0;

 	if (legacy) {
 		np_temp = &ks_pcie->legacy_intc_np;
 		max_host_irqs = PCI_NUM_INTX;
 		host_irqs = &ks_pcie->legacy_host_irqs[0];
 	} else {
 		np_temp = &ks_pcie->msi_intc_np;
 		max_host_irqs = MAX_MSI_HOST_IRQS;
 		host_irqs =  &ks_pcie->msi_host_irqs[0];
 	}

 	/* interrupt controller is in a child node */
 	*np_temp = of_get_child_by_name(np_pcie, controller);
 	if (!(*np_temp)) {
 		dev_err(dev, "Node for %s is absent\n", controller);
 		return -EINVAL;
 	}

 	temp = of_irq_count(*np_temp);
 	if (!temp) {
 		dev_err(dev, "No IRQ entries in %s\n", controller);
 		of_node_put(*np_temp);
 		return -EINVAL;
 	}

 	if (temp > max_host_irqs)
 		dev_warn(dev, "Too many %s interrupts defined %u\n",
 			(legacy ? "legacy" : "MSI"), temp);

 	/*
 	 * support upto max_host_irqs. In dt from index 0 to 3 (legacy) or 0 to
 	 * 7 (MSI)
 	 */
 	for (temp = 0; temp < max_host_irqs; temp++) {
 		host_irqs[temp] = irq_of_parse_and_map(*np_temp, temp);
 		if (!host_irqs[temp])
 			break;
 	}

 	of_node_put(*np_temp);

 	if (temp) {
 		*num_irqs = temp;
 		return 0;
 	}

 	return -EINVAL;
 }

 static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
 {
 	int i;

 	/* Legacy IRQ */
 	for (i = 0; i < ks_pcie->num_legacy_host_irqs; i++) {
 		irq_set_chained_handler_and_data(ks_pcie->legacy_host_irqs[i],
 						 ks_pcie_legacy_irq_handler,
 						 ks_pcie);
 	}
 	ks_dw_pcie_enable_legacy_irqs(ks_pcie);

 	/* MSI IRQ */
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		for (i = 0; i < ks_pcie->num_msi_host_irqs; i++) {
 			irq_set_chained_handler_and_data(ks_pcie->msi_host_irqs[i],
 							 ks_pcie_msi_irq_handler,
 							 ks_pcie);
 		}
 	}

 	if (ks_pcie->error_irq > 0)
 		ks_dw_pcie_enable_error_irq(ks_pcie);
 }

 #ifdef CONFIG_ARM
 /*
  * When a PCI device does not exist during config cycles, keystone host gets a
  * bus error instead of returning 0xffffffff. This handler always returns 0
  * for this kind of faults.
  */
 static int keystone_pcie_fault(unsigned long addr, unsigned int fsr,
 				struct pt_regs *regs)
 {
 	unsigned long instr = *(unsigned long *) instruction_pointer(regs);

 	if ((instr & 0x0e100090) == 0x00100090) {
 		int reg = (instr >> 12) & 15;

 		regs->uregs[reg] = -1;
 		regs->ARM_pc += 4;
 	}

 	return 0;
 }
 #endif

 static int __init ks_pcie_host_init(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
 	u32 val;

 	ks_pcie_establish_link(ks_pcie);
 	ks_dw_pcie_setup_rc_app_regs(ks_pcie);
 	ks_pcie_setup_interrupts(ks_pcie);
 	writew(PCI_IO_RANGE_TYPE_32 | (PCI_IO_RANGE_TYPE_32 << 8),
 			pci->dbi_base + PCI_IO_BASE);

 	/* update the Vendor ID */
 	writew(ks_pcie->device_id, pci->dbi_base + PCI_DEVICE_ID);

 	/* update the DEV_STAT_CTRL to publish right mrrs */
 	val = readl(pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);
 	val &= ~PCI_EXP_DEVCTL_READRQ;
 	/* set the mrrs to 256 bytes */
 	val |= BIT(12);
 	writel(val, pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);

 #ifdef CONFIG_ARM
 	/*
 	 * PCIe access errors that result into OCP errors are caught by ARM as
 	 * "External aborts"
 	 */
 	hook_fault_code(17, keystone_pcie_fault, SIGBUS, 0,
 			"Asynchronous external abort");
 #endif

 	return 0;
 }

 static const struct dw_pcie_host_ops keystone_pcie_host_ops = {
 	.rd_other_conf = ks_dw_pcie_rd_other_conf,
 	.wr_other_conf = ks_dw_pcie_wr_other_conf,
 	.host_init = ks_pcie_host_init,
 	.msi_set_irq = ks_dw_pcie_msi_set_irq,
 	.msi_clear_irq = ks_dw_pcie_msi_clear_irq,
 	.get_msi_addr = ks_dw_pcie_get_msi_addr,
 	.msi_host_init = ks_dw_pcie_msi_host_init,
 	.scan_bus = ks_dw_pcie_v3_65_scan_bus,
 };

 static irqreturn_t pcie_err_irq_handler(int irq, void *priv)
 {
 	struct keystone_pcie *ks_pcie = priv;

 	return ks_dw_pcie_handle_error_irq(ks_pcie);
 }

 static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
 			 struct platform_device *pdev)
 {
 	struct dw_pcie *pci = ks_pcie->pci;
 	struct pcie_port *pp = &pci->pp;
 	struct device *dev = &pdev->dev;
 	int ret;

 	ret = ks_pcie_get_irq_controller_info(ks_pcie,
 					"legacy-interrupt-controller",
 					&ks_pcie->num_legacy_host_irqs);
 	if (ret)
 		return ret;

 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		ret = ks_pcie_get_irq_controller_info(ks_pcie,
 						"msi-interrupt-controller",
 						&ks_pcie->num_msi_host_irqs);
 		if (ret)
 			return ret;
 	}

 	/*
 	 * Index 0 is the platform interrupt for error interrupt
 	 * from RC.  This is optional.
 	 */
 	ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0);
 	if (ks_pcie->error_irq <= 0)
 		dev_info(dev, "no error IRQ defined\n");
 	else {
 		ret = request_irq(ks_pcie->error_irq, pcie_err_irq_handler,
 				  IRQF_SHARED, "pcie-error-irq", ks_pcie);
 		if (ret < 0) {
 			dev_err(dev, "failed to request error IRQ %d\n",
 				ks_pcie->error_irq);
 			return ret;
 		}
 	}

 	pp->root_bus_nr = -1;
 	pp->ops = &keystone_pcie_host_ops;
 	ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np);
 	if (ret) {
 		dev_err(dev, "failed to initialize host\n");
 		return ret;
 	}

 	return 0;
 }

 static const struct of_device_id ks_pcie_of_match[] = {
 	{
 		.type = "pci",
 		.compatible = "ti,keystone-pcie",
 	},
 	{ },
 };

 static const struct dw_pcie_ops dw_pcie_ops = {
 	.link_up = ks_dw_pcie_link_up,
 };

 static int ks_pcie_remove(struct platform_device *pdev)
 {
 	struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev);

 	clk_disable_unprepare(ks_pcie->clk);

 	return 0;
 }

 static int ks_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct dw_pcie *pci;
 	struct keystone_pcie *ks_pcie;
 	struct resource *res;
 	void __iomem *reg_p;
 	struct phy *phy;
 	int ret;

 	ks_pcie = devm_kzalloc(dev, sizeof(*ks_pcie), GFP_KERNEL);
 	if (!ks_pcie)
 		return -ENOMEM;

 	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
 	if (!pci)
 		return -ENOMEM;

 	pci->dev = dev;
 	pci->ops = &dw_pcie_ops;

 	ks_pcie->pci = pci;

 	/* initialize SerDes Phy if present */
 	phy = devm_phy_get(dev, "pcie-phy");
 	if (PTR_ERR_OR_ZERO(phy) == -EPROBE_DEFER)
 		return PTR_ERR(phy);

 	if (!IS_ERR_OR_NULL(phy)) {
 		ret = phy_init(phy);
 		if (ret < 0)
 			return ret;
 	}

 	/* index 2 is to read PCI DEVICE_ID */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 	reg_p = devm_ioremap_resource(dev, res);
 	if (IS_ERR(reg_p))
 		return PTR_ERR(reg_p);
 	ks_pcie->device_id = readl(reg_p) >> 16;
 	devm_iounmap(dev, reg_p);
 	devm_release_mem_region(dev, res->start, resource_size(res));

 	ks_pcie->np = dev->of_node;
 	platform_set_drvdata(pdev, ks_pcie);
 	ks_pcie->clk = devm_clk_get(dev, "pcie");
 	if (IS_ERR(ks_pcie->clk)) {
 		dev_err(dev, "Failed to get pcie rc clock\n");
 		return PTR_ERR(ks_pcie->clk);
 	}
 	ret = clk_prepare_enable(ks_pcie->clk);
 	if (ret)
 		return ret;

 	platform_set_drvdata(pdev, ks_pcie);

 	ret = ks_add_pcie_port(ks_pcie, pdev);
 	if (ret < 0)
 		goto fail_clk;

 	return 0;
 fail_clk:
 	clk_disable_unprepare(ks_pcie->clk);

 	return ret;
 }

 static struct platform_driver ks_pcie_driver = {
 	.probe  = ks_pcie_probe,
 	.remove = ks_pcie_remove,
 	.driver = {
 		.name	= "keystone-pcie",
 		.of_match_table = of_match_ptr(ks_pcie_of_match),
 	},
 };
 builtin_platform_driver(ks_pcie_driver);
	/*
	* PCIe host controller driver for Texas Instruments Keystone SoCs
	*
	* Copyright (C) 2013-2014 Texas Instruments., Ltd.
	* http://www.ti.com
	*
	* Author: Murali Karicheri <m-karicheri2@ti.com>
	* Implementation based on pci-exynos.c and pcie-designware.c
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/irqchip/chained_irq.h>
	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/irqdomain.h>
	#include <linux/init.h>
	#include <linux/msi.h>
	#include <linux/of_irq.h>
	#include <linux/of.h>
	#include <linux/of_pci.h>
	#include <linux/platform_device.h>
	#include <linux/phy/phy.h>
	#include <linux/resource.h>
	#include <linux/signal.h>

	#include "pcie-designware.h"
	#include "pci-keystone.h"

	#define DRIVER_NAME "keystone-pcie"

	/* DEV_STAT_CTRL */
	#define PCIE_CAP_BASE 0x70

	/* PCIE controller device IDs */
	#define PCIE_RC_K2HK 0xb008
	#define PCIE_RC_K2E 0xb009
	#define PCIE_RC_K2L 0xb00a
	#define PCIE_RC_K2G 0xb00b

	#define to_keystone_pcie(x) dev_get_drvdata((x)->dev)

	static void quirk_limit_mrrs(struct pci_dev *dev)
	{
	struct pci_bus *bus = dev->bus;
	struct pci_dev *bridge = bus->self;
	static const struct pci_device_id rc_pci_devids[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2HK),
	.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2E),
	.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2L),
	.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCIE_RC_K2G),
	.class = PCI_CLASS_BRIDGE_PCI << 8, .class_mask = ~0, },
	{ 0, },
	};

	if (pci_is_root_bus(bus))
	return;

	/* look for the host bridge */
	while (!pci_is_root_bus(bus)) {
	bridge = bus->self;
	bus = bus->parent;
	}

	if (bridge) {
	/*
	* Keystone PCI controller has a h/w limitation of
	* 256 bytes maximum read request size. It can't handle
	* anything higher than this. So force this limit on
	* all downstream devices.
	*/
	if (pci_match_id(rc_pci_devids, bridge)) {
	if (pcie_get_readrq(dev) > 256) {
	dev_info(&dev->dev, "limiting MRRS to 256\n");
	pcie_set_readrq(dev, 256);
	}
	}
	}
	}
	DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, quirk_limit_mrrs);

	static int ks_pcie_establish_link(struct keystone_pcie *ks_pcie)
	{
	struct dw_pcie *pci = ks_pcie->pci;
	struct pcie_port *pp = &pci->pp;
	struct device *dev = pci->dev;
	unsigned int retries;

	dw_pcie_setup_rc(pp);

	if (dw_pcie_link_up(pci)) {
	dev_err(dev, "Link already up\n");
	return 0;
	}

	/* check if the link is up or not */
	for (retries = 0; retries < 5; retries++) {
	ks_dw_pcie_initiate_link_train(ks_pcie);
	if (!dw_pcie_wait_for_link(pci))
	return 0;
	}

	dev_err(dev, "phy link never came up\n");
	return -ETIMEDOUT;
	}

	static void ks_pcie_msi_irq_handler(struct irq_desc *desc)
	{
	unsigned int irq = irq_desc_get_irq(desc);
	struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
	u32 offset = irq - ks_pcie->msi_host_irqs[0];
	struct dw_pcie *pci = ks_pcie->pci;
	struct device *dev = pci->dev;
	struct irq_chip *chip = irq_desc_get_chip(desc);

	dev_dbg(dev, "%s, irq %d\n", __func__, irq);

	/*
	* The chained irq handler installation would have replaced normal
	* interrupt driver handler so we need to take care of mask/unmask and
	* ack operation.
	*/
	chained_irq_enter(chip, desc);
	ks_dw_pcie_handle_msi_irq(ks_pcie, offset);
	chained_irq_exit(chip, desc);
	}

	/**
	* ks_pcie_legacy_irq_handler() - Handle legacy interrupt
	* @irq: IRQ line for legacy interrupts
	* @desc: Pointer to irq descriptor
	*
	* Traverse through pending legacy interrupts and invoke handler for each. Also
	* takes care of interrupt controller level mask/ack operation.
	*/
	static void ks_pcie_legacy_irq_handler(struct irq_desc *desc)
	{
	unsigned int irq = irq_desc_get_irq(desc);
	struct keystone_pcie *ks_pcie = irq_desc_get_handler_data(desc);
	struct dw_pcie *pci = ks_pcie->pci;
	struct device *dev = pci->dev;
	u32 irq_offset = irq - ks_pcie->legacy_host_irqs[0];
	struct irq_chip *chip = irq_desc_get_chip(desc);

	dev_dbg(dev, ": Handling legacy irq %d\n", irq);

	/*
	* The chained irq handler installation would have replaced normal
	* interrupt driver handler so we need to take care of mask/unmask and
	* ack operation.
	*/
	chained_irq_enter(chip, desc);
	ks_dw_pcie_handle_legacy_irq(ks_pcie, irq_offset);
	chained_irq_exit(chip, desc);
	}

	static int ks_pcie_get_irq_controller_info(struct keystone_pcie *ks_pcie,
	char controller, int num_irqs)
	{
	int temp, max_host_irqs, legacy = 1, *host_irqs;
	struct device *dev = ks_pcie->pci->dev;
	struct device_node np_pcie = dev->of_node, *np_temp;

	if (!strcmp(controller, "msi-interrupt-controller"))
	legacy = 0;

	if (legacy) {
	np_temp = &ks_pcie->legacy_intc_np;
	max_host_irqs = PCI_NUM_INTX;
	host_irqs = &ks_pcie->legacy_host_irqs[0];
	} else {
	np_temp = &ks_pcie->msi_intc_np;
	max_host_irqs = MAX_MSI_HOST_IRQS;
	host_irqs = &ks_pcie->msi_host_irqs[0];
	}

	/* interrupt controller is in a child node */
	*np_temp = of_get_child_by_name(np_pcie, controller);
	if (!(*np_temp)) {
	dev_err(dev, "Node for %s is absent\n", controller);
	return -EINVAL;
	}

	temp = of_irq_count(*np_temp);
	if (!temp) {
	dev_err(dev, "No IRQ entries in %s\n", controller);
	of_node_put(*np_temp);
	return -EINVAL;
	}

	if (temp > max_host_irqs)
	dev_warn(dev, "Too many %s interrupts defined %u\n",
	(legacy ? "legacy" : "MSI"), temp);

	/*
	* support upto max_host_irqs. In dt from index 0 to 3 (legacy) or 0 to
	* 7 (MSI)
	*/
	for (temp = 0; temp < max_host_irqs; temp++) {
	host_irqs[temp] = irq_of_parse_and_map(*np_temp, temp);
	if (!host_irqs[temp])
	break;
	}

	of_node_put(*np_temp);

	if (temp) {
	*num_irqs = temp;
	return 0;
	}

	return -EINVAL;
	}

	static void ks_pcie_setup_interrupts(struct keystone_pcie *ks_pcie)
	{
	int i;

	/* Legacy IRQ */
	for (i = 0; i < ks_pcie->num_legacy_host_irqs; i++) {
	irq_set_chained_handler_and_data(ks_pcie->legacy_host_irqs[i],
	ks_pcie_legacy_irq_handler,
	ks_pcie);
	}
	ks_dw_pcie_enable_legacy_irqs(ks_pcie);

	/* MSI IRQ */
	if (IS_ENABLED(CONFIG_PCI_MSI)) {
	for (i = 0; i < ks_pcie->num_msi_host_irqs; i++) {
	irq_set_chained_handler_and_data(ks_pcie->msi_host_irqs[i],
	ks_pcie_msi_irq_handler,
	ks_pcie);
	}
	}

	if (ks_pcie->error_irq > 0)
	ks_dw_pcie_enable_error_irq(ks_pcie);
	}

	#ifdef CONFIG_ARM
	/*
	* When a PCI device does not exist during config cycles, keystone host gets a
	* bus error instead of returning 0xffffffff. This handler always returns 0
	* for this kind of faults.
	*/
	static int keystone_pcie_fault(unsigned long addr, unsigned int fsr,
	struct pt_regs *regs)
	{
	unsigned long instr = (unsigned long ) instruction_pointer(regs);

	if ((instr & 0x0e100090) == 0x00100090) {
	int reg = (instr >> 12) & 15;

	regs->uregs[reg] = -1;
	regs->ARM_pc += 4;
	}

	return 0;
	}
	#endif

	static int __init ks_pcie_host_init(struct pcie_port *pp)
	{
	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
	struct keystone_pcie *ks_pcie = to_keystone_pcie(pci);
	u32 val;

	ks_pcie_establish_link(ks_pcie);
	ks_dw_pcie_setup_rc_app_regs(ks_pcie);
	ks_pcie_setup_interrupts(ks_pcie);
	writew(PCI_IO_RANGE_TYPE_32 \| (PCI_IO_RANGE_TYPE_32 << 8),
	pci->dbi_base + PCI_IO_BASE);

	/* update the Vendor ID */
	writew(ks_pcie->device_id, pci->dbi_base + PCI_DEVICE_ID);

	/* update the DEV_STAT_CTRL to publish right mrrs */
	val = readl(pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);
	val &= ~PCI_EXP_DEVCTL_READRQ;
	/* set the mrrs to 256 bytes */
	val \|= BIT(12);
	writel(val, pci->dbi_base + PCIE_CAP_BASE + PCI_EXP_DEVCTL);

	#ifdef CONFIG_ARM
	/*
	* PCIe access errors that result into OCP errors are caught by ARM as
	* "External aborts"
	*/
	hook_fault_code(17, keystone_pcie_fault, SIGBUS, 0,
	"Asynchronous external abort");
	#endif

	return 0;
	}

	static const struct dw_pcie_host_ops keystone_pcie_host_ops = {
	.rd_other_conf = ks_dw_pcie_rd_other_conf,
	.wr_other_conf = ks_dw_pcie_wr_other_conf,
	.host_init = ks_pcie_host_init,
	.msi_set_irq = ks_dw_pcie_msi_set_irq,
	.msi_clear_irq = ks_dw_pcie_msi_clear_irq,
	.get_msi_addr = ks_dw_pcie_get_msi_addr,
	.msi_host_init = ks_dw_pcie_msi_host_init,
	.scan_bus = ks_dw_pcie_v3_65_scan_bus,
	};

	static irqreturn_t pcie_err_irq_handler(int irq, void *priv)
	{
	struct keystone_pcie *ks_pcie = priv;

	return ks_dw_pcie_handle_error_irq(ks_pcie);
	}

	static int __init ks_add_pcie_port(struct keystone_pcie *ks_pcie,
	struct platform_device *pdev)
	{
	struct dw_pcie *pci = ks_pcie->pci;
	struct pcie_port *pp = &pci->pp;
	struct device *dev = &pdev->dev;
	int ret;

	ret = ks_pcie_get_irq_controller_info(ks_pcie,
	"legacy-interrupt-controller",
	&ks_pcie->num_legacy_host_irqs);
	if (ret)
	return ret;

	if (IS_ENABLED(CONFIG_PCI_MSI)) {
	ret = ks_pcie_get_irq_controller_info(ks_pcie,
	"msi-interrupt-controller",
	&ks_pcie->num_msi_host_irqs);
	if (ret)
	return ret;
	}

	/*
	* Index 0 is the platform interrupt for error interrupt
	* from RC. This is optional.
	*/
	ks_pcie->error_irq = irq_of_parse_and_map(ks_pcie->np, 0);
	if (ks_pcie->error_irq <= 0)
	dev_info(dev, "no error IRQ defined\n");
	else {
	ret = request_irq(ks_pcie->error_irq, pcie_err_irq_handler,
	IRQF_SHARED, "pcie-error-irq", ks_pcie);
	if (ret < 0) {
	dev_err(dev, "failed to request error IRQ %d\n",
	ks_pcie->error_irq);
	return ret;
	}
	}

	pp->root_bus_nr = -1;
	pp->ops = &keystone_pcie_host_ops;
	ret = ks_dw_pcie_host_init(ks_pcie, ks_pcie->msi_intc_np);
	if (ret) {
	dev_err(dev, "failed to initialize host\n");
	return ret;
	}

	return 0;
	}

	static const struct of_device_id ks_pcie_of_match[] = {
	{
	.type = "pci",
	.compatible = "ti,keystone-pcie",
	},
	{ },
	};

	static const struct dw_pcie_ops dw_pcie_ops = {
	.link_up = ks_dw_pcie_link_up,
	};

	static int ks_pcie_remove(struct platform_device *pdev)
	{
	struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev);

	clk_disable_unprepare(ks_pcie->clk);

	return 0;
	}

	static int ks_pcie_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct dw_pcie *pci;
	struct keystone_pcie *ks_pcie;
	struct resource *res;
	void __iomem *reg_p;
	struct phy *phy;
	int ret;

	ks_pcie = devm_kzalloc(dev, sizeof(*ks_pcie), GFP_KERNEL);
	if (!ks_pcie)
	return -ENOMEM;

	pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
	if (!pci)
	return -ENOMEM;

	pci->dev = dev;
	pci->ops = &dw_pcie_ops;

	ks_pcie->pci = pci;

	/* initialize SerDes Phy if present */
	phy = devm_phy_get(dev, "pcie-phy");
	if (PTR_ERR_OR_ZERO(phy) == -EPROBE_DEFER)
	return PTR_ERR(phy);

	if (!IS_ERR_OR_NULL(phy)) {
	ret = phy_init(phy);
	if (ret < 0)
	return ret;
	}

	/* index 2 is to read PCI DEVICE_ID */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
	reg_p = devm_ioremap_resource(dev, res);
	if (IS_ERR(reg_p))
	return PTR_ERR(reg_p);
	ks_pcie->device_id = readl(reg_p) >> 16;
	devm_iounmap(dev, reg_p);
	devm_release_mem_region(dev, res->start, resource_size(res));

	ks_pcie->np = dev->of_node;
	platform_set_drvdata(pdev, ks_pcie);
	ks_pcie->clk = devm_clk_get(dev, "pcie");
	if (IS_ERR(ks_pcie->clk)) {
	dev_err(dev, "Failed to get pcie rc clock\n");
	return PTR_ERR(ks_pcie->clk);
	}
	ret = clk_prepare_enable(ks_pcie->clk);
	if (ret)
	return ret;

	platform_set_drvdata(pdev, ks_pcie);

	ret = ks_add_pcie_port(ks_pcie, pdev);
	if (ret < 0)
	goto fail_clk;

	return 0;
	fail_clk:
	clk_disable_unprepare(ks_pcie->clk);

	return ret;
	}

	static struct platform_driver ks_pcie_driver = {
	.probe = ks_pcie_probe,
	.remove = ks_pcie_remove,
	.driver = {
	.name = "keystone-pcie",
	.of_match_table = of_match_ptr(ks_pcie_of_match),
	},
	};
	builtin_platform_driver(ks_pcie_driver);