drivers/pci/controller/cadence/pci-j721e.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * pci-j721e - PCIe controller driver for TI's J721E SoCs
  *
  * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
  * Author: Kishon Vijay Abraham I <kishon@ti.com>
  */

 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/mfd/syscon.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
 #include <linux/pci.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>

 #include "../../pci.h"
 #include "pcie-cadence.h"

 #define ENABLE_REG_SYS_2	0x108
 #define STATUS_REG_SYS_2	0x508
 #define STATUS_CLR_REG_SYS_2	0x708
 #define LINK_DOWN		BIT(1)
 #define J7200_LINK_DOWN		BIT(10)

 #define J721E_PCIE_USER_CMD_STATUS	0x4
 #define LINK_TRAINING_ENABLE		BIT(0)

 #define J721E_PCIE_USER_LINKSTATUS	0x14
 #define LINK_STATUS			GENMASK(1, 0)

 enum link_status {
 	NO_RECEIVERS_DETECTED,
 	LINK_TRAINING_IN_PROGRESS,
 	LINK_UP_DL_IN_PROGRESS,
 	LINK_UP_DL_COMPLETED,
 };

 #define J721E_MODE_RC			BIT(7)
 #define LANE_COUNT_MASK			BIT(8)
 #define LANE_COUNT(n)			((n) << 8)

 #define GENERATION_SEL_MASK		GENMASK(1, 0)

 #define MAX_LANES			2

 struct j721e_pcie {
 	struct device		*dev;
 	struct clk		*refclk;
 	u32			mode;
 	u32			num_lanes;
 	struct cdns_pcie	*cdns_pcie;
 	void __iomem		*user_cfg_base;
 	void __iomem		*intd_cfg_base;
 	u32			linkdown_irq_regfield;
 };

 enum j721e_pcie_mode {
 	PCI_MODE_RC,
 	PCI_MODE_EP,
 };

 struct j721e_pcie_data {
 	enum j721e_pcie_mode	mode;
 	unsigned int		quirk_retrain_flag:1;
 	unsigned int		quirk_detect_quiet_flag:1;
 	u32			linkdown_irq_regfield;
 	unsigned int		byte_access_allowed:1;
 };

 static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
 {
 	return readl(pcie->user_cfg_base + offset);
 }

 static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
 					  u32 value)
 {
 	writel(value, pcie->user_cfg_base + offset);
 }

 static inline u32 j721e_pcie_intd_readl(struct j721e_pcie *pcie, u32 offset)
 {
 	return readl(pcie->intd_cfg_base + offset);
 }

 static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
 					  u32 value)
 {
 	writel(value, pcie->intd_cfg_base + offset);
 }

 static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
 {
 	struct j721e_pcie *pcie = priv;
 	struct device *dev = pcie->dev;
 	u32 reg;

 	reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
 	if (!(reg & pcie->linkdown_irq_regfield))
 		return IRQ_NONE;

 	dev_err(dev, "LINK DOWN!\n");

 	j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, pcie->linkdown_irq_regfield);
 	return IRQ_HANDLED;
 }

 static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
 {
 	u32 reg;

 	reg = j721e_pcie_intd_readl(pcie, ENABLE_REG_SYS_2);
 	reg |= pcie->linkdown_irq_regfield;
 	j721e_pcie_intd_writel(pcie, ENABLE_REG_SYS_2, reg);
 }

 static int j721e_pcie_start_link(struct cdns_pcie *cdns_pcie)
 {
 	struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
 	u32 reg;

 	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
 	reg |= LINK_TRAINING_ENABLE;
 	j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);

 	return 0;
 }

 static void j721e_pcie_stop_link(struct cdns_pcie *cdns_pcie)
 {
 	struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
 	u32 reg;

 	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
 	reg &= ~LINK_TRAINING_ENABLE;
 	j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
 }

 static bool j721e_pcie_link_up(struct cdns_pcie *cdns_pcie)
 {
 	struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
 	u32 reg;

 	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
 	reg &= LINK_STATUS;
 	if (reg == LINK_UP_DL_COMPLETED)
 		return true;

 	return false;
 }

 static const struct cdns_pcie_ops j721e_pcie_ops = {
 	.start_link = j721e_pcie_start_link,
 	.stop_link = j721e_pcie_stop_link,
 	.link_up = j721e_pcie_link_up,
 };

 static int j721e_pcie_set_mode(struct j721e_pcie *pcie, struct regmap *syscon,
 			       unsigned int offset)
 {
 	struct device *dev = pcie->dev;
 	u32 mask = J721E_MODE_RC;
 	u32 mode = pcie->mode;
 	u32 val = 0;
 	int ret = 0;

 	if (mode == PCI_MODE_RC)
 		val = J721E_MODE_RC;

 	ret = regmap_update_bits(syscon, offset, mask, val);
 	if (ret)
 		dev_err(dev, "failed to set pcie mode\n");

 	return ret;
 }

 static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
 				     struct regmap *syscon, unsigned int offset)
 {
 	struct device *dev = pcie->dev;
 	struct device_node *np = dev->of_node;
 	int link_speed;
 	u32 val = 0;
 	int ret;

 	link_speed = of_pci_get_max_link_speed(np);
 	if (link_speed < 2)
 		link_speed = 2;

 	val = link_speed - 1;
 	ret = regmap_update_bits(syscon, offset, GENERATION_SEL_MASK, val);
 	if (ret)
 		dev_err(dev, "failed to set link speed\n");

 	return ret;
 }

 static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
 				     struct regmap *syscon, unsigned int offset)
 {
 	struct device *dev = pcie->dev;
 	u32 lanes = pcie->num_lanes;
 	u32 val = 0;
 	int ret;

 	val = LANE_COUNT(lanes - 1);
 	ret = regmap_update_bits(syscon, offset, LANE_COUNT_MASK, val);
 	if (ret)
 		dev_err(dev, "failed to set link count\n");

 	return ret;
 }

 static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
 {
 	struct device *dev = pcie->dev;
 	struct device_node *node = dev->of_node;
 	struct of_phandle_args args;
 	unsigned int offset = 0;
 	struct regmap *syscon;
 	int ret;

 	syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-pcie-ctrl");
 	if (IS_ERR(syscon)) {
 		dev_err(dev, "Unable to get ti,syscon-pcie-ctrl regmap\n");
 		return PTR_ERR(syscon);
 	}

 	/* Do not error out to maintain old DT compatibility */
 	ret = of_parse_phandle_with_fixed_args(node, "ti,syscon-pcie-ctrl", 1,
 					       0, &args);
 	if (!ret)
 		offset = args.args[0];

 	ret = j721e_pcie_set_mode(pcie, syscon, offset);
 	if (ret < 0) {
 		dev_err(dev, "Failed to set pci mode\n");
 		return ret;
 	}

 	ret = j721e_pcie_set_link_speed(pcie, syscon, offset);
 	if (ret < 0) {
 		dev_err(dev, "Failed to set link speed\n");
 		return ret;
 	}

 	ret = j721e_pcie_set_lane_count(pcie, syscon, offset);
 	if (ret < 0) {
 		dev_err(dev, "Failed to set num-lanes\n");
 		return ret;
 	}

 	return 0;
 }

 static int cdns_ti_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
 				    int where, int size, u32 *value)
 {
 	if (pci_is_root_bus(bus))
 		return pci_generic_config_read32(bus, devfn, where, size,
 						 value);

 	return pci_generic_config_read(bus, devfn, where, size, value);
 }

 static int cdns_ti_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
 				     int where, int size, u32 value)
 {
 	if (pci_is_root_bus(bus))
 		return pci_generic_config_write32(bus, devfn, where, size,
 						  value);

 	return pci_generic_config_write(bus, devfn, where, size, value);
 }

 static struct pci_ops cdns_ti_pcie_host_ops = {
 	.map_bus	= cdns_pci_map_bus,
 	.read		= cdns_ti_pcie_config_read,
 	.write		= cdns_ti_pcie_config_write,
 };

 static const struct j721e_pcie_data j721e_pcie_rc_data = {
 	.mode = PCI_MODE_RC,
 	.quirk_retrain_flag = true,
 	.byte_access_allowed = false,
 	.linkdown_irq_regfield = LINK_DOWN,
 };

 static const struct j721e_pcie_data j721e_pcie_ep_data = {
 	.mode = PCI_MODE_EP,
 	.linkdown_irq_regfield = LINK_DOWN,
 };

 static const struct j721e_pcie_data j7200_pcie_rc_data = {
 	.mode = PCI_MODE_RC,
 	.quirk_detect_quiet_flag = true,
 	.linkdown_irq_regfield = J7200_LINK_DOWN,
 	.byte_access_allowed = true,
 };

 static const struct j721e_pcie_data j7200_pcie_ep_data = {
 	.mode = PCI_MODE_EP,
 	.quirk_detect_quiet_flag = true,
 };

 static const struct j721e_pcie_data am64_pcie_rc_data = {
 	.mode = PCI_MODE_RC,
 	.linkdown_irq_regfield = J7200_LINK_DOWN,
 	.byte_access_allowed = true,
 };

 static const struct j721e_pcie_data am64_pcie_ep_data = {
 	.mode = PCI_MODE_EP,
 	.linkdown_irq_regfield = J7200_LINK_DOWN,
 };

 static const struct of_device_id of_j721e_pcie_match[] = {
 	{
 		.compatible = "ti,j721e-pcie-host",
 		.data = &j721e_pcie_rc_data,
 	},
 	{
 		.compatible = "ti,j721e-pcie-ep",
 		.data = &j721e_pcie_ep_data,
 	},
 	{
 		.compatible = "ti,j7200-pcie-host",
 		.data = &j7200_pcie_rc_data,
 	},
 	{
 		.compatible = "ti,j7200-pcie-ep",
 		.data = &j7200_pcie_ep_data,
 	},
 	{
 		.compatible = "ti,am64-pcie-host",
 		.data = &am64_pcie_rc_data,
 	},
 	{
 		.compatible = "ti,am64-pcie-ep",
 		.data = &am64_pcie_ep_data,
 	},
 	{},
 };

 static int j721e_pcie_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *node = dev->of_node;
 	struct pci_host_bridge *bridge;
 	struct j721e_pcie_data *data;
 	struct cdns_pcie *cdns_pcie;
 	struct j721e_pcie *pcie;
 	struct cdns_pcie_rc *rc;
 	struct cdns_pcie_ep *ep;
 	struct gpio_desc *gpiod;
 	void __iomem *base;
 	struct clk *clk;
 	u32 num_lanes;
 	u32 mode;
 	int ret;
 	int irq;

 	data = (struct j721e_pcie_data *)of_device_get_match_data(dev);
 	if (!data)
 		return -EINVAL;

 	mode = (u32)data->mode;

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

 	pcie->dev = dev;
 	pcie->mode = mode;
 	pcie->linkdown_irq_regfield = data->linkdown_irq_regfield;

 	base = devm_platform_ioremap_resource_byname(pdev, "intd_cfg");
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 	pcie->intd_cfg_base = base;

 	base = devm_platform_ioremap_resource_byname(pdev, "user_cfg");
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 	pcie->user_cfg_base = base;

 	ret = of_property_read_u32(node, "num-lanes", &num_lanes);
 	if (ret || num_lanes > MAX_LANES)
 		num_lanes = 1;
 	pcie->num_lanes = num_lanes;

 	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48)))
 		return -EINVAL;

 	irq = platform_get_irq_byname(pdev, "link_state");
 	if (irq < 0)
 		return irq;

 	dev_set_drvdata(dev, pcie);
 	pm_runtime_enable(dev);
 	ret = pm_runtime_get_sync(dev);
 	if (ret < 0) {
 		dev_err(dev, "pm_runtime_get_sync failed\n");
 		goto err_get_sync;
 	}

 	ret = j721e_pcie_ctrl_init(pcie);
 	if (ret < 0) {
 		dev_err(dev, "pm_runtime_get_sync failed\n");
 		goto err_get_sync;
 	}

 	ret = devm_request_irq(dev, irq, j721e_pcie_link_irq_handler, 0,
 			       "j721e-pcie-link-down-irq", pcie);
 	if (ret < 0) {
 		dev_err(dev, "failed to request link state IRQ %d\n", irq);
 		goto err_get_sync;
 	}

 	j721e_pcie_config_link_irq(pcie);

 	switch (mode) {
 	case PCI_MODE_RC:
 		if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)) {
 			ret = -ENODEV;
 			goto err_get_sync;
 		}

 		bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
 		if (!bridge) {
 			ret = -ENOMEM;
 			goto err_get_sync;
 		}

 		if (!data->byte_access_allowed)
 			bridge->ops = &cdns_ti_pcie_host_ops;
 		rc = pci_host_bridge_priv(bridge);
 		rc->quirk_retrain_flag = data->quirk_retrain_flag;
 		rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;

 		cdns_pcie = &rc->pcie;
 		cdns_pcie->dev = dev;
 		cdns_pcie->ops = &j721e_pcie_ops;
 		pcie->cdns_pcie = cdns_pcie;

 		gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
 		if (IS_ERR(gpiod)) {
 			ret = PTR_ERR(gpiod);
 			if (ret != -EPROBE_DEFER)
 				dev_err(dev, "Failed to get reset GPIO\n");
 			goto err_get_sync;
 		}

 		ret = cdns_pcie_init_phy(dev, cdns_pcie);
 		if (ret) {
 			dev_err(dev, "Failed to init phy\n");
 			goto err_get_sync;
 		}

 		clk = devm_clk_get_optional(dev, "pcie_refclk");
 		if (IS_ERR(clk)) {
 			ret = PTR_ERR(clk);
 			dev_err(dev, "failed to get pcie_refclk\n");
 			goto err_pcie_setup;
 		}

 		ret = clk_prepare_enable(clk);
 		if (ret) {
 			dev_err(dev, "failed to enable pcie_refclk\n");
 			goto err_get_sync;
 		}
 		pcie->refclk = clk;

 		/*
 		 * "Power Sequencing and Reset Signal Timings" table in
 		 * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0
 		 * indicates PERST# should be deasserted after minimum of 100us
 		 * once REFCLK is stable. The REFCLK to the connector in RC
 		 * mode is selected while enabling the PHY. So deassert PERST#
 		 * after 100 us.
 		 */
 		if (gpiod) {
 			usleep_range(100, 200);
 			gpiod_set_value_cansleep(gpiod, 1);
 		}

 		ret = cdns_pcie_host_setup(rc);
 		if (ret < 0) {
 			clk_disable_unprepare(pcie->refclk);
 			goto err_pcie_setup;
 		}

 		break;
 	case PCI_MODE_EP:
 		if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP)) {
 			ret = -ENODEV;
 			goto err_get_sync;
 		}

 		ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
 		if (!ep) {
 			ret = -ENOMEM;
 			goto err_get_sync;
 		}
 		ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;

 		cdns_pcie = &ep->pcie;
 		cdns_pcie->dev = dev;
 		cdns_pcie->ops = &j721e_pcie_ops;
 		pcie->cdns_pcie = cdns_pcie;

 		ret = cdns_pcie_init_phy(dev, cdns_pcie);
 		if (ret) {
 			dev_err(dev, "Failed to init phy\n");
 			goto err_get_sync;
 		}

 		ret = cdns_pcie_ep_setup(ep);
 		if (ret < 0)
 			goto err_pcie_setup;

 		break;
 	default:
 		dev_err(dev, "INVALID device type %d\n", mode);
 	}

 	return 0;

 err_pcie_setup:
 	cdns_pcie_disable_phy(cdns_pcie);

 err_get_sync:
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);

 	return ret;
 }

 static int j721e_pcie_remove(struct platform_device *pdev)
 {
 	struct j721e_pcie *pcie = platform_get_drvdata(pdev);
 	struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
 	struct device *dev = &pdev->dev;

 	clk_disable_unprepare(pcie->refclk);
 	cdns_pcie_disable_phy(cdns_pcie);
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);

 	return 0;
 }

 static struct platform_driver j721e_pcie_driver = {
 	.probe  = j721e_pcie_probe,
 	.remove = j721e_pcie_remove,
 	.driver = {
 		.name	= "j721e-pcie",
 		.of_match_table = of_j721e_pcie_match,
 		.suppress_bind_attrs = true,
 	},
 };
 builtin_platform_driver(j721e_pcie_driver);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* pci-j721e - PCIe controller driver for TI's J721E SoCs
	*
	* Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
	* Author: Kishon Vijay Abraham I <kishon@ti.com>
	*/

	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/gpio/consumer.h>
	#include <linux/io.h>
	#include <linux/irqchip/chained_irq.h>
	#include <linux/irqdomain.h>
	#include <linux/mfd/syscon.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/of_irq.h>
	#include <linux/pci.h>
	#include <linux/pm_runtime.h>
	#include <linux/regmap.h>

	#include "../../pci.h"
	#include "pcie-cadence.h"

	#define ENABLE_REG_SYS_2 0x108
	#define STATUS_REG_SYS_2 0x508
	#define STATUS_CLR_REG_SYS_2 0x708
	#define LINK_DOWN BIT(1)
	#define J7200_LINK_DOWN BIT(10)

	#define J721E_PCIE_USER_CMD_STATUS 0x4
	#define LINK_TRAINING_ENABLE BIT(0)

	#define J721E_PCIE_USER_LINKSTATUS 0x14
	#define LINK_STATUS GENMASK(1, 0)

	enum link_status {
	NO_RECEIVERS_DETECTED,
	LINK_TRAINING_IN_PROGRESS,
	LINK_UP_DL_IN_PROGRESS,
	LINK_UP_DL_COMPLETED,
	};

	#define J721E_MODE_RC BIT(7)
	#define LANE_COUNT_MASK BIT(8)
	#define LANE_COUNT(n) ((n) << 8)

	#define GENERATION_SEL_MASK GENMASK(1, 0)

	#define MAX_LANES 2

	struct j721e_pcie {
	struct device *dev;
	struct clk *refclk;
	u32 mode;
	u32 num_lanes;
	struct cdns_pcie *cdns_pcie;
	void __iomem *user_cfg_base;
	void __iomem *intd_cfg_base;
	u32 linkdown_irq_regfield;
	};

	enum j721e_pcie_mode {
	PCI_MODE_RC,
	PCI_MODE_EP,
	};

	struct j721e_pcie_data {
	enum j721e_pcie_mode mode;
	unsigned int quirk_retrain_flag:1;
	unsigned int quirk_detect_quiet_flag:1;
	u32 linkdown_irq_regfield;
	unsigned int byte_access_allowed:1;
	};

	static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
	{
	return readl(pcie->user_cfg_base + offset);
	}

	static inline void j721e_pcie_user_writel(struct j721e_pcie *pcie, u32 offset,
	u32 value)
	{
	writel(value, pcie->user_cfg_base + offset);
	}

	static inline u32 j721e_pcie_intd_readl(struct j721e_pcie *pcie, u32 offset)
	{
	return readl(pcie->intd_cfg_base + offset);
	}

	static inline void j721e_pcie_intd_writel(struct j721e_pcie *pcie, u32 offset,
	u32 value)
	{
	writel(value, pcie->intd_cfg_base + offset);
	}

	static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
	{
	struct j721e_pcie *pcie = priv;
	struct device *dev = pcie->dev;
	u32 reg;

	reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
	if (!(reg & pcie->linkdown_irq_regfield))
	return IRQ_NONE;

	dev_err(dev, "LINK DOWN!\n");

	j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, pcie->linkdown_irq_regfield);
	return IRQ_HANDLED;
	}

	static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
	{
	u32 reg;

	reg = j721e_pcie_intd_readl(pcie, ENABLE_REG_SYS_2);
	reg \|= pcie->linkdown_irq_regfield;
	j721e_pcie_intd_writel(pcie, ENABLE_REG_SYS_2, reg);
	}

	static int j721e_pcie_start_link(struct cdns_pcie *cdns_pcie)
	{
	struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
	u32 reg;

	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
	reg \|= LINK_TRAINING_ENABLE;
	j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);

	return 0;
	}

	static void j721e_pcie_stop_link(struct cdns_pcie *cdns_pcie)
	{
	struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
	u32 reg;

	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_CMD_STATUS);
	reg &= ~LINK_TRAINING_ENABLE;
	j721e_pcie_user_writel(pcie, J721E_PCIE_USER_CMD_STATUS, reg);
	}

	static bool j721e_pcie_link_up(struct cdns_pcie *cdns_pcie)
	{
	struct j721e_pcie *pcie = dev_get_drvdata(cdns_pcie->dev);
	u32 reg;

	reg = j721e_pcie_user_readl(pcie, J721E_PCIE_USER_LINKSTATUS);
	reg &= LINK_STATUS;
	if (reg == LINK_UP_DL_COMPLETED)
	return true;

	return false;
	}

	static const struct cdns_pcie_ops j721e_pcie_ops = {
	.start_link = j721e_pcie_start_link,
	.stop_link = j721e_pcie_stop_link,
	.link_up = j721e_pcie_link_up,
	};

	static int j721e_pcie_set_mode(struct j721e_pcie pcie, struct regmap syscon,
	unsigned int offset)
	{
	struct device *dev = pcie->dev;
	u32 mask = J721E_MODE_RC;
	u32 mode = pcie->mode;
	u32 val = 0;
	int ret = 0;

	if (mode == PCI_MODE_RC)
	val = J721E_MODE_RC;

	ret = regmap_update_bits(syscon, offset, mask, val);
	if (ret)
	dev_err(dev, "failed to set pcie mode\n");

	return ret;
	}

	static int j721e_pcie_set_link_speed(struct j721e_pcie *pcie,
	struct regmap *syscon, unsigned int offset)
	{
	struct device *dev = pcie->dev;
	struct device_node *np = dev->of_node;
	int link_speed;
	u32 val = 0;
	int ret;

	link_speed = of_pci_get_max_link_speed(np);
	if (link_speed < 2)
	link_speed = 2;

	val = link_speed - 1;
	ret = regmap_update_bits(syscon, offset, GENERATION_SEL_MASK, val);
	if (ret)
	dev_err(dev, "failed to set link speed\n");

	return ret;
	}

	static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie,
	struct regmap *syscon, unsigned int offset)
	{
	struct device *dev = pcie->dev;
	u32 lanes = pcie->num_lanes;
	u32 val = 0;
	int ret;

	val = LANE_COUNT(lanes - 1);
	ret = regmap_update_bits(syscon, offset, LANE_COUNT_MASK, val);
	if (ret)
	dev_err(dev, "failed to set link count\n");

	return ret;
	}

	static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie)
	{
	struct device *dev = pcie->dev;
	struct device_node *node = dev->of_node;
	struct of_phandle_args args;
	unsigned int offset = 0;
	struct regmap *syscon;
	int ret;

	syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-pcie-ctrl");
	if (IS_ERR(syscon)) {
	dev_err(dev, "Unable to get ti,syscon-pcie-ctrl regmap\n");
	return PTR_ERR(syscon);
	}

	/* Do not error out to maintain old DT compatibility */
	ret = of_parse_phandle_with_fixed_args(node, "ti,syscon-pcie-ctrl", 1,
	0, &args);
	if (!ret)
	offset = args.args[0];

	ret = j721e_pcie_set_mode(pcie, syscon, offset);
	if (ret < 0) {
	dev_err(dev, "Failed to set pci mode\n");
	return ret;
	}

	ret = j721e_pcie_set_link_speed(pcie, syscon, offset);
	if (ret < 0) {
	dev_err(dev, "Failed to set link speed\n");
	return ret;
	}

	ret = j721e_pcie_set_lane_count(pcie, syscon, offset);
	if (ret < 0) {
	dev_err(dev, "Failed to set num-lanes\n");
	return ret;
	}

	return 0;
	}

	static int cdns_ti_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
	int where, int size, u32 *value)
	{
	if (pci_is_root_bus(bus))
	return pci_generic_config_read32(bus, devfn, where, size,
	value);

	return pci_generic_config_read(bus, devfn, where, size, value);
	}

	static int cdns_ti_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
	int where, int size, u32 value)
	{
	if (pci_is_root_bus(bus))
	return pci_generic_config_write32(bus, devfn, where, size,
	value);

	return pci_generic_config_write(bus, devfn, where, size, value);
	}

	static struct pci_ops cdns_ti_pcie_host_ops = {
	.map_bus = cdns_pci_map_bus,
	.read = cdns_ti_pcie_config_read,
	.write = cdns_ti_pcie_config_write,
	};

	static const struct j721e_pcie_data j721e_pcie_rc_data = {
	.mode = PCI_MODE_RC,
	.quirk_retrain_flag = true,
	.byte_access_allowed = false,
	.linkdown_irq_regfield = LINK_DOWN,
	};

	static const struct j721e_pcie_data j721e_pcie_ep_data = {
	.mode = PCI_MODE_EP,
	.linkdown_irq_regfield = LINK_DOWN,
	};

	static const struct j721e_pcie_data j7200_pcie_rc_data = {
	.mode = PCI_MODE_RC,
	.quirk_detect_quiet_flag = true,
	.linkdown_irq_regfield = J7200_LINK_DOWN,
	.byte_access_allowed = true,
	};

	static const struct j721e_pcie_data j7200_pcie_ep_data = {
	.mode = PCI_MODE_EP,
	.quirk_detect_quiet_flag = true,
	};

	static const struct j721e_pcie_data am64_pcie_rc_data = {
	.mode = PCI_MODE_RC,
	.linkdown_irq_regfield = J7200_LINK_DOWN,
	.byte_access_allowed = true,
	};

	static const struct j721e_pcie_data am64_pcie_ep_data = {
	.mode = PCI_MODE_EP,
	.linkdown_irq_regfield = J7200_LINK_DOWN,
	};

	static const struct of_device_id of_j721e_pcie_match[] = {
	{
	.compatible = "ti,j721e-pcie-host",
	.data = &j721e_pcie_rc_data,
	},
	{
	.compatible = "ti,j721e-pcie-ep",
	.data = &j721e_pcie_ep_data,
	},
	{
	.compatible = "ti,j7200-pcie-host",
	.data = &j7200_pcie_rc_data,
	},
	{
	.compatible = "ti,j7200-pcie-ep",
	.data = &j7200_pcie_ep_data,
	},
	{
	.compatible = "ti,am64-pcie-host",
	.data = &am64_pcie_rc_data,
	},
	{
	.compatible = "ti,am64-pcie-ep",
	.data = &am64_pcie_ep_data,
	},
	{},
	};

	static int j721e_pcie_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *node = dev->of_node;
	struct pci_host_bridge *bridge;
	struct j721e_pcie_data *data;
	struct cdns_pcie *cdns_pcie;
	struct j721e_pcie *pcie;
	struct cdns_pcie_rc *rc;
	struct cdns_pcie_ep *ep;
	struct gpio_desc *gpiod;
	void __iomem *base;
	struct clk *clk;
	u32 num_lanes;
	u32 mode;
	int ret;
	int irq;

	data = (struct j721e_pcie_data *)of_device_get_match_data(dev);
	if (!data)
	return -EINVAL;

	mode = (u32)data->mode;

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

	pcie->dev = dev;
	pcie->mode = mode;
	pcie->linkdown_irq_regfield = data->linkdown_irq_regfield;

	base = devm_platform_ioremap_resource_byname(pdev, "intd_cfg");
	if (IS_ERR(base))
	return PTR_ERR(base);
	pcie->intd_cfg_base = base;

	base = devm_platform_ioremap_resource_byname(pdev, "user_cfg");
	if (IS_ERR(base))
	return PTR_ERR(base);
	pcie->user_cfg_base = base;

	ret = of_property_read_u32(node, "num-lanes", &num_lanes);
	if (ret \|\| num_lanes > MAX_LANES)
	num_lanes = 1;
	pcie->num_lanes = num_lanes;

	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(48)))
	return -EINVAL;

	irq = platform_get_irq_byname(pdev, "link_state");
	if (irq < 0)
	return irq;

	dev_set_drvdata(dev, pcie);
	pm_runtime_enable(dev);
	ret = pm_runtime_get_sync(dev);
	if (ret < 0) {
	dev_err(dev, "pm_runtime_get_sync failed\n");
	goto err_get_sync;
	}

	ret = j721e_pcie_ctrl_init(pcie);
	if (ret < 0) {
	dev_err(dev, "pm_runtime_get_sync failed\n");
	goto err_get_sync;
	}

	ret = devm_request_irq(dev, irq, j721e_pcie_link_irq_handler, 0,
	"j721e-pcie-link-down-irq", pcie);
	if (ret < 0) {
	dev_err(dev, "failed to request link state IRQ %d\n", irq);
	goto err_get_sync;
	}

	j721e_pcie_config_link_irq(pcie);

	switch (mode) {
	case PCI_MODE_RC:
	if (!IS_ENABLED(CONFIG_PCIE_CADENCE_HOST)) {
	ret = -ENODEV;
	goto err_get_sync;
	}

	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
	if (!bridge) {
	ret = -ENOMEM;
	goto err_get_sync;
	}

	if (!data->byte_access_allowed)
	bridge->ops = &cdns_ti_pcie_host_ops;
	rc = pci_host_bridge_priv(bridge);
	rc->quirk_retrain_flag = data->quirk_retrain_flag;
	rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;

	cdns_pcie = &rc->pcie;
	cdns_pcie->dev = dev;
	cdns_pcie->ops = &j721e_pcie_ops;
	pcie->cdns_pcie = cdns_pcie;

	gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(gpiod)) {
	ret = PTR_ERR(gpiod);
	if (ret != -EPROBE_DEFER)
	dev_err(dev, "Failed to get reset GPIO\n");
	goto err_get_sync;
	}

	ret = cdns_pcie_init_phy(dev, cdns_pcie);
	if (ret) {
	dev_err(dev, "Failed to init phy\n");
	goto err_get_sync;
	}

	clk = devm_clk_get_optional(dev, "pcie_refclk");
	if (IS_ERR(clk)) {
	ret = PTR_ERR(clk);
	dev_err(dev, "failed to get pcie_refclk\n");
	goto err_pcie_setup;
	}

	ret = clk_prepare_enable(clk);
	if (ret) {
	dev_err(dev, "failed to enable pcie_refclk\n");
	goto err_get_sync;
	}
	pcie->refclk = clk;

	/*
	* "Power Sequencing and Reset Signal Timings" table in
	* PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0
	* indicates PERST# should be deasserted after minimum of 100us
	* once REFCLK is stable. The REFCLK to the connector in RC
	* mode is selected while enabling the PHY. So deassert PERST#
	* after 100 us.
	*/
	if (gpiod) {
	usleep_range(100, 200);
	gpiod_set_value_cansleep(gpiod, 1);
	}

	ret = cdns_pcie_host_setup(rc);
	if (ret < 0) {
	clk_disable_unprepare(pcie->refclk);
	goto err_pcie_setup;
	}

	break;
	case PCI_MODE_EP:
	if (!IS_ENABLED(CONFIG_PCIE_CADENCE_EP)) {
	ret = -ENODEV;
	goto err_get_sync;
	}

	ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
	if (!ep) {
	ret = -ENOMEM;
	goto err_get_sync;
	}
	ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;

	cdns_pcie = &ep->pcie;
	cdns_pcie->dev = dev;
	cdns_pcie->ops = &j721e_pcie_ops;
	pcie->cdns_pcie = cdns_pcie;

	ret = cdns_pcie_init_phy(dev, cdns_pcie);
	if (ret) {
	dev_err(dev, "Failed to init phy\n");
	goto err_get_sync;
	}

	ret = cdns_pcie_ep_setup(ep);
	if (ret < 0)
	goto err_pcie_setup;

	break;
	default:
	dev_err(dev, "INVALID device type %d\n", mode);
	}

	return 0;

	err_pcie_setup:
	cdns_pcie_disable_phy(cdns_pcie);

	err_get_sync:
	pm_runtime_put(dev);
	pm_runtime_disable(dev);

	return ret;
	}

	static int j721e_pcie_remove(struct platform_device *pdev)
	{
	struct j721e_pcie *pcie = platform_get_drvdata(pdev);
	struct cdns_pcie *cdns_pcie = pcie->cdns_pcie;
	struct device *dev = &pdev->dev;

	clk_disable_unprepare(pcie->refclk);
	cdns_pcie_disable_phy(cdns_pcie);
	pm_runtime_put(dev);
	pm_runtime_disable(dev);

	return 0;
	}

	static struct platform_driver j721e_pcie_driver = {
	.probe = j721e_pcie_probe,
	.remove = j721e_pcie_remove,
	.driver = {
	.name = "j721e-pcie",
	.of_match_table = of_j721e_pcie_match,
	.suppress_bind_attrs = true,
	},
	};
	builtin_platform_driver(j721e_pcie_driver);