drivers/pci/controller/pci-rcar-gen2.c - linux/kernel/git/paulmck/linux-rcu - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  pci-rcar-gen2: internal PCI bus support
  *
  * Copyright (C) 2013 Renesas Solutions Corp.
  * Copyright (C) 2013 Cogent Embedded, Inc.
  *
  * Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
  */

 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>

 #include "../pci.h"

 /* AHB-PCI Bridge PCI communication registers */
 #define RCAR_AHBPCI_PCICOM_OFFSET	0x800

 #define RCAR_PCIAHB_WIN1_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x00)
 #define RCAR_PCIAHB_WIN2_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x04)
 #define RCAR_PCIAHB_PREFETCH0		0x0
 #define RCAR_PCIAHB_PREFETCH4		0x1
 #define RCAR_PCIAHB_PREFETCH8		0x2
 #define RCAR_PCIAHB_PREFETCH16		0x3

 #define RCAR_AHBPCI_WIN1_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x10)
 #define RCAR_AHBPCI_WIN2_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x14)
 #define RCAR_AHBPCI_WIN_CTR_MEM		(3 << 1)
 #define RCAR_AHBPCI_WIN_CTR_CFG		(5 << 1)
 #define RCAR_AHBPCI_WIN1_HOST		(1 << 30)
 #define RCAR_AHBPCI_WIN1_DEVICE		(1 << 31)

 #define RCAR_PCI_INT_ENABLE_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x20)
 #define RCAR_PCI_INT_STATUS_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x24)
 #define RCAR_PCI_INT_SIGTABORT		(1 << 0)
 #define RCAR_PCI_INT_SIGRETABORT	(1 << 1)
 #define RCAR_PCI_INT_REMABORT		(1 << 2)
 #define RCAR_PCI_INT_PERR		(1 << 3)
 #define RCAR_PCI_INT_SIGSERR		(1 << 4)
 #define RCAR_PCI_INT_RESERR		(1 << 5)
 #define RCAR_PCI_INT_WIN1ERR		(1 << 12)
 #define RCAR_PCI_INT_WIN2ERR		(1 << 13)
 #define RCAR_PCI_INT_A			(1 << 16)
 #define RCAR_PCI_INT_B			(1 << 17)
 #define RCAR_PCI_INT_PME		(1 << 19)
 #define RCAR_PCI_INT_ALLERRORS (RCAR_PCI_INT_SIGTABORT		| \
 				RCAR_PCI_INT_SIGRETABORT	| \
 				RCAR_PCI_INT_REMABORT		| \
 				RCAR_PCI_INT_PERR		| \
 				RCAR_PCI_INT_SIGSERR		| \
 				RCAR_PCI_INT_RESERR		| \
 				RCAR_PCI_INT_WIN1ERR		| \
 				RCAR_PCI_INT_WIN2ERR)

 #define RCAR_AHB_BUS_CTR_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x30)
 #define RCAR_AHB_BUS_MMODE_HTRANS	(1 << 0)
 #define RCAR_AHB_BUS_MMODE_BYTE_BURST	(1 << 1)
 #define RCAR_AHB_BUS_MMODE_WR_INCR	(1 << 2)
 #define RCAR_AHB_BUS_MMODE_HBUS_REQ	(1 << 7)
 #define RCAR_AHB_BUS_SMODE_READYCTR	(1 << 17)
 #define RCAR_AHB_BUS_MODE		(RCAR_AHB_BUS_MMODE_HTRANS |	\
 					RCAR_AHB_BUS_MMODE_BYTE_BURST |	\
 					RCAR_AHB_BUS_MMODE_WR_INCR |	\
 					RCAR_AHB_BUS_MMODE_HBUS_REQ |	\
 					RCAR_AHB_BUS_SMODE_READYCTR)

 #define RCAR_USBCTR_REG			(RCAR_AHBPCI_PCICOM_OFFSET + 0x34)
 #define RCAR_USBCTR_USBH_RST		(1 << 0)
 #define RCAR_USBCTR_PCICLK_MASK		(1 << 1)
 #define RCAR_USBCTR_PLL_RST		(1 << 2)
 #define RCAR_USBCTR_DIRPD		(1 << 8)
 #define RCAR_USBCTR_PCIAHB_WIN2_EN	(1 << 9)
 #define RCAR_USBCTR_PCIAHB_WIN1_256M	(0 << 10)
 #define RCAR_USBCTR_PCIAHB_WIN1_512M	(1 << 10)
 #define RCAR_USBCTR_PCIAHB_WIN1_1G	(2 << 10)
 #define RCAR_USBCTR_PCIAHB_WIN1_2G	(3 << 10)
 #define RCAR_USBCTR_PCIAHB_WIN1_MASK	(3 << 10)

 #define RCAR_PCI_ARBITER_CTR_REG	(RCAR_AHBPCI_PCICOM_OFFSET + 0x40)
 #define RCAR_PCI_ARBITER_PCIREQ0	(1 << 0)
 #define RCAR_PCI_ARBITER_PCIREQ1	(1 << 1)
 #define RCAR_PCI_ARBITER_PCIBP_MODE	(1 << 12)

 #define RCAR_PCI_UNIT_REV_REG		(RCAR_AHBPCI_PCICOM_OFFSET + 0x48)

 struct rcar_pci {
 	struct device *dev;
 	void __iomem *reg;
 	struct resource mem_res;
 	struct resource *cfg_res;
 	int irq;
 };

 /* PCI configuration space operations */
 static void __iomem *rcar_pci_cfg_base(struct pci_bus *bus, unsigned int devfn,
 				       int where)
 {
 	struct rcar_pci *priv = bus->sysdata;
 	int slot, val;

 	if (!pci_is_root_bus(bus) || PCI_FUNC(devfn))
 		return NULL;

 	/* Only one EHCI/OHCI device built-in */
 	slot = PCI_SLOT(devfn);
 	if (slot > 2)
 		return NULL;

 	/* bridge logic only has registers to 0x40 */
 	if (slot == 0x0 && where >= 0x40)
 		return NULL;

 	val = slot ? RCAR_AHBPCI_WIN1_DEVICE | RCAR_AHBPCI_WIN_CTR_CFG :
 		     RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG;

 	iowrite32(val, priv->reg + RCAR_AHBPCI_WIN1_CTR_REG);
 	return priv->reg + (slot >> 1) * 0x100 + where;
 }

 #ifdef CONFIG_PCI_DEBUG
 /* if debug enabled, then attach an error handler irq to the bridge */

 static irqreturn_t rcar_pci_err_irq(int irq, void *pw)
 {
 	struct rcar_pci *priv = pw;
 	struct device *dev = priv->dev;
 	u32 status = ioread32(priv->reg + RCAR_PCI_INT_STATUS_REG);

 	if (status & RCAR_PCI_INT_ALLERRORS) {
 		dev_err(dev, "error irq: status %08x\n", status);

 		/* clear the error(s) */
 		iowrite32(status & RCAR_PCI_INT_ALLERRORS,
 			  priv->reg + RCAR_PCI_INT_STATUS_REG);
 		return IRQ_HANDLED;
 	}

 	return IRQ_NONE;
 }

 static void rcar_pci_setup_errirq(struct rcar_pci *priv)
 {
 	struct device *dev = priv->dev;
 	int ret;
 	u32 val;

 	ret = devm_request_irq(dev, priv->irq, rcar_pci_err_irq,
 			       IRQF_SHARED, "error irq", priv);
 	if (ret) {
 		dev_err(dev, "cannot claim IRQ for error handling\n");
 		return;
 	}

 	val = ioread32(priv->reg + RCAR_PCI_INT_ENABLE_REG);
 	val |= RCAR_PCI_INT_ALLERRORS;
 	iowrite32(val, priv->reg + RCAR_PCI_INT_ENABLE_REG);
 }
 #else
 static inline void rcar_pci_setup_errirq(struct rcar_pci *priv) { }
 #endif

 /* PCI host controller setup */
 static void rcar_pci_setup(struct rcar_pci *priv)
 {
 	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(priv);
 	struct device *dev = priv->dev;
 	void __iomem *reg = priv->reg;
 	struct resource_entry *entry;
 	unsigned long window_size;
 	unsigned long window_addr;
 	unsigned long window_pci;
 	u32 val;

 	entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
 	if (!entry) {
 		window_addr = 0x40000000;
 		window_pci = 0x40000000;
 		window_size = SZ_1G;
 	} else {
 		window_addr = entry->res->start;
 		window_pci = entry->res->start - entry->offset;
 		window_size = resource_size(entry->res);
 	}

 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);

 	val = ioread32(reg + RCAR_PCI_UNIT_REV_REG);
 	dev_info(dev, "PCI: revision %x\n", val);

 	/* Disable Direct Power Down State and assert reset */
 	val = ioread32(reg + RCAR_USBCTR_REG) & ~RCAR_USBCTR_DIRPD;
 	val |= RCAR_USBCTR_USBH_RST | RCAR_USBCTR_PLL_RST;
 	iowrite32(val, reg + RCAR_USBCTR_REG);
 	udelay(4);

 	/* De-assert reset and reset PCIAHB window1 size */
 	val &= ~(RCAR_USBCTR_PCIAHB_WIN1_MASK | RCAR_USBCTR_PCICLK_MASK |
 		 RCAR_USBCTR_USBH_RST | RCAR_USBCTR_PLL_RST);

 	/* Setup PCIAHB window1 size */
 	switch (window_size) {
 	case SZ_2G:
 		val |= RCAR_USBCTR_PCIAHB_WIN1_2G;
 		break;
 	case SZ_1G:
 		val |= RCAR_USBCTR_PCIAHB_WIN1_1G;
 		break;
 	case SZ_512M:
 		val |= RCAR_USBCTR_PCIAHB_WIN1_512M;
 		break;
 	default:
 		pr_warn("unknown window size %ld - defaulting to 256M\n",
 			window_size);
 		window_size = SZ_256M;
 		fallthrough;
 	case SZ_256M:
 		val |= RCAR_USBCTR_PCIAHB_WIN1_256M;
 		break;
 	}
 	iowrite32(val, reg + RCAR_USBCTR_REG);

 	/* Configure AHB master and slave modes */
 	iowrite32(RCAR_AHB_BUS_MODE, reg + RCAR_AHB_BUS_CTR_REG);

 	/* Configure PCI arbiter */
 	val = ioread32(reg + RCAR_PCI_ARBITER_CTR_REG);
 	val |= RCAR_PCI_ARBITER_PCIREQ0 | RCAR_PCI_ARBITER_PCIREQ1 |
 	       RCAR_PCI_ARBITER_PCIBP_MODE;
 	iowrite32(val, reg + RCAR_PCI_ARBITER_CTR_REG);

 	/* PCI-AHB mapping */
 	iowrite32(window_addr | RCAR_PCIAHB_PREFETCH16,
 		  reg + RCAR_PCIAHB_WIN1_CTR_REG);

 	/* AHB-PCI mapping: OHCI/EHCI registers */
 	val = priv->mem_res.start | RCAR_AHBPCI_WIN_CTR_MEM;
 	iowrite32(val, reg + RCAR_AHBPCI_WIN2_CTR_REG);

 	/* Enable AHB-PCI bridge PCI configuration access */
 	iowrite32(RCAR_AHBPCI_WIN1_HOST | RCAR_AHBPCI_WIN_CTR_CFG,
 		  reg + RCAR_AHBPCI_WIN1_CTR_REG);
 	/* Set PCI-AHB Window1 address */
 	iowrite32(window_pci | PCI_BASE_ADDRESS_MEM_PREFETCH,
 		  reg + PCI_BASE_ADDRESS_1);
 	/* Set AHB-PCI bridge PCI communication area address */
 	val = priv->cfg_res->start + RCAR_AHBPCI_PCICOM_OFFSET;
 	iowrite32(val, reg + PCI_BASE_ADDRESS_0);

 	val = ioread32(reg + PCI_COMMAND);
 	val |= PCI_COMMAND_SERR | PCI_COMMAND_PARITY |
 	       PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER;
 	iowrite32(val, reg + PCI_COMMAND);

 	/* Enable PCI interrupts */
 	iowrite32(RCAR_PCI_INT_A | RCAR_PCI_INT_B | RCAR_PCI_INT_PME,
 		  reg + RCAR_PCI_INT_ENABLE_REG);

 	rcar_pci_setup_errirq(priv);
 }

 static struct pci_ops rcar_pci_ops = {
 	.map_bus = rcar_pci_cfg_base,
 	.read	= pci_generic_config_read,
 	.write	= pci_generic_config_write,
 };

 static int rcar_pci_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct resource *cfg_res, *mem_res;
 	struct rcar_pci *priv;
 	struct pci_host_bridge *bridge;
 	void __iomem *reg;

 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*priv));
 	if (!bridge)
 		return -ENOMEM;

 	priv = pci_host_bridge_priv(bridge);
 	bridge->sysdata = priv;

 	cfg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	reg = devm_ioremap_resource(dev, cfg_res);
 	if (IS_ERR(reg))
 		return PTR_ERR(reg);

 	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 	if (!mem_res || !mem_res->start)
 		return -ENODEV;

 	if (mem_res->start & 0xFFFF)
 		return -EINVAL;

 	priv->mem_res = *mem_res;
 	priv->cfg_res = cfg_res;

 	priv->irq = platform_get_irq(pdev, 0);
 	priv->reg = reg;
 	priv->dev = dev;

 	if (priv->irq < 0) {
 		dev_err(dev, "no valid irq found\n");
 		return priv->irq;
 	}

 	bridge->ops = &rcar_pci_ops;

 	pci_add_flags(PCI_REASSIGN_ALL_BUS);

 	rcar_pci_setup(priv);

 	return pci_host_probe(bridge);
 }

 static const struct of_device_id rcar_pci_of_match[] = {
 	{ .compatible = "renesas,pci-r8a7790", },
 	{ .compatible = "renesas,pci-r8a7791", },
 	{ .compatible = "renesas,pci-r8a7794", },
 	{ .compatible = "renesas,pci-rcar-gen2", },
 	{ .compatible = "renesas,pci-rzn1", },
 	{ },
 };

 static struct platform_driver rcar_pci_driver = {
 	.driver = {
 		.name = "pci-rcar-gen2",
 		.suppress_bind_attrs = true,
 		.of_match_table = rcar_pci_of_match,
 	},
 	.probe = rcar_pci_probe,
 };
 builtin_platform_driver(rcar_pci_driver);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* pci-rcar-gen2: internal PCI bus support
	*
	* Copyright (C) 2013 Renesas Solutions Corp.
	* Copyright (C) 2013 Cogent Embedded, Inc.
	*
	* Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
	*/

	#include <linux/delay.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/of_address.h>
	#include <linux/of_pci.h>
	#include <linux/pci.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/sizes.h>
	#include <linux/slab.h>

	#include "../pci.h"

	/* AHB-PCI Bridge PCI communication registers */
	#define RCAR_AHBPCI_PCICOM_OFFSET 0x800

	#define RCAR_PCIAHB_WIN1_CTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x00)
	#define RCAR_PCIAHB_WIN2_CTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x04)
	#define RCAR_PCIAHB_PREFETCH0 0x0
	#define RCAR_PCIAHB_PREFETCH4 0x1
	#define RCAR_PCIAHB_PREFETCH8 0x2
	#define RCAR_PCIAHB_PREFETCH16 0x3

	#define RCAR_AHBPCI_WIN1_CTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x10)
	#define RCAR_AHBPCI_WIN2_CTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x14)
	#define RCAR_AHBPCI_WIN_CTR_MEM (3 << 1)
	#define RCAR_AHBPCI_WIN_CTR_CFG (5 << 1)
	#define RCAR_AHBPCI_WIN1_HOST (1 << 30)
	#define RCAR_AHBPCI_WIN1_DEVICE (1 << 31)

	#define RCAR_PCI_INT_ENABLE_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x20)
	#define RCAR_PCI_INT_STATUS_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x24)
	#define RCAR_PCI_INT_SIGTABORT (1 << 0)
	#define RCAR_PCI_INT_SIGRETABORT (1 << 1)
	#define RCAR_PCI_INT_REMABORT (1 << 2)
	#define RCAR_PCI_INT_PERR (1 << 3)
	#define RCAR_PCI_INT_SIGSERR (1 << 4)
	#define RCAR_PCI_INT_RESERR (1 << 5)
	#define RCAR_PCI_INT_WIN1ERR (1 << 12)
	#define RCAR_PCI_INT_WIN2ERR (1 << 13)
	#define RCAR_PCI_INT_A (1 << 16)
	#define RCAR_PCI_INT_B (1 << 17)
	#define RCAR_PCI_INT_PME (1 << 19)
	#define RCAR_PCI_INT_ALLERRORS (RCAR_PCI_INT_SIGTABORT \| \
	RCAR_PCI_INT_SIGRETABORT \| \
	RCAR_PCI_INT_REMABORT \| \
	RCAR_PCI_INT_PERR \| \
	RCAR_PCI_INT_SIGSERR \| \
	RCAR_PCI_INT_RESERR \| \
	RCAR_PCI_INT_WIN1ERR \| \
	RCAR_PCI_INT_WIN2ERR)

	#define RCAR_AHB_BUS_CTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x30)
	#define RCAR_AHB_BUS_MMODE_HTRANS (1 << 0)
	#define RCAR_AHB_BUS_MMODE_BYTE_BURST (1 << 1)
	#define RCAR_AHB_BUS_MMODE_WR_INCR (1 << 2)
	#define RCAR_AHB_BUS_MMODE_HBUS_REQ (1 << 7)
	#define RCAR_AHB_BUS_SMODE_READYCTR (1 << 17)
	#define RCAR_AHB_BUS_MODE (RCAR_AHB_BUS_MMODE_HTRANS \| \
	RCAR_AHB_BUS_MMODE_BYTE_BURST \| \
	RCAR_AHB_BUS_MMODE_WR_INCR \| \
	RCAR_AHB_BUS_MMODE_HBUS_REQ \| \
	RCAR_AHB_BUS_SMODE_READYCTR)

	#define RCAR_USBCTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x34)
	#define RCAR_USBCTR_USBH_RST (1 << 0)
	#define RCAR_USBCTR_PCICLK_MASK (1 << 1)
	#define RCAR_USBCTR_PLL_RST (1 << 2)
	#define RCAR_USBCTR_DIRPD (1 << 8)
	#define RCAR_USBCTR_PCIAHB_WIN2_EN (1 << 9)
	#define RCAR_USBCTR_PCIAHB_WIN1_256M (0 << 10)
	#define RCAR_USBCTR_PCIAHB_WIN1_512M (1 << 10)
	#define RCAR_USBCTR_PCIAHB_WIN1_1G (2 << 10)
	#define RCAR_USBCTR_PCIAHB_WIN1_2G (3 << 10)
	#define RCAR_USBCTR_PCIAHB_WIN1_MASK (3 << 10)

	#define RCAR_PCI_ARBITER_CTR_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x40)
	#define RCAR_PCI_ARBITER_PCIREQ0 (1 << 0)
	#define RCAR_PCI_ARBITER_PCIREQ1 (1 << 1)
	#define RCAR_PCI_ARBITER_PCIBP_MODE (1 << 12)

	#define RCAR_PCI_UNIT_REV_REG (RCAR_AHBPCI_PCICOM_OFFSET + 0x48)

	struct rcar_pci {
	struct device *dev;
	void __iomem *reg;
	struct resource mem_res;
	struct resource *cfg_res;
	int irq;
	};

	/* PCI configuration space operations */
	static void __iomem rcar_pci_cfg_base(struct pci_bus bus, unsigned int devfn,
	int where)
	{
	struct rcar_pci *priv = bus->sysdata;
	int slot, val;

	if (!pci_is_root_bus(bus) \|\| PCI_FUNC(devfn))
	return NULL;

	/* Only one EHCI/OHCI device built-in */
	slot = PCI_SLOT(devfn);
	if (slot > 2)
	return NULL;

	/* bridge logic only has registers to 0x40 */
	if (slot == 0x0 && where >= 0x40)
	return NULL;

	val = slot ? RCAR_AHBPCI_WIN1_DEVICE \| RCAR_AHBPCI_WIN_CTR_CFG :
	RCAR_AHBPCI_WIN1_HOST \| RCAR_AHBPCI_WIN_CTR_CFG;

	iowrite32(val, priv->reg + RCAR_AHBPCI_WIN1_CTR_REG);
	return priv->reg + (slot >> 1) * 0x100 + where;
	}

	#ifdef CONFIG_PCI_DEBUG
	/* if debug enabled, then attach an error handler irq to the bridge */

	static irqreturn_t rcar_pci_err_irq(int irq, void *pw)
	{
	struct rcar_pci *priv = pw;
	struct device *dev = priv->dev;
	u32 status = ioread32(priv->reg + RCAR_PCI_INT_STATUS_REG);

	if (status & RCAR_PCI_INT_ALLERRORS) {
	dev_err(dev, "error irq: status %08x\n", status);

	/* clear the error(s) */
	iowrite32(status & RCAR_PCI_INT_ALLERRORS,
	priv->reg + RCAR_PCI_INT_STATUS_REG);
	return IRQ_HANDLED;
	}

	return IRQ_NONE;
	}

	static void rcar_pci_setup_errirq(struct rcar_pci *priv)
	{
	struct device *dev = priv->dev;
	int ret;
	u32 val;

	ret = devm_request_irq(dev, priv->irq, rcar_pci_err_irq,
	IRQF_SHARED, "error irq", priv);
	if (ret) {
	dev_err(dev, "cannot claim IRQ for error handling\n");
	return;
	}

	val = ioread32(priv->reg + RCAR_PCI_INT_ENABLE_REG);
	val \|= RCAR_PCI_INT_ALLERRORS;
	iowrite32(val, priv->reg + RCAR_PCI_INT_ENABLE_REG);
	}
	#else
	static inline void rcar_pci_setup_errirq(struct rcar_pci *priv) { }
	#endif

	/* PCI host controller setup */
	static void rcar_pci_setup(struct rcar_pci *priv)
	{
	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(priv);
	struct device *dev = priv->dev;
	void __iomem *reg = priv->reg;
	struct resource_entry *entry;
	unsigned long window_size;
	unsigned long window_addr;
	unsigned long window_pci;
	u32 val;

	entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
	if (!entry) {
	window_addr = 0x40000000;
	window_pci = 0x40000000;
	window_size = SZ_1G;
	} else {
	window_addr = entry->res->start;
	window_pci = entry->res->start - entry->offset;
	window_size = resource_size(entry->res);
	}

	pm_runtime_enable(dev);
	pm_runtime_get_sync(dev);

	val = ioread32(reg + RCAR_PCI_UNIT_REV_REG);
	dev_info(dev, "PCI: revision %x\n", val);

	/* Disable Direct Power Down State and assert reset */
	val = ioread32(reg + RCAR_USBCTR_REG) & ~RCAR_USBCTR_DIRPD;
	val \|= RCAR_USBCTR_USBH_RST \| RCAR_USBCTR_PLL_RST;
	iowrite32(val, reg + RCAR_USBCTR_REG);
	udelay(4);

	/* De-assert reset and reset PCIAHB window1 size */
	val &= ~(RCAR_USBCTR_PCIAHB_WIN1_MASK \| RCAR_USBCTR_PCICLK_MASK \|
	RCAR_USBCTR_USBH_RST \| RCAR_USBCTR_PLL_RST);

	/* Setup PCIAHB window1 size */
	switch (window_size) {
	case SZ_2G:
	val \|= RCAR_USBCTR_PCIAHB_WIN1_2G;
	break;
	case SZ_1G:
	val \|= RCAR_USBCTR_PCIAHB_WIN1_1G;
	break;
	case SZ_512M:
	val \|= RCAR_USBCTR_PCIAHB_WIN1_512M;
	break;
	default:
	pr_warn("unknown window size %ld - defaulting to 256M\n",
	window_size);
	window_size = SZ_256M;
	fallthrough;
	case SZ_256M:
	val \|= RCAR_USBCTR_PCIAHB_WIN1_256M;
	break;
	}
	iowrite32(val, reg + RCAR_USBCTR_REG);

	/* Configure AHB master and slave modes */
	iowrite32(RCAR_AHB_BUS_MODE, reg + RCAR_AHB_BUS_CTR_REG);

	/* Configure PCI arbiter */
	val = ioread32(reg + RCAR_PCI_ARBITER_CTR_REG);
	val \|= RCAR_PCI_ARBITER_PCIREQ0 \| RCAR_PCI_ARBITER_PCIREQ1 \|
	RCAR_PCI_ARBITER_PCIBP_MODE;
	iowrite32(val, reg + RCAR_PCI_ARBITER_CTR_REG);

	/* PCI-AHB mapping */
	iowrite32(window_addr \| RCAR_PCIAHB_PREFETCH16,
	reg + RCAR_PCIAHB_WIN1_CTR_REG);

	/* AHB-PCI mapping: OHCI/EHCI registers */
	val = priv->mem_res.start \| RCAR_AHBPCI_WIN_CTR_MEM;
	iowrite32(val, reg + RCAR_AHBPCI_WIN2_CTR_REG);

	/* Enable AHB-PCI bridge PCI configuration access */
	iowrite32(RCAR_AHBPCI_WIN1_HOST \| RCAR_AHBPCI_WIN_CTR_CFG,
	reg + RCAR_AHBPCI_WIN1_CTR_REG);
	/* Set PCI-AHB Window1 address */
	iowrite32(window_pci \| PCI_BASE_ADDRESS_MEM_PREFETCH,
	reg + PCI_BASE_ADDRESS_1);
	/* Set AHB-PCI bridge PCI communication area address */
	val = priv->cfg_res->start + RCAR_AHBPCI_PCICOM_OFFSET;
	iowrite32(val, reg + PCI_BASE_ADDRESS_0);

	val = ioread32(reg + PCI_COMMAND);
	val \|= PCI_COMMAND_SERR \| PCI_COMMAND_PARITY \|
	PCI_COMMAND_MEMORY \| PCI_COMMAND_MASTER;
	iowrite32(val, reg + PCI_COMMAND);

	/* Enable PCI interrupts */
	iowrite32(RCAR_PCI_INT_A \| RCAR_PCI_INT_B \| RCAR_PCI_INT_PME,
	reg + RCAR_PCI_INT_ENABLE_REG);

	rcar_pci_setup_errirq(priv);
	}

	static struct pci_ops rcar_pci_ops = {
	.map_bus = rcar_pci_cfg_base,
	.read = pci_generic_config_read,
	.write = pci_generic_config_write,
	};

	static int rcar_pci_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct resource cfg_res, mem_res;
	struct rcar_pci *priv;
	struct pci_host_bridge *bridge;
	void __iomem *reg;

	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*priv));
	if (!bridge)
	return -ENOMEM;

	priv = pci_host_bridge_priv(bridge);
	bridge->sysdata = priv;

	cfg_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	reg = devm_ioremap_resource(dev, cfg_res);
	if (IS_ERR(reg))
	return PTR_ERR(reg);

	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	if (!mem_res \|\| !mem_res->start)
	return -ENODEV;

	if (mem_res->start & 0xFFFF)
	return -EINVAL;

	priv->mem_res = *mem_res;
	priv->cfg_res = cfg_res;

	priv->irq = platform_get_irq(pdev, 0);
	priv->reg = reg;
	priv->dev = dev;

	if (priv->irq < 0) {
	dev_err(dev, "no valid irq found\n");
	return priv->irq;
	}

	bridge->ops = &rcar_pci_ops;

	pci_add_flags(PCI_REASSIGN_ALL_BUS);

	rcar_pci_setup(priv);

	return pci_host_probe(bridge);
	}

	static const struct of_device_id rcar_pci_of_match[] = {
	{ .compatible = "renesas,pci-r8a7790", },
	{ .compatible = "renesas,pci-r8a7791", },
	{ .compatible = "renesas,pci-r8a7794", },
	{ .compatible = "renesas,pci-rcar-gen2", },
	{ .compatible = "renesas,pci-rzn1", },
	{ },
	};

	static struct platform_driver rcar_pci_driver = {
	.driver = {
	.name = "pci-rcar-gen2",
	.suppress_bind_attrs = true,
	.of_match_table = rcar_pci_of_match,
	},
	.probe = rcar_pci_probe,
	};
	builtin_platform_driver(rcar_pci_driver);