drivers/pci/controller/dwc/pcie-al.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * PCIe host controller driver for Amazon's Annapurna Labs IP (used in chips
  * such as Graviton and Alpine)
  *
  * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
  *
  * Author: Jonathan Chocron <jonnyc@amazon.com>
  */

 #include <linux/pci.h>
 #include <linux/pci-ecam.h>
 #include <linux/pci-acpi.h>
 #include "../../pci.h"

 #if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)

 struct al_pcie_acpi  {
 	void __iomem *dbi_base;
 };

 static void __iomem *al_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
 				     int where)
 {
 	struct pci_config_window *cfg = bus->sysdata;
 	struct al_pcie_acpi *pcie = cfg->priv;
 	void __iomem *dbi_base = pcie->dbi_base;

 	if (bus->number == cfg->busr.start) {
 		/*
 		 * The DW PCIe core doesn't filter out transactions to other
 		 * devices/functions on the root bus num, so we do this here.
 		 */
 		if (PCI_SLOT(devfn) > 0)
 			return NULL;
 		else
 			return dbi_base + where;
 	}

 	return pci_ecam_map_bus(bus, devfn, where);
 }

 static int al_pcie_init(struct pci_config_window *cfg)
 {
 	struct device *dev = cfg->parent;
 	struct acpi_device *adev = to_acpi_device(dev);
 	struct acpi_pci_root *root = acpi_driver_data(adev);
 	struct al_pcie_acpi *al_pcie;
 	struct resource *res;
 	int ret;

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

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

 	ret = acpi_get_rc_resources(dev, "AMZN0001", root->segment, res);
 	if (ret) {
 		dev_err(dev, "can't get rc dbi base address for SEG %d\n",
 			root->segment);
 		return ret;
 	}

 	dev_dbg(dev, "Root port dbi res: %pR\n", res);

 	al_pcie->dbi_base = devm_pci_remap_cfg_resource(dev, res);
 	if (IS_ERR(al_pcie->dbi_base)) {
 		long err = PTR_ERR(al_pcie->dbi_base);

 		dev_err(dev, "couldn't remap dbi base %pR (err:%ld)\n",
 			res, err);
 		return err;
 	}

 	cfg->priv = al_pcie;

 	return 0;
 }

 const struct pci_ecam_ops al_pcie_ops = {
 	.bus_shift    = 20,
 	.init         =  al_pcie_init,
 	.pci_ops      = {
 		.map_bus    = al_pcie_map_bus,
 		.read       = pci_generic_config_read,
 		.write      = pci_generic_config_write,
 	}
 };

 #endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */

 #ifdef CONFIG_PCIE_AL

 #include <linux/of_pci.h>
 #include "pcie-designware.h"

 #define AL_PCIE_REV_ID_2	2
 #define AL_PCIE_REV_ID_3	3
 #define AL_PCIE_REV_ID_4	4

 #define AXI_BASE_OFFSET		0x0

 #define DEVICE_ID_OFFSET	0x16c

 #define DEVICE_REV_ID			0x0
 #define DEVICE_REV_ID_DEV_ID_MASK	GENMASK(31, 16)

 #define DEVICE_REV_ID_DEV_ID_X4		0
 #define DEVICE_REV_ID_DEV_ID_X8		2
 #define DEVICE_REV_ID_DEV_ID_X16	4

 #define OB_CTRL_REV1_2_OFFSET	0x0040
 #define OB_CTRL_REV3_5_OFFSET	0x0030

 #define CFG_TARGET_BUS			0x0
 #define CFG_TARGET_BUS_MASK_MASK	GENMASK(7, 0)
 #define CFG_TARGET_BUS_BUSNUM_MASK	GENMASK(15, 8)

 #define CFG_CONTROL			0x4
 #define CFG_CONTROL_SUBBUS_MASK		GENMASK(15, 8)
 #define CFG_CONTROL_SEC_BUS_MASK	GENMASK(23, 16)

 struct al_pcie_reg_offsets {
 	unsigned int ob_ctrl;
 };

 struct al_pcie_target_bus_cfg {
 	u8 reg_val;
 	u8 reg_mask;
 	u8 ecam_mask;
 };

 struct al_pcie {
 	struct dw_pcie *pci;
 	void __iomem *controller_base; /* base of PCIe unit (not DW core) */
 	struct device *dev;
 	resource_size_t ecam_size;
 	unsigned int controller_rev_id;
 	struct al_pcie_reg_offsets reg_offsets;
 	struct al_pcie_target_bus_cfg target_bus_cfg;
 };

 #define PCIE_ECAM_DEVFN(x)		(((x) & 0xff) << 12)

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

 static inline u32 al_pcie_controller_readl(struct al_pcie *pcie, u32 offset)
 {
 	return readl_relaxed(pcie->controller_base + offset);
 }

 static inline void al_pcie_controller_writel(struct al_pcie *pcie, u32 offset,
 					     u32 val)
 {
 	writel_relaxed(val, pcie->controller_base + offset);
 }

 static int al_pcie_rev_id_get(struct al_pcie *pcie, unsigned int *rev_id)
 {
 	u32 dev_rev_id_val;
 	u32 dev_id_val;

 	dev_rev_id_val = al_pcie_controller_readl(pcie, AXI_BASE_OFFSET +
 						  DEVICE_ID_OFFSET +
 						  DEVICE_REV_ID);
 	dev_id_val = FIELD_GET(DEVICE_REV_ID_DEV_ID_MASK, dev_rev_id_val);

 	switch (dev_id_val) {
 	case DEVICE_REV_ID_DEV_ID_X4:
 		*rev_id = AL_PCIE_REV_ID_2;
 		break;
 	case DEVICE_REV_ID_DEV_ID_X8:
 		*rev_id = AL_PCIE_REV_ID_3;
 		break;
 	case DEVICE_REV_ID_DEV_ID_X16:
 		*rev_id = AL_PCIE_REV_ID_4;
 		break;
 	default:
 		dev_err(pcie->dev, "Unsupported dev_id_val (0x%x)\n",
 			dev_id_val);
 		return -EINVAL;
 	}

 	dev_dbg(pcie->dev, "dev_id_val: 0x%x\n", dev_id_val);

 	return 0;
 }

 static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
 {
 	switch (pcie->controller_rev_id) {
 	case AL_PCIE_REV_ID_2:
 		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
 		break;
 	case AL_PCIE_REV_ID_3:
 	case AL_PCIE_REV_ID_4:
 		pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
 		break;
 	default:
 		dev_err(pcie->dev, "Unsupported controller rev_id: 0x%x\n",
 			pcie->controller_rev_id);
 		return -EINVAL;
 	}

 	return 0;
 }

 static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
 					  u8 target_bus,
 					  u8 mask_target_bus)
 {
 	u32 reg;

 	reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK, mask_target_bus) |
 	      FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK, target_bus);

 	al_pcie_controller_writel(pcie, AXI_BASE_OFFSET +
 				  pcie->reg_offsets.ob_ctrl + CFG_TARGET_BUS,
 				  reg);
 }

 static void __iomem *al_pcie_conf_addr_map(struct al_pcie *pcie,
 					   unsigned int busnr,
 					   unsigned int devfn)
 {
 	struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie->target_bus_cfg;
 	unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
 	unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
 	struct pcie_port *pp = &pcie->pci->pp;
 	void __iomem *pci_base_addr;

 	pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
 					 (busnr_ecam << 20) +
 					 PCIE_ECAM_DEVFN(devfn));

 	if (busnr_reg != target_bus_cfg->reg_val) {
 		dev_dbg(pcie->pci->dev, "Changing target bus busnum val from 0x%x to 0x%x\n",
 			target_bus_cfg->reg_val, busnr_reg);
 		target_bus_cfg->reg_val = busnr_reg;
 		al_pcie_target_bus_set(pcie,
 				       target_bus_cfg->reg_val,
 				       target_bus_cfg->reg_mask);
 	}

 	return pci_base_addr;
 }

 static int al_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 				 unsigned int devfn, int where, int size,
 				 u32 *val)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct al_pcie *pcie = to_al_pcie(pci);
 	unsigned int busnr = bus->number;
 	void __iomem *pci_addr;
 	int rc;

 	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);

 	rc = dw_pcie_read(pci_addr + where, size, val);

 	dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
 		size, pci_domain_nr(bus), bus->number,
 		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
 		(pci_addr + where), *val);

 	return rc;
 }

 static int al_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 				 unsigned int devfn, int where, int size,
 				 u32 val)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct al_pcie *pcie = to_al_pcie(pci);
 	unsigned int busnr = bus->number;
 	void __iomem *pci_addr;
 	int rc;

 	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);

 	rc = dw_pcie_write(pci_addr + where, size, val);

 	dev_dbg(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
 		size, pci_domain_nr(bus), bus->number,
 		PCI_SLOT(devfn), PCI_FUNC(devfn), where,
 		(pci_addr + where), val);

 	return rc;
 }

 static void al_pcie_config_prepare(struct al_pcie *pcie)
 {
 	struct al_pcie_target_bus_cfg *target_bus_cfg;
 	struct pcie_port *pp = &pcie->pci->pp;
 	unsigned int ecam_bus_mask;
 	u32 cfg_control_offset;
 	u8 subordinate_bus;
 	u8 secondary_bus;
 	u32 cfg_control;
 	u32 reg;

 	target_bus_cfg = &pcie->target_bus_cfg;

 	ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
 	if (ecam_bus_mask > 255) {
 		dev_warn(pcie->dev, "ECAM window size is larger than 256MB. Cutting off at 256\n");
 		ecam_bus_mask = 255;
 	}

 	/* This portion is taken from the transaction address */
 	target_bus_cfg->ecam_mask = ecam_bus_mask;
 	/* This portion is taken from the cfg_target_bus reg */
 	target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
 	target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg->reg_mask;

 	al_pcie_target_bus_set(pcie, target_bus_cfg->reg_val,
 			       target_bus_cfg->reg_mask);

 	secondary_bus = pp->busn->start + 1;
 	subordinate_bus = pp->busn->end;

 	/* Set the valid values of secondary and subordinate buses */
 	cfg_control_offset = AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl +
 			     CFG_CONTROL;

 	cfg_control = al_pcie_controller_readl(pcie, cfg_control_offset);

 	reg = cfg_control &
 	      ~(CFG_CONTROL_SEC_BUS_MASK | CFG_CONTROL_SUBBUS_MASK);

 	reg |= FIELD_PREP(CFG_CONTROL_SUBBUS_MASK, subordinate_bus) |
 	       FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);

 	al_pcie_controller_writel(pcie, cfg_control_offset, reg);
 }

 static int al_pcie_host_init(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct al_pcie *pcie = to_al_pcie(pci);
 	int rc;

 	rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
 	if (rc)
 		return rc;

 	rc = al_pcie_reg_offsets_set(pcie);
 	if (rc)
 		return rc;

 	al_pcie_config_prepare(pcie);

 	return 0;
 }

 static const struct dw_pcie_host_ops al_pcie_host_ops = {
 	.rd_other_conf = al_pcie_rd_other_conf,
 	.wr_other_conf = al_pcie_wr_other_conf,
 	.host_init = al_pcie_host_init,
 };

 static int al_add_pcie_port(struct pcie_port *pp,
 			    struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	int ret;

 	pp->ops = &al_pcie_host_ops;

 	ret = dw_pcie_host_init(pp);
 	if (ret) {
 		dev_err(dev, "failed to initialize host\n");
 		return ret;
 	}

 	return 0;
 }

 static const struct dw_pcie_ops dw_pcie_ops = {
 };

 static int al_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct resource *controller_res;
 	struct resource *ecam_res;
 	struct resource *dbi_res;
 	struct al_pcie *al_pcie;
 	struct dw_pcie *pci;

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

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

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

 	al_pcie->pci = pci;
 	al_pcie->dev = dev;

 	dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
 	pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_res);
 	if (IS_ERR(pci->dbi_base)) {
 		dev_err(dev, "couldn't remap dbi base %pR\n", dbi_res);
 		return PTR_ERR(pci->dbi_base);
 	}

 	ecam_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
 	if (!ecam_res) {
 		dev_err(dev, "couldn't find 'config' reg in DT\n");
 		return -ENOENT;
 	}
 	al_pcie->ecam_size = resource_size(ecam_res);

 	controller_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 						      "controller");
 	al_pcie->controller_base = devm_ioremap_resource(dev, controller_res);
 	if (IS_ERR(al_pcie->controller_base)) {
 		dev_err(dev, "couldn't remap controller base %pR\n",
 			controller_res);
 		return PTR_ERR(al_pcie->controller_base);
 	}

 	dev_dbg(dev, "From DT: dbi_base: %pR, controller_base: %pR\n",
 		dbi_res, controller_res);

 	platform_set_drvdata(pdev, al_pcie);

 	return al_add_pcie_port(&pci->pp, pdev);
 }

 static const struct of_device_id al_pcie_of_match[] = {
 	{ .compatible = "amazon,al-alpine-v2-pcie",
 	},
 	{ .compatible = "amazon,al-alpine-v3-pcie",
 	},
 	{},
 };

 static struct platform_driver al_pcie_driver = {
 	.driver = {
 		.name	= "al-pcie",
 		.of_match_table = al_pcie_of_match,
 		.suppress_bind_attrs = true,
 	},
 	.probe = al_pcie_probe,
 };
 builtin_platform_driver(al_pcie_driver);

 #endif /* CONFIG_PCIE_AL*/
	// SPDX-License-Identifier: GPL-2.0
	/*
	* PCIe host controller driver for Amazon's Annapurna Labs IP (used in chips
	* such as Graviton and Alpine)
	*
	* Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
	*
	* Author: Jonathan Chocron <jonnyc@amazon.com>
	*/

	#include <linux/pci.h>
	#include <linux/pci-ecam.h>
	#include <linux/pci-acpi.h>
	#include "../../pci.h"

	#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)

	struct al_pcie_acpi {
	void __iomem *dbi_base;
	};

	static void __iomem al_pcie_map_bus(struct pci_bus bus, unsigned int devfn,
	int where)
	{
	struct pci_config_window *cfg = bus->sysdata;
	struct al_pcie_acpi *pcie = cfg->priv;
	void __iomem *dbi_base = pcie->dbi_base;

	if (bus->number == cfg->busr.start) {
	/*
	* The DW PCIe core doesn't filter out transactions to other
	* devices/functions on the root bus num, so we do this here.
	*/
	if (PCI_SLOT(devfn) > 0)
	return NULL;
	else
	return dbi_base + where;
	}

	return pci_ecam_map_bus(bus, devfn, where);
	}

	static int al_pcie_init(struct pci_config_window *cfg)
	{
	struct device *dev = cfg->parent;
	struct acpi_device *adev = to_acpi_device(dev);
	struct acpi_pci_root *root = acpi_driver_data(adev);
	struct al_pcie_acpi *al_pcie;
	struct resource *res;
	int ret;

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

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

	ret = acpi_get_rc_resources(dev, "AMZN0001", root->segment, res);
	if (ret) {
	dev_err(dev, "can't get rc dbi base address for SEG %d\n",
	root->segment);
	return ret;
	}

	dev_dbg(dev, "Root port dbi res: %pR\n", res);

	al_pcie->dbi_base = devm_pci_remap_cfg_resource(dev, res);
	if (IS_ERR(al_pcie->dbi_base)) {
	long err = PTR_ERR(al_pcie->dbi_base);

	dev_err(dev, "couldn't remap dbi base %pR (err:%ld)\n",
	res, err);
	return err;
	}

	cfg->priv = al_pcie;

	return 0;
	}

	const struct pci_ecam_ops al_pcie_ops = {
	.bus_shift = 20,
	.init = al_pcie_init,
	.pci_ops = {
	.map_bus = al_pcie_map_bus,
	.read = pci_generic_config_read,
	.write = pci_generic_config_write,
	}
	};

	#endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */

	#ifdef CONFIG_PCIE_AL

	#include <linux/of_pci.h>
	#include "pcie-designware.h"

	#define AL_PCIE_REV_ID_2 2
	#define AL_PCIE_REV_ID_3 3
	#define AL_PCIE_REV_ID_4 4

	#define AXI_BASE_OFFSET 0x0

	#define DEVICE_ID_OFFSET 0x16c

	#define DEVICE_REV_ID 0x0
	#define DEVICE_REV_ID_DEV_ID_MASK GENMASK(31, 16)

	#define DEVICE_REV_ID_DEV_ID_X4 0
	#define DEVICE_REV_ID_DEV_ID_X8 2
	#define DEVICE_REV_ID_DEV_ID_X16 4

	#define OB_CTRL_REV1_2_OFFSET 0x0040
	#define OB_CTRL_REV3_5_OFFSET 0x0030

	#define CFG_TARGET_BUS 0x0
	#define CFG_TARGET_BUS_MASK_MASK GENMASK(7, 0)
	#define CFG_TARGET_BUS_BUSNUM_MASK GENMASK(15, 8)

	#define CFG_CONTROL 0x4
	#define CFG_CONTROL_SUBBUS_MASK GENMASK(15, 8)
	#define CFG_CONTROL_SEC_BUS_MASK GENMASK(23, 16)

	struct al_pcie_reg_offsets {
	unsigned int ob_ctrl;
	};

	struct al_pcie_target_bus_cfg {
	u8 reg_val;
	u8 reg_mask;
	u8 ecam_mask;
	};

	struct al_pcie {
	struct dw_pcie *pci;
	void __iomem controller_base; / base of PCIe unit (not DW core) */
	struct device *dev;
	resource_size_t ecam_size;
	unsigned int controller_rev_id;
	struct al_pcie_reg_offsets reg_offsets;
	struct al_pcie_target_bus_cfg target_bus_cfg;
	};

	#define PCIE_ECAM_DEVFN(x) (((x) & 0xff) << 12)

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

	static inline u32 al_pcie_controller_readl(struct al_pcie *pcie, u32 offset)
	{
	return readl_relaxed(pcie->controller_base + offset);
	}

	static inline void al_pcie_controller_writel(struct al_pcie *pcie, u32 offset,
	u32 val)
	{
	writel_relaxed(val, pcie->controller_base + offset);
	}

	static int al_pcie_rev_id_get(struct al_pcie pcie, unsigned int rev_id)
	{
	u32 dev_rev_id_val;
	u32 dev_id_val;

	dev_rev_id_val = al_pcie_controller_readl(pcie, AXI_BASE_OFFSET +
	DEVICE_ID_OFFSET +
	DEVICE_REV_ID);
	dev_id_val = FIELD_GET(DEVICE_REV_ID_DEV_ID_MASK, dev_rev_id_val);

	switch (dev_id_val) {
	case DEVICE_REV_ID_DEV_ID_X4:
	*rev_id = AL_PCIE_REV_ID_2;
	break;
	case DEVICE_REV_ID_DEV_ID_X8:
	*rev_id = AL_PCIE_REV_ID_3;
	break;
	case DEVICE_REV_ID_DEV_ID_X16:
	*rev_id = AL_PCIE_REV_ID_4;
	break;
	default:
	dev_err(pcie->dev, "Unsupported dev_id_val (0x%x)\n",
	dev_id_val);
	return -EINVAL;
	}

	dev_dbg(pcie->dev, "dev_id_val: 0x%x\n", dev_id_val);

	return 0;
	}

	static int al_pcie_reg_offsets_set(struct al_pcie *pcie)
	{
	switch (pcie->controller_rev_id) {
	case AL_PCIE_REV_ID_2:
	pcie->reg_offsets.ob_ctrl = OB_CTRL_REV1_2_OFFSET;
	break;
	case AL_PCIE_REV_ID_3:
	case AL_PCIE_REV_ID_4:
	pcie->reg_offsets.ob_ctrl = OB_CTRL_REV3_5_OFFSET;
	break;
	default:
	dev_err(pcie->dev, "Unsupported controller rev_id: 0x%x\n",
	pcie->controller_rev_id);
	return -EINVAL;
	}

	return 0;
	}

	static inline void al_pcie_target_bus_set(struct al_pcie *pcie,
	u8 target_bus,
	u8 mask_target_bus)
	{
	u32 reg;

	reg = FIELD_PREP(CFG_TARGET_BUS_MASK_MASK, mask_target_bus) \|
	FIELD_PREP(CFG_TARGET_BUS_BUSNUM_MASK, target_bus);

	al_pcie_controller_writel(pcie, AXI_BASE_OFFSET +
	pcie->reg_offsets.ob_ctrl + CFG_TARGET_BUS,
	reg);
	}

	static void __iomem al_pcie_conf_addr_map(struct al_pcie pcie,
	unsigned int busnr,
	unsigned int devfn)
	{
	struct al_pcie_target_bus_cfg *target_bus_cfg = &pcie->target_bus_cfg;
	unsigned int busnr_ecam = busnr & target_bus_cfg->ecam_mask;
	unsigned int busnr_reg = busnr & target_bus_cfg->reg_mask;
	struct pcie_port *pp = &pcie->pci->pp;
	void __iomem *pci_base_addr;

	pci_base_addr = (void __iomem *)((uintptr_t)pp->va_cfg0_base +
	(busnr_ecam << 20) +
	PCIE_ECAM_DEVFN(devfn));

	if (busnr_reg != target_bus_cfg->reg_val) {
	dev_dbg(pcie->pci->dev, "Changing target bus busnum val from 0x%x to 0x%x\n",
	target_bus_cfg->reg_val, busnr_reg);
	target_bus_cfg->reg_val = busnr_reg;
	al_pcie_target_bus_set(pcie,
	target_bus_cfg->reg_val,
	target_bus_cfg->reg_mask);
	}

	return pci_base_addr;
	}

	static int al_pcie_rd_other_conf(struct pcie_port pp, struct pci_bus bus,
	unsigned int devfn, int where, int size,
	u32 *val)
	{
	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
	struct al_pcie *pcie = to_al_pcie(pci);
	unsigned int busnr = bus->number;
	void __iomem *pci_addr;
	int rc;

	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);

	rc = dw_pcie_read(pci_addr + where, size, val);

	dev_dbg(pci->dev, "%d-byte config read from %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
	size, pci_domain_nr(bus), bus->number,
	PCI_SLOT(devfn), PCI_FUNC(devfn), where,
	(pci_addr + where), *val);

	return rc;
	}

	static int al_pcie_wr_other_conf(struct pcie_port pp, struct pci_bus bus,
	unsigned int devfn, int where, int size,
	u32 val)
	{
	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
	struct al_pcie *pcie = to_al_pcie(pci);
	unsigned int busnr = bus->number;
	void __iomem *pci_addr;
	int rc;

	pci_addr = al_pcie_conf_addr_map(pcie, busnr, devfn);

	rc = dw_pcie_write(pci_addr + where, size, val);

	dev_dbg(pci->dev, "%d-byte config write to %04x:%02x:%02x.%d offset 0x%x (pci_addr: 0x%px) - val:0x%x\n",
	size, pci_domain_nr(bus), bus->number,
	PCI_SLOT(devfn), PCI_FUNC(devfn), where,
	(pci_addr + where), val);

	return rc;
	}

	static void al_pcie_config_prepare(struct al_pcie *pcie)
	{
	struct al_pcie_target_bus_cfg *target_bus_cfg;
	struct pcie_port *pp = &pcie->pci->pp;
	unsigned int ecam_bus_mask;
	u32 cfg_control_offset;
	u8 subordinate_bus;
	u8 secondary_bus;
	u32 cfg_control;
	u32 reg;

	target_bus_cfg = &pcie->target_bus_cfg;

	ecam_bus_mask = (pcie->ecam_size >> 20) - 1;
	if (ecam_bus_mask > 255) {
	dev_warn(pcie->dev, "ECAM window size is larger than 256MB. Cutting off at 256\n");
	ecam_bus_mask = 255;
	}

	/* This portion is taken from the transaction address */
	target_bus_cfg->ecam_mask = ecam_bus_mask;
	/* This portion is taken from the cfg_target_bus reg */
	target_bus_cfg->reg_mask = ~target_bus_cfg->ecam_mask;
	target_bus_cfg->reg_val = pp->busn->start & target_bus_cfg->reg_mask;

	al_pcie_target_bus_set(pcie, target_bus_cfg->reg_val,
	target_bus_cfg->reg_mask);

	secondary_bus = pp->busn->start + 1;
	subordinate_bus = pp->busn->end;

	/* Set the valid values of secondary and subordinate buses */
	cfg_control_offset = AXI_BASE_OFFSET + pcie->reg_offsets.ob_ctrl +
	CFG_CONTROL;

	cfg_control = al_pcie_controller_readl(pcie, cfg_control_offset);

	reg = cfg_control &
	~(CFG_CONTROL_SEC_BUS_MASK \| CFG_CONTROL_SUBBUS_MASK);

	reg \|= FIELD_PREP(CFG_CONTROL_SUBBUS_MASK, subordinate_bus) \|
	FIELD_PREP(CFG_CONTROL_SEC_BUS_MASK, secondary_bus);

	al_pcie_controller_writel(pcie, cfg_control_offset, reg);
	}

	static int al_pcie_host_init(struct pcie_port *pp)
	{
	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
	struct al_pcie *pcie = to_al_pcie(pci);
	int rc;

	rc = al_pcie_rev_id_get(pcie, &pcie->controller_rev_id);
	if (rc)
	return rc;

	rc = al_pcie_reg_offsets_set(pcie);
	if (rc)
	return rc;

	al_pcie_config_prepare(pcie);

	return 0;
	}

	static const struct dw_pcie_host_ops al_pcie_host_ops = {
	.rd_other_conf = al_pcie_rd_other_conf,
	.wr_other_conf = al_pcie_wr_other_conf,
	.host_init = al_pcie_host_init,
	};

	static int al_add_pcie_port(struct pcie_port *pp,
	struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	int ret;

	pp->ops = &al_pcie_host_ops;

	ret = dw_pcie_host_init(pp);
	if (ret) {
	dev_err(dev, "failed to initialize host\n");
	return ret;
	}

	return 0;
	}

	static const struct dw_pcie_ops dw_pcie_ops = {
	};

	static int al_pcie_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct resource *controller_res;
	struct resource *ecam_res;
	struct resource *dbi_res;
	struct al_pcie *al_pcie;
	struct dw_pcie *pci;

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

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

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

	al_pcie->pci = pci;
	al_pcie->dev = dev;

	dbi_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
	pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_res);
	if (IS_ERR(pci->dbi_base)) {
	dev_err(dev, "couldn't remap dbi base %pR\n", dbi_res);
	return PTR_ERR(pci->dbi_base);
	}

	ecam_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "config");
	if (!ecam_res) {
	dev_err(dev, "couldn't find 'config' reg in DT\n");
	return -ENOENT;
	}
	al_pcie->ecam_size = resource_size(ecam_res);

	controller_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
	"controller");
	al_pcie->controller_base = devm_ioremap_resource(dev, controller_res);
	if (IS_ERR(al_pcie->controller_base)) {
	dev_err(dev, "couldn't remap controller base %pR\n",
	controller_res);
	return PTR_ERR(al_pcie->controller_base);
	}

	dev_dbg(dev, "From DT: dbi_base: %pR, controller_base: %pR\n",
	dbi_res, controller_res);

	platform_set_drvdata(pdev, al_pcie);

	return al_add_pcie_port(&pci->pp, pdev);
	}

	static const struct of_device_id al_pcie_of_match[] = {
	{ .compatible = "amazon,al-alpine-v2-pcie",
	},
	{ .compatible = "amazon,al-alpine-v3-pcie",
	},
	{},
	};

	static struct platform_driver al_pcie_driver = {
	.driver = {
	.name = "al-pcie",
	.of_match_table = al_pcie_of_match,
	.suppress_bind_attrs = true,
	},
	.probe = al_pcie_probe,
	};
	builtin_platform_driver(al_pcie_driver);

	#endif /* CONFIG_PCIE_AL*/